crypto: hisilicon/sec2 - fix for aead auth key length

According to the HMAC RFC, the authentication key
can be 0 bytes, and the hardware can handle this
scenario. Therefore, remove the incorrect validation
for this case.

Fixes: 2f072d7 ("crypto: hisilicon - Add aead support on SEC2")
Signed-off-by: Wenkai Lin <[email protected]>
Signed-off-by: Chenghai Huang <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

Author: lin755

drivers/crypto/hisilicon/sec2/sec_crypto.c

@@ -1090,11 +1090,6 @@ static int sec_aead_auth_set_key(struct sec_auth_ctx *ctx,
 	struct crypto_shash *hash_tfm = ctx->hash_tfm;
 	int blocksize, digestsize, ret;
 
-	if (!keys->authkeylen) {
-		pr_err("hisi_sec2: aead auth key error!\n");
-		return -EINVAL;
-	}
-
 	blocksize = crypto_shash_blocksize(hash_tfm);
 	digestsize = crypto_shash_digestsize(hash_tfm);
 	if (keys->authkeylen > blocksize) {
@@ -1106,7 +1101,8 @@ static int sec_aead_auth_set_key(struct sec_auth_ctx *ctx,
 		}
 		ctx->a_key_len = digestsize;
 	} else {
-		memcpy(ctx->a_key, keys->authkey, keys->authkeylen);
+		if (keys->authkeylen)
+			memcpy(ctx->a_key, keys->authkey, keys->authkeylen);
 		ctx->a_key_len = keys->authkeylen;
 	}