Dees_Troy | 51a0e82 | 2012-09-05 15:24:24 -0400 | [diff] [blame] | 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/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 | char *me = "cryptfs"; |
| 63 | |
| 64 | static unsigned char saved_master_key[KEY_LEN_BYTES]; |
| 65 | static char *saved_data_blkdev; |
| 66 | static char *saved_mount_point; |
| 67 | static int master_key_saved = 0; |
| 68 | #define FSTAB_PREFIX "/fstab." |
| 69 | static char fstab_filename[PROPERTY_VALUE_MAX + sizeof(FSTAB_PREFIX)]; |
| 70 | |
| 71 | static 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 | |
| 85 | static 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 | |
| 116 | static 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 | */ |
| 130 | static 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 | */ |
| 143 | static 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 | |
| 236 | errout: |
| 237 | close(fd); |
| 238 | return rc; |
| 239 | |
| 240 | } |
| 241 | |
| 242 | static 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 | */ |
Dees_Troy | a13d74f | 2013-03-24 08:54:55 -0500 | [diff] [blame^] | 320 | if (lseek64(fd, crypt_ftr->ftr_size - sizeof(struct crypt_mnt_ftr), SEEK_CUR) == -1) { |
Dees_Troy | 51a0e82 | 2012-09-05 15:24:24 -0400 | [diff] [blame] | 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 | |
| 350 | errout: |
| 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 | */ |
| 358 | void 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 | |
| 378 | static 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 | |
| 446 | errout: |
| 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 | |
| 452 | static 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 | |
| 475 | errout: |
| 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 | |
| 482 | static 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 | |
| 489 | static 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 | |
| 526 | static 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 | |
| 558 | static 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 | |
| 575 | static 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 |
| 608 | static 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 | |
| 637 | int 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 | |
| 714 | static 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 | |
| 760 | static 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 | */ |
| 851 | int 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 | */ |
| 861 | int 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 | |
| 899 | int cryptfs_crypto_complete(void) |
| 900 | { |
| 901 | return do_crypto_complete("/data"); |
| 902 | } |
| 903 | |
| 904 | int 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 | |
| 913 | int 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 | */ |
| 969 | static 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 | |
| 983 | static 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 | |
| 1011 | static 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 | |
| 1018 | static 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) |
| 1027 | static 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 | |
| 1097 | errout: |
| 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 | |
| 1109 | static inline int should_encrypt(struct volume_info *volume) |
| 1110 | { |
| 1111 | return (volume->flags & (VOL_ENCRYPTABLE | VOL_NONREMOVABLE)) == |
| 1112 | (VOL_ENCRYPTABLE | VOL_NONREMOVABLE); |
| 1113 | } |
| 1114 | |
| 1115 | int cryptfs_enable(char *howarg, char *passwd) |
| 1116 | { |
| 1117 | // Code removed because it needs other parts of vold that aren't needed for decryption |
| 1118 | return -1; |
| 1119 | } |
| 1120 | |
| 1121 | int cryptfs_changepw(char *newpw) |
| 1122 | { |
| 1123 | struct crypt_mnt_ftr crypt_ftr; |
| 1124 | unsigned char encrypted_master_key[KEY_LEN_BYTES], decrypted_master_key[KEY_LEN_BYTES]; |
| 1125 | unsigned char salt[SALT_LEN]; |
| 1126 | char real_blkdev[MAXPATHLEN]; |
| 1127 | |
| 1128 | /* This is only allowed after we've successfully decrypted the master key */ |
| 1129 | if (! master_key_saved) { |
| 1130 | SLOGE("Key not saved, aborting"); |
| 1131 | return -1; |
| 1132 | } |
| 1133 | |
| 1134 | fs_mgr_get_crypt_info(get_fstab_filename(), 0, real_blkdev, sizeof(real_blkdev)); |
| 1135 | if (strlen(real_blkdev) == 0) { |
| 1136 | SLOGE("Can't find real blkdev"); |
| 1137 | return -1; |
| 1138 | } |
| 1139 | |
| 1140 | /* get key */ |
| 1141 | if (get_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt)) { |
| 1142 | SLOGE("Error getting crypt footer and key"); |
| 1143 | return -1; |
| 1144 | } |
| 1145 | |
| 1146 | encrypt_master_key(newpw, salt, saved_master_key, encrypted_master_key); |
| 1147 | |
| 1148 | /* save the key */ |
| 1149 | put_crypt_ftr_and_key(real_blkdev, &crypt_ftr, encrypted_master_key, salt); |
| 1150 | |
| 1151 | return 0; |
| 1152 | } |