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