KEYS: Add a key type op to permit the key description to be vetted

Add a key type operation to permit the key type to vet the description of a new
key that key_alloc() is about to allocate.  The operation may reject the
description if it wishes with an error of its choosing.  If it does this, the
key will not be allocated.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/key-type.h b/include/linux/key-type.h
index 65833d4d5998..fc8525e838b7 100644
--- a/include/linux/key-type.h
+++ b/include/linux/key-type.h
@@ -41,6 +41,9 @@ struct key_type {
          */
         size_t def_datalen;
 
+        /* vet a description */
+        int (*vet_description)(const char *description);
+
         /* instantiate a key of this type
          * - this method should call key_payload_reserve() to determine if the
          *   user's quota will hold the payload