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 } 390 391 static int skcipher_copy_iv(struct skcipher_walk *walk) 392 { 393 unsigned a = crypto_tfm_ctx_alignment() - 1; 394 unsigned alignmask = walk->alignmask; 395 unsigned ivsize = walk->ivsize; 396 unsigned bs = walk->stride; 397 unsigned aligned_bs; 398 unsigned size; 399 u8 *iv; 400 401 aligned_bs = ALIGN(bs, alignmask); 402 403 /* Minimum size to align buffer by alignmask. */ 404 size = alignmask & ~a; 405 406 if (walk->flags & SKCIPHER_WALK_PHYS) 407 size += ivsize; 408 else { 409 size += aligned_bs + ivsize; 410 411 /* Minimum size to ensure buffer does not straddle a page. */ 412 size += (bs - 1) & ~(alignmask | a); 413 } 414 415 walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); 416 if (!walk->buffer) 417 return -ENOMEM; 418 419 iv = PTR_ALIGN(walk->buffer, alignmask + 1); 420 iv = skcipher_get_spot(iv, bs) + aligned_bs; 421 422 walk->iv = memcpy(iv, walk->iv, walk->ivsize); 423 return 0; 424 } 425 426 static int skcipher_walk_first(struct skcipher_walk *walk) 427 { 428 if (WARN_ON_ONCE(in_irq())) 429 return -EDEADLK; 430 431 walk->buffer = NULL; 432 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { 433 int err = skcipher_copy_iv(walk); 434 if (err) 435 return err; 436 } 437 438 walk->page = NULL; 439 walk->nbytes = walk->total; 440 441 return skcipher_walk_next(walk); 442 } 443 444 static int skcipher_walk_skcipher(struct skcipher_walk *walk, 445 struct skcipher_request *req) 446 { 447 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 448 449 walk->total = req->cryptlen; 450 walk->nbytes = 0; 451 walk->iv = req->iv; 452 walk->oiv = req->iv; 453 454 if (unlikely(!walk->total)) 455 return 0; 456 457 scatterwalk_start(&walk->in, req->src); 458 scatterwalk_start(&walk->out, req->dst); 459 460 walk->flags &= ~SKCIPHER_WALK_SLEEP; 461 walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 462 SKCIPHER_WALK_SLEEP : 0; 463 464 walk->blocksize = crypto_skcipher_blocksize(tfm); 465 walk->stride = crypto_skcipher_walksize(tfm); 466 walk->ivsize = crypto_skcipher_ivsize(tfm); 467 walk->alignmask = crypto_skcipher_alignmask(tfm); 468 469 return skcipher_walk_first(walk); 470 } 471 472 int skcipher_walk_virt(struct skcipher_walk *walk, 473 struct skcipher_request *req, bool atomic) 474 { 475 int err; 476 477 walk->flags &= ~SKCIPHER_WALK_PHYS; 478 479 err = skcipher_walk_skcipher(walk, req); 480 481 walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0; 482 483 return err; 484 } 485 EXPORT_SYMBOL_GPL(skcipher_walk_virt); 486 487 void skcipher_walk_atomise(struct skcipher_walk *walk) 488 { 489 walk->flags &= ~SKCIPHER_WALK_SLEEP; 490 } 491 EXPORT_SYMBOL_GPL(skcipher_walk_atomise); 492 493 int skcipher_walk_async(struct skcipher_walk *walk, 494 struct skcipher_request *req) 495 { 496 walk->flags |= SKCIPHER_WALK_PHYS; 497 498 INIT_LIST_HEAD(&walk->buffers); 499 500 return skcipher_walk_skcipher(walk, req); 501 } 502 EXPORT_SYMBOL_GPL(skcipher_walk_async); 503 504 static int skcipher_walk_aead_common(struct skcipher_walk *walk, 505 struct aead_request *req, bool atomic) 506 { 507 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 508 int err; 509 510 walk->nbytes = 0; 511 walk->iv = req->iv; 512 walk->oiv = req->iv; 513 514 if (unlikely(!walk->total)) 515 return 0; 516 517 walk->flags &= ~SKCIPHER_WALK_PHYS; 518 519 scatterwalk_start(&walk->in, req->src); 520 scatterwalk_start(&walk->out, req->dst); 521 522 scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2); 523 scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2); 524 525 scatterwalk_done(&walk->in, 0, walk->total); 526 scatterwalk_done(&walk->out, 0, walk->total); 527 528 if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) 529 walk->flags |= SKCIPHER_WALK_SLEEP; 530 else 531 walk->flags &= ~SKCIPHER_WALK_SLEEP; 532 533 walk->blocksize = crypto_aead_blocksize(tfm); 534 walk->stride = crypto_aead_chunksize(tfm); 535 walk->ivsize = crypto_aead_ivsize(tfm); 536 walk->alignmask = crypto_aead_alignmask(tfm); 537 538 err = skcipher_walk_first(walk); 539 540 if (atomic) 541 walk->flags &= ~SKCIPHER_WALK_SLEEP; 542 543 return err; 544 } 545 546 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req, 547 bool atomic) 548 { 549 walk->total = req->cryptlen; 550 551 return skcipher_walk_aead_common(walk, req, atomic); 552 } 553 EXPORT_SYMBOL_GPL(skcipher_walk_aead); 554 555 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk, 556 struct aead_request *req, bool atomic) 557 { 558 walk->total = req->cryptlen; 559 560 return skcipher_walk_aead_common(walk, req, atomic); 561 } 562 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt); 563 564 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, 565 struct aead_request *req, bool atomic) 566 { 567 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 568 569 walk->total = req->cryptlen - crypto_aead_authsize(tfm); 570 571 return skcipher_walk_aead_common(walk, req, atomic); 572 } 573 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt); 574 575 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg) 576 { 577 if (alg->cra_type == &crypto_blkcipher_type) 578 return sizeof(struct crypto_blkcipher *); 579 580 if (alg->cra_type == &crypto_ablkcipher_type || 581 alg->cra_type == &crypto_givcipher_type) 582 return sizeof(struct crypto_ablkcipher *); 583 584 return crypto_alg_extsize(alg); 585 } 586 587 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm, 588 const u8 *key, unsigned int keylen) 589 { 590 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 591 struct crypto_blkcipher *blkcipher = *ctx; 592 int err; 593 594 crypto_blkcipher_clear_flags(blkcipher, ~0); 595 crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) & 596 CRYPTO_TFM_REQ_MASK); 597 err = crypto_blkcipher_setkey(blkcipher, key, keylen); 598 crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) & 599 CRYPTO_TFM_RES_MASK); 600 if (err) 601 return err; 602 603 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 604 return 0; 605 } 606 607 static int skcipher_crypt_blkcipher(struct skcipher_request *req, 608 int (*crypt)(struct blkcipher_desc *, 609 struct scatterlist *, 610 struct scatterlist *, 611 unsigned int)) 612 { 613 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 614 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 615 struct blkcipher_desc desc = { 616 .tfm = *ctx, 617 .info = req->iv, 618 .flags = req->base.flags, 619 }; 620 621 622 return crypt(&desc, req->dst, req->src, req->cryptlen); 623 } 624 625 static int skcipher_encrypt_blkcipher(struct skcipher_request *req) 626 { 627 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 628 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 629 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 630 631 return skcipher_crypt_blkcipher(req, alg->encrypt); 632 } 633 634 static int skcipher_decrypt_blkcipher(struct skcipher_request *req) 635 { 636 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 637 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 638 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 639 640 return skcipher_crypt_blkcipher(req, alg->decrypt); 641 } 642 643 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 644 { 645 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 646 647 crypto_free_blkcipher(*ctx); 648 } 649 650 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 651 { 652 struct crypto_alg *calg = tfm->__crt_alg; 653 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 654 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 655 struct crypto_blkcipher *blkcipher; 656 struct crypto_tfm *btfm; 657 658 if (!crypto_mod_get(calg)) 659 return -EAGAIN; 660 661 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, 662 CRYPTO_ALG_TYPE_MASK); 663 if (IS_ERR(btfm)) { 664 crypto_mod_put(calg); 665 return PTR_ERR(btfm); 666 } 667 668 blkcipher = __crypto_blkcipher_cast(btfm); 669 *ctx = blkcipher; 670 tfm->exit = crypto_exit_skcipher_ops_blkcipher; 671 672 skcipher->setkey = skcipher_setkey_blkcipher; 673 skcipher->encrypt = skcipher_encrypt_blkcipher; 674 skcipher->decrypt = skcipher_decrypt_blkcipher; 675 676 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); 677 skcipher->keysize = calg->cra_blkcipher.max_keysize; 678 679 if (skcipher->keysize) 680 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); 681 682 return 0; 683 } 684 685 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, 686 const u8 *key, unsigned int keylen) 687 { 688 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 689 struct crypto_ablkcipher *ablkcipher = *ctx; 690 int err; 691 692 crypto_ablkcipher_clear_flags(ablkcipher, ~0); 693 crypto_ablkcipher_set_flags(ablkcipher, 694 crypto_skcipher_get_flags(tfm) & 695 CRYPTO_TFM_REQ_MASK); 696 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); 697 crypto_skcipher_set_flags(tfm, 698 crypto_ablkcipher_get_flags(ablkcipher) & 699 CRYPTO_TFM_RES_MASK); 700 if (err) 701 return err; 702 703 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 704 return 0; 705 } 706 707 static int skcipher_crypt_ablkcipher(struct skcipher_request *req, 708 int (*crypt)(struct ablkcipher_request *)) 709 { 710 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 711 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 712 struct ablkcipher_request *subreq = skcipher_request_ctx(req); 713 714 ablkcipher_request_set_tfm(subreq, *ctx); 715 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), 716 req->base.complete, req->base.data); 717 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, 718 req->iv); 719 720 return crypt(subreq); 721 } 722 723 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req) 724 { 725 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 726 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 727 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 728 729 return skcipher_crypt_ablkcipher(req, alg->encrypt); 730 } 731 732 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) 733 { 734 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 735 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 736 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 737 738 return skcipher_crypt_ablkcipher(req, alg->decrypt); 739 } 740 741 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 742 { 743 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 744 745 crypto_free_ablkcipher(*ctx); 746 } 747 748 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 749 { 750 struct crypto_alg *calg = tfm->__crt_alg; 751 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 752 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 753 struct crypto_ablkcipher *ablkcipher; 754 struct crypto_tfm *abtfm; 755 756 if (!crypto_mod_get(calg)) 757 return -EAGAIN; 758 759 abtfm = __crypto_alloc_tfm(calg, 0, 0); 760 if (IS_ERR(abtfm)) { 761 crypto_mod_put(calg); 762 return PTR_ERR(abtfm); 763 } 764 765 ablkcipher = __crypto_ablkcipher_cast(abtfm); 766 *ctx = ablkcipher; 767 tfm->exit = crypto_exit_skcipher_ops_ablkcipher; 768 769 skcipher->setkey = skcipher_setkey_ablkcipher; 770 skcipher->encrypt = skcipher_encrypt_ablkcipher; 771 skcipher->decrypt = skcipher_decrypt_ablkcipher; 772 773 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); 774 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + 775 sizeof(struct ablkcipher_request); 776 skcipher->keysize = calg->cra_ablkcipher.max_keysize; 777 778 if (skcipher->keysize) 779 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); 780 781 return 0; 782 } 783 784 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 785 const u8 *key, unsigned int keylen) 786 { 787 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 788 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 789 u8 *buffer, *alignbuffer; 790 unsigned long absize; 791 int ret; 792 793 absize = keylen + alignmask; 794 buffer = kmalloc(absize, GFP_ATOMIC); 795 if (!buffer) 796 return -ENOMEM; 797 798 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 799 memcpy(alignbuffer, key, keylen); 800 ret = cipher->setkey(tfm, alignbuffer, keylen); 801 kzfree(buffer); 802 return ret; 803 } 804 805 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 806 unsigned int keylen) 807 { 808 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 809 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 810 int err; 811 812 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 813 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 814 return -EINVAL; 815 } 816 817 if ((unsigned long)key & alignmask) 818 err = skcipher_setkey_unaligned(tfm, key, keylen); 819 else 820 err = cipher->setkey(tfm, key, keylen); 821 822 if (err) 823 return err; 824 825 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 826 return 0; 827 } 828 829 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 830 { 831 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 832 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 833 834 alg->exit(skcipher); 835 } 836 837 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 838 { 839 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 840 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 841 842 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) 843 return crypto_init_skcipher_ops_blkcipher(tfm); 844 845 if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type || 846 tfm->__crt_alg->cra_type == &crypto_givcipher_type) 847 return crypto_init_skcipher_ops_ablkcipher(tfm); 848 849 skcipher->setkey = skcipher_setkey; 850 skcipher->encrypt = alg->encrypt; 851 skcipher->decrypt = alg->decrypt; 852 skcipher->ivsize = alg->ivsize; 853 skcipher->keysize = alg->max_keysize; 854 855 if (skcipher->keysize) 856 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); 857 858 if (alg->exit) 859 skcipher->base.exit = crypto_skcipher_exit_tfm; 860 861 if (alg->init) 862 return alg->init(skcipher); 863 864 return 0; 865 } 866 867 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 868 { 869 struct skcipher_instance *skcipher = 870 container_of(inst, struct skcipher_instance, s.base); 871 872 skcipher->free(skcipher); 873 } 874 875 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 876 __maybe_unused; 877 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 878 { 879 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 880 base); 881 882 seq_printf(m, "type : skcipher\n"); 883 seq_printf(m, "async : %s\n", 884 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 885 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 886 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 887 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 888 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 889 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 890 seq_printf(m, "walksize : %u\n", skcipher->walksize); 891 } 892 893 #ifdef CONFIG_NET 894 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 895 { 896 struct crypto_report_blkcipher rblkcipher; 897 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 898 base); 899 900 strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 901 strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 902 903 rblkcipher.blocksize = alg->cra_blocksize; 904 rblkcipher.min_keysize = skcipher->min_keysize; 905 rblkcipher.max_keysize = skcipher->max_keysize; 906 rblkcipher.ivsize = skcipher->ivsize; 907 908 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 909 sizeof(struct crypto_report_blkcipher), &rblkcipher)) 910 goto nla_put_failure; 911 return 0; 912 913 nla_put_failure: 914 return -EMSGSIZE; 915 } 916 #else 917 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 918 { 919 return -ENOSYS; 920 } 921 #endif 922 923 static const struct crypto_type crypto_skcipher_type2 = { 924 .extsize = crypto_skcipher_extsize, 925 .init_tfm = crypto_skcipher_init_tfm, 926 .free = crypto_skcipher_free_instance, 927 #ifdef CONFIG_PROC_FS 928 .show = crypto_skcipher_show, 929 #endif 930 .report = crypto_skcipher_report, 931 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 932 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, 933 .type = CRYPTO_ALG_TYPE_SKCIPHER, 934 .tfmsize = offsetof(struct crypto_skcipher, base), 935 }; 936 937 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 938 const char *name, u32 type, u32 mask) 939 { 940 spawn->base.frontend = &crypto_skcipher_type2; 941 return crypto_grab_spawn(&spawn->base, name, type, mask); 942 } 943 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 944 945 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 946 u32 type, u32 mask) 947 { 948 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 949 } 950 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 951 952 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask) 953 { 954 return crypto_type_has_alg(alg_name, &crypto_skcipher_type2, 955 type, mask); 956 } 957 EXPORT_SYMBOL_GPL(crypto_has_skcipher2); 958 959 static int skcipher_prepare_alg(struct skcipher_alg *alg) 960 { 961 struct crypto_alg *base = &alg->base; 962 963 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 964 alg->walksize > PAGE_SIZE / 8) 965 return -EINVAL; 966 967 if (!alg->chunksize) 968 alg->chunksize = base->cra_blocksize; 969 if (!alg->walksize) 970 alg->walksize = alg->chunksize; 971 972 base->cra_type = &crypto_skcipher_type2; 973 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 974 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 975 976 return 0; 977 } 978 979 int crypto_register_skcipher(struct skcipher_alg *alg) 980 { 981 struct crypto_alg *base = &alg->base; 982 int err; 983 984 err = skcipher_prepare_alg(alg); 985 if (err) 986 return err; 987 988 return crypto_register_alg(base); 989 } 990 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 991 992 void crypto_unregister_skcipher(struct skcipher_alg *alg) 993 { 994 crypto_unregister_alg(&alg->base); 995 } 996 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 997 998 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 999 { 1000 int i, ret; 1001 1002 for (i = 0; i < count; i++) { 1003 ret = crypto_register_skcipher(&algs[i]); 1004 if (ret) 1005 goto err; 1006 } 1007 1008 return 0; 1009 1010 err: 1011 for (--i; i >= 0; --i) 1012 crypto_unregister_skcipher(&algs[i]); 1013 1014 return ret; 1015 } 1016 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 1017 1018 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 1019 { 1020 int i; 1021 1022 for (i = count - 1; i >= 0; --i) 1023 crypto_unregister_skcipher(&algs[i]); 1024 } 1025 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 1026 1027 int skcipher_register_instance(struct crypto_template *tmpl, 1028 struct skcipher_instance *inst) 1029 { 1030 int err; 1031 1032 err = skcipher_prepare_alg(&inst->alg); 1033 if (err) 1034 return err; 1035 1036 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 1037 } 1038 EXPORT_SYMBOL_GPL(skcipher_register_instance); 1039 1040 MODULE_LICENSE("GPL"); 1041 MODULE_DESCRIPTION("Symmetric key cipher type"); 1042