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Import Upstream version 2.2.19
2022-05-13 23:35:49 +08:00
This is gnupg.info, produced by makeinfo version 6.5 from gnupg.texi.
This is the 'The GNU Privacy Guard Manual' (version 2.2.18-beta55,
November 2019).
(C) 2002, 2004, 2005, 2006, 2007, 2010 Free Software Foundation, Inc.
(C) 2013, 2014, 2015 Werner Koch.
(C) 2015, 2016, 2017 g10 Code GmbH.
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the
License, or (at your option) any later version. The text of the
license can be found in the section entitled "Copying".
INFO-DIR-SECTION GNU Utilities
START-INFO-DIR-ENTRY
* gpg2: (gnupg). OpenPGP encryption and signing tool.
* gpgsm: (gnupg). S/MIME encryption and signing tool.
* gpg-agent: (gnupg). The secret key daemon.
* dirmngr: (gnupg). X.509 CRL and OCSP server.
* dirmngr-client: (gnupg). X.509 CRL and OCSP client.
END-INFO-DIR-ENTRY

File: gnupg.info, Node: Top, Next: Installation, Up: (dir)
Using the GNU Privacy Guard
***************************
This is the 'The GNU Privacy Guard Manual' (version 2.2.18-beta55,
November 2019).
(C) 2002, 2004, 2005, 2006, 2007, 2010 Free Software Foundation, Inc.
(C) 2013, 2014, 2015 Werner Koch.
(C) 2015, 2016, 2017 g10 Code GmbH.
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the
License, or (at your option) any later version. The text of the
license can be found in the section entitled "Copying".
This manual documents how to use the GNU Privacy Guard system as well
as the administration and the architecture.
* Menu:
* Installation:: A short installation guide.
* Invoking GPG-AGENT:: How to launch the secret key daemon.
* Invoking DIRMNGR:: How to launch the CRL and OCSP daemon.
* Invoking GPG:: Using the OpenPGP protocol.
* Invoking GPGSM:: Using the S/MIME protocol.
* Invoking SCDAEMON:: How to handle Smartcards.
* Specify a User ID:: How to Specify a User Id.
* Trust Values:: How GnuPG displays trust values.
* Helper Tools:: Description of small helper tools
* Web Key Service:: Tools for the Web Key Service
* Howtos:: How to do certain things.
* System Notes:: Notes pertaining to certain OSes.
* Debugging:: How to solve problems
* Copying:: GNU General Public License says
how you can copy and share GnuPG
* Contributors:: People who have contributed to GnuPG.
* Glossary:: Short description of terms used.
* Option Index:: Index to command line options.
* Environment Index:: Index to environment variables and files.
* Index:: Index of concepts and symbol names.

File: gnupg.info, Node: Installation, Next: Invoking GPG-AGENT, Prev: Top, Up: Top
1 A short installation guide
****************************
Unfortunately the installation guide has not been finished in time.
Instead of delaying the release of GnuPG 2.0 even further, I decided to
release without that guide. The chapter on gpg-agent and gpgsm do
include brief information on how to set up the whole thing. Please
watch the GnuPG website for updates of the documentation. In the
meantime you may search the GnuPG mailing list archives or ask on the
gnupg-users mailing list for advise on how to solve problems or how to
get that whole thing up and running.
** Building the software
Building the software is described in the file 'INSTALL'. Given that
you are already reading this documentation we can only give some extra
hints.
To comply with the rules on GNU systems you should have build time
configured 'gnupg' using:
./configure --sysconfdir=/etc --localstatedir=/var
This is to make sure that system wide configuration files are
searched in the directory '/etc' and variable data below '/var'; the
default would be to also install them below '/usr/local' where the
binaries get installed. If you selected to use the '--prefix=/' you
obviously don't need those option as they are the default then.
** Notes on setting a root CA key to trusted
X.509 is based on a hierarchical key infrastructure. At the root of
the tree a trusted anchor (root certificate) is required. There are
usually no other means of verifying whether this root certificate is
trustworthy than looking it up in a list. GnuPG uses a file
('trustlist.txt') to keep track of all root certificates it knows about.
There are 3 ways to get certificates into this list:
* Use the list which comes with GnuPG. However this list only
contains a few root certificates. Most installations will need
more.
* Let 'gpgsm' ask you whether you want to insert a new root
certificate. This feature is enabled by default; you may disable
it using the option 'no-allow-mark-trusted' into 'gpg-agent.conf'.
* Manually maintain the list of trusted root certificates. For a
multi user installation this can be done once for all users on a
machine. Specific changes on a per-user base are also possible.

File: gnupg.info, Node: Invoking GPG-AGENT, Next: Invoking DIRMNGR, Prev: Installation, Up: Top
2 Invoking GPG-AGENT
********************
'gpg-agent' is a daemon to manage secret (private) keys independently
from any protocol. It is used as a backend for 'gpg' and 'gpgsm' as
well as for a couple of other utilities.
The agent is automatically started on demand by 'gpg', 'gpgsm',
'gpgconf', or 'gpg-connect-agent'. Thus there is no reason to start it
manually. In case you want to use the included Secure Shell Agent you
may start the agent using:
gpg-connect-agent /bye
If you want to manually terminate the currently-running agent, you can
safely do so with:
gpgconf --kill gpg-agent
You should always add the following lines to your '.bashrc' or whatever
initialization file is used for all shell invocations:
GPG_TTY=$(tty)
export GPG_TTY
It is important that this environment variable always reflects the
output of the 'tty' command. For W32 systems this option is not
required.
Please make sure that a proper pinentry program has been installed
under the default filename (which is system dependent) or use the option
'pinentry-program' to specify the full name of that program. It is
often useful to install a symbolic link from the actual used pinentry
(e.g. '/usr/local/bin/pinentry-gtk') to the expected one (e.g.
'/usr/local/bin/pinentry').
*Note Option Index::, for an index to 'GPG-AGENT''s commands and
options.
* Menu:
* Agent Commands:: List of all commands.
* Agent Options:: List of all options.
* Agent Configuration:: Configuration files.
* Agent Signals:: Use of some signals.
* Agent Examples:: Some usage examples.
* Agent Protocol:: The protocol the agent uses.

File: gnupg.info, Node: Agent Commands, Next: Agent Options, Up: Invoking GPG-AGENT
2.1 Commands
============
Commands are not distinguished from options except for the fact that
only one command is allowed.
'--version'
Print the program version and licensing information. Note that you
cannot abbreviate this command.
'--help'
'-h'
Print a usage message summarizing the most useful command-line
options. Note that you cannot abbreviate this command.
'--dump-options'
Print a list of all available options and commands. Note that you
cannot abbreviate this command.
'--server'
Run in server mode and wait for commands on the 'stdin'. The
default mode is to create a socket and listen for commands there.
'--daemon [COMMAND LINE]'
Start the gpg-agent as a daemon; that is, detach it from the
console and run it in the background.
As an alternative you may create a new process as a child of
gpg-agent: 'gpg-agent --daemon /bin/sh'. This way you get a new
shell with the environment setup properly; after you exit from this
shell, gpg-agent terminates within a few seconds.
'--supervised'
Run in the foreground, sending logs by default to stderr, and
listening on provided file descriptors, which must already be bound
to listening sockets. This command is useful when running under
systemd or other similar process supervision schemes. This option
is not supported on Windows.
In -supervised mode, different file descriptors can be provided for
use as different socket types (e.g. ssh, extra) as long as they
are identified in the environment variable 'LISTEN_FDNAMES' (see
sd_listen_fds(3) on some Linux distributions for more information
on this convention).

File: gnupg.info, Node: Agent Options, Next: Agent Configuration, Prev: Agent Commands, Up: Invoking GPG-AGENT
2.2 Option Summary
==================
Options may either be used on the command line or, after stripping off
the two leading dashes, in the configuration file.
'--options FILE'
Reads configuration from FILE instead of from the default per-user
configuration file. The default configuration file is named
'gpg-agent.conf' and expected in the '.gnupg' directory directly
below the home directory of the user. This option is ignored if
used in an options file.
'--homedir DIR'
Set the name of the home directory to DIR. If this option is not
used, the home directory defaults to '~/.gnupg'. It is only
recognized when given on the command line. It also overrides any
home directory stated through the environment variable 'GNUPGHOME'
or (on Windows systems) by means of the Registry entry
HKCU\SOFTWARE\GNU\GNUPG:HOMEDIR.
On Windows systems it is possible to install GnuPG as a portable
application. In this case only this command line option is
considered, all other ways to set a home directory are ignored.
To install GnuPG as a portable application under Windows, create an
empty file named 'gpgconf.ctl' in the same directory as the tool
'gpgconf.exe'. The root of the installation is then that
directory; or, if 'gpgconf.exe' has been installed directly below a
directory named 'bin', its parent directory. You also need to make
sure that the following directories exist and are writable:
'ROOT/home' for the GnuPG home and 'ROOT/usr/local/var/cache/gnupg'
for internal cache files.
'-v'
'--verbose'
Outputs additional information while running. You can increase the
verbosity by giving several verbose commands to 'gpg-agent', such
as '-vv'.
'-q'
'--quiet'
Try to be as quiet as possible.
'--batch'
Don't invoke a pinentry or do any other thing requiring human
interaction.
'--faked-system-time EPOCH'
This option is only useful for testing; it sets the system time
back or forth to EPOCH which is the number of seconds elapsed since
the year 1970.
'--debug-level LEVEL'
Select the debug level for investigating problems. LEVEL may be a
numeric value or a keyword:
'none'
No debugging at all. A value of less than 1 may be used
instead of the keyword.
'basic'
Some basic debug messages. A value between 1 and 2 may be
used instead of the keyword.
'advanced'
More verbose debug messages. A value between 3 and 5 may be
used instead of the keyword.
'expert'
Even more detailed messages. A value between 6 and 8 may be
used instead of the keyword.
'guru'
All of the debug messages you can get. A value greater than 8
may be used instead of the keyword. The creation of hash
tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not
specified and may change with newer releases of this program. They
are however carefully selected to best aid in debugging.
'--debug FLAGS'
This option is only useful for debugging and the behavior may
change at any time without notice. FLAGS are bit encoded and may
be given in usual C-Syntax. The currently defined bits are:
'0 (1)'
X.509 or OpenPGP protocol related data
'1 (2)'
values of big number integers
'2 (4)'
low level crypto operations
'5 (32)'
memory allocation
'6 (64)'
caching
'7 (128)'
show memory statistics
'9 (512)'
write hashed data to files named 'dbgmd-000*'
'10 (1024)'
trace Assuan protocol
'12 (4096)'
bypass all certificate validation
'--debug-all'
Same as '--debug=0xffffffff'
'--debug-wait N'
When running in server mode, wait N seconds before entering the
actual processing loop and print the pid. This gives time to
attach a debugger.
'--debug-quick-random'
This option inhibits the use of the very secure random quality
level (Libgcrypt’s 'GCRY_VERY_STRONG_RANDOM') and degrades all
request down to standard random quality. It is only used for
testing and should not be used for any production quality keys.
This option is only effective when given on the command line.
On GNU/Linux, another way to quickly generate insecure keys is to
use 'rngd' to fill the kernel's entropy pool with lower quality
random data. 'rngd' is typically provided by the 'rng-tools'
package. It can be run as follows: 'sudo rngd -f -r /dev/urandom'.
'--debug-pinentry'
This option enables extra debug information pertaining to the
Pinentry. As of now it is only useful when used along with
'--debug 1024'.
'--no-detach'
Don't detach the process from the console. This is mainly useful
for debugging.
'-s'
'--sh'
'-c'
'--csh'
Format the info output in daemon mode for use with the standard
Bourne shell or the C-shell respectively. The default is to guess
it based on the environment variable 'SHELL' which is correct in
almost all cases.
'--grab'
'--no-grab'
Tell the pinentry to grab the keyboard and mouse. This option
should be used on X-Servers to avoid X-sniffing attacks. Any use
of the option '--grab' overrides an used option '--no-grab'. The
default is '--no-grab'.
'--log-file FILE'
Append all logging output to FILE. This is very helpful in seeing
what the agent actually does. Use 'socket://' to log to socket.
If neither a log file nor a log file descriptor has been set on a
Windows platform, the Registry entry
'HKCU\Software\GNU\GnuPG:DefaultLogFile', if set, is used to
specify the logging output.
'--no-allow-mark-trusted'
Do not allow clients to mark keys as trusted, i.e. put them into
the 'trustlist.txt' file. This makes it harder for users to
inadvertently accept Root-CA keys.
'--allow-preset-passphrase'
This option allows the use of 'gpg-preset-passphrase' to seed the
internal cache of 'gpg-agent' with passphrases.
'--no-allow-loopback-pinentry'
'--allow-loopback-pinentry'
Disallow or allow clients to use the loopback pinentry features;
see the option 'pinentry-mode' for details. Allow is the default.
The '--force' option of the Assuan command 'DELETE_KEY' is also
controlled by this option: The option is ignored if a loopback
pinentry is disallowed.
'--no-allow-external-cache'
Tell Pinentry not to enable features which use an external cache
for passphrases.
Some desktop environments prefer to unlock all credentials with one
master password and may have installed a Pinentry which employs an
additional external cache to implement such a policy. By using
this option the Pinentry is advised not to make use of such a cache
and instead always ask the user for the requested passphrase.
'--allow-emacs-pinentry'
Tell Pinentry to allow features to divert the passphrase entry to a
running Emacs instance. How this is exactly handled depends on the
version of the used Pinentry.
'--ignore-cache-for-signing'
This option will let 'gpg-agent' bypass the passphrase cache for
all signing operation. Note that there is also a per-session
option to control this behavior but this command line option takes
precedence.
'--default-cache-ttl N'
Set the time a cache entry is valid to N seconds. The default is
600 seconds. Each time a cache entry is accessed, the entry's
timer is reset. To set an entry's maximum lifetime, use
'max-cache-ttl'. Note that a cached passphrase may not evicted
immediately from memory if no client requests a cache operation.
This is due to an internal housekeeping function which is only run
every few seconds.
'--default-cache-ttl-ssh N'
Set the time a cache entry used for SSH keys is valid to N seconds.
The default is 1800 seconds. Each time a cache entry is accessed,
the entry's timer is reset. To set an entry's maximum lifetime,
use 'max-cache-ttl-ssh'.
'--max-cache-ttl N'
Set the maximum time a cache entry is valid to N seconds. After
this time a cache entry will be expired even if it has been
accessed recently or has been set using 'gpg-preset-passphrase'.
The default is 2 hours (7200 seconds).
'--max-cache-ttl-ssh N'
Set the maximum time a cache entry used for SSH keys is valid to N
seconds. After this time a cache entry will be expired even if it
has been accessed recently or has been set using
'gpg-preset-passphrase'. The default is 2 hours (7200 seconds).
'--enforce-passphrase-constraints'
Enforce the passphrase constraints by not allowing the user to
bypass them using the "Take it anyway" button.
'--min-passphrase-len N'
Set the minimal length of a passphrase. When entering a new
passphrase shorter than this value a warning will be displayed.
Defaults to 8.
'--min-passphrase-nonalpha N'
Set the minimal number of digits or special characters required in
a passphrase. When entering a new passphrase with less than this
number of digits or special characters a warning will be displayed.
Defaults to 1.
'--check-passphrase-pattern FILE'
Check the passphrase against the pattern given in FILE. When
entering a new passphrase matching one of these pattern a warning
will be displayed. FILE should be an absolute filename. The
default is not to use any pattern file.
Security note: It is known that checking a passphrase against a
list of pattern or even against a complete dictionary is not very
effective to enforce good passphrases. Users will soon figure up
ways to bypass such a policy. A better policy is to educate users
on good security behavior and optionally to run a passphrase
cracker regularly on all users passphrases to catch the very simple
ones.
'--max-passphrase-days N'
Ask the user to change the passphrase if N days have passed since
the last change. With '--enforce-passphrase-constraints' set the
user may not bypass this check.
'--enable-passphrase-history'
This option does nothing yet.
'--pinentry-invisible-char CHAR'
This option asks the Pinentry to use CHAR for displaying hidden
characters. CHAR must be one character UTF-8 string. A Pinentry
may or may not honor this request.
'--pinentry-timeout N'
This option asks the Pinentry to timeout after N seconds with no
user input. The default value of 0 does not ask the pinentry to
timeout, however a Pinentry may use its own default timeout value
in this case. A Pinentry may or may not honor this request.
'--pinentry-program FILENAME'
Use program FILENAME as the PIN entry. The default is installation
dependent. With the default configuration the name of the default
pinentry is 'pinentry'; if that file does not exist but a
'pinentry-basic' exist the latter is used.
On a Windows platform the default is to use the first existing
program from this list: 'bin\pinentry.exe',
'..\Gpg4win\bin\pinentry.exe', '..\Gpg4win\pinentry.exe',
'..\GNU\GnuPG\pinentry.exe', '..\GNU\bin\pinentry.exe',
'bin\pinentry-basic.exe' where the file names are relative to the
GnuPG installation directory.
'--pinentry-touch-file FILENAME'
By default the filename of the socket gpg-agent is listening for
requests is passed to Pinentry, so that it can touch that file
before exiting (it does this only in curses mode). This option
changes the file passed to Pinentry to FILENAME. The special name
'/dev/null' may be used to completely disable this feature. Note
that Pinentry will not create that file, it will only change the
modification and access time.
'--scdaemon-program FILENAME'
Use program FILENAME as the Smartcard daemon. The default is
installation dependent and can be shown with the 'gpgconf' command.
'--disable-scdaemon'
Do not make use of the scdaemon tool. This option has the effect
of disabling the ability to do smartcard operations. Note, that
enabling this option at runtime does not kill an already forked
scdaemon.
'--disable-check-own-socket'
'gpg-agent' employs a periodic self-test to detect a stolen socket.
This usually means a second instance of 'gpg-agent' has taken over
the socket and 'gpg-agent' will then terminate itself. This option
may be used to disable this self-test for debugging purposes.
'--use-standard-socket'
'--no-use-standard-socket'
'--use-standard-socket-p'
Since GnuPG 2.1 the standard socket is always used. These options
have no more effect. The command 'gpg-agent
--use-standard-socket-p' will thus always return success.
'--display STRING'
'--ttyname STRING'
'--ttytype STRING'
'--lc-ctype STRING'
'--lc-messages STRING'
'--xauthority STRING'
These options are used with the server mode to pass localization
information.
'--keep-tty'
'--keep-display'
Ignore requests to change the current 'tty' or X window system's
'DISPLAY' variable respectively. This is useful to lock the
pinentry to pop up at the 'tty' or display you started the agent.
'--listen-backlog N'
Set the size of the queue for pending connections. The default is
64.
'--extra-socket NAME'
The extra socket is created by default, you may use this option to
change the name of the socket. To disable the creation of the
socket use "none" or "/dev/null" for NAME.
Also listen on native gpg-agent connections on the given socket.
The intended use for this extra socket is to setup a Unix domain
socket forwarding from a remote machine to this socket on the local
machine. A 'gpg' running on the remote machine may then connect to
the local gpg-agent and use its private keys. This enables
decrypting or signing data on a remote machine without exposing the
private keys to the remote machine.
'--enable-extended-key-format'
This option creates keys in the extended private key format.
Changing the passphrase of a key will also convert the key to that
new format. Using this option makes the private keys unreadable
for gpg-agent versions before 2.1.12. The advantage of the
extended private key format is that it is text based and can carry
additional meta data. Note that this option also changes the key
protection format to use OCB mode.
'--enable-ssh-support'
'--enable-putty-support'
The OpenSSH Agent protocol is always enabled, but 'gpg-agent' will
only set the 'SSH_AUTH_SOCK' variable if this flag is given.
In this mode of operation, the agent does not only implement the
gpg-agent protocol, but also the agent protocol used by OpenSSH
(through a separate socket). Consequently, it should be possible
to use the gpg-agent as a drop-in replacement for the well known
ssh-agent.
SSH Keys, which are to be used through the agent, need to be added
to the gpg-agent initially through the ssh-add utility. When a key
is added, ssh-add will ask for the password of the provided key
file and send the unprotected key material to the agent; this
causes the gpg-agent to ask for a passphrase, which is to be used
for encrypting the newly received key and storing it in a gpg-agent
specific directory.
Once a key has been added to the gpg-agent this way, the gpg-agent
will be ready to use the key.
Note: in case the gpg-agent receives a signature request, the user
might need to be prompted for a passphrase, which is necessary for
decrypting the stored key. Since the ssh-agent protocol does not
contain a mechanism for telling the agent on which display/terminal
it is running, gpg-agent's ssh-support will use the TTY or X
display where gpg-agent has been started. To switch this display
to the current one, the following command may be used:
gpg-connect-agent updatestartuptty /bye
Although all GnuPG components try to start the gpg-agent as needed,
this is not possible for the ssh support because ssh does not know
about it. Thus if no GnuPG tool which accesses the agent has been
run, there is no guarantee that ssh is able to use gpg-agent for
authentication. To fix this you may start gpg-agent if needed
using this simple command:
gpg-connect-agent /bye
Adding the '--verbose' shows the progress of starting the agent.
The '--enable-putty-support' is only available under Windows and
allows the use of gpg-agent with the ssh implementation 'putty'.
This is similar to the regular ssh-agent support but makes use of
Windows message queue as required by 'putty'.
'--ssh-fingerprint-digest'
Select the digest algorithm used to compute ssh fingerprints that
are communicated to the user, e.g. in pinentry dialogs. OpenSSH
has transitioned from using MD5 to the more secure SHA256.
'--auto-expand-secmem N'
Allow Libgcrypt to expand its secure memory area as required. The
optional value N is a non-negative integer with a suggested size in
bytes of each additionally allocated secure memory area. The value
is rounded up to the next 32 KiB; usual C style prefixes are
allowed. For an heavy loaded gpg-agent with many concurrent
connection this option avoids sign or decrypt errors due to out of
secure memory error returns.
'--s2k-calibration MILLISECONDS'
Change the default calibration time to MILLISECONDS. The given
value is capped at 60 seconds; a value of 0 resets to the
compiled-in default. This option is re-read on a SIGHUP (or
'gpgconf --reload gpg-agent') and the S2K count is then
re-calibrated.
'--s2k-count N'
Specify the iteration count used to protect the passphrase. This
option can be used to override the auto-calibration done by
default. The auto-calibration computes a count which requires by
default 100ms to mangle a given passphrase. See also
'--s2k-calibration'.
To view the actually used iteration count and the milliseconds
required for an S2K operation use:
gpg-connect-agent 'GETINFO s2k_count' /bye
gpg-connect-agent 'GETINFO s2k_time' /bye
To view the auto-calibrated count use:
gpg-connect-agent 'GETINFO s2k_count_cal' /bye

File: gnupg.info, Node: Agent Configuration, Next: Agent Signals, Prev: Agent Options, Up: Invoking GPG-AGENT
2.3 Configuration
=================
There are a few configuration files needed for the operation of the
agent. By default they may all be found in the current home directory
(*note option --homedir::).
'gpg-agent.conf'
This is the standard configuration file read by 'gpg-agent' on
startup. It may contain any valid long option; the leading two
dashes may not be entered and the option may not be abbreviated.
This file is also read after a 'SIGHUP' however only a few options
will actually have an effect. This default name may be changed on
the command line (*note option --options::). You should backup
this file.
'trustlist.txt'
This is the list of trusted keys. You should backup this file.
Comment lines, indicated by a leading hash mark, as well as empty
lines are ignored. To mark a key as trusted you need to enter its
fingerprint followed by a space and a capital letter 'S'. Colons
may optionally be used to separate the bytes of a fingerprint; this
enables cutting and pasting the fingerprint from a key listing
output. If the line is prefixed with a '!' the key is explicitly
marked as not trusted.
Here is an example where two keys are marked as ultimately trusted
and one as not trusted:
# CN=Wurzel ZS 3,O=Intevation GmbH,C=DE
A6935DD34EF3087973C706FC311AA2CCF733765B S
# CN=PCA-1-Verwaltung-02/O=PKI-1-Verwaltung/C=DE
DC:BD:69:25:48:BD:BB:7E:31:6E:BB:80:D3:00:80:35:D4:F8:A6:CD S
# CN=Root-CA/O=Schlapphuete/L=Pullach/C=DE
!14:56:98:D3:FE:9C:CA:5A:31:6E:BC:81:D3:11:4E:00:90:A3:44:C2 S
Before entering a key into this file, you need to ensure its
authenticity. How to do this depends on your organisation; your
administrator might have already entered those keys which are
deemed trustworthy enough into this file. Places where to look for
the fingerprint of a root certificate are letters received from the
CA or the website of the CA (after making 100% sure that this is
indeed the website of that CA). You may want to consider
disallowing interactive updates of this file by using the *note
option --no-allow-mark-trusted::. It might even be advisable to
change the permissions to read-only so that this file can't be
changed inadvertently.
As a special feature a line 'include-default' will include a global
list of trusted certificates (e.g. '/etc/gnupg/trustlist.txt').
This global list is also used if the local list is not available.
It is possible to add further flags after the 'S' for use by the
caller:
'relax'
Relax checking of some root certificate requirements. As of
now this flag allows the use of root certificates with a
missing basicConstraints attribute (despite that it is a MUST
for CA certificates) and disables CRL checking for the root
certificate.
'cm'
If validation of a certificate finally issued by a CA with
this flag set fails, try again using the chain validation
model.
'sshcontrol'
This file is used when support for the secure shell agent protocol
has been enabled (*note option --enable-ssh-support::). Only keys
present in this file are used in the SSH protocol. You should
backup this file.
The 'ssh-add' tool may be used to add new entries to this file; you
may also add them manually. Comment lines, indicated by a leading
hash mark, as well as empty lines are ignored. An entry starts
with optional whitespace, followed by the keygrip of the key given
as 40 hex digits, optionally followed by the caching TTL in seconds
and another optional field for arbitrary flags. A non-zero TTL
overrides the global default as set by '--default-cache-ttl-ssh'.
The only flag support is 'confirm'. If this flag is found for a
key, each use of the key will pop up a pinentry to confirm the use
of that key. The flag is automatically set if a new key was loaded
into 'gpg-agent' using the option '-c' of the 'ssh-add' command.
The keygrip may be prefixed with a '!' to disable an entry.
The following example lists exactly one key. Note that keys
available through a OpenPGP smartcard in the active smartcard
reader are implicitly added to this list; i.e. there is no need to
list them.
# Key added on: 2011-07-20 20:38:46
# Fingerprint: 5e:8d:c4:ad:e7:af:6e:27:8a:d6:13:e4:79:ad:0b:81
34B62F25E277CF13D3C6BCEBFD3F85D08F0A864B 0 confirm
'private-keys-v1.d/'
This is the directory where gpg-agent stores the private keys.
Each key is stored in a file with the name made up of the keygrip
and the suffix 'key'. You should backup all files in this
directory and take great care to keep this backup closed away.
Note that on larger installations, it is useful to put predefined
files into the directory '/etc/skel/.gnupg' so that newly created users
start up with a working configuration. For existing users the a small
helper script is provided to create these files (*note addgnupghome::).

File: gnupg.info, Node: Agent Signals, Next: Agent Examples, Prev: Agent Configuration, Up: Invoking GPG-AGENT
2.4 Use of some signals
=======================
A running 'gpg-agent' may be controlled by signals, i.e. using the
'kill' command to send a signal to the process.
Here is a list of supported signals:
'SIGHUP'
This signal flushes all cached passphrases and if the program has
been started with a configuration file, the configuration file is
read again. Only certain options are honored: 'quiet', 'verbose',
'debug', 'debug-all', 'debug-level', 'debug-pinentry', 'no-grab',
'pinentry-program', 'pinentry-invisible-char', 'default-cache-ttl',
'max-cache-ttl', 'ignore-cache-for-signing', 's2k-count',
'no-allow-external-cache', 'allow-emacs-pinentry',
'no-allow-mark-trusted', 'disable-scdaemon', and
'disable-check-own-socket'. 'scdaemon-program' is also supported
but due to the current implementation, which calls the scdaemon
only once, it is not of much use unless you manually kill the
scdaemon.
'SIGTERM'
Shuts down the process but waits until all current requests are
fulfilled. If the process has received 3 of these signals and
requests are still pending, a shutdown is forced.
'SIGINT'
Shuts down the process immediately.
'SIGUSR1'
Dump internal information to the log file.
'SIGUSR2'
This signal is used for internal purposes.

File: gnupg.info, Node: Agent Examples, Next: Agent Protocol, Prev: Agent Signals, Up: Invoking GPG-AGENT
2.5 Examples
============
It is important to set the environment variable 'GPG_TTY' in your login
shell, for example in the '~/.bashrc' init script:
export GPG_TTY=$(tty)
If you enabled the Ssh Agent Support, you also need to tell ssh about
it by adding this to your init script:
unset SSH_AGENT_PID
if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then
export SSH_AUTH_SOCK="$(gpgconf --list-dirs agent-ssh-socket)"
fi

File: gnupg.info, Node: Agent Protocol, Prev: Agent Examples, Up: Invoking GPG-AGENT
2.6 Agent's Assuan Protocol
===========================
Note: this section does only document the protocol, which is used by
GnuPG components; it does not deal with the ssh-agent protocol. To see
the full specification of each command, use
gpg-connect-agent 'help COMMAND' /bye
or just 'help' to list all available commands.
The 'gpg-agent' daemon is started on demand by the GnuPG components.
To identify a key we use a thing called keygrip which is the SHA-1
hash of an canonical encoded S-Expression of the public key as used in
Libgcrypt. For the purpose of this interface the keygrip is given as a
hex string. The advantage of using this and not the hash of a
certificate is that it will be possible to use the same keypair for
different protocols, thereby saving space on the token used to keep the
secret keys.
The 'gpg-agent' may send status messages during a command or when
returning from a command to inform a client about the progress or result
of an operation. For example, the INQUIRE_MAXLEN status message may be
sent during a server inquire to inform the client of the maximum usable
length of the inquired data (which should not be exceeded).
* Menu:
* Agent PKDECRYPT:: Decrypting a session key
* Agent PKSIGN:: Signing a Hash
* Agent GENKEY:: Generating a Key
* Agent IMPORT:: Importing a Secret Key
* Agent EXPORT:: Exporting a Secret Key
* Agent ISTRUSTED:: Importing a Root Certificate
* Agent GET_PASSPHRASE:: Ask for a passphrase
* Agent CLEAR_PASSPHRASE:: Expire a cached passphrase
* Agent PRESET_PASSPHRASE:: Set a passphrase for a keygrip
* Agent GET_CONFIRMATION:: Ask for confirmation
* Agent HAVEKEY:: Check whether a key is available
* Agent LEARN:: Register a smartcard
* Agent PASSWD:: Change a Passphrase
* Agent UPDATESTARTUPTTY:: Change the Standard Display
* Agent GETEVENTCOUNTER:: Get the Event Counters
* Agent GETINFO:: Return information about the process
* Agent OPTION:: Set options for the session

File: gnupg.info, Node: Agent PKDECRYPT, Next: Agent PKSIGN, Up: Agent Protocol
2.6.1 Decrypting a session key
------------------------------
The client asks the server to decrypt a session key. The encrypted
session key should have all information needed to select the appropriate
secret key or to delegate it to a smartcard.
SETKEY <keyGrip>
Tell the server about the key to be used for decryption. If this is
not used, 'gpg-agent' may try to figure out the key by trying to decrypt
the message with each key available.
PKDECRYPT
The agent checks whether this command is allowed and then does an
INQUIRY to get the ciphertext the client should then send the cipher
text.
S: INQUIRE CIPHERTEXT
C: D (xxxxxx
C: D xxxx)
C: END
Please note that the server may send status info lines while reading
the data lines from the client. The data send is a SPKI like S-Exp with
this structure:
(enc-val
(<algo>
(<param_name1> <mpi>)
...
(<param_namen> <mpi>)))
Where algo is a string with the name of the algorithm; see the
libgcrypt documentation for a list of valid algorithms. The number and
names of the parameters depend on the algorithm. The agent does return
an error if there is an inconsistency.
If the decryption was successful the decrypted data is returned by
means of "D" lines.
Here is an example session:
C: PKDECRYPT
S: INQUIRE CIPHERTEXT
C: D (enc-val elg (a 349324324)
C: D (b 3F444677CA)))
C: END
S: # session key follows
S: S PADDING 0
S: D (value 1234567890ABCDEF0)
S: OK decryption successful
The “PADDING” status line is only send if gpg-agent can tell what
kind of padding is used. As of now only the value 0 is used to indicate
that the padding has been removed.

File: gnupg.info, Node: Agent PKSIGN, Next: Agent GENKEY, Prev: Agent PKDECRYPT, Up: Agent Protocol
2.6.2 Signing a Hash
--------------------
The client asks the agent to sign a given hash value. A default key
will be chosen if no key has been set. To set a key a client first
uses:
SIGKEY <keyGrip>
This can be used multiple times to create multiple signature, the
list of keys is reset with the next PKSIGN command or a RESET. The
server tests whether the key is a valid key to sign something and
responds with okay.
SETHASH --hash=<name>|<algo> <hexstring>
The client can use this command to tell the server about the data
<hexstring> (which usually is a hash) to be signed. <algo> is the
decimal encoded hash algorithm number as used by Libgcrypt. Either
<algo> or -hash=<name> must be given. Valid names for <name> are:
'sha1'
The SHA-1 hash algorithm
'sha256'
The SHA-256 hash algorithm
'rmd160'
The RIPE-MD160 hash algorithm
'md5'
The old and broken MD5 hash algorithm
'tls-md5sha1'
A combined hash algorithm as used by the TLS protocol.
The actual signing is done using
PKSIGN <options>
Options are not yet defined, but may later be used to choose among
different algorithms. The agent does then some checks, asks for the
passphrase and as a result the server returns the signature as an SPKI
like S-expression in "D" lines:
(sig-val
(<algo>
(<param_name1> <mpi>)
...
(<param_namen> <mpi>)))
The operation is affected by the option
OPTION use-cache-for-signing=0|1
The default of '1' uses the cache. Setting this option to '0' will
lead 'gpg-agent' to ignore the passphrase cache. Note, that there is
also a global command line option for 'gpg-agent' to globally disable
the caching.
Here is an example session:
C: SIGKEY <keyGrip>
S: OK key available
C: SIGKEY <keyGrip>
S: OK key available
C: PKSIGN
S: # I did ask the user whether he really wants to sign
S: # I did ask the user for the passphrase
S: INQUIRE HASHVAL
C: D ABCDEF012345678901234
C: END
S: # signature follows
S: D (sig-val rsa (s 45435453654612121212))
S: OK

File: gnupg.info, Node: Agent GENKEY, Next: Agent IMPORT, Prev: Agent PKSIGN, Up: Agent Protocol
2.6.3 Generating a Key
----------------------
This is used to create a new keypair and store the secret key inside the
active PSE -- which is in most cases a Soft-PSE. A not-yet-defined
option allows choosing the storage location. To get the secret key out
of the PSE, a special export tool has to be used.
GENKEY [--no-protection] [--preset] [<cache_nonce>]
Invokes the key generation process and the server will then inquire
on the generation parameters, like:
S: INQUIRE KEYPARM
C: D (genkey (rsa (nbits 1024)))
C: END
The format of the key parameters which depends on the algorithm is of
the form:
(genkey
(algo
(parameter_name_1 ....)
....
(parameter_name_n ....)))
If everything succeeds, the server returns the *public key* in a SPKI
like S-Expression like this:
(public-key
(rsa
(n <mpi>)
(e <mpi>)))
Here is an example session:
C: GENKEY
S: INQUIRE KEYPARM
C: D (genkey (rsa (nbits 1024)))
C: END
S: D (public-key
S: D (rsa (n 326487324683264) (e 10001)))
S OK key created
The '--no-protection' option may be used to prevent prompting for a
passphrase to protect the secret key while leaving the secret key
unprotected. The '--preset' option may be used to add the passphrase to
the cache using the default cache parameters.
The '--inq-passwd' option may be used to create the key with a
supplied passphrase. When used the agent does an inquiry with the
keyword 'NEWPASSWD' to retrieve that passphrase. This option takes
precedence over '--no-protection'; however if the client sends a empty
(zero-length) passphrase, this is identical to '--no-protection'.

File: gnupg.info, Node: Agent IMPORT, Next: Agent EXPORT, Prev: Agent GENKEY, Up: Agent Protocol
2.6.4 Importing a Secret Key
----------------------------
This operation is not yet supported by GpgAgent. Specialized tools are
to be used for this.
There is no actual need because we can expect that secret keys
created by a 3rd party are stored on a smartcard. If we have generated
the key ourselves, we do not need to import it.

File: gnupg.info, Node: Agent EXPORT, Next: Agent ISTRUSTED, Prev: Agent IMPORT, Up: Agent Protocol
2.6.5 Export a Secret Key
-------------------------
Not implemented.
Should be done by an extra tool.

File: gnupg.info, Node: Agent ISTRUSTED, Next: Agent GET_PASSPHRASE, Prev: Agent EXPORT, Up: Agent Protocol
2.6.6 Importing a Root Certificate
----------------------------------
Actually we do not import a Root Cert but provide a way to validate any
piece of data by storing its Hash along with a description and an
identifier in the PSE. Here is the interface description:
ISTRUSTED <fingerprint>
Check whether the OpenPGP primary key or the X.509 certificate with
the given fingerprint is an ultimately trusted key or a trusted Root CA
certificate. The fingerprint should be given as a hexstring (without
any blanks or colons or whatever in between) and may be left padded with
00 in case of an MD5 fingerprint. GPGAgent will answer with:
OK
The key is in the table of trusted keys.
ERR 304 (Not Trusted)
The key is not in this table.
Gpg needs the entire list of trusted keys to maintain the web of
trust; the following command is therefore quite helpful:
LISTTRUSTED
GpgAgent returns a list of trusted keys line by line:
S: D 000000001234454556565656677878AF2F1ECCFF P
S: D 340387563485634856435645634856438576457A P
S: D FEDC6532453745367FD83474357495743757435D S
S: OK
The first item on a line is the hexified fingerprint where MD5
fingerprints are '00' padded to the left and the second item is a flag
to indicate the type of key (so that gpg is able to only take care of
PGP keys). P = OpenPGP, S = S/MIME. A client should ignore the rest of
the line, so that we can extend the format in the future.
Finally a client should be able to mark a key as trusted:
MARKTRUSTED FINGERPRINT "P"|"S"
The server will then pop up a window to ask the user whether she
really trusts this key. For this it will probably ask for a text to be
displayed like this:
S: INQUIRE TRUSTDESC
C: D Do you trust the key with the fingerprint @FPR@
C: D bla fasel blurb.
C: END
S: OK
Known sequences with the pattern @foo@ are replaced according to this
table:
'@FPR16@'
Format the fingerprint according to gpg rules for a v3 keys.
'@FPR20@'
Format the fingerprint according to gpg rules for a v4 keys.
'@FPR@'
Choose an appropriate format to format the fingerprint.
'@@'
Replaced by a single '@'.

File: gnupg.info, Node: Agent GET_PASSPHRASE, Next: Agent CLEAR_PASSPHRASE, Prev: Agent ISTRUSTED, Up: Agent Protocol
2.6.7 Ask for a passphrase
--------------------------
This function is usually used to ask for a passphrase to be used for
symmetric encryption, but may also be used by programs which need
special handling of passphrases. This command uses a syntax which helps
clients to use the agent with minimum effort.
GET_PASSPHRASE [--data] [--check] [--no-ask] [--repeat[=N]] \
[--qualitybar] CACHE_ID \
[ERROR_MESSAGE PROMPT DESCRIPTION]
CACHE_ID is expected to be a string used to identify a cached
passphrase. Use a 'X' to bypass the cache. With no other arguments the
agent returns a cached passphrase or an error. By convention either the
hexified fingerprint of the key shall be used for CACHE_ID or an
arbitrary string prefixed with the name of the calling application and a
colon: Like 'gpg:somestring'.
ERROR_MESSAGE is either a single 'X' for no error message or a string
to be shown as an error message like (e.g. "invalid passphrase").
Blanks must be percent escaped or replaced by '+''.
PROMPT is either a single 'X' for a default prompt or the text to be
shown as the prompt. Blanks must be percent escaped or replaced by '+'.
DESCRIPTION is a text shown above the entry field. Blanks must be
percent escaped or replaced by '+'.
The agent either returns with an error or with a OK followed by the
hex encoded passphrase. Note that the length of the strings is
implicitly limited by the maximum length of a command. If the option
'--data' is used, the passphrase is not returned on the OK line but by
regular data lines; this is the preferred method.
If the option '--check' is used, the standard passphrase constraints
checks are applied. A check is not done if the passphrase has been
found in the cache.
If the option '--no-ask' is used and the passphrase is not in the
cache the user will not be asked to enter a passphrase but the error
code 'GPG_ERR_NO_DATA' is returned.
If the option '--qualitybar' is used and a minimum passphrase length
has been configured, a visual indication of the entered passphrase
quality is shown.
CLEAR_PASSPHRASE CACHE_ID
may be used to invalidate the cache entry for a passphrase. The
function returns with OK even when there is no cached passphrase.

File: gnupg.info, Node: Agent CLEAR_PASSPHRASE, Next: Agent PRESET_PASSPHRASE, Prev: Agent GET_PASSPHRASE, Up: Agent Protocol
2.6.8 Remove a cached passphrase
--------------------------------
Use this command to remove a cached passphrase.
CLEAR_PASSPHRASE [--mode=normal] <cache_id>
The '--mode=normal' option can be used to clear a CACHE_ID that was
set by gpg-agent.

File: gnupg.info, Node: Agent PRESET_PASSPHRASE, Next: Agent GET_CONFIRMATION, Prev: Agent CLEAR_PASSPHRASE, Up: Agent Protocol
2.6.9 Set a passphrase for a keygrip
------------------------------------
This command adds a passphrase to the cache for the specified KEYGRIP.
PRESET_PASSPHRASE [--inquire] <string_or_keygrip> <timeout> [<hexstring>]
The passphrase is a hexadecimal string when specified. When not
specified, the passphrase will be retrieved from the pinentry module
unless the '--inquire' option was specified in which case the passphrase
will be retrieved from the client.
The TIMEOUT parameter keeps the passphrase cached for the specified
number of seconds. A value of '-1' means infinite while '0' means the
default (currently only a timeout of -1 is allowed, which means to never
expire it).

File: gnupg.info, Node: Agent GET_CONFIRMATION, Next: Agent HAVEKEY, Prev: Agent PRESET_PASSPHRASE, Up: Agent Protocol
2.6.10 Ask for confirmation
---------------------------
This command may be used to ask for a simple confirmation by presenting
a text and 2 buttons: Okay and Cancel.
GET_CONFIRMATION DESCRIPTION
DESCRIPTIONis displayed along with a Okay and Cancel button. Blanks
must be percent escaped or replaced by '+'. A 'X' may be used to
display confirmation dialog with a default text.
The agent either returns with an error or with a OK. Note, that the
length of DESCRIPTION is implicitly limited by the maximum length of a
command.

File: gnupg.info, Node: Agent HAVEKEY, Next: Agent LEARN, Prev: Agent GET_CONFIRMATION, Up: Agent Protocol
2.6.11 Check whether a key is available
---------------------------------------
This can be used to see whether a secret key is available. It does not
return any information on whether the key is somehow protected.
HAVEKEY KEYGRIPS
The agent answers either with OK or 'No_Secret_Key' (208). The
caller may want to check for other error codes as well. More than one
keygrip may be given. In this case the command returns success if at
least one of the keygrips corresponds to an available secret key.

File: gnupg.info, Node: Agent LEARN, Next: Agent PASSWD, Prev: Agent HAVEKEY, Up: Agent Protocol
2.6.12 Register a smartcard
---------------------------
LEARN [--send]
This command is used to register a smartcard. With the '--send'
option given the certificates are sent back.

File: gnupg.info, Node: Agent PASSWD, Next: Agent UPDATESTARTUPTTY, Prev: Agent LEARN, Up: Agent Protocol
2.6.13 Change a Passphrase
--------------------------
PASSWD [--cache-nonce=<c>] [--passwd-nonce=<s>] [--preset] KEYGRIP
This command is used to interactively change the passphrase of the
key identified by the hex string KEYGRIP. The '--preset' option may be
used to add the new passphrase to the cache using the default cache
parameters.

File: gnupg.info, Node: Agent UPDATESTARTUPTTY, Next: Agent GETEVENTCOUNTER, Prev: Agent PASSWD, Up: Agent Protocol
2.6.14 Change the standard display
----------------------------------
UPDATESTARTUPTTY
Set the startup TTY and X-DISPLAY variables to the values of this
session. This command is useful to direct future pinentry invocations
to another screen. It is only required because there is no way in the
ssh-agent protocol to convey this information.

File: gnupg.info, Node: Agent GETEVENTCOUNTER, Next: Agent GETINFO, Prev: Agent UPDATESTARTUPTTY, Up: Agent Protocol
2.6.15 Get the Event Counters
-----------------------------
GETEVENTCOUNTER
This function return one status line with the current values of the
event counters. The event counters are useful to avoid polling by
delaying a poll until something has changed. The values are decimal
numbers in the range '0' to 'UINT_MAX' and wrapping around to 0. The
actual values should not be relied upon; they shall only be used to
detect a change.
The currently defined counters are:
'ANY'
Incremented with any change of any of the other counters.
'KEY'
Incremented for added or removed private keys.
'CARD'
Incremented for changes of the card readers stati.

File: gnupg.info, Node: Agent GETINFO, Next: Agent OPTION, Prev: Agent GETEVENTCOUNTER, Up: Agent Protocol
2.6.16 Return information about the process
-------------------------------------------
This is a multipurpose function to return a variety of information.
GETINFO WHAT
The value of WHAT specifies the kind of information returned:
'version'
Return the version of the program.
'pid'
Return the process id of the process.
'socket_name'
Return the name of the socket used to connect the agent.
'ssh_socket_name'
Return the name of the socket used for SSH connections. If SSH
support has not been enabled the error 'GPG_ERR_NO_DATA' will be
returned.

File: gnupg.info, Node: Agent OPTION, Prev: Agent GETINFO, Up: Agent Protocol
2.6.17 Set options for the session
----------------------------------
Here is a list of session options which are not yet described with other
commands. The general syntax for an Assuan option is:
OPTION KEY=VALUE
Supported KEYs are:
'agent-awareness'
This may be used to tell gpg-agent of which gpg-agent version the
client is aware of. gpg-agent uses this information to enable
features which might break older clients.
'putenv'
Change the session's environment to be used for the Pinentry.
Valid values are:
'NAME'
Delete envvar NAME
'NAME='
Set envvar NAME to the empty string
'NAME=VALUE'
Set envvar NAME to the string VALUE.
'use-cache-for-signing'
See Assuan command 'PKSIGN'.
'allow-pinentry-notify'
This does not need any value. It is used to enable the
PINENTRY_LAUNCHED inquiry.
'pinentry-mode'
This option is used to change the operation mode of the pinentry.
The following values are defined:
'ask'
This is the default mode which pops up a pinentry as needed.
'cancel'
Instead of popping up a pinentry, return the error code
'GPG_ERR_CANCELED'.
'error'
Instead of popping up a pinentry, return the error code
'GPG_ERR_NO_PIN_ENTRY'.
'loopback'
Use a loopback pinentry. This fakes a pinentry by using
inquiries back to the caller to ask for a passphrase. This
option may only be set if the agent has been configured for
that. To disable this feature use *note option
--no-allow-loopback-pinentry::.
'cache-ttl-opt-preset'
This option sets the cache TTL for new entries created by GENKEY
and PASSWD commands when using the '--preset' option. It is not
used a default value is used.
's2k-count'
Instead of using the standard S2K count (which is computed on the
fly), the given S2K count is used for new keys or when changing the
passphrase of a key. Values below 65536 are considered to be 0.
This option is valid for the entire session or until reset to 0.
This option is useful if the key is later used on boxes which are
either much slower or faster than the actual box.
'pretend-request-origin'
This option switches the connection into a restricted mode which
handles all further commands in the same way as they would be
handled when originating from the extra or browser socket. Note
that this option is not available in the restricted mode. Valid
values for this option are:
'none'
'local'
This is a NOP and leaves the connection in the standard way.
'remote'
Pretend to come from a remote origin in the same way as
connections from the '--extra-socket'.
'browser'
Pretend to come from a local web browser in the same way as
connections from the '--browser-socket'.

File: gnupg.info, Node: Invoking DIRMNGR, Next: Invoking GPG, Prev: Invoking GPG-AGENT, Up: Top
3 Invoking DIRMNGR
******************
Since version 2.1 of GnuPG, 'dirmngr' takes care of accessing the
OpenPGP keyservers. As with previous versions it is also used as a
server for managing and downloading certificate revocation lists (CRLs)
for X.509 certificates, downloading X.509 certificates, and providing
access to OCSP providers. Dirmngr is invoked internally by 'gpg',
'gpgsm', or via the 'gpg-connect-agent' tool.
*Note Option Index::,for an index to 'DIRMNGR''s commands and options.
* Menu:
* Dirmngr Commands:: List of all commands.
* Dirmngr Options:: List of all options.
* Dirmngr Configuration:: Configuration files.
* Dirmngr Signals:: Use of signals.
* Dirmngr Examples:: Some usage examples.
* Dirmngr Protocol:: The protocol dirmngr uses.

File: gnupg.info, Node: Dirmngr Commands, Next: Dirmngr Options, Up: Invoking DIRMNGR
3.1 Commands
============
Commands are not distinguished from options except for the fact that
only one command is allowed.
'--version'
Print the program version and licensing information. Note that you
cannot abbreviate this command.
'--help, -h'
Print a usage message summarizing the most useful command-line
options. Note that you cannot abbreviate this command.
'--dump-options'
Print a list of all available options and commands. Note that you
cannot abbreviate this command.
'--server'
Run in server mode and wait for commands on the 'stdin'. The
default mode is to create a socket and listen for commands there.
This is only used for testing.
'--daemon'
Run in background daemon mode and listen for commands on a socket.
This is the way 'dirmngr' is started on demand by the other GnuPG
components. To force starting 'dirmngr' it is in general best to
use 'gpgconf --launch dirmngr'.
'--supervised'
Run in the foreground, sending logs to stderr, and listening on
file descriptor 3, which must already be bound to a listening
socket. This is useful when running under systemd or other similar
process supervision schemes. This option is not supported on
Windows.
'--list-crls'
List the contents of the CRL cache on 'stdout'. This is probably
only useful for debugging purposes.
'--load-crl FILE'
This command requires a filename as additional argument, and it
will make Dirmngr try to import the CRL in FILE into it's cache.
Note, that this is only possible if Dirmngr is able to retrieve the
CA's certificate directly by its own means. In general it is
better to use 'gpgsm''s '--call-dirmngr loadcrl filename' command
so that 'gpgsm' can help dirmngr.
'--fetch-crl URL'
This command requires an URL as additional argument, and it will
make dirmngr try to retrieve and import the CRL from that URL into
it's cache. This is mainly useful for debugging purposes. The
'dirmngr-client' provides the same feature for a running dirmngr.
'--shutdown'
This commands shuts down an running instance of Dirmngr. This
command has currently no effect.
'--flush'
This command removes all CRLs from Dirmngr's cache. Client
requests will thus trigger reading of fresh CRLs.

File: gnupg.info, Node: Dirmngr Options, Next: Dirmngr Configuration, Prev: Dirmngr Commands, Up: Invoking DIRMNGR
3.2 Option Summary
==================
Note that all long options with the exception of '--options' and
'--homedir' may also be given in the configuration file after stripping
off the two leading dashes.
'--options FILE'
Reads configuration from FILE instead of from the default per-user
configuration file. The default configuration file is named
'dirmngr.conf' and expected in the home directory.
'--homedir DIR'
Set the name of the home directory to DIR. This option is only
effective when used on the command line. The default is the
directory named '.gnupg' directly below the home directory of the
user unless the environment variable 'GNUPGHOME' has been set in
which case its value will be used. Many kinds of data are stored
within this directory.
'-v'
'--verbose'
Outputs additional information while running. You can increase the
verbosity by giving several verbose commands to DIRMNGR, such as
'-vv'.
'--log-file FILE'
Append all logging output to FILE. This is very helpful in seeing
what the agent actually does. Use 'socket://' to log to socket.
'--debug-level LEVEL'
Select the debug level for investigating problems. LEVEL may be a
numeric value or by a keyword:
'none'
No debugging at all. A value of less than 1 may be used
instead of the keyword.
'basic'
Some basic debug messages. A value between 1 and 2 may be
used instead of the keyword.
'advanced'
More verbose debug messages. A value between 3 and 5 may be
used instead of the keyword.
'expert'
Even more detailed messages. A value between 6 and 8 may be
used instead of the keyword.
'guru'
All of the debug messages you can get. A value greater than 8
may be used instead of the keyword. The creation of hash
tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not
specified and may change with newer releases of this program. They
are however carefully selected to best aid in debugging.
'--debug FLAGS'
Set debugging flags. This option is only useful for debugging and
its behavior may change with a new release. All flags are or-ed
and may be given in C syntax (e.g. 0x0042) or as a comma separated
list of flag names. To get a list of all supported flags the
single word "help" can be used.
'--debug-all'
Same as '--debug=0xffffffff'
'--tls-debug LEVEL'
Enable debugging of the TLS layer at LEVEL. The details of the
debug level depend on the used TLS library and are not set in
stone.
'--debug-wait N'
When running in server mode, wait N seconds before entering the
actual processing loop and print the pid. This gives time to
attach a debugger.
'--disable-check-own-socket'
On some platforms 'dirmngr' is able to detect the removal of its
socket file and shutdown itself. This option disable this
self-test for debugging purposes.
'-s'
'--sh'
'-c'
'--csh'
Format the info output in daemon mode for use with the standard
Bourne shell respective the C-shell. The default is to guess it
based on the environment variable 'SHELL' which is in almost all
cases sufficient.
'--force'
Enabling this option forces loading of expired CRLs; this is only
useful for debugging.
'--use-tor'
'--no-use-tor'
The option '--use-tor' switches Dirmngr and thus GnuPG into "Tor
mode" to route all network access via Tor (an anonymity network).
Certain other features are disabled in this mode. The effect of
'--use-tor' cannot be overridden by any other command or even by
reloading dirmngr. The use of '--no-use-tor' disables the use of
Tor. The default is to use Tor if it is available on startup or
after reloading dirmngr.
'--standard-resolver'
This option forces the use of the system's standard DNS resolver
code. This is mainly used for debugging. Note that on Windows a
standard resolver is not used and all DNS access will return the
error "Not Implemented" if this option is used. Using this
together with enabled Tor mode returns the error "Not Enabled".
'--recursive-resolver'
When possible use a recursive resolver instead of a stub resolver.
'--resolver-timeout N'
Set the timeout for the DNS resolver to N seconds. The default are
30 seconds.
'--connect-timeout N'
'--connect-quick-timeout N'
Set the timeout for HTTP and generic TCP connection attempts to N
seconds. The value set with the quick variant is used when the
-quick option has been given to certain Assuan commands. The quick
value is capped at the value of the regular connect timeout. The
default values are 15 and 2 seconds. Note that the timeout values
are for each connection attempt; the connection code will attempt
to connect all addresses listed for a server.
'--listen-backlog N'
Set the size of the queue for pending connections. The default is
64.
'--allow-version-check'
Allow Dirmngr to connect to 'https://versions.gnupg.org' to get the
list of current software versions. If this option is enabled the
list is retrieved in case the local copy does not exist or is older
than 5 to 7 days. See the option '--query-swdb' of the command
'gpgconf' for more details. Note, that regardless of this option a
version check can always be triggered using this command:
gpg-connect-agent --dirmngr 'loadswdb --force' /bye
'--keyserver NAME'
Use NAME as your keyserver. This is the server that 'gpg'
communicates with to receive keys, send keys, and search for keys.
The format of the NAME is a URI: 'scheme:[//]keyservername[:port]'
The scheme is the type of keyserver: "hkp" for the HTTP (or
compatible) keyservers, "ldap" for the LDAP keyservers, or "mailto"
for the Graff email keyserver. Note that your particular
installation of GnuPG may have other keyserver types available as
well. Keyserver schemes are case-insensitive. After the keyserver
name, optional keyserver configuration options may be provided.
These are the same as the '--keyserver-options' of 'gpg', but apply
only to this particular keyserver.
Most keyservers synchronize with each other, so there is generally
no need to send keys to more than one server. The keyserver
'hkp://keys.gnupg.net' uses round robin DNS to give a different
keyserver each time you use it.
If exactly two keyservers are configured and only one is a Tor
hidden service (.onion), Dirmngr selects the keyserver to use
depending on whether Tor is locally running or not. The check for
a running Tor is done for each new connection.
If no keyserver is explicitly configured, dirmngr will use the
built-in default of hkps://hkps.pool.sks-keyservers.net.
'--nameserver IPADDR'
In "Tor mode" Dirmngr uses a public resolver via Tor to resolve DNS
names. If the default public resolver, which is '8.8.8.8', shall
not be used a different one can be given using this option. Note
that a numerical IP address must be given (IPv6 or IPv4) and that
no error checking is done for IPADDR.
'--disable-ipv4'
'--disable-ipv6'
Disable the use of all IPv4 or IPv6 addresses.
'--disable-ldap'
Entirely disables the use of LDAP.
'--disable-http'
Entirely disables the use of HTTP.
'--ignore-http-dp'
When looking for the location of a CRL, the to be tested
certificate usually contains so called "CRL Distribution Point"
(DP) entries which are URLs describing the way to access the CRL.
The first found DP entry is used. With this option all entries
using the HTTP scheme are ignored when looking for a suitable DP.
'--ignore-ldap-dp'
This is similar to '--ignore-http-dp' but ignores entries using the
LDAP scheme. Both options may be combined resulting in ignoring
DPs entirely.
'--ignore-ocsp-service-url'
Ignore all OCSP URLs contained in the certificate. The effect is
to force the use of the default responder.
'--honor-http-proxy'
If the environment variable 'http_proxy' has been set, use its
value to access HTTP servers.
'--http-proxy HOST[:PORT]'
Use HOST and PORT to access HTTP servers. The use of this option
overrides the environment variable 'http_proxy' regardless whether
'--honor-http-proxy' has been set.
'--ldap-proxy HOST[:PORT]'
Use HOST and PORT to connect to LDAP servers. If PORT is omitted,
port 389 (standard LDAP port) is used. This overrides any
specified host and port part in a LDAP URL and will also be used if
host and port have been omitted from the URL.
'--only-ldap-proxy'
Never use anything else but the LDAP "proxy" as configured with
'--ldap-proxy'. Usually 'dirmngr' tries to use other configured
LDAP server if the connection using the "proxy" failed.
'--ldapserverlist-file FILE'
Read the list of LDAP servers to consult for CRLs and certificates
from file instead of the default per-user ldap server list file.
The default value for FILE is 'dirmngr_ldapservers.conf'.
This server list file contains one LDAP server per line in the
format
HOSTNAME:PORT:USERNAME:PASSWORD:BASE_DN
Lines starting with a '#' are comments.
Note that as usual all strings entered are expected to be UTF-8
encoded. Obviously this will lead to problems if the password has
originally been encoded as Latin-1. There is no other solution
here than to put such a password in the binary encoding into the
file (i.e. non-ascii characters won't show up readable).(1)
'--ldaptimeout SECS'
Specify the number of seconds to wait for an LDAP query before
timing out. The default are 15 seconds. 0 will never timeout.
'--add-servers'
This option makes dirmngr add any servers it discovers when
validating certificates against CRLs to the internal list of
servers to consult for certificates and CRLs.
This option is useful when trying to validate a certificate that
has a CRL distribution point that points to a server that is not
already listed in the ldapserverlist. Dirmngr will always go to
this server and try to download the CRL, but chances are high that
the certificate used to sign the CRL is located on the same server.
So if dirmngr doesn't add that new server to list, it will often
not be able to verify the signature of the CRL unless the
'--add-servers' option is used.
Note: The current version of dirmngr has this option disabled by
default.
'--allow-ocsp'
This option enables OCSP support if requested by the client.
OCSP requests are rejected by default because they may violate the
privacy of the user; for example it is possible to track the time
when a user is reading a mail.
'--ocsp-responder URL'
Use URL as the default OCSP Responder if the certificate does not
contain information about an assigned responder. Note, that
'--ocsp-signer' must also be set to a valid certificate.
'--ocsp-signer FPR|FILE'
Use the certificate with the fingerprint FPR to check the responses
of the default OCSP Responder. Alternatively a filename can be
given in which case the response is expected to be signed by one of
the certificates described in that file. Any argument which
contains a slash, dot or tilde is considered a filename. Usual
filename expansion takes place: A tilde at the start followed by a
slash is replaced by the content of 'HOME', no slash at start
describes a relative filename which will be searched at the home
directory. To make sure that the FILE is searched in the home
directory, either prepend the name with "./" or use a name which
contains a dot.
If a response has been signed by a certificate described by these
fingerprints no further check upon the validity of this certificate
is done.
The format of the FILE is a list of SHA-1 fingerprint, one per line
with optional colons between the bytes. Empty lines and lines
prefix with a hash mark are ignored.
'--ocsp-max-clock-skew N'
The number of seconds a skew between the OCSP responder and them
local clock is accepted. Default is 600 (10 minutes).
'--ocsp-max-period N'
Seconds a response is at maximum considered valid after the time
given in the thisUpdate field. Default is 7776000 (90 days).
'--ocsp-current-period N'
The number of seconds an OCSP response is considered valid after
the time given in the NEXT_UPDATE datum. Default is 10800 (3
hours).
'--max-replies N'
Do not return more that N items in one query. The default is 10.
'--ignore-cert-extension OID'
Add OID to the list of ignored certificate extensions. The OID is
expected to be in dotted decimal form, like '2.5.29.3'. This
option may be used more than once. Critical flagged certificate
extensions matching one of the OIDs in the list are treated as if
they are actually handled and thus the certificate won't be
rejected due to an unknown critical extension. Use this option
with care because extensions are usually flagged as critical for a
reason.
'--hkp-cacert FILE'
Use the root certificates in FILE for verification of the TLS
certificates used with 'hkps' (keyserver access over TLS). If the
file is in PEM format a suffix of '.pem' is expected for FILE.
This option may be given multiple times to add more root
certificates. Tilde expansion is supported.
If no 'hkp-cacert' directive is present, dirmngr will make a
reasonable choice: if the keyserver in question is the special pool
'hkps.pool.sks-keyservers.net', it will use the bundled root
certificate for that pool. Otherwise, it will use the system CAs.
---------- Footnotes ----------
(1) The 'gpgconf' tool might be helpful for frontends as it enables
editing this configuration file using percent-escaped strings.

File: gnupg.info, Node: Dirmngr Configuration, Next: Dirmngr Signals, Prev: Dirmngr Options, Up: Invoking DIRMNGR
3.3 Configuration
=================
Dirmngr makes use of several directories when running in daemon mode:
There are a few configuration files whih control the operation of
dirmngr. By default they may all be found in the current home directory
(*note option --homedir::).
'dirmngr.conf'
This is the standard configuration file read by 'dirmngr' on
startup. It may contain any valid long option; the leading two
dashes may not be entered and the option may not be abbreviated.
This file is also read after a 'SIGHUP' however not all options
will actually have an effect. This default name may be changed on
the command line (*note option --options::). You should backup
this file.
'/etc/gnupg/trusted-certs'
This directory should be filled with certificates of Root CAs you
are trusting in checking the CRLs and signing OCSP Responses.
Usually these are the same certificates you use with the
applications making use of dirmngr. It is expected that each of
these certificate files contain exactly one DER encoded certificate
in a file with the suffix '.crt' or '.der'. 'dirmngr' reads those
certificates on startup and when given a SIGHUP. Certificates which
are not readable or do not make up a proper X.509 certificate are
ignored; see the log file for details.
Applications using dirmngr (e.g. gpgsm) can request these
certificates to complete a trust chain in the same way as with the
extra-certs directory (see below).
Note that for OCSP responses the certificate specified using the
option '--ocsp-signer' is always considered valid to sign OCSP
requests.
'/etc/gnupg/extra-certs'
This directory may contain extra certificates which are preloaded
into the internal cache on startup. Applications using dirmngr
(e.g. gpgsm) can request cached certificates to complete a trust
chain. This is convenient in cases you have a couple intermediate
CA certificates or certificates usually used to sign OCSP
responses. These certificates are first tried before going out to
the net to look for them. These certificates must also be DER
encoded and suffixed with '.crt' or '.der'.
'~/.gnupg/crls.d'
This directory is used to store cached CRLs. The 'crls.d' part
will be created by dirmngr if it does not exists but you need to
make sure that the upper directory exists.
To be able to see what's going on you should create the configure
file '~/gnupg/dirmngr.conf' with at least one line:
log-file ~/dirmngr.log
To be able to perform OCSP requests you probably want to add the
line:
allow-ocsp
To make sure that new options are read and that after the
installation of a new GnuPG versions the installed dirmngr is running,
you may want to kill an existing dirmngr first:
gpgconf --kill dirmngr
You may check the log file to see whether all desired root
certificates have been loaded correctly.

File: gnupg.info, Node: Dirmngr Signals, Next: Dirmngr Examples, Prev: Dirmngr Configuration, Up: Invoking DIRMNGR
3.4 Use of signals
==================
A running 'dirmngr' may be controlled by signals, i.e. using the 'kill'
command to send a signal to the process.
Here is a list of supported signals:
'SIGHUP'
This signal flushes all internally cached CRLs as well as any
cached certificates. Then the certificate cache is reinitialized
as on startup. Options are re-read from the configuration file.
Instead of sending this signal it is better to use
gpgconf --reload dirmngr
'SIGTERM'
Shuts down the process but waits until all current requests are
fulfilled. If the process has received 3 of these signals and
requests are still pending, a shutdown is forced. You may also use
gpgconf --kill dirmngr
instead of this signal
'SIGINT'
Shuts down the process immediately.
'SIGUSR1'
This prints some caching statistics to the log file.

File: gnupg.info, Node: Dirmngr Examples, Next: Dirmngr Protocol, Prev: Dirmngr Signals, Up: Invoking DIRMNGR
3.5 Examples
============
Here is an example on how to show dirmngr's internal table of OpenPGP
keyserver addresses. The output is intended for debugging purposes and
not part of a defined API.
gpg-connect-agent --dirmngr 'keyserver --hosttable' /bye
To inhibit the use of a particular host you have noticed in one of
the keyserver pools, you may use
gpg-connect-agent --dirmngr 'keyserver --dead pgpkeys.bnd.de' /bye
The description of the 'keyserver' command can be printed using
gpg-connect-agent --dirmngr 'help keyserver' /bye

File: gnupg.info, Node: Dirmngr Protocol, Prev: Dirmngr Examples, Up: Invoking DIRMNGR
3.6 Dirmngr's Assuan Protocol
=============================
Assuan is the IPC protocol used to access dirmngr. This is a
description of the commands implemented by dirmngr.
* Menu:
* Dirmngr LOOKUP:: Look up a certificate via LDAP
* Dirmngr ISVALID:: Validate a certificate using a CRL or OCSP.
* Dirmngr CHECKCRL:: Validate a certificate using a CRL.
* Dirmngr CHECKOCSP:: Validate a certificate using OCSP.
* Dirmngr CACHECERT:: Put a certificate into the internal cache.
* Dirmngr VALIDATE:: Validate a certificate for debugging.

File: gnupg.info, Node: Dirmngr LOOKUP, Next: Dirmngr ISVALID, Up: Dirmngr Protocol
3.6.1 Return the certificate(s) found
-------------------------------------
Lookup certificate. To allow multiple patterns (which are ORed) quoting
is required: Spaces are to be translated into "+" or into "%20";
obviously this requires that the usual escape quoting rules are applied.
The server responds with:
S: D <DER encoded certificate>
S: END
S: D <second DER encoded certificate>
S: END
S: OK
In this example 2 certificates are returned. The server may return
any number of certificates; OK will also be returned when no
certificates were found. The dirmngr might return a status line
S: S TRUNCATED <n>
To indicate that the output was truncated to N items due to a
limitation of the server or by an arbitrary set limit.
The option '--url' may be used if instead of a search pattern a
complete URL to the certificate is known:
C: LOOKUP --url CN%3DWerner%20Koch,o%3DIntevation%20GmbH,c%3DDE?userCertificate
If the option '--cache-only' is given, no external lookup is done so
that only certificates from the cache are returned.
With the option '--single', the first and only the first match will
be returned. Unless option '--cache-only' is also used, no local lookup
will be done in this case.

File: gnupg.info, Node: Dirmngr ISVALID, Next: Dirmngr CHECKCRL, Prev: Dirmngr LOOKUP, Up: Dirmngr Protocol
3.6.2 Validate a certificate using a CRL or OCSP
------------------------------------------------
ISVALID [--only-ocsp] [--force-default-responder] CERTID|CERTFPR
Check whether the certificate described by the CERTID has been
revoked. Due to caching, the Dirmngr is able to answer immediately in
most cases.
The CERTID is a hex encoded string consisting of two parts, delimited
by a single dot. The first part is the SHA-1 hash of the issuer name
and the second part the serial number.
Alternatively the certificate's SHA-1 fingerprint CERTFPR may be
given in which case an OCSP request is done before consulting the CRL.
If the option '--only-ocsp' is given, no fallback to a CRL check will be
used. If the option '--force-default-responder' is given, only the
default OCSP responder will be used and any other methods of obtaining
an OCSP responder URL won't be used.
Common return values are:
'GPG_ERR_NO_ERROR (0)'
This is the positive answer: The certificate is not revoked and we
have an up-to-date revocation list for that certificate. If OCSP
was used the responder confirmed that the certificate has not been
revoked.
'GPG_ERR_CERT_REVOKED'
This is the negative answer: The certificate has been revoked.
Either it is in a CRL and that list is up to date or an OCSP
responder informed us that it has been revoked.
'GPG_ERR_NO_CRL_KNOWN'
No CRL is known for this certificate or the CRL is not valid or out
of date.
'GPG_ERR_NO_DATA'
The OCSP responder returned an "unknown" status. This means that
it is not aware of the certificate's status.
'GPG_ERR_NOT_SUPPORTED'
This is commonly seen if OCSP support has not been enabled in the
configuration.
If DirMngr has not enough information about the given certificate
(which is the case for not yet cached certificates), it will inquire the
missing data:
S: INQUIRE SENDCERT <CertID>
C: D <DER encoded certificate>
C: END
A client should be aware that DirMngr may ask for more than one
certificate.
If Dirmngr has a certificate but the signature of the certificate
could not been validated because the root certificate is not known to
dirmngr as trusted, it may ask back to see whether the client trusts
this the root certificate:
S: INQUIRE ISTRUSTED <CertHexfpr>
C: D 1
C: END
Only this answer will let Dirmngr consider the certificate as valid.

File: gnupg.info, Node: Dirmngr CHECKCRL, Next: Dirmngr CHECKOCSP, Prev: Dirmngr ISVALID, Up: Dirmngr Protocol
3.6.3 Validate a certificate using a CRL
----------------------------------------
Check whether the certificate with FINGERPRINT (SHA-1 hash of the entire
X.509 certificate blob) is valid or not by consulting the CRL
responsible for this certificate. If the fingerprint has not been given
or the certificate is not known, the function inquires the certificate
using:
S: INQUIRE TARGETCERT
C: D <DER encoded certificate>
C: END
Thus the caller is expected to return the certificate for the request
(which should match FINGERPRINT) as a binary blob. Processing then
takes place without further interaction; in particular dirmngr tries to
locate other required certificate by its own mechanism which includes a
local certificate store as well as a list of trusted root certificates.
The return code is 0 for success; i.e. the certificate has not been
revoked or one of the usual error codes from libgpg-error.

File: gnupg.info, Node: Dirmngr CHECKOCSP, Next: Dirmngr CACHECERT, Prev: Dirmngr CHECKCRL, Up: Dirmngr Protocol
3.6.4 Validate a certificate using OCSP
---------------------------------------
CHECKOCSP [--force-default-responder] [FINGERPRINT]
Check whether the certificate with FINGERPRINT (the SHA-1 hash of the
entire X.509 certificate blob) is valid by consulting the appropriate
OCSP responder. If the fingerprint has not been given or the
certificate is not known by Dirmngr, the function inquires the
certificate using:
S: INQUIRE TARGETCERT
C: D <DER encoded certificate>
C: END
Thus the caller is expected to return the certificate for the request
(which should match FINGERPRINT) as a binary blob. Processing then
takes place without further interaction; in particular dirmngr tries to
locate other required certificates by its own mechanism which includes a
local certificate store as well as a list of trusted root certificates.
If the option '--force-default-responder' is given, only the default
OCSP responder is used. This option is the per-command variant of the
global option '--ignore-ocsp-service-url'.
The return code is 0 for success; i.e. the certificate has not been
revoked or one of the usual error codes from libgpg-error.

File: gnupg.info, Node: Dirmngr CACHECERT, Next: Dirmngr VALIDATE, Prev: Dirmngr CHECKOCSP, Up: Dirmngr Protocol
3.6.5 Put a certificate into the internal cache
-----------------------------------------------
Put a certificate into the internal cache. This command might be useful
if a client knows in advance certificates required for a test and wants
to make sure they get added to the internal cache. It is also helpful
for debugging. To get the actual certificate, this command immediately
inquires it using
S: INQUIRE TARGETCERT
C: D <DER encoded certificate>
C: END
Thus the caller is expected to return the certificate for the request
as a binary blob.
The return code is 0 for success; i.e. the certificate has not been
successfully cached or one of the usual error codes from libgpg-error.

File: gnupg.info, Node: Dirmngr VALIDATE, Prev: Dirmngr CACHECERT, Up: Dirmngr Protocol
3.6.6 Validate a certificate for debugging
------------------------------------------
Validate a certificate using the certificate validation function used
internally by dirmngr. This command is only useful for debugging. To
get the actual certificate, this command immediately inquires it using
S: INQUIRE TARGETCERT
C: D <DER encoded certificate>
C: END
Thus the caller is expected to return the certificate for the request
as a binary blob.

File: gnupg.info, Node: Invoking GPG, Next: Invoking GPGSM, Prev: Invoking DIRMNGR, Up: Top
4 Invoking GPG
**************
'gpg' is the OpenPGP part of the GNU Privacy Guard (GnuPG). It is a tool
to provide digital encryption and signing services using the OpenPGP
standard. 'gpg' features complete key management and all the bells and
whistles you would expect from a full OpenPGP implementation.
There are two main versions of GnuPG: GnuPG 1.x and GnuPG 2.x. GnuPG
2.x supports modern encryption algorithms and thus should be preferred
over GnuPG 1.x. You only need to use GnuPG 1.x if your platform doesn't
support GnuPG 2.x, or you need support for some features that GnuPG 2.x
has deprecated, e.g., decrypting data created with PGP-2 keys.
If you are looking for version 1 of GnuPG, you may find that version
installed under the name 'gpg1'.
*Note Option Index::, for an index to 'gpg''s commands and options.
* Menu:
* GPG Commands:: List of all commands.
* GPG Options:: List of all options.
* GPG Configuration:: Configuration files.
* GPG Examples:: Some usage examples.
Developer information:
* Unattended Usage of GPG:: Using 'gpg' from other programs.

File: gnupg.info, Node: GPG Commands, Next: GPG Options, Up: Invoking GPG
4.1 Commands
============
Commands are not distinguished from options except for the fact that
only one command is allowed. Generally speaking, irrelevant options are
silently ignored, and may not be checked for correctness.
'gpg' may be run with no commands. In this case it will print a
warning perform a reasonable action depending on the type of file it is
given as input (an encrypted message is decrypted, a signature is
verified, a file containing keys is listed, etc.).
If you run into any problems, please add the option '--verbose' to
the invocation to see more diagnostics.
* Menu:
* General GPG Commands:: Commands not specific to the functionality.
* Operational GPG Commands:: Commands to select the type of operation.
* OpenPGP Key Management:: How to manage your keys.

File: gnupg.info, Node: General GPG Commands, Next: Operational GPG Commands, Up: GPG Commands
4.1.1 Commands not specific to the function
-------------------------------------------
'--version'
Print the program version and licensing information. Note that you
cannot abbreviate this command.
'--help'
'-h'
Print a usage message summarizing the most useful command-line
options. Note that you cannot arbitrarily abbreviate this command
(though you can use its short form '-h').
'--warranty'
Print warranty information.
'--dump-options'
Print a list of all available options and commands. Note that you
cannot abbreviate this command.

File: gnupg.info, Node: Operational GPG Commands, Next: OpenPGP Key Management, Prev: General GPG Commands, Up: GPG Commands
4.1.2 Commands to select the type of operation
----------------------------------------------
'--sign'
'-s'
Sign a message. This command may be combined with '--encrypt' (to
sign and encrypt a message), '--symmetric' (to sign and
symmetrically encrypt a message), or both '--encrypt' and
'--symmetric' (to sign and encrypt a message that can be decrypted
using a secret key or a passphrase). The signing key is chosen by
default or can be set explicitly using the '--local-user' and
'--default-key' options.
'--clear-sign'
'--clearsign'
Make a cleartext signature. The content in a cleartext signature
is readable without any special software. OpenPGP software is only
needed to verify the signature. cleartext signatures may modify
end-of-line whitespace for platform independence and are not
intended to be reversible. The signing key is chosen by default or
can be set explicitly using the '--local-user' and '--default-key'
options.
'--detach-sign'
'-b'
Make a detached signature.
'--encrypt'
'-e'
Encrypt data to one or more public keys. This command may be
combined with '--sign' (to sign and encrypt a message),
'--symmetric' (to encrypt a message that can be decrypted using a
secret key or a passphrase), or '--sign' and '--symmetric' together
(for a signed message that can be decrypted using a secret key or a
passphrase). '--recipient' and related options specify which
public keys to use for encryption.
'--symmetric'
'-c'
Encrypt with a symmetric cipher using a passphrase. The default
symmetric cipher used is AES-128, but may be chosen with the
'--cipher-algo' option. This command may be combined with '--sign'
(for a signed and symmetrically encrypted message), '--encrypt'
(for a message that may be decrypted via a secret key or a
passphrase), or '--sign' and '--encrypt' together (for a signed
message that may be decrypted via a secret key or a passphrase).
'gpg' caches the passphrase used for symmetric encryption so that a
decrypt operation may not require that the user needs to enter the
passphrase. The option '--no-symkey-cache' can be used to disable
this feature.
'--store'
Store only (make a simple literal data packet).
'--decrypt'
'-d'
Decrypt the file given on the command line (or STDIN if no file is
specified) and write it to STDOUT (or the file specified with
'--output'). If the decrypted file is signed, the signature is
also verified. This command differs from the default operation, as
it never writes to the filename which is included in the file and
it rejects files that don't begin with an encrypted message.
'--verify'
Assume that the first argument is a signed file and verify it
without generating any output. With no arguments, the signature
packet is read from STDIN. If only one argument is given, the
specified file is expected to include a complete signature.
With more than one argument, the first argument should specify a
file with a detached signature and the remaining files should
contain the signed data. To read the signed data from STDIN, use
'-' as the second filename. For security reasons, a detached
signature will not read the signed material from STDIN if not
explicitly specified.
Note: If the option '--batch' is not used, 'gpg' may assume that a
single argument is a file with a detached signature, and it will
try to find a matching data file by stripping certain suffixes.
Using this historical feature to verify a detached signature is
strongly discouraged; you should always specify the data file
explicitly.
Note: When verifying a cleartext signature, 'gpg' verifies only
what makes up the cleartext signed data and not any extra data
outside of the cleartext signature or the header lines directly
following the dash marker line. The option '--output' may be used
to write out the actual signed data, but there are other pitfalls
with this format as well. It is suggested to avoid cleartext
signatures in favor of detached signatures.
Note: Sometimes the use of the 'gpgv' tool is easier than using the
full-fledged 'gpg' with this option. 'gpgv' is designed to compare
signed data against a list of trusted keys and returns with success
only for a good signature. It has its own manual page.
'--multifile'
This modifies certain other commands to accept multiple files for
processing on the command line or read from STDIN with each
filename on a separate line. This allows for many files to be
processed at once. '--multifile' may currently be used along with
'--verify', '--encrypt', and '--decrypt'. Note that '--multifile
--verify' may not be used with detached signatures.
'--verify-files'
Identical to '--multifile --verify'.
'--encrypt-files'
Identical to '--multifile --encrypt'.
'--decrypt-files'
Identical to '--multifile --decrypt'.
'--list-keys'
'-k'
'--list-public-keys'
List the specified keys. If no keys are specified, then all keys
from the configured public keyrings are listed.
Never use the output of this command in scripts or other programs.
The output is intended only for humans and its format is likely to
change. The '--with-colons' option emits the output in a stable,
machine-parseable format, which is intended for use by scripts and
other programs.
'--list-secret-keys'
'-K'
List the specified secret keys. If no keys are specified, then all
known secret keys are listed. A '#' after the initial tags 'sec'
or 'ssb' means that the secret key or subkey is currently not
usable. We also say that this key has been taken offline (for
example, a primary key can be taken offline by exporting the key
using the command '--export-secret-subkeys'). A '>' after these
tags indicate that the key is stored on a smartcard. See also
'--list-keys'.
'--check-signatures'
'--check-sigs'
Same as '--list-keys', but the key signatures are verified and
listed too. Note that for performance reasons the revocation
status of a signing key is not shown. This command has the same
effect as using '--list-keys' with '--with-sig-check'.
The status of the verification is indicated by a flag directly
following the "sig" tag (and thus before the flags described below.
A "!" indicates that the signature has been successfully verified,
a "-" denotes a bad signature and a "%" is used if an error
occurred while checking the signature (e.g. a non supported
algorithm). Signatures where the public key is not available are
not listed; to see their keyids the command '--list-sigs' can be
used.
For each signature listed, there are several flags in between the
signature status flag and keyid. These flags give additional
information about each key signature. From left to right, they are
the numbers 1-3 for certificate check level (see
'--ask-cert-level'), "L" for a local or non-exportable signature
(see '--lsign-key'), "R" for a nonRevocable signature (see the
'--edit-key' command "nrsign"), "P" for a signature that contains a
policy URL (see '--cert-policy-url'), "N" for a signature that
contains a notation (see '--cert-notation'), "X" for an eXpired
signature (see '--ask-cert-expire'), and the numbers 1-9 or "T" for
10 and above to indicate trust signature levels (see the
'--edit-key' command "tsign").
'--locate-keys'
'--locate-external-keys'
Locate the keys given as arguments. This command basically uses
the same algorithm as used when locating keys for encryption or
signing and may thus be used to see what keys 'gpg' might use. In
particular external methods as defined by '--auto-key-locate' may
be used to locate a key. Only public keys are listed. The variant
'--locate-external-keys' does not consider a locally existing key
and can thus be used to force the refresh of a key via the defined
external methods.
'--show-keys'
This commands takes OpenPGP keys as input and prints information
about them in the same way the command '--list-keys' does for
locally stored key. In addition the list options
'show-unusable-uids', 'show-unusable-subkeys', 'show-notations' and
'show-policy-urls' are also enabled. As usual for automated
processing, this command should be combined with the option
'--with-colons'.
'--fingerprint'
List all keys (or the specified ones) along with their
fingerprints. This is the same output as '--list-keys' but with
the additional output of a line with the fingerprint. May also be
combined with '--check-signatures'. If this command is given
twice, the fingerprints of all secondary keys are listed too. This
command also forces pretty printing of fingerprints if the keyid
format has been set to "none".
'--list-packets'
List only the sequence of packets. This command is only useful for
debugging. When used with option '--verbose' the actual MPI values
are dumped and not only their lengths. Note that the output of
this command may change with new releases.
'--edit-card'
'--card-edit'
Present a menu to work with a smartcard. The subcommand "help"
provides an overview on available commands. For a detailed
description, please see the Card HOWTO at
https://gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO .
'--card-status'
Show the content of the smart card.
'--change-pin'
Present a menu to allow changing the PIN of a smartcard. This
functionality is also available as the subcommand "passwd" with the
'--edit-card' command.
'--delete-keys NAME'
Remove key from the public keyring. In batch mode either '--yes'
is required or the key must be specified by fingerprint. This is a
safeguard against accidental deletion of multiple keys. If the
exclamation mark syntax is used with the fingerprint of a subkey
only that subkey is deleted; if the exclamation mark is used with
the fingerprint of the primary key the entire public key is
deleted.
'--delete-secret-keys NAME'
Remove key from the secret keyring. In batch mode the key must be
specified by fingerprint. The option '--yes' can be used to advice
gpg-agent not to request a confirmation. This extra pre-caution is
done because 'gpg' can't be sure that the secret key (as controlled
by gpg-agent) is only used for the given OpenPGP public key. If
the exclamation mark syntax is used with the fingerprint of a
subkey only the secret part of that subkey is deleted; if the
exclamation mark is used with the fingerprint of the primary key
only the secret part of the primary key is deleted.
'--delete-secret-and-public-key NAME'
Same as '--delete-key', but if a secret key exists, it will be
removed first. In batch mode the key must be specified by
fingerprint. The option '--yes' can be used to advice gpg-agent
not to request a confirmation.
'--export'
Either export all keys from all keyrings (default keyrings and
those registered via option '--keyring'), or if at least one name
is given, those of the given name. The exported keys are written
to STDOUT or to the file given with option '--output'. Use
together with '--armor' to mail those keys.
'--send-keys KEYIDS'
Similar to '--export' but sends the keys to a keyserver.
Fingerprints may be used instead of key IDs. Don't send your
complete keyring to a keyserver -- select only those keys which are
new or changed by you. If no KEYIDS are given, 'gpg' does nothing.
'--export-secret-keys'
'--export-secret-subkeys'
Same as '--export', but exports the secret keys instead. The
exported keys are written to STDOUT or to the file given with
option '--output'. This command is often used along with the
option '--armor' to allow for easy printing of the key for paper
backup; however the external tool 'paperkey' does a better job of
creating backups on paper. Note that exporting a secret key can be
a security risk if the exported keys are sent over an insecure
channel.
The second form of the command has the special property to render
the secret part of the primary key useless; this is a GNU extension
to OpenPGP and other implementations can not be expected to
successfully import such a key. Its intended use is in generating
a full key with an additional signing subkey on a dedicated
machine. This command then exports the key without the primary key
to the main machine.
GnuPG may ask you to enter the passphrase for the key. This is
required, because the internal protection method of the secret key
is different from the one specified by the OpenPGP protocol.
'--export-ssh-key'
This command is used to export a key in the OpenSSH public key
format. It requires the specification of one key by the usual
means and exports the latest valid subkey which has an
authentication capability to STDOUT or to the file given with
option '--output'. That output can directly be added to ssh's
'authorized_key' file.
By specifying the key to export using a key ID or a fingerprint
suffixed with an exclamation mark (!), a specific subkey or the
primary key can be exported. This does not even require that the
key has the authentication capability flag set.
'--import'
'--fast-import'
Import/merge keys. This adds the given keys to the keyring. The
fast version is currently just a synonym.
There are a few other options which control how this command works.
Most notable here is the '--import-options merge-only' option which
does not insert new keys but does only the merging of new
signatures, user-IDs and subkeys.
'--receive-keys KEYIDS'
'--recv-keys KEYIDS'
Import the keys with the given KEYIDS from a keyserver.
'--refresh-keys'
Request updates from a keyserver for keys that already exist on the
local keyring. This is useful for updating a key with the latest
signatures, user IDs, etc. Calling this with no arguments will
refresh the entire keyring.
'--search-keys NAMES'
Search the keyserver for the given NAMES. Multiple names given
here will be joined together to create the search string for the
keyserver. Note that keyservers search for NAMES in a different
and simpler way than gpg does. The best choice is to use a mail
address. Due to data privacy reasons keyservers may even not even
allow searching by user id or mail address and thus may only return
results when being used with the '--recv-key' command to search by
key fingerprint or keyid.
'--fetch-keys URIS'
Retrieve keys located at the specified URIS. Note that different
installations of GnuPG may support different protocols (HTTP, FTP,
LDAP, etc.). When using HTTPS the system provided root
certificates are used by this command.
'--update-trustdb'
Do trust database maintenance. This command iterates over all keys
and builds the Web of Trust. This is an interactive command
because it may have to ask for the "ownertrust" values for keys.
The user has to give an estimation of how far she trusts the owner
of the displayed key to correctly certify (sign) other keys. GnuPG
only asks for the ownertrust value if it has not yet been assigned
to a key. Using the '--edit-key' menu, the assigned value can be
changed at any time.
'--check-trustdb'
Do trust database maintenance without user interaction. From time
to time the trust database must be updated so that expired keys or
signatures and the resulting changes in the Web of Trust can be
tracked. Normally, GnuPG will calculate when this is required and
do it automatically unless '--no-auto-check-trustdb' is set. This
command can be used to force a trust database check at any time.
The processing is identical to that of '--update-trustdb' but it
skips keys with a not yet defined "ownertrust".
For use with cron jobs, this command can be used together with
'--batch' in which case the trust database check is done only if a
check is needed. To force a run even in batch mode add the option
'--yes'.
'--export-ownertrust'
Send the ownertrust values to STDOUT. This is useful for backup
purposes as these values are the only ones which can't be
re-created from a corrupted trustdb. Example:
gpg --export-ownertrust > otrust.txt
'--import-ownertrust'
Update the trustdb with the ownertrust values stored in 'files' (or
STDIN if not given); existing values will be overwritten. In case
of a severely damaged trustdb and if you have a recent backup of
the ownertrust values (e.g. in the file 'otrust.txt'), you may
re-create the trustdb using these commands:
cd ~/.gnupg
rm trustdb.gpg
gpg --import-ownertrust < otrust.txt
'--rebuild-keydb-caches'
When updating from version 1.0.6 to 1.0.7 this command should be
used to create signature caches in the keyring. It might be handy
in other situations too.
'--print-md ALGO'
'--print-mds'
Print message digest of algorithm ALGO for all given files or
STDIN. With the second form (or a deprecated "*" for ALGO) digests
for all available algorithms are printed.
'--gen-random 0|1|2 COUNT'
Emit COUNT random bytes of the given quality level 0, 1 or 2. If
COUNT is not given or zero, an endless sequence of random bytes
will be emitted. If used with '--armor' the output will be base64
encoded. PLEASE, don't use this command unless you know what you
are doing; it may remove precious entropy from the system!
'--gen-prime MODE BITS'
Use the source, Luke :-). The output format is subject to change
with ant release.
'--enarmor'
'--dearmor'
Pack or unpack an arbitrary input into/from an OpenPGP ASCII armor.
This is a GnuPG extension to OpenPGP and in general not very
useful.
'--tofu-policy {auto|good|unknown|bad|ask} KEYS'
Set the TOFU policy for all the bindings associated with the
specified KEYS. For more information about the meaning of the
policies, *note trust-model-tofu::. The KEYS may be specified
either by their fingerprint (preferred) or their keyid.

File: gnupg.info, Node: OpenPGP Key Management, Prev: Operational GPG Commands, Up: GPG Commands
4.1.3 How to manage your keys
-----------------------------
This section explains the main commands for key management.
'--quick-generate-key USER-ID [ALGO [USAGE [EXPIRE]]]'
'--quick-gen-key'
This is a simple command to generate a standard key with one user
id. In contrast to '--generate-key' the key is generated directly
without the need to answer a bunch of prompts. Unless the option
'--yes' is given, the key creation will be canceled if the given
user id already exists in the keyring.
If invoked directly on the console without any special options an
answer to a "Continue?" style confirmation prompt is required. In
case the user id already exists in the keyring a second prompt to
force the creation of the key will show up.
If ALGO or USAGE are given, only the primary key is created and no
prompts are shown. To specify an expiration date but still create
a primary and subkey use "default" or "future-default" for ALGO and
"default" for USAGE. For a description of these optional arguments
see the command '--quick-add-key'. The USAGE accepts also the
value "cert" which can be used to create a certification only
primary key; the default is to a create certification and signing
key.
The EXPIRE argument can be used to specify an expiration date for
the key. Several formats are supported; commonly the ISO formats
"YYYY-MM-DD" or "YYYYMMDDThhmmss" are used. To make the key expire
in N seconds, N days, N weeks, N months, or N years use
"seconds=N", "Nd", "Nw", "Nm", or "Ny" respectively. Not
specifying a value, or using "-" results in a key expiring in a
reasonable default interval. The values "never", "none" can be
used for no expiration date.
If this command is used with '--batch', '--pinentry-mode' has been
set to 'loopback', and one of the passphrase options
('--passphrase', '--passphrase-fd', or 'passphrase-file') is used,
the supplied passphrase is used for the new key and the agent does
not ask for it. To create a key without any protection
'--passphrase ''' may be used.
To create an OpenPGP key from the keys available on the currently
inserted smartcard, the special string "card" can be used for ALGO.
If the card features an encryption and a signing key, gpg will
figure them out and creates an OpenPGP key consisting of the usual
primary key and one subkey. This works only with certain
smartcards. Note that the interactive '--full-gen-key' command
allows to do the same but with greater flexibility in the selection
of the smartcard keys.
Note that it is possible to create a primary key and a subkey using
non-default algorithms by using "default" and changing the default
parameters using the option '--default-new-key-algo'.
'--quick-set-expire FPR EXPIRE [*|SUBFPRS]'
With two arguments given, directly set the expiration time of the
primary key identified by FPR to EXPIRE. To remove the expiration
time '0' can be used. With three arguments and the third given as
an asterisk, the expiration time of all non-revoked and not yet
expired subkeys are set to EXPIRE. With more than two arguments
and a list of fingerprints given for SUBFPRS, all non-revoked
subkeys matching these fingerprints are set to EXPIRE.
'--quick-add-key FPR [ALGO [USAGE [EXPIRE]]]'
Directly add a subkey to the key identified by the fingerprint FPR.
Without the optional arguments an encryption subkey is added. If
any of the arguments are given a more specific subkey is added.
ALGO may be any of the supported algorithms or curve names given in
the format as used by key listings. To use the default algorithm
the string "default" or "-" can be used. Supported algorithms are
"rsa", "dsa", "elg", "ed25519", "cv25519", and other ECC curves.
For example the string "rsa" adds an RSA key with the default key
length; a string "rsa4096" requests that the key length is 4096
bits. The string "future-default" is an alias for the algorithm
which will likely be used as default algorithm in future versions
of gpg. To list the supported ECC curves the command 'gpg
--with-colons --list-config curve' can be used.
Depending on the given ALGO the subkey may either be an encryption
subkey or a signing subkey. If an algorithm is capable of signing
and encryption and such a subkey is desired, a USAGE string must be
given. This string is either "default" or "-" to keep the default
or a comma delimited list (or space delimited list) of keywords:
"sign" for a signing subkey, "auth" for an authentication subkey,
and "encr" for an encryption subkey ("encrypt" can be used as alias
for "encr"). The valid combinations depend on the algorithm.
The EXPIRE argument can be used to specify an expiration date for
the key. Several formats are supported; commonly the ISO formats
"YYYY-MM-DD" or "YYYYMMDDThhmmss" are used. To make the key expire
in N seconds, N days, N weeks, N months, or N years use
"seconds=N", "Nd", "Nw", "Nm", or "Ny" respectively. Not
specifying a value, or using "-" results in a key expiring in a
reasonable default interval. The values "never", "none" can be
used for no expiration date.
'--generate-key'
'--gen-key'
Generate a new key pair using the current default parameters. This
is the standard command to create a new key. In addition to the
key a revocation certificate is created and stored in the
'openpgp-revocs.d' directory below the GnuPG home directory.
'--full-generate-key'
'--full-gen-key'
Generate a new key pair with dialogs for all options. This is an
extended version of '--generate-key'.
There is also a feature which allows you to create keys in batch
mode. See the manual section "Unattended key generation" on how to
use this.
'--generate-revocation NAME'
'--gen-revoke NAME'
Generate a revocation certificate for the complete key. To only
revoke a subkey or a key signature, use the '--edit' command.
This command merely creates the revocation certificate so that it
can be used to revoke the key if that is ever needed. To actually
revoke a key the created revocation certificate needs to be merged
with the key to revoke. This is done by importing the revocation
certificate using the '--import' command. Then the revoked key
needs to be published, which is best done by sending the key to a
keyserver (command '--send-key') and by exporting ('--export') it
to a file which is then send to frequent communication partners.
'--generate-designated-revocation NAME'
'--desig-revoke NAME'
Generate a designated revocation certificate for a key. This
allows a user (with the permission of the keyholder) to revoke
someone else's key.
'--edit-key'
Present a menu which enables you to do most of the key management
related tasks. It expects the specification of a key on the
command line.
uid N
Toggle selection of user ID or photographic user ID with index
N. Use '*' to select all and '0' to deselect all.
key N
Toggle selection of subkey with index N or key ID N. Use '*'
to select all and '0' to deselect all.
sign
Make a signature on key of user 'name'. If the key is not yet
signed by the default user (or the users given with '-u'), the
program displays the information of the key again, together
with its fingerprint and asks whether it should be signed.
This question is repeated for all users specified with '-u'.
lsign
Same as "sign" but the signature is marked as non-exportable
and will therefore never be used by others. This may be used
to make keys valid only in the local environment.
nrsign
Same as "sign" but the signature is marked as non-revocable
and can therefore never be revoked.
tsign
Make a trust signature. This is a signature that combines the
notions of certification (like a regular signature), and trust
(like the "trust" command). It is generally only useful in
distinct communities or groups. For more information please
read the sections "Trust Signature" and "Regular Expression"
in RFC-4880.
Note that "l" (for local / non-exportable), "nr" (for
non-revocable, and "t" (for trust) may be freely mixed and prefixed
to "sign" to create a signature of any type desired.
If the option '--only-sign-text-ids' is specified, then any
non-text based user ids (e.g., photo IDs) will not be selected for
signing.
delsig
Delete a signature. Note that it is not possible to retract a
signature, once it has been send to the public (i.e. to a
keyserver). In that case you better use 'revsig'.
revsig
Revoke a signature. For every signature which has been
generated by one of the secret keys, GnuPG asks whether a
revocation certificate should be generated.
check
Check the signatures on all selected user IDs. With the extra
option 'selfsig' only self-signatures are shown.
adduid
Create an additional user ID.
addphoto
Create a photographic user ID. This will prompt for a JPEG
file that will be embedded into the user ID. Note that a very
large JPEG will make for a very large key. Also note that
some programs will display your JPEG unchanged (GnuPG), and
some programs will scale it to fit in a dialog box (PGP).
showphoto
Display the selected photographic user ID.
deluid
Delete a user ID or photographic user ID. Note that it is not
possible to retract a user id, once it has been send to the
public (i.e. to a keyserver). In that case you better use
'revuid'.
revuid
Revoke a user ID or photographic user ID.
primary
Flag the current user id as the primary one, removes the
primary user id flag from all other user ids and sets the
timestamp of all affected self-signatures one second ahead.
Note that setting a photo user ID as primary makes it primary
over other photo user IDs, and setting a regular user ID as
primary makes it primary over other regular user IDs.
keyserver
Set a preferred keyserver for the specified user ID(s). This
allows other users to know where you prefer they get your key
from. See '--keyserver-options honor-keyserver-url' for more
on how this works. Setting a value of "none" removes an
existing preferred keyserver.
notation
Set a name=value notation for the specified user ID(s). See
'--cert-notation' for more on how this works. Setting a value
of "none" removes all notations, setting a notation prefixed
with a minus sign (-) removes that notation, and setting a
notation name (without the =value) prefixed with a minus sign
removes all notations with that name.
pref
List preferences from the selected user ID. This shows the
actual preferences, without including any implied preferences.
showpref
More verbose preferences listing for the selected user ID.
This shows the preferences in effect by including the implied
preferences of 3DES (cipher), SHA-1 (digest), and Uncompressed
(compression) if they are not already included in the
preference list. In addition, the preferred keyserver and
signature notations (if any) are shown.
setpref STRING
Set the list of user ID preferences to STRING for all (or just
the selected) user IDs. Calling setpref with no arguments
sets the preference list to the default (either built-in or
set via '--default-preference-list'), and calling setpref with
"none" as the argument sets an empty preference list. Use
'gpg --version' to get a list of available algorithms. Note
that while you can change the preferences on an attribute user
ID (aka "photo ID"), GnuPG does not select keys via attribute
user IDs so these preferences will not be used by GnuPG.
When setting preferences, you should list the algorithms in
the order which you'd like to see them used by someone else
when encrypting a message to your key. If you don't include
3DES, it will be automatically added at the end. Note that
there are many factors that go into choosing an algorithm (for
example, your key may not be the only recipient), and so the
remote OpenPGP application being used to send to you may or
may not follow your exact chosen order for a given message.
It will, however, only choose an algorithm that is present on
the preference list of every recipient key. See also the
INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section below.
addkey
Add a subkey to this key.
addcardkey
Generate a subkey on a card and add it to this key.
keytocard
Transfer the selected secret subkey (or the primary key if no
subkey has been selected) to a smartcard. The secret key in
the keyring will be replaced by a stub if the key could be
stored successfully on the card and you use the save command
later. Only certain key types may be transferred to the card.
A sub menu allows you to select on what card to store the key.
Note that it is not possible to get that key back from the
card - if the card gets broken your secret key will be lost
unless you have a backup somewhere.
bkuptocard FILE
Restore the given FILE to a card. This command may be used to
restore a backup key (as generated during card initialization)
to a new card. In almost all cases this will be the
encryption key. You should use this command only with the
corresponding public key and make sure that the file given as
argument is indeed the backup to restore. You should then
select 2 to restore as encryption key. You will first be
asked to enter the passphrase of the backup key and then for
the Admin PIN of the card.
delkey
Remove a subkey (secondary key). Note that it is not possible
to retract a subkey, once it has been send to the public (i.e.
to a keyserver). In that case you better use 'revkey'. Also
note that this only deletes the public part of a key.
revkey
Revoke a subkey.
expire
Change the key or subkey expiration time. If a subkey is
selected, the expiration time of this subkey will be changed.
With no selection, the key expiration of the primary key is
changed.
trust
Change the owner trust value for the key. This updates the
trust-db immediately and no save is required.
disable
enable
Disable or enable an entire key. A disabled key can not
normally be used for encryption.
addrevoker
Add a designated revoker to the key. This takes one optional
argument: "sensitive". If a designated revoker is marked as
sensitive, it will not be exported by default (see
export-options).
passwd
Change the passphrase of the secret key.
toggle
This is dummy command which exists only for backward
compatibility.
clean
Compact (by removing all signatures except the selfsig) any
user ID that is no longer usable (e.g. revoked, or expired).
Then, remove any signatures that are not usable by the trust
calculations. Specifically, this removes any signature that
does not validate, any signature that is superseded by a later
signature, revoked signatures, and signatures issued by keys
that are not present on the keyring.
minimize
Make the key as small as possible. This removes all
signatures from each user ID except for the most recent
self-signature.
change-usage
Change the usage flags (capabilities) of the primary key or of
subkeys. These usage flags (e.g. Certify, Sign,
Authenticate, Encrypt) are set during key creation. Sometimes
it is useful to have the opportunity to change them (for
example to add Authenticate) after they have been created.
Please take care when doing this; the allowed usage flags
depend on the key algorithm.
cross-certify
Add cross-certification signatures to signing subkeys that may
not currently have them. Cross-certification signatures
protect against a subtle attack against signing subkeys. See
'--require-cross-certification'. All new keys generated have
this signature by default, so this command is only useful to
bring older keys up to date.
save
Save all changes to the keyrings and quit.
quit
Quit the program without updating the keyrings.
The listing shows you the key with its secondary keys and all user
IDs. The primary user ID is indicated by a dot, and selected keys
or user IDs are indicated by an asterisk. The trust value is
displayed with the primary key: "trust" is the assigned owner trust
and "validity" is the calculated validity of the key. Validity
values are also displayed for all user IDs. For possible values of
trust, *note trust-values::.
'--sign-key NAME'
Signs a public key with your secret key. This is a shortcut
version of the subcommand "sign" from '--edit'.
'--lsign-key NAME'
Signs a public key with your secret key but marks it as
non-exportable. This is a shortcut version of the subcommand
"lsign" from '--edit-key'.
'--quick-sign-key FPR [NAMES]'
'--quick-lsign-key FPR [NAMES]'
Directly sign a key from the passphrase without any further user
interaction. The FPR must be the verified primary fingerprint of a
key in the local keyring. If no NAMES are given, all useful user
ids are signed; with given [NAMES] only useful user ids matching
one of theses names are signed. By default, or if a name is
prefixed with a '*', a case insensitive substring match is used.
If a name is prefixed with a '=' a case sensitive exact match is
done.
The command '--quick-lsign-key' marks the signatures as
non-exportable. If such a non-exportable signature already exists
the '--quick-sign-key' turns it into a exportable signature.
This command uses reasonable defaults and thus does not provide the
full flexibility of the "sign" subcommand from '--edit-key'. Its
intended use is to help unattended key signing by utilizing a list
of verified fingerprints.
'--quick-add-uid USER-ID NEW-USER-ID'
This command adds a new user id to an existing key. In contrast to
the interactive sub-command 'adduid' of '--edit-key' the
NEW-USER-ID is added verbatim with only leading and trailing white
space removed, it is expected to be UTF-8 encoded, and no checks on
its form are applied.
'--quick-revoke-uid USER-ID USER-ID-TO-REVOKE'
This command revokes a user ID on an existing key. It cannot be
used to revoke the last user ID on key (some non-revoked user ID
must remain), with revocation reason "User ID is no longer valid".
If you want to specify a different revocation reason, or to supply
supplementary revocation text, you should use the interactive
sub-command 'revuid' of '--edit-key'.
'--quick-set-primary-uid USER-ID PRIMARY-USER-ID'
This command sets or updates the primary user ID flag on an
existing key. USER-ID specifies the key and PRIMARY-USER-ID the
user ID which shall be flagged as the primary user ID. The primary
user ID flag is removed from all other user ids and the timestamp
of all affected self-signatures is set one second ahead.
'--change-passphrase USER-ID'
'--passwd USER-ID'
Change the passphrase of the secret key belonging to the
certificate specified as USER-ID. This is a shortcut for the
sub-command 'passwd' of the edit key menu. When using together
with the option '--dry-run' this will not actually change the
passphrase but check that the current passphrase is correct.

File: gnupg.info, Node: GPG Options, Next: GPG Configuration, Prev: GPG Commands, Up: Invoking GPG
4.2 Option Summary
==================
'gpg' features a bunch of options to control the exact behaviour and to
change the default configuration.
* Menu:
* GPG Configuration Options:: How to change the configuration.
* GPG Key related Options:: Key related options.
* GPG Input and Output:: Input and Output.
* OpenPGP Options:: OpenPGP protocol specific options.
* Compliance Options:: Compliance options.
* GPG Esoteric Options:: Doing things one usually doesn't want to do.
* Deprecated Options:: Deprecated options.
Long options can be put in an options file (default
"~/.gnupg/gpg.conf"). Short option names will not work - for example,
"armor" is a valid option for the options file, while "a" is not. Do
not write the 2 dashes, but simply the name of the option and any
required arguments. Lines with a hash ('#') as the first
non-white-space character are ignored. Commands may be put in this file
too, but that is not generally useful as the command will execute
automatically with every execution of gpg.
Please remember that option parsing stops as soon as a non-option is
encountered, you can explicitly stop parsing by using the special option
'--'.

File: gnupg.info, Node: GPG Configuration Options, Next: GPG Key related Options, Up: GPG Options
4.2.1 How to change the configuration
-------------------------------------
These options are used to change the configuration and are usually found
in the option file.
'--default-key NAME'
Use NAME as the default key to sign with. If this option is not
used, the default key is the first key found in the secret keyring.
Note that '-u' or '--local-user' overrides this option. This
option may be given multiple times. In this case, the last key for
which a secret key is available is used. If there is no secret key
available for any of the specified values, GnuPG will not emit an
error message but continue as if this option wasn't given.
'--default-recipient NAME'
Use NAME as default recipient if option '--recipient' is not used
and don't ask if this is a valid one. NAME must be non-empty.
'--default-recipient-self'
Use the default key as default recipient if option '--recipient' is
not used and don't ask if this is a valid one. The default key is
the first one from the secret keyring or the one set with
'--default-key'.
'--no-default-recipient'
Reset '--default-recipient' and '--default-recipient-self'.
'-v, --verbose'
Give more information during processing. If used twice, the input
data is listed in detail.
'--no-verbose'
Reset verbose level to 0.
'-q, --quiet'
Try to be as quiet as possible.
'--batch'
'--no-batch'
Use batch mode. Never ask, do not allow interactive commands.
'--no-batch' disables this option. Note that even with a filename
given on the command line, gpg might still need to read from STDIN
(in particular if gpg figures that the input is a detached
signature and no data file has been specified). Thus if you do not
want to feed data via STDIN, you should connect STDIN to
g'/dev/null'.
It is highly recommended to use this option along with the options
'--status-fd' and '--with-colons' for any unattended use of 'gpg'.
'--no-tty'
Make sure that the TTY (terminal) is never used for any output.
This option is needed in some cases because GnuPG sometimes prints
warnings to the TTY even if '--batch' is used.
'--yes'
Assume "yes" on most questions.
'--no'
Assume "no" on most questions.
'--list-options PARAMETERS'
This is a space or comma delimited string that gives options used
when listing keys and signatures (that is, '--list-keys',
'--check-signatures', '--list-public-keys', '--list-secret-keys',
and the '--edit-key' functions). Options can be prepended with a
'no-' (after the two dashes) to give the opposite meaning. The
options are:
show-photos
Causes '--list-keys', '--check-signatures',
'--list-public-keys', and '--list-secret-keys' to display any
photo IDs attached to the key. Defaults to no. See also
'--photo-viewer'. Does not work with '--with-colons': see
'--attribute-fd' for the appropriate way to get photo data for
scripts and other frontends.
show-usage
Show usage information for keys and subkeys in the standard
key listing. This is a list of letters indicating the allowed
usage for a key ('E'=encryption, 'S'=signing,
'C'=certification, 'A'=authentication). Defaults to yes.
show-policy-urls
Show policy URLs in the '--check-signatures' listings.
Defaults to no.
show-notations
show-std-notations
show-user-notations
Show all, IETF standard, or user-defined signature notations
in the '--check-signatures' listings. Defaults to no.
show-keyserver-urls
Show any preferred keyserver URL in the '--check-signatures'
listings. Defaults to no.
show-uid-validity
Display the calculated validity of user IDs during key
listings. Defaults to yes.
show-unusable-uids
Show revoked and expired user IDs in key listings. Defaults
to no.
show-unusable-subkeys
Show revoked and expired subkeys in key listings. Defaults to
no.
show-keyring
Display the keyring name at the head of key listings to show
which keyring a given key resides on. Defaults to no.
show-sig-expire
Show signature expiration dates (if any) during
'--check-signatures' listings. Defaults to no.
show-sig-subpackets
Include signature subpackets in the key listing. This option
can take an optional argument list of the subpackets to list.
If no argument is passed, list all subpackets. Defaults to
no. This option is only meaningful when using '--with-colons'
along with '--check-signatures'.
show-only-fpr-mbox
For each user-id which has a valid mail address print only the
fingerprint followed by the mail address.
'--verify-options PARAMETERS'
This is a space or comma delimited string that gives options used
when verifying signatures. Options can be prepended with a 'no-'
to give the opposite meaning. The options are:
show-photos
Display any photo IDs present on the key that issued the
signature. Defaults to no. See also '--photo-viewer'.
show-policy-urls
Show policy URLs in the signature being verified. Defaults to
yes.
show-notations
show-std-notations
show-user-notations
Show all, IETF standard, or user-defined signature notations
in the signature being verified. Defaults to IETF standard.
show-keyserver-urls
Show any preferred keyserver URL in the signature being
verified. Defaults to yes.
show-uid-validity
Display the calculated validity of the user IDs on the key
that issued the signature. Defaults to yes.
show-unusable-uids
Show revoked and expired user IDs during signature
verification. Defaults to no.
show-primary-uid-only
Show only the primary user ID during signature verification.
That is all the AKA lines as well as photo Ids are not shown
with the signature verification status.
pka-lookups
Enable PKA lookups to verify sender addresses. Note that PKA
is based on DNS, and so enabling this option may disclose
information on when and what signatures are verified or to
whom data is encrypted. This is similar to the "web bug"
described for the '--auto-key-retrieve' option.
pka-trust-increase
Raise the trust in a signature to full if the signature passes
PKA validation. This option is only meaningful if pka-lookups
is set.
'--enable-large-rsa'
'--disable-large-rsa'
With -generate-key and -batch, enable the creation of RSA secret
keys as large as 8192 bit. Note: 8192 bit is more than is
generally recommended. These large keys don't significantly
improve security, but they are more expensive to use, and their
signatures and certifications are larger. This option is only
available if the binary was build with large-secmem support.
'--enable-dsa2'
'--disable-dsa2'
Enable hash truncation for all DSA keys even for old DSA Keys up to
1024 bit. This is also the default with '--openpgp'. Note that
older versions of GnuPG also required this flag to allow the
generation of DSA larger than 1024 bit.
'--photo-viewer STRING'
This is the command line that should be run to view a photo ID.
"%i" will be expanded to a filename containing the photo. "%I"
does the same, except the file will not be deleted once the viewer
exits. Other flags are "%k" for the key ID, "%K" for the long key
ID, "%f" for the key fingerprint, "%t" for the extension of the
image type (e.g. "jpg"), "%T" for the MIME type of the image (e.g.
"image/jpeg"), "%v" for the single-character calculated validity of
the image being viewed (e.g. "f"), "%V" for the calculated
validity as a string (e.g. "full"), "%U" for a base32 encoded hash
of the user ID, and "%%" for an actual percent sign. If neither %i
or %I are present, then the photo will be supplied to the viewer on
standard input.
On Unix the default viewer is 'xloadimage -fork -quiet -title
'KeyID 0x%k' STDIN' with a fallback to 'display -title 'KeyID 0x%k'
%i' and finally to 'xdg-open %i'. On Windows '!ShellExecute 400
%i' is used; here the command is a meta command to use that API
call followed by a wait time in milliseconds which is used to give
the viewer time to read the temporary image file before gpg deletes
it again. Note that if your image viewer program is not secure,
then executing it from gpg does not make it secure.
'--exec-path STRING'
Sets a list of directories to search for photo viewers If not
provided photo viewers use the 'PATH' environment variable.
'--keyring FILE'
Add FILE to the current list of keyrings. If FILE begins with a
tilde and a slash, these are replaced by the $HOME directory. If
the filename does not contain a slash, it is assumed to be in the
GnuPG home directory ("~/.gnupg" if '--homedir' or $GNUPGHOME is
not used).
Note that this adds a keyring to the current list. If the intent
is to use the specified keyring alone, use '--keyring' along with
'--no-default-keyring'.
If the option '--no-keyring' has been used no keyrings will be used
at all.
'--secret-keyring FILE'
This is an obsolete option and ignored. All secret keys are stored
in the 'private-keys-v1.d' directory below the GnuPG home
directory.
'--primary-keyring FILE'
Designate FILE as the primary public keyring. This means that
newly imported keys (via '--import' or keyserver '--recv-from')
will go to this keyring.
'--trustdb-name FILE'
Use FILE instead of the default trustdb. If FILE begins with a
tilde and a slash, these are replaced by the $HOME directory. If
the filename does not contain a slash, it is assumed to be in the
GnuPG home directory ('~/.gnupg' if '--homedir' or $GNUPGHOME is
not used).
'--homedir DIR'
Set the name of the home directory to DIR. If this option is not
used, the home directory defaults to '~/.gnupg'. It is only
recognized when given on the command line. It also overrides any
home directory stated through the environment variable 'GNUPGHOME'
or (on Windows systems) by means of the Registry entry
HKCU\SOFTWARE\GNU\GNUPG:HOMEDIR.
On Windows systems it is possible to install GnuPG as a portable
application. In this case only this command line option is
considered, all other ways to set a home directory are ignored.
To install GnuPG as a portable application under Windows, create an
empty file named 'gpgconf.ctl' in the same directory as the tool
'gpgconf.exe'. The root of the installation is then that
directory; or, if 'gpgconf.exe' has been installed directly below a
directory named 'bin', its parent directory. You also need to make
sure that the following directories exist and are writable:
'ROOT/home' for the GnuPG home and 'ROOT/usr/local/var/cache/gnupg'
for internal cache files.
'--display-charset NAME'
Set the name of the native character set. This is used to convert
some informational strings like user IDs to the proper UTF-8
encoding. Note that this has nothing to do with the character set
of data to be encrypted or signed; GnuPG does not recode
user-supplied data. If this option is not used, the default
character set is determined from the current locale. A verbosity
level of 3 shows the chosen set. Valid values for NAME are:
iso-8859-1
This is the Latin 1 set.
iso-8859-2
The Latin 2 set.
iso-8859-15
This is currently an alias for the Latin 1 set.
koi8-r
The usual Russian set (RFC-1489).
utf-8
Bypass all translations and assume that the OS uses native
UTF-8 encoding.
'--utf8-strings'
'--no-utf8-strings'
Assume that command line arguments are given as UTF-8 strings. The
default ('--no-utf8-strings') is to assume that arguments are
encoded in the character set as specified by '--display-charset'.
These options affect all following arguments. Both options may be
used multiple times.
'--options FILE'
Read options from FILE and do not try to read them from the default
options file in the homedir (see '--homedir'). This option is
ignored if used in an options file.
'--no-options'
Shortcut for '--options /dev/null'. This option is detected before
an attempt to open an option file. Using this option will also
prevent the creation of a '~/.gnupg' homedir.
'-z N'
'--compress-level N'
'--bzip2-compress-level N'
Set compression level to N for the ZIP and ZLIB compression
algorithms. The default is to use the default compression level of
zlib (normally 6). '--bzip2-compress-level' sets the compression
level for the BZIP2 compression algorithm (defaulting to 6 as
well). This is a different option from '--compress-level' since
BZIP2 uses a significant amount of memory for each additional
compression level. '-z' sets both. A value of 0 for N disables
compression.
'--bzip2-decompress-lowmem'
Use a different decompression method for BZIP2 compressed files.
This alternate method uses a bit more than half the memory, but
also runs at half the speed. This is useful under extreme low
memory circumstances when the file was originally compressed at a
high '--bzip2-compress-level'.
'--mangle-dos-filenames'
'--no-mangle-dos-filenames'
Older version of Windows cannot handle filenames with more than one
dot. '--mangle-dos-filenames' causes GnuPG to replace (rather than
add to) the extension of an output filename to avoid this problem.
This option is off by default and has no effect on non-Windows
platforms.
'--ask-cert-level'
'--no-ask-cert-level'
When making a key signature, prompt for a certification level. If
this option is not specified, the certification level used is set
via '--default-cert-level'. See '--default-cert-level' for
information on the specific levels and how they are used.
'--no-ask-cert-level' disables this option. This option defaults
to no.
'--default-cert-level N'
The default to use for the check level when signing a key.
0 means you make no particular claim as to how carefully you
verified the key.
1 means you believe the key is owned by the person who claims to
own it but you could not, or did not verify the key at all. This
is useful for a "persona" verification, where you sign the key of a
pseudonymous user.
2 means you did casual verification of the key. For example, this
could mean that you verified the key fingerprint and checked the
user ID on the key against a photo ID.
3 means you did extensive verification of the key. For example,
this could mean that you verified the key fingerprint with the
owner of the key in person, and that you checked, by means of a
hard to forge document with a photo ID (such as a passport) that
the name of the key owner matches the name in the user ID on the
key, and finally that you verified (by exchange of email) that the
email address on the key belongs to the key owner.
Note that the examples given above for levels 2 and 3 are just
that: examples. In the end, it is up to you to decide just what
"casual" and "extensive" mean to you.
This option defaults to 0 (no particular claim).
'--min-cert-level'
When building the trust database, treat any signatures with a
certification level below this as invalid. Defaults to 2, which
disregards level 1 signatures. Note that level 0 "no particular
claim" signatures are always accepted.
'--trusted-key LONG KEY ID'
Assume that the specified key (which must be given as a full 8 byte
key ID) is as trustworthy as one of your own secret keys. This
option is useful if you don't want to keep your secret keys (or one
of them) online but still want to be able to check the validity of
a given recipient's or signator's key.
'--trust-model {pgp|classic|tofu|tofu+pgp|direct|always|auto}'
Set what trust model GnuPG should follow. The models are:
pgp
This is the Web of Trust combined with trust signatures as
used in PGP 5.x and later. This is the default trust model
when creating a new trust database.
classic
This is the standard Web of Trust as introduced by PGP 2.
tofu
TOFU stands for Trust On First Use. In this trust model, the
first time a key is seen, it is memorized. If later another
key with a user id with the same email address is seen, both
keys are marked as suspect. In that case, the next time
either is used, a warning is displayed describing the
conflict, why it might have occurred (either the user
generated a new key and failed to cross sign the old and new
keys, the key is forgery, or a man-in-the-middle attack is
being attempted), and the user is prompted to manually confirm
the validity of the key in question.
Because a potential attacker is able to control the email
address and thereby circumvent the conflict detection
algorithm by using an email address that is similar in
appearance to a trusted email address, whenever a message is
verified, statistics about the number of messages signed with
the key are shown. In this way, a user can easily identify
attacks using fake keys for regular correspondents.
When compared with the Web of Trust, TOFU offers significantly
weaker security guarantees. In particular, TOFU only helps
ensure consistency (that is, that the binding between a key
and email address doesn't change). A major advantage of TOFU
is that it requires little maintenance to use correctly. To
use the web of trust properly, you need to actively sign keys
and mark users as trusted introducers. This is a
time-consuming process and anecdotal evidence suggests that
even security-conscious users rarely take the time to do this
thoroughly and instead rely on an ad-hoc TOFU process.
In the TOFU model, policies are associated with bindings
between keys and email addresses (which are extracted from
user ids and normalized). There are five policies, which can
be set manually using the '--tofu-policy' option. The default
policy can be set using the '--tofu-default-policy' option.
The TOFU policies are: 'auto', 'good', 'unknown', 'bad' and
'ask'. The 'auto' policy is used by default (unless
overridden by '--tofu-default-policy') and marks a binding as
marginally trusted. The 'good', 'unknown' and 'bad' policies
mark a binding as fully trusted, as having unknown trust or as
having trust never, respectively. The 'unknown' policy is
useful for just using TOFU to detect conflicts, but to never
assign positive trust to a binding. The final policy, 'ask'
prompts the user to indicate the binding's trust. If batch
mode is enabled (or input is inappropriate in the context),
then the user is not prompted and the 'undefined' trust level
is returned.
tofu+pgp
This trust model combines TOFU with the Web of Trust. This is
done by computing the trust level for each model and then
taking the maximum trust level where the trust levels are
ordered as follows: 'unknown < undefined < marginal < fully <
ultimate < expired < never'.
By setting '--tofu-default-policy=unknown', this model can be
used to implement the web of trust with TOFU's conflict
detection algorithm, but without its assignment of positive
trust values, which some security-conscious users don't like.
direct
Key validity is set directly by the user and not calculated
via the Web of Trust. This model is solely based on the key
and does not distinguish user IDs. Note that when changing to
another trust model the trust values assigned to a key are
transformed into ownertrust values, which also indicate how
you trust the owner of the key to sign other keys.
always
Skip key validation and assume that used keys are always fully
valid. You generally won't use this unless you are using some
external validation scheme. This option also suppresses the
"[uncertain]" tag printed with signature checks when there is
no evidence that the user ID is bound to the key. Note that
this trust model still does not allow the use of expired,
revoked, or disabled keys.
auto
Select the trust model depending on whatever the internal
trust database says. This is the default model if such a
database already exists. Note that a tofu trust model is not
considered here and must be enabled explicitly.
'--auto-key-locate MECHANISMS'
'--no-auto-key-locate'
GnuPG can automatically locate and retrieve keys as needed using
this option. This happens when encrypting to an email address (in
the "user@example.com" form), and there are no "user@example.com"
keys on the local keyring. This option takes any number of the
mechanisms listed below, in the order they are to be tried.
Instead of listing the mechanisms as comma delimited arguments, the
option may also be given several times to add more mechanism. The
option '--no-auto-key-locate' or the mechanism "clear" resets the
list. The default is "local,wkd".
cert
Locate a key using DNS CERT, as specified in RFC-4398.
pka
Locate a key using DNS PKA.
dane
Locate a key using DANE, as specified in
draft-ietf-dane-openpgpkey-05.txt.
wkd
Locate a key using the Web Key Directory protocol.
ldap
Using DNS Service Discovery, check the domain in question for
any LDAP keyservers to use. If this fails, attempt to locate
the key using the PGP Universal method of checking
'ldap://keys.(thedomain)'.
keyserver
Locate a key using a keyserver.
keyserver-URL
In addition, a keyserver URL as used in the 'dirmngr'
configuration may be used here to query that particular
keyserver.
local
Locate the key using the local keyrings. This mechanism
allows the user to select the order a local key lookup is
done. Thus using '--auto-key-locate local' is identical to
'--no-auto-key-locate'.
nodefault
This flag disables the standard local key lookup, done before
any of the mechanisms defined by the '--auto-key-locate' are
tried. The position of this mechanism in the list does not
matter. It is not required if 'local' is also used.
clear
Clear all defined mechanisms. This is useful to override
mechanisms given in a config file. Note that a 'nodefault' in
MECHANISMS will also be cleared unless it is given after the
'clear'.
'--auto-key-retrieve'
'--no-auto-key-retrieve'
These options enable or disable the automatic retrieving of keys
from a keyserver when verifying signatures made by keys that are
not on the local keyring. The default is '--no-auto-key-retrieve'.
The order of methods tried to lookup the key is:
1. If a preferred keyserver is specified in the signature and the
option 'honor-keyserver-url' is active (which is not the default),
that keyserver is tried. Note that the creator of the signature
uses the option '--sig-keyserver-url' to specify the preferred
keyserver for data signatures.
2. If the signature has the Signer's UID set (e.g. using
'--sender' while creating the signature) a Web Key Directory (WKD)
lookup is done. This is the default configuration but can be
disabled by removing WKD from the auto-key-locate list or by using
the option '--disable-signer-uid'.
3. If the option 'honor-pka-record' is active, the legacy PKA
method is used.
4. If any keyserver is configured and the Issuer Fingerprint is
part of the signature (since GnuPG 2.1.16), the configured
keyservers are tried.
Note that this option makes a "web bug" like behavior possible.
Keyserver or Web Key Directory operators can see which keys you
request, so by sending you a message signed by a brand new key
(which you naturally will not have on your local keyring), the
operator can tell both your IP address and the time when you
verified the signature.
'--keyid-format {none|short|0xshort|long|0xlong}'
Select how to display key IDs. "none" does not show the key ID at
all but shows the fingerprint in a separate line. "short" is the
traditional 8-character key ID. "long" is the more accurate (but
less convenient) 16-character key ID. Add an "0x" to either to
include an "0x" at the beginning of the key ID, as in 0x99242560.
Note that this option is ignored if the option '--with-colons' is
used.
'--keyserver NAME'
This option is deprecated - please use the '--keyserver' in
'dirmngr.conf' instead.
Use NAME as your keyserver. This is the server that
'--receive-keys', '--send-keys', and '--search-keys' will
communicate with to receive keys from, send keys to, and search for
keys on. The format of the NAME is a URI:
'scheme:[//]keyservername[:port]' The scheme is the type of
keyserver: "hkp" for the HTTP (or compatible) keyservers, "ldap"
for the LDAP keyservers, or "mailto" for the Graff email keyserver.
Note that your particular installation of GnuPG may have other
keyserver types available as well. Keyserver schemes are
case-insensitive. After the keyserver name, optional keyserver
configuration options may be provided. These are the same as the
global '--keyserver-options' from below, but apply only to this
particular keyserver.
Most keyservers synchronize with each other, so there is generally
no need to send keys to more than one server. The keyserver
'hkp://keys.gnupg.net' uses round robin DNS to give a different
keyserver each time you use it.
'--keyserver-options {NAME=VALUE}'
This is a space or comma delimited string that gives options for
the keyserver. Options can be prefixed with a 'no-' to give the
opposite meaning. Valid import-options or export-options may be
used here as well to apply to importing ('--recv-key') or exporting
('--send-key') a key from a keyserver. While not all options are
available for all keyserver types, some common options are:
include-revoked
When searching for a key with '--search-keys', include keys
that are marked on the keyserver as revoked. Note that not
all keyservers differentiate between revoked and unrevoked
keys, and for such keyservers this option is meaningless.
Note also that most keyservers do not have cryptographic
verification of key revocations, and so turning this option
off may result in skipping keys that are incorrectly marked as
revoked.
include-disabled
When searching for a key with '--search-keys', include keys
that are marked on the keyserver as disabled. Note that this
option is not used with HKP keyservers.
auto-key-retrieve
This is an obsolete alias for the option 'auto-key-retrieve'.
Please do not use it; it will be removed in future versions..
honor-keyserver-url
When using '--refresh-keys', if the key in question has a
preferred keyserver URL, then use that preferred keyserver to
refresh the key from. In addition, if auto-key-retrieve is
set, and the signature being verified has a preferred
keyserver URL, then use that preferred keyserver to fetch the
key from. Note that this option introduces a "web bug": The
creator of the key can see when the keys is refreshed. Thus
this option is not enabled by default.
honor-pka-record
If '--auto-key-retrieve' is used, and the signature being
verified has a PKA record, then use the PKA information to
fetch the key. Defaults to "yes".
include-subkeys
When receiving a key, include subkeys as potential targets.
Note that this option is not used with HKP keyservers, as they
do not support retrieving keys by subkey id.
timeout
http-proxy=VALUE
verbose
debug
check-cert
ca-cert-file
These options have no more function since GnuPG 2.1. Use the
'dirmngr' configuration options instead.
The default list of options is: "self-sigs-only, import-clean,
repair-keys, repair-pks-subkey-bug, export-attributes,
honor-pka-record".
'--completes-needed N'
Number of completely trusted users to introduce a new key signer
(defaults to 1).
'--marginals-needed N'
Number of marginally trusted users to introduce a new key signer
(defaults to 3)
'--tofu-default-policy {auto|good|unknown|bad|ask}'
The default TOFU policy (defaults to 'auto'). For more information
about the meaning of this option, *note trust-model-tofu::.
'--max-cert-depth N'
Maximum depth of a certification chain (default is 5).
'--no-sig-cache'
Do not cache the verification status of key signatures. Caching
gives a much better performance in key listings. However, if you
suspect that your public keyring is not safe against write
modifications, you can use this option to disable the caching. It
probably does not make sense to disable it because all kind of
damage can be done if someone else has write access to your public
keyring.
'--auto-check-trustdb'
'--no-auto-check-trustdb'
If GnuPG feels that its information about the Web of Trust has to
be updated, it automatically runs the '--check-trustdb' command
internally. This may be a time consuming process.
'--no-auto-check-trustdb' disables this option.
'--use-agent'
'--no-use-agent'
This is dummy option. 'gpg' always requires the agent.
'--gpg-agent-info'
This is dummy option. It has no effect when used with 'gpg'.
'--agent-program FILE'
Specify an agent program to be used for secret key operations. The
default value is determined by running 'gpgconf' with the option
'--list-dirs'. Note that the pipe symbol ('|') is used for a
regression test suite hack and may thus not be used in the file
name.
'--dirmngr-program FILE'
Specify a dirmngr program to be used for keyserver access. The
default value is '/usr/local/bin/dirmngr'.
'--disable-dirmngr'
Entirely disable the use of the Dirmngr.
'--no-autostart'
Do not start the gpg-agent or the dirmngr if it has not yet been
started and its service is required. This option is mostly useful
on machines where the connection to gpg-agent has been redirected
to another machines. If dirmngr is required on the remote machine,
it may be started manually using 'gpgconf --launch dirmngr'.
'--lock-once'
Lock the databases the first time a lock is requested and do not
release the lock until the process terminates.
'--lock-multiple'
Release the locks every time a lock is no longer needed. Use this
to override a previous '--lock-once' from a config file.
'--lock-never'
Disable locking entirely. This option should be used only in very
special environments, where it can be assured that only one process
is accessing those files. A bootable floppy with a stand-alone
encryption system will probably use this. Improper usage of this
option may lead to data and key corruption.
'--exit-on-status-write-error'
This option will cause write errors on the status FD to immediately
terminate the process. That should in fact be the default but it
never worked this way and thus we need an option to enable this, so
that the change won't break applications which close their end of a
status fd connected pipe too early. Using this option along with
'--enable-progress-filter' may be used to cleanly cancel long
running gpg operations.
'--limit-card-insert-tries N'
With N greater than 0 the number of prompts asking to insert a
smartcard gets limited to N-1. Thus with a value of 1 gpg won't at
all ask to insert a card if none has been inserted at startup.
This option is useful in the configuration file in case an
application does not know about the smartcard support and waits ad
infinitum for an inserted card.
'--no-random-seed-file'
GnuPG uses a file to store its internal random pool over
invocations. This makes random generation faster; however
sometimes write operations are not desired. This option can be
used to achieve that with the cost of slower random generation.
'--no-greeting'
Suppress the initial copyright message.
'--no-secmem-warning'
Suppress the warning about "using insecure memory".
'--no-permission-warning'
Suppress the warning about unsafe file and home directory
('--homedir') permissions. Note that the permission checks that
GnuPG performs are not intended to be authoritative, but rather
they simply warn about certain common permission problems. Do not
assume that the lack of a warning means that your system is secure.
Note that the warning for unsafe '--homedir' permissions cannot be
suppressed in the gpg.conf file, as this would allow an attacker to
place an unsafe gpg.conf file in place, and use this file to
suppress warnings about itself. The '--homedir' permissions
warning may only be suppressed on the command line.
'--require-secmem'
'--no-require-secmem'
Refuse to run if GnuPG cannot get secure memory. Defaults to no
(i.e. run, but give a warning).
'--require-cross-certification'
'--no-require-cross-certification'
When verifying a signature made from a subkey, ensure that the
cross certification "back signature" on the subkey is present and
valid. This protects against a subtle attack against subkeys that
can sign. Defaults to '--require-cross-certification' for 'gpg'.
'--expert'
'--no-expert'
Allow the user to do certain nonsensical or "silly" things like
signing an expired or revoked key, or certain potentially
incompatible things like generating unusual key types. This also
disables certain warning messages about potentially incompatible
actions. As the name implies, this option is for experts only. If
you don't fully understand the implications of what it allows you
to do, leave this off. '--no-expert' disables this option.

File: gnupg.info, Node: GPG Key related Options, Next: GPG Input and Output, Prev: GPG Configuration Options, Up: GPG Options
4.2.2 Key related options
-------------------------
'--recipient NAME'
'-r'
Encrypt for user id NAME. If this option or '--hidden-recipient'
is not specified, GnuPG asks for the user-id unless
'--default-recipient' is given.
'--hidden-recipient NAME'
'-R'
Encrypt for user ID NAME, but hide the key ID of this user's key.
This option helps to hide the receiver of the message and is a
limited countermeasure against traffic analysis. If this option or
'--recipient' is not specified, GnuPG asks for the user ID unless
'--default-recipient' is given.
'--recipient-file FILE'
'-f'
This option is similar to '--recipient' except that it encrypts to
a key stored in the given file. FILE must be the name of a file
containing exactly one key. 'gpg' assumes that the key in this
file is fully valid.
'--hidden-recipient-file FILE'
'-F'
This option is similar to '--hidden-recipient' except that it
encrypts to a key stored in the given file. FILE must be the name
of a file containing exactly one key. 'gpg' assumes that the key
in this file is fully valid.
'--encrypt-to NAME'
Same as '--recipient' but this one is intended for use in the
options file and may be used with your own user-id as an
"encrypt-to-self". These keys are only used when there are other
recipients given either by use of '--recipient' or by the asked
user id. No trust checking is performed for these user ids and
even disabled keys can be used.
'--hidden-encrypt-to NAME'
Same as '--hidden-recipient' but this one is intended for use in
the options file and may be used with your own user-id as a hidden
"encrypt-to-self". These keys are only used when there are other
recipients given either by use of '--recipient' or by the asked
user id. No trust checking is performed for these user ids and
even disabled keys can be used.
'--no-encrypt-to'
Disable the use of all '--encrypt-to' and '--hidden-encrypt-to'
keys.
'--group {NAME=VALUE}'
Sets up a named group, which is similar to aliases in email
programs. Any time the group name is a recipient ('-r' or
'--recipient'), it will be expanded to the values specified.
Multiple groups with the same name are automatically merged into a
single group.
The values are 'key IDs' or fingerprints, but any key description
is accepted. Note that a value with spaces in it will be treated
as two different values. Note also there is only one level of
expansion -- you cannot make an group that points to another group.
When used from the command line, it may be necessary to quote the
argument to this option to prevent the shell from treating it as
multiple arguments.
'--ungroup NAME'
Remove a given entry from the '--group' list.
'--no-groups'
Remove all entries from the '--group' list.
'--local-user NAME'
'-u'
Use NAME as the key to sign with. Note that this option overrides
'--default-key'.
'--sender MBOX'
This option has two purposes. MBOX must either be a complete user
id with a proper mail address or just a mail address. When
creating a signature this option tells gpg the user id of a key
used to make a signature if the key was not directly specified by a
user id. When verifying a signature the MBOX is used to restrict
the information printed by the TOFU code to matching user ids.
'--try-secret-key NAME'
For hidden recipients GPG needs to know the keys to use for trial
decryption. The key set with '--default-key' is always tried
first, but this is often not sufficient. This option allows
setting more keys to be used for trial decryption. Although any
valid user-id specification may be used for NAME it makes sense to
use at least the long keyid to avoid ambiguities. Note that
gpg-agent might pop up a pinentry for a lot keys to do the trial
decryption. If you want to stop all further trial decryption you
may use close-window button instead of the cancel button.
'--try-all-secrets'
Don't look at the key ID as stored in the message but try all
secret keys in turn to find the right decryption key. This option
forces the behaviour as used by anonymous recipients (created by
using '--throw-keyids' or '--hidden-recipient') and might come
handy in case where an encrypted message contains a bogus key ID.
'--skip-hidden-recipients'
'--no-skip-hidden-recipients'
During decryption skip all anonymous recipients. This option helps
in the case that people use the hidden recipients feature to hide
their own encrypt-to key from others. If one has many secret keys
this may lead to a major annoyance because all keys are tried in
turn to decrypt something which was not really intended for it.
The drawback of this option is that it is currently not possible to
decrypt a message which includes real anonymous recipients.

File: gnupg.info, Node: GPG Input and Output, Next: OpenPGP Options, Prev: GPG Key related Options, Up: GPG Options
4.2.3 Input and Output
----------------------
'--armor'
'-a'
Create ASCII armored output. The default is to create the binary
OpenPGP format.
'--no-armor'
Assume the input data is not in ASCII armored format.
'--output FILE'
'-o FILE'
Write output to FILE. To write to stdout use '-' as the filename.
'--max-output N'
This option sets a limit on the number of bytes that will be
generated when processing a file. Since OpenPGP supports various
levels of compression, it is possible that the plaintext of a given
message may be significantly larger than the original OpenPGP
message. While GnuPG works properly with such messages, there is
often a desire to set a maximum file size that will be generated
before processing is forced to stop by the OS limits. Defaults to
0, which means "no limit".
'--input-size-hint N'
This option can be used to tell GPG the size of the input data in
bytes. N must be a positive base-10 number. This option is only
useful if the input is not taken from a file. GPG may use this
hint to optimize its buffer allocation strategy. It is also used
by the '--status-fd' line "PROGRESS" to provide a value for "total"
if that is not available by other means.
'--key-origin STRING[,URL]'
gpg can track the origin of a key. Certain origins are implicitly
known (e.g. keyserver, web key directory) and set. For a standard
import the origin of the keys imported can be set with this option.
To list the possible values use "help" for STRING. Some origins
can store an optional URL argument. That URL can appended to
STRING after a comma.
'--import-options PARAMETERS'
This is a space or comma delimited string that gives options for
importing keys. Options can be prepended with a 'no-' to give the
opposite meaning. The options are:
import-local-sigs
Allow importing key signatures marked as "local". This is not
generally useful unless a shared keyring scheme is being used.
Defaults to no.
keep-ownertrust
Normally possible still existing ownertrust values of a key
are cleared if a key is imported. This is in general
desirable so that a formerly deleted key does not
automatically gain an ownertrust values merely due to import.
On the other hand it is sometimes necessary to re-import a
trusted set of keys again but keeping already assigned
ownertrust values. This can be achieved by using this option.
repair-pks-subkey-bug
During import, attempt to repair the damage caused by the PKS
keyserver bug (pre version 0.9.6) that mangles keys with
multiple subkeys. Note that this cannot completely repair the
damaged key as some crucial data is removed by the keyserver,
but it does at least give you back one subkey. Defaults to no
for regular '--import' and to yes for keyserver
'--receive-keys'.
import-show
show-only
Show a listing of the key as imported right before it is
stored. This can be combined with the option '--dry-run' to
only look at keys; the option 'show-only' is a shortcut for
this combination. The command '--show-keys' is another
shortcut for this. Note that suffixes like '#' for "sec" and
"sbb" lines may or may not be printed.
import-export
Run the entire import code but instead of storing the key to
the local keyring write it to the output. The export options
'export-pka' and 'export-dane' affect the output. This option
can be used to remove all invalid parts from a key without the
need to store it.
merge-only
During import, allow key updates to existing keys, but do not
allow any new keys to be imported. Defaults to no.
import-clean
After import, compact (remove all signatures except the
self-signature) any user IDs from the new key that are not
usable. Then, remove any signatures from the new key that are
not usable. This includes signatures that were issued by keys
that are not present on the keyring. This option is the same
as running the '--edit-key' command "clean" after import.
Defaults to no.
self-sigs-only
Accept only self-signatures while importing a key. All other
key signatures are skipped at an early import stage. This
option can be used with 'keyserver-options' to mitigate
attempts to flood a key with bogus signatures from a
keyserver. The drawback is that all other valid key
signatures, as required by the Web of Trust are also not
imported. Note that when using this option along with
import-clean it suppresses the final clean step after merging
the imported key into the existing key.
repair-keys
After import, fix various problems with the keys. For
example, this reorders signatures, and strips duplicate
signatures. Defaults to yes.
import-minimal
Import the smallest key possible. This removes all signatures
except the most recent self-signature on each user ID. This
option is the same as running the '--edit-key' command
"minimize" after import. Defaults to no.
restore
import-restore
Import in key restore mode. This imports all data which is
usually skipped during import; including all GnuPG specific
data. All other contradicting options are overridden.
'--import-filter {NAME=EXPR}'
'--export-filter {NAME=EXPR}'
These options define an import/export filter which are applied to
the imported/exported keyblock right before it will be
stored/written. NAME defines the type of filter to use, EXPR the
expression to evaluate. The option can be used several times which
then appends more expression to the same NAME.
The available filter types are:
keep-uid
This filter will keep a user id packet and its dependent
packets in the keyblock if the expression evaluates to true.
drop-subkey
This filter drops the selected subkeys. Currently only
implemented for -export-filter.
drop-sig
This filter drops the selected key signatures on user ids.
Self-signatures are not considered. Currently only
implemented for -import-filter.
For the syntax of the expression see the chapter "FILTER
EXPRESSIONS". The property names for the expressions depend on the
actual filter type and are indicated in the following table.
The available properties are:
uid
A string with the user id. (keep-uid)
mbox
The addr-spec part of a user id with mailbox or the empty
string. (keep-uid)
key_algo
A number with the public key algorithm of a key or subkey
packet. (drop-subkey)
key_created
key_created_d
The first is the timestamp a public key or subkey packet was
created. The second is the same but given as an ISO string,
e.g. "2016-08-17". (drop-subkey)
primary
Boolean indicating whether the user id is the primary one.
(keep-uid)
expired
Boolean indicating whether a user id (keep-uid), a key
(drop-subkey), or a signature (drop-sig) expired.
revoked
Boolean indicating whether a user id (keep-uid) or a key
(drop-subkey) has been revoked.
disabled
Boolean indicating whether a primary key is disabled. (not
used)
secret
Boolean indicating whether a key or subkey is a secret one.
(drop-subkey)
usage
A string indicating the usage flags for the subkey, from the
sequence "ecsa?". For example, a subkey capable of just
signing and authentication would be an exact match for "sa".
(drop-subkey)
sig_created
sig_created_d
The first is the timestamp a signature packet was created.
The second is the same but given as an ISO date string, e.g.
"2016-08-17". (drop-sig)
sig_algo
A number with the public key algorithm of a signature packet.
(drop-sig)
sig_digest_algo
A number with the digest algorithm of a signature packet.
(drop-sig)
'--export-options PARAMETERS'
This is a space or comma delimited string that gives options for
exporting keys. Options can be prepended with a 'no-' to give the
opposite meaning. The options are:
export-local-sigs
Allow exporting key signatures marked as "local". This is not
generally useful unless a shared keyring scheme is being used.
Defaults to no.
export-attributes
Include attribute user IDs (photo IDs) while exporting. Not
including attribute user IDs is useful to export keys that are
going to be used by an OpenPGP program that does not accept
attribute user IDs. Defaults to yes.
export-sensitive-revkeys
Include designated revoker information that was marked as
"sensitive". Defaults to no.
backup
export-backup
Export for use as a backup. The exported data includes all
data which is needed to restore the key or keys later with
GnuPG. The format is basically the OpenPGP format but enhanced
with GnuPG specific data. All other contradicting options are
overridden.
export-clean
Compact (remove all signatures from) user IDs on the key being
exported if the user IDs are not usable. Also, do not export
any signatures that are not usable. This includes signatures
that were issued by keys that are not present on the keyring.
This option is the same as running the '--edit-key' command
"clean" before export except that the local copy of the key is
not modified. Defaults to no.
export-minimal
Export the smallest key possible. This removes all signatures
except the most recent self-signature on each user ID. This
option is the same as running the '--edit-key' command
"minimize" before export except that the local copy of the key
is not modified. Defaults to no.
export-pka
Instead of outputting the key material output PKA records
suitable to put into DNS zone files. An ORIGIN line is
printed before each record to allow diverting the records to
the corresponding zone file.
export-dane
Instead of outputting the key material output OpenPGP DANE
records suitable to put into DNS zone files. An ORIGIN line
is printed before each record to allow diverting the records
to the corresponding zone file.
'--with-colons'
Print key listings delimited by colons. Note that the output will
be encoded in UTF-8 regardless of any '--display-charset' setting.
This format is useful when GnuPG is called from scripts and other
programs as it is easily machine parsed. The details of this
format are documented in the file 'doc/DETAILS', which is included
in the GnuPG source distribution.
'--fixed-list-mode'
Do not merge primary user ID and primary key in '--with-colon'
listing mode and print all timestamps as seconds since 1970-01-01.
Since GnuPG 2.0.10, this mode is always used and thus this option
is obsolete; it does not harm to use it though.
'--legacy-list-mode'
Revert to the pre-2.1 public key list mode. This only affects the
human readable output and not the machine interface (i.e.
'--with-colons'). Note that the legacy format does not convey
suitable information for elliptic curves.
'--with-fingerprint'
Same as the command '--fingerprint' but changes only the format of
the output and may be used together with another command.
'--with-subkey-fingerprint'
If a fingerprint is printed for the primary key, this option forces
printing of the fingerprint for all subkeys. This could also be
achieved by using the '--with-fingerprint' twice but by using this
option along with keyid-format "none" a compact fingerprint is
printed.
'--with-icao-spelling'
Print the ICAO spelling of the fingerprint in addition to the hex
digits.
'--with-keygrip'
Include the keygrip in the key listings. In '--with-colons' mode
this is implicitly enable for secret keys.
'--with-key-origin'
Include the locally held information on the origin and last update
of a key in a key listing. In '--with-colons' mode this is always
printed. This data is currently experimental and shall not be
considered part of the stable API.
'--with-wkd-hash'
Print a Web Key Directory identifier along with each user ID in key
listings. This is an experimental feature and semantics may
change.
'--with-secret'
Include info about the presence of a secret key in public key
listings done with '--with-colons'.

File: gnupg.info, Node: OpenPGP Options, Next: Compliance Options, Prev: GPG Input and Output, Up: GPG Options
4.2.4 OpenPGP protocol specific options
---------------------------------------
'-t, --textmode'
'--no-textmode'
Treat input files as text and store them in the OpenPGP canonical
text form with standard "CRLF" line endings. This also sets the
necessary flags to inform the recipient that the encrypted or
signed data is text and may need its line endings converted back to
whatever the local system uses. This option is useful when
communicating between two platforms that have different line ending
conventions (UNIX-like to Mac, Mac to Windows, etc).
'--no-textmode' disables this option, and is the default.
'--force-v3-sigs'
'--no-force-v3-sigs'
'--force-v4-certs'
'--no-force-v4-certs'
These options are obsolete and have no effect since GnuPG 2.1.
'--force-mdc'
'--disable-mdc'
These options are obsolete and have no effect since GnuPG 2.2.8.
The MDC is always used. But note: If the creation of a legacy
non-MDC message is exceptionally required, the option '--rfc2440'
allows for this.
'--disable-signer-uid'
By default the user ID of the signing key is embedded in the data
signature. As of now this is only done if the signing key has been
specified with 'local-user' using a mail address, or with 'sender'.
This information can be helpful for verifier to locate the key; see
option '--auto-key-retrieve'.
'--personal-cipher-preferences STRING'
Set the list of personal cipher preferences to STRING. Use 'gpg
--version' to get a list of available algorithms, and use 'none' to
set no preference at all. This allows the user to safely override
the algorithm chosen by the recipient key preferences, as GPG will
only select an algorithm that is usable by all recipients. The
most highly ranked cipher in this list is also used for the
'--symmetric' encryption command.
'--personal-digest-preferences STRING'
Set the list of personal digest preferences to STRING. Use 'gpg
--version' to get a list of available algorithms, and use 'none' to
set no preference at all. This allows the user to safely override
the algorithm chosen by the recipient key preferences, as GPG will
only select an algorithm that is usable by all recipients. The
most highly ranked digest algorithm in this list is also used when
signing without encryption (e.g. '--clear-sign' or '--sign').
'--personal-compress-preferences STRING'
Set the list of personal compression preferences to STRING. Use
'gpg --version' to get a list of available algorithms, and use
'none' to set no preference at all. This allows the user to safely
override the algorithm chosen by the recipient key preferences, as
GPG will only select an algorithm that is usable by all recipients.
The most highly ranked compression algorithm in this list is also
used when there are no recipient keys to consider (e.g.
'--symmetric').
'--s2k-cipher-algo NAME'
Use NAME as the cipher algorithm for symmetric encryption with a
passphrase if '--personal-cipher-preferences' and '--cipher-algo'
are not given. The default is AES-128.
'--s2k-digest-algo NAME'
Use NAME as the digest algorithm used to mangle the passphrases for
symmetric encryption. The default is SHA-1.
'--s2k-mode N'
Selects how passphrases for symmetric encryption are mangled. If N
is 0 a plain passphrase (which is in general not recommended) will
be used, a 1 adds a salt (which should not be used) to the
passphrase and a 3 (the default) iterates the whole process a
number of times (see '--s2k-count').
'--s2k-count N'
Specify how many times the passphrases mangling for symmetric
encryption is repeated. This value may range between 1024 and
65011712 inclusive. The default is inquired from gpg-agent. Note
that not all values in the 1024-65011712 range are legal and if an
illegal value is selected, GnuPG will round up to the nearest legal
value. This option is only meaningful if '--s2k-mode' is set to
the default of 3.

File: gnupg.info, Node: Compliance Options, Next: GPG Esoteric Options, Prev: OpenPGP Options, Up: GPG Options
4.2.5 Compliance options
------------------------
These options control what GnuPG is compliant to. Only one of these
options may be active at a time. Note that the default setting of this
is nearly always the correct one. See the INTEROPERABILITY WITH OTHER
OPENPGP PROGRAMS section below before using one of these options.
'--gnupg'
Use standard GnuPG behavior. This is essentially OpenPGP behavior
(see '--openpgp'), but with some additional workarounds for common
compatibility problems in different versions of PGP. This is the
default option, so it is not generally needed, but it may be useful
to override a different compliance option in the gpg.conf file.
'--openpgp'
Reset all packet, cipher and digest options to strict OpenPGP
behavior. Use this option to reset all previous options like
'--s2k-*', '--cipher-algo', '--digest-algo' and '--compress-algo'
to OpenPGP compliant values. All PGP workarounds are disabled.
'--rfc4880'
Reset all packet, cipher and digest options to strict RFC-4880
behavior. Note that this is currently the same thing as
'--openpgp'.
'--rfc4880bis'
Enable experimental features from proposed updates to RFC-4880.
This option can be used in addition to the other compliance
options. Warning: The behavior may change with any GnuPG release
and created keys or data may not be usable with future GnuPG
versions.
'--rfc2440'
Reset all packet, cipher and digest options to strict RFC-2440
behavior. Note that by using this option encryption packets are
created in a legacy mode without MDC protection. This is dangerous
and should thus only be used for experiments. See also option
'--ignore-mdc-error'.
'--pgp6'
Set up all options to be as PGP 6 compliant as possible. This
restricts you to the ciphers IDEA (if the IDEA plugin is
installed), 3DES, and CAST5, the hashes MD5, SHA1 and RIPEMD160,
and the compression algorithms none and ZIP. This also disables
'--throw-keyids', and making signatures with signing subkeys as PGP
6 does not understand signatures made by signing subkeys.
This option implies '--escape-from-lines'.
'--pgp7'
Set up all options to be as PGP 7 compliant as possible. This is
identical to '--pgp6' except that MDCs are not disabled, and the
list of allowable ciphers is expanded to add AES128, AES192,
AES256, and TWOFISH.
'--pgp8'
Set up all options to be as PGP 8 compliant as possible. PGP 8 is
a lot closer to the OpenPGP standard than previous versions of PGP,
so all this does is disable '--throw-keyids' and set
'--escape-from-lines'. All algorithms are allowed except for the
SHA224, SHA384, and SHA512 digests.
'--compliance STRING'
This option can be used instead of one of the options above. Valid
values for STRING are the above option names (without the double
dash) and possibly others as shown when using "help" for VALUE.

File: gnupg.info, Node: GPG Esoteric Options, Next: Deprecated Options, Prev: Compliance Options, Up: GPG Options
4.2.6 Doing things one usually doesn't want to do
-------------------------------------------------
'-n'
'--dry-run'
Don't make any changes (this is not completely implemented).
'--list-only'
Changes the behaviour of some commands. This is like '--dry-run'
but different in some cases. The semantic of this option may be
extended in the future. Currently it only skips the actual
decryption pass and therefore enables a fast listing of the
encryption keys.
'-i'
'--interactive'
Prompt before overwriting any files.
'--debug-level LEVEL'
Select the debug level for investigating problems. LEVEL may be a
numeric value or by a keyword:
'none'
No debugging at all. A value of less than 1 may be used
instead of the keyword.
'basic'
Some basic debug messages. A value between 1 and 2 may be
used instead of the keyword.
'advanced'
More verbose debug messages. A value between 3 and 5 may be
used instead of the keyword.
'expert'
Even more detailed messages. A value between 6 and 8 may be
used instead of the keyword.
'guru'
All of the debug messages you can get. A value greater than 8
may be used instead of the keyword. The creation of hash
tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not
specified and may change with newer releases of this program. They
are however carefully selected to best aid in debugging.
'--debug FLAGS'
Set debugging flags. All flags are or-ed and FLAGS may be given in
C syntax (e.g. 0x0042) or as a comma separated list of flag names.
To get a list of all supported flags the single word "help" can be
used.
'--debug-all'
Set all useful debugging flags.
'--debug-iolbf'
Set stdout into line buffered mode. This option is only honored
when given on the command line.
'--faked-system-time EPOCH'
This option is only useful for testing; it sets the system time
back or forth to EPOCH which is the number of seconds elapsed since
the year 1970. Alternatively EPOCH may be given as a full ISO time
string (e.g. "20070924T154812").
If you suffix EPOCH with an exclamation mark (!), the system time
will appear to be frozen at the specified time.
'--enable-progress-filter'
Enable certain PROGRESS status outputs. This option allows
frontends to display a progress indicator while gpg is processing
larger files. There is a slight performance overhead using it.
'--status-fd N'
Write special status strings to the file descriptor N. See the
file DETAILS in the documentation for a listing of them.
'--status-file FILE'
Same as '--status-fd', except the status data is written to file
FILE.
'--logger-fd N'
Write log output to file descriptor N and not to STDERR.
'--log-file FILE'
'--logger-file FILE'
Same as '--logger-fd', except the logger data is written to file
FILE. Use 'socket://' to log to a socket. Note that in this
version of gpg the option has only an effect if '--batch' is also
used.
'--attribute-fd N'
Write attribute subpackets to the file descriptor N. This is most
useful for use with '--status-fd', since the status messages are
needed to separate out the various subpackets from the stream
delivered to the file descriptor.
'--attribute-file FILE'
Same as '--attribute-fd', except the attribute data is written to
file FILE.
'--comment STRING'
'--no-comments'
Use STRING as a comment string in cleartext signatures and ASCII
armored messages or keys (see '--armor'). The default behavior is
not to use a comment string. '--comment' may be repeated multiple
times to get multiple comment strings. '--no-comments' removes all
comments. It is a good idea to keep the length of a single comment
below 60 characters to avoid problems with mail programs wrapping
such lines. Note that comment lines, like all other header lines,
are not protected by the signature.
'--emit-version'
'--no-emit-version'
Force inclusion of the version string in ASCII armored output. If
given once only the name of the program and the major number is
emitted, given twice the minor is also emitted, given thrice the
micro is added, and given four times an operating system
identification is also emitted. '--no-emit-version' (default)
disables the version line.
'--sig-notation {NAME=VALUE}'
'--cert-notation {NAME=VALUE}'
'-N, --set-notation {NAME=VALUE}'
Put the name value pair into the signature as notation data. NAME
must consist only of printable characters or spaces, and must
contain a '@' character in the form keyname@domain.example.com
(substituting the appropriate keyname and domain name, of course).
This is to help prevent pollution of the IETF reserved notation
namespace. The '--expert' flag overrides the '@' check. VALUE may
be any printable string; it will be encoded in UTF-8, so you should
check that your '--display-charset' is set correctly. If you
prefix NAME with an exclamation mark (!), the notation data will be
flagged as critical (rfc4880:5.2.3.16). '--sig-notation' sets a
notation for data signatures. '--cert-notation' sets a notation
for key signatures (certifications). '--set-notation' sets both.
There are special codes that may be used in notation names. "%k"
will be expanded into the key ID of the key being signed, "%K" into
the long key ID of the key being signed, "%f" into the fingerprint
of the key being signed, "%s" into the key ID of the key making the
signature, "%S" into the long key ID of the key making the
signature, "%g" into the fingerprint of the key making the
signature (which might be a subkey), "%p" into the fingerprint of
the primary key of the key making the signature, "%c" into the
signature count from the OpenPGP smartcard, and "%%" results in a
single "%". %k, %K, and %f are only meaningful when making a key
signature (certification), and %c is only meaningful when using the
OpenPGP smartcard.
'--known-notation NAME'
Adds NAME to a list of known critical signature notations. The
effect of this is that gpg will not mark a signature with a
critical signature notation of that name as bad. Note that gpg
already knows by default about a few critical signatures notation
names.
'--sig-policy-url STRING'
'--cert-policy-url STRING'
'--set-policy-url STRING'
Use STRING as a Policy URL for signatures (rfc4880:5.2.3.20). If
you prefix it with an exclamation mark (!), the policy URL packet
will be flagged as critical. '--sig-policy-url' sets a policy url
for data signatures. '--cert-policy-url' sets a policy url for key
signatures (certifications). '--set-policy-url' sets both.
The same %-expandos used for notation data are available here as
well.
'--sig-keyserver-url STRING'
Use STRING as a preferred keyserver URL for data signatures. If
you prefix it with an exclamation mark (!), the keyserver URL
packet will be flagged as critical.
The same %-expandos used for notation data are available here as
well.
'--set-filename STRING'
Use STRING as the filename which is stored inside messages. This
overrides the default, which is to use the actual filename of the
file being encrypted. Using the empty string for STRING
effectively removes the filename from the output.
'--for-your-eyes-only'
'--no-for-your-eyes-only'
Set the 'for your eyes only' flag in the message. This causes
GnuPG to refuse to save the file unless the '--output' option is
given, and PGP to use a "secure viewer" with a claimed
Tempest-resistant font to display the message. This option
overrides '--set-filename'. '--no-for-your-eyes-only' disables
this option.
'--use-embedded-filename'
'--no-use-embedded-filename'
Try to create a file with a name as embedded in the data. This can
be a dangerous option as it enables overwriting files. Defaults to
no. Note that the option '--output' overrides this option.
'--cipher-algo NAME'
Use NAME as cipher algorithm. Running the program with the command
'--version' yields a list of supported algorithms. If this is not
used the cipher algorithm is selected from the preferences stored
with the key. In general, you do not want to use this option as it
allows you to violate the OpenPGP standard.
'--personal-cipher-preferences' is the safe way to accomplish the
same thing.
'--digest-algo NAME'
Use NAME as the message digest algorithm. Running the program with
the command '--version' yields a list of supported algorithms. In
general, you do not want to use this option as it allows you to
violate the OpenPGP standard. '--personal-digest-preferences' is
the safe way to accomplish the same thing.
'--compress-algo NAME'
Use compression algorithm NAME. "zlib" is RFC-1950 ZLIB
compression. "zip" is RFC-1951 ZIP compression which is used by
PGP. "bzip2" is a more modern compression scheme that can compress
some things better than zip or zlib, but at the cost of more memory
used during compression and decompression. "uncompressed" or
"none" disables compression. If this option is not used, the
default behavior is to examine the recipient key preferences to see
which algorithms the recipient supports. If all else fails, ZIP is
used for maximum compatibility.
ZLIB may give better compression results than ZIP, as the
compression window size is not limited to 8k. BZIP2 may give even
better compression results than that, but will use a significantly
larger amount of memory while compressing and decompressing. This
may be significant in low memory situations. Note, however, that
PGP (all versions) only supports ZIP compression. Using any
algorithm other than ZIP or "none" will make the message unreadable
with PGP. In general, you do not want to use this option as it
allows you to violate the OpenPGP standard.
'--personal-compress-preferences' is the safe way to accomplish the
same thing.
'--cert-digest-algo NAME'
Use NAME as the message digest algorithm used when signing a key.
Running the program with the command '--version' yields a list of
supported algorithms. Be aware that if you choose an algorithm
that GnuPG supports but other OpenPGP implementations do not, then
some users will not be able to use the key signatures you make, or
quite possibly your entire key.
'--disable-cipher-algo NAME'
Never allow the use of NAME as cipher algorithm. The given name
will not be checked so that a later loaded algorithm will still get
disabled.
'--disable-pubkey-algo NAME'
Never allow the use of NAME as public key algorithm. The given
name will not be checked so that a later loaded algorithm will
still get disabled.
'--throw-keyids'
'--no-throw-keyids'
Do not put the recipient key IDs into encrypted messages. This
helps to hide the receivers of the message and is a limited
countermeasure against traffic analysis.(1) On the receiving side,
it may slow down the decryption process because all available
secret keys must be tried. '--no-throw-keyids' disables this
option. This option is essentially the same as using
'--hidden-recipient' for all recipients.
'--not-dash-escaped'
This option changes the behavior of cleartext signatures so that
they can be used for patch files. You should not send such an
armored file via email because all spaces and line endings are
hashed too. You can not use this option for data which has 5
dashes at the beginning of a line, patch files don't have this. A
special armor header line tells GnuPG about this cleartext
signature option.
'--escape-from-lines'
'--no-escape-from-lines'
Because some mailers change lines starting with "From " to ">From "
it is good to handle such lines in a special way when creating
cleartext signatures to prevent the mail system from breaking the
signature. Note that all other PGP versions do it this way too.
Enabled by default. '--no-escape-from-lines' disables this option.
'--passphrase-repeat N'
Specify how many times 'gpg' will request a new passphrase be
repeated. This is useful for helping memorize a passphrase.
Defaults to 1 repetition.
'--passphrase-fd N'
Read the passphrase from file descriptor N. Only the first line
will be read from file descriptor N. If you use 0 for N, the
passphrase will be read from STDIN. This can only be used if only
one passphrase is supplied.
Note that since Version 2.0 this passphrase is only used if the
option '--batch' has also been given. Since Version 2.1 the
'--pinentry-mode' also needs to be set to 'loopback'.
'--passphrase-file FILE'
Read the passphrase from file FILE. Only the first line will be
read from file FILE. This can only be used if only one passphrase
is supplied. Obviously, a passphrase stored in a file is of
questionable security if other users can read this file. Don't use
this option if you can avoid it.
Note that since Version 2.0 this passphrase is only used if the
option '--batch' has also been given. Since Version 2.1 the
'--pinentry-mode' also needs to be set to 'loopback'.
'--passphrase STRING'
Use STRING as the passphrase. This can only be used if only one
passphrase is supplied. Obviously, this is of very questionable
security on a multi-user system. Don't use this option if you can
avoid it.
Note that since Version 2.0 this passphrase is only used if the
option '--batch' has also been given. Since Version 2.1 the
'--pinentry-mode' also needs to be set to 'loopback'.
'--pinentry-mode MODE'
Set the pinentry mode to MODE. Allowed values for MODE are:
default
Use the default of the agent, which is 'ask'.
ask
Force the use of the Pinentry.
cancel
Emulate use of Pinentry's cancel button.
error
Return a Pinentry error ("No Pinentry").
loopback
Redirect Pinentry queries to the caller. Note that in
contrast to Pinentry the user is not prompted again if he
enters a bad password.
'--no-symkey-cache'
Disable the passphrase cache used for symmetrical en- and
decryption. This cache is based on the message specific salt value
(cf. '--s2k-mode').
'--request-origin ORIGIN'
Tell gpg to assume that the operation ultimately originated at
ORIGIN. Depending on the origin certain restrictions are applied
and the Pinentry may include an extra note on the origin.
Supported values for ORIGIN are: 'local' which is the default,
'remote' to indicate a remote origin or 'browser' for an operation
requested by a web browser.
'--command-fd N'
This is a replacement for the deprecated shared-memory IPC mode.
If this option is enabled, user input on questions is not expected
from the TTY but from the given file descriptor. It should be used
together with '--status-fd'. See the file doc/DETAILS in the
source distribution for details on how to use it.
'--command-file FILE'
Same as '--command-fd', except the commands are read out of file
FILE
'--allow-non-selfsigned-uid'
'--no-allow-non-selfsigned-uid'
Allow the import and use of keys with user IDs which are not
self-signed. This is not recommended, as a non self-signed user ID
is trivial to forge. '--no-allow-non-selfsigned-uid' disables.
'--allow-freeform-uid'
Disable all checks on the form of the user ID while generating a
new one. This option should only be used in very special
environments as it does not ensure the de-facto standard format of
user IDs.
'--ignore-time-conflict'
GnuPG normally checks that the timestamps associated with keys and
signatures have plausible values. However, sometimes a signature
seems to be older than the key due to clock problems. This option
makes these checks just a warning. See also '--ignore-valid-from'
for timestamp issues on subkeys.
'--ignore-valid-from'
GnuPG normally does not select and use subkeys created in the
future. This option allows the use of such keys and thus exhibits
the pre-1.0.7 behaviour. You should not use this option unless
there is some clock problem. See also '--ignore-time-conflict' for
timestamp issues with signatures.
'--ignore-crc-error'
The ASCII armor used by OpenPGP is protected by a CRC checksum
against transmission errors. Occasionally the CRC gets mangled
somewhere on the transmission channel but the actual content (which
is protected by the OpenPGP protocol anyway) is still okay. This
option allows GnuPG to ignore CRC errors.
'--ignore-mdc-error'
This option changes a MDC integrity protection failure into a
warning. It is required to decrypt old messages which did not use
an MDC. It may also be useful if a message is partially garbled,
but it is necessary to get as much data as possible out of that
garbled message. Be aware that a missing or failed MDC can be an
indication of an attack. Use with great caution; see also option
'--rfc2440'.
'--allow-weak-digest-algos'
Signatures made with known-weak digest algorithms are normally
rejected with an "invalid digest algorithm" message. This option
allows the verification of signatures made with such weak
algorithms. MD5 is the only digest algorithm considered weak by
default. See also '--weak-digest' to reject other digest
algorithms.
'--weak-digest NAME'
Treat the specified digest algorithm as weak. Signatures made over
weak digests algorithms are normally rejected. This option can be
supplied multiple times if multiple algorithms should be considered
weak. See also '--allow-weak-digest-algos' to disable rejection of
weak digests. MD5 is always considered weak, and does not need to
be listed explicitly.
'--allow-weak-key-signatures'
To avoid a minor risk of collision attacks on third-party key
signatures made using SHA-1, those key signatures are considered
invalid. This options allows to override this restriction.
'--no-default-keyring'
Do not add the default keyrings to the list of keyrings. Note that
GnuPG will not operate without any keyrings, so if you use this
option and do not provide alternate keyrings via '--keyring' or
'--secret-keyring', then GnuPG will still use the default public or
secret keyrings.
'--no-keyring'
Do not use any keyring at all. This overrides the default and all
options which specify keyrings.
'--skip-verify'
Skip the signature verification step. This may be used to make the
decryption faster if the signature verification is not needed.
'--with-key-data'
Print key listings delimited by colons (like '--with-colons') and
print the public key data.
'--list-signatures'
'--list-sigs'
Same as '--list-keys', but the signatures are listed too. This
command has the same effect as using '--list-keys' with
'--with-sig-list'. Note that in contrast to '--check-signatures'
the key signatures are not verified. This command can be used to
create a list of signing keys missing in the local keyring; for
example:
gpg --list-sigs --with-colons USERID | \
awk -F: '$1=="sig" && $2=="?" {if($13){print $13}else{print $5}}'
'--fast-list-mode'
Changes the output of the list commands to work faster; this is
achieved by leaving some parts empty. Some applications don't need
the user ID and the trust information given in the listings. By
using this options they can get a faster listing. The exact
behaviour of this option may change in future versions. If you are
missing some information, don't use this option.
'--no-literal'
This is not for normal use. Use the source to see for what it
might be useful.
'--set-filesize'
This is not for normal use. Use the source to see for what it
might be useful.
'--show-session-key'
Display the session key used for one message. See
'--override-session-key' for the counterpart of this option.
We think that Key Escrow is a Bad Thing; however the user should
have the freedom to decide whether to go to prison or to reveal the
content of one specific message without compromising all messages
ever encrypted for one secret key.
You can also use this option if you receive an encrypted message
which is abusive or offensive, to prove to the administrators of
the messaging system that the ciphertext transmitted corresponds to
an inappropriate plaintext so they can take action against the
offending user.
'--override-session-key STRING'
'--override-session-key-fd FD'
Don't use the public key but the session key STRING respective the
session key taken from the first line read from file descriptor FD.
The format of this string is the same as the one printed by
'--show-session-key'. This option is normally not used but comes
handy in case someone forces you to reveal the content of an
encrypted message; using this option you can do this without
handing out the secret key. Note that using
'--override-session-key' may reveal the session key to all local
users via the global process table. Often it is useful to combine
this option with '--no-keyring'.
'--ask-sig-expire'
'--no-ask-sig-expire'
When making a data signature, prompt for an expiration time. If
this option is not specified, the expiration time set via
'--default-sig-expire' is used. '--no-ask-sig-expire' disables
this option.
'--default-sig-expire'
The default expiration time to use for signature expiration. Valid
values are "0" for no expiration, a number followed by the letter d
(for days), w (for weeks), m (for months), or y (for years) (for
example "2m" for two months, or "5y" for five years), or an
absolute date in the form YYYY-MM-DD. Defaults to "0".
'--ask-cert-expire'
'--no-ask-cert-expire'
When making a key signature, prompt for an expiration time. If
this option is not specified, the expiration time set via
'--default-cert-expire' is used. '--no-ask-cert-expire' disables
this option.
'--default-cert-expire'
The default expiration time to use for key signature expiration.
Valid values are "0" for no expiration, a number followed by the
letter d (for days), w (for weeks), m (for months), or y (for
years) (for example "2m" for two months, or "5y" for five years),
or an absolute date in the form YYYY-MM-DD. Defaults to "0".
'--default-new-key-algo STRING'
This option can be used to change the default algorithms for key
generation. The STRING is similar to the arguments required for
the command '--quick-add-key' but slightly different. For example
the current default of '"rsa2048/cert,sign+rsa2048/encr"' (or
'"rsa3072"') can be changed to the value of what we currently call
future default, which is '"ed25519/cert,sign+cv25519/encr"'. You
need to consult the source code to learn the details. Note that
the advanced key generation commands can always be used to specify
a key algorithm directly.
'--allow-secret-key-import'
This is an obsolete option and is not used anywhere.
'--allow-multiple-messages'
'--no-allow-multiple-messages'
Allow processing of multiple OpenPGP messages contained in a single
file or stream. Some programs that call GPG are not prepared to
deal with multiple messages being processed together, so this
option defaults to no. Note that versions of GPG prior to 1.4.7
always allowed multiple messages.
Warning: Do not use this option unless you need it as a temporary
workaround!
'--enable-special-filenames'
This option enables a mode in which filenames of the form '-&n',
where n is a non-negative decimal number, refer to the file
descriptor n and not to a file with that name.
'--no-expensive-trust-checks'
Experimental use only.
'--preserve-permissions'
Don't change the permissions of a secret keyring back to user
read/write only. Use this option only if you really know what you
are doing.
'--default-preference-list STRING'
Set the list of default preferences to STRING. This preference
list is used for new keys and becomes the default for "setpref" in
the edit menu.
'--default-keyserver-url NAME'
Set the default keyserver URL to NAME. This keyserver will be used
as the keyserver URL when writing a new self-signature on a key,
which includes key generation and changing preferences.
'--list-config'
Display various internal configuration parameters of GnuPG. This
option is intended for external programs that call GnuPG to perform
tasks, and is thus not generally useful. See the file
'doc/DETAILS' in the source distribution for the details of which
configuration items may be listed. '--list-config' is only usable
with '--with-colons' set.
'--list-gcrypt-config'
Display various internal configuration parameters of Libgcrypt.
'--gpgconf-list'
This command is similar to '--list-config' but in general only
internally used by the 'gpgconf' tool.
'--gpgconf-test'
This is more or less dummy action. However it parses the
configuration file and returns with failure if the configuration
file would prevent 'gpg' from startup. Thus it may be used to run
a syntax check on the configuration file.
---------- Footnotes ----------
(1) Using a little social engineering anyone who is able to decrypt
the message can check whether one of the other recipients is the one he
suspects.

File: gnupg.info, Node: Deprecated Options, Prev: GPG Esoteric Options, Up: GPG Options
4.2.7 Deprecated options
------------------------
'--show-photos'
'--no-show-photos'
Causes '--list-keys', '--list-signatures', '--list-public-keys',
'--list-secret-keys', and verifying a signature to also display the
photo ID attached to the key, if any. See also '--photo-viewer'.
These options are deprecated. Use '--list-options
[no-]show-photos' and/or '--verify-options [no-]show-photos'
instead.
'--show-keyring'
Display the keyring name at the head of key listings to show which
keyring a given key resides on. This option is deprecated: use
'--list-options [no-]show-keyring' instead.
'--always-trust'
Identical to '--trust-model always'. This option is deprecated.
'--show-notation'
'--no-show-notation'
Show signature notations in the '--list-signatures' or
'--check-signatures' listings as well as when verifying a signature
with a notation in it. These options are deprecated. Use
'--list-options [no-]show-notation' and/or '--verify-options
[no-]show-notation' instead.
'--show-policy-url'
'--no-show-policy-url'
Show policy URLs in the '--list-signatures' or '--check-signatures'
listings as well as when verifying a signature with a policy URL in
it. These options are deprecated. Use '--list-options
[no-]show-policy-url' and/or '--verify-options
[no-]show-policy-url' instead.

File: gnupg.info, Node: GPG Configuration, Next: GPG Examples, Prev: GPG Options, Up: Invoking GPG
4.3 Configuration files
=======================
There are a few configuration files to control certain aspects of
'gpg''s operation. Unless noted, they are expected in the current home
directory (*note option --homedir::).
'gpg.conf'
This is the standard configuration file read by 'gpg' on startup.
It may contain any valid long option; the leading two dashes may
not be entered and the option may not be abbreviated. This default
name may be changed on the command line (*note gpg-option
--options::). You should backup this file.
Note that on larger installations, it is useful to put predefined
files into the directory '/etc/skel/.gnupg' so that newly created users
start up with a working configuration. For existing users a small
helper script is provided to create these files (*note addgnupghome::).
For internal purposes 'gpg' creates and maintains a few other files;
They all live in the current home directory (*note option --homedir::).
Only the 'gpg' program may modify these files.
'~/.gnupg'
This is the default home directory which is used if neither the
environment variable 'GNUPGHOME' nor the option '--homedir' is
given.
'~/.gnupg/pubring.gpg'
The public keyring. You should backup this file.
'~/.gnupg/pubring.gpg.lock'
The lock file for the public keyring.
'~/.gnupg/pubring.kbx'
The public keyring using a different format. This file is shared
with 'gpgsm'. You should backup this file.
'~/.gnupg/pubring.kbx.lock'
The lock file for 'pubring.kbx'.
'~/.gnupg/secring.gpg'
A secret keyring as used by GnuPG versions before 2.1. It is not
used by GnuPG 2.1 and later.
'~/.gnupg/secring.gpg.lock'
The lock file for the secret keyring.
'~/.gnupg/.gpg-v21-migrated'
File indicating that a migration to GnuPG 2.1 has been done.
'~/.gnupg/trustdb.gpg'
The trust database. There is no need to backup this file; it is
better to backup the ownertrust values (*note option
--export-ownertrust::).
'~/.gnupg/trustdb.gpg.lock'
The lock file for the trust database.
'~/.gnupg/random_seed'
A file used to preserve the state of the internal random pool.
'~/.gnupg/openpgp-revocs.d/'
This is the directory where gpg stores pre-generated revocation
certificates. The file name corresponds to the OpenPGP fingerprint
of the respective key. It is suggested to backup those
certificates and if the primary private key is not stored on the
disk to move them to an external storage device. Anyone who can
access theses files is able to revoke the corresponding key. You
may want to print them out. You should backup all files in this
directory and take care to keep this backup closed away.
Operation is further controlled by a few environment variables:
HOME
Used to locate the default home directory.
GNUPGHOME
If set directory used instead of "~/.gnupg".
GPG_AGENT_INFO
This variable is obsolete; it was used by GnuPG versions before
2.1.
PINENTRY_USER_DATA
This value is passed via gpg-agent to pinentry. It is useful to
convey extra information to a custom pinentry.
COLUMNS
LINES
Used to size some displays to the full size of the screen.
LANGUAGE
Apart from its use by GNU, it is used in the W32 version to
override the language selection done through the Registry. If used
and set to a valid and available language name (LANGID), the file
with the translation is loaded from 'GPGDIR/gnupg.nls/LANGID.mo'.
Here GPGDIR is the directory out of which the gpg binary has been
loaded. If it can't be loaded the Registry is tried and as last
resort the native Windows locale system is used.
When calling the gpg-agent component 'gpg' sends a set of environment
variables to gpg-agent. The names of these variables can be listed
using the command:
gpg-connect-agent 'getinfo std_env_names' /bye | awk '$1=="D" {print $2}'

File: gnupg.info, Node: GPG Examples, Next: Unattended Usage of GPG, Prev: GPG Configuration, Up: Invoking GPG
4.4 Examples
============
gpg -se -r 'Bob' 'file'
sign and encrypt for user Bob
gpg -clear-sign 'file'
make a cleartext signature
gpg -sb 'file'
make a detached signature
gpg -u 0x12345678 -sb 'file'
make a detached signature with the key 0x12345678
gpg -list-keys 'user_ID'
show keys
gpg -fingerprint 'user_ID'
show fingerprint
gpg -verify 'pgpfile'
gpg -verify 'sigfile' ['datafile']
Verify the signature of the file but do not output the data unless
requested. The second form is used for detached signatures, where
'sigfile' is the detached signature (either ASCII armored or
binary) and 'datafile' are the signed data; if this is not given,
the name of the file holding the signed data is constructed by
cutting off the extension (".asc" or ".sig") of 'sigfile' or by
asking the user for the filename. If the option '--output' is also
used the signed data is written to the file specified by that
option; use '-' to write the signed data to stdout.
FILTER EXPRESSIONS
******************
The options '--import-filter' and '--export-filter' use expressions with
this syntax (square brackets indicate an optional part and curly braces
a repetition, white space between the elements are allowed):
[lc] {[{flag}] PROPNAME op VALUE [lc]}
The name of a property (PROPNAME) may only consist of letters, digits
and underscores. The description for the filter type describes which
properties are defined. If an undefined property is used it evaluates
to the empty string. Unless otherwise noted, the VALUE must always be
given and may not be the empty string. No quoting is defined for the
value, thus the value may not contain the strings '&&' or '||', which
are used as logical connection operators. The flag '--' can be used to
remove this restriction.
Numerical values are computed as long int; standard C notation
applies. LC is the logical connection operator; either '&&' for a
conjunction or '||' for a disjunction. A conjunction is assumed at the
begin of an expression. Conjunctions have higher precedence than
disjunctions. If VALUE starts with one of the characters used in any OP
a space after the OP is required.
The supported operators (OP) are:
=~
Substring must match.
!~
Substring must not match.
=
The full string must match.
<>
The full string must not match.
==
The numerical value must match.
!=
The numerical value must not match.
<=
The numerical value of the field must be LE than the value.
<
The numerical value of the field must be LT than the value.
>
The numerical value of the field must be GT than the value.
>=
The numerical value of the field must be GE than the value.
-le
The string value of the field must be less or equal than the value.
-lt
The string value of the field must be less than the value.
-gt
The string value of the field must be greater than the value.
-ge
The string value of the field must be greater or equal than the
value.
-n
True if value is not empty (no value allowed).
-z
True if value is empty (no value allowed).
-t
Alias for "PROPNAME != 0" (no value allowed).
-f
Alias for "PROPNAME == 0" (no value allowed).
Values for FLAG must be space separated. The supported flags are:
-
VALUE spans to the end of the expression.
-c
The string match in this part is done case-sensitive.
The filter options concatenate several specifications for a filter of
the same type. For example the four options in this example:
--import-filter keep-uid="uid =~ Alfa"
--import-filter keep-uid="&& uid !~ Test"
--import-filter keep-uid="|| uid =~ Alpha"
--import-filter keep-uid="uid !~ Test"
which is equivalent to
--import-filter \
keep-uid="uid =~ Alfa" && uid !~ Test" || uid =~ Alpha" && "uid !~ Test"
imports only the user ids of a key containing the strings "Alfa" or
"Alpha" but not the string "test".
RETURN VALUE
************
The program returns 0 if everything was fine, 1 if at least a signature
was bad, and other error codes for fatal errors.
WARNINGS
********
Use a *good* password for your user account and a *good* passphrase to
protect your secret key. This passphrase is the weakest part of the
whole system. Programs to do dictionary attacks on your secret keyring
are very easy to write and so you should protect your "~/.gnupg/"
directory very well.
Keep in mind that, if this program is used over a network (telnet),
it is *very* easy to spy out your passphrase!
If you are going to verify detached signatures, make sure that the
program knows about it; either give both filenames on the command line
or use '-' to specify STDIN.
For scripted or other unattended use of 'gpg' make sure to use the
machine-parseable interface and not the default interface which is
intended for direct use by humans. The machine-parseable interface
provides a stable and well documented API independent of the locale or
future changes of 'gpg'. To enable this interface use the options
'--with-colons' and '--status-fd'. For certain operations the option
'--command-fd' may come handy too. See this man page and the file
'DETAILS' for the specification of the interface. Note that the GnuPG
"info" pages as well as the PDF version of the GnuPG manual features a
chapter on unattended use of GnuPG. As an alternative the library
'GPGME' can be used as a high-level abstraction on top of that
interface.
INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS
********************************************
GnuPG tries to be a very flexible implementation of the OpenPGP
standard. In particular, GnuPG implements many of the optional parts of
the standard, such as the SHA-512 hash, and the ZLIB and BZIP2
compression algorithms. It is important to be aware that not all
OpenPGP programs implement these optional algorithms and that by forcing
their use via the '--cipher-algo', '--digest-algo',
'--cert-digest-algo', or '--compress-algo' options in GnuPG, it is
possible to create a perfectly valid OpenPGP message, but one that
cannot be read by the intended recipient.
There are dozens of variations of OpenPGP programs available, and
each supports a slightly different subset of these optional algorithms.
For example, until recently, no (unhacked) version of PGP supported the
BLOWFISH cipher algorithm. A message using BLOWFISH simply could not be
read by a PGP user. By default, GnuPG uses the standard OpenPGP
preferences system that will always do the right thing and create
messages that are usable by all recipients, regardless of which OpenPGP
program they use. Only override this safe default if you really know
what you are doing.
If you absolutely must override the safe default, or if the
preferences on a given key are invalid for some reason, you are far
better off using the '--pgp6', '--pgp7', or '--pgp8' options. These
options are safe as they do not force any particular algorithms in
violation of OpenPGP, but rather reduce the available algorithms to a
"PGP-safe" list.
BUGS
****
On older systems this program should be installed as setuid(root). This
is necessary to lock memory pages. Locking memory pages prevents the
operating system from writing memory pages (which may contain
passphrases or other sensitive material) to disk. If you get no warning
message about insecure memory your operating system supports locking
without being root. The program drops root privileges as soon as locked
memory is allocated.
Note also that some systems (especially laptops) have the ability to
"suspend to disk" (also known as "safe sleep" or "hibernate"). This
writes all memory to disk before going into a low power or even powered
off mode. Unless measures are taken in the operating system to protect
the saved memory, passphrases or other sensitive material may be
recoverable from it later.
Before you report a bug you should first search the mailing list
archives for similar problems and second check whether such a bug has
already been reported to our bug tracker at <https://bugs.gnupg.org>.

File: gnupg.info, Node: Unattended Usage of GPG, Prev: GPG Examples, Up: Invoking GPG
4.5 Unattended Usage
====================
'gpg' is often used as a backend engine by other software. To help with
this a machine interface has been defined to have an unambiguous way to
do this. The options '--status-fd' and '--batch' are almost always
required for this.
* Menu:
* Programmatic use of GnuPG:: Programmatic use of GnuPG
* Ephemeral home directories:: Ephemeral home directories
* The quick key manipulation interface:: The quick key manipulation interface
* Unattended GPG key generation:: Unattended key generation

File: gnupg.info, Node: Programmatic use of GnuPG, Next: Ephemeral home directories, Up: Unattended Usage of GPG
4.5.1 Programmatic use of GnuPG
-------------------------------
Please consider using GPGME instead of calling 'gpg' directly. GPGME
offers a stable, backend-independent interface for many cryptographic
operations. It supports OpenPGP and S/MIME, and also allows interaction
with various GnuPG components.
GPGME provides a C-API, and comes with bindings for C++, Qt, and
Python. Bindings for other languages are available.

File: gnupg.info, Node: Ephemeral home directories, Next: The quick key manipulation interface, Prev: Programmatic use of GnuPG, Up: Unattended Usage of GPG
4.5.2 Ephemeral home directories
--------------------------------
Sometimes you want to contain effects of some operation, for example you
want to import a key to inspect it, but you do not want this key to be
added to your keyring. In earlier versions of GnuPG, it was possible to
specify alternate keyring files for both public and secret keys. In
modern GnuPG versions, however, we changed how secret keys are stored in
order to better protect secret key material, and it was not possible to
preserve this interface.
The preferred way to do this is to use ephemeral home directories.
This technique works across all versions of GnuPG.
Create a temporary directory, create (or copy) a configuration that
meets your needs, make 'gpg' use this directory either using the
environment variable GNUPGHOME, or the option '--homedir'. GPGME
supports this too on a per-context basis, by modifying the engine info
of contexts. Now execute whatever operation you like, import and export
key material as necessary. Once finished, you can delete the directory.
All GnuPG backend services that were started will detect this and shut
down.

File: gnupg.info, Node: The quick key manipulation interface, Next: Unattended GPG key generation, Prev: Ephemeral home directories, Up: Unattended Usage of GPG
4.5.3 The quick key manipulation interface
------------------------------------------
Recent versions of GnuPG have an interface to manipulate keys without
using the interactive command '--edit-key'. This interface was added
mainly for the benefit of GPGME (please consider using GPGME, see the
manual subsection "Programmatic use of GnuPG"). This interface is
described in the subsection "How to manage your keys".

File: gnupg.info, Node: Unattended GPG key generation, Prev: The quick key manipulation interface, Up: Unattended Usage of GPG
4.5.4 Unattended key generation
-------------------------------
The command '--generate-key' may be used along with the option '--batch'
for unattended key generation. This is the most flexible way of
generating keys, but it is also the most complex one. Consider using
the quick key manipulation interface described in the previous
subsection "The quick key manipulation interface".
The parameters for the key are either read from stdin or given as a
file on the command line. The format of the parameter file is as
follows:
* Text only, line length is limited to about 1000 characters.
* UTF-8 encoding must be used to specify non-ASCII characters.
* Empty lines are ignored.
* Leading and trailing white space is ignored.
* A hash sign as the first non white space character indicates a
comment line.
* Control statements are indicated by a leading percent sign, the
arguments are separated by white space from the keyword.
* Parameters are specified by a keyword, followed by a colon.
Arguments are separated by white space.
* The first parameter must be 'Key-Type'; control statements may be
placed anywhere.
* The order of the parameters does not matter except for 'Key-Type'
which must be the first parameter. The parameters are only used
for the generated keyblock (primary and subkeys); parameters from
previous sets are not used. Some syntactically checks may be
performed.
* Key generation takes place when either the end of the parameter
file is reached, the next 'Key-Type' parameter is encountered or at
the control statement '%commit' is encountered.
Control statements:
%echo TEXT
Print TEXT as diagnostic.
%dry-run
Suppress actual key generation (useful for syntax checking).
%commit
Perform the key generation. Note that an implicit commit is done
at the next Key-Type parameter.
%pubring FILENAME
Do not write the key to the default or commandline given keyring
but to FILENAME. This must be given before the first commit to
take place, duplicate specification of the same filename is
ignored, the last filename before a commit is used. The filename
is used until a new filename is used (at commit points) and all
keys are written to that file. If a new filename is given, this
file is created (and overwrites an existing one).
See the previous subsection "Ephemeral home directories" for a more
robust way to contain side-effects.
%secring FILENAME
This option is a no-op for GnuPG 2.1 and later.
See the previous subsection "Ephemeral home directories".
%ask-passphrase
%no-ask-passphrase
This option is a no-op for GnuPG 2.1 and later.
%no-protection
Using this option allows the creation of keys without any
passphrase protection. This option is mainly intended for
regression tests.
%transient-key
If given the keys are created using a faster and a somewhat less
secure random number generator. This option may be used for keys
which are only used for a short time and do not require full
cryptographic strength. It takes only effect if used together with
the control statement '%no-protection'.
General Parameters:
Key-Type: ALGO
Starts a new parameter block by giving the type of the primary key.
The algorithm must be capable of signing. This is a required
parameter. ALGO may either be an OpenPGP algorithm number or a
string with the algorithm name. The special value 'default' may be
used for ALGO to create the default key type; in this case a
'Key-Usage' shall not be given and 'default' also be used for
'Subkey-Type'.
Key-Length: NBITS
The requested length of the generated key in bits. The default is
returned by running the command 'gpg --gpgconf-list'.
Key-Grip: HEXSTRING
This is optional and used to generate a CSR or certificate for an
already existing key. Key-Length will be ignored when given.
Key-Usage: USAGE-LIST
Space or comma delimited list of key usages. Allowed values are
'encrypt', 'sign', and 'auth'. This is used to generate the key
flags. Please make sure that the algorithm is capable of this
usage. Note that OpenPGP requires that all primary keys are
capable of certification, so no matter what usage is given here,
the 'cert' flag will be on. If no 'Key-Usage' is specified and the
'Key-Type' is not 'default', all allowed usages for that particular
algorithm are used; if it is not given but 'default' is used the
usage will be 'sign'.
Subkey-Type: ALGO
This generates a secondary key (subkey). Currently only one subkey
can be handled. See also 'Key-Type' above.
Subkey-Length: NBITS
Length of the secondary key (subkey) in bits. The default is
returned by running the command 'gpg --gpgconf-list'.
Subkey-Usage: USAGE-LIST
Key usage lists for a subkey; similar to 'Key-Usage'.
Passphrase: STRING
If you want to specify a passphrase for the secret key, enter it
here. Default is to use the Pinentry dialog to ask for a
passphrase.
Name-Real: NAME
Name-Comment: COMMENT
Name-Email: EMAIL
The three parts of a user name. Remember to use UTF-8 encoding
here. If you don't give any of them, no user ID is created.
Expire-Date: ISO-DATE|(NUMBER[d|w|m|y])
Set the expiration date for the key (and the subkey). It may
either be entered in ISO date format (e.g. "20000815T145012") or
as number of days, weeks, month or years after the creation date.
The special notation "seconds=N" is also allowed to specify a
number of seconds since creation. Without a letter days are
assumed. Note that there is no check done on the overflow of the
type used by OpenPGP for timestamps. Thus you better make sure
that the given value make sense. Although OpenPGP works with time
intervals, GnuPG uses an absolute value internally and thus the
last year we can represent is 2105.
Creation-Date: ISO-DATE
Set the creation date of the key as stored in the key information
and which is also part of the fingerprint calculation. Either a
date like "1986-04-26" or a full timestamp like "19860426T042640"
may be used. The time is considered to be UTC. The special
notation "seconds=N" may be used to directly specify a the number
of seconds since Epoch (Unix time). If it is not given the current
time is used.
Preferences: STRING
Set the cipher, hash, and compression preference values for this
key. This expects the same type of string as the sub-command
'setpref' in the '--edit-key' menu.
Revoker: ALGO:FPR [sensitive]
Add a designated revoker to the generated key. Algo is the public
key algorithm of the designated revoker (i.e. RSA=1, DSA=17, etc.)
FPR is the fingerprint of the designated revoker. The optional
'sensitive' flag marks the designated revoker as sensitive
information. Only v4 keys may be designated revokers.
Keyserver: STRING
This is an optional parameter that specifies the preferred
keyserver URL for the key.
Handle: STRING
This is an optional parameter only used with the status lines
KEY_CREATED and KEY_NOT_CREATED. STRING may be up to 100 characters
and should not contain spaces. It is useful for batch key
generation to associate a key parameter block with a status line.
Here is an example on how to create a key in an ephemeral home
directory:
$ export GNUPGHOME="$(mktemp -d)"
$ cat >foo <<EOF
%echo Generating a basic OpenPGP key
Key-Type: DSA
Key-Length: 1024
Subkey-Type: ELG-E
Subkey-Length: 1024
Name-Real: Joe Tester
Name-Comment: with stupid passphrase
Name-Email: joe@foo.bar
Expire-Date: 0
Passphrase: abc
# Do a commit here, so that we can later print "done" :-)
%commit
%echo done
EOF
$ gpg --batch --generate-key foo
[...]
$ gpg --list-secret-keys
/tmp/tmp.0NQxB74PEf/pubring.kbx
-------------------------------
sec dsa1024 2016-12-16 [SCA]
768E895903FC1C44045C8CB95EEBDB71E9E849D0
uid [ultimate] Joe Tester (with stupid passphrase) <joe@foo.bar>
ssb elg1024 2016-12-16 [E]
If you want to create a key with the default algorithms you would use
these parameters:
%echo Generating a default key
Key-Type: default
Subkey-Type: default
Name-Real: Joe Tester
Name-Comment: with stupid passphrase
Name-Email: joe@foo.bar
Expire-Date: 0
Passphrase: abc
# Do a commit here, so that we can later print "done" :-)
%commit
%echo done

File: gnupg.info, Node: Invoking GPGSM, Next: Invoking SCDAEMON, Prev: Invoking GPG, Up: Top
5 Invoking GPGSM
****************
'gpgsm' is a tool similar to 'gpg' to provide digital encryption and
signing services on X.509 certificates and the CMS protocol. It is
mainly used as a backend for S/MIME mail processing. 'gpgsm' includes a
full featured certificate management and complies with all rules defined
for the German Sphinx project.
*Note Option Index::, for an index to 'GPGSM''s commands and options.
* Menu:
* GPGSM Commands:: List of all commands.
* GPGSM Options:: List of all options.
* GPGSM Configuration:: Configuration files.
* GPGSM Examples:: Some usage examples.
Developer information:
* Unattended Usage:: Using 'gpgsm' from other programs.
* GPGSM Protocol:: The protocol the server mode uses.

File: gnupg.info, Node: GPGSM Commands, Next: GPGSM Options, Up: Invoking GPGSM
5.1 Commands
============
Commands are not distinguished from options except for the fact that
only one command is allowed.
* Menu:
* General GPGSM Commands:: Commands not specific to the functionality.
* Operational GPGSM Commands:: Commands to select the type of operation.
* Certificate Management:: How to manage certificates.

File: gnupg.info, Node: General GPGSM Commands, Next: Operational GPGSM Commands, Up: GPGSM Commands
5.1.1 Commands not specific to the function
-------------------------------------------
'--version'
Print the program version and licensing information. Note that you
cannot abbreviate this command.
'--help, -h'
Print a usage message summarizing the most useful command-line
options. Note that you cannot abbreviate this command.
'--warranty'
Print warranty information. Note that you cannot abbreviate this
command.
'--dump-options'
Print a list of all available options and commands. Note that you
cannot abbreviate this command.

File: gnupg.info, Node: Operational GPGSM Commands, Next: Certificate Management, Prev: General GPGSM Commands, Up: GPGSM Commands
5.1.2 Commands to select the type of operation
----------------------------------------------
'--encrypt'
Perform an encryption. The keys the data is encrypted to must be
set using the option '--recipient'.
'--decrypt'
Perform a decryption; the type of input is automatically
determined. It may either be in binary form or PEM encoded;
automatic determination of base-64 encoding is not done.
'--sign'
Create a digital signature. The key used is either the fist one
found in the keybox or those set with the '--local-user' option.
'--verify'
Check a signature file for validity. Depending on the arguments a
detached signature may also be checked.
'--server'
Run in server mode and wait for commands on the 'stdin'.
'--call-dirmngr COMMAND [ARGS]'
Behave as a Dirmngr client issuing the request COMMAND with the
optional list of ARGS. The output of the Dirmngr is printed
stdout. Please note that file names given as arguments should have
an absolute file name (i.e. commencing with '/') because they are
passed verbatim to the Dirmngr and the working directory of the
Dirmngr might not be the same as the one of this client. Currently
it is not possible to pass data via stdin to the Dirmngr. COMMAND
should not contain spaces.
This is command is required for certain maintaining tasks of the
dirmngr where a dirmngr must be able to call back to 'gpgsm'. See
the Dirmngr manual for details.
'--call-protect-tool ARGUMENTS'
Certain maintenance operations are done by an external program call
'gpg-protect-tool'; this is usually not installed in a directory
listed in the PATH variable. This command provides a simple
wrapper to access this tool. ARGUMENTS are passed verbatim to this
command; use '--help' to get a list of supported operations.

File: gnupg.info, Node: Certificate Management, Prev: Operational GPGSM Commands, Up: GPGSM Commands
5.1.3 How to manage the certificates and keys
---------------------------------------------
'--generate-key'
'--gen-key'
This command allows the creation of a certificate signing request
or a self-signed certificate. It is commonly used along with the
'--output' option to save the created CSR or certificate into a
file. If used with the '--batch' a parameter file is used to
create the CSR or certificate and it is further possible to create
non-self-signed certificates.
'--list-keys'
'-k'
List all available certificates stored in the local key database.
Note that the displayed data might be reformatted for better human
readability and illegal characters are replaced by safe
substitutes.
'--list-secret-keys'
'-K'
List all available certificates for which a corresponding a secret
key is available.
'--list-external-keys PATTERN'
List certificates matching PATTERN using an external server. This
utilizes the 'dirmngr' service.
'--list-chain'
Same as '--list-keys' but also prints all keys making up the chain.
'--dump-cert'
'--dump-keys'
List all available certificates stored in the local key database
using a format useful mainly for debugging.
'--dump-chain'
Same as '--dump-keys' but also prints all keys making up the chain.
'--dump-secret-keys'
List all available certificates for which a corresponding a secret
key is available using a format useful mainly for debugging.
'--dump-external-keys PATTERN'
List certificates matching PATTERN using an external server. This
utilizes the 'dirmngr' service. It uses a format useful mainly for
debugging.
'--keydb-clear-some-cert-flags'
This is a debugging aid to reset certain flags in the key database
which are used to cache certain certificate stati. It is
especially useful if a bad CRL or a weird running OCSP responder
did accidentally revoke certificate. There is no security issue
with this command because 'gpgsm' always make sure that the
validity of a certificate is checked right before it is used.
'--delete-keys PATTERN'
Delete the keys matching PATTERN. Note that there is no command to
delete the secret part of the key directly. In case you need to do
this, you should run the command 'gpgsm --dump-secret-keys KEYID'
before you delete the key, copy the string of hex-digits in the
"keygrip" line and delete the file consisting of these hex-digits
and the suffix '.key' from the 'private-keys-v1.d' directory below
our GnuPG home directory (usually '~/.gnupg').
'--export [PATTERN]'
Export all certificates stored in the Keybox or those specified by
the optional PATTERN. Those pattern consist of a list of user ids
(*note how-to-specify-a-user-id::). When used along with the
'--armor' option a few informational lines are prepended before
each block. There is one limitation: As there is no commonly
agreed upon way to pack more than one certificate into an ASN.1
structure, the binary export (i.e. without using 'armor') works
only for the export of one certificate. Thus it is required to
specify a PATTERN which yields exactly one certificate. Ephemeral
certificate are only exported if all PATTERN are given as
fingerprints or keygrips.
'--export-secret-key-p12 KEY-ID'
Export the private key and the certificate identified by KEY-ID
using the PKCS#12 format. When used with the '--armor' option a
few informational lines are prepended to the output. Note, that
the PKCS#12 format is not very secure and proper transport security
should be used to convey the exported key. (*Note option
--p12-charset::.)
'--export-secret-key-p8 KEY-ID'
'--export-secret-key-raw KEY-ID'
Export the private key of the certificate identified by KEY-ID with
any encryption stripped. The '...-raw' command exports in PKCS#1
format; the '...-p8' command exports in PKCS#8 format. When used
with the '--armor' option a few informational lines are prepended
to the output. These commands are useful to prepare a key for use
on a TLS server.
'--import [FILES]'
Import the certificates from the PEM or binary encoded files as
well as from signed-only messages. This command may also be used
to import a secret key from a PKCS#12 file.
'--learn-card'
Read information about the private keys from the smartcard and
import the certificates from there. This command utilizes the
'gpg-agent' and in turn the 'scdaemon'.
'--change-passphrase USER_ID'
'--passwd USER_ID'
Change the passphrase of the private key belonging to the
certificate specified as USER_ID. Note, that changing the
passphrase/PIN of a smartcard is not yet supported.

File: gnupg.info, Node: GPGSM Options, Next: GPGSM Configuration, Prev: GPGSM Commands, Up: Invoking GPGSM
5.2 Option Summary
==================
'GPGSM' features a bunch of options to control the exact behaviour and
to change the default configuration.
* Menu:
* Configuration Options:: How to change the configuration.
* Certificate Options:: Certificate related options.
* Input and Output:: Input and Output.
* CMS Options:: How to change how the CMS is created.
* Esoteric Options:: Doing things one usually do not want to do.

File: gnupg.info, Node: Configuration Options, Next: Certificate Options, Up: GPGSM Options
5.2.1 How to change the configuration
-------------------------------------
These options are used to change the configuration and are usually found
in the option file.
'--options FILE'
Reads configuration from FILE instead of from the default per-user
configuration file. The default configuration file is named
'gpgsm.conf' and expected in the '.gnupg' directory directly below
the home directory of the user.
'--homedir DIR'
Set the name of the home directory to DIR. If this option is not
used, the home directory defaults to '~/.gnupg'. It is only
recognized when given on the command line. It also overrides any
home directory stated through the environment variable 'GNUPGHOME'
or (on Windows systems) by means of the Registry entry
HKCU\SOFTWARE\GNU\GNUPG:HOMEDIR.
On Windows systems it is possible to install GnuPG as a portable
application. In this case only this command line option is
considered, all other ways to set a home directory are ignored.
To install GnuPG as a portable application under Windows, create an
empty file named 'gpgconf.ctl' in the same directory as the tool
'gpgconf.exe'. The root of the installation is then that
directory; or, if 'gpgconf.exe' has been installed directly below a
directory named 'bin', its parent directory. You also need to make
sure that the following directories exist and are writable:
'ROOT/home' for the GnuPG home and 'ROOT/usr/local/var/cache/gnupg'
for internal cache files.
'-v'
'--verbose'
Outputs additional information while running. You can increase the
verbosity by giving several verbose commands to 'gpgsm', such as
'-vv'.
'--policy-file FILENAME'
Change the default name of the policy file to FILENAME.
'--agent-program FILE'
Specify an agent program to be used for secret key operations. The
default value is determined by running the command 'gpgconf'. Note
that the pipe symbol ('|') is used for a regression test suite hack
and may thus not be used in the file name.
'--dirmngr-program FILE'
Specify a dirmngr program to be used for CRL checks. The default
value is '/usr/local/bin/dirmngr'.
'--prefer-system-dirmngr'
This option is obsolete and ignored.
'--disable-dirmngr'
Entirely disable the use of the Dirmngr.
'--no-autostart'
Do not start the gpg-agent or the dirmngr if it has not yet been
started and its service is required. This option is mostly useful
on machines where the connection to gpg-agent has been redirected
to another machines. If dirmngr is required on the remote machine,
it may be started manually using 'gpgconf --launch dirmngr'.
'--no-secmem-warning'
Do not print a warning when the so called "secure memory" cannot be
used.
'--log-file FILE'
When running in server mode, append all logging output to FILE.
Use 'socket://' to log to socket.

File: gnupg.info, Node: Certificate Options, Next: Input and Output, Prev: Configuration Options, Up: GPGSM Options
5.2.2 Certificate related options
---------------------------------
'--enable-policy-checks'
'--disable-policy-checks'
By default policy checks are enabled. These options may be used to
change it.
'--enable-crl-checks'
'--disable-crl-checks'
By default the CRL checks are enabled and the DirMngr is used to
check for revoked certificates. The disable option is most useful
with an off-line network connection to suppress this check.
'--enable-trusted-cert-crl-check'
'--disable-trusted-cert-crl-check'
By default the CRL for trusted root certificates are checked like
for any other certificates. This allows a CA to revoke its own
certificates voluntary without the need of putting all ever issued
certificates into a CRL. The disable option may be used to switch
this extra check off. Due to the caching done by the Dirmngr,
there will not be any noticeable performance gain. Note, that this
also disables possible OCSP checks for trusted root certificates.
A more specific way of disabling this check is by adding the
"relax" keyword to the root CA line of the 'trustlist.txt'
'--force-crl-refresh'
Tell the dirmngr to reload the CRL for each request. For better
performance, the dirmngr will actually optimize this by suppressing
the loading for short time intervals (e.g. 30 minutes). This
option is useful to make sure that a fresh CRL is available for
certificates hold in the keybox. The suggested way of doing this
is by using it along with the option '--with-validation' for a key
listing command. This option should not be used in a configuration
file.
'--enable-ocsp'
'--disable-ocsp'
By default OCSP checks are disabled. The enable option may be used
to enable OCSP checks via Dirmngr. If CRL checks are also enabled,
CRLs will be used as a fallback if for some reason an OCSP request
will not succeed. Note, that you have to allow OCSP requests in
Dirmngr's configuration too (option '--allow-ocsp') and configure
Dirmngr properly. If you do not do so you will get the error code
'Not supported'.
'--auto-issuer-key-retrieve'
If a required certificate is missing while validating the chain of
certificates, try to load that certificate from an external
location. This usually means that Dirmngr is employed to search
for the certificate. Note that this option makes a "web bug" like
behavior possible. LDAP server operators can see which keys you
request, so by sending you a message signed by a brand new key
(which you naturally will not have on your local keybox), the
operator can tell both your IP address and the time when you
verified the signature.
'--validation-model NAME'
This option changes the default validation model. The only
possible values are "shell" (which is the default), "chain" which
forces the use of the chain model and "steed" for a new simplified
model. The chain model is also used if an option in the
'trustlist.txt' or an attribute of the certificate requests it.
However the standard model (shell) is in that case always tried
first.
'--ignore-cert-extension OID'
Add OID to the list of ignored certificate extensions. The OID is
expected to be in dotted decimal form, like '2.5.29.3'. This
option may be used more than once. Critical flagged certificate
extensions matching one of the OIDs in the list are treated as if
they are actually handled and thus the certificate will not be
rejected due to an unknown critical extension. Use this option
with care because extensions are usually flagged as critical for a
reason.

File: gnupg.info, Node: Input and Output, Next: CMS Options, Prev: Certificate Options, Up: GPGSM Options
5.2.3 Input and Output
----------------------
'--armor'
'-a'
Create PEM encoded output. Default is binary output.
'--base64'
Create Base-64 encoded output; i.e. PEM without the header lines.
'--assume-armor'
Assume the input data is PEM encoded. Default is to autodetect the
encoding but this is may fail.
'--assume-base64'
Assume the input data is plain base-64 encoded.
'--assume-binary'
Assume the input data is binary encoded.
'--p12-charset NAME'
'gpgsm' uses the UTF-8 encoding when encoding passphrases for
PKCS#12 files. This option may be used to force the passphrase to
be encoded in the specified encoding NAME. This is useful if the
application used to import the key uses a different encoding and
thus will not be able to import a file generated by 'gpgsm'.
Commonly used values for NAME are 'Latin1' and 'CP850'. Note that
'gpgsm' itself automagically imports any file with a passphrase
encoded to the most commonly used encodings.
'--default-key USER_ID'
Use USER_ID as the standard key for signing. This key is used if
no other key has been defined as a signing key. Note, that the
first '--local-users' option also sets this key if it has not yet
been set; however '--default-key' always overrides this.
'--local-user USER_ID'
'-u USER_ID'
Set the user(s) to be used for signing. The default is the first
secret key found in the database.
'--recipient NAME'
'-r'
Encrypt to the user id NAME. There are several ways a user id may
be given (*note how-to-specify-a-user-id::).
'--output FILE'
'-o FILE'
Write output to FILE. The default is to write it to stdout.
'--with-key-data'
Displays extra information with the '--list-keys' commands.
Especially a line tagged 'grp' is printed which tells you the
keygrip of a key. This string is for example used as the file name
of the secret key. Implies '--with-colons'.
'--with-validation'
When doing a key listing, do a full validation check for each key
and print the result. This is usually a slow operation because it
requires a CRL lookup and other operations.
When used along with '--import', a validation of the certificate to
import is done and only imported if it succeeds the test. Note
that this does not affect an already available certificate in the
DB. This option is therefore useful to simply verify a certificate.
'--with-md5-fingerprint'
For standard key listings, also print the MD5 fingerprint of the
certificate.
'--with-keygrip'
Include the keygrip in standard key listings. Note that the
keygrip is always listed in '--with-colons' mode.
'--with-secret'
Include info about the presence of a secret key in public key
listings done with '--with-colons'.

File: gnupg.info, Node: CMS Options, Next: Esoteric Options, Prev: Input and Output, Up: GPGSM Options
5.2.4 How to change how the CMS is created
------------------------------------------
'--include-certs N'
Using N of -2 includes all certificate except for the root cert, -1
includes all certs, 0 does not include any certs, 1 includes only
the signers cert and all other positive values include up to N
certificates starting with the signer cert. The default is -2.
'--cipher-algo OID'
Use the cipher algorithm with the ASN.1 object identifier OID for
encryption. For convenience the strings '3DES', 'AES' and 'AES256'
may be used instead of their OIDs. The default is 'AES'
(2.16.840.1.101.3.4.1.2).
'--digest-algo name'
Use 'name' as the message digest algorithm. Usually this algorithm
is deduced from the respective signing certificate. This option
forces the use of the given algorithm and may lead to severe
interoperability problems.

File: gnupg.info, Node: Esoteric Options, Prev: CMS Options, Up: GPGSM Options
5.2.5 Doing things one usually do not want to do
------------------------------------------------
'--extra-digest-algo NAME'
Sometimes signatures are broken in that they announce a different
digest algorithm than actually used. 'gpgsm' uses a one-pass data
processing model and thus needs to rely on the announced digest
algorithms to properly hash the data. As a workaround this option
may be used to tell 'gpgsm' to also hash the data using the
algorithm NAME; this slows processing down a little bit but allows
verification of such broken signatures. If 'gpgsm' prints an error
like "digest algo 8 has not been enabled" you may want to try this
option, with 'SHA256' for NAME.
'--faked-system-time EPOCH'
This option is only useful for testing; it sets the system time
back or forth to EPOCH which is the number of seconds elapsed since
the year 1970. Alternatively EPOCH may be given as a full ISO time
string (e.g. "20070924T154812").
'--with-ephemeral-keys'
Include ephemeral flagged keys in the output of key listings. Note
that they are included anyway if the key specification for a
listing is given as fingerprint or keygrip.
'--debug-level LEVEL'
Select the debug level for investigating problems. LEVEL may be a
numeric value or by a keyword:
'none'
No debugging at all. A value of less than 1 may be used
instead of the keyword.
'basic'
Some basic debug messages. A value between 1 and 2 may be
used instead of the keyword.
'advanced'
More verbose debug messages. A value between 3 and 5 may be
used instead of the keyword.
'expert'
Even more detailed messages. A value between 6 and 8 may be
used instead of the keyword.
'guru'
All of the debug messages you can get. A value greater than 8
may be used instead of the keyword. The creation of hash
tracing files is only enabled if the keyword is used.
How these messages are mapped to the actual debugging flags is not
specified and may change with newer releases of this program. They
are however carefully selected to best aid in debugging.
'--debug FLAGS'
This option is only useful for debugging and the behaviour may
change at any time without notice; using '--debug-levels' is the
preferred method to select the debug verbosity. FLAGS are bit
encoded and may be given in usual C-Syntax. The currently defined
bits are:
'0 (1)'
X.509 or OpenPGP protocol related data
'1 (2)'
values of big number integers
'2 (4)'
low level crypto operations
'5 (32)'
memory allocation
'6 (64)'
caching
'7 (128)'
show memory statistics
'9 (512)'
write hashed data to files named 'dbgmd-000*'
'10 (1024)'
trace Assuan protocol
Note, that all flags set using this option may get overridden by
'--debug-level'.
'--debug-all'
Same as '--debug=0xffffffff'
'--debug-allow-core-dump'
Usually 'gpgsm' tries to avoid dumping core by well written code
and by disabling core dumps for security reasons. However, bugs
are pretty durable beasts and to squash them it is sometimes useful
to have a core dump. This option enables core dumps unless the Bad
Thing happened before the option parsing.
'--debug-no-chain-validation'
This is actually not a debugging option but only useful as such.
It lets 'gpgsm' bypass all certificate chain validation checks.
'--debug-ignore-expiration'
This is actually not a debugging option but only useful as such.
It lets 'gpgsm' ignore all notAfter dates, this is used by the
regression tests.
'--passphrase-fd n'
Read the passphrase from file descriptor 'n'. Only the first line
will be read from file descriptor 'n'. If you use 0 for 'n', the
passphrase will be read from STDIN. This can only be used if only
one passphrase is supplied.
Note that this passphrase is only used if the option '--batch' has
also been given.
'--pinentry-mode mode'
Set the pinentry mode to 'mode'. Allowed values for 'mode' are:
default
Use the default of the agent, which is 'ask'.
ask
Force the use of the Pinentry.
cancel
Emulate use of Pinentry's cancel button.
error
Return a Pinentry error ("No Pinentry").
loopback
Redirect Pinentry queries to the caller. Note that in
contrast to Pinentry the user is not prompted again if he
enters a bad password.
'--request-origin ORIGIN'
Tell gpgsm to assume that the operation ultimately originated at
ORIGIN. Depending on the origin certain restrictions are applied
and the Pinentry may include an extra note on the origin.
Supported values for ORIGIN are: 'local' which is the default,
'remote' to indicate a remote origin or 'browser' for an operation
requested by a web browser.
'--no-common-certs-import'
Suppress the import of common certificates on keybox creation.
All the long options may also be given in the configuration file
after stripping off the two leading dashes.

File: gnupg.info, Node: GPGSM Configuration, Next: GPGSM Examples, Prev: GPGSM Options, Up: Invoking GPGSM
5.3 Configuration files
=======================
There are a few configuration files to control certain aspects of
'gpgsm''s operation. Unless noted, they are expected in the current
home directory (*note option --homedir::).
'gpgsm.conf'
This is the standard configuration file read by 'gpgsm' on startup.
It may contain any valid long option; the leading two dashes may
not be entered and the option may not be abbreviated. This default
name may be changed on the command line (*note gpgsm-option
--options::). You should backup this file.
'policies.txt'
This is a list of allowed CA policies. This file should list the
object identifiers of the policies line by line. Empty lines and
lines starting with a hash mark are ignored. Policies missing in
this file and not marked as critical in the certificate will print
only a warning; certificates with policies marked as critical and
not listed in this file will fail the signature verification. You
should backup this file.
For example, to allow only the policy 2.289.9.9, the file should
look like this:
# Allowed policies
2.289.9.9
'qualified.txt'
This is the list of root certificates used for qualified
certificates. They are defined as certificates capable of creating
legally binding signatures in the same way as handwritten
signatures are. Comments start with a hash mark and empty lines
are ignored. Lines do have a length limit but this is not a
serious limitation as the format of the entries is fixed and
checked by 'gpgsm': A non-comment line starts with optional
whitespace, followed by exactly 40 hex characters, white space and
a lowercased 2 letter country code. Additional data delimited with
by a white space is current ignored but might late be used for
other purposes.
Note that even if a certificate is listed in this file, this does
not mean that the certificate is trusted; in general the
certificates listed in this file need to be listed also in
'trustlist.txt'.
This is a global file an installed in the data directory (e.g.
'/usr/local/share/gnupg/qualified.txt'). GnuPG installs a suitable
file with root certificates as used in Germany. As new Root-CA
certificates may be issued over time, these entries may need to be
updated; new distributions of this software should come with an
updated list but it is still the responsibility of the
Administrator to check that this list is correct.
Every time 'gpgsm' uses a certificate for signing or verification
this file will be consulted to check whether the certificate under
question has ultimately been issued by one of these CAs. If this
is the case the user will be informed that the verified signature
represents a legally binding ("qualified") signature. When
creating a signature using such a certificate an extra prompt will
be issued to let the user confirm that such a legally binding
signature shall really be created.
Because this software has not yet been approved for use with such
certificates, appropriate notices will be shown to indicate this
fact.
'help.txt'
This is plain text file with a few help entries used with
'pinentry' as well as a large list of help items for 'gpg' and
'gpgsm'. The standard file has English help texts; to install
localized versions use filenames like 'help.LL.txt' with LL
denoting the locale. GnuPG comes with a set of predefined help
files in the data directory (e.g.
'/usr/local/share/gnupg/gnupg/help.de.txt') and allows overriding
of any help item by help files stored in the system configuration
directory (e.g. '/etc/gnupg/help.de.txt'). For a reference of the
help file's syntax, please see the installed 'help.txt' file.
'com-certs.pem'
This file is a collection of common certificates used to populated
a newly created 'pubring.kbx'. An administrator may replace this
file with a custom one. The format is a concatenation of PEM
encoded X.509 certificates. This global file is installed in the
data directory (e.g. '/usr/local/share/gnupg/com-certs.pem').
Note that on larger installations, it is useful to put predefined
files into the directory '/etc/skel/.gnupg/' so that newly created users
start up with a working configuration. For existing users a small
helper script is provided to create these files (*note addgnupghome::).
For internal purposes 'gpgsm' creates and maintains a few other
files; they all live in the current home directory (*note option
--homedir::). Only 'gpgsm' may modify these files.
'pubring.kbx'
This a database file storing the certificates as well as meta
information. For debugging purposes the tool 'kbxutil' may be used
to show the internal structure of this file. You should backup
this file.
'random_seed'
This content of this file is used to maintain the internal state of
the random number generator across invocations. The same file is
used by other programs of this software too.
'S.gpg-agent'
If this file exists 'gpgsm' will first try to connect to this
socket for accessing 'gpg-agent' before starting a new 'gpg-agent'
instance. Under Windows this socket (which in reality be a plain
file describing a regular TCP listening port) is the standard way
of connecting the 'gpg-agent'.

File: gnupg.info, Node: GPGSM Examples, Next: Unattended Usage, Prev: GPGSM Configuration, Up: Invoking GPGSM
5.4 Examples
============
$ gpgsm -er goo@bar.net <plaintext >ciphertext

File: gnupg.info, Node: Unattended Usage, Next: GPGSM Protocol, Prev: GPGSM Examples, Up: Invoking GPGSM
5.5 Unattended Usage
====================
'gpgsm' is often used as a backend engine by other software. To help
with this a machine interface has been defined to have an unambiguous
way to do this. This is most likely used with the '--server' command
but may also be used in the standard operation mode by using the
'--status-fd' option.
* Menu:
* Automated signature checking:: Automated signature checking.
* CSR and certificate creation:: CSR and certificate creation.

File: gnupg.info, Node: Automated signature checking, Next: CSR and certificate creation, Up: Unattended Usage
5.5.1 Automated signature checking
----------------------------------
It is very important to understand the semantics used with signature
verification. Checking a signature is not as simple as it may sound and
so the operation is a bit complicated. In most cases it is required to
look at several status lines. Here is a table of all cases a signed
message may have:
The signature is valid
This does mean that the signature has been successfully verified,
the certificates are all sane. However there are two subcases with
important information: One of the certificates may have expired or
a signature of a message itself as expired. It is a sound practise
to consider such a signature still as valid but additional
information should be displayed. Depending on the subcase 'gpgsm'
will issue these status codes:
signature valid and nothing did expire
'GOODSIG', 'VALIDSIG', 'TRUST_FULLY'
signature valid but at least one certificate has expired
'EXPKEYSIG', 'VALIDSIG', 'TRUST_FULLY'
signature valid but expired
'EXPSIG', 'VALIDSIG', 'TRUST_FULLY' Note, that this case is
currently not implemented.
The signature is invalid
This means that the signature verification failed (this is an
indication of a transfer error, a program error or tampering with
the message). 'gpgsm' issues one of these status codes sequences:
'BADSIG'
'GOODSIG, VALIDSIG TRUST_NEVER'
Error verifying a signature
For some reason the signature could not be verified, i.e. it
cannot be decided whether the signature is valid or invalid. A
common reason for this is a missing certificate.

File: gnupg.info, Node: CSR and certificate creation, Prev: Automated signature checking, Up: Unattended Usage
5.5.2 CSR and certificate creation
----------------------------------
The command '--generate-key' may be used along with the option '--batch'
to either create a certificate signing request (CSR) or an X.509
certificate. This is controlled by a parameter file; the format of this
file is as follows:
* Text only, line length is limited to about 1000 characters.
* UTF-8 encoding must be used to specify non-ASCII characters.
* Empty lines are ignored.
* Leading and trailing while space is ignored.
* A hash sign as the first non white space character indicates a
comment line.
* Control statements are indicated by a leading percent sign, the
arguments are separated by white space from the keyword.
* Parameters are specified by a keyword, followed by a colon.
Arguments are separated by white space.
* The first parameter must be 'Key-Type', control statements may be
placed anywhere.
* The order of the parameters does not matter except for 'Key-Type'
which must be the first parameter. The parameters are only used
for the generated CSR/certificate; parameters from previous sets
are not used. Some syntactically checks may be performed.
* Key generation takes place when either the end of the parameter
file is reached, the next 'Key-Type' parameter is encountered or at
the control statement '%commit' is encountered.
Control statements:
%echo TEXT
Print TEXT as diagnostic.
%dry-run
Suppress actual key generation (useful for syntax checking).
%commit
Perform the key generation. Note that an implicit commit is done
at the next Key-Type parameter.
General Parameters:
Key-Type: ALGO
Starts a new parameter block by giving the type of the primary key.
The algorithm must be capable of signing. This is a required
parameter. The only supported value for ALGO is 'rsa'.
Key-Length: NBITS
The requested length of a generated key in bits. Defaults to 3072.
Key-Grip: HEXSTRING
This is optional and used to generate a CSR or certificate for an
already existing key. Key-Length will be ignored when given.
Key-Usage: USAGE-LIST
Space or comma delimited list of key usage, allowed values are
'encrypt', 'sign' and 'cert'. This is used to generate the
keyUsage extension. Please make sure that the algorithm is capable
of this usage. Default is to allow encrypt and sign.
Name-DN: SUBJECT-NAME
This is the Distinguished Name (DN) of the subject in RFC-2253
format.
Name-Email: STRING
This is an email address for the altSubjectName. This parameter is
optional but may occur several times to add several email addresses
to a certificate.
Name-DNS: STRING
The is an DNS name for the altSubjectName. This parameter is
optional but may occur several times to add several DNS names to a
certificate.
Name-URI: STRING
This is an URI for the altSubjectName. This parameter is optional
but may occur several times to add several URIs to a certificate.
Additional parameters used to create a certificate (in contrast to a
certificate signing request):
Serial: SN
If this parameter is given an X.509 certificate will be generated.
SN is expected to be a hex string representing an unsigned integer
of arbitrary length. The special value 'random' can be used to
create a 64 bit random serial number.
Issuer-DN: ISSUER-NAME
This is the DN name of the issuer in RFC-2253 format. If it is not
set it will default to the subject DN and a special GnuPG extension
will be included in the certificate to mark it as a standalone
certificate.
Creation-Date: ISO-DATE
Not-Before: ISO-DATE
Set the notBefore date of the certificate. Either a date like
'1986-04-26' or '1986-04-26 12:00' or a standard ISO timestamp like
'19860426T042640' may be used. The time is considered to be UTC.
If it is not given the current date is used.
Expire-Date: ISO-DATE
Not-After: ISO-DATE
Set the notAfter date of the certificate. Either a date like
'2063-04-05' or '2063-04-05 17:00' or a standard ISO timestamp like
'20630405T170000' may be used. The time is considered to be UTC.
If it is not given a default value in the not too far future is
used.
Signing-Key: KEYGRIP
This gives the keygrip of the key used to sign the certificate. If
it is not given a self-signed certificate will be created. For
compatibility with future versions, it is suggested to prefix the
keygrip with a '&'.
Hash-Algo: HASH-ALGO
Use HASH-ALGO for this CSR or certificate. The supported hash
algorithms are: 'sha1', 'sha256', 'sha384' and 'sha512'; they may
also be specified with uppercase letters. The default is 'sha256'.

File: gnupg.info, Node: GPGSM Protocol, Prev: Unattended Usage, Up: Invoking GPGSM
5.6 The Protocol the Server Mode Uses
=====================================
Description of the protocol used to access 'GPGSM'. 'GPGSM' does
implement the Assuan protocol and in addition provides a regular command
line interface which exhibits a full client to this protocol (but uses
internal linking). To start 'gpgsm' as a server the command line the
option '--server' must be used. Additional options are provided to
select the communication method (i.e. the name of the socket).
We assume that the connection has already been established; see the
Assuan manual for details.
* Menu:
* GPGSM ENCRYPT:: Encrypting a message.
* GPGSM DECRYPT:: Decrypting a message.
* GPGSM SIGN:: Signing a message.
* GPGSM VERIFY:: Verifying a message.
* GPGSM GENKEY:: Generating a key.
* GPGSM LISTKEYS:: List available keys.
* GPGSM EXPORT:: Export certificates.
* GPGSM IMPORT:: Import certificates.
* GPGSM DELETE:: Delete certificates.
* GPGSM GETAUDITLOG:: Retrieve an audit log.
* GPGSM GETINFO:: Information about the process
* GPGSM OPTION:: Session options.

File: gnupg.info, Node: GPGSM ENCRYPT, Next: GPGSM DECRYPT, Up: GPGSM Protocol
5.6.1 Encrypting a Message
--------------------------
Before encryption can be done the recipient must be set using the
command:
RECIPIENT USERID
Set the recipient for the encryption. USERID should be the internal
representation of the key; the server may accept any other way of
specification. If this is a valid and trusted recipient the server does
respond with OK, otherwise the return is an ERR with the reason why the
recipient cannot be used, the encryption will then not be done for this
recipient. If the policy is not to encrypt at all if not all recipients
are valid, the client has to take care of this. All 'RECIPIENT'
commands are cumulative until a 'RESET' or an successful 'ENCRYPT'
command.
INPUT FD[=N] [--armor|--base64|--binary]
Set the file descriptor for the message to be encrypted to N.
Obviously the pipe must be open at that point, the server establishes
its own end. If the server returns an error the client should consider
this session failed. If N is not given, this commands uses the last
file descriptor passed to the application. *Note the assuan_sendfd
function: (assuan)fun-assuan_sendfd, on how to do descriptor passing.
The '--armor' option may be used to advice the server that the input
data is in PEM format, '--base64' advices that a raw base-64 encoding is
used, '--binary' advices of raw binary input (BER). If none of these
options is used, the server tries to figure out the used encoding, but
this may not always be correct.
OUTPUT FD[=N] [--armor|--base64]
Set the file descriptor to be used for the output (i.e. the
encrypted message). Obviously the pipe must be open at that point, the
server establishes its own end. If the server returns an error the
client should consider this session failed.
The option '--armor' encodes the output in PEM format, the '--base64'
option applies just a base-64 encoding. No option creates binary output
(BER).
The actual encryption is done using the command
ENCRYPT
It takes the plaintext from the 'INPUT' command, writes to the
ciphertext to the file descriptor set with the 'OUTPUT' command, take
the recipients from all the recipients set so far. If this command
fails the clients should try to delete all output currently done or
otherwise mark it as invalid. 'GPGSM' does ensure that there will not
be any security problem with leftover data on the output in this case.
This command should in general not fail, as all necessary checks have
been done while setting the recipients. The input and output pipes are
closed.

File: gnupg.info, Node: GPGSM DECRYPT, Next: GPGSM SIGN, Prev: GPGSM ENCRYPT, Up: GPGSM Protocol
5.6.2 Decrypting a message
--------------------------
Input and output FDs are set the same way as in encryption, but 'INPUT'
refers to the ciphertext and 'OUTPUT' to the plaintext. There is no
need to set recipients. 'GPGSM' automatically strips any S/MIME headers
from the input, so it is valid to pass an entire MIME part to the INPUT
pipe.
The decryption is done by using the command
DECRYPT
It performs the decrypt operation after doing some check on the
internal state (e.g. that all needed data has been set). Because it
utilizes the GPG-Agent for the session key decryption, there is no need
to ask the client for a protecting passphrase - GpgAgent takes care of
this by requesting this from the user.

File: gnupg.info, Node: GPGSM SIGN, Next: GPGSM VERIFY, Prev: GPGSM DECRYPT, Up: GPGSM Protocol
5.6.3 Signing a Message
-----------------------
Signing is usually done with these commands:
INPUT FD[=N] [--armor|--base64|--binary]
This tells 'GPGSM' to read the data to sign from file descriptor N.
OUTPUT FD[=M] [--armor|--base64]
Write the output to file descriptor M. If a detached signature is
requested, only the signature is written.
SIGN [--detached]
Sign the data set with the 'INPUT' command and write it to the sink
set by 'OUTPUT'. With '--detached', a detached signature is created
(surprise).
The key used for signing is the default one or the one specified in
the configuration file. To get finer control over the keys, it is
possible to use the command
SIGNER USERID
to set the signer's key. USERID should be the internal
representation of the key; the server may accept any other way of
specification. If this is a valid and trusted recipient the server does
respond with OK, otherwise the return is an ERR with the reason why the
key cannot be used, the signature will then not be created using this
key. If the policy is not to sign at all if not all keys are valid, the
client has to take care of this. All 'SIGNER' commands are cumulative
until a 'RESET' is done. Note that a 'SIGN' does not reset this list of
signers which is in contrast to the 'RECIPIENT' command.

File: gnupg.info, Node: GPGSM VERIFY, Next: GPGSM GENKEY, Prev: GPGSM SIGN, Up: GPGSM Protocol
5.6.4 Verifying a Message
-------------------------
To verify a message the command:
VERIFY
is used. It does a verify operation on the message send to the input
FD. The result is written out using status lines. If an output FD was
given, the signed text will be written to that. If the signature is a
detached one, the server will inquire about the signed material and the
client must provide it.

File: gnupg.info, Node: GPGSM GENKEY, Next: GPGSM LISTKEYS, Prev: GPGSM VERIFY, Up: GPGSM Protocol
5.6.5 Generating a Key
----------------------
This is used to generate a new keypair, store the secret part in the PSE
and the public key in the key database. We will probably add optional
commands to allow the client to select whether a hardware token is used
to store the key. Configuration options to 'GPGSM' can be used to
restrict the use of this command.
GENKEY
'GPGSM' checks whether this command is allowed and then does an
INQUIRY to get the key parameters, the client should then send the key
parameters in the native format:
S: INQUIRE KEY_PARAM native
C: D foo:fgfgfg
C: D bar
C: END
Please note that the server may send Status info lines while reading
the data lines from the client. After this the key generation takes
place and the server eventually does send an ERR or OK response. Status
lines may be issued as a progress indicator.

File: gnupg.info, Node: GPGSM LISTKEYS, Next: GPGSM EXPORT, Prev: GPGSM GENKEY, Up: GPGSM Protocol
5.6.6 List available keys
-------------------------
To list the keys in the internal database or using an external key
provider, the command:
LISTKEYS PATTERN
is used. To allow multiple patterns (which are ORed during the
search) quoting is required: Spaces are to be translated into "+" or
into "%20"; in turn this requires that the usual escape quoting rules
are done.
LISTSECRETKEYS PATTERN
Lists only the keys where a secret key is available.
The list commands are affected by the option
OPTION list-mode=MODE
where mode may be:
'0'
Use default (which is usually the same as 1).
'1'
List only the internal keys.
'2'
List only the external keys.
'3'
List internal and external keys.
Note that options are valid for the entire session.

File: gnupg.info, Node: GPGSM EXPORT, Next: GPGSM IMPORT, Prev: GPGSM LISTKEYS, Up: GPGSM Protocol
5.6.7 Export certificates
-------------------------
To export certificate from the internal key database the command:
EXPORT [--data [--armor] [--base64]] [--] PATTERN
is used. To allow multiple patterns (which are ORed) quoting is
required: Spaces are to be translated into "+" or into "%20"; in turn
this requires that the usual escape quoting rules are done.
If the '--data' option has not been given, the format of the output
depends on what was set with the 'OUTPUT' command. When using PEM
encoding a few informational lines are prepended.
If the '--data' has been given, a target set via 'OUTPUT' is ignored
and the data is returned inline using standard 'D'-lines. This avoids
the need for an extra file descriptor. In this case the options
'--armor' and '--base64' may be used in the same way as with the
'OUTPUT' command.

File: gnupg.info, Node: GPGSM IMPORT, Next: GPGSM DELETE, Prev: GPGSM EXPORT, Up: GPGSM Protocol
5.6.8 Import certificates
-------------------------
To import certificates into the internal key database, the command
IMPORT [--re-import]
is used. The data is expected on the file descriptor set with the
'INPUT' command. Certain checks are performed on the certificate. Note
that the code will also handle PKCS#12 files and import private keys; a
helper program is used for that.
With the option '--re-import' the input data is expected to a be a
linefeed separated list of fingerprints. The command will re-import the
corresponding certificates; that is they are made permanent by removing
their ephemeral flag.

File: gnupg.info, Node: GPGSM DELETE, Next: GPGSM GETAUDITLOG, Prev: GPGSM IMPORT, Up: GPGSM Protocol
5.6.9 Delete certificates
-------------------------
To delete a certificate the command
DELKEYS PATTERN
is used. To allow multiple patterns (which are ORed) quoting is
required: Spaces are to be translated into "+" or into "%20"; in turn
this requires that the usual escape quoting rules are done.
The certificates must be specified unambiguously otherwise an error
is returned.

File: gnupg.info, Node: GPGSM GETAUDITLOG, Next: GPGSM GETINFO, Prev: GPGSM DELETE, Up: GPGSM Protocol
5.6.10 Retrieve an audit log
----------------------------
This command is used to retrieve an audit log.
GETAUDITLOG [--data] [--html]
If '--data' is used, the audit log is send using D-lines instead of
being sent to the file descriptor given by an 'OUTPUT' command. If
'--html' is used, the output is formatted as an XHTML block. This is
designed to be incorporated into a HTML document.

File: gnupg.info, Node: GPGSM GETINFO, Next: GPGSM OPTION, Prev: GPGSM GETAUDITLOG, Up: GPGSM Protocol
5.6.11 Return information about the process
-------------------------------------------
This is a multipurpose function to return a variety of information.
GETINFO WHAT
The value of WHAT specifies the kind of information returned:
'version'
Return the version of the program.
'pid'
Return the process id of the process.
'agent-check'
Return OK if the agent is running.
'cmd_has_option CMD OPT'
Return OK if the command CMD implements the option OPT. The
leading two dashes usually used with OPT shall not be given.
'offline'
Return OK if the connection is in offline mode. This may be either
due to a 'OPTION offline=1' or due to 'gpgsm' being started with
option '--disable-dirmngr'.

File: gnupg.info, Node: GPGSM OPTION, Prev: GPGSM GETINFO, Up: GPGSM Protocol
5.6.12 Session options
----------------------
The standard Assuan option handler supports these options.
OPTION NAME[=VALUE]
These NAMEs are recognized:
'putenv'
Change the session's environment to be passed via gpg-agent to
Pinentry. VALUE is a string of the form '<KEY>[=[<STRING>]]'. If
only '<KEY>' is given the environment variable '<KEY>' is removed
from the session environment, if '<KEY>=' is given that environment
variable is set to the empty string, and if '<STRING>' is given it
is set to that string.
'display'
Set the session environment variable 'DISPLAY' is set to VALUE.
'ttyname'
Set the session environment variable 'GPG_TTY' is set to VALUE.
'ttytype'
Set the session environment variable 'TERM' is set to VALUE.
'lc-ctype'
Set the session environment variable 'LC_CTYPE' is set to VALUE.
'lc-messages'
Set the session environment variable 'LC_MESSAGES' is set to VALUE.
'xauthority'
Set the session environment variable 'XAUTHORITY' is set to VALUE.
'pinentry-user-data'
Set the session environment variable 'PINENTRY_USER_DATA' is set to
VALUE.
'include-certs'
This option overrides the command line option '--include-certs'. A
VALUE of -2 includes all certificates except for the root
certificate, -1 includes all certificates, 0 does not include any
certificates, 1 includes only the signers certificate and all other
positive values include up to VALUE certificates starting with the
signer cert.
'list-mode'
*Note gpgsm-cmd listkeys::.
'list-to-output'
If VALUE is true the output of the list commands (*note gpgsm-cmd
listkeys::) is written to the file descriptor set with the last
'OUTPUT' command. If VALUE is false the output is written via data
lines; this is the default.
'with-validation'
If VALUE is true for each listed certificate the validation status
is printed. This may result in the download of a CRL or the user
being asked about the trustworthiness of a root certificate. The
default is given by a command line option (*note gpgsm-option
--with-validation::).
'with-secret'
If VALUE is true certificates with a corresponding private key are
marked by the list commands.
'validation-model'
This option overrides the command line option 'validation-model'
for the session. (*Note gpgsm-option --validation-model::.)
'with-key-data'
This option globally enables the command line option
'--with-key-data'. (*Note gpgsm-option --with-key-data::.)
'enable-audit-log'
If VALUE is true data to write an audit log is gathered. (*Note
gpgsm-cmd getauditlog::.)
'allow-pinentry-notify'
If this option is used notifications about the launch of a Pinentry
are passed back to the client.
'with-ephemeral-keys'
If VALUE is true ephemeral certificates are included in the output
of the list commands.
'no-encrypt-to'
If this option is used all keys set by the command line option
'--encrypt-to' are ignored.
'offline'
If VALUE is true or VALUE is not given all network access is
disabled for this session. This is the same as the command line
option '--disable-dirmngr'.