crypto/ablkcipher.c

   1 /*
   2  * Asynchronous block chaining cipher operations.
   3  *
   4  * This is the asynchronous version of blkcipher.c indicating completion
   5  * via a callback.
   6  *
   7  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the Free
  11  * Software Foundation; either version 2 of the License, or (at your option)
  12  * any later version.
  13  *
  14  */
  15
  16 #include <crypto/internal/skcipher.h>
  17 #include <linux/cpumask.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/rtnetlink.h>
  23 #include <linux/sched.h>
  24 #include <linux/slab.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/cryptouser.h>
  27 #include <net/netlink.h>
  28
  29 #include <crypto/scatterwalk.h>
  30
  31 #include "internal.h"
  32
  33 static const char *skcipher_default_geniv __read_mostly;
  34
  35 struct ablkcipher_buffer {
  36         struct list_head        entry;
  37         struct scatter_walk     dst;
  38         unsigned int            len;
  39         void                    *data;
  40 };
  41
  42 enum {
  43         ABLKCIPHER_WALK_SLOW = 1 << 0,
  44 };
  45
  46 static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
  47 {
  48         scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
  49 }
  50
  51 void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
  52 {
  53         struct ablkcipher_buffer *p, *tmp;
  54
  55         list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
  56                 ablkcipher_buffer_write(p);
  57                 list_del(&p->entry);
  58                 kfree(p);
  59         }
  60 }
  61 EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
  62
  63 static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
  64                                           struct ablkcipher_buffer *p)
  65 {
  66         p->dst = walk->out;
  67         list_add_tail(&p->entry, &walk->buffers);
  68 }
  69
  70 /* Get a spot of the specified length that does not straddle a page.
  71  * The caller needs to ensure that there is enough space for this operation.
  72  */
  73 static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
  74 {
  75         u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  76         return max(start, end_page);
  77 }
  78
  79 static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
  80                                                 unsigned int bsize)
  81 {
  82         unsigned int n = bsize;
  83
  84         for (;;) {
  85                 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
  86
  87                 if (len_this_page > n)
  88                         len_this_page = n;
  89                 scatterwalk_advance(&walk->out, n);
  90                 if (n == len_this_page)
  91                         break;
  92                 n -= len_this_page;
  93                 scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
  94         }
  95
  96         return bsize;
  97 }
  98
  99 static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
 100                                                 unsigned int n)
 101 {
 102         scatterwalk_advance(&walk->in, n);
 103         scatterwalk_advance(&walk->out, n);
 104
 105         return n;
 106 }
 107
 108 static int ablkcipher_walk_next(struct ablkcipher_request *req,
 109                                 struct ablkcipher_walk *walk);
 110
 111 int ablkcipher_walk_done(struct ablkcipher_request *req,
 112                          struct ablkcipher_walk *walk, int err)
 113 {
 114         struct crypto_tfm *tfm = req->base.tfm;
 115         unsigned int nbytes = 0;
 116
 117         if (likely(err >= 0)) {
 118                 unsigned int n = walk->nbytes - err;
 119
 120                 if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
 121                         n = ablkcipher_done_fast(walk, n);
 122                 else if (WARN_ON(err)) {
 123                         err = -EINVAL;
 124                         goto err;
 125                 } else
 126                         n = ablkcipher_done_slow(walk, n);
 127
 128                 nbytes = walk->total - n;
 129                 err = 0;
 130         }
 131
 132         scatterwalk_done(&walk->in, 0, nbytes);
 133         scatterwalk_done(&walk->out, 1, nbytes);
 134
 135 err:
 136         walk->total = nbytes;
 137         walk->nbytes = nbytes;
 138
 139         if (nbytes) {
 140                 crypto_yield(req->base.flags);
 141                 return ablkcipher_walk_next(req, walk);
 142         }
 143
 144         if (walk->iv != req->info)
 145                 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
 146         kfree(walk->iv_buffer);
 147
 148         return err;
 149 }
 150 EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
 151
 152 static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
 153                                        struct ablkcipher_walk *walk,
 154                                        unsigned int bsize,
 155                                        unsigned int alignmask,
 156                                        void **src_p, void **dst_p)
 157 {
 158         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 159         struct ablkcipher_buffer *p;
 160         void *src, *dst, *base;
 161         unsigned int n;
 162
 163         n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
 164         n += (aligned_bsize * 3 - (alignmask + 1) +
 165               (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
 166
 167         p = kmalloc(n, GFP_ATOMIC);
 168         if (!p)
 169                 return ablkcipher_walk_done(req, walk, -ENOMEM);
 170
 171         base = p + 1;
 172
 173         dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
 174         src = dst = ablkcipher_get_spot(dst, bsize);
 175
 176         p->len = bsize;
 177         p->data = dst;
 178
 179         scatterwalk_copychunks(src, &walk->in, bsize, 0);
 180
 181         ablkcipher_queue_write(walk, p);
 182
 183         walk->nbytes = bsize;
 184         walk->flags |= ABLKCIPHER_WALK_SLOW;
 185
 186         *src_p = src;
 187         *dst_p = dst;
 188
 189         return 0;
 190 }
 191
 192 static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
 193                                      struct crypto_tfm *tfm,
 194                                      unsigned int alignmask)
 195 {
 196         unsigned bs = walk->blocksize;
 197         unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
 198         unsigned aligned_bs = ALIGN(bs, alignmask + 1);
 199         unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
 200                             (alignmask + 1);
 201         u8 *iv;
 202
 203         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 204         walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
 205         if (!walk->iv_buffer)
 206                 return -ENOMEM;
 207
 208         iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
 209         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
 210         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
 211         iv = ablkcipher_get_spot(iv, ivsize);
 212
 213         walk->iv = memcpy(iv, walk->iv, ivsize);
 214         return 0;
 215 }
 216
 217 static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
 218                                        struct ablkcipher_walk *walk)
 219 {
 220         walk->src.page = scatterwalk_page(&walk->in);
 221         walk->src.offset = offset_in_page(walk->in.offset);
 222         walk->dst.page = scatterwalk_page(&walk->out);
 223         walk->dst.offset = offset_in_page(walk->out.offset);
 224
 225         return 0;
 226 }
 227
 228 static int ablkcipher_walk_next(struct ablkcipher_request *req,
 229                                 struct ablkcipher_walk *walk)
 230 {
 231         struct crypto_tfm *tfm = req->base.tfm;
 232         unsigned int alignmask, bsize, n;
 233         void *src, *dst;
 234         int err;
 235
 236         alignmask = crypto_tfm_alg_alignmask(tfm);
 237         n = walk->total;
 238         if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
 239                 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 240                 return ablkcipher_walk_done(req, walk, -EINVAL);
 241         }
 242
 243         walk->flags &= ~ABLKCIPHER_WALK_SLOW;
 244         src = dst = NULL;
 245
 246         bsize = min(walk->blocksize, n);
 247         n = scatterwalk_clamp(&walk->in, n);
 248         n = scatterwalk_clamp(&walk->out, n);
 249
 250         if (n < bsize ||
 251             !scatterwalk_aligned(&walk->in, alignmask) ||
 252             !scatterwalk_aligned(&walk->out, alignmask)) {
 253                 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
 254                                            &src, &dst);
 255                 goto set_phys_lowmem;
 256         }
 257
 258         walk->nbytes = n;
 259
 260         return ablkcipher_next_fast(req, walk);
 261
 262 set_phys_lowmem:
 263         if (err >= 0) {
 264                 walk->src.page = virt_to_page(src);
 265                 walk->dst.page = virt_to_page(dst);
 266                 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
 267                 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
 268         }
 269
 270         return err;
 271 }
 272
 273 static int ablkcipher_walk_first(struct ablkcipher_request *req,
 274                                  struct ablkcipher_walk *walk)
 275 {
 276         struct crypto_tfm *tfm = req->base.tfm;
 277         unsigned int alignmask;
 278
 279         alignmask = crypto_tfm_alg_alignmask(tfm);
 280         if (WARN_ON_ONCE(in_irq()))
 281                 return -EDEADLK;
 282
 283         walk->nbytes = walk->total;
 284         if (unlikely(!walk->total))
 285                 return 0;
 286
 287         walk->iv_buffer = NULL;
 288         walk->iv = req->info;
 289         if (unlikely(((unsigned long)walk->iv & alignmask))) {
 290                 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
 291                 if (err)
 292                         return err;
 293         }
 294
 295         scatterwalk_start(&walk->in, walk->in.sg);
 296         scatterwalk_start(&walk->out, walk->out.sg);
 297
 298         return ablkcipher_walk_next(req, walk);
 299 }
 300
 301 int ablkcipher_walk_phys(struct ablkcipher_request *req,
 302                          struct ablkcipher_walk *walk)
 303 {
 304         walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
 305         return ablkcipher_walk_first(req, walk);
 306 }
 307 EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
 308
 309 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
 310                             unsigned int keylen)
 311 {
 312         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
 313         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 314         int ret;
 315         u8 *buffer, *alignbuffer;
 316         unsigned long absize;
 317
 318         absize = keylen + alignmask;
 319         buffer = kmalloc(absize, GFP_ATOMIC);
 320         if (!buffer)
 321                 return -ENOMEM;
 322
 323         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 324         memcpy(alignbuffer, key, keylen);
 325         ret = cipher->setkey(tfm, alignbuffer, keylen);
 326         memset(alignbuffer, 0, keylen);
 327         kfree(buffer);
 328         return ret;
 329 }
 330
 331 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 332                   unsigned int keylen)
 333 {
 334         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
 335         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 336
 337         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 338                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 339                 return -EINVAL;
 340         }
 341
 342         if ((unsigned long)key & alignmask)
 343                 return setkey_unaligned(tfm, key, keylen);
 344
 345         return cipher->setkey(tfm, key, keylen);
 346 }
 347
 348 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 349                                               u32 mask)
 350 {
 351         return alg->cra_ctxsize;
 352 }
 353
 354 int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
 355 {
 356         return crypto_ablkcipher_encrypt(&req->creq);
 357 }
 358
 359 int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
 360 {
 361         return crypto_ablkcipher_decrypt(&req->creq);
 362 }
 363
 364 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
 365                                       u32 mask)
 366 {
 367         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 368         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 369
 370         if (alg->ivsize > PAGE_SIZE / 8)
 371                 return -EINVAL;
 372
 373         crt->setkey = setkey;
 374         crt->encrypt = alg->encrypt;
 375         crt->decrypt = alg->decrypt;
 376         if (!alg->ivsize) {
 377                 crt->givencrypt = skcipher_null_givencrypt;
 378                 crt->givdecrypt = skcipher_null_givdecrypt;
 379         }
 380         crt->base = __crypto_ablkcipher_cast(tfm);
 381         crt->ivsize = alg->ivsize;
 382
 383         return 0;
 384 }
 385
 386 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 387 {
 388         struct crypto_report_blkcipher rblkcipher;
 389
 390         snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "ablkcipher");
 391         snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
 392                  alg->cra_ablkcipher.geniv ?: "<default>");
 393
 394         rblkcipher.blocksize = alg->cra_blocksize;
 395         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 396         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 397         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 398
 399         NLA_PUT(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 400                 sizeof(struct crypto_report_blkcipher), &rblkcipher);
 401
 402         return 0;
 403
 404 nla_put_failure:
 405         return -EMSGSIZE;
 406 }
 407
 408 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 409         __attribute__ ((unused));
 410 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 411 {
 412         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 413
 414         seq_printf(m, "type         : ablkcipher\n");
 415         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 416                                              "yes" : "no");
 417         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 418         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 419         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 420         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 421         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
 422 }
 423
 424 const struct crypto_type crypto_ablkcipher_type = {
 425         .ctxsize = crypto_ablkcipher_ctxsize,
 426         .init = crypto_init_ablkcipher_ops,
 427 #ifdef CONFIG_PROC_FS
 428         .show = crypto_ablkcipher_show,
 429 #endif
 430         .report = crypto_ablkcipher_report,
 431 };
 432 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 433
 434 static int no_givdecrypt(struct skcipher_givcrypt_request *req)
 435 {
 436         return -ENOSYS;
 437 }
 438
 439 static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
 440                                       u32 mask)
 441 {
 442         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 443         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 444
 445         if (alg->ivsize > PAGE_SIZE / 8)
 446                 return -EINVAL;
 447
 448         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 449                       alg->setkey : setkey;
 450         crt->encrypt = alg->encrypt;
 451         crt->decrypt = alg->decrypt;
 452         crt->givencrypt = alg->givencrypt;
 453         crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
 454         crt->base = __crypto_ablkcipher_cast(tfm);
 455         crt->ivsize = alg->ivsize;
 456
 457         return 0;
 458 }
 459
 460 static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 461 {
 462         struct crypto_report_blkcipher rblkcipher;
 463
 464         snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "givcipher");
 465         snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
 466                  alg->cra_ablkcipher.geniv ?: "<built-in>");
 467
 468         rblkcipher.blocksize = alg->cra_blocksize;
 469         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 470         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 471         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 472
 473         NLA_PUT(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 474                 sizeof(struct crypto_report_blkcipher), &rblkcipher);
 475
 476         return 0;
 477
 478 nla_put_failure:
 479         return -EMSGSIZE;
 480 }
 481
 482 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 483         __attribute__ ((unused));
 484 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 485 {
 486         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 487
 488         seq_printf(m, "type         : givcipher\n");
 489         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 490                                              "yes" : "no");
 491         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 492         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 493         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 494         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 495         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
 496 }
 497
 498 const struct crypto_type crypto_givcipher_type = {
 499         .ctxsize = crypto_ablkcipher_ctxsize,
 500         .init = crypto_init_givcipher_ops,
 501 #ifdef CONFIG_PROC_FS
 502         .show = crypto_givcipher_show,
 503 #endif
 504         .report = crypto_givcipher_report,
 505 };
 506 EXPORT_SYMBOL_GPL(crypto_givcipher_type);
 507
 508 const char *crypto_default_geniv(const struct crypto_alg *alg)
 509 {
 510         if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 511              CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 512                                          alg->cra_ablkcipher.ivsize) !=
 513             alg->cra_blocksize)
 514                 return "chainiv";
 515
 516         return alg->cra_flags & CRYPTO_ALG_ASYNC ?
 517                "eseqiv" : skcipher_default_geniv;
 518 }
 519
 520 static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
 521 {
 522         struct rtattr *tb[3];
 523         struct {
 524                 struct rtattr attr;
 525                 struct crypto_attr_type data;
 526         } ptype;
 527         struct {
 528                 struct rtattr attr;
 529                 struct crypto_attr_alg data;
 530         } palg;
 531         struct crypto_template *tmpl;
 532         struct crypto_instance *inst;
 533         struct crypto_alg *larval;
 534         const char *geniv;
 535         int err;
 536
 537         larval = crypto_larval_lookup(alg->cra_driver_name,
 538                                       (type & ~CRYPTO_ALG_TYPE_MASK) |
 539                                       CRYPTO_ALG_TYPE_GIVCIPHER,
 540                                       mask | CRYPTO_ALG_TYPE_MASK);
 541         err = PTR_ERR(larval);
 542         if (IS_ERR(larval))
 543                 goto out;
 544
 545         err = -EAGAIN;
 546         if (!crypto_is_larval(larval))
 547                 goto drop_larval;
 548
 549         ptype.attr.rta_len = sizeof(ptype);
 550         ptype.attr.rta_type = CRYPTOA_TYPE;
 551         ptype.data.type = type | CRYPTO_ALG_GENIV;
 552         /* GENIV tells the template that we're making a default geniv. */
 553         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 554         tb[0] = &ptype.attr;
 555
 556         palg.attr.rta_len = sizeof(palg);
 557         palg.attr.rta_type = CRYPTOA_ALG;
 558         /* Must use the exact name to locate ourselves. */
 559         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 560         tb[1] = &palg.attr;
 561
 562         tb[2] = NULL;
 563
 564         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 565             CRYPTO_ALG_TYPE_BLKCIPHER)
 566                 geniv = alg->cra_blkcipher.geniv;
 567         else
 568                 geniv = alg->cra_ablkcipher.geniv;
 569
 570         if (!geniv)
 571                 geniv = crypto_default_geniv(alg);
 572
 573         tmpl = crypto_lookup_template(geniv);
 574         err = -ENOENT;
 575         if (!tmpl)
 576                 goto kill_larval;
 577
 578         inst = tmpl->alloc(tb);
 579         err = PTR_ERR(inst);
 580         if (IS_ERR(inst))
 581                 goto put_tmpl;
 582
 583         if ((err = crypto_register_instance(tmpl, inst))) {
 584                 tmpl->free(inst);
 585                 goto put_tmpl;
 586         }
 587
 588         /* Redo the lookup to use the instance we just registered. */
 589         err = -EAGAIN;
 590
 591 put_tmpl:
 592         crypto_tmpl_put(tmpl);
 593 kill_larval:
 594         crypto_larval_kill(larval);
 595 drop_larval:
 596         crypto_mod_put(larval);
 597 out:
 598         crypto_mod_put(alg);
 599         return err;
 600 }
 601
 602 static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
 603                                                  u32 mask)
 604 {
 605         struct crypto_alg *alg;
 606
 607         alg = crypto_alg_mod_lookup(name, type, mask);
 608         if (IS_ERR(alg))
 609                 return alg;
 610
 611         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 612             CRYPTO_ALG_TYPE_GIVCIPHER)
 613                 return alg;
 614
 615         if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 616               CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 617                                           alg->cra_ablkcipher.ivsize))
 618                 return alg;
 619
 620         crypto_mod_put(alg);
 621         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 622                                     mask & ~CRYPTO_ALG_TESTED);
 623         if (IS_ERR(alg))
 624                 return alg;
 625
 626         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 627             CRYPTO_ALG_TYPE_GIVCIPHER) {
 628                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 629                         crypto_mod_put(alg);
 630                         alg = ERR_PTR(-ENOENT);
 631                 }
 632                 return alg;
 633         }
 634
 635         BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 636                  CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 637                                              alg->cra_ablkcipher.ivsize));
 638
 639         return ERR_PTR(crypto_givcipher_default(alg, type, mask));
 640 }
 641
 642 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 643                          u32 type, u32 mask)
 644 {
 645         struct crypto_alg *alg;
 646         int err;
 647
 648         type = crypto_skcipher_type(type);
 649         mask = crypto_skcipher_mask(mask);
 650
 651         alg = crypto_lookup_skcipher(name, type, mask);
 652         if (IS_ERR(alg))
 653                 return PTR_ERR(alg);
 654
 655         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 656         crypto_mod_put(alg);
 657         return err;
 658 }
 659 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 660
 661 struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
 662                                                   u32 type, u32 mask)
 663 {
 664         struct crypto_tfm *tfm;
 665         int err;
 666
 667         type = crypto_skcipher_type(type);
 668         mask = crypto_skcipher_mask(mask);
 669
 670         for (;;) {
 671                 struct crypto_alg *alg;
 672
 673                 alg = crypto_lookup_skcipher(alg_name, type, mask);
 674                 if (IS_ERR(alg)) {
 675                         err = PTR_ERR(alg);
 676                         goto err;
 677                 }
 678
 679                 tfm = __crypto_alloc_tfm(alg, type, mask);
 680                 if (!IS_ERR(tfm))
 681                         return __crypto_ablkcipher_cast(tfm);
 682
 683                 crypto_mod_put(alg);
 684                 err = PTR_ERR(tfm);
 685
 686 err:
 687                 if (err != -EAGAIN)
 688                         break;
 689                 if (signal_pending(current)) {
 690                         err = -EINTR;
 691                         break;
 692                 }
 693         }
 694
 695         return ERR_PTR(err);
 696 }
 697 EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
 698
 699 static int __init skcipher_module_init(void)
 700 {
 701         skcipher_default_geniv = num_possible_cpus() > 1 ?
 702                                  "eseqiv" : "chainiv";
 703         return 0;
 704 }
 705
 706 static void skcipher_module_exit(void)
 707 {
 708 }
 709
 710 module_init(skcipher_module_init);
 711 module_exit(skcipher_module_exit);