Encode b == NULL or blen == 0 as zero.

PR#3904

Reviewed-by: Rich Salz <rsalz@openssl.org>

diff --git a/crypto/asn1/a_int.c b/crypto/asn1/a_int.c
index 9a58378b8a61132f02d34870b029ed511d65a1c6..0d020e0c13031b440588e6a304685c61693bffc5 100644 (file)
--- 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 {