From f2dc4d517fa11208b90ba0e92a2590f8cfdafb28 Mon Sep 17 00:00:00 2001
From: "Dr. Stephen Henson" <steve@openssl.org>
Date: Fri, 12 Jun 2015 22:18:36 +0100
Subject: [PATCH] Encode b == NULL or blen == 0 as zero.

PR#3904

Reviewed-by: Rich Salz <rsalz@openssl.org>
---
 crypto/asn1/a_int.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crypto/asn1/a_int.c b/crypto/asn1/a_int.c
index 9a58378b8a..0d020e0c13 100644
--- a/crypto/asn1/a_int.c
+++ b/crypto/asn1/a_int.c
@@ -158,8 +158,8 @@ static size_t i2c_ibuf(const unsigned char *b, size_t blen, int neg,
 
     if (pad)
         *(p++) = pb;
-    if (blen == 0)
-        *(p++) = 0;
+    if (b == NULL || blen == 0)
+        *p = 0;
     else if (!neg)
         memcpy(p, b, blen);
     else {
-- 
2.40.0