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) 2012-2013, 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         if (params->passphrase_size > TCRYPT_KEY_POOL_LEN) {
 489                 log_err(cd, _("Maximum TCRYPT passphrase length (%d) exceeded.\n"),
 490                               TCRYPT_KEY_POOL_LEN);
 491                 return -EPERM;
 492         }
 493
 494         /* Calculate pool content from keyfiles */
 495         for (i = 0; i < params->keyfiles_count; i++) {
 496                 r = TCRYPT_pool_keyfile(cd, pwd, params->keyfiles[i]);
 497                 if (r < 0)
 498                         goto out;
 499         }
 500
 501         /* If provided password, combine it with pool */
 502         for (i = 0; i < params->passphrase_size; i++)
 503                 pwd[i] += params->passphrase[i];
 504
 505         legacy_modes = params->flags & CRYPT_TCRYPT_LEGACY_MODES ? 1 : 0;
 506         for (i = 0; tcrypt_kdf[i].name; i++) {
 507                 if (!legacy_modes && tcrypt_kdf[i].legacy)
 508                         continue;
 509                 /* Derive header key */
 510                 log_dbg("TCRYPT: trying KDF: %s-%s-%d.",
 511                         tcrypt_kdf[i].name, tcrypt_kdf[i].hash, tcrypt_kdf[i].iterations);
 512                 r = crypt_pbkdf(tcrypt_kdf[i].name, tcrypt_kdf[i].hash,
 513                                 (char*)pwd, passphrase_size,
 514                                 hdr->salt, TCRYPT_HDR_SALT_LEN,
 515                                 key, TCRYPT_HDR_KEY_LEN,
 516                                 tcrypt_kdf[i].iterations);
 517                 if (r < 0 && crypt_hash_size(tcrypt_kdf[i].hash) < 0) {
 518                         log_verbose(cd, _("PBKDF2 hash algorithm %s not available, skipping.\n"),
 519                                       tcrypt_kdf[i].hash);
 520                         continue;
 521                 }
 522                 if (r < 0)
 523                         break;
 524
 525                 /* Decrypt header */
 526                 r = TCRYPT_decrypt_hdr(cd, hdr, key, legacy_modes);
 527                 if (r == -ENOENT) {
 528                         skipped++;
 529                         continue;
 530                 }
 531                 if (r != -EPERM)
 532                         break;
 533         }
 534
 535         if ((skipped && skipped == i) || r == -ENOTSUP) {
 536                 log_err(cd, _("Required kernel crypto interface not available.\n"));
 537 #ifdef ENABLE_AF_ALG
 538                 log_err(cd, _("Ensure you have algif_skcipher kernel module loaded.\n"));
 539 #endif
 540         }
 541         if (r < 0)
 542                 goto out;
 543
 544         r = TCRYPT_hdr_from_disk(hdr, params, i, r);
 545         if (!r) {
 546                 log_dbg("TCRYPT: Header version: %d, req. %d, sector %d"
 547                         ", mk_offset %" PRIu64 ", hidden_size %" PRIu64
 548                         ", volume size %" PRIu64, (int)hdr->d.version,
 549                         (int)hdr->d.version_tc, (int)hdr->d.sector_size,
 550                         hdr->d.mk_offset, hdr->d.hidden_volume_size, hdr->d.volume_size);
 551                 log_dbg("TCRYPT: Header cipher %s-%s, key size %d",
 552                         params->cipher, params->mode, params->key_size);
 553         }
 554 out:
 555         memset(pwd, 0, TCRYPT_KEY_POOL_LEN);
 556         if (key)
 557                 memset(key, 0, TCRYPT_HDR_KEY_LEN);
 558         free(key);
 559         return r;
 560 }
 561
 562 int TCRYPT_read_phdr(struct crypt_device *cd,
 563                      struct tcrypt_phdr *hdr,
 564                      struct crypt_params_tcrypt *params)
 565 {
 566         struct device *device = crypt_metadata_device(cd);
 567         ssize_t hdr_size = sizeof(struct tcrypt_phdr);
 568         int devfd = 0, r, bs;
 569
 570         assert(sizeof(struct tcrypt_phdr) == 512);
 571
 572         log_dbg("Reading TCRYPT header of size %d bytes from device %s.",
 573                 hdr_size, device_path(device));
 574
 575         bs = device_block_size(device);
 576         if (bs < 0)
 577                 return bs;
 578
 579         devfd = device_open(device, O_RDONLY);
 580         if (devfd == -1) {
 581                 log_err(cd, _("Cannot open device %s.\n"), device_path(device));
 582                 return -EINVAL;
 583         }
 584
 585         r = -EIO;
 586         if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) {
 587                 if (lseek(devfd, TCRYPT_HDR_SYSTEM_OFFSET, SEEK_SET) >= 0 &&
 588                     read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size) {
 589                         r = TCRYPT_init_hdr(cd, hdr, params);
 590                         if (r == -EPERM && crypt_dev_is_partition(device_path(device)))
 591                                 log_std(cd, _("WARNING: device %s is a partition, for TCRYPT "
 592                                               "system encryption you usually need to use "
 593                                               "whole block device path.\n"), device_path(device));
 594                 }
 595         } else if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) {
 596                 if (params->flags & CRYPT_TCRYPT_BACKUP_HEADER) {
 597                         if (lseek(devfd, TCRYPT_HDR_HIDDEN_OFFSET_BCK, SEEK_END) >= 0 &&
 598                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 599                                 r = TCRYPT_init_hdr(cd, hdr, params);
 600                 } else {
 601                         if (lseek(devfd, TCRYPT_HDR_HIDDEN_OFFSET, SEEK_SET) >= 0 &&
 602                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 603                                 r = TCRYPT_init_hdr(cd, hdr, params);
 604                         if (r &&
 605                             lseek(devfd, TCRYPT_HDR_HIDDEN_OFFSET_OLD, SEEK_END) >= 0 &&
 606                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 607                                 r = TCRYPT_init_hdr(cd, hdr, params);
 608                 }
 609         } else if (params->flags & CRYPT_TCRYPT_BACKUP_HEADER) {
 610                 if (lseek(devfd, TCRYPT_HDR_OFFSET_BCK, SEEK_END) >= 0 &&
 611                             read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 612                         r = TCRYPT_init_hdr(cd, hdr, params);
 613         } else if (read_blockwise(devfd, bs, hdr, hdr_size) == hdr_size)
 614                 r = TCRYPT_init_hdr(cd, hdr, params);
 615
 616         close(devfd);
 617         if (r < 0)
 618                 memset(hdr, 0, sizeof (*hdr));
 619         return r;
 620 }
 621
 622 static struct tcrypt_algs *TCRYPT_get_algs(const char *cipher, const char *mode)
 623 {
 624         int i;
 625
 626         if (!cipher || !mode)
 627                 return NULL;
 628
 629         for (i = 0; tcrypt_cipher[i].chain_count; i++)
 630                 if (!strcmp(tcrypt_cipher[i].long_name, cipher) &&
 631                     !strcmp(tcrypt_cipher[i].mode, mode))
 632                     return &tcrypt_cipher[i];
 633
 634         return NULL;
 635 }
 636
 637 int TCRYPT_activate(struct crypt_device *cd,
 638                      const char *name,
 639                      struct tcrypt_phdr *hdr,
 640                      struct crypt_params_tcrypt *params,
 641                      uint32_t flags)
 642 {
 643         char cipher[MAX_CIPHER_LEN], dm_name[PATH_MAX], dm_dev_name[PATH_MAX];
 644         char *part_path;
 645         struct device *device = NULL, *part_device = NULL;
 646         unsigned int i;
 647         int r;
 648         struct tcrypt_algs *algs;
 649         enum devcheck device_check;
 650         struct crypt_dm_active_device dmd = {
 651                 .target = DM_CRYPT,
 652                 .size   = 0,
 653                 .data_device = crypt_data_device(cd),
 654                 .u.crypt  = {
 655                         .cipher = cipher,
 656                         .offset = crypt_get_data_offset(cd),
 657                         .iv_offset = crypt_get_iv_offset(cd),
 658                 }
 659         };
 660
 661         if (!hdr->d.version) {
 662                 log_dbg("TCRYPT: this function is not supported without encrypted header load.");
 663                 return -ENOTSUP;
 664         }
 665
 666         if (hdr->d.sector_size && hdr->d.sector_size != SECTOR_SIZE) {
 667                 log_err(cd, _("Activation is not supported for %d sector size.\n"),
 668                         hdr->d.sector_size);
 669                 return -ENOTSUP;
 670         }
 671
 672         if (strstr(params->mode, "-tcrypt")) {
 673                 log_err(cd, _("Kernel doesn't support activation for this TCRYPT legacy mode.\n"));
 674                 return -ENOTSUP;
 675         }
 676
 677         algs = TCRYPT_get_algs(params->cipher, params->mode);
 678         if (!algs)
 679                 return -EINVAL;
 680
 681         if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER)
 682                 dmd.size = hdr->d.hidden_volume_size / hdr->d.sector_size;
 683         else
 684                 dmd.size = hdr->d.volume_size / hdr->d.sector_size;
 685
 686         /*
 687          * System encryption use the whole device mapping, there can
 688          * be active partitions.
 689          * FIXME: This will allow multiple mappings unexpectedly.
 690          */
 691         if ((dmd.flags & CRYPT_ACTIVATE_SHARED) ||
 692             (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER))
 693                 device_check = DEV_SHARED;
 694         else
 695                 device_check = DEV_EXCL;
 696
 697         if ((params->flags & CRYPT_TCRYPT_SYSTEM_HEADER) &&
 698                 (part_path = crypt_get_partition_device(device_path(dmd.data_device),
 699                                  dmd.u.crypt.offset, dmd.size))) {
 700                 if (!device_alloc(&part_device, part_path)) {
 701                         log_verbose(cd, _("Activating TCRYPT system encryption for partition %s.\n"),
 702                                     part_path);
 703                         dmd.data_device = part_device;
 704                         dmd.u.crypt.offset = 0;
 705                 }
 706                 free(part_path);
 707         }
 708
 709         r = device_block_adjust(cd, dmd.data_device, device_check,
 710                                 dmd.u.crypt.offset, &dmd.size, &dmd.flags);
 711         if (r)
 712                 return r;
 713
 714         /* Frome here, key size for every cipher must be the same */
 715         dmd.u.crypt.vk = crypt_alloc_volume_key(algs->cipher[0].key_size, NULL);
 716         if (!dmd.u.crypt.vk)
 717                 return -ENOMEM;
 718
 719         for (i = algs->chain_count; i > 0; i--) {
 720                 if (i == 1) {
 721                         strncpy(dm_name, name, sizeof(dm_name));
 722                         dmd.flags = flags;
 723                 } else {
 724                         snprintf(dm_name, sizeof(dm_name), "%s_%d", name, i-1);
 725                         dmd.flags = flags | CRYPT_ACTIVATE_PRIVATE;
 726                 }
 727
 728                 snprintf(cipher, sizeof(cipher), "%s-%s",
 729                          algs->cipher[i-1].name, algs->mode);
 730
 731                 TCRYPT_copy_key(&algs->cipher[i-1], algs->mode,
 732                                 dmd.u.crypt.vk->key, hdr->d.keys);
 733
 734                 if (algs->chain_count != i) {
 735                         snprintf(dm_dev_name, sizeof(dm_dev_name), "%s/%s_%d",
 736                                  dm_get_dir(), name, i);
 737                         r = device_alloc(&device, dm_dev_name);
 738                         if (r)
 739                                 break;
 740                         dmd.data_device = device;
 741                         dmd.u.crypt.offset = 0;
 742                 }
 743
 744                 log_dbg("Trying to activate TCRYPT device %s using cipher %s.",
 745                         dm_name, dmd.u.crypt.cipher);
 746                 r = dm_create_device(cd, dm_name, CRYPT_TCRYPT, &dmd, 0);
 747
 748                 device_free(device);
 749                 device = NULL;
 750
 751                 if (r)
 752                         break;
 753         }
 754
 755         if (r < 0 && !(dm_flags() & DM_PLAIN64_SUPPORTED)) {
 756                 log_err(cd, _("Kernel doesn't support plain64 IV.\n"));
 757                 r = -ENOTSUP;
 758         }
 759
 760         device_free(part_device);
 761         crypt_free_volume_key(dmd.u.crypt.vk);
 762         return r;
 763 }
 764
 765 static int TCRYPT_remove_one(struct crypt_device *cd, const char *name,
 766                       const char *base_uuid, int index)
 767 {
 768         struct crypt_dm_active_device dmd = {};
 769         char dm_name[PATH_MAX];
 770         int r;
 771
 772         if (snprintf(dm_name, sizeof(dm_name), "%s_%d", name, index) < 0)
 773                 return -ENOMEM;
 774
 775         r = dm_status_device(cd, dm_name);
 776         if (r < 0)
 777                 return r;
 778
 779         r = dm_query_device(cd, dm_name, DM_ACTIVE_UUID, &dmd);
 780         if (!r && !strncmp(dmd.uuid, base_uuid, strlen(base_uuid)))
 781                 r = dm_remove_device(cd, dm_name, 0, 0);
 782
 783         free(CONST_CAST(void*)dmd.uuid);
 784         return r;
 785 }
 786
 787 int TCRYPT_deactivate(struct crypt_device *cd, const char *name)
 788 {
 789         struct crypt_dm_active_device dmd = {};
 790         int r;
 791
 792         r = dm_query_device(cd, name, DM_ACTIVE_UUID, &dmd);
 793         if (r < 0)
 794                 return r;
 795         if (!dmd.uuid)
 796                 return -EINVAL;
 797
 798         r = dm_remove_device(cd, name, 0, 0);
 799         if (r < 0)
 800                 goto out;
 801
 802         r = TCRYPT_remove_one(cd, name, dmd.uuid, 1);
 803         if (r < 0)
 804                 goto out;
 805
 806         r = TCRYPT_remove_one(cd, name, dmd.uuid, 2);
 807         if (r < 0)
 808                 goto out;
 809 out:
 810         free(CONST_CAST(void*)dmd.uuid);
 811         return (r == -ENODEV) ? 0 : r;
 812 }
 813
 814 static int TCRYPT_status_one(struct crypt_device *cd, const char *name,
 815                               const char *base_uuid, int index,
 816                               size_t *key_size, char *cipher,
 817                               uint64_t *data_offset, struct device **device)
 818 {
 819         struct crypt_dm_active_device dmd = {};
 820         char dm_name[PATH_MAX], *c;
 821         int r;
 822
 823         if (snprintf(dm_name, sizeof(dm_name), "%s_%d", name, index) < 0)
 824                 return -ENOMEM;
 825
 826         r = dm_status_device(cd, dm_name);
 827         if (r < 0)
 828                 return r;
 829
 830         r = dm_query_device(cd, dm_name, DM_ACTIVE_DEVICE |
 831                                           DM_ACTIVE_UUID |
 832                                           DM_ACTIVE_CRYPT_CIPHER |
 833                                           DM_ACTIVE_CRYPT_KEYSIZE, &dmd);
 834         if (r > 0)
 835                 r = 0;
 836         if (!r && !strncmp(dmd.uuid, base_uuid, strlen(base_uuid))) {
 837                 if ((c = strchr(dmd.u.crypt.cipher, '-')))
 838                         *c = '\0';
 839                 strcat(cipher, "-");
 840                 strncat(cipher, dmd.u.crypt.cipher, MAX_CIPHER_LEN);
 841                 *key_size += dmd.u.crypt.vk->keylength;
 842                 *data_offset = dmd.u.crypt.offset * SECTOR_SIZE;
 843                 device_free(*device);
 844                 *device = dmd.data_device;
 845         } else {
 846                 device_free(dmd.data_device);
 847                 r = -ENODEV;
 848         }
 849
 850         free(CONST_CAST(void*)dmd.uuid);
 851         free(CONST_CAST(void*)dmd.u.crypt.cipher);
 852         crypt_free_volume_key(dmd.u.crypt.vk);
 853         return r;
 854 }
 855
 856 int TCRYPT_init_by_name(struct crypt_device *cd, const char *name,
 857                         const struct crypt_dm_active_device *dmd,
 858                         struct device **device,
 859                         struct crypt_params_tcrypt *tcrypt_params,
 860                         struct tcrypt_phdr *tcrypt_hdr)
 861 {
 862         struct tcrypt_algs *algs;
 863         char cipher[MAX_CIPHER_LEN * 4], mode[MAX_CIPHER_LEN], *tmp;
 864         size_t key_size;
 865         int r;
 866
 867         memset(tcrypt_params, 0, sizeof(*tcrypt_params));
 868         memset(tcrypt_hdr, 0, sizeof(*tcrypt_hdr));
 869         tcrypt_hdr->d.sector_size = SECTOR_SIZE;
 870         tcrypt_hdr->d.mk_offset = dmd->u.crypt.offset * SECTOR_SIZE;
 871
 872         strncpy(cipher, dmd->u.crypt.cipher, MAX_CIPHER_LEN);
 873         tmp = strchr(cipher, '-');
 874         if (!tmp)
 875                 return -EINVAL;
 876         *tmp = '\0';
 877         strncpy(mode, ++tmp, MAX_CIPHER_LEN);
 878
 879         key_size = dmd->u.crypt.vk->keylength;
 880         r = TCRYPT_status_one(cd, name, dmd->uuid, 1, &key_size,
 881                               cipher, &tcrypt_hdr->d.mk_offset, device);
 882         if (!r)
 883                 r = TCRYPT_status_one(cd, name, dmd->uuid, 2, &key_size,
 884                                       cipher, &tcrypt_hdr->d.mk_offset, device);
 885
 886         if (r < 0 && r != -ENODEV)
 887                 return r;
 888
 889         algs = TCRYPT_get_algs(cipher, mode);
 890         if (!algs || key_size != algs->chain_key_size)
 891                 return -EINVAL;
 892
 893         tcrypt_params->key_size = algs->chain_key_size;
 894         tcrypt_params->cipher = algs->long_name;
 895         tcrypt_params->mode = algs->mode;
 896         return 0;
 897 }
 898
 899 uint64_t TCRYPT_get_data_offset(struct crypt_device *cd,
 900                                  struct tcrypt_phdr *hdr,
 901                                  struct crypt_params_tcrypt *params)
 902 {
 903         uint64_t size;
 904
 905         /* No real header loaded, initialized by active device */
 906         if (!hdr->d.version)
 907                 goto hdr_offset;
 908
 909         /* Mapping through whole device, not partition! */
 910         if (params->flags & CRYPT_TCRYPT_SYSTEM_HEADER)
 911                 goto hdr_offset;
 912
 913         if (params->mode && !strncmp(params->mode, "xts", 3)) {
 914                 if (hdr->d.version < 3)
 915                         return 1;
 916
 917                 if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) {
 918                         if (hdr->d.version > 3)
 919                                 return (hdr->d.mk_offset / hdr->d.sector_size);
 920                         if (device_size(crypt_metadata_device(cd), &size) < 0)
 921                                 return 0;
 922                         return (size - hdr->d.hidden_volume_size +
 923                                 (TCRYPT_HDR_HIDDEN_OFFSET_OLD)) / hdr->d.sector_size;
 924                 }
 925                 goto hdr_offset;
 926         }
 927
 928         if (params->flags & CRYPT_TCRYPT_HIDDEN_HEADER) {
 929                 if (device_size(crypt_metadata_device(cd), &size) < 0)
 930                         return 0;
 931                 return (size - hdr->d.hidden_volume_size +
 932                         (TCRYPT_HDR_HIDDEN_OFFSET_OLD)) / hdr->d.sector_size;
 933         }
 934
 935 hdr_offset:
 936         return hdr->d.mk_offset / hdr->d.sector_size;
 937 }
 938
 939 uint64_t TCRYPT_get_iv_offset(struct crypt_device *cd,
 940                               struct tcrypt_phdr *hdr,
 941                               struct crypt_params_tcrypt *params
 942 )
 943 {
 944         if (params->mode && !strncmp(params->mode, "xts", 3))
 945                 return TCRYPT_get_data_offset(cd, hdr, params);
 946         else if (params->mode && !strncmp(params->mode, "lrw", 3))
 947                 return 0;
 948
 949         return hdr->d.mk_offset / hdr->d.sector_size;
 950 }
 951
 952 int TCRYPT_get_volume_key(struct crypt_device *cd,
 953                           struct tcrypt_phdr *hdr,
 954                           struct crypt_params_tcrypt *params,
 955                           struct volume_key **vk)
 956 {
 957         struct tcrypt_algs *algs;
 958         unsigned int i, key_index;
 959
 960         if (!hdr->d.version) {
 961                 log_err(cd, _("This function is not supported without TCRYPT header load."));
 962                 return -ENOTSUP;
 963         }
 964
 965         algs = TCRYPT_get_algs(params->cipher, params->mode);
 966         if (!algs)
 967                 return -EINVAL;
 968
 969         *vk = crypt_alloc_volume_key(params->key_size, NULL);
 970         if (!*vk)
 971                 return -ENOMEM;
 972
 973         for (i = 0, key_index = 0; i < algs->chain_count; i++) {
 974                 TCRYPT_copy_key(&algs->cipher[i], algs->mode,
 975                                 &(*vk)->key[key_index], hdr->d.keys);
 976                 key_index += algs->cipher[i].key_size;
 977         }
 978
 979         return 0;
 980 }
 981
 982 int TCRYPT_dump(struct crypt_device *cd,
 983                 struct tcrypt_phdr *hdr,
 984                 struct crypt_params_tcrypt *params)
 985 {
 986         log_std(cd, "TCRYPT header information for %s\n",
 987                 device_path(crypt_metadata_device(cd)));
 988         if (hdr->d.version) {
 989                 log_std(cd, "Version:       \t%d\n", hdr->d.version);
 990                 log_std(cd, "Driver req.:\t%d\n", hdr->d.version_tc);
 991
 992                 log_std(cd, "Sector size:\t%" PRIu32 "\n", hdr->d.sector_size);
 993                 log_std(cd, "MK offset:\t%" PRIu64 "\n", hdr->d.mk_offset);
 994                 log_std(cd, "PBKDF2 hash:\t%s\n", params->hash_name);
 995         }
 996         log_std(cd, "Cipher chain:\t%s\n", params->cipher);
 997         log_std(cd, "Cipher mode:\t%s\n", params->mode);
 998         log_std(cd, "MK bits:       \t%d\n", params->key_size * 8);
 999         return 0;
1000 }