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
  73         return max(start, end_page);
  74 }
  75
  76 static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
  77                                                 unsigned int bsize)
  78 {
  79         unsigned int n = bsize;
  80
  81         for (;;) {
  82                 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
  83
  84                 if (len_this_page > n)
  85                         len_this_page = n;
  86                 scatterwalk_advance(&walk->out, n);
  87                 if (n == len_this_page)
  88                         break;
  89                 n -= len_this_page;
  90                 scatterwalk_start(&walk->out, sg_next(walk->out.sg));
  91         }
  92
  93         return bsize;
  94 }
  95
  96 static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
  97                                                 unsigned int n)
  98 {
  99         scatterwalk_advance(&walk->in, n);
 100         scatterwalk_advance(&walk->out, n);
 101
 102         return n;
 103 }
 104
 105 static int ablkcipher_walk_next(struct ablkcipher_request *req,
 106                                 struct ablkcipher_walk *walk);
 107
 108 int ablkcipher_walk_done(struct ablkcipher_request *req,
 109                          struct ablkcipher_walk *walk, int err)
 110 {
 111         struct crypto_tfm *tfm = req->base.tfm;
 112         unsigned int nbytes = 0;
 113
 114         if (likely(err >= 0)) {
 115                 unsigned int n = walk->nbytes - err;
 116
 117                 if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
 118                         n = ablkcipher_done_fast(walk, n);
 119                 else if (WARN_ON(err)) {
 120                         err = -EINVAL;
 121                         goto err;
 122                 } else
 123                         n = ablkcipher_done_slow(walk, n);
 124
 125                 nbytes = walk->total - n;
 126                 err = 0;
 127         }
 128
 129         scatterwalk_done(&walk->in, 0, nbytes);
 130         scatterwalk_done(&walk->out, 1, nbytes);
 131
 132 err:
 133         walk->total = nbytes;
 134         walk->nbytes = nbytes;
 135
 136         if (nbytes) {
 137                 crypto_yield(req->base.flags);
 138                 return ablkcipher_walk_next(req, walk);
 139         }
 140
 141         if (walk->iv != req->info)
 142                 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
 143         kfree(walk->iv_buffer);
 144
 145         return err;
 146 }
 147 EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
 148
 149 static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
 150                                        struct ablkcipher_walk *walk,
 151                                        unsigned int bsize,
 152                                        unsigned int alignmask,
 153                                        void **src_p, void **dst_p)
 154 {
 155         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 156         struct ablkcipher_buffer *p;
 157         void *src, *dst, *base;
 158         unsigned int n;
 159
 160         n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
 161         n += (aligned_bsize * 3 - (alignmask + 1) +
 162               (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
 163
 164         p = kmalloc(n, GFP_ATOMIC);
 165         if (!p)
 166                 return ablkcipher_walk_done(req, walk, -ENOMEM);
 167
 168         base = p + 1;
 169
 170         dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
 171         src = dst = ablkcipher_get_spot(dst, bsize);
 172
 173         p->len = bsize;
 174         p->data = dst;
 175
 176         scatterwalk_copychunks(src, &walk->in, bsize, 0);
 177
 178         ablkcipher_queue_write(walk, p);
 179
 180         walk->nbytes = bsize;
 181         walk->flags |= ABLKCIPHER_WALK_SLOW;
 182
 183         *src_p = src;
 184         *dst_p = dst;
 185
 186         return 0;
 187 }
 188
 189 static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
 190                                      struct crypto_tfm *tfm,
 191                                      unsigned int alignmask)
 192 {
 193         unsigned bs = walk->blocksize;
 194         unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
 195         unsigned aligned_bs = ALIGN(bs, alignmask + 1);
 196         unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
 197                             (alignmask + 1);
 198         u8 *iv;
 199
 200         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 201         walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
 202         if (!walk->iv_buffer)
 203                 return -ENOMEM;
 204
 205         iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
 206         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
 207         iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
 208         iv = ablkcipher_get_spot(iv, ivsize);
 209
 210         walk->iv = memcpy(iv, walk->iv, ivsize);
 211         return 0;
 212 }
 213
 214 static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
 215                                        struct ablkcipher_walk *walk)
 216 {
 217         walk->src.page = scatterwalk_page(&walk->in);
 218         walk->src.offset = offset_in_page(walk->in.offset);
 219         walk->dst.page = scatterwalk_page(&walk->out);
 220         walk->dst.offset = offset_in_page(walk->out.offset);
 221
 222         return 0;
 223 }
 224
 225 static int ablkcipher_walk_next(struct ablkcipher_request *req,
 226                                 struct ablkcipher_walk *walk)
 227 {
 228         struct crypto_tfm *tfm = req->base.tfm;
 229         unsigned int alignmask, bsize, n;
 230         void *src, *dst;
 231         int err;
 232
 233         alignmask = crypto_tfm_alg_alignmask(tfm);
 234         n = walk->total;
 235         if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
 236                 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 237                 return ablkcipher_walk_done(req, walk, -EINVAL);
 238         }
 239
 240         walk->flags &= ~ABLKCIPHER_WALK_SLOW;
 241         src = dst = NULL;
 242
 243         bsize = min(walk->blocksize, n);
 244         n = scatterwalk_clamp(&walk->in, n);
 245         n = scatterwalk_clamp(&walk->out, n);
 246
 247         if (n < bsize ||
 248             !scatterwalk_aligned(&walk->in, alignmask) ||
 249             !scatterwalk_aligned(&walk->out, alignmask)) {
 250                 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
 251                                            &src, &dst);
 252                 goto set_phys_lowmem;
 253         }
 254
 255         walk->nbytes = n;
 256
 257         return ablkcipher_next_fast(req, walk);
 258
 259 set_phys_lowmem:
 260         if (err >= 0) {
 261                 walk->src.page = virt_to_page(src);
 262                 walk->dst.page = virt_to_page(dst);
 263                 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
 264                 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
 265         }
 266
 267         return err;
 268 }
 269
 270 static int ablkcipher_walk_first(struct ablkcipher_request *req,
 271                                  struct ablkcipher_walk *walk)
 272 {
 273         struct crypto_tfm *tfm = req->base.tfm;
 274         unsigned int alignmask;
 275
 276         alignmask = crypto_tfm_alg_alignmask(tfm);
 277         if (WARN_ON_ONCE(in_irq()))
 278                 return -EDEADLK;
 279
 280         walk->nbytes = walk->total;
 281         if (unlikely(!walk->total))
 282                 return 0;
 283
 284         walk->iv_buffer = NULL;
 285         walk->iv = req->info;
 286         if (unlikely(((unsigned long)walk->iv & alignmask))) {
 287                 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
 288
 289                 if (err)
 290                         return err;
 291         }
 292
 293         scatterwalk_start(&walk->in, walk->in.sg);
 294         scatterwalk_start(&walk->out, walk->out.sg);
 295
 296         return ablkcipher_walk_next(req, walk);
 297 }
 298
 299 int ablkcipher_walk_phys(struct ablkcipher_request *req,
 300                          struct ablkcipher_walk *walk)
 301 {
 302         walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
 303         return ablkcipher_walk_first(req, walk);
 304 }
 305 EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
 306
 307 static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
 308                             unsigned int keylen)
 309 {
 310         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
 311         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 312         int ret;
 313         u8 *buffer, *alignbuffer;
 314         unsigned long absize;
 315
 316         absize = keylen + alignmask;
 317         buffer = kmalloc(absize, GFP_ATOMIC);
 318         if (!buffer)
 319                 return -ENOMEM;
 320
 321         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 322         memcpy(alignbuffer, key, keylen);
 323         ret = cipher->setkey(tfm, alignbuffer, keylen);
 324         memset(alignbuffer, 0, keylen);
 325         kfree(buffer);
 326         return ret;
 327 }
 328
 329 static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 330                   unsigned int keylen)
 331 {
 332         struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
 333         unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
 334
 335         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 336                 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 337                 return -EINVAL;
 338         }
 339
 340         if ((unsigned long)key & alignmask)
 341                 return setkey_unaligned(tfm, key, keylen);
 342
 343         return cipher->setkey(tfm, key, keylen);
 344 }
 345
 346 static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 347                                               u32 mask)
 348 {
 349         return alg->cra_ctxsize;
 350 }
 351
 352 int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
 353 {
 354         return crypto_ablkcipher_encrypt(&req->creq);
 355 }
 356
 357 int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
 358 {
 359         return crypto_ablkcipher_decrypt(&req->creq);
 360 }
 361
 362 static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
 363                                       u32 mask)
 364 {
 365         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 366         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 367
 368         if (alg->ivsize > PAGE_SIZE / 8)
 369                 return -EINVAL;
 370
 371         crt->setkey = setkey;
 372         crt->encrypt = alg->encrypt;
 373         crt->decrypt = alg->decrypt;
 374         if (!alg->ivsize) {
 375                 crt->givencrypt = skcipher_null_givencrypt;
 376                 crt->givdecrypt = skcipher_null_givdecrypt;
 377         }
 378         crt->base = __crypto_ablkcipher_cast(tfm);
 379         crt->ivsize = alg->ivsize;
 380
 381         return 0;
 382 }
 383
 384 #ifdef CONFIG_NET
 385 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 386 {
 387         struct crypto_report_blkcipher rblkcipher;
 388
 389         strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
 390         strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
 391                 sizeof(rblkcipher.geniv));
 392
 393         rblkcipher.blocksize = alg->cra_blocksize;
 394         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 395         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 396         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 397
 398         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 399                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 400                 goto nla_put_failure;
 401         return 0;
 402
 403 nla_put_failure:
 404         return -EMSGSIZE;
 405 }
 406 #else
 407 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 408 {
 409         return -ENOSYS;
 410 }
 411 #endif
 412
 413 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 414         __attribute__ ((unused));
 415 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 416 {
 417         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 418
 419         seq_printf(m, "type         : ablkcipher\n");
 420         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 421                                              "yes" : "no");
 422         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 423         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 424         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 425         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 426         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
 427 }
 428
 429 const struct crypto_type crypto_ablkcipher_type = {
 430         .ctxsize = crypto_ablkcipher_ctxsize,
 431         .init = crypto_init_ablkcipher_ops,
 432 #ifdef CONFIG_PROC_FS
 433         .show = crypto_ablkcipher_show,
 434 #endif
 435         .report = crypto_ablkcipher_report,
 436 };
 437 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 438
 439 static int no_givdecrypt(struct skcipher_givcrypt_request *req)
 440 {
 441         return -ENOSYS;
 442 }
 443
 444 static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
 445                                       u32 mask)
 446 {
 447         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 448         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 449
 450         if (alg->ivsize > PAGE_SIZE / 8)
 451                 return -EINVAL;
 452
 453         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 454                       alg->setkey : setkey;
 455         crt->encrypt = alg->encrypt;
 456         crt->decrypt = alg->decrypt;
 457         crt->givencrypt = alg->givencrypt ?: no_givdecrypt;
 458         crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
 459         crt->base = __crypto_ablkcipher_cast(tfm);
 460         crt->ivsize = alg->ivsize;
 461
 462         return 0;
 463 }
 464
 465 #ifdef CONFIG_NET
 466 static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 467 {
 468         struct crypto_report_blkcipher rblkcipher;
 469
 470         strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
 471         strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
 472                 sizeof(rblkcipher.geniv));
 473
 474         rblkcipher.blocksize = alg->cra_blocksize;
 475         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 476         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 477         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 478
 479         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 480                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 481                 goto nla_put_failure;
 482         return 0;
 483
 484 nla_put_failure:
 485         return -EMSGSIZE;
 486 }
 487 #else
 488 static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 489 {
 490         return -ENOSYS;
 491 }
 492 #endif
 493
 494 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 495         __attribute__ ((unused));
 496 static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
 497 {
 498         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 499
 500         seq_printf(m, "type         : givcipher\n");
 501         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 502                                              "yes" : "no");
 503         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 504         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 505         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 506         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 507         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
 508 }
 509
 510 const struct crypto_type crypto_givcipher_type = {
 511         .ctxsize = crypto_ablkcipher_ctxsize,
 512         .init = crypto_init_givcipher_ops,
 513 #ifdef CONFIG_PROC_FS
 514         .show = crypto_givcipher_show,
 515 #endif
 516         .report = crypto_givcipher_report,
 517 };
 518 EXPORT_SYMBOL_GPL(crypto_givcipher_type);
 519
 520 const char *crypto_default_geniv(const struct crypto_alg *alg)
 521 {
 522         if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 523              CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 524                                          alg->cra_ablkcipher.ivsize) !=
 525             alg->cra_blocksize)
 526                 return "chainiv";
 527
 528         return "eseqiv";
 529 }
 530
 531 static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
 532 {
 533         struct rtattr *tb[3];
 534         struct {
 535                 struct rtattr attr;
 536                 struct crypto_attr_type data;
 537         } ptype;
 538         struct {
 539                 struct rtattr attr;
 540                 struct crypto_attr_alg data;
 541         } palg;
 542         struct crypto_template *tmpl;
 543         struct crypto_instance *inst;
 544         struct crypto_alg *larval;
 545         const char *geniv;
 546         int err;
 547
 548         larval = crypto_larval_lookup(alg->cra_driver_name,
 549                                       (type & ~CRYPTO_ALG_TYPE_MASK) |
 550                                       CRYPTO_ALG_TYPE_GIVCIPHER,
 551                                       mask | CRYPTO_ALG_TYPE_MASK);
 552         err = PTR_ERR(larval);
 553         if (IS_ERR(larval))
 554                 goto out;
 555
 556         err = -EAGAIN;
 557         if (!crypto_is_larval(larval))
 558                 goto drop_larval;
 559
 560         ptype.attr.rta_len = sizeof(ptype);
 561         ptype.attr.rta_type = CRYPTOA_TYPE;
 562         ptype.data.type = type | CRYPTO_ALG_GENIV;
 563         /* GENIV tells the template that we're making a default geniv. */
 564         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 565         tb[0] = &ptype.attr;
 566
 567         palg.attr.rta_len = sizeof(palg);
 568         palg.attr.rta_type = CRYPTOA_ALG;
 569         /* Must use the exact name to locate ourselves. */
 570         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 571         tb[1] = &palg.attr;
 572
 573         tb[2] = NULL;
 574
 575         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 576             CRYPTO_ALG_TYPE_BLKCIPHER)
 577                 geniv = alg->cra_blkcipher.geniv;
 578         else
 579                 geniv = alg->cra_ablkcipher.geniv;
 580
 581         if (!geniv)
 582                 geniv = crypto_default_geniv(alg);
 583
 584         tmpl = crypto_lookup_template(geniv);
 585         err = -ENOENT;
 586         if (!tmpl)
 587                 goto kill_larval;
 588
 589         if (tmpl->create) {
 590                 err = tmpl->create(tmpl, tb);
 591                 if (err)
 592                         goto put_tmpl;
 593                 goto ok;
 594         }
 595
 596         inst = tmpl->alloc(tb);
 597         err = PTR_ERR(inst);
 598         if (IS_ERR(inst))
 599                 goto put_tmpl;
 600
 601         err = crypto_register_instance(tmpl, inst);
 602         if (err) {
 603                 tmpl->free(inst);
 604                 goto put_tmpl;
 605         }
 606
 607 ok:
 608         /* Redo the lookup to use the instance we just registered. */
 609         err = -EAGAIN;
 610
 611 put_tmpl:
 612         crypto_tmpl_put(tmpl);
 613 kill_larval:
 614         crypto_larval_kill(larval);
 615 drop_larval:
 616         crypto_mod_put(larval);
 617 out:
 618         crypto_mod_put(alg);
 619         return err;
 620 }
 621
 622 struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
 623 {
 624         struct crypto_alg *alg;
 625
 626         alg = crypto_alg_mod_lookup(name, type, mask);
 627         if (IS_ERR(alg))
 628                 return alg;
 629
 630         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 631             CRYPTO_ALG_TYPE_GIVCIPHER)
 632                 return alg;
 633
 634         if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 635               CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 636                                           alg->cra_ablkcipher.ivsize))
 637                 return alg;
 638
 639         crypto_mod_put(alg);
 640         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 641                                     mask & ~CRYPTO_ALG_TESTED);
 642         if (IS_ERR(alg))
 643                 return alg;
 644
 645         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 646             CRYPTO_ALG_TYPE_GIVCIPHER) {
 647                 if (~alg->cra_flags & (type ^ ~mask) & CRYPTO_ALG_TESTED) {
 648                         crypto_mod_put(alg);
 649                         alg = ERR_PTR(-ENOENT);
 650                 }
 651                 return alg;
 652         }
 653
 654         BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 655                  CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 656                                              alg->cra_ablkcipher.ivsize));
 657
 658         return ERR_PTR(crypto_givcipher_default(alg, type, mask));
 659 }
 660 EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
 661
 662 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 663                          u32 type, u32 mask)
 664 {
 665         struct crypto_alg *alg;
 666         int err;
 667
 668         type = crypto_skcipher_type(type);
 669         mask = crypto_skcipher_mask(mask);
 670
 671         alg = crypto_lookup_skcipher(name, type, mask);
 672         if (IS_ERR(alg))
 673                 return PTR_ERR(alg);
 674
 675         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 676         crypto_mod_put(alg);
 677         return err;
 678 }
 679 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 680
 681 struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
 682                                                   u32 type, u32 mask)
 683 {
 684         struct crypto_tfm *tfm;
 685         int err;
 686
 687         type = crypto_skcipher_type(type);
 688         mask = crypto_skcipher_mask(mask);
 689
 690         for (;;) {
 691                 struct crypto_alg *alg;
 692
 693                 alg = crypto_lookup_skcipher(alg_name, type, mask);
 694                 if (IS_ERR(alg)) {
 695                         err = PTR_ERR(alg);
 696                         goto err;
 697                 }
 698
 699                 tfm = __crypto_alloc_tfm(alg, type, mask);
 700                 if (!IS_ERR(tfm))
 701                         return __crypto_ablkcipher_cast(tfm);
 702
 703                 crypto_mod_put(alg);
 704                 err = PTR_ERR(tfm);
 705
 706 err:
 707                 if (err != -EAGAIN)
 708                         break;
 709                 if (fatal_signal_pending(current)) {
 710                         err = -EINTR;
 711                         break;
 712                 }
 713         }
 714
 715         return ERR_PTR(err);
 716 }
 717 EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);