release/src/router/openssl/crypto/modes/cts128.c

   1 /* ====================================================================
   2  * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
   3  *
   4  * Rights for redistribution and usage in source and binary
   5  * forms are granted according to the OpenSSL license.
   6  */
   7
   8 #include <openssl/crypto.h>
   9 #include "modes_lcl.h"
  10 #include <string.h>
  11
  12 #ifndef MODES_DEBUG
  13 # ifndef NDEBUG
  14 #  define NDEBUG
  15 # endif
  16 #endif
  17 #include <assert.h>
  18
  19 /*
  20  * Trouble with Ciphertext Stealing, CTS, mode is that there is no
  21  * common official specification, but couple of cipher/application
  22  * specific ones: RFC2040 and RFC3962. Then there is 'Proposal to
  23  * Extend CBC Mode By "Ciphertext Stealing"' at NIST site, which
  24  * deviates from mentioned RFCs. Most notably it allows input to be
  25  * of block length and it doesn't flip the order of the last two
  26  * blocks. CTS is being discussed even in ECB context, but it's not
  27  * adopted for any known application. This implementation provides
  28  * two interfaces: one compliant with above mentioned RFCs and one
  29  * compliant with the NIST proposal, both extending CBC mode.
  30  */
  31
  32 size_t CRYPTO_cts128_encrypt_block(const unsigned char *in, unsigned char *out,
  33                         size_t len, const void *key,
  34                         unsigned char ivec[16], block128_f block)
  35 {       size_t residue, n;
  36
  37         assert (in && out && key && ivec);
  38
  39         if (len <= 16) return 0;
  40
  41         if ((residue=len%16) == 0) residue = 16;
  42
  43         len -= residue;
  44
  45         CRYPTO_cbc128_encrypt(in,out,len,key,ivec,block);
  46
  47         in  += len;
  48         out += len;
  49
  50         for (n=0; n<residue; ++n)
  51                 ivec[n] ^= in[n];
  52         (*block)(ivec,ivec,key);
  53         memcpy(out,out-16,residue);
  54         memcpy(out-16,ivec,16);
  55
  56         return len+residue;
  57 }
  58
  59 size_t CRYPTO_nistcts128_encrypt_block(const unsigned char *in, unsigned char *out,
  60                         size_t len, const void *key,
  61                         unsigned char ivec[16], block128_f block)
  62 {       size_t residue, n;
  63
  64         assert (in && out && key && ivec);
  65
  66         if (len < 16) return 0;
  67
  68         residue=len%16;
  69
  70         len -= residue;
  71
  72         CRYPTO_cbc128_encrypt(in,out,len,key,ivec,block);
  73
  74         if (residue==0) return len;
  75
  76         in  += len;
  77         out += len;
  78
  79         for (n=0; n<residue; ++n)
  80                 ivec[n] ^= in[n];
  81         (*block)(ivec,ivec,key);
  82         memcpy(out-16+residue,ivec,16);
  83
  84         return len+residue;
  85 }
  86
  87 size_t CRYPTO_cts128_encrypt(const unsigned char *in, unsigned char *out,
  88                         size_t len, const void *key,
  89                         unsigned char ivec[16], cbc128_f cbc)
  90 {       size_t residue;
  91         union { size_t align; unsigned char c[16]; } tmp;
  92
  93         assert (in && out && key && ivec);
  94
  95         if (len <= 16) return 0;
  96
  97         if ((residue=len%16) == 0) residue = 16;
  98
  99         len -= residue;
 100
 101         (*cbc)(in,out,len,key,ivec,1);
 102
 103         in  += len;
 104         out += len;
 105
 106 #if defined(CBC_HANDLES_TRUNCATED_IO)
 107         memcpy(tmp.c,out-16,16);
 108         (*cbc)(in,out-16,residue,key,ivec,1);
 109         memcpy(out,tmp.c,residue);
 110 #else
 111         {
 112         size_t n;
 113         for (n=0; n<16; n+=sizeof(size_t))
 114                 *(size_t *)(tmp.c+n) = 0;
 115         memcpy(tmp.c,in,residue);
 116         }
 117         memcpy(out,out-16,residue);
 118         (*cbc)(tmp.c,out-16,16,key,ivec,1);
 119 #endif
 120         return len+residue;
 121 }
 122
 123 size_t CRYPTO_nistcts128_encrypt(const unsigned char *in, unsigned char *out,
 124                         size_t len, const void *key,
 125                         unsigned char ivec[16], cbc128_f cbc)
 126 {       size_t residue;
 127         union { size_t align; unsigned char c[16]; } tmp;
 128
 129         assert (in && out && key && ivec);
 130
 131         if (len < 16) return 0;
 132
 133         residue=len%16;
 134
 135         len -= residue;
 136
 137         (*cbc)(in,out,len,key,ivec,1);
 138
 139         if (residue==0) return len;
 140
 141         in  += len;
 142         out += len;
 143
 144 #if defined(CBC_HANDLES_TRUNCATED_IO)
 145         (*cbc)(in,out-16+residue,residue,key,ivec,1);
 146 #else
 147         {
 148         size_t n;
 149         for (n=0; n<16; n+=sizeof(size_t))
 150                 *(size_t *)(tmp.c+n) = 0;
 151         memcpy(tmp.c,in,residue);
 152         }
 153         (*cbc)(tmp.c,out-16+residue,16,key,ivec,1);
 154 #endif
 155         return len+residue;
 156 }
 157
 158 size_t CRYPTO_cts128_decrypt_block(const unsigned char *in, unsigned char *out,
 159                         size_t len, const void *key,
 160                         unsigned char ivec[16], block128_f block)
 161 {       size_t residue, n;
 162         union { size_t align; unsigned char c[32]; } tmp;
 163
 164         assert (in && out && key && ivec);
 165
 166         if (len<=16) return 0;
 167
 168         if ((residue=len%16) == 0) residue = 16;
 169
 170         len -= 16+residue;
 171
 172         if (len) {
 173                 CRYPTO_cbc128_decrypt(in,out,len,key,ivec,block);
 174                 in  += len;
 175                 out += len;
 176         }
 177
 178         (*block)(in,tmp.c+16,key);
 179
 180         for (n=0; n<16; n+=sizeof(size_t))
 181                 *(size_t *)(tmp.c+n) = *(size_t *)(tmp.c+16+n);
 182         memcpy(tmp.c,in+16,residue);
 183         (*block)(tmp.c,tmp.c,key);
 184
 185         for(n=0; n<16; ++n) {
 186                 unsigned char c = in[n];
 187                 out[n] = tmp.c[n] ^ ivec[n];
 188                 ivec[n] = c;
 189         }
 190         for(residue+=16; n<residue; ++n)
 191                 out[n] = tmp.c[n] ^ in[n];
 192
 193         return 16+len+residue;
 194 }
 195
 196 size_t CRYPTO_nistcts128_decrypt_block(const unsigned char *in, unsigned char *out,
 197                         size_t len, const void *key,
 198                         unsigned char ivec[16], block128_f block)
 199 {       size_t residue, n;
 200         union { size_t align; unsigned char c[32]; } tmp;
 201
 202         assert (in && out && key && ivec);
 203
 204         if (len<16) return 0;
 205
 206         residue=len%16;
 207
 208         if (residue==0) {
 209                 CRYPTO_cbc128_decrypt(in,out,len,key,ivec,block);
 210                 return len;
 211         }
 212
 213         len -= 16+residue;
 214
 215         if (len) {
 216                 CRYPTO_cbc128_decrypt(in,out,len,key,ivec,block);
 217                 in  += len;
 218                 out += len;
 219         }
 220
 221         (*block)(in+residue,tmp.c+16,key);
 222
 223         for (n=0; n<16; n+=sizeof(size_t))
 224                 *(size_t *)(tmp.c+n) = *(size_t *)(tmp.c+16+n);
 225         memcpy(tmp.c,in,residue);
 226         (*block)(tmp.c,tmp.c,key);
 227
 228         for(n=0; n<16; ++n) {
 229                 unsigned char c = in[n];
 230                 out[n] = tmp.c[n] ^ ivec[n];
 231                 ivec[n] = in[n+residue];
 232                 tmp.c[n] = c;
 233         }
 234         for(residue+=16; n<residue; ++n)
 235                 out[n] = tmp.c[n] ^ tmp.c[n-16];
 236
 237         return 16+len+residue;
 238 }
 239
 240 size_t CRYPTO_cts128_decrypt(const unsigned char *in, unsigned char *out,
 241                         size_t len, const void *key,
 242                         unsigned char ivec[16], cbc128_f cbc)
 243 {       size_t residue, n;
 244         union { size_t align; unsigned char c[32]; } tmp;
 245
 246         assert (in && out && key && ivec);
 247
 248         if (len<=16) return 0;
 249
 250         if ((residue=len%16) == 0) residue = 16;
 251
 252         len -= 16+residue;
 253
 254         if (len) {
 255                 (*cbc)(in,out,len,key,ivec,0);
 256                 in  += len;
 257                 out += len;
 258         }
 259
 260         for (n=16; n<32; n+=sizeof(size_t))
 261                 *(size_t *)(tmp.c+n) = 0;
 262         /* this places in[16] at &tmp.c[16] and decrypted block at &tmp.c[0] */
 263         (*cbc)(in,tmp.c,16,key,tmp.c+16,0);
 264
 265         memcpy(tmp.c,in+16,residue);
 266 #if defined(CBC_HANDLES_TRUNCATED_IO)
 267         (*cbc)(tmp.c,out,16+residue,key,ivec,0);
 268 #else
 269         (*cbc)(tmp.c,tmp.c,32,key,ivec,0);
 270         memcpy(out,tmp.c,16+residue);
 271 #endif
 272         return 16+len+residue;
 273 }
 274
 275 size_t CRYPTO_nistcts128_decrypt(const unsigned char *in, unsigned char *out,
 276                         size_t len, const void *key,
 277                         unsigned char ivec[16], cbc128_f cbc)
 278 {       size_t residue, n;
 279         union { size_t align; unsigned char c[32]; } tmp;
 280
 281         assert (in && out && key && ivec);
 282
 283         if (len<16) return 0;
 284
 285         residue=len%16;
 286
 287         if (residue==0) {
 288                 (*cbc)(in,out,len,key,ivec,0);
 289                 return len;
 290         }
 291
 292         len -= 16+residue;
 293
 294         if (len) {
 295                 (*cbc)(in,out,len,key,ivec,0);
 296                 in  += len;
 297                 out += len;
 298         }
 299
 300         for (n=16; n<32; n+=sizeof(size_t))
 301                 *(size_t *)(tmp.c+n) = 0;
 302         /* this places in[16] at &tmp.c[16] and decrypted block at &tmp.c[0] */
 303         (*cbc)(in+residue,tmp.c,16,key,tmp.c+16,0);
 304
 305         memcpy(tmp.c,in,residue);
 306 #if defined(CBC_HANDLES_TRUNCATED_IO)
 307         (*cbc)(tmp.c,out,16+residue,key,ivec,0);
 308 #else
 309         (*cbc)(tmp.c,tmp.c,32,key,ivec,0);
 310         memcpy(out,tmp.c,16+residue);
 311 #endif
 312         return 16+len+residue;
 313 }
 314
 315 #if defined(SELFTEST)
 316 #include <stdio.h>
 317 #include <openssl/aes.h>
 318
 319 /* test vectors from RFC 3962 */
 320 static const unsigned char test_key[16] = "chicken teriyaki";
 321 static const unsigned char test_input[64] =
 322                 "I would like the" " General Gau's C"
 323                 "hicken, please, " "and wonton soup.";
 324 static const unsigned char test_iv[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
 325
 326 static const unsigned char vector_17[17] =
 327 {0xc6,0x35,0x35,0x68,0xf2,0xbf,0x8c,0xb4, 0xd8,0xa5,0x80,0x36,0x2d,0xa7,0xff,0x7f,
 328  0x97};
 329 static const unsigned char vector_31[31] =
 330 {0xfc,0x00,0x78,0x3e,0x0e,0xfd,0xb2,0xc1, 0xd4,0x45,0xd4,0xc8,0xef,0xf7,0xed,0x22,
 331  0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5};
 332 static const unsigned char vector_32[32] =
 333 {0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5,0xa8,
 334  0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84};
 335 static const unsigned char vector_47[47] =
 336 {0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84,
 337  0xb3,0xff,0xfd,0x94,0x0c,0x16,0xa1,0x8c, 0x1b,0x55,0x49,0xd2,0xf8,0x38,0x02,0x9e,
 338  0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5};
 339 static const unsigned char vector_48[48] =
 340 {0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84,
 341  0x9d,0xad,0x8b,0xbb,0x96,0xc4,0xcd,0xc0, 0x3b,0xc1,0x03,0xe1,0xa1,0x94,0xbb,0xd8,
 342  0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5,0xa8};
 343 static const unsigned char vector_64[64] =
 344 {0x97,0x68,0x72,0x68,0xd6,0xec,0xcc,0xc0, 0xc0,0x7b,0x25,0xe2,0x5e,0xcf,0xe5,0x84,
 345  0x39,0x31,0x25,0x23,0xa7,0x86,0x62,0xd5, 0xbe,0x7f,0xcb,0xcc,0x98,0xeb,0xf5,0xa8,
 346  0x48,0x07,0xef,0xe8,0x36,0xee,0x89,0xa5, 0x26,0x73,0x0d,0xbc,0x2f,0x7b,0xc8,0x40,
 347  0x9d,0xad,0x8b,0xbb,0x96,0xc4,0xcd,0xc0, 0x3b,0xc1,0x03,0xe1,0xa1,0x94,0xbb,0xd8};
 348
 349 static AES_KEY encks, decks;
 350
 351 void test_vector(const unsigned char *vector,size_t len)
 352 {       unsigned char iv[sizeof(test_iv)];
 353         unsigned char cleartext[64],ciphertext[64];
 354         size_t tail;
 355
 356         printf("vector_%d\n",len); fflush(stdout);
 357
 358         if ((tail=len%16) == 0) tail = 16;
 359         tail += 16;
 360
 361         /* test block-based encryption */
 362         memcpy(iv,test_iv,sizeof(test_iv));
 363         CRYPTO_cts128_encrypt_block(test_input,ciphertext,len,&encks,iv,(block128_f)AES_encrypt);
 364         if (memcmp(ciphertext,vector,len))
 365                 fprintf(stderr,"output_%d mismatch\n",len), exit(1);
 366         if (memcmp(iv,vector+len-tail,sizeof(iv)))
 367                 fprintf(stderr,"iv_%d mismatch\n",len), exit(1);
 368
 369         /* test block-based decryption */
 370         memcpy(iv,test_iv,sizeof(test_iv));
 371         CRYPTO_cts128_decrypt_block(ciphertext,cleartext,len,&decks,iv,(block128_f)AES_decrypt);
 372         if (memcmp(cleartext,test_input,len))
 373                 fprintf(stderr,"input_%d mismatch\n",len), exit(2);
 374         if (memcmp(iv,vector+len-tail,sizeof(iv)))
 375                 fprintf(stderr,"iv_%d mismatch\n",len), exit(2);
 376
 377         /* test streamed encryption */
 378         memcpy(iv,test_iv,sizeof(test_iv));
 379         CRYPTO_cts128_encrypt(test_input,ciphertext,len,&encks,iv,(cbc128_f)AES_cbc_encrypt);
 380         if (memcmp(ciphertext,vector,len))
 381                 fprintf(stderr,"output_%d mismatch\n",len), exit(3);
 382         if (memcmp(iv,vector+len-tail,sizeof(iv)))
 383                 fprintf(stderr,"iv_%d mismatch\n",len), exit(3);
 384
 385         /* test streamed decryption */
 386         memcpy(iv,test_iv,sizeof(test_iv));
 387         CRYPTO_cts128_decrypt(ciphertext,cleartext,len,&decks,iv,(cbc128_f)AES_cbc_encrypt);
 388         if (memcmp(cleartext,test_input,len))
 389                 fprintf(stderr,"input_%d mismatch\n",len), exit(4);
 390         if (memcmp(iv,vector+len-tail,sizeof(iv)))
 391                 fprintf(stderr,"iv_%d mismatch\n",len), exit(4);
 392 }
 393
 394 void test_nistvector(const unsigned char *vector,size_t len)
 395 {       unsigned char iv[sizeof(test_iv)];
 396         unsigned char cleartext[64],ciphertext[64],nistvector[64];
 397         size_t tail;
 398
 399         printf("nistvector_%d\n",len); fflush(stdout);
 400
 401         if ((tail=len%16) == 0) tail = 16;
 402
 403         len -= 16 + tail;
 404         memcpy(nistvector,vector,len);
 405         /* flip two last blocks */
 406         memcpy(nistvector+len,vector+len+16,tail);
 407         memcpy(nistvector+len+tail,vector+len,16);
 408         len += 16 + tail;
 409         tail = 16;
 410
 411         /* test block-based encryption */
 412         memcpy(iv,test_iv,sizeof(test_iv));
 413         CRYPTO_nistcts128_encrypt_block(test_input,ciphertext,len,&encks,iv,(block128_f)AES_encrypt);
 414         if (memcmp(ciphertext,nistvector,len))
 415                 fprintf(stderr,"output_%d mismatch\n",len), exit(1);
 416         if (memcmp(iv,nistvector+len-tail,sizeof(iv)))
 417                 fprintf(stderr,"iv_%d mismatch\n",len), exit(1);
 418
 419         /* test block-based decryption */
 420         memcpy(iv,test_iv,sizeof(test_iv));
 421         CRYPTO_nistcts128_decrypt_block(ciphertext,cleartext,len,&decks,iv,(block128_f)AES_decrypt);
 422         if (memcmp(cleartext,test_input,len))
 423                 fprintf(stderr,"input_%d mismatch\n",len), exit(2);
 424         if (memcmp(iv,nistvector+len-tail,sizeof(iv)))
 425                 fprintf(stderr,"iv_%d mismatch\n",len), exit(2);
 426
 427         /* test streamed encryption */
 428         memcpy(iv,test_iv,sizeof(test_iv));
 429         CRYPTO_nistcts128_encrypt(test_input,ciphertext,len,&encks,iv,(cbc128_f)AES_cbc_encrypt);
 430         if (memcmp(ciphertext,nistvector,len))
 431                 fprintf(stderr,"output_%d mismatch\n",len), exit(3);
 432         if (memcmp(iv,nistvector+len-tail,sizeof(iv)))
 433                 fprintf(stderr,"iv_%d mismatch\n",len), exit(3);
 434
 435         /* test streamed decryption */
 436         memcpy(iv,test_iv,sizeof(test_iv));
 437         CRYPTO_nistcts128_decrypt(ciphertext,cleartext,len,&decks,iv,(cbc128_f)AES_cbc_encrypt);
 438         if (memcmp(cleartext,test_input,len))
 439                 fprintf(stderr,"input_%d mismatch\n",len), exit(4);
 440         if (memcmp(iv,nistvector+len-tail,sizeof(iv)))
 441                 fprintf(stderr,"iv_%d mismatch\n",len), exit(4);
 442 }
 443
 444 int main()
 445 {
 446         AES_set_encrypt_key(test_key,128,&encks);
 447         AES_set_decrypt_key(test_key,128,&decks);
 448
 449         test_vector(vector_17,sizeof(vector_17));
 450         test_vector(vector_31,sizeof(vector_31));
 451         test_vector(vector_32,sizeof(vector_32));
 452         test_vector(vector_47,sizeof(vector_47));
 453         test_vector(vector_48,sizeof(vector_48));
 454         test_vector(vector_64,sizeof(vector_64));
 455
 456         test_nistvector(vector_17,sizeof(vector_17));
 457         test_nistvector(vector_31,sizeof(vector_31));
 458         test_nistvector(vector_32,sizeof(vector_32));
 459         test_nistvector(vector_47,sizeof(vector_47));
 460         test_nistvector(vector_48,sizeof(vector_48));
 461         test_nistvector(vector_64,sizeof(vector_64));
 462
 463         return 0;
 464 }
 465 #endif