1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Symmetric key cipher operations. 4 * 5 * Generic encrypt/decrypt wrapper for ciphers, handles operations across 6 * multiple page boundaries by using temporary blocks. In user context, 7 * the kernel is given a chance to schedule us once per page. 8 * 9 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> 10 */ 11 12 #include <crypto/internal/aead.h> 13 #include <crypto/internal/skcipher.h> 14 #include <crypto/scatterwalk.h> 15 #include <linux/bug.h> 16 #include <linux/cryptouser.h> 17 #include <linux/compiler.h> 18 #include <linux/list.h> 19 #include <linux/module.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/seq_file.h> 22 #include <net/netlink.h> 23 24 #include "internal.h" 25 26 enum { 27 SKCIPHER_WALK_PHYS = 1 << 0, 28 SKCIPHER_WALK_SLOW = 1 << 1, 29 SKCIPHER_WALK_COPY = 1 << 2, 30 SKCIPHER_WALK_DIFF = 1 << 3, 31 SKCIPHER_WALK_SLEEP = 1 << 4, 32 }; 33 34 struct skcipher_walk_buffer { 35 struct list_head entry; 36 struct scatter_walk dst; 37 unsigned int len; 38 u8 *data; 39 u8 buffer[]; 40 }; 41 42 static int skcipher_walk_next(struct skcipher_walk *walk); 43 44 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr) 45 { 46 if (PageHighMem(scatterwalk_page(walk))) 47 kunmap_atomic(vaddr); 48 } 49 50 static inline void *skcipher_map(struct scatter_walk *walk) 51 { 52 struct page *page = scatterwalk_page(walk); 53 54 return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) + 55 offset_in_page(walk->offset); 56 } 57 58 static inline void skcipher_map_src(struct skcipher_walk *walk) 59 { 60 walk->src.virt.addr = skcipher_map(&walk->in); 61 } 62 63 static inline void skcipher_map_dst(struct skcipher_walk *walk) 64 { 65 walk->dst.virt.addr = skcipher_map(&walk->out); 66 } 67 68 static inline void skcipher_unmap_src(struct skcipher_walk *walk) 69 { 70 skcipher_unmap(&walk->in, walk->src.virt.addr); 71 } 72 73 static inline void skcipher_unmap_dst(struct skcipher_walk *walk) 74 { 75 skcipher_unmap(&walk->out, walk->dst.virt.addr); 76 } 77 78 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) 79 { 80 return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; 81 } 82 83 /* Get a spot of the specified length that does not straddle a page. 84 * The caller needs to ensure that there is enough space for this operation. 85 */ 86 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len) 87 { 88 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); 89 90 return max(start, end_page); 91 } 92 93 static void skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize) 94 { 95 u8 *addr; 96 97 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); 98 addr = skcipher_get_spot(addr, bsize); 99 scatterwalk_copychunks(addr, &walk->out, bsize, 100 (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1); 101 } 102 103 int skcipher_walk_done(struct skcipher_walk *walk, int err) 104 { 105 unsigned int n; /* bytes processed */ 106 bool more; 107 108 if (unlikely(err < 0)) 109 goto finish; 110 111 n = walk->nbytes - err; 112 walk->total -= n; 113 more = (walk->total != 0); 114 115 if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | 116 SKCIPHER_WALK_SLOW | 117 SKCIPHER_WALK_COPY | 118 SKCIPHER_WALK_DIFF)))) { 119 unmap_src: 120 skcipher_unmap_src(walk); 121 } else if (walk->flags & SKCIPHER_WALK_DIFF) { 122 skcipher_unmap_dst(walk); 123 goto unmap_src; 124 } else if (walk->flags & SKCIPHER_WALK_COPY) { 125 skcipher_map_dst(walk); 126 memcpy(walk->dst.virt.addr, walk->page, n); 127 skcipher_unmap_dst(walk); 128 } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) { 129 if (err) { 130 /* 131 * Didn't process all bytes. Either the algorithm is 132 * broken, or this was the last step and it turned out 133 * the message wasn't evenly divisible into blocks but 134 * the algorithm requires it. 135 */ 136 err = -EINVAL; 137 goto finish; 138 } 139 skcipher_done_slow(walk, n); 140 goto already_advanced; 141 } 142 143 scatterwalk_advance(&walk->in, n); 144 scatterwalk_advance(&walk->out, n); 145 already_advanced: 146 scatterwalk_done(&walk->in, 0, more); 147 scatterwalk_done(&walk->out, 1, more); 148 149 if (more) { 150 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? 151 CRYPTO_TFM_REQ_MAY_SLEEP : 0); 152 return skcipher_walk_next(walk); 153 } 154 err = 0; 155 finish: 156 walk->nbytes = 0; 157 158 /* Short-circuit for the common/fast path. */ 159 if (!((unsigned long)walk->buffer | (unsigned long)walk->page)) 160 goto out; 161 162 if (walk->flags & SKCIPHER_WALK_PHYS) 163 goto out; 164 165 if (walk->iv != walk->oiv) 166 memcpy(walk->oiv, walk->iv, walk->ivsize); 167 if (walk->buffer != walk->page) 168 kfree(walk->buffer); 169 if (walk->page) 170 free_page((unsigned long)walk->page); 171 172 out: 173 return err; 174 } 175 EXPORT_SYMBOL_GPL(skcipher_walk_done); 176 177 void skcipher_walk_complete(struct skcipher_walk *walk, int err) 178 { 179 struct skcipher_walk_buffer *p, *tmp; 180 181 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) { 182 u8 *data; 183 184 if (err) 185 goto done; 186 187 data = p->data; 188 if (!data) { 189 data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1); 190 data = skcipher_get_spot(data, walk->stride); 191 } 192 193 scatterwalk_copychunks(data, &p->dst, p->len, 1); 194 195 if (offset_in_page(p->data) + p->len + walk->stride > 196 PAGE_SIZE) 197 free_page((unsigned long)p->data); 198 199 done: 200 list_del(&p->entry); 201 kfree(p); 202 } 203 204 if (!err && walk->iv != walk->oiv) 205 memcpy(walk->oiv, walk->iv, walk->ivsize); 206 if (walk->buffer != walk->page) 207 kfree(walk->buffer); 208 if (walk->page) 209 free_page((unsigned long)walk->page); 210 } 211 EXPORT_SYMBOL_GPL(skcipher_walk_complete); 212 213 static void skcipher_queue_write(struct skcipher_walk *walk, 214 struct skcipher_walk_buffer *p) 215 { 216 p->dst = walk->out; 217 list_add_tail(&p->entry, &walk->buffers); 218 } 219 220 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) 221 { 222 bool phys = walk->flags & SKCIPHER_WALK_PHYS; 223 unsigned alignmask = walk->alignmask; 224 struct skcipher_walk_buffer *p; 225 unsigned a; 226 unsigned n; 227 u8 *buffer; 228 void *v; 229 230 if (!phys) { 231 if (!walk->buffer) 232 walk->buffer = walk->page; 233 buffer = walk->buffer; 234 if (buffer) 235 goto ok; 236 } 237 238 /* Start with the minimum alignment of kmalloc. */ 239 a = crypto_tfm_ctx_alignment() - 1; 240 n = bsize; 241 242 if (phys) { 243 /* Calculate the minimum alignment of p->buffer. */ 244 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1; 245 n += sizeof(*p); 246 } 247 248 /* Minimum size to align p->buffer by alignmask. */ 249 n += alignmask & ~a; 250 251 /* Minimum size to ensure p->buffer does not straddle a page. */ 252 n += (bsize - 1) & ~(alignmask | a); 253 254 v = kzalloc(n, skcipher_walk_gfp(walk)); 255 if (!v) 256 return skcipher_walk_done(walk, -ENOMEM); 257 258 if (phys) { 259 p = v; 260 p->len = bsize; 261 skcipher_queue_write(walk, p); 262 buffer = p->buffer; 263 } else { 264 walk->buffer = v; 265 buffer = v; 266 } 267 268 ok: 269 walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1); 270 walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize); 271 walk->src.virt.addr = walk->dst.virt.addr; 272 273 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); 274 275 walk->nbytes = bsize; 276 walk->flags |= SKCIPHER_WALK_SLOW; 277 278 return 0; 279 } 280 281 static int skcipher_next_copy(struct skcipher_walk *walk) 282 { 283 struct skcipher_walk_buffer *p; 284 u8 *tmp = walk->page; 285 286 skcipher_map_src(walk); 287 memcpy(tmp, walk->src.virt.addr, walk->nbytes); 288 skcipher_unmap_src(walk); 289 290 walk->src.virt.addr = tmp; 291 walk->dst.virt.addr = tmp; 292 293 if (!(walk->flags & SKCIPHER_WALK_PHYS)) 294 return 0; 295 296 p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk)); 297 if (!p) 298 return -ENOMEM; 299 300 p->data = walk->page; 301 p->len = walk->nbytes; 302 skcipher_queue_write(walk, p); 303 304 if (offset_in_page(walk->page) + walk->nbytes + walk->stride > 305 PAGE_SIZE) 306 walk->page = NULL; 307 else 308 walk->page += walk->nbytes; 309 310 return 0; 311 } 312 313 static int skcipher_next_fast(struct skcipher_walk *walk) 314 { 315 unsigned long diff; 316 317 walk->src.phys.page = scatterwalk_page(&walk->in); 318 walk->src.phys.offset = offset_in_page(walk->in.offset); 319 walk->dst.phys.page = scatterwalk_page(&walk->out); 320 walk->dst.phys.offset = offset_in_page(walk->out.offset); 321 322 if (walk->flags & SKCIPHER_WALK_PHYS) 323 return 0; 324 325 diff = walk->src.phys.offset - walk->dst.phys.offset; 326 diff |= walk->src.virt.page - walk->dst.virt.page; 327 328 skcipher_map_src(walk); 329 walk->dst.virt.addr = walk->src.virt.addr; 330 331 if (diff) { 332 walk->flags |= SKCIPHER_WALK_DIFF; 333 skcipher_map_dst(walk); 334 } 335 336 return 0; 337 } 338 339 static int skcipher_walk_next(struct skcipher_walk *walk) 340 { 341 unsigned int bsize; 342 unsigned int n; 343 int err; 344 345 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | 346 SKCIPHER_WALK_DIFF); 347 348 n = walk->total; 349 bsize = min(walk->stride, max(n, walk->blocksize)); 350 n = scatterwalk_clamp(&walk->in, n); 351 n = scatterwalk_clamp(&walk->out, n); 352 353 if (unlikely(n < bsize)) { 354 if (unlikely(walk->total < walk->blocksize)) 355 return skcipher_walk_done(walk, -EINVAL); 356 357 slow_path: 358 err = skcipher_next_slow(walk, bsize); 359 goto set_phys_lowmem; 360 } 361 362 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { 363 if (!walk->page) { 364 gfp_t gfp = skcipher_walk_gfp(walk); 365 366 walk->page = (void *)__get_free_page(gfp); 367 if (!walk->page) 368 goto slow_path; 369 } 370 371 walk->nbytes = min_t(unsigned, n, 372 PAGE_SIZE - offset_in_page(walk->page)); 373 walk->flags |= SKCIPHER_WALK_COPY; 374 err = skcipher_next_copy(walk); 375 goto set_phys_lowmem; 376 } 377 378 walk->nbytes = n; 379 380 return skcipher_next_fast(walk); 381 382 set_phys_lowmem: 383 if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) { 384 walk->src.phys.page = virt_to_page(walk->src.virt.addr); 385 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); 386 walk->src.phys.offset &= PAGE_SIZE - 1; 387 walk->dst.phys.offset &= PAGE_SIZE - 1; 388 } 389 return err; 390 } 391 392 static int skcipher_copy_iv(struct skcipher_walk *walk) 393 { 394 unsigned a = crypto_tfm_ctx_alignment() - 1; 395 unsigned alignmask = walk->alignmask; 396 unsigned ivsize = walk->ivsize; 397 unsigned bs = walk->stride; 398 unsigned aligned_bs; 399 unsigned size; 400 u8 *iv; 401 402 aligned_bs = ALIGN(bs, alignmask + 1); 403 404 /* Minimum size to align buffer by alignmask. */ 405 size = alignmask & ~a; 406 407 if (walk->flags & SKCIPHER_WALK_PHYS) 408 size += ivsize; 409 else { 410 size += aligned_bs + ivsize; 411 412 /* Minimum size to ensure buffer does not straddle a page. */ 413 size += (bs - 1) & ~(alignmask | a); 414 } 415 416 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); 417 if (!walk->buffer) 418 return -ENOMEM; 419 420 iv = PTR_ALIGN(walk->buffer, alignmask + 1); 421 iv = skcipher_get_spot(iv, bs) + aligned_bs; 422 423 walk->iv = memcpy(iv, walk->iv, walk->ivsize); 424 return 0; 425 } 426 427 static int skcipher_walk_first(struct skcipher_walk *walk) 428 { 429 if (WARN_ON_ONCE(in_irq())) 430 return -EDEADLK; 431 432 walk->buffer = NULL; 433 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { 434 int err = skcipher_copy_iv(walk); 435 if (err) 436 return err; 437 } 438 439 walk->page = NULL; 440 441 return skcipher_walk_next(walk); 442 } 443 444 static int skcipher_walk_skcipher(struct skcipher_walk *walk, 445 struct skcipher_request *req) 446 { 447 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 448 449 walk->total = req->cryptlen; 450 walk->nbytes = 0; 451 walk->iv = req->iv; 452 walk->oiv = req->iv; 453 454 if (unlikely(!walk->total)) 455 return 0; 456 457 scatterwalk_start(&walk->in, req->src); 458 scatterwalk_start(&walk->out, req->dst); 459 460 walk->flags &= ~SKCIPHER_WALK_SLEEP; 461 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 462 SKCIPHER_WALK_SLEEP : 0; 463 464 walk->blocksize = crypto_skcipher_blocksize(tfm); 465 walk->stride = crypto_skcipher_walksize(tfm); 466 walk->ivsize = crypto_skcipher_ivsize(tfm); 467 walk->alignmask = crypto_skcipher_alignmask(tfm); 468 469 return skcipher_walk_first(walk); 470 } 471 472 int skcipher_walk_virt(struct skcipher_walk *walk, 473 struct skcipher_request *req, bool atomic) 474 { 475 int err; 476 477 might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 478 479 walk->flags &= ~SKCIPHER_WALK_PHYS; 480 481 err = skcipher_walk_skcipher(walk, req); 482 483 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0; 484 485 return err; 486 } 487 EXPORT_SYMBOL_GPL(skcipher_walk_virt); 488 489 void skcipher_walk_atomise(struct skcipher_walk *walk) 490 { 491 walk->flags &= ~SKCIPHER_WALK_SLEEP; 492 } 493 EXPORT_SYMBOL_GPL(skcipher_walk_atomise); 494 495 int skcipher_walk_async(struct skcipher_walk *walk, 496 struct skcipher_request *req) 497 { 498 walk->flags |= SKCIPHER_WALK_PHYS; 499 500 INIT_LIST_HEAD(&walk->buffers); 501 502 return skcipher_walk_skcipher(walk, req); 503 } 504 EXPORT_SYMBOL_GPL(skcipher_walk_async); 505 506 static int skcipher_walk_aead_common(struct skcipher_walk *walk, 507 struct aead_request *req, bool atomic) 508 { 509 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 510 int err; 511 512 walk->nbytes = 0; 513 walk->iv = req->iv; 514 walk->oiv = req->iv; 515 516 if (unlikely(!walk->total)) 517 return 0; 518 519 walk->flags &= ~SKCIPHER_WALK_PHYS; 520 521 scatterwalk_start(&walk->in, req->src); 522 scatterwalk_start(&walk->out, req->dst); 523 524 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); 525 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); 526 527 scatterwalk_done(&walk->in, 0, walk->total); 528 scatterwalk_done(&walk->out, 0, walk->total); 529 530 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) 531 walk->flags |= SKCIPHER_WALK_SLEEP; 532 else 533 walk->flags &= ~SKCIPHER_WALK_SLEEP; 534 535 walk->blocksize = crypto_aead_blocksize(tfm); 536 walk->stride = crypto_aead_chunksize(tfm); 537 walk->ivsize = crypto_aead_ivsize(tfm); 538 walk->alignmask = crypto_aead_alignmask(tfm); 539 540 err = skcipher_walk_first(walk); 541 542 if (atomic) 543 walk->flags &= ~SKCIPHER_WALK_SLEEP; 544 545 return err; 546 } 547 548 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, 549 bool atomic) 550 { 551 walk->total = req->cryptlen; 552 553 return skcipher_walk_aead_common(walk, req, atomic); 554 } 555 EXPORT_SYMBOL_GPL(skcipher_walk_aead); 556 557 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, 558 struct aead_request *req, bool atomic) 559 { 560 walk->total = req->cryptlen; 561 562 return skcipher_walk_aead_common(walk, req, atomic); 563 } 564 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); 565 566 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 567 struct aead_request *req, bool atomic) 568 { 569 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 570 571 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 572 573 return skcipher_walk_aead_common(walk, req, atomic); 574 } 575 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 576 577 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) 578 { 579 if (alg->cra_type == &crypto_blkcipher_type) 580 return sizeof(struct crypto_blkcipher *); 581 582 if (alg->cra_type == &crypto_ablkcipher_type) 583 return sizeof(struct crypto_ablkcipher *); 584 585 return crypto_alg_extsize(alg); 586 } 587 588 static void skcipher_set_needkey(struct crypto_skcipher *tfm) 589 { 590 if (tfm->keysize) 591 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY); 592 } 593 594 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, 595 const u8 *key, unsigned int keylen) 596 { 597 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 598 struct crypto_blkcipher *blkcipher = *ctx; 599 int err; 600 601 crypto_blkcipher_clear_flags(blkcipher, ~0); 602 crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) & 603 CRYPTO_TFM_REQ_MASK); 604 err = crypto_blkcipher_setkey(blkcipher, key, keylen); 605 crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & 606 CRYPTO_TFM_RES_MASK); 607 if (unlikely(err)) { 608 skcipher_set_needkey(tfm); 609 return err; 610 } 611 612 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 613 return 0; 614 } 615 616 static int skcipher_crypt_blkcipher(struct skcipher_request *req, 617 int (*crypt)(struct blkcipher_desc *, 618 struct scatterlist *, 619 struct scatterlist *, 620 unsigned int)) 621 { 622 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 623 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 624 struct blkcipher_desc desc = { 625 .tfm = *ctx, 626 .info = req->iv, 627 .flags = req->base.flags, 628 }; 629 630 631 return crypt(&desc, req->dst, req->src, req->cryptlen); 632 } 633 634 static int skcipher_encrypt_blkcipher(struct skcipher_request *req) 635 { 636 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 637 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 638 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 639 640 return skcipher_crypt_blkcipher(req, alg->encrypt); 641 } 642 643 static int skcipher_decrypt_blkcipher(struct skcipher_request *req) 644 { 645 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 646 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 647 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 648 649 return skcipher_crypt_blkcipher(req, alg->decrypt); 650 } 651 652 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 653 { 654 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 655 656 crypto_free_blkcipher(*ctx); 657 } 658 659 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 660 { 661 struct crypto_alg *calg = tfm->__crt_alg; 662 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 663 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 664 struct crypto_blkcipher *blkcipher; 665 struct crypto_tfm *btfm; 666 667 if (!crypto_mod_get(calg)) 668 return -EAGAIN; 669 670 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, 671 CRYPTO_ALG_TYPE_MASK); 672 if (IS_ERR(btfm)) { 673 crypto_mod_put(calg); 674 return PTR_ERR(btfm); 675 } 676 677 blkcipher = __crypto_blkcipher_cast(btfm); 678 *ctx = blkcipher; 679 tfm->exit = crypto_exit_skcipher_ops_blkcipher; 680 681 skcipher->setkey = skcipher_setkey_blkcipher; 682 skcipher->encrypt = skcipher_encrypt_blkcipher; 683 skcipher->decrypt = skcipher_decrypt_blkcipher; 684 685 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); 686 skcipher->keysize = calg->cra_blkcipher.max_keysize; 687 688 skcipher_set_needkey(skcipher); 689 690 return 0; 691 } 692 693 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, 694 const u8 *key, unsigned int keylen) 695 { 696 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 697 struct crypto_ablkcipher *ablkcipher = *ctx; 698 int err; 699 700 crypto_ablkcipher_clear_flags(ablkcipher, ~0); 701 crypto_ablkcipher_set_flags(ablkcipher, 702 crypto_skcipher_get_flags(tfm) & 703 CRYPTO_TFM_REQ_MASK); 704 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); 705 crypto_skcipher_set_flags(tfm, 706 crypto_ablkcipher_get_flags(ablkcipher) & 707 CRYPTO_TFM_RES_MASK); 708 if (unlikely(err)) { 709 skcipher_set_needkey(tfm); 710 return err; 711 } 712 713 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 714 return 0; 715 } 716 717 static int skcipher_crypt_ablkcipher(struct skcipher_request *req, 718 int (*crypt)(struct ablkcipher_request *)) 719 { 720 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 721 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 722 struct ablkcipher_request *subreq = skcipher_request_ctx(req); 723 724 ablkcipher_request_set_tfm(subreq, *ctx); 725 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), 726 req->base.complete, req->base.data); 727 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, 728 req->iv); 729 730 return crypt(subreq); 731 } 732 733 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req) 734 { 735 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 736 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 737 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 738 739 return skcipher_crypt_ablkcipher(req, alg->encrypt); 740 } 741 742 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) 743 { 744 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 745 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 746 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 747 748 return skcipher_crypt_ablkcipher(req, alg->decrypt); 749 } 750 751 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 752 { 753 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 754 755 crypto_free_ablkcipher(*ctx); 756 } 757 758 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 759 { 760 struct crypto_alg *calg = tfm->__crt_alg; 761 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 762 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 763 struct crypto_ablkcipher *ablkcipher; 764 struct crypto_tfm *abtfm; 765 766 if (!crypto_mod_get(calg)) 767 return -EAGAIN; 768 769 abtfm = __crypto_alloc_tfm(calg, 0, 0); 770 if (IS_ERR(abtfm)) { 771 crypto_mod_put(calg); 772 return PTR_ERR(abtfm); 773 } 774 775 ablkcipher = __crypto_ablkcipher_cast(abtfm); 776 *ctx = ablkcipher; 777 tfm->exit = crypto_exit_skcipher_ops_ablkcipher; 778 779 skcipher->setkey = skcipher_setkey_ablkcipher; 780 skcipher->encrypt = skcipher_encrypt_ablkcipher; 781 skcipher->decrypt = skcipher_decrypt_ablkcipher; 782 783 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); 784 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + 785 sizeof(struct ablkcipher_request); 786 skcipher->keysize = calg->cra_ablkcipher.max_keysize; 787 788 skcipher_set_needkey(skcipher); 789 790 return 0; 791 } 792 793 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 794 const u8 *key, unsigned int keylen) 795 { 796 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 797 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 798 u8 *buffer, *alignbuffer; 799 unsigned long absize; 800 int ret; 801 802 absize = keylen + alignmask; 803 buffer = kmalloc(absize, GFP_ATOMIC); 804 if (!buffer) 805 return -ENOMEM; 806 807 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 808 memcpy(alignbuffer, key, keylen); 809 ret = cipher->setkey(tfm, alignbuffer, keylen); 810 kzfree(buffer); 811 return ret; 812 } 813 814 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 815 unsigned int keylen) 816 { 817 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 818 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 819 int err; 820 821 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 822 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 823 return -EINVAL; 824 } 825 826 if ((unsigned long)key & alignmask) 827 err = skcipher_setkey_unaligned(tfm, key, keylen); 828 else 829 err = cipher->setkey(tfm, key, keylen); 830 831 if (unlikely(err)) { 832 skcipher_set_needkey(tfm); 833 return err; 834 } 835 836 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 837 return 0; 838 } 839 840 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 841 { 842 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 843 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 844 845 alg->exit(skcipher); 846 } 847 848 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 849 { 850 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 851 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 852 853 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) 854 return crypto_init_skcipher_ops_blkcipher(tfm); 855 856 if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type) 857 return crypto_init_skcipher_ops_ablkcipher(tfm); 858 859 skcipher->setkey = skcipher_setkey; 860 skcipher->encrypt = alg->encrypt; 861 skcipher->decrypt = alg->decrypt; 862 skcipher->ivsize = alg->ivsize; 863 skcipher->keysize = alg->max_keysize; 864 865 skcipher_set_needkey(skcipher); 866 867 if (alg->exit) 868 skcipher->base.exit = crypto_skcipher_exit_tfm; 869 870 if (alg->init) 871 return alg->init(skcipher); 872 873 return 0; 874 } 875 876 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 877 { 878 struct skcipher_instance *skcipher = 879 container_of(inst, struct skcipher_instance, s.base); 880 881 skcipher->free(skcipher); 882 } 883 884 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 885 __maybe_unused; 886 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 887 { 888 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 889 base); 890 891 seq_printf(m, "type : skcipher\n"); 892 seq_printf(m, "async : %s\n", 893 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 894 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 895 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 896 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 897 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 898 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 899 seq_printf(m, "walksize : %u\n", skcipher->walksize); 900 } 901 902 #ifdef CONFIG_NET 903 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 904 { 905 struct crypto_report_blkcipher rblkcipher; 906 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 907 base); 908 909 memset(&rblkcipher, 0, sizeof(rblkcipher)); 910 911 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 912 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 913 914 rblkcipher.blocksize = alg->cra_blocksize; 915 rblkcipher.min_keysize = skcipher->min_keysize; 916 rblkcipher.max_keysize = skcipher->max_keysize; 917 rblkcipher.ivsize = skcipher->ivsize; 918 919 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 920 sizeof(rblkcipher), &rblkcipher); 921 } 922 #else 923 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 924 { 925 return -ENOSYS; 926 } 927 #endif 928 929 static const struct crypto_type crypto_skcipher_type2 = { 930 .extsize = crypto_skcipher_extsize, 931 .init_tfm = crypto_skcipher_init_tfm, 932 .free = crypto_skcipher_free_instance, 933 #ifdef CONFIG_PROC_FS 934 .show = crypto_skcipher_show, 935 #endif 936 .report = crypto_skcipher_report, 937 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 938 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, 939 .type = CRYPTO_ALG_TYPE_SKCIPHER, 940 .tfmsize = offsetof(struct crypto_skcipher, base), 941 }; 942 943 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 944 const char *name, u32 type, u32 mask) 945 { 946 spawn->base.frontend = &crypto_skcipher_type2; 947 return crypto_grab_spawn(&spawn->base, name, type, mask); 948 } 949 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 950 951 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 952 u32 type, u32 mask) 953 { 954 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 955 } 956 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 957 958 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher( 959 const char *alg_name, u32 type, u32 mask) 960 { 961 struct crypto_skcipher *tfm; 962 963 /* Only sync algorithms allowed. */ 964 mask |= CRYPTO_ALG_ASYNC; 965 966 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 967 968 /* 969 * Make sure we do not allocate something that might get used with 970 * an on-stack request: check the request size. 971 */ 972 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) > 973 MAX_SYNC_SKCIPHER_REQSIZE)) { 974 crypto_free_skcipher(tfm); 975 return ERR_PTR(-EINVAL); 976 } 977 978 return (struct crypto_sync_skcipher *)tfm; 979 } 980 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher); 981 982 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask) 983 { 984 return crypto_type_has_alg(alg_name, &crypto_skcipher_type2, 985 type, mask); 986 } 987 EXPORT_SYMBOL_GPL(crypto_has_skcipher2); 988 989 static int skcipher_prepare_alg(struct skcipher_alg *alg) 990 { 991 struct crypto_alg *base = &alg->base; 992 993 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 994 alg->walksize > PAGE_SIZE / 8) 995 return -EINVAL; 996 997 if (!alg->chunksize) 998 alg->chunksize = base->cra_blocksize; 999 if (!alg->walksize) 1000 alg->walksize = alg->chunksize; 1001 1002 base->cra_type = &crypto_skcipher_type2; 1003 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 1004 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 1005 1006 return 0; 1007 } 1008 1009 int crypto_register_skcipher(struct skcipher_alg *alg) 1010 { 1011 struct crypto_alg *base = &alg->base; 1012 int err; 1013 1014 err = skcipher_prepare_alg(alg); 1015 if (err) 1016 return err; 1017 1018 return crypto_register_alg(base); 1019 } 1020 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 1021 1022 void crypto_unregister_skcipher(struct skcipher_alg *alg) 1023 { 1024 crypto_unregister_alg(&alg->base); 1025 } 1026 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 1027 1028 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 1029 { 1030 int i, ret; 1031 1032 for (i = 0; i < count; i++) { 1033 ret = crypto_register_skcipher(&algs[i]); 1034 if (ret) 1035 goto err; 1036 } 1037 1038 return 0; 1039 1040 err: 1041 for (--i; i >= 0; --i) 1042 crypto_unregister_skcipher(&algs[i]); 1043 1044 return ret; 1045 } 1046 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 1047 1048 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 1049 { 1050 int i; 1051 1052 for (i = count - 1; i >= 0; --i) 1053 crypto_unregister_skcipher(&algs[i]); 1054 } 1055 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 1056 1057 int skcipher_register_instance(struct crypto_template *tmpl, 1058 struct skcipher_instance *inst) 1059 { 1060 int err; 1061 1062 err = skcipher_prepare_alg(&inst->alg); 1063 if (err) 1064 return err; 1065 1066 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 1067 } 1068 EXPORT_SYMBOL_GPL(skcipher_register_instance); 1069 1070 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key, 1071 unsigned int keylen) 1072 { 1073 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); 1074 int err; 1075 1076 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); 1077 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) & 1078 CRYPTO_TFM_REQ_MASK); 1079 err = crypto_cipher_setkey(cipher, key, keylen); 1080 crypto_skcipher_set_flags(tfm, crypto_cipher_get_flags(cipher) & 1081 CRYPTO_TFM_RES_MASK); 1082 return err; 1083 } 1084 1085 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm) 1086 { 1087 struct skcipher_instance *inst = skcipher_alg_instance(tfm); 1088 struct crypto_spawn *spawn = skcipher_instance_ctx(inst); 1089 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 1090 struct crypto_cipher *cipher; 1091 1092 cipher = crypto_spawn_cipher(spawn); 1093 if (IS_ERR(cipher)) 1094 return PTR_ERR(cipher); 1095 1096 ctx->cipher = cipher; 1097 return 0; 1098 } 1099 1100 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm) 1101 { 1102 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 1103 1104 crypto_free_cipher(ctx->cipher); 1105 } 1106 1107 static void skcipher_free_instance_simple(struct skcipher_instance *inst) 1108 { 1109 crypto_drop_spawn(skcipher_instance_ctx(inst)); 1110 kfree(inst); 1111 } 1112 1113 /** 1114 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode 1115 * 1116 * Allocate an skcipher_instance for a simple block cipher mode of operation, 1117 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, 1118 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, 1119 * alignmask, and priority are set from the underlying cipher but can be 1120 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and 1121 * default ->setkey(), ->init(), and ->exit() methods are installed. 1122 * 1123 * @tmpl: the template being instantiated 1124 * @tb: the template parameters 1125 * @cipher_alg_ret: on success, a pointer to the underlying cipher algorithm is 1126 * returned here. It must be dropped with crypto_mod_put(). 1127 * 1128 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still 1129 * needs to register the instance. 1130 */ 1131 struct skcipher_instance * 1132 skcipher_alloc_instance_simple(struct crypto_template *tmpl, struct rtattr **tb, 1133 struct crypto_alg **cipher_alg_ret) 1134 { 1135 struct crypto_attr_type *algt; 1136 struct crypto_alg *cipher_alg; 1137 struct skcipher_instance *inst; 1138 struct crypto_spawn *spawn; 1139 u32 mask; 1140 int err; 1141 1142 algt = crypto_get_attr_type(tb); 1143 if (IS_ERR(algt)) 1144 return ERR_CAST(algt); 1145 1146 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) 1147 return ERR_PTR(-EINVAL); 1148 1149 mask = CRYPTO_ALG_TYPE_MASK | 1150 crypto_requires_off(algt->type, algt->mask, 1151 CRYPTO_ALG_NEED_FALLBACK); 1152 1153 cipher_alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask); 1154 if (IS_ERR(cipher_alg)) 1155 return ERR_CAST(cipher_alg); 1156 1157 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 1158 if (!inst) { 1159 err = -ENOMEM; 1160 goto err_put_cipher_alg; 1161 } 1162 spawn = skcipher_instance_ctx(inst); 1163 1164 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name, 1165 cipher_alg); 1166 if (err) 1167 goto err_free_inst; 1168 1169 err = crypto_init_spawn(spawn, cipher_alg, 1170 skcipher_crypto_instance(inst), 1171 CRYPTO_ALG_TYPE_MASK); 1172 if (err) 1173 goto err_free_inst; 1174 inst->free = skcipher_free_instance_simple; 1175 1176 /* Default algorithm properties, can be overridden */ 1177 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize; 1178 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask; 1179 inst->alg.base.cra_priority = cipher_alg->cra_priority; 1180 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize; 1181 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize; 1182 inst->alg.ivsize = cipher_alg->cra_blocksize; 1183 1184 /* Use skcipher_ctx_simple by default, can be overridden */ 1185 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple); 1186 inst->alg.setkey = skcipher_setkey_simple; 1187 inst->alg.init = skcipher_init_tfm_simple; 1188 inst->alg.exit = skcipher_exit_tfm_simple; 1189 1190 *cipher_alg_ret = cipher_alg; 1191 return inst; 1192 1193 err_free_inst: 1194 kfree(inst); 1195 err_put_cipher_alg: 1196 crypto_mod_put(cipher_alg); 1197 return ERR_PTR(err); 1198 } 1199 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple); 1200 1201 MODULE_LICENSE("GPL"); 1202 MODULE_DESCRIPTION("Symmetric key cipher type"); 1203