The Tor Browser: netwerk/srtp/src/crypto/hash/hmac.c@6474c204b198 (annotated)

netwerk/srtp/src/crypto/hash/hmac.c@6474c204b198 (annotated)

netwerk/srtp/src/crypto/hash/hmac.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * 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 = {
 ,                  /* 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] = {
 x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
 x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
 x0b, 0x0b, 0x0b, 0x0b
 };
 uint8_t
 hmac_test_case_0_data[8] = {
 x48, 0x69, 0x20, 0x54, 0x68, 0x65, 0x72, 0x65   /* "Hi There" */
 };
 uint8_t
 hmac_test_case_0_tag[20] = {
 xb6, 0x17, 0x31, 0x86, 0x55, 0x05, 0x72, 0x64,
 xe2, 0x8b, 0xc0, 0xb6, 0xfb, 0x37, 0x8c, 0x8e,
 xf1, 0x46, 0xbe, 0x00
 };
 auth_test_case_t
 hmac_test_case_0 = {
 ,                        /* octets in key            */
   hmac_test_case_0_key,      /* key                      */
 ,                         /* octets in data           */
   hmac_test_case_0_data,     /* data                     */
 ,                        /* 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
 };

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netwerk/srtp/src/crypto/hash/hmac.c@6474c204b198 (annotated)

netwerk/srtp/src/crypto/hash/hmac.c