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