From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Tue, 4 Apr 2017 13:53:05 +0000 (+0200)
Subject: _gnutls_x509_write_uint32: ensure we prepend leading zero when writing
X-Git-Tag: gnutls_3_6_0~695
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a2cf89a42aff91e009ca024d24bee33970c37103;p=thirdparty%2Fgnutls.git

_gnutls_x509_write_uint32: ensure we prepend leading zero when writing

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>
---

diff --git a/lib/x509/mpi.c b/lib/x509/mpi.c
index 2e7cdc2802..2bb3e54aaa 100644
--- a/lib/x509/mpi.c
+++ b/lib/x509/mpi.c
@@ -28,6 +28,7 @@
 #include "common.h"
 #include "x509_int.h"
 #include <num.h>
+#include <limits.h>
 
 /* Reads an Integer from the DER encoded data
  */
@@ -319,12 +320,17 @@ _gnutls_x509_read_uint(ASN1_TYPE node, const char *value,
 int
 _gnutls_x509_write_uint32(ASN1_TYPE node, const char *value, uint32_t num)
 {
-	uint8_t tmpstr[4];
+	uint8_t tmpstr[5];
 	int result;
 
-	_gnutls_write_uint32(num, tmpstr);
+	tmpstr[0] = 0;
+	_gnutls_write_uint32(num, tmpstr+1);
 
-	result = asn1_write_value(node, value, tmpstr, 4);
+	if (tmpstr[1] > SCHAR_MAX) {
+		result = asn1_write_value(node, value, tmpstr, 5);
+	} else {
+		result = asn1_write_value(node, value, tmpstr+1, 4);
+	}
 
 	if (result != ASN1_SUCCESS) {
 		gnutls_assert();