crypto/cipher-builtin.c.inc

   1 /*
   2  * QEMU Crypto cipher built-in algorithms
   3  *
   4  * Copyright (c) 2015 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "crypto/aes.h"
  22 #include "crypto/desrfb.h"
  23 #include "crypto/xts.h"
  24
  25 typedef struct QCryptoCipherBuiltinAESContext QCryptoCipherBuiltinAESContext;
  26 struct QCryptoCipherBuiltinAESContext {
  27     AES_KEY enc;
  28     AES_KEY dec;
  29 };
  30 typedef struct QCryptoCipherBuiltinAES QCryptoCipherBuiltinAES;
  31 struct QCryptoCipherBuiltinAES {
  32     QCryptoCipherBuiltinAESContext key;
  33     QCryptoCipherBuiltinAESContext key_tweak;
  34     uint8_t iv[AES_BLOCK_SIZE];
  35 };
  36 typedef struct QCryptoCipherBuiltinDESRFB QCryptoCipherBuiltinDESRFB;
  37 struct QCryptoCipherBuiltinDESRFB {
  38     uint8_t *key;
  39     size_t nkey;
  40 };
  41
  42 typedef struct QCryptoCipherBuiltin QCryptoCipherBuiltin;
  43 struct QCryptoCipherBuiltin {
  44     union {
  45         QCryptoCipherBuiltinAES aes;
  46         QCryptoCipherBuiltinDESRFB desrfb;
  47     } state;
  48     size_t blocksize;
  49     void (*free)(QCryptoCipher *cipher);
  50     int (*setiv)(QCryptoCipher *cipher,
  51                  const uint8_t *iv, size_t niv,
  52                  Error **errp);
  53     int (*encrypt)(QCryptoCipher *cipher,
  54                    const void *in,
  55                    void *out,
  56                    size_t len,
  57                    Error **errp);
  58     int (*decrypt)(QCryptoCipher *cipher,
  59                    const void *in,
  60                    void *out,
  61                    size_t len,
  62                    Error **errp);
  63 };
  64
  65
  66 static void qcrypto_cipher_free_aes(QCryptoCipher *cipher)
  67 {
  68     QCryptoCipherBuiltin *ctxt = cipher->opaque;
  69
  70     g_free(ctxt);
  71     cipher->opaque = NULL;
  72 }
  73
  74
  75 static void qcrypto_cipher_aes_ecb_encrypt(const AES_KEY *key,
  76                                            const void *in,
  77                                            void *out,
  78                                            size_t len)
  79 {
  80     const uint8_t *inptr = in;
  81     uint8_t *outptr = out;
  82     while (len) {
  83         if (len > AES_BLOCK_SIZE) {
  84             AES_encrypt(inptr, outptr, key);
  85             inptr += AES_BLOCK_SIZE;
  86             outptr += AES_BLOCK_SIZE;
  87             len -= AES_BLOCK_SIZE;
  88         } else {
  89             uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
  90             memcpy(tmp1, inptr, len);
  91             /* Fill with 0 to avoid valgrind uninitialized reads */
  92             memset(tmp1 + len, 0, sizeof(tmp1) - len);
  93             AES_encrypt(tmp1, tmp2, key);
  94             memcpy(outptr, tmp2, len);
  95             len = 0;
  96         }
  97     }
  98 }
  99
 100
 101 static void qcrypto_cipher_aes_ecb_decrypt(const AES_KEY *key,
 102                                            const void *in,
 103                                            void *out,
 104                                            size_t len)
 105 {
 106     const uint8_t *inptr = in;
 107     uint8_t *outptr = out;
 108     while (len) {
 109         if (len > AES_BLOCK_SIZE) {
 110             AES_decrypt(inptr, outptr, key);
 111             inptr += AES_BLOCK_SIZE;
 112             outptr += AES_BLOCK_SIZE;
 113             len -= AES_BLOCK_SIZE;
 114         } else {
 115             uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
 116             memcpy(tmp1, inptr, len);
 117             /* Fill with 0 to avoid valgrind uninitialized reads */
 118             memset(tmp1 + len, 0, sizeof(tmp1) - len);
 119             AES_decrypt(tmp1, tmp2, key);
 120             memcpy(outptr, tmp2, len);
 121             len = 0;
 122         }
 123     }
 124 }
 125
 126
 127 static void qcrypto_cipher_aes_xts_encrypt(const void *ctx,
 128                                            size_t length,
 129                                            uint8_t *dst,
 130                                            const uint8_t *src)
 131 {
 132     const QCryptoCipherBuiltinAESContext *aesctx = ctx;
 133
 134     qcrypto_cipher_aes_ecb_encrypt(&aesctx->enc, src, dst, length);
 135 }
 136
 137
 138 static void qcrypto_cipher_aes_xts_decrypt(const void *ctx,
 139                                            size_t length,
 140                                            uint8_t *dst,
 141                                            const uint8_t *src)
 142 {
 143     const QCryptoCipherBuiltinAESContext *aesctx = ctx;
 144
 145     qcrypto_cipher_aes_ecb_decrypt(&aesctx->dec, src, dst, length);
 146 }
 147
 148
 149 static int qcrypto_cipher_encrypt_aes(QCryptoCipher *cipher,
 150                                       const void *in,
 151                                       void *out,
 152                                       size_t len,
 153                                       Error **errp)
 154 {
 155     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 156
 157     switch (cipher->mode) {
 158     case QCRYPTO_CIPHER_MODE_ECB:
 159         qcrypto_cipher_aes_ecb_encrypt(&ctxt->state.aes.key.enc,
 160                                        in, out, len);
 161         break;
 162     case QCRYPTO_CIPHER_MODE_CBC:
 163         AES_cbc_encrypt(in, out, len,
 164                         &ctxt->state.aes.key.enc,
 165                         ctxt->state.aes.iv, 1);
 166         break;
 167     case QCRYPTO_CIPHER_MODE_XTS:
 168         xts_encrypt(&ctxt->state.aes.key,
 169                     &ctxt->state.aes.key_tweak,
 170                     qcrypto_cipher_aes_xts_encrypt,
 171                     qcrypto_cipher_aes_xts_decrypt,
 172                     ctxt->state.aes.iv,
 173                     len, out, in);
 174         break;
 175     default:
 176         g_assert_not_reached();
 177     }
 178
 179     return 0;
 180 }
 181
 182
 183 static int qcrypto_cipher_decrypt_aes(QCryptoCipher *cipher,
 184                                       const void *in,
 185                                       void *out,
 186                                       size_t len,
 187                                       Error **errp)
 188 {
 189     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 190
 191     switch (cipher->mode) {
 192     case QCRYPTO_CIPHER_MODE_ECB:
 193         qcrypto_cipher_aes_ecb_decrypt(&ctxt->state.aes.key.dec,
 194                                        in, out, len);
 195         break;
 196     case QCRYPTO_CIPHER_MODE_CBC:
 197         AES_cbc_encrypt(in, out, len,
 198                         &ctxt->state.aes.key.dec,
 199                         ctxt->state.aes.iv, 0);
 200         break;
 201     case QCRYPTO_CIPHER_MODE_XTS:
 202         xts_decrypt(&ctxt->state.aes.key,
 203                     &ctxt->state.aes.key_tweak,
 204                     qcrypto_cipher_aes_xts_encrypt,
 205                     qcrypto_cipher_aes_xts_decrypt,
 206                     ctxt->state.aes.iv,
 207                     len, out, in);
 208         break;
 209     default:
 210         g_assert_not_reached();
 211     }
 212
 213     return 0;
 214 }
 215
 216 static int qcrypto_cipher_setiv_aes(QCryptoCipher *cipher,
 217                                      const uint8_t *iv, size_t niv,
 218                                      Error **errp)
 219 {
 220     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 221     if (niv != AES_BLOCK_SIZE) {
 222         error_setg(errp, "IV must be %d bytes not %zu",
 223                    AES_BLOCK_SIZE, niv);
 224         return -1;
 225     }
 226
 227     memcpy(ctxt->state.aes.iv, iv, AES_BLOCK_SIZE);
 228
 229     return 0;
 230 }
 231
 232
 233
 234
 235 static QCryptoCipherBuiltin *
 236 qcrypto_cipher_init_aes(QCryptoCipherMode mode,
 237                         const uint8_t *key, size_t nkey,
 238                         Error **errp)
 239 {
 240     QCryptoCipherBuiltin *ctxt;
 241
 242     if (mode != QCRYPTO_CIPHER_MODE_CBC &&
 243         mode != QCRYPTO_CIPHER_MODE_ECB &&
 244         mode != QCRYPTO_CIPHER_MODE_XTS) {
 245         error_setg(errp, "Unsupported cipher mode %s",
 246                    QCryptoCipherMode_str(mode));
 247         return NULL;
 248     }
 249
 250     ctxt = g_new0(QCryptoCipherBuiltin, 1);
 251
 252     if (mode == QCRYPTO_CIPHER_MODE_XTS) {
 253         if (AES_set_encrypt_key(key, nkey * 4, &ctxt->state.aes.key.enc) != 0) {
 254             error_setg(errp, "Failed to set encryption key");
 255             goto error;
 256         }
 257
 258         if (AES_set_decrypt_key(key, nkey * 4, &ctxt->state.aes.key.dec) != 0) {
 259             error_setg(errp, "Failed to set decryption key");
 260             goto error;
 261         }
 262
 263         if (AES_set_encrypt_key(key + (nkey / 2), nkey * 4,
 264                                 &ctxt->state.aes.key_tweak.enc) != 0) {
 265             error_setg(errp, "Failed to set encryption key");
 266             goto error;
 267         }
 268
 269         if (AES_set_decrypt_key(key + (nkey / 2), nkey * 4,
 270                                 &ctxt->state.aes.key_tweak.dec) != 0) {
 271             error_setg(errp, "Failed to set decryption key");
 272             goto error;
 273         }
 274     } else {
 275         if (AES_set_encrypt_key(key, nkey * 8, &ctxt->state.aes.key.enc) != 0) {
 276             error_setg(errp, "Failed to set encryption key");
 277             goto error;
 278         }
 279
 280         if (AES_set_decrypt_key(key, nkey * 8, &ctxt->state.aes.key.dec) != 0) {
 281             error_setg(errp, "Failed to set decryption key");
 282             goto error;
 283         }
 284     }
 285
 286     ctxt->blocksize = AES_BLOCK_SIZE;
 287     ctxt->free = qcrypto_cipher_free_aes;
 288     ctxt->setiv = qcrypto_cipher_setiv_aes;
 289     ctxt->encrypt = qcrypto_cipher_encrypt_aes;
 290     ctxt->decrypt = qcrypto_cipher_decrypt_aes;
 291
 292     return ctxt;
 293
 294  error:
 295     g_free(ctxt);
 296     return NULL;
 297 }
 298
 299
 300 static void qcrypto_cipher_free_des_rfb(QCryptoCipher *cipher)
 301 {
 302     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 303
 304     g_free(ctxt->state.desrfb.key);
 305     g_free(ctxt);
 306     cipher->opaque = NULL;
 307 }
 308
 309
 310 static int qcrypto_cipher_encrypt_des_rfb(QCryptoCipher *cipher,
 311                                           const void *in,
 312                                           void *out,
 313                                           size_t len,
 314                                           Error **errp)
 315 {
 316     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 317     size_t i;
 318
 319     if (len % 8) {
 320         error_setg(errp, "Buffer size must be multiple of 8 not %zu",
 321                    len);
 322         return -1;
 323     }
 324
 325     deskey(ctxt->state.desrfb.key, EN0);
 326
 327     for (i = 0; i < len; i += 8) {
 328         des((void *)in + i, out + i);
 329     }
 330
 331     return 0;
 332 }
 333
 334
 335 static int qcrypto_cipher_decrypt_des_rfb(QCryptoCipher *cipher,
 336                                           const void *in,
 337                                           void *out,
 338                                           size_t len,
 339                                           Error **errp)
 340 {
 341     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 342     size_t i;
 343
 344     if (len % 8) {
 345         error_setg(errp, "Buffer size must be multiple of 8 not %zu",
 346                    len);
 347         return -1;
 348     }
 349
 350     deskey(ctxt->state.desrfb.key, DE1);
 351
 352     for (i = 0; i < len; i += 8) {
 353         des((void *)in + i, out + i);
 354     }
 355
 356     return 0;
 357 }
 358
 359
 360 static int qcrypto_cipher_setiv_des_rfb(QCryptoCipher *cipher,
 361                                         const uint8_t *iv, size_t niv,
 362                                         Error **errp)
 363 {
 364     error_setg(errp, "Setting IV is not supported");
 365     return -1;
 366 }
 367
 368
 369 static QCryptoCipherBuiltin *
 370 qcrypto_cipher_init_des_rfb(QCryptoCipherMode mode,
 371                             const uint8_t *key, size_t nkey,
 372                             Error **errp)
 373 {
 374     QCryptoCipherBuiltin *ctxt;
 375
 376     if (mode != QCRYPTO_CIPHER_MODE_ECB) {
 377         error_setg(errp, "Unsupported cipher mode %s",
 378                    QCryptoCipherMode_str(mode));
 379         return NULL;
 380     }
 381
 382     ctxt = g_new0(QCryptoCipherBuiltin, 1);
 383
 384     ctxt->state.desrfb.key = g_new0(uint8_t, nkey);
 385     memcpy(ctxt->state.desrfb.key, key, nkey);
 386     ctxt->state.desrfb.nkey = nkey;
 387
 388     ctxt->blocksize = 8;
 389     ctxt->free = qcrypto_cipher_free_des_rfb;
 390     ctxt->setiv = qcrypto_cipher_setiv_des_rfb;
 391     ctxt->encrypt = qcrypto_cipher_encrypt_des_rfb;
 392     ctxt->decrypt = qcrypto_cipher_decrypt_des_rfb;
 393
 394     return ctxt;
 395 }
 396
 397
 398 bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
 399                              QCryptoCipherMode mode)
 400 {
 401     switch (alg) {
 402     case QCRYPTO_CIPHER_ALG_DES_RFB:
 403     case QCRYPTO_CIPHER_ALG_AES_128:
 404     case QCRYPTO_CIPHER_ALG_AES_192:
 405     case QCRYPTO_CIPHER_ALG_AES_256:
 406         break;
 407     default:
 408         return false;
 409     }
 410
 411     switch (mode) {
 412     case QCRYPTO_CIPHER_MODE_ECB:
 413     case QCRYPTO_CIPHER_MODE_CBC:
 414     case QCRYPTO_CIPHER_MODE_XTS:
 415         return true;
 416     case QCRYPTO_CIPHER_MODE_CTR:
 417         return false;
 418     default:
 419         return false;
 420     }
 421 }
 422
 423
 424 static QCryptoCipherBuiltin *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
 425                                                     QCryptoCipherMode mode,
 426                                                     const uint8_t *key,
 427                                                     size_t nkey,
 428                                                     Error **errp)
 429 {
 430     QCryptoCipherBuiltin *ctxt;
 431
 432     switch (mode) {
 433     case QCRYPTO_CIPHER_MODE_ECB:
 434     case QCRYPTO_CIPHER_MODE_CBC:
 435     case QCRYPTO_CIPHER_MODE_XTS:
 436         break;
 437     default:
 438         error_setg(errp, "Unsupported cipher mode %s",
 439                    QCryptoCipherMode_str(mode));
 440         return NULL;
 441     }
 442
 443     if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
 444         return NULL;
 445     }
 446
 447     switch (alg) {
 448     case QCRYPTO_CIPHER_ALG_DES_RFB:
 449         ctxt = qcrypto_cipher_init_des_rfb(mode, key, nkey, errp);
 450         break;
 451     case QCRYPTO_CIPHER_ALG_AES_128:
 452     case QCRYPTO_CIPHER_ALG_AES_192:
 453     case QCRYPTO_CIPHER_ALG_AES_256:
 454         ctxt = qcrypto_cipher_init_aes(mode, key, nkey, errp);
 455         break;
 456     default:
 457         error_setg(errp,
 458                    "Unsupported cipher algorithm %s",
 459                    QCryptoCipherAlgorithm_str(alg));
 460         return NULL;
 461     }
 462
 463     return ctxt;
 464 }
 465
 466 static void
 467 qcrypto_builtin_cipher_ctx_free(QCryptoCipher *cipher)
 468 {
 469     QCryptoCipherBuiltin *ctxt;
 470
 471     ctxt = cipher->opaque;
 472     ctxt->free(cipher);
 473 }
 474
 475
 476 static int
 477 qcrypto_builtin_cipher_encrypt(QCryptoCipher *cipher,
 478                                const void *in,
 479                                void *out,
 480                                size_t len,
 481                                Error **errp)
 482 {
 483     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 484
 485     if (len & (ctxt->blocksize - 1)) {
 486         error_setg(errp, "Length %zu must be a multiple of block size %zu",
 487                    len, ctxt->blocksize);
 488         return -1;
 489     }
 490
 491     return ctxt->encrypt(cipher, in, out, len, errp);
 492 }
 493
 494
 495 static int
 496 qcrypto_builtin_cipher_decrypt(QCryptoCipher *cipher,
 497                                const void *in,
 498                                void *out,
 499                                size_t len,
 500                                Error **errp)
 501 {
 502     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 503
 504     if (len & (ctxt->blocksize - 1)) {
 505         error_setg(errp, "Length %zu must be a multiple of block size %zu",
 506                    len, ctxt->blocksize);
 507         return -1;
 508     }
 509
 510     return ctxt->decrypt(cipher, in, out, len, errp);
 511 }
 512
 513
 514 static int
 515 qcrypto_builtin_cipher_setiv(QCryptoCipher *cipher,
 516                              const uint8_t *iv, size_t niv,
 517                              Error **errp)
 518 {
 519     QCryptoCipherBuiltin *ctxt = cipher->opaque;
 520
 521     return ctxt->setiv(cipher, iv, niv, errp);
 522 }
 523
 524
 525 static const struct QCryptoCipherDriver qcrypto_cipher_lib_driver = {
 526     .cipher_encrypt = qcrypto_builtin_cipher_encrypt,
 527     .cipher_decrypt = qcrypto_builtin_cipher_decrypt,
 528     .cipher_setiv = qcrypto_builtin_cipher_setiv,
 529     .cipher_free = qcrypto_builtin_cipher_ctx_free,
 530 };