1/* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17/* TO DO: 18 * 1. Perhaps keep several copies of the encrypted key, in case something 19 * goes horribly wrong? 20 * 21 */ 22 23#include <sys/types.h> 24#include <sys/wait.h> 25#include <sys/stat.h> 26#include <fcntl.h> 27#include <unistd.h> 28#include <stdio.h> 29#include <sys/ioctl.h> 30#include <linux/dm-ioctl.h> 31#include <libgen.h> 32#include <stdlib.h> 33#include <sys/param.h> 34#include <string.h> 35#include <sys/mount.h> 36#include <openssl/evp.h> 37#include <openssl/sha.h> 38#include <errno.h> 39#include <ext4.h> 40#include <linux/kdev_t.h> 41#include <fs_mgr.h> 42#include "cryptfs.h" 43#define LOG_TAG "Cryptfs" 44#include "cutils/log.h" 45#include "cutils/properties.h" 46#include "cutils/android_reboot.h" 47#include "hardware_legacy/power.h" 48#include <logwrap/logwrap.h> 49#include "VolumeManager.h" 50#include "VoldUtil.h" 51#include "crypto_scrypt.h" 52 53#define DM_CRYPT_BUF_SIZE 4096 54#define DATA_MNT_POINT "/data" 55 56#define HASH_COUNT 2000 57#define KEY_LEN_BYTES 16 58#define IV_LEN_BYTES 16 59 60#define KEY_IN_FOOTER "footer" 61 62#define EXT4_FS 1 63#define FAT_FS 2 64 65#define TABLE_LOAD_RETRIES 10 66 67char *me = "cryptfs"; 68 69static unsigned char saved_master_key[KEY_LEN_BYTES]; 70static char *saved_mount_point; 71static int master_key_saved = 0; 72static struct crypt_persist_data *persist_data = NULL; 73 74extern struct fstab *fstab; 75 76static void cryptfs_reboot(int recovery) 77{ 78 if (recovery) { 79 property_set(ANDROID_RB_PROPERTY, "reboot,recovery"); 80 } else { 81 property_set(ANDROID_RB_PROPERTY, "reboot"); 82 } 83 sleep(20); 84 85 /* Shouldn't get here, reboot should happen before sleep times out */ 86 return; 87} 88 89static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags) 90{ 91 memset(io, 0, dataSize); 92 io->data_size = dataSize; 93 io->data_start = sizeof(struct dm_ioctl); 94 io->version[0] = 4; 95 io->version[1] = 0; 96 io->version[2] = 0; 97 io->flags = flags; 98 if (name) { 99 strncpy(io->name, name, sizeof(io->name)); 100 } 101} 102 103/** 104 * Gets the default device scrypt parameters for key derivation time tuning. 105 * The parameters should lead to about one second derivation time for the 106 * given device. 107 */ 108static void get_device_scrypt_params(struct crypt_mnt_ftr *ftr) { 109 const int default_params[] = SCRYPT_DEFAULTS; 110 int params[] = SCRYPT_DEFAULTS; 111 char paramstr[PROPERTY_VALUE_MAX]; 112 char *token; 113 char *saveptr; 114 int i; 115 116 property_get(SCRYPT_PROP, paramstr, ""); 117 if (paramstr[0] != '\0') { 118 /* 119 * The token we're looking for should be three integers separated by 120 * colons (e.g., "12:8:1"). Scan the property to make sure it matches. 121 */ 122 for (i = 0, token = strtok_r(paramstr, ":", &saveptr); 123 token != NULL && i < 3; 124 i++, token = strtok_r(NULL, ":", &saveptr)) { 125 char *endptr; 126 params[i] = strtol(token, &endptr, 10); 127 128 /* 129 * Check that there was a valid number and it's 8-bit. If not, 130 * break out and the end check will take the default values. 131 */ 132 if ((*token == '\0') || (*endptr != '\0') || params[i] < 0 || params[i] > 255) { 133 break; 134 } 135 } 136 137 /* 138 * If there were not enough tokens or a token was malformed (not an 139 * integer), it will end up here and the default parameters can be 140 * taken. 141 */ 142 if ((i != 3) || (token != NULL)) { 143 SLOGW("bad scrypt parameters '%s' should be like '12:8:1'; using defaults", paramstr); 144 memcpy(params, default_params, sizeof(params)); 145 } 146 } 147 148 ftr->N_factor = params[0]; 149 ftr->r_factor = params[1]; 150 ftr->p_factor = params[2]; 151} 152 153static unsigned int get_fs_size(char *dev) 154{ 155 int fd, block_size; 156 struct ext4_super_block sb; 157 off64_t len; 158 159 if ((fd = open(dev, O_RDONLY)) < 0) { 160 SLOGE("Cannot open device to get filesystem size "); 161 return 0; 162 } 163 164 if (lseek64(fd, 1024, SEEK_SET) < 0) { 165 SLOGE("Cannot seek to superblock"); 166 return 0; 167 } 168 169 if (read(fd, &sb, sizeof(sb)) != sizeof(sb)) { 170 SLOGE("Cannot read superblock"); 171 return 0; 172 } 173 174 close(fd); 175 176 block_size = 1024 << sb.s_log_block_size; 177 /* compute length in bytes */ 178 len = ( ((off64_t)sb.s_blocks_count_hi << 32) + sb.s_blocks_count_lo) * block_size; 179 180 /* return length in sectors */ 181 return (unsigned int) (len / 512); 182} 183 184static int get_crypt_ftr_info(char **metadata_fname, off64_t *off) 185{ 186 static int cached_data = 0; 187 static off64_t cached_off = 0; 188 static char cached_metadata_fname[PROPERTY_VALUE_MAX] = ""; 189 int fd; 190 char key_loc[PROPERTY_VALUE_MAX]; 191 char real_blkdev[PROPERTY_VALUE_MAX]; 192 unsigned int nr_sec; 193 int rc = -1; 194 195 if (!cached_data) { 196 fs_mgr_get_crypt_info(fstab, key_loc, real_blkdev, sizeof(key_loc)); 197 198 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 199 if ( (fd = open(real_blkdev, O_RDWR)) < 0) { 200 SLOGE("Cannot open real block device %s\n", real_blkdev); 201 return -1; 202 } 203 204 if ((nr_sec = get_blkdev_size(fd))) { 205 /* If it's an encrypted Android partition, the last 16 Kbytes contain the 206 * encryption info footer and key, and plenty of bytes to spare for future 207 * growth. 208 */ 209 strlcpy(cached_metadata_fname, real_blkdev, sizeof(cached_metadata_fname)); 210 cached_off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; 211 cached_data = 1; 212 } else { 213 SLOGE("Cannot get size of block device %s\n", real_blkdev); 214 } 215 close(fd); 216 } else { 217 strlcpy(cached_metadata_fname, key_loc, sizeof(cached_metadata_fname)); 218 cached_off = 0; 219 cached_data = 1; 220 } 221 } 222 223 if (cached_data) { 224 if (metadata_fname) { 225 *metadata_fname = cached_metadata_fname; 226 } 227 if (off) { 228 *off = cached_off; 229 } 230 rc = 0; 231 } 232 233 return rc; 234} 235 236/* key or salt can be NULL, in which case just skip writing that value. Useful to 237 * update the failed mount count but not change the key. 238 */ 239static int put_crypt_ftr_and_key(struct crypt_mnt_ftr *crypt_ftr) 240{ 241 int fd; 242 unsigned int nr_sec, cnt; 243 /* starting_off is set to the SEEK_SET offset 244 * where the crypto structure starts 245 */ 246 off64_t starting_off; 247 int rc = -1; 248 char *fname = NULL; 249 struct stat statbuf; 250 251 if (get_crypt_ftr_info(&fname, &starting_off)) { 252 SLOGE("Unable to get crypt_ftr_info\n"); 253 return -1; 254 } 255 if (fname[0] != '/') { 256 SLOGE("Unexpected value for crypto key location\n"); 257 return -1; 258 } 259 if ( (fd = open(fname, O_RDWR | O_CREAT, 0600)) < 0) { 260 SLOGE("Cannot open footer file %s for put\n", fname); 261 return -1; 262 } 263 264 /* Seek to the start of the crypt footer */ 265 if (lseek64(fd, starting_off, SEEK_SET) == -1) { 266 SLOGE("Cannot seek to real block device footer\n"); 267 goto errout; 268 } 269 270 if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) { 271 SLOGE("Cannot write real block device footer\n"); 272 goto errout; 273 } 274 275 fstat(fd, &statbuf); 276 /* If the keys are kept on a raw block device, do not try to truncate it. */ 277 if (S_ISREG(statbuf.st_mode)) { 278 if (ftruncate(fd, 0x4000)) { 279 SLOGE("Cannot set footer file size\n", fname); 280 goto errout; 281 } 282 } 283 284 /* Success! */ 285 rc = 0; 286 287errout: 288 close(fd); 289 return rc; 290 291} 292 293static inline int unix_read(int fd, void* buff, int len) 294{ 295 return TEMP_FAILURE_RETRY(read(fd, buff, len)); 296} 297 298static inline int unix_write(int fd, const void* buff, int len) 299{ 300 return TEMP_FAILURE_RETRY(write(fd, buff, len)); 301} 302 303static void init_empty_persist_data(struct crypt_persist_data *pdata, int len) 304{ 305 memset(pdata, 0, len); 306 pdata->persist_magic = PERSIST_DATA_MAGIC; 307 pdata->persist_valid_entries = 0; 308} 309 310/* A routine to update the passed in crypt_ftr to the lastest version. 311 * fd is open read/write on the device that holds the crypto footer and persistent 312 * data, crypt_ftr is a pointer to the struct to be updated, and offset is the 313 * absolute offset to the start of the crypt_mnt_ftr on the passed in fd. 314 */ 315static void upgrade_crypt_ftr(int fd, struct crypt_mnt_ftr *crypt_ftr, off64_t offset) 316{ 317 int orig_major = crypt_ftr->major_version; 318 int orig_minor = crypt_ftr->minor_version; 319 320 if ((crypt_ftr->major_version == 1) && (crypt_ftr->minor_version == 0)) { 321 struct crypt_persist_data *pdata; 322 off64_t pdata_offset = offset + CRYPT_FOOTER_TO_PERSIST_OFFSET; 323 324 SLOGW("upgrading crypto footer to 1.1"); 325 326 pdata = malloc(CRYPT_PERSIST_DATA_SIZE); 327 if (pdata == NULL) { 328 SLOGE("Cannot allocate persisent data\n"); 329 return; 330 } 331 memset(pdata, 0, CRYPT_PERSIST_DATA_SIZE); 332 333 /* Need to initialize the persistent data area */ 334 if (lseek64(fd, pdata_offset, SEEK_SET) == -1) { 335 SLOGE("Cannot seek to persisent data offset\n"); 336 return; 337 } 338 /* Write all zeros to the first copy, making it invalid */ 339 unix_write(fd, pdata, CRYPT_PERSIST_DATA_SIZE); 340 341 /* Write a valid but empty structure to the second copy */ 342 init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE); 343 unix_write(fd, pdata, CRYPT_PERSIST_DATA_SIZE); 344 345 /* Update the footer */ 346 crypt_ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE; 347 crypt_ftr->persist_data_offset[0] = pdata_offset; 348 crypt_ftr->persist_data_offset[1] = pdata_offset + CRYPT_PERSIST_DATA_SIZE; 349 crypt_ftr->minor_version = 1; 350 } 351 352 if ((crypt_ftr->major_version == 1) && (crypt_ftr->minor_version)) { 353 SLOGW("upgrading crypto footer to 1.2"); 354 crypt_ftr->kdf_type = KDF_PBKDF2; 355 get_device_scrypt_params(crypt_ftr); 356 crypt_ftr->minor_version = 2; 357 } 358 359 if ((orig_major != crypt_ftr->major_version) || (orig_minor != crypt_ftr->minor_version)) { 360 if (lseek64(fd, offset, SEEK_SET) == -1) { 361 SLOGE("Cannot seek to crypt footer\n"); 362 return; 363 } 364 unix_write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr)); 365 } 366} 367 368 369static int get_crypt_ftr_and_key(struct crypt_mnt_ftr *crypt_ftr) 370{ 371 int fd; 372 unsigned int nr_sec, cnt; 373 off64_t starting_off; 374 int rc = -1; 375 char *fname = NULL; 376 struct stat statbuf; 377 378 if (get_crypt_ftr_info(&fname, &starting_off)) { 379 SLOGE("Unable to get crypt_ftr_info\n"); 380 return -1; 381 } 382 if (fname[0] != '/') { 383 SLOGE("Unexpected value for crypto key location\n"); 384 return -1; 385 } 386 if ( (fd = open(fname, O_RDWR)) < 0) { 387 SLOGE("Cannot open footer file %s for get\n", fname); 388 return -1; 389 } 390 391 /* Make sure it's 16 Kbytes in length */ 392 fstat(fd, &statbuf); 393 if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) { 394 SLOGE("footer file %s is not the expected size!\n", fname); 395 goto errout; 396 } 397 398 /* Seek to the start of the crypt footer */ 399 if (lseek64(fd, starting_off, SEEK_SET) == -1) { 400 SLOGE("Cannot seek to real block device footer\n"); 401 goto errout; 402 } 403 404 if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) { 405 SLOGE("Cannot read real block device footer\n"); 406 goto errout; 407 } 408 409 if (crypt_ftr->magic != CRYPT_MNT_MAGIC) { 410 SLOGE("Bad magic for real block device %s\n", fname); 411 goto errout; 412 } 413 414 if (crypt_ftr->major_version != CURRENT_MAJOR_VERSION) { 415 SLOGE("Cannot understand major version %d real block device footer; expected %d\n", 416 crypt_ftr->major_version, CURRENT_MAJOR_VERSION); 417 goto errout; 418 } 419 420 if (crypt_ftr->minor_version > CURRENT_MINOR_VERSION) { 421 SLOGW("Warning: crypto footer minor version %d, expected <= %d, continuing...\n", 422 crypt_ftr->minor_version, CURRENT_MINOR_VERSION); 423 } 424 425 /* If this is a verion 1.0 crypt_ftr, make it a 1.1 crypt footer, and update the 426 * copy on disk before returning. 427 */ 428 if (crypt_ftr->minor_version < CURRENT_MINOR_VERSION) { 429 upgrade_crypt_ftr(fd, crypt_ftr, starting_off); 430 } 431 432 /* Success! */ 433 rc = 0; 434 435errout: 436 close(fd); 437 return rc; 438} 439 440static int validate_persistent_data_storage(struct crypt_mnt_ftr *crypt_ftr) 441{ 442 if (crypt_ftr->persist_data_offset[0] + crypt_ftr->persist_data_size > 443 crypt_ftr->persist_data_offset[1]) { 444 SLOGE("Crypt_ftr persist data regions overlap"); 445 return -1; 446 } 447 448 if (crypt_ftr->persist_data_offset[0] >= crypt_ftr->persist_data_offset[1]) { 449 SLOGE("Crypt_ftr persist data region 0 starts after region 1"); 450 return -1; 451 } 452 453 if (((crypt_ftr->persist_data_offset[1] + crypt_ftr->persist_data_size) - 454 (crypt_ftr->persist_data_offset[0] - CRYPT_FOOTER_TO_PERSIST_OFFSET)) > 455 CRYPT_FOOTER_OFFSET) { 456 SLOGE("Persistent data extends past crypto footer"); 457 return -1; 458 } 459 460 return 0; 461} 462 463static int load_persistent_data(void) 464{ 465 struct crypt_mnt_ftr crypt_ftr; 466 struct crypt_persist_data *pdata = NULL; 467 char encrypted_state[PROPERTY_VALUE_MAX]; 468 char *fname; 469 int found = 0; 470 int fd; 471 int ret; 472 int i; 473 474 if (persist_data) { 475 /* Nothing to do, we've already loaded or initialized it */ 476 return 0; 477 } 478 479 480 /* If not encrypted, just allocate an empty table and initialize it */ 481 property_get("ro.crypto.state", encrypted_state, ""); 482 if (strcmp(encrypted_state, "encrypted") ) { 483 pdata = malloc(CRYPT_PERSIST_DATA_SIZE); 484 if (pdata) { 485 init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE); 486 persist_data = pdata; 487 return 0; 488 } 489 return -1; 490 } 491 492 if(get_crypt_ftr_and_key(&crypt_ftr)) { 493 return -1; 494 } 495 496 if ((crypt_ftr.major_version != 1) || (crypt_ftr.minor_version != 1)) { 497 SLOGE("Crypt_ftr version doesn't support persistent data"); 498 return -1; 499 } 500 501 if (get_crypt_ftr_info(&fname, NULL)) { 502 return -1; 503 } 504 505 ret = validate_persistent_data_storage(&crypt_ftr); 506 if (ret) { 507 return -1; 508 } 509 510 fd = open(fname, O_RDONLY); 511 if (fd < 0) { 512 SLOGE("Cannot open %s metadata file", fname); 513 return -1; 514 } 515 516 if (persist_data == NULL) { 517 pdata = malloc(crypt_ftr.persist_data_size); 518 if (pdata == NULL) { 519 SLOGE("Cannot allocate memory for persistent data"); 520 goto err; 521 } 522 } 523 524 for (i = 0; i < 2; i++) { 525 if (lseek64(fd, crypt_ftr.persist_data_offset[i], SEEK_SET) < 0) { 526 SLOGE("Cannot seek to read persistent data on %s", fname); 527 goto err2; 528 } 529 if (unix_read(fd, pdata, crypt_ftr.persist_data_size) < 0){ 530 SLOGE("Error reading persistent data on iteration %d", i); 531 goto err2; 532 } 533 if (pdata->persist_magic == PERSIST_DATA_MAGIC) { 534 found = 1; 535 break; 536 } 537 } 538 539 if (!found) { 540 SLOGI("Could not find valid persistent data, creating"); 541 init_empty_persist_data(pdata, crypt_ftr.persist_data_size); 542 } 543 544 /* Success */ 545 persist_data = pdata; 546 close(fd); 547 return 0; 548 549err2: 550 free(pdata); 551 552err: 553 close(fd); 554 return -1; 555} 556 557static int save_persistent_data(void) 558{ 559 struct crypt_mnt_ftr crypt_ftr; 560 struct crypt_persist_data *pdata; 561 char *fname; 562 off64_t write_offset; 563 off64_t erase_offset; 564 int found = 0; 565 int fd; 566 int ret; 567 568 if (persist_data == NULL) { 569 SLOGE("No persistent data to save"); 570 return -1; 571 } 572 573 if(get_crypt_ftr_and_key(&crypt_ftr)) { 574 return -1; 575 } 576 577 if ((crypt_ftr.major_version != 1) || (crypt_ftr.minor_version != 1)) { 578 SLOGE("Crypt_ftr version doesn't support persistent data"); 579 return -1; 580 } 581 582 ret = validate_persistent_data_storage(&crypt_ftr); 583 if (ret) { 584 return -1; 585 } 586 587 if (get_crypt_ftr_info(&fname, NULL)) { 588 return -1; 589 } 590 591 fd = open(fname, O_RDWR); 592 if (fd < 0) { 593 SLOGE("Cannot open %s metadata file", fname); 594 return -1; 595 } 596 597 pdata = malloc(crypt_ftr.persist_data_size); 598 if (pdata == NULL) { 599 SLOGE("Cannot allocate persistant data"); 600 goto err; 601 } 602 603 if (lseek64(fd, crypt_ftr.persist_data_offset[0], SEEK_SET) < 0) { 604 SLOGE("Cannot seek to read persistent data on %s", fname); 605 goto err2; 606 } 607 608 if (unix_read(fd, pdata, crypt_ftr.persist_data_size) < 0) { 609 SLOGE("Error reading persistent data before save"); 610 goto err2; 611 } 612 613 if (pdata->persist_magic == PERSIST_DATA_MAGIC) { 614 /* The first copy is the curent valid copy, so write to 615 * the second copy and erase this one */ 616 write_offset = crypt_ftr.persist_data_offset[1]; 617 erase_offset = crypt_ftr.persist_data_offset[0]; 618 } else { 619 /* The second copy must be the valid copy, so write to 620 * the first copy, and erase the second */ 621 write_offset = crypt_ftr.persist_data_offset[0]; 622 erase_offset = crypt_ftr.persist_data_offset[1]; 623 } 624 625 /* Write the new copy first, if successful, then erase the old copy */ 626 if (lseek(fd, write_offset, SEEK_SET) < 0) { 627 SLOGE("Cannot seek to write persistent data"); 628 goto err2; 629 } 630 if (unix_write(fd, persist_data, crypt_ftr.persist_data_size) == 631 (int) crypt_ftr.persist_data_size) { 632 if (lseek(fd, erase_offset, SEEK_SET) < 0) { 633 SLOGE("Cannot seek to erase previous persistent data"); 634 goto err2; 635 } 636 fsync(fd); 637 memset(pdata, 0, crypt_ftr.persist_data_size); 638 if (unix_write(fd, pdata, crypt_ftr.persist_data_size) != 639 (int) crypt_ftr.persist_data_size) { 640 SLOGE("Cannot write to erase previous persistent data"); 641 goto err2; 642 } 643 fsync(fd); 644 } else { 645 SLOGE("Cannot write to save persistent data"); 646 goto err2; 647 } 648 649 /* Success */ 650 free(pdata); 651 close(fd); 652 return 0; 653 654err2: 655 free(pdata); 656err: 657 close(fd); 658 return -1; 659} 660 661/* Convert a binary key of specified length into an ascii hex string equivalent, 662 * without the leading 0x and with null termination 663 */ 664void convert_key_to_hex_ascii(unsigned char *master_key, unsigned int keysize, 665 char *master_key_ascii) 666{ 667 unsigned int i, a; 668 unsigned char nibble; 669 670 for (i=0, a=0; i<keysize; i++, a+=2) { 671 /* For each byte, write out two ascii hex digits */ 672 nibble = (master_key[i] >> 4) & 0xf; 673 master_key_ascii[a] = nibble + (nibble > 9 ? 0x37 : 0x30); 674 675 nibble = master_key[i] & 0xf; 676 master_key_ascii[a+1] = nibble + (nibble > 9 ? 0x37 : 0x30); 677 } 678 679 /* Add the null termination */ 680 master_key_ascii[a] = '\0'; 681 682} 683 684static int load_crypto_mapping_table(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key, 685 char *real_blk_name, const char *name, int fd, 686 char *extra_params) 687{ 688 char buffer[DM_CRYPT_BUF_SIZE]; 689 struct dm_ioctl *io; 690 struct dm_target_spec *tgt; 691 char *crypt_params; 692 char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ 693 int i; 694 695 io = (struct dm_ioctl *) buffer; 696 697 /* Load the mapping table for this device */ 698 tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)]; 699 700 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 701 io->target_count = 1; 702 tgt->status = 0; 703 tgt->sector_start = 0; 704 tgt->length = crypt_ftr->fs_size; 705 strcpy(tgt->target_type, "crypt"); 706 707 crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec); 708 convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii); 709 sprintf(crypt_params, "%s %s 0 %s 0 %s", crypt_ftr->crypto_type_name, 710 master_key_ascii, real_blk_name, extra_params); 711 crypt_params += strlen(crypt_params) + 1; 712 crypt_params = (char *) (((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */ 713 tgt->next = crypt_params - buffer; 714 715 for (i = 0; i < TABLE_LOAD_RETRIES; i++) { 716 if (! ioctl(fd, DM_TABLE_LOAD, io)) { 717 break; 718 } 719 usleep(500000); 720 } 721 722 if (i == TABLE_LOAD_RETRIES) { 723 /* We failed to load the table, return an error */ 724 return -1; 725 } else { 726 return i + 1; 727 } 728} 729 730 731static int get_dm_crypt_version(int fd, const char *name, int *version) 732{ 733 char buffer[DM_CRYPT_BUF_SIZE]; 734 struct dm_ioctl *io; 735 struct dm_target_versions *v; 736 int i; 737 738 io = (struct dm_ioctl *) buffer; 739 740 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 741 742 if (ioctl(fd, DM_LIST_VERSIONS, io)) { 743 return -1; 744 } 745 746 /* Iterate over the returned versions, looking for name of "crypt". 747 * When found, get and return the version. 748 */ 749 v = (struct dm_target_versions *) &buffer[sizeof(struct dm_ioctl)]; 750 while (v->next) { 751 if (! strcmp(v->name, "crypt")) { 752 /* We found the crypt driver, return the version, and get out */ 753 version[0] = v->version[0]; 754 version[1] = v->version[1]; 755 version[2] = v->version[2]; 756 return 0; 757 } 758 v = (struct dm_target_versions *)(((char *)v) + v->next); 759 } 760 761 return -1; 762} 763 764static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key, 765 char *real_blk_name, char *crypto_blk_name, const char *name) 766{ 767 char buffer[DM_CRYPT_BUF_SIZE]; 768 char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ 769 char *crypt_params; 770 struct dm_ioctl *io; 771 struct dm_target_spec *tgt; 772 unsigned int minor; 773 int fd; 774 int i; 775 int retval = -1; 776 int version[3]; 777 char *extra_params; 778 int load_count; 779 780 if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { 781 SLOGE("Cannot open device-mapper\n"); 782 goto errout; 783 } 784 785 io = (struct dm_ioctl *) buffer; 786 787 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 788 if (ioctl(fd, DM_DEV_CREATE, io)) { 789 SLOGE("Cannot create dm-crypt device\n"); 790 goto errout; 791 } 792 793 /* Get the device status, in particular, the name of it's device file */ 794 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 795 if (ioctl(fd, DM_DEV_STATUS, io)) { 796 SLOGE("Cannot retrieve dm-crypt device status\n"); 797 goto errout; 798 } 799 minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00); 800 snprintf(crypto_blk_name, MAXPATHLEN, "/dev/block/dm-%u", minor); 801 802 extra_params = ""; 803 if (! get_dm_crypt_version(fd, name, version)) { 804 /* Support for allow_discards was added in version 1.11.0 */ 805 if ((version[0] >= 2) || 806 ((version[0] == 1) && (version[1] >= 11))) { 807 extra_params = "1 allow_discards"; 808 SLOGI("Enabling support for allow_discards in dmcrypt.\n"); 809 } 810 } 811 812 load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name, 813 fd, extra_params); 814 if (load_count < 0) { 815 SLOGE("Cannot load dm-crypt mapping table.\n"); 816 goto errout; 817 } else if (load_count > 1) { 818 SLOGI("Took %d tries to load dmcrypt table.\n", load_count); 819 } 820 821 /* Resume this device to activate it */ 822 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 823 824 if (ioctl(fd, DM_DEV_SUSPEND, io)) { 825 SLOGE("Cannot resume the dm-crypt device\n"); 826 goto errout; 827 } 828 829 /* We made it here with no errors. Woot! */ 830 retval = 0; 831 832errout: 833 close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */ 834 835 return retval; 836} 837 838static int delete_crypto_blk_dev(char *name) 839{ 840 int fd; 841 char buffer[DM_CRYPT_BUF_SIZE]; 842 struct dm_ioctl *io; 843 int retval = -1; 844 845 if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { 846 SLOGE("Cannot open device-mapper\n"); 847 goto errout; 848 } 849 850 io = (struct dm_ioctl *) buffer; 851 852 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 853 if (ioctl(fd, DM_DEV_REMOVE, io)) { 854 SLOGE("Cannot remove dm-crypt device\n"); 855 goto errout; 856 } 857 858 /* We made it here with no errors. Woot! */ 859 retval = 0; 860 861errout: 862 close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */ 863 864 return retval; 865 866} 867 868static void pbkdf2(char *passwd, unsigned char *salt, unsigned char *ikey, void *params) { 869 /* Turn the password into a key and IV that can decrypt the master key */ 870 PKCS5_PBKDF2_HMAC_SHA1(passwd, strlen(passwd), salt, SALT_LEN, 871 HASH_COUNT, KEY_LEN_BYTES+IV_LEN_BYTES, ikey); 872} 873 874static void scrypt(char *passwd, unsigned char *salt, unsigned char *ikey, void *params) { 875 struct crypt_mnt_ftr *ftr = (struct crypt_mnt_ftr *) params; 876 877 int N = 1 << ftr->N_factor; 878 int r = 1 << ftr->r_factor; 879 int p = 1 << ftr->p_factor; 880 881 /* Turn the password into a key and IV that can decrypt the master key */ 882 crypto_scrypt((unsigned char *) passwd, strlen(passwd), salt, SALT_LEN, N, r, p, ikey, 883 KEY_LEN_BYTES + IV_LEN_BYTES); 884} 885 886static int encrypt_master_key(char *passwd, unsigned char *salt, 887 unsigned char *decrypted_master_key, 888 unsigned char *encrypted_master_key, 889 struct crypt_mnt_ftr *crypt_ftr) 890{ 891 unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ 892 EVP_CIPHER_CTX e_ctx; 893 int encrypted_len, final_len; 894 895 /* Turn the password into a key and IV that can decrypt the master key */ 896 get_device_scrypt_params(crypt_ftr); 897 scrypt(passwd, salt, ikey, crypt_ftr); 898 899 /* Initialize the decryption engine */ 900 if (! EVP_EncryptInit(&e_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) { 901 SLOGE("EVP_EncryptInit failed\n"); 902 return -1; 903 } 904 EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */ 905 906 /* Encrypt the master key */ 907 if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len, 908 decrypted_master_key, KEY_LEN_BYTES)) { 909 SLOGE("EVP_EncryptUpdate failed\n"); 910 return -1; 911 } 912 if (! EVP_EncryptFinal(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) { 913 SLOGE("EVP_EncryptFinal failed\n"); 914 return -1; 915 } 916 917 if (encrypted_len + final_len != KEY_LEN_BYTES) { 918 SLOGE("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len); 919 return -1; 920 } else { 921 return 0; 922 } 923} 924 925static int decrypt_master_key(char *passwd, unsigned char *salt, 926 unsigned char *encrypted_master_key, 927 unsigned char *decrypted_master_key, 928 kdf_func kdf, void *kdf_params) 929{ 930 unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ 931 EVP_CIPHER_CTX d_ctx; 932 int decrypted_len, final_len; 933 934 /* Turn the password into a key and IV that can decrypt the master key */ 935 kdf(passwd, salt, ikey, kdf_params); 936 937 /* Initialize the decryption engine */ 938 if (! EVP_DecryptInit(&d_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) { 939 return -1; 940 } 941 EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */ 942 /* Decrypt the master key */ 943 if (! EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len, 944 encrypted_master_key, KEY_LEN_BYTES)) { 945 return -1; 946 } 947 if (! EVP_DecryptFinal(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) { 948 return -1; 949 } 950 951 if (decrypted_len + final_len != KEY_LEN_BYTES) { 952 return -1; 953 } else { 954 return 0; 955 } 956} 957 958static void get_kdf_func(struct crypt_mnt_ftr *ftr, kdf_func *kdf, void** kdf_params) 959{ 960 if (ftr->kdf_type == KDF_SCRYPT) { 961 *kdf = scrypt; 962 *kdf_params = ftr; 963 } else { 964 *kdf = pbkdf2; 965 *kdf_params = NULL; 966 } 967} 968 969static int decrypt_master_key_and_upgrade(char *passwd, unsigned char *decrypted_master_key, 970 struct crypt_mnt_ftr *crypt_ftr) 971{ 972 kdf_func kdf; 973 void *kdf_params; 974 int ret; 975 976 get_kdf_func(crypt_ftr, &kdf, &kdf_params); 977 ret = decrypt_master_key(passwd, crypt_ftr->salt, crypt_ftr->master_key, decrypted_master_key, kdf, 978 kdf_params); 979 if (ret != 0) { 980 SLOGW("failure decrypting master key"); 981 return ret; 982 } 983 984 /* 985 * Upgrade if we're not using the latest KDF. 986 */ 987 if (crypt_ftr->kdf_type != KDF_SCRYPT) { 988 crypt_ftr->kdf_type = KDF_SCRYPT; 989 encrypt_master_key(passwd, crypt_ftr->salt, decrypted_master_key, crypt_ftr->master_key, 990 crypt_ftr); 991 put_crypt_ftr_and_key(crypt_ftr); 992 } 993 994 return ret; 995} 996 997static int create_encrypted_random_key(char *passwd, unsigned char *master_key, unsigned char *salt, 998 struct crypt_mnt_ftr *crypt_ftr) { 999 int fd; 1000 unsigned char key_buf[KEY_LEN_BYTES]; 1001 EVP_CIPHER_CTX e_ctx; 1002 int encrypted_len, final_len; 1003 1004 /* Get some random bits for a key */ 1005 fd = open("/dev/urandom", O_RDONLY); 1006 read(fd, key_buf, sizeof(key_buf)); 1007 read(fd, salt, SALT_LEN); 1008 close(fd); 1009 1010 /* Now encrypt it with the password */ 1011 return encrypt_master_key(passwd, salt, key_buf, master_key, crypt_ftr); 1012} 1013 1014static int wait_and_unmount(char *mountpoint) 1015{ 1016 int i, rc; 1017#define WAIT_UNMOUNT_COUNT 20 1018 1019 /* Now umount the tmpfs filesystem */ 1020 for (i=0; i<WAIT_UNMOUNT_COUNT; i++) { 1021 if (umount(mountpoint)) { 1022 if (errno == EINVAL) { 1023 /* EINVAL is returned if the directory is not a mountpoint, 1024 * i.e. there is no filesystem mounted there. So just get out. 1025 */ 1026 break; 1027 } 1028 sleep(1); 1029 i++; 1030 } else { 1031 break; 1032 } 1033 } 1034 1035 if (i < WAIT_UNMOUNT_COUNT) { 1036 SLOGD("unmounting %s succeeded\n", mountpoint); 1037 rc = 0; 1038 } else { 1039 SLOGE("unmounting %s failed\n", mountpoint); 1040 rc = -1; 1041 } 1042 1043 return rc; 1044} 1045 1046#define DATA_PREP_TIMEOUT 200 1047static int prep_data_fs(void) 1048{ 1049 int i; 1050 1051 /* Do the prep of the /data filesystem */ 1052 property_set("vold.post_fs_data_done", "0"); 1053 property_set("vold.decrypt", "trigger_post_fs_data"); 1054 SLOGD("Just triggered post_fs_data\n"); 1055 1056 /* Wait a max of 50 seconds, hopefully it takes much less */ 1057 for (i=0; i<DATA_PREP_TIMEOUT; i++) { 1058 char p[PROPERTY_VALUE_MAX]; 1059 1060 property_get("vold.post_fs_data_done", p, "0"); 1061 if (*p == '1') { 1062 break; 1063 } else { 1064 usleep(250000); 1065 } 1066 } 1067 if (i == DATA_PREP_TIMEOUT) { 1068 /* Ugh, we failed to prep /data in time. Bail. */ 1069 SLOGE("post_fs_data timed out!\n"); 1070 return -1; 1071 } else { 1072 SLOGD("post_fs_data done\n"); 1073 return 0; 1074 } 1075} 1076 1077int cryptfs_restart(void) 1078{ 1079 char fs_type[32]; 1080 char real_blkdev[MAXPATHLEN]; 1081 char crypto_blkdev[MAXPATHLEN]; 1082 char fs_options[256]; 1083 unsigned long mnt_flags; 1084 struct stat statbuf; 1085 int rc = -1, i; 1086 static int restart_successful = 0; 1087 1088 /* Validate that it's OK to call this routine */ 1089 if (! master_key_saved) { 1090 SLOGE("Encrypted filesystem not validated, aborting"); 1091 return -1; 1092 } 1093 1094 if (restart_successful) { 1095 SLOGE("System already restarted with encrypted disk, aborting"); 1096 return -1; 1097 } 1098 1099 /* Here is where we shut down the framework. The init scripts 1100 * start all services in one of three classes: core, main or late_start. 1101 * On boot, we start core and main. Now, we stop main, but not core, 1102 * as core includes vold and a few other really important things that 1103 * we need to keep running. Once main has stopped, we should be able 1104 * to umount the tmpfs /data, then mount the encrypted /data. 1105 * We then restart the class main, and also the class late_start. 1106 * At the moment, I've only put a few things in late_start that I know 1107 * are not needed to bring up the framework, and that also cause problems 1108 * with unmounting the tmpfs /data, but I hope to add add more services 1109 * to the late_start class as we optimize this to decrease the delay 1110 * till the user is asked for the password to the filesystem. 1111 */ 1112 1113 /* The init files are setup to stop the class main when vold.decrypt is 1114 * set to trigger_reset_main. 1115 */ 1116 property_set("vold.decrypt", "trigger_reset_main"); 1117 SLOGD("Just asked init to shut down class main\n"); 1118 1119 /* Ugh, shutting down the framework is not synchronous, so until it 1120 * can be fixed, this horrible hack will wait a moment for it all to 1121 * shut down before proceeding. Without it, some devices cannot 1122 * restart the graphics services. 1123 */ 1124 sleep(2); 1125 1126 /* Now that the framework is shutdown, we should be able to umount() 1127 * the tmpfs filesystem, and mount the real one. 1128 */ 1129 1130 property_get("ro.crypto.fs_crypto_blkdev", crypto_blkdev, ""); 1131 if (strlen(crypto_blkdev) == 0) { 1132 SLOGE("fs_crypto_blkdev not set\n"); 1133 return -1; 1134 } 1135 1136 if (! (rc = wait_and_unmount(DATA_MNT_POINT)) ) { 1137 /* If that succeeded, then mount the decrypted filesystem */ 1138 fs_mgr_do_mount(fstab, DATA_MNT_POINT, crypto_blkdev, 0); 1139 1140 property_set("vold.decrypt", "trigger_load_persist_props"); 1141 /* Create necessary paths on /data */ 1142 if (prep_data_fs()) { 1143 return -1; 1144 } 1145 1146 /* startup service classes main and late_start */ 1147 property_set("vold.decrypt", "trigger_restart_framework"); 1148 SLOGD("Just triggered restart_framework\n"); 1149 1150 /* Give it a few moments to get started */ 1151 sleep(1); 1152 } 1153 1154 if (rc == 0) { 1155 restart_successful = 1; 1156 } 1157 1158 return rc; 1159} 1160 1161static int do_crypto_complete(char *mount_point) 1162{ 1163 struct crypt_mnt_ftr crypt_ftr; 1164 char encrypted_state[PROPERTY_VALUE_MAX]; 1165 char key_loc[PROPERTY_VALUE_MAX]; 1166 1167 property_get("ro.crypto.state", encrypted_state, ""); 1168 if (strcmp(encrypted_state, "encrypted") ) { 1169 SLOGE("not running with encryption, aborting"); 1170 return 1; 1171 } 1172 1173 if (get_crypt_ftr_and_key(&crypt_ftr)) { 1174 fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc)); 1175 1176 /* 1177 * Only report this error if key_loc is a file and it exists. 1178 * If the device was never encrypted, and /data is not mountable for 1179 * some reason, returning 1 should prevent the UI from presenting the 1180 * a "enter password" screen, or worse, a "press button to wipe the 1181 * device" screen. 1182 */ 1183 if ((key_loc[0] == '/') && (access("key_loc", F_OK) == -1)) { 1184 SLOGE("master key file does not exist, aborting"); 1185 return 1; 1186 } else { 1187 SLOGE("Error getting crypt footer and key\n"); 1188 return -1; 1189 } 1190 } 1191 1192 if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) { 1193 SLOGE("Encryption process didn't finish successfully\n"); 1194 return -2; /* -2 is the clue to the UI that there is no usable data on the disk, 1195 * and give the user an option to wipe the disk */ 1196 } 1197 1198 /* We passed the test! We shall diminish, and return to the west */ 1199 return 0; 1200} 1201 1202static int test_mount_encrypted_fs(char *passwd, char *mount_point, char *label) 1203{ 1204 struct crypt_mnt_ftr crypt_ftr; 1205 /* Allocate enough space for a 256 bit key, but we may use less */ 1206 unsigned char decrypted_master_key[32]; 1207 char crypto_blkdev[MAXPATHLEN]; 1208 char real_blkdev[MAXPATHLEN]; 1209 char tmp_mount_point[64]; 1210 unsigned int orig_failed_decrypt_count; 1211 char encrypted_state[PROPERTY_VALUE_MAX]; 1212 int rc; 1213 kdf_func kdf; 1214 void *kdf_params; 1215 1216 property_get("ro.crypto.state", encrypted_state, ""); 1217 if ( master_key_saved || strcmp(encrypted_state, "encrypted") ) { 1218 SLOGE("encrypted fs already validated or not running with encryption, aborting"); 1219 return -1; 1220 } 1221 1222 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 1223 1224 if (get_crypt_ftr_and_key(&crypt_ftr)) { 1225 SLOGE("Error getting crypt footer and key\n"); 1226 return -1; 1227 } 1228 1229 SLOGD("crypt_ftr->fs_size = %lld\n", crypt_ftr.fs_size); 1230 orig_failed_decrypt_count = crypt_ftr.failed_decrypt_count; 1231 1232 if (! (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) ) { 1233 decrypt_master_key_and_upgrade(passwd, decrypted_master_key, &crypt_ftr); 1234 } 1235 1236 if (create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, 1237 real_blkdev, crypto_blkdev, label)) { 1238 SLOGE("Error creating decrypted block device\n"); 1239 return -1; 1240 } 1241 1242 /* If init detects an encrypted filesystem, it writes a file for each such 1243 * encrypted fs into the tmpfs /data filesystem, and then the framework finds those 1244 * files and passes that data to me */ 1245 /* Create a tmp mount point to try mounting the decryptd fs 1246 * Since we're here, the mount_point should be a tmpfs filesystem, so make 1247 * a directory in it to test mount the decrypted filesystem. 1248 */ 1249 sprintf(tmp_mount_point, "%s/tmp_mnt", mount_point); 1250 mkdir(tmp_mount_point, 0755); 1251 if (fs_mgr_do_mount(fstab, DATA_MNT_POINT, crypto_blkdev, tmp_mount_point)) { 1252 SLOGE("Error temp mounting decrypted block device\n"); 1253 delete_crypto_blk_dev(label); 1254 crypt_ftr.failed_decrypt_count++; 1255 } else { 1256 /* Success, so just umount and we'll mount it properly when we restart 1257 * the framework. 1258 */ 1259 umount(tmp_mount_point); 1260 crypt_ftr.failed_decrypt_count = 0; 1261 } 1262 1263 if (orig_failed_decrypt_count != crypt_ftr.failed_decrypt_count) { 1264 put_crypt_ftr_and_key(&crypt_ftr); 1265 } 1266 1267 if (crypt_ftr.failed_decrypt_count) { 1268 /* We failed to mount the device, so return an error */ 1269 rc = crypt_ftr.failed_decrypt_count; 1270 1271 } else { 1272 /* Woot! Success! Save the name of the crypto block device 1273 * so we can mount it when restarting the framework. 1274 */ 1275 property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev); 1276 1277 /* Also save a the master key so we can reencrypted the key 1278 * the key when we want to change the password on it. 1279 */ 1280 memcpy(saved_master_key, decrypted_master_key, KEY_LEN_BYTES); 1281 saved_mount_point = strdup(mount_point); 1282 master_key_saved = 1; 1283 rc = 0; 1284 } 1285 1286 return rc; 1287} 1288 1289/* Called by vold when it wants to undo the crypto mapping of a volume it 1290 * manages. This is usually in response to a factory reset, when we want 1291 * to undo the crypto mapping so the volume is formatted in the clear. 1292 */ 1293int cryptfs_revert_volume(const char *label) 1294{ 1295 return delete_crypto_blk_dev((char *)label); 1296} 1297 1298/* 1299 * Called by vold when it's asked to mount an encrypted, nonremovable volume. 1300 * Setup a dm-crypt mapping, use the saved master key from 1301 * setting up the /data mapping, and return the new device path. 1302 */ 1303int cryptfs_setup_volume(const char *label, int major, int minor, 1304 char *crypto_sys_path, unsigned int max_path, 1305 int *new_major, int *new_minor) 1306{ 1307 char real_blkdev[MAXPATHLEN], crypto_blkdev[MAXPATHLEN]; 1308 struct crypt_mnt_ftr sd_crypt_ftr; 1309 struct stat statbuf; 1310 int nr_sec, fd; 1311 1312 sprintf(real_blkdev, "/dev/block/vold/%d:%d", major, minor); 1313 1314 get_crypt_ftr_and_key(&sd_crypt_ftr); 1315 1316 /* Update the fs_size field to be the size of the volume */ 1317 fd = open(real_blkdev, O_RDONLY); 1318 nr_sec = get_blkdev_size(fd); 1319 close(fd); 1320 if (nr_sec == 0) { 1321 SLOGE("Cannot get size of volume %s\n", real_blkdev); 1322 return -1; 1323 } 1324 1325 sd_crypt_ftr.fs_size = nr_sec; 1326 create_crypto_blk_dev(&sd_crypt_ftr, saved_master_key, real_blkdev, 1327 crypto_blkdev, label); 1328 1329 stat(crypto_blkdev, &statbuf); 1330 *new_major = MAJOR(statbuf.st_rdev); 1331 *new_minor = MINOR(statbuf.st_rdev); 1332 1333 /* Create path to sys entry for this block device */ 1334 snprintf(crypto_sys_path, max_path, "/devices/virtual/block/%s", strrchr(crypto_blkdev, '/')+1); 1335 1336 return 0; 1337} 1338 1339int cryptfs_crypto_complete(void) 1340{ 1341 return do_crypto_complete("/data"); 1342} 1343 1344int cryptfs_check_passwd(char *passwd) 1345{ 1346 int rc = -1; 1347 1348 rc = test_mount_encrypted_fs(passwd, DATA_MNT_POINT, "userdata"); 1349 1350 return rc; 1351} 1352 1353int cryptfs_verify_passwd(char *passwd) 1354{ 1355 struct crypt_mnt_ftr crypt_ftr; 1356 /* Allocate enough space for a 256 bit key, but we may use less */ 1357 unsigned char decrypted_master_key[32]; 1358 char encrypted_state[PROPERTY_VALUE_MAX]; 1359 int rc; 1360 1361 property_get("ro.crypto.state", encrypted_state, ""); 1362 if (strcmp(encrypted_state, "encrypted") ) { 1363 SLOGE("device not encrypted, aborting"); 1364 return -2; 1365 } 1366 1367 if (!master_key_saved) { 1368 SLOGE("encrypted fs not yet mounted, aborting"); 1369 return -1; 1370 } 1371 1372 if (!saved_mount_point) { 1373 SLOGE("encrypted fs failed to save mount point, aborting"); 1374 return -1; 1375 } 1376 1377 if (get_crypt_ftr_and_key(&crypt_ftr)) { 1378 SLOGE("Error getting crypt footer and key\n"); 1379 return -1; 1380 } 1381 1382 if (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) { 1383 /* If the device has no password, then just say the password is valid */ 1384 rc = 0; 1385 } else { 1386 decrypt_master_key_and_upgrade(passwd, decrypted_master_key, &crypt_ftr); 1387 if (!memcmp(decrypted_master_key, saved_master_key, crypt_ftr.keysize)) { 1388 /* They match, the password is correct */ 1389 rc = 0; 1390 } else { 1391 /* If incorrect, sleep for a bit to prevent dictionary attacks */ 1392 sleep(1); 1393 rc = 1; 1394 } 1395 } 1396 1397 return rc; 1398} 1399 1400/* Initialize a crypt_mnt_ftr structure. The keysize is 1401 * defaulted to 16 bytes, and the filesystem size to 0. 1402 * Presumably, at a minimum, the caller will update the 1403 * filesystem size and crypto_type_name after calling this function. 1404 */ 1405static void cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr) 1406{ 1407 off64_t off; 1408 1409 memset(ftr, 0, sizeof(struct crypt_mnt_ftr)); 1410 ftr->magic = CRYPT_MNT_MAGIC; 1411 ftr->major_version = CURRENT_MAJOR_VERSION; 1412 ftr->minor_version = CURRENT_MINOR_VERSION; 1413 ftr->ftr_size = sizeof(struct crypt_mnt_ftr); 1414 ftr->keysize = KEY_LEN_BYTES; 1415 1416 ftr->kdf_type = KDF_SCRYPT; 1417 get_device_scrypt_params(ftr); 1418 1419 ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE; 1420 if (get_crypt_ftr_info(NULL, &off) == 0) { 1421 ftr->persist_data_offset[0] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET; 1422 ftr->persist_data_offset[1] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET + 1423 ftr->persist_data_size; 1424 } 1425} 1426 1427static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size, int type) 1428{ 1429 const char *args[10]; 1430 char size_str[32]; /* Must be large enough to hold a %lld and null byte */ 1431 int num_args; 1432 int status; 1433 int tmp; 1434 int rc = -1; 1435 1436 if (type == EXT4_FS) { 1437 args[0] = "/system/bin/make_ext4fs"; 1438 args[1] = "-a"; 1439 args[2] = "/data"; 1440 args[3] = "-l"; 1441 snprintf(size_str, sizeof(size_str), "%lld", size * 512); 1442 args[4] = size_str; 1443 args[5] = crypto_blkdev; 1444 num_args = 6; 1445 SLOGI("Making empty filesystem with command %s %s %s %s %s %s\n", 1446 args[0], args[1], args[2], args[3], args[4], args[5]); 1447 } else if (type== FAT_FS) { 1448 args[0] = "/system/bin/newfs_msdos"; 1449 args[1] = "-F"; 1450 args[2] = "32"; 1451 args[3] = "-O"; 1452 args[4] = "android"; 1453 args[5] = "-c"; 1454 args[6] = "8"; 1455 args[7] = "-s"; 1456 snprintf(size_str, sizeof(size_str), "%lld", size); 1457 args[8] = size_str; 1458 args[9] = crypto_blkdev; 1459 num_args = 10; 1460 SLOGI("Making empty filesystem with command %s %s %s %s %s %s %s %s %s %s\n", 1461 args[0], args[1], args[2], args[3], args[4], args[5], 1462 args[6], args[7], args[8], args[9]); 1463 } else { 1464 SLOGE("cryptfs_enable_wipe(): unknown filesystem type %d\n", type); 1465 return -1; 1466 } 1467 1468 tmp = android_fork_execvp(num_args, (char **)args, &status, false, true); 1469 1470 if (tmp != 0) { 1471 SLOGE("Error creating empty filesystem on %s due to logwrap error\n", crypto_blkdev); 1472 } else { 1473 if (WIFEXITED(status)) { 1474 if (WEXITSTATUS(status)) { 1475 SLOGE("Error creating filesystem on %s, exit status %d ", 1476 crypto_blkdev, WEXITSTATUS(status)); 1477 } else { 1478 SLOGD("Successfully created filesystem on %s\n", crypto_blkdev); 1479 rc = 0; 1480 } 1481 } else { 1482 SLOGE("Error creating filesystem on %s, did not exit normally\n", crypto_blkdev); 1483 } 1484 } 1485 1486 return rc; 1487} 1488 1489#define CRYPT_INPLACE_BUFSIZE 4096 1490#define CRYPT_SECTORS_PER_BUFSIZE (CRYPT_INPLACE_BUFSIZE / 512) 1491static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_t size, 1492 off64_t *size_already_done, off64_t tot_size) 1493{ 1494 int realfd, cryptofd; 1495 char *buf[CRYPT_INPLACE_BUFSIZE]; 1496 int rc = -1; 1497 off64_t numblocks, i, remainder; 1498 off64_t one_pct, cur_pct, new_pct; 1499 off64_t blocks_already_done, tot_numblocks; 1500 1501 if ( (realfd = open(real_blkdev, O_RDONLY)) < 0) { 1502 SLOGE("Error opening real_blkdev %s for inplace encrypt\n", real_blkdev); 1503 return -1; 1504 } 1505 1506 if ( (cryptofd = open(crypto_blkdev, O_WRONLY)) < 0) { 1507 SLOGE("Error opening crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1508 close(realfd); 1509 return -1; 1510 } 1511 1512 /* This is pretty much a simple loop of reading 4K, and writing 4K. 1513 * The size passed in is the number of 512 byte sectors in the filesystem. 1514 * So compute the number of whole 4K blocks we should read/write, 1515 * and the remainder. 1516 */ 1517 numblocks = size / CRYPT_SECTORS_PER_BUFSIZE; 1518 remainder = size % CRYPT_SECTORS_PER_BUFSIZE; 1519 tot_numblocks = tot_size / CRYPT_SECTORS_PER_BUFSIZE; 1520 blocks_already_done = *size_already_done / CRYPT_SECTORS_PER_BUFSIZE; 1521 1522 SLOGE("Encrypting filesystem in place..."); 1523 1524 one_pct = tot_numblocks / 100; 1525 cur_pct = 0; 1526 /* process the majority of the filesystem in blocks */ 1527 for (i=0; i<numblocks; i++) { 1528 new_pct = (i + blocks_already_done) / one_pct; 1529 if (new_pct > cur_pct) { 1530 char buf[8]; 1531 1532 cur_pct = new_pct; 1533 snprintf(buf, sizeof(buf), "%lld", cur_pct); 1534 property_set("vold.encrypt_progress", buf); 1535 } 1536 if (unix_read(realfd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) { 1537 SLOGE("Error reading real_blkdev %s for inplace encrypt\n", crypto_blkdev); 1538 goto errout; 1539 } 1540 if (unix_write(cryptofd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) { 1541 SLOGE("Error writing crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1542 goto errout; 1543 } 1544 } 1545 1546 /* Do any remaining sectors */ 1547 for (i=0; i<remainder; i++) { 1548 if (unix_read(realfd, buf, 512) <= 0) { 1549 SLOGE("Error reading rival sectors from real_blkdev %s for inplace encrypt\n", crypto_blkdev); 1550 goto errout; 1551 } 1552 if (unix_write(cryptofd, buf, 512) <= 0) { 1553 SLOGE("Error writing final sectors to crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1554 goto errout; 1555 } 1556 } 1557 1558 *size_already_done += size; 1559 rc = 0; 1560 1561errout: 1562 close(realfd); 1563 close(cryptofd); 1564 1565 return rc; 1566} 1567 1568#define CRYPTO_ENABLE_WIPE 1 1569#define CRYPTO_ENABLE_INPLACE 2 1570 1571#define FRAMEWORK_BOOT_WAIT 60 1572 1573static inline int should_encrypt(struct volume_info *volume) 1574{ 1575 return (volume->flags & (VOL_ENCRYPTABLE | VOL_NONREMOVABLE)) == 1576 (VOL_ENCRYPTABLE | VOL_NONREMOVABLE); 1577} 1578 1579int cryptfs_enable(char *howarg, char *passwd) 1580{ 1581 int how = 0; 1582 char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN], sd_crypto_blkdev[MAXPATHLEN]; 1583 unsigned long nr_sec; 1584 unsigned char decrypted_master_key[KEY_LEN_BYTES]; 1585 int rc=-1, fd, i, ret; 1586 struct crypt_mnt_ftr crypt_ftr, sd_crypt_ftr;; 1587 struct crypt_persist_data *pdata; 1588 char tmpfs_options[PROPERTY_VALUE_MAX]; 1589 char encrypted_state[PROPERTY_VALUE_MAX]; 1590 char lockid[32] = { 0 }; 1591 char key_loc[PROPERTY_VALUE_MAX]; 1592 char fuse_sdcard[PROPERTY_VALUE_MAX]; 1593 char *sd_mnt_point; 1594 char sd_blk_dev[256] = { 0 }; 1595 int num_vols; 1596 struct volume_info *vol_list = 0; 1597 off64_t cur_encryption_done=0, tot_encryption_size=0; 1598 1599 property_get("ro.crypto.state", encrypted_state, ""); 1600 if (strcmp(encrypted_state, "unencrypted")) { 1601 SLOGE("Device is already running encrypted, aborting"); 1602 goto error_unencrypted; 1603 } 1604 1605 fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc)); 1606 1607 if (!strcmp(howarg, "wipe")) { 1608 how = CRYPTO_ENABLE_WIPE; 1609 } else if (! strcmp(howarg, "inplace")) { 1610 how = CRYPTO_ENABLE_INPLACE; 1611 } else { 1612 /* Shouldn't happen, as CommandListener vets the args */ 1613 goto error_unencrypted; 1614 } 1615 1616 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 1617 1618 /* Get the size of the real block device */ 1619 fd = open(real_blkdev, O_RDONLY); 1620 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 1621 SLOGE("Cannot get size of block device %s\n", real_blkdev); 1622 goto error_unencrypted; 1623 } 1624 close(fd); 1625 1626 /* If doing inplace encryption, make sure the orig fs doesn't include the crypto footer */ 1627 if ((how == CRYPTO_ENABLE_INPLACE) && (!strcmp(key_loc, KEY_IN_FOOTER))) { 1628 unsigned int fs_size_sec, max_fs_size_sec; 1629 1630 fs_size_sec = get_fs_size(real_blkdev); 1631 max_fs_size_sec = nr_sec - (CRYPT_FOOTER_OFFSET / 512); 1632 1633 if (fs_size_sec > max_fs_size_sec) { 1634 SLOGE("Orig filesystem overlaps crypto footer region. Cannot encrypt in place."); 1635 goto error_unencrypted; 1636 } 1637 } 1638 1639 /* Get a wakelock as this may take a while, and we don't want the 1640 * device to sleep on us. We'll grab a partial wakelock, and if the UI 1641 * wants to keep the screen on, it can grab a full wakelock. 1642 */ 1643 snprintf(lockid, sizeof(lockid), "enablecrypto%d", (int) getpid()); 1644 acquire_wake_lock(PARTIAL_WAKE_LOCK, lockid); 1645 1646 /* Get the sdcard mount point */ 1647 sd_mnt_point = getenv("EMULATED_STORAGE_SOURCE"); 1648 if (!sd_mnt_point) { 1649 sd_mnt_point = getenv("EXTERNAL_STORAGE"); 1650 } 1651 if (!sd_mnt_point) { 1652 sd_mnt_point = "/mnt/sdcard"; 1653 } 1654 1655 num_vols=vold_getNumDirectVolumes(); 1656 vol_list = malloc(sizeof(struct volume_info) * num_vols); 1657 vold_getDirectVolumeList(vol_list); 1658 1659 for (i=0; i<num_vols; i++) { 1660 if (should_encrypt(&vol_list[i])) { 1661 fd = open(vol_list[i].blk_dev, O_RDONLY); 1662 if ( (vol_list[i].size = get_blkdev_size(fd)) == 0) { 1663 SLOGE("Cannot get size of block device %s\n", vol_list[i].blk_dev); 1664 goto error_unencrypted; 1665 } 1666 close(fd); 1667 1668 ret=vold_disableVol(vol_list[i].label); 1669 if ((ret < 0) && (ret != UNMOUNT_NOT_MOUNTED_ERR)) { 1670 /* -2 is returned when the device exists but is not currently mounted. 1671 * ignore the error and continue. */ 1672 SLOGE("Failed to unmount volume %s\n", vol_list[i].label); 1673 goto error_unencrypted; 1674 } 1675 } 1676 } 1677 1678 /* The init files are setup to stop the class main and late start when 1679 * vold sets trigger_shutdown_framework. 1680 */ 1681 property_set("vold.decrypt", "trigger_shutdown_framework"); 1682 SLOGD("Just asked init to shut down class main\n"); 1683 1684 if (vold_unmountAllAsecs()) { 1685 /* Just report the error. If any are left mounted, 1686 * umounting /data below will fail and handle the error. 1687 */ 1688 SLOGE("Error unmounting internal asecs"); 1689 } 1690 1691 property_get("ro.crypto.fuse_sdcard", fuse_sdcard, ""); 1692 if (!strcmp(fuse_sdcard, "true")) { 1693 /* This is a device using the fuse layer to emulate the sdcard semantics 1694 * on top of the userdata partition. vold does not manage it, it is managed 1695 * by the sdcard service. The sdcard service was killed by the property trigger 1696 * above, so just unmount it now. We must do this _AFTER_ killing the framework, 1697 * unlike the case for vold managed devices above. 1698 */ 1699 if (wait_and_unmount(sd_mnt_point)) { 1700 goto error_shutting_down; 1701 } 1702 } 1703 1704 /* Now unmount the /data partition. */ 1705 if (wait_and_unmount(DATA_MNT_POINT)) { 1706 goto error_shutting_down; 1707 } 1708 1709 /* Do extra work for a better UX when doing the long inplace encryption */ 1710 if (how == CRYPTO_ENABLE_INPLACE) { 1711 /* Now that /data is unmounted, we need to mount a tmpfs 1712 * /data, set a property saying we're doing inplace encryption, 1713 * and restart the framework. 1714 */ 1715 if (fs_mgr_do_tmpfs_mount(DATA_MNT_POINT)) { 1716 goto error_shutting_down; 1717 } 1718 /* Tells the framework that inplace encryption is starting */ 1719 property_set("vold.encrypt_progress", "0"); 1720 1721 /* restart the framework. */ 1722 /* Create necessary paths on /data */ 1723 if (prep_data_fs()) { 1724 goto error_shutting_down; 1725 } 1726 1727 /* Ugh, shutting down the framework is not synchronous, so until it 1728 * can be fixed, this horrible hack will wait a moment for it all to 1729 * shut down before proceeding. Without it, some devices cannot 1730 * restart the graphics services. 1731 */ 1732 sleep(2); 1733 1734 /* startup service classes main and late_start */ 1735 property_set("vold.decrypt", "trigger_restart_min_framework"); 1736 SLOGD("Just triggered restart_min_framework\n"); 1737 1738 /* OK, the framework is restarted and will soon be showing a 1739 * progress bar. Time to setup an encrypted mapping, and 1740 * either write a new filesystem, or encrypt in place updating 1741 * the progress bar as we work. 1742 */ 1743 } 1744 1745 /* Start the actual work of making an encrypted filesystem */ 1746 /* Initialize a crypt_mnt_ftr for the partition */ 1747 cryptfs_init_crypt_mnt_ftr(&crypt_ftr); 1748 1749 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 1750 crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / 512); 1751 } else { 1752 crypt_ftr.fs_size = nr_sec; 1753 } 1754 crypt_ftr.flags |= CRYPT_ENCRYPTION_IN_PROGRESS; 1755 strcpy((char *)crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256"); 1756 1757 /* Make an encrypted master key */ 1758 if (create_encrypted_random_key(passwd, crypt_ftr.master_key, crypt_ftr.salt, &crypt_ftr)) { 1759 SLOGE("Cannot create encrypted master key\n"); 1760 goto error_unencrypted; 1761 } 1762 1763 /* Write the key to the end of the partition */ 1764 put_crypt_ftr_and_key(&crypt_ftr); 1765 1766 /* If any persistent data has been remembered, save it. 1767 * If none, create a valid empty table and save that. 1768 */ 1769 if (!persist_data) { 1770 pdata = malloc(CRYPT_PERSIST_DATA_SIZE); 1771 if (pdata) { 1772 init_empty_persist_data(pdata, CRYPT_PERSIST_DATA_SIZE); 1773 persist_data = pdata; 1774 } 1775 } 1776 if (persist_data) { 1777 save_persistent_data(); 1778 } 1779 1780 decrypt_master_key_and_upgrade(passwd, decrypted_master_key, &crypt_ftr); 1781 create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev, 1782 "userdata"); 1783 1784 /* The size of the userdata partition, and add in the vold volumes below */ 1785 tot_encryption_size = crypt_ftr.fs_size; 1786 1787 /* setup crypto mapping for all encryptable volumes handled by vold */ 1788 for (i=0; i<num_vols; i++) { 1789 if (should_encrypt(&vol_list[i])) { 1790 vol_list[i].crypt_ftr = crypt_ftr; /* gotta love struct assign */ 1791 vol_list[i].crypt_ftr.fs_size = vol_list[i].size; 1792 create_crypto_blk_dev(&vol_list[i].crypt_ftr, decrypted_master_key, 1793 vol_list[i].blk_dev, vol_list[i].crypto_blkdev, 1794 vol_list[i].label); 1795 tot_encryption_size += vol_list[i].size; 1796 } 1797 } 1798 1799 if (how == CRYPTO_ENABLE_WIPE) { 1800 rc = cryptfs_enable_wipe(crypto_blkdev, crypt_ftr.fs_size, EXT4_FS); 1801 /* Encrypt all encryptable volumes handled by vold */ 1802 if (!rc) { 1803 for (i=0; i<num_vols; i++) { 1804 if (should_encrypt(&vol_list[i])) { 1805 rc = cryptfs_enable_wipe(vol_list[i].crypto_blkdev, 1806 vol_list[i].crypt_ftr.fs_size, FAT_FS); 1807 } 1808 } 1809 } 1810 } else if (how == CRYPTO_ENABLE_INPLACE) { 1811 rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr.fs_size, 1812 &cur_encryption_done, tot_encryption_size); 1813 /* Encrypt all encryptable volumes handled by vold */ 1814 if (!rc) { 1815 for (i=0; i<num_vols; i++) { 1816 if (should_encrypt(&vol_list[i])) { 1817 rc = cryptfs_enable_inplace(vol_list[i].crypto_blkdev, 1818 vol_list[i].blk_dev, 1819 vol_list[i].crypt_ftr.fs_size, 1820 &cur_encryption_done, tot_encryption_size); 1821 } 1822 } 1823 } 1824 if (!rc) { 1825 /* The inplace routine never actually sets the progress to 100% 1826 * due to the round down nature of integer division, so set it here */ 1827 property_set("vold.encrypt_progress", "100"); 1828 } 1829 } else { 1830 /* Shouldn't happen */ 1831 SLOGE("cryptfs_enable: internal error, unknown option\n"); 1832 goto error_unencrypted; 1833 } 1834 1835 /* Undo the dm-crypt mapping whether we succeed or not */ 1836 delete_crypto_blk_dev("userdata"); 1837 for (i=0; i<num_vols; i++) { 1838 if (should_encrypt(&vol_list[i])) { 1839 delete_crypto_blk_dev(vol_list[i].label); 1840 } 1841 } 1842 1843 free(vol_list); 1844 1845 if (! rc) { 1846 /* Success */ 1847 1848 /* Clear the encryption in progres flag in the footer */ 1849 crypt_ftr.flags &= ~CRYPT_ENCRYPTION_IN_PROGRESS; 1850 put_crypt_ftr_and_key(&crypt_ftr); 1851 1852 sleep(2); /* Give the UI a chance to show 100% progress */ 1853 cryptfs_reboot(0); 1854 } else { 1855 char value[PROPERTY_VALUE_MAX]; 1856 1857 property_get("ro.vold.wipe_on_crypt_fail", value, "0"); 1858 if (!strcmp(value, "1")) { 1859 /* wipe data if encryption failed */ 1860 SLOGE("encryption failed - rebooting into recovery to wipe data\n"); 1861 mkdir("/cache/recovery", 0700); 1862 int fd = open("/cache/recovery/command", O_RDWR|O_CREAT|O_TRUNC, 0600); 1863 if (fd >= 0) { 1864 write(fd, "--wipe_data", strlen("--wipe_data") + 1); 1865 close(fd); 1866 } else { 1867 SLOGE("could not open /cache/recovery/command\n"); 1868 } 1869 cryptfs_reboot(1); 1870 } else { 1871 /* set property to trigger dialog */ 1872 property_set("vold.encrypt_progress", "error_partially_encrypted"); 1873 release_wake_lock(lockid); 1874 } 1875 return -1; 1876 } 1877 1878 /* hrm, the encrypt step claims success, but the reboot failed. 1879 * This should not happen. 1880 * Set the property and return. Hope the framework can deal with it. 1881 */ 1882 property_set("vold.encrypt_progress", "error_reboot_failed"); 1883 release_wake_lock(lockid); 1884 return rc; 1885 1886error_unencrypted: 1887 free(vol_list); 1888 property_set("vold.encrypt_progress", "error_not_encrypted"); 1889 if (lockid[0]) { 1890 release_wake_lock(lockid); 1891 } 1892 return -1; 1893 1894error_shutting_down: 1895 /* we failed, and have not encrypted anthing, so the users's data is still intact, 1896 * but the framework is stopped and not restarted to show the error, so it's up to 1897 * vold to restart the system. 1898 */ 1899 SLOGE("Error enabling encryption after framework is shutdown, no data changed, restarting system"); 1900 cryptfs_reboot(0); 1901 1902 /* shouldn't get here */ 1903 property_set("vold.encrypt_progress", "error_shutting_down"); 1904 free(vol_list); 1905 if (lockid[0]) { 1906 release_wake_lock(lockid); 1907 } 1908 return -1; 1909} 1910 1911int cryptfs_changepw(char *newpw) 1912{ 1913 struct crypt_mnt_ftr crypt_ftr; 1914 unsigned char decrypted_master_key[KEY_LEN_BYTES]; 1915 1916 /* This is only allowed after we've successfully decrypted the master key */ 1917 if (! master_key_saved) { 1918 SLOGE("Key not saved, aborting"); 1919 return -1; 1920 } 1921 1922 /* get key */ 1923 if (get_crypt_ftr_and_key(&crypt_ftr)) { 1924 SLOGE("Error getting crypt footer and key"); 1925 return -1; 1926 } 1927 1928 encrypt_master_key(newpw, crypt_ftr.salt, saved_master_key, crypt_ftr.master_key, &crypt_ftr); 1929 1930 /* save the key */ 1931 put_crypt_ftr_and_key(&crypt_ftr); 1932 1933 return 0; 1934} 1935 1936static int persist_get_key(char *fieldname, char *value) 1937{ 1938 unsigned int i; 1939 1940 if (persist_data == NULL) { 1941 return -1; 1942 } 1943 for (i = 0; i < persist_data->persist_valid_entries; i++) { 1944 if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) { 1945 /* We found it! */ 1946 strlcpy(value, persist_data->persist_entry[i].val, PROPERTY_VALUE_MAX); 1947 return 0; 1948 } 1949 } 1950 1951 return -1; 1952} 1953 1954static int persist_set_key(char *fieldname, char *value, int encrypted) 1955{ 1956 unsigned int i; 1957 unsigned int num; 1958 struct crypt_mnt_ftr crypt_ftr; 1959 unsigned int max_persistent_entries; 1960 unsigned int dsize; 1961 1962 if (persist_data == NULL) { 1963 return -1; 1964 } 1965 1966 /* If encrypted, use the values from the crypt_ftr, otherwise 1967 * use the values for the current spec. 1968 */ 1969 if (encrypted) { 1970 if(get_crypt_ftr_and_key(&crypt_ftr)) { 1971 return -1; 1972 } 1973 dsize = crypt_ftr.persist_data_size; 1974 } else { 1975 dsize = CRYPT_PERSIST_DATA_SIZE; 1976 } 1977 max_persistent_entries = (dsize - sizeof(struct crypt_persist_data)) / 1978 sizeof(struct crypt_persist_entry); 1979 1980 num = persist_data->persist_valid_entries; 1981 1982 for (i = 0; i < num; i++) { 1983 if (!strncmp(persist_data->persist_entry[i].key, fieldname, PROPERTY_KEY_MAX)) { 1984 /* We found an existing entry, update it! */ 1985 memset(persist_data->persist_entry[i].val, 0, PROPERTY_VALUE_MAX); 1986 strlcpy(persist_data->persist_entry[i].val, value, PROPERTY_VALUE_MAX); 1987 return 0; 1988 } 1989 } 1990 1991 /* We didn't find it, add it to the end, if there is room */ 1992 if (persist_data->persist_valid_entries < max_persistent_entries) { 1993 memset(&persist_data->persist_entry[num], 0, sizeof(struct crypt_persist_entry)); 1994 strlcpy(persist_data->persist_entry[num].key, fieldname, PROPERTY_KEY_MAX); 1995 strlcpy(persist_data->persist_entry[num].val, value, PROPERTY_VALUE_MAX); 1996 persist_data->persist_valid_entries++; 1997 return 0; 1998 } 1999 2000 return -1; 2001} 2002 2003/* Return the value of the specified field. */ 2004int cryptfs_getfield(char *fieldname, char *value, int len) 2005{ 2006 char temp_value[PROPERTY_VALUE_MAX]; 2007 char real_blkdev[MAXPATHLEN]; 2008 /* 0 is success, 1 is not encrypted, 2009 * -1 is value not set, -2 is any other error 2010 */ 2011 int rc = -2; 2012 2013 if (persist_data == NULL) { 2014 load_persistent_data(); 2015 if (persist_data == NULL) { 2016 SLOGE("Getfield error, cannot load persistent data"); 2017 goto out; 2018 } 2019 } 2020 2021 if (!persist_get_key(fieldname, temp_value)) { 2022 /* We found it, copy it to the caller's buffer and return */ 2023 strlcpy(value, temp_value, len); 2024 rc = 0; 2025 } else { 2026 /* Sadness, it's not there. Return the error */ 2027 rc = -1; 2028 } 2029 2030out: 2031 return rc; 2032} 2033 2034/* Set the value of the specified field. */ 2035int cryptfs_setfield(char *fieldname, char *value) 2036{ 2037 struct crypt_persist_data stored_pdata; 2038 struct crypt_persist_data *pdata_p; 2039 struct crypt_mnt_ftr crypt_ftr; 2040 char encrypted_state[PROPERTY_VALUE_MAX]; 2041 /* 0 is success, -1 is an error */ 2042 int rc = -1; 2043 int encrypted = 0; 2044 2045 if (persist_data == NULL) { 2046 load_persistent_data(); 2047 if (persist_data == NULL) { 2048 SLOGE("Setfield error, cannot load persistent data"); 2049 goto out; 2050 } 2051 } 2052 2053 property_get("ro.crypto.state", encrypted_state, ""); 2054 if (!strcmp(encrypted_state, "encrypted") ) { 2055 encrypted = 1; 2056 } 2057 2058 if (persist_set_key(fieldname, value, encrypted)) { 2059 goto out; 2060 } 2061 2062 /* If we are running encrypted, save the persistent data now */ 2063 if (encrypted) { 2064 if (save_persistent_data()) { 2065 SLOGE("Setfield error, cannot save persistent data"); 2066 goto out; 2067 } 2068 } 2069 2070 rc = 0; 2071 2072out: 2073 return rc; 2074} 2075