1 /*
2 * HMAC-SHA-224/256/384/512 implementation
3 * Last update: 06/15/2005
4 * Issue date: 06/15/2005
5 *
6 * Copyright (C) 2005 Olivier Gay <olivier.gay@a3.epfl.ch>
7 * All rights reserved.
8 *
9 * Copyright (c) 2016, Linaro Limited
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the project nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <string.h>
38
39 #include "hmac_sha2.h"
40
41 /* HMAC-SHA-256 functions */
42
hmac_sha256_init(hmac_sha256_ctx * ctx,const unsigned char * key,unsigned int key_size)43 void hmac_sha256_init(hmac_sha256_ctx *ctx, const unsigned char *key,
44 unsigned int key_size)
45 {
46 unsigned int fill = 0;
47 unsigned int num = 0;
48 const unsigned char *key_used = NULL;
49 unsigned char key_temp[SHA256_DIGEST_SIZE] = { 0 };
50 int i = 0;
51
52 if (key_size == SHA256_BLOCK_SIZE) {
53 key_used = key;
54 num = SHA256_BLOCK_SIZE;
55 } else {
56 if (key_size > SHA256_BLOCK_SIZE){
57 num = SHA256_DIGEST_SIZE;
58 sha256(key, key_size, key_temp);
59 key_used = key_temp;
60 } else { /* key_size > SHA256_BLOCK_SIZE */
61 key_used = key;
62 num = key_size;
63 }
64 fill = SHA256_BLOCK_SIZE - num;
65
66 memset(ctx->block_ipad + num, 0x36, fill);
67 memset(ctx->block_opad + num, 0x5c, fill);
68 }
69
70 for (i = 0; i < (int) num; i++) {
71 ctx->block_ipad[i] = key_used[i] ^ 0x36;
72 ctx->block_opad[i] = key_used[i] ^ 0x5c;
73 }
74
75 sha256_init(&ctx->ctx_inside);
76 sha256_update(&ctx->ctx_inside, ctx->block_ipad, SHA256_BLOCK_SIZE);
77
78 sha256_init(&ctx->ctx_outside);
79 sha256_update(&ctx->ctx_outside, ctx->block_opad,
80 SHA256_BLOCK_SIZE);
81
82 /* for hmac_reinit */
83 memcpy(&ctx->ctx_inside_reinit, &ctx->ctx_inside,
84 sizeof(sha256_ctx));
85 memcpy(&ctx->ctx_outside_reinit, &ctx->ctx_outside,
86 sizeof(sha256_ctx));
87 }
88
hmac_sha256_reinit(hmac_sha256_ctx * ctx)89 void hmac_sha256_reinit(hmac_sha256_ctx *ctx)
90 {
91 memcpy(&ctx->ctx_inside, &ctx->ctx_inside_reinit,
92 sizeof(sha256_ctx));
93 memcpy(&ctx->ctx_outside, &ctx->ctx_outside_reinit,
94 sizeof(sha256_ctx));
95 }
96
hmac_sha256_update(hmac_sha256_ctx * ctx,const unsigned char * message,unsigned int message_len)97 void hmac_sha256_update(hmac_sha256_ctx *ctx, const unsigned char *message,
98 unsigned int message_len)
99 {
100 sha256_update(&ctx->ctx_inside, message, message_len);
101 }
102
hmac_sha256_final(hmac_sha256_ctx * ctx,unsigned char * mac,unsigned int mac_size)103 void hmac_sha256_final(hmac_sha256_ctx *ctx, unsigned char *mac,
104 unsigned int mac_size)
105 {
106 unsigned char digest_inside[SHA256_DIGEST_SIZE] = { 0 };
107 unsigned char mac_temp[SHA256_DIGEST_SIZE] = { 0 };
108
109 sha256_final(&ctx->ctx_inside, digest_inside);
110 sha256_update(&ctx->ctx_outside, digest_inside, SHA256_DIGEST_SIZE);
111 sha256_final(&ctx->ctx_outside, mac_temp);
112 memcpy(mac, mac_temp, mac_size);
113 }
114
hmac_sha256(const unsigned char * key,unsigned int key_size,const unsigned char * message,unsigned int message_len,unsigned char * mac,unsigned mac_size)115 void hmac_sha256(const unsigned char *key, unsigned int key_size,
116 const unsigned char *message, unsigned int message_len,
117 unsigned char *mac, unsigned mac_size)
118 {
119 hmac_sha256_ctx ctx;
120
121 memset(&ctx, 0, sizeof(ctx));
122
123 hmac_sha256_init(&ctx, key, key_size);
124 hmac_sha256_update(&ctx, message, message_len);
125 hmac_sha256_final(&ctx, mac, mac_size);
126 }
127