1 /* 2 * Symmetric key cipher operations. 3 * 4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across 5 * multiple page boundaries by using temporary blocks. In user context, 6 * the kernel is given a chance to schedule us once per page. 7 * 8 * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the Free 12 * Software Foundation; either version 2 of the License, or (at your option) 13 * any later version. 14 * 15 */ 16 17 #include <crypto/internal/aead.h> 18 #include <crypto/internal/skcipher.h> 19 #include <crypto/scatterwalk.h> 20 #include <linux/bug.h> 21 #include <linux/cryptouser.h> 22 #include <linux/compiler.h> 23 #include <linux/list.h> 24 #include <linux/module.h> 25 #include <linux/rtnetlink.h> 26 #include <linux/seq_file.h> 27 #include <net/netlink.h> 28 29 #include "internal.h" 30 31 enum { 32 SKCIPHER_WALK_PHYS = 1 << 0, 33 SKCIPHER_WALK_SLOW = 1 << 1, 34 SKCIPHER_WALK_COPY = 1 << 2, 35 SKCIPHER_WALK_DIFF = 1 << 3, 36 SKCIPHER_WALK_SLEEP = 1 << 4, 37 }; 38 39 struct skcipher_walk_buffer { 40 struct list_head entry; 41 struct scatter_walk dst; 42 unsigned int len; 43 u8 *data; 44 u8 buffer[]; 45 }; 46 47 static int skcipher_walk_next(struct skcipher_walk *walk); 48 49 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr) 50 { 51 if (PageHighMem(scatterwalk_page(walk))) 52 kunmap_atomic(vaddr); 53 } 54 55 static inline void *skcipher_map(struct scatter_walk *walk) 56 { 57 struct page *page = scatterwalk_page(walk); 58 59 return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) + 60 offset_in_page(walk->offset); 61 } 62 63 static inline void skcipher_map_src(struct skcipher_walk *walk) 64 { 65 walk->src.virt.addr = skcipher_map(&walk->in); 66 } 67 68 static inline void skcipher_map_dst(struct skcipher_walk *walk) 69 { 70 walk->dst.virt.addr = skcipher_map(&walk->out); 71 } 72 73 static inline void skcipher_unmap_src(struct skcipher_walk *walk) 74 { 75 skcipher_unmap(&walk->in, walk->src.virt.addr); 76 } 77 78 static inline void skcipher_unmap_dst(struct skcipher_walk *walk) 79 { 80 skcipher_unmap(&walk->out, walk->dst.virt.addr); 81 } 82 83 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) 84 { 85 return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; 86 } 87 88 /* Get a spot of the specified length that does not straddle a page. 89 * The caller needs to ensure that there is enough space for this operation. 90 */ 91 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len) 92 { 93 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); 94 95 return max(start, end_page); 96 } 97 98 static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize) 99 { 100 u8 *addr; 101 102 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); 103 addr = skcipher_get_spot(addr, bsize); 104 scatterwalk_copychunks(addr, &walk->out, bsize, 105 (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1); 106 return 0; 107 } 108 109 int skcipher_walk_done(struct skcipher_walk *walk, int err) 110 { 111 unsigned int n = walk->nbytes - err; 112 unsigned int nbytes; 113 114 nbytes = walk->total - n; 115 116 if (unlikely(err < 0)) { 117 nbytes = 0; 118 n = 0; 119 } else if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | 120 SKCIPHER_WALK_SLOW | 121 SKCIPHER_WALK_COPY | 122 SKCIPHER_WALK_DIFF)))) { 123 unmap_src: 124 skcipher_unmap_src(walk); 125 } else if (walk->flags & SKCIPHER_WALK_DIFF) { 126 skcipher_unmap_dst(walk); 127 goto unmap_src; 128 } else if (walk->flags & SKCIPHER_WALK_COPY) { 129 skcipher_map_dst(walk); 130 memcpy(walk->dst.virt.addr, walk->page, n); 131 skcipher_unmap_dst(walk); 132 } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) { 133 if (WARN_ON(err)) { 134 err = -EINVAL; 135 nbytes = 0; 136 } else 137 n = skcipher_done_slow(walk, n); 138 } 139 140 if (err > 0) 141 err = 0; 142 143 walk->total = nbytes; 144 walk->nbytes = nbytes; 145 146 scatterwalk_advance(&walk->in, n); 147 scatterwalk_advance(&walk->out, n); 148 scatterwalk_done(&walk->in, 0, nbytes); 149 scatterwalk_done(&walk->out, 1, nbytes); 150 151 if (nbytes) { 152 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ? 153 CRYPTO_TFM_REQ_MAY_SLEEP : 0); 154 return skcipher_walk_next(walk); 155 } 156 157 /* Short-circuit for the common/fast path. */ 158 if (!((unsigned long)walk->buffer | (unsigned long)walk->page)) 159 goto out; 160 161 if (walk->flags & SKCIPHER_WALK_PHYS) 162 goto out; 163 164 if (walk->iv != walk->oiv) 165 memcpy(walk->oiv, walk->iv, walk->ivsize); 166 if (walk->buffer != walk->page) 167 kfree(walk->buffer); 168 if (walk->page) 169 free_page((unsigned long)walk->page); 170 171 out: 172 return err; 173 } 174 EXPORT_SYMBOL_GPL(skcipher_walk_done); 175 176 void skcipher_walk_complete(struct skcipher_walk *walk, int err) 177 { 178 struct skcipher_walk_buffer *p, *tmp; 179 180 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) { 181 u8 *data; 182 183 if (err) 184 goto done; 185 186 data = p->data; 187 if (!data) { 188 data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1); 189 data = skcipher_get_spot(data, walk->stride); 190 } 191 192 scatterwalk_copychunks(data, &p->dst, p->len, 1); 193 194 if (offset_in_page(p->data) + p->len + walk->stride > 195 PAGE_SIZE) 196 free_page((unsigned long)p->data); 197 198 done: 199 list_del(&p->entry); 200 kfree(p); 201 } 202 203 if (!err && walk->iv != walk->oiv) 204 memcpy(walk->oiv, walk->iv, walk->ivsize); 205 if (walk->buffer != walk->page) 206 kfree(walk->buffer); 207 if (walk->page) 208 free_page((unsigned long)walk->page); 209 } 210 EXPORT_SYMBOL_GPL(skcipher_walk_complete); 211 212 static void skcipher_queue_write(struct skcipher_walk *walk, 213 struct skcipher_walk_buffer *p) 214 { 215 p->dst = walk->out; 216 list_add_tail(&p->entry, &walk->buffers); 217 } 218 219 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) 220 { 221 bool phys = walk->flags & SKCIPHER_WALK_PHYS; 222 unsigned alignmask = walk->alignmask; 223 struct skcipher_walk_buffer *p; 224 unsigned a; 225 unsigned n; 226 u8 *buffer; 227 void *v; 228 229 if (!phys) { 230 if (!walk->buffer) 231 walk->buffer = walk->page; 232 buffer = walk->buffer; 233 if (buffer) 234 goto ok; 235 } 236 237 /* Start with the minimum alignment of kmalloc. */ 238 a = crypto_tfm_ctx_alignment() - 1; 239 n = bsize; 240 241 if (phys) { 242 /* Calculate the minimum alignment of p->buffer. */ 243 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1; 244 n += sizeof(*p); 245 } 246 247 /* Minimum size to align p->buffer by alignmask. */ 248 n += alignmask & ~a; 249 250 /* Minimum size to ensure p->buffer does not straddle a page. */ 251 n += (bsize - 1) & ~(alignmask | a); 252 253 v = kzalloc(n, skcipher_walk_gfp(walk)); 254 if (!v) 255 return skcipher_walk_done(walk, -ENOMEM); 256 257 if (phys) { 258 p = v; 259 p->len = bsize; 260 skcipher_queue_write(walk, p); 261 buffer = p->buffer; 262 } else { 263 walk->buffer = v; 264 buffer = v; 265 } 266 267 ok: 268 walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1); 269 walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize); 270 walk->src.virt.addr = walk->dst.virt.addr; 271 272 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); 273 274 walk->nbytes = bsize; 275 walk->flags |= SKCIPHER_WALK_SLOW; 276 277 return 0; 278 } 279 280 static int skcipher_next_copy(struct skcipher_walk *walk) 281 { 282 struct skcipher_walk_buffer *p; 283 u8 *tmp = walk->page; 284 285 skcipher_map_src(walk); 286 memcpy(tmp, walk->src.virt.addr, walk->nbytes); 287 skcipher_unmap_src(walk); 288 289 walk->src.virt.addr = tmp; 290 walk->dst.virt.addr = tmp; 291 292 if (!(walk->flags & SKCIPHER_WALK_PHYS)) 293 return 0; 294 295 p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk)); 296 if (!p) 297 return -ENOMEM; 298 299 p->data = walk->page; 300 p->len = walk->nbytes; 301 skcipher_queue_write(walk, p); 302 303 if (offset_in_page(walk->page) + walk->nbytes + walk->stride > 304 PAGE_SIZE) 305 walk->page = NULL; 306 else 307 walk->page += walk->nbytes; 308 309 return 0; 310 } 311 312 static int skcipher_next_fast(struct skcipher_walk *walk) 313 { 314 unsigned long diff; 315 316 walk->src.phys.page = scatterwalk_page(&walk->in); 317 walk->src.phys.offset = offset_in_page(walk->in.offset); 318 walk->dst.phys.page = scatterwalk_page(&walk->out); 319 walk->dst.phys.offset = offset_in_page(walk->out.offset); 320 321 if (walk->flags & SKCIPHER_WALK_PHYS) 322 return 0; 323 324 diff = walk->src.phys.offset - walk->dst.phys.offset; 325 diff |= walk->src.virt.page - walk->dst.virt.page; 326 327 skcipher_map_src(walk); 328 walk->dst.virt.addr = walk->src.virt.addr; 329 330 if (diff) { 331 walk->flags |= SKCIPHER_WALK_DIFF; 332 skcipher_map_dst(walk); 333 } 334 335 return 0; 336 } 337 338 static int skcipher_walk_next(struct skcipher_walk *walk) 339 { 340 unsigned int bsize; 341 unsigned int n; 342 int err; 343 344 walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | 345 SKCIPHER_WALK_DIFF); 346 347 n = walk->total; 348 bsize = min(walk->stride, max(n, walk->blocksize)); 349 n = scatterwalk_clamp(&walk->in, n); 350 n = scatterwalk_clamp(&walk->out, n); 351 352 if (unlikely(n < bsize)) { 353 if (unlikely(walk->total < walk->blocksize)) 354 return skcipher_walk_done(walk, -EINVAL); 355 356 slow_path: 357 err = skcipher_next_slow(walk, bsize); 358 goto set_phys_lowmem; 359 } 360 361 if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { 362 if (!walk->page) { 363 gfp_t gfp = skcipher_walk_gfp(walk); 364 365 walk->page = (void *)__get_free_page(gfp); 366 if (!walk->page) 367 goto slow_path; 368 } 369 370 walk->nbytes = min_t(unsigned, n, 371 PAGE_SIZE - offset_in_page(walk->page)); 372 walk->flags |= SKCIPHER_WALK_COPY; 373 err = skcipher_next_copy(walk); 374 goto set_phys_lowmem; 375 } 376 377 walk->nbytes = n; 378 379 return skcipher_next_fast(walk); 380 381 set_phys_lowmem: 382 if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) { 383 walk->src.phys.page = virt_to_page(walk->src.virt.addr); 384 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); 385 walk->src.phys.offset &= PAGE_SIZE - 1; 386 walk->dst.phys.offset &= PAGE_SIZE - 1; 387 } 388 return err; 389 } 390 EXPORT_SYMBOL_GPL(skcipher_walk_next); 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); 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 walk->nbytes = 0; 430 431 if (WARN_ON_ONCE(in_irq())) 432 return -EDEADLK; 433 434 if (unlikely(!walk->total)) 435 return 0; 436 437 walk->buffer = NULL; 438 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { 439 int err = skcipher_copy_iv(walk); 440 if (err) 441 return err; 442 } 443 444 walk->page = NULL; 445 walk->nbytes = walk->total; 446 447 return skcipher_walk_next(walk); 448 } 449 450 static int skcipher_walk_skcipher(struct skcipher_walk *walk, 451 struct skcipher_request *req) 452 { 453 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 454 455 scatterwalk_start(&walk->in, req->src); 456 scatterwalk_start(&walk->out, req->dst); 457 458 walk->total = req->cryptlen; 459 walk->iv = req->iv; 460 walk->oiv = req->iv; 461 462 walk->flags &= ~SKCIPHER_WALK_SLEEP; 463 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 464 SKCIPHER_WALK_SLEEP : 0; 465 466 walk->blocksize = crypto_skcipher_blocksize(tfm); 467 walk->stride = crypto_skcipher_walksize(tfm); 468 walk->ivsize = crypto_skcipher_ivsize(tfm); 469 walk->alignmask = crypto_skcipher_alignmask(tfm); 470 471 return skcipher_walk_first(walk); 472 } 473 474 int skcipher_walk_virt(struct skcipher_walk *walk, 475 struct skcipher_request *req, bool atomic) 476 { 477 int err; 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->flags &= ~SKCIPHER_WALK_PHYS; 513 514 scatterwalk_start(&walk->in, req->src); 515 scatterwalk_start(&walk->out, req->dst); 516 517 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); 518 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); 519 520 walk->iv = req->iv; 521 walk->oiv = req->iv; 522 523 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) 524 walk->flags |= SKCIPHER_WALK_SLEEP; 525 else 526 walk->flags &= ~SKCIPHER_WALK_SLEEP; 527 528 walk->blocksize = crypto_aead_blocksize(tfm); 529 walk->stride = crypto_aead_chunksize(tfm); 530 walk->ivsize = crypto_aead_ivsize(tfm); 531 walk->alignmask = crypto_aead_alignmask(tfm); 532 533 err = skcipher_walk_first(walk); 534 535 if (atomic) 536 walk->flags &= ~SKCIPHER_WALK_SLEEP; 537 538 return err; 539 } 540 541 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, 542 bool atomic) 543 { 544 walk->total = req->cryptlen; 545 546 return skcipher_walk_aead_common(walk, req, atomic); 547 } 548 EXPORT_SYMBOL_GPL(skcipher_walk_aead); 549 550 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, 551 struct aead_request *req, bool atomic) 552 { 553 walk->total = req->cryptlen; 554 555 return skcipher_walk_aead_common(walk, req, atomic); 556 } 557 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); 558 559 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 560 struct aead_request *req, bool atomic) 561 { 562 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 563 564 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 565 566 return skcipher_walk_aead_common(walk, req, atomic); 567 } 568 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 569 570 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) 571 { 572 if (alg->cra_type == &crypto_blkcipher_type) 573 return sizeof(struct crypto_blkcipher *); 574 575 if (alg->cra_type == &crypto_ablkcipher_type || 576 alg->cra_type == &crypto_givcipher_type) 577 return sizeof(struct crypto_ablkcipher *); 578 579 return crypto_alg_extsize(alg); 580 } 581 582 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, 583 const u8 *key, unsigned int keylen) 584 { 585 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 586 struct crypto_blkcipher *blkcipher = *ctx; 587 int err; 588 589 crypto_blkcipher_clear_flags(blkcipher, ~0); 590 crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) & 591 CRYPTO_TFM_REQ_MASK); 592 err = crypto_blkcipher_setkey(blkcipher, key, keylen); 593 crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & 594 CRYPTO_TFM_RES_MASK); 595 596 return err; 597 } 598 599 static int skcipher_crypt_blkcipher(struct skcipher_request *req, 600 int (*crypt)(struct blkcipher_desc *, 601 struct scatterlist *, 602 struct scatterlist *, 603 unsigned int)) 604 { 605 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 606 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 607 struct blkcipher_desc desc = { 608 .tfm = *ctx, 609 .info = req->iv, 610 .flags = req->base.flags, 611 }; 612 613 614 return crypt(&desc, req->dst, req->src, req->cryptlen); 615 } 616 617 static int skcipher_encrypt_blkcipher(struct skcipher_request *req) 618 { 619 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 620 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 621 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 622 623 return skcipher_crypt_blkcipher(req, alg->encrypt); 624 } 625 626 static int skcipher_decrypt_blkcipher(struct skcipher_request *req) 627 { 628 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 629 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 630 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 631 632 return skcipher_crypt_blkcipher(req, alg->decrypt); 633 } 634 635 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 636 { 637 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 638 639 crypto_free_blkcipher(*ctx); 640 } 641 642 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 643 { 644 struct crypto_alg *calg = tfm->__crt_alg; 645 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 646 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 647 struct crypto_blkcipher *blkcipher; 648 struct crypto_tfm *btfm; 649 650 if (!crypto_mod_get(calg)) 651 return -EAGAIN; 652 653 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, 654 CRYPTO_ALG_TYPE_MASK); 655 if (IS_ERR(btfm)) { 656 crypto_mod_put(calg); 657 return PTR_ERR(btfm); 658 } 659 660 blkcipher = __crypto_blkcipher_cast(btfm); 661 *ctx = blkcipher; 662 tfm->exit = crypto_exit_skcipher_ops_blkcipher; 663 664 skcipher->setkey = skcipher_setkey_blkcipher; 665 skcipher->encrypt = skcipher_encrypt_blkcipher; 666 skcipher->decrypt = skcipher_decrypt_blkcipher; 667 668 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); 669 skcipher->keysize = calg->cra_blkcipher.max_keysize; 670 671 return 0; 672 } 673 674 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, 675 const u8 *key, unsigned int keylen) 676 { 677 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 678 struct crypto_ablkcipher *ablkcipher = *ctx; 679 int err; 680 681 crypto_ablkcipher_clear_flags(ablkcipher, ~0); 682 crypto_ablkcipher_set_flags(ablkcipher, 683 crypto_skcipher_get_flags(tfm) & 684 CRYPTO_TFM_REQ_MASK); 685 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); 686 crypto_skcipher_set_flags(tfm, 687 crypto_ablkcipher_get_flags(ablkcipher) & 688 CRYPTO_TFM_RES_MASK); 689 690 return err; 691 } 692 693 static int skcipher_crypt_ablkcipher(struct skcipher_request *req, 694 int (*crypt)(struct ablkcipher_request *)) 695 { 696 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 697 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 698 struct ablkcipher_request *subreq = skcipher_request_ctx(req); 699 700 ablkcipher_request_set_tfm(subreq, *ctx); 701 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), 702 req->base.complete, req->base.data); 703 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, 704 req->iv); 705 706 return crypt(subreq); 707 } 708 709 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req) 710 { 711 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 712 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 713 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 714 715 return skcipher_crypt_ablkcipher(req, alg->encrypt); 716 } 717 718 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) 719 { 720 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 721 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 722 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 723 724 return skcipher_crypt_ablkcipher(req, alg->decrypt); 725 } 726 727 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 728 { 729 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 730 731 crypto_free_ablkcipher(*ctx); 732 } 733 734 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 735 { 736 struct crypto_alg *calg = tfm->__crt_alg; 737 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 738 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 739 struct crypto_ablkcipher *ablkcipher; 740 struct crypto_tfm *abtfm; 741 742 if (!crypto_mod_get(calg)) 743 return -EAGAIN; 744 745 abtfm = __crypto_alloc_tfm(calg, 0, 0); 746 if (IS_ERR(abtfm)) { 747 crypto_mod_put(calg); 748 return PTR_ERR(abtfm); 749 } 750 751 ablkcipher = __crypto_ablkcipher_cast(abtfm); 752 *ctx = ablkcipher; 753 tfm->exit = crypto_exit_skcipher_ops_ablkcipher; 754 755 skcipher->setkey = skcipher_setkey_ablkcipher; 756 skcipher->encrypt = skcipher_encrypt_ablkcipher; 757 skcipher->decrypt = skcipher_decrypt_ablkcipher; 758 759 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); 760 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + 761 sizeof(struct ablkcipher_request); 762 skcipher->keysize = calg->cra_ablkcipher.max_keysize; 763 764 return 0; 765 } 766 767 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 768 const u8 *key, unsigned int keylen) 769 { 770 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 771 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 772 u8 *buffer, *alignbuffer; 773 unsigned long absize; 774 int ret; 775 776 absize = keylen + alignmask; 777 buffer = kmalloc(absize, GFP_ATOMIC); 778 if (!buffer) 779 return -ENOMEM; 780 781 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 782 memcpy(alignbuffer, key, keylen); 783 ret = cipher->setkey(tfm, alignbuffer, keylen); 784 kzfree(buffer); 785 return ret; 786 } 787 788 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 789 unsigned int keylen) 790 { 791 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 792 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 793 794 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 795 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 796 return -EINVAL; 797 } 798 799 if ((unsigned long)key & alignmask) 800 return skcipher_setkey_unaligned(tfm, key, keylen); 801 802 return cipher->setkey(tfm, key, keylen); 803 } 804 805 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 806 { 807 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 808 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 809 810 alg->exit(skcipher); 811 } 812 813 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 814 { 815 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 816 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 817 818 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) 819 return crypto_init_skcipher_ops_blkcipher(tfm); 820 821 if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type || 822 tfm->__crt_alg->cra_type == &crypto_givcipher_type) 823 return crypto_init_skcipher_ops_ablkcipher(tfm); 824 825 skcipher->setkey = skcipher_setkey; 826 skcipher->encrypt = alg->encrypt; 827 skcipher->decrypt = alg->decrypt; 828 skcipher->ivsize = alg->ivsize; 829 skcipher->keysize = alg->max_keysize; 830 831 if (alg->exit) 832 skcipher->base.exit = crypto_skcipher_exit_tfm; 833 834 if (alg->init) 835 return alg->init(skcipher); 836 837 return 0; 838 } 839 840 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 841 { 842 struct skcipher_instance *skcipher = 843 container_of(inst, struct skcipher_instance, s.base); 844 845 skcipher->free(skcipher); 846 } 847 848 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 849 __maybe_unused; 850 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 851 { 852 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 853 base); 854 855 seq_printf(m, "type : skcipher\n"); 856 seq_printf(m, "async : %s\n", 857 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 858 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 859 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 860 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 861 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 862 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 863 seq_printf(m, "walksize : %u\n", skcipher->walksize); 864 } 865 866 #ifdef CONFIG_NET 867 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 868 { 869 struct crypto_report_blkcipher rblkcipher; 870 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 871 base); 872 873 strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 874 strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 875 876 rblkcipher.blocksize = alg->cra_blocksize; 877 rblkcipher.min_keysize = skcipher->min_keysize; 878 rblkcipher.max_keysize = skcipher->max_keysize; 879 rblkcipher.ivsize = skcipher->ivsize; 880 881 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 882 sizeof(struct crypto_report_blkcipher), &rblkcipher)) 883 goto nla_put_failure; 884 return 0; 885 886 nla_put_failure: 887 return -EMSGSIZE; 888 } 889 #else 890 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 891 { 892 return -ENOSYS; 893 } 894 #endif 895 896 static const struct crypto_type crypto_skcipher_type2 = { 897 .extsize = crypto_skcipher_extsize, 898 .init_tfm = crypto_skcipher_init_tfm, 899 .free = crypto_skcipher_free_instance, 900 #ifdef CONFIG_PROC_FS 901 .show = crypto_skcipher_show, 902 #endif 903 .report = crypto_skcipher_report, 904 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 905 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, 906 .type = CRYPTO_ALG_TYPE_SKCIPHER, 907 .tfmsize = offsetof(struct crypto_skcipher, base), 908 }; 909 910 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 911 const char *name, u32 type, u32 mask) 912 { 913 spawn->base.frontend = &crypto_skcipher_type2; 914 return crypto_grab_spawn(&spawn->base, name, type, mask); 915 } 916 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 917 918 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 919 u32 type, u32 mask) 920 { 921 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 922 } 923 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 924 925 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask) 926 { 927 return crypto_type_has_alg(alg_name, &crypto_skcipher_type2, 928 type, mask); 929 } 930 EXPORT_SYMBOL_GPL(crypto_has_skcipher2); 931 932 static int skcipher_prepare_alg(struct skcipher_alg *alg) 933 { 934 struct crypto_alg *base = &alg->base; 935 936 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 937 alg->walksize > PAGE_SIZE / 8) 938 return -EINVAL; 939 940 if (!alg->chunksize) 941 alg->chunksize = base->cra_blocksize; 942 if (!alg->walksize) 943 alg->walksize = alg->chunksize; 944 945 base->cra_type = &crypto_skcipher_type2; 946 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 947 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 948 949 return 0; 950 } 951 952 int crypto_register_skcipher(struct skcipher_alg *alg) 953 { 954 struct crypto_alg *base = &alg->base; 955 int err; 956 957 err = skcipher_prepare_alg(alg); 958 if (err) 959 return err; 960 961 return crypto_register_alg(base); 962 } 963 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 964 965 void crypto_unregister_skcipher(struct skcipher_alg *alg) 966 { 967 crypto_unregister_alg(&alg->base); 968 } 969 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 970 971 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 972 { 973 int i, ret; 974 975 for (i = 0; i < count; i++) { 976 ret = crypto_register_skcipher(&algs[i]); 977 if (ret) 978 goto err; 979 } 980 981 return 0; 982 983 err: 984 for (--i; i >= 0; --i) 985 crypto_unregister_skcipher(&algs[i]); 986 987 return ret; 988 } 989 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 990 991 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 992 { 993 int i; 994 995 for (i = count - 1; i >= 0; --i) 996 crypto_unregister_skcipher(&algs[i]); 997 } 998 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 999 1000 int skcipher_register_instance(struct crypto_template *tmpl, 1001 struct skcipher_instance *inst) 1002 { 1003 int err; 1004 1005 err = skcipher_prepare_alg(&inst->alg); 1006 if (err) 1007 return err; 1008 1009 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 1010 } 1011 EXPORT_SYMBOL_GPL(skcipher_register_instance); 1012 1013 MODULE_LICENSE("GPL"); 1014 MODULE_DESCRIPTION("Symmetric key cipher type"); 1015