1 | /* |
2 | * cc_cmp_safe.c |
3 | * corecrypto |
4 | * |
5 | * Created on 04/22/2014 |
6 | * |
7 | * Copyright (c) 2014,2015 Apple Inc. All rights reserved. |
8 | * |
9 | * |
10 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
11 | * |
12 | * This file contains Original Code and/or Modifications of Original Code |
13 | * as defined in and that are subject to the Apple Public Source License |
14 | * Version 2.0 (the 'License'). You may not use this file except in |
15 | * compliance with the License. The rights granted to you under the License |
16 | * may not be used to create, or enable the creation or redistribution of, |
17 | * unlawful or unlicensed copies of an Apple operating system, or to |
18 | * circumvent, violate, or enable the circumvention or violation of, any |
19 | * terms of an Apple operating system software license agreement. |
20 | * |
21 | * Please obtain a copy of the License at |
22 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
23 | * |
24 | * The Original Code and all software distributed under the License are |
25 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
26 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
27 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
28 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
29 | * Please see the License for the specific language governing rights and |
30 | * limitations under the License. |
31 | * |
32 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
33 | */ |
34 | |
35 | #include <corecrypto/cc_priv.h> |
36 | |
37 | int cc_cmp_safe (size_t num, const void * ptr1, const void * ptr2) |
38 | { |
39 | size_t i; |
40 | const uint8_t *s=(const uint8_t *)ptr1; |
41 | const uint8_t *t=(const uint8_t *)ptr2; |
42 | uint8_t flag=((num<=0)?1:0); // If 0 return an error |
43 | for (i=0;i<num;i++) |
44 | { |
45 | flag|=(s[i]^t[i]); |
46 | } |
47 | HEAVISIDE_STEP_UINT8(flag,flag); // flag=(flag==0)?0:1; |
48 | return flag; // 0 iff all bytes were equal, 1 if there is any difference |
49 | } |
50 | |