linux/crypto/blkcipher.c
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   1/*
   2 * Block chaining cipher operations.
   3 * 
   4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
   5 * multiple page boundaries by using temporary blocks.  In user context,
   6 * the kernel is given a chance to schedule us once per page.
   7 *
   8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   9 *
  10 * This program is free software; you can redistribute it and/or modify it
  11 * under the terms of the GNU General Public License as published by the Free
  12 * Software Foundation; either version 2 of the License, or (at your option) 
  13 * any later version.
  14 *
  15 */
  16
  17#include <crypto/internal/skcipher.h>
  18#include <crypto/scatterwalk.h>
  19#include <linux/errno.h>
  20#include <linux/hardirq.h>
  21#include <linux/kernel.h>
  22#include <linux/module.h>
  23#include <linux/scatterlist.h>
  24#include <linux/seq_file.h>
  25#include <linux/slab.h>
  26#include <linux/string.h>
  27#include <linux/cryptouser.h>
  28#include <net/netlink.h>
  29
  30#include "internal.h"
  31
  32enum {
  33        BLKCIPHER_WALK_PHYS = 1 << 0,
  34        BLKCIPHER_WALK_SLOW = 1 << 1,
  35        BLKCIPHER_WALK_COPY = 1 << 2,
  36        BLKCIPHER_WALK_DIFF = 1 << 3,
  37};
  38
  39static int blkcipher_walk_next(struct blkcipher_desc *desc,
  40                               struct blkcipher_walk *walk);
  41static int blkcipher_walk_first(struct blkcipher_desc *desc,
  42                                struct blkcipher_walk *walk);
  43
  44static inline void blkcipher_map_src(struct blkcipher_walk *walk)
  45{
  46        walk->src.virt.addr = scatterwalk_map(&walk->in);
  47}
  48
  49static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
  50{
  51        walk->dst.virt.addr = scatterwalk_map(&walk->out);
  52}
  53
  54static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
  55{
  56        scatterwalk_unmap(walk->src.virt.addr);
  57}
  58
  59static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
  60{
  61        scatterwalk_unmap(walk->dst.virt.addr);
  62}
  63
  64/* Get a spot of the specified length that does not straddle a page.
  65 * The caller needs to ensure that there is enough space for this operation.
  66 */
  67static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
  68{
  69        u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  70        return max(start, end_page);
  71}
  72
  73static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
  74                                               struct blkcipher_walk *walk,
  75                                               unsigned int bsize)
  76{
  77        u8 *addr;
  78        unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
  79
  80        addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
  81        addr = blkcipher_get_spot(addr, bsize);
  82        scatterwalk_copychunks(addr, &walk->out, bsize, 1);
  83        return bsize;
  84}
  85
  86static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
  87                                               unsigned int n)
  88{
  89        if (walk->flags & BLKCIPHER_WALK_COPY) {
  90                blkcipher_map_dst(walk);
  91                memcpy(walk->dst.virt.addr, walk->page, n);
  92                blkcipher_unmap_dst(walk);
  93        } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
  94                if (walk->flags & BLKCIPHER_WALK_DIFF)
  95                        blkcipher_unmap_dst(walk);
  96                blkcipher_unmap_src(walk);
  97        }
  98
  99        scatterwalk_advance(&walk->in, n);
 100        scatterwalk_advance(&walk->out, n);
 101
 102        return n;
 103}
 104
 105int blkcipher_walk_done(struct blkcipher_desc *desc,
 106                        struct blkcipher_walk *walk, int err)
 107{
 108        struct crypto_blkcipher *tfm = desc->tfm;
 109        unsigned int nbytes = 0;
 110
 111        if (likely(err >= 0)) {
 112                unsigned int n = walk->nbytes - err;
 113
 114                if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
 115                        n = blkcipher_done_fast(walk, n);
 116                else if (WARN_ON(err)) {
 117                        err = -EINVAL;
 118                        goto err;
 119                } else
 120                        n = blkcipher_done_slow(tfm, walk, n);
 121
 122                nbytes = walk->total - n;
 123                err = 0;
 124        }
 125
 126        scatterwalk_done(&walk->in, 0, nbytes);
 127        scatterwalk_done(&walk->out, 1, nbytes);
 128
 129err:
 130        walk->total = nbytes;
 131        walk->nbytes = nbytes;
 132
 133        if (nbytes) {
 134                crypto_yield(desc->flags);
 135                return blkcipher_walk_next(desc, walk);
 136        }
 137
 138        if (walk->iv != desc->info)
 139                memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
 140        if (walk->buffer != walk->page)
 141                kfree(walk->buffer);
 142        if (walk->page)
 143                free_page((unsigned long)walk->page);
 144
 145        return err;
 146}
 147EXPORT_SYMBOL_GPL(blkcipher_walk_done);
 148
 149static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
 150                                      struct blkcipher_walk *walk,
 151                                      unsigned int bsize,
 152                                      unsigned int alignmask)
 153{
 154        unsigned int n;
 155        unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 156
 157        if (walk->buffer)
 158                goto ok;
 159
 160        walk->buffer = walk->page;
 161        if (walk->buffer)
 162                goto ok;
 163
 164        n = aligned_bsize * 3 - (alignmask + 1) +
 165            (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
 166        walk->buffer = kmalloc(n, GFP_ATOMIC);
 167        if (!walk->buffer)
 168                return blkcipher_walk_done(desc, walk, -ENOMEM);
 169
 170ok:
 171        walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
 172                                          alignmask + 1);
 173        walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
 174        walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
 175                                                 aligned_bsize, bsize);
 176
 177        scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 178
 179        walk->nbytes = bsize;
 180        walk->flags |= BLKCIPHER_WALK_SLOW;
 181
 182        return 0;
 183}
 184
 185static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
 186{
 187        u8 *tmp = walk->page;
 188
 189        blkcipher_map_src(walk);
 190        memcpy(tmp, walk->src.virt.addr, walk->nbytes);
 191        blkcipher_unmap_src(walk);
 192
 193        walk->src.virt.addr = tmp;
 194        walk->dst.virt.addr = tmp;
 195
 196        return 0;
 197}
 198
 199static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
 200                                      struct blkcipher_walk *walk)
 201{
 202        unsigned long diff;
 203
 204        walk->src.phys.page = scatterwalk_page(&walk->in);
 205        walk->src.phys.offset = offset_in_page(walk->in.offset);
 206        walk->dst.phys.page = scatterwalk_page(&walk->out);
 207        walk->dst.phys.offset = offset_in_page(walk->out.offset);
 208
 209        if (walk->flags & BLKCIPHER_WALK_PHYS)
 210                return 0;
 211
 212        diff = walk->src.phys.offset - walk->dst.phys.offset;
 213        diff |= walk->src.virt.page - walk->dst.virt.page;
 214
 215        blkcipher_map_src(walk);
 216        walk->dst.virt.addr = walk->src.virt.addr;
 217
 218        if (diff) {
 219                walk->flags |= BLKCIPHER_WALK_DIFF;
 220                blkcipher_map_dst(walk);
 221        }
 222
 223        return 0;
 224}
 225
 226static int blkcipher_walk_next(struct blkcipher_desc *desc,
 227                               struct blkcipher_walk *walk)
 228{
 229        struct crypto_blkcipher *tfm = desc->tfm;
 230        unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
 231        unsigned int bsize;
 232        unsigned int n;
 233        int err;
 234
 235        n = walk->total;
 236        if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
 237                desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 238                return blkcipher_walk_done(desc, walk, -EINVAL);
 239        }
 240
 241        walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
 242                         BLKCIPHER_WALK_DIFF);
 243        if (!scatterwalk_aligned(&walk->in, alignmask) ||
 244            !scatterwalk_aligned(&walk->out, alignmask)) {
 245                walk->flags |= BLKCIPHER_WALK_COPY;
 246                if (!walk->page) {
 247                        walk->page = (void *)__get_free_page(GFP_ATOMIC);
 248                        if (!walk->page)
 249                                n = 0;
 250                }
 251        }
 252
 253        bsize = min(walk->blocksize, n);
 254        n = scatterwalk_clamp(&walk->in, n);
 255        n = scatterwalk_clamp(&walk->out, n);
 256
 257        if (unlikely(n < bsize)) {
 258                err = blkcipher_next_slow(desc, walk, bsize, alignmask);
 259                goto set_phys_lowmem;
 260        }
 261
 262        walk->nbytes = n;
 263        if (walk->flags & BLKCIPHER_WALK_COPY) {
 264                err = blkcipher_next_copy(walk);
 265                goto set_phys_lowmem;
 266        }
 267
 268        return blkcipher_next_fast(desc, walk);
 269
 270set_phys_lowmem:
 271        if (walk->flags & BLKCIPHER_WALK_PHYS) {
 272                walk->src.phys.page = virt_to_page(walk->src.virt.addr);
 273                walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
 274                walk->src.phys.offset &= PAGE_SIZE - 1;
 275                walk->dst.phys.offset &= PAGE_SIZE - 1;
 276        }
 277        return err;
 278}
 279
 280static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
 281                                    struct crypto_blkcipher *tfm,
 282                                    unsigned int alignmask)
 283{
 284        unsigned bs = walk->blocksize;
 285        unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
 286        unsigned aligned_bs = ALIGN(bs, alignmask + 1);
 287        unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
 288                            (alignmask + 1);
 289        u8 *iv;
 290
 291        size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 292        walk->buffer = kmalloc(size, GFP_ATOMIC);
 293        if (!walk->buffer)
 294                return -ENOMEM;
 295
 296        iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
 297        iv = blkcipher_get_spot(iv, bs) + aligned_bs;
 298        iv = blkcipher_get_spot(iv, bs) + aligned_bs;
 299        iv = blkcipher_get_spot(iv, ivsize);
 300
 301        walk->iv = memcpy(iv, walk->iv, ivsize);
 302        return 0;
 303}
 304
 305int blkcipher_walk_virt(struct blkcipher_desc *desc,
 306                        struct blkcipher_walk *walk)
 307{
 308        walk->flags &= ~BLKCIPHER_WALK_PHYS;
 309        walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
 310        return blkcipher_walk_first(desc, walk);
 311}
 312EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
 313
 314int blkcipher_walk_phys(struct blkcipher_desc *desc,
 315                        struct blkcipher_walk *walk)
 316{
 317        walk->flags |= BLKCIPHER_WALK_PHYS;
 318        walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
 319        return blkcipher_walk_first(desc, walk);
 320}
 321EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
 322
 323static int blkcipher_walk_first(struct blkcipher_desc *desc,
 324                                struct blkcipher_walk *walk)
 325{
 326        struct crypto_blkcipher *tfm = desc->tfm;
 327        unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
 328
 329        if (WARN_ON_ONCE(in_irq()))
 330                return -EDEADLK;
 331
 332        walk->nbytes = walk->total;
 333        if (unlikely(!walk->total))
 334                return 0;
 335
 336        walk->buffer = NULL;
 337        walk->iv = desc->info;
 338        if (unlikely(((unsigned long)walk->iv & alignmask))) {
 339                int err = blkcipher_copy_iv(walk, tfm, alignmask);
 340                if (err)
 341                        return err;
 342        }
 343
 344        scatterwalk_start(&walk->in, walk->in.sg);
 345        scatterwalk_start(&walk->out, walk->out.sg);
 346        walk->page = NULL;
 347
 348        return blkcipher_walk_next(desc, walk);
 349}
 350
 351int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
 352                              struct blkcipher_walk *walk,
 353                              unsigned int blocksize)
 354{
 355        walk->flags &= ~BLKCIPHER_WALK_PHYS;
 356        walk->blocksize = blocksize;
 357        return blkcipher_walk_first(desc, walk);
 358}
 359EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
 360
 361static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
 362                            unsigned int keylen)
 363{
 364        struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
 365        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 366        int ret;
 367        u8 *buffer, *alignbuffer;
 368        unsigned long absize;
 369
 370        absize = keylen + alignmask;
 371        buffer = kmalloc(absize, GFP_ATOMIC);
 372        if (!buffer)
 373                return -ENOMEM;
 374
 375        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 376        memcpy(alignbuffer, key, keylen);
 377        ret = cipher->setkey(tfm, alignbuffer, keylen);
 378        memset(alignbuffer, 0, keylen);
 379        kfree(buffer);
 380        return ret;
 381}
 382
 383static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 384{
 385        struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
 386        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 387
 388        if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 389                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 390                return -EINVAL;
 391        }
 392
 393        if ((unsigned long)key & alignmask)
 394                return setkey_unaligned(tfm, key, keylen);
 395
 396        return cipher->setkey(tfm, key, keylen);
 397}
 398
 399static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 400                        unsigned int keylen)
 401{
 402        return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
 403}
 404
 405static int async_encrypt(struct ablkcipher_request *req)
 406{
 407        struct crypto_tfm *tfm = req->base.tfm;
 408        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 409        struct blkcipher_desc desc = {
 410                .tfm = __crypto_blkcipher_cast(tfm),
 411                .info = req->info,
 412                .flags = req->base.flags,
 413        };
 414
 415
 416        return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
 417}
 418
 419static int async_decrypt(struct ablkcipher_request *req)
 420{
 421        struct crypto_tfm *tfm = req->base.tfm;
 422        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 423        struct blkcipher_desc desc = {
 424                .tfm = __crypto_blkcipher_cast(tfm),
 425                .info = req->info,
 426                .flags = req->base.flags,
 427        };
 428
 429        return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
 430}
 431
 432static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 433                                             u32 mask)
 434{
 435        struct blkcipher_alg *cipher = &alg->cra_blkcipher;
 436        unsigned int len = alg->cra_ctxsize;
 437
 438        if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
 439            cipher->ivsize) {
 440                len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
 441                len += cipher->ivsize;
 442        }
 443
 444        return len;
 445}
 446
 447static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
 448{
 449        struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 450        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 451
 452        crt->setkey = async_setkey;
 453        crt->encrypt = async_encrypt;
 454        crt->decrypt = async_decrypt;
 455        if (!alg->ivsize) {
 456                crt->givencrypt = skcipher_null_givencrypt;
 457                crt->givdecrypt = skcipher_null_givdecrypt;
 458        }
 459        crt->base = __crypto_ablkcipher_cast(tfm);
 460        crt->ivsize = alg->ivsize;
 461
 462        return 0;
 463}
 464
 465static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
 466{
 467        struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
 468        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 469        unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
 470        unsigned long addr;
 471
 472        crt->setkey = setkey;
 473        crt->encrypt = alg->encrypt;
 474        crt->decrypt = alg->decrypt;
 475
 476        addr = (unsigned long)crypto_tfm_ctx(tfm);
 477        addr = ALIGN(addr, align);
 478        addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
 479        crt->iv = (void *)addr;
 480
 481        return 0;
 482}
 483
 484static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 485{
 486        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 487
 488        if (alg->ivsize > PAGE_SIZE / 8)
 489                return -EINVAL;
 490
 491        if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
 492                return crypto_init_blkcipher_ops_sync(tfm);
 493        else
 494                return crypto_init_blkcipher_ops_async(tfm);
 495}
 496
 497#ifdef CONFIG_NET
 498static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 499{
 500        struct crypto_report_blkcipher rblkcipher;
 501
 502        snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "blkcipher");
 503        snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
 504                 alg->cra_blkcipher.geniv ?: "<default>");
 505
 506        rblkcipher.blocksize = alg->cra_blocksize;
 507        rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
 508        rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
 509        rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
 510
 511        if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 512                    sizeof(struct crypto_report_blkcipher), &rblkcipher))
 513                goto nla_put_failure;
 514        return 0;
 515
 516nla_put_failure:
 517        return -EMSGSIZE;
 518}
 519#else
 520static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 521{
 522        return -ENOSYS;
 523}
 524#endif
 525
 526static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 527        __attribute__ ((unused));
 528static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 529{
 530        seq_printf(m, "type         : blkcipher\n");
 531        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 532        seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
 533        seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
 534        seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
 535        seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
 536                                             "<default>");
 537}
 538
 539const struct crypto_type crypto_blkcipher_type = {
 540        .ctxsize = crypto_blkcipher_ctxsize,
 541        .init = crypto_init_blkcipher_ops,
 542#ifdef CONFIG_PROC_FS
 543        .show = crypto_blkcipher_show,
 544#endif
 545        .report = crypto_blkcipher_report,
 546};
 547EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
 548
 549static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
 550                                const char *name, u32 type, u32 mask)
 551{
 552        struct crypto_alg *alg;
 553        int err;
 554
 555        type = crypto_skcipher_type(type);
 556        mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
 557
 558        alg = crypto_alg_mod_lookup(name, type, mask);
 559        if (IS_ERR(alg))
 560                return PTR_ERR(alg);
 561
 562        err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 563        crypto_mod_put(alg);
 564        return err;
 565}
 566
 567struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
 568                                             struct rtattr **tb, u32 type,
 569                                             u32 mask)
 570{
 571        struct {
 572                int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
 573                              unsigned int keylen);
 574                int (*encrypt)(struct ablkcipher_request *req);
 575                int (*decrypt)(struct ablkcipher_request *req);
 576
 577                unsigned int min_keysize;
 578                unsigned int max_keysize;
 579                unsigned int ivsize;
 580
 581                const char *geniv;
 582        } balg;
 583        const char *name;
 584        struct crypto_skcipher_spawn *spawn;
 585        struct crypto_attr_type *algt;
 586        struct crypto_instance *inst;
 587        struct crypto_alg *alg;
 588        int err;
 589
 590        algt = crypto_get_attr_type(tb);
 591        err = PTR_ERR(algt);
 592        if (IS_ERR(algt))
 593                return ERR_PTR(err);
 594
 595        if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
 596            algt->mask)
 597                return ERR_PTR(-EINVAL);
 598
 599        name = crypto_attr_alg_name(tb[1]);
 600        err = PTR_ERR(name);
 601        if (IS_ERR(name))
 602                return ERR_PTR(err);
 603
 604        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 605        if (!inst)
 606                return ERR_PTR(-ENOMEM);
 607
 608        spawn = crypto_instance_ctx(inst);
 609
 610        /* Ignore async algorithms if necessary. */
 611        mask |= crypto_requires_sync(algt->type, algt->mask);
 612
 613        crypto_set_skcipher_spawn(spawn, inst);
 614        err = crypto_grab_nivcipher(spawn, name, type, mask);
 615        if (err)
 616                goto err_free_inst;
 617
 618        alg = crypto_skcipher_spawn_alg(spawn);
 619
 620        if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 621            CRYPTO_ALG_TYPE_BLKCIPHER) {
 622                balg.ivsize = alg->cra_blkcipher.ivsize;
 623                balg.min_keysize = alg->cra_blkcipher.min_keysize;
 624                balg.max_keysize = alg->cra_blkcipher.max_keysize;
 625
 626                balg.setkey = async_setkey;
 627                balg.encrypt = async_encrypt;
 628                balg.decrypt = async_decrypt;
 629
 630                balg.geniv = alg->cra_blkcipher.geniv;
 631        } else {
 632                balg.ivsize = alg->cra_ablkcipher.ivsize;
 633                balg.min_keysize = alg->cra_ablkcipher.min_keysize;
 634                balg.max_keysize = alg->cra_ablkcipher.max_keysize;
 635
 636                balg.setkey = alg->cra_ablkcipher.setkey;
 637                balg.encrypt = alg->cra_ablkcipher.encrypt;
 638                balg.decrypt = alg->cra_ablkcipher.decrypt;
 639
 640                balg.geniv = alg->cra_ablkcipher.geniv;
 641        }
 642
 643        err = -EINVAL;
 644        if (!balg.ivsize)
 645                goto err_drop_alg;
 646
 647        /*
 648         * This is only true if we're constructing an algorithm with its
 649         * default IV generator.  For the default generator we elide the
 650         * template name and double-check the IV generator.
 651         */
 652        if (algt->mask & CRYPTO_ALG_GENIV) {
 653                if (!balg.geniv)
 654                        balg.geniv = crypto_default_geniv(alg);
 655                err = -EAGAIN;
 656                if (strcmp(tmpl->name, balg.geniv))
 657                        goto err_drop_alg;
 658
 659                memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 660                memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 661                       CRYPTO_MAX_ALG_NAME);
 662        } else {
 663                err = -ENAMETOOLONG;
 664                if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 665                             "%s(%s)", tmpl->name, alg->cra_name) >=
 666                    CRYPTO_MAX_ALG_NAME)
 667                        goto err_drop_alg;
 668                if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 669                             "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 670                    CRYPTO_MAX_ALG_NAME)
 671                        goto err_drop_alg;
 672        }
 673
 674        inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
 675        inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 676        inst->alg.cra_priority = alg->cra_priority;
 677        inst->alg.cra_blocksize = alg->cra_blocksize;
 678        inst->alg.cra_alignmask = alg->cra_alignmask;
 679        inst->alg.cra_type = &crypto_givcipher_type;
 680
 681        inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
 682        inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
 683        inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
 684        inst->alg.cra_ablkcipher.geniv = balg.geniv;
 685
 686        inst->alg.cra_ablkcipher.setkey = balg.setkey;
 687        inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
 688        inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
 689
 690out:
 691        return inst;
 692
 693err_drop_alg:
 694        crypto_drop_skcipher(spawn);
 695err_free_inst:
 696        kfree(inst);
 697        inst = ERR_PTR(err);
 698        goto out;
 699}
 700EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
 701
 702void skcipher_geniv_free(struct crypto_instance *inst)
 703{
 704        crypto_drop_skcipher(crypto_instance_ctx(inst));
 705        kfree(inst);
 706}
 707EXPORT_SYMBOL_GPL(skcipher_geniv_free);
 708
 709int skcipher_geniv_init(struct crypto_tfm *tfm)
 710{
 711        struct crypto_instance *inst = (void *)tfm->__crt_alg;
 712        struct crypto_ablkcipher *cipher;
 713
 714        cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
 715        if (IS_ERR(cipher))
 716                return PTR_ERR(cipher);
 717
 718        tfm->crt_ablkcipher.base = cipher;
 719        tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
 720
 721        return 0;
 722}
 723EXPORT_SYMBOL_GPL(skcipher_geniv_init);
 724
 725void skcipher_geniv_exit(struct crypto_tfm *tfm)
 726{
 727        crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
 728}
 729EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
 730
 731MODULE_LICENSE("GPL");
 732MODULE_DESCRIPTION("Generic block chaining cipher type");
 733
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