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 int 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         return 0;
 107 }
 108
 109 int skcipher_walk_done(struct skcipher_walk *walk, int err)
 110 {
 111         unsigned int n = walk->nbytes;
 112         unsigned int nbytes = 0;
 113
 114         if (!n)
 115                 goto finish;
 116
 117         if (likely(err >= 0)) {
 118                 n -= err;
 119                 nbytes = walk->total - n;
 120         }
 121
 122         if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
 123                                     SKCIPHER_WALK_SLOW |
 124                                     SKCIPHER_WALK_COPY |
 125                                     SKCIPHER_WALK_DIFF)))) {
 126 unmap_src:
 127                 skcipher_unmap_src(walk);
 128         } else if (walk->flags & SKCIPHER_WALK_DIFF) {
 129                 skcipher_unmap_dst(walk);
 130                 goto unmap_src;
 131         } else if (walk->flags & SKCIPHER_WALK_COPY) {
 132                 skcipher_map_dst(walk);
 133                 memcpy(walk->dst.virt.addr, walk->page, n);
 134                 skcipher_unmap_dst(walk);
 135         } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
 136                 if (err > 0) {
 137                         /*
 138                          * Didn't process all bytes.  Either the algorithm is
 139                          * broken, or this was the last step and it turned out
 140                          * the message wasn't evenly divisible into blocks but
 141                          * the algorithm requires it.
 142                          */
 143                         err = -EINVAL;
 144                         nbytes = 0;
 145                 } else
 146                         n = skcipher_done_slow(walk, n);
 147         }
 148
 149         if (err > 0)
 150                 err = 0;
 151
 152         walk->total = nbytes;
 153         walk->nbytes = 0;
 154
 155         scatterwalk_advance(&walk->in, n);
 156         scatterwalk_advance(&walk->out, n);
 157         scatterwalk_done(&walk->in, 0, nbytes);
 158         scatterwalk_done(&walk->out, 1, nbytes);
 159
 160         if (nbytes) {
 161                 crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
 162                              CRYPTO_TFM_REQ_MAY_SLEEP : 0);
 163                 return skcipher_walk_next(walk);
 164         }
 165
 166 finish:
 167         /* Short-circuit for the common/fast path. */
 168         if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
 169                 goto out;
 170
 171         if (walk->flags & SKCIPHER_WALK_PHYS)
 172                 goto out;
 173
 174         if (walk->iv != walk->oiv)
 175                 memcpy(walk->oiv, walk->iv, walk->ivsize);
 176         if (walk->buffer != walk->page)
 177                 kfree(walk->buffer);
 178         if (walk->page)
 179                 free_page((unsigned long)walk->page);
 180
 181 out:
 182         return err;
 183 }
 184 EXPORT_SYMBOL_GPL(skcipher_walk_done);
 185
 186 void skcipher_walk_complete(struct skcipher_walk *walk, int err)
 187 {
 188         struct skcipher_walk_buffer *p, *tmp;
 189
 190         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 191                 u8 *data;
 192
 193                 if (err)
 194                         goto done;
 195
 196                 data = p->data;
 197                 if (!data) {
 198                         data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
 199                         data = skcipher_get_spot(data, walk->stride);
 200                 }
 201
 202                 scatterwalk_copychunks(data, &p->dst, p->len, 1);
 203
 204                 if (offset_in_page(p->data) + p->len + walk->stride >
 205                     PAGE_SIZE)
 206                         free_page((unsigned long)p->data);
 207
 208 done:
 209                 list_del(&p->entry);
 210                 kfree(p);
 211         }
 212
 213         if (!err && walk->iv != walk->oiv)
 214                 memcpy(walk->oiv, walk->iv, walk->ivsize);
 215         if (walk->buffer != walk->page)
 216                 kfree(walk->buffer);
 217         if (walk->page)
 218                 free_page((unsigned long)walk->page);
 219 }
 220 EXPORT_SYMBOL_GPL(skcipher_walk_complete);
 221
 222 static void skcipher_queue_write(struct skcipher_walk *walk,
 223                                  struct skcipher_walk_buffer *p)
 224 {
 225         p->dst = walk->out;
 226         list_add_tail(&p->entry, &walk->buffers);
 227 }
 228
 229 static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
 230 {
 231         bool phys = walk->flags & SKCIPHER_WALK_PHYS;
 232         unsigned alignmask = walk->alignmask;
 233         struct skcipher_walk_buffer *p;
 234         unsigned a;
 235         unsigned n;
 236         u8 *buffer;
 237         void *v;
 238
 239         if (!phys) {
 240                 if (!walk->buffer)
 241                         walk->buffer = walk->page;
 242                 buffer = walk->buffer;
 243                 if (buffer)
 244                         goto ok;
 245         }
 246
 247         /* Start with the minimum alignment of kmalloc. */
 248         a = crypto_tfm_ctx_alignment() - 1;
 249         n = bsize;
 250
 251         if (phys) {
 252                 /* Calculate the minimum alignment of p->buffer. */
 253                 a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
 254                 n += sizeof(*p);
 255         }
 256
 257         /* Minimum size to align p->buffer by alignmask. */
 258         n += alignmask & ~a;
 259
 260         /* Minimum size to ensure p->buffer does not straddle a page. */
 261         n += (bsize - 1) & ~(alignmask | a);
 262
 263         v = kzalloc(n, skcipher_walk_gfp(walk));
 264         if (!v)
 265                 return skcipher_walk_done(walk, -ENOMEM);
 266
 267         if (phys) {
 268                 p = v;
 269                 p->len = bsize;
 270                 skcipher_queue_write(walk, p);
 271                 buffer = p->buffer;
 272         } else {
 273                 walk->buffer = v;
 274                 buffer = v;
 275         }
 276
 277 ok:
 278         walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
 279         walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
 280         walk->src.virt.addr = walk->dst.virt.addr;
 281
 282         scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 283
 284         walk->nbytes = bsize;
 285         walk->flags |= SKCIPHER_WALK_SLOW;
 286
 287         return 0;
 288 }
 289
 290 static int skcipher_next_copy(struct skcipher_walk *walk)
 291 {
 292         struct skcipher_walk_buffer *p;
 293         u8 *tmp = walk->page;
 294
 295         skcipher_map_src(walk);
 296         memcpy(tmp, walk->src.virt.addr, walk->nbytes);
 297         skcipher_unmap_src(walk);
 298
 299         walk->src.virt.addr = tmp;
 300         walk->dst.virt.addr = tmp;
 301
 302         if (!(walk->flags & SKCIPHER_WALK_PHYS))
 303                 return 0;
 304
 305         p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
 306         if (!p)
 307                 return -ENOMEM;
 308
 309         p->data = walk->page;
 310         p->len = walk->nbytes;
 311         skcipher_queue_write(walk, p);
 312
 313         if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
 314             PAGE_SIZE)
 315                 walk->page = NULL;
 316         else
 317                 walk->page += walk->nbytes;
 318
 319         return 0;
 320 }
 321
 322 static int skcipher_next_fast(struct skcipher_walk *walk)
 323 {
 324         unsigned long diff;
 325
 326         walk->src.phys.page = scatterwalk_page(&walk->in);
 327         walk->src.phys.offset = offset_in_page(walk->in.offset);
 328         walk->dst.phys.page = scatterwalk_page(&walk->out);
 329         walk->dst.phys.offset = offset_in_page(walk->out.offset);
 330
 331         if (walk->flags & SKCIPHER_WALK_PHYS)
 332                 return 0;
 333
 334         diff = walk->src.phys.offset - walk->dst.phys.offset;
 335         diff |= walk->src.virt.page - walk->dst.virt.page;
 336
 337         skcipher_map_src(walk);
 338         walk->dst.virt.addr = walk->src.virt.addr;
 339
 340         if (diff) {
 341                 walk->flags |= SKCIPHER_WALK_DIFF;
 342                 skcipher_map_dst(walk);
 343         }
 344
 345         return 0;
 346 }
 347
 348 static int skcipher_walk_next(struct skcipher_walk *walk)
 349 {
 350         unsigned int bsize;
 351         unsigned int n;
 352         int err;
 353
 354         walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
 355                          SKCIPHER_WALK_DIFF);
 356
 357         n = walk->total;
 358         bsize = min(walk->stride, max(n, walk->blocksize));
 359         n = scatterwalk_clamp(&walk->in, n);
 360         n = scatterwalk_clamp(&walk->out, n);
 361
 362         if (unlikely(n < bsize)) {
 363                 if (unlikely(walk->total < walk->blocksize))
 364                         return skcipher_walk_done(walk, -EINVAL);
 365
 366 slow_path:
 367                 err = skcipher_next_slow(walk, bsize);
 368                 goto set_phys_lowmem;
 369         }
 370
 371         if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
 372                 if (!walk->page) {
 373                         gfp_t gfp = skcipher_walk_gfp(walk);
 374
 375                         walk->page = (void *)__get_free_page(gfp);
 376                         if (!walk->page)
 377                                 goto slow_path;
 378                 }
 379
 380                 walk->nbytes = min_t(unsigned, n,
 381                                      PAGE_SIZE - offset_in_page(walk->page));
 382                 walk->flags |= SKCIPHER_WALK_COPY;
 383                 err = skcipher_next_copy(walk);
 384                 goto set_phys_lowmem;
 385         }
 386
 387         walk->nbytes = n;
 388
 389         return skcipher_next_fast(walk);
 390
 391 set_phys_lowmem:
 392         if (!err && (walk->flags & SKCIPHER_WALK_PHYS)) {
 393                 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
 394                 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
 395                 walk->src.phys.offset &= PAGE_SIZE - 1;
 396                 walk->dst.phys.offset &= PAGE_SIZE - 1;
 397         }
 398         return err;
 399 }
 400
 401 static int skcipher_copy_iv(struct skcipher_walk *walk)
 402 {
 403         unsigned a = crypto_tfm_ctx_alignment() - 1;
 404         unsigned alignmask = walk->alignmask;
 405         unsigned ivsize = walk->ivsize;
 406         unsigned bs = walk->stride;
 407         unsigned aligned_bs;
 408         unsigned size;
 409         u8 *iv;
 410
 411         aligned_bs = ALIGN(bs, alignmask + 1);
 412
 413         /* Minimum size to align buffer by alignmask. */
 414         size = alignmask & ~a;
 415
 416         if (walk->flags & SKCIPHER_WALK_PHYS)
 417                 size += ivsize;
 418         else {
 419                 size += aligned_bs + ivsize;
 420
 421                 /* Minimum size to ensure buffer does not straddle a page. */
 422                 size += (bs - 1) & ~(alignmask | a);
 423         }
 424
 425         walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
 426         if (!walk->buffer)
 427                 return -ENOMEM;
 428
 429         iv = PTR_ALIGN(walk->buffer, alignmask + 1);
 430         iv = skcipher_get_spot(iv, bs) + aligned_bs;
 431
 432         walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 433         return 0;
 434 }
 435
 436 static int skcipher_walk_first(struct skcipher_walk *walk)
 437 {
 438         if (WARN_ON_ONCE(in_irq()))
 439                 return -EDEADLK;
 440
 441         walk->buffer = NULL;
 442         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 443                 int err = skcipher_copy_iv(walk);
 444                 if (err)
 445                         return err;
 446         }
 447
 448         walk->page = NULL;
 449
 450         return skcipher_walk_next(walk);
 451 }
 452
 453 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 454                                   struct skcipher_request *req)
 455 {
 456         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 457
 458         walk->total = req->cryptlen;
 459         walk->nbytes = 0;
 460         walk->iv = req->iv;
 461         walk->oiv = req->iv;
 462
 463         if (unlikely(!walk->total))
 464                 return 0;
 465
 466         scatterwalk_start(&walk->in, req->src);
 467         scatterwalk_start(&walk->out, req->dst);
 468
 469         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 470         walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 471                        SKCIPHER_WALK_SLEEP : 0;
 472
 473         walk->blocksize = crypto_skcipher_blocksize(tfm);
 474         walk->stride = crypto_skcipher_walksize(tfm);
 475         walk->ivsize = crypto_skcipher_ivsize(tfm);
 476         walk->alignmask = crypto_skcipher_alignmask(tfm);
 477
 478         return skcipher_walk_first(walk);
 479 }
 480
 481 int skcipher_walk_virt(struct skcipher_walk *walk,
 482                        struct skcipher_request *req, bool atomic)
 483 {
 484         int err;
 485
 486         walk->flags &= ~SKCIPHER_WALK_PHYS;
 487
 488         err = skcipher_walk_skcipher(walk, req);
 489
 490         walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
 491
 492         return err;
 493 }
 494 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
 495
 496 void skcipher_walk_atomise(struct skcipher_walk *walk)
 497 {
 498         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 499 }
 500 EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
 501
 502 int skcipher_walk_async(struct skcipher_walk *walk,
 503                         struct skcipher_request *req)
 504 {
 505         walk->flags |= SKCIPHER_WALK_PHYS;
 506
 507         INIT_LIST_HEAD(&walk->buffers);
 508
 509         return skcipher_walk_skcipher(walk, req);
 510 }
 511 EXPORT_SYMBOL_GPL(skcipher_walk_async);
 512
 513 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 514                                      struct aead_request *req, bool atomic)
 515 {
 516         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 517         int err;
 518
 519         walk->nbytes = 0;
 520         walk->iv = req->iv;
 521         walk->oiv = req->iv;
 522
 523         if (unlikely(!walk->total))
 524                 return 0;
 525
 526         walk->flags &= ~SKCIPHER_WALK_PHYS;
 527
 528         scatterwalk_start(&walk->in, req->src);
 529         scatterwalk_start(&walk->out, req->dst);
 530
 531         scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
 532         scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
 533
 534         scatterwalk_done(&walk->in, 0, walk->total);
 535         scatterwalk_done(&walk->out, 0, walk->total);
 536
 537         if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 538                 walk->flags |= SKCIPHER_WALK_SLEEP;
 539         else
 540                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 541
 542         walk->blocksize = crypto_aead_blocksize(tfm);
 543         walk->stride = crypto_aead_chunksize(tfm);
 544         walk->ivsize = crypto_aead_ivsize(tfm);
 545         walk->alignmask = crypto_aead_alignmask(tfm);
 546
 547         err = skcipher_walk_first(walk);
 548
 549         if (atomic)
 550                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 551
 552         return err;
 553 }
 554
 555 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
 556                        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);
 563
 564 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
 565                                struct aead_request *req, bool atomic)
 566 {
 567         walk->total = req->cryptlen;
 568
 569         return skcipher_walk_aead_common(walk, req, atomic);
 570 }
 571 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
 572
 573 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
 574                                struct aead_request *req, bool atomic)
 575 {
 576         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 577
 578         walk->total = req->cryptlen - crypto_aead_authsize(tfm);
 579
 580         return skcipher_walk_aead_common(walk, req, atomic);
 581 }
 582 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
 583
 584 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
 585 {
 586         if (alg->cra_type == &crypto_blkcipher_type)
 587                 return sizeof(struct crypto_blkcipher *);
 588
 589         if (alg->cra_type == &crypto_ablkcipher_type ||
 590             alg->cra_type == &crypto_givcipher_type)
 591                 return sizeof(struct crypto_ablkcipher *);
 592
 593         return crypto_alg_extsize(alg);
 594 }
 595
 596 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
 597 {
 598         if (tfm->keysize)
 599                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 600 }
 601
 602 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
 603                                      const u8 *key, unsigned int keylen)
 604 {
 605         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 606         struct crypto_blkcipher *blkcipher = *ctx;
 607         int err;
 608
 609         crypto_blkcipher_clear_flags(blkcipher, ~0);
 610         crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
 611                                               CRYPTO_TFM_REQ_MASK);
 612         err = crypto_blkcipher_setkey(blkcipher, key, keylen);
 613         crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
 614                                        CRYPTO_TFM_RES_MASK);
 615         if (unlikely(err)) {
 616                 skcipher_set_needkey(tfm);
 617                 return err;
 618         }
 619
 620         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 621         return 0;
 622 }
 623
 624 static int skcipher_crypt_blkcipher(struct skcipher_request *req,
 625                                     int (*crypt)(struct blkcipher_desc *,
 626                                                  struct scatterlist *,
 627                                                  struct scatterlist *,
 628                                                  unsigned int))
 629 {
 630         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 631         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 632         struct blkcipher_desc desc = {
 633                 .tfm = *ctx,
 634                 .info = req->iv,
 635                 .flags = req->base.flags,
 636         };
 637
 638
 639         return crypt(&desc, req->dst, req->src, req->cryptlen);
 640 }
 641
 642 static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
 643 {
 644         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 645         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 646         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 647
 648         return skcipher_crypt_blkcipher(req, alg->encrypt);
 649 }
 650
 651 static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
 652 {
 653         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 654         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 655         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 656
 657         return skcipher_crypt_blkcipher(req, alg->decrypt);
 658 }
 659
 660 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 661 {
 662         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 663
 664         crypto_free_blkcipher(*ctx);
 665 }
 666
 667 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 668 {
 669         struct crypto_alg *calg = tfm->__crt_alg;
 670         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 671         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 672         struct crypto_blkcipher *blkcipher;
 673         struct crypto_tfm *btfm;
 674
 675         if (!crypto_mod_get(calg))
 676                 return -EAGAIN;
 677
 678         btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
 679                                         CRYPTO_ALG_TYPE_MASK);
 680         if (IS_ERR(btfm)) {
 681                 crypto_mod_put(calg);
 682                 return PTR_ERR(btfm);
 683         }
 684
 685         blkcipher = __crypto_blkcipher_cast(btfm);
 686         *ctx = blkcipher;
 687         tfm->exit = crypto_exit_skcipher_ops_blkcipher;
 688
 689         skcipher->setkey = skcipher_setkey_blkcipher;
 690         skcipher->encrypt = skcipher_encrypt_blkcipher;
 691         skcipher->decrypt = skcipher_decrypt_blkcipher;
 692
 693         skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
 694         skcipher->keysize = calg->cra_blkcipher.max_keysize;
 695
 696         skcipher_set_needkey(skcipher);
 697
 698         return 0;
 699 }
 700
 701 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
 702                                       const u8 *key, unsigned int keylen)
 703 {
 704         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 705         struct crypto_ablkcipher *ablkcipher = *ctx;
 706         int err;
 707
 708         crypto_ablkcipher_clear_flags(ablkcipher, ~0);
 709         crypto_ablkcipher_set_flags(ablkcipher,
 710                                     crypto_skcipher_get_flags(tfm) &
 711                                     CRYPTO_TFM_REQ_MASK);
 712         err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
 713         crypto_skcipher_set_flags(tfm,
 714                                   crypto_ablkcipher_get_flags(ablkcipher) &
 715                                   CRYPTO_TFM_RES_MASK);
 716         if (unlikely(err)) {
 717                 skcipher_set_needkey(tfm);
 718                 return err;
 719         }
 720
 721         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 722         return 0;
 723 }
 724
 725 static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
 726                                      int (*crypt)(struct ablkcipher_request *))
 727 {
 728         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 729         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 730         struct ablkcipher_request *subreq = skcipher_request_ctx(req);
 731
 732         ablkcipher_request_set_tfm(subreq, *ctx);
 733         ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
 734                                         req->base.complete, req->base.data);
 735         ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
 736                                      req->iv);
 737
 738         return crypt(subreq);
 739 }
 740
 741 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
 742 {
 743         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 744         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 745         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 746
 747         return skcipher_crypt_ablkcipher(req, alg->encrypt);
 748 }
 749
 750 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
 751 {
 752         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 753         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 754         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 755
 756         return skcipher_crypt_ablkcipher(req, alg->decrypt);
 757 }
 758
 759 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 760 {
 761         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 762
 763         crypto_free_ablkcipher(*ctx);
 764 }
 765
 766 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 767 {
 768         struct crypto_alg *calg = tfm->__crt_alg;
 769         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 770         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 771         struct crypto_ablkcipher *ablkcipher;
 772         struct crypto_tfm *abtfm;
 773
 774         if (!crypto_mod_get(calg))
 775                 return -EAGAIN;
 776
 777         abtfm = __crypto_alloc_tfm(calg, 0, 0);
 778         if (IS_ERR(abtfm)) {
 779                 crypto_mod_put(calg);
 780                 return PTR_ERR(abtfm);
 781         }
 782
 783         ablkcipher = __crypto_ablkcipher_cast(abtfm);
 784         *ctx = ablkcipher;
 785         tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
 786
 787         skcipher->setkey = skcipher_setkey_ablkcipher;
 788         skcipher->encrypt = skcipher_encrypt_ablkcipher;
 789         skcipher->decrypt = skcipher_decrypt_ablkcipher;
 790
 791         skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
 792         skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
 793                             sizeof(struct ablkcipher_request);
 794         skcipher->keysize = calg->cra_ablkcipher.max_keysize;
 795
 796         skcipher_set_needkey(skcipher);
 797
 798         return 0;
 799 }
 800
 801 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 802                                      const u8 *key, unsigned int keylen)
 803 {
 804         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 805         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 806         u8 *buffer, *alignbuffer;
 807         unsigned long absize;
 808         int ret;
 809
 810         absize = keylen + alignmask;
 811         buffer = kmalloc(absize, GFP_ATOMIC);
 812         if (!buffer)
 813                 return -ENOMEM;
 814
 815         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 816         memcpy(alignbuffer, key, keylen);
 817         ret = cipher->setkey(tfm, alignbuffer, keylen);
 818         kzfree(buffer);
 819         return ret;
 820 }
 821
 822 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
 823                            unsigned int keylen)
 824 {
 825         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 826         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 827         int err;
 828
 829         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 830                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 831                 return -EINVAL;
 832         }
 833
 834         if ((unsigned long)key & alignmask)
 835                 err = skcipher_setkey_unaligned(tfm, key, keylen);
 836         else
 837                 err = cipher->setkey(tfm, key, keylen);
 838
 839         if (unlikely(err)) {
 840                 skcipher_set_needkey(tfm);
 841                 return err;
 842         }
 843
 844         crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 845         return 0;
 846 }
 847
 848 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
 849 {
 850         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 851         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 852
 853         alg->exit(skcipher);
 854 }
 855
 856 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
 857 {
 858         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 859         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 860
 861         if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
 862                 return crypto_init_skcipher_ops_blkcipher(tfm);
 863
 864         if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
 865             tfm->__crt_alg->cra_type == &crypto_givcipher_type)
 866                 return crypto_init_skcipher_ops_ablkcipher(tfm);
 867
 868         skcipher->setkey = skcipher_setkey;
 869         skcipher->encrypt = alg->encrypt;
 870         skcipher->decrypt = alg->decrypt;
 871         skcipher->ivsize = alg->ivsize;
 872         skcipher->keysize = alg->max_keysize;
 873
 874         skcipher_set_needkey(skcipher);
 875
 876         if (alg->exit)
 877                 skcipher->base.exit = crypto_skcipher_exit_tfm;
 878
 879         if (alg->init)
 880                 return alg->init(skcipher);
 881
 882         return 0;
 883 }
 884
 885 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
 886 {
 887         struct skcipher_instance *skcipher =
 888                 container_of(inst, struct skcipher_instance, s.base);
 889
 890         skcipher->free(skcipher);
 891 }
 892
 893 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 894         __maybe_unused;
 895 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 896 {
 897         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 898                                                      base);
 899
 900         seq_printf(m, "type         : skcipher\n");
 901         seq_printf(m, "async        : %s\n",
 902                    alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
 903         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 904         seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
 905         seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
 906         seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
 907         seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
 908         seq_printf(m, "walksize     : %u\n", skcipher->walksize);
 909 }
 910
 911 #ifdef CONFIG_NET
 912 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 913 {
 914         struct crypto_report_blkcipher rblkcipher;
 915         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 916                                                      base);
 917
 918         strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
 919         strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
 920
 921         rblkcipher.blocksize = alg->cra_blocksize;
 922         rblkcipher.min_keysize = skcipher->min_keysize;
 923         rblkcipher.max_keysize = skcipher->max_keysize;
 924         rblkcipher.ivsize = skcipher->ivsize;
 925
 926         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 927                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 928                 goto nla_put_failure;
 929         return 0;
 930
 931 nla_put_failure:
 932         return -EMSGSIZE;
 933 }
 934 #else
 935 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 936 {
 937         return -ENOSYS;
 938 }
 939 #endif
 940
 941 static const struct crypto_type crypto_skcipher_type2 = {
 942         .extsize = crypto_skcipher_extsize,
 943         .init_tfm = crypto_skcipher_init_tfm,
 944         .free = crypto_skcipher_free_instance,
 945 #ifdef CONFIG_PROC_FS
 946         .show = crypto_skcipher_show,
 947 #endif
 948         .report = crypto_skcipher_report,
 949         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 950         .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
 951         .type = CRYPTO_ALG_TYPE_SKCIPHER,
 952         .tfmsize = offsetof(struct crypto_skcipher, base),
 953 };
 954
 955 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 956                           const char *name, u32 type, u32 mask)
 957 {
 958         spawn->base.frontend = &crypto_skcipher_type2;
 959         return crypto_grab_spawn(&spawn->base, name, type, mask);
 960 }
 961 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 962
 963 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 964                                               u32 type, u32 mask)
 965 {
 966         return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
 967 }
 968 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
 969
 970 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
 971 {
 972         return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
 973                                    type, mask);
 974 }
 975 EXPORT_SYMBOL_GPL(crypto_has_skcipher2);
 976
 977 static int skcipher_prepare_alg(struct skcipher_alg *alg)
 978 {
 979         struct crypto_alg *base = &alg->base;
 980
 981         if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
 982             alg->walksize > PAGE_SIZE / 8)
 983                 return -EINVAL;
 984
 985         if (!alg->chunksize)
 986                 alg->chunksize = base->cra_blocksize;
 987         if (!alg->walksize)
 988                 alg->walksize = alg->chunksize;
 989
 990         base->cra_type = &crypto_skcipher_type2;
 991         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 992         base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
 993
 994         return 0;
 995 }
 996
 997 int crypto_register_skcipher(struct skcipher_alg *alg)
 998 {
 999         struct crypto_alg *base = &alg->base;
1000         int err;
1001
1002         err = skcipher_prepare_alg(alg);
1003         if (err)
1004                 return err;
1005
1006         return crypto_register_alg(base);
1007 }
1008 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
1009
1010 void crypto_unregister_skcipher(struct skcipher_alg *alg)
1011 {
1012         crypto_unregister_alg(&alg->base);
1013 }
1014 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
1015
1016 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
1017 {
1018         int i, ret;
1019
1020         for (i = 0; i < count; i++) {
1021                 ret = crypto_register_skcipher(&algs[i]);
1022                 if (ret)
1023                         goto err;
1024         }
1025
1026         return 0;
1027
1028 err:
1029         for (--i; i >= 0; --i)
1030                 crypto_unregister_skcipher(&algs[i]);
1031
1032         return ret;
1033 }
1034 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
1035
1036 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
1037 {
1038         int i;
1039
1040         for (i = count - 1; i >= 0; --i)
1041                 crypto_unregister_skcipher(&algs[i]);
1042 }
1043 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
1044
1045 int skcipher_register_instance(struct crypto_template *tmpl,
1046                            struct skcipher_instance *inst)
1047 {
1048         int err;
1049
1050         err = skcipher_prepare_alg(&inst->alg);
1051         if (err)
1052                 return err;
1053
1054         return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
1055 }
1056 EXPORT_SYMBOL_GPL(skcipher_register_instance);
1057
1058 MODULE_LICENSE("GPL");
1059 MODULE_DESCRIPTION("Symmetric key cipher type");