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 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 walk->nbytes = walk->total; 441 442 return skcipher_walk_next(walk); 443 } 444 445 static int skcipher_walk_skcipher(struct skcipher_walk *walk, 446 struct skcipher_request *req) 447 { 448 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 449 450 walk->total = req->cryptlen; 451 walk->nbytes = 0; 452 walk->iv = req->iv; 453 walk->oiv = req->iv; 454 455 if (unlikely(!walk->total)) 456 return 0; 457 458 scatterwalk_start(&walk->in, req->src); 459 scatterwalk_start(&walk->out, req->dst); 460 461 walk->flags &= ~SKCIPHER_WALK_SLEEP; 462 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 463 SKCIPHER_WALK_SLEEP : 0; 464 465 walk->blocksize = crypto_skcipher_blocksize(tfm); 466 walk->stride = crypto_skcipher_walksize(tfm); 467 walk->ivsize = crypto_skcipher_ivsize(tfm); 468 walk->alignmask = crypto_skcipher_alignmask(tfm); 469 470 return skcipher_walk_first(walk); 471 } 472 473 int skcipher_walk_virt(struct skcipher_walk *walk, 474 struct skcipher_request *req, bool atomic) 475 { 476 int err; 477 478 walk->flags &= ~SKCIPHER_WALK_PHYS; 479 480 err = skcipher_walk_skcipher(walk, req); 481 482 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0; 483 484 return err; 485 } 486 EXPORT_SYMBOL_GPL(skcipher_walk_virt); 487 488 void skcipher_walk_atomise(struct skcipher_walk *walk) 489 { 490 walk->flags &= ~SKCIPHER_WALK_SLEEP; 491 } 492 EXPORT_SYMBOL_GPL(skcipher_walk_atomise); 493 494 int skcipher_walk_async(struct skcipher_walk *walk, 495 struct skcipher_request *req) 496 { 497 walk->flags |= SKCIPHER_WALK_PHYS; 498 499 INIT_LIST_HEAD(&walk->buffers); 500 501 return skcipher_walk_skcipher(walk, req); 502 } 503 EXPORT_SYMBOL_GPL(skcipher_walk_async); 504 505 static int skcipher_walk_aead_common(struct skcipher_walk *walk, 506 struct aead_request *req, bool atomic) 507 { 508 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 509 int err; 510 511 walk->nbytes = 0; 512 walk->iv = req->iv; 513 walk->oiv = req->iv; 514 515 if (unlikely(!walk->total)) 516 return 0; 517 518 walk->flags &= ~SKCIPHER_WALK_PHYS; 519 520 scatterwalk_start(&walk->in, req->src); 521 scatterwalk_start(&walk->out, req->dst); 522 523 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); 524 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); 525 526 scatterwalk_done(&walk->in, 0, walk->total); 527 scatterwalk_done(&walk->out, 0, walk->total); 528 529 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) 530 walk->flags |= SKCIPHER_WALK_SLEEP; 531 else 532 walk->flags &= ~SKCIPHER_WALK_SLEEP; 533 534 walk->blocksize = crypto_aead_blocksize(tfm); 535 walk->stride = crypto_aead_chunksize(tfm); 536 walk->ivsize = crypto_aead_ivsize(tfm); 537 walk->alignmask = crypto_aead_alignmask(tfm); 538 539 err = skcipher_walk_first(walk); 540 541 if (atomic) 542 walk->flags &= ~SKCIPHER_WALK_SLEEP; 543 544 return err; 545 } 546 547 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, 548 bool atomic) 549 { 550 walk->total = req->cryptlen; 551 552 return skcipher_walk_aead_common(walk, req, atomic); 553 } 554 EXPORT_SYMBOL_GPL(skcipher_walk_aead); 555 556 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, 557 struct aead_request *req, bool atomic) 558 { 559 walk->total = req->cryptlen; 560 561 return skcipher_walk_aead_common(walk, req, atomic); 562 } 563 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); 564 565 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 566 struct aead_request *req, bool atomic) 567 { 568 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 569 570 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 571 572 return skcipher_walk_aead_common(walk, req, atomic); 573 } 574 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 575 576 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) 577 { 578 if (alg->cra_type == &crypto_blkcipher_type) 579 return sizeof(struct crypto_blkcipher *); 580 581 if (alg->cra_type == &crypto_ablkcipher_type || 582 alg->cra_type == &crypto_givcipher_type) 583 return sizeof(struct crypto_ablkcipher *); 584 585 return crypto_alg_extsize(alg); 586 } 587 588 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, 589 const u8 *key, unsigned int keylen) 590 { 591 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 592 struct crypto_blkcipher *blkcipher = *ctx; 593 int err; 594 595 crypto_blkcipher_clear_flags(blkcipher, ~0); 596 crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) & 597 CRYPTO_TFM_REQ_MASK); 598 err = crypto_blkcipher_setkey(blkcipher, key, keylen); 599 crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & 600 CRYPTO_TFM_RES_MASK); 601 602 return err; 603 } 604 605 static int skcipher_crypt_blkcipher(struct skcipher_request *req, 606 int (*crypt)(struct blkcipher_desc *, 607 struct scatterlist *, 608 struct scatterlist *, 609 unsigned int)) 610 { 611 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 612 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 613 struct blkcipher_desc desc = { 614 .tfm = *ctx, 615 .info = req->iv, 616 .flags = req->base.flags, 617 }; 618 619 620 return crypt(&desc, req->dst, req->src, req->cryptlen); 621 } 622 623 static int skcipher_encrypt_blkcipher(struct skcipher_request *req) 624 { 625 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 626 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 627 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 628 629 return skcipher_crypt_blkcipher(req, alg->encrypt); 630 } 631 632 static int skcipher_decrypt_blkcipher(struct skcipher_request *req) 633 { 634 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 635 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 636 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 637 638 return skcipher_crypt_blkcipher(req, alg->decrypt); 639 } 640 641 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 642 { 643 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 644 645 crypto_free_blkcipher(*ctx); 646 } 647 648 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 649 { 650 struct crypto_alg *calg = tfm->__crt_alg; 651 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 652 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 653 struct crypto_blkcipher *blkcipher; 654 struct crypto_tfm *btfm; 655 656 if (!crypto_mod_get(calg)) 657 return -EAGAIN; 658 659 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, 660 CRYPTO_ALG_TYPE_MASK); 661 if (IS_ERR(btfm)) { 662 crypto_mod_put(calg); 663 return PTR_ERR(btfm); 664 } 665 666 blkcipher = __crypto_blkcipher_cast(btfm); 667 *ctx = blkcipher; 668 tfm->exit = crypto_exit_skcipher_ops_blkcipher; 669 670 skcipher->setkey = skcipher_setkey_blkcipher; 671 skcipher->encrypt = skcipher_encrypt_blkcipher; 672 skcipher->decrypt = skcipher_decrypt_blkcipher; 673 674 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); 675 skcipher->keysize = calg->cra_blkcipher.max_keysize; 676 677 return 0; 678 } 679 680 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, 681 const u8 *key, unsigned int keylen) 682 { 683 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 684 struct crypto_ablkcipher *ablkcipher = *ctx; 685 int err; 686 687 crypto_ablkcipher_clear_flags(ablkcipher, ~0); 688 crypto_ablkcipher_set_flags(ablkcipher, 689 crypto_skcipher_get_flags(tfm) & 690 CRYPTO_TFM_REQ_MASK); 691 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); 692 crypto_skcipher_set_flags(tfm, 693 crypto_ablkcipher_get_flags(ablkcipher) & 694 CRYPTO_TFM_RES_MASK); 695 696 return err; 697 } 698 699 static int skcipher_crypt_ablkcipher(struct skcipher_request *req, 700 int (*crypt)(struct ablkcipher_request *)) 701 { 702 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 703 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 704 struct ablkcipher_request *subreq = skcipher_request_ctx(req); 705 706 ablkcipher_request_set_tfm(subreq, *ctx); 707 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), 708 req->base.complete, req->base.data); 709 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, 710 req->iv); 711 712 return crypt(subreq); 713 } 714 715 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req) 716 { 717 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 718 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 719 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 720 721 return skcipher_crypt_ablkcipher(req, alg->encrypt); 722 } 723 724 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) 725 { 726 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 727 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 728 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 729 730 return skcipher_crypt_ablkcipher(req, alg->decrypt); 731 } 732 733 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 734 { 735 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 736 737 crypto_free_ablkcipher(*ctx); 738 } 739 740 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 741 { 742 struct crypto_alg *calg = tfm->__crt_alg; 743 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 744 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 745 struct crypto_ablkcipher *ablkcipher; 746 struct crypto_tfm *abtfm; 747 748 if (!crypto_mod_get(calg)) 749 return -EAGAIN; 750 751 abtfm = __crypto_alloc_tfm(calg, 0, 0); 752 if (IS_ERR(abtfm)) { 753 crypto_mod_put(calg); 754 return PTR_ERR(abtfm); 755 } 756 757 ablkcipher = __crypto_ablkcipher_cast(abtfm); 758 *ctx = ablkcipher; 759 tfm->exit = crypto_exit_skcipher_ops_ablkcipher; 760 761 skcipher->setkey = skcipher_setkey_ablkcipher; 762 skcipher->encrypt = skcipher_encrypt_ablkcipher; 763 skcipher->decrypt = skcipher_decrypt_ablkcipher; 764 765 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); 766 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + 767 sizeof(struct ablkcipher_request); 768 skcipher->keysize = calg->cra_ablkcipher.max_keysize; 769 770 return 0; 771 } 772 773 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 774 const u8 *key, unsigned int keylen) 775 { 776 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 777 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 778 u8 *buffer, *alignbuffer; 779 unsigned long absize; 780 int ret; 781 782 absize = keylen + alignmask; 783 buffer = kmalloc(absize, GFP_ATOMIC); 784 if (!buffer) 785 return -ENOMEM; 786 787 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 788 memcpy(alignbuffer, key, keylen); 789 ret = cipher->setkey(tfm, alignbuffer, keylen); 790 kzfree(buffer); 791 return ret; 792 } 793 794 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 795 unsigned int keylen) 796 { 797 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 798 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 799 800 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 801 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 802 return -EINVAL; 803 } 804 805 if ((unsigned long)key & alignmask) 806 return skcipher_setkey_unaligned(tfm, key, keylen); 807 808 return cipher->setkey(tfm, key, keylen); 809 } 810 811 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 812 { 813 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 814 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 815 816 alg->exit(skcipher); 817 } 818 819 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 820 { 821 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 822 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 823 824 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) 825 return crypto_init_skcipher_ops_blkcipher(tfm); 826 827 if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type || 828 tfm->__crt_alg->cra_type == &crypto_givcipher_type) 829 return crypto_init_skcipher_ops_ablkcipher(tfm); 830 831 skcipher->setkey = skcipher_setkey; 832 skcipher->encrypt = alg->encrypt; 833 skcipher->decrypt = alg->decrypt; 834 skcipher->ivsize = alg->ivsize; 835 skcipher->keysize = alg->max_keysize; 836 837 if (alg->exit) 838 skcipher->base.exit = crypto_skcipher_exit_tfm; 839 840 if (alg->init) 841 return alg->init(skcipher); 842 843 return 0; 844 } 845 846 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 847 { 848 struct skcipher_instance *skcipher = 849 container_of(inst, struct skcipher_instance, s.base); 850 851 skcipher->free(skcipher); 852 } 853 854 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 855 __maybe_unused; 856 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 857 { 858 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 859 base); 860 861 seq_printf(m, "type : skcipher\n"); 862 seq_printf(m, "async : %s\n", 863 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 864 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 865 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 866 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 867 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 868 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 869 seq_printf(m, "walksize : %u\n", skcipher->walksize); 870 } 871 872 #ifdef CONFIG_NET 873 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 874 { 875 struct crypto_report_blkcipher rblkcipher; 876 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 877 base); 878 879 strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 880 strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 881 882 rblkcipher.blocksize = alg->cra_blocksize; 883 rblkcipher.min_keysize = skcipher->min_keysize; 884 rblkcipher.max_keysize = skcipher->max_keysize; 885 rblkcipher.ivsize = skcipher->ivsize; 886 887 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 888 sizeof(struct crypto_report_blkcipher), &rblkcipher)) 889 goto nla_put_failure; 890 return 0; 891 892 nla_put_failure: 893 return -EMSGSIZE; 894 } 895 #else 896 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 897 { 898 return -ENOSYS; 899 } 900 #endif 901 902 static const struct crypto_type crypto_skcipher_type2 = { 903 .extsize = crypto_skcipher_extsize, 904 .init_tfm = crypto_skcipher_init_tfm, 905 .free = crypto_skcipher_free_instance, 906 #ifdef CONFIG_PROC_FS 907 .show = crypto_skcipher_show, 908 #endif 909 .report = crypto_skcipher_report, 910 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 911 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, 912 .type = CRYPTO_ALG_TYPE_SKCIPHER, 913 .tfmsize = offsetof(struct crypto_skcipher, base), 914 }; 915 916 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 917 const char *name, u32 type, u32 mask) 918 { 919 spawn->base.frontend = &crypto_skcipher_type2; 920 return crypto_grab_spawn(&spawn->base, name, type, mask); 921 } 922 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 923 924 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 925 u32 type, u32 mask) 926 { 927 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 928 } 929 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 930 931 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask) 932 { 933 return crypto_type_has_alg(alg_name, &crypto_skcipher_type2, 934 type, mask); 935 } 936 EXPORT_SYMBOL_GPL(crypto_has_skcipher2); 937 938 static int skcipher_prepare_alg(struct skcipher_alg *alg) 939 { 940 struct crypto_alg *base = &alg->base; 941 942 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 943 alg->walksize > PAGE_SIZE / 8) 944 return -EINVAL; 945 946 if (!alg->chunksize) 947 alg->chunksize = base->cra_blocksize; 948 if (!alg->walksize) 949 alg->walksize = alg->chunksize; 950 951 base->cra_type = &crypto_skcipher_type2; 952 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 953 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 954 955 return 0; 956 } 957 958 int crypto_register_skcipher(struct skcipher_alg *alg) 959 { 960 struct crypto_alg *base = &alg->base; 961 int err; 962 963 err = skcipher_prepare_alg(alg); 964 if (err) 965 return err; 966 967 return crypto_register_alg(base); 968 } 969 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 970 971 void crypto_unregister_skcipher(struct skcipher_alg *alg) 972 { 973 crypto_unregister_alg(&alg->base); 974 } 975 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 976 977 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 978 { 979 int i, ret; 980 981 for (i = 0; i < count; i++) { 982 ret = crypto_register_skcipher(&algs[i]); 983 if (ret) 984 goto err; 985 } 986 987 return 0; 988 989 err: 990 for (--i; i >= 0; --i) 991 crypto_unregister_skcipher(&algs[i]); 992 993 return ret; 994 } 995 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 996 997 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 998 { 999 int i; 1000 1001 for (i = count - 1; i >= 0; --i) 1002 crypto_unregister_skcipher(&algs[i]); 1003 } 1004 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 1005 1006 int skcipher_register_instance(struct crypto_template *tmpl, 1007 struct skcipher_instance *inst) 1008 { 1009 int err; 1010 1011 err = skcipher_prepare_alg(&inst->alg); 1012 if (err) 1013 return err; 1014 1015 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 1016 } 1017 EXPORT_SYMBOL_GPL(skcipher_register_instance); 1018 1019 MODULE_LICENSE("GPL"); 1020 MODULE_DESCRIPTION("Symmetric key cipher type"); 1021