crypto/skcipher.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Symmetric key cipher operations.
   4  *
   5  * Generic encrypt/decrypt wrapper for ciphers, handles operations across
   6  * multiple page boundaries by using temporary blocks.  In user context,
   7  * the kernel is given a chance to schedule us once per page.
   8  *
   9  * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
  10  */
  11
  12 #include <crypto/internal/aead.h>
  13 #include <crypto/internal/skcipher.h>
  14 #include <crypto/scatterwalk.h>
  15 #include <linux/bug.h>
  16 #include <linux/cryptouser.h>
  17 #include <linux/compiler.h>
  18 #include <linux/list.h>
  19 #include <linux/module.h>
  20 #include <linux/rtnetlink.h>
  21 #include <linux/seq_file.h>
  22 #include <net/netlink.h>
  23
  24 #include "internal.h"
  25
  26 enum {
  27         SKCIPHER_WALK_PHYS = 1 << 0,
  28         SKCIPHER_WALK_SLOW = 1 << 1,
  29         SKCIPHER_WALK_COPY = 1 << 2,
  30         SKCIPHER_WALK_DIFF = 1 << 3,
  31         SKCIPHER_WALK_SLEEP = 1 << 4,
  32 };
  33
  34 struct skcipher_walk_buffer {
  35         struct list_head entry;
  36         struct scatter_walk dst;
  37         unsigned int len;
  38         u8 *data;
  39         u8 buffer[];
  40 };
  41
  42 static int skcipher_walk_next(struct skcipher_walk *walk);
  43
  44 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
  45 {
  46         if (PageHighMem(scatterwalk_page(walk)))
  47                 kunmap_atomic(vaddr);
  48 }
  49
  50 static inline void *skcipher_map(struct scatter_walk *walk)
  51 {
  52         struct page *page = scatterwalk_page(walk);
  53
  54         return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
  55                offset_in_page(walk->offset);
  56 }
  57
  58 static inline void skcipher_map_src(struct skcipher_walk *walk)
  59 {
  60         walk->src.virt.addr = skcipher_map(&walk->in);
  61 }
  62
  63 static inline void skcipher_map_dst(struct skcipher_walk *walk)
  64 {
  65         walk->dst.virt.addr = skcipher_map(&walk->out);
  66 }
  67
  68 static inline void skcipher_unmap_src(struct skcipher_walk *walk)
  69 {
  70         skcipher_unmap(&walk->in, walk->src.virt.addr);
  71 }
  72
  73 static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
  74 {
  75         skcipher_unmap(&walk->out, walk->dst.virt.addr);
  76 }
  77
  78 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
  79 {
  80         return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
  81 }
  82
  83 /* Get a spot of the specified length that does not straddle a page.
  84  * The caller needs to ensure that there is enough space for this operation.
  85  */
  86 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
  87 {
  88         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  89
  90         return max(start, end_page);
  91 }
  92
  93 static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
  94 {
  95         u8 *addr;
  96
  97         addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
  98         addr = skcipher_get_spot(addr, bsize);
  99         scatterwalk_copychunks(addr, &walk->out, bsize,
 100                                (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
 101         return 0;
 102 }
 103
 104 int skcipher_walk_done(struct skcipher_walk *walk, int err)
 105 {
 106         unsigned int n = walk->nbytes;
 107         unsigned int nbytes = 0;
 108
 109         if (!n)
 110                 goto finish;
 111
 112         if (likely(err >= 0)) {
 113                 n -= err;
 114                 nbytes = walk->total - n;
 115         }
 116
 117         if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
 118                                     SKCIPHER_WALK_SLOW |
 119                                     SKCIPHER_WALK_COPY |
 120                                     SKCIPHER_WALK_DIFF)))) {
 121 unmap_src:
 122                 skcipher_unmap_src(walk);
 123         } else if (walk->flags & SKCIPHER_WALK_DIFF) {
 124                 skcipher_unmap_dst(walk);
 125                 goto unmap_src;
 126         } else if (walk->flags & SKCIPHER_WALK_COPY) {
 127                 skcipher_map_dst(walk);
 128                 memcpy(walk->dst.virt.addr, walk->page, n);
 129                 skcipher_unmap_dst(walk);
 130         } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
 131                 if (err > 0) {
 132                         /*
 133                          * Didn't process all bytes.  Either the algorithm is
 134                          * broken, or this was the last step and it turned out
 135                          * the message wasn't evenly divisible into blocks but
 136                          * the algorithm requires it.
 137                          */
 138                         err = -EINVAL;
 139                         nbytes = 0;
 140                 } else
 141                         n = skcipher_done_slow(walk, n);
 142         }
 143
 144         if (err > 0)
 145                 err = 0;
 146
 147         walk->total = nbytes;
 148         walk->nbytes = 0;
 149
 150         scatterwalk_advance(&walk->in, n);
 151         scatterwalk_advance(&walk->out, n);
 152         scatterwalk_done(&walk->in, 0, nbytes);
 153         scatterwalk_done(&walk->out, 1, nbytes);
 154
 155         if (nbytes) {
 156                 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
 157                              CRYPTO_TFM_REQ_MAY_SLEEP : 0);
 158                 return skcipher_walk_next(walk);
 159         }
 160
 161 finish:
 162         /* Short-circuit for the common/fast path. */
 163         if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
 164                 goto out;
 165
 166         if (walk->flags & SKCIPHER_WALK_PHYS)
 167                 goto out;
 168
 169         if (walk->iv != walk->oiv)
 170                 memcpy(walk->oiv, walk->iv, walk->ivsize);
 171         if (walk->buffer != walk->page)
 172                 kfree(walk->buffer);
 173         if (walk->page)
 174                 free_page((unsigned long)walk->page);
 175
 176 out:
 177         return err;
 178 }
 179 EXPORT_SYMBOL_GPL(skcipher_walk_done);
 180
 181 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
 182 {
 183         struct skcipher_walk_buffer *p, *tmp;
 184
 185         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 186                 u8 *data;
 187
 188                 if (err)
 189                         goto done;
 190
 191                 data = p->data;
 192                 if (!data) {
 193                         data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
 194                         data = skcipher_get_spot(data, walk->stride);
 195                 }
 196
 197                 scatterwalk_copychunks(data, &p->dst, p->len, 1);
 198
 199                 if (offset_in_page(p->data) + p->len + walk->stride >
 200                     PAGE_SIZE)
 201                         free_page((unsigned long)p->data);
 202
 203 done:
 204                 list_del(&p->entry);
 205                 kfree(p);
 206         }
 207
 208         if (!err && walk->iv != walk->oiv)
 209                 memcpy(walk->oiv, walk->iv, walk->ivsize);
 210         if (walk->buffer != walk->page)
 211                 kfree(walk->buffer);
 212         if (walk->page)
 213                 free_page((unsigned long)walk->page);
 214 }
 215 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
 216
 217 static void skcipher_queue_write(struct skcipher_walk *walk,
 218                                  struct skcipher_walk_buffer *p)
 219 {
 220         p->dst = walk->out;
 221         list_add_tail(&p->entry, &walk->buffers);
 222 }
 223
 224 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
 225 {
 226         bool phys = walk->flags & SKCIPHER_WALK_PHYS;
 227         unsigned alignmask = walk->alignmask;
 228         struct skcipher_walk_buffer *p;
 229         unsigned a;
 230         unsigned n;
 231         u8 *buffer;
 232         void *v;
 233
 234         if (!phys) {
 235                 if (!walk->buffer)
 236                         walk->buffer = walk->page;
 237                 buffer = walk->buffer;
 238                 if (buffer)
 239                         goto ok;
 240         }
 241
 242         /* Start with the minimum alignment of kmalloc. */
 243         a = crypto_tfm_ctx_alignment() - 1;
 244         n = bsize;
 245
 246         if (phys) {
 247                 /* Calculate the minimum alignment of p->buffer. */
 248                 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
 249                 n += sizeof(*p);
 250         }
 251
 252         /* Minimum size to align p->buffer by alignmask. */
 253         n += alignmask & ~a;
 254
 255         /* Minimum size to ensure p->buffer does not straddle a page. */
 256         n += (bsize - 1) & ~(alignmask | a);
 257
 258         v = kzalloc(n, skcipher_walk_gfp(walk));
 259         if (!v)
 260                 return skcipher_walk_done(walk, -ENOMEM);
 261
 262         if (phys) {
 263                 p = v;
 264                 p->len = bsize;
 265                 skcipher_queue_write(walk, p);
 266                 buffer = p->buffer;
 267         } else {
 268                 walk->buffer = v;
 269                 buffer = v;
 270         }
 271
 272 ok:
 273         walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
 274         walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
 275         walk->src.virt.addr = walk->dst.virt.addr;
 276
 277         scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 278
 279         walk->nbytes = bsize;
 280         walk->flags |= SKCIPHER_WALK_SLOW;
 281
 282         return 0;
 283 }
 284
 285 static int skcipher_next_copy(struct skcipher_walk *walk)
 286 {
 287         struct skcipher_walk_buffer *p;
 288         u8 *tmp = walk->page;
 289
 290         skcipher_map_src(walk);
 291         memcpy(tmp, walk->src.virt.addr, walk->nbytes);
 292         skcipher_unmap_src(walk);
 293
 294         walk->src.virt.addr = tmp;
 295         walk->dst.virt.addr = tmp;
 296
 297         if (!(walk->flags & SKCIPHER_WALK_PHYS))
 298                 return 0;
 299
 300         p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
 301         if (!p)
 302                 return -ENOMEM;
 303
 304         p->data = walk->page;
 305         p->len = walk->nbytes;
 306         skcipher_queue_write(walk, p);
 307
 308         if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
 309             PAGE_SIZE)
 310                 walk->page = NULL;
 311         else
 312                 walk->page += walk->nbytes;
 313
 314         return 0;
 315 }
 316
 317 static int skcipher_next_fast(struct skcipher_walk *walk)
 318 {
 319         unsigned long diff;
 320
 321         walk->src.phys.page = scatterwalk_page(&walk->in);
 322         walk->src.phys.offset = offset_in_page(walk->in.offset);
 323         walk->dst.phys.page = scatterwalk_page(&walk->out);
 324         walk->dst.phys.offset = offset_in_page(walk->out.offset);
 325
 326         if (walk->flags & SKCIPHER_WALK_PHYS)
 327                 return 0;
 328
 329         diff = walk->src.phys.offset - walk->dst.phys.offset;
 330         diff |= walk->src.virt.page - walk->dst.virt.page;
 331
 332         skcipher_map_src(walk);
 333         walk->dst.virt.addr = walk->src.virt.addr;
 334
 335         if (diff) {
 336                 walk->flags |= SKCIPHER_WALK_DIFF;
 337                 skcipher_map_dst(walk);
 338         }
 339
 340         return 0;
 341 }
 342
 343 static int skcipher_walk_next(struct skcipher_walk *walk)
 344 {
 345         unsigned int bsize;
 346         unsigned int n;
 347         int err;
 348
 349         walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
 350                          SKCIPHER_WALK_DIFF);
 351
 352         n = walk->total;
 353         bsize = min(walk->stride, max(n, walk->blocksize));
 354         n = scatterwalk_clamp(&walk->in, n);
 355         n = scatterwalk_clamp(&walk->out, n);
 356
 357         if (unlikely(n < bsize)) {
 358                 if (unlikely(walk->total < walk->blocksize))
 359                         return skcipher_walk_done(walk, -EINVAL);
 360
 361 slow_path:
 362                 err = skcipher_next_slow(walk, bsize);
 363                 goto set_phys_lowmem;
 364         }
 365
 366         if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
 367                 if (!walk->page) {
 368                         gfp_t gfp = skcipher_walk_gfp(walk);
 369
 370                         walk->page = (void *)__get_free_page(gfp);
 371                         if (!walk->page)
 372                                 goto slow_path;
 373                 }
 374
 375                 walk->nbytes = min_t(unsigned, n,
 376                                      PAGE_SIZE - offset_in_page(walk->page));
 377                 walk->flags |= SKCIPHER_WALK_COPY;
 378                 err = skcipher_next_copy(walk);
 379                 goto set_phys_lowmem;
 380         }
 381
 382         walk->nbytes = n;
 383
 384         return skcipher_next_fast(walk);
 385
 386 set_phys_lowmem:
 387         if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
 388                 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
 389                 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
 390                 walk->src.phys.offset &= PAGE_SIZE - 1;
 391                 walk->dst.phys.offset &= PAGE_SIZE - 1;
 392         }
 393         return err;
 394 }
 395
 396 static int skcipher_copy_iv(struct skcipher_walk *walk)
 397 {
 398         unsigned a = crypto_tfm_ctx_alignment() - 1;
 399         unsigned alignmask = walk->alignmask;
 400         unsigned ivsize = walk->ivsize;
 401         unsigned bs = walk->stride;
 402         unsigned aligned_bs;
 403         unsigned size;
 404         u8 *iv;
 405
 406         aligned_bs = ALIGN(bs, alignmask + 1);
 407
 408         /* Minimum size to align buffer by alignmask. */
 409         size = alignmask & ~a;
 410
 411         if (walk->flags & SKCIPHER_WALK_PHYS)
 412                 size += ivsize;
 413         else {
 414                 size += aligned_bs + ivsize;
 415
 416                 /* Minimum size to ensure buffer does not straddle a page. */
 417                 size += (bs - 1) & ~(alignmask | a);
 418         }
 419
 420         walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
 421         if (!walk->buffer)
 422                 return -ENOMEM;
 423
 424         iv = PTR_ALIGN(walk->buffer, alignmask + 1);
 425         iv = skcipher_get_spot(iv, bs) + aligned_bs;
 426
 427         walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 428         return 0;
 429 }
 430
 431 static int skcipher_walk_first(struct skcipher_walk *walk)
 432 {
 433         if (WARN_ON_ONCE(in_irq()))
 434                 return -EDEADLK;
 435
 436         walk->buffer = NULL;
 437         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 438                 int err = skcipher_copy_iv(walk);
 439                 if (err)
 440                         return err;
 441         }
 442
 443         walk->page = NULL;
 444
 445         return skcipher_walk_next(walk);
 446 }
 447
 448 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 449                                   struct skcipher_request *req)
 450 {
 451         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 452
 453         walk->total = req->cryptlen;
 454         walk->nbytes = 0;
 455         walk->iv = req->iv;
 456         walk->oiv = req->iv;
 457
 458         if (unlikely(!walk->total))
 459                 return 0;
 460
 461         scatterwalk_start(&walk->in, req->src);
 462         scatterwalk_start(&walk->out, req->dst);
 463
 464         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 465         walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 466                        SKCIPHER_WALK_SLEEP : 0;
 467
 468         walk->blocksize = crypto_skcipher_blocksize(tfm);
 469         walk->stride = crypto_skcipher_walksize(tfm);
 470         walk->ivsize = crypto_skcipher_ivsize(tfm);
 471         walk->alignmask = crypto_skcipher_alignmask(tfm);
 472
 473         return skcipher_walk_first(walk);
 474 }
 475
 476 int skcipher_walk_virt(struct skcipher_walk *walk,
 477                        struct skcipher_request *req, bool atomic)
 478 {
 479         int err;
 480
 481         might_sleep_if(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 482
 483         walk->flags &= ~SKCIPHER_WALK_PHYS;
 484
 485         err = skcipher_walk_skcipher(walk, req);
 486
 487         walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
 488
 489         return err;
 490 }
 491 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
 492
 493 void skcipher_walk_atomise(struct skcipher_walk *walk)
 494 {
 495         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 496 }
 497 EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
 498
 499 int skcipher_walk_async(struct skcipher_walk *walk,
 500                         struct skcipher_request *req)
 501 {
 502         walk->flags |= SKCIPHER_WALK_PHYS;
 503
 504         INIT_LIST_HEAD(&walk->buffers);
 505
 506         return skcipher_walk_skcipher(walk, req);
 507 }
 508 EXPORT_SYMBOL_GPL(skcipher_walk_async);
 509
 510 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 511                                      struct aead_request *req, bool atomic)
 512 {
 513         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 514         int err;
 515
 516         walk->nbytes = 0;
 517         walk->iv = req->iv;
 518         walk->oiv = req->iv;
 519
 520         if (unlikely(!walk->total))
 521                 return 0;
 522
 523         walk->flags &= ~SKCIPHER_WALK_PHYS;
 524
 525         scatterwalk_start(&walk->in, req->src);
 526         scatterwalk_start(&walk->out, req->dst);
 527
 528         scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
 529         scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
 530
 531         scatterwalk_done(&walk->in, 0, walk->total);
 532         scatterwalk_done(&walk->out, 0, walk->total);
 533
 534         if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 535                 walk->flags |= SKCIPHER_WALK_SLEEP;
 536         else
 537                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 538
 539         walk->blocksize = crypto_aead_blocksize(tfm);
 540         walk->stride = crypto_aead_chunksize(tfm);
 541         walk->ivsize = crypto_aead_ivsize(tfm);
 542         walk->alignmask = crypto_aead_alignmask(tfm);
 543
 544         err = skcipher_walk_first(walk);
 545
 546         if (atomic)
 547                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 548
 549         return err;
 550 }
 551
 552 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
 553                                struct aead_request *req, bool atomic)
 554 {
 555         walk->total = req->cryptlen;
 556
 557         return skcipher_walk_aead_common(walk, req, atomic);
 558 }
 559 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
 560
 561 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
 562                                struct aead_request *req, bool atomic)
 563 {
 564         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 565
 566         walk->total = req->cryptlen - crypto_aead_authsize(tfm);
 567
 568         return skcipher_walk_aead_common(walk, req, atomic);
 569 }
 570 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
 571
 572 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
 573 {
 574         if (crypto_skcipher_max_keysize(tfm) != 0)
 575                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 576 }
 577
 578 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 579                                      const u8 *key, unsigned int keylen)
 580 {
 581         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 582         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 583         u8 *buffer, *alignbuffer;
 584         unsigned long absize;
 585         int ret;
 586
 587         absize = keylen + alignmask;
 588         buffer = kmalloc(absize, GFP_ATOMIC);
 589         if (!buffer)
 590                 return -ENOMEM;
 591
 592         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 593         memcpy(alignbuffer, key, keylen);
 594         ret = cipher->setkey(tfm, alignbuffer, keylen);
 595         kfree_sensitive(buffer);
 596         return ret;
 597 }
 598
 599 int crypto_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
 600                            unsigned int keylen)
 601 {
 602         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 603         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 604         int err;
 605
 606         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize)
 607                 return -EINVAL;
 608
 609         if ((unsigned long)key & alignmask)
 610                 err = skcipher_setkey_unaligned(tfm, key, keylen);
 611         else
 612                 err = cipher->setkey(tfm, key, keylen);
 613
 614         if (unlikely(err)) {
 615                 skcipher_set_needkey(tfm);
 616                 return err;
 617         }
 618
 619         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 620         return 0;
 621 }
 622 EXPORT_SYMBOL_GPL(crypto_skcipher_setkey);
 623
 624 int crypto_skcipher_encrypt(struct skcipher_request *req)
 625 {
 626         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 627         struct crypto_alg *alg = tfm->base.__crt_alg;
 628         unsigned int cryptlen = req->cryptlen;
 629         int ret;
 630
 631         crypto_stats_get(alg);
 632         if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 633                 ret = -ENOKEY;
 634         else
 635                 ret = crypto_skcipher_alg(tfm)->encrypt(req);
 636         crypto_stats_skcipher_encrypt(cryptlen, ret, alg);
 637         return ret;
 638 }
 639 EXPORT_SYMBOL_GPL(crypto_skcipher_encrypt);
 640
 641 int crypto_skcipher_decrypt(struct skcipher_request *req)
 642 {
 643         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 644         struct crypto_alg *alg = tfm->base.__crt_alg;
 645         unsigned int cryptlen = req->cryptlen;
 646         int ret;
 647
 648         crypto_stats_get(alg);
 649         if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 650                 ret = -ENOKEY;
 651         else
 652                 ret = crypto_skcipher_alg(tfm)->decrypt(req);
 653         crypto_stats_skcipher_decrypt(cryptlen, ret, alg);
 654         return ret;
 655 }
 656 EXPORT_SYMBOL_GPL(crypto_skcipher_decrypt);
 657
 658 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
 659 {
 660         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 661         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 662
 663         alg->exit(skcipher);
 664 }
 665
 666 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
 667 {
 668         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 669         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 670
 671         skcipher_set_needkey(skcipher);
 672
 673         if (alg->exit)
 674                 skcipher->base.exit = crypto_skcipher_exit_tfm;
 675
 676         if (alg->init)
 677                 return alg->init(skcipher);
 678
 679         return 0;
 680 }
 681
 682 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
 683 {
 684         struct skcipher_instance *skcipher =
 685                 container_of(inst, struct skcipher_instance, s.base);
 686
 687         skcipher->free(skcipher);
 688 }
 689
 690 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 691         __maybe_unused;
 692 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 693 {
 694         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 695                                                      base);
 696
 697         seq_printf(m, "type         : skcipher\n");
 698         seq_printf(m, "async        : %s\n",
 699                    alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
 700         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 701         seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
 702         seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
 703         seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
 704         seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
 705         seq_printf(m, "walksize     : %u\n", skcipher->walksize);
 706 }
 707
 708 #ifdef CONFIG_NET
 709 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 710 {
 711         struct crypto_report_blkcipher rblkcipher;
 712         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 713                                                      base);
 714
 715         memset(&rblkcipher, 0, sizeof(rblkcipher));
 716
 717         strscpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
 718         strscpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
 719
 720         rblkcipher.blocksize = alg->cra_blocksize;
 721         rblkcipher.min_keysize = skcipher->min_keysize;
 722         rblkcipher.max_keysize = skcipher->max_keysize;
 723         rblkcipher.ivsize = skcipher->ivsize;
 724
 725         return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 726                        sizeof(rblkcipher), &rblkcipher);
 727 }
 728 #else
 729 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 730 {
 731         return -ENOSYS;
 732 }
 733 #endif
 734
 735 static const struct crypto_type crypto_skcipher_type = {
 736         .extsize = crypto_alg_extsize,
 737         .init_tfm = crypto_skcipher_init_tfm,
 738         .free = crypto_skcipher_free_instance,
 739 #ifdef CONFIG_PROC_FS
 740         .show = crypto_skcipher_show,
 741 #endif
 742         .report = crypto_skcipher_report,
 743         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 744         .maskset = CRYPTO_ALG_TYPE_MASK,
 745         .type = CRYPTO_ALG_TYPE_SKCIPHER,
 746         .tfmsize = offsetof(struct crypto_skcipher, base),
 747 };
 748
 749 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 750                          struct crypto_instance *inst,
 751                          const char *name, u32 type, u32 mask)
 752 {
 753         spawn->base.frontend = &crypto_skcipher_type;
 754         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 755 }
 756 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 757
 758 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 759                                               u32 type, u32 mask)
 760 {
 761         return crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
 762 }
 763 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
 764
 765 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(
 766                                 const char *alg_name, u32 type, u32 mask)
 767 {
 768         struct crypto_skcipher *tfm;
 769
 770         /* Only sync algorithms allowed. */
 771         mask |= CRYPTO_ALG_ASYNC;
 772
 773         tfm = crypto_alloc_tfm(alg_name, &crypto_skcipher_type, type, mask);
 774
 775         /*
 776          * Make sure we do not allocate something that might get used with
 777          * an on-stack request: check the request size.
 778          */
 779         if (!IS_ERR(tfm) && WARN_ON(crypto_skcipher_reqsize(tfm) >
 780                                     MAX_SYNC_SKCIPHER_REQSIZE)) {
 781                 crypto_free_skcipher(tfm);
 782                 return ERR_PTR(-EINVAL);
 783         }
 784
 785         return (struct crypto_sync_skcipher *)tfm;
 786 }
 787 EXPORT_SYMBOL_GPL(crypto_alloc_sync_skcipher);
 788
 789 int crypto_has_skcipher(const char *alg_name, u32 type, u32 mask)
 790 {
 791         return crypto_type_has_alg(alg_name, &crypto_skcipher_type, type, mask);
 792 }
 793 EXPORT_SYMBOL_GPL(crypto_has_skcipher);
 794
 795 static int skcipher_prepare_alg(struct skcipher_alg *alg)
 796 {
 797         struct crypto_alg *base = &alg->base;
 798
 799         if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
 800             alg->walksize > PAGE_SIZE / 8)
 801                 return -EINVAL;
 802
 803         if (!alg->chunksize)
 804                 alg->chunksize = base->cra_blocksize;
 805         if (!alg->walksize)
 806                 alg->walksize = alg->chunksize;
 807
 808         base->cra_type = &crypto_skcipher_type;
 809         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 810         base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
 811
 812         return 0;
 813 }
 814
 815 int crypto_register_skcipher(struct skcipher_alg *alg)
 816 {
 817         struct crypto_alg *base = &alg->base;
 818         int err;
 819
 820         err = skcipher_prepare_alg(alg);
 821         if (err)
 822                 return err;
 823
 824         return crypto_register_alg(base);
 825 }
 826 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
 827
 828 void crypto_unregister_skcipher(struct skcipher_alg *alg)
 829 {
 830         crypto_unregister_alg(&alg->base);
 831 }
 832 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
 833
 834 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
 835 {
 836         int i, ret;
 837
 838         for (i = 0; i < count; i++) {
 839                 ret = crypto_register_skcipher(&algs[i]);
 840                 if (ret)
 841                         goto err;
 842         }
 843
 844         return 0;
 845
 846 err:
 847         for (--i; i >= 0; --i)
 848                 crypto_unregister_skcipher(&algs[i]);
 849
 850         return ret;
 851 }
 852 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
 853
 854 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
 855 {
 856         int i;
 857
 858         for (i = count - 1; i >= 0; --i)
 859                 crypto_unregister_skcipher(&algs[i]);
 860 }
 861 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
 862
 863 int skcipher_register_instance(struct crypto_template *tmpl,
 864                            struct skcipher_instance *inst)
 865 {
 866         int err;
 867
 868         if (WARN_ON(!inst->free))
 869                 return -EINVAL;
 870
 871         err = skcipher_prepare_alg(&inst->alg);
 872         if (err)
 873                 return err;
 874
 875         return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
 876 }
 877 EXPORT_SYMBOL_GPL(skcipher_register_instance);
 878
 879 static int skcipher_setkey_simple(struct crypto_skcipher *tfm, const u8 *key,
 880                                   unsigned int keylen)
 881 {
 882         struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
 883
 884         crypto_cipher_clear_flags(cipher, CRYPTO_TFM_REQ_MASK);
 885         crypto_cipher_set_flags(cipher, crypto_skcipher_get_flags(tfm) &
 886                                 CRYPTO_TFM_REQ_MASK);
 887         return crypto_cipher_setkey(cipher, key, keylen);
 888 }
 889
 890 static int skcipher_init_tfm_simple(struct crypto_skcipher *tfm)
 891 {
 892         struct skcipher_instance *inst = skcipher_alg_instance(tfm);
 893         struct crypto_cipher_spawn *spawn = skcipher_instance_ctx(inst);
 894         struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
 895         struct crypto_cipher *cipher;
 896
 897         cipher = crypto_spawn_cipher(spawn);
 898         if (IS_ERR(cipher))
 899                 return PTR_ERR(cipher);
 900
 901         ctx->cipher = cipher;
 902         return 0;
 903 }
 904
 905 static void skcipher_exit_tfm_simple(struct crypto_skcipher *tfm)
 906 {
 907         struct skcipher_ctx_simple *ctx = crypto_skcipher_ctx(tfm);
 908
 909         crypto_free_cipher(ctx->cipher);
 910 }
 911
 912 static void skcipher_free_instance_simple(struct skcipher_instance *inst)
 913 {
 914         crypto_drop_cipher(skcipher_instance_ctx(inst));
 915         kfree(inst);
 916 }
 917
 918 /**
 919  * skcipher_alloc_instance_simple - allocate instance of simple block cipher mode
 920  *
 921  * Allocate an skcipher_instance for a simple block cipher mode of operation,
 922  * e.g. cbc or ecb.  The instance context will have just a single crypto_spawn,
 923  * that for the underlying cipher.  The {min,max}_keysize, ivsize, blocksize,
 924  * alignmask, and priority are set from the underlying cipher but can be
 925  * overridden if needed.  The tfm context defaults to skcipher_ctx_simple, and
 926  * default ->setkey(), ->init(), and ->exit() methods are installed.
 927  *
 928  * @tmpl: the template being instantiated
 929  * @tb: the template parameters
 930  *
 931  * Return: a pointer to the new instance, or an ERR_PTR().  The caller still
 932  *         needs to register the instance.
 933  */
 934 struct skcipher_instance *skcipher_alloc_instance_simple(
 935         struct crypto_template *tmpl, struct rtattr **tb)
 936 {
 937         u32 mask;
 938         struct skcipher_instance *inst;
 939         struct crypto_cipher_spawn *spawn;
 940         struct crypto_alg *cipher_alg;
 941         int err;
 942
 943         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
 944         if (err)
 945                 return ERR_PTR(err);
 946
 947         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 948         if (!inst)
 949                 return ERR_PTR(-ENOMEM);
 950         spawn = skcipher_instance_ctx(inst);
 951
 952         err = crypto_grab_cipher(spawn, skcipher_crypto_instance(inst),
 953                                  crypto_attr_alg_name(tb[1]), 0, mask);
 954         if (err)
 955                 goto err_free_inst;
 956         cipher_alg = crypto_spawn_cipher_alg(spawn);
 957
 958         err = crypto_inst_setname(skcipher_crypto_instance(inst), tmpl->name,
 959                                   cipher_alg);
 960         if (err)
 961                 goto err_free_inst;
 962
 963         inst->free = skcipher_free_instance_simple;
 964
 965         /* Default algorithm properties, can be overridden */
 966         inst->alg.base.cra_blocksize = cipher_alg->cra_blocksize;
 967         inst->alg.base.cra_alignmask = cipher_alg->cra_alignmask;
 968         inst->alg.base.cra_priority = cipher_alg->cra_priority;
 969         inst->alg.min_keysize = cipher_alg->cra_cipher.cia_min_keysize;
 970         inst->alg.max_keysize = cipher_alg->cra_cipher.cia_max_keysize;
 971         inst->alg.ivsize = cipher_alg->cra_blocksize;
 972
 973         /* Use skcipher_ctx_simple by default, can be overridden */
 974         inst->alg.base.cra_ctxsize = sizeof(struct skcipher_ctx_simple);
 975         inst->alg.setkey = skcipher_setkey_simple;
 976         inst->alg.init = skcipher_init_tfm_simple;
 977         inst->alg.exit = skcipher_exit_tfm_simple;
 978
 979         return inst;
 980
 981 err_free_inst:
 982         skcipher_free_instance_simple(inst);
 983         return ERR_PTR(err);
 984 }
 985 EXPORT_SYMBOL_GPL(skcipher_alloc_instance_simple);
 986
 987 MODULE_LICENSE("GPL");
 988 MODULE_DESCRIPTION("Symmetric key cipher type");