crypto: af_alg - Allow arbitrarily long algorithm names

This patch removes the hard-coded 64-byte limit on the length
of the algorithm name through bind(2).  The address length can
now exceed that.  The user-space structure remains unchanged.
In order to use a longer name simply extend the salg_name array
beyond its defined 64 bytes length.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/af_alg.c

@@ -160,11 +160,11 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	if (sock->state == SS_CONNECTED)
 		return -EINVAL;
 
-	if (addr_len != sizeof(*sa))
+	if (addr_len < sizeof(*sa))
 		return -EINVAL;
 
 	sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
-	sa->salg_name[sizeof(sa->salg_name) - 1] = 0;
+	sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;
 
 	type = alg_get_type(sa->salg_type);
 	if (IS_ERR(type) && PTR_ERR(type) == -ENOENT) {