| /* Copyright (c) 2013 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| * |
| * Utility functions that need to be built as part of the firmware. |
| */ |
| |
| #include "sysincludes.h" |
| |
| #include "utility.h" |
| |
| int SafeMemcmp(const void *s1, const void *s2, size_t n) { |
| const unsigned char *us1 = s1; |
| const unsigned char *us2 = s2; |
| int result = 0; |
| |
| if (0 == n) |
| return 0; |
| |
| /* |
| * Code snippet without data-dependent branch due to Nate Lawson |
| * (nate@root.org) of Root Labs. |
| */ |
| while (n--) |
| result |= *us1++ ^ *us2++; |
| |
| return result != 0; |
| } |