From 417ff1b0f2a09b85b5db085e5bb10b2f57ec4d2e Mon Sep 17 00:00:00 2001
From: Takashi Kojo <kojo@wolfssl.com>
Date: Fri, 30 Oct 2020 16:13:37 +0900
Subject: [PATCH] set tag for zero len case

---
 wolfcrypt/src/evp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/wolfcrypt/src/evp.c b/wolfcrypt/src/evp.c
index 363149e61..e84ccf3f9 100644
--- a/wolfcrypt/src/evp.c
+++ b/wolfcrypt/src/evp.c
@@ -770,8 +770,8 @@ int  wolfSSL_EVP_CipherFinal(WOLFSSL_EVP_CIPHER_CTX *ctx,
         case AES_128_GCM_TYPE:
         case AES_192_GCM_TYPE:
         case AES_256_GCM_TYPE:
-            if (ctx->gcmBuffer &&
-                    ctx->gcmBufferLen > 0) {
+            if ((ctx->gcmBuffer && ctx->gcmBufferLen > 0)
+             || (ctx->gcmBuffer == NULL && ctx->gcmBufferLen == 0)) {
                 ret = 0;
                 if (ctx->gcmAuthIn) {
                     /* authenticated, non-confidential data*/