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 EXPORT_SYMBOL_GPL(skcipher_walk_next);
 401
 402 static int skcipher_copy_iv(struct skcipher_walk *walk)
 403 {
 404         unsigned a = crypto_tfm_ctx_alignment() - 1;
 405         unsigned alignmask = walk->alignmask;
 406         unsigned ivsize = walk->ivsize;
 407         unsigned bs = walk->stride;
 408         unsigned aligned_bs;
 409         unsigned size;
 410         u8 *iv;
 411
 412         aligned_bs = ALIGN(bs, alignmask + 1);
 413
 414         /* Minimum size to align buffer by alignmask. */
 415         size = alignmask & ~a;
 416
 417         if (walk->flags & SKCIPHER_WALK_PHYS)
 418                 size += ivsize;
 419         else {
 420                 size += aligned_bs + ivsize;
 421
 422                 /* Minimum size to ensure buffer does not straddle a page. */
 423                 size += (bs - 1) & ~(alignmask | a);
 424         }
 425
 426         walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
 427         if (!walk->buffer)
 428                 return -ENOMEM;
 429
 430         iv = PTR_ALIGN(walk->buffer, alignmask + 1);
 431         iv = skcipher_get_spot(iv, bs) + aligned_bs;
 432
 433         walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 434         return 0;
 435 }
 436
 437 static int skcipher_walk_first(struct skcipher_walk *walk)
 438 {
 439         if (WARN_ON_ONCE(in_irq()))
 440                 return -EDEADLK;
 441
 442         walk->buffer = NULL;
 443         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 444                 int err = skcipher_copy_iv(walk);
 445                 if (err)
 446                         return err;
 447         }
 448
 449         walk->page = NULL;
 450         walk->nbytes = walk->total;
 451
 452         return skcipher_walk_next(walk);
 453 }
 454
 455 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 456                                   struct skcipher_request *req)
 457 {
 458         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 459
 460         walk->total = req->cryptlen;
 461         walk->nbytes = 0;
 462         walk->iv = req->iv;
 463         walk->oiv = req->iv;
 464
 465         if (unlikely(!walk->total))
 466                 return 0;
 467
 468         scatterwalk_start(&walk->in, req->src);
 469         scatterwalk_start(&walk->out, req->dst);
 470
 471         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 472         walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 473                        SKCIPHER_WALK_SLEEP : 0;
 474
 475         walk->blocksize = crypto_skcipher_blocksize(tfm);
 476         walk->stride = crypto_skcipher_walksize(tfm);
 477         walk->ivsize = crypto_skcipher_ivsize(tfm);
 478         walk->alignmask = crypto_skcipher_alignmask(tfm);
 479
 480         return skcipher_walk_first(walk);
 481 }
 482
 483 int skcipher_walk_virt(struct skcipher_walk *walk,
 484                        struct skcipher_request *req, bool atomic)
 485 {
 486         int err;
 487
 488         walk->flags &= ~SKCIPHER_WALK_PHYS;
 489
 490         err = skcipher_walk_skcipher(walk, req);
 491
 492         walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;
 493
 494         return err;
 495 }
 496 EXPORT_SYMBOL_GPL(skcipher_walk_virt);
 497
 498 void skcipher_walk_atomise(struct skcipher_walk *walk)
 499 {
 500         walk->flags &= ~SKCIPHER_WALK_SLEEP;
 501 }
 502 EXPORT_SYMBOL_GPL(skcipher_walk_atomise);
 503
 504 int skcipher_walk_async(struct skcipher_walk *walk,
 505                         struct skcipher_request *req)
 506 {
 507         walk->flags |= SKCIPHER_WALK_PHYS;
 508
 509         INIT_LIST_HEAD(&walk->buffers);
 510
 511         return skcipher_walk_skcipher(walk, req);
 512 }
 513 EXPORT_SYMBOL_GPL(skcipher_walk_async);
 514
 515 static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 516                                      struct aead_request *req, bool atomic)
 517 {
 518         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 519         int err;
 520
 521         walk->nbytes = 0;
 522         walk->iv = req->iv;
 523         walk->oiv = req->iv;
 524
 525         if (unlikely(!walk->total))
 526                 return 0;
 527
 528         walk->flags &= ~SKCIPHER_WALK_PHYS;
 529
 530         scatterwalk_start(&walk->in, req->src);
 531         scatterwalk_start(&walk->out, req->dst);
 532
 533         scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
 534         scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
 535
 536         scatterwalk_done(&walk->in, 0, walk->total);
 537         scatterwalk_done(&walk->out, 0, walk->total);
 538
 539         if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 540                 walk->flags |= SKCIPHER_WALK_SLEEP;
 541         else
 542                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 543
 544         walk->blocksize = crypto_aead_blocksize(tfm);
 545         walk->stride = crypto_aead_chunksize(tfm);
 546         walk->ivsize = crypto_aead_ivsize(tfm);
 547         walk->alignmask = crypto_aead_alignmask(tfm);
 548
 549         err = skcipher_walk_first(walk);
 550
 551         if (atomic)
 552                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 553
 554         return err;
 555 }
 556
 557 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
 558                        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);
 565
 566 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
 567                                struct aead_request *req, bool atomic)
 568 {
 569         walk->total = req->cryptlen;
 570
 571         return skcipher_walk_aead_common(walk, req, atomic);
 572 }
 573 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
 574
 575 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
 576                                struct aead_request *req, bool atomic)
 577 {
 578         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 579
 580         walk->total = req->cryptlen - crypto_aead_authsize(tfm);
 581
 582         return skcipher_walk_aead_common(walk, req, atomic);
 583 }
 584 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
 585
 586 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
 587 {
 588         if (alg->cra_type == &crypto_blkcipher_type)
 589                 return sizeof(struct crypto_blkcipher *);
 590
 591         if (alg->cra_type == &crypto_ablkcipher_type ||
 592             alg->cra_type == &crypto_givcipher_type)
 593                 return sizeof(struct crypto_ablkcipher *);
 594
 595         return crypto_alg_extsize(alg);
 596 }
 597
 598 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
 599                                      const u8 *key, unsigned int keylen)
 600 {
 601         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 602         struct crypto_blkcipher *blkcipher = *ctx;
 603         int err;
 604
 605         crypto_blkcipher_clear_flags(blkcipher, ~0);
 606         crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
 607                                               CRYPTO_TFM_REQ_MASK);
 608         err = crypto_blkcipher_setkey(blkcipher, key, keylen);
 609         crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
 610                                        CRYPTO_TFM_RES_MASK);
 611
 612         return err;
 613 }
 614
 615 static int skcipher_crypt_blkcipher(struct skcipher_request *req,
 616                                     int (*crypt)(struct blkcipher_desc *,
 617                                                  struct scatterlist *,
 618                                                  struct scatterlist *,
 619                                                  unsigned int))
 620 {
 621         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 622         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 623         struct blkcipher_desc desc = {
 624                 .tfm = *ctx,
 625                 .info = req->iv,
 626                 .flags = req->base.flags,
 627         };
 628
 629
 630         return crypt(&desc, req->dst, req->src, req->cryptlen);
 631 }
 632
 633 static int skcipher_encrypt_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->encrypt);
 640 }
 641
 642 static int skcipher_decrypt_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->decrypt);
 649 }
 650
 651 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 652 {
 653         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 654
 655         crypto_free_blkcipher(*ctx);
 656 }
 657
 658 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 659 {
 660         struct crypto_alg *calg = tfm->__crt_alg;
 661         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 662         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 663         struct crypto_blkcipher *blkcipher;
 664         struct crypto_tfm *btfm;
 665
 666         if (!crypto_mod_get(calg))
 667                 return -EAGAIN;
 668
 669         btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
 670                                         CRYPTO_ALG_TYPE_MASK);
 671         if (IS_ERR(btfm)) {
 672                 crypto_mod_put(calg);
 673                 return PTR_ERR(btfm);
 674         }
 675
 676         blkcipher = __crypto_blkcipher_cast(btfm);
 677         *ctx = blkcipher;
 678         tfm->exit = crypto_exit_skcipher_ops_blkcipher;
 679
 680         skcipher->setkey = skcipher_setkey_blkcipher;
 681         skcipher->encrypt = skcipher_encrypt_blkcipher;
 682         skcipher->decrypt = skcipher_decrypt_blkcipher;
 683
 684         skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
 685         skcipher->keysize = calg->cra_blkcipher.max_keysize;
 686
 687         return 0;
 688 }
 689
 690 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
 691                                       const u8 *key, unsigned int keylen)
 692 {
 693         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 694         struct crypto_ablkcipher *ablkcipher = *ctx;
 695         int err;
 696
 697         crypto_ablkcipher_clear_flags(ablkcipher, ~0);
 698         crypto_ablkcipher_set_flags(ablkcipher,
 699                                     crypto_skcipher_get_flags(tfm) &
 700                                     CRYPTO_TFM_REQ_MASK);
 701         err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
 702         crypto_skcipher_set_flags(tfm,
 703                                   crypto_ablkcipher_get_flags(ablkcipher) &
 704                                   CRYPTO_TFM_RES_MASK);
 705
 706         return err;
 707 }
 708
 709 static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
 710                                      int (*crypt)(struct ablkcipher_request *))
 711 {
 712         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 713         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 714         struct ablkcipher_request *subreq = skcipher_request_ctx(req);
 715
 716         ablkcipher_request_set_tfm(subreq, *ctx);
 717         ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
 718                                         req->base.complete, req->base.data);
 719         ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
 720                                      req->iv);
 721
 722         return crypt(subreq);
 723 }
 724
 725 static int skcipher_encrypt_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->encrypt);
 732 }
 733
 734 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
 735 {
 736         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 737         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 738         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 739
 740         return skcipher_crypt_ablkcipher(req, alg->decrypt);
 741 }
 742
 743 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 744 {
 745         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 746
 747         crypto_free_ablkcipher(*ctx);
 748 }
 749
 750 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 751 {
 752         struct crypto_alg *calg = tfm->__crt_alg;
 753         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 754         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 755         struct crypto_ablkcipher *ablkcipher;
 756         struct crypto_tfm *abtfm;
 757
 758         if (!crypto_mod_get(calg))
 759                 return -EAGAIN;
 760
 761         abtfm = __crypto_alloc_tfm(calg, 0, 0);
 762         if (IS_ERR(abtfm)) {
 763                 crypto_mod_put(calg);
 764                 return PTR_ERR(abtfm);
 765         }
 766
 767         ablkcipher = __crypto_ablkcipher_cast(abtfm);
 768         *ctx = ablkcipher;
 769         tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
 770
 771         skcipher->setkey = skcipher_setkey_ablkcipher;
 772         skcipher->encrypt = skcipher_encrypt_ablkcipher;
 773         skcipher->decrypt = skcipher_decrypt_ablkcipher;
 774
 775         skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
 776         skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
 777                             sizeof(struct ablkcipher_request);
 778         skcipher->keysize = calg->cra_ablkcipher.max_keysize;
 779
 780         return 0;
 781 }
 782
 783 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 784                                      const u8 *key, unsigned int keylen)
 785 {
 786         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 787         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 788         u8 *buffer, *alignbuffer;
 789         unsigned long absize;
 790         int ret;
 791
 792         absize = keylen + alignmask;
 793         buffer = kmalloc(absize, GFP_ATOMIC);
 794         if (!buffer)
 795                 return -ENOMEM;
 796
 797         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 798         memcpy(alignbuffer, key, keylen);
 799         ret = cipher->setkey(tfm, alignbuffer, keylen);
 800         kzfree(buffer);
 801         return ret;
 802 }
 803
 804 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
 805                            unsigned int keylen)
 806 {
 807         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 808         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 809
 810         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 811                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 812                 return -EINVAL;
 813         }
 814
 815         if ((unsigned long)key & alignmask)
 816                 return skcipher_setkey_unaligned(tfm, key, keylen);
 817
 818         return cipher->setkey(tfm, key, keylen);
 819 }
 820
 821 static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
 822 {
 823         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 824         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 825
 826         alg->exit(skcipher);
 827 }
 828
 829 static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
 830 {
 831         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 832         struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
 833
 834         if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
 835                 return crypto_init_skcipher_ops_blkcipher(tfm);
 836
 837         if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
 838             tfm->__crt_alg->cra_type == &crypto_givcipher_type)
 839                 return crypto_init_skcipher_ops_ablkcipher(tfm);
 840
 841         skcipher->setkey = skcipher_setkey;
 842         skcipher->encrypt = alg->encrypt;
 843         skcipher->decrypt = alg->decrypt;
 844         skcipher->ivsize = alg->ivsize;
 845         skcipher->keysize = alg->max_keysize;
 846
 847         if (alg->exit)
 848                 skcipher->base.exit = crypto_skcipher_exit_tfm;
 849
 850         if (alg->init)
 851                 return alg->init(skcipher);
 852
 853         return 0;
 854 }
 855
 856 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
 857 {
 858         struct skcipher_instance *skcipher =
 859                 container_of(inst, struct skcipher_instance, s.base);
 860
 861         skcipher->free(skcipher);
 862 }
 863
 864 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 865         __maybe_unused;
 866 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 867 {
 868         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 869                                                      base);
 870
 871         seq_printf(m, "type         : skcipher\n");
 872         seq_printf(m, "async        : %s\n",
 873                    alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
 874         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 875         seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
 876         seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
 877         seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
 878         seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
 879         seq_printf(m, "walksize     : %u\n", skcipher->walksize);
 880 }
 881
 882 #ifdef CONFIG_NET
 883 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 884 {
 885         struct crypto_report_blkcipher rblkcipher;
 886         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 887                                                      base);
 888
 889         strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
 890         strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
 891
 892         rblkcipher.blocksize = alg->cra_blocksize;
 893         rblkcipher.min_keysize = skcipher->min_keysize;
 894         rblkcipher.max_keysize = skcipher->max_keysize;
 895         rblkcipher.ivsize = skcipher->ivsize;
 896
 897         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 898                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 899                 goto nla_put_failure;
 900         return 0;
 901
 902 nla_put_failure:
 903         return -EMSGSIZE;
 904 }
 905 #else
 906 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 907 {
 908         return -ENOSYS;
 909 }
 910 #endif
 911
 912 static const struct crypto_type crypto_skcipher_type2 = {
 913         .extsize = crypto_skcipher_extsize,
 914         .init_tfm = crypto_skcipher_init_tfm,
 915         .free = crypto_skcipher_free_instance,
 916 #ifdef CONFIG_PROC_FS
 917         .show = crypto_skcipher_show,
 918 #endif
 919         .report = crypto_skcipher_report,
 920         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 921         .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
 922         .type = CRYPTO_ALG_TYPE_SKCIPHER,
 923         .tfmsize = offsetof(struct crypto_skcipher, base),
 924 };
 925
 926 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 927                           const char *name, u32 type, u32 mask)
 928 {
 929         spawn->base.frontend = &crypto_skcipher_type2;
 930         return crypto_grab_spawn(&spawn->base, name, type, mask);
 931 }
 932 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 933
 934 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 935                                               u32 type, u32 mask)
 936 {
 937         return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
 938 }
 939 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
 940
 941 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
 942 {
 943         return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
 944                                    type, mask);
 945 }
 946 EXPORT_SYMBOL_GPL(crypto_has_skcipher2);
 947
 948 static int skcipher_prepare_alg(struct skcipher_alg *alg)
 949 {
 950         struct crypto_alg *base = &alg->base;
 951
 952         if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
 953             alg->walksize > PAGE_SIZE / 8)
 954                 return -EINVAL;
 955
 956         if (!alg->chunksize)
 957                 alg->chunksize = base->cra_blocksize;
 958         if (!alg->walksize)
 959                 alg->walksize = alg->chunksize;
 960
 961         base->cra_type = &crypto_skcipher_type2;
 962         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 963         base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
 964
 965         return 0;
 966 }
 967
 968 int crypto_register_skcipher(struct skcipher_alg *alg)
 969 {
 970         struct crypto_alg *base = &alg->base;
 971         int err;
 972
 973         err = skcipher_prepare_alg(alg);
 974         if (err)
 975                 return err;
 976
 977         return crypto_register_alg(base);
 978 }
 979 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
 980
 981 void crypto_unregister_skcipher(struct skcipher_alg *alg)
 982 {
 983         crypto_unregister_alg(&alg->base);
 984 }
 985 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
 986
 987 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
 988 {
 989         int i, ret;
 990
 991         for (i = 0; i < count; i++) {
 992                 ret = crypto_register_skcipher(&algs[i]);
 993                 if (ret)
 994                         goto err;
 995         }
 996
 997         return 0;
 998
 999 err:
1000         for (--i; i >= 0; --i)
1001                 crypto_unregister_skcipher(&algs[i]);
1002
1003         return ret;
1004 }
1005 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
1006
1007 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
1008 {
1009         int i;
1010
1011         for (i = count - 1; i >= 0; --i)
1012                 crypto_unregister_skcipher(&algs[i]);
1013 }
1014 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
1015
1016 int skcipher_register_instance(struct crypto_template *tmpl,
1017                            struct skcipher_instance *inst)
1018 {
1019         int err;
1020
1021         err = skcipher_prepare_alg(&inst->alg);
1022         if (err)
1023                 return err;
1024
1025         return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
1026 }
1027 EXPORT_SYMBOL_GPL(skcipher_register_instance);
1028
1029 MODULE_LICENSE("GPL");
1030 MODULE_DESCRIPTION("Symmetric key cipher type");