cryptfs.c revision 56ad03cae13524b32898dc4ccf01040ced5a53b4
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/stat.h> 25#include <fcntl.h> 26#include <unistd.h> 27#include <stdio.h> 28#include <sys/ioctl.h> 29#include <linux/dm-ioctl.h> 30#include <libgen.h> 31#include <stdlib.h> 32#include <sys/param.h> 33#include <string.h> 34#include <sys/mount.h> 35#include <openssl/evp.h> 36#include <openssl/sha.h> 37#include <errno.h> 38#include <cutils/android_reboot.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/android_reboot.h" 45#include "cutils/log.h" 46#include "cutils/properties.h" 47#include "hardware_legacy/power.h" 48#include "VolumeManager.h" 49 50#define DM_CRYPT_BUF_SIZE 4096 51#define DATA_MNT_POINT "/data" 52 53#define HASH_COUNT 2000 54#define KEY_LEN_BYTES 16 55#define IV_LEN_BYTES 16 56 57#define KEY_IN_FOOTER "footer" 58 59#define EXT4_FS 1 60#define FAT_FS 2 61 62#define TABLE_LOAD_RETRIES 10 63 64char *me = "cryptfs"; 65 66static unsigned char saved_master_key[KEY_LEN_BYTES]; 67static char *saved_data_blkdev; 68static char *saved_mount_point; 69static int master_key_saved = 0; 70 71extern struct fstab *fstab; 72 73static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags) 74{ 75 memset(io, 0, dataSize); 76 io->data_size = dataSize; 77 io->data_start = sizeof(struct dm_ioctl); 78 io->version[0] = 4; 79 io->version[1] = 0; 80 io->version[2] = 0; 81 io->flags = flags; 82 if (name) { 83 strncpy(io->name, name, sizeof(io->name)); 84 } 85} 86 87static unsigned int get_fs_size(char *dev) 88{ 89 int fd, block_size; 90 struct ext4_super_block sb; 91 off64_t len; 92 93 if ((fd = open(dev, O_RDONLY)) < 0) { 94 SLOGE("Cannot open device to get filesystem size "); 95 return 0; 96 } 97 98 if (lseek64(fd, 1024, SEEK_SET) < 0) { 99 SLOGE("Cannot seek to superblock"); 100 return 0; 101 } 102 103 if (read(fd, &sb, sizeof(sb)) != sizeof(sb)) { 104 SLOGE("Cannot read superblock"); 105 return 0; 106 } 107 108 close(fd); 109 110 block_size = 1024 << sb.s_log_block_size; 111 /* compute length in bytes */ 112 len = ( ((off64_t)sb.s_blocks_count_hi << 32) + sb.s_blocks_count_lo) * block_size; 113 114 /* return length in sectors */ 115 return (unsigned int) (len / 512); 116} 117 118static unsigned int get_blkdev_size(int fd) 119{ 120 unsigned int nr_sec; 121 122 if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) { 123 nr_sec = 0; 124 } 125 126 return nr_sec; 127} 128 129/* key or salt can be NULL, in which case just skip writing that value. Useful to 130 * update the failed mount count but not change the key. 131 */ 132static int put_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr, 133 unsigned char *key, unsigned char *salt) 134{ 135 int fd; 136 unsigned int nr_sec, cnt; 137 off64_t off; 138 int rc = -1; 139 char *fname; 140 char key_loc[PROPERTY_VALUE_MAX]; 141 struct stat statbuf; 142 143 fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc)); 144 145 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 146 fname = real_blk_name; 147 if ( (fd = open(fname, O_RDWR)) < 0) { 148 SLOGE("Cannot open real block device %s\n", fname); 149 return -1; 150 } 151 152 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 153 SLOGE("Cannot get size of block device %s\n", fname); 154 goto errout; 155 } 156 157 /* If it's an encrypted Android partition, the last 16 Kbytes contain the 158 * encryption info footer and key, and plenty of bytes to spare for future 159 * growth. 160 */ 161 off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; 162 163 if (lseek64(fd, off, SEEK_SET) == -1) { 164 SLOGE("Cannot seek to real block device footer\n"); 165 goto errout; 166 } 167 } else if (key_loc[0] == '/') { 168 fname = key_loc; 169 if ( (fd = open(fname, O_RDWR | O_CREAT, 0600)) < 0) { 170 SLOGE("Cannot open footer file %s\n", fname); 171 return -1; 172 } 173 } else { 174 SLOGE("Unexpected value for crypto key location\n"); 175 return -1;; 176 } 177 178 if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) { 179 SLOGE("Cannot write real block device footer\n"); 180 goto errout; 181 } 182 183 if (key) { 184 if (crypt_ftr->keysize != KEY_LEN_BYTES) { 185 SLOGE("Keysize of %d bits not supported for real block device %s\n", 186 crypt_ftr->keysize*8, fname); 187 goto errout; 188 } 189 190 if ( (cnt = write(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) { 191 SLOGE("Cannot write key for real block device %s\n", fname); 192 goto errout; 193 } 194 } 195 196 if (salt) { 197 /* Compute the offset from the last write to the salt */ 198 off = KEY_TO_SALT_PADDING; 199 if (! key) 200 off += crypt_ftr->keysize; 201 202 if (lseek64(fd, off, SEEK_CUR) == -1) { 203 SLOGE("Cannot seek to real block device salt \n"); 204 goto errout; 205 } 206 207 if ( (cnt = write(fd, salt, SALT_LEN)) != SALT_LEN) { 208 SLOGE("Cannot write salt for real block device %s\n", fname); 209 goto errout; 210 } 211 } 212 213 fstat(fd, &statbuf); 214 /* If the keys are kept on a raw block device, do not try to truncate it. */ 215 if (S_ISREG(statbuf.st_mode) && (key_loc[0] == '/')) { 216 if (ftruncate(fd, 0x4000)) { 217 SLOGE("Cannot set footer file size\n", fname); 218 goto errout; 219 } 220 } 221 222 /* Success! */ 223 rc = 0; 224 225errout: 226 close(fd); 227 return rc; 228 229} 230 231static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr, 232 unsigned char *key, unsigned char *salt) 233{ 234 int fd; 235 unsigned int nr_sec, cnt; 236 off64_t off; 237 int rc = -1; 238 char key_loc[PROPERTY_VALUE_MAX]; 239 char *fname; 240 struct stat statbuf; 241 242 fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc)); 243 244 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 245 fname = real_blk_name; 246 if ( (fd = open(fname, O_RDONLY)) < 0) { 247 SLOGE("Cannot open real block device %s\n", fname); 248 return -1; 249 } 250 251 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 252 SLOGE("Cannot get size of block device %s\n", fname); 253 goto errout; 254 } 255 256 /* If it's an encrypted Android partition, the last 16 Kbytes contain the 257 * encryption info footer and key, and plenty of bytes to spare for future 258 * growth. 259 */ 260 off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; 261 262 if (lseek64(fd, off, SEEK_SET) == -1) { 263 SLOGE("Cannot seek to real block device footer\n"); 264 goto errout; 265 } 266 } else if (key_loc[0] == '/') { 267 fname = key_loc; 268 if ( (fd = open(fname, O_RDONLY)) < 0) { 269 SLOGE("Cannot open footer file %s\n", fname); 270 return -1; 271 } 272 273 /* Make sure it's 16 Kbytes in length */ 274 fstat(fd, &statbuf); 275 if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) { 276 SLOGE("footer file %s is not the expected size!\n", fname); 277 goto errout; 278 } 279 } else { 280 SLOGE("Unexpected value for crypto key location\n"); 281 return -1;; 282 } 283 284 if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) { 285 SLOGE("Cannot read real block device footer\n"); 286 goto errout; 287 } 288 289 if (crypt_ftr->magic != CRYPT_MNT_MAGIC) { 290 SLOGE("Bad magic for real block device %s\n", fname); 291 goto errout; 292 } 293 294 if (crypt_ftr->major_version != 1) { 295 SLOGE("Cannot understand major version %d real block device footer\n", 296 crypt_ftr->major_version); 297 goto errout; 298 } 299 300 if (crypt_ftr->minor_version != 0) { 301 SLOGW("Warning: crypto footer minor version %d, expected 0, continuing...\n", 302 crypt_ftr->minor_version); 303 } 304 305 if (crypt_ftr->ftr_size > sizeof(struct crypt_mnt_ftr)) { 306 /* the footer size is bigger than we expected. 307 * Skip to it's stated end so we can read the key. 308 */ 309 if (lseek(fd, crypt_ftr->ftr_size - sizeof(struct crypt_mnt_ftr), SEEK_CUR) == -1) { 310 SLOGE("Cannot seek to start of key\n"); 311 goto errout; 312 } 313 } 314 315 if (crypt_ftr->keysize != KEY_LEN_BYTES) { 316 SLOGE("Keysize of %d bits not supported for real block device %s\n", 317 crypt_ftr->keysize * 8, fname); 318 goto errout; 319 } 320 321 if ( (cnt = read(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) { 322 SLOGE("Cannot read key for real block device %s\n", fname); 323 goto errout; 324 } 325 326 if (lseek64(fd, KEY_TO_SALT_PADDING, SEEK_CUR) == -1) { 327 SLOGE("Cannot seek to real block device salt\n"); 328 goto errout; 329 } 330 331 if ( (cnt = read(fd, salt, SALT_LEN)) != SALT_LEN) { 332 SLOGE("Cannot read salt for real block device %s\n", fname); 333 goto errout; 334 } 335 336 /* Success! */ 337 rc = 0; 338 339errout: 340 close(fd); 341 return rc; 342} 343 344/* Convert a binary key of specified length into an ascii hex string equivalent, 345 * without the leading 0x and with null termination 346 */ 347void convert_key_to_hex_ascii(unsigned char *master_key, unsigned int keysize, 348 char *master_key_ascii) 349{ 350 unsigned int i, a; 351 unsigned char nibble; 352 353 for (i=0, a=0; i<keysize; i++, a+=2) { 354 /* For each byte, write out two ascii hex digits */ 355 nibble = (master_key[i] >> 4) & 0xf; 356 master_key_ascii[a] = nibble + (nibble > 9 ? 0x37 : 0x30); 357 358 nibble = master_key[i] & 0xf; 359 master_key_ascii[a+1] = nibble + (nibble > 9 ? 0x37 : 0x30); 360 } 361 362 /* Add the null termination */ 363 master_key_ascii[a] = '\0'; 364 365} 366 367static int load_crypto_mapping_table(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key, 368 char *real_blk_name, const char *name, int fd, 369 char *extra_params) 370{ 371 char buffer[DM_CRYPT_BUF_SIZE]; 372 struct dm_ioctl *io; 373 struct dm_target_spec *tgt; 374 char *crypt_params; 375 char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ 376 int i; 377 378 io = (struct dm_ioctl *) buffer; 379 380 /* Load the mapping table for this device */ 381 tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)]; 382 383 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 384 io->target_count = 1; 385 tgt->status = 0; 386 tgt->sector_start = 0; 387 tgt->length = crypt_ftr->fs_size; 388 strcpy(tgt->target_type, "crypt"); 389 390 crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec); 391 convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii); 392 sprintf(crypt_params, "%s %s 0 %s 0 %s", crypt_ftr->crypto_type_name, 393 master_key_ascii, real_blk_name, extra_params); 394 crypt_params += strlen(crypt_params) + 1; 395 crypt_params = (char *) (((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */ 396 tgt->next = crypt_params - buffer; 397 398 for (i = 0; i < TABLE_LOAD_RETRIES; i++) { 399 if (! ioctl(fd, DM_TABLE_LOAD, io)) { 400 break; 401 } 402 usleep(500000); 403 } 404 405 if (i == TABLE_LOAD_RETRIES) { 406 /* We failed to load the table, return an error */ 407 return -1; 408 } else { 409 return i + 1; 410 } 411} 412 413 414static int get_dm_crypt_version(int fd, const char *name, int *version) 415{ 416 char buffer[DM_CRYPT_BUF_SIZE]; 417 struct dm_ioctl *io; 418 struct dm_target_versions *v; 419 int i; 420 421 io = (struct dm_ioctl *) buffer; 422 423 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 424 425 if (ioctl(fd, DM_LIST_VERSIONS, io)) { 426 return -1; 427 } 428 429 /* Iterate over the returned versions, looking for name of "crypt". 430 * When found, get and return the version. 431 */ 432 v = (struct dm_target_versions *) &buffer[sizeof(struct dm_ioctl)]; 433 while (v->next) { 434 if (! strcmp(v->name, "crypt")) { 435 /* We found the crypt driver, return the version, and get out */ 436 version[0] = v->version[0]; 437 version[1] = v->version[1]; 438 version[2] = v->version[2]; 439 return 0; 440 } 441 v = (struct dm_target_versions *)(((char *)v) + v->next); 442 } 443 444 return -1; 445} 446 447static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key, 448 char *real_blk_name, char *crypto_blk_name, const char *name) 449{ 450 char buffer[DM_CRYPT_BUF_SIZE]; 451 char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ 452 char *crypt_params; 453 struct dm_ioctl *io; 454 struct dm_target_spec *tgt; 455 unsigned int minor; 456 int fd; 457 int i; 458 int retval = -1; 459 int version[3]; 460 char *extra_params; 461 int load_count; 462 463 if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { 464 SLOGE("Cannot open device-mapper\n"); 465 goto errout; 466 } 467 468 io = (struct dm_ioctl *) buffer; 469 470 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 471 if (ioctl(fd, DM_DEV_CREATE, io)) { 472 SLOGE("Cannot create dm-crypt device\n"); 473 goto errout; 474 } 475 476 /* Get the device status, in particular, the name of it's device file */ 477 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 478 if (ioctl(fd, DM_DEV_STATUS, io)) { 479 SLOGE("Cannot retrieve dm-crypt device status\n"); 480 goto errout; 481 } 482 minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00); 483 snprintf(crypto_blk_name, MAXPATHLEN, "/dev/block/dm-%u", minor); 484 485 extra_params = ""; 486 if (! get_dm_crypt_version(fd, name, version)) { 487 /* Support for allow_discards was added in version 1.11.0 */ 488 if ((version[0] >= 2) || 489 ((version[0] == 1) && (version[1] >= 11))) { 490 extra_params = "1 allow_discards"; 491 SLOGI("Enabling support for allow_discards in dmcrypt.\n"); 492 } 493 } 494 495 load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name, 496 fd, extra_params); 497 if (load_count < 0) { 498 SLOGE("Cannot load dm-crypt mapping table.\n"); 499 goto errout; 500 } else if (load_count > 1) { 501 SLOGI("Took %d tries to load dmcrypt table.\n", load_count); 502 } 503 504 /* Resume this device to activate it */ 505 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 506 507 if (ioctl(fd, DM_DEV_SUSPEND, io)) { 508 SLOGE("Cannot resume the dm-crypt device\n"); 509 goto errout; 510 } 511 512 /* We made it here with no errors. Woot! */ 513 retval = 0; 514 515errout: 516 close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */ 517 518 return retval; 519} 520 521static int delete_crypto_blk_dev(char *name) 522{ 523 int fd; 524 char buffer[DM_CRYPT_BUF_SIZE]; 525 struct dm_ioctl *io; 526 int retval = -1; 527 528 if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { 529 SLOGE("Cannot open device-mapper\n"); 530 goto errout; 531 } 532 533 io = (struct dm_ioctl *) buffer; 534 535 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 536 if (ioctl(fd, DM_DEV_REMOVE, io)) { 537 SLOGE("Cannot remove dm-crypt device\n"); 538 goto errout; 539 } 540 541 /* We made it here with no errors. Woot! */ 542 retval = 0; 543 544errout: 545 close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */ 546 547 return retval; 548 549} 550 551static void pbkdf2(char *passwd, unsigned char *salt, unsigned char *ikey) 552{ 553 /* Turn the password into a key and IV that can decrypt the master key */ 554 PKCS5_PBKDF2_HMAC_SHA1(passwd, strlen(passwd), salt, SALT_LEN, 555 HASH_COUNT, KEY_LEN_BYTES+IV_LEN_BYTES, ikey); 556} 557 558static int encrypt_master_key(char *passwd, unsigned char *salt, 559 unsigned char *decrypted_master_key, 560 unsigned char *encrypted_master_key) 561{ 562 unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ 563 EVP_CIPHER_CTX e_ctx; 564 int encrypted_len, final_len; 565 566 /* Turn the password into a key and IV that can decrypt the master key */ 567 pbkdf2(passwd, salt, ikey); 568 569 /* Initialize the decryption engine */ 570 if (! EVP_EncryptInit(&e_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) { 571 SLOGE("EVP_EncryptInit failed\n"); 572 return -1; 573 } 574 EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */ 575 576 /* Encrypt the master key */ 577 if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len, 578 decrypted_master_key, KEY_LEN_BYTES)) { 579 SLOGE("EVP_EncryptUpdate failed\n"); 580 return -1; 581 } 582 if (! EVP_EncryptFinal(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) { 583 SLOGE("EVP_EncryptFinal failed\n"); 584 return -1; 585 } 586 587 if (encrypted_len + final_len != KEY_LEN_BYTES) { 588 SLOGE("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len); 589 return -1; 590 } else { 591 return 0; 592 } 593} 594 595static int decrypt_master_key(char *passwd, unsigned char *salt, 596 unsigned char *encrypted_master_key, 597 unsigned char *decrypted_master_key) 598{ 599 unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ 600 EVP_CIPHER_CTX d_ctx; 601 int decrypted_len, final_len; 602 603 /* Turn the password into a key and IV that can decrypt the master key */ 604 pbkdf2(passwd, salt, ikey); 605 606 /* Initialize the decryption engine */ 607 if (! EVP_DecryptInit(&d_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) { 608 return -1; 609 } 610 EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */ 611 /* Decrypt the master key */ 612 if (! EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len, 613 encrypted_master_key, KEY_LEN_BYTES)) { 614 return -1; 615 } 616 if (! EVP_DecryptFinal(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) { 617 return -1; 618 } 619 620 if (decrypted_len + final_len != KEY_LEN_BYTES) { 621 return -1; 622 } else { 623 return 0; 624 } 625} 626 627static int create_encrypted_random_key(char *passwd, unsigned char *master_key, unsigned char *salt) 628{ 629 int fd; 630 unsigned char key_buf[KEY_LEN_BYTES]; 631 EVP_CIPHER_CTX e_ctx; 632 int encrypted_len, final_len; 633 634 /* Get some random bits for a key */ 635 fd = open("/dev/urandom", O_RDONLY); 636 read(fd, key_buf, sizeof(key_buf)); 637 read(fd, salt, SALT_LEN); 638 close(fd); 639 640 /* Now encrypt it with the password */ 641 return encrypt_master_key(passwd, salt, key_buf, master_key); 642} 643 644static int wait_and_unmount(char *mountpoint) 645{ 646 int i, rc; 647#define WAIT_UNMOUNT_COUNT 20 648 649 /* Now umount the tmpfs filesystem */ 650 for (i=0; i<WAIT_UNMOUNT_COUNT; i++) { 651 if (umount(mountpoint)) { 652 if (errno == EINVAL) { 653 /* EINVAL is returned if the directory is not a mountpoint, 654 * i.e. there is no filesystem mounted there. So just get out. 655 */ 656 break; 657 } 658 sleep(1); 659 i++; 660 } else { 661 break; 662 } 663 } 664 665 if (i < WAIT_UNMOUNT_COUNT) { 666 SLOGD("unmounting %s succeeded\n", mountpoint); 667 rc = 0; 668 } else { 669 SLOGE("unmounting %s failed\n", mountpoint); 670 rc = -1; 671 } 672 673 return rc; 674} 675 676#define DATA_PREP_TIMEOUT 100 677static int prep_data_fs(void) 678{ 679 int i; 680 681 /* Do the prep of the /data filesystem */ 682 property_set("vold.post_fs_data_done", "0"); 683 property_set("vold.decrypt", "trigger_post_fs_data"); 684 SLOGD("Just triggered post_fs_data\n"); 685 686 /* Wait a max of 25 seconds, hopefully it takes much less */ 687 for (i=0; i<DATA_PREP_TIMEOUT; i++) { 688 char p[PROPERTY_VALUE_MAX]; 689 690 property_get("vold.post_fs_data_done", p, "0"); 691 if (*p == '1') { 692 break; 693 } else { 694 usleep(250000); 695 } 696 } 697 if (i == DATA_PREP_TIMEOUT) { 698 /* Ugh, we failed to prep /data in time. Bail. */ 699 return -1; 700 } else { 701 SLOGD("post_fs_data done\n"); 702 return 0; 703 } 704} 705 706int cryptfs_restart(void) 707{ 708 char fs_type[32]; 709 char real_blkdev[MAXPATHLEN]; 710 char crypto_blkdev[MAXPATHLEN]; 711 char fs_options[256]; 712 unsigned long mnt_flags; 713 struct stat statbuf; 714 int rc = -1, i; 715 static int restart_successful = 0; 716 717 /* Validate that it's OK to call this routine */ 718 if (! master_key_saved) { 719 SLOGE("Encrypted filesystem not validated, aborting"); 720 return -1; 721 } 722 723 if (restart_successful) { 724 SLOGE("System already restarted with encrypted disk, aborting"); 725 return -1; 726 } 727 728 /* Here is where we shut down the framework. The init scripts 729 * start all services in one of three classes: core, main or late_start. 730 * On boot, we start core and main. Now, we stop main, but not core, 731 * as core includes vold and a few other really important things that 732 * we need to keep running. Once main has stopped, we should be able 733 * to umount the tmpfs /data, then mount the encrypted /data. 734 * We then restart the class main, and also the class late_start. 735 * At the moment, I've only put a few things in late_start that I know 736 * are not needed to bring up the framework, and that also cause problems 737 * with unmounting the tmpfs /data, but I hope to add add more services 738 * to the late_start class as we optimize this to decrease the delay 739 * till the user is asked for the password to the filesystem. 740 */ 741 742 /* The init files are setup to stop the class main when vold.decrypt is 743 * set to trigger_reset_main. 744 */ 745 property_set("vold.decrypt", "trigger_reset_main"); 746 SLOGD("Just asked init to shut down class main\n"); 747 748 /* Ugh, shutting down the framework is not synchronous, so until it 749 * can be fixed, this horrible hack will wait a moment for it all to 750 * shut down before proceeding. Without it, some devices cannot 751 * restart the graphics services. 752 */ 753 sleep(2); 754 755 /* Now that the framework is shutdown, we should be able to umount() 756 * the tmpfs filesystem, and mount the real one. 757 */ 758 759 property_get("ro.crypto.fs_crypto_blkdev", crypto_blkdev, ""); 760 if (strlen(crypto_blkdev) == 0) { 761 SLOGE("fs_crypto_blkdev not set\n"); 762 return -1; 763 } 764 765 if (! (rc = wait_and_unmount(DATA_MNT_POINT)) ) { 766 /* If that succeeded, then mount the decrypted filesystem */ 767 fs_mgr_do_mount(fstab, DATA_MNT_POINT, crypto_blkdev, 0); 768 769 property_set("vold.decrypt", "trigger_load_persist_props"); 770 /* Create necessary paths on /data */ 771 if (prep_data_fs()) { 772 return -1; 773 } 774 775 /* startup service classes main and late_start */ 776 property_set("vold.decrypt", "trigger_restart_framework"); 777 SLOGD("Just triggered restart_framework\n"); 778 779 /* Give it a few moments to get started */ 780 sleep(1); 781 } 782 783 if (rc == 0) { 784 restart_successful = 1; 785 } 786 787 return rc; 788} 789 790static int do_crypto_complete(char *mount_point) 791{ 792 struct crypt_mnt_ftr crypt_ftr; 793 unsigned char encrypted_master_key[32]; 794 unsigned char salt[SALT_LEN]; 795 char real_blkdev[MAXPATHLEN]; 796 char encrypted_state[PROPERTY_VALUE_MAX]; 797 char key_loc[PROPERTY_VALUE_MAX]; 798 799 property_get("ro.crypto.state", encrypted_state, ""); 800 if (strcmp(encrypted_state, "encrypted") ) { 801 SLOGE("not running with encryption, aborting"); 802 return 1; 803 } 804 805 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 806 807 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 808 fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc)); 809 810 /* 811 * Only report this error if key_loc is a file and it exists. 812 * If the device was never encrypted, and /data is not mountable for 813 * some reason, returning 1 should prevent the UI from presenting the 814 * a "enter password" screen, or worse, a "press button to wipe the 815 * device" screen. 816 */ 817 if ((key_loc[0] == '/') && (access("key_loc", F_OK) == -1)) { 818 SLOGE("master key file does not exist, aborting"); 819 return 1; 820 } else { 821 SLOGE("Error getting crypt footer and key\n"); 822 return -1; 823 } 824 } 825 826 if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) { 827 SLOGE("Encryption process didn't finish successfully\n"); 828 return -2; /* -2 is the clue to the UI that there is no usable data on the disk, 829 * and give the user an option to wipe the disk */ 830 } 831 832 /* We passed the test! We shall diminish, and return to the west */ 833 return 0; 834} 835 836static int test_mount_encrypted_fs(char *passwd, char *mount_point, char *label) 837{ 838 struct crypt_mnt_ftr crypt_ftr; 839 /* Allocate enough space for a 256 bit key, but we may use less */ 840 unsigned char encrypted_master_key[32], decrypted_master_key[32]; 841 unsigned char salt[SALT_LEN]; 842 char crypto_blkdev[MAXPATHLEN]; 843 char real_blkdev[MAXPATHLEN]; 844 char tmp_mount_point[64]; 845 unsigned int orig_failed_decrypt_count; 846 char encrypted_state[PROPERTY_VALUE_MAX]; 847 int rc; 848 849 property_get("ro.crypto.state", encrypted_state, ""); 850 if ( master_key_saved || strcmp(encrypted_state, "encrypted") ) { 851 SLOGE("encrypted fs already validated or not running with encryption, aborting"); 852 return -1; 853 } 854 855 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 856 857 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 858 SLOGE("Error getting crypt footer and key\n"); 859 return -1; 860 } 861 862 SLOGD("crypt_ftr->fs_size = %lld\n", crypt_ftr.fs_size); 863 orig_failed_decrypt_count = crypt_ftr.failed_decrypt_count; 864 865 if (! (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) ) { 866 decrypt_master_key(passwd, salt, encrypted_master_key, decrypted_master_key); 867 } 868 869 if (create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, 870 real_blkdev, crypto_blkdev, label)) { 871 SLOGE("Error creating decrypted block device\n"); 872 return -1; 873 } 874 875 /* If init detects an encrypted filesystme, it writes a file for each such 876 * encrypted fs into the tmpfs /data filesystem, and then the framework finds those 877 * files and passes that data to me */ 878 /* Create a tmp mount point to try mounting the decryptd fs 879 * Since we're here, the mount_point should be a tmpfs filesystem, so make 880 * a directory in it to test mount the decrypted filesystem. 881 */ 882 sprintf(tmp_mount_point, "%s/tmp_mnt", mount_point); 883 mkdir(tmp_mount_point, 0755); 884 if (fs_mgr_do_mount(fstab, DATA_MNT_POINT, crypto_blkdev, tmp_mount_point)) { 885 SLOGE("Error temp mounting decrypted block device\n"); 886 delete_crypto_blk_dev(label); 887 crypt_ftr.failed_decrypt_count++; 888 } else { 889 /* Success, so just umount and we'll mount it properly when we restart 890 * the framework. 891 */ 892 umount(tmp_mount_point); 893 crypt_ftr.failed_decrypt_count = 0; 894 } 895 896 if (orig_failed_decrypt_count != crypt_ftr.failed_decrypt_count) { 897 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0); 898 } 899 900 if (crypt_ftr.failed_decrypt_count) { 901 /* We failed to mount the device, so return an error */ 902 rc = crypt_ftr.failed_decrypt_count; 903 904 } else { 905 /* Woot! Success! Save the name of the crypto block device 906 * so we can mount it when restarting the framework. 907 */ 908 property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev); 909 910 /* Also save a the master key so we can reencrypted the key 911 * the key when we want to change the password on it. 912 */ 913 memcpy(saved_master_key, decrypted_master_key, KEY_LEN_BYTES); 914 saved_data_blkdev = strdup(real_blkdev); 915 saved_mount_point = strdup(mount_point); 916 master_key_saved = 1; 917 rc = 0; 918 } 919 920 return rc; 921} 922 923/* Called by vold when it wants to undo the crypto mapping of a volume it 924 * manages. This is usually in response to a factory reset, when we want 925 * to undo the crypto mapping so the volume is formatted in the clear. 926 */ 927int cryptfs_revert_volume(const char *label) 928{ 929 return delete_crypto_blk_dev((char *)label); 930} 931 932/* 933 * Called by vold when it's asked to mount an encrypted, nonremovable volume. 934 * Setup a dm-crypt mapping, use the saved master key from 935 * setting up the /data mapping, and return the new device path. 936 */ 937int cryptfs_setup_volume(const char *label, int major, int minor, 938 char *crypto_sys_path, unsigned int max_path, 939 int *new_major, int *new_minor) 940{ 941 char real_blkdev[MAXPATHLEN], crypto_blkdev[MAXPATHLEN]; 942 struct crypt_mnt_ftr sd_crypt_ftr; 943 unsigned char key[32], salt[32]; 944 struct stat statbuf; 945 int nr_sec, fd; 946 947 sprintf(real_blkdev, "/dev/block/vold/%d:%d", major, minor); 948 949 /* Just want the footer, but gotta get it all */ 950 get_crypt_ftr_and_key(saved_data_blkdev, &sd_crypt_ftr, key, salt); 951 952 /* Update the fs_size field to be the size of the volume */ 953 fd = open(real_blkdev, O_RDONLY); 954 nr_sec = get_blkdev_size(fd); 955 close(fd); 956 if (nr_sec == 0) { 957 SLOGE("Cannot get size of volume %s\n", real_blkdev); 958 return -1; 959 } 960 961 sd_crypt_ftr.fs_size = nr_sec; 962 create_crypto_blk_dev(&sd_crypt_ftr, saved_master_key, real_blkdev, 963 crypto_blkdev, label); 964 965 stat(crypto_blkdev, &statbuf); 966 *new_major = MAJOR(statbuf.st_rdev); 967 *new_minor = MINOR(statbuf.st_rdev); 968 969 /* Create path to sys entry for this block device */ 970 snprintf(crypto_sys_path, max_path, "/devices/virtual/block/%s", strrchr(crypto_blkdev, '/')+1); 971 972 return 0; 973} 974 975int cryptfs_crypto_complete(void) 976{ 977 return do_crypto_complete("/data"); 978} 979 980int cryptfs_check_passwd(char *passwd) 981{ 982 int rc = -1; 983 984 rc = test_mount_encrypted_fs(passwd, DATA_MNT_POINT, "userdata"); 985 986 return rc; 987} 988 989int cryptfs_verify_passwd(char *passwd) 990{ 991 struct crypt_mnt_ftr crypt_ftr; 992 /* Allocate enough space for a 256 bit key, but we may use less */ 993 unsigned char encrypted_master_key[32], decrypted_master_key[32]; 994 unsigned char salt[SALT_LEN]; 995 char real_blkdev[MAXPATHLEN]; 996 char encrypted_state[PROPERTY_VALUE_MAX]; 997 int rc; 998 999 property_get("ro.crypto.state", encrypted_state, ""); 1000 if (strcmp(encrypted_state, "encrypted") ) { 1001 SLOGE("device not encrypted, aborting"); 1002 return -2; 1003 } 1004 1005 if (!master_key_saved) { 1006 SLOGE("encrypted fs not yet mounted, aborting"); 1007 return -1; 1008 } 1009 1010 if (!saved_mount_point) { 1011 SLOGE("encrypted fs failed to save mount point, aborting"); 1012 return -1; 1013 } 1014 1015 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 1016 1017 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 1018 SLOGE("Error getting crypt footer and key\n"); 1019 return -1; 1020 } 1021 1022 if (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) { 1023 /* If the device has no password, then just say the password is valid */ 1024 rc = 0; 1025 } else { 1026 decrypt_master_key(passwd, salt, encrypted_master_key, decrypted_master_key); 1027 if (!memcmp(decrypted_master_key, saved_master_key, crypt_ftr.keysize)) { 1028 /* They match, the password is correct */ 1029 rc = 0; 1030 } else { 1031 /* If incorrect, sleep for a bit to prevent dictionary attacks */ 1032 sleep(1); 1033 rc = 1; 1034 } 1035 } 1036 1037 return rc; 1038} 1039 1040/* Initialize a crypt_mnt_ftr structure. The keysize is 1041 * defaulted to 16 bytes, and the filesystem size to 0. 1042 * Presumably, at a minimum, the caller will update the 1043 * filesystem size and crypto_type_name after calling this function. 1044 */ 1045static void cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr) 1046{ 1047 ftr->magic = CRYPT_MNT_MAGIC; 1048 ftr->major_version = 1; 1049 ftr->minor_version = 0; 1050 ftr->ftr_size = sizeof(struct crypt_mnt_ftr); 1051 ftr->flags = 0; 1052 ftr->keysize = KEY_LEN_BYTES; 1053 ftr->spare1 = 0; 1054 ftr->fs_size = 0; 1055 ftr->failed_decrypt_count = 0; 1056 ftr->crypto_type_name[0] = '\0'; 1057} 1058 1059static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size, int type) 1060{ 1061 char cmdline[256]; 1062 int rc = -1; 1063 1064 if (type == EXT4_FS) { 1065 snprintf(cmdline, sizeof(cmdline), "/system/bin/make_ext4fs -a /data -l %lld %s", 1066 size * 512, crypto_blkdev); 1067 SLOGI("Making empty filesystem with command %s\n", cmdline); 1068 } else if (type== FAT_FS) { 1069 snprintf(cmdline, sizeof(cmdline), "/system/bin/newfs_msdos -F 32 -O android -c 8 -s %lld %s", 1070 size, crypto_blkdev); 1071 SLOGI("Making empty filesystem with command %s\n", cmdline); 1072 } else { 1073 SLOGE("cryptfs_enable_wipe(): unknown filesystem type %d\n", type); 1074 return -1; 1075 } 1076 1077 if (system(cmdline)) { 1078 SLOGE("Error creating empty filesystem on %s\n", crypto_blkdev); 1079 } else { 1080 SLOGD("Successfully created empty filesystem on %s\n", crypto_blkdev); 1081 rc = 0; 1082 } 1083 1084 return rc; 1085} 1086 1087static inline int unix_read(int fd, void* buff, int len) 1088{ 1089 int ret; 1090 do { ret = read(fd, buff, len); } while (ret < 0 && errno == EINTR); 1091 return ret; 1092} 1093 1094static inline int unix_write(int fd, const void* buff, int len) 1095{ 1096 int ret; 1097 do { ret = write(fd, buff, len); } while (ret < 0 && errno == EINTR); 1098 return ret; 1099} 1100 1101#define CRYPT_INPLACE_BUFSIZE 4096 1102#define CRYPT_SECTORS_PER_BUFSIZE (CRYPT_INPLACE_BUFSIZE / 512) 1103static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_t size, 1104 off64_t *size_already_done, off64_t tot_size) 1105{ 1106 int realfd, cryptofd; 1107 char *buf[CRYPT_INPLACE_BUFSIZE]; 1108 int rc = -1; 1109 off64_t numblocks, i, remainder; 1110 off64_t one_pct, cur_pct, new_pct; 1111 off64_t blocks_already_done, tot_numblocks; 1112 1113 if ( (realfd = open(real_blkdev, O_RDONLY)) < 0) { 1114 SLOGE("Error opening real_blkdev %s for inplace encrypt\n", real_blkdev); 1115 return -1; 1116 } 1117 1118 if ( (cryptofd = open(crypto_blkdev, O_WRONLY)) < 0) { 1119 SLOGE("Error opening crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1120 close(realfd); 1121 return -1; 1122 } 1123 1124 /* This is pretty much a simple loop of reading 4K, and writing 4K. 1125 * The size passed in is the number of 512 byte sectors in the filesystem. 1126 * So compute the number of whole 4K blocks we should read/write, 1127 * and the remainder. 1128 */ 1129 numblocks = size / CRYPT_SECTORS_PER_BUFSIZE; 1130 remainder = size % CRYPT_SECTORS_PER_BUFSIZE; 1131 tot_numblocks = tot_size / CRYPT_SECTORS_PER_BUFSIZE; 1132 blocks_already_done = *size_already_done / CRYPT_SECTORS_PER_BUFSIZE; 1133 1134 SLOGE("Encrypting filesystem in place..."); 1135 1136 one_pct = tot_numblocks / 100; 1137 cur_pct = 0; 1138 /* process the majority of the filesystem in blocks */ 1139 for (i=0; i<numblocks; i++) { 1140 new_pct = (i + blocks_already_done) / one_pct; 1141 if (new_pct > cur_pct) { 1142 char buf[8]; 1143 1144 cur_pct = new_pct; 1145 snprintf(buf, sizeof(buf), "%lld", cur_pct); 1146 property_set("vold.encrypt_progress", buf); 1147 } 1148 if (unix_read(realfd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) { 1149 SLOGE("Error reading real_blkdev %s for inplace encrypt\n", crypto_blkdev); 1150 goto errout; 1151 } 1152 if (unix_write(cryptofd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) { 1153 SLOGE("Error writing crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1154 goto errout; 1155 } 1156 } 1157 1158 /* Do any remaining sectors */ 1159 for (i=0; i<remainder; i++) { 1160 if (unix_read(realfd, buf, 512) <= 0) { 1161 SLOGE("Error reading rival sectors from real_blkdev %s for inplace encrypt\n", crypto_blkdev); 1162 goto errout; 1163 } 1164 if (unix_write(cryptofd, buf, 512) <= 0) { 1165 SLOGE("Error writing final sectors to crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1166 goto errout; 1167 } 1168 } 1169 1170 *size_already_done += size; 1171 rc = 0; 1172 1173errout: 1174 close(realfd); 1175 close(cryptofd); 1176 1177 return rc; 1178} 1179 1180#define CRYPTO_ENABLE_WIPE 1 1181#define CRYPTO_ENABLE_INPLACE 2 1182 1183#define FRAMEWORK_BOOT_WAIT 60 1184 1185static inline int should_encrypt(struct volume_info *volume) 1186{ 1187 return (volume->flags & (VOL_ENCRYPTABLE | VOL_NONREMOVABLE)) == 1188 (VOL_ENCRYPTABLE | VOL_NONREMOVABLE); 1189} 1190 1191int cryptfs_enable(char *howarg, char *passwd) 1192{ 1193 int how = 0; 1194 char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN], sd_crypto_blkdev[MAXPATHLEN]; 1195 unsigned long nr_sec; 1196 unsigned char master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES]; 1197 unsigned char salt[SALT_LEN]; 1198 int rc=-1, fd, i, ret; 1199 struct crypt_mnt_ftr crypt_ftr, sd_crypt_ftr;; 1200 char tmpfs_options[PROPERTY_VALUE_MAX]; 1201 char encrypted_state[PROPERTY_VALUE_MAX]; 1202 char lockid[32] = { 0 }; 1203 char key_loc[PROPERTY_VALUE_MAX]; 1204 char fuse_sdcard[PROPERTY_VALUE_MAX]; 1205 char *sd_mnt_point; 1206 char sd_blk_dev[256] = { 0 }; 1207 int num_vols; 1208 struct volume_info *vol_list = 0; 1209 off64_t cur_encryption_done=0, tot_encryption_size=0; 1210 1211 property_get("ro.crypto.state", encrypted_state, ""); 1212 if (strcmp(encrypted_state, "unencrypted")) { 1213 SLOGE("Device is already running encrypted, aborting"); 1214 goto error_unencrypted; 1215 } 1216 1217 fs_mgr_get_crypt_info(fstab, key_loc, 0, sizeof(key_loc)); 1218 1219 if (!strcmp(howarg, "wipe")) { 1220 how = CRYPTO_ENABLE_WIPE; 1221 } else if (! strcmp(howarg, "inplace")) { 1222 how = CRYPTO_ENABLE_INPLACE; 1223 } else { 1224 /* Shouldn't happen, as CommandListener vets the args */ 1225 goto error_unencrypted; 1226 } 1227 1228 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 1229 1230 /* Get the size of the real block device */ 1231 fd = open(real_blkdev, O_RDONLY); 1232 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 1233 SLOGE("Cannot get size of block device %s\n", real_blkdev); 1234 goto error_unencrypted; 1235 } 1236 close(fd); 1237 1238 /* If doing inplace encryption, make sure the orig fs doesn't include the crypto footer */ 1239 if ((how == CRYPTO_ENABLE_INPLACE) && (!strcmp(key_loc, KEY_IN_FOOTER))) { 1240 unsigned int fs_size_sec, max_fs_size_sec; 1241 1242 fs_size_sec = get_fs_size(real_blkdev); 1243 max_fs_size_sec = nr_sec - (CRYPT_FOOTER_OFFSET / 512); 1244 1245 if (fs_size_sec > max_fs_size_sec) { 1246 SLOGE("Orig filesystem overlaps crypto footer region. Cannot encrypt in place."); 1247 goto error_unencrypted; 1248 } 1249 } 1250 1251 /* Get a wakelock as this may take a while, and we don't want the 1252 * device to sleep on us. We'll grab a partial wakelock, and if the UI 1253 * wants to keep the screen on, it can grab a full wakelock. 1254 */ 1255 snprintf(lockid, sizeof(lockid), "enablecrypto%d", (int) getpid()); 1256 acquire_wake_lock(PARTIAL_WAKE_LOCK, lockid); 1257 1258 /* Get the sdcard mount point */ 1259 sd_mnt_point = getenv("EMULATED_STORAGE_SOURCE"); 1260 if (!sd_mnt_point) { 1261 sd_mnt_point = getenv("EXTERNAL_STORAGE"); 1262 } 1263 if (!sd_mnt_point) { 1264 sd_mnt_point = "/mnt/sdcard"; 1265 } 1266 1267 num_vols=vold_getNumDirectVolumes(); 1268 vol_list = malloc(sizeof(struct volume_info) * num_vols); 1269 vold_getDirectVolumeList(vol_list); 1270 1271 for (i=0; i<num_vols; i++) { 1272 if (should_encrypt(&vol_list[i])) { 1273 fd = open(vol_list[i].blk_dev, O_RDONLY); 1274 if ( (vol_list[i].size = get_blkdev_size(fd)) == 0) { 1275 SLOGE("Cannot get size of block device %s\n", vol_list[i].blk_dev); 1276 goto error_unencrypted; 1277 } 1278 close(fd); 1279 1280 ret=vold_disableVol(vol_list[i].label); 1281 if ((ret < 0) && (ret != UNMOUNT_NOT_MOUNTED_ERR)) { 1282 /* -2 is returned when the device exists but is not currently mounted. 1283 * ignore the error and continue. */ 1284 SLOGE("Failed to unmount volume %s\n", vol_list[i].label); 1285 goto error_unencrypted; 1286 } 1287 } 1288 } 1289 1290 /* The init files are setup to stop the class main and late start when 1291 * vold sets trigger_shutdown_framework. 1292 */ 1293 property_set("vold.decrypt", "trigger_shutdown_framework"); 1294 SLOGD("Just asked init to shut down class main\n"); 1295 1296 if (vold_unmountAllAsecs()) { 1297 /* Just report the error. If any are left mounted, 1298 * umounting /data below will fail and handle the error. 1299 */ 1300 SLOGE("Error unmounting internal asecs"); 1301 } 1302 1303 property_get("ro.crypto.fuse_sdcard", fuse_sdcard, ""); 1304 if (!strcmp(fuse_sdcard, "true")) { 1305 /* This is a device using the fuse layer to emulate the sdcard semantics 1306 * on top of the userdata partition. vold does not manage it, it is managed 1307 * by the sdcard service. The sdcard service was killed by the property trigger 1308 * above, so just unmount it now. We must do this _AFTER_ killing the framework, 1309 * unlike the case for vold managed devices above. 1310 */ 1311 if (wait_and_unmount(sd_mnt_point)) { 1312 goto error_shutting_down; 1313 } 1314 } 1315 1316 /* Now unmount the /data partition. */ 1317 if (wait_and_unmount(DATA_MNT_POINT)) { 1318 goto error_shutting_down; 1319 } 1320 1321 /* Do extra work for a better UX when doing the long inplace encryption */ 1322 if (how == CRYPTO_ENABLE_INPLACE) { 1323 /* Now that /data is unmounted, we need to mount a tmpfs 1324 * /data, set a property saying we're doing inplace encryption, 1325 * and restart the framework. 1326 */ 1327 if (fs_mgr_do_tmpfs_mount(DATA_MNT_POINT)) { 1328 goto error_shutting_down; 1329 } 1330 /* Tells the framework that inplace encryption is starting */ 1331 property_set("vold.encrypt_progress", "0"); 1332 1333 /* restart the framework. */ 1334 /* Create necessary paths on /data */ 1335 if (prep_data_fs()) { 1336 goto error_shutting_down; 1337 } 1338 1339 /* Ugh, shutting down the framework is not synchronous, so until it 1340 * can be fixed, this horrible hack will wait a moment for it all to 1341 * shut down before proceeding. Without it, some devices cannot 1342 * restart the graphics services. 1343 */ 1344 sleep(2); 1345 1346 /* startup service classes main and late_start */ 1347 property_set("vold.decrypt", "trigger_restart_min_framework"); 1348 SLOGD("Just triggered restart_min_framework\n"); 1349 1350 /* OK, the framework is restarted and will soon be showing a 1351 * progress bar. Time to setup an encrypted mapping, and 1352 * either write a new filesystem, or encrypt in place updating 1353 * the progress bar as we work. 1354 */ 1355 } 1356 1357 /* Start the actual work of making an encrypted filesystem */ 1358 /* Initialize a crypt_mnt_ftr for the partition */ 1359 cryptfs_init_crypt_mnt_ftr(&crypt_ftr); 1360 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 1361 crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / 512); 1362 } else { 1363 crypt_ftr.fs_size = nr_sec; 1364 } 1365 crypt_ftr.flags |= CRYPT_ENCRYPTION_IN_PROGRESS; 1366 strcpy((char *)crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256"); 1367 1368 /* Make an encrypted master key */ 1369 if (create_encrypted_random_key(passwd, master_key, salt)) { 1370 SLOGE("Cannot create encrypted master key\n"); 1371 goto error_unencrypted; 1372 } 1373 1374 /* Write the key to the end of the partition */ 1375 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, master_key, salt); 1376 1377 decrypt_master_key(passwd, salt, master_key, decrypted_master_key); 1378 create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev, 1379 "userdata"); 1380 1381 /* The size of the userdata partition, and add in the vold volumes below */ 1382 tot_encryption_size = crypt_ftr.fs_size; 1383 1384 /* setup crypto mapping for all encryptable volumes handled by vold */ 1385 for (i=0; i<num_vols; i++) { 1386 if (should_encrypt(&vol_list[i])) { 1387 vol_list[i].crypt_ftr = crypt_ftr; /* gotta love struct assign */ 1388 vol_list[i].crypt_ftr.fs_size = vol_list[i].size; 1389 create_crypto_blk_dev(&vol_list[i].crypt_ftr, decrypted_master_key, 1390 vol_list[i].blk_dev, vol_list[i].crypto_blkdev, 1391 vol_list[i].label); 1392 tot_encryption_size += vol_list[i].size; 1393 } 1394 } 1395 1396 if (how == CRYPTO_ENABLE_WIPE) { 1397 rc = cryptfs_enable_wipe(crypto_blkdev, crypt_ftr.fs_size, EXT4_FS); 1398 /* Encrypt all encryptable volumes handled by vold */ 1399 if (!rc) { 1400 for (i=0; i<num_vols; i++) { 1401 if (should_encrypt(&vol_list[i])) { 1402 rc = cryptfs_enable_wipe(vol_list[i].crypto_blkdev, 1403 vol_list[i].crypt_ftr.fs_size, FAT_FS); 1404 } 1405 } 1406 } 1407 } else if (how == CRYPTO_ENABLE_INPLACE) { 1408 rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr.fs_size, 1409 &cur_encryption_done, tot_encryption_size); 1410 /* Encrypt all encryptable volumes handled by vold */ 1411 if (!rc) { 1412 for (i=0; i<num_vols; i++) { 1413 if (should_encrypt(&vol_list[i])) { 1414 rc = cryptfs_enable_inplace(vol_list[i].crypto_blkdev, 1415 vol_list[i].blk_dev, 1416 vol_list[i].crypt_ftr.fs_size, 1417 &cur_encryption_done, tot_encryption_size); 1418 } 1419 } 1420 } 1421 if (!rc) { 1422 /* The inplace routine never actually sets the progress to 100% 1423 * due to the round down nature of integer division, so set it here */ 1424 property_set("vold.encrypt_progress", "100"); 1425 } 1426 } else { 1427 /* Shouldn't happen */ 1428 SLOGE("cryptfs_enable: internal error, unknown option\n"); 1429 goto error_unencrypted; 1430 } 1431 1432 /* Undo the dm-crypt mapping whether we succeed or not */ 1433 delete_crypto_blk_dev("userdata"); 1434 for (i=0; i<num_vols; i++) { 1435 if (should_encrypt(&vol_list[i])) { 1436 delete_crypto_blk_dev(vol_list[i].label); 1437 } 1438 } 1439 1440 free(vol_list); 1441 1442 if (! rc) { 1443 /* Success */ 1444 1445 /* Clear the encryption in progres flag in the footer */ 1446 crypt_ftr.flags &= ~CRYPT_ENCRYPTION_IN_PROGRESS; 1447 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0); 1448 1449 sleep(2); /* Give the UI a chance to show 100% progress */ 1450 android_reboot(ANDROID_RB_RESTART, 0, 0); 1451 } else { 1452 char value[PROPERTY_VALUE_MAX]; 1453 1454 property_get("ro.vold.wipe_on_crypt_fail", value, "0"); 1455 if (!strcmp(value, "1")) { 1456 /* wipe data if encryption failed */ 1457 SLOGE("encryption failed - rebooting into recovery to wipe data\n"); 1458 mkdir("/cache/recovery", 0700); 1459 int fd = open("/cache/recovery/command", O_RDWR|O_CREAT|O_TRUNC, 0600); 1460 if (fd >= 0) { 1461 write(fd, "--wipe_data", strlen("--wipe_data") + 1); 1462 close(fd); 1463 } else { 1464 SLOGE("could not open /cache/recovery/command\n"); 1465 } 1466 android_reboot(ANDROID_RB_RESTART2, 0, "recovery"); 1467 } else { 1468 /* set property to trigger dialog */ 1469 property_set("vold.encrypt_progress", "error_partially_encrypted"); 1470 release_wake_lock(lockid); 1471 } 1472 return -1; 1473 } 1474 1475 /* hrm, the encrypt step claims success, but the reboot failed. 1476 * This should not happen. 1477 * Set the property and return. Hope the framework can deal with it. 1478 */ 1479 property_set("vold.encrypt_progress", "error_reboot_failed"); 1480 release_wake_lock(lockid); 1481 return rc; 1482 1483error_unencrypted: 1484 free(vol_list); 1485 property_set("vold.encrypt_progress", "error_not_encrypted"); 1486 if (lockid[0]) { 1487 release_wake_lock(lockid); 1488 } 1489 return -1; 1490 1491error_shutting_down: 1492 /* we failed, and have not encrypted anthing, so the users's data is still intact, 1493 * but the framework is stopped and not restarted to show the error, so it's up to 1494 * vold to restart the system. 1495 */ 1496 SLOGE("Error enabling encryption after framework is shutdown, no data changed, restarting system"); 1497 android_reboot(ANDROID_RB_RESTART, 0, 0); 1498 1499 /* shouldn't get here */ 1500 property_set("vold.encrypt_progress", "error_shutting_down"); 1501 free(vol_list); 1502 if (lockid[0]) { 1503 release_wake_lock(lockid); 1504 } 1505 return -1; 1506} 1507 1508int cryptfs_changepw(char *newpw) 1509{ 1510 struct crypt_mnt_ftr crypt_ftr; 1511 unsigned char encrypted_master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES]; 1512 unsigned char salt[SALT_LEN]; 1513 char real_blkdev[MAXPATHLEN]; 1514 1515 /* This is only allowed after we've successfully decrypted the master key */ 1516 if (! master_key_saved) { 1517 SLOGE("Key not saved, aborting"); 1518 return -1; 1519 } 1520 1521 fs_mgr_get_crypt_info(fstab, 0, real_blkdev, sizeof(real_blkdev)); 1522 if (strlen(real_blkdev) == 0) { 1523 SLOGE("Can't find real blkdev"); 1524 return -1; 1525 } 1526 1527 /* get key */ 1528 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 1529 SLOGE("Error getting crypt footer and key"); 1530 return -1; 1531 } 1532 1533 encrypt_master_key(newpw, salt, saved_master_key, encrypted_master_key); 1534 1535 /* save the key */ 1536 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt); 1537 1538 return 0; 1539} 1540