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         if (WARN_ON_ONCE(in_irq()))
 430                 return -EDEADLK;
 431
 432         walk->buffer = NULL;
 433         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 434                 int err = skcipher_copy_iv(walk);
 435                 if (err)
 436                         return err;
 437         }
 438
 439         walk->page = NULL;
 440         walk->nbytes = walk->total;
 441
 442         return skcipher_walk_next(walk);
 443 }
 444
 445 static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 446                                   struct skcipher_request *req)
 447 {
 448         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 449
 450         walk->total = req->cryptlen;
 451         walk->nbytes = 0;
 452
 453         if (unlikely(!walk->total))
 454                 return 0;
 455
 456         scatterwalk_start(&walk->in, req->src);
 457         scatterwalk_start(&walk->out, req->dst);
 458
 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->nbytes = 0;
 513
 514         if (unlikely(!walk->total))
 515                 return 0;
 516
 517         walk->flags &= ~SKCIPHER_WALK_PHYS;
 518
 519         scatterwalk_start(&walk->in, req->src);
 520         scatterwalk_start(&walk->out, req->dst);
 521
 522         scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
 523         scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);
 524
 525         scatterwalk_done(&walk->in, 0, walk->total);
 526         scatterwalk_done(&walk->out, 0, walk->total);
 527
 528         walk->iv = req->iv;
 529         walk->oiv = req->iv;
 530
 531         if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 532                 walk->flags |= SKCIPHER_WALK_SLEEP;
 533         else
 534                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 535
 536         walk->blocksize = crypto_aead_blocksize(tfm);
 537         walk->stride = crypto_aead_chunksize(tfm);
 538         walk->ivsize = crypto_aead_ivsize(tfm);
 539         walk->alignmask = crypto_aead_alignmask(tfm);
 540
 541         err = skcipher_walk_first(walk);
 542
 543         if (atomic)
 544                 walk->flags &= ~SKCIPHER_WALK_SLEEP;
 545
 546         return err;
 547 }
 548
 549 int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
 550                        bool atomic)
 551 {
 552         walk->total = req->cryptlen;
 553
 554         return skcipher_walk_aead_common(walk, req, atomic);
 555 }
 556 EXPORT_SYMBOL_GPL(skcipher_walk_aead);
 557
 558 int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
 559                                struct aead_request *req, bool atomic)
 560 {
 561         walk->total = req->cryptlen;
 562
 563         return skcipher_walk_aead_common(walk, req, atomic);
 564 }
 565 EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);
 566
 567 int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
 568                                struct aead_request *req, bool atomic)
 569 {
 570         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 571
 572         walk->total = req->cryptlen - crypto_aead_authsize(tfm);
 573
 574         return skcipher_walk_aead_common(walk, req, atomic);
 575 }
 576 EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);
 577
 578 static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
 579 {
 580         if (alg->cra_type == &crypto_blkcipher_type)
 581                 return sizeof(struct crypto_blkcipher *);
 582
 583         if (alg->cra_type == &crypto_ablkcipher_type ||
 584             alg->cra_type == &crypto_givcipher_type)
 585                 return sizeof(struct crypto_ablkcipher *);
 586
 587         return crypto_alg_extsize(alg);
 588 }
 589
 590 static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
 591                                      const u8 *key, unsigned int keylen)
 592 {
 593         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 594         struct crypto_blkcipher *blkcipher = *ctx;
 595         int err;
 596
 597         crypto_blkcipher_clear_flags(blkcipher, ~0);
 598         crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
 599                                               CRYPTO_TFM_REQ_MASK);
 600         err = crypto_blkcipher_setkey(blkcipher, key, keylen);
 601         crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
 602                                        CRYPTO_TFM_RES_MASK);
 603
 604         return err;
 605 }
 606
 607 static int skcipher_crypt_blkcipher(struct skcipher_request *req,
 608                                     int (*crypt)(struct blkcipher_desc *,
 609                                                  struct scatterlist *,
 610                                                  struct scatterlist *,
 611                                                  unsigned int))
 612 {
 613         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 614         struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
 615         struct blkcipher_desc desc = {
 616                 .tfm = *ctx,
 617                 .info = req->iv,
 618                 .flags = req->base.flags,
 619         };
 620
 621
 622         return crypt(&desc, req->dst, req->src, req->cryptlen);
 623 }
 624
 625 static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
 626 {
 627         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 628         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 629         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 630
 631         return skcipher_crypt_blkcipher(req, alg->encrypt);
 632 }
 633
 634 static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
 635 {
 636         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 637         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 638         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 639
 640         return skcipher_crypt_blkcipher(req, alg->decrypt);
 641 }
 642
 643 static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 644 {
 645         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 646
 647         crypto_free_blkcipher(*ctx);
 648 }
 649
 650 static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
 651 {
 652         struct crypto_alg *calg = tfm->__crt_alg;
 653         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 654         struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
 655         struct crypto_blkcipher *blkcipher;
 656         struct crypto_tfm *btfm;
 657
 658         if (!crypto_mod_get(calg))
 659                 return -EAGAIN;
 660
 661         btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
 662                                         CRYPTO_ALG_TYPE_MASK);
 663         if (IS_ERR(btfm)) {
 664                 crypto_mod_put(calg);
 665                 return PTR_ERR(btfm);
 666         }
 667
 668         blkcipher = __crypto_blkcipher_cast(btfm);
 669         *ctx = blkcipher;
 670         tfm->exit = crypto_exit_skcipher_ops_blkcipher;
 671
 672         skcipher->setkey = skcipher_setkey_blkcipher;
 673         skcipher->encrypt = skcipher_encrypt_blkcipher;
 674         skcipher->decrypt = skcipher_decrypt_blkcipher;
 675
 676         skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
 677         skcipher->keysize = calg->cra_blkcipher.max_keysize;
 678
 679         return 0;
 680 }
 681
 682 static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
 683                                       const u8 *key, unsigned int keylen)
 684 {
 685         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 686         struct crypto_ablkcipher *ablkcipher = *ctx;
 687         int err;
 688
 689         crypto_ablkcipher_clear_flags(ablkcipher, ~0);
 690         crypto_ablkcipher_set_flags(ablkcipher,
 691                                     crypto_skcipher_get_flags(tfm) &
 692                                     CRYPTO_TFM_REQ_MASK);
 693         err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
 694         crypto_skcipher_set_flags(tfm,
 695                                   crypto_ablkcipher_get_flags(ablkcipher) &
 696                                   CRYPTO_TFM_RES_MASK);
 697
 698         return err;
 699 }
 700
 701 static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
 702                                      int (*crypt)(struct ablkcipher_request *))
 703 {
 704         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 705         struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
 706         struct ablkcipher_request *subreq = skcipher_request_ctx(req);
 707
 708         ablkcipher_request_set_tfm(subreq, *ctx);
 709         ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
 710                                         req->base.complete, req->base.data);
 711         ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
 712                                      req->iv);
 713
 714         return crypt(subreq);
 715 }
 716
 717 static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
 718 {
 719         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 720         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 721         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 722
 723         return skcipher_crypt_ablkcipher(req, alg->encrypt);
 724 }
 725
 726 static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
 727 {
 728         struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 729         struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
 730         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 731
 732         return skcipher_crypt_ablkcipher(req, alg->decrypt);
 733 }
 734
 735 static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 736 {
 737         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 738
 739         crypto_free_ablkcipher(*ctx);
 740 }
 741
 742 static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
 743 {
 744         struct crypto_alg *calg = tfm->__crt_alg;
 745         struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
 746         struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
 747         struct crypto_ablkcipher *ablkcipher;
 748         struct crypto_tfm *abtfm;
 749
 750         if (!crypto_mod_get(calg))
 751                 return -EAGAIN;
 752
 753         abtfm = __crypto_alloc_tfm(calg, 0, 0);
 754         if (IS_ERR(abtfm)) {
 755                 crypto_mod_put(calg);
 756                 return PTR_ERR(abtfm);
 757         }
 758
 759         ablkcipher = __crypto_ablkcipher_cast(abtfm);
 760         *ctx = ablkcipher;
 761         tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
 762
 763         skcipher->setkey = skcipher_setkey_ablkcipher;
 764         skcipher->encrypt = skcipher_encrypt_ablkcipher;
 765         skcipher->decrypt = skcipher_decrypt_ablkcipher;
 766
 767         skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
 768         skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
 769                             sizeof(struct ablkcipher_request);
 770         skcipher->keysize = calg->cra_ablkcipher.max_keysize;
 771
 772         return 0;
 773 }
 774
 775 static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 776                                      const u8 *key, unsigned int keylen)
 777 {
 778         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 779         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 780         u8 *buffer, *alignbuffer;
 781         unsigned long absize;
 782         int ret;
 783
 784         absize = keylen + alignmask;
 785         buffer = kmalloc(absize, GFP_ATOMIC);
 786         if (!buffer)
 787                 return -ENOMEM;
 788
 789         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 790         memcpy(alignbuffer, key, keylen);
 791         ret = cipher->setkey(tfm, alignbuffer, keylen);
 792         kzfree(buffer);
 793         return ret;
 794 }
 795
 796 static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
 797                            unsigned int keylen)
 798 {
 799         struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
 800         unsigned long alignmask = crypto_skcipher_alignmask(tfm);
 801
 802         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 803                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 804                 return -EINVAL;
 805         }
 806
 807         if ((unsigned long)key & alignmask)
 808                 return skcipher_setkey_unaligned(tfm, key, keylen);
 809
 810         return cipher->setkey(tfm, key, keylen);
 811 }
 812
 813 static void crypto_skcipher_exit_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         alg->exit(skcipher);
 819 }
 820
 821 static int crypto_skcipher_init_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         if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
 827                 return crypto_init_skcipher_ops_blkcipher(tfm);
 828
 829         if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
 830             tfm->__crt_alg->cra_type == &crypto_givcipher_type)
 831                 return crypto_init_skcipher_ops_ablkcipher(tfm);
 832
 833         skcipher->setkey = skcipher_setkey;
 834         skcipher->encrypt = alg->encrypt;
 835         skcipher->decrypt = alg->decrypt;
 836         skcipher->ivsize = alg->ivsize;
 837         skcipher->keysize = alg->max_keysize;
 838
 839         if (alg->exit)
 840                 skcipher->base.exit = crypto_skcipher_exit_tfm;
 841
 842         if (alg->init)
 843                 return alg->init(skcipher);
 844
 845         return 0;
 846 }
 847
 848 static void crypto_skcipher_free_instance(struct crypto_instance *inst)
 849 {
 850         struct skcipher_instance *skcipher =
 851                 container_of(inst, struct skcipher_instance, s.base);
 852
 853         skcipher->free(skcipher);
 854 }
 855
 856 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 857         __maybe_unused;
 858 static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
 859 {
 860         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 861                                                      base);
 862
 863         seq_printf(m, "type         : skcipher\n");
 864         seq_printf(m, "async        : %s\n",
 865                    alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
 866         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 867         seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
 868         seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
 869         seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
 870         seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
 871         seq_printf(m, "walksize     : %u\n", skcipher->walksize);
 872 }
 873
 874 #ifdef CONFIG_NET
 875 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 876 {
 877         struct crypto_report_blkcipher rblkcipher;
 878         struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
 879                                                      base);
 880
 881         strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
 882         strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
 883
 884         rblkcipher.blocksize = alg->cra_blocksize;
 885         rblkcipher.min_keysize = skcipher->min_keysize;
 886         rblkcipher.max_keysize = skcipher->max_keysize;
 887         rblkcipher.ivsize = skcipher->ivsize;
 888
 889         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 890                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 891                 goto nla_put_failure;
 892         return 0;
 893
 894 nla_put_failure:
 895         return -EMSGSIZE;
 896 }
 897 #else
 898 static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 899 {
 900         return -ENOSYS;
 901 }
 902 #endif
 903
 904 static const struct crypto_type crypto_skcipher_type2 = {
 905         .extsize = crypto_skcipher_extsize,
 906         .init_tfm = crypto_skcipher_init_tfm,
 907         .free = crypto_skcipher_free_instance,
 908 #ifdef CONFIG_PROC_FS
 909         .show = crypto_skcipher_show,
 910 #endif
 911         .report = crypto_skcipher_report,
 912         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 913         .maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
 914         .type = CRYPTO_ALG_TYPE_SKCIPHER,
 915         .tfmsize = offsetof(struct crypto_skcipher, base),
 916 };
 917
 918 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
 919                           const char *name, u32 type, u32 mask)
 920 {
 921         spawn->base.frontend = &crypto_skcipher_type2;
 922         return crypto_grab_spawn(&spawn->base, name, type, mask);
 923 }
 924 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 925
 926 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
 927                                               u32 type, u32 mask)
 928 {
 929         return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
 930 }
 931 EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
 932
 933 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
 934 {
 935         return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
 936                                    type, mask);
 937 }
 938 EXPORT_SYMBOL_GPL(crypto_has_skcipher2);
 939
 940 static int skcipher_prepare_alg(struct skcipher_alg *alg)
 941 {
 942         struct crypto_alg *base = &alg->base;
 943
 944         if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
 945             alg->walksize > PAGE_SIZE / 8)
 946                 return -EINVAL;
 947
 948         if (!alg->chunksize)
 949                 alg->chunksize = base->cra_blocksize;
 950         if (!alg->walksize)
 951                 alg->walksize = alg->chunksize;
 952
 953         base->cra_type = &crypto_skcipher_type2;
 954         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 955         base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
 956
 957         return 0;
 958 }
 959
 960 int crypto_register_skcipher(struct skcipher_alg *alg)
 961 {
 962         struct crypto_alg *base = &alg->base;
 963         int err;
 964
 965         err = skcipher_prepare_alg(alg);
 966         if (err)
 967                 return err;
 968
 969         return crypto_register_alg(base);
 970 }
 971 EXPORT_SYMBOL_GPL(crypto_register_skcipher);
 972
 973 void crypto_unregister_skcipher(struct skcipher_alg *alg)
 974 {
 975         crypto_unregister_alg(&alg->base);
 976 }
 977 EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
 978
 979 int crypto_register_skciphers(struct skcipher_alg *algs, int count)
 980 {
 981         int i, ret;
 982
 983         for (i = 0; i < count; i++) {
 984                 ret = crypto_register_skcipher(&algs[i]);
 985                 if (ret)
 986                         goto err;
 987         }
 988
 989         return 0;
 990
 991 err:
 992         for (--i; i >= 0; --i)
 993                 crypto_unregister_skcipher(&algs[i]);
 994
 995         return ret;
 996 }
 997 EXPORT_SYMBOL_GPL(crypto_register_skciphers);
 998
 999 void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
1000 {
1001         int i;
1002
1003         for (i = count - 1; i >= 0; --i)
1004                 crypto_unregister_skcipher(&algs[i]);
1005 }
1006 EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
1007
1008 int skcipher_register_instance(struct crypto_template *tmpl,
1009                            struct skcipher_instance *inst)
1010 {
1011         int err;
1012
1013         err = skcipher_prepare_alg(&inst->alg);
1014         if (err)
1015                 return err;
1016
1017         return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
1018 }
1019 EXPORT_SYMBOL_GPL(skcipher_register_instance);
1020
1021 MODULE_LICENSE("GPL");
1022 MODULE_DESCRIPTION("Symmetric key cipher type");