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 if (err) 602 return err; 603 604 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 605 return 0; 606 } 607 608 static int skcipher_crypt_blkcipher(struct skcipher_request *req, 609 int (*crypt)(struct blkcipher_desc *, 610 struct scatterlist *, 611 struct scatterlist *, 612 unsigned int)) 613 { 614 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 615 struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm); 616 struct blkcipher_desc desc = { 617 .tfm = *ctx, 618 .info = req->iv, 619 .flags = req->base.flags, 620 }; 621 622 623 return crypt(&desc, req->dst, req->src, req->cryptlen); 624 } 625 626 static int skcipher_encrypt_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->encrypt); 633 } 634 635 static int skcipher_decrypt_blkcipher(struct skcipher_request *req) 636 { 637 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 638 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 639 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 640 641 return skcipher_crypt_blkcipher(req, alg->decrypt); 642 } 643 644 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 645 { 646 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 647 648 crypto_free_blkcipher(*ctx); 649 } 650 651 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm) 652 { 653 struct crypto_alg *calg = tfm->__crt_alg; 654 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 655 struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm); 656 struct crypto_blkcipher *blkcipher; 657 struct crypto_tfm *btfm; 658 659 if (!crypto_mod_get(calg)) 660 return -EAGAIN; 661 662 btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER, 663 CRYPTO_ALG_TYPE_MASK); 664 if (IS_ERR(btfm)) { 665 crypto_mod_put(calg); 666 return PTR_ERR(btfm); 667 } 668 669 blkcipher = __crypto_blkcipher_cast(btfm); 670 *ctx = blkcipher; 671 tfm->exit = crypto_exit_skcipher_ops_blkcipher; 672 673 skcipher->setkey = skcipher_setkey_blkcipher; 674 skcipher->encrypt = skcipher_encrypt_blkcipher; 675 skcipher->decrypt = skcipher_decrypt_blkcipher; 676 677 skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher); 678 skcipher->keysize = calg->cra_blkcipher.max_keysize; 679 680 if (skcipher->keysize) 681 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); 682 683 return 0; 684 } 685 686 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm, 687 const u8 *key, unsigned int keylen) 688 { 689 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 690 struct crypto_ablkcipher *ablkcipher = *ctx; 691 int err; 692 693 crypto_ablkcipher_clear_flags(ablkcipher, ~0); 694 crypto_ablkcipher_set_flags(ablkcipher, 695 crypto_skcipher_get_flags(tfm) & 696 CRYPTO_TFM_REQ_MASK); 697 err = crypto_ablkcipher_setkey(ablkcipher, key, keylen); 698 crypto_skcipher_set_flags(tfm, 699 crypto_ablkcipher_get_flags(ablkcipher) & 700 CRYPTO_TFM_RES_MASK); 701 if (err) 702 return err; 703 704 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 705 return 0; 706 } 707 708 static int skcipher_crypt_ablkcipher(struct skcipher_request *req, 709 int (*crypt)(struct ablkcipher_request *)) 710 { 711 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 712 struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm); 713 struct ablkcipher_request *subreq = skcipher_request_ctx(req); 714 715 ablkcipher_request_set_tfm(subreq, *ctx); 716 ablkcipher_request_set_callback(subreq, skcipher_request_flags(req), 717 req->base.complete, req->base.data); 718 ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen, 719 req->iv); 720 721 return crypt(subreq); 722 } 723 724 static int skcipher_encrypt_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->encrypt); 731 } 732 733 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req) 734 { 735 struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req); 736 struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher); 737 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; 738 739 return skcipher_crypt_ablkcipher(req, alg->decrypt); 740 } 741 742 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 743 { 744 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 745 746 crypto_free_ablkcipher(*ctx); 747 } 748 749 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm) 750 { 751 struct crypto_alg *calg = tfm->__crt_alg; 752 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 753 struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm); 754 struct crypto_ablkcipher *ablkcipher; 755 struct crypto_tfm *abtfm; 756 757 if (!crypto_mod_get(calg)) 758 return -EAGAIN; 759 760 abtfm = __crypto_alloc_tfm(calg, 0, 0); 761 if (IS_ERR(abtfm)) { 762 crypto_mod_put(calg); 763 return PTR_ERR(abtfm); 764 } 765 766 ablkcipher = __crypto_ablkcipher_cast(abtfm); 767 *ctx = ablkcipher; 768 tfm->exit = crypto_exit_skcipher_ops_ablkcipher; 769 770 skcipher->setkey = skcipher_setkey_ablkcipher; 771 skcipher->encrypt = skcipher_encrypt_ablkcipher; 772 skcipher->decrypt = skcipher_decrypt_ablkcipher; 773 774 skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher); 775 skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) + 776 sizeof(struct ablkcipher_request); 777 skcipher->keysize = calg->cra_ablkcipher.max_keysize; 778 779 if (skcipher->keysize) 780 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); 781 782 return 0; 783 } 784 785 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm, 786 const u8 *key, unsigned int keylen) 787 { 788 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 789 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 790 u8 *buffer, *alignbuffer; 791 unsigned long absize; 792 int ret; 793 794 absize = keylen + alignmask; 795 buffer = kmalloc(absize, GFP_ATOMIC); 796 if (!buffer) 797 return -ENOMEM; 798 799 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 800 memcpy(alignbuffer, key, keylen); 801 ret = cipher->setkey(tfm, alignbuffer, keylen); 802 kzfree(buffer); 803 return ret; 804 } 805 806 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key, 807 unsigned int keylen) 808 { 809 struct skcipher_alg *cipher = crypto_skcipher_alg(tfm); 810 unsigned long alignmask = crypto_skcipher_alignmask(tfm); 811 int err; 812 813 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 814 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 815 return -EINVAL; 816 } 817 818 if ((unsigned long)key & alignmask) 819 err = skcipher_setkey_unaligned(tfm, key, keylen); 820 else 821 err = cipher->setkey(tfm, key, keylen); 822 823 if (err) 824 return err; 825 826 crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY); 827 return 0; 828 } 829 830 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm) 831 { 832 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 833 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 834 835 alg->exit(skcipher); 836 } 837 838 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm) 839 { 840 struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm); 841 struct skcipher_alg *alg = crypto_skcipher_alg(skcipher); 842 843 if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type) 844 return crypto_init_skcipher_ops_blkcipher(tfm); 845 846 if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type || 847 tfm->__crt_alg->cra_type == &crypto_givcipher_type) 848 return crypto_init_skcipher_ops_ablkcipher(tfm); 849 850 skcipher->setkey = skcipher_setkey; 851 skcipher->encrypt = alg->encrypt; 852 skcipher->decrypt = alg->decrypt; 853 skcipher->ivsize = alg->ivsize; 854 skcipher->keysize = alg->max_keysize; 855 856 if (skcipher->keysize) 857 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY); 858 859 if (alg->exit) 860 skcipher->base.exit = crypto_skcipher_exit_tfm; 861 862 if (alg->init) 863 return alg->init(skcipher); 864 865 return 0; 866 } 867 868 static void crypto_skcipher_free_instance(struct crypto_instance *inst) 869 { 870 struct skcipher_instance *skcipher = 871 container_of(inst, struct skcipher_instance, s.base); 872 873 skcipher->free(skcipher); 874 } 875 876 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 877 __maybe_unused; 878 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg) 879 { 880 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 881 base); 882 883 seq_printf(m, "type : skcipher\n"); 884 seq_printf(m, "async : %s\n", 885 alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); 886 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 887 seq_printf(m, "min keysize : %u\n", skcipher->min_keysize); 888 seq_printf(m, "max keysize : %u\n", skcipher->max_keysize); 889 seq_printf(m, "ivsize : %u\n", skcipher->ivsize); 890 seq_printf(m, "chunksize : %u\n", skcipher->chunksize); 891 seq_printf(m, "walksize : %u\n", skcipher->walksize); 892 } 893 894 #ifdef CONFIG_NET 895 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 896 { 897 struct crypto_report_blkcipher rblkcipher; 898 struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg, 899 base); 900 901 strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type)); 902 strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv)); 903 904 rblkcipher.blocksize = alg->cra_blocksize; 905 rblkcipher.min_keysize = skcipher->min_keysize; 906 rblkcipher.max_keysize = skcipher->max_keysize; 907 rblkcipher.ivsize = skcipher->ivsize; 908 909 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 910 sizeof(struct crypto_report_blkcipher), &rblkcipher)) 911 goto nla_put_failure; 912 return 0; 913 914 nla_put_failure: 915 return -EMSGSIZE; 916 } 917 #else 918 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 919 { 920 return -ENOSYS; 921 } 922 #endif 923 924 static const struct crypto_type crypto_skcipher_type2 = { 925 .extsize = crypto_skcipher_extsize, 926 .init_tfm = crypto_skcipher_init_tfm, 927 .free = crypto_skcipher_free_instance, 928 #ifdef CONFIG_PROC_FS 929 .show = crypto_skcipher_show, 930 #endif 931 .report = crypto_skcipher_report, 932 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 933 .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK, 934 .type = CRYPTO_ALG_TYPE_SKCIPHER, 935 .tfmsize = offsetof(struct crypto_skcipher, base), 936 }; 937 938 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, 939 const char *name, u32 type, u32 mask) 940 { 941 spawn->base.frontend = &crypto_skcipher_type2; 942 return crypto_grab_spawn(&spawn->base, name, type, mask); 943 } 944 EXPORT_SYMBOL_GPL(crypto_grab_skcipher); 945 946 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 947 u32 type, u32 mask) 948 { 949 return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask); 950 } 951 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher); 952 953 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask) 954 { 955 return crypto_type_has_alg(alg_name, &crypto_skcipher_type2, 956 type, mask); 957 } 958 EXPORT_SYMBOL_GPL(crypto_has_skcipher2); 959 960 static int skcipher_prepare_alg(struct skcipher_alg *alg) 961 { 962 struct crypto_alg *base = &alg->base; 963 964 if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 || 965 alg->walksize > PAGE_SIZE / 8) 966 return -EINVAL; 967 968 if (!alg->chunksize) 969 alg->chunksize = base->cra_blocksize; 970 if (!alg->walksize) 971 alg->walksize = alg->chunksize; 972 973 base->cra_type = &crypto_skcipher_type2; 974 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 975 base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER; 976 977 return 0; 978 } 979 980 int crypto_register_skcipher(struct skcipher_alg *alg) 981 { 982 struct crypto_alg *base = &alg->base; 983 int err; 984 985 err = skcipher_prepare_alg(alg); 986 if (err) 987 return err; 988 989 return crypto_register_alg(base); 990 } 991 EXPORT_SYMBOL_GPL(crypto_register_skcipher); 992 993 void crypto_unregister_skcipher(struct skcipher_alg *alg) 994 { 995 crypto_unregister_alg(&alg->base); 996 } 997 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher); 998 999 int crypto_register_skciphers(struct skcipher_alg *algs, int count) 1000 { 1001 int i, ret; 1002 1003 for (i = 0; i < count; i++) { 1004 ret = crypto_register_skcipher(&algs[i]); 1005 if (ret) 1006 goto err; 1007 } 1008 1009 return 0; 1010 1011 err: 1012 for (--i; i >= 0; --i) 1013 crypto_unregister_skcipher(&algs[i]); 1014 1015 return ret; 1016 } 1017 EXPORT_SYMBOL_GPL(crypto_register_skciphers); 1018 1019 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count) 1020 { 1021 int i; 1022 1023 for (i = count - 1; i >= 0; --i) 1024 crypto_unregister_skcipher(&algs[i]); 1025 } 1026 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers); 1027 1028 int skcipher_register_instance(struct crypto_template *tmpl, 1029 struct skcipher_instance *inst) 1030 { 1031 int err; 1032 1033 err = skcipher_prepare_alg(&inst->alg); 1034 if (err) 1035 return err; 1036 1037 return crypto_register_instance(tmpl, skcipher_crypto_instance(inst)); 1038 } 1039 EXPORT_SYMBOL_GPL(skcipher_register_instance); 1040 1041 MODULE_LICENSE("GPL"); 1042 MODULE_DESCRIPTION("Symmetric key cipher type"); 1043