crypto: s390 - Forbid 2-key 3DES in FIPS mode

This patch forbids the use of 2-key 3DES (K1 == K3) in FIPS mode.

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

arch/s390/crypto/des_s390.c

@@ -224,24 +224,11 @@ static int des3_setkey(struct crypto_tfm *tfm, const u8 *key,
 		       unsigned int key_len)
 {
 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
+	int err;
 
-	if (!(crypto_memneq(key, &key[DES_KEY_SIZE], DES_KEY_SIZE) &&
-	    crypto_memneq(&key[DES_KEY_SIZE], &key[DES_KEY_SIZE * 2],
-			  DES_KEY_SIZE)) &&
-	    (tfm->crt_flags & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)) {
-		tfm->crt_flags |= CRYPTO_TFM_RES_WEAK_KEY;
-		return -EINVAL;
-	}
-
-	/* in fips mode, ensure k1 != k2 and k2 != k3 and k1 != k3 */
-	if (fips_enabled &&
-	    !(crypto_memneq(key, &key[DES_KEY_SIZE], DES_KEY_SIZE) &&
-	      crypto_memneq(&key[DES_KEY_SIZE], &key[DES_KEY_SIZE * 2],
-			    DES_KEY_SIZE) &&
-	      crypto_memneq(key, &key[DES_KEY_SIZE * 2], DES_KEY_SIZE))) {
-		tfm->crt_flags |= CRYPTO_TFM_RES_WEAK_KEY;
-		return -EINVAL;
-	}
+	err = __des3_verify_key(&tfm->crt_flags, key);
+	if (unlikely(err))
+		return err;
 
 	memcpy(ctx->key, key, key_len);
 	return 0;