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