Add the following:
(1) A new system keyring that is used to store information about
blacklisted certificates and signatures.
(2) A new key type (called 'blacklist') that is used to store a
blacklisted hash in its description as a hex string. The key accepts
no payload.
(3) The ability to configure a list of blacklisted hashes into the kernel
at build time. This is done by setting
CONFIG_SYSTEM_BLACKLIST_HASH_LIST to the filename of a list of hashes
that are in the form:
"<hash>", "<hash>", ..., "<hash>"
where each <hash> is a hex string representation of the hash and must
include all necessary leading zeros to pad the hash to the right size.
The above are enabled with CONFIG_SYSTEM_BLACKLIST_KEYRING.
Once the kernel is booted, the blacklist keyring can be listed:
root@andromeda ~]# keyctl show %:.blacklist
Keyring
723359729 ---lswrv 0 0 keyring: .blacklist
676257228 ---lswrv 0 0 \_ blacklist: 123412341234c55c1dcc601ab8e172917706aa32fb5eaf826813547fdf02dd46
The blacklist cannot currently be modified by userspace, but it will be
possible to load it, for example, from the UEFI blacklist database.
A later commit will make it possible to load blacklisted asymmetric keys in
here too.
Signed-off-by: David Howells <dhowells@redhat.com>
When a user calls 'make -s', we can assume they don't want to
see any output except for warnings and errors, but instead
they see this for a warning free build:
###
### Now generating an X.509 key pair to be used for signing modules.
###
### If this takes a long time, you might wish to run rngd in the
### background to keep the supply of entropy topped up. It
### needs to be run as root, and uses a hardware random
### number generator if one is available.
###
Generating a 4096 bit RSA private key
.................................................................................................................................................................................................................................++
..............................................................................................................................++
writing new private key to 'certs/signing_key.pem'
-----
###
### Key pair generated.
###
The output can confuse simple build testing scripts that just check
for an empty build log.
This patch silences all the output:
- "echo" is changed to "@$(kecho)", which is dropped when "-s" gets
passed
- the openssl command itself is only printed with V=1, using the
$(Q) macro
- The output of openssl gets redirected to /dev/null on "-s" builds.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Since commit 1329e8cc69 ("modsign: Extract signing cert from
CONFIG_MODULE_SIG_KEY if needed"), the build system has carefully coped
with the signing key being specified as a relative path in either the
source or or the build trees.
However, the actual signing of modules has not worked if the filename
is relative to the source tree.
Fix that by moving the config_filename helper into scripts/Kbuild.include
so that it can be used from elsewhere, and then using it in the top-level
Makefile to find the signing key file.
Kill the intermediate $(MODPUBKEY) and $(MODSECKEY) variables too, while
we're at it. There's no need for them.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
We couldn't use if_changed for this before, because it didn't live in
the kernel/ directory so we couldn't add it to $(targets). It was easier
just to leave it as it was.
Now it's in the certs/ directory we can use if_changed, the same as we
do for the trusted certificate list.
Aside from making things consistent, this means we don't need to depend
explicitly on the include/config/module/sig/key.h file. And we also get
to automatically do the right thing and re-extract the cert if the user
does odd things like using a relative filename and then playing silly
buggers with adding/removing that file in both the source and object
trees. We always favour the one in the object tree if it exists, and
now we'll correctly re-extract the cert when it changes. Previously we'd
*only* re-extract the cert if the config option changed, even if the
actual file we're using did change.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Move certificate handling out of the kernel/ directory and into a certs/
directory to get all the weird stuff in one place and move the generated
signing keys into this directory.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
David Howells