OLD | NEW |
| (Empty) |
1 /* | |
2 * hmac_ossl.c | |
3 * | |
4 * Implementation of hmac auth_type_t that leverages OpenSSL | |
5 * | |
6 * John A. Foley | |
7 * Cisco Systems, Inc. | |
8 */ | |
9 /* | |
10 * | |
11 * Copyright(c) 2013, Cisco Systems, Inc. | |
12 * All rights reserved. | |
13 * | |
14 * Redistribution and use in source and binary forms, with or without | |
15 * modification, are permitted provided that the following conditions | |
16 * are met: | |
17 * | |
18 * Redistributions of source code must retain the above copyright | |
19 * notice, this list of conditions and the following disclaimer. | |
20 * | |
21 * Redistributions in binary form must reproduce the above | |
22 * copyright notice, this list of conditions and the following | |
23 * disclaimer in the documentation and/or other materials provided | |
24 * with the distribution. | |
25 * | |
26 * Neither the name of the Cisco Systems, Inc. nor the names of its | |
27 * contributors may be used to endorse or promote products derived | |
28 * from this software without specific prior written permission. | |
29 * | |
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |
33 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | |
34 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, | |
35 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
36 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
37 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
41 * OF THE POSSIBILITY OF SUCH DAMAGE. | |
42 * | |
43 */ | |
44 | |
45 #ifdef HAVE_CONFIG_H | |
46 #include <config.h> | |
47 #endif | |
48 | |
49 #include "hmac.h" | |
50 #include "alloc.h" | |
51 #include <openssl/evp.h> | |
52 | |
53 #define HMAC_KEYLEN_MAX 20 | |
54 | |
55 /* the debug module for authentiation */ | |
56 | |
57 debug_module_t mod_hmac = { | |
58 0, /* debugging is off by default */ | |
59 "hmac sha-1 openssl" /* printable name for module */ | |
60 }; | |
61 | |
62 | |
63 err_status_t | |
64 hmac_alloc (auth_t **a, int key_len, int out_len) | |
65 { | |
66 extern auth_type_t hmac; | |
67 uint8_t *pointer; | |
68 hmac_ctx_t *new_hmac_ctx; | |
69 | |
70 debug_print(mod_hmac, "allocating auth func with key length %d", key_len); | |
71 debug_print(mod_hmac, " tag length %d", out_len); | |
72 | |
73 /* | |
74 * check key length - note that we don't support keys larger | |
75 * than 20 bytes yet | |
76 */ | |
77 if (key_len > HMAC_KEYLEN_MAX) { | |
78 return err_status_bad_param; | |
79 } | |
80 | |
81 /* check output length - should be less than 20 bytes */ | |
82 if (out_len > HMAC_KEYLEN_MAX) { | |
83 return err_status_bad_param; | |
84 } | |
85 | |
86 /* allocate memory for auth and hmac_ctx_t structures */ | |
87 pointer = (uint8_t*)crypto_alloc(sizeof(hmac_ctx_t) + sizeof(auth_t)); | |
88 if (pointer == NULL) { | |
89 return err_status_alloc_fail; | |
90 } | |
91 | |
92 /* set pointers */ | |
93 *a = (auth_t*)pointer; | |
94 (*a)->type = &hmac; | |
95 (*a)->state = pointer + sizeof(auth_t); | |
96 (*a)->out_len = out_len; | |
97 (*a)->key_len = key_len; | |
98 (*a)->prefix_len = 0; | |
99 new_hmac_ctx = (hmac_ctx_t*)((*a)->state); | |
100 memset(new_hmac_ctx, 0, sizeof(hmac_ctx_t)); | |
101 | |
102 /* increment global count of all hmac uses */ | |
103 hmac.ref_count++; | |
104 | |
105 return err_status_ok; | |
106 } | |
107 | |
108 err_status_t | |
109 hmac_dealloc (auth_t *a) | |
110 { | |
111 extern auth_type_t hmac; | |
112 hmac_ctx_t *hmac_ctx; | |
113 | |
114 hmac_ctx = (hmac_ctx_t*)a->state; | |
115 if (hmac_ctx->ctx_initialized) { | |
116 EVP_MD_CTX_cleanup(&hmac_ctx->ctx); | |
117 } | |
118 if (hmac_ctx->init_ctx_initialized) { | |
119 EVP_MD_CTX_cleanup(&hmac_ctx->init_ctx); | |
120 } | |
121 | |
122 /* zeroize entire state*/ | |
123 octet_string_set_to_zero((uint8_t*)a, | |
124 sizeof(hmac_ctx_t) + sizeof(auth_t)); | |
125 | |
126 /* free memory */ | |
127 crypto_free(a); | |
128 | |
129 /* decrement global count of all hmac uses */ | |
130 hmac.ref_count--; | |
131 | |
132 return err_status_ok; | |
133 } | |
134 | |
135 err_status_t | |
136 hmac_init (hmac_ctx_t *state, const uint8_t *key, int key_len) | |
137 { | |
138 int i; | |
139 uint8_t ipad[64]; | |
140 | |
141 /* | |
142 * check key length - note that we don't support keys larger | |
143 * than 20 bytes yet | |
144 */ | |
145 if (key_len > HMAC_KEYLEN_MAX) { | |
146 return err_status_bad_param; | |
147 } | |
148 | |
149 /* | |
150 * set values of ipad and opad by exoring the key into the | |
151 * appropriate constant values | |
152 */ | |
153 for (i = 0; i < key_len; i++) { | |
154 ipad[i] = key[i] ^ 0x36; | |
155 state->opad[i] = key[i] ^ 0x5c; | |
156 } | |
157 /* set the rest of ipad, opad to constant values */ | |
158 for (; i < sizeof(ipad); i++) { | |
159 ipad[i] = 0x36; | |
160 ((uint8_t*)state->opad)[i] = 0x5c; | |
161 } | |
162 | |
163 debug_print(mod_hmac, "ipad: %s", octet_string_hex_string(ipad, sizeof(ipad)
)); | |
164 | |
165 /* initialize sha1 context */ | |
166 sha1_init(&state->init_ctx); | |
167 state->init_ctx_initialized = 1; | |
168 | |
169 /* hash ipad ^ key */ | |
170 sha1_update(&state->init_ctx, ipad, sizeof(ipad)); | |
171 return (hmac_start(state)); | |
172 } | |
173 | |
174 err_status_t | |
175 hmac_start (hmac_ctx_t *state) | |
176 { | |
177 if (state->ctx_initialized) { | |
178 EVP_MD_CTX_cleanup(&state->ctx); | |
179 } | |
180 if (!EVP_MD_CTX_copy(&state->ctx, &state->init_ctx)) { | |
181 return err_status_auth_fail; | |
182 } else { | |
183 state->ctx_initialized = 1; | |
184 return err_status_ok; | |
185 } | |
186 } | |
187 | |
188 err_status_t | |
189 hmac_update (hmac_ctx_t *state, const uint8_t *message, int msg_octets) | |
190 { | |
191 debug_print(mod_hmac, "input: %s", | |
192 octet_string_hex_string(message, msg_octets)); | |
193 | |
194 /* hash message into sha1 context */ | |
195 sha1_update(&state->ctx, message, msg_octets); | |
196 | |
197 return err_status_ok; | |
198 } | |
199 | |
200 err_status_t | |
201 hmac_compute (hmac_ctx_t *state, const void *message, | |
202 int msg_octets, int tag_len, uint8_t *result) | |
203 { | |
204 uint32_t hash_value[5]; | |
205 uint32_t H[5]; | |
206 int i; | |
207 | |
208 /* check tag length, return error if we can't provide the value expected */ | |
209 if (tag_len > HMAC_KEYLEN_MAX) { | |
210 return err_status_bad_param; | |
211 } | |
212 | |
213 /* hash message, copy output into H */ | |
214 sha1_update(&state->ctx, message, msg_octets); | |
215 sha1_final(&state->ctx, H); | |
216 | |
217 /* | |
218 * note that we don't need to debug_print() the input, since the | |
219 * function hmac_update() already did that for us | |
220 */ | |
221 debug_print(mod_hmac, "intermediate state: %s", | |
222 octet_string_hex_string((uint8_t*)H, sizeof(H))); | |
223 | |
224 /* re-initialize hash context */ | |
225 sha1_init(&state->ctx); | |
226 | |
227 /* hash opad ^ key */ | |
228 sha1_update(&state->ctx, (uint8_t*)state->opad, sizeof(state->opad)); | |
229 | |
230 /* hash the result of the inner hash */ | |
231 sha1_update(&state->ctx, (uint8_t*)H, sizeof(H)); | |
232 | |
233 /* the result is returned in the array hash_value[] */ | |
234 sha1_final(&state->ctx, hash_value); | |
235 | |
236 /* copy hash_value to *result */ | |
237 for (i = 0; i < tag_len; i++) { | |
238 result[i] = ((uint8_t*)hash_value)[i]; | |
239 } | |
240 | |
241 debug_print(mod_hmac, "output: %s", | |
242 octet_string_hex_string((uint8_t*)hash_value, tag_len)); | |
243 | |
244 return err_status_ok; | |
245 } | |
246 | |
247 | |
248 /* begin test case 0 */ | |
249 | |
250 uint8_t | |
251 hmac_test_case_0_key[HMAC_KEYLEN_MAX] = { | |
252 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, | |
253 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, | |
254 0x0b, 0x0b, 0x0b, 0x0b | |
255 }; | |
256 | |
257 uint8_t | |
258 hmac_test_case_0_data[8] = { | |
259 0x48, 0x69, 0x20, 0x54, 0x68, 0x65, 0x72, 0x65 /* "Hi There" */ | |
260 }; | |
261 | |
262 uint8_t | |
263 hmac_test_case_0_tag[HMAC_KEYLEN_MAX] = { | |
264 0xb6, 0x17, 0x31, 0x86, 0x55, 0x05, 0x72, 0x64, | |
265 0xe2, 0x8b, 0xc0, 0xb6, 0xfb, 0x37, 0x8c, 0x8e, | |
266 0xf1, 0x46, 0xbe, 0x00 | |
267 }; | |
268 | |
269 auth_test_case_t | |
270 hmac_test_case_0 = { | |
271 sizeof(hmac_test_case_0_key), /* octets in key */ | |
272 hmac_test_case_0_key, /* key */ | |
273 sizeof(hmac_test_case_0_data), /* octets in data */ | |
274 hmac_test_case_0_data, /* data */ | |
275 sizeof(hmac_test_case_0_tag), /* octets in tag */ | |
276 hmac_test_case_0_tag, /* tag */ | |
277 NULL /* pointer to next testcase */ | |
278 }; | |
279 | |
280 /* end test case 0 */ | |
281 | |
282 char hmac_description[] = "hmac sha-1 authentication function"; | |
283 | |
284 /* | |
285 * auth_type_t hmac is the hmac metaobject | |
286 */ | |
287 | |
288 auth_type_t | |
289 hmac = { | |
290 (auth_alloc_func) hmac_alloc, | |
291 (auth_dealloc_func) hmac_dealloc, | |
292 (auth_init_func) hmac_init, | |
293 (auth_compute_func) hmac_compute, | |
294 (auth_update_func) hmac_update, | |
295 (auth_start_func) hmac_start, | |
296 (char*) hmac_description, | |
297 (int) 0, /* instance count */ | |
298 (auth_test_case_t*) &hmac_test_case_0, | |
299 (debug_module_t*) &mod_hmac, | |
300 (auth_type_id_t) HMAC_SHA1 | |
301 }; | |
302 | |
OLD | NEW |