hmac.c revision 284285
1/* crypto/hmac/hmac.c */ 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#include <stdio.h> 59#include <stdlib.h> 60#include <string.h> 61#include "cryptlib.h" 62#include <openssl/hmac.h> 63 64#ifdef OPENSSL_FIPS 65# include <openssl/fips.h> 66#endif 67 68int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, 69 const EVP_MD *md, ENGINE *impl) 70{ 71 int i, j, reset = 0; 72 unsigned char pad[HMAC_MAX_MD_CBLOCK]; 73 74#ifdef OPENSSL_FIPS 75 if (FIPS_mode()) { 76 /* If we have an ENGINE need to allow non FIPS */ 77 if ((impl || ctx->i_ctx.engine) 78 && !(ctx->i_ctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) { 79 EVPerr(EVP_F_HMAC_INIT_EX, EVP_R_DISABLED_FOR_FIPS); 80 return 0; 81 } 82 /* 83 * Other algorithm blocking will be done in FIPS_cmac_init, via 84 * FIPS_hmac_init_ex(). 85 */ 86 if (!impl && !ctx->i_ctx.engine) 87 return FIPS_hmac_init_ex(ctx, key, len, md, NULL); 88 } 89#endif 90 91 if (md != NULL) { 92 reset = 1; 93 ctx->md = md; 94 } else if (ctx->md) { 95 md = ctx->md; 96 } else { 97 return 0; 98 } 99 100 if (!ctx->key_init && key == NULL) 101 return 0; 102 103 if (key != NULL) { 104 reset = 1; 105 j = EVP_MD_block_size(md); 106 OPENSSL_assert(j <= (int)sizeof(ctx->key)); 107 if (j < len) { 108 if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl)) 109 goto err; 110 if (!EVP_DigestUpdate(&ctx->md_ctx, key, len)) 111 goto err; 112 if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key, 113 &ctx->key_length)) 114 goto err; 115 } else { 116 if (len < 0 || len > (int)sizeof(ctx->key)) 117 return 0; 118 memcpy(ctx->key, key, len); 119 ctx->key_length = len; 120 } 121 if (ctx->key_length != HMAC_MAX_MD_CBLOCK) 122 memset(&ctx->key[ctx->key_length], 0, 123 HMAC_MAX_MD_CBLOCK - ctx->key_length); 124 ctx->key_init = 1; 125 } 126 127 if (reset) { 128 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++) 129 pad[i] = 0x36 ^ ctx->key[i]; 130 if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl)) 131 goto err; 132 if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md))) 133 goto err; 134 135 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++) 136 pad[i] = 0x5c ^ ctx->key[i]; 137 if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl)) 138 goto err; 139 if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md))) 140 goto err; 141 } 142 if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx)) 143 goto err; 144 return 1; 145 err: 146 return 0; 147} 148 149int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md) 150{ 151 if (key && md) 152 HMAC_CTX_init(ctx); 153 return HMAC_Init_ex(ctx, key, len, md, NULL); 154} 155 156int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len) 157{ 158#ifdef OPENSSL_FIPS 159 if (FIPS_mode() && !ctx->i_ctx.engine) 160 return FIPS_hmac_update(ctx, data, len); 161#endif 162 if (!ctx->key_init) 163 return 0; 164 165 return EVP_DigestUpdate(&ctx->md_ctx, data, len); 166} 167 168int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len) 169{ 170 unsigned int i; 171 unsigned char buf[EVP_MAX_MD_SIZE]; 172#ifdef OPENSSL_FIPS 173 if (FIPS_mode() && !ctx->i_ctx.engine) 174 return FIPS_hmac_final(ctx, md, len); 175#endif 176 177 if (!ctx->key_init) 178 goto err; 179 180 if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i)) 181 goto err; 182 if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx)) 183 goto err; 184 if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i)) 185 goto err; 186 if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len)) 187 goto err; 188 return 1; 189 err: 190 return 0; 191} 192 193void HMAC_CTX_init(HMAC_CTX *ctx) 194{ 195 EVP_MD_CTX_init(&ctx->i_ctx); 196 EVP_MD_CTX_init(&ctx->o_ctx); 197 EVP_MD_CTX_init(&ctx->md_ctx); 198 ctx->key_init = 0; 199 ctx->md = NULL; 200} 201 202int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx) 203{ 204 if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx)) 205 goto err; 206 if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx)) 207 goto err; 208 if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx)) 209 goto err; 210 dctx->key_init = sctx->key_init; 211 if (sctx->key_init) { 212 memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK); 213 dctx->key_length = sctx->key_length; 214 } 215 dctx->md = sctx->md; 216 return 1; 217 err: 218 return 0; 219} 220 221void HMAC_CTX_cleanup(HMAC_CTX *ctx) 222{ 223#ifdef OPENSSL_FIPS 224 if (FIPS_mode() && !ctx->i_ctx.engine) { 225 FIPS_hmac_ctx_cleanup(ctx); 226 return; 227 } 228#endif 229 EVP_MD_CTX_cleanup(&ctx->i_ctx); 230 EVP_MD_CTX_cleanup(&ctx->o_ctx); 231 EVP_MD_CTX_cleanup(&ctx->md_ctx); 232 memset(ctx, 0, sizeof *ctx); 233} 234 235unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len, 236 const unsigned char *d, size_t n, unsigned char *md, 237 unsigned int *md_len) 238{ 239 HMAC_CTX c; 240 static unsigned char m[EVP_MAX_MD_SIZE]; 241 242 if (md == NULL) 243 md = m; 244 HMAC_CTX_init(&c); 245 if (!HMAC_Init(&c, key, key_len, evp_md)) 246 goto err; 247 if (!HMAC_Update(&c, d, n)) 248 goto err; 249 if (!HMAC_Final(&c, md, md_len)) 250 goto err; 251 HMAC_CTX_cleanup(&c); 252 return md; 253 err: 254 HMAC_CTX_cleanup(&c); 255 return NULL; 256} 257 258void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags) 259{ 260 EVP_MD_CTX_set_flags(&ctx->i_ctx, flags); 261 EVP_MD_CTX_set_flags(&ctx->o_ctx, flags); 262 EVP_MD_CTX_set_flags(&ctx->md_ctx, flags); 263} 264