tree 0db5cee0ddb99cfe1cbd7f8314653f36ddf5005f
parent 80eae209d63ac6361c7b445f7e7e41f39c044772
author Mimi Zohar <zohar@linux.vnet.ibm.com> 1447162486 -0500
committer Mimi Zohar <zohar@linux.vnet.ibm.com> 1450191703 -0500

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>