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 int 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 return 0; 102 } 103 104 int skcipher_walk_done(struct skcipher_walk *walk, int err) 105 { 106 unsigned int n = walk->nbytes; 107 unsigned int nbytes = 0; 108 109 if (!n) 110 goto finish; 111 112 if (likely(err >= 0)) { 113 n -= err; 114 nbytes = walk->total - n; 115 } 116 117 if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | 118 SKCIPHER_WALK_SLOW | 119 SKCIPHER_WALK_COPY | 120 SKCIPHER_WALK_DIFF)))) { 121 unmap_src: 122 skcipher_unmap_src(walk); 123 } else if (walk->flags & SKCIPHER_WALK_DIFF) { 124 skcipher_unmap_dst(walk); 125 goto unmap_src; 126 } else if (walk->flags & SKCIPHER_WALK_COPY) { 127 skcipher_map_dst(walk); 128 memcpy(walk->dst.virt.addr, walk->page, n); 129 skcipher_unmap_dst(walk); 130 } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) { 131 if (err > 0) { 132 /* 133 * Didn't process all bytes. Either the algorithm is 134 * broken, or this was the last step and it turned out 135 * the message wasn't evenly divisible into blocks but 136 * the algorithm requires it. 137 */ 138 err = -EINVAL; 139 nbytes = 0; 140 } else 141 n = skcipher_done_slow(walk, n); 142 } 143 144 if (err > 0) 145 err = 0; 146 147 walk->total = nbytes; 148 walk->nbytes = 0; 149 150 scatterwalk_advance(&walk->in, n); 151 scatterwalk_advance(&walk->out, n); 152 scatterwalk_done(&walk->in, 0, nbytes); 153 scatterwalk_done(&walk->out, 1, nbytes); 154 155 if (nbytes) { 156 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? 157 CRYPTO_TFM_REQ_MAY_SLEEP : 0); 158 return skcipher_walk_next(walk); 159 } 160 161 finish: 162 /* Short-circuit for the common/fast path. */ 163 if (!((unsigned long)walk->buffer | (unsigned long)walk->page)) 164 goto out; 165 166 if (walk->flags & SKCIPHER_WALK_PHYS) 167 goto out; 168 169 if (walk->iv != walk->oiv) 170 memcpy(walk->oiv, walk->iv, walk->ivsize); 171 if (walk->buffer != walk->page) 172 kfree(walk->buffer); 173 if (walk->page) 174 free_page((unsigned long)walk->page); 175 176 out: 177 return err; 178 } 179 EXPORT_SYMBOL_GPL(skcipher_walk_done); 180 181 void skcipher_walk_complete(struct skcipher_walk *walk, int err) 182 { 183 struct skcipher_walk_buffer *p, *tmp; 184 185 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) { 186 u8 *data; 187 188 if (err) 189 goto done; 190 191 data = p->data; 192 if (!data) { 193 data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1); 194 data = skcipher_get_spot(data, walk->stride); 195 } 196 197 scatterwalk_copychunks(data, &p->dst, p->len, 1); 198 199 if (offset_in_page(p->data) + p->len + walk->stride > 200 PAGE_SIZE) 201 free_page((unsigned long)p->data); 202 203 done: 204 list_del(&p->entry); 205 kfree(p); 206 } 207 208 if (!err && walk->iv != walk->oiv) 209 memcpy(walk->oiv, walk->iv, walk->ivsize); 210 if (walk->buffer != walk->page) 211 kfree(walk->buffer); 212 if (walk->page) 213 free_page((unsigned long)walk->page); 214 } 215 EXPORT_SYMBOL_GPL(skcipher_walk_complete); 216 217 static void skcipher_queue_write(struct skcipher_walk *walk, 218 struct skcipher_walk_buffer *p) 219 { 220 p->dst = walk->out; 221 list_add_tail(&p->entry, &walk->buffers); 222 } 223 224 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) 225 { 226 bool phys = walk->flags & SKCIPHER_WALK_PHYS; 227 unsigned alignmask = walk->alignmask; 228 struct skcipher_walk_buffer *p; 229 unsigned a; 230 unsigned n; 231 u8 *buffer; 232 void *v; 233 234 if (!phys) { 235 if (!walk->buffer) 236 walk->buffer = walk->page; 237 buffer = walk->buffer; 238 if (buffer) 239 goto ok; 240 } 241 242 /* Start with the minimum alignment of kmalloc. */ 243 a = crypto_tfm_ctx_alignment() - 1; 244 n = bsize; 245 246 if (phys) { 247 /* Calculate the minimum alignment of p->buffer. */ 248 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1; 249 n += sizeof(*p); 250 } 251 252 /* Minimum size to align p->buffer by alignmask. */ 253 n += alignmask & ~a; 254 255 /* Minimum size to ensure p->buffer does not straddle a page. */ 256 n += (bsize - 1) & ~(alignmask | a); 257 258 v = kzalloc(n, skcipher_walk_gfp(walk)); 259 if (!v) 260 return skcipher_walk_done(walk, -ENOMEM); 261 262 if (phys) { 263 p = v; 264 p->len = bsize; 265 skcipher_queue_write(walk, p); 266 buffer = p->buffer; 267 } else { 268 walk->buffer = v; 269 buffer = v; 270 } 271 272 ok: 273 walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1); 274 walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize); 275 walk->src.virt.addr = walk->dst.virt.addr; 276 277 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); 278 279 walk->nbytes = bsize; 280 walk->flags |= SKCIPHER_WALK_SLOW; 281 282 return 0; 283 } 284 285 static int skcipher_next_copy(struct skcipher_walk *walk) 286 { 287 struct skcipher_walk_buffer *p; 288 u8 *tmp = walk->page; 289 290 skcipher_map_src(walk); 291 memcpy(tmp, walk->src.virt.addr, walk->nbytes); 292 skcipher_unmap_src(walk); 293 294 walk->src.virt.addr = tmp; 295 walk->dst.virt.addr = tmp; 296 297 if (!(walk->flags & SKCIPHER_WALK_PHYS)) 298 return 0; 299 300 p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk)); 301 if (!p) 302 return -ENOMEM; 303 304 p->data = walk->page; 305 p->len = walk->nbytes; 306 skcipher_queue_write(walk, p); 307 308 if (offset_in_page(walk->page) + walk->nbytes + walk->stride > 309 PAGE_SIZE) 310 walk->page = NULL; 311 else 312 walk->page += walk->nbytes; 313 314 return 0; 315 } 316 317 static int skcipher_next_fast(struct skcipher_walk *walk) 318 { 319 unsigned long diff; 320 321 walk->src.phys.page = scatterwalk_page(&walk->in); 322 walk->src.phys.offset = offset_in_page(walk->in.offset); 323 walk->dst.phys.page = scatterwalk_page(&walk->out); 324 walk->dst.phys.offset = offset_in_page(walk->out.offset); 325 326 if (walk->flags & SKCIPHER_WALK_PHYS) 327 return 0; 328 329 diff = walk->src.phys.offset - walk->dst.phys.offset; 330 diff |= walk->src.virt.page - walk->dst.virt.page; 331 332 skcipher_map_src(walk); 333 walk->dst.virt.addr = walk->src.virt.addr; 334 335 if (diff) { 336 walk->flags |= SKCIPHER_WALK_DIFF; 337 skcipher_map_dst(walk); 338 } 339 340 return 0; 341 } 342 343 static int skcipher_walk_next(struct skcipher_walk *walk) 344 { 345 unsigned int bsize; 346 unsigned int n; 347 int err; 348 349 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | 350 SKCIPHER_WALK_DIFF); 351 352 n = walk->total; 353 bsize = min(walk->stride, max(n, walk->blocksize)); 354 n = scatterwalk_clamp(&walk->in, n); 355 n = scatterwalk_clamp(&walk->out, n); 356 357 if (unlikely(n < bsize)) { 358 if (unlikely(walk->total < walk->blocksize)) 359 return skcipher_walk_done(walk, -EINVAL); 360 361 slow_path: 362 err = skcipher_next_slow(walk, bsize); 363 goto set_phys_lowmem; 364 } 365 366 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { 367 if (!walk->page) { 368 gfp_t gfp = skcipher_walk_gfp(walk); 369 370 walk->page = (void *)__get_free_page(gfp); 371 if (!walk->page) 372 goto slow_path; 373 } 374 375 walk->nbytes = min_t(unsigned, n, 376 PAGE_SIZE - offset_in_page(walk->page)); 377 walk->flags |= SKCIPHER_WALK_COPY; 378 err = skcipher_next_copy(walk); 379 goto set_phys_lowmem; 380 } 381 382 walk->nbytes = n; 383 384 return skcipher_next_fast(walk); 385 386 set_phys_lowmem: 387 if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) { 388 walk->src.phys.page = virt_to_page(walk->src.virt.addr); 389 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); 390 walk->src.phys.offset &= PAGE_SIZE - 1; 391 walk->dst.phys.offset &= PAGE_SIZE - 1; 392 } 393 return err; 394 } 395 396 static int skcipher_copy_iv(struct skcipher_walk *walk) 397 { 398 unsigned a = crypto_tfm_ctx_alignment() - 1; 399 unsigned alignmask = walk->alignmask; 400 unsigned ivsize = walk->ivsize; 401 unsigned bs = walk->stride; 402 unsigned aligned_bs; 403 unsigned size; 404 u8 *iv; 405 406 aligned_bs = ALIGN(bs, alignmask + 1); 407 408 /* Minimum size to align buffer by alignmask. */ 409 size = alignmask & ~a; 410 411 if (walk->flags & SKCIPHER_WALK_PHYS) 412 size += ivsize; 413 else { 414 size += aligned_bs + ivsize; 415 416 /* Minimum size to ensure buffer does not straddle a page. */ 417 size += (bs - 1) & ~(alignmask | a); 418 } 419 420 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); 421 if (!walk->buffer) 422 return -ENOMEM; 423 424 iv = PTR_ALIGN(walk->buffer, alignmask + 1); 425 iv = skcipher_get_spot(iv, bs) + aligned_bs; 426 427 walk->iv = memcpy(iv, walk->iv, walk->ivsize); 428 return 0; 429 } 430 431 static int skcipher_walk_first(struct skcipher_walk *walk) 432 { 433 if (WARN_ON_ONCE(in_irq())) 434 return -EDEADLK; 435 436 walk->buffer = NULL; 437 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { 438 int err = skcipher_copy_iv(walk); 439 if (err) 440 return err; 441 } 442 443 walk->page = NULL; 444 445 return skcipher_walk_next(walk); 446 } 447 448 static int skcipher_walk_skcipher(struct skcipher_walk *walk, 449 struct skcipher_request *req) 450 { 451 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 452 453 walk->total = req->cryptlen; 454 walk->nbytes = 0; 455 walk->iv = req->iv; 456 walk->oiv = req->iv; 457 458 if (unlikely(!walk->total)) 459 return 0; 460 461 scatterwalk_start(&walk->in, req->src); 462 scatterwalk_start(&walk->out, req->dst); 463 464 walk->flags &= ~SKCIPHER_WALK_SLEEP; 465 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 466 SKCIPHER_WALK_SLEEP : 0; 467 468 walk->blocksize = crypto_skcipher_blocksize(tfm); 469 walk->stride = crypto_skcipher_walksize(tfm); 470 walk->ivsize = crypto_skcipher_ivsize(tfm); 471 walk->alignmask = crypto_skcipher_alignmask(tfm); 472 473 return skcipher_walk_first(walk); 474 } 475 476 int skcipher_walk_virt(struct skcipher_walk *walk, 477 struct skcipher_request *req, bool atomic) 478 { 479 int err; 480 481 might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 482 483 walk->flags &= ~SKCIPHER_WALK_PHYS; 484 485 err = skcipher_walk_skcipher(walk, req); 486 487 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0; 488 489 return err; 490 } 491 EXPORT_SYMBOL_GPL(skcipher_walk_virt); 492 493 void skcipher_walk_atomise(struct skcipher_walk *walk) 494 { 495 walk->flags &= ~SKCIPHER_WALK_SLEEP; 496 } 497 EXPORT_SYMBOL_GPL(skcipher_walk_atomise); 498 499 int skcipher_walk_async(struct skcipher_walk *walk, 500 struct skcipher_request *req) 501 { 502 walk->flags |= SKCIPHER_WALK_PHYS; 503 504 INIT_LIST_HEAD(&walk->buffers); 505 506 return skcipher_walk_skcipher(walk, req); 507 } 508 EXPORT_SYMBOL_GPL(skcipher_walk_async); 509 510 static int skcipher_walk_aead_common(struct skcipher_walk *walk, 511 struct aead_request *req, bool atomic) 512 { 513 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 514 int err; 515 516 walk->nbytes = 0; 517 walk->iv = req->iv; 518 walk->oiv = req->iv; 519 520 if (unlikely(!walk->total)) 521 return 0; 522 523 walk->flags &= ~SKCIPHER_WALK_PHYS; 524 525 scatterwalk_start(&walk->in, req->src); 526 scatterwalk_start(&walk->out, req->dst); 527 528 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); 529 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); 530 531 scatterwalk_done(&walk->in, 0, walk->total); 532 scatterwalk_done(&walk->out, 0, walk->total); 533 534 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) 535 walk->flags |= SKCIPHER_WALK_SLEEP; 536 else 537 walk->flags &= ~SKCIPHER_WALK_SLEEP; 538 539 walk->blocksize = crypto_aead_blocksize(tfm); 540 walk->stride = crypto_aead_chunksize(tfm); 541 walk->ivsize = crypto_aead_ivsize(tfm); 542 walk->alignmask = crypto_aead_alignmask(tfm); 543 544 err = skcipher_walk_first(walk); 545 546 if (atomic) 547 walk->flags &= ~SKCIPHER_WALK_SLEEP; 548 549 return err; 550 } 551 552 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, 553 bool atomic) 554 { 555 walk->total = req->cryptlen; 556 557 return skcipher_walk_aead_common(walk, req, atomic); 558 } 559 EXPORT_SYMBOL_GPL(skcipher_walk_aead); 560 561 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, 562 struct aead_request *req, bool atomic) 563 { 564 walk->total = req->cryptlen; 565 566 return skcipher_walk_aead_common(walk, req, atomic); 567 } 568 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); 569 570 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 571 struct aead_request *req, bool atomic) 572 { 573 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 574 575 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 576 577 return skcipher_walk_aead_common(walk, req, atomic); 578 } 579 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 580 581 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) 582 { 583 return crypto_alg_extsize(alg); 584 } 585 586 static void skcipher_set_needkey(struct crypto_skcipher *tfm) 587 { 588 if (tfm->keysize) 589 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY); 590 } 591 592 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 593 const u8 *key, unsigned int keylen) 594 { 595 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 596 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 597 u8 *buffer, *alignbuffer; 598 unsigned long absize; 599 int ret; 600 601 absize = keylen + alignmask; 602 buffer = kmalloc(absize, GFP_ATOMIC); 603 if (!buffer) 604 return -ENOMEM; 605 606 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 607 memcpy(alignbuffer, key, keylen); 608 ret = cipher->setkey(tfm, alignbuffer, keylen); 609 kzfree(buffer); 610 return ret; 611 } 612 613 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 614 unsigned int keylen) 615 { 616 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 617 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 618 int err; 619 620 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 621 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 622 return -EINVAL; 623 } 624 625 if ((unsigned long)key & alignmask) 626 err = skcipher_setkey_unaligned(tfm, key, keylen); 627 else 628 err = cipher->setkey(tfm, key, keylen); 629 630 if (unlikely(err)) { 631 skcipher_set_needkey(tfm); 632 return err; 633 } 634 635 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 636 return 0; 637 } 638 639 int crypto_skcipher_encrypt(struct skcipher_request *req) 640 { 641 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 642 struct crypto_alg *alg = tfm->base.__crt_alg; 643 unsigned int cryptlen = req->cryptlen; 644 int ret; 645 646 crypto_stats_get(alg); 647 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 648 ret = -ENOKEY; 649 else 650 ret = tfm->encrypt(req); 651 crypto_stats_skcipher_encrypt(cryptlen, ret, alg); 652 return ret; 653 } 654 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt); 655 656 int crypto_skcipher_decrypt(struct skcipher_request *req) 657 { 658 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 659 struct crypto_alg *alg = tfm->base.__crt_alg; 660 unsigned int cryptlen = req->cryptlen; 661 int ret; 662 663 crypto_stats_get(alg); 664 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 665 ret = -ENOKEY; 666 else 667 ret = tfm->decrypt(req); 668 crypto_stats_skcipher_decrypt(cryptlen, ret, alg); 669 return ret; 670 } 671 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt); 672 673 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 674 { 675 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 676 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 677 678 alg->exit(skcipher); 679 } 680 681 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 682 { 683 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 684 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 685 686 skcipher->setkey = skcipher_setkey; 687 skcipher->encrypt = alg->encrypt; 688 skcipher->decrypt = alg->decrypt; 689 skcipher->ivsize = alg->ivsize; 690 skcipher->keysize = alg->max_keysize; 691 692 skcipher_set_needkey(skcipher); 693 694 if (alg->exit) 695 skcipher->base.exit = crypto_skcipher_exit_tfm; 696 697 if (alg->init) 698 return alg->init(skcipher); 699 700 return 0; 701 } 702 703 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 704 { 705 struct skcipher_instance *skcipher = 706 container_of(inst, struct skcipher_instance, s.base); 707 708 skcipher->free(skcipher); 709 } 710 711 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 712 __maybe_unused; 713 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 714 { 715 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 716 base); 717 718 seq_printf(m, "type : skcipher\n"); 719 seq_printf(m, "async : %s\n", 720 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 721 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 722 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 723 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 724 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 725 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 726 seq_printf(m, "walksize : %u\n", skcipher->walksize); 727 } 728 729 #ifdef CONFIG_NET 730 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 731 { 732 struct crypto_report_blkcipher rblkcipher; 733 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 734 base); 735 736 memset(&rblkcipher, 0, sizeof(rblkcipher)); 737 738 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 739 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 740 741 rblkcipher.blocksize = alg->cra_blocksize; 742 rblkcipher.min_keysize = skcipher->min_keysize; 743 rblkcipher.max_keysize = skcipher->max_keysize; 744 rblkcipher.ivsize = skcipher->ivsize; 745 746 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 747 sizeof(rblkcipher), &rblkcipher); 748 } 749 #else 750 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 751 { 752 return -ENOSYS; 753 } 754 #endif 755 756 static const struct crypto_type crypto_skcipher_type = { 757 .extsize = crypto_skcipher_extsize, 758 .init_tfm = crypto_skcipher_init_tfm, 759 .free = crypto_skcipher_free_instance, 760 #ifdef CONFIG_PROC_FS 761 .show = crypto_skcipher_show, 762 #endif 763 .report = crypto_skcipher_report, 764 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 765 .maskset = CRYPTO_ALG_TYPE_MASK, 766 .type = CRYPTO_ALG_TYPE_SKCIPHER, 767 .tfmsize = offsetof(struct crypto_skcipher, base), 768 }; 769 770 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 771 const char *name, u32 type, u32 mask) 772 { 773 spawn->base.frontend = &crypto_skcipher_type; 774 return crypto_grab_spawn(&spawn->base, name, type, mask); 775 } 776 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 777 778 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 779 u32 type, u32 mask) 780 { 781 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); 782 } 783 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 784 785 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher( 786 const char *alg_name, u32 type, u32 mask) 787 { 788 struct crypto_skcipher *tfm; 789 790 /* Only sync algorithms allowed. */ 791 mask |= CRYPTO_ALG_ASYNC; 792 793 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); 794 795 /* 796 * Make sure we do not allocate something that might get used with 797 * an on-stack request: check the request size. 798 */ 799 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) > 800 MAX_SYNC_SKCIPHER_REQSIZE)) { 801 crypto_free_skcipher(tfm); 802 return ERR_PTR(-EINVAL); 803 } 804 805 return (struct crypto_sync_skcipher *)tfm; 806 } 807 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher); 808 809 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask) 810 { 811 return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask); 812 } 813 EXPORT_SYMBOL_GPL(crypto_has_skcipher); 814 815 static int skcipher_prepare_alg(struct skcipher_alg *alg) 816 { 817 struct crypto_alg *base = &alg->base; 818 819 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 820 alg->walksize > PAGE_SIZE / 8) 821 return -EINVAL; 822 823 if (!alg->chunksize) 824 alg->chunksize = base->cra_blocksize; 825 if (!alg->walksize) 826 alg->walksize = alg->chunksize; 827 828 base->cra_type = &crypto_skcipher_type; 829 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 830 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 831 832 return 0; 833 } 834 835 int crypto_register_skcipher(struct skcipher_alg *alg) 836 { 837 struct crypto_alg *base = &alg->base; 838 int err; 839 840 err = skcipher_prepare_alg(alg); 841 if (err) 842 return err; 843 844 return crypto_register_alg(base); 845 } 846 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 847 848 void crypto_unregister_skcipher(struct skcipher_alg *alg) 849 { 850 crypto_unregister_alg(&alg->base); 851 } 852 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 853 854 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 855 { 856 int i, ret; 857 858 for (i = 0; i < count; i++) { 859 ret = crypto_register_skcipher(&algs[i]); 860 if (ret) 861 goto err; 862 } 863 864 return 0; 865 866 err: 867 for (--i; i >= 0; --i) 868 crypto_unregister_skcipher(&algs[i]); 869 870 return ret; 871 } 872 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 873 874 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 875 { 876 int i; 877 878 for (i = count - 1; i >= 0; --i) 879 crypto_unregister_skcipher(&algs[i]); 880 } 881 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 882 883 int skcipher_register_instance(struct crypto_template *tmpl, 884 struct skcipher_instance *inst) 885 { 886 int err; 887 888 err = skcipher_prepare_alg(&inst->alg); 889 if (err) 890 return err; 891 892 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 893 } 894 EXPORT_SYMBOL_GPL(skcipher_register_instance); 895 896 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key, 897 unsigned int keylen) 898 { 899 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); 900 int err; 901 902 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); 903 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) & 904 CRYPTO_TFM_REQ_MASK); 905 err = crypto_cipher_setkey(cipher, key, keylen); 906 crypto_skcipher_set_flags(tfm, crypto_cipher_get_flags(cipher) & 907 CRYPTO_TFM_RES_MASK); 908 return err; 909 } 910 911 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm) 912 { 913 struct skcipher_instance *inst = skcipher_alg_instance(tfm); 914 struct crypto_spawn *spawn = skcipher_instance_ctx(inst); 915 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 916 struct crypto_cipher *cipher; 917 918 cipher = crypto_spawn_cipher(spawn); 919 if (IS_ERR(cipher)) 920 return PTR_ERR(cipher); 921 922 ctx->cipher = cipher; 923 return 0; 924 } 925 926 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm) 927 { 928 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 929 930 crypto_free_cipher(ctx->cipher); 931 } 932 933 static void skcipher_free_instance_simple(struct skcipher_instance *inst) 934 { 935 crypto_drop_spawn(skcipher_instance_ctx(inst)); 936 kfree(inst); 937 } 938 939 /** 940 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode 941 * 942 * Allocate an skcipher_instance for a simple block cipher mode of operation, 943 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, 944 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, 945 * alignmask, and priority are set from the underlying cipher but can be 946 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and 947 * default ->setkey(), ->init(), and ->exit() methods are installed. 948 * 949 * @tmpl: the template being instantiated 950 * @tb: the template parameters 951 * @cipher_alg_ret: on success, a pointer to the underlying cipher algorithm is 952 * returned here. It must be dropped with crypto_mod_put(). 953 * 954 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still 955 * needs to register the instance. 956 */ 957 struct skcipher_instance * 958 skcipher_alloc_instance_simple(struct crypto_template *tmpl, struct rtattr **tb, 959 struct crypto_alg **cipher_alg_ret) 960 { 961 struct crypto_attr_type *algt; 962 struct crypto_alg *cipher_alg; 963 struct skcipher_instance *inst; 964 struct crypto_spawn *spawn; 965 u32 mask; 966 int err; 967 968 algt = crypto_get_attr_type(tb); 969 if (IS_ERR(algt)) 970 return ERR_CAST(algt); 971 972 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) 973 return ERR_PTR(-EINVAL); 974 975 mask = CRYPTO_ALG_TYPE_MASK | 976 crypto_requires_off(algt->type, algt->mask, 977 CRYPTO_ALG_NEED_FALLBACK); 978 979 cipher_alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask); 980 if (IS_ERR(cipher_alg)) 981 return ERR_CAST(cipher_alg); 982 983 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 984 if (!inst) { 985 err = -ENOMEM; 986 goto err_put_cipher_alg; 987 } 988 spawn = skcipher_instance_ctx(inst); 989 990 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name, 991 cipher_alg); 992 if (err) 993 goto err_free_inst; 994 995 err = crypto_init_spawn(spawn, cipher_alg, 996 skcipher_crypto_instance(inst), 997 CRYPTO_ALG_TYPE_MASK); 998 if (err) 999 goto err_free_inst; 1000 inst->free = skcipher_free_instance_simple; 1001 1002 /* Default algorithm properties, can be overridden */ 1003 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize; 1004 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask; 1005 inst->alg.base.cra_priority = cipher_alg->cra_priority; 1006 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize; 1007 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize; 1008 inst->alg.ivsize = cipher_alg->cra_blocksize; 1009 1010 /* Use skcipher_ctx_simple by default, can be overridden */ 1011 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple); 1012 inst->alg.setkey = skcipher_setkey_simple; 1013 inst->alg.init = skcipher_init_tfm_simple; 1014 inst->alg.exit = skcipher_exit_tfm_simple; 1015 1016 *cipher_alg_ret = cipher_alg; 1017 return inst; 1018 1019 err_free_inst: 1020 kfree(inst); 1021 err_put_cipher_alg: 1022 crypto_mod_put(cipher_alg); 1023 return ERR_PTR(err); 1024 } 1025 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple); 1026 1027 MODULE_LICENSE("GPL"); 1028 MODULE_DESCRIPTION("Symmetric key cipher type"); 1029