[PATCH] Keys: Add LSM hooks for key management [try #3]

The attached patch adds LSM hooks for key management facilities. The notable
changes are:

 (1) The key struct now supports a security pointer for the use of security
     modules. This will permit key labelling and restrictions on which
     programs may access a key.

 (2) Security modules get a chance to note (or abort) the allocation of a key.

 (3) The key permission checking can now be enhanced by the security modules;
     the permissions check consults LSM if all other checks bear out.

 (4) The key permissions checking functions now return an error code rather
     than a boolean value.

 (5) An extra permission has been added to govern the modification of
     attributes (UID, GID, permissions).

Note that there isn't an LSM hook specifically for each keyctl() operation,
but rather the permissions hook allows control of individual operations based
on the permission request bits.

Key management access control through LSM is enabled by automatically if both
CONFIG_KEYS and CONFIG_SECURITY are enabled.

This should be applied on top of the patch ensubjected:

	[PATCH] Keys: Possessor permissions should be additive

Signed-Off-By: David Howells <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
David Howells 2005-10-30 15:02:44 -08:00 • committed by Linus Torvalds
commit 29db919063
10 changed files with 191 additions and 49 deletions

View file

@ -196,7 +196,7 @@ KEY ACCESS PERMISSIONS
Keys have an owner user ID, a group access ID, and a permissions mask. The mask
has up to eight bits each for possessor, user, group and other access. Only
five of each set of eight bits are defined. These permissions granted are:
six of each set of eight bits are defined. These permissions granted are:
(*) View
@ -224,6 +224,10 @@ five of each set of eight bits are defined. These permissions granted are:
keyring to a key, a process must have Write permission on the keyring and
Link permission on the key.
(*) Set Attribute
This permits a key's UID, GID and permissions mask to be changed.
For changing the ownership, group ID or permissions mask, being the owner of
the key or having the sysadmin capability is sufficient.
@ -242,15 +246,15 @@ about the status of the key service:
this way:
SERIAL FLAGS USAGE EXPY PERM UID GID TYPE DESCRIPTION: SUMMARY
00000001 I----- 39 perm 1f1f0000 0 0 keyring _uid_ses.0: 1/4
00000002 I----- 2 perm 1f1f0000 0 0 keyring _uid.0: empty
00000007 I----- 1 perm 1f1f0000 0 0 keyring _pid.1: empty
0000018d I----- 1 perm 1f1f0000 0 0 keyring _pid.412: empty
000004d2 I--Q-- 1 perm 1f1f0000 32 -1 keyring _uid.32: 1/4
000004d3 I--Q-- 3 perm 1f1f0000 32 -1 keyring _uid_ses.32: empty
00000001 I----- 39 perm 1f3f0000 0 0 keyring _uid_ses.0: 1/4
00000002 I----- 2 perm 1f3f0000 0 0 keyring _uid.0: empty
00000007 I----- 1 perm 1f3f0000 0 0 keyring _pid.1: empty
0000018d I----- 1 perm 1f3f0000 0 0 keyring _pid.412: empty
000004d2 I--Q-- 1 perm 1f3f0000 32 -1 keyring _uid.32: 1/4
000004d3 I--Q-- 3 perm 1f3f0000 32 -1 keyring _uid_ses.32: empty
00000892 I--QU- 1 perm 1f000000 0 0 user metal:copper: 0
00000893 I--Q-N 1 35s 1f1f0000 0 0 user metal:silver: 0
00000894 I--Q-- 1 10h 001f0000 0 0 user metal:gold: 0
00000893 I--Q-N 1 35s 1f3f0000 0 0 user metal:silver: 0
00000894 I--Q-- 1 10h 003f0000 0 0 user metal:gold: 0
The flags are: