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 (err) {
 135                         /*
 136                          * Didn't process all bytes.  Either the algorithm is
 137                          * broken, or this was the last step and it turned out
 138                          * the message wasn't evenly divisible into blocks but
 139                          * the algorithm requires it.
 140                          */
 141                         err = -EINVAL;
 142                         goto finish;
 143                 }
 144                 skcipher_done_slow(walk, n);
 145                 goto already_advanced;
 146         }
 147
 148         scatterwalk_advance(&walk->in, n);
 149         scatterwalk_advance(&walk->out, n);
 150 already_advanced:
 151         scatterwalk_done(&walk->in, 0, more);
 152         scatterwalk_done(&walk->out, 1, more);
 153
 154         if (more) {
 155                 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
 156                              CRYPTO_TFM_REQ_MAY_SLEEP : 0);
 157                 return skcipher_walk_next(walk);
 158         }
 159         err = 0;
 160 finish:
 161         walk->nbytes = 0;
 162
 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_irq()))
 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         walk->flags &= ~SKCIPHER_WALK_PHYS;
 483
 484         err = skcipher_walk_skcipher(walk, req);
 485
 486         walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
 487
 488         return err;
 489 }
 490 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
 491
 492 void skcipher_walk_atomise(struct skcipher_walk *walk)
 493 {
 494         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 495 }
 496 EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
 497
 498 int skcipher_walk_async(struct skcipher_walk *walk,
 499                         struct skcipher_request *req)
 500 {
 501         walk->flags |= SKCIPHER_WALK_PHYS;
 502
 503         INIT_LIST_HEAD(&walk->buffers);
 504
 505         return skcipher_walk_skcipher(walk, req);
 506 }
 507 EXPORT_SYMBOL_GPL(skcipher_walk_async);
 508
 509 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 510                                      struct aead_request *req, bool atomic)
 511 {
 512         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 513         int err;
 514
 515         walk->nbytes = 0;
 516         walk->iv = req->iv;
 517         walk->oiv = req->iv;
 518
 519         if (unlikely(!walk->total))
 520                 return 0;
 521
 522         walk->flags &= ~SKCIPHER_WALK_PHYS;
 523
 524         scatterwalk_start(&walk->in, req->src);
 525         scatterwalk_start(&walk->out, req->dst);
 526
 527         scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
 528         scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
 529
 530         scatterwalk_done(&walk->in, 0, walk->total);
 531         scatterwalk_done(&walk->out, 0, walk->total);
 532
 533         if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 534                 walk->flags |= SKCIPHER_WALK_SLEEP;
 535         else
 536                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 537
 538         walk->blocksize = crypto_aead_blocksize(tfm);
 539         walk->stride = crypto_aead_chunksize(tfm);
 540         walk->ivsize = crypto_aead_ivsize(tfm);
 541         walk->alignmask = crypto_aead_alignmask(tfm);
 542
 543         err = skcipher_walk_first(walk);
 544
 545         if (atomic)
 546                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 547
 548         return err;
 549 }
 550
 551 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
 552                        bool atomic)
 553 {
 554         walk->total = req->cryptlen;
 555
 556         return skcipher_walk_aead_common(walk, req, atomic);
 557 }
 558 EXPORT_SYMBOL_GPL(skcipher_walk_aead);
 559
 560 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
 561                                struct aead_request *req, bool atomic)
 562 {
 563         walk->total = req->cryptlen;
 564
 565         return skcipher_walk_aead_common(walk, req, atomic);
 566 }
 567 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
 568
 569 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
 570                                struct aead_request *req, bool atomic)
 571 {
 572         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 573
 574         walk->total = req->cryptlen - crypto_aead_authsize(tfm);
 575
 576         return skcipher_walk_aead_common(walk, req, atomic);
 577 }
 578 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
 579
 580 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
 581 {
 582         if (alg->cra_type == &crypto_blkcipher_type)
 583                 return sizeof(struct crypto_blkcipher *);
 584
 585         if (alg->cra_type == &crypto_ablkcipher_type ||
 586             alg->cra_type == &crypto_givcipher_type)
 587                 return sizeof(struct crypto_ablkcipher *);
 588
 589         return crypto_alg_extsize(alg);
 590 }
 591
 592 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
 593 {
 594         if (tfm->keysize)
 595                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 596 }
 597
 598 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
 599                                      const u8 *key, unsigned int keylen)
 600 {
 601         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 602         struct crypto_blkcipher *blkcipher = *ctx;
 603         int err;
 604
 605         crypto_blkcipher_clear_flags(blkcipher, ~0);
 606         crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
 607                                               CRYPTO_TFM_REQ_MASK);
 608         err = crypto_blkcipher_setkey(blkcipher, key, keylen);
 609         crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
 610                                        CRYPTO_TFM_RES_MASK);
 611         if (unlikely(err)) {
 612                 skcipher_set_needkey(tfm);
 613                 return err;
 614         }
 615
 616         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 617         return 0;
 618 }
 619
 620 static int skcipher_crypt_blkcipher(struct skcipher_request *req,
 621                                     int (*crypt)(struct blkcipher_desc *,
 622                                                  struct scatterlist *,
 623                                                  struct scatterlist *,
 624                                                  unsigned int))
 625 {
 626         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 627         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 628         struct blkcipher_desc desc = {
 629                 .tfm = *ctx,
 630                 .info = req->iv,
 631                 .flags = req->base.flags,
 632         };
 633
 634
 635         return crypt(&desc, req->dst, req->src, req->cryptlen);
 636 }
 637
 638 static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
 639 {
 640         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 641         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 642         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 643
 644         return skcipher_crypt_blkcipher(req, alg->encrypt);
 645 }
 646
 647 static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
 648 {
 649         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 650         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 651         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 652
 653         return skcipher_crypt_blkcipher(req, alg->decrypt);
 654 }
 655
 656 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 657 {
 658         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 659
 660         crypto_free_blkcipher(*ctx);
 661 }
 662
 663 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 664 {
 665         struct crypto_alg *calg = tfm->__crt_alg;
 666         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 667         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 668         struct crypto_blkcipher *blkcipher;
 669         struct crypto_tfm *btfm;
 670
 671         if (!crypto_mod_get(calg))
 672                 return -EAGAIN;
 673
 674         btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
 675                                         CRYPTO_ALG_TYPE_MASK);
 676         if (IS_ERR(btfm)) {
 677                 crypto_mod_put(calg);
 678                 return PTR_ERR(btfm);
 679         }
 680
 681         blkcipher = __crypto_blkcipher_cast(btfm);
 682         *ctx = blkcipher;
 683         tfm->exit = crypto_exit_skcipher_ops_blkcipher;
 684
 685         skcipher->setkey = skcipher_setkey_blkcipher;
 686         skcipher->encrypt = skcipher_encrypt_blkcipher;
 687         skcipher->decrypt = skcipher_decrypt_blkcipher;
 688
 689         skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
 690         skcipher->keysize = calg->cra_blkcipher.max_keysize;
 691
 692         skcipher_set_needkey(skcipher);
 693
 694         return 0;
 695 }
 696
 697 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
 698                                       const u8 *key, unsigned int keylen)
 699 {
 700         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 701         struct crypto_ablkcipher *ablkcipher = *ctx;
 702         int err;
 703
 704         crypto_ablkcipher_clear_flags(ablkcipher, ~0);
 705         crypto_ablkcipher_set_flags(ablkcipher,
 706                                     crypto_skcipher_get_flags(tfm) &
 707                                     CRYPTO_TFM_REQ_MASK);
 708         err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
 709         crypto_skcipher_set_flags(tfm,
 710                                   crypto_ablkcipher_get_flags(ablkcipher) &
 711                                   CRYPTO_TFM_RES_MASK);
 712         if (unlikely(err)) {
 713                 skcipher_set_needkey(tfm);
 714                 return err;
 715         }
 716
 717         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 718         return 0;
 719 }
 720
 721 static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
 722                                      int (*crypt)(struct ablkcipher_request *))
 723 {
 724         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 725         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 726         struct ablkcipher_request *subreq = skcipher_request_ctx(req);
 727
 728         ablkcipher_request_set_tfm(subreq, *ctx);
 729         ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
 730                                         req->base.complete, req->base.data);
 731         ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
 732                                      req->iv);
 733
 734         return crypt(subreq);
 735 }
 736
 737 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
 738 {
 739         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 740         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 741         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 742
 743         return skcipher_crypt_ablkcipher(req, alg->encrypt);
 744 }
 745
 746 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
 747 {
 748         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 749         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 750         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 751
 752         return skcipher_crypt_ablkcipher(req, alg->decrypt);
 753 }
 754
 755 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 756 {
 757         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 758
 759         crypto_free_ablkcipher(*ctx);
 760 }
 761
 762 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 763 {
 764         struct crypto_alg *calg = tfm->__crt_alg;
 765         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 766         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 767         struct crypto_ablkcipher *ablkcipher;
 768         struct crypto_tfm *abtfm;
 769
 770         if (!crypto_mod_get(calg))
 771                 return -EAGAIN;
 772
 773         abtfm = __crypto_alloc_tfm(calg, 0, 0);
 774         if (IS_ERR(abtfm)) {
 775                 crypto_mod_put(calg);
 776                 return PTR_ERR(abtfm);
 777         }
 778
 779         ablkcipher = __crypto_ablkcipher_cast(abtfm);
 780         *ctx = ablkcipher;
 781         tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
 782
 783         skcipher->setkey = skcipher_setkey_ablkcipher;
 784         skcipher->encrypt = skcipher_encrypt_ablkcipher;
 785         skcipher->decrypt = skcipher_decrypt_ablkcipher;
 786
 787         skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
 788         skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
 789                             sizeof(struct ablkcipher_request);
 790         skcipher->keysize = calg->cra_ablkcipher.max_keysize;
 791
 792         skcipher_set_needkey(skcipher);
 793
 794         return 0;
 795 }
 796
 797 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 798                                      const u8 *key, unsigned int keylen)
 799 {
 800         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 801         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 802         u8 *buffer, *alignbuffer;
 803         unsigned long absize;
 804         int ret;
 805
 806         absize = keylen + alignmask;
 807         buffer = kmalloc(absize, GFP_ATOMIC);
 808         if (!buffer)
 809                 return -ENOMEM;
 810
 811         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 812         memcpy(alignbuffer, key, keylen);
 813         ret = cipher->setkey(tfm, alignbuffer, keylen);
 814         kzfree(buffer);
 815         return ret;
 816 }
 817
 818 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
 819                            unsigned int keylen)
 820 {
 821         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 822         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 823         int err;
 824
 825         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 826                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 827                 return -EINVAL;
 828         }
 829
 830         if ((unsigned long)key & alignmask)
 831                 err = skcipher_setkey_unaligned(tfm, key, keylen);
 832         else
 833                 err = cipher->setkey(tfm, key, keylen);
 834
 835         if (unlikely(err)) {
 836                 skcipher_set_needkey(tfm);
 837                 return err;
 838         }
 839
 840         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 841         return 0;
 842 }
 843
 844 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
 845 {
 846         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 847         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 848
 849         alg->exit(skcipher);
 850 }
 851
 852 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
 853 {
 854         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 855         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 856
 857         if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
 858                 return crypto_init_skcipher_ops_blkcipher(tfm);
 859
 860         if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
 861             tfm->__crt_alg->cra_type == &crypto_givcipher_type)
 862                 return crypto_init_skcipher_ops_ablkcipher(tfm);
 863
 864         skcipher->setkey = skcipher_setkey;
 865         skcipher->encrypt = alg->encrypt;
 866         skcipher->decrypt = alg->decrypt;
 867         skcipher->ivsize = alg->ivsize;
 868         skcipher->keysize = alg->max_keysize;
 869
 870         skcipher_set_needkey(skcipher);
 871
 872         if (alg->exit)
 873                 skcipher->base.exit = crypto_skcipher_exit_tfm;
 874
 875         if (alg->init)
 876                 return alg->init(skcipher);
 877
 878         return 0;
 879 }
 880
 881 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
 882 {
 883         struct skcipher_instance *skcipher =
 884                 container_of(inst, struct skcipher_instance, s.base);
 885
 886         skcipher->free(skcipher);
 887 }
 888
 889 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 890         __maybe_unused;
 891 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 892 {
 893         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 894                                                      base);
 895
 896         seq_printf(m, "type         : skcipher\n");
 897         seq_printf(m, "async        : %s\n",
 898                    alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
 899         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 900         seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
 901         seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
 902         seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
 903         seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
 904         seq_printf(m, "walksize     : %u\n", skcipher->walksize);
 905 }
 906
 907 #ifdef CONFIG_NET
 908 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 909 {
 910         struct crypto_report_blkcipher rblkcipher;
 911         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 912                                                      base);
 913
 914         strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
 915         strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
 916
 917         rblkcipher.blocksize = alg->cra_blocksize;
 918         rblkcipher.min_keysize = skcipher->min_keysize;
 919         rblkcipher.max_keysize = skcipher->max_keysize;
 920         rblkcipher.ivsize = skcipher->ivsize;
 921
 922         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 923                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 924                 goto nla_put_failure;
 925         return 0;
 926
 927 nla_put_failure:
 928         return -EMSGSIZE;
 929 }
 930 #else
 931 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 932 {
 933         return -ENOSYS;
 934 }
 935 #endif
 936
 937 static const struct crypto_type crypto_skcipher_type2 = {
 938         .extsize = crypto_skcipher_extsize,
 939         .init_tfm = crypto_skcipher_init_tfm,
 940         .free = crypto_skcipher_free_instance,
 941 #ifdef CONFIG_PROC_FS
 942         .show = crypto_skcipher_show,
 943 #endif
 944         .report = crypto_skcipher_report,
 945         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 946         .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
 947         .type = CRYPTO_ALG_TYPE_SKCIPHER,
 948         .tfmsize = offsetof(struct crypto_skcipher, base),
 949 };
 950
 951 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 952                           const char *name, u32 type, u32 mask)
 953 {
 954         spawn->base.frontend = &crypto_skcipher_type2;
 955         return crypto_grab_spawn(&spawn->base, name, type, mask);
 956 }
 957 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 958
 959 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 960                                               u32 type, u32 mask)
 961 {
 962         return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
 963 }
 964 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
 965
 966 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
 967 {
 968         return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
 969                                    type, mask);
 970 }
 971 EXPORT_SYMBOL_GPL(crypto_has_skcipher2);
 972
 973 static int skcipher_prepare_alg(struct skcipher_alg *alg)
 974 {
 975         struct crypto_alg *base = &alg->base;
 976
 977         if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
 978             alg->walksize > PAGE_SIZE / 8)
 979                 return -EINVAL;
 980
 981         if (!alg->chunksize)
 982                 alg->chunksize = base->cra_blocksize;
 983         if (!alg->walksize)
 984                 alg->walksize = alg->chunksize;
 985
 986         base->cra_type = &crypto_skcipher_type2;
 987         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 988         base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
 989
 990         return 0;
 991 }
 992
 993 int crypto_register_skcipher(struct skcipher_alg *alg)
 994 {
 995         struct crypto_alg *base = &alg->base;
 996         int err;
 997
 998         err = skcipher_prepare_alg(alg);
 999         if (err)
1000                 return err;
1001
1002         return crypto_register_alg(base);
1003 }
1004 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
1005
1006 void crypto_unregister_skcipher(struct skcipher_alg *alg)
1007 {
1008         crypto_unregister_alg(&alg->base);
1009 }
1010 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
1011
1012 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
1013 {
1014         int i, ret;
1015
1016         for (i = 0; i < count; i++) {
1017                 ret = crypto_register_skcipher(&algs[i]);
1018                 if (ret)
1019                         goto err;
1020         }
1021
1022         return 0;
1023
1024 err:
1025         for (--i; i >= 0; --i)
1026                 crypto_unregister_skcipher(&algs[i]);
1027
1028         return ret;
1029 }
1030 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
1031
1032 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
1033 {
1034         int i;
1035
1036         for (i = count - 1; i >= 0; --i)
1037                 crypto_unregister_skcipher(&algs[i]);
1038 }
1039 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
1040
1041 int skcipher_register_instance(struct crypto_template *tmpl,
1042                            struct skcipher_instance *inst)
1043 {
1044         int err;
1045
1046         err = skcipher_prepare_alg(&inst->alg);
1047         if (err)
1048                 return err;
1049
1050         return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
1051 }
1052 EXPORT_SYMBOL_GPL(skcipher_register_instance);
1053
1054 MODULE_LICENSE("GPL");
1055 MODULE_DESCRIPTION("Symmetric key cipher type");