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_encrypt(struct skcipher_walk *walk, 553 struct aead_request *req, 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_encrypt); 560 561 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 562 struct aead_request *req, bool atomic) 563 { 564 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 565 566 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 567 568 return skcipher_walk_aead_common(walk, req, atomic); 569 } 570 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 571 572 static void skcipher_set_needkey(struct crypto_skcipher *tfm) 573 { 574 if (crypto_skcipher_max_keysize(tfm) != 0) 575 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY); 576 } 577 578 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 579 const u8 *key, unsigned int keylen) 580 { 581 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 582 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 583 u8 *buffer, *alignbuffer; 584 unsigned long absize; 585 int ret; 586 587 absize = keylen + alignmask; 588 buffer = kmalloc(absize, GFP_ATOMIC); 589 if (!buffer) 590 return -ENOMEM; 591 592 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 593 memcpy(alignbuffer, key, keylen); 594 ret = cipher->setkey(tfm, alignbuffer, keylen); 595 kzfree(buffer); 596 return ret; 597 } 598 599 int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 600 unsigned int keylen) 601 { 602 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 603 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 604 int err; 605 606 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 607 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 608 return -EINVAL; 609 } 610 611 if ((unsigned long)key & alignmask) 612 err = skcipher_setkey_unaligned(tfm, key, keylen); 613 else 614 err = cipher->setkey(tfm, key, keylen); 615 616 if (unlikely(err)) { 617 skcipher_set_needkey(tfm); 618 return err; 619 } 620 621 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 622 return 0; 623 } 624 EXPORT_SYMBOL_GPL(crypto_skcipher_setkey); 625 626 int crypto_skcipher_encrypt(struct skcipher_request *req) 627 { 628 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 629 struct crypto_alg *alg = tfm->base.__crt_alg; 630 unsigned int cryptlen = req->cryptlen; 631 int ret; 632 633 crypto_stats_get(alg); 634 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 635 ret = -ENOKEY; 636 else 637 ret = crypto_skcipher_alg(tfm)->encrypt(req); 638 crypto_stats_skcipher_encrypt(cryptlen, ret, alg); 639 return ret; 640 } 641 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt); 642 643 int crypto_skcipher_decrypt(struct skcipher_request *req) 644 { 645 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 646 struct crypto_alg *alg = tfm->base.__crt_alg; 647 unsigned int cryptlen = req->cryptlen; 648 int ret; 649 650 crypto_stats_get(alg); 651 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 652 ret = -ENOKEY; 653 else 654 ret = crypto_skcipher_alg(tfm)->decrypt(req); 655 crypto_stats_skcipher_decrypt(cryptlen, ret, alg); 656 return ret; 657 } 658 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt); 659 660 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 661 { 662 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 663 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 664 665 alg->exit(skcipher); 666 } 667 668 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 669 { 670 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 671 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 672 673 skcipher_set_needkey(skcipher); 674 675 if (alg->exit) 676 skcipher->base.exit = crypto_skcipher_exit_tfm; 677 678 if (alg->init) 679 return alg->init(skcipher); 680 681 return 0; 682 } 683 684 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 685 { 686 struct skcipher_instance *skcipher = 687 container_of(inst, struct skcipher_instance, s.base); 688 689 skcipher->free(skcipher); 690 } 691 692 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 693 __maybe_unused; 694 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 695 { 696 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 697 base); 698 699 seq_printf(m, "type : skcipher\n"); 700 seq_printf(m, "async : %s\n", 701 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 702 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 703 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 704 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 705 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 706 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 707 seq_printf(m, "walksize : %u\n", skcipher->walksize); 708 } 709 710 #ifdef CONFIG_NET 711 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 712 { 713 struct crypto_report_blkcipher rblkcipher; 714 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 715 base); 716 717 memset(&rblkcipher, 0, sizeof(rblkcipher)); 718 719 strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 720 strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 721 722 rblkcipher.blocksize = alg->cra_blocksize; 723 rblkcipher.min_keysize = skcipher->min_keysize; 724 rblkcipher.max_keysize = skcipher->max_keysize; 725 rblkcipher.ivsize = skcipher->ivsize; 726 727 return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 728 sizeof(rblkcipher), &rblkcipher); 729 } 730 #else 731 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 732 { 733 return -ENOSYS; 734 } 735 #endif 736 737 static const struct crypto_type crypto_skcipher_type = { 738 .extsize = crypto_alg_extsize, 739 .init_tfm = crypto_skcipher_init_tfm, 740 .free = crypto_skcipher_free_instance, 741 #ifdef CONFIG_PROC_FS 742 .show = crypto_skcipher_show, 743 #endif 744 .report = crypto_skcipher_report, 745 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 746 .maskset = CRYPTO_ALG_TYPE_MASK, 747 .type = CRYPTO_ALG_TYPE_SKCIPHER, 748 .tfmsize = offsetof(struct crypto_skcipher, base), 749 }; 750 751 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 752 const char *name, u32 type, u32 mask) 753 { 754 spawn->base.frontend = &crypto_skcipher_type; 755 return crypto_grab_spawn(&spawn->base, name, type, mask); 756 } 757 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 758 759 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 760 u32 type, u32 mask) 761 { 762 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); 763 } 764 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 765 766 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher( 767 const char *alg_name, u32 type, u32 mask) 768 { 769 struct crypto_skcipher *tfm; 770 771 /* Only sync algorithms allowed. */ 772 mask |= CRYPTO_ALG_ASYNC; 773 774 tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask); 775 776 /* 777 * Make sure we do not allocate something that might get used with 778 * an on-stack request: check the request size. 779 */ 780 if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) > 781 MAX_SYNC_SKCIPHER_REQSIZE)) { 782 crypto_free_skcipher(tfm); 783 return ERR_PTR(-EINVAL); 784 } 785 786 return (struct crypto_sync_skcipher *)tfm; 787 } 788 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher); 789 790 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask) 791 { 792 return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask); 793 } 794 EXPORT_SYMBOL_GPL(crypto_has_skcipher); 795 796 static int skcipher_prepare_alg(struct skcipher_alg *alg) 797 { 798 struct crypto_alg *base = &alg->base; 799 800 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 801 alg->walksize > PAGE_SIZE / 8) 802 return -EINVAL; 803 804 if (!alg->chunksize) 805 alg->chunksize = base->cra_blocksize; 806 if (!alg->walksize) 807 alg->walksize = alg->chunksize; 808 809 base->cra_type = &crypto_skcipher_type; 810 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 811 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 812 813 return 0; 814 } 815 816 int crypto_register_skcipher(struct skcipher_alg *alg) 817 { 818 struct crypto_alg *base = &alg->base; 819 int err; 820 821 err = skcipher_prepare_alg(alg); 822 if (err) 823 return err; 824 825 return crypto_register_alg(base); 826 } 827 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 828 829 void crypto_unregister_skcipher(struct skcipher_alg *alg) 830 { 831 crypto_unregister_alg(&alg->base); 832 } 833 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 834 835 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 836 { 837 int i, ret; 838 839 for (i = 0; i < count; i++) { 840 ret = crypto_register_skcipher(&algs[i]); 841 if (ret) 842 goto err; 843 } 844 845 return 0; 846 847 err: 848 for (--i; i >= 0; --i) 849 crypto_unregister_skcipher(&algs[i]); 850 851 return ret; 852 } 853 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 854 855 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 856 { 857 int i; 858 859 for (i = count - 1; i >= 0; --i) 860 crypto_unregister_skcipher(&algs[i]); 861 } 862 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 863 864 int skcipher_register_instance(struct crypto_template *tmpl, 865 struct skcipher_instance *inst) 866 { 867 int err; 868 869 err = skcipher_prepare_alg(&inst->alg); 870 if (err) 871 return err; 872 873 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 874 } 875 EXPORT_SYMBOL_GPL(skcipher_register_instance); 876 877 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key, 878 unsigned int keylen) 879 { 880 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); 881 int err; 882 883 crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK); 884 crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) & 885 CRYPTO_TFM_REQ_MASK); 886 err = crypto_cipher_setkey(cipher, key, keylen); 887 crypto_skcipher_set_flags(tfm, crypto_cipher_get_flags(cipher) & 888 CRYPTO_TFM_RES_MASK); 889 return err; 890 } 891 892 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm) 893 { 894 struct skcipher_instance *inst = skcipher_alg_instance(tfm); 895 struct crypto_spawn *spawn = skcipher_instance_ctx(inst); 896 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 897 struct crypto_cipher *cipher; 898 899 cipher = crypto_spawn_cipher(spawn); 900 if (IS_ERR(cipher)) 901 return PTR_ERR(cipher); 902 903 ctx->cipher = cipher; 904 return 0; 905 } 906 907 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm) 908 { 909 struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm); 910 911 crypto_free_cipher(ctx->cipher); 912 } 913 914 static void skcipher_free_instance_simple(struct skcipher_instance *inst) 915 { 916 crypto_drop_spawn(skcipher_instance_ctx(inst)); 917 kfree(inst); 918 } 919 920 /** 921 * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode 922 * 923 * Allocate an skcipher_instance for a simple block cipher mode of operation, 924 * e.g. cbc or ecb. The instance context will have just a single crypto_spawn, 925 * that for the underlying cipher. The {min,max}_keysize, ivsize, blocksize, 926 * alignmask, and priority are set from the underlying cipher but can be 927 * overridden if needed. The tfm context defaults to skcipher_ctx_simple, and 928 * default ->setkey(), ->init(), and ->exit() methods are installed. 929 * 930 * @tmpl: the template being instantiated 931 * @tb: the template parameters 932 * 933 * Return: a pointer to the new instance, or an ERR_PTR(). The caller still 934 * needs to register the instance. 935 */ 936 struct skcipher_instance *skcipher_alloc_instance_simple( 937 struct crypto_template *tmpl, struct rtattr **tb) 938 { 939 struct crypto_attr_type *algt; 940 struct crypto_alg *cipher_alg; 941 struct skcipher_instance *inst; 942 struct crypto_spawn *spawn; 943 u32 mask; 944 int err; 945 946 algt = crypto_get_attr_type(tb); 947 if (IS_ERR(algt)) 948 return ERR_CAST(algt); 949 950 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) 951 return ERR_PTR(-EINVAL); 952 953 mask = CRYPTO_ALG_TYPE_MASK | 954 crypto_requires_off(algt->type, algt->mask, 955 CRYPTO_ALG_NEED_FALLBACK); 956 957 cipher_alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask); 958 if (IS_ERR(cipher_alg)) 959 return ERR_CAST(cipher_alg); 960 961 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 962 if (!inst) { 963 err = -ENOMEM; 964 goto err_put_cipher_alg; 965 } 966 spawn = skcipher_instance_ctx(inst); 967 968 err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name, 969 cipher_alg); 970 if (err) 971 goto err_free_inst; 972 973 spawn->dropref = true; 974 err = crypto_init_spawn(spawn, cipher_alg, 975 skcipher_crypto_instance(inst), 976 CRYPTO_ALG_TYPE_MASK); 977 if (err) 978 goto err_free_inst; 979 inst->free = skcipher_free_instance_simple; 980 981 /* Default algorithm properties, can be overridden */ 982 inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize; 983 inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask; 984 inst->alg.base.cra_priority = cipher_alg->cra_priority; 985 inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize; 986 inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize; 987 inst->alg.ivsize = cipher_alg->cra_blocksize; 988 989 /* Use skcipher_ctx_simple by default, can be overridden */ 990 inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple); 991 inst->alg.setkey = skcipher_setkey_simple; 992 inst->alg.init = skcipher_init_tfm_simple; 993 inst->alg.exit = skcipher_exit_tfm_simple; 994 995 return inst; 996 997 err_free_inst: 998 kfree(inst); 999 err_put_cipher_alg: 1000 crypto_mod_put(cipher_alg); 1001 return ERR_PTR(err); 1002 } 1003 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple); 1004 1005 MODULE_LICENSE("GPL"); 1006 MODULE_DESCRIPTION("Symmetric key cipher type"); 1007