1 /* 2 * Symmetric key cipher operations. 3 * 4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across 5 * multiple page boundaries by using temporary blocks. In user context, 6 * the kernel is given a chance to schedule us once per page. 7 * 8 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the Free 12 * Software Foundation; either version 2 of the License, or (at your option) 13 * any later version. 14 * 15 */ 16 17 #include <crypto/internal/aead.h> 18 #include <crypto/internal/skcipher.h> 19 #include <crypto/scatterwalk.h> 20 #include <linux/bug.h> 21 #include <linux/cryptouser.h> 22 #include <linux/compiler.h> 23 #include <linux/list.h> 24 #include <linux/module.h> 25 #include <linux/rtnetlink.h> 26 #include <linux/seq_file.h> 27 #include <net/netlink.h> 28 29 #include "internal.h" 30 31 enum { 32 SKCIPHER_WALK_PHYS = 1 << 0, 33 SKCIPHER_WALK_SLOW = 1 << 1, 34 SKCIPHER_WALK_COPY = 1 << 2, 35 SKCIPHER_WALK_DIFF = 1 << 3, 36 SKCIPHER_WALK_SLEEP = 1 << 4, 37 }; 38 39 struct skcipher_walk_buffer { 40 struct list_head entry; 41 struct scatter_walk dst; 42 unsigned int len; 43 u8 *data; 44 u8 buffer[]; 45 }; 46 47 static int skcipher_walk_next(struct skcipher_walk *walk); 48 49 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr) 50 { 51 if (PageHighMem(scatterwalk_page(walk))) 52 kunmap_atomic(vaddr); 53 } 54 55 static inline void *skcipher_map(struct scatter_walk *walk) 56 { 57 struct page *page = scatterwalk_page(walk); 58 59 return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) + 60 offset_in_page(walk->offset); 61 } 62 63 static inline void skcipher_map_src(struct skcipher_walk *walk) 64 { 65 walk->src.virt.addr = skcipher_map(&walk->in); 66 } 67 68 static inline void skcipher_map_dst(struct skcipher_walk *walk) 69 { 70 walk->dst.virt.addr = skcipher_map(&walk->out); 71 } 72 73 static inline void skcipher_unmap_src(struct skcipher_walk *walk) 74 { 75 skcipher_unmap(&walk->in, walk->src.virt.addr); 76 } 77 78 static inline void skcipher_unmap_dst(struct skcipher_walk *walk) 79 { 80 skcipher_unmap(&walk->out, walk->dst.virt.addr); 81 } 82 83 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) 84 { 85 return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; 86 } 87 88 /* Get a spot of the specified length that does not straddle a page. 89 * The caller needs to ensure that there is enough space for this operation. 90 */ 91 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len) 92 { 93 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); 94 95 return max(start, end_page); 96 } 97 98 static void skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize) 99 { 100 u8 *addr; 101 102 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); 103 addr = skcipher_get_spot(addr, bsize); 104 scatterwalk_copychunks(addr, &walk->out, bsize, 105 (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1); 106 } 107 108 int skcipher_walk_done(struct skcipher_walk *walk, int err) 109 { 110 unsigned int n; /* bytes processed */ 111 bool more; 112 113 if (unlikely(err < 0)) 114 goto finish; 115 116 n = walk->nbytes - err; 117 walk->total -= n; 118 more = (walk->total != 0); 119 120 if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | 121 SKCIPHER_WALK_SLOW | 122 SKCIPHER_WALK_COPY | 123 SKCIPHER_WALK_DIFF)))) { 124 unmap_src: 125 skcipher_unmap_src(walk); 126 } else if (walk->flags & SKCIPHER_WALK_DIFF) { 127 skcipher_unmap_dst(walk); 128 goto unmap_src; 129 } else if (walk->flags & SKCIPHER_WALK_COPY) { 130 skcipher_map_dst(walk); 131 memcpy(walk->dst.virt.addr, walk->page, n); 132 skcipher_unmap_dst(walk); 133 } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) { 134 if (err) { 135 /* 136 * Didn't process all bytes. Either the algorithm is 137 * broken, or this was the last step and it turned out 138 * the message wasn't evenly divisible into blocks but 139 * the algorithm requires it. 140 */ 141 err = -EINVAL; 142 goto finish; 143 } 144 skcipher_done_slow(walk, n); 145 goto already_advanced; 146 } 147 148 scatterwalk_advance(&walk->in, n); 149 scatterwalk_advance(&walk->out, n); 150 already_advanced: 151 scatterwalk_done(&walk->in, 0, more); 152 scatterwalk_done(&walk->out, 1, more); 153 154 if (more) { 155 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? 156 CRYPTO_TFM_REQ_MAY_SLEEP : 0); 157 return skcipher_walk_next(walk); 158 } 159 err = 0; 160 finish: 161 walk->nbytes = 0; 162 163 /* Short-circuit for the common/fast path. */ 164 if (!((unsigned long)walk->buffer | (unsigned long)walk->page)) 165 goto out; 166 167 if (walk->flags & SKCIPHER_WALK_PHYS) 168 goto out; 169 170 if (walk->iv != walk->oiv) 171 memcpy(walk->oiv, walk->iv, walk->ivsize); 172 if (walk->buffer != walk->page) 173 kfree(walk->buffer); 174 if (walk->page) 175 free_page((unsigned long)walk->page); 176 177 out: 178 return err; 179 } 180 EXPORT_SYMBOL_GPL(skcipher_walk_done); 181 182 void skcipher_walk_complete(struct skcipher_walk *walk, int err) 183 { 184 struct skcipher_walk_buffer *p, *tmp; 185 186 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) { 187 u8 *data; 188 189 if (err) 190 goto done; 191 192 data = p->data; 193 if (!data) { 194 data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1); 195 data = skcipher_get_spot(data, walk->stride); 196 } 197 198 scatterwalk_copychunks(data, &p->dst, p->len, 1); 199 200 if (offset_in_page(p->data) + p->len + walk->stride > 201 PAGE_SIZE) 202 free_page((unsigned long)p->data); 203 204 done: 205 list_del(&p->entry); 206 kfree(p); 207 } 208 209 if (!err && walk->iv != walk->oiv) 210 memcpy(walk->oiv, walk->iv, walk->ivsize); 211 if (walk->buffer != walk->page) 212 kfree(walk->buffer); 213 if (walk->page) 214 free_page((unsigned long)walk->page); 215 } 216 EXPORT_SYMBOL_GPL(skcipher_walk_complete); 217 218 static void skcipher_queue_write(struct skcipher_walk *walk, 219 struct skcipher_walk_buffer *p) 220 { 221 p->dst = walk->out; 222 list_add_tail(&p->entry, &walk->buffers); 223 } 224 225 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) 226 { 227 bool phys = walk->flags & SKCIPHER_WALK_PHYS; 228 unsigned alignmask = walk->alignmask; 229 struct skcipher_walk_buffer *p; 230 unsigned a; 231 unsigned n; 232 u8 *buffer; 233 void *v; 234 235 if (!phys) { 236 if (!walk->buffer) 237 walk->buffer = walk->page; 238 buffer = walk->buffer; 239 if (buffer) 240 goto ok; 241 } 242 243 /* Start with the minimum alignment of kmalloc. */ 244 a = crypto_tfm_ctx_alignment() - 1; 245 n = bsize; 246 247 if (phys) { 248 /* Calculate the minimum alignment of p->buffer. */ 249 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1; 250 n += sizeof(*p); 251 } 252 253 /* Minimum size to align p->buffer by alignmask. */ 254 n += alignmask & ~a; 255 256 /* Minimum size to ensure p->buffer does not straddle a page. */ 257 n += (bsize - 1) & ~(alignmask | a); 258 259 v = kzalloc(n, skcipher_walk_gfp(walk)); 260 if (!v) 261 return skcipher_walk_done(walk, -ENOMEM); 262 263 if (phys) { 264 p = v; 265 p->len = bsize; 266 skcipher_queue_write(walk, p); 267 buffer = p->buffer; 268 } else { 269 walk->buffer = v; 270 buffer = v; 271 } 272 273 ok: 274 walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1); 275 walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize); 276 walk->src.virt.addr = walk->dst.virt.addr; 277 278 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); 279 280 walk->nbytes = bsize; 281 walk->flags |= SKCIPHER_WALK_SLOW; 282 283 return 0; 284 } 285 286 static int skcipher_next_copy(struct skcipher_walk *walk) 287 { 288 struct skcipher_walk_buffer *p; 289 u8 *tmp = walk->page; 290 291 skcipher_map_src(walk); 292 memcpy(tmp, walk->src.virt.addr, walk->nbytes); 293 skcipher_unmap_src(walk); 294 295 walk->src.virt.addr = tmp; 296 walk->dst.virt.addr = tmp; 297 298 if (!(walk->flags & SKCIPHER_WALK_PHYS)) 299 return 0; 300 301 p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk)); 302 if (!p) 303 return -ENOMEM; 304 305 p->data = walk->page; 306 p->len = walk->nbytes; 307 skcipher_queue_write(walk, p); 308 309 if (offset_in_page(walk->page) + walk->nbytes + walk->stride > 310 PAGE_SIZE) 311 walk->page = NULL; 312 else 313 walk->page += walk->nbytes; 314 315 return 0; 316 } 317 318 static int skcipher_next_fast(struct skcipher_walk *walk) 319 { 320 unsigned long diff; 321 322 walk->src.phys.page = scatterwalk_page(&walk->in); 323 walk->src.phys.offset = offset_in_page(walk->in.offset); 324 walk->dst.phys.page = scatterwalk_page(&walk->out); 325 walk->dst.phys.offset = offset_in_page(walk->out.offset); 326 327 if (walk->flags & SKCIPHER_WALK_PHYS) 328 return 0; 329 330 diff = walk->src.phys.offset - walk->dst.phys.offset; 331 diff |= walk->src.virt.page - walk->dst.virt.page; 332 333 skcipher_map_src(walk); 334 walk->dst.virt.addr = walk->src.virt.addr; 335 336 if (diff) { 337 walk->flags |= SKCIPHER_WALK_DIFF; 338 skcipher_map_dst(walk); 339 } 340 341 return 0; 342 } 343 344 static int skcipher_walk_next(struct skcipher_walk *walk) 345 { 346 unsigned int bsize; 347 unsigned int n; 348 int err; 349 350 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | 351 SKCIPHER_WALK_DIFF); 352 353 n = walk->total; 354 bsize = min(walk->stride, max(n, walk->blocksize)); 355 n = scatterwalk_clamp(&walk->in, n); 356 n = scatterwalk_clamp(&walk->out, n); 357 358 if (unlikely(n < bsize)) { 359 if (unlikely(walk->total < walk->blocksize)) 360 return skcipher_walk_done(walk, -EINVAL); 361 362 slow_path: 363 err = skcipher_next_slow(walk, bsize); 364 goto set_phys_lowmem; 365 } 366 367 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { 368 if (!walk->page) { 369 gfp_t gfp = skcipher_walk_gfp(walk); 370 371 walk->page = (void *)__get_free_page(gfp); 372 if (!walk->page) 373 goto slow_path; 374 } 375 376 walk->nbytes = min_t(unsigned, n, 377 PAGE_SIZE - offset_in_page(walk->page)); 378 walk->flags |= SKCIPHER_WALK_COPY; 379 err = skcipher_next_copy(walk); 380 goto set_phys_lowmem; 381 } 382 383 walk->nbytes = n; 384 385 return skcipher_next_fast(walk); 386 387 set_phys_lowmem: 388 if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) { 389 walk->src.phys.page = virt_to_page(walk->src.virt.addr); 390 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); 391 walk->src.phys.offset &= PAGE_SIZE - 1; 392 walk->dst.phys.offset &= PAGE_SIZE - 1; 393 } 394 return err; 395 } 396 397 static int skcipher_copy_iv(struct skcipher_walk *walk) 398 { 399 unsigned a = crypto_tfm_ctx_alignment() - 1; 400 unsigned alignmask = walk->alignmask; 401 unsigned ivsize = walk->ivsize; 402 unsigned bs = walk->stride; 403 unsigned aligned_bs; 404 unsigned size; 405 u8 *iv; 406 407 aligned_bs = ALIGN(bs, alignmask + 1); 408 409 /* Minimum size to align buffer by alignmask. */ 410 size = alignmask & ~a; 411 412 if (walk->flags & SKCIPHER_WALK_PHYS) 413 size += ivsize; 414 else { 415 size += aligned_bs + ivsize; 416 417 /* Minimum size to ensure buffer does not straddle a page. */ 418 size += (bs - 1) & ~(alignmask | a); 419 } 420 421 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); 422 if (!walk->buffer) 423 return -ENOMEM; 424 425 iv = PTR_ALIGN(walk->buffer, alignmask + 1); 426 iv = skcipher_get_spot(iv, bs) + aligned_bs; 427 428 walk->iv = memcpy(iv, walk->iv, walk->ivsize); 429 return 0; 430 } 431 432 static int skcipher_walk_first(struct skcipher_walk *walk) 433 { 434 if (WARN_ON_ONCE(in_irq())) 435 return -EDEADLK; 436 437 walk->buffer = NULL; 438 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { 439 int err = skcipher_copy_iv(walk); 440 if (err) 441 return err; 442 } 443 444 walk->page = NULL; 445 446 return skcipher_walk_next(walk); 447 } 448 449 static int skcipher_walk_skcipher(struct skcipher_walk *walk, 450 struct skcipher_request *req) 451 { 452 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 453 454 walk->total = req->cryptlen; 455 walk->nbytes = 0; 456 walk->iv = req->iv; 457 walk->oiv = req->iv; 458 459 if (unlikely(!walk->total)) 460 return 0; 461 462 scatterwalk_start(&walk->in, req->src); 463 scatterwalk_start(&walk->out, req->dst); 464 465 walk->flags &= ~SKCIPHER_WALK_SLEEP; 466 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 467 SKCIPHER_WALK_SLEEP : 0; 468 469 walk->blocksize = crypto_skcipher_blocksize(tfm); 470 walk->stride = crypto_skcipher_walksize(tfm); 471 walk->ivsize = crypto_skcipher_ivsize(tfm); 472 walk->alignmask = crypto_skcipher_alignmask(tfm); 473 474 return skcipher_walk_first(walk); 475 } 476 477 int skcipher_walk_virt(struct skcipher_walk *walk, 478 struct skcipher_request *req, bool atomic) 479 { 480 int err; 481 482 might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 483 484 walk->flags &= ~SKCIPHER_WALK_PHYS; 485 486 err = skcipher_walk_skcipher(walk, req); 487 488 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0; 489 490 return err; 491 } 492 EXPORT_SYMBOL_GPL(skcipher_walk_virt); 493 494 void skcipher_walk_atomise(struct skcipher_walk *walk) 495 { 496 walk->flags &= ~SKCIPHER_WALK_SLEEP; 497 } 498 EXPORT_SYMBOL_GPL(skcipher_walk_atomise); 499 500 int skcipher_walk_async(struct skcipher_walk *walk, 501 struct skcipher_request *req) 502 { 503 walk->flags |= SKCIPHER_WALK_PHYS; 504 505 INIT_LIST_HEAD(&walk->buffers); 506 507 return skcipher_walk_skcipher(walk, req); 508 } 509 EXPORT_SYMBOL_GPL(skcipher_walk_async); 510 511 static int skcipher_walk_aead_common(struct skcipher_walk *walk, 512 struct aead_request *req, bool atomic) 513 { 514 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 515 int err; 516 517 walk->nbytes = 0; 518 walk->iv = req->iv; 519 walk->oiv = req->iv; 520 521 if (unlikely(!walk->total)) 522 return 0; 523 524 walk->flags &= ~SKCIPHER_WALK_PHYS; 525 526 scatterwalk_start(&walk->in, req->src); 527 scatterwalk_start(&walk->out, req->dst); 528 529 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); 530 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); 531 532 scatterwalk_done(&walk->in, 0, walk->total); 533 scatterwalk_done(&walk->out, 0, walk->total); 534 535 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) 536 walk->flags |= SKCIPHER_WALK_SLEEP; 537 else 538 walk->flags &= ~SKCIPHER_WALK_SLEEP; 539 540 walk->blocksize = crypto_aead_blocksize(tfm); 541 walk->stride = crypto_aead_chunksize(tfm); 542 walk->ivsize = crypto_aead_ivsize(tfm); 543 walk->alignmask = crypto_aead_alignmask(tfm); 544 545 err = skcipher_walk_first(walk); 546 547 if (atomic) 548 walk->flags &= ~SKCIPHER_WALK_SLEEP; 549 550 return err; 551 } 552 553 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, 554 bool atomic) 555 { 556 walk->total = req->cryptlen; 557 558 return skcipher_walk_aead_common(walk, req, atomic); 559 } 560 EXPORT_SYMBOL_GPL(skcipher_walk_aead); 561 562 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, 563 struct aead_request *req, bool atomic) 564 { 565 walk->total = req->cryptlen; 566 567 return skcipher_walk_aead_common(walk, req, atomic); 568 } 569 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); 570 571 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 572 struct aead_request *req, bool atomic) 573 { 574 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 575 576 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 577 578 return skcipher_walk_aead_common(walk, req, atomic); 579 } 580 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 581 582 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) 583 { 584 if (alg->cra_type == &crypto_blkcipher_type) 585 return sizeof(struct crypto_blkcipher *); 586 587 if (alg->cra_type == &crypto_ablkcipher_type) 588 return sizeof(struct crypto_ablkcipher *); 589 590 return crypto_alg_extsize(alg); 591 } 592 593 static void skcipher_set_needkey(struct crypto_skcipher *tfm) 594 { 595 if (tfm->keysize) 596 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY); 597 } 598 599 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, 600 const u8 *key, unsigned int keylen) 601 { 602 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 603 struct crypto_blkcipher *blkcipher = *ctx; 604 int err; 605 606 crypto_blkcipher_clear_flags(blkcipher, ~0); 607 crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) & 608 CRYPTO_TFM_REQ_MASK); 609 err = crypto_blkcipher_setkey(blkcipher, key, keylen); 610 crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & 611 CRYPTO_TFM_RES_MASK); 612 if (unlikely(err)) { 613 skcipher_set_needkey(tfm); 614 return err; 615 } 616 617 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 618 return 0; 619 } 620 621 static int skcipher_crypt_blkcipher(struct skcipher_request *req, 622 int (*crypt)(struct blkcipher_desc *, 623 struct scatterlist *, 624 struct scatterlist *, 625 unsigned int)) 626 { 627 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 628 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 629 struct blkcipher_desc desc = { 630 .tfm = *ctx, 631 .info = req->iv, 632 .flags = req->base.flags, 633 }; 634 635 636 return crypt(&desc, req->dst, req->src, req->cryptlen); 637 } 638 639 static int skcipher_encrypt_blkcipher(struct skcipher_request *req) 640 { 641 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 642 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 643 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 644 645 return skcipher_crypt_blkcipher(req, alg->encrypt); 646 } 647 648 static int skcipher_decrypt_blkcipher(struct skcipher_request *req) 649 { 650 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 651 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 652 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 653 654 return skcipher_crypt_blkcipher(req, alg->decrypt); 655 } 656 657 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 658 { 659 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 660 661 crypto_free_blkcipher(*ctx); 662 } 663 664 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 665 { 666 struct crypto_alg *calg = tfm->__crt_alg; 667 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 668 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 669 struct crypto_blkcipher *blkcipher; 670 struct crypto_tfm *btfm; 671 672 if (!crypto_mod_get(calg)) 673 return -EAGAIN; 674 675 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, 676 CRYPTO_ALG_TYPE_MASK); 677 if (IS_ERR(btfm)) { 678 crypto_mod_put(calg); 679 return PTR_ERR(btfm); 680 } 681 682 blkcipher = __crypto_blkcipher_cast(btfm); 683 *ctx = blkcipher; 684 tfm->exit = crypto_exit_skcipher_ops_blkcipher; 685 686 skcipher->setkey = skcipher_setkey_blkcipher; 687 skcipher->encrypt = skcipher_encrypt_blkcipher; 688 skcipher->decrypt = skcipher_decrypt_blkcipher; 689 690 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); 691 skcipher->keysize = calg->cra_blkcipher.max_keysize; 692 693 skcipher_set_needkey(skcipher); 694 695 return 0; 696 } 697 698 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, 699 const u8 *key, unsigned int keylen) 700 { 701 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 702 struct crypto_ablkcipher *ablkcipher = *ctx; 703 int err; 704 705 crypto_ablkcipher_clear_flags(ablkcipher, ~0); 706 crypto_ablkcipher_set_flags(ablkcipher, 707 crypto_skcipher_get_flags(tfm) & 708 CRYPTO_TFM_REQ_MASK); 709 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); 710 crypto_skcipher_set_flags(tfm, 711 crypto_ablkcipher_get_flags(ablkcipher) & 712 CRYPTO_TFM_RES_MASK); 713 if (unlikely(err)) { 714 skcipher_set_needkey(tfm); 715 return err; 716 } 717 718 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 719 return 0; 720 } 721 722 static int skcipher_crypt_ablkcipher(struct skcipher_request *req, 723 int (*crypt)(struct ablkcipher_request *)) 724 { 725 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 726 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 727 struct ablkcipher_request *subreq = skcipher_request_ctx(req); 728 729 ablkcipher_request_set_tfm(subreq, *ctx); 730 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), 731 req->base.complete, req->base.data); 732 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, 733 req->iv); 734 735 return crypt(subreq); 736 } 737 738 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req) 739 { 740 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 741 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 742 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 743 744 return skcipher_crypt_ablkcipher(req, alg->encrypt); 745 } 746 747 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) 748 { 749 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 750 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 751 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 752 753 return skcipher_crypt_ablkcipher(req, alg->decrypt); 754 } 755 756 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 757 { 758 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 759 760 crypto_free_ablkcipher(*ctx); 761 } 762 763 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 764 { 765 struct crypto_alg *calg = tfm->__crt_alg; 766 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 767 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 768 struct crypto_ablkcipher *ablkcipher; 769 struct crypto_tfm *abtfm; 770 771 if (!crypto_mod_get(calg)) 772 return -EAGAIN; 773 774 abtfm = __crypto_alloc_tfm(calg, 0, 0); 775 if (IS_ERR(abtfm)) { 776 crypto_mod_put(calg); 777 return PTR_ERR(abtfm); 778 } 779 780 ablkcipher = __crypto_ablkcipher_cast(abtfm); 781 *ctx = ablkcipher; 782 tfm->exit = crypto_exit_skcipher_ops_ablkcipher; 783 784 skcipher->setkey = skcipher_setkey_ablkcipher; 785 skcipher->encrypt = skcipher_encrypt_ablkcipher; 786 skcipher->decrypt = skcipher_decrypt_ablkcipher; 787 788 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); 789 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + 790 sizeof(struct ablkcipher_request); 791 skcipher->keysize = calg->cra_ablkcipher.max_keysize; 792 793 skcipher_set_needkey(skcipher); 794 795 return 0; 796 } 797 798 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 799 const u8 *key, unsigned int keylen) 800 { 801 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 802 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 803 u8 *buffer, *alignbuffer; 804 unsigned long absize; 805 int ret; 806 807 absize = keylen + alignmask; 808 buffer = kmalloc(absize, GFP_ATOMIC); 809 if (!buffer) 810 return -ENOMEM; 811 812 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 813 memcpy(alignbuffer, key, keylen); 814 ret = cipher->setkey(tfm, alignbuffer, keylen); 815 kzfree(buffer); 816 return ret; 817 } 818 819 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 820 unsigned int keylen) 821 { 822 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 823 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 824 int err; 825 826 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 827 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 828 return -EINVAL; 829 } 830 831 if ((unsigned long)key & alignmask) 832 err = skcipher_setkey_unaligned(tfm, key, keylen); 833 else 834 err = cipher->setkey(tfm, key, keylen); 835 836 if (unlikely(err)) { 837 skcipher_set_needkey(tfm); 838 return err; 839 } 840 841 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 842 return 0; 843 } 844 845 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 846 { 847 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 848 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 849 850 alg->exit(skcipher); 851 } 852 853 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 854 { 855 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 856 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 857 858 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) 859 return crypto_init_skcipher_ops_blkcipher(tfm); 860 861 if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type) 862 return crypto_init_skcipher_ops_ablkcipher(tfm); 863 864 skcipher->setkey = skcipher_setkey; 865 skcipher->encrypt = alg->encrypt; 866 skcipher->decrypt = alg->decrypt; 867 skcipher->ivsize = alg->ivsize; 868 skcipher->keysize = alg->max_keysize; 869 870 skcipher_set_needkey(skcipher); 871 872 if (alg->exit) 873 skcipher->base.exit = crypto_skcipher_exit_tfm; 874 875 if (alg->init) 876 return alg->init(skcipher); 877 878 return 0; 879 } 880 881 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 882 { 883 struct skcipher_instance *skcipher = 884 container_of(inst, struct skcipher_instance, s.base); 885 886 skcipher->free(skcipher); 887 } 888 889 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 890 __maybe_unused; 891 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 892 { 893 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 894 base); 895 896 seq_printf(m, "type : skcipher\n"); 897 seq_printf(m, "async : %s\n", 898 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 899 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 900 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 901 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 902 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 903 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 904 seq_printf(m, "walksize : %u\n", skcipher->walksize); 905 } 906 907 #ifdef CONFIG_NET 908 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 909 { 910 struct crypto_report_blkcipher rblkcipher; 911 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 912 base); 913 914 memset(&rblkcipher, 0, sizeof(rblkcipher)); 915 916 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 917 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 918 919 rblkcipher.blocksize = alg->cra_blocksize; 920 rblkcipher.min_keysize = skcipher->min_keysize; 921 rblkcipher.max_keysize = skcipher->max_keysize; 922 rblkcipher.ivsize = skcipher->ivsize; 923 924 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 925 sizeof(rblkcipher), &rblkcipher); 926 } 927 #else 928 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 929 { 930 return -ENOSYS; 931 } 932 #endif 933 934 static const struct crypto_type crypto_skcipher_type2 = { 935 .extsize = crypto_skcipher_extsize, 936 .init_tfm = crypto_skcipher_init_tfm, 937 .free = crypto_skcipher_free_instance, 938 #ifdef CONFIG_PROC_FS 939 .show = crypto_skcipher_show, 940 #endif 941 .report = crypto_skcipher_report, 942 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 943 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, 944 .type = CRYPTO_ALG_TYPE_SKCIPHER, 945 .tfmsize = offsetof(struct crypto_skcipher, base), 946 }; 947 948 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 949 const char *name, u32 type, u32 mask) 950 { 951 spawn->base.frontend = &crypto_skcipher_type2; 952 return crypto_grab_spawn(&spawn->base, name, type, mask); 953 } 954 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 955 956 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 957 u32 type, u32 mask) 958 { 959 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 960 } 961 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 962 963 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher( 964 const char *alg_name, u32 type, u32 mask) 965 { 966 struct crypto_skcipher *tfm; 967 968 /* Only sync algorithms allowed. */ 969 mask |= CRYPTO_ALG_ASYNC; 970 971 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 972 973 /* 974 * Make sure we do not allocate something that might get used with 975 * an on-stack request: check the request size. 976 */ 977 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) > 978 MAX_SYNC_SKCIPHER_REQSIZE)) { 979 crypto_free_skcipher(tfm); 980 return ERR_PTR(-EINVAL); 981 } 982 983 return (struct crypto_sync_skcipher *)tfm; 984 } 985 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher); 986 987 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask) 988 { 989 return crypto_type_has_alg(alg_name, &crypto_skcipher_type2, 990 type, mask); 991 } 992 EXPORT_SYMBOL_GPL(crypto_has_skcipher2); 993 994 static int skcipher_prepare_alg(struct skcipher_alg *alg) 995 { 996 struct crypto_alg *base = &alg->base; 997 998 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 999 alg->walksize > PAGE_SIZE / 8) 1000 return -EINVAL; 1001 1002 if (!alg->chunksize) 1003 alg->chunksize = base->cra_blocksize; 1004 if (!alg->walksize) 1005 alg->walksize = alg->chunksize; 1006 1007 base->cra_type = &crypto_skcipher_type2; 1008 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 1009 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 1010 1011 return 0; 1012 } 1013 1014 int crypto_register_skcipher(struct skcipher_alg *alg) 1015 { 1016 struct crypto_alg *base = &alg->base; 1017 int err; 1018 1019 err = skcipher_prepare_alg(alg); 1020 if (err) 1021 return err; 1022 1023 return crypto_register_alg(base); 1024 } 1025 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 1026 1027 void crypto_unregister_skcipher(struct skcipher_alg *alg) 1028 { 1029 crypto_unregister_alg(&alg->base); 1030 } 1031 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 1032 1033 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 1034 { 1035 int i, ret; 1036 1037 for (i = 0; i < count; i++) { 1038 ret = crypto_register_skcipher(&algs[i]); 1039 if (ret) 1040 goto err; 1041 } 1042 1043 return 0; 1044 1045 err: 1046 for (--i; i >= 0; --i) 1047 crypto_unregister_skcipher(&algs[i]); 1048 1049 return ret; 1050 } 1051 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 1052 1053 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 1054 { 1055 int i; 1056 1057 for (i = count - 1; i >= 0; --i) 1058 crypto_unregister_skcipher(&algs[i]); 1059 } 1060 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 1061 1062 int skcipher_register_instance(struct crypto_template *tmpl, 1063 struct skcipher_instance *inst) 1064 { 1065 int err; 1066 1067 err = skcipher_prepare_alg(&inst->alg); 1068 if (err) 1069 return err; 1070 1071 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 1072 } 1073 EXPORT_SYMBOL_GPL(skcipher_register_instance); 1074 1075 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key, 1076 unsigned int keylen) 1077 { 1078 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); 1079 int err; 1080 1081 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); 1082 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) & 1083 CRYPTO_TFM_REQ_MASK); 1084 err = crypto_cipher_setkey(cipher, key, keylen); 1085 crypto_skcipher_set_flags(tfm, crypto_cipher_get_flags(cipher) & 1086 CRYPTO_TFM_RES_MASK); 1087 return err; 1088 } 1089 1090 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm) 1091 { 1092 struct skcipher_instance *inst = skcipher_alg_instance(tfm); 1093 struct crypto_spawn *spawn = skcipher_instance_ctx(inst); 1094 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 1095 struct crypto_cipher *cipher; 1096 1097 cipher = crypto_spawn_cipher(spawn); 1098 if (IS_ERR(cipher)) 1099 return PTR_ERR(cipher); 1100 1101 ctx->cipher = cipher; 1102 return 0; 1103 } 1104 1105 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm) 1106 { 1107 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 1108 1109 crypto_free_cipher(ctx->cipher); 1110 } 1111 1112 static void skcipher_free_instance_simple(struct skcipher_instance *inst) 1113 { 1114 crypto_drop_spawn(skcipher_instance_ctx(inst)); 1115 kfree(inst); 1116 } 1117 1118 /** 1119 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode 1120 * 1121 * Allocate an skcipher_instance for a simple block cipher mode of operation, 1122 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, 1123 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, 1124 * alignmask, and priority are set from the underlying cipher but can be 1125 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and 1126 * default ->setkey(), ->init(), and ->exit() methods are installed. 1127 * 1128 * @tmpl: the template being instantiated 1129 * @tb: the template parameters 1130 * @cipher_alg_ret: on success, a pointer to the underlying cipher algorithm is 1131 * returned here. It must be dropped with crypto_mod_put(). 1132 * 1133 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still 1134 * needs to register the instance. 1135 */ 1136 struct skcipher_instance * 1137 skcipher_alloc_instance_simple(struct crypto_template *tmpl, struct rtattr **tb, 1138 struct crypto_alg **cipher_alg_ret) 1139 { 1140 struct crypto_attr_type *algt; 1141 struct crypto_alg *cipher_alg; 1142 struct skcipher_instance *inst; 1143 struct crypto_spawn *spawn; 1144 u32 mask; 1145 int err; 1146 1147 algt = crypto_get_attr_type(tb); 1148 if (IS_ERR(algt)) 1149 return ERR_CAST(algt); 1150 1151 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) 1152 return ERR_PTR(-EINVAL); 1153 1154 mask = CRYPTO_ALG_TYPE_MASK | 1155 crypto_requires_off(algt->type, algt->mask, 1156 CRYPTO_ALG_NEED_FALLBACK); 1157 1158 cipher_alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask); 1159 if (IS_ERR(cipher_alg)) 1160 return ERR_CAST(cipher_alg); 1161 1162 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 1163 if (!inst) { 1164 err = -ENOMEM; 1165 goto err_put_cipher_alg; 1166 } 1167 spawn = skcipher_instance_ctx(inst); 1168 1169 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name, 1170 cipher_alg); 1171 if (err) 1172 goto err_free_inst; 1173 1174 err = crypto_init_spawn(spawn, cipher_alg, 1175 skcipher_crypto_instance(inst), 1176 CRYPTO_ALG_TYPE_MASK); 1177 if (err) 1178 goto err_free_inst; 1179 inst->free = skcipher_free_instance_simple; 1180 1181 /* Default algorithm properties, can be overridden */ 1182 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize; 1183 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask; 1184 inst->alg.base.cra_priority = cipher_alg->cra_priority; 1185 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize; 1186 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize; 1187 inst->alg.ivsize = cipher_alg->cra_blocksize; 1188 1189 /* Use skcipher_ctx_simple by default, can be overridden */ 1190 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple); 1191 inst->alg.setkey = skcipher_setkey_simple; 1192 inst->alg.init = skcipher_init_tfm_simple; 1193 inst->alg.exit = skcipher_exit_tfm_simple; 1194 1195 *cipher_alg_ret = cipher_alg; 1196 return inst; 1197 1198 err_free_inst: 1199 kfree(inst); 1200 err_put_cipher_alg: 1201 crypto_mod_put(cipher_alg); 1202 return ERR_PTR(err); 1203 } 1204 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple); 1205 1206 MODULE_LICENSE("GPL"); 1207 MODULE_DESCRIPTION("Symmetric key cipher type"); 1208