crypto/libressl/crypto/hmac/hmac.c

   1 /* $OpenBSD: hmac.c,v 1.28 2022/05/05 18:29:34 tb 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/err.h>
  64 #include <openssl/hmac.h>
  65
  66 #include "evp_locl.h"
  67 #include "hmac_local.h"
  68
  69 int
  70 HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md,
  71     ENGINE *impl)
  72 {
  73         int i, j, reset = 0;
  74         unsigned char pad[HMAC_MAX_MD_CBLOCK];
  75
  76         /* If we are changing MD then we must have a key */
  77         if (md != NULL && md != ctx->md && (key == NULL || len < 0))
  78                 return 0;
  79
  80         if (md != NULL) {
  81                 reset = 1;
  82                 ctx->md = md;
  83         } else if (ctx->md != NULL)
  84                 md = ctx->md;
  85         else
  86                 return 0;
  87
  88         if (key != NULL) {
  89                 reset = 1;
  90                 j = EVP_MD_block_size(md);
  91                 if ((size_t)j > sizeof(ctx->key)) {
  92                         EVPerror(EVP_R_BAD_BLOCK_LENGTH);
  93                         goto err;
  94                 }
  95                 if (j < len) {
  96                         if (!EVP_DigestInit_ex(&ctx->md_ctx, md, impl))
  97                                 goto err;
  98                         if (!EVP_DigestUpdate(&ctx->md_ctx, key, len))
  99                                 goto err;
 100                         if (!EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key,
 101                             &ctx->key_length))
 102                                 goto err;
 103                 } else {
 104                         if (len < 0 || (size_t)len > sizeof(ctx->key)) {
 105                                 EVPerror(EVP_R_BAD_KEY_LENGTH);
 106                                 goto err;
 107                         }
 108                         memcpy(ctx->key, key, len);
 109                         ctx->key_length = len;
 110                 }
 111                 if (ctx->key_length != HMAC_MAX_MD_CBLOCK)
 112                         memset(&ctx->key[ctx->key_length], 0,
 113                             HMAC_MAX_MD_CBLOCK - ctx->key_length);
 114         }
 115
 116         if (reset) {
 117                 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 118                         pad[i] = 0x36 ^ ctx->key[i];
 119                 if (!EVP_DigestInit_ex(&ctx->i_ctx, md, impl))
 120                         goto err;
 121                 if (!EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md)))
 122                         goto err;
 123
 124                 for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
 125                         pad[i] = 0x5c ^ ctx->key[i];
 126                 if (!EVP_DigestInit_ex(&ctx->o_ctx, md, impl))
 127                         goto err;
 128                 if (!EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md)))
 129                         goto err;
 130         }
 131         if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx))
 132                 goto err;
 133         return 1;
 134 err:
 135         return 0;
 136 }
 137
 138 int
 139 HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
 140 {
 141         if (key && md)
 142                 HMAC_CTX_init(ctx);
 143         return HMAC_Init_ex(ctx, key, len, md, NULL);
 144 }
 145
 146 int
 147 HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
 148 {
 149         if (ctx->md == NULL)
 150                 return 0;
 151
 152         return EVP_DigestUpdate(&ctx->md_ctx, data, len);
 153 }
 154
 155 int
 156 HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
 157 {
 158         unsigned int i;
 159         unsigned char buf[EVP_MAX_MD_SIZE];
 160
 161         if (ctx->md == NULL)
 162                 goto err;
 163
 164         if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i))
 165                 goto err;
 166         if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx))
 167                 goto err;
 168         if (!EVP_DigestUpdate(&ctx->md_ctx, buf, i))
 169                 goto err;
 170         if (!EVP_DigestFinal_ex(&ctx->md_ctx, md, len))
 171                 goto err;
 172         return 1;
 173 err:
 174         return 0;
 175 }
 176
 177 HMAC_CTX *
 178 HMAC_CTX_new(void)
 179 {
 180         HMAC_CTX *ctx;
 181
 182         if ((ctx = calloc(1, sizeof(*ctx))) == NULL)
 183                 return NULL;
 184
 185         HMAC_CTX_init(ctx);
 186
 187         return ctx;
 188 }
 189
 190 void
 191 HMAC_CTX_free(HMAC_CTX *ctx)
 192 {
 193         if (ctx == NULL)
 194                 return;
 195
 196         HMAC_CTX_cleanup(ctx);
 197
 198         free(ctx);
 199 }
 200
 201 int
 202 HMAC_CTX_reset(HMAC_CTX *ctx)
 203 {
 204         HMAC_CTX_cleanup(ctx);
 205         HMAC_CTX_init(ctx);
 206         return 1;
 207 }
 208
 209 void
 210 HMAC_CTX_init(HMAC_CTX *ctx)
 211 {
 212         EVP_MD_CTX_init(&ctx->i_ctx);
 213         EVP_MD_CTX_init(&ctx->o_ctx);
 214         EVP_MD_CTX_init(&ctx->md_ctx);
 215         ctx->md = NULL;
 216 }
 217
 218 int
 219 HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
 220 {
 221         if (!EVP_MD_CTX_copy(&dctx->i_ctx, &sctx->i_ctx))
 222                 goto err;
 223         if (!EVP_MD_CTX_copy(&dctx->o_ctx, &sctx->o_ctx))
 224                 goto err;
 225         if (!EVP_MD_CTX_copy(&dctx->md_ctx, &sctx->md_ctx))
 226                 goto err;
 227         memcpy(dctx->key, sctx->key, HMAC_MAX_MD_CBLOCK);
 228         dctx->key_length = sctx->key_length;
 229         dctx->md = sctx->md;
 230         return 1;
 231 err:
 232         return 0;
 233 }
 234
 235 void
 236 HMAC_CTX_cleanup(HMAC_CTX *ctx)
 237 {
 238         EVP_MD_CTX_cleanup(&ctx->i_ctx);
 239         EVP_MD_CTX_cleanup(&ctx->o_ctx);
 240         EVP_MD_CTX_cleanup(&ctx->md_ctx);
 241         explicit_bzero(ctx, sizeof(*ctx));
 242 }
 243
 244 void
 245 HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
 246 {
 247         EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
 248         EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
 249         EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
 250 }
 251
 252 const EVP_MD *
 253 HMAC_CTX_get_md(const HMAC_CTX *ctx)
 254 {
 255         return ctx->md;
 256 }
 257
 258 unsigned char *
 259 HMAC(const EVP_MD *evp_md, const void *key, int key_len, const unsigned char *d,
 260     size_t n, unsigned char *md, unsigned int *md_len)
 261 {
 262         HMAC_CTX c;
 263         static unsigned char m[EVP_MAX_MD_SIZE];
 264         const unsigned char dummy_key[1] = { 0 };
 265
 266         if (md == NULL)
 267                 md = m;
 268         if (key == NULL) {
 269                 key = dummy_key;
 270                 key_len = 0;
 271         }
 272         HMAC_CTX_init(&c);
 273         if (!HMAC_Init_ex(&c, key, key_len, evp_md, NULL))
 274                 goto err;
 275         if (!HMAC_Update(&c, d, n))
 276                 goto err;
 277         if (!HMAC_Final(&c, md, md_len))
 278                 goto err;
 279         HMAC_CTX_cleanup(&c);
 280         return md;
 281 err:
 282         HMAC_CTX_cleanup(&c);
 283         return NULL;
 284 }