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/aead.h>
  18#include <crypto/internal/skcipher.h>
  19#include <crypto/scatterwalk.h>
  20#include <linux/errno.h>
  21#include <linux/hardirq.h>
  22#include <linux/kernel.h>
  23#include <linux/module.h>
  24#include <linux/scatterlist.h>
  25#include <linux/seq_file.h>
  26#include <linux/slab.h>
  27#include <linux/string.h>
  28#include <linux/cryptouser.h>
  29#include <net/netlink.h>
  30
  31#include "internal.h"
  32
  33enum {
  34        BLKCIPHER_WALK_PHYS = 1 << 0,
  35        BLKCIPHER_WALK_SLOW = 1 << 1,
  36        BLKCIPHER_WALK_COPY = 1 << 2,
  37        BLKCIPHER_WALK_DIFF = 1 << 3,
  38};
  39
  40static int blkcipher_walk_next(struct blkcipher_desc *desc,
  41                               struct blkcipher_walk *walk);
  42static int blkcipher_walk_first(struct blkcipher_desc *desc,
  43                                struct blkcipher_walk *walk);
  44
  45static inline void blkcipher_map_src(struct blkcipher_walk *walk)
  46{
  47        walk->src.virt.addr = scatterwalk_map(&walk->in);
  48}
  49
  50static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
  51{
  52        walk->dst.virt.addr = scatterwalk_map(&walk->out);
  53}
  54
  55static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
  56{
  57        scatterwalk_unmap(walk->src.virt.addr);
  58}
  59
  60static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
  61{
  62        scatterwalk_unmap(walk->dst.virt.addr);
  63}
  64
  65/* Get a spot of the specified length that does not straddle a page.
  66 * The caller needs to ensure that there is enough space for this operation.
  67 */
  68static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
  69{
  70        u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
  71        return max(start, end_page);
  72}
  73
  74static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
  75                                               unsigned int bsize)
  76{
  77        u8 *addr;
  78
  79        addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
  80        addr = blkcipher_get_spot(addr, bsize);
  81        scatterwalk_copychunks(addr, &walk->out, bsize, 1);
  82        return bsize;
  83}
  84
  85static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
  86                                               unsigned int n)
  87{
  88        if (walk->flags & BLKCIPHER_WALK_COPY) {
  89                blkcipher_map_dst(walk);
  90                memcpy(walk->dst.virt.addr, walk->page, n);
  91                blkcipher_unmap_dst(walk);
  92        } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
  93                if (walk->flags & BLKCIPHER_WALK_DIFF)
  94                        blkcipher_unmap_dst(walk);
  95                blkcipher_unmap_src(walk);
  96        }
  97
  98        scatterwalk_advance(&walk->in, n);
  99        scatterwalk_advance(&walk->out, n);
 100
 101        return n;
 102}
 103
 104int blkcipher_walk_done(struct blkcipher_desc *desc,
 105                        struct blkcipher_walk *walk, int err)
 106{
 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(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, walk->ivsize);
 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        unsigned int bsize;
 228        unsigned int n;
 229        int err;
 230
 231        n = walk->total;
 232        if (unlikely(n < walk->cipher_blocksize)) {
 233                desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 234                return blkcipher_walk_done(desc, walk, -EINVAL);
 235        }
 236
 237        walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
 238                         BLKCIPHER_WALK_DIFF);
 239        if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
 240            !scatterwalk_aligned(&walk->out, walk->alignmask)) {
 241                walk->flags |= BLKCIPHER_WALK_COPY;
 242                if (!walk->page) {
 243                        walk->page = (void *)__get_free_page(GFP_ATOMIC);
 244                        if (!walk->page)
 245                                n = 0;
 246                }
 247        }
 248
 249        bsize = min(walk->walk_blocksize, n);
 250        n = scatterwalk_clamp(&walk->in, n);
 251        n = scatterwalk_clamp(&walk->out, n);
 252
 253        if (unlikely(n < bsize)) {
 254                err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
 255                goto set_phys_lowmem;
 256        }
 257
 258        walk->nbytes = n;
 259        if (walk->flags & BLKCIPHER_WALK_COPY) {
 260                err = blkcipher_next_copy(walk);
 261                goto set_phys_lowmem;
 262        }
 263
 264        return blkcipher_next_fast(desc, walk);
 265
 266set_phys_lowmem:
 267        if (walk->flags & BLKCIPHER_WALK_PHYS) {
 268                walk->src.phys.page = virt_to_page(walk->src.virt.addr);
 269                walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
 270                walk->src.phys.offset &= PAGE_SIZE - 1;
 271                walk->dst.phys.offset &= PAGE_SIZE - 1;
 272        }
 273        return err;
 274}
 275
 276static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
 277{
 278        unsigned bs = walk->walk_blocksize;
 279        unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
 280        unsigned int size = aligned_bs * 2 +
 281                            walk->ivsize + max(aligned_bs, walk->ivsize) -
 282                            (walk->alignmask + 1);
 283        u8 *iv;
 284
 285        size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1);
 286        walk->buffer = kmalloc(size, GFP_ATOMIC);
 287        if (!walk->buffer)
 288                return -ENOMEM;
 289
 290        iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
 291        iv = blkcipher_get_spot(iv, bs) + aligned_bs;
 292        iv = blkcipher_get_spot(iv, bs) + aligned_bs;
 293        iv = blkcipher_get_spot(iv, walk->ivsize);
 294
 295        walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 296        return 0;
 297}
 298
 299int blkcipher_walk_virt(struct blkcipher_desc *desc,
 300                        struct blkcipher_walk *walk)
 301{
 302        walk->flags &= ~BLKCIPHER_WALK_PHYS;
 303        walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
 304        walk->cipher_blocksize = walk->walk_blocksize;
 305        walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
 306        walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 307        return blkcipher_walk_first(desc, walk);
 308}
 309EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
 310
 311int blkcipher_walk_phys(struct blkcipher_desc *desc,
 312                        struct blkcipher_walk *walk)
 313{
 314        walk->flags |= BLKCIPHER_WALK_PHYS;
 315        walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
 316        walk->cipher_blocksize = walk->walk_blocksize;
 317        walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
 318        walk->alignmask = crypto_blkcipher_alignmask(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        if (WARN_ON_ONCE(in_irq()))
 327                return -EDEADLK;
 328
 329        walk->iv = desc->info;
 330        walk->nbytes = walk->total;
 331        if (unlikely(!walk->total))
 332                return 0;
 333
 334        walk->buffer = NULL;
 335        if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
 336                int err = blkcipher_copy_iv(walk);
 337                if (err)
 338                        return err;
 339        }
 340
 341        scatterwalk_start(&walk->in, walk->in.sg);
 342        scatterwalk_start(&walk->out, walk->out.sg);
 343        walk->page = NULL;
 344
 345        return blkcipher_walk_next(desc, walk);
 346}
 347
 348int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
 349                              struct blkcipher_walk *walk,
 350                              unsigned int blocksize)
 351{
 352        walk->flags &= ~BLKCIPHER_WALK_PHYS;
 353        walk->walk_blocksize = blocksize;
 354        walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
 355        walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
 356        walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 357        return blkcipher_walk_first(desc, walk);
 358}
 359EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
 360
 361int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
 362                                   struct blkcipher_walk *walk,
 363                                   struct crypto_aead *tfm,
 364                                   unsigned int blocksize)
 365{
 366        walk->flags &= ~BLKCIPHER_WALK_PHYS;
 367        walk->walk_blocksize = blocksize;
 368        walk->cipher_blocksize = crypto_aead_blocksize(tfm);
 369        walk->ivsize = crypto_aead_ivsize(tfm);
 370        walk->alignmask = crypto_aead_alignmask(tfm);
 371        return blkcipher_walk_first(desc, walk);
 372}
 373EXPORT_SYMBOL_GPL(blkcipher_aead_walk_virt_block);
 374
 375static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
 376                            unsigned int keylen)
 377{
 378        struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
 379        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 380        int ret;
 381        u8 *buffer, *alignbuffer;
 382        unsigned long absize;
 383
 384        absize = keylen + alignmask;
 385        buffer = kmalloc(absize, GFP_ATOMIC);
 386        if (!buffer)
 387                return -ENOMEM;
 388
 389        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 390        memcpy(alignbuffer, key, keylen);
 391        ret = cipher->setkey(tfm, alignbuffer, keylen);
 392        memset(alignbuffer, 0, keylen);
 393        kfree(buffer);
 394        return ret;
 395}
 396
 397static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 398{
 399        struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
 400        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 401
 402        if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 403                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 404                return -EINVAL;
 405        }
 406
 407        if ((unsigned long)key & alignmask)
 408                return setkey_unaligned(tfm, key, keylen);
 409
 410        return cipher->setkey(tfm, key, keylen);
 411}
 412
 413static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
 414                        unsigned int keylen)
 415{
 416        return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
 417}
 418
 419static int async_encrypt(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
 430        return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
 431}
 432
 433static int async_decrypt(struct ablkcipher_request *req)
 434{
 435        struct crypto_tfm *tfm = req->base.tfm;
 436        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 437        struct blkcipher_desc desc = {
 438                .tfm = __crypto_blkcipher_cast(tfm),
 439                .info = req->info,
 440                .flags = req->base.flags,
 441        };
 442
 443        return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
 444}
 445
 446static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
 447                                             u32 mask)
 448{
 449        struct blkcipher_alg *cipher = &alg->cra_blkcipher;
 450        unsigned int len = alg->cra_ctxsize;
 451
 452        if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
 453            cipher->ivsize) {
 454                len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
 455                len += cipher->ivsize;
 456        }
 457
 458        return len;
 459}
 460
 461static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
 462{
 463        struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
 464        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 465
 466        crt->setkey = async_setkey;
 467        crt->encrypt = async_encrypt;
 468        crt->decrypt = async_decrypt;
 469        if (!alg->ivsize) {
 470                crt->givencrypt = skcipher_null_givencrypt;
 471                crt->givdecrypt = skcipher_null_givdecrypt;
 472        }
 473        crt->base = __crypto_ablkcipher_cast(tfm);
 474        crt->ivsize = alg->ivsize;
 475
 476        return 0;
 477}
 478
 479static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
 480{
 481        struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
 482        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 483        unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
 484        unsigned long addr;
 485
 486        crt->setkey = setkey;
 487        crt->encrypt = alg->encrypt;
 488        crt->decrypt = alg->decrypt;
 489
 490        addr = (unsigned long)crypto_tfm_ctx(tfm);
 491        addr = ALIGN(addr, align);
 492        addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
 493        crt->iv = (void *)addr;
 494
 495        return 0;
 496}
 497
 498static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 499{
 500        struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
 501
 502        if (alg->ivsize > PAGE_SIZE / 8)
 503                return -EINVAL;
 504
 505        if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
 506                return crypto_init_blkcipher_ops_sync(tfm);
 507        else
 508                return crypto_init_blkcipher_ops_async(tfm);
 509}
 510
 511#ifdef CONFIG_NET
 512static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 513{
 514        struct crypto_report_blkcipher rblkcipher;
 515
 516        strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
 517        strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
 518                sizeof(rblkcipher.geniv));
 519
 520        rblkcipher.blocksize = alg->cra_blocksize;
 521        rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
 522        rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
 523        rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
 524
 525        if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
 526                    sizeof(struct crypto_report_blkcipher), &rblkcipher))
 527                goto nla_put_failure;
 528        return 0;
 529
 530nla_put_failure:
 531        return -EMSGSIZE;
 532}
 533#else
 534static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
 535{
 536        return -ENOSYS;
 537}
 538#endif
 539
 540static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 541        __attribute__ ((unused));
 542static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 543{
 544        seq_printf(m, "type         : blkcipher\n");
 545        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 546        seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
 547        seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
 548        seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
 549        seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
 550                                             "<default>");
 551}
 552
 553const struct crypto_type crypto_blkcipher_type = {
 554        .ctxsize = crypto_blkcipher_ctxsize,
 555        .init = crypto_init_blkcipher_ops,
 556#ifdef CONFIG_PROC_FS
 557        .show = crypto_blkcipher_show,
 558#endif
 559        .report = crypto_blkcipher_report,
 560};
 561EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
 562
 563static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
 564                                const char *name, u32 type, u32 mask)
 565{
 566        struct crypto_alg *alg;
 567        int err;
 568
 569        type = crypto_skcipher_type(type);
 570        mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
 571
 572        alg = crypto_alg_mod_lookup(name, type, mask);
 573        if (IS_ERR(alg))
 574                return PTR_ERR(alg);
 575
 576        err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 577        crypto_mod_put(alg);
 578        return err;
 579}
 580
 581struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
 582                                             struct rtattr **tb, u32 type,
 583                                             u32 mask)
 584{
 585        struct {
 586                int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
 587                              unsigned int keylen);
 588                int (*encrypt)(struct ablkcipher_request *req);
 589                int (*decrypt)(struct ablkcipher_request *req);
 590
 591                unsigned int min_keysize;
 592                unsigned int max_keysize;
 593                unsigned int ivsize;
 594
 595                const char *geniv;
 596        } balg;
 597        const char *name;
 598        struct crypto_skcipher_spawn *spawn;
 599        struct crypto_attr_type *algt;
 600        struct crypto_instance *inst;
 601        struct crypto_alg *alg;
 602        int err;
 603
 604        algt = crypto_get_attr_type(tb);
 605        if (IS_ERR(algt))
 606                return ERR_CAST(algt);
 607
 608        if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
 609            algt->mask)
 610                return ERR_PTR(-EINVAL);
 611
 612        name = crypto_attr_alg_name(tb[1]);
 613        if (IS_ERR(name))
 614                return ERR_CAST(name);
 615
 616        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 617        if (!inst)
 618                return ERR_PTR(-ENOMEM);
 619
 620        spawn = crypto_instance_ctx(inst);
 621
 622        /* Ignore async algorithms if necessary. */
 623        mask |= crypto_requires_sync(algt->type, algt->mask);
 624
 625        crypto_set_skcipher_spawn(spawn, inst);
 626        err = crypto_grab_nivcipher(spawn, name, type, mask);
 627        if (err)
 628                goto err_free_inst;
 629
 630        alg = crypto_skcipher_spawn_alg(spawn);
 631
 632        if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
 633            CRYPTO_ALG_TYPE_BLKCIPHER) {
 634                balg.ivsize = alg->cra_blkcipher.ivsize;
 635                balg.min_keysize = alg->cra_blkcipher.min_keysize;
 636                balg.max_keysize = alg->cra_blkcipher.max_keysize;
 637
 638                balg.setkey = async_setkey;
 639                balg.encrypt = async_encrypt;
 640                balg.decrypt = async_decrypt;
 641
 642                balg.geniv = alg->cra_blkcipher.geniv;
 643        } else {
 644                balg.ivsize = alg->cra_ablkcipher.ivsize;
 645                balg.min_keysize = alg->cra_ablkcipher.min_keysize;
 646                balg.max_keysize = alg->cra_ablkcipher.max_keysize;
 647
 648                balg.setkey = alg->cra_ablkcipher.setkey;
 649                balg.encrypt = alg->cra_ablkcipher.encrypt;
 650                balg.decrypt = alg->cra_ablkcipher.decrypt;
 651
 652                balg.geniv = alg->cra_ablkcipher.geniv;
 653        }
 654
 655        err = -EINVAL;
 656        if (!balg.ivsize)
 657                goto err_drop_alg;
 658
 659        /*
 660         * This is only true if we're constructing an algorithm with its
 661         * default IV generator.  For the default generator we elide the
 662         * template name and double-check the IV generator.
 663         */
 664        if (algt->mask & CRYPTO_ALG_GENIV) {
 665                if (!balg.geniv)
 666                        balg.geniv = crypto_default_geniv(alg);
 667                err = -EAGAIN;
 668                if (strcmp(tmpl->name, balg.geniv))
 669                        goto err_drop_alg;
 670
 671                memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 672                memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 673                       CRYPTO_MAX_ALG_NAME);
 674        } else {
 675                err = -ENAMETOOLONG;
 676                if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 677                             "%s(%s)", tmpl->name, alg->cra_name) >=
 678                    CRYPTO_MAX_ALG_NAME)
 679                        goto err_drop_alg;
 680                if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 681                             "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 682                    CRYPTO_MAX_ALG_NAME)
 683                        goto err_drop_alg;
 684        }
 685
 686        inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
 687        inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 688        inst->alg.cra_priority = alg->cra_priority;
 689        inst->alg.cra_blocksize = alg->cra_blocksize;
 690        inst->alg.cra_alignmask = alg->cra_alignmask;
 691        inst->alg.cra_type = &crypto_givcipher_type;
 692
 693        inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
 694        inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
 695        inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
 696        inst->alg.cra_ablkcipher.geniv = balg.geniv;
 697
 698        inst->alg.cra_ablkcipher.setkey = balg.setkey;
 699        inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
 700        inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
 701
 702out:
 703        return inst;
 704
 705err_drop_alg:
 706        crypto_drop_skcipher(spawn);
 707err_free_inst:
 708        kfree(inst);
 709        inst = ERR_PTR(err);
 710        goto out;
 711}
 712EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
 713
 714void skcipher_geniv_free(struct crypto_instance *inst)
 715{
 716        crypto_drop_skcipher(crypto_instance_ctx(inst));
 717        kfree(inst);
 718}
 719EXPORT_SYMBOL_GPL(skcipher_geniv_free);
 720
 721int skcipher_geniv_init(struct crypto_tfm *tfm)
 722{
 723        struct crypto_instance *inst = (void *)tfm->__crt_alg;
 724        struct crypto_ablkcipher *cipher;
 725
 726        cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
 727        if (IS_ERR(cipher))
 728                return PTR_ERR(cipher);
 729
 730        tfm->crt_ablkcipher.base = cipher;
 731        tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
 732
 733        return 0;
 734}
 735EXPORT_SYMBOL_GPL(skcipher_geniv_init);
 736
 737void skcipher_geniv_exit(struct crypto_tfm *tfm)
 738{
 739        crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
 740}
 741EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
 742
 743MODULE_LICENSE("GPL");
 744MODULE_DESCRIPTION("Generic block chaining cipher type");
 745