cryptfs.c revision 3be890f59c04f94537f2f66f1d2841ed591f1a6e
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 "cryptfs.h" 42#define LOG_TAG "Cryptfs" 43#include "cutils/log.h" 44#include "cutils/properties.h" 45#include "hardware_legacy/power.h" 46#include "VolumeManager.h" 47 48#define DM_CRYPT_BUF_SIZE 4096 49#define DATA_MNT_POINT "/data" 50 51#define HASH_COUNT 2000 52#define KEY_LEN_BYTES 16 53#define IV_LEN_BYTES 16 54 55#define KEY_LOC_PROP "ro.crypto.keyfile.userdata" 56#define KEY_IN_FOOTER "footer" 57 58#define EXT4_FS 1 59#define FAT_FS 2 60 61char *me = "cryptfs"; 62 63static unsigned char saved_master_key[KEY_LEN_BYTES]; 64static char *saved_data_blkdev; 65static int master_key_saved = 0; 66 67static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags) 68{ 69 memset(io, 0, dataSize); 70 io->data_size = dataSize; 71 io->data_start = sizeof(struct dm_ioctl); 72 io->version[0] = 4; 73 io->version[1] = 0; 74 io->version[2] = 0; 75 io->flags = flags; 76 if (name) { 77 strncpy(io->name, name, sizeof(io->name)); 78 } 79} 80 81static unsigned int get_fs_size(char *dev) 82{ 83 int fd, block_size; 84 struct ext4_super_block sb; 85 off64_t len; 86 87 if ((fd = open(dev, O_RDONLY)) < 0) { 88 SLOGE("Cannot open device to get filesystem size "); 89 return 0; 90 } 91 92 if (lseek64(fd, 1024, SEEK_SET) < 0) { 93 SLOGE("Cannot seek to superblock"); 94 return 0; 95 } 96 97 if (read(fd, &sb, sizeof(sb)) != sizeof(sb)) { 98 SLOGE("Cannot read superblock"); 99 return 0; 100 } 101 102 close(fd); 103 104 block_size = 1024 << sb.s_log_block_size; 105 /* compute length in bytes */ 106 len = ( ((off64_t)sb.s_blocks_count_hi << 32) + sb.s_blocks_count_lo) * block_size; 107 108 /* return length in sectors */ 109 return (unsigned int) (len / 512); 110} 111 112static unsigned int get_blkdev_size(int fd) 113{ 114 unsigned int nr_sec; 115 116 if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) { 117 nr_sec = 0; 118 } 119 120 return nr_sec; 121} 122 123/* key or salt can be NULL, in which case just skip writing that value. Useful to 124 * update the failed mount count but not change the key. 125 */ 126static int put_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr, 127 unsigned char *key, unsigned char *salt) 128{ 129 int fd; 130 unsigned int nr_sec, cnt; 131 off64_t off; 132 int rc = -1; 133 char *fname; 134 char key_loc[PROPERTY_VALUE_MAX]; 135 struct stat statbuf; 136 137 property_get(KEY_LOC_PROP, key_loc, KEY_IN_FOOTER); 138 139 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 140 fname = real_blk_name; 141 if ( (fd = open(fname, O_RDWR)) < 0) { 142 SLOGE("Cannot open real block device %s\n", fname); 143 return -1; 144 } 145 146 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 147 SLOGE("Cannot get size of block device %s\n", fname); 148 goto errout; 149 } 150 151 /* If it's an encrypted Android partition, the last 16 Kbytes contain the 152 * encryption info footer and key, and plenty of bytes to spare for future 153 * growth. 154 */ 155 off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; 156 157 if (lseek64(fd, off, SEEK_SET) == -1) { 158 SLOGE("Cannot seek to real block device footer\n"); 159 goto errout; 160 } 161 } else if (key_loc[0] == '/') { 162 fname = key_loc; 163 if ( (fd = open(fname, O_RDWR | O_CREAT, 0600)) < 0) { 164 SLOGE("Cannot open footer file %s\n", fname); 165 return -1; 166 } 167 } else { 168 SLOGE("Unexpected value for" KEY_LOC_PROP "\n"); 169 return -1;; 170 } 171 172 if ((cnt = write(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) { 173 SLOGE("Cannot write real block device footer\n"); 174 goto errout; 175 } 176 177 if (key) { 178 if (crypt_ftr->keysize != KEY_LEN_BYTES) { 179 SLOGE("Keysize of %d bits not supported for real block device %s\n", 180 crypt_ftr->keysize*8, fname); 181 goto errout; 182 } 183 184 if ( (cnt = write(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) { 185 SLOGE("Cannot write key for real block device %s\n", fname); 186 goto errout; 187 } 188 } 189 190 if (salt) { 191 /* Compute the offset from the last write to the salt */ 192 off = KEY_TO_SALT_PADDING; 193 if (! key) 194 off += crypt_ftr->keysize; 195 196 if (lseek64(fd, off, SEEK_CUR) == -1) { 197 SLOGE("Cannot seek to real block device salt \n"); 198 goto errout; 199 } 200 201 if ( (cnt = write(fd, salt, SALT_LEN)) != SALT_LEN) { 202 SLOGE("Cannot write salt for real block device %s\n", fname); 203 goto errout; 204 } 205 } 206 207 fstat(fd, &statbuf); 208 /* If the keys are kept on a raw block device, do not try to truncate it. */ 209 if (S_ISREG(statbuf.st_mode) && (key_loc[0] == '/')) { 210 if (ftruncate(fd, 0x4000)) { 211 SLOGE("Cannot set footer file size\n", fname); 212 goto errout; 213 } 214 } 215 216 /* Success! */ 217 rc = 0; 218 219errout: 220 close(fd); 221 return rc; 222 223} 224 225static int get_crypt_ftr_and_key(char *real_blk_name, struct crypt_mnt_ftr *crypt_ftr, 226 unsigned char *key, unsigned char *salt) 227{ 228 int fd; 229 unsigned int nr_sec, cnt; 230 off64_t off; 231 int rc = -1; 232 char key_loc[PROPERTY_VALUE_MAX]; 233 char *fname; 234 struct stat statbuf; 235 236 property_get(KEY_LOC_PROP, key_loc, KEY_IN_FOOTER); 237 238 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 239 fname = real_blk_name; 240 if ( (fd = open(fname, O_RDONLY)) < 0) { 241 SLOGE("Cannot open real block device %s\n", fname); 242 return -1; 243 } 244 245 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 246 SLOGE("Cannot get size of block device %s\n", fname); 247 goto errout; 248 } 249 250 /* If it's an encrypted Android partition, the last 16 Kbytes contain the 251 * encryption info footer and key, and plenty of bytes to spare for future 252 * growth. 253 */ 254 off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; 255 256 if (lseek64(fd, off, SEEK_SET) == -1) { 257 SLOGE("Cannot seek to real block device footer\n"); 258 goto errout; 259 } 260 } else if (key_loc[0] == '/') { 261 fname = key_loc; 262 if ( (fd = open(fname, O_RDONLY)) < 0) { 263 SLOGE("Cannot open footer file %s\n", fname); 264 return -1; 265 } 266 267 /* Make sure it's 16 Kbytes in length */ 268 fstat(fd, &statbuf); 269 if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) { 270 SLOGE("footer file %s is not the expected size!\n", fname); 271 goto errout; 272 } 273 } else { 274 SLOGE("Unexpected value for" KEY_LOC_PROP "\n"); 275 return -1;; 276 } 277 278 if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) { 279 SLOGE("Cannot read real block device footer\n"); 280 goto errout; 281 } 282 283 if (crypt_ftr->magic != CRYPT_MNT_MAGIC) { 284 SLOGE("Bad magic for real block device %s\n", fname); 285 goto errout; 286 } 287 288 if (crypt_ftr->major_version != 1) { 289 SLOGE("Cannot understand major version %d real block device footer\n", 290 crypt_ftr->major_version); 291 goto errout; 292 } 293 294 if (crypt_ftr->minor_version != 0) { 295 SLOGW("Warning: crypto footer minor version %d, expected 0, continuing...\n", 296 crypt_ftr->minor_version); 297 } 298 299 if (crypt_ftr->ftr_size > sizeof(struct crypt_mnt_ftr)) { 300 /* the footer size is bigger than we expected. 301 * Skip to it's stated end so we can read the key. 302 */ 303 if (lseek(fd, crypt_ftr->ftr_size - sizeof(struct crypt_mnt_ftr), SEEK_CUR) == -1) { 304 SLOGE("Cannot seek to start of key\n"); 305 goto errout; 306 } 307 } 308 309 if (crypt_ftr->keysize != KEY_LEN_BYTES) { 310 SLOGE("Keysize of %d bits not supported for real block device %s\n", 311 crypt_ftr->keysize * 8, fname); 312 goto errout; 313 } 314 315 if ( (cnt = read(fd, key, crypt_ftr->keysize)) != crypt_ftr->keysize) { 316 SLOGE("Cannot read key for real block device %s\n", fname); 317 goto errout; 318 } 319 320 if (lseek64(fd, KEY_TO_SALT_PADDING, SEEK_CUR) == -1) { 321 SLOGE("Cannot seek to real block device salt\n"); 322 goto errout; 323 } 324 325 if ( (cnt = read(fd, salt, SALT_LEN)) != SALT_LEN) { 326 SLOGE("Cannot read salt for real block device %s\n", fname); 327 goto errout; 328 } 329 330 /* Success! */ 331 rc = 0; 332 333errout: 334 close(fd); 335 return rc; 336} 337 338/* Convert a binary key of specified length into an ascii hex string equivalent, 339 * without the leading 0x and with null termination 340 */ 341void convert_key_to_hex_ascii(unsigned char *master_key, unsigned int keysize, 342 char *master_key_ascii) 343{ 344 unsigned int i, a; 345 unsigned char nibble; 346 347 for (i=0, a=0; i<keysize; i++, a+=2) { 348 /* For each byte, write out two ascii hex digits */ 349 nibble = (master_key[i] >> 4) & 0xf; 350 master_key_ascii[a] = nibble + (nibble > 9 ? 0x37 : 0x30); 351 352 nibble = master_key[i] & 0xf; 353 master_key_ascii[a+1] = nibble + (nibble > 9 ? 0x37 : 0x30); 354 } 355 356 /* Add the null termination */ 357 master_key_ascii[a] = '\0'; 358 359} 360 361static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key, 362 char *real_blk_name, char *crypto_blk_name, const char *name) 363{ 364 char buffer[DM_CRYPT_BUF_SIZE]; 365 char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */ 366 char *crypt_params; 367 struct dm_ioctl *io; 368 struct dm_target_spec *tgt; 369 unsigned int minor; 370 int fd; 371 int retval = -1; 372 373 if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { 374 SLOGE("Cannot open device-mapper\n"); 375 goto errout; 376 } 377 378 io = (struct dm_ioctl *) buffer; 379 380 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 381 if (ioctl(fd, DM_DEV_CREATE, io)) { 382 SLOGE("Cannot create dm-crypt device\n"); 383 goto errout; 384 } 385 386 /* Get the device status, in particular, the name of it's device file */ 387 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 388 if (ioctl(fd, DM_DEV_STATUS, io)) { 389 SLOGE("Cannot retrieve dm-crypt device status\n"); 390 goto errout; 391 } 392 minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00); 393 snprintf(crypto_blk_name, MAXPATHLEN, "/dev/block/dm-%u", minor); 394 395 /* Load the mapping table for this device */ 396 tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)]; 397 398 ioctl_init(io, 4096, name, 0); 399 io->target_count = 1; 400 tgt->status = 0; 401 tgt->sector_start = 0; 402 tgt->length = crypt_ftr->fs_size; 403 strcpy(tgt->target_type, "crypt"); 404 405 crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec); 406 convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii); 407 sprintf(crypt_params, "%s %s 0 %s 0", crypt_ftr->crypto_type_name, 408 master_key_ascii, real_blk_name); 409 crypt_params += strlen(crypt_params) + 1; 410 crypt_params = (char *) (((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */ 411 tgt->next = crypt_params - buffer; 412 413 if (ioctl(fd, DM_TABLE_LOAD, io)) { 414 SLOGE("Cannot load dm-crypt mapping table.\n"); 415 goto errout; 416 } 417 418 /* Resume this device to activate it */ 419 ioctl_init(io, 4096, name, 0); 420 421 if (ioctl(fd, DM_DEV_SUSPEND, io)) { 422 SLOGE("Cannot resume the dm-crypt device\n"); 423 goto errout; 424 } 425 426 /* We made it here with no errors. Woot! */ 427 retval = 0; 428 429errout: 430 close(fd); /* If fd is <0 from a failed open call, it's safe to just ignore the close error */ 431 432 return retval; 433} 434 435static int delete_crypto_blk_dev(char *name) 436{ 437 int fd; 438 char buffer[DM_CRYPT_BUF_SIZE]; 439 struct dm_ioctl *io; 440 int retval = -1; 441 442 if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) { 443 SLOGE("Cannot open device-mapper\n"); 444 goto errout; 445 } 446 447 io = (struct dm_ioctl *) buffer; 448 449 ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0); 450 if (ioctl(fd, DM_DEV_REMOVE, io)) { 451 SLOGE("Cannot remove 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} 464 465static void pbkdf2(char *passwd, unsigned char *salt, unsigned char *ikey) 466{ 467 /* Turn the password into a key and IV that can decrypt the master key */ 468 PKCS5_PBKDF2_HMAC_SHA1(passwd, strlen(passwd), salt, SALT_LEN, 469 HASH_COUNT, KEY_LEN_BYTES+IV_LEN_BYTES, ikey); 470} 471 472static int encrypt_master_key(char *passwd, unsigned char *salt, 473 unsigned char *decrypted_master_key, 474 unsigned char *encrypted_master_key) 475{ 476 unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ 477 EVP_CIPHER_CTX e_ctx; 478 int encrypted_len, final_len; 479 480 /* Turn the password into a key and IV that can decrypt the master key */ 481 pbkdf2(passwd, salt, ikey); 482 483 /* Initialize the decryption engine */ 484 if (! EVP_EncryptInit(&e_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) { 485 SLOGE("EVP_EncryptInit failed\n"); 486 return -1; 487 } 488 EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */ 489 490 /* Encrypt the master key */ 491 if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len, 492 decrypted_master_key, KEY_LEN_BYTES)) { 493 SLOGE("EVP_EncryptUpdate failed\n"); 494 return -1; 495 } 496 if (! EVP_EncryptFinal(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) { 497 SLOGE("EVP_EncryptFinal failed\n"); 498 return -1; 499 } 500 501 if (encrypted_len + final_len != KEY_LEN_BYTES) { 502 SLOGE("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len); 503 return -1; 504 } else { 505 return 0; 506 } 507} 508 509static int decrypt_master_key(char *passwd, unsigned char *salt, 510 unsigned char *encrypted_master_key, 511 unsigned char *decrypted_master_key) 512{ 513 unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */ 514 EVP_CIPHER_CTX d_ctx; 515 int decrypted_len, final_len; 516 517 /* Turn the password into a key and IV that can decrypt the master key */ 518 pbkdf2(passwd, salt, ikey); 519 520 /* Initialize the decryption engine */ 521 if (! EVP_DecryptInit(&d_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) { 522 return -1; 523 } 524 EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */ 525 /* Decrypt the master key */ 526 if (! EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len, 527 encrypted_master_key, KEY_LEN_BYTES)) { 528 return -1; 529 } 530 if (! EVP_DecryptFinal(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) { 531 return -1; 532 } 533 534 if (decrypted_len + final_len != KEY_LEN_BYTES) { 535 return -1; 536 } else { 537 return 0; 538 } 539} 540 541static int create_encrypted_random_key(char *passwd, unsigned char *master_key, unsigned char *salt) 542{ 543 int fd; 544 unsigned char key_buf[KEY_LEN_BYTES]; 545 EVP_CIPHER_CTX e_ctx; 546 int encrypted_len, final_len; 547 548 /* Get some random bits for a key */ 549 fd = open("/dev/urandom", O_RDONLY); 550 read(fd, key_buf, sizeof(key_buf)); 551 read(fd, salt, SALT_LEN); 552 close(fd); 553 554 /* Now encrypt it with the password */ 555 return encrypt_master_key(passwd, salt, key_buf, master_key); 556} 557 558static int get_orig_mount_parms(char *mount_point, char *fs_type, char *real_blkdev, 559 unsigned long *mnt_flags, char *fs_options) 560{ 561 char mount_point2[PROPERTY_VALUE_MAX]; 562 char fs_flags[PROPERTY_VALUE_MAX]; 563 564 property_get("ro.crypto.fs_type", fs_type, ""); 565 property_get("ro.crypto.fs_real_blkdev", real_blkdev, ""); 566 property_get("ro.crypto.fs_mnt_point", mount_point2, ""); 567 property_get("ro.crypto.fs_options", fs_options, ""); 568 property_get("ro.crypto.fs_flags", fs_flags, ""); 569 *mnt_flags = strtol(fs_flags, 0, 0); 570 571 if (strcmp(mount_point, mount_point2)) { 572 /* Consistency check. These should match. If not, something odd happened. */ 573 return -1; 574 } 575 576 return 0; 577} 578 579static int wait_and_unmount(char *mountpoint) 580{ 581 int i, rc; 582#define WAIT_UNMOUNT_COUNT 20 583 584 /* Now umount the tmpfs filesystem */ 585 for (i=0; i<WAIT_UNMOUNT_COUNT; i++) { 586 if (umount(mountpoint)) { 587 if (errno == EINVAL) { 588 /* EINVAL is returned if the directory is not a mountpoint, 589 * i.e. there is no filesystem mounted there. So just get out. 590 */ 591 break; 592 } 593 sleep(1); 594 i++; 595 } else { 596 break; 597 } 598 } 599 600 if (i < WAIT_UNMOUNT_COUNT) { 601 SLOGD("unmounting %s succeeded\n", mountpoint); 602 rc = 0; 603 } else { 604 SLOGE("unmounting %s failed\n", mountpoint); 605 rc = -1; 606 } 607 608 return rc; 609} 610 611#define DATA_PREP_TIMEOUT 100 612static int prep_data_fs(void) 613{ 614 int i; 615 616 /* Do the prep of the /data filesystem */ 617 property_set("vold.post_fs_data_done", "0"); 618 property_set("vold.decrypt", "trigger_post_fs_data"); 619 SLOGD("Just triggered post_fs_data\n"); 620 621 /* Wait a max of 25 seconds, hopefully it takes much less */ 622 for (i=0; i<DATA_PREP_TIMEOUT; i++) { 623 char p[PROPERTY_VALUE_MAX]; 624 625 property_get("vold.post_fs_data_done", p, "0"); 626 if (*p == '1') { 627 break; 628 } else { 629 usleep(250000); 630 } 631 } 632 if (i == DATA_PREP_TIMEOUT) { 633 /* Ugh, we failed to prep /data in time. Bail. */ 634 return -1; 635 } else { 636 SLOGD("post_fs_data done\n"); 637 return 0; 638 } 639} 640 641int cryptfs_restart(void) 642{ 643 char fs_type[32]; 644 char real_blkdev[MAXPATHLEN]; 645 char crypto_blkdev[MAXPATHLEN]; 646 char fs_options[256]; 647 unsigned long mnt_flags; 648 struct stat statbuf; 649 int rc = -1, i; 650 static int restart_successful = 0; 651 652 /* Validate that it's OK to call this routine */ 653 if (! master_key_saved) { 654 SLOGE("Encrypted filesystem not validated, aborting"); 655 return -1; 656 } 657 658 if (restart_successful) { 659 SLOGE("System already restarted with encrypted disk, aborting"); 660 return -1; 661 } 662 663 /* Here is where we shut down the framework. The init scripts 664 * start all services in one of three classes: core, main or late_start. 665 * On boot, we start core and main. Now, we stop main, but not core, 666 * as core includes vold and a few other really important things that 667 * we need to keep running. Once main has stopped, we should be able 668 * to umount the tmpfs /data, then mount the encrypted /data. 669 * We then restart the class main, and also the class late_start. 670 * At the moment, I've only put a few things in late_start that I know 671 * are not needed to bring up the framework, and that also cause problems 672 * with unmounting the tmpfs /data, but I hope to add add more services 673 * to the late_start class as we optimize this to decrease the delay 674 * till the user is asked for the password to the filesystem. 675 */ 676 677 /* The init files are setup to stop the class main when vold.decrypt is 678 * set to trigger_reset_main. 679 */ 680 property_set("vold.decrypt", "trigger_reset_main"); 681 SLOGD("Just asked init to shut down class main\n"); 682 683 /* Now that the framework is shutdown, we should be able to umount() 684 * the tmpfs filesystem, and mount the real one. 685 */ 686 687 property_get("ro.crypto.fs_crypto_blkdev", crypto_blkdev, ""); 688 if (strlen(crypto_blkdev) == 0) { 689 SLOGE("fs_crypto_blkdev not set\n"); 690 return -1; 691 } 692 693 if (! get_orig_mount_parms(DATA_MNT_POINT, fs_type, real_blkdev, &mnt_flags, fs_options)) { 694 SLOGD("Just got orig mount parms\n"); 695 696 if (! (rc = wait_and_unmount(DATA_MNT_POINT)) ) { 697 /* If that succeeded, then mount the decrypted filesystem */ 698 mount(crypto_blkdev, DATA_MNT_POINT, fs_type, mnt_flags, fs_options); 699 700 property_set("vold.decrypt", "trigger_load_persist_props"); 701 /* Create necessary paths on /data */ 702 if (prep_data_fs()) { 703 return -1; 704 } 705 706 /* startup service classes main and late_start */ 707 property_set("vold.decrypt", "trigger_restart_framework"); 708 SLOGD("Just triggered restart_framework\n"); 709 710 /* Give it a few moments to get started */ 711 sleep(1); 712 } 713 } 714 715 if (rc == 0) { 716 restart_successful = 1; 717 } 718 719 return rc; 720} 721 722static int do_crypto_complete(char *mount_point) 723{ 724 struct crypt_mnt_ftr crypt_ftr; 725 unsigned char encrypted_master_key[32]; 726 unsigned char salt[SALT_LEN]; 727 char real_blkdev[MAXPATHLEN]; 728 char fs_type[PROPERTY_VALUE_MAX]; 729 char fs_options[PROPERTY_VALUE_MAX]; 730 unsigned long mnt_flags; 731 char encrypted_state[PROPERTY_VALUE_MAX]; 732 733 property_get("ro.crypto.state", encrypted_state, ""); 734 if (strcmp(encrypted_state, "encrypted") ) { 735 SLOGE("not running with encryption, aborting"); 736 return 1; 737 } 738 739 if (get_orig_mount_parms(mount_point, fs_type, real_blkdev, &mnt_flags, fs_options)) { 740 SLOGE("Error reading original mount parms for mount point %s\n", mount_point); 741 return -1; 742 } 743 744 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 745 SLOGE("Error getting crypt footer and key\n"); 746 return -1; 747 } 748 749 if (crypt_ftr.flags & CRYPT_ENCRYPTION_IN_PROGRESS) { 750 SLOGE("Encryption process didn't finish successfully\n"); 751 return -2; /* -2 is the clue to the UI that there is no usable data on the disk, 752 * and give the user an option to wipe the disk */ 753 } 754 755 /* We passed the test! We shall diminish, and return to the west */ 756 return 0; 757} 758 759static int test_mount_encrypted_fs(char *passwd, char *mount_point, char *label) 760{ 761 struct crypt_mnt_ftr crypt_ftr; 762 /* Allocate enough space for a 256 bit key, but we may use less */ 763 unsigned char encrypted_master_key[32], decrypted_master_key[32]; 764 unsigned char salt[SALT_LEN]; 765 char crypto_blkdev[MAXPATHLEN]; 766 char real_blkdev[MAXPATHLEN]; 767 char fs_type[PROPERTY_VALUE_MAX]; 768 char fs_options[PROPERTY_VALUE_MAX]; 769 char tmp_mount_point[64]; 770 unsigned long mnt_flags; 771 unsigned int orig_failed_decrypt_count; 772 char encrypted_state[PROPERTY_VALUE_MAX]; 773 int rc; 774 775 property_get("ro.crypto.state", encrypted_state, ""); 776 if ( master_key_saved || strcmp(encrypted_state, "encrypted") ) { 777 SLOGE("encrypted fs already validated or not running with encryption, aborting"); 778 return -1; 779 } 780 781 if (get_orig_mount_parms(mount_point, fs_type, real_blkdev, &mnt_flags, fs_options)) { 782 SLOGE("Error reading original mount parms for mount point %s\n", mount_point); 783 return -1; 784 } 785 786 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 787 SLOGE("Error getting crypt footer and key\n"); 788 return -1; 789 } 790 791 SLOGD("crypt_ftr->fs_size = %lld\n", crypt_ftr.fs_size); 792 orig_failed_decrypt_count = crypt_ftr.failed_decrypt_count; 793 794 if (! (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) ) { 795 decrypt_master_key(passwd, salt, encrypted_master_key, decrypted_master_key); 796 } 797 798 if (create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, 799 real_blkdev, crypto_blkdev, label)) { 800 SLOGE("Error creating decrypted block device\n"); 801 return -1; 802 } 803 804 /* If init detects an encrypted filesystme, it writes a file for each such 805 * encrypted fs into the tmpfs /data filesystem, and then the framework finds those 806 * files and passes that data to me */ 807 /* Create a tmp mount point to try mounting the decryptd fs 808 * Since we're here, the mount_point should be a tmpfs filesystem, so make 809 * a directory in it to test mount the decrypted filesystem. 810 */ 811 sprintf(tmp_mount_point, "%s/tmp_mnt", mount_point); 812 mkdir(tmp_mount_point, 0755); 813 if ( mount(crypto_blkdev, tmp_mount_point, "ext4", MS_RDONLY, "") ) { 814 SLOGE("Error temp mounting decrypted block device\n"); 815 delete_crypto_blk_dev(label); 816 crypt_ftr.failed_decrypt_count++; 817 } else { 818 /* Success, so just umount and we'll mount it properly when we restart 819 * the framework. 820 */ 821 umount(tmp_mount_point); 822 crypt_ftr.failed_decrypt_count = 0; 823 } 824 825 if (orig_failed_decrypt_count != crypt_ftr.failed_decrypt_count) { 826 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0); 827 } 828 829 if (crypt_ftr.failed_decrypt_count) { 830 /* We failed to mount the device, so return an error */ 831 rc = crypt_ftr.failed_decrypt_count; 832 833 } else { 834 /* Woot! Success! Save the name of the crypto block device 835 * so we can mount it when restarting the framework. 836 */ 837 property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev); 838 839 /* Also save a the master key so we can reencrypted the key 840 * the key when we want to change the password on it. 841 */ 842 memcpy(saved_master_key, decrypted_master_key, KEY_LEN_BYTES); 843 saved_data_blkdev = strdup(real_blkdev); 844 master_key_saved = 1; 845 rc = 0; 846 } 847 848 return rc; 849} 850 851/* Called by vold when it wants to undo the crypto mapping of a volume it 852 * manages. This is usually in response to a factory reset, when we want 853 * to undo the crypto mapping so the volume is formatted in the clear. 854 */ 855int cryptfs_revert_volume(const char *label) 856{ 857 return delete_crypto_blk_dev((char *)label); 858} 859 860/* 861 * Called by vold when it's asked to mount an encrypted, nonremovable volume. 862 * Setup a dm-crypt mapping, use the saved master key from 863 * setting up the /data mapping, and return the new device path. 864 */ 865int cryptfs_setup_volume(const char *label, int major, int minor, 866 char *crypto_sys_path, unsigned int max_path, 867 int *new_major, int *new_minor) 868{ 869 char real_blkdev[MAXPATHLEN], crypto_blkdev[MAXPATHLEN]; 870 struct crypt_mnt_ftr sd_crypt_ftr; 871 unsigned char key[32], salt[32]; 872 struct stat statbuf; 873 int nr_sec, fd; 874 875 sprintf(real_blkdev, "/dev/block/vold/%d:%d", major, minor); 876 877 /* Just want the footer, but gotta get it all */ 878 get_crypt_ftr_and_key(saved_data_blkdev, &sd_crypt_ftr, key, salt); 879 880 /* Update the fs_size field to be the size of the volume */ 881 fd = open(real_blkdev, O_RDONLY); 882 nr_sec = get_blkdev_size(fd); 883 close(fd); 884 if (nr_sec == 0) { 885 SLOGE("Cannot get size of volume %s\n", real_blkdev); 886 return -1; 887 } 888 889 sd_crypt_ftr.fs_size = nr_sec; 890 create_crypto_blk_dev(&sd_crypt_ftr, saved_master_key, real_blkdev, 891 crypto_blkdev, label); 892 893 stat(crypto_blkdev, &statbuf); 894 *new_major = MAJOR(statbuf.st_rdev); 895 *new_minor = MINOR(statbuf.st_rdev); 896 897 /* Create path to sys entry for this block device */ 898 snprintf(crypto_sys_path, max_path, "/devices/virtual/block/%s", strrchr(crypto_blkdev, '/')+1); 899 900 return 0; 901} 902 903int cryptfs_crypto_complete(void) 904{ 905 return do_crypto_complete("/data"); 906} 907 908int cryptfs_check_passwd(char *passwd) 909{ 910 int rc = -1; 911 912 rc = test_mount_encrypted_fs(passwd, DATA_MNT_POINT, "userdata"); 913 914 return rc; 915} 916 917/* Initialize a crypt_mnt_ftr structure. The keysize is 918 * defaulted to 16 bytes, and the filesystem size to 0. 919 * Presumably, at a minimum, the caller will update the 920 * filesystem size and crypto_type_name after calling this function. 921 */ 922static void cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr) 923{ 924 ftr->magic = CRYPT_MNT_MAGIC; 925 ftr->major_version = 1; 926 ftr->minor_version = 0; 927 ftr->ftr_size = sizeof(struct crypt_mnt_ftr); 928 ftr->flags = 0; 929 ftr->keysize = KEY_LEN_BYTES; 930 ftr->spare1 = 0; 931 ftr->fs_size = 0; 932 ftr->failed_decrypt_count = 0; 933 ftr->crypto_type_name[0] = '\0'; 934} 935 936static int cryptfs_enable_wipe(char *crypto_blkdev, off64_t size, int type) 937{ 938 char cmdline[256]; 939 int rc = -1; 940 941 if (type == EXT4_FS) { 942 snprintf(cmdline, sizeof(cmdline), "/system/bin/make_ext4fs -a /data -l %lld %s", 943 size * 512, crypto_blkdev); 944 SLOGI("Making empty filesystem with command %s\n", cmdline); 945 } else if (type== FAT_FS) { 946 snprintf(cmdline, sizeof(cmdline), "/system/bin/newfs_msdos -F 32 -O android -c 8 -s %lld %s", 947 size, crypto_blkdev); 948 SLOGI("Making empty filesystem with command %s\n", cmdline); 949 } else { 950 SLOGE("cryptfs_enable_wipe(): unknown filesystem type %d\n", type); 951 return -1; 952 } 953 954 if (system(cmdline)) { 955 SLOGE("Error creating empty filesystem on %s\n", crypto_blkdev); 956 } else { 957 SLOGD("Successfully created empty filesystem on %s\n", crypto_blkdev); 958 rc = 0; 959 } 960 961 return rc; 962} 963 964static inline int unix_read(int fd, void* buff, int len) 965{ 966 int ret; 967 do { ret = read(fd, buff, len); } while (ret < 0 && errno == EINTR); 968 return ret; 969} 970 971static inline int unix_write(int fd, const void* buff, int len) 972{ 973 int ret; 974 do { ret = write(fd, buff, len); } while (ret < 0 && errno == EINTR); 975 return ret; 976} 977 978#define CRYPT_INPLACE_BUFSIZE 4096 979#define CRYPT_SECTORS_PER_BUFSIZE (CRYPT_INPLACE_BUFSIZE / 512) 980static int cryptfs_enable_inplace(char *crypto_blkdev, char *real_blkdev, off64_t size, 981 off64_t *size_already_done, off64_t tot_size) 982{ 983 int realfd, cryptofd; 984 char *buf[CRYPT_INPLACE_BUFSIZE]; 985 int rc = -1; 986 off64_t numblocks, i, remainder; 987 off64_t one_pct, cur_pct, new_pct; 988 off64_t blocks_already_done, tot_numblocks; 989 990 if ( (realfd = open(real_blkdev, O_RDONLY)) < 0) { 991 SLOGE("Error opening real_blkdev %s for inplace encrypt\n", real_blkdev); 992 return -1; 993 } 994 995 if ( (cryptofd = open(crypto_blkdev, O_WRONLY)) < 0) { 996 SLOGE("Error opening crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 997 close(realfd); 998 return -1; 999 } 1000 1001 /* This is pretty much a simple loop of reading 4K, and writing 4K. 1002 * The size passed in is the number of 512 byte sectors in the filesystem. 1003 * So compute the number of whole 4K blocks we should read/write, 1004 * and the remainder. 1005 */ 1006 numblocks = size / CRYPT_SECTORS_PER_BUFSIZE; 1007 remainder = size % CRYPT_SECTORS_PER_BUFSIZE; 1008 tot_numblocks = tot_size / CRYPT_SECTORS_PER_BUFSIZE; 1009 blocks_already_done = *size_already_done / CRYPT_SECTORS_PER_BUFSIZE; 1010 1011 SLOGE("Encrypting filesystem in place..."); 1012 1013 one_pct = tot_numblocks / 100; 1014 cur_pct = 0; 1015 /* process the majority of the filesystem in blocks */ 1016 for (i=0; i<numblocks; i++) { 1017 new_pct = (i + blocks_already_done) / one_pct; 1018 if (new_pct > cur_pct) { 1019 char buf[8]; 1020 1021 cur_pct = new_pct; 1022 snprintf(buf, sizeof(buf), "%lld", cur_pct); 1023 property_set("vold.encrypt_progress", buf); 1024 } 1025 if (unix_read(realfd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) { 1026 SLOGE("Error reading real_blkdev %s for inplace encrypt\n", crypto_blkdev); 1027 goto errout; 1028 } 1029 if (unix_write(cryptofd, buf, CRYPT_INPLACE_BUFSIZE) <= 0) { 1030 SLOGE("Error writing crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1031 goto errout; 1032 } 1033 } 1034 1035 /* Do any remaining sectors */ 1036 for (i=0; i<remainder; i++) { 1037 if (unix_read(realfd, buf, 512) <= 0) { 1038 SLOGE("Error reading rival sectors from real_blkdev %s for inplace encrypt\n", crypto_blkdev); 1039 goto errout; 1040 } 1041 if (unix_write(cryptofd, buf, 512) <= 0) { 1042 SLOGE("Error writing final sectors to crypto_blkdev %s for inplace encrypt\n", crypto_blkdev); 1043 goto errout; 1044 } 1045 } 1046 1047 *size_already_done += size; 1048 rc = 0; 1049 1050errout: 1051 close(realfd); 1052 close(cryptofd); 1053 1054 return rc; 1055} 1056 1057#define CRYPTO_ENABLE_WIPE 1 1058#define CRYPTO_ENABLE_INPLACE 2 1059 1060#define FRAMEWORK_BOOT_WAIT 60 1061 1062static inline int should_encrypt(struct volume_info *volume) 1063{ 1064 return (volume->flags & (VOL_ENCRYPTABLE | VOL_NONREMOVABLE)) == 1065 (VOL_ENCRYPTABLE | VOL_NONREMOVABLE); 1066} 1067 1068int cryptfs_enable(char *howarg, char *passwd) 1069{ 1070 int how = 0; 1071 char crypto_blkdev[MAXPATHLEN], real_blkdev[MAXPATHLEN], sd_crypto_blkdev[MAXPATHLEN]; 1072 char fs_type[PROPERTY_VALUE_MAX], fs_options[PROPERTY_VALUE_MAX], 1073 mount_point[PROPERTY_VALUE_MAX]; 1074 unsigned long mnt_flags, nr_sec; 1075 unsigned char master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES]; 1076 unsigned char salt[SALT_LEN]; 1077 int rc=-1, fd, i, ret; 1078 struct crypt_mnt_ftr crypt_ftr, sd_crypt_ftr;; 1079 char tmpfs_options[PROPERTY_VALUE_MAX]; 1080 char encrypted_state[PROPERTY_VALUE_MAX]; 1081 char lockid[32] = { 0 }; 1082 char key_loc[PROPERTY_VALUE_MAX]; 1083 char fuse_sdcard[PROPERTY_VALUE_MAX]; 1084 char *sd_mnt_point; 1085 char sd_blk_dev[256] = { 0 }; 1086 int num_vols; 1087 struct volume_info *vol_list = 0; 1088 off64_t cur_encryption_done=0, tot_encryption_size=0; 1089 1090 property_get("ro.crypto.state", encrypted_state, ""); 1091 if (strcmp(encrypted_state, "unencrypted")) { 1092 SLOGE("Device is already running encrypted, aborting"); 1093 goto error_unencrypted; 1094 } 1095 1096 property_get(KEY_LOC_PROP, key_loc, KEY_IN_FOOTER); 1097 1098 if (!strcmp(howarg, "wipe")) { 1099 how = CRYPTO_ENABLE_WIPE; 1100 } else if (! strcmp(howarg, "inplace")) { 1101 how = CRYPTO_ENABLE_INPLACE; 1102 } else { 1103 /* Shouldn't happen, as CommandListener vets the args */ 1104 goto error_unencrypted; 1105 } 1106 1107 get_orig_mount_parms(mount_point, fs_type, real_blkdev, &mnt_flags, fs_options); 1108 1109 /* Get the size of the real block device */ 1110 fd = open(real_blkdev, O_RDONLY); 1111 if ( (nr_sec = get_blkdev_size(fd)) == 0) { 1112 SLOGE("Cannot get size of block device %s\n", real_blkdev); 1113 goto error_unencrypted; 1114 } 1115 close(fd); 1116 1117 /* If doing inplace encryption, make sure the orig fs doesn't include the crypto footer */ 1118 if ((how == CRYPTO_ENABLE_INPLACE) && (!strcmp(key_loc, KEY_IN_FOOTER))) { 1119 unsigned int fs_size_sec, max_fs_size_sec; 1120 1121 fs_size_sec = get_fs_size(real_blkdev); 1122 max_fs_size_sec = nr_sec - (CRYPT_FOOTER_OFFSET / 512); 1123 1124 if (fs_size_sec > max_fs_size_sec) { 1125 SLOGE("Orig filesystem overlaps crypto footer region. Cannot encrypt in place."); 1126 goto error_unencrypted; 1127 } 1128 } 1129 1130 /* Get a wakelock as this may take a while, and we don't want the 1131 * device to sleep on us. We'll grab a partial wakelock, and if the UI 1132 * wants to keep the screen on, it can grab a full wakelock. 1133 */ 1134 snprintf(lockid, sizeof(lockid), "enablecrypto%d", (int) getpid()); 1135 acquire_wake_lock(PARTIAL_WAKE_LOCK, lockid); 1136 1137 /* Get the sdcard mount point */ 1138 sd_mnt_point = getenv("EXTERNAL_STORAGE"); 1139 if (! sd_mnt_point) { 1140 sd_mnt_point = "/mnt/sdcard"; 1141 } 1142 1143 num_vols=vold_getNumDirectVolumes(); 1144 vol_list = malloc(sizeof(struct volume_info) * num_vols); 1145 vold_getDirectVolumeList(vol_list); 1146 1147 for (i=0; i<num_vols; i++) { 1148 if (should_encrypt(&vol_list[i])) { 1149 fd = open(vol_list[i].blk_dev, O_RDONLY); 1150 if ( (vol_list[i].size = get_blkdev_size(fd)) == 0) { 1151 SLOGE("Cannot get size of block device %s\n", vol_list[i].blk_dev); 1152 goto error_unencrypted; 1153 } 1154 close(fd); 1155 1156 ret=vold_disableVol(vol_list[i].label); 1157 if ((ret < 0) && (ret != UNMOUNT_NOT_MOUNTED_ERR)) { 1158 /* -2 is returned when the device exists but is not currently mounted. 1159 * ignore the error and continue. */ 1160 SLOGE("Failed to unmount volume %s\n", vol_list[i].label); 1161 goto error_unencrypted; 1162 } 1163 } 1164 } 1165 1166 /* The init files are setup to stop the class main and late start when 1167 * vold sets trigger_shutdown_framework. 1168 */ 1169 property_set("vold.decrypt", "trigger_shutdown_framework"); 1170 SLOGD("Just asked init to shut down class main\n"); 1171 1172 property_get("ro.crypto.fuse_sdcard", fuse_sdcard, ""); 1173 if (!strcmp(fuse_sdcard, "true")) { 1174 /* This is a device using the fuse layer to emulate the sdcard semantics 1175 * on top of the userdata partition. vold does not manage it, it is managed 1176 * by the sdcard service. The sdcard service was killed by the property trigger 1177 * above, so just unmount it now. We must do this _AFTER_ killing the framework, 1178 * unlike the case for vold managed devices above. 1179 */ 1180 if (wait_and_unmount(sd_mnt_point)) { 1181 goto error_shutting_down; 1182 } 1183 } 1184 1185 /* Now unmount the /data partition. */ 1186 if (wait_and_unmount(DATA_MNT_POINT)) { 1187 goto error_shutting_down; 1188 } 1189 1190 /* Do extra work for a better UX when doing the long inplace encryption */ 1191 if (how == CRYPTO_ENABLE_INPLACE) { 1192 /* Now that /data is unmounted, we need to mount a tmpfs 1193 * /data, set a property saying we're doing inplace encryption, 1194 * and restart the framework. 1195 */ 1196 property_get("ro.crypto.tmpfs_options", tmpfs_options, ""); 1197 if (mount("tmpfs", DATA_MNT_POINT, "tmpfs", MS_NOATIME | MS_NOSUID | MS_NODEV, 1198 tmpfs_options) < 0) { 1199 goto error_shutting_down; 1200 } 1201 /* Tells the framework that inplace encryption is starting */ 1202 property_set("vold.encrypt_progress", "0"); 1203 1204 /* restart the framework. */ 1205 /* Create necessary paths on /data */ 1206 if (prep_data_fs()) { 1207 goto error_shutting_down; 1208 } 1209 1210 /* startup service classes main and late_start */ 1211 property_set("vold.decrypt", "trigger_restart_min_framework"); 1212 SLOGD("Just triggered restart_min_framework\n"); 1213 1214 /* OK, the framework is restarted and will soon be showing a 1215 * progress bar. Time to setup an encrypted mapping, and 1216 * either write a new filesystem, or encrypt in place updating 1217 * the progress bar as we work. 1218 */ 1219 } 1220 1221 /* Start the actual work of making an encrypted filesystem */ 1222 /* Initialize a crypt_mnt_ftr for the partition */ 1223 cryptfs_init_crypt_mnt_ftr(&crypt_ftr); 1224 if (!strcmp(key_loc, KEY_IN_FOOTER)) { 1225 crypt_ftr.fs_size = nr_sec - (CRYPT_FOOTER_OFFSET / 512); 1226 } else { 1227 crypt_ftr.fs_size = nr_sec; 1228 } 1229 crypt_ftr.flags |= CRYPT_ENCRYPTION_IN_PROGRESS; 1230 strcpy((char *)crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256"); 1231 1232 /* Make an encrypted master key */ 1233 if (create_encrypted_random_key(passwd, master_key, salt)) { 1234 SLOGE("Cannot create encrypted master key\n"); 1235 goto error_unencrypted; 1236 } 1237 1238 /* Write the key to the end of the partition */ 1239 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, master_key, salt); 1240 1241 decrypt_master_key(passwd, salt, master_key, decrypted_master_key); 1242 create_crypto_blk_dev(&crypt_ftr, decrypted_master_key, real_blkdev, crypto_blkdev, 1243 "userdata"); 1244 1245 /* The size of the userdata partition, and add in the vold volumes below */ 1246 tot_encryption_size = crypt_ftr.fs_size; 1247 1248 /* setup crypto mapping for all encryptable volumes handled by vold */ 1249 for (i=0; i<num_vols; i++) { 1250 if (should_encrypt(&vol_list[i])) { 1251 vol_list[i].crypt_ftr = crypt_ftr; /* gotta love struct assign */ 1252 vol_list[i].crypt_ftr.fs_size = vol_list[i].size; 1253 create_crypto_blk_dev(&vol_list[i].crypt_ftr, decrypted_master_key, 1254 vol_list[i].blk_dev, vol_list[i].crypto_blkdev, 1255 vol_list[i].label); 1256 tot_encryption_size += vol_list[i].size; 1257 } 1258 } 1259 1260 if (how == CRYPTO_ENABLE_WIPE) { 1261 rc = cryptfs_enable_wipe(crypto_blkdev, crypt_ftr.fs_size, EXT4_FS); 1262 /* Encrypt all encryptable volumes handled by vold */ 1263 if (!rc) { 1264 for (i=0; i<num_vols; i++) { 1265 if (should_encrypt(&vol_list[i])) { 1266 rc = cryptfs_enable_wipe(vol_list[i].crypto_blkdev, 1267 vol_list[i].crypt_ftr.fs_size, FAT_FS); 1268 } 1269 } 1270 } 1271 } else if (how == CRYPTO_ENABLE_INPLACE) { 1272 rc = cryptfs_enable_inplace(crypto_blkdev, real_blkdev, crypt_ftr.fs_size, 1273 &cur_encryption_done, tot_encryption_size); 1274 /* Encrypt all encryptable volumes handled by vold */ 1275 if (!rc) { 1276 for (i=0; i<num_vols; i++) { 1277 if (should_encrypt(&vol_list[i])) { 1278 rc = cryptfs_enable_inplace(vol_list[i].crypto_blkdev, 1279 vol_list[i].blk_dev, 1280 vol_list[i].crypt_ftr.fs_size, 1281 &cur_encryption_done, tot_encryption_size); 1282 } 1283 } 1284 } 1285 if (!rc) { 1286 /* The inplace routine never actually sets the progress to 100% 1287 * due to the round down nature of integer division, so set it here */ 1288 property_set("vold.encrypt_progress", "100"); 1289 } 1290 } else { 1291 /* Shouldn't happen */ 1292 SLOGE("cryptfs_enable: internal error, unknown option\n"); 1293 goto error_unencrypted; 1294 } 1295 1296 /* Undo the dm-crypt mapping whether we succeed or not */ 1297 delete_crypto_blk_dev("userdata"); 1298 for (i=0; i<num_vols; i++) { 1299 if (should_encrypt(&vol_list[i])) { 1300 delete_crypto_blk_dev(vol_list[i].label); 1301 } 1302 } 1303 1304 free(vol_list); 1305 1306 if (! rc) { 1307 /* Success */ 1308 1309 /* Clear the encryption in progres flag in the footer */ 1310 crypt_ftr.flags &= ~CRYPT_ENCRYPTION_IN_PROGRESS; 1311 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, 0, 0); 1312 1313 sleep(2); /* Give the UI a chance to show 100% progress */ 1314 android_reboot(ANDROID_RB_RESTART, 0, 0); 1315 } else { 1316 property_set("vold.encrypt_progress", "error_partially_encrypted"); 1317 release_wake_lock(lockid); 1318 return -1; 1319 } 1320 1321 /* hrm, the encrypt step claims success, but the reboot failed. 1322 * This should not happen. 1323 * Set the property and return. Hope the framework can deal with it. 1324 */ 1325 property_set("vold.encrypt_progress", "error_reboot_failed"); 1326 release_wake_lock(lockid); 1327 return rc; 1328 1329error_unencrypted: 1330 free(vol_list); 1331 property_set("vold.encrypt_progress", "error_not_encrypted"); 1332 if (lockid[0]) { 1333 release_wake_lock(lockid); 1334 } 1335 return -1; 1336 1337error_shutting_down: 1338 /* we failed, and have not encrypted anthing, so the users's data is still intact, 1339 * but the framework is stopped and not restarted to show the error, so it's up to 1340 * vold to restart the system. 1341 */ 1342 SLOGE("Error enabling encryption after framework is shutdown, no data changed, restarting system"); 1343 android_reboot(ANDROID_RB_RESTART, 0, 0); 1344 1345 /* shouldn't get here */ 1346 property_set("vold.encrypt_progress", "error_shutting_down"); 1347 free(vol_list); 1348 if (lockid[0]) { 1349 release_wake_lock(lockid); 1350 } 1351 return -1; 1352} 1353 1354int cryptfs_changepw(char *newpw) 1355{ 1356 struct crypt_mnt_ftr crypt_ftr; 1357 unsigned char encrypted_master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES]; 1358 unsigned char salt[SALT_LEN]; 1359 char real_blkdev[MAXPATHLEN]; 1360 1361 /* This is only allowed after we've successfully decrypted the master key */ 1362 if (! master_key_saved) { 1363 SLOGE("Key not saved, aborting"); 1364 return -1; 1365 } 1366 1367 property_get("ro.crypto.fs_real_blkdev", real_blkdev, ""); 1368 if (strlen(real_blkdev) == 0) { 1369 SLOGE("Can't find real blkdev"); 1370 return -1; 1371 } 1372 1373 /* get key */ 1374 if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { 1375 SLOGE("Error getting crypt footer and key"); 1376 return -1; 1377 } 1378 1379 encrypt_master_key(newpw, salt, saved_master_key, encrypted_master_key); 1380 1381 /* save the key */ 1382 put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt); 1383 1384 return 0; 1385} 1386