crypto: cryptd - pass through absence of ->setkey()

BugLink: http://bugs.launchpad.net/bugs/1756121

commit 841a3ff3 upstream.

When the cryptd template is used to wrap an unkeyed hash algorithm,
don't install a ->setkey() method to the cryptd instance.  This change
is necessary for cryptd to keep working with unkeyed hash algorithms
once we start enforcing that ->setkey() is called when present.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

crypto/cryptd.c

@@ -654,7 +654,8 @@ static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
 	inst->alg.finup  = cryptd_hash_finup_enqueue;
 	inst->alg.export = cryptd_hash_export;
 	inst->alg.import = cryptd_hash_import;
-	inst->alg.setkey = cryptd_hash_setkey;
+	if (crypto_shash_alg_has_setkey(salg))
+		inst->alg.setkey = cryptd_hash_setkey;
 	inst->alg.digest = cryptd_hash_digest_enqueue;
 
 	err = ahash_register_instance(tmpl, inst);