release/src/router/openssl/crypto/cmac/cmac.c

   1 /* crypto/cmac/cmac.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2010 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  */
  53
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include "cryptlib.h"
  58 #include <openssl/cmac.h>
  59
  60 #ifdef OPENSSL_FIPS
  61 #include <openssl/fips.h>
  62 #endif
  63
  64 struct CMAC_CTX_st
  65         {
  66         /* Cipher context to use */
  67         EVP_CIPHER_CTX cctx;
  68         /* Keys k1 and k2 */
  69         unsigned char k1[EVP_MAX_BLOCK_LENGTH];
  70         unsigned char k2[EVP_MAX_BLOCK_LENGTH];
  71         /* Temporary block */
  72         unsigned char tbl[EVP_MAX_BLOCK_LENGTH];
  73         /* Last (possibly partial) block */
  74         unsigned char last_block[EVP_MAX_BLOCK_LENGTH];
  75         /* Number of bytes in last block: -1 means context not initialised */
  76         int nlast_block;
  77         };
  78
  79
  80 /* Make temporary keys K1 and K2 */
  81
  82 static void make_kn(unsigned char *k1, unsigned char *l, int bl)
  83         {
  84         int i;
  85         /* Shift block to left, including carry */
  86         for (i = 0; i < bl; i++)
  87                 {
  88                 k1[i] = l[i] << 1;
  89                 if (i < bl - 1 && l[i + 1] & 0x80)
  90                         k1[i] |= 1;
  91                 }
  92         /* If MSB set fixup with R */
  93         if (l[0] & 0x80)
  94                 k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b;
  95         }
  96
  97 CMAC_CTX *CMAC_CTX_new(void)
  98         {
  99         CMAC_CTX *ctx;
 100         ctx = OPENSSL_malloc(sizeof(CMAC_CTX));
 101         if (!ctx)
 102                 return NULL;
 103         EVP_CIPHER_CTX_init(&ctx->cctx);
 104         ctx->nlast_block = -1;
 105         return ctx;
 106         }
 107
 108 void CMAC_CTX_cleanup(CMAC_CTX *ctx)
 109         {
 110 #ifdef OPENSSL_FIPS
 111         if (FIPS_mode() && !ctx->cctx.engine)
 112                 {
 113                 FIPS_cmac_ctx_cleanup(ctx);
 114                 return;
 115                 }
 116 #endif
 117         EVP_CIPHER_CTX_cleanup(&ctx->cctx);
 118         OPENSSL_cleanse(ctx->tbl, EVP_MAX_BLOCK_LENGTH);
 119         OPENSSL_cleanse(ctx->k1, EVP_MAX_BLOCK_LENGTH);
 120         OPENSSL_cleanse(ctx->k2, EVP_MAX_BLOCK_LENGTH);
 121         OPENSSL_cleanse(ctx->last_block, EVP_MAX_BLOCK_LENGTH);
 122         ctx->nlast_block = -1;
 123         }
 124
 125 EVP_CIPHER_CTX *CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx)
 126         {
 127         return &ctx->cctx;
 128         }
 129
 130 void CMAC_CTX_free(CMAC_CTX *ctx)
 131         {
 132         CMAC_CTX_cleanup(ctx);
 133         OPENSSL_free(ctx);
 134         }
 135
 136 int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in)
 137         {
 138         int bl;
 139         if (in->nlast_block == -1)
 140                 return 0;
 141         if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx))
 142                 return 0;
 143         bl = EVP_CIPHER_CTX_block_size(&in->cctx);
 144         memcpy(out->k1, in->k1, bl);
 145         memcpy(out->k2, in->k2, bl);
 146         memcpy(out->tbl, in->tbl, bl);
 147         memcpy(out->last_block, in->last_block, bl);
 148         out->nlast_block = in->nlast_block;
 149         return 1;
 150         }
 151
 152 int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,
 153                         const EVP_CIPHER *cipher, ENGINE *impl)
 154         {
 155         static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];
 156 #ifdef OPENSSL_FIPS
 157         if (FIPS_mode())
 158                 {
 159                 /* If we have an ENGINE need to allow non FIPS */
 160                 if ((impl || ctx->cctx.engine)
 161                         && !(ctx->cctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW))
 162
 163                         {
 164                         EVPerr(EVP_F_CMAC_INIT, EVP_R_DISABLED_FOR_FIPS);
 165                         return 0;
 166                         }
 167                 /* Other algorithm blocking will be done in FIPS_cmac_init,
 168                  * via FIPS_cipherinit().
 169                  */
 170                 if (!impl && !ctx->cctx.engine)
 171                         return FIPS_cmac_init(ctx, key, keylen, cipher, NULL);
 172                 }
 173 #endif
 174         /* All zeros means restart */
 175         if (!key && !cipher && !impl && keylen == 0)
 176                 {
 177                 /* Not initialised */
 178                 if (ctx->nlast_block == -1)
 179                         return 0;
 180                 if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
 181                         return 0;
 182                 memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx));
 183                 ctx->nlast_block = 0;
 184                 return 1;
 185                 }
 186         /* Initialiase context */
 187         if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL))
 188                 return 0;
 189         /* Non-NULL key means initialisation complete */
 190         if (key)
 191                 {
 192                 int bl;
 193                 if (!EVP_CIPHER_CTX_cipher(&ctx->cctx))
 194                         return 0;
 195                 if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen))
 196                         return 0;
 197                 if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv))
 198                         return 0;
 199                 bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
 200                 if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl))
 201                         return 0;
 202                 make_kn(ctx->k1, ctx->tbl, bl);
 203                 make_kn(ctx->k2, ctx->k1, bl);
 204                 OPENSSL_cleanse(ctx->tbl, bl);
 205                 /* Reset context again ready for first data block */
 206                 if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
 207                         return 0;
 208                 /* Zero tbl so resume works */
 209                 memset(ctx->tbl, 0, bl);
 210                 ctx->nlast_block = 0;
 211                 }
 212         return 1;
 213         }
 214
 215 int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen)
 216         {
 217         const unsigned char *data = in;
 218         size_t bl;
 219 #ifdef OPENSSL_FIPS
 220         if (FIPS_mode() && !ctx->cctx.engine)
 221                 return FIPS_cmac_update(ctx, in, dlen);
 222 #endif
 223         if (ctx->nlast_block == -1)
 224                 return 0;
 225         if (dlen == 0)
 226                 return 1;
 227         bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
 228         /* Copy into partial block if we need to */
 229         if (ctx->nlast_block > 0)
 230                 {
 231                 size_t nleft;
 232                 nleft = bl - ctx->nlast_block;
 233                 if (dlen < nleft)
 234                         nleft = dlen;
 235                 memcpy(ctx->last_block + ctx->nlast_block, data, nleft);
 236                 dlen -= nleft;
 237                 ctx->nlast_block += nleft;
 238                 /* If no more to process return */
 239                 if (dlen == 0)
 240                         return 1;
 241                 data += nleft;
 242                 /* Else not final block so encrypt it */
 243                 if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block,bl))
 244                         return 0;
 245                 }
 246         /* Encrypt all but one of the complete blocks left */
 247         while(dlen > bl)
 248                 {
 249                 if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl))
 250                         return 0;
 251                 dlen -= bl;
 252                 data += bl;
 253                 }
 254         /* Copy any data left to last block buffer */
 255         memcpy(ctx->last_block, data, dlen);
 256         ctx->nlast_block = dlen;
 257         return 1;
 258
 259         }
 260
 261 int CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen)
 262         {
 263         int i, bl, lb;
 264 #ifdef OPENSSL_FIPS
 265         if (FIPS_mode() && !ctx->cctx.engine)
 266                 return FIPS_cmac_final(ctx, out, poutlen);
 267 #endif
 268         if (ctx->nlast_block == -1)
 269                 return 0;
 270         bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
 271         *poutlen = (size_t)bl;
 272         if (!out)
 273                 return 1;
 274         lb = ctx->nlast_block;
 275         /* Is last block complete? */
 276         if (lb == bl)
 277                 {
 278                 for (i = 0; i < bl; i++)
 279                         out[i] = ctx->last_block[i] ^ ctx->k1[i];
 280                 }
 281         else
 282                 {
 283                 ctx->last_block[lb] = 0x80;
 284                 if (bl - lb > 1)
 285                         memset(ctx->last_block + lb + 1, 0, bl - lb - 1);
 286                 for (i = 0; i < bl; i++)
 287                         out[i] = ctx->last_block[i] ^ ctx->k2[i];
 288                 }
 289         if (!EVP_Cipher(&ctx->cctx, out, out, bl))
 290                 {
 291                 OPENSSL_cleanse(out, bl);
 292                 return 0;
 293                 }
 294         return 1;
 295         }
 296
 297 int CMAC_resume(CMAC_CTX *ctx)
 298         {
 299         if (ctx->nlast_block == -1)
 300                 return 0;
 301         /* The buffer "tbl" containes the last fully encrypted block
 302          * which is the last IV (or all zeroes if no last encrypted block).
 303          * The last block has not been modified since CMAC_final().
 304          * So reinitliasing using the last decrypted block will allow
 305          * CMAC to continue after calling CMAC_Final().
 306          */
 307         return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl);
 308         }