KEYS: prevent keys from being removed from specified keyrings

Userspace should not be allowed to remove keys from certain keyrings
(eg. blacklist), though the keys themselves can expire.

This patch defines a new key flag named KEY_FLAG_KEEP to prevent
userspace from being able to unlink, revoke, invalidate or timed
out a key on a keyring.  When this flag is set on the keyring, all
keys subsequently added are flagged.

In addition, when this flag is set, the keyring itself can not be
cleared.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
This commit is contained in:
Mimi Zohar
2015-11-10 08:34:46 -05:00
parent 80eae209d6
commit d3600bcf9d
3 changed files with 52 additions and 11 deletions

View File

@@ -177,6 +177,7 @@ struct key {
#define KEY_FLAG_TRUSTED_ONLY 9 /* set if keyring only accepts links to trusted keys */
#define KEY_FLAG_BUILTIN 10 /* set if key is builtin */
#define KEY_FLAG_ROOT_CAN_INVAL 11 /* set if key can be invalidated by root without permission */
#define KEY_FLAG_KEEP 12 /* set if key should not be removed */
/* the key type and key description string
* - the desc is used to match a key against search criteria