diff options
Diffstat (limited to 'netwerk/srtp/src/crypto/hash/hmac.c')
| -rw-r--r-- | netwerk/srtp/src/crypto/hash/hmac.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/netwerk/srtp/src/crypto/hash/hmac.c b/netwerk/srtp/src/crypto/hash/hmac.c new file mode 100644 index 000000000..4f389fe18 --- /dev/null +++ b/netwerk/srtp/src/crypto/hash/hmac.c @@ -0,0 +1,268 @@ +/* + * hmac.c + * + * implementation of hmac auth_type_t + * + * David A. McGrew + * Cisco Systems, Inc. + */ +/* + * + * Copyright(c) 2001-2006 Cisco Systems, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * Neither the name of the Cisco Systems, Inc. nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include "hmac.h" +#include "alloc.h" + +/* the debug module for authentiation */ + +debug_module_t mod_hmac = { + 0, /* debugging is off by default */ + "hmac sha-1" /* printable name for module */ +}; + + +err_status_t +hmac_alloc(auth_t **a, int key_len, int out_len) { + extern auth_type_t hmac; + uint8_t *pointer; + + debug_print(mod_hmac, "allocating auth func with key length %d", key_len); + debug_print(mod_hmac, " tag length %d", out_len); + + /* + * check key length - note that we don't support keys larger + * than 20 bytes yet + */ + if (key_len > 20) + return err_status_bad_param; + + /* check output length - should be less than 20 bytes */ + if (out_len > 20) + return err_status_bad_param; + + /* allocate memory for auth and hmac_ctx_t structures */ + pointer = (uint8_t*)crypto_alloc(sizeof(hmac_ctx_t) + sizeof(auth_t)); + if (pointer == NULL) + return err_status_alloc_fail; + + /* set pointers */ + *a = (auth_t *)pointer; + (*a)->type = &hmac; + (*a)->state = pointer + sizeof(auth_t); + (*a)->out_len = out_len; + (*a)->key_len = key_len; + (*a)->prefix_len = 0; + + /* increment global count of all hmac uses */ + hmac.ref_count++; + + return err_status_ok; +} + +err_status_t +hmac_dealloc(auth_t *a) { + extern auth_type_t hmac; + + /* zeroize entire state*/ + octet_string_set_to_zero((uint8_t *)a, + sizeof(hmac_ctx_t) + sizeof(auth_t)); + + /* free memory */ + crypto_free(a); + + /* decrement global count of all hmac uses */ + hmac.ref_count--; + + return err_status_ok; +} + +err_status_t +hmac_init(hmac_ctx_t *state, const uint8_t *key, int key_len) { + int i; + uint8_t ipad[64]; + + /* + * check key length - note that we don't support keys larger + * than 20 bytes yet + */ + if (key_len > 20) + return err_status_bad_param; + + /* + * set values of ipad and opad by exoring the key into the + * appropriate constant values + */ + for (i=0; i < key_len; i++) { + ipad[i] = key[i] ^ 0x36; + state->opad[i] = key[i] ^ 0x5c; + } + /* set the rest of ipad, opad to constant values */ + for ( ; i < 64; i++) { + ipad[i] = 0x36; + ((uint8_t *)state->opad)[i] = 0x5c; + } + + debug_print(mod_hmac, "ipad: %s", octet_string_hex_string(ipad, 64)); + + /* initialize sha1 context */ + sha1_init(&state->init_ctx); + + /* hash ipad ^ key */ + sha1_update(&state->init_ctx, ipad, 64); + memcpy(&state->ctx, &state->init_ctx, sizeof(sha1_ctx_t)); + + return err_status_ok; +} + +err_status_t +hmac_start(hmac_ctx_t *state) { + + memcpy(&state->ctx, &state->init_ctx, sizeof(sha1_ctx_t)); + + return err_status_ok; +} + +err_status_t +hmac_update(hmac_ctx_t *state, const uint8_t *message, int msg_octets) { + + debug_print(mod_hmac, "input: %s", + octet_string_hex_string(message, msg_octets)); + + /* hash message into sha1 context */ + sha1_update(&state->ctx, message, msg_octets); + + return err_status_ok; +} + +err_status_t +hmac_compute(hmac_ctx_t *state, const void *message, + int msg_octets, int tag_len, uint8_t *result) { + uint32_t hash_value[5]; + uint32_t H[5]; + int i; + + /* check tag length, return error if we can't provide the value expected */ + if (tag_len > 20) + return err_status_bad_param; + + /* hash message, copy output into H */ + hmac_update(state, (const uint8_t*)message, msg_octets); + sha1_final(&state->ctx, H); + + /* + * note that we don't need to debug_print() the input, since the + * function hmac_update() already did that for us + */ + debug_print(mod_hmac, "intermediate state: %s", + octet_string_hex_string((uint8_t *)H, 20)); + + /* re-initialize hash context */ + sha1_init(&state->ctx); + + /* hash opad ^ key */ + sha1_update(&state->ctx, (uint8_t *)state->opad, 64); + + /* hash the result of the inner hash */ + sha1_update(&state->ctx, (uint8_t *)H, 20); + + /* the result is returned in the array hash_value[] */ + sha1_final(&state->ctx, hash_value); + + /* copy hash_value to *result */ + for (i=0; i < tag_len; i++) + result[i] = ((uint8_t *)hash_value)[i]; + + debug_print(mod_hmac, "output: %s", + octet_string_hex_string((uint8_t *)hash_value, tag_len)); + + return err_status_ok; +} + + +/* begin test case 0 */ + +uint8_t +hmac_test_case_0_key[20] = { + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b +}; + +uint8_t +hmac_test_case_0_data[8] = { + 0x48, 0x69, 0x20, 0x54, 0x68, 0x65, 0x72, 0x65 /* "Hi There" */ +}; + +uint8_t +hmac_test_case_0_tag[20] = { + 0xb6, 0x17, 0x31, 0x86, 0x55, 0x05, 0x72, 0x64, + 0xe2, 0x8b, 0xc0, 0xb6, 0xfb, 0x37, 0x8c, 0x8e, + 0xf1, 0x46, 0xbe, 0x00 +}; + +auth_test_case_t +hmac_test_case_0 = { + 20, /* octets in key */ + hmac_test_case_0_key, /* key */ + 8, /* octets in data */ + hmac_test_case_0_data, /* data */ + 20, /* octets in tag */ + hmac_test_case_0_tag, /* tag */ + NULL /* pointer to next testcase */ +}; + +/* end test case 0 */ + +char hmac_description[] = "hmac sha-1 authentication function"; + +/* + * auth_type_t hmac is the hmac metaobject + */ + +auth_type_t +hmac = { + (auth_alloc_func) hmac_alloc, + (auth_dealloc_func) hmac_dealloc, + (auth_init_func) hmac_init, + (auth_compute_func) hmac_compute, + (auth_update_func) hmac_update, + (auth_start_func) hmac_start, + (char *) hmac_description, + (int) 0, /* instance count */ + (auth_test_case_t *) &hmac_test_case_0, + (debug_module_t *) &mod_hmac, + (auth_type_id_t) HMAC_SHA1 +}; + |