crypto/blkcipher.c

   1 /*
   2  * Block chaining 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) 2006 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/aead.h>
  18 #include <crypto/internal/skcipher.h>
  19 #include <crypto/scatterwalk.h>
  20 #include <linux/errno.h>
  21 #include <linux/hardirq.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/scatterlist.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/slab.h>
  27 #include <linux/string.h>
  28 #include <linux/cryptouser.h>
  29 #include <net/netlink.h>
  30
  31 #include "internal.h"
  32
  33 enum {
  34         BLKCIPHER_WALK_PHYS = 1 << 0,
  35         BLKCIPHER_WALK_SLOW = 1 << 1,
  36         BLKCIPHER_WALK_COPY = 1 << 2,
  37         BLKCIPHER_WALK_DIFF = 1 << 3,
  38 };
  39
  40 static int blkcipher_walk_next(struct blkcipher_desc *desc,
  41                                struct blkcipher_walk *walk);
  42 static int blkcipher_walk_first(struct blkcipher_desc *desc,
  43                                 struct blkcipher_walk *walk);
  44
  45 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
  46 {
  47         walk->src.virt.addr = scatterwalk_map(&walk->in);
  48 }
  49
  50 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
  51 {
  52         walk->dst.virt.addr = scatterwalk_map(&walk->out);
  53 }
  54
  55 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
  56 {
  57         scatterwalk_unmap(walk->src.virt.addr);
  58 }
  59
  60 static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
  61 {
  62         scatterwalk_unmap(walk->dst.virt.addr);
  63 }
  64
  65 /* Get a spot of the specified length that does not straddle a page.
  66  * The caller needs to ensure that there is enough space for this operation.
  67  */
  68 static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
  69 {
  70         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  71         return max(start, end_page);
  72 }
  73
  74 static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
  75                                                unsigned int bsize)
  76 {
  77         u8 *addr;
  78
  79         addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
  80         addr = blkcipher_get_spot(addr, bsize);
  81         scatterwalk_copychunks(addr, &walk->out, bsize, 1);
  82         return bsize;
  83 }
  84
  85 static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
  86                                                unsigned int n)
  87 {
  88         if (walk->flags & BLKCIPHER_WALK_COPY) {
  89                 blkcipher_map_dst(walk);
  90                 memcpy(walk->dst.virt.addr, walk->page, n);
  91                 blkcipher_unmap_dst(walk);
  92         } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
  93                 if (walk->flags & BLKCIPHER_WALK_DIFF)
  94                         blkcipher_unmap_dst(walk);
  95                 blkcipher_unmap_src(walk);
  96         }
  97
  98         scatterwalk_advance(&walk->in, n);
  99         scatterwalk_advance(&walk->out, n);
 100
 101         return n;
 102 }
 103
 104 int blkcipher_walk_done(struct blkcipher_desc *desc,
 105                         struct blkcipher_walk *walk, int err)
 106 {
 107         unsigned int nbytes = 0;
 108
 109         if (likely(err >= 0)) {
 110                 unsigned int n = walk->nbytes - err;
 111
 112                 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
 113                         n = blkcipher_done_fast(walk, n);
 114                 else if (WARN_ON(err)) {
 115                         err = -EINVAL;
 116                         goto err;
 117                 } else
 118                         n = blkcipher_done_slow(walk, n);
 119
 120                 nbytes = walk->total - n;
 121                 err = 0;
 122         }
 123
 124         scatterwalk_done(&walk->in, 0, nbytes);
 125         scatterwalk_done(&walk->out, 1, nbytes);
 126
 127 err:
 128         walk->total = nbytes;
 129         walk->nbytes = nbytes;
 130
 131         if (nbytes) {
 132                 crypto_yield(desc->flags);
 133                 return blkcipher_walk_next(desc, walk);
 134         }
 135
 136         if (walk->iv != desc->info)
 137                 memcpy(desc->info, walk->iv, walk->ivsize);
 138         if (walk->buffer != walk->page)
 139                 kfree(walk->buffer);
 140         if (walk->page)
 141                 free_page((unsigned long)walk->page);
 142
 143         return err;
 144 }
 145 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
 146
 147 static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
 148                                       struct blkcipher_walk *walk,
 149                                       unsigned int bsize,
 150                                       unsigned int alignmask)
 151 {
 152         unsigned int n;
 153         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 154
 155         if (walk->buffer)
 156                 goto ok;
 157
 158         walk->buffer = walk->page;
 159         if (walk->buffer)
 160                 goto ok;
 161
 162         n = aligned_bsize * 3 - (alignmask + 1) +
 163             (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
 164         walk->buffer = kmalloc(n, GFP_ATOMIC);
 165         if (!walk->buffer)
 166                 return blkcipher_walk_done(desc, walk, -ENOMEM);
 167
 168 ok:
 169         walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
 170                                           alignmask + 1);
 171         walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
 172         walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
 173                                                  aligned_bsize, bsize);
 174
 175         scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 176
 177         walk->nbytes = bsize;
 178         walk->flags |= BLKCIPHER_WALK_SLOW;
 179
 180         return 0;
 181 }
 182
 183 static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
 184 {
 185         u8 *tmp = walk->page;
 186
 187         blkcipher_map_src(walk);
 188         memcpy(tmp, walk->src.virt.addr, walk->nbytes);
 189         blkcipher_unmap_src(walk);
 190
 191         walk->src.virt.addr = tmp;
 192         walk->dst.virt.addr = tmp;
 193
 194         return 0;
 195 }
 196
 197 static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
 198                                       struct blkcipher_walk *walk)
 199 {
 200         unsigned long diff;
 201
 202         walk->src.phys.page = scatterwalk_page(&walk->in);
 203         walk->src.phys.offset = offset_in_page(walk->in.offset);
 204         walk->dst.phys.page = scatterwalk_page(&walk->out);
 205         walk->dst.phys.offset = offset_in_page(walk->out.offset);
 206
 207         if (walk->flags & BLKCIPHER_WALK_PHYS)
 208                 return 0;
 209
 210         diff = walk->src.phys.offset - walk->dst.phys.offset;
 211         diff |= walk->src.virt.page - walk->dst.virt.page;
 212
 213         blkcipher_map_src(walk);
 214         walk->dst.virt.addr = walk->src.virt.addr;
 215
 216         if (diff) {
 217                 walk->flags |= BLKCIPHER_WALK_DIFF;
 218                 blkcipher_map_dst(walk);
 219         }
 220
 221         return 0;
 222 }
 223
 224 static int blkcipher_walk_next(struct blkcipher_desc *desc,
 225                                struct blkcipher_walk *walk)
 226 {
 227         unsigned int bsize;
 228         unsigned int n;
 229         int err;
 230
 231         n = walk->total;
 232         if (unlikely(n < walk->cipher_blocksize)) {
 233                 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 234                 return blkcipher_walk_done(desc, walk, -EINVAL);
 235         }
 236
 237         bsize = min(walk->walk_blocksize, n);
 238
 239         walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
 240                          BLKCIPHER_WALK_DIFF);
 241         if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
 242             !scatterwalk_aligned(&walk->out, walk->alignmask)) {
 243                 walk->flags |= BLKCIPHER_WALK_COPY;
 244                 if (!walk->page) {
 245                         walk->page = (void *)__get_free_page(GFP_ATOMIC);
 246                         if (!walk->page)
 247                                 n = 0;
 248                 }
 249         }
 250
 251         n = scatterwalk_clamp(&walk->in, n);
 252         n = scatterwalk_clamp(&walk->out, n);
 253
 254         if (unlikely(n < bsize)) {
 255                 err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
 256                 goto set_phys_lowmem;
 257         }
 258
 259         walk->nbytes = n;
 260         if (walk->flags & BLKCIPHER_WALK_COPY) {
 261                 err = blkcipher_next_copy(walk);
 262                 goto set_phys_lowmem;
 263         }
 264
 265         return blkcipher_next_fast(desc, walk);
 266
 267 set_phys_lowmem:
 268         if (walk->flags & BLKCIPHER_WALK_PHYS) {
 269                 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
 270                 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
 271                 walk->src.phys.offset &= PAGE_SIZE - 1;
 272                 walk->dst.phys.offset &= PAGE_SIZE - 1;
 273         }
 274         return err;
 275 }
 276
 277 static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
 278 {
 279         unsigned bs = walk->walk_blocksize;
 280         unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
 281         unsigned int size = aligned_bs * 2 +
 282                             walk->ivsize + max(aligned_bs, walk->ivsize) -
 283                             (walk->alignmask + 1);
 284         u8 *iv;
 285
 286         size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 287         walk->buffer = kmalloc(size, GFP_ATOMIC);
 288         if (!walk->buffer)
 289                 return -ENOMEM;
 290
 291         iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
 292         iv = blkcipher_get_spot(iv, bs) + aligned_bs;
 293         iv = blkcipher_get_spot(iv, bs) + aligned_bs;
 294         iv = blkcipher_get_spot(iv, walk->ivsize);
 295
 296         walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 297         return 0;
 298 }
 299
 300 int blkcipher_walk_virt(struct blkcipher_desc *desc,
 301                         struct blkcipher_walk *walk)
 302 {
 303         walk->flags &= ~BLKCIPHER_WALK_PHYS;
 304         walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
 305         walk->cipher_blocksize = walk->walk_blocksize;
 306         walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
 307         walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 308         return blkcipher_walk_first(desc, walk);
 309 }
 310 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
 311
 312 int blkcipher_walk_phys(struct blkcipher_desc *desc,
 313                         struct blkcipher_walk *walk)
 314 {
 315         walk->flags |= BLKCIPHER_WALK_PHYS;
 316         walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
 317         walk->cipher_blocksize = walk->walk_blocksize;
 318         walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
 319         walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 320         return blkcipher_walk_first(desc, walk);
 321 }
 322 EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
 323
 324 static int blkcipher_walk_first(struct blkcipher_desc *desc,
 325                                 struct blkcipher_walk *walk)
 326 {
 327         if (WARN_ON_ONCE(in_irq()))
 328                 return -EDEADLK;
 329
 330         walk->iv = desc->info;
 331         walk->nbytes = walk->total;
 332         if (unlikely(!walk->total))
 333                 return 0;
 334
 335         walk->buffer = NULL;
 336         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 337                 int err = blkcipher_copy_iv(walk);
 338                 if (err)
 339                         return err;
 340         }
 341
 342         scatterwalk_start(&walk->in, walk->in.sg);
 343         scatterwalk_start(&walk->out, walk->out.sg);
 344         walk->page = NULL;
 345
 346         return blkcipher_walk_next(desc, walk);
 347 }
 348
 349 int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
 350                               struct blkcipher_walk *walk,
 351                               unsigned int blocksize)
 352 {
 353         walk->flags &= ~BLKCIPHER_WALK_PHYS;
 354         walk->walk_blocksize = blocksize;
 355         walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
 356         walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
 357         walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 358         return blkcipher_walk_first(desc, walk);
 359 }
 360 EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
 361
 362 int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
 363                                    struct blkcipher_walk *walk,
 364                                    struct crypto_aead *tfm,
 365                                    unsigned int blocksize)
 366 {
 367         walk->flags &= ~BLKCIPHER_WALK_PHYS;
 368         walk->walk_blocksize = blocksize;
 369         walk->cipher_blocksize = crypto_aead_blocksize(tfm);
 370         walk->ivsize = crypto_aead_ivsize(tfm);
 371         walk->alignmask = crypto_aead_alignmask(tfm);
 372         return blkcipher_walk_first(desc, walk);
 373 }
 374 EXPORT_SYMBOL_GPL(blkcipher_aead_walk_virt_block);
 375
 376 /*
 377  * This function allows ablkcipher algorithms to use the blkcipher_walk API to
 378  * walk over their data.  The specified crypto_ablkcipher tfm is used to
 379  * initialize the struct blkcipher_walk, and the crypto_blkcipher specified in
 380  * desc->tfm is never used so it can be left NULL.  (Yes, this design is ugly,
 381  * but it parallels blkcipher_aead_walk_virt_block() above.  In the 4.10 kernel
 382  * this is starting to be cleaned up...)
 383  */
 384 int blkcipher_ablkcipher_walk_virt(struct blkcipher_desc *desc,
 385                                    struct blkcipher_walk *walk,
 386                                    struct crypto_ablkcipher *tfm)
 387 {
 388         walk->flags &= ~BLKCIPHER_WALK_PHYS;
 389         walk->walk_blocksize = crypto_ablkcipher_blocksize(tfm);
 390         walk->cipher_blocksize = walk->walk_blocksize;
 391         walk->ivsize = crypto_ablkcipher_ivsize(tfm);
 392         walk->alignmask = crypto_ablkcipher_alignmask(tfm);
 393         return blkcipher_walk_first(desc, walk);
 394 }
 395 EXPORT_SYMBOL_GPL(blkcipher_ablkcipher_walk_virt);
 396
 397 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
 398                             unsigned int keylen)
 399 {
 400         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
 401         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 402         int ret;
 403         u8 *buffer, *alignbuffer;
 404         unsigned long absize;
 405
 406         absize = keylen + alignmask;
 407         buffer = kmalloc(absize, GFP_ATOMIC);
 408         if (!buffer)
 409                 return -ENOMEM;
 410
 411         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 412         memcpy(alignbuffer, key, keylen);
 413         ret = cipher->setkey(tfm, alignbuffer, keylen);
 414         memset(alignbuffer, 0, keylen);
 415         kfree(buffer);
 416         return ret;
 417 }
 418
 419 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 420 {
 421         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
 422         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 423
 424         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 425                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 426                 return -EINVAL;
 427         }
 428
 429         if ((unsigned long)key & alignmask)
 430                 return setkey_unaligned(tfm, key, keylen);
 431
 432         return cipher->setkey(tfm, key, keylen);
 433 }
 434
 435 static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 436                         unsigned int keylen)
 437 {
 438         return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
 439 }
 440
 441 static int async_encrypt(struct ablkcipher_request *req)
 442 {
 443         struct crypto_tfm *tfm = req->base.tfm;
 444         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 445         struct blkcipher_desc desc = {
 446                 .tfm = __crypto_blkcipher_cast(tfm),
 447                 .info = req->info,
 448                 .flags = req->base.flags,
 449         };
 450
 451
 452         return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
 453 }
 454
 455 static int async_decrypt(struct ablkcipher_request *req)
 456 {
 457         struct crypto_tfm *tfm = req->base.tfm;
 458         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 459         struct blkcipher_desc desc = {
 460                 .tfm = __crypto_blkcipher_cast(tfm),
 461                 .info = req->info,
 462                 .flags = req->base.flags,
 463         };
 464
 465         return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
 466 }
 467
 468 static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 469                                              u32 mask)
 470 {
 471         struct blkcipher_alg *cipher = &alg->cra_blkcipher;
 472         unsigned int len = alg->cra_ctxsize;
 473
 474         if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
 475             cipher->ivsize) {
 476                 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
 477                 len += cipher->ivsize;
 478         }
 479
 480         return len;
 481 }
 482
 483 static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
 484 {
 485         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 486         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 487
 488         crt->setkey = async_setkey;
 489         crt->encrypt = async_encrypt;
 490         crt->decrypt = async_decrypt;
 491         if (!alg->ivsize) {
 492                 crt->givencrypt = skcipher_null_givencrypt;
 493                 crt->givdecrypt = skcipher_null_givdecrypt;
 494         }
 495         crt->base = __crypto_ablkcipher_cast(tfm);
 496         crt->ivsize = alg->ivsize;
 497
 498         return 0;
 499 }
 500
 501 static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
 502 {
 503         struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
 504         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 505         unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
 506         unsigned long addr;
 507
 508         crt->setkey = setkey;
 509         crt->encrypt = alg->encrypt;
 510         crt->decrypt = alg->decrypt;
 511
 512         addr = (unsigned long)crypto_tfm_ctx(tfm);
 513         addr = ALIGN(addr, align);
 514         addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
 515         crt->iv = (void *)addr;
 516
 517         return 0;
 518 }
 519
 520 static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 521 {
 522         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 523
 524         if (alg->ivsize > PAGE_SIZE / 8)
 525                 return -EINVAL;
 526
 527         if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
 528                 return crypto_init_blkcipher_ops_sync(tfm);
 529         else
 530                 return crypto_init_blkcipher_ops_async(tfm);
 531 }
 532
 533 #ifdef CONFIG_NET
 534 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 535 {
 536         struct crypto_report_blkcipher rblkcipher;
 537
 538         strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
 539         strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
 540                 sizeof(rblkcipher.geniv));
 541
 542         rblkcipher.blocksize = alg->cra_blocksize;
 543         rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
 544         rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
 545         rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
 546
 547         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 548                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 549                 goto nla_put_failure;
 550         return 0;
 551
 552 nla_put_failure:
 553         return -EMSGSIZE;
 554 }
 555 #else
 556 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 557 {
 558         return -ENOSYS;
 559 }
 560 #endif
 561
 562 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 563         __attribute__ ((unused));
 564 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 565 {
 566         seq_printf(m, "type         : blkcipher\n");
 567         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 568         seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
 569         seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
 570         seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
 571         seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
 572                                              "<default>");
 573 }
 574
 575 const struct crypto_type crypto_blkcipher_type = {
 576         .ctxsize = crypto_blkcipher_ctxsize,
 577         .init = crypto_init_blkcipher_ops,
 578 #ifdef CONFIG_PROC_FS
 579         .show = crypto_blkcipher_show,
 580 #endif
 581         .report = crypto_blkcipher_report,
 582 };
 583 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
 584
 585 static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
 586                                 const char *name, u32 type, u32 mask)
 587 {
 588         struct crypto_alg *alg;
 589         int err;
 590
 591         type = crypto_skcipher_type(type);
 592         mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
 593
 594         alg = crypto_alg_mod_lookup(name, type, mask);
 595         if (IS_ERR(alg))
 596                 return PTR_ERR(alg);
 597
 598         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 599         crypto_mod_put(alg);
 600         return err;
 601 }
 602
 603 struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
 604                                              struct rtattr **tb, u32 type,
 605                                              u32 mask)
 606 {
 607         struct {
 608                 int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
 609                               unsigned int keylen);
 610                 int (*encrypt)(struct ablkcipher_request *req);
 611                 int (*decrypt)(struct ablkcipher_request *req);
 612
 613                 unsigned int min_keysize;
 614                 unsigned int max_keysize;
 615                 unsigned int ivsize;
 616
 617                 const char *geniv;
 618         } balg;
 619         const char *name;
 620         struct crypto_skcipher_spawn *spawn;
 621         struct crypto_attr_type *algt;
 622         struct crypto_instance *inst;
 623         struct crypto_alg *alg;
 624         int err;
 625
 626         algt = crypto_get_attr_type(tb);
 627         if (IS_ERR(algt))
 628                 return ERR_CAST(algt);
 629
 630         if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
 631             algt->mask)
 632                 return ERR_PTR(-EINVAL);
 633
 634         name = crypto_attr_alg_name(tb[1]);
 635         if (IS_ERR(name))
 636                 return ERR_CAST(name);
 637
 638         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 639         if (!inst)
 640                 return ERR_PTR(-ENOMEM);
 641
 642         spawn = crypto_instance_ctx(inst);
 643
 644         /* Ignore async algorithms if necessary. */
 645         mask |= crypto_requires_sync(algt->type, algt->mask);
 646
 647         crypto_set_skcipher_spawn(spawn, inst);
 648         err = crypto_grab_nivcipher(spawn, name, type, mask);
 649         if (err)
 650                 goto err_free_inst;
 651
 652         alg = crypto_skcipher_spawn_alg(spawn);
 653
 654         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 655             CRYPTO_ALG_TYPE_BLKCIPHER) {
 656                 balg.ivsize = alg->cra_blkcipher.ivsize;
 657                 balg.min_keysize = alg->cra_blkcipher.min_keysize;
 658                 balg.max_keysize = alg->cra_blkcipher.max_keysize;
 659
 660                 balg.setkey = async_setkey;
 661                 balg.encrypt = async_encrypt;
 662                 balg.decrypt = async_decrypt;
 663
 664                 balg.geniv = alg->cra_blkcipher.geniv;
 665         } else {
 666                 balg.ivsize = alg->cra_ablkcipher.ivsize;
 667                 balg.min_keysize = alg->cra_ablkcipher.min_keysize;
 668                 balg.max_keysize = alg->cra_ablkcipher.max_keysize;
 669
 670                 balg.setkey = alg->cra_ablkcipher.setkey;
 671                 balg.encrypt = alg->cra_ablkcipher.encrypt;
 672                 balg.decrypt = alg->cra_ablkcipher.decrypt;
 673
 674                 balg.geniv = alg->cra_ablkcipher.geniv;
 675         }
 676
 677         err = -EINVAL;
 678         if (!balg.ivsize)
 679                 goto err_drop_alg;
 680
 681         /*
 682          * This is only true if we're constructing an algorithm with its
 683          * default IV generator.  For the default generator we elide the
 684          * template name and double-check the IV generator.
 685          */
 686         if (algt->mask & CRYPTO_ALG_GENIV) {
 687                 if (!balg.geniv)
 688                         balg.geniv = crypto_default_geniv(alg);
 689                 err = -EAGAIN;
 690                 if (strcmp(tmpl->name, balg.geniv))
 691                         goto err_drop_alg;
 692
 693                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 694                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 695                        CRYPTO_MAX_ALG_NAME);
 696         } else {
 697                 err = -ENAMETOOLONG;
 698                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 699                              "%s(%s)", tmpl->name, alg->cra_name) >=
 700                     CRYPTO_MAX_ALG_NAME)
 701                         goto err_drop_alg;
 702                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 703                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 704                     CRYPTO_MAX_ALG_NAME)
 705                         goto err_drop_alg;
 706         }
 707
 708         inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
 709         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 710         inst->alg.cra_priority = alg->cra_priority;
 711         inst->alg.cra_blocksize = alg->cra_blocksize;
 712         inst->alg.cra_alignmask = alg->cra_alignmask;
 713         inst->alg.cra_type = &crypto_givcipher_type;
 714
 715         inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
 716         inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
 717         inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
 718         inst->alg.cra_ablkcipher.geniv = balg.geniv;
 719
 720         inst->alg.cra_ablkcipher.setkey = balg.setkey;
 721         inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
 722         inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
 723
 724 out:
 725         return inst;
 726
 727 err_drop_alg:
 728         crypto_drop_skcipher(spawn);
 729 err_free_inst:
 730         kfree(inst);
 731         inst = ERR_PTR(err);
 732         goto out;
 733 }
 734 EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
 735
 736 void skcipher_geniv_free(struct crypto_instance *inst)
 737 {
 738         crypto_drop_skcipher(crypto_instance_ctx(inst));
 739         kfree(inst);
 740 }
 741 EXPORT_SYMBOL_GPL(skcipher_geniv_free);
 742
 743 int skcipher_geniv_init(struct crypto_tfm *tfm)
 744 {
 745         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 746         struct crypto_ablkcipher *cipher;
 747
 748         cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
 749         if (IS_ERR(cipher))
 750                 return PTR_ERR(cipher);
 751
 752         tfm->crt_ablkcipher.base = cipher;
 753         tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
 754
 755         return 0;
 756 }
 757 EXPORT_SYMBOL_GPL(skcipher_geniv_init);
 758
 759 void skcipher_geniv_exit(struct crypto_tfm *tfm)
 760 {
 761         crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
 762 }
 763 EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
 764
 765 MODULE_LICENSE("GPL");
 766 MODULE_DESCRIPTION("Generic block chaining cipher type");