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