1 /* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 *
5 * Utility functions that need to be built as part of the firmware.
6 */
7
8 #include "sysincludes.h"
9
10 #include "utility.h"
11
SafeMemcmp(const void * s1,const void * s2,size_t n)12 int SafeMemcmp(const void *s1, const void *s2, size_t n) {
13 const unsigned char *us1 = s1;
14 const unsigned char *us2 = s2;
15 int result = 0;
16
17 if (0 == n)
18 return 0;
19
20 /*
21 * Code snippet without data-dependent branch due to Nate Lawson
22 * (nate@root.org) of Root Labs.
23 */
24 while (n--)
25 result |= *us1++ ^ *us2++;
26
27 return result != 0;
28 }
29