crypto/skcipher.c

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