1 /*
2 * Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/types.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <hmac.h>
39
40 void
HMAC_CTX_init(HMAC_CTX * ctx)41 HMAC_CTX_init(HMAC_CTX *ctx)
42 {
43 memset(ctx, 0, sizeof(*ctx));
44 }
45
46 void
HMAC_CTX_cleanup(HMAC_CTX * ctx)47 HMAC_CTX_cleanup(HMAC_CTX *ctx)
48 {
49 if (ctx->buf) {
50 memset(ctx->buf, 0, ctx->key_length);
51 free(ctx->buf);
52 ctx->buf = NULL;
53 }
54 if (ctx->opad) {
55 memset(ctx->opad, 0, EVP_MD_block_size(ctx->md));
56 free(ctx->opad);
57 ctx->opad = NULL;
58 }
59 if (ctx->ipad) {
60 memset(ctx->ipad, 0, EVP_MD_block_size(ctx->md));
61 free(ctx->ipad);
62 ctx->ipad = NULL;
63 }
64 if (ctx->ctx) {
65 EVP_MD_CTX_destroy(ctx->ctx);
66 ctx->ctx = NULL;
67 }
68 }
69
70 size_t
HMAC_size(const HMAC_CTX * ctx)71 HMAC_size(const HMAC_CTX *ctx)
72 {
73 return EVP_MD_size(ctx->md);
74 }
75
76 void
HMAC_Init_ex(HMAC_CTX * ctx,const void * key,size_t keylen,const EVP_MD * md,ENGINE * engine)77 HMAC_Init_ex(HMAC_CTX *ctx,
78 const void *key,
79 size_t keylen,
80 const EVP_MD *md,
81 ENGINE *engine)
82 {
83 unsigned char *p;
84 size_t i;
85
86 if (ctx->md != md) {
87 ctx->md = md;
88 if (ctx->buf) {
89 memset(ctx->buf, 0, ctx->key_length);
90 free (ctx->buf);
91 }
92 ctx->key_length = EVP_MD_size(ctx->md);
93 ctx->buf = malloc(ctx->key_length);
94 }
95 #if 0
96 ctx->engine = engine;
97 #endif
98
99 if (keylen > EVP_MD_block_size(ctx->md)) {
100 EVP_Digest(key, keylen, ctx->buf, NULL, ctx->md, engine);
101 key = ctx->buf;
102 keylen = EVP_MD_size(ctx->md);
103 }
104
105 if (ctx->opad) {
106 memset(ctx->opad, 0, ctx->key_length);
107 free(ctx->opad);
108 }
109 if (ctx->ipad) {
110 memset(ctx->ipad, 0, ctx->key_length);
111 free(ctx->ipad);
112 }
113
114 ctx->opad = malloc(EVP_MD_block_size(ctx->md));
115 ctx->ipad = malloc(EVP_MD_block_size(ctx->md));
116 memset(ctx->ipad, 0x36, EVP_MD_block_size(ctx->md));
117 memset(ctx->opad, 0x5c, EVP_MD_block_size(ctx->md));
118
119 for (i = 0, p = ctx->ipad; i < keylen; i++)
120 p[i] ^= ((const unsigned char *)key)[i];
121 for (i = 0, p = ctx->opad; i < keylen; i++)
122 p[i] ^= ((const unsigned char *)key)[i];
123
124 if (ctx->ctx == NULL)
125 ctx->ctx = EVP_MD_CTX_create();
126
127 EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine);
128 EVP_DigestUpdate(ctx->ctx, ctx->ipad, EVP_MD_block_size(ctx->md));
129 }
130
131 void
HMAC_Update(HMAC_CTX * ctx,const void * data,size_t len)132 HMAC_Update(HMAC_CTX *ctx, const void *data, size_t len)
133 {
134 EVP_DigestUpdate(ctx->ctx, data, len);
135 }
136
137 void
HMAC_Final(HMAC_CTX * ctx,void * md,unsigned int * len)138 HMAC_Final(HMAC_CTX *ctx, void *md, unsigned int *len)
139 {
140 EVP_DigestFinal_ex(ctx->ctx, ctx->buf, NULL);
141
142 EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine);
143 EVP_DigestUpdate(ctx->ctx, ctx->opad, EVP_MD_block_size(ctx->md));
144 EVP_DigestUpdate(ctx->ctx, ctx->buf, ctx->key_length);
145 EVP_DigestFinal_ex(ctx->ctx, md, len);
146 }
147
148 void *
HMAC(const EVP_MD * md,const void * key,size_t key_size,const void * data,size_t data_size,void * hash,unsigned int * hash_len)149 HMAC(const EVP_MD *md,
150 const void *key, size_t key_size,
151 const void *data, size_t data_size,
152 void *hash, unsigned int *hash_len)
153 {
154 HMAC_CTX ctx;
155
156 HMAC_CTX_init(&ctx);
157 HMAC_Init_ex(&ctx, key, key_size, md, NULL);
158 HMAC_Update(&ctx, data, data_size);
159 HMAC_Final(&ctx, hash, hash_len);
160 HMAC_CTX_cleanup(&ctx);
161 return hash;
162 }
163