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