1 /* $OpenBSD: hmac.c,v 1.21 2014/07/11 08:44:48 jsing Exp $ */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59 #include <stdio.h> 60 #include <stdlib.h> 61 #include <string.h> 62 63 #include <openssl/hmac.h> 64 65 int 66 HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md, 67 ENGINE *impl) 68 { 69 int i, j, reset = 0; 70 unsigned char pad[HMAC_MAX_MD_CBLOCK]; 71 72 if (md != NULL) { 73 reset = 1; 74 ctx->md = md; 75 } else 76 md = ctx->md; 77 78 if (key != NULL) { 79 reset = 1; 80 j = EVP_MD_block_size(md); 81 OPENSSL_assert(j <= (int)sizeof(ctx->key)); 82 if (j < len) { 83 if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl)) 84 goto err; 85 if (!EVP_DigestUpdate(&ctx->md_ctx, key, len)) 86 goto err; 87 if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key, 88 &ctx->key_length)) 89 goto err; 90 } else { 91 OPENSSL_assert(len >= 0 && 92 len <= (int)sizeof(ctx->key)); 93 memcpy(ctx->key, key, len); 94 ctx->key_length = len; 95 } 96 if (ctx->key_length != HMAC_MAX_MD_CBLOCK) 97 memset(&ctx->key[ctx->key_length], 0, 98 HMAC_MAX_MD_CBLOCK - ctx->key_length); 99 } 100 101 if (reset) { 102 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++) 103 pad[i] = 0x36 ^ ctx->key[i]; 104 if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl)) 105 goto err; 106 if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md))) 107 goto err; 108 109 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++) 110 pad[i] = 0x5c ^ ctx->key[i]; 111 if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl)) 112 goto err; 113 if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md))) 114 goto err; 115 } 116 if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx)) 117 goto err; 118 return 1; 119 err: 120 return 0; 121 } 122 123 int 124 HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md) 125 { 126 if (key && md) 127 HMAC_CTX_init(ctx); 128 return HMAC_Init_ex(ctx, key, len, md, NULL); 129 } 130 131 int 132 HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len) 133 { 134 return EVP_DigestUpdate(&ctx->md_ctx, data, len); 135 } 136 137 int 138 HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len) 139 { 140 unsigned int i; 141 unsigned char buf[EVP_MAX_MD_SIZE]; 142 143 if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i)) 144 goto err; 145 if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx)) 146 goto err; 147 if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i)) 148 goto err; 149 if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len)) 150 goto err; 151 return 1; 152 err: 153 return 0; 154 } 155 156 void 157 HMAC_CTX_init(HMAC_CTX *ctx) 158 { 159 EVP_MD_CTX_init(&ctx->i_ctx); 160 EVP_MD_CTX_init(&ctx->o_ctx); 161 EVP_MD_CTX_init(&ctx->md_ctx); 162 } 163 164 int 165 HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx) 166 { 167 if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx)) 168 goto err; 169 if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx)) 170 goto err; 171 if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx)) 172 goto err; 173 memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK); 174 dctx->key_length = sctx->key_length; 175 dctx->md = sctx->md; 176 return 1; 177 err: 178 return 0; 179 } 180 181 void 182 HMAC_CTX_cleanup(HMAC_CTX *ctx) 183 { 184 EVP_MD_CTX_cleanup(&ctx->i_ctx); 185 EVP_MD_CTX_cleanup(&ctx->o_ctx); 186 EVP_MD_CTX_cleanup(&ctx->md_ctx); 187 memset(ctx, 0, sizeof *ctx); 188 } 189 190 unsigned char * 191 HMAC(const EVP_MD *evp_md, const void *key, int key_len, const unsigned char *d, 192 size_t n, unsigned char *md, unsigned int *md_len) 193 { 194 HMAC_CTX c; 195 static unsigned char m[EVP_MAX_MD_SIZE]; 196 197 if (md == NULL) 198 md = m; 199 HMAC_CTX_init(&c); 200 if (!HMAC_Init(&c, key, key_len, evp_md)) 201 goto err; 202 if (!HMAC_Update(&c, d, n)) 203 goto err; 204 if (!HMAC_Final(&c, md, md_len)) 205 goto err; 206 HMAC_CTX_cleanup(&c); 207 return md; 208 err: 209 return NULL; 210 } 211 212 void 213 HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags) 214 { 215 EVP_MD_CTX_set_flags(&ctx->i_ctx, flags); 216 EVP_MD_CTX_set_flags(&ctx->o_ctx, flags); 217 EVP_MD_CTX_set_flags(&ctx->md_ctx, flags); 218 } 219