1 /* 2 * Copyright (C) 2003 Jana Saout <jana@saout.de> 3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 4 * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved. 5 * Copyright (C) 2013-2017 Milan Broz <gmazyland@gmail.com> 6 * 7 * This file is released under the GPL. 8 */ 9 10 #include <linux/completion.h> 11 #include <linux/err.h> 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/key.h> 16 #include <linux/bio.h> 17 #include <linux/blkdev.h> 18 #include <linux/mempool.h> 19 #include <linux/slab.h> 20 #include <linux/crypto.h> 21 #include <linux/workqueue.h> 22 #include <linux/kthread.h> 23 #include <linux/backing-dev.h> 24 #include <linux/atomic.h> 25 #include <linux/scatterlist.h> 26 #include <linux/rbtree.h> 27 #include <linux/ctype.h> 28 #include <asm/page.h> 29 #include <asm/unaligned.h> 30 #include <crypto/hash.h> 31 #include <crypto/md5.h> 32 #include <crypto/algapi.h> 33 #include <crypto/skcipher.h> 34 #include <crypto/aead.h> 35 #include <crypto/authenc.h> 36 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ 37 #include <keys/user-type.h> 38 39 #include <linux/device-mapper.h> 40 41 #define DM_MSG_PREFIX "crypt" 42 43 /* 44 * context holding the current state of a multi-part conversion 45 */ 46 struct convert_context { 47 struct completion restart; 48 struct bio *bio_in; 49 struct bio *bio_out; 50 struct bvec_iter iter_in; 51 struct bvec_iter iter_out; 52 sector_t cc_sector; 53 atomic_t cc_pending; 54 union { 55 struct skcipher_request *req; 56 struct aead_request *req_aead; 57 } r; 58 59 }; 60 61 /* 62 * per bio private data 63 */ 64 struct dm_crypt_io { 65 struct crypt_config *cc; 66 struct bio *base_bio; 67 u8 *integrity_metadata; 68 bool integrity_metadata_from_pool; 69 struct work_struct work; 70 71 struct convert_context ctx; 72 73 atomic_t io_pending; 74 blk_status_t error; 75 sector_t sector; 76 77 struct rb_node rb_node; 78 } CRYPTO_MINALIGN_ATTR; 79 80 struct dm_crypt_request { 81 struct convert_context *ctx; 82 struct scatterlist sg_in[4]; 83 struct scatterlist sg_out[4]; 84 sector_t iv_sector; 85 }; 86 87 struct crypt_config; 88 89 struct crypt_iv_operations { 90 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 91 const char *opts); 92 void (*dtr)(struct crypt_config *cc); 93 int (*init)(struct crypt_config *cc); 94 int (*wipe)(struct crypt_config *cc); 95 int (*generator)(struct crypt_config *cc, u8 *iv, 96 struct dm_crypt_request *dmreq); 97 int (*post)(struct crypt_config *cc, u8 *iv, 98 struct dm_crypt_request *dmreq); 99 }; 100 101 struct iv_essiv_private { 102 struct crypto_ahash *hash_tfm; 103 u8 *salt; 104 }; 105 106 struct iv_benbi_private { 107 int shift; 108 }; 109 110 #define LMK_SEED_SIZE 64 /* hash + 0 */ 111 struct iv_lmk_private { 112 struct crypto_shash *hash_tfm; 113 u8 *seed; 114 }; 115 116 #define TCW_WHITENING_SIZE 16 117 struct iv_tcw_private { 118 struct crypto_shash *crc32_tfm; 119 u8 *iv_seed; 120 u8 *whitening; 121 }; 122 123 /* 124 * Crypt: maps a linear range of a block device 125 * and encrypts / decrypts at the same time. 126 */ 127 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, 128 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD }; 129 130 enum cipher_flags { 131 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */ 132 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ 133 }; 134 135 /* 136 * The fields in here must be read only after initialization. 137 */ 138 struct crypt_config { 139 struct dm_dev *dev; 140 sector_t start; 141 142 /* 143 * pool for per bio private data, crypto requests, 144 * encryption requeusts/buffer pages and integrity tags 145 */ 146 mempool_t *req_pool; 147 mempool_t *page_pool; 148 mempool_t *tag_pool; 149 unsigned tag_pool_max_sectors; 150 151 struct bio_set *bs; 152 struct mutex bio_alloc_lock; 153 154 struct workqueue_struct *io_queue; 155 struct workqueue_struct *crypt_queue; 156 157 struct task_struct *write_thread; 158 wait_queue_head_t write_thread_wait; 159 struct rb_root write_tree; 160 161 char *cipher; 162 char *cipher_string; 163 char *cipher_auth; 164 char *key_string; 165 166 const struct crypt_iv_operations *iv_gen_ops; 167 union { 168 struct iv_essiv_private essiv; 169 struct iv_benbi_private benbi; 170 struct iv_lmk_private lmk; 171 struct iv_tcw_private tcw; 172 } iv_gen_private; 173 sector_t iv_offset; 174 unsigned int iv_size; 175 unsigned short int sector_size; 176 unsigned char sector_shift; 177 178 /* ESSIV: struct crypto_cipher *essiv_tfm */ 179 void *iv_private; 180 union { 181 struct crypto_skcipher **tfms; 182 struct crypto_aead **tfms_aead; 183 } cipher_tfm; 184 unsigned tfms_count; 185 unsigned long cipher_flags; 186 187 /* 188 * Layout of each crypto request: 189 * 190 * struct skcipher_request 191 * context 192 * padding 193 * struct dm_crypt_request 194 * padding 195 * IV 196 * 197 * The padding is added so that dm_crypt_request and the IV are 198 * correctly aligned. 199 */ 200 unsigned int dmreq_start; 201 202 unsigned int per_bio_data_size; 203 204 unsigned long flags; 205 unsigned int key_size; 206 unsigned int key_parts; /* independent parts in key buffer */ 207 unsigned int key_extra_size; /* additional keys length */ 208 unsigned int key_mac_size; /* MAC key size for authenc(...) */ 209 210 unsigned int integrity_tag_size; 211 unsigned int integrity_iv_size; 212 unsigned int on_disk_tag_size; 213 214 u8 *authenc_key; /* space for keys in authenc() format (if used) */ 215 u8 key[0]; 216 }; 217 218 #define MIN_IOS 64 219 #define MAX_TAG_SIZE 480 220 #define POOL_ENTRY_SIZE 512 221 222 static void clone_init(struct dm_crypt_io *, struct bio *); 223 static void kcryptd_queue_crypt(struct dm_crypt_io *io); 224 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 225 struct scatterlist *sg); 226 227 /* 228 * Use this to access cipher attributes that are independent of the key. 229 */ 230 static struct crypto_skcipher *any_tfm(struct crypt_config *cc) 231 { 232 return cc->cipher_tfm.tfms[0]; 233 } 234 235 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) 236 { 237 return cc->cipher_tfm.tfms_aead[0]; 238 } 239 240 /* 241 * Different IV generation algorithms: 242 * 243 * plain: the initial vector is the 32-bit little-endian version of the sector 244 * number, padded with zeros if necessary. 245 * 246 * plain64: the initial vector is the 64-bit little-endian version of the sector 247 * number, padded with zeros if necessary. 248 * 249 * plain64be: the initial vector is the 64-bit big-endian version of the sector 250 * number, padded with zeros if necessary. 251 * 252 * essiv: "encrypted sector|salt initial vector", the sector number is 253 * encrypted with the bulk cipher using a salt as key. The salt 254 * should be derived from the bulk cipher's key via hashing. 255 * 256 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 257 * (needed for LRW-32-AES and possible other narrow block modes) 258 * 259 * null: the initial vector is always zero. Provides compatibility with 260 * obsolete loop_fish2 devices. Do not use for new devices. 261 * 262 * lmk: Compatible implementation of the block chaining mode used 263 * by the Loop-AES block device encryption system 264 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ 265 * It operates on full 512 byte sectors and uses CBC 266 * with an IV derived from the sector number, the data and 267 * optionally extra IV seed. 268 * This means that after decryption the first block 269 * of sector must be tweaked according to decrypted data. 270 * Loop-AES can use three encryption schemes: 271 * version 1: is plain aes-cbc mode 272 * version 2: uses 64 multikey scheme with lmk IV generator 273 * version 3: the same as version 2 with additional IV seed 274 * (it uses 65 keys, last key is used as IV seed) 275 * 276 * tcw: Compatible implementation of the block chaining mode used 277 * by the TrueCrypt device encryption system (prior to version 4.1). 278 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat 279 * It operates on full 512 byte sectors and uses CBC 280 * with an IV derived from initial key and the sector number. 281 * In addition, whitening value is applied on every sector, whitening 282 * is calculated from initial key, sector number and mixed using CRC32. 283 * Note that this encryption scheme is vulnerable to watermarking attacks 284 * and should be used for old compatible containers access only. 285 * 286 * plumb: unimplemented, see: 287 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 288 */ 289 290 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, 291 struct dm_crypt_request *dmreq) 292 { 293 memset(iv, 0, cc->iv_size); 294 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); 295 296 return 0; 297 } 298 299 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, 300 struct dm_crypt_request *dmreq) 301 { 302 memset(iv, 0, cc->iv_size); 303 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 304 305 return 0; 306 } 307 308 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, 309 struct dm_crypt_request *dmreq) 310 { 311 memset(iv, 0, cc->iv_size); 312 /* iv_size is at least of size u64; usually it is 16 bytes */ 313 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector); 314 315 return 0; 316 } 317 318 /* Initialise ESSIV - compute salt but no local memory allocations */ 319 static int crypt_iv_essiv_init(struct crypt_config *cc) 320 { 321 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; 322 AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm); 323 struct scatterlist sg; 324 struct crypto_cipher *essiv_tfm; 325 int err; 326 327 sg_init_one(&sg, cc->key, cc->key_size); 328 ahash_request_set_tfm(req, essiv->hash_tfm); 329 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); 330 ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size); 331 332 err = crypto_ahash_digest(req); 333 ahash_request_zero(req); 334 if (err) 335 return err; 336 337 essiv_tfm = cc->iv_private; 338 339 err = crypto_cipher_setkey(essiv_tfm, essiv->salt, 340 crypto_ahash_digestsize(essiv->hash_tfm)); 341 if (err) 342 return err; 343 344 return 0; 345 } 346 347 /* Wipe salt and reset key derived from volume key */ 348 static int crypt_iv_essiv_wipe(struct crypt_config *cc) 349 { 350 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; 351 unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm); 352 struct crypto_cipher *essiv_tfm; 353 int r, err = 0; 354 355 memset(essiv->salt, 0, salt_size); 356 357 essiv_tfm = cc->iv_private; 358 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size); 359 if (r) 360 err = r; 361 362 return err; 363 } 364 365 /* Allocate the cipher for ESSIV */ 366 static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc, 367 struct dm_target *ti, 368 const u8 *salt, 369 unsigned int saltsize) 370 { 371 struct crypto_cipher *essiv_tfm; 372 int err; 373 374 /* Setup the essiv_tfm with the given salt */ 375 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 376 if (IS_ERR(essiv_tfm)) { 377 ti->error = "Error allocating crypto tfm for ESSIV"; 378 return essiv_tfm; 379 } 380 381 if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) { 382 ti->error = "Block size of ESSIV cipher does " 383 "not match IV size of block cipher"; 384 crypto_free_cipher(essiv_tfm); 385 return ERR_PTR(-EINVAL); 386 } 387 388 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); 389 if (err) { 390 ti->error = "Failed to set key for ESSIV cipher"; 391 crypto_free_cipher(essiv_tfm); 392 return ERR_PTR(err); 393 } 394 395 return essiv_tfm; 396 } 397 398 static void crypt_iv_essiv_dtr(struct crypt_config *cc) 399 { 400 struct crypto_cipher *essiv_tfm; 401 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; 402 403 crypto_free_ahash(essiv->hash_tfm); 404 essiv->hash_tfm = NULL; 405 406 kzfree(essiv->salt); 407 essiv->salt = NULL; 408 409 essiv_tfm = cc->iv_private; 410 411 if (essiv_tfm) 412 crypto_free_cipher(essiv_tfm); 413 414 cc->iv_private = NULL; 415 } 416 417 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, 418 const char *opts) 419 { 420 struct crypto_cipher *essiv_tfm = NULL; 421 struct crypto_ahash *hash_tfm = NULL; 422 u8 *salt = NULL; 423 int err; 424 425 if (!opts) { 426 ti->error = "Digest algorithm missing for ESSIV mode"; 427 return -EINVAL; 428 } 429 430 /* Allocate hash algorithm */ 431 hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC); 432 if (IS_ERR(hash_tfm)) { 433 ti->error = "Error initializing ESSIV hash"; 434 err = PTR_ERR(hash_tfm); 435 goto bad; 436 } 437 438 salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL); 439 if (!salt) { 440 ti->error = "Error kmallocing salt storage in ESSIV"; 441 err = -ENOMEM; 442 goto bad; 443 } 444 445 cc->iv_gen_private.essiv.salt = salt; 446 cc->iv_gen_private.essiv.hash_tfm = hash_tfm; 447 448 essiv_tfm = alloc_essiv_cipher(cc, ti, salt, 449 crypto_ahash_digestsize(hash_tfm)); 450 if (IS_ERR(essiv_tfm)) { 451 crypt_iv_essiv_dtr(cc); 452 return PTR_ERR(essiv_tfm); 453 } 454 cc->iv_private = essiv_tfm; 455 456 return 0; 457 458 bad: 459 if (hash_tfm && !IS_ERR(hash_tfm)) 460 crypto_free_ahash(hash_tfm); 461 kfree(salt); 462 return err; 463 } 464 465 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 466 struct dm_crypt_request *dmreq) 467 { 468 struct crypto_cipher *essiv_tfm = cc->iv_private; 469 470 memset(iv, 0, cc->iv_size); 471 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 472 crypto_cipher_encrypt_one(essiv_tfm, iv, iv); 473 474 return 0; 475 } 476 477 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 478 const char *opts) 479 { 480 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc)); 481 int log = ilog2(bs); 482 483 /* we need to calculate how far we must shift the sector count 484 * to get the cipher block count, we use this shift in _gen */ 485 486 if (1 << log != bs) { 487 ti->error = "cypher blocksize is not a power of 2"; 488 return -EINVAL; 489 } 490 491 if (log > 9) { 492 ti->error = "cypher blocksize is > 512"; 493 return -EINVAL; 494 } 495 496 cc->iv_gen_private.benbi.shift = 9 - log; 497 498 return 0; 499 } 500 501 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 502 { 503 } 504 505 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 506 struct dm_crypt_request *dmreq) 507 { 508 __be64 val; 509 510 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 511 512 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 513 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 514 515 return 0; 516 } 517 518 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 519 struct dm_crypt_request *dmreq) 520 { 521 memset(iv, 0, cc->iv_size); 522 523 return 0; 524 } 525 526 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 527 { 528 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 529 530 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 531 crypto_free_shash(lmk->hash_tfm); 532 lmk->hash_tfm = NULL; 533 534 kzfree(lmk->seed); 535 lmk->seed = NULL; 536 } 537 538 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 539 const char *opts) 540 { 541 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 542 543 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 544 ti->error = "Unsupported sector size for LMK"; 545 return -EINVAL; 546 } 547 548 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); 549 if (IS_ERR(lmk->hash_tfm)) { 550 ti->error = "Error initializing LMK hash"; 551 return PTR_ERR(lmk->hash_tfm); 552 } 553 554 /* No seed in LMK version 2 */ 555 if (cc->key_parts == cc->tfms_count) { 556 lmk->seed = NULL; 557 return 0; 558 } 559 560 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 561 if (!lmk->seed) { 562 crypt_iv_lmk_dtr(cc); 563 ti->error = "Error kmallocing seed storage in LMK"; 564 return -ENOMEM; 565 } 566 567 return 0; 568 } 569 570 static int crypt_iv_lmk_init(struct crypt_config *cc) 571 { 572 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 573 int subkey_size = cc->key_size / cc->key_parts; 574 575 /* LMK seed is on the position of LMK_KEYS + 1 key */ 576 if (lmk->seed) 577 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 578 crypto_shash_digestsize(lmk->hash_tfm)); 579 580 return 0; 581 } 582 583 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 584 { 585 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 586 587 if (lmk->seed) 588 memset(lmk->seed, 0, LMK_SEED_SIZE); 589 590 return 0; 591 } 592 593 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 594 struct dm_crypt_request *dmreq, 595 u8 *data) 596 { 597 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 598 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 599 struct md5_state md5state; 600 __le32 buf[4]; 601 int i, r; 602 603 desc->tfm = lmk->hash_tfm; 604 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; 605 606 r = crypto_shash_init(desc); 607 if (r) 608 return r; 609 610 if (lmk->seed) { 611 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 612 if (r) 613 return r; 614 } 615 616 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 617 r = crypto_shash_update(desc, data + 16, 16 * 31); 618 if (r) 619 return r; 620 621 /* Sector is cropped to 56 bits here */ 622 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 623 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 624 buf[2] = cpu_to_le32(4024); 625 buf[3] = 0; 626 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 627 if (r) 628 return r; 629 630 /* No MD5 padding here */ 631 r = crypto_shash_export(desc, &md5state); 632 if (r) 633 return r; 634 635 for (i = 0; i < MD5_HASH_WORDS; i++) 636 __cpu_to_le32s(&md5state.hash[i]); 637 memcpy(iv, &md5state.hash, cc->iv_size); 638 639 return 0; 640 } 641 642 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 643 struct dm_crypt_request *dmreq) 644 { 645 struct scatterlist *sg; 646 u8 *src; 647 int r = 0; 648 649 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 650 sg = crypt_get_sg_data(cc, dmreq->sg_in); 651 src = kmap_atomic(sg_page(sg)); 652 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 653 kunmap_atomic(src); 654 } else 655 memset(iv, 0, cc->iv_size); 656 657 return r; 658 } 659 660 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 661 struct dm_crypt_request *dmreq) 662 { 663 struct scatterlist *sg; 664 u8 *dst; 665 int r; 666 667 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 668 return 0; 669 670 sg = crypt_get_sg_data(cc, dmreq->sg_out); 671 dst = kmap_atomic(sg_page(sg)); 672 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 673 674 /* Tweak the first block of plaintext sector */ 675 if (!r) 676 crypto_xor(dst + sg->offset, iv, cc->iv_size); 677 678 kunmap_atomic(dst); 679 return r; 680 } 681 682 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 683 { 684 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 685 686 kzfree(tcw->iv_seed); 687 tcw->iv_seed = NULL; 688 kzfree(tcw->whitening); 689 tcw->whitening = NULL; 690 691 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 692 crypto_free_shash(tcw->crc32_tfm); 693 tcw->crc32_tfm = NULL; 694 } 695 696 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 697 const char *opts) 698 { 699 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 700 701 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 702 ti->error = "Unsupported sector size for TCW"; 703 return -EINVAL; 704 } 705 706 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 707 ti->error = "Wrong key size for TCW"; 708 return -EINVAL; 709 } 710 711 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); 712 if (IS_ERR(tcw->crc32_tfm)) { 713 ti->error = "Error initializing CRC32 in TCW"; 714 return PTR_ERR(tcw->crc32_tfm); 715 } 716 717 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 718 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 719 if (!tcw->iv_seed || !tcw->whitening) { 720 crypt_iv_tcw_dtr(cc); 721 ti->error = "Error allocating seed storage in TCW"; 722 return -ENOMEM; 723 } 724 725 return 0; 726 } 727 728 static int crypt_iv_tcw_init(struct crypt_config *cc) 729 { 730 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 731 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 732 733 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 734 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 735 TCW_WHITENING_SIZE); 736 737 return 0; 738 } 739 740 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 741 { 742 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 743 744 memset(tcw->iv_seed, 0, cc->iv_size); 745 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 746 747 return 0; 748 } 749 750 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 751 struct dm_crypt_request *dmreq, 752 u8 *data) 753 { 754 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 755 __le64 sector = cpu_to_le64(dmreq->iv_sector); 756 u8 buf[TCW_WHITENING_SIZE]; 757 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 758 int i, r; 759 760 /* xor whitening with sector number */ 761 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 762 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 763 764 /* calculate crc32 for every 32bit part and xor it */ 765 desc->tfm = tcw->crc32_tfm; 766 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; 767 for (i = 0; i < 4; i++) { 768 r = crypto_shash_init(desc); 769 if (r) 770 goto out; 771 r = crypto_shash_update(desc, &buf[i * 4], 4); 772 if (r) 773 goto out; 774 r = crypto_shash_final(desc, &buf[i * 4]); 775 if (r) 776 goto out; 777 } 778 crypto_xor(&buf[0], &buf[12], 4); 779 crypto_xor(&buf[4], &buf[8], 4); 780 781 /* apply whitening (8 bytes) to whole sector */ 782 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 783 crypto_xor(data + i * 8, buf, 8); 784 out: 785 memzero_explicit(buf, sizeof(buf)); 786 return r; 787 } 788 789 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 790 struct dm_crypt_request *dmreq) 791 { 792 struct scatterlist *sg; 793 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 794 __le64 sector = cpu_to_le64(dmreq->iv_sector); 795 u8 *src; 796 int r = 0; 797 798 /* Remove whitening from ciphertext */ 799 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 800 sg = crypt_get_sg_data(cc, dmreq->sg_in); 801 src = kmap_atomic(sg_page(sg)); 802 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 803 kunmap_atomic(src); 804 } 805 806 /* Calculate IV */ 807 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 808 if (cc->iv_size > 8) 809 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 810 cc->iv_size - 8); 811 812 return r; 813 } 814 815 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 816 struct dm_crypt_request *dmreq) 817 { 818 struct scatterlist *sg; 819 u8 *dst; 820 int r; 821 822 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 823 return 0; 824 825 /* Apply whitening on ciphertext */ 826 sg = crypt_get_sg_data(cc, dmreq->sg_out); 827 dst = kmap_atomic(sg_page(sg)); 828 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 829 kunmap_atomic(dst); 830 831 return r; 832 } 833 834 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 835 struct dm_crypt_request *dmreq) 836 { 837 /* Used only for writes, there must be an additional space to store IV */ 838 get_random_bytes(iv, cc->iv_size); 839 return 0; 840 } 841 842 static const struct crypt_iv_operations crypt_iv_plain_ops = { 843 .generator = crypt_iv_plain_gen 844 }; 845 846 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 847 .generator = crypt_iv_plain64_gen 848 }; 849 850 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 851 .generator = crypt_iv_plain64be_gen 852 }; 853 854 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 855 .ctr = crypt_iv_essiv_ctr, 856 .dtr = crypt_iv_essiv_dtr, 857 .init = crypt_iv_essiv_init, 858 .wipe = crypt_iv_essiv_wipe, 859 .generator = crypt_iv_essiv_gen 860 }; 861 862 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 863 .ctr = crypt_iv_benbi_ctr, 864 .dtr = crypt_iv_benbi_dtr, 865 .generator = crypt_iv_benbi_gen 866 }; 867 868 static const struct crypt_iv_operations crypt_iv_null_ops = { 869 .generator = crypt_iv_null_gen 870 }; 871 872 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 873 .ctr = crypt_iv_lmk_ctr, 874 .dtr = crypt_iv_lmk_dtr, 875 .init = crypt_iv_lmk_init, 876 .wipe = crypt_iv_lmk_wipe, 877 .generator = crypt_iv_lmk_gen, 878 .post = crypt_iv_lmk_post 879 }; 880 881 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 882 .ctr = crypt_iv_tcw_ctr, 883 .dtr = crypt_iv_tcw_dtr, 884 .init = crypt_iv_tcw_init, 885 .wipe = crypt_iv_tcw_wipe, 886 .generator = crypt_iv_tcw_gen, 887 .post = crypt_iv_tcw_post 888 }; 889 890 static struct crypt_iv_operations crypt_iv_random_ops = { 891 .generator = crypt_iv_random_gen 892 }; 893 894 /* 895 * Integrity extensions 896 */ 897 static bool crypt_integrity_aead(struct crypt_config *cc) 898 { 899 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 900 } 901 902 static bool crypt_integrity_hmac(struct crypt_config *cc) 903 { 904 return crypt_integrity_aead(cc) && cc->key_mac_size; 905 } 906 907 /* Get sg containing data */ 908 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 909 struct scatterlist *sg) 910 { 911 if (unlikely(crypt_integrity_aead(cc))) 912 return &sg[2]; 913 914 return sg; 915 } 916 917 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 918 { 919 struct bio_integrity_payload *bip; 920 unsigned int tag_len; 921 int ret; 922 923 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 924 return 0; 925 926 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 927 if (IS_ERR(bip)) 928 return PTR_ERR(bip); 929 930 tag_len = io->cc->on_disk_tag_size * bio_sectors(bio); 931 932 bip->bip_iter.bi_size = tag_len; 933 bip->bip_iter.bi_sector = io->cc->start + io->sector; 934 935 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 936 tag_len, offset_in_page(io->integrity_metadata)); 937 if (unlikely(ret != tag_len)) 938 return -ENOMEM; 939 940 return 0; 941 } 942 943 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 944 { 945 #ifdef CONFIG_BLK_DEV_INTEGRITY 946 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 947 948 /* From now we require underlying device with our integrity profile */ 949 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 950 ti->error = "Integrity profile not supported."; 951 return -EINVAL; 952 } 953 954 if (bi->tag_size != cc->on_disk_tag_size || 955 bi->tuple_size != cc->on_disk_tag_size) { 956 ti->error = "Integrity profile tag size mismatch."; 957 return -EINVAL; 958 } 959 if (1 << bi->interval_exp != cc->sector_size) { 960 ti->error = "Integrity profile sector size mismatch."; 961 return -EINVAL; 962 } 963 964 if (crypt_integrity_aead(cc)) { 965 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 966 DMINFO("Integrity AEAD, tag size %u, IV size %u.", 967 cc->integrity_tag_size, cc->integrity_iv_size); 968 969 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 970 ti->error = "Integrity AEAD auth tag size is not supported."; 971 return -EINVAL; 972 } 973 } else if (cc->integrity_iv_size) 974 DMINFO("Additional per-sector space %u bytes for IV.", 975 cc->integrity_iv_size); 976 977 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 978 ti->error = "Not enough space for integrity tag in the profile."; 979 return -EINVAL; 980 } 981 982 return 0; 983 #else 984 ti->error = "Integrity profile not supported."; 985 return -EINVAL; 986 #endif 987 } 988 989 static void crypt_convert_init(struct crypt_config *cc, 990 struct convert_context *ctx, 991 struct bio *bio_out, struct bio *bio_in, 992 sector_t sector) 993 { 994 ctx->bio_in = bio_in; 995 ctx->bio_out = bio_out; 996 if (bio_in) 997 ctx->iter_in = bio_in->bi_iter; 998 if (bio_out) 999 ctx->iter_out = bio_out->bi_iter; 1000 ctx->cc_sector = sector + cc->iv_offset; 1001 init_completion(&ctx->restart); 1002 } 1003 1004 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1005 void *req) 1006 { 1007 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1008 } 1009 1010 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1011 { 1012 return (void *)((char *)dmreq - cc->dmreq_start); 1013 } 1014 1015 static u8 *iv_of_dmreq(struct crypt_config *cc, 1016 struct dm_crypt_request *dmreq) 1017 { 1018 if (crypt_integrity_aead(cc)) 1019 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1020 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1021 else 1022 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1023 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1024 } 1025 1026 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1027 struct dm_crypt_request *dmreq) 1028 { 1029 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1030 } 1031 1032 static uint64_t *org_sector_of_dmreq(struct crypt_config *cc, 1033 struct dm_crypt_request *dmreq) 1034 { 1035 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1036 return (uint64_t*) ptr; 1037 } 1038 1039 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1040 struct dm_crypt_request *dmreq) 1041 { 1042 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1043 cc->iv_size + sizeof(uint64_t); 1044 return (unsigned int*)ptr; 1045 } 1046 1047 static void *tag_from_dmreq(struct crypt_config *cc, 1048 struct dm_crypt_request *dmreq) 1049 { 1050 struct convert_context *ctx = dmreq->ctx; 1051 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1052 1053 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1054 cc->on_disk_tag_size]; 1055 } 1056 1057 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1058 struct dm_crypt_request *dmreq) 1059 { 1060 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1061 } 1062 1063 static int crypt_convert_block_aead(struct crypt_config *cc, 1064 struct convert_context *ctx, 1065 struct aead_request *req, 1066 unsigned int tag_offset) 1067 { 1068 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1069 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1070 struct dm_crypt_request *dmreq; 1071 u8 *iv, *org_iv, *tag_iv, *tag; 1072 uint64_t *sector; 1073 int r = 0; 1074 1075 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1076 1077 /* Reject unexpected unaligned bio. */ 1078 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1079 return -EIO; 1080 1081 dmreq = dmreq_of_req(cc, req); 1082 dmreq->iv_sector = ctx->cc_sector; 1083 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1084 dmreq->iv_sector >>= cc->sector_shift; 1085 dmreq->ctx = ctx; 1086 1087 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1088 1089 sector = org_sector_of_dmreq(cc, dmreq); 1090 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1091 1092 iv = iv_of_dmreq(cc, dmreq); 1093 org_iv = org_iv_of_dmreq(cc, dmreq); 1094 tag = tag_from_dmreq(cc, dmreq); 1095 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1096 1097 /* AEAD request: 1098 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1099 * | (authenticated) | (auth+encryption) | | 1100 * | sector_LE | IV | sector in/out | tag in/out | 1101 */ 1102 sg_init_table(dmreq->sg_in, 4); 1103 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1104 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1105 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1106 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1107 1108 sg_init_table(dmreq->sg_out, 4); 1109 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1110 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1111 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1112 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1113 1114 if (cc->iv_gen_ops) { 1115 /* For READs use IV stored in integrity metadata */ 1116 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1117 memcpy(org_iv, tag_iv, cc->iv_size); 1118 } else { 1119 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1120 if (r < 0) 1121 return r; 1122 /* Store generated IV in integrity metadata */ 1123 if (cc->integrity_iv_size) 1124 memcpy(tag_iv, org_iv, cc->iv_size); 1125 } 1126 /* Working copy of IV, to be modified in crypto API */ 1127 memcpy(iv, org_iv, cc->iv_size); 1128 } 1129 1130 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1131 if (bio_data_dir(ctx->bio_in) == WRITE) { 1132 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1133 cc->sector_size, iv); 1134 r = crypto_aead_encrypt(req); 1135 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1136 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1137 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1138 } else { 1139 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1140 cc->sector_size + cc->integrity_tag_size, iv); 1141 r = crypto_aead_decrypt(req); 1142 } 1143 1144 if (r == -EBADMSG) 1145 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu", 1146 (unsigned long long)le64_to_cpu(*sector)); 1147 1148 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1149 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1150 1151 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1152 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1153 1154 return r; 1155 } 1156 1157 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1158 struct convert_context *ctx, 1159 struct skcipher_request *req, 1160 unsigned int tag_offset) 1161 { 1162 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1163 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1164 struct scatterlist *sg_in, *sg_out; 1165 struct dm_crypt_request *dmreq; 1166 u8 *iv, *org_iv, *tag_iv; 1167 uint64_t *sector; 1168 int r = 0; 1169 1170 /* Reject unexpected unaligned bio. */ 1171 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1172 return -EIO; 1173 1174 dmreq = dmreq_of_req(cc, req); 1175 dmreq->iv_sector = ctx->cc_sector; 1176 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1177 dmreq->iv_sector >>= cc->sector_shift; 1178 dmreq->ctx = ctx; 1179 1180 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1181 1182 iv = iv_of_dmreq(cc, dmreq); 1183 org_iv = org_iv_of_dmreq(cc, dmreq); 1184 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1185 1186 sector = org_sector_of_dmreq(cc, dmreq); 1187 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1188 1189 /* For skcipher we use only the first sg item */ 1190 sg_in = &dmreq->sg_in[0]; 1191 sg_out = &dmreq->sg_out[0]; 1192 1193 sg_init_table(sg_in, 1); 1194 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1195 1196 sg_init_table(sg_out, 1); 1197 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1198 1199 if (cc->iv_gen_ops) { 1200 /* For READs use IV stored in integrity metadata */ 1201 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1202 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1203 } else { 1204 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1205 if (r < 0) 1206 return r; 1207 /* Store generated IV in integrity metadata */ 1208 if (cc->integrity_iv_size) 1209 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1210 } 1211 /* Working copy of IV, to be modified in crypto API */ 1212 memcpy(iv, org_iv, cc->iv_size); 1213 } 1214 1215 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1216 1217 if (bio_data_dir(ctx->bio_in) == WRITE) 1218 r = crypto_skcipher_encrypt(req); 1219 else 1220 r = crypto_skcipher_decrypt(req); 1221 1222 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1223 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1224 1225 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1226 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1227 1228 return r; 1229 } 1230 1231 static void kcryptd_async_done(struct crypto_async_request *async_req, 1232 int error); 1233 1234 static void crypt_alloc_req_skcipher(struct crypt_config *cc, 1235 struct convert_context *ctx) 1236 { 1237 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); 1238 1239 if (!ctx->r.req) 1240 ctx->r.req = mempool_alloc(cc->req_pool, GFP_NOIO); 1241 1242 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1243 1244 /* 1245 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1246 * requests if driver request queue is full. 1247 */ 1248 skcipher_request_set_callback(ctx->r.req, 1249 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, 1250 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1251 } 1252 1253 static void crypt_alloc_req_aead(struct crypt_config *cc, 1254 struct convert_context *ctx) 1255 { 1256 if (!ctx->r.req_aead) 1257 ctx->r.req_aead = mempool_alloc(cc->req_pool, GFP_NOIO); 1258 1259 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1260 1261 /* 1262 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1263 * requests if driver request queue is full. 1264 */ 1265 aead_request_set_callback(ctx->r.req_aead, 1266 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, 1267 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1268 } 1269 1270 static void crypt_alloc_req(struct crypt_config *cc, 1271 struct convert_context *ctx) 1272 { 1273 if (crypt_integrity_aead(cc)) 1274 crypt_alloc_req_aead(cc, ctx); 1275 else 1276 crypt_alloc_req_skcipher(cc, ctx); 1277 } 1278 1279 static void crypt_free_req_skcipher(struct crypt_config *cc, 1280 struct skcipher_request *req, struct bio *base_bio) 1281 { 1282 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1283 1284 if ((struct skcipher_request *)(io + 1) != req) 1285 mempool_free(req, cc->req_pool); 1286 } 1287 1288 static void crypt_free_req_aead(struct crypt_config *cc, 1289 struct aead_request *req, struct bio *base_bio) 1290 { 1291 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1292 1293 if ((struct aead_request *)(io + 1) != req) 1294 mempool_free(req, cc->req_pool); 1295 } 1296 1297 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1298 { 1299 if (crypt_integrity_aead(cc)) 1300 crypt_free_req_aead(cc, req, base_bio); 1301 else 1302 crypt_free_req_skcipher(cc, req, base_bio); 1303 } 1304 1305 /* 1306 * Encrypt / decrypt data from one bio to another one (can be the same one) 1307 */ 1308 static blk_status_t crypt_convert(struct crypt_config *cc, 1309 struct convert_context *ctx) 1310 { 1311 unsigned int tag_offset = 0; 1312 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1313 int r; 1314 1315 atomic_set(&ctx->cc_pending, 1); 1316 1317 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1318 1319 crypt_alloc_req(cc, ctx); 1320 atomic_inc(&ctx->cc_pending); 1321 1322 if (crypt_integrity_aead(cc)) 1323 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1324 else 1325 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1326 1327 switch (r) { 1328 /* 1329 * The request was queued by a crypto driver 1330 * but the driver request queue is full, let's wait. 1331 */ 1332 case -EBUSY: 1333 wait_for_completion(&ctx->restart); 1334 reinit_completion(&ctx->restart); 1335 /* fall through */ 1336 /* 1337 * The request is queued and processed asynchronously, 1338 * completion function kcryptd_async_done() will be called. 1339 */ 1340 case -EINPROGRESS: 1341 ctx->r.req = NULL; 1342 ctx->cc_sector += sector_step; 1343 tag_offset++; 1344 continue; 1345 /* 1346 * The request was already processed (synchronously). 1347 */ 1348 case 0: 1349 atomic_dec(&ctx->cc_pending); 1350 ctx->cc_sector += sector_step; 1351 tag_offset++; 1352 cond_resched(); 1353 continue; 1354 /* 1355 * There was a data integrity error. 1356 */ 1357 case -EBADMSG: 1358 atomic_dec(&ctx->cc_pending); 1359 return BLK_STS_PROTECTION; 1360 /* 1361 * There was an error while processing the request. 1362 */ 1363 default: 1364 atomic_dec(&ctx->cc_pending); 1365 return BLK_STS_IOERR; 1366 } 1367 } 1368 1369 return 0; 1370 } 1371 1372 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1373 1374 /* 1375 * Generate a new unfragmented bio with the given size 1376 * This should never violate the device limitations (but only because 1377 * max_segment_size is being constrained to PAGE_SIZE). 1378 * 1379 * This function may be called concurrently. If we allocate from the mempool 1380 * concurrently, there is a possibility of deadlock. For example, if we have 1381 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1382 * the mempool concurrently, it may deadlock in a situation where both processes 1383 * have allocated 128 pages and the mempool is exhausted. 1384 * 1385 * In order to avoid this scenario we allocate the pages under a mutex. 1386 * 1387 * In order to not degrade performance with excessive locking, we try 1388 * non-blocking allocations without a mutex first but on failure we fallback 1389 * to blocking allocations with a mutex. 1390 */ 1391 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 1392 { 1393 struct crypt_config *cc = io->cc; 1394 struct bio *clone; 1395 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1396 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1397 unsigned i, len, remaining_size; 1398 struct page *page; 1399 1400 retry: 1401 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1402 mutex_lock(&cc->bio_alloc_lock); 1403 1404 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); 1405 if (!clone) 1406 goto out; 1407 1408 clone_init(io, clone); 1409 1410 remaining_size = size; 1411 1412 for (i = 0; i < nr_iovecs; i++) { 1413 page = mempool_alloc(cc->page_pool, gfp_mask); 1414 if (!page) { 1415 crypt_free_buffer_pages(cc, clone); 1416 bio_put(clone); 1417 gfp_mask |= __GFP_DIRECT_RECLAIM; 1418 goto retry; 1419 } 1420 1421 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1422 1423 bio_add_page(clone, page, len, 0); 1424 1425 remaining_size -= len; 1426 } 1427 1428 /* Allocate space for integrity tags */ 1429 if (dm_crypt_integrity_io_alloc(io, clone)) { 1430 crypt_free_buffer_pages(cc, clone); 1431 bio_put(clone); 1432 clone = NULL; 1433 } 1434 out: 1435 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1436 mutex_unlock(&cc->bio_alloc_lock); 1437 1438 return clone; 1439 } 1440 1441 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1442 { 1443 unsigned int i; 1444 struct bio_vec *bv; 1445 1446 bio_for_each_segment_all(bv, clone, i) { 1447 BUG_ON(!bv->bv_page); 1448 mempool_free(bv->bv_page, cc->page_pool); 1449 } 1450 } 1451 1452 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1453 struct bio *bio, sector_t sector) 1454 { 1455 io->cc = cc; 1456 io->base_bio = bio; 1457 io->sector = sector; 1458 io->error = 0; 1459 io->ctx.r.req = NULL; 1460 io->integrity_metadata = NULL; 1461 io->integrity_metadata_from_pool = false; 1462 atomic_set(&io->io_pending, 0); 1463 } 1464 1465 static void crypt_inc_pending(struct dm_crypt_io *io) 1466 { 1467 atomic_inc(&io->io_pending); 1468 } 1469 1470 /* 1471 * One of the bios was finished. Check for completion of 1472 * the whole request and correctly clean up the buffer. 1473 */ 1474 static void crypt_dec_pending(struct dm_crypt_io *io) 1475 { 1476 struct crypt_config *cc = io->cc; 1477 struct bio *base_bio = io->base_bio; 1478 blk_status_t error = io->error; 1479 1480 if (!atomic_dec_and_test(&io->io_pending)) 1481 return; 1482 1483 if (io->ctx.r.req) 1484 crypt_free_req(cc, io->ctx.r.req, base_bio); 1485 1486 if (unlikely(io->integrity_metadata_from_pool)) 1487 mempool_free(io->integrity_metadata, io->cc->tag_pool); 1488 else 1489 kfree(io->integrity_metadata); 1490 1491 base_bio->bi_status = error; 1492 bio_endio(base_bio); 1493 } 1494 1495 /* 1496 * kcryptd/kcryptd_io: 1497 * 1498 * Needed because it would be very unwise to do decryption in an 1499 * interrupt context. 1500 * 1501 * kcryptd performs the actual encryption or decryption. 1502 * 1503 * kcryptd_io performs the IO submission. 1504 * 1505 * They must be separated as otherwise the final stages could be 1506 * starved by new requests which can block in the first stages due 1507 * to memory allocation. 1508 * 1509 * The work is done per CPU global for all dm-crypt instances. 1510 * They should not depend on each other and do not block. 1511 */ 1512 static void crypt_endio(struct bio *clone) 1513 { 1514 struct dm_crypt_io *io = clone->bi_private; 1515 struct crypt_config *cc = io->cc; 1516 unsigned rw = bio_data_dir(clone); 1517 blk_status_t error; 1518 1519 /* 1520 * free the processed pages 1521 */ 1522 if (rw == WRITE) 1523 crypt_free_buffer_pages(cc, clone); 1524 1525 error = clone->bi_status; 1526 bio_put(clone); 1527 1528 if (rw == READ && !error) { 1529 kcryptd_queue_crypt(io); 1530 return; 1531 } 1532 1533 if (unlikely(error)) 1534 io->error = error; 1535 1536 crypt_dec_pending(io); 1537 } 1538 1539 static void clone_init(struct dm_crypt_io *io, struct bio *clone) 1540 { 1541 struct crypt_config *cc = io->cc; 1542 1543 clone->bi_private = io; 1544 clone->bi_end_io = crypt_endio; 1545 bio_set_dev(clone, cc->dev->bdev); 1546 clone->bi_opf = io->base_bio->bi_opf; 1547 } 1548 1549 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1550 { 1551 struct crypt_config *cc = io->cc; 1552 struct bio *clone; 1553 1554 /* 1555 * We need the original biovec array in order to decrypt 1556 * the whole bio data *afterwards* -- thanks to immutable 1557 * biovecs we don't need to worry about the block layer 1558 * modifying the biovec array; so leverage bio_clone_fast(). 1559 */ 1560 clone = bio_clone_fast(io->base_bio, gfp, cc->bs); 1561 if (!clone) 1562 return 1; 1563 1564 crypt_inc_pending(io); 1565 1566 clone_init(io, clone); 1567 clone->bi_iter.bi_sector = cc->start + io->sector; 1568 1569 if (dm_crypt_integrity_io_alloc(io, clone)) { 1570 crypt_dec_pending(io); 1571 bio_put(clone); 1572 return 1; 1573 } 1574 1575 generic_make_request(clone); 1576 return 0; 1577 } 1578 1579 static void kcryptd_io_read_work(struct work_struct *work) 1580 { 1581 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1582 1583 crypt_inc_pending(io); 1584 if (kcryptd_io_read(io, GFP_NOIO)) 1585 io->error = BLK_STS_RESOURCE; 1586 crypt_dec_pending(io); 1587 } 1588 1589 static void kcryptd_queue_read(struct dm_crypt_io *io) 1590 { 1591 struct crypt_config *cc = io->cc; 1592 1593 INIT_WORK(&io->work, kcryptd_io_read_work); 1594 queue_work(cc->io_queue, &io->work); 1595 } 1596 1597 static void kcryptd_io_write(struct dm_crypt_io *io) 1598 { 1599 struct bio *clone = io->ctx.bio_out; 1600 1601 generic_make_request(clone); 1602 } 1603 1604 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1605 1606 static int dmcrypt_write(void *data) 1607 { 1608 struct crypt_config *cc = data; 1609 struct dm_crypt_io *io; 1610 1611 while (1) { 1612 struct rb_root write_tree; 1613 struct blk_plug plug; 1614 1615 DECLARE_WAITQUEUE(wait, current); 1616 1617 spin_lock_irq(&cc->write_thread_wait.lock); 1618 continue_locked: 1619 1620 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1621 goto pop_from_list; 1622 1623 set_current_state(TASK_INTERRUPTIBLE); 1624 __add_wait_queue(&cc->write_thread_wait, &wait); 1625 1626 spin_unlock_irq(&cc->write_thread_wait.lock); 1627 1628 if (unlikely(kthread_should_stop())) { 1629 set_current_state(TASK_RUNNING); 1630 remove_wait_queue(&cc->write_thread_wait, &wait); 1631 break; 1632 } 1633 1634 schedule(); 1635 1636 set_current_state(TASK_RUNNING); 1637 spin_lock_irq(&cc->write_thread_wait.lock); 1638 __remove_wait_queue(&cc->write_thread_wait, &wait); 1639 goto continue_locked; 1640 1641 pop_from_list: 1642 write_tree = cc->write_tree; 1643 cc->write_tree = RB_ROOT; 1644 spin_unlock_irq(&cc->write_thread_wait.lock); 1645 1646 BUG_ON(rb_parent(write_tree.rb_node)); 1647 1648 /* 1649 * Note: we cannot walk the tree here with rb_next because 1650 * the structures may be freed when kcryptd_io_write is called. 1651 */ 1652 blk_start_plug(&plug); 1653 do { 1654 io = crypt_io_from_node(rb_first(&write_tree)); 1655 rb_erase(&io->rb_node, &write_tree); 1656 kcryptd_io_write(io); 1657 } while (!RB_EMPTY_ROOT(&write_tree)); 1658 blk_finish_plug(&plug); 1659 } 1660 return 0; 1661 } 1662 1663 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1664 { 1665 struct bio *clone = io->ctx.bio_out; 1666 struct crypt_config *cc = io->cc; 1667 unsigned long flags; 1668 sector_t sector; 1669 struct rb_node **rbp, *parent; 1670 1671 if (unlikely(io->error)) { 1672 crypt_free_buffer_pages(cc, clone); 1673 bio_put(clone); 1674 crypt_dec_pending(io); 1675 return; 1676 } 1677 1678 /* crypt_convert should have filled the clone bio */ 1679 BUG_ON(io->ctx.iter_out.bi_size); 1680 1681 clone->bi_iter.bi_sector = cc->start + io->sector; 1682 1683 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) { 1684 generic_make_request(clone); 1685 return; 1686 } 1687 1688 spin_lock_irqsave(&cc->write_thread_wait.lock, flags); 1689 rbp = &cc->write_tree.rb_node; 1690 parent = NULL; 1691 sector = io->sector; 1692 while (*rbp) { 1693 parent = *rbp; 1694 if (sector < crypt_io_from_node(parent)->sector) 1695 rbp = &(*rbp)->rb_left; 1696 else 1697 rbp = &(*rbp)->rb_right; 1698 } 1699 rb_link_node(&io->rb_node, parent, rbp); 1700 rb_insert_color(&io->rb_node, &cc->write_tree); 1701 1702 wake_up_locked(&cc->write_thread_wait); 1703 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags); 1704 } 1705 1706 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 1707 { 1708 struct crypt_config *cc = io->cc; 1709 struct bio *clone; 1710 int crypt_finished; 1711 sector_t sector = io->sector; 1712 blk_status_t r; 1713 1714 /* 1715 * Prevent io from disappearing until this function completes. 1716 */ 1717 crypt_inc_pending(io); 1718 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); 1719 1720 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 1721 if (unlikely(!clone)) { 1722 io->error = BLK_STS_IOERR; 1723 goto dec; 1724 } 1725 1726 io->ctx.bio_out = clone; 1727 io->ctx.iter_out = clone->bi_iter; 1728 1729 sector += bio_sectors(clone); 1730 1731 crypt_inc_pending(io); 1732 r = crypt_convert(cc, &io->ctx); 1733 if (r) 1734 io->error = r; 1735 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending); 1736 1737 /* Encryption was already finished, submit io now */ 1738 if (crypt_finished) { 1739 kcryptd_crypt_write_io_submit(io, 0); 1740 io->sector = sector; 1741 } 1742 1743 dec: 1744 crypt_dec_pending(io); 1745 } 1746 1747 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 1748 { 1749 crypt_dec_pending(io); 1750 } 1751 1752 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 1753 { 1754 struct crypt_config *cc = io->cc; 1755 blk_status_t r; 1756 1757 crypt_inc_pending(io); 1758 1759 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 1760 io->sector); 1761 1762 r = crypt_convert(cc, &io->ctx); 1763 if (r) 1764 io->error = r; 1765 1766 if (atomic_dec_and_test(&io->ctx.cc_pending)) 1767 kcryptd_crypt_read_done(io); 1768 1769 crypt_dec_pending(io); 1770 } 1771 1772 static void kcryptd_async_done(struct crypto_async_request *async_req, 1773 int error) 1774 { 1775 struct dm_crypt_request *dmreq = async_req->data; 1776 struct convert_context *ctx = dmreq->ctx; 1777 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1778 struct crypt_config *cc = io->cc; 1779 1780 /* 1781 * A request from crypto driver backlog is going to be processed now, 1782 * finish the completion and continue in crypt_convert(). 1783 * (Callback will be called for the second time for this request.) 1784 */ 1785 if (error == -EINPROGRESS) { 1786 complete(&ctx->restart); 1787 return; 1788 } 1789 1790 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 1791 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 1792 1793 if (error == -EBADMSG) { 1794 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu", 1795 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); 1796 io->error = BLK_STS_PROTECTION; 1797 } else if (error < 0) 1798 io->error = BLK_STS_IOERR; 1799 1800 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 1801 1802 if (!atomic_dec_and_test(&ctx->cc_pending)) 1803 return; 1804 1805 if (bio_data_dir(io->base_bio) == READ) 1806 kcryptd_crypt_read_done(io); 1807 else 1808 kcryptd_crypt_write_io_submit(io, 1); 1809 } 1810 1811 static void kcryptd_crypt(struct work_struct *work) 1812 { 1813 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1814 1815 if (bio_data_dir(io->base_bio) == READ) 1816 kcryptd_crypt_read_convert(io); 1817 else 1818 kcryptd_crypt_write_convert(io); 1819 } 1820 1821 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 1822 { 1823 struct crypt_config *cc = io->cc; 1824 1825 INIT_WORK(&io->work, kcryptd_crypt); 1826 queue_work(cc->crypt_queue, &io->work); 1827 } 1828 1829 static void crypt_free_tfms_aead(struct crypt_config *cc) 1830 { 1831 if (!cc->cipher_tfm.tfms_aead) 1832 return; 1833 1834 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1835 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 1836 cc->cipher_tfm.tfms_aead[0] = NULL; 1837 } 1838 1839 kfree(cc->cipher_tfm.tfms_aead); 1840 cc->cipher_tfm.tfms_aead = NULL; 1841 } 1842 1843 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 1844 { 1845 unsigned i; 1846 1847 if (!cc->cipher_tfm.tfms) 1848 return; 1849 1850 for (i = 0; i < cc->tfms_count; i++) 1851 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 1852 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 1853 cc->cipher_tfm.tfms[i] = NULL; 1854 } 1855 1856 kfree(cc->cipher_tfm.tfms); 1857 cc->cipher_tfm.tfms = NULL; 1858 } 1859 1860 static void crypt_free_tfms(struct crypt_config *cc) 1861 { 1862 if (crypt_integrity_aead(cc)) 1863 crypt_free_tfms_aead(cc); 1864 else 1865 crypt_free_tfms_skcipher(cc); 1866 } 1867 1868 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 1869 { 1870 unsigned i; 1871 int err; 1872 1873 cc->cipher_tfm.tfms = kzalloc(cc->tfms_count * 1874 sizeof(struct crypto_skcipher *), GFP_KERNEL); 1875 if (!cc->cipher_tfm.tfms) 1876 return -ENOMEM; 1877 1878 for (i = 0; i < cc->tfms_count; i++) { 1879 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0); 1880 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 1881 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 1882 crypt_free_tfms(cc); 1883 return err; 1884 } 1885 } 1886 1887 return 0; 1888 } 1889 1890 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 1891 { 1892 int err; 1893 1894 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 1895 if (!cc->cipher_tfm.tfms) 1896 return -ENOMEM; 1897 1898 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0); 1899 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1900 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 1901 crypt_free_tfms(cc); 1902 return err; 1903 } 1904 1905 return 0; 1906 } 1907 1908 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 1909 { 1910 if (crypt_integrity_aead(cc)) 1911 return crypt_alloc_tfms_aead(cc, ciphermode); 1912 else 1913 return crypt_alloc_tfms_skcipher(cc, ciphermode); 1914 } 1915 1916 static unsigned crypt_subkey_size(struct crypt_config *cc) 1917 { 1918 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 1919 } 1920 1921 static unsigned crypt_authenckey_size(struct crypt_config *cc) 1922 { 1923 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 1924 } 1925 1926 /* 1927 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 1928 * the key must be for some reason in special format. 1929 * This funcion converts cc->key to this special format. 1930 */ 1931 static void crypt_copy_authenckey(char *p, const void *key, 1932 unsigned enckeylen, unsigned authkeylen) 1933 { 1934 struct crypto_authenc_key_param *param; 1935 struct rtattr *rta; 1936 1937 rta = (struct rtattr *)p; 1938 param = RTA_DATA(rta); 1939 param->enckeylen = cpu_to_be32(enckeylen); 1940 rta->rta_len = RTA_LENGTH(sizeof(*param)); 1941 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 1942 p += RTA_SPACE(sizeof(*param)); 1943 memcpy(p, key + enckeylen, authkeylen); 1944 p += authkeylen; 1945 memcpy(p, key, enckeylen); 1946 } 1947 1948 static int crypt_setkey(struct crypt_config *cc) 1949 { 1950 unsigned subkey_size; 1951 int err = 0, i, r; 1952 1953 /* Ignore extra keys (which are used for IV etc) */ 1954 subkey_size = crypt_subkey_size(cc); 1955 1956 if (crypt_integrity_hmac(cc)) { 1957 if (subkey_size < cc->key_mac_size) 1958 return -EINVAL; 1959 1960 crypt_copy_authenckey(cc->authenc_key, cc->key, 1961 subkey_size - cc->key_mac_size, 1962 cc->key_mac_size); 1963 } 1964 1965 for (i = 0; i < cc->tfms_count; i++) { 1966 if (crypt_integrity_hmac(cc)) 1967 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1968 cc->authenc_key, crypt_authenckey_size(cc)); 1969 else if (crypt_integrity_aead(cc)) 1970 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1971 cc->key + (i * subkey_size), 1972 subkey_size); 1973 else 1974 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 1975 cc->key + (i * subkey_size), 1976 subkey_size); 1977 if (r) 1978 err = r; 1979 } 1980 1981 if (crypt_integrity_hmac(cc)) 1982 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 1983 1984 return err; 1985 } 1986 1987 #ifdef CONFIG_KEYS 1988 1989 static bool contains_whitespace(const char *str) 1990 { 1991 while (*str) 1992 if (isspace(*str++)) 1993 return true; 1994 return false; 1995 } 1996 1997 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 1998 { 1999 char *new_key_string, *key_desc; 2000 int ret; 2001 struct key *key; 2002 const struct user_key_payload *ukp; 2003 2004 /* 2005 * Reject key_string with whitespace. dm core currently lacks code for 2006 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2007 */ 2008 if (contains_whitespace(key_string)) { 2009 DMERR("whitespace chars not allowed in key string"); 2010 return -EINVAL; 2011 } 2012 2013 /* look for next ':' separating key_type from key_description */ 2014 key_desc = strpbrk(key_string, ":"); 2015 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2016 return -EINVAL; 2017 2018 if (strncmp(key_string, "logon:", key_desc - key_string + 1) && 2019 strncmp(key_string, "user:", key_desc - key_string + 1)) 2020 return -EINVAL; 2021 2022 new_key_string = kstrdup(key_string, GFP_KERNEL); 2023 if (!new_key_string) 2024 return -ENOMEM; 2025 2026 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user, 2027 key_desc + 1, NULL); 2028 if (IS_ERR(key)) { 2029 kzfree(new_key_string); 2030 return PTR_ERR(key); 2031 } 2032 2033 down_read(&key->sem); 2034 2035 ukp = user_key_payload_locked(key); 2036 if (!ukp) { 2037 up_read(&key->sem); 2038 key_put(key); 2039 kzfree(new_key_string); 2040 return -EKEYREVOKED; 2041 } 2042 2043 if (cc->key_size != ukp->datalen) { 2044 up_read(&key->sem); 2045 key_put(key); 2046 kzfree(new_key_string); 2047 return -EINVAL; 2048 } 2049 2050 memcpy(cc->key, ukp->data, cc->key_size); 2051 2052 up_read(&key->sem); 2053 key_put(key); 2054 2055 /* clear the flag since following operations may invalidate previously valid key */ 2056 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2057 2058 ret = crypt_setkey(cc); 2059 2060 if (!ret) { 2061 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2062 kzfree(cc->key_string); 2063 cc->key_string = new_key_string; 2064 } else 2065 kzfree(new_key_string); 2066 2067 return ret; 2068 } 2069 2070 static int get_key_size(char **key_string) 2071 { 2072 char *colon, dummy; 2073 int ret; 2074 2075 if (*key_string[0] != ':') 2076 return strlen(*key_string) >> 1; 2077 2078 /* look for next ':' in key string */ 2079 colon = strpbrk(*key_string + 1, ":"); 2080 if (!colon) 2081 return -EINVAL; 2082 2083 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2084 return -EINVAL; 2085 2086 *key_string = colon; 2087 2088 /* remaining key string should be :<logon|user>:<key_desc> */ 2089 2090 return ret; 2091 } 2092 2093 #else 2094 2095 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2096 { 2097 return -EINVAL; 2098 } 2099 2100 static int get_key_size(char **key_string) 2101 { 2102 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2103 } 2104 2105 #endif 2106 2107 static int crypt_set_key(struct crypt_config *cc, char *key) 2108 { 2109 int r = -EINVAL; 2110 int key_string_len = strlen(key); 2111 2112 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2113 if (!cc->key_size && strcmp(key, "-")) 2114 goto out; 2115 2116 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2117 if (key[0] == ':') { 2118 r = crypt_set_keyring_key(cc, key + 1); 2119 goto out; 2120 } 2121 2122 /* clear the flag since following operations may invalidate previously valid key */ 2123 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2124 2125 /* wipe references to any kernel keyring key */ 2126 kzfree(cc->key_string); 2127 cc->key_string = NULL; 2128 2129 /* Decode key from its hex representation. */ 2130 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2131 goto out; 2132 2133 r = crypt_setkey(cc); 2134 if (!r) 2135 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2136 2137 out: 2138 /* Hex key string not needed after here, so wipe it. */ 2139 memset(key, '0', key_string_len); 2140 2141 return r; 2142 } 2143 2144 static int crypt_wipe_key(struct crypt_config *cc) 2145 { 2146 int r; 2147 2148 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2149 get_random_bytes(&cc->key, cc->key_size); 2150 kzfree(cc->key_string); 2151 cc->key_string = NULL; 2152 r = crypt_setkey(cc); 2153 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2154 2155 return r; 2156 } 2157 2158 static void crypt_dtr(struct dm_target *ti) 2159 { 2160 struct crypt_config *cc = ti->private; 2161 2162 ti->private = NULL; 2163 2164 if (!cc) 2165 return; 2166 2167 if (cc->write_thread) 2168 kthread_stop(cc->write_thread); 2169 2170 if (cc->io_queue) 2171 destroy_workqueue(cc->io_queue); 2172 if (cc->crypt_queue) 2173 destroy_workqueue(cc->crypt_queue); 2174 2175 crypt_free_tfms(cc); 2176 2177 if (cc->bs) 2178 bioset_free(cc->bs); 2179 2180 mempool_destroy(cc->page_pool); 2181 mempool_destroy(cc->req_pool); 2182 mempool_destroy(cc->tag_pool); 2183 2184 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2185 cc->iv_gen_ops->dtr(cc); 2186 2187 if (cc->dev) 2188 dm_put_device(ti, cc->dev); 2189 2190 kzfree(cc->cipher); 2191 kzfree(cc->cipher_string); 2192 kzfree(cc->key_string); 2193 kzfree(cc->cipher_auth); 2194 kzfree(cc->authenc_key); 2195 2196 mutex_destroy(&cc->bio_alloc_lock); 2197 2198 /* Must zero key material before freeing */ 2199 kzfree(cc); 2200 } 2201 2202 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2203 { 2204 struct crypt_config *cc = ti->private; 2205 2206 if (crypt_integrity_aead(cc)) 2207 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2208 else 2209 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2210 2211 if (cc->iv_size) 2212 /* at least a 64 bit sector number should fit in our buffer */ 2213 cc->iv_size = max(cc->iv_size, 2214 (unsigned int)(sizeof(u64) / sizeof(u8))); 2215 else if (ivmode) { 2216 DMWARN("Selected cipher does not support IVs"); 2217 ivmode = NULL; 2218 } 2219 2220 /* Choose ivmode, see comments at iv code. */ 2221 if (ivmode == NULL) 2222 cc->iv_gen_ops = NULL; 2223 else if (strcmp(ivmode, "plain") == 0) 2224 cc->iv_gen_ops = &crypt_iv_plain_ops; 2225 else if (strcmp(ivmode, "plain64") == 0) 2226 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2227 else if (strcmp(ivmode, "plain64be") == 0) 2228 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2229 else if (strcmp(ivmode, "essiv") == 0) 2230 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2231 else if (strcmp(ivmode, "benbi") == 0) 2232 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2233 else if (strcmp(ivmode, "null") == 0) 2234 cc->iv_gen_ops = &crypt_iv_null_ops; 2235 else if (strcmp(ivmode, "lmk") == 0) { 2236 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2237 /* 2238 * Version 2 and 3 is recognised according 2239 * to length of provided multi-key string. 2240 * If present (version 3), last key is used as IV seed. 2241 * All keys (including IV seed) are always the same size. 2242 */ 2243 if (cc->key_size % cc->key_parts) { 2244 cc->key_parts++; 2245 cc->key_extra_size = cc->key_size / cc->key_parts; 2246 } 2247 } else if (strcmp(ivmode, "tcw") == 0) { 2248 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2249 cc->key_parts += 2; /* IV + whitening */ 2250 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2251 } else if (strcmp(ivmode, "random") == 0) { 2252 cc->iv_gen_ops = &crypt_iv_random_ops; 2253 /* Need storage space in integrity fields. */ 2254 cc->integrity_iv_size = cc->iv_size; 2255 } else { 2256 ti->error = "Invalid IV mode"; 2257 return -EINVAL; 2258 } 2259 2260 return 0; 2261 } 2262 2263 /* 2264 * Workaround to parse cipher algorithm from crypto API spec. 2265 * The cc->cipher is currently used only in ESSIV. 2266 * This should be probably done by crypto-api calls (once available...) 2267 */ 2268 static int crypt_ctr_blkdev_cipher(struct crypt_config *cc) 2269 { 2270 const char *alg_name = NULL; 2271 char *start, *end; 2272 2273 if (crypt_integrity_aead(cc)) { 2274 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc))); 2275 if (!alg_name) 2276 return -EINVAL; 2277 if (crypt_integrity_hmac(cc)) { 2278 alg_name = strchr(alg_name, ','); 2279 if (!alg_name) 2280 return -EINVAL; 2281 } 2282 alg_name++; 2283 } else { 2284 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc))); 2285 if (!alg_name) 2286 return -EINVAL; 2287 } 2288 2289 start = strchr(alg_name, '('); 2290 end = strchr(alg_name, ')'); 2291 2292 if (!start && !end) { 2293 cc->cipher = kstrdup(alg_name, GFP_KERNEL); 2294 return cc->cipher ? 0 : -ENOMEM; 2295 } 2296 2297 if (!start || !end || ++start >= end) 2298 return -EINVAL; 2299 2300 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL); 2301 if (!cc->cipher) 2302 return -ENOMEM; 2303 2304 strncpy(cc->cipher, start, end - start); 2305 2306 return 0; 2307 } 2308 2309 /* 2310 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2311 * The HMAC is needed to calculate tag size (HMAC digest size). 2312 * This should be probably done by crypto-api calls (once available...) 2313 */ 2314 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2315 { 2316 char *start, *end, *mac_alg = NULL; 2317 struct crypto_ahash *mac; 2318 2319 if (!strstarts(cipher_api, "authenc(")) 2320 return 0; 2321 2322 start = strchr(cipher_api, '('); 2323 end = strchr(cipher_api, ','); 2324 if (!start || !end || ++start > end) 2325 return -EINVAL; 2326 2327 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2328 if (!mac_alg) 2329 return -ENOMEM; 2330 strncpy(mac_alg, start, end - start); 2331 2332 mac = crypto_alloc_ahash(mac_alg, 0, 0); 2333 kfree(mac_alg); 2334 2335 if (IS_ERR(mac)) 2336 return PTR_ERR(mac); 2337 2338 cc->key_mac_size = crypto_ahash_digestsize(mac); 2339 crypto_free_ahash(mac); 2340 2341 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2342 if (!cc->authenc_key) 2343 return -ENOMEM; 2344 2345 return 0; 2346 } 2347 2348 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2349 char **ivmode, char **ivopts) 2350 { 2351 struct crypt_config *cc = ti->private; 2352 char *tmp, *cipher_api; 2353 int ret = -EINVAL; 2354 2355 cc->tfms_count = 1; 2356 2357 /* 2358 * New format (capi: prefix) 2359 * capi:cipher_api_spec-iv:ivopts 2360 */ 2361 tmp = &cipher_in[strlen("capi:")]; 2362 cipher_api = strsep(&tmp, "-"); 2363 *ivmode = strsep(&tmp, ":"); 2364 *ivopts = tmp; 2365 2366 if (*ivmode && !strcmp(*ivmode, "lmk")) 2367 cc->tfms_count = 64; 2368 2369 cc->key_parts = cc->tfms_count; 2370 2371 /* Allocate cipher */ 2372 ret = crypt_alloc_tfms(cc, cipher_api); 2373 if (ret < 0) { 2374 ti->error = "Error allocating crypto tfm"; 2375 return ret; 2376 } 2377 2378 /* Alloc AEAD, can be used only in new format. */ 2379 if (crypt_integrity_aead(cc)) { 2380 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2381 if (ret < 0) { 2382 ti->error = "Invalid AEAD cipher spec"; 2383 return -ENOMEM; 2384 } 2385 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2386 } else 2387 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2388 2389 ret = crypt_ctr_blkdev_cipher(cc); 2390 if (ret < 0) { 2391 ti->error = "Cannot allocate cipher string"; 2392 return -ENOMEM; 2393 } 2394 2395 return 0; 2396 } 2397 2398 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2399 char **ivmode, char **ivopts) 2400 { 2401 struct crypt_config *cc = ti->private; 2402 char *tmp, *cipher, *chainmode, *keycount; 2403 char *cipher_api = NULL; 2404 int ret = -EINVAL; 2405 char dummy; 2406 2407 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2408 ti->error = "Bad cipher specification"; 2409 return -EINVAL; 2410 } 2411 2412 /* 2413 * Legacy dm-crypt cipher specification 2414 * cipher[:keycount]-mode-iv:ivopts 2415 */ 2416 tmp = cipher_in; 2417 keycount = strsep(&tmp, "-"); 2418 cipher = strsep(&keycount, ":"); 2419 2420 if (!keycount) 2421 cc->tfms_count = 1; 2422 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2423 !is_power_of_2(cc->tfms_count)) { 2424 ti->error = "Bad cipher key count specification"; 2425 return -EINVAL; 2426 } 2427 cc->key_parts = cc->tfms_count; 2428 2429 cc->cipher = kstrdup(cipher, GFP_KERNEL); 2430 if (!cc->cipher) 2431 goto bad_mem; 2432 2433 chainmode = strsep(&tmp, "-"); 2434 *ivopts = strsep(&tmp, "-"); 2435 *ivmode = strsep(&*ivopts, ":"); 2436 2437 if (tmp) 2438 DMWARN("Ignoring unexpected additional cipher options"); 2439 2440 /* 2441 * For compatibility with the original dm-crypt mapping format, if 2442 * only the cipher name is supplied, use cbc-plain. 2443 */ 2444 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2445 chainmode = "cbc"; 2446 *ivmode = "plain"; 2447 } 2448 2449 if (strcmp(chainmode, "ecb") && !*ivmode) { 2450 ti->error = "IV mechanism required"; 2451 return -EINVAL; 2452 } 2453 2454 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2455 if (!cipher_api) 2456 goto bad_mem; 2457 2458 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2459 "%s(%s)", chainmode, cipher); 2460 if (ret < 0) { 2461 kfree(cipher_api); 2462 goto bad_mem; 2463 } 2464 2465 /* Allocate cipher */ 2466 ret = crypt_alloc_tfms(cc, cipher_api); 2467 if (ret < 0) { 2468 ti->error = "Error allocating crypto tfm"; 2469 kfree(cipher_api); 2470 return ret; 2471 } 2472 kfree(cipher_api); 2473 2474 return 0; 2475 bad_mem: 2476 ti->error = "Cannot allocate cipher strings"; 2477 return -ENOMEM; 2478 } 2479 2480 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 2481 { 2482 struct crypt_config *cc = ti->private; 2483 char *ivmode = NULL, *ivopts = NULL; 2484 int ret; 2485 2486 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 2487 if (!cc->cipher_string) { 2488 ti->error = "Cannot allocate cipher strings"; 2489 return -ENOMEM; 2490 } 2491 2492 if (strstarts(cipher_in, "capi:")) 2493 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 2494 else 2495 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 2496 if (ret) 2497 return ret; 2498 2499 /* Initialize IV */ 2500 ret = crypt_ctr_ivmode(ti, ivmode); 2501 if (ret < 0) 2502 return ret; 2503 2504 /* Initialize and set key */ 2505 ret = crypt_set_key(cc, key); 2506 if (ret < 0) { 2507 ti->error = "Error decoding and setting key"; 2508 return ret; 2509 } 2510 2511 /* Allocate IV */ 2512 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 2513 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 2514 if (ret < 0) { 2515 ti->error = "Error creating IV"; 2516 return ret; 2517 } 2518 } 2519 2520 /* Initialize IV (set keys for ESSIV etc) */ 2521 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 2522 ret = cc->iv_gen_ops->init(cc); 2523 if (ret < 0) { 2524 ti->error = "Error initialising IV"; 2525 return ret; 2526 } 2527 } 2528 2529 /* wipe the kernel key payload copy */ 2530 if (cc->key_string) 2531 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2532 2533 return ret; 2534 } 2535 2536 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 2537 { 2538 struct crypt_config *cc = ti->private; 2539 struct dm_arg_set as; 2540 static const struct dm_arg _args[] = { 2541 {0, 6, "Invalid number of feature args"}, 2542 }; 2543 unsigned int opt_params, val; 2544 const char *opt_string, *sval; 2545 char dummy; 2546 int ret; 2547 2548 /* Optional parameters */ 2549 as.argc = argc; 2550 as.argv = argv; 2551 2552 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 2553 if (ret) 2554 return ret; 2555 2556 while (opt_params--) { 2557 opt_string = dm_shift_arg(&as); 2558 if (!opt_string) { 2559 ti->error = "Not enough feature arguments"; 2560 return -EINVAL; 2561 } 2562 2563 if (!strcasecmp(opt_string, "allow_discards")) 2564 ti->num_discard_bios = 1; 2565 2566 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 2567 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2568 2569 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 2570 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2571 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 2572 if (val == 0 || val > MAX_TAG_SIZE) { 2573 ti->error = "Invalid integrity arguments"; 2574 return -EINVAL; 2575 } 2576 cc->on_disk_tag_size = val; 2577 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 2578 if (!strcasecmp(sval, "aead")) { 2579 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 2580 } else if (strcasecmp(sval, "none")) { 2581 ti->error = "Unknown integrity profile"; 2582 return -EINVAL; 2583 } 2584 2585 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 2586 if (!cc->cipher_auth) 2587 return -ENOMEM; 2588 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 2589 if (cc->sector_size < (1 << SECTOR_SHIFT) || 2590 cc->sector_size > 4096 || 2591 (cc->sector_size & (cc->sector_size - 1))) { 2592 ti->error = "Invalid feature value for sector_size"; 2593 return -EINVAL; 2594 } 2595 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 2596 ti->error = "Device size is not multiple of sector_size feature"; 2597 return -EINVAL; 2598 } 2599 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 2600 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 2601 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2602 else { 2603 ti->error = "Invalid feature arguments"; 2604 return -EINVAL; 2605 } 2606 } 2607 2608 return 0; 2609 } 2610 2611 /* 2612 * Construct an encryption mapping: 2613 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 2614 */ 2615 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 2616 { 2617 struct crypt_config *cc; 2618 int key_size; 2619 unsigned int align_mask; 2620 unsigned long long tmpll; 2621 int ret; 2622 size_t iv_size_padding, additional_req_size; 2623 char dummy; 2624 2625 if (argc < 5) { 2626 ti->error = "Not enough arguments"; 2627 return -EINVAL; 2628 } 2629 2630 key_size = get_key_size(&argv[1]); 2631 if (key_size < 0) { 2632 ti->error = "Cannot parse key size"; 2633 return -EINVAL; 2634 } 2635 2636 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); 2637 if (!cc) { 2638 ti->error = "Cannot allocate encryption context"; 2639 return -ENOMEM; 2640 } 2641 cc->key_size = key_size; 2642 cc->sector_size = (1 << SECTOR_SHIFT); 2643 cc->sector_shift = 0; 2644 2645 ti->private = cc; 2646 2647 /* Optional parameters need to be read before cipher constructor */ 2648 if (argc > 5) { 2649 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 2650 if (ret) 2651 goto bad; 2652 } 2653 2654 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 2655 if (ret < 0) 2656 goto bad; 2657 2658 if (crypt_integrity_aead(cc)) { 2659 cc->dmreq_start = sizeof(struct aead_request); 2660 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 2661 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 2662 } else { 2663 cc->dmreq_start = sizeof(struct skcipher_request); 2664 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 2665 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 2666 } 2667 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 2668 2669 if (align_mask < CRYPTO_MINALIGN) { 2670 /* Allocate the padding exactly */ 2671 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 2672 & align_mask; 2673 } else { 2674 /* 2675 * If the cipher requires greater alignment than kmalloc 2676 * alignment, we don't know the exact position of the 2677 * initialization vector. We must assume worst case. 2678 */ 2679 iv_size_padding = align_mask; 2680 } 2681 2682 ret = -ENOMEM; 2683 2684 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 2685 additional_req_size = sizeof(struct dm_crypt_request) + 2686 iv_size_padding + cc->iv_size + 2687 cc->iv_size + 2688 sizeof(uint64_t) + 2689 sizeof(unsigned int); 2690 2691 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + additional_req_size); 2692 if (!cc->req_pool) { 2693 ti->error = "Cannot allocate crypt request mempool"; 2694 goto bad; 2695 } 2696 2697 cc->per_bio_data_size = ti->per_io_data_size = 2698 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 2699 ARCH_KMALLOC_MINALIGN); 2700 2701 cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0); 2702 if (!cc->page_pool) { 2703 ti->error = "Cannot allocate page mempool"; 2704 goto bad; 2705 } 2706 2707 cc->bs = bioset_create(MIN_IOS, 0, BIOSET_NEED_BVECS); 2708 if (!cc->bs) { 2709 ti->error = "Cannot allocate crypt bioset"; 2710 goto bad; 2711 } 2712 2713 mutex_init(&cc->bio_alloc_lock); 2714 2715 ret = -EINVAL; 2716 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 2717 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 2718 ti->error = "Invalid iv_offset sector"; 2719 goto bad; 2720 } 2721 cc->iv_offset = tmpll; 2722 2723 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 2724 if (ret) { 2725 ti->error = "Device lookup failed"; 2726 goto bad; 2727 } 2728 2729 ret = -EINVAL; 2730 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { 2731 ti->error = "Invalid device sector"; 2732 goto bad; 2733 } 2734 cc->start = tmpll; 2735 2736 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 2737 ret = crypt_integrity_ctr(cc, ti); 2738 if (ret) 2739 goto bad; 2740 2741 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 2742 if (!cc->tag_pool_max_sectors) 2743 cc->tag_pool_max_sectors = 1; 2744 2745 cc->tag_pool = mempool_create_kmalloc_pool(MIN_IOS, 2746 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 2747 if (!cc->tag_pool) { 2748 ti->error = "Cannot allocate integrity tags mempool"; 2749 ret = -ENOMEM; 2750 goto bad; 2751 } 2752 2753 cc->tag_pool_max_sectors <<= cc->sector_shift; 2754 } 2755 2756 ret = -ENOMEM; 2757 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); 2758 if (!cc->io_queue) { 2759 ti->error = "Couldn't create kcryptd io queue"; 2760 goto bad; 2761 } 2762 2763 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2764 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); 2765 else 2766 cc->crypt_queue = alloc_workqueue("kcryptd", 2767 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 2768 num_online_cpus()); 2769 if (!cc->crypt_queue) { 2770 ti->error = "Couldn't create kcryptd queue"; 2771 goto bad; 2772 } 2773 2774 init_waitqueue_head(&cc->write_thread_wait); 2775 cc->write_tree = RB_ROOT; 2776 2777 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); 2778 if (IS_ERR(cc->write_thread)) { 2779 ret = PTR_ERR(cc->write_thread); 2780 cc->write_thread = NULL; 2781 ti->error = "Couldn't spawn write thread"; 2782 goto bad; 2783 } 2784 wake_up_process(cc->write_thread); 2785 2786 ti->num_flush_bios = 1; 2787 2788 return 0; 2789 2790 bad: 2791 crypt_dtr(ti); 2792 return ret; 2793 } 2794 2795 static int crypt_map(struct dm_target *ti, struct bio *bio) 2796 { 2797 struct dm_crypt_io *io; 2798 struct crypt_config *cc = ti->private; 2799 2800 /* 2801 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 2802 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 2803 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 2804 */ 2805 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 2806 bio_op(bio) == REQ_OP_DISCARD)) { 2807 bio_set_dev(bio, cc->dev->bdev); 2808 if (bio_sectors(bio)) 2809 bio->bi_iter.bi_sector = cc->start + 2810 dm_target_offset(ti, bio->bi_iter.bi_sector); 2811 return DM_MAPIO_REMAPPED; 2812 } 2813 2814 /* 2815 * Check if bio is too large, split as needed. 2816 */ 2817 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && 2818 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 2819 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); 2820 2821 /* 2822 * Ensure that bio is a multiple of internal sector encryption size 2823 * and is aligned to this size as defined in IO hints. 2824 */ 2825 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 2826 return DM_MAPIO_KILL; 2827 2828 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 2829 return DM_MAPIO_KILL; 2830 2831 io = dm_per_bio_data(bio, cc->per_bio_data_size); 2832 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 2833 2834 if (cc->on_disk_tag_size) { 2835 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 2836 2837 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 2838 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 2839 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 2840 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 2841 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 2842 io->integrity_metadata = mempool_alloc(cc->tag_pool, GFP_NOIO); 2843 io->integrity_metadata_from_pool = true; 2844 } 2845 } 2846 2847 if (crypt_integrity_aead(cc)) 2848 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 2849 else 2850 io->ctx.r.req = (struct skcipher_request *)(io + 1); 2851 2852 if (bio_data_dir(io->base_bio) == READ) { 2853 if (kcryptd_io_read(io, GFP_NOWAIT)) 2854 kcryptd_queue_read(io); 2855 } else 2856 kcryptd_queue_crypt(io); 2857 2858 return DM_MAPIO_SUBMITTED; 2859 } 2860 2861 static void crypt_status(struct dm_target *ti, status_type_t type, 2862 unsigned status_flags, char *result, unsigned maxlen) 2863 { 2864 struct crypt_config *cc = ti->private; 2865 unsigned i, sz = 0; 2866 int num_feature_args = 0; 2867 2868 switch (type) { 2869 case STATUSTYPE_INFO: 2870 result[0] = '\0'; 2871 break; 2872 2873 case STATUSTYPE_TABLE: 2874 DMEMIT("%s ", cc->cipher_string); 2875 2876 if (cc->key_size > 0) { 2877 if (cc->key_string) 2878 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 2879 else 2880 for (i = 0; i < cc->key_size; i++) 2881 DMEMIT("%02x", cc->key[i]); 2882 } else 2883 DMEMIT("-"); 2884 2885 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 2886 cc->dev->name, (unsigned long long)cc->start); 2887 2888 num_feature_args += !!ti->num_discard_bios; 2889 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2890 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2891 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 2892 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2893 if (cc->on_disk_tag_size) 2894 num_feature_args++; 2895 if (num_feature_args) { 2896 DMEMIT(" %d", num_feature_args); 2897 if (ti->num_discard_bios) 2898 DMEMIT(" allow_discards"); 2899 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2900 DMEMIT(" same_cpu_crypt"); 2901 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 2902 DMEMIT(" submit_from_crypt_cpus"); 2903 if (cc->on_disk_tag_size) 2904 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 2905 if (cc->sector_size != (1 << SECTOR_SHIFT)) 2906 DMEMIT(" sector_size:%d", cc->sector_size); 2907 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 2908 DMEMIT(" iv_large_sectors"); 2909 } 2910 2911 break; 2912 } 2913 } 2914 2915 static void crypt_postsuspend(struct dm_target *ti) 2916 { 2917 struct crypt_config *cc = ti->private; 2918 2919 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2920 } 2921 2922 static int crypt_preresume(struct dm_target *ti) 2923 { 2924 struct crypt_config *cc = ti->private; 2925 2926 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 2927 DMERR("aborting resume - crypt key is not set."); 2928 return -EAGAIN; 2929 } 2930 2931 return 0; 2932 } 2933 2934 static void crypt_resume(struct dm_target *ti) 2935 { 2936 struct crypt_config *cc = ti->private; 2937 2938 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2939 } 2940 2941 /* Message interface 2942 * key set <key> 2943 * key wipe 2944 */ 2945 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) 2946 { 2947 struct crypt_config *cc = ti->private; 2948 int key_size, ret = -EINVAL; 2949 2950 if (argc < 2) 2951 goto error; 2952 2953 if (!strcasecmp(argv[0], "key")) { 2954 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 2955 DMWARN("not suspended during key manipulation."); 2956 return -EINVAL; 2957 } 2958 if (argc == 3 && !strcasecmp(argv[1], "set")) { 2959 /* The key size may not be changed. */ 2960 key_size = get_key_size(&argv[2]); 2961 if (key_size < 0 || cc->key_size != key_size) { 2962 memset(argv[2], '0', strlen(argv[2])); 2963 return -EINVAL; 2964 } 2965 2966 ret = crypt_set_key(cc, argv[2]); 2967 if (ret) 2968 return ret; 2969 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 2970 ret = cc->iv_gen_ops->init(cc); 2971 /* wipe the kernel key payload copy */ 2972 if (cc->key_string) 2973 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2974 return ret; 2975 } 2976 if (argc == 2 && !strcasecmp(argv[1], "wipe")) { 2977 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 2978 ret = cc->iv_gen_ops->wipe(cc); 2979 if (ret) 2980 return ret; 2981 } 2982 return crypt_wipe_key(cc); 2983 } 2984 } 2985 2986 error: 2987 DMWARN("unrecognised message received."); 2988 return -EINVAL; 2989 } 2990 2991 static int crypt_iterate_devices(struct dm_target *ti, 2992 iterate_devices_callout_fn fn, void *data) 2993 { 2994 struct crypt_config *cc = ti->private; 2995 2996 return fn(ti, cc->dev, cc->start, ti->len, data); 2997 } 2998 2999 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3000 { 3001 struct crypt_config *cc = ti->private; 3002 3003 /* 3004 * Unfortunate constraint that is required to avoid the potential 3005 * for exceeding underlying device's max_segments limits -- due to 3006 * crypt_alloc_buffer() possibly allocating pages for the encryption 3007 * bio that are not as physically contiguous as the original bio. 3008 */ 3009 limits->max_segment_size = PAGE_SIZE; 3010 3011 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 3012 limits->logical_block_size = cc->sector_size; 3013 limits->physical_block_size = cc->sector_size; 3014 blk_limits_io_min(limits, cc->sector_size); 3015 } 3016 } 3017 3018 static struct target_type crypt_target = { 3019 .name = "crypt", 3020 .version = {1, 18, 1}, 3021 .module = THIS_MODULE, 3022 .ctr = crypt_ctr, 3023 .dtr = crypt_dtr, 3024 .map = crypt_map, 3025 .status = crypt_status, 3026 .postsuspend = crypt_postsuspend, 3027 .preresume = crypt_preresume, 3028 .resume = crypt_resume, 3029 .message = crypt_message, 3030 .iterate_devices = crypt_iterate_devices, 3031 .io_hints = crypt_io_hints, 3032 }; 3033 3034 static int __init dm_crypt_init(void) 3035 { 3036 int r; 3037 3038 r = dm_register_target(&crypt_target); 3039 if (r < 0) 3040 DMERR("register failed %d", r); 3041 3042 return r; 3043 } 3044 3045 static void __exit dm_crypt_exit(void) 3046 { 3047 dm_unregister_target(&crypt_target); 3048 } 3049 3050 module_init(dm_crypt_init); 3051 module_exit(dm_crypt_exit); 3052 3053 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3054 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3055 MODULE_LICENSE("GPL"); 3056