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comparison: netwerk/srtp/src/crypto/hash/hmac.c
netwerk/srtp/src/crypto/hash/hmac.c
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| 1 /* | |
| 2 * hmac.c | |
| 3 * | |
| 4 * implementation of hmac auth_type_t | |
| 5 * | |
| 6 * David A. McGrew | |
| 7 * Cisco Systems, Inc. | |
| 8 */ | |
| 9 /* | |
| 10 * | |
| 11 * Copyright(c) 2001-2006 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 #include "hmac.h" | |
| 46 #include "alloc.h" | |
| 47 | |
| 48 /* the debug module for authentiation */ | |
| 49 | |
| 50 debug_module_t mod_hmac = { | |
| 51 0, /* debugging is off by default */ | |
| 52 "hmac sha-1" /* printable name for module */ | |
| 53 }; | |
| 54 | |
| 55 | |
| 56 err_status_t | |
| 57 hmac_alloc(auth_t **a, int key_len, int out_len) { | |
| 58 extern auth_type_t hmac; | |
| 59 uint8_t *pointer; | |
| 60 | |
| 61 debug_print(mod_hmac, "allocating auth func with key length %d", key_len); | |
| 62 debug_print(mod_hmac, " tag length %d", out_len); | |
| 63 | |
| 64 /* | |
| 65 * check key length - note that we don't support keys larger | |
| 66 * than 20 bytes yet | |
| 67 */ | |
| 68 if (key_len > 20) | |
| 69 return err_status_bad_param; | |
| 70 | |
| 71 /* check output length - should be less than 20 bytes */ | |
| 72 if (out_len > 20) | |
| 73 return err_status_bad_param; | |
| 74 | |
| 75 /* allocate memory for auth and hmac_ctx_t structures */ | |
| 76 pointer = (uint8_t*)crypto_alloc(sizeof(hmac_ctx_t) + sizeof(auth_t)); | |
| 77 if (pointer == NULL) | |
| 78 return err_status_alloc_fail; | |
| 79 | |
| 80 /* set pointers */ | |
| 81 *a = (auth_t *)pointer; | |
| 82 (*a)->type = &hmac; | |
| 83 (*a)->state = pointer + sizeof(auth_t); | |
| 84 (*a)->out_len = out_len; | |
| 85 (*a)->key_len = key_len; | |
| 86 (*a)->prefix_len = 0; | |
| 87 | |
| 88 /* increment global count of all hmac uses */ | |
| 89 hmac.ref_count++; | |
| 90 | |
| 91 return err_status_ok; | |
| 92 } | |
| 93 | |
| 94 err_status_t | |
| 95 hmac_dealloc(auth_t *a) { | |
| 96 extern auth_type_t hmac; | |
| 97 | |
| 98 /* zeroize entire state*/ | |
| 99 octet_string_set_to_zero((uint8_t *)a, | |
| 100 sizeof(hmac_ctx_t) + sizeof(auth_t)); | |
| 101 | |
| 102 /* free memory */ | |
| 103 crypto_free(a); | |
| 104 | |
| 105 /* decrement global count of all hmac uses */ | |
| 106 hmac.ref_count--; | |
| 107 | |
| 108 return err_status_ok; | |
| 109 } | |
| 110 | |
| 111 err_status_t | |
| 112 hmac_init(hmac_ctx_t *state, const uint8_t *key, int key_len) { | |
| 113 int i; | |
| 114 uint8_t ipad[64]; | |
| 115 | |
| 116 /* | |
| 117 * check key length - note that we don't support keys larger | |
| 118 * than 20 bytes yet | |
| 119 */ | |
| 120 if (key_len > 20) | |
| 121 return err_status_bad_param; | |
| 122 | |
| 123 /* | |
| 124 * set values of ipad and opad by exoring the key into the | |
| 125 * appropriate constant values | |
| 126 */ | |
| 127 for (i=0; i < key_len; i++) { | |
| 128 ipad[i] = key[i] ^ 0x36; | |
| 129 state->opad[i] = key[i] ^ 0x5c; | |
| 130 } | |
| 131 /* set the rest of ipad, opad to constant values */ | |
| 132 for ( ; i < 64; i++) { | |
| 133 ipad[i] = 0x36; | |
| 134 ((uint8_t *)state->opad)[i] = 0x5c; | |
| 135 } | |
| 136 | |
| 137 debug_print(mod_hmac, "ipad: %s", octet_string_hex_string(ipad, 64)); | |
| 138 | |
| 139 /* initialize sha1 context */ | |
| 140 sha1_init(&state->init_ctx); | |
| 141 | |
| 142 /* hash ipad ^ key */ | |
| 143 sha1_update(&state->init_ctx, ipad, 64); | |
| 144 memcpy(&state->ctx, &state->init_ctx, sizeof(sha1_ctx_t)); | |
| 145 | |
| 146 return err_status_ok; | |
| 147 } | |
| 148 | |
| 149 err_status_t | |
| 150 hmac_start(hmac_ctx_t *state) { | |
| 151 | |
| 152 memcpy(&state->ctx, &state->init_ctx, sizeof(sha1_ctx_t)); | |
| 153 | |
| 154 return err_status_ok; | |
| 155 } | |
| 156 | |
| 157 err_status_t | |
| 158 hmac_update(hmac_ctx_t *state, const uint8_t *message, int msg_octets) { | |
| 159 | |
| 160 debug_print(mod_hmac, "input: %s", | |
| 161 octet_string_hex_string(message, msg_octets)); | |
| 162 | |
| 163 /* hash message into sha1 context */ | |
| 164 sha1_update(&state->ctx, message, msg_octets); | |
| 165 | |
| 166 return err_status_ok; | |
| 167 } | |
| 168 | |
| 169 err_status_t | |
| 170 hmac_compute(hmac_ctx_t *state, const void *message, | |
| 171 int msg_octets, int tag_len, uint8_t *result) { | |
| 172 uint32_t hash_value[5]; | |
| 173 uint32_t H[5]; | |
| 174 int i; | |
| 175 | |
| 176 /* check tag length, return error if we can't provide the value expected */ | |
| 177 if (tag_len > 20) | |
| 178 return err_status_bad_param; | |
| 179 | |
| 180 /* hash message, copy output into H */ | |
| 181 hmac_update(state, (const uint8_t*)message, msg_octets); | |
| 182 sha1_final(&state->ctx, H); | |
| 183 | |
| 184 /* | |
| 185 * note that we don't need to debug_print() the input, since the | |
| 186 * function hmac_update() already did that for us | |
| 187 */ | |
| 188 debug_print(mod_hmac, "intermediate state: %s", | |
| 189 octet_string_hex_string((uint8_t *)H, 20)); | |
| 190 | |
| 191 /* re-initialize hash context */ | |
| 192 sha1_init(&state->ctx); | |
| 193 | |
| 194 /* hash opad ^ key */ | |
| 195 sha1_update(&state->ctx, (uint8_t *)state->opad, 64); | |
| 196 | |
| 197 /* hash the result of the inner hash */ | |
| 198 sha1_update(&state->ctx, (uint8_t *)H, 20); | |
| 199 | |
| 200 /* the result is returned in the array hash_value[] */ | |
| 201 sha1_final(&state->ctx, hash_value); | |
| 202 | |
| 203 /* copy hash_value to *result */ | |
| 204 for (i=0; i < tag_len; i++) | |
| 205 result[i] = ((uint8_t *)hash_value)[i]; | |
| 206 | |
| 207 debug_print(mod_hmac, "output: %s", | |
| 208 octet_string_hex_string((uint8_t *)hash_value, tag_len)); | |
| 209 | |
| 210 return err_status_ok; | |
| 211 } | |
| 212 | |
| 213 | |
| 214 /* begin test case 0 */ | |
| 215 | |
| 216 uint8_t | |
| 217 hmac_test_case_0_key[20] = { | |
| 218 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, | |
| 219 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, | |
| 220 0x0b, 0x0b, 0x0b, 0x0b | |
| 221 }; | |
| 222 | |
| 223 uint8_t | |
| 224 hmac_test_case_0_data[8] = { | |
| 225 0x48, 0x69, 0x20, 0x54, 0x68, 0x65, 0x72, 0x65 /* "Hi There" */ | |
| 226 }; | |
| 227 | |
| 228 uint8_t | |
| 229 hmac_test_case_0_tag[20] = { | |
| 230 0xb6, 0x17, 0x31, 0x86, 0x55, 0x05, 0x72, 0x64, | |
| 231 0xe2, 0x8b, 0xc0, 0xb6, 0xfb, 0x37, 0x8c, 0x8e, | |
| 232 0xf1, 0x46, 0xbe, 0x00 | |
| 233 }; | |
| 234 | |
| 235 auth_test_case_t | |
| 236 hmac_test_case_0 = { | |
| 237 20, /* octets in key */ | |
| 238 hmac_test_case_0_key, /* key */ | |
| 239 8, /* octets in data */ | |
| 240 hmac_test_case_0_data, /* data */ | |
| 241 20, /* octets in tag */ | |
| 242 hmac_test_case_0_tag, /* tag */ | |
| 243 NULL /* pointer to next testcase */ | |
| 244 }; | |
| 245 | |
| 246 /* end test case 0 */ | |
| 247 | |
| 248 char hmac_description[] = "hmac sha-1 authentication function"; | |
| 249 | |
| 250 /* | |
| 251 * auth_type_t hmac is the hmac metaobject | |
| 252 */ | |
| 253 | |
| 254 auth_type_t | |
| 255 hmac = { | |
| 256 (auth_alloc_func) hmac_alloc, | |
| 257 (auth_dealloc_func) hmac_dealloc, | |
| 258 (auth_init_func) hmac_init, | |
| 259 (auth_compute_func) hmac_compute, | |
| 260 (auth_update_func) hmac_update, | |
| 261 (auth_start_func) hmac_start, | |
| 262 (char *) hmac_description, | |
| 263 (int) 0, /* instance count */ | |
| 264 (auth_test_case_t *) &hmac_test_case_0, | |
| 265 (debug_module_t *) &mod_hmac, | |
| 266 (auth_type_id_t) HMAC_SHA1 | |
| 267 }; | |
| 268 |
