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