tree 662839ffc98b691fe598cef81a1bab0c2b123ccd
parent 0620fddb56dfaf0e1034eeb69d79c73b361debbf
author Eric Biggers <ebiggers@google.com> 1496929774 +0100
committer James Morris <james.l.morris@oracle.com> 1496978989 +1000

KEYS: DH: forbid using digest_null as the KDF hash

Requesting "digest_null" in the keyctl_kdf_params caused an infinite
loop in kdf_ctr() because the "null" hash has a digest size of 0.  Fix
it by rejecting hash algorithms with a digest size of 0.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: James Morris <james.l.morris@oracle.com>