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