[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 <dhowells@redhat.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/key-ui.h b/include/linux/key-ui.h
index 7a2e332..e8b8a7a 100644
--- a/include/linux/key-ui.h
+++ b/include/linux/key-ui.h
@@ -24,7 +24,8 @@ extern spinlock_t key_serial_lock;
 #define	KEY_WRITE	0x04	/* require permission to update / modify */
 #define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
 #define	KEY_LINK	0x10	/* require permission to link */
-#define	KEY_ALL		0x1f	/* all the above permissions */
+#define	KEY_SETATTR	0x20	/* require permission to change attributes */
+#define	KEY_ALL		0x3f	/* all the above permissions */
 
 /*
  * the keyring payload contains a list of the keys to which the keyring is