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, 7 insertions, 0 deletions

diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index e4dbbdb..cf68d1f 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -1062,6 +1062,13 @@ The structure has a number of fields, some of which are mandatory:
      viable.
 
 
+ (*) int (*vet_description)(const char *description);
+
+     This optional method is called to vet a key description.  If the key type
+     doesn't approve of the key description, it may return an error, otherwise
+     it should return 0.
+
+
  (*) int (*instantiate)(struct key *key, const void *data, size_t datalen);
 
      This method is called to attach a payload to a key during construction.