crypto/skcipher.c

   1 /*
   2  * Symmetric key cipher operations.
   3  *
   4  * Generic encrypt/decrypt wrapper for ciphers, handles operations across
   5  * multiple page boundaries by using temporary blocks.  In user context,
   6  * the kernel is given a chance to schedule us once per page.
   7  *
   8  * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 2 of the License, or (at your option)
  13  * any later version.
  14  *
  15  */
  16
  17 #include <crypto/internal/aead.h>
  18 #include <crypto/internal/skcipher.h>
  19 #include <crypto/scatterwalk.h>
  20 #include <linux/bug.h>
  21 #include <linux/cryptouser.h>
  22 #include <linux/compiler.h>
  23 #include <linux/list.h>
  24 #include <linux/module.h>
  25 #include <linux/rtnetlink.h>
  26 #include <linux/seq_file.h>
  27 #include <net/netlink.h>
  28
  29 #include "internal.h"
  30
  31 enum {
  32         SKCIPHER_WALK_PHYS = 1 << 0,
  33         SKCIPHER_WALK_SLOW = 1 << 1,
  34         SKCIPHER_WALK_COPY = 1 << 2,
  35         SKCIPHER_WALK_DIFF = 1 << 3,
  36         SKCIPHER_WALK_SLEEP = 1 << 4,
  37 };
  38
  39 struct skcipher_walk_buffer {
  40         struct list_head entry;
  41         struct scatter_walk dst;
  42         unsigned int len;
  43         u8 *data;
  44         u8 buffer[];
  45 };
  46
  47 static int skcipher_walk_next(struct skcipher_walk *walk);
  48
  49 static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
  50 {
  51         if (PageHighMem(scatterwalk_page(walk)))
  52                 kunmap_atomic(vaddr);
  53 }
  54
  55 static inline void *skcipher_map(struct scatter_walk *walk)
  56 {
  57         struct page *page = scatterwalk_page(walk);
  58
  59         return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
  60                offset_in_page(walk->offset);
  61 }
  62
  63 static inline void skcipher_map_src(struct skcipher_walk *walk)
  64 {
  65         walk->src.virt.addr = skcipher_map(&walk->in);
  66 }
  67
  68 static inline void skcipher_map_dst(struct skcipher_walk *walk)
  69 {
  70         walk->dst.virt.addr = skcipher_map(&walk->out);
  71 }
  72
  73 static inline void skcipher_unmap_src(struct skcipher_walk *walk)
  74 {
  75         skcipher_unmap(&walk->in, walk->src.virt.addr);
  76 }
  77
  78 static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
  79 {
  80         skcipher_unmap(&walk->out, walk->dst.virt.addr);
  81 }
  82
  83 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
  84 {
  85         return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
  86 }
  87
  88 /* Get a spot of the specified length that does not straddle a page.
  89  * The caller needs to ensure that there is enough space for this operation.
  90  */
  91 static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
  92 {
  93         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  94
  95         return max(start, end_page);
  96 }
  97
  98 static void skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
  99 {
 100         u8 *addr;
 101
 102         addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
 103         addr = skcipher_get_spot(addr, bsize);
 104         scatterwalk_copychunks(addr, &walk->out, bsize,
 105                                (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
 106 }
 107
 108 int skcipher_walk_done(struct skcipher_walk *walk, int err)
 109 {
 110         unsigned int n; /* bytes processed */
 111         bool more;
 112
 113         if (unlikely(err < 0))
 114                 goto finish;
 115
 116         n = walk->nbytes - err;
 117         walk->total -= n;
 118         more = (walk->total != 0);
 119
 120         if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
 121                                     SKCIPHER_WALK_SLOW |
 122                                     SKCIPHER_WALK_COPY |
 123                                     SKCIPHER_WALK_DIFF)))) {
 124 unmap_src:
 125                 skcipher_unmap_src(walk);
 126         } else if (walk->flags & SKCIPHER_WALK_DIFF) {
 127                 skcipher_unmap_dst(walk);
 128                 goto unmap_src;
 129         } else if (walk->flags & SKCIPHER_WALK_COPY) {
 130                 skcipher_map_dst(walk);
 131                 memcpy(walk->dst.virt.addr, walk->page, n);
 132                 skcipher_unmap_dst(walk);
 133         } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
 134                 if (WARN_ON(err)) {
 135                         /* unexpected case; didn't process all bytes */
 136                         err = -EINVAL;
 137                         goto finish;
 138                 }
 139                 skcipher_done_slow(walk, n);
 140                 goto already_advanced;
 141         }
 142
 143         scatterwalk_advance(&walk->in, n);
 144         scatterwalk_advance(&walk->out, n);
 145 already_advanced:
 146         scatterwalk_done(&walk->in, 0, more);
 147         scatterwalk_done(&walk->out, 1, more);
 148
 149         if (more) {
 150                 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
 151                              CRYPTO_TFM_REQ_MAY_SLEEP : 0);
 152                 return skcipher_walk_next(walk);
 153         }
 154         err = 0;
 155 finish:
 156         walk->nbytes = 0;
 157
 158         /* Short-circuit for the common/fast path. */
 159         if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
 160                 goto out;
 161
 162         if (walk->flags & SKCIPHER_WALK_PHYS)
 163                 goto out;
 164
 165         if (walk->iv != walk->oiv)
 166                 memcpy(walk->oiv, walk->iv, walk->ivsize);
 167         if (walk->buffer != walk->page)
 168                 kfree(walk->buffer);
 169         if (walk->page)
 170                 free_page((unsigned long)walk->page);
 171
 172 out:
 173         return err;
 174 }
 175 EXPORT_SYMBOL_GPL(skcipher_walk_done);
 176
 177 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
 178 {
 179         struct skcipher_walk_buffer *p, *tmp;
 180
 181         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 182                 u8 *data;
 183
 184                 if (err)
 185                         goto done;
 186
 187                 data = p->data;
 188                 if (!data) {
 189                         data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
 190                         data = skcipher_get_spot(data, walk->stride);
 191                 }
 192
 193                 scatterwalk_copychunks(data, &p->dst, p->len, 1);
 194
 195                 if (offset_in_page(p->data) + p->len + walk->stride >
 196                     PAGE_SIZE)
 197                         free_page((unsigned long)p->data);
 198
 199 done:
 200                 list_del(&p->entry);
 201                 kfree(p);
 202         }
 203
 204         if (!err && walk->iv != walk->oiv)
 205                 memcpy(walk->oiv, walk->iv, walk->ivsize);
 206         if (walk->buffer != walk->page)
 207                 kfree(walk->buffer);
 208         if (walk->page)
 209                 free_page((unsigned long)walk->page);
 210 }
 211 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
 212
 213 static void skcipher_queue_write(struct skcipher_walk *walk,
 214                                  struct skcipher_walk_buffer *p)
 215 {
 216         p->dst = walk->out;
 217         list_add_tail(&p->entry, &walk->buffers);
 218 }
 219
 220 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
 221 {
 222         bool phys = walk->flags & SKCIPHER_WALK_PHYS;
 223         unsigned alignmask = walk->alignmask;
 224         struct skcipher_walk_buffer *p;
 225         unsigned a;
 226         unsigned n;
 227         u8 *buffer;
 228         void *v;
 229
 230         if (!phys) {
 231                 if (!walk->buffer)
 232                         walk->buffer = walk->page;
 233                 buffer = walk->buffer;
 234                 if (buffer)
 235                         goto ok;
 236         }
 237
 238         /* Start with the minimum alignment of kmalloc. */
 239         a = crypto_tfm_ctx_alignment() - 1;
 240         n = bsize;
 241
 242         if (phys) {
 243                 /* Calculate the minimum alignment of p->buffer. */
 244                 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
 245                 n += sizeof(*p);
 246         }
 247
 248         /* Minimum size to align p->buffer by alignmask. */
 249         n += alignmask & ~a;
 250
 251         /* Minimum size to ensure p->buffer does not straddle a page. */
 252         n += (bsize - 1) & ~(alignmask | a);
 253
 254         v = kzalloc(n, skcipher_walk_gfp(walk));
 255         if (!v)
 256                 return skcipher_walk_done(walk, -ENOMEM);
 257
 258         if (phys) {
 259                 p = v;
 260                 p->len = bsize;
 261                 skcipher_queue_write(walk, p);
 262                 buffer = p->buffer;
 263         } else {
 264                 walk->buffer = v;
 265                 buffer = v;
 266         }
 267
 268 ok:
 269         walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
 270         walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
 271         walk->src.virt.addr = walk->dst.virt.addr;
 272
 273         scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 274
 275         walk->nbytes = bsize;
 276         walk->flags |= SKCIPHER_WALK_SLOW;
 277
 278         return 0;
 279 }
 280
 281 static int skcipher_next_copy(struct skcipher_walk *walk)
 282 {
 283         struct skcipher_walk_buffer *p;
 284         u8 *tmp = walk->page;
 285
 286         skcipher_map_src(walk);
 287         memcpy(tmp, walk->src.virt.addr, walk->nbytes);
 288         skcipher_unmap_src(walk);
 289
 290         walk->src.virt.addr = tmp;
 291         walk->dst.virt.addr = tmp;
 292
 293         if (!(walk->flags & SKCIPHER_WALK_PHYS))
 294                 return 0;
 295
 296         p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
 297         if (!p)
 298                 return -ENOMEM;
 299
 300         p->data = walk->page;
 301         p->len = walk->nbytes;
 302         skcipher_queue_write(walk, p);
 303
 304         if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
 305             PAGE_SIZE)
 306                 walk->page = NULL;
 307         else
 308                 walk->page += walk->nbytes;
 309
 310         return 0;
 311 }
 312
 313 static int skcipher_next_fast(struct skcipher_walk *walk)
 314 {
 315         unsigned long diff;
 316
 317         walk->src.phys.page = scatterwalk_page(&walk->in);
 318         walk->src.phys.offset = offset_in_page(walk->in.offset);
 319         walk->dst.phys.page = scatterwalk_page(&walk->out);
 320         walk->dst.phys.offset = offset_in_page(walk->out.offset);
 321
 322         if (walk->flags & SKCIPHER_WALK_PHYS)
 323                 return 0;
 324
 325         diff = walk->src.phys.offset - walk->dst.phys.offset;
 326         diff |= walk->src.virt.page - walk->dst.virt.page;
 327
 328         skcipher_map_src(walk);
 329         walk->dst.virt.addr = walk->src.virt.addr;
 330
 331         if (diff) {
 332                 walk->flags |= SKCIPHER_WALK_DIFF;
 333                 skcipher_map_dst(walk);
 334         }
 335
 336         return 0;
 337 }
 338
 339 static int skcipher_walk_next(struct skcipher_walk *walk)
 340 {
 341         unsigned int bsize;
 342         unsigned int n;
 343         int err;
 344
 345         walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
 346                          SKCIPHER_WALK_DIFF);
 347
 348         n = walk->total;
 349         bsize = min(walk->stride, max(n, walk->blocksize));
 350         n = scatterwalk_clamp(&walk->in, n);
 351         n = scatterwalk_clamp(&walk->out, n);
 352
 353         if (unlikely(n < bsize)) {
 354                 if (unlikely(walk->total < walk->blocksize))
 355                         return skcipher_walk_done(walk, -EINVAL);
 356
 357 slow_path:
 358                 err = skcipher_next_slow(walk, bsize);
 359                 goto set_phys_lowmem;
 360         }
 361
 362         if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
 363                 if (!walk->page) {
 364                         gfp_t gfp = skcipher_walk_gfp(walk);
 365
 366                         walk->page = (void *)__get_free_page(gfp);
 367                         if (!walk->page)
 368                                 goto slow_path;
 369                 }
 370
 371                 walk->nbytes = min_t(unsigned, n,
 372                                      PAGE_SIZE - offset_in_page(walk->page));
 373                 walk->flags |= SKCIPHER_WALK_COPY;
 374                 err = skcipher_next_copy(walk);
 375                 goto set_phys_lowmem;
 376         }
 377
 378         walk->nbytes = n;
 379
 380         return skcipher_next_fast(walk);
 381
 382 set_phys_lowmem:
 383         if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
 384                 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
 385                 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
 386                 walk->src.phys.offset &= PAGE_SIZE - 1;
 387                 walk->dst.phys.offset &= PAGE_SIZE - 1;
 388         }
 389         return err;
 390 }
 391
 392 static int skcipher_copy_iv(struct skcipher_walk *walk)
 393 {
 394         unsigned a = crypto_tfm_ctx_alignment() - 1;
 395         unsigned alignmask = walk->alignmask;
 396         unsigned ivsize = walk->ivsize;
 397         unsigned bs = walk->stride;
 398         unsigned aligned_bs;
 399         unsigned size;
 400         u8 *iv;
 401
 402         aligned_bs = ALIGN(bs, alignmask + 1);
 403
 404         /* Minimum size to align buffer by alignmask. */
 405         size = alignmask & ~a;
 406
 407         if (walk->flags & SKCIPHER_WALK_PHYS)
 408                 size += ivsize;
 409         else {
 410                 size += aligned_bs + ivsize;
 411
 412                 /* Minimum size to ensure buffer does not straddle a page. */
 413                 size += (bs - 1) & ~(alignmask | a);
 414         }
 415
 416         walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
 417         if (!walk->buffer)
 418                 return -ENOMEM;
 419
 420         iv = PTR_ALIGN(walk->buffer, alignmask + 1);
 421         iv = skcipher_get_spot(iv, bs) + aligned_bs;
 422
 423         walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 424         return 0;
 425 }
 426
 427 static int skcipher_walk_first(struct skcipher_walk *walk)
 428 {
 429         if (WARN_ON_ONCE(in_irq()))
 430                 return -EDEADLK;
 431
 432         walk->buffer = NULL;
 433         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 434                 int err = skcipher_copy_iv(walk);
 435                 if (err)
 436                         return err;
 437         }
 438
 439         walk->page = NULL;
 440
 441         return skcipher_walk_next(walk);
 442 }
 443
 444 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 445                                   struct skcipher_request *req)
 446 {
 447         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 448
 449         walk->total = req->cryptlen;
 450         walk->nbytes = 0;
 451         walk->iv = req->iv;
 452         walk->oiv = req->iv;
 453
 454         if (unlikely(!walk->total))
 455                 return 0;
 456
 457         scatterwalk_start(&walk->in, req->src);
 458         scatterwalk_start(&walk->out, req->dst);
 459
 460         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 461         walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 462                        SKCIPHER_WALK_SLEEP : 0;
 463
 464         walk->blocksize = crypto_skcipher_blocksize(tfm);
 465         walk->stride = crypto_skcipher_walksize(tfm);
 466         walk->ivsize = crypto_skcipher_ivsize(tfm);
 467         walk->alignmask = crypto_skcipher_alignmask(tfm);
 468
 469         return skcipher_walk_first(walk);
 470 }
 471
 472 int skcipher_walk_virt(struct skcipher_walk *walk,
 473                        struct skcipher_request *req, bool atomic)
 474 {
 475         int err;
 476
 477         walk->flags &= ~SKCIPHER_WALK_PHYS;
 478
 479         err = skcipher_walk_skcipher(walk, req);
 480
 481         walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
 482
 483         return err;
 484 }
 485 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
 486
 487 void skcipher_walk_atomise(struct skcipher_walk *walk)
 488 {
 489         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 490 }
 491 EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
 492
 493 int skcipher_walk_async(struct skcipher_walk *walk,
 494                         struct skcipher_request *req)
 495 {
 496         walk->flags |= SKCIPHER_WALK_PHYS;
 497
 498         INIT_LIST_HEAD(&walk->buffers);
 499
 500         return skcipher_walk_skcipher(walk, req);
 501 }
 502 EXPORT_SYMBOL_GPL(skcipher_walk_async);
 503
 504 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 505                                      struct aead_request *req, bool atomic)
 506 {
 507         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 508         int err;
 509
 510         walk->nbytes = 0;
 511         walk->iv = req->iv;
 512         walk->oiv = req->iv;
 513
 514         if (unlikely(!walk->total))
 515                 return 0;
 516
 517         walk->flags &= ~SKCIPHER_WALK_PHYS;
 518
 519         scatterwalk_start(&walk->in, req->src);
 520         scatterwalk_start(&walk->out, req->dst);
 521
 522         scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
 523         scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
 524
 525         scatterwalk_done(&walk->in, 0, walk->total);
 526         scatterwalk_done(&walk->out, 0, walk->total);
 527
 528         if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 529                 walk->flags |= SKCIPHER_WALK_SLEEP;
 530         else
 531                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 532
 533         walk->blocksize = crypto_aead_blocksize(tfm);
 534         walk->stride = crypto_aead_chunksize(tfm);
 535         walk->ivsize = crypto_aead_ivsize(tfm);
 536         walk->alignmask = crypto_aead_alignmask(tfm);
 537
 538         err = skcipher_walk_first(walk);
 539
 540         if (atomic)
 541                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 542
 543         return err;
 544 }
 545
 546 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
 547                        bool atomic)
 548 {
 549         walk->total = req->cryptlen;
 550
 551         return skcipher_walk_aead_common(walk, req, atomic);
 552 }
 553 EXPORT_SYMBOL_GPL(skcipher_walk_aead);
 554
 555 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
 556                                struct aead_request *req, bool atomic)
 557 {
 558         walk->total = req->cryptlen;
 559
 560         return skcipher_walk_aead_common(walk, req, atomic);
 561 }
 562 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
 563
 564 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
 565                                struct aead_request *req, bool atomic)
 566 {
 567         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 568
 569         walk->total = req->cryptlen - crypto_aead_authsize(tfm);
 570
 571         return skcipher_walk_aead_common(walk, req, atomic);
 572 }
 573 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
 574
 575 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
 576 {
 577         if (alg->cra_type == &crypto_blkcipher_type)
 578                 return sizeof(struct crypto_blkcipher *);
 579
 580         if (alg->cra_type == &crypto_ablkcipher_type ||
 581             alg->cra_type == &crypto_givcipher_type)
 582                 return sizeof(struct crypto_ablkcipher *);
 583
 584         return crypto_alg_extsize(alg);
 585 }
 586
 587 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
 588                                      const u8 *key, unsigned int keylen)
 589 {
 590         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 591         struct crypto_blkcipher *blkcipher = *ctx;
 592         int err;
 593
 594         crypto_blkcipher_clear_flags(blkcipher, ~0);
 595         crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
 596                                               CRYPTO_TFM_REQ_MASK);
 597         err = crypto_blkcipher_setkey(blkcipher, key, keylen);
 598         crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
 599                                        CRYPTO_TFM_RES_MASK);
 600         if (err)
 601                 return err;
 602
 603         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 604         return 0;
 605 }
 606
 607 static int skcipher_crypt_blkcipher(struct skcipher_request *req,
 608                                     int (*crypt)(struct blkcipher_desc *,
 609                                                  struct scatterlist *,
 610                                                  struct scatterlist *,
 611                                                  unsigned int))
 612 {
 613         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 614         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 615         struct blkcipher_desc desc = {
 616                 .tfm = *ctx,
 617                 .info = req->iv,
 618                 .flags = req->base.flags,
 619         };
 620
 621
 622         return crypt(&desc, req->dst, req->src, req->cryptlen);
 623 }
 624
 625 static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
 626 {
 627         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 628         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 629         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 630
 631         return skcipher_crypt_blkcipher(req, alg->encrypt);
 632 }
 633
 634 static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
 635 {
 636         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 637         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 638         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 639
 640         return skcipher_crypt_blkcipher(req, alg->decrypt);
 641 }
 642
 643 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 644 {
 645         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 646
 647         crypto_free_blkcipher(*ctx);
 648 }
 649
 650 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 651 {
 652         struct crypto_alg *calg = tfm->__crt_alg;
 653         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 654         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 655         struct crypto_blkcipher *blkcipher;
 656         struct crypto_tfm *btfm;
 657
 658         if (!crypto_mod_get(calg))
 659                 return -EAGAIN;
 660
 661         btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
 662                                         CRYPTO_ALG_TYPE_MASK);
 663         if (IS_ERR(btfm)) {
 664                 crypto_mod_put(calg);
 665                 return PTR_ERR(btfm);
 666         }
 667
 668         blkcipher = __crypto_blkcipher_cast(btfm);
 669         *ctx = blkcipher;
 670         tfm->exit = crypto_exit_skcipher_ops_blkcipher;
 671
 672         skcipher->setkey = skcipher_setkey_blkcipher;
 673         skcipher->encrypt = skcipher_encrypt_blkcipher;
 674         skcipher->decrypt = skcipher_decrypt_blkcipher;
 675
 676         skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
 677         skcipher->keysize = calg->cra_blkcipher.max_keysize;
 678
 679         if (skcipher->keysize)
 680                 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);
 681
 682         return 0;
 683 }
 684
 685 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
 686                                       const u8 *key, unsigned int keylen)
 687 {
 688         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 689         struct crypto_ablkcipher *ablkcipher = *ctx;
 690         int err;
 691
 692         crypto_ablkcipher_clear_flags(ablkcipher, ~0);
 693         crypto_ablkcipher_set_flags(ablkcipher,
 694                                     crypto_skcipher_get_flags(tfm) &
 695                                     CRYPTO_TFM_REQ_MASK);
 696         err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
 697         crypto_skcipher_set_flags(tfm,
 698                                   crypto_ablkcipher_get_flags(ablkcipher) &
 699                                   CRYPTO_TFM_RES_MASK);
 700         if (err)
 701                 return err;
 702
 703         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 704         return 0;
 705 }
 706
 707 static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
 708                                      int (*crypt)(struct ablkcipher_request *))
 709 {
 710         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 711         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 712         struct ablkcipher_request *subreq = skcipher_request_ctx(req);
 713
 714         ablkcipher_request_set_tfm(subreq, *ctx);
 715         ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
 716                                         req->base.complete, req->base.data);
 717         ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
 718                                      req->iv);
 719
 720         return crypt(subreq);
 721 }
 722
 723 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
 724 {
 725         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 726         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 727         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 728
 729         return skcipher_crypt_ablkcipher(req, alg->encrypt);
 730 }
 731
 732 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
 733 {
 734         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 735         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 736         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 737
 738         return skcipher_crypt_ablkcipher(req, alg->decrypt);
 739 }
 740
 741 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 742 {
 743         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 744
 745         crypto_free_ablkcipher(*ctx);
 746 }
 747
 748 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 749 {
 750         struct crypto_alg *calg = tfm->__crt_alg;
 751         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 752         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 753         struct crypto_ablkcipher *ablkcipher;
 754         struct crypto_tfm *abtfm;
 755
 756         if (!crypto_mod_get(calg))
 757                 return -EAGAIN;
 758
 759         abtfm = __crypto_alloc_tfm(calg, 0, 0);
 760         if (IS_ERR(abtfm)) {
 761                 crypto_mod_put(calg);
 762                 return PTR_ERR(abtfm);
 763         }
 764
 765         ablkcipher = __crypto_ablkcipher_cast(abtfm);
 766         *ctx = ablkcipher;
 767         tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
 768
 769         skcipher->setkey = skcipher_setkey_ablkcipher;
 770         skcipher->encrypt = skcipher_encrypt_ablkcipher;
 771         skcipher->decrypt = skcipher_decrypt_ablkcipher;
 772
 773         skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
 774         skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
 775                             sizeof(struct ablkcipher_request);
 776         skcipher->keysize = calg->cra_ablkcipher.max_keysize;
 777
 778         if (skcipher->keysize)
 779                 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);
 780
 781         return 0;
 782 }
 783
 784 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 785                                      const u8 *key, unsigned int keylen)
 786 {
 787         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 788         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 789         u8 *buffer, *alignbuffer;
 790         unsigned long absize;
 791         int ret;
 792
 793         absize = keylen + alignmask;
 794         buffer = kmalloc(absize, GFP_ATOMIC);
 795         if (!buffer)
 796                 return -ENOMEM;
 797
 798         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 799         memcpy(alignbuffer, key, keylen);
 800         ret = cipher->setkey(tfm, alignbuffer, keylen);
 801         kzfree(buffer);
 802         return ret;
 803 }
 804
 805 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
 806                            unsigned int keylen)
 807 {
 808         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 809         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 810         int err;
 811
 812         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 813                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 814                 return -EINVAL;
 815         }
 816
 817         if ((unsigned long)key & alignmask)
 818                 err = skcipher_setkey_unaligned(tfm, key, keylen);
 819         else
 820                 err = cipher->setkey(tfm, key, keylen);
 821
 822         if (err)
 823                 return err;
 824
 825         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 826         return 0;
 827 }
 828
 829 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
 830 {
 831         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 832         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 833
 834         alg->exit(skcipher);
 835 }
 836
 837 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
 838 {
 839         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 840         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 841
 842         if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
 843                 return crypto_init_skcipher_ops_blkcipher(tfm);
 844
 845         if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
 846             tfm->__crt_alg->cra_type == &crypto_givcipher_type)
 847                 return crypto_init_skcipher_ops_ablkcipher(tfm);
 848
 849         skcipher->setkey = skcipher_setkey;
 850         skcipher->encrypt = alg->encrypt;
 851         skcipher->decrypt = alg->decrypt;
 852         skcipher->ivsize = alg->ivsize;
 853         skcipher->keysize = alg->max_keysize;
 854
 855         if (skcipher->keysize)
 856                 crypto_skcipher_set_flags(skcipher, CRYPTO_TFM_NEED_KEY);
 857
 858         if (alg->exit)
 859                 skcipher->base.exit = crypto_skcipher_exit_tfm;
 860
 861         if (alg->init)
 862                 return alg->init(skcipher);
 863
 864         return 0;
 865 }
 866
 867 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
 868 {
 869         struct skcipher_instance *skcipher =
 870                 container_of(inst, struct skcipher_instance, s.base);
 871
 872         skcipher->free(skcipher);
 873 }
 874
 875 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 876         __maybe_unused;
 877 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 878 {
 879         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 880                                                      base);
 881
 882         seq_printf(m, "type         : skcipher\n");
 883         seq_printf(m, "async        : %s\n",
 884                    alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
 885         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 886         seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
 887         seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
 888         seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
 889         seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
 890         seq_printf(m, "walksize     : %u\n", skcipher->walksize);
 891 }
 892
 893 #ifdef CONFIG_NET
 894 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 895 {
 896         struct crypto_report_blkcipher rblkcipher;
 897         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 898                                                      base);
 899
 900         strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
 901         strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
 902
 903         rblkcipher.blocksize = alg->cra_blocksize;
 904         rblkcipher.min_keysize = skcipher->min_keysize;
 905         rblkcipher.max_keysize = skcipher->max_keysize;
 906         rblkcipher.ivsize = skcipher->ivsize;
 907
 908         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 909                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 910                 goto nla_put_failure;
 911         return 0;
 912
 913 nla_put_failure:
 914         return -EMSGSIZE;
 915 }
 916 #else
 917 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 918 {
 919         return -ENOSYS;
 920 }
 921 #endif
 922
 923 static const struct crypto_type crypto_skcipher_type2 = {
 924         .extsize = crypto_skcipher_extsize,
 925         .init_tfm = crypto_skcipher_init_tfm,
 926         .free = crypto_skcipher_free_instance,
 927 #ifdef CONFIG_PROC_FS
 928         .show = crypto_skcipher_show,
 929 #endif
 930         .report = crypto_skcipher_report,
 931         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 932         .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
 933         .type = CRYPTO_ALG_TYPE_SKCIPHER,
 934         .tfmsize = offsetof(struct crypto_skcipher, base),
 935 };
 936
 937 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 938                           const char *name, u32 type, u32 mask)
 939 {
 940         spawn->base.frontend = &crypto_skcipher_type2;
 941         return crypto_grab_spawn(&spawn->base, name, type, mask);
 942 }
 943 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 944
 945 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 946                                               u32 type, u32 mask)
 947 {
 948         return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
 949 }
 950 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
 951
 952 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
 953 {
 954         return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
 955                                    type, mask);
 956 }
 957 EXPORT_SYMBOL_GPL(crypto_has_skcipher2);
 958
 959 static int skcipher_prepare_alg(struct skcipher_alg *alg)
 960 {
 961         struct crypto_alg *base = &alg->base;
 962
 963         if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
 964             alg->walksize > PAGE_SIZE / 8)
 965                 return -EINVAL;
 966
 967         if (!alg->chunksize)
 968                 alg->chunksize = base->cra_blocksize;
 969         if (!alg->walksize)
 970                 alg->walksize = alg->chunksize;
 971
 972         base->cra_type = &crypto_skcipher_type2;
 973         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 974         base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
 975
 976         return 0;
 977 }
 978
 979 int crypto_register_skcipher(struct skcipher_alg *alg)
 980 {
 981         struct crypto_alg *base = &alg->base;
 982         int err;
 983
 984         err = skcipher_prepare_alg(alg);
 985         if (err)
 986                 return err;
 987
 988         return crypto_register_alg(base);
 989 }
 990 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
 991
 992 void crypto_unregister_skcipher(struct skcipher_alg *alg)
 993 {
 994         crypto_unregister_alg(&alg->base);
 995 }
 996 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
 997
 998 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
 999 {
1000         int i, ret;
1001
1002         for (i = 0; i < count; i++) {
1003                 ret = crypto_register_skcipher(&algs[i]);
1004                 if (ret)
1005                         goto err;
1006         }
1007
1008         return 0;
1009
1010 err:
1011         for (--i; i >= 0; --i)
1012                 crypto_unregister_skcipher(&algs[i]);
1013
1014         return ret;
1015 }
1016 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
1017
1018 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
1019 {
1020         int i;
1021
1022         for (i = count - 1; i >= 0; --i)
1023                 crypto_unregister_skcipher(&algs[i]);
1024 }
1025 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
1026
1027 int skcipher_register_instance(struct crypto_template *tmpl,
1028                            struct skcipher_instance *inst)
1029 {
1030         int err;
1031
1032         err = skcipher_prepare_alg(&inst->alg);
1033         if (err)
1034                 return err;
1035
1036         return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
1037 }
1038 EXPORT_SYMBOL_GPL(skcipher_register_instance);
1039
1040 MODULE_LICENSE("GPL");
1041 MODULE_DESCRIPTION("Symmetric key cipher type");