crypto/modes/ccm128.c

   1 /* ====================================================================
   2  * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  *
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in
  13  *    the documentation and/or other materials provided with the
  14  *    distribution.
  15  *
  16  * 3. All advertising materials mentioning features or use of this
  17  *    software must display the following acknowledgment:
  18  *    "This product includes software developed by the OpenSSL Project
  19  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  20  *
  21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  22  *    endorse or promote products derived from this software without
  23  *    prior written permission. For written permission, please contact
  24  *    openssl-core@openssl.org.
  25  *
  26  * 5. Products derived from this software may not be called "OpenSSL"
  27  *    nor may "OpenSSL" appear in their names without prior written
  28  *    permission of the OpenSSL Project.
  29  *
  30  * 6. Redistributions of any form whatsoever must retain the following
  31  *    acknowledgment:
  32  *    "This product includes software developed by the OpenSSL Project
  33  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  46  * OF THE POSSIBILITY OF SUCH DAMAGE.
  47  * ====================================================================
  48  */
  49
  50 #include <openssl/crypto.h>
  51 #include "modes_lcl.h"
  52 #include <string.h>
  53
  54 #ifndef MODES_DEBUG
  55 # ifndef NDEBUG
  56 #  define NDEBUG
  57 # endif
  58 #endif
  59 #include <assert.h>
  60
  61 typedef struct {
  62         union { u8 c[16]; size_t s[16/sizeof(size_t)]; } nonce, cmac,
  63                                                          scratch, inp;
  64         u64 blocks;
  65         block128_f block;
  66         void *key;
  67 } CCM128_CONTEXT;
  68
  69 /* First you setup M and L parameters and pass the key schedule */
  70 void CRYPTO_ccm128_init(CCM128_CONTEXT *ctx,
  71         unsigned int M,unsigned int L,void *key)
  72 {
  73         memset(ctx->nonce.c,0,sizeof(ctx->nonce.c));
  74         ctx->nonce.c[0] = ((u8)(L-1)&7) | (u8)(((M-2)/2)&7)<<3;
  75         ctx->blocks = 0;
  76         ctx->key = key;
  77 }
  78
  79 /* !!! Following interfaces are to be called *once* per packet !!! */
  80
  81 /* Then you setup per-message nonce and pass the length of the message */
  82 int CRYPTO_ccm128_setiv(CCM128_CONTEXT *ctx,
  83         const unsigned char *nonce,size_t nlen,size_t mlen)
  84 {
  85         unsigned int L = ctx->nonce.c[0]&7;     /* the L parameter */
  86
  87         if (nlen<(14-L)) return -1;             /* nonce is too short */
  88
  89         if (sizeof(mlen)==8 && L>=3) {
  90                 ctx->nonce.c[8]  = (u8)(mlen>>(56%(sizeof(mlen)*8)));
  91                 ctx->nonce.c[9]  = (u8)(mlen>>(48%(sizeof(mlen)*8)));
  92                 ctx->nonce.c[10] = (u8)(mlen>>(40%(sizeof(mlen)*8)));
  93                 ctx->nonce.c[11] = (u8)(mlen>>(32%(sizeof(mlen)*8)));
  94         }
  95         else
  96                 *((size_t *)&ctx->nonce.s[8]) = 0;
  97
  98         ctx->nonce.c[12] = (u8)(mlen>>24);
  99         ctx->nonce.c[13] = (u8)(mlen>>16);
 100         ctx->nonce.c[14] = (u8)(mlen>>8);
 101         ctx->nonce.c[15] = (u8)mlen;
 102
 103         ctx->nonce.c[0] &= ~0x40;       /* clear Adata flag */
 104         memcpy(&ctx->nonce.c[1],nonce,14-L);
 105
 106         return 0;
 107 }
 108
 109 /* Then you pass additional authentication data, this is optional */
 110 void CRYPTO_ccm128_aad(CCM128_CONTEXT *ctx,
 111         const unsigned char *aad,size_t alen)
 112 {       unsigned int i;
 113
 114         if (alen==0) return;
 115
 116         ctx->nonce.c[0] |= 0x40;        /* set Adata flag */
 117         (*ctx->block)(ctx->nonce.c,ctx->cmac.c,ctx->key),
 118         ctx->blocks++;
 119
 120         if (alen<(0x10000-0x100)) {
 121                 ctx->cmac.c[0] ^= (u8)(alen>>8);
 122                 ctx->cmac.c[1] ^= (u8)alen;
 123                 i=2;
 124         }
 125         else if (sizeof(alen)==8 && alen>=(size_t)1<<32) {
 126                 ctx->cmac.c[0] ^= 0xFF;
 127                 ctx->cmac.c[1] ^= 0xFF;
 128                 ctx->cmac.c[2] ^= (u8)(alen>>(56%(sizeof(alen)*8)));
 129                 ctx->cmac.c[3] ^= (u8)(alen>>(48%(sizeof(alen)*8)));
 130                 ctx->cmac.c[4] ^= (u8)(alen>>(40%(sizeof(alen)*8)));
 131                 ctx->cmac.c[5] ^= (u8)(alen>>(32%(sizeof(alen)*8)));
 132                 ctx->cmac.c[6] ^= (u8)(alen>>24);
 133                 ctx->cmac.c[7] ^= (u8)(alen>>16);
 134                 ctx->cmac.c[8] ^= (u8)(alen>>8);
 135                 ctx->cmac.c[9] ^= (u8)alen;
 136                 i=10;
 137         }
 138         else {
 139                 ctx->cmac.c[0] ^= 0xFF;
 140                 ctx->cmac.c[1] ^= 0xFE;
 141                 ctx->cmac.c[2] ^= (u8)(alen>>24);
 142                 ctx->cmac.c[3] ^= (u8)(alen>>16);
 143                 ctx->cmac.c[4] ^= (u8)(alen>>8);
 144                 ctx->cmac.c[5] ^= (u8)alen;
 145                 i=6;
 146         }
 147
 148         do {
 149                 for(;i<16 && alen;++i,++aad,--alen)
 150                         ctx->cmac.c[i] ^= *aad;
 151                 (*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key),
 152                 ctx->blocks++;
 153                 i=0;
 154         } while (alen);
 155 }
 156
 157 /* Finally you encrypt or decrypt the message */
 158
 159 static void ctr128_inc(unsigned char *counter) {
 160         unsigned int n=16;
 161         u8  c;
 162
 163         do {
 164                 --n;
 165                 c = counter[n];
 166                 ++c;
 167                 counter[n] = c;
 168                 if (c) return;
 169         } while (n);
 170 }
 171
 172 int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
 173         const unsigned char *inp, unsigned char *out,
 174         size_t len)
 175 {
 176         size_t          n;
 177         unsigned int    i;
 178         unsigned char   flags = ctx->nonce.c[0];
 179
 180         if (!(flags&0x40))
 181                 (*ctx->block)(ctx->nonce.c,ctx->cmac.c,ctx->key),
 182                 ctx->blocks++;
 183
 184         flags &= 7;     /* extract the L parameter */
 185         for (n=0,i=15-flags;i<15;++i) {
 186                 n |= ctx->nonce.c[i]; ctx->nonce.c[i]=0;
 187                 n <<= 8;
 188         }
 189         n |= ctx->nonce.c[15];  /* reconstructed length */
 190         ctx->nonce.c[15]=1;
 191
 192         if (n!=len) return -1;  /* length mismatch */
 193
 194         ctx->blocks += ((len+15)>>3)|1;
 195         if (ctx->blocks > (U64(1)<<61)) return -2; /* too much data */
 196
 197         while (len>=16) {
 198 #if defined(STRICT_ALIGNMENT)
 199                 memcpy (ctx->inp.c,inp,16);
 200                 for (i=0; i<16/sizeof(size_t); ++i)
 201                         ctx->cmac.s[i] ^= ctx->inp.s[i];
 202 #else
 203                 for (i=0; i<16/sizeof(size_t); ++i)
 204                         ctx->cmac.s[i] ^= ((size_t*)inp)[i];
 205 #endif
 206                 (*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
 207                 (*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
 208                 ctr128_inc(ctx->nonce.c);
 209 #if defined(STRICT_ALIGNMENT)
 210                 for (i=0; i<16/sizeof(size_t); ++i)
 211                         ctx->inp.s[i] ^= ctx->scratch.s[i];
 212                 memcpy(out,ctx->inp.c,16);
 213 #else
 214                 for (i=0; i<16/sizeof(size_t); ++i)
 215                         ((size_t*)out)[i] = ctx->scratch.s[i]^((size_t*)inp)[i];
 216 #endif
 217                 inp += 16;
 218                 out += 16;
 219                 len -= 16;
 220         }
 221
 222         if (len) {
 223                 for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
 224                 (*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
 225                 (*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
 226                 for (i=0; i<len; ++i) out[i] = ctx->scratch.c[i]^inp[i];
 227         }
 228
 229         for (i=15-flags;i<16;++i)
 230                 ctx->nonce.c[i]=0;
 231
 232         (*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
 233         for (i=0; i<16/sizeof(size_t); ++i)
 234                 ctx->cmac.s[i] ^= ctx->scratch.s[i];
 235
 236         return 0;
 237 }
 238
 239 int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
 240         const unsigned char *inp, unsigned char *out,
 241         size_t len)
 242 {
 243         size_t          n;
 244         unsigned int    i;
 245         unsigned char   flags = ctx->nonce.c[0];
 246
 247         if (!(flags&0x40))
 248                 (*ctx->block)(ctx->nonce.c,ctx->cmac.c,ctx->key);
 249
 250         flags &= 7;     /* extract the L parameter */
 251         for (n=0,i=15-flags;i<15;++i) {
 252                 n |= ctx->nonce.c[i]; ctx->nonce.c[i]=0;
 253                 n <<= 8;
 254         }
 255         n |= ctx->nonce.c[15];  /* reconstructed length */
 256         ctx->nonce.c[15]=1;
 257
 258         if (n!=len) return -1;
 259
 260         while (len>=16) {
 261                 (*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
 262                 ctr128_inc(ctx->nonce.c);
 263 #if defined(STRICT_ALIGNMENT)
 264                 memcpy (ctx->inp.c,inp,16);
 265                 for (i=0; i<16/sizeof(size_t); ++i)
 266                         ctx->cmac.s[i] ^= (ctx->scratch.s[i] ^= ctx->inp.s[i]);
 267                 memcpy (out,ctx->scratch,16);
 268 #else
 269                 for (i=0; i<16/sizeof(size_t); ++i)
 270                         ctx->cmac.s[i] ^= ((size_t*)out)[i] = ctx->scratch.s[i]^((size_t*)inp)[i];
 271 #endif
 272                 (*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
 273
 274                 inp += 16;
 275                 out += 16;
 276                 len -= 16;
 277         }
 278
 279         if (len) {
 280                 (*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
 281                 for (i=0; i<len; ++len)
 282                         ctx->cmac.c[i] ^= (out[i] = ctx->scratch.c[i]^inp[i]);
 283                 (*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
 284         }
 285
 286         for (i=15-flags;i<16;++i)
 287                 ctx->nonce.c[i]=0;
 288
 289         (*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
 290         for (i=0; i<16/sizeof(size_t); ++i)
 291                 ctx->cmac.s[i] ^= ctx->scratch.s[i];
 292
 293         return 0;
 294 }
 295
 296 size_t CRYPTO_ccm128_tag(CCM128_CONTEXT *ctx,unsigned char *tag,size_t len)
 297 {       unsigned int M = (ctx->nonce.c[0]>>3)&7;        /* the M parameter */
 298
 299         M *= 2; M += 2;
 300         if (len<M)      return 0;
 301         memcpy(tag,ctx->cmac.c,M);
 302         return M;
 303 }