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->iv = req->info;
 280         walk->nbytes = walk->total;
 281         if (unlikely(!walk->total))
 282                 return 0;
 283
 284         walk->iv_buffer = NULL;
 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         crt->has_setkey = alg->max_keysize;
 379
 380         return 0;
 381 }
 382
 383 #ifdef CONFIG_NET
 384 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 385 {
 386         struct crypto_report_blkcipher rblkcipher;
 387
 388         strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
 389         strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
 390                 sizeof(rblkcipher.geniv));
 391
 392         rblkcipher.blocksize = alg->cra_blocksize;
 393         rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
 394         rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
 395         rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
 396
 397         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 398                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
 399                 goto nla_put_failure;
 400         return 0;
 401
 402 nla_put_failure:
 403         return -EMSGSIZE;
 404 }
 405 #else
 406 static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 407 {
 408         return -ENOSYS;
 409 }
 410 #endif
 411
 412 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 413         __attribute__ ((unused));
 414 static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 415 {
 416         struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
 417
 418         seq_printf(m, "type         : ablkcipher\n");
 419         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 420                                              "yes" : "no");
 421         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 422         seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
 423         seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
 424         seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
 425         seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
 426 }
 427
 428 const struct crypto_type crypto_ablkcipher_type = {
 429         .ctxsize = crypto_ablkcipher_ctxsize,
 430         .init = crypto_init_ablkcipher_ops,
 431 #ifdef CONFIG_PROC_FS
 432         .show = crypto_ablkcipher_show,
 433 #endif
 434         .report = crypto_ablkcipher_report,
 435 };
 436 EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
 437
 438 static int no_givdecrypt(struct skcipher_givcrypt_request *req)
 439 {
 440         return -ENOSYS;
 441 }
 442
 443 static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
 444                                       u32 mask)
 445 {
 446         struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
 447         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 448
 449         if (alg->ivsize > PAGE_SIZE / 8)
 450                 return -EINVAL;
 451
 452         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 453                       alg->setkey : setkey;
 454         crt->encrypt = alg->encrypt;
 455         crt->decrypt = alg->decrypt;
 456         crt->givencrypt = alg->givencrypt;
 457         crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
 458         crt->base = __crypto_ablkcipher_cast(tfm);
 459         crt->ivsize = alg->ivsize;
 460         crt->has_setkey = alg->max_keysize;
 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         inst = tmpl->alloc(tb);
 590         err = PTR_ERR(inst);
 591         if (IS_ERR(inst))
 592                 goto put_tmpl;
 593
 594         if ((err = crypto_register_instance(tmpl, inst))) {
 595                 tmpl->free(inst);
 596                 goto put_tmpl;
 597         }
 598
 599         /* Redo the lookup to use the instance we just registered. */
 600         err = -EAGAIN;
 601
 602 put_tmpl:
 603         crypto_tmpl_put(tmpl);
 604 kill_larval:
 605         crypto_larval_kill(larval);
 606 drop_larval:
 607         crypto_mod_put(larval);
 608 out:
 609         crypto_mod_put(alg);
 610         return err;
 611 }
 612
 613 struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
 614 {
 615         struct crypto_alg *alg;
 616
 617         alg = crypto_alg_mod_lookup(name, type, mask);
 618         if (IS_ERR(alg))
 619                 return alg;
 620
 621         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 622             CRYPTO_ALG_TYPE_GIVCIPHER)
 623                 return alg;
 624
 625         if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 626               CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 627                                           alg->cra_ablkcipher.ivsize))
 628                 return alg;
 629
 630         crypto_mod_put(alg);
 631         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 632                                     mask & ~CRYPTO_ALG_TESTED);
 633         if (IS_ERR(alg))
 634                 return alg;
 635
 636         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 637             CRYPTO_ALG_TYPE_GIVCIPHER) {
 638                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 639                         crypto_mod_put(alg);
 640                         alg = ERR_PTR(-ENOENT);
 641                 }
 642                 return alg;
 643         }
 644
 645         BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 646                  CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
 647                                              alg->cra_ablkcipher.ivsize));
 648
 649         return ERR_PTR(crypto_givcipher_default(alg, type, mask));
 650 }
 651 EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
 652
 653 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
 654                          u32 type, u32 mask)
 655 {
 656         struct crypto_alg *alg;
 657         int err;
 658
 659         type = crypto_skcipher_type(type);
 660         mask = crypto_skcipher_mask(mask);
 661
 662         alg = crypto_lookup_skcipher(name, type, mask);
 663         if (IS_ERR(alg))
 664                 return PTR_ERR(alg);
 665
 666         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 667         crypto_mod_put(alg);
 668         return err;
 669 }
 670 EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
 671
 672 struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
 673                                                   u32 type, u32 mask)
 674 {
 675         struct crypto_tfm *tfm;
 676         int err;
 677
 678         type = crypto_skcipher_type(type);
 679         mask = crypto_skcipher_mask(mask);
 680
 681         for (;;) {
 682                 struct crypto_alg *alg;
 683
 684                 alg = crypto_lookup_skcipher(alg_name, type, mask);
 685                 if (IS_ERR(alg)) {
 686                         err = PTR_ERR(alg);
 687                         goto err;
 688                 }
 689
 690                 tfm = __crypto_alloc_tfm(alg, type, mask);
 691                 if (!IS_ERR(tfm))
 692                         return __crypto_ablkcipher_cast(tfm);
 693
 694                 crypto_mod_put(alg);
 695                 err = PTR_ERR(tfm);
 696
 697 err:
 698                 if (err != -EAGAIN)
 699                         break;
 700                 if (fatal_signal_pending(current)) {
 701                         err = -EINTR;
 702                         break;
 703                 }
 704         }
 705
 706         return ERR_PTR(err);
 707 }
 708 EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);