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