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