From 8824c6144c73fe4b6355df6dfaee3e80e068c3b1 Mon Sep 17 00:00:00 2001
From: Hao Wu <hao.a.wu@intel.com>
Date: Fri, 1 Jul 2016 15:12:40 +0800
Subject: [PATCH] CryptoPkg BaseCryptLib: Avoid passing NULL ptr to function
 BN_bn2bin()

This commit modifies the code logic to avoid passing NULL pointer to
function BN_bn2bin().

Cc: Long Qin <qin.long@intel.com>
Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Qin Long <qin.long@intel.com>
---
 CryptoPkg/Library/BaseCryptLib/Pk/CryptDh.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptDh.c b/CryptoPkg/Library/BaseCryptLib/Pk/CryptDh.c
index 9cbf182c70..5e0447b488 100644
--- a/CryptoPkg/Library/BaseCryptLib/Pk/CryptDh.c
+++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptDh.c
@@ -1,7 +1,7 @@
 /** @file
   Diffie-Hellman Wrapper Implementation over OpenSSL.
 
-Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2010 - 2016, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -246,7 +246,11 @@ DhGenerateKey (
   RetVal = (BOOLEAN) DH_generate_key (DhContext);
   if (RetVal) {
     Size = BN_num_bytes (Dh->pub_key);
-    if ((Size > 0) && (*PublicKeySize < (UINTN) Size)) {
+    if (Size <= 0) {
+      *PublicKeySize = 0;
+      return FALSE;
+    }
+    if (*PublicKeySize < (UINTN) Size) {
       *PublicKeySize = Size;
       return FALSE;
     }
-- 
2.39.2