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