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