KEYS: fix "ca_keys=" partial key matching

The call to asymmetric_key_hex_to_key_id() from ca_keys_setup()
silently fails with -ENOMEM.  Instead of dynamically allocating
memory from a __setup function, this patch defines a variable
and calls __asymmetric_key_hex_to_key_id(), a new helper function,
directly.

This bug was introduced by 'commit 517fcc6309ae ("KEYS: Overhaul
key identification when searching for asymmetric keys")'.

Changelog:
- for clarification, rename hexlen to asciihexlen in
  asymmetric_key_hex_to_key_id()
- add size argument to __asymmetric_key_hex_to_key_id() - David Howells
- inline __asymmetric_key_hex_to_key_id() - David Howells
- remove duplicate strlen() calls

Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.18

1 files changed, 3 insertions, 0 deletions

diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h
index f9733088..3f5b537a 100644
--- a/crypto/asymmetric_keys/asymmetric_keys.h
+++ b/crypto/asymmetric_keys/asymmetric_keys.h
@@ -11,6 +11,9 @@
 
 extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id);
 
+extern int __asymmetric_key_hex_to_key_id(const char *id,
+					  struct asymmetric_key_id *match_id,
+					  size_t hexlen);
 static inline
 const struct asymmetric_key_ids *asymmetric_key_ids(const struct key *key)
 {