lib/tcrypt/tcrypt.c

   1 /*
   2  * TCRYPT (TrueCrypt-compatible) volume handling
   3  *
   4  * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
   5  * Copyright (C) 2012, Milan Broz
   6  *
   7  * This file is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This file is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this file; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  */
  21
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <fcntl.h>
  27 #include <assert.h>
  28
  29 #include "libcryptsetup.h"
  30 #include "tcrypt.h"
  31 #include "internal.h"
  32
  33 /* TCRYPT PBKDF variants */
  34 static struct {
  35         unsigned int legacy:1;
  36         const char *name;
  37         const char *hash;
  38         unsigned int iterations;
  39 } tcrypt_kdf[] = {
  40         { 0, "pbkdf2", "ripemd160", 2000 },
  41         { 0, "pbkdf2", "ripemd160", 1000 },
  42         { 0, "pbkdf2", "sha512",    1000 },
  43         { 0, "pbkdf2", "whirlpool", 1000 },
  44         { 1, "pbkdf2", "sha1",      2000 },
  45         { 0, NULL,     NULL,           0 }
  46 };
  47
  48 struct tcrypt_alg {
  49                 const char *name;
  50                 unsigned int key_size;
  51                 unsigned int iv_size;
  52                 unsigned int key_offset;
  53                 unsigned int iv_offset; /* or tweak key offset */
  54 };
  55
  56 struct tcrypt_algs {
  57         unsigned int legacy:1;
  58         unsigned int chain_count;
  59         unsigned int chain_key_size;
  60         const char *long_name;
  61         const char *mode;
  62         struct tcrypt_alg cipher[3];
  63 };
  64
  65 /* TCRYPT cipher variants */
  66 static struct tcrypt_algs tcrypt_cipher[] = {
  67 /* XTS mode */
  68 {0,1,64,"aes","xts-plain64",
  69         {{"aes",    64,16,0,32}}},
  70 {0,1,64,"serpent","xts-plain64",
  71         {{"serpent",64,16,0,32}}},
  72 {0,1,64,"twofish","xts-plain64",
  73         {{"twofish",64,16,0,32}}},
  74 {0,2,128,"twofish-aes","xts-plain64",
  75         {{"twofish",64,16, 0,64},
  76          {"aes",    64,16,32,96}}},
  77 {0,3,192,"serpent-twofish-aes","xts-plain64",
  78         {{"serpent",64,16, 0, 96},
  79          {"twofish",64,16,32,128},
  80          {"aes",    64,16,64,160}}},
  81 {0,2,128,"aes-serpent","xts-plain64",
  82         {{"aes",    64,16, 0,64},
  83          {"serpent",64,16,32,96}}},
  84 {0,3,192,"aes-twofish-serpent","xts-plain64",
  85         {{"aes",    64,16, 0, 96},
  86          {"twofish",64,16,32,128},
  87          {"serpent",64,16,64,160}}},
  88 {0,2,128,"serpent-twofish","xts-plain64",
  89         {{"serpent",64,16, 0,64},
  90          {"twofish",64,16,32,96}}},
  91 /* LRW mode */
  92 {0,1,48,"aes","lrw-benbi",
  93         {{"aes",    48,16,32,0}}},
  94 {0,1,48,"serpent","lrw-benbi",
  95         {{"serpent",48,16,32,0}}},
  96 {0,1,48,"twofish","lrw-benbi",
  97         {{"twofish",48,16,32,0}}},
  98 {0,2,96,"twofish-aes","lrw-benbi",
  99         {{"twofish",48,16,32,0},
 100          {"aes",    48,16,64,0}}},
 101 {0,3,144,"serpent-twofish-aes","lrw-benbi",
 102         {{"serpent",48,16,32,0},
 103          {"twofish",48,16,64,0},
 104          {"aes",    48,16,96,0}}},
 105 {0,2,96,"aes-serpent","lrw-benbi",
 106         {{"aes",    48,16,32,0},
 107          {"serpent",48,16,64,0}}},
 108 {0,3,144,"aes-twofish-serpent","lrw-benbi",
 109         {{"aes",    48,16,32,0},
 110          {"twofish",48,16,64,0},
 111          {"serpent",48,16,96,0}}},
 112 {0,2,96,"serpent-twofish", "lrw-benbi",
 113         {{"serpent",48,16,32,0},
 114          {"twofish",48,16,64,0}}},
 115 /* Kernel LRW block size is fixed to 16 bytes for GF(2^128)
 116  * thus cannot be used with blowfish where block is 8 bytes.
 117  * There also no GF(2^64) support.
 118 {1,1,64,"blowfish_le","lrw-benbi",
 119          {{"blowfish_le",64,8,32,0}}},
 120 {1,2,112,"blowfish_le-aes","lrw-benbi",
 121          {{"blowfish_le",64, 8,32,0},
 122           {"aes",        48,16,88,0}}},
 123 {1,3,160,"serpent-blowfish_le-aes","lrw-benbi",
 124           {{"serpent",    48,16, 32,0},
 125            {"blowfish_le",64, 8, 64,0},
 126            {"aes",        48,16,120,0}}},*/
 127 /* CBC + "outer" CBC (both with whitening) */
 128 {1,1,32,"aes","cbc-tcrypt",
 129         {{"aes",    32,16,32,0}}},
 130 {1,1,32,"serpent","cbc-tcrypt",
 131         {{"serpent",32,16,32,0}}},
 132 {1,1,32,"twofish","cbc-tcrypt",
 133         {{"twofish",32,16,32,0}}},
 134 {1,2,64,"twofish-aes","cbci-tcrypt",
 135         {{"twofish",32,16,32,0},
 136          {"aes",    32,16,64,0}}},
 137 {1,3,96,"serpent-twofish-aes","cbci-tcrypt",
 138         {{"serpent",32,16,32,0},
 139          {"twofish",32,16,64,0},
 140          {"aes",    32,16,96,0}}},
 141 {1,2,64,"aes-serpent","cbci-tcrypt",
 142         {{"aes",    32,16,32,0},
 143          {"serpent",32,16,64,0}}},
 144 {1,3,96,"aes-twofish-serpent", "cbci-tcrypt",
 145         {{"aes",    32,16,32,0},
 146          {"twofish",32,16,64,0},
 147          {"serpent",32,16,96,0}}},
 148 {1,2,64,"serpent-twofish", "cbci-tcrypt",
 149         {{"serpent",32,16,32,0},
 150          {"twofish",32,16,64,0}}},
 151 {1,1,16,"cast5","cbc-tcrypt",
 152         {{"cast5",   16,8,32,0}}},
 153 {1,1,24,"des3_ede","cbc-tcrypt",
 154         {{"des3_ede",24,8,32,0}}},
 155 {1,1,56,"blowfish_le","cbc-tcrypt",
 156         {{"blowfish_le",56,8,32,0}}},
 157 {1,2,88,"blowfish_le-aes","cbc-tcrypt",
 158         {{"blowfish_le",56, 8,32,0},
 159          {"aes",        32,16,88,0}}},
 160 {1,3,120,"serpent-blowfish_le-aes","cbc-tcrypt",
 161         {{"serpent",    32,16, 32,0},
 162          {"blowfish_le",56, 8, 64,0},
 163          {"aes",        32,16,120,0}}},
 164 {}
 165 };
 166
 167 static int TCRYPT_hdr_from_disk(struct tcrypt_phdr *hdr,
 168                                 struct crypt_params_tcrypt *params,
 169                                 int kdf_index, int cipher_index)
 170 {
 171         uint32_t crc32;
 172         size_t size;
 173
 174         /* Check CRC32 of header */
 175         size = TCRYPT_HDR_LEN - sizeof(hdr->d.keys) - sizeof(hdr->d.header_crc32);
 176         crc32 = crypt_crc32(~0, (unsigned char*)&hdr->d, size) ^ ~0;
 177         if (be16_to_cpu(hdr->d.version) > 3 &&
 178             crc32 != be32_to_cpu(hdr->d.header_crc32)) {
 179                 log_dbg("TCRYPT header CRC32 mismatch.");
 180                 return -EINVAL;
 181         }
 182
 183         /* Check CRC32 of keys */
 184         crc32 = crypt_crc32(~0, (unsigned char*)hdr->d.keys, sizeof(hdr->d.keys)) ^ ~0;
 185         if (crc32 != be32_to_cpu(hdr->d.keys_crc32)) {
 186                 log_dbg("TCRYPT keys CRC32 mismatch.");
 187                 return -EINVAL;
 188         }
 189
 190         /* Convert header to cpu format */
 191         hdr->d.version  =  be16_to_cpu(hdr->d.version);
 192         hdr->d.version_tc = le16_to_cpu(hdr->d.version_tc);
 193
 194         hdr->d.keys_crc32 = be32_to_cpu(hdr->d.keys_crc32);
 195
 196         hdr->d.hidden_volume_size = be64_to_cpu(hdr->d.hidden_volume_size);
 197         hdr->d.volume_size        = be64_to_cpu(hdr->d.volume_size);
 198
 199         hdr->d.mk_offset = be64_to_cpu(hdr->d.mk_offset);
 200         if (!hdr->d.mk_offset)
 201                 hdr->d.mk_offset = 512;
 202
 203         hdr->d.mk_size = be64_to_cpu(hdr->d.mk_size);
 204
 205         hdr->d.flags = be32_to_cpu(hdr->d.flags);
 206
 207         hdr->d.sector_size = be32_to_cpu(hdr->d.sector_size);
 208         if (!hdr->d.sector_size)
 209                 hdr->d.sector_size = 512;
 210
 211         hdr->d.header_crc32 = be32_to_cpu(hdr->d.header_crc32);
 212
 213         /* Set params */
 214         params->passphrase = NULL;
 215         params->passphrase_size = 0;
 216         params->hash_name  = tcrypt_kdf[kdf_index].hash;
 217         params->key_size = tcrypt_cipher[cipher_index].chain_key_size;
 218         params->cipher = tcrypt_cipher[cipher_index].long_name;
 219         params->mode = tcrypt_cipher[cipher_index].mode;
 220
 221         return 0;
 222 }
 223
 224 /*
 225  * Kernel implements just big-endian version of blowfish, hack it here
 226  */
 227 static void TCRYPT_swab_le(char *buf)
 228 {
 229         uint32_t *l = (uint32_t*)&buf[0];
 230         uint32_t *r = (uint32_t*)&buf[4];
 231         *l = swab32(*l);
 232         *r = swab32(*r);
 233 }
 234
 235 static int decrypt_blowfish_le_cbc(struct tcrypt_alg *alg,
 236                                    const char *key, char *buf)
 237 {
 238         int bs = alg->iv_size;
 239         char iv[bs], iv_old[bs];
 240         struct crypt_cipher *cipher = NULL;
 241         int i, j, r;
 242
 243         assert(bs == 2*sizeof(uint32_t));
 244
 245         r = crypt_cipher_init(&cipher, "blowfish", "ecb",
 246                               &key[alg->key_offset], alg->key_size);
 247         if (r < 0)
 248                 return r;
 249
 250         memcpy(iv, &key[alg->iv_offset], alg->iv_size);
 251         for (i = 0; i < TCRYPT_HDR_LEN; i += bs) {
 252                 memcpy(iv_old, &buf[i], bs);
 253                 TCRYPT_swab_le(&buf[i]);
 254                 r = crypt_cipher_decrypt(cipher, &buf[i], &buf[i],
 255                                           bs, NULL, 0);
 256                 TCRYPT_swab_le(&buf[i]);
 257                 if (r < 0)
 258                         break;
 259                 for (j = 0; j < bs; j++)
 260                         buf[i + j] ^= iv[j];
 261                 memcpy(iv, iv_old, bs);
 262         }
 263
 264         crypt_cipher_destroy(cipher);
 265         memset(iv, 0, bs);
 266         memset(iv_old, 0, bs);
 267         return r;
 268 }
 269
 270 static void TCRYPT_remove_whitening(char *buf, const char *key)
 271 {
 272         int j;
 273
 274         for (j = 0; j < TCRYPT_HDR_LEN; j++)
 275                 buf[j] ^= key[j % 8];
 276 }
 277
 278 static void TCRYPT_copy_key(struct tcrypt_alg *alg, const char *mode,
 279                              char *out_key, const char *key)
 280 {
 281         int ks2;
 282         if (!strncmp(mode, "xts", 3)) {
 283                 ks2 = alg->key_size / 2;
 284                 memcpy(out_key, &key[alg->key_offset], ks2);
 285                 memcpy(&out_key[ks2], &key[alg->iv_offset], ks2);
 286         } else if (!strncmp(mode, "lrw", 3)) {
 287                 ks2 = alg->key_size - TCRYPT_LRW_IKEY_LEN;
 288                 memcpy(out_key, &key[alg->key_offset], ks2);
 289                 memcpy(&out_key[ks2], key, TCRYPT_LRW_IKEY_LEN);
 290         } else if (!strncmp(mode, "cbc", 3)) {
 291                 memcpy(out_key, &key[alg->key_offset], alg->key_size);
 292         }
 293 }
 294
 295 static int TCRYPT_decrypt_hdr_one(struct tcrypt_alg *alg, const char *mode,
 296                                    const char *key,struct tcrypt_phdr *hdr)
 297 {
 298         char backend_key[TCRYPT_HDR_KEY_LEN];
 299         char iv[TCRYPT_HDR_IV_LEN] = {};
 300         char mode_name[MAX_CIPHER_LEN];
 301         struct crypt_cipher *cipher;
 302         char *c, *buf = (char*)&hdr->e;
 303         int r;
 304
 305         /* Remove IV if present */
 306         strncpy(mode_name, mode, MAX_CIPHER_LEN);
 307         c = strchr(mode_name, '-');
 308         if (c)
 309                 *c = '\0';
 310
 311         if (!strncmp(mode, "lrw", 3))
 312                 iv[alg->iv_size - 1] = 1;
 313         else if (!strncmp(mode, "cbc", 3)) {
 314                 TCRYPT_remove_whitening(buf, &key[8]);
 315                 if (!strcmp(alg->name, "blowfish_le"))
 316                         return decrypt_blowfish_le_cbc(alg, key, buf);
 317                 memcpy(iv, &key[alg->iv_offset], alg->iv_size);
 318         }
 319
 320         TCRYPT_copy_key(alg, mode, backend_key, key);
 321         r = crypt_cipher_init(&cipher, alg->name, mode_name,
 322                               backend_key, alg->key_size);
 323         if (!r) {
 324                 r = crypt_cipher_decrypt(cipher, buf, buf, TCRYPT_HDR_LEN,
 325                                          iv, alg->iv_size);
 326                 crypt_cipher_destroy(cipher);
 327         }
 328
 329         memset(backend_key, 0, sizeof(backend_key));
 330         memset(iv, 0, TCRYPT_HDR_IV_LEN);
 331         return r;
 332 }
 333
 334 /*
 335  * For chanined ciphers and CBC mode we need "outer" decryption.
 336  * Backend doesn't provide this, so implement it here directly using ECB.
 337  */
 338 static int TCRYPT_decrypt_cbci(struct tcrypt_algs *ciphers,
 339                                 const char *key, struct tcrypt_phdr *hdr)
 340 {
 341         struct crypt_cipher *cipher[ciphers->chain_count];
 342         unsigned int bs = ciphers->cipher[0].iv_size;
 343         char *buf = (char*)&hdr->e, iv[bs], iv_old[bs];
 344         unsigned int i, j;
 345         int r = -EINVAL;
 346
 347         TCRYPT_remove_whitening(buf, &key[8]);
 348
 349         memcpy(iv, &key[ciphers->cipher[0].iv_offset], bs);
 350
 351         /* Initialize all ciphers in chain in ECB mode */
 352         for (j = 0; j < ciphers->chain_count; j++)
 353                 cipher[j] = NULL;
 354         for (j = 0; j < ciphers->chain_count; j++) {
 355                 r = crypt_cipher_init(&cipher[j], ciphers->cipher[j].name, "ecb",
 356                                       &key[ciphers->cipher[j].key_offset],
 357                                       ciphers->cipher[j].key_size);
 358                 if (r < 0)
 359                         goto out;
 360         }
 361
 362         /* Implements CBC with chained ciphers in loop inside */
 363         for (i = 0; i < TCRYPT_HDR_LEN; i += bs) {
 364                 memcpy(iv_old, &buf[i], bs);
 365                 for (j = ciphers->chain_count; j > 0; j--) {
 366                         r = crypt_cipher_decrypt(cipher[j - 1], &buf[i], &buf[i],
 367                                                   bs, NULL, 0);
 368                         if (r < 0)
 369                                 goto out;
 370                 }
 371                 for (j = 0; j < bs; j++)
 372                         buf[i + j] ^= iv[j];
 373                 memcpy(iv, iv_old, bs);
 374         }
 375 out:
 376         for (j = 0; j < ciphers->chain_count; j++)
 377                 if (cipher[j])
 378                         crypt_cipher_destroy(cipher[j]);
 379
 380         memset(iv, 0, bs);
 381         memset(iv_old, 0, bs);
 382         return r;
 383 }
 384
 385 static int TCRYPT_decrypt_hdr(struct crypt_device *cd, struct tcrypt_phdr *hdr,
 386                                const char *key, int legacy_modes)
 387 {
 388         struct tcrypt_phdr hdr2;
 389         int i, j, r = -EINVAL;
 390
 391         for (i = 0; tcrypt_cipher[i].chain_count; i++) {
 392                 if (!legacy_modes && tcrypt_cipher[i].legacy)
 393                         continue;
 394                 log_dbg("TCRYPT:  trying cipher %s-%s",
 395                         tcrypt_cipher[i].long_name, tcrypt_cipher[i].mode);
 396
 397                 memcpy(&hdr2.e, &hdr->e, TCRYPT_HDR_LEN);
 398
 399                 if (!strncmp(tcrypt_cipher[i].mode, "cbci", 4))
 400                         r = TCRYPT_decrypt_cbci(&tcrypt_cipher[i], key, &hdr2);
 401                 else for (j = tcrypt_cipher[i].chain_count - 1; j >= 0 ; j--) {
 402                         if (!tcrypt_cipher[i].cipher[j].name)
 403                                 continue;
 404                         r = TCRYPT_decrypt_hdr_one(&tcrypt_cipher[i].cipher[j],
 405                                             tcrypt_cipher[i].mode, key, &hdr2);
 406                         if (r < 0)
 407                                 break;
 408                 }
 409
 410                 if (r < 0) {
 411                         log_dbg("TCRYPT:   returned error %d, skipped.", r);
 412                         if (r == -ENOTSUP)
 413                                 break;
 414                         r = -ENOENT;
 415                         continue;
 416                 }
 417
 418                 if (!strncmp(hdr2.d.magic, TCRYPT_HDR_MAGIC, TCRYPT_HDR_MAGIC_LEN)) {
 419                         log_dbg("TCRYPT: Signature magic detected.");
 420                         memcpy(&hdr->e, &hdr2.e, TCRYPT_HDR_LEN);
 421                         r = i;
 422                         break;
 423                 }
 424                 r = -EPERM;
 425         }
 426
 427         memset(&hdr2, 0, sizeof(hdr2));
 428         return r;
 429 }
 430
 431 static int TCRYPT_pool_keyfile(struct crypt_device *cd,
 432                                 unsigned char pool[TCRYPT_KEY_POOL_LEN],
 433                                 const char *keyfile)
 434 {
 435         unsigned char data[TCRYPT_KEYFILE_LEN];
 436         int i, j, fd, data_size;
 437         uint32_t crc;
 438
 439         log_dbg("TCRYPT: using keyfile %s.", keyfile);
 440
 441         fd = open(keyfile, O_RDONLY);
 442         if (fd < 0) {
 443                 log_err(cd, _("Failed to open key file.\n"));
 444                 return -EIO;
 445         }
 446
 447         /* FIXME: add while */
 448         data_size = read(fd, data, TCRYPT_KEYFILE_LEN);
 449         close(fd);
 450         if (data_size < 0) {
 451                 log_err(cd, _("Error reading keyfile %s.\n"), keyfile);
 452                 return -EIO;
 453         }
 454
 455         for (i = 0, j = 0, crc = ~0U; i < data_size; i++) {
 456                 crc = crypt_crc32(crc, &data[i], 1);
 457                 pool[j++] += (unsigned char)(crc >> 24);
 458                 pool[j++] += (unsigned char)(crc >> 16);
 459                 pool[j++] += (unsigned char)(crc >>  8);
 460                 pool[j++] += (unsigned char)(crc);
 461                 j %= TCRYPT_KEY_POOL_LEN;
 462         }
 463
 464         memset(&crc, 0, sizeof(crc));
 465         memset(data, 0, TCRYPT_KEYFILE_LEN);
 466
 467         return 0;
 468 }
 469
 470 static int TCRYPT_init_hdr(struct crypt_device *cd,
 471                            struct tcrypt_phdr *hdr,
 472                            struct crypt_params_tcrypt *params)
 473 {
 474         unsigned char pwd[TCRYPT_KEY_POOL_LEN] = {};
 475         size_t passphrase_size;
 476         char *key;
 477         unsigned int i, skipped = 0;
 478         int r = -EINVAL, legacy_modes;
 479
 480         if (posix_memalign((void*)&key, crypt_getpagesize(), TCRYPT_HDR_KEY_LEN))
 481                 return -ENOMEM;
 482
 483         if (params->keyfiles_count)
 484                 passphrase_size = TCRYPT_KEY_POOL_LEN;
 485         else
 486                 passphrase_size = params->passphrase_size;
 487
 488         /* Calculate pool content from keyfiles */
 489         for (i = 0; i < params->keyfiles_count; i++) {
 490                 r = TCRYPT_pool_keyfile(cd, pwd, params->keyfiles[i]);
 491                 if (r < 0)
 492                         goto out;
 493         }
 494
 495         /* If provided password, combine it with pool */
 496         for (i = 0; i < params->passphrase_size; i++)
 497                 pwd[i] += params->passphrase[i];
 498
 499         legacy_modes = params->flags & CRYPT_TCRYPT_LEGACY_MODES ? 1 : 0;
 500         for (i = 0; tcrypt_kdf[i].name; i++) {
 501                 if (!legacy_modes && tcrypt_kdf[i].legacy)
 502                         continue;
 503                 /* Derive header key */
 504                 log_dbg("TCRYPT: trying KDF: %s-%s-%d.",
 505                         tcrypt_kdf[i].name, tcrypt_kdf[i].hash, tcrypt_kdf[i].iterations);
 506                 r = crypt_pbkdf(tcrypt_kdf[i].name, tcrypt_kdf[i].hash,
 507                                 (char*)pwd, passphrase_size,
 508                                 hdr->salt, TCRYPT_HDR_SALT_LEN,
 509                                 key, TCRYPT_HDR_KEY_LEN,
 510                                 tcrypt_kdf[i].iterations);
 511                 if (r < 0 && crypt_hash_size(tcrypt_kdf[i].hash) < 0) {
 512                         log_verbose(cd, _("PBKDF2 hash algorithm %s not available, skipping.\n"),
 513                                       tcrypt_kdf[i].hash);
 514                         continue;
 515                 }
 516                 if (r < 0)
 517                         break;
 518
 519                 /* Decrypt header */
 520                 r = TCRYPT_decrypt_hdr(cd, hdr, key, legacy_modes);
 521                 if (r == -ENOENT) {
 522                         skipped++;
 523                         continue;
 524                 }
 525                 if (r != -EPERM)
 526                         break;
 527         }
 528
 529         if ((skipped && skipped == i) || r == -ENOTSUP) {
 530                 log_err(cd, _("Required kernel crypto interface not available.\n"));
 531 #ifdef ENABLE_AF_ALG
 532                 log_err(cd, _("Ensure you have algif_skcipher kernel module loaded.\n"));
 533 #endif
 534         }
 535         if (r < 0)
 536                 goto out;
 537
 538         r = TCRYPT_hdr_from_disk(hdr, params, i, r);
 539         if (!r) {
 540                 log_dbg("TCRYPT: Header version: %d, req. %d, sector %d"
 541                         ", mk_offset %" PRIu64 ", hidden_size %" PRIu64
 542                         ", volume size %" PRIu64, (int)hdr->d.version,
 543                         (int)hdr->d.version_tc, (int)hdr->d.sector_size,
 544                         hdr->d.mk_offset, hdr->d.hidden_volume_size, hdr->d.volume_size);
 545                 log_dbg("TCRYPT: Header cipher %s-%s, key size %d",
 546                         params->cipher, params->mode, params->key_size);
 547         }
 548 out:
 549         memset(pwd, 0, TCRYPT_KEY_POOL_LEN);
 550         if (key)
 551                 memset(key, 0, TCRYPT_HDR_KEY_LEN);
 552         free(key);
 553         return r;
 554 }
 555
 556 int TCRYPT_read_phdr(struct crypt_device *cd,
 557                      struct tcrypt_phdr *hdr,
 558                      struct crypt_params_tcrypt *params)
 559 {
 560         struct device *device = crypt_metadata_device(cd);
 561         ssize_t hdr_size = sizeof(struct tcrypt_phdr);
 562         int devfd = 0, r, bs;
 563
 564         assert(sizeof(struct tcrypt_phdr) == 512);
 565
 566         log_dbg("Reading TCRYPT header of size %d bytes from device %s.",
 567                 hdr_size, device_path(device));
 568
 569         bs = device_block_size(device);
 570         if (bs < 0)
 571                 return bs;
 572
 573         devfd = device_open(device, O_RDONLY);
 574         if (devfd == -1) {
 575                 log_err(cd, _("Cannot open device %s.\n"), device_path(device));
 576                 return -EINVAL;
 577         }
 578
 579         r = -EIO;
 580         if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) {
 581                 if (lseek(devfd, TCRYPT_HDR_SYSTEM_OFFSET, SEEK_SET) >= 0 &&
 582                     read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 583                         r = TCRYPT_init_hdr(cd, hdr, params);
 584         } else if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) {
 585                 if (params->flags & CRYPT_TCRYPT_BACKUP_HEADER) {
 586                         if (lseek(devfd, TCRYPT_HDR_HIDDEN_OFFSET_BCK, SEEK_END) >= 0 &&
 587                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 588                                 r = TCRYPT_init_hdr(cd, hdr, params);
 589                 } else {
 590                         if (lseek(devfd, TCRYPT_HDR_HIDDEN_OFFSET, SEEK_SET) >= 0 &&
 591                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 592                                 r = TCRYPT_init_hdr(cd, hdr, params);
 593                         if (r &&
 594                             lseek(devfd, TCRYPT_HDR_HIDDEN_OFFSET_OLD, SEEK_END) >= 0 &&
 595                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 596                                 r = TCRYPT_init_hdr(cd, hdr, params);
 597                 }
 598         } else if (params->flags & CRYPT_TCRYPT_BACKUP_HEADER) {
 599                 if (lseek(devfd, TCRYPT_HDR_OFFSET_BCK, SEEK_END) >= 0 &&
 600                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 601                         r = TCRYPT_init_hdr(cd, hdr, params);
 602         } else if (read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 603                 r = TCRYPT_init_hdr(cd, hdr, params);
 604
 605         close(devfd);
 606         if (r < 0)
 607                 memset(hdr, 0, sizeof (*hdr));
 608         return r;
 609 }
 610
 611 static struct tcrypt_algs *TCRYPT_get_algs(const char *cipher, const char *mode)
 612 {
 613         int i;
 614
 615         if (!cipher || !mode)
 616                 return NULL;
 617
 618         for (i = 0; tcrypt_cipher[i].chain_count; i++)
 619                 if (!strcmp(tcrypt_cipher[i].long_name, cipher) &&
 620                     !strcmp(tcrypt_cipher[i].mode, mode))
 621                     return &tcrypt_cipher[i];
 622
 623         return NULL;
 624 }
 625
 626 int TCRYPT_activate(struct crypt_device *cd,
 627                      const char *name,
 628                      struct tcrypt_phdr *hdr,
 629                      struct crypt_params_tcrypt *params,
 630                      uint32_t flags)
 631 {
 632         char cipher[MAX_CIPHER_LEN], dm_name[PATH_MAX], dm_dev_name[PATH_MAX];
 633         struct device *device = NULL;
 634         unsigned int i;
 635         int r;
 636         struct tcrypt_algs *algs;
 637         struct crypt_dm_active_device dmd = {
 638                 .target = DM_CRYPT,
 639                 .size   = 0,
 640                 .data_device = crypt_data_device(cd),
 641                 .u.crypt  = {
 642                         .cipher = cipher,
 643                         .offset = crypt_get_data_offset(cd),
 644                         .iv_offset = crypt_get_iv_offset(cd),
 645                 }
 646         };
 647
 648         if (!hdr->d.version) {
 649                 log_dbg("TCRYPT: this function is not supported without encrypted header load.");
 650                 return -ENOTSUP;
 651         }
 652
 653         if (hdr->d.sector_size && hdr->d.sector_size != SECTOR_SIZE) {
 654                 log_err(cd, _("Activation is not supported for %d sector size.\n"),
 655                         hdr->d.sector_size);
 656                 return -ENOTSUP;
 657         }
 658
 659         if (strstr(params->mode, "-tcrypt")) {
 660                 log_err(cd, _("Kernel doesn't support activation for this TCRYPT legacy mode.\n"));
 661                 return -ENOTSUP;
 662         }
 663
 664         algs = TCRYPT_get_algs(params->cipher, params->mode);
 665         if (!algs)
 666                 return -EINVAL;
 667
 668         if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER)
 669                 dmd.size = hdr->d.hidden_volume_size / hdr->d.sector_size;
 670         else
 671                 dmd.size = hdr->d.volume_size / hdr->d.sector_size;
 672
 673         r = device_block_adjust(cd, dmd.data_device, DEV_EXCL,
 674                                 dmd.u.crypt.offset, &dmd.size, &dmd.flags);
 675         if (r)
 676                 return r;
 677
 678         /* Frome here, key size for every cipher must be the same */
 679         dmd.u.crypt.vk = crypt_alloc_volume_key(algs->cipher[0].key_size, NULL);
 680         if (!dmd.u.crypt.vk)
 681                 return -ENOMEM;
 682
 683         for (i = algs->chain_count; i > 0; i--) {
 684                 if (i == 1) {
 685                         strncpy(dm_name, name, sizeof(dm_name));
 686                         dmd.flags = flags;
 687                 } else {
 688                         snprintf(dm_name, sizeof(dm_name), "%s_%d", name, i-1);
 689                         dmd.flags = flags | CRYPT_ACTIVATE_PRIVATE;
 690                 }
 691
 692                 snprintf(cipher, sizeof(cipher), "%s-%s",
 693                          algs->cipher[i-1].name, algs->mode);
 694
 695                 TCRYPT_copy_key(&algs->cipher[i-1], algs->mode,
 696                                 dmd.u.crypt.vk->key, hdr->d.keys);
 697
 698                 if (algs->chain_count != i) {
 699                         snprintf(dm_dev_name, sizeof(dm_dev_name), "%s/%s_%d",
 700                                  dm_get_dir(), name, i);
 701                         r = device_alloc(&device, dm_dev_name);
 702                         if (r)
 703                                 break;
 704                         dmd.data_device = device;
 705                         dmd.u.crypt.offset = 0;
 706                 }
 707
 708                 log_dbg("Trying to activate TCRYPT device %s using cipher %s.",
 709                         dm_name, dmd.u.crypt.cipher);
 710                 r = dm_create_device(cd, dm_name, CRYPT_TCRYPT, &dmd, 0);
 711
 712                 device_free(device);
 713                 device = NULL;
 714
 715                 if (r)
 716                         break;
 717         }
 718
 719         if (r < 0 && !(dm_flags() & DM_PLAIN64_SUPPORTED)) {
 720                 log_err(cd, _("Kernel doesn't support plain64 IV.\n"));
 721                 r = -ENOTSUP;
 722         }
 723
 724         crypt_free_volume_key(dmd.u.crypt.vk);
 725         return r;
 726 }
 727
 728 static int TCRYPT_remove_one(struct crypt_device *cd, const char *name,
 729                       const char *base_uuid, int index)
 730 {
 731         struct crypt_dm_active_device dmd = {};
 732         char dm_name[PATH_MAX];
 733         int r;
 734
 735         if (snprintf(dm_name, sizeof(dm_name), "%s_%d", name, index) < 0)
 736                 return -ENOMEM;
 737
 738         r = dm_status_device(cd, dm_name);
 739         if (r < 0)
 740                 return r;
 741
 742         r = dm_query_device(cd, dm_name, DM_ACTIVE_UUID, &dmd);
 743         if (!r && !strncmp(dmd.uuid, base_uuid, strlen(base_uuid)))
 744                 r = dm_remove_device(cd, dm_name, 0, 0);
 745
 746         free(CONST_CAST(void*)dmd.uuid);
 747         return r;
 748 }
 749
 750 int TCRYPT_deactivate(struct crypt_device *cd, const char *name)
 751 {
 752         struct crypt_dm_active_device dmd = {};
 753         int r;
 754
 755         r = dm_query_device(cd, name, DM_ACTIVE_UUID, &dmd);
 756         if (r < 0)
 757                 return r;
 758         if (!dmd.uuid)
 759                 return -EINVAL;
 760
 761         r = dm_remove_device(cd, name, 0, 0);
 762         if (r < 0)
 763                 goto out;
 764
 765         r = TCRYPT_remove_one(cd, name, dmd.uuid, 1);
 766         if (r < 0)
 767                 goto out;
 768
 769         r = TCRYPT_remove_one(cd, name, dmd.uuid, 2);
 770         if (r < 0)
 771                 goto out;
 772 out:
 773         free(CONST_CAST(void*)dmd.uuid);
 774         return (r == -ENODEV) ? 0 : r;
 775 }
 776
 777 static int TCRYPT_status_one(struct crypt_device *cd, const char *name,
 778                               const char *base_uuid, int index,
 779                               size_t *key_size, char *cipher,
 780                               uint64_t *data_offset, struct device **device)
 781 {
 782         struct crypt_dm_active_device dmd = {};
 783         char dm_name[PATH_MAX], *c;
 784         int r;
 785
 786         if (snprintf(dm_name, sizeof(dm_name), "%s_%d", name, index) < 0)
 787                 return -ENOMEM;
 788
 789         r = dm_status_device(cd, dm_name);
 790         if (r < 0)
 791                 return r;
 792
 793         r = dm_query_device(cd, dm_name, DM_ACTIVE_DEVICE |
 794                                           DM_ACTIVE_UUID |
 795                                           DM_ACTIVE_CRYPT_CIPHER |
 796                                           DM_ACTIVE_CRYPT_KEYSIZE, &dmd);
 797         if (r > 0)
 798                 r = 0;
 799         if (!r && !strncmp(dmd.uuid, base_uuid, strlen(base_uuid))) {
 800                 if ((c = strchr(dmd.u.crypt.cipher, '-')))
 801                         *c = '\0';
 802                 strcat(cipher, "-");
 803                 strncat(cipher, dmd.u.crypt.cipher, MAX_CIPHER_LEN);
 804                 *key_size += dmd.u.crypt.vk->keylength;
 805                 *data_offset = dmd.u.crypt.offset * SECTOR_SIZE;
 806                 device_free(*device);
 807                 *device = dmd.data_device;
 808         } else {
 809                 device_free(dmd.data_device);
 810                 r = -ENODEV;
 811         }
 812
 813         free(CONST_CAST(void*)dmd.uuid);
 814         free(CONST_CAST(void*)dmd.u.crypt.cipher);
 815         crypt_free_volume_key(dmd.u.crypt.vk);
 816         return r;
 817 }
 818
 819 int TCRYPT_init_by_name(struct crypt_device *cd, const char *name,
 820                         const struct crypt_dm_active_device *dmd,
 821                         struct device **device,
 822                         struct crypt_params_tcrypt *tcrypt_params,
 823                         struct tcrypt_phdr *tcrypt_hdr)
 824 {
 825         struct tcrypt_algs *algs;
 826         char cipher[MAX_CIPHER_LEN * 4], mode[MAX_CIPHER_LEN], *tmp;
 827         size_t key_size;
 828         int r;
 829
 830         memset(tcrypt_params, 0, sizeof(*tcrypt_params));
 831         memset(tcrypt_hdr, 0, sizeof(*tcrypt_hdr));
 832         tcrypt_hdr->d.sector_size = SECTOR_SIZE;
 833         tcrypt_hdr->d.mk_offset = dmd->u.crypt.offset * SECTOR_SIZE;
 834
 835         strncpy(cipher, dmd->u.crypt.cipher, MAX_CIPHER_LEN);
 836         tmp = strchr(cipher, '-');
 837         if (!tmp)
 838                 return -EINVAL;
 839         *tmp = '\0';
 840         strncpy(mode, ++tmp, MAX_CIPHER_LEN);
 841
 842         key_size = dmd->u.crypt.vk->keylength;
 843         r = TCRYPT_status_one(cd, name, dmd->uuid, 1, &key_size,
 844                               cipher, &tcrypt_hdr->d.mk_offset, device);
 845         if (!r)
 846                 r = TCRYPT_status_one(cd, name, dmd->uuid, 2, &key_size,
 847                                       cipher, &tcrypt_hdr->d.mk_offset, device);
 848
 849         if (r < 0 && r != -ENODEV)
 850                 return r;
 851
 852         algs = TCRYPT_get_algs(cipher, mode);
 853         if (!algs || key_size != algs->chain_key_size)
 854                 return -EINVAL;
 855
 856         tcrypt_params->key_size = algs->chain_key_size;
 857         tcrypt_params->cipher = algs->long_name;
 858         tcrypt_params->mode = algs->mode;
 859         return 0;
 860 }
 861
 862 uint64_t TCRYPT_get_data_offset(struct crypt_device *cd,
 863                                  struct tcrypt_phdr *hdr,
 864                                  struct crypt_params_tcrypt *params)
 865 {
 866         uint64_t size;
 867
 868         /* No real header loaded, initialized by active device */
 869         if (!hdr->d.version)
 870                 goto hdr_offset;
 871
 872         /* Mapping through whole device, not partition! */
 873         if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER)
 874                 goto hdr_offset;
 875
 876         if (params->mode && !strncmp(params->mode, "xts", 3)) {
 877                 if (hdr->d.version < 3)
 878                         return 1;
 879
 880                 if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) {
 881                         if (hdr->d.version > 3)
 882                                 return (hdr->d.mk_offset / hdr->d.sector_size);
 883                         if (device_size(crypt_metadata_device(cd), &size) < 0)
 884                                 return 0;
 885                         return (size - hdr->d.hidden_volume_size +
 886                                 (TCRYPT_HDR_HIDDEN_OFFSET_OLD)) / hdr->d.sector_size;
 887                 }
 888                 goto hdr_offset;
 889         }
 890
 891         if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) {
 892                 if (device_size(crypt_metadata_device(cd), &size) < 0)
 893                         return 0;
 894                 return (size - hdr->d.hidden_volume_size +
 895                         (TCRYPT_HDR_HIDDEN_OFFSET_OLD)) / hdr->d.sector_size;
 896         }
 897
 898 hdr_offset:
 899         return hdr->d.mk_offset / hdr->d.sector_size;
 900 }
 901
 902 uint64_t TCRYPT_get_iv_offset(struct crypt_device *cd,
 903                               struct tcrypt_phdr *hdr,
 904                               struct crypt_params_tcrypt *params
 905 )
 906 {
 907         if (params->mode && !strncmp(params->mode, "xts", 3))
 908                 return TCRYPT_get_data_offset(cd, hdr, params);
 909         else if (params->mode && !strncmp(params->mode, "lrw", 3))
 910                 return 0;
 911
 912         return hdr->d.mk_offset / hdr->d.sector_size;
 913 }
 914
 915 int TCRYPT_get_volume_key(struct crypt_device *cd,
 916                           struct tcrypt_phdr *hdr,
 917                           struct crypt_params_tcrypt *params,
 918                           struct volume_key **vk)
 919 {
 920         struct tcrypt_algs *algs;
 921         unsigned int i, key_index;
 922
 923         if (!hdr->d.version) {
 924                 log_err(cd, _("This function is not supported without TCRYPT header load."));
 925                 return -ENOTSUP;
 926         }
 927
 928         algs = TCRYPT_get_algs(params->cipher, params->mode);
 929         if (!algs)
 930                 return -EINVAL;
 931
 932         *vk = crypt_alloc_volume_key(params->key_size, NULL);
 933         if (!*vk)
 934                 return -ENOMEM;
 935
 936         for (i = 0, key_index = 0; i < algs->chain_count; i++) {
 937                 TCRYPT_copy_key(&algs->cipher[i], algs->mode,
 938                                 &(*vk)->key[key_index], hdr->d.keys);
 939                 key_index += algs->cipher[i].key_size;
 940         }
 941
 942         return 0;
 943 }
 944
 945 int TCRYPT_dump(struct crypt_device *cd,
 946                 struct tcrypt_phdr *hdr,
 947                 struct crypt_params_tcrypt *params)
 948 {
 949         log_std(cd, "TCRYPT header information for %s\n",
 950                 device_path(crypt_metadata_device(cd)));
 951         if (hdr->d.version) {
 952                 log_std(cd, "Version:       \t%d\n", hdr->d.version);
 953                 log_std(cd, "Driver req.:\t%d\n", hdr->d.version_tc);
 954
 955                 log_std(cd, "Sector size:\t%" PRIu32 "\n", hdr->d.sector_size);
 956                 log_std(cd, "MK offset:\t%" PRIu64 "\n", hdr->d.mk_offset);
 957                 log_std(cd, "PBKDF2 hash:\t%s\n", params->hash_name);
 958         }
 959         log_std(cd, "Cipher chain:\t%s\n", params->cipher);
 960         log_std(cd, "Cipher mode:\t%s\n", params->mode);
 961         log_std(cd, "MK bits:       \t%d\n", params->key_size * 8);
 962         return 0;
 963 }