mirror of https://gitee.com/openkylin/linux.git
digsig.txt: standardize document format
Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - comment the internal index; - use the proper markups for titles; - mark literal blocks. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Mauro Carvalho Chehab
Jonathan Corbet
parent
7effa5b0e8
commit
a2fbbcea7b
|
|
@ -1,13 +1,20 @@
|
|||
==================================
|
||||
Digital Signature Verification API
|
||||
==================================
|
||||
|
||||
CONTENTS
|
||||
|
||||
1. Introduction
|
||||
2. API
|
||||
3. User-space utilities
|
||||
:Author: Dmitry Kasatkin
|
||||
:Date: 06.10.2011
|
||||
|
||||
|
||||
1. Introduction
|
||||
.. CONTENTS
|
||||
|
||||
1. Introduction
|
||||
2. API
|
||||
3. User-space utilities
|
||||
|
||||
|
||||
Introduction
|
||||
============
|
||||
|
||||
Digital signature verification API provides a method to verify digital signature.
|
||||
Currently digital signatures are used by the IMA/EVM integrity protection subsystem.
|
||||
|
|
@ -17,25 +24,25 @@ GnuPG multi-precision integers (MPI) library. The kernel port provides
|
|||
memory allocation errors handling, has been refactored according to kernel
|
||||
coding style, and checkpatch.pl reported errors and warnings have been fixed.
|
||||
|
||||
Public key and signature consist of header and MPIs.
|
||||
Public key and signature consist of header and MPIs::
|
||||
|
||||
struct pubkey_hdr {
|
||||
uint8_t version; /* key format version */
|
||||
time_t timestamp; /* key made, always 0 for now */
|
||||
uint8_t algo;
|
||||
uint8_t nmpi;
|
||||
char mpi[0];
|
||||
} __packed;
|
||||
struct pubkey_hdr {
|
||||
uint8_t version; /* key format version */
|
||||
time_t timestamp; /* key made, always 0 for now */
|
||||
uint8_t algo;
|
||||
uint8_t nmpi;
|
||||
char mpi[0];
|
||||
} __packed;
|
||||
|
||||
struct signature_hdr {
|
||||
uint8_t version; /* signature format version */
|
||||
time_t timestamp; /* signature made */
|
||||
uint8_t algo;
|
||||
uint8_t hash;
|
||||
uint8_t keyid[8];
|
||||
uint8_t nmpi;
|
||||
char mpi[0];
|
||||
} __packed;
|
||||
struct signature_hdr {
|
||||
uint8_t version; /* signature format version */
|
||||
time_t timestamp; /* signature made */
|
||||
uint8_t algo;
|
||||
uint8_t hash;
|
||||
uint8_t keyid[8];
|
||||
uint8_t nmpi;
|
||||
char mpi[0];
|
||||
} __packed;
|
||||
|
||||
keyid equals to SHA1[12-19] over the total key content.
|
||||
Signature header is used as an input to generate a signature.
|
||||
|
|
@ -43,31 +50,33 @@ Such approach insures that key or signature header could not be changed.
|
|||
It protects timestamp from been changed and can be used for rollback
|
||||
protection.
|
||||
|
||||
2. API
|
||||
API
|
||||
===
|
||||
|
||||
API currently includes only 1 function:
|
||||
API currently includes only 1 function::
|
||||
|
||||
digsig_verify() - digital signature verification with public key
|
||||
|
||||
|
||||
/**
|
||||
* digsig_verify() - digital signature verification with public key
|
||||
* @keyring: keyring to search key in
|
||||
* @sig: digital signature
|
||||
* @sigen: length of the signature
|
||||
* @data: data
|
||||
* @datalen: length of the data
|
||||
* @return: 0 on success, -EINVAL otherwise
|
||||
*
|
||||
* Verifies data integrity against digital signature.
|
||||
* Currently only RSA is supported.
|
||||
* Normally hash of the content is used as a data for this function.
|
||||
*
|
||||
*/
|
||||
int digsig_verify(struct key *keyring, const char *sig, int siglen,
|
||||
const char *data, int datalen);
|
||||
/**
|
||||
* digsig_verify() - digital signature verification with public key
|
||||
* @keyring: keyring to search key in
|
||||
* @sig: digital signature
|
||||
* @sigen: length of the signature
|
||||
* @data: data
|
||||
* @datalen: length of the data
|
||||
* @return: 0 on success, -EINVAL otherwise
|
||||
*
|
||||
* Verifies data integrity against digital signature.
|
||||
* Currently only RSA is supported.
|
||||
* Normally hash of the content is used as a data for this function.
|
||||
*
|
||||
*/
|
||||
int digsig_verify(struct key *keyring, const char *sig, int siglen,
|
||||
const char *data, int datalen);
|
||||
|
||||
3. User-space utilities
|
||||
User-space utilities
|
||||
====================
|
||||
|
||||
The signing and key management utilities evm-utils provide functionality
|
||||
to generate signatures, to load keys into the kernel keyring.
|
||||
|
|
@ -75,22 +84,18 @@ Keys can be in PEM or converted to the kernel format.
|
|||
When the key is added to the kernel keyring, the keyid defines the name
|
||||
of the key: 5D2B05FC633EE3E8 in the example bellow.
|
||||
|
||||
Here is example output of the keyctl utility.
|
||||
Here is example output of the keyctl utility::
|
||||
|
||||
$ keyctl show
|
||||
Session Keyring
|
||||
-3 --alswrv 0 0 keyring: _ses
|
||||
603976250 --alswrv 0 -1 \_ keyring: _uid.0
|
||||
817777377 --alswrv 0 0 \_ user: kmk
|
||||
891974900 --alswrv 0 0 \_ encrypted: evm-key
|
||||
170323636 --alswrv 0 0 \_ keyring: _module
|
||||
548221616 --alswrv 0 0 \_ keyring: _ima
|
||||
128198054 --alswrv 0 0 \_ keyring: _evm
|
||||
$ keyctl show
|
||||
Session Keyring
|
||||
-3 --alswrv 0 0 keyring: _ses
|
||||
603976250 --alswrv 0 -1 \_ keyring: _uid.0
|
||||
817777377 --alswrv 0 0 \_ user: kmk
|
||||
891974900 --alswrv 0 0 \_ encrypted: evm-key
|
||||
170323636 --alswrv 0 0 \_ keyring: _module
|
||||
548221616 --alswrv 0 0 \_ keyring: _ima
|
||||
128198054 --alswrv 0 0 \_ keyring: _evm
|
||||
|
||||
$ keyctl list 128198054
|
||||
1 key in keyring:
|
||||
620789745: --alswrv 0 0 user: 5D2B05FC633EE3E8
|
||||
|
||||
|
||||
Dmitry Kasatkin
|
||||
06.10.2011
|
||||
$ keyctl list 128198054
|
||||
1 key in keyring:
|
||||
620789745: --alswrv 0 0 user: 5D2B05FC633EE3E8
|
||||
|
|
|
|||
Loading…
Reference in New Issue