1/* 2 * Copyright (c) 2006 - 2007 Kungliga Tekniska H��gskolan 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 40void 41HMAC_CTX_init(HMAC_CTX *ctx) 42{ 43 memset(ctx, 0, sizeof(*ctx)); 44} 45 46void 47HMAC_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->ipad, 0, ctx->key_length); 56 free(ctx->opad); 57 ctx->opad = NULL; 58 } 59 if (ctx->ipad) { 60 memset(ctx->ipad, 0, ctx->key_length); 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 70size_t 71HMAC_size(const HMAC_CTX *ctx) 72{ 73 return EVP_MD_size(ctx->md); 74} 75 76void 77HMAC_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 ctx->ctx = EVP_MD_CTX_create(); 125 126 EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine); 127 EVP_DigestUpdate(ctx->ctx, ctx->ipad, EVP_MD_block_size(ctx->md)); 128} 129 130void 131HMAC_Update(HMAC_CTX *ctx, const void *data, size_t len) 132{ 133 EVP_DigestUpdate(ctx->ctx, data, len); 134} 135 136void 137HMAC_Final(HMAC_CTX *ctx, void *md, unsigned int *len) 138{ 139 EVP_DigestFinal_ex(ctx->ctx, ctx->buf, NULL); 140 141 EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine); 142 EVP_DigestUpdate(ctx->ctx, ctx->opad, EVP_MD_block_size(ctx->md)); 143 EVP_DigestUpdate(ctx->ctx, ctx->buf, ctx->key_length); 144 EVP_DigestFinal_ex(ctx->ctx, md, len); 145} 146 147void * 148HMAC(const EVP_MD *md, 149 const void *key, size_t key_size, 150 const void *data, size_t data_size, 151 void *hash, unsigned int *hash_len) 152{ 153 HMAC_CTX ctx; 154 155 HMAC_CTX_init(&ctx); 156 HMAC_Init_ex(&ctx, key, key_size, md, NULL); 157 HMAC_Update(&ctx, data, data_size); 158 HMAC_Final(&ctx, hash, hash_len); 159 HMAC_CTX_cleanup(&ctx); 160 return hash; 161} 162