linux/crypto/shash.c
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   1/*
   2 * Synchronous Cryptographic Hash operations.
   3 *
   4 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License as published by the Free
   8 * Software Foundation; either version 2 of the License, or (at your option)
   9 * any later version.
  10 *
  11 */
  12
  13#include <crypto/scatterwalk.h>
  14#include <crypto/internal/hash.h>
  15#include <linux/err.h>
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/slab.h>
  19#include <linux/seq_file.h>
  20#include <linux/cryptouser.h>
  21#include <net/netlink.h>
  22
  23#include "internal.h"
  24
  25static const struct crypto_type crypto_shash_type;
  26
  27static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  28                           unsigned int keylen)
  29{
  30        return -ENOSYS;
  31}
  32
  33static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  34                                  unsigned int keylen)
  35{
  36        struct shash_alg *shash = crypto_shash_alg(tfm);
  37        unsigned long alignmask = crypto_shash_alignmask(tfm);
  38        unsigned long absize;
  39        u8 *buffer, *alignbuffer;
  40        int err;
  41
  42        absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  43        buffer = kmalloc(absize, GFP_KERNEL);
  44        if (!buffer)
  45                return -ENOMEM;
  46
  47        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  48        memcpy(alignbuffer, key, keylen);
  49        err = shash->setkey(tfm, alignbuffer, keylen);
  50        kzfree(buffer);
  51        return err;
  52}
  53
  54int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  55                        unsigned int keylen)
  56{
  57        struct shash_alg *shash = crypto_shash_alg(tfm);
  58        unsigned long alignmask = crypto_shash_alignmask(tfm);
  59
  60        if ((unsigned long)key & alignmask)
  61                return shash_setkey_unaligned(tfm, key, keylen);
  62
  63        return shash->setkey(tfm, key, keylen);
  64}
  65EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  66
  67static inline unsigned int shash_align_buffer_size(unsigned len,
  68                                                   unsigned long mask)
  69{
  70        typedef u8 __attribute__ ((aligned)) u8_aligned;
  71        return len + (mask & ~(__alignof__(u8_aligned) - 1));
  72}
  73
  74static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  75                                  unsigned int len)
  76{
  77        struct crypto_shash *tfm = desc->tfm;
  78        struct shash_alg *shash = crypto_shash_alg(tfm);
  79        unsigned long alignmask = crypto_shash_alignmask(tfm);
  80        unsigned int unaligned_len = alignmask + 1 -
  81                                     ((unsigned long)data & alignmask);
  82        u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  83                __attribute__ ((aligned));
  84        u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  85        int err;
  86
  87        if (unaligned_len > len)
  88                unaligned_len = len;
  89
  90        memcpy(buf, data, unaligned_len);
  91        err = shash->update(desc, buf, unaligned_len);
  92        memset(buf, 0, unaligned_len);
  93
  94        return err ?:
  95               shash->update(desc, data + unaligned_len, len - unaligned_len);
  96}
  97
  98int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  99                        unsigned int len)
 100{
 101        struct crypto_shash *tfm = desc->tfm;
 102        struct shash_alg *shash = crypto_shash_alg(tfm);
 103        unsigned long alignmask = crypto_shash_alignmask(tfm);
 104
 105        if ((unsigned long)data & alignmask)
 106                return shash_update_unaligned(desc, data, len);
 107
 108        return shash->update(desc, data, len);
 109}
 110EXPORT_SYMBOL_GPL(crypto_shash_update);
 111
 112static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 113{
 114        struct crypto_shash *tfm = desc->tfm;
 115        unsigned long alignmask = crypto_shash_alignmask(tfm);
 116        struct shash_alg *shash = crypto_shash_alg(tfm);
 117        unsigned int ds = crypto_shash_digestsize(tfm);
 118        u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 119                __attribute__ ((aligned));
 120        u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 121        int err;
 122
 123        err = shash->final(desc, buf);
 124        if (err)
 125                goto out;
 126
 127        memcpy(out, buf, ds);
 128
 129out:
 130        memset(buf, 0, ds);
 131        return err;
 132}
 133
 134int crypto_shash_final(struct shash_desc *desc, u8 *out)
 135{
 136        struct crypto_shash *tfm = desc->tfm;
 137        struct shash_alg *shash = crypto_shash_alg(tfm);
 138        unsigned long alignmask = crypto_shash_alignmask(tfm);
 139
 140        if ((unsigned long)out & alignmask)
 141                return shash_final_unaligned(desc, out);
 142
 143        return shash->final(desc, out);
 144}
 145EXPORT_SYMBOL_GPL(crypto_shash_final);
 146
 147static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 148                                 unsigned int len, u8 *out)
 149{
 150        return crypto_shash_update(desc, data, len) ?:
 151               crypto_shash_final(desc, out);
 152}
 153
 154int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 155                       unsigned int len, u8 *out)
 156{
 157        struct crypto_shash *tfm = desc->tfm;
 158        struct shash_alg *shash = crypto_shash_alg(tfm);
 159        unsigned long alignmask = crypto_shash_alignmask(tfm);
 160
 161        if (((unsigned long)data | (unsigned long)out) & alignmask)
 162                return shash_finup_unaligned(desc, data, len, out);
 163
 164        return shash->finup(desc, data, len, out);
 165}
 166EXPORT_SYMBOL_GPL(crypto_shash_finup);
 167
 168static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 169                                  unsigned int len, u8 *out)
 170{
 171        return crypto_shash_init(desc) ?:
 172               crypto_shash_finup(desc, data, len, out);
 173}
 174
 175int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 176                        unsigned int len, u8 *out)
 177{
 178        struct crypto_shash *tfm = desc->tfm;
 179        struct shash_alg *shash = crypto_shash_alg(tfm);
 180        unsigned long alignmask = crypto_shash_alignmask(tfm);
 181
 182        if (((unsigned long)data | (unsigned long)out) & alignmask)
 183                return shash_digest_unaligned(desc, data, len, out);
 184
 185        return shash->digest(desc, data, len, out);
 186}
 187EXPORT_SYMBOL_GPL(crypto_shash_digest);
 188
 189static int shash_default_export(struct shash_desc *desc, void *out)
 190{
 191        memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 192        return 0;
 193}
 194
 195static int shash_default_import(struct shash_desc *desc, const void *in)
 196{
 197        memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 198        return 0;
 199}
 200
 201static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 202                              unsigned int keylen)
 203{
 204        struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 205
 206        return crypto_shash_setkey(*ctx, key, keylen);
 207}
 208
 209static int shash_async_init(struct ahash_request *req)
 210{
 211        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 212        struct shash_desc *desc = ahash_request_ctx(req);
 213
 214        desc->tfm = *ctx;
 215        desc->flags = req->base.flags;
 216
 217        return crypto_shash_init(desc);
 218}
 219
 220int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 221{
 222        struct crypto_hash_walk walk;
 223        int nbytes;
 224
 225        for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 226             nbytes = crypto_hash_walk_done(&walk, nbytes))
 227                nbytes = crypto_shash_update(desc, walk.data, nbytes);
 228
 229        return nbytes;
 230}
 231EXPORT_SYMBOL_GPL(shash_ahash_update);
 232
 233static int shash_async_update(struct ahash_request *req)
 234{
 235        return shash_ahash_update(req, ahash_request_ctx(req));
 236}
 237
 238static int shash_async_final(struct ahash_request *req)
 239{
 240        return crypto_shash_final(ahash_request_ctx(req), req->result);
 241}
 242
 243int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 244{
 245        struct crypto_hash_walk walk;
 246        int nbytes;
 247
 248        nbytes = crypto_hash_walk_first(req, &walk);
 249        if (!nbytes)
 250                return crypto_shash_final(desc, req->result);
 251
 252        do {
 253                nbytes = crypto_hash_walk_last(&walk) ?
 254                         crypto_shash_finup(desc, walk.data, nbytes,
 255                                            req->result) :
 256                         crypto_shash_update(desc, walk.data, nbytes);
 257                nbytes = crypto_hash_walk_done(&walk, nbytes);
 258        } while (nbytes > 0);
 259
 260        return nbytes;
 261}
 262EXPORT_SYMBOL_GPL(shash_ahash_finup);
 263
 264static int shash_async_finup(struct ahash_request *req)
 265{
 266        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 267        struct shash_desc *desc = ahash_request_ctx(req);
 268
 269        desc->tfm = *ctx;
 270        desc->flags = req->base.flags;
 271
 272        return shash_ahash_finup(req, desc);
 273}
 274
 275int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 276{
 277        struct scatterlist *sg = req->src;
 278        unsigned int offset = sg->offset;
 279        unsigned int nbytes = req->nbytes;
 280        int err;
 281
 282        if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 283                void *data;
 284
 285                data = kmap_atomic(sg_page(sg));
 286                err = crypto_shash_digest(desc, data + offset, nbytes,
 287                                          req->result);
 288                kunmap_atomic(data);
 289                crypto_yield(desc->flags);
 290        } else
 291                err = crypto_shash_init(desc) ?:
 292                      shash_ahash_finup(req, desc);
 293
 294        return err;
 295}
 296EXPORT_SYMBOL_GPL(shash_ahash_digest);
 297
 298static int shash_async_digest(struct ahash_request *req)
 299{
 300        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 301        struct shash_desc *desc = ahash_request_ctx(req);
 302
 303        desc->tfm = *ctx;
 304        desc->flags = req->base.flags;
 305
 306        return shash_ahash_digest(req, desc);
 307}
 308
 309static int shash_async_export(struct ahash_request *req, void *out)
 310{
 311        return crypto_shash_export(ahash_request_ctx(req), out);
 312}
 313
 314static int shash_async_import(struct ahash_request *req, const void *in)
 315{
 316        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 317        struct shash_desc *desc = ahash_request_ctx(req);
 318
 319        desc->tfm = *ctx;
 320        desc->flags = req->base.flags;
 321
 322        return crypto_shash_import(desc, in);
 323}
 324
 325static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 326{
 327        struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 328
 329        crypto_free_shash(*ctx);
 330}
 331
 332int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 333{
 334        struct crypto_alg *calg = tfm->__crt_alg;
 335        struct shash_alg *alg = __crypto_shash_alg(calg);
 336        struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 337        struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 338        struct crypto_shash *shash;
 339
 340        if (!crypto_mod_get(calg))
 341                return -EAGAIN;
 342
 343        shash = crypto_create_tfm(calg, &crypto_shash_type);
 344        if (IS_ERR(shash)) {
 345                crypto_mod_put(calg);
 346                return PTR_ERR(shash);
 347        }
 348
 349        *ctx = shash;
 350        tfm->exit = crypto_exit_shash_ops_async;
 351
 352        crt->init = shash_async_init;
 353        crt->update = shash_async_update;
 354        crt->final = shash_async_final;
 355        crt->finup = shash_async_finup;
 356        crt->digest = shash_async_digest;
 357        crt->setkey = shash_async_setkey;
 358
 359        crt->has_setkey = alg->setkey != shash_no_setkey;
 360
 361        if (alg->export)
 362                crt->export = shash_async_export;
 363        if (alg->import)
 364                crt->import = shash_async_import;
 365
 366        crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 367
 368        return 0;
 369}
 370
 371static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 372{
 373        struct crypto_shash *hash = __crypto_shash_cast(tfm);
 374
 375        hash->descsize = crypto_shash_alg(hash)->descsize;
 376        return 0;
 377}
 378
 379#ifdef CONFIG_NET
 380static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 381{
 382        struct crypto_report_hash rhash;
 383        struct shash_alg *salg = __crypto_shash_alg(alg);
 384
 385        strncpy(rhash.type, "shash", sizeof(rhash.type));
 386
 387        rhash.blocksize = alg->cra_blocksize;
 388        rhash.digestsize = salg->digestsize;
 389
 390        if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 391                    sizeof(struct crypto_report_hash), &rhash))
 392                goto nla_put_failure;
 393        return 0;
 394
 395nla_put_failure:
 396        return -EMSGSIZE;
 397}
 398#else
 399static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 400{
 401        return -ENOSYS;
 402}
 403#endif
 404
 405static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 406        __attribute__ ((unused));
 407static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 408{
 409        struct shash_alg *salg = __crypto_shash_alg(alg);
 410
 411        seq_printf(m, "type         : shash\n");
 412        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 413        seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 414}
 415
 416static const struct crypto_type crypto_shash_type = {
 417        .extsize = crypto_alg_extsize,
 418        .init_tfm = crypto_shash_init_tfm,
 419#ifdef CONFIG_PROC_FS
 420        .show = crypto_shash_show,
 421#endif
 422        .report = crypto_shash_report,
 423        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 424        .maskset = CRYPTO_ALG_TYPE_MASK,
 425        .type = CRYPTO_ALG_TYPE_SHASH,
 426        .tfmsize = offsetof(struct crypto_shash, base),
 427};
 428
 429struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 430                                        u32 mask)
 431{
 432        return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 433}
 434EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 435
 436static int shash_prepare_alg(struct shash_alg *alg)
 437{
 438        struct crypto_alg *base = &alg->base;
 439
 440        if (alg->digestsize > PAGE_SIZE / 8 ||
 441            alg->descsize > PAGE_SIZE / 8 ||
 442            alg->statesize > PAGE_SIZE / 8)
 443                return -EINVAL;
 444
 445        base->cra_type = &crypto_shash_type;
 446        base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 447        base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 448
 449        if (!alg->finup)
 450                alg->finup = shash_finup_unaligned;
 451        if (!alg->digest)
 452                alg->digest = shash_digest_unaligned;
 453        if (!alg->export) {
 454                alg->export = shash_default_export;
 455                alg->import = shash_default_import;
 456                alg->statesize = alg->descsize;
 457        }
 458        if (!alg->setkey)
 459                alg->setkey = shash_no_setkey;
 460
 461        return 0;
 462}
 463
 464int crypto_register_shash(struct shash_alg *alg)
 465{
 466        struct crypto_alg *base = &alg->base;
 467        int err;
 468
 469        err = shash_prepare_alg(alg);
 470        if (err)
 471                return err;
 472
 473        return crypto_register_alg(base);
 474}
 475EXPORT_SYMBOL_GPL(crypto_register_shash);
 476
 477int crypto_unregister_shash(struct shash_alg *alg)
 478{
 479        return crypto_unregister_alg(&alg->base);
 480}
 481EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 482
 483int crypto_register_shashes(struct shash_alg *algs, int count)
 484{
 485        int i, ret;
 486
 487        for (i = 0; i < count; i++) {
 488                ret = crypto_register_shash(&algs[i]);
 489                if (ret)
 490                        goto err;
 491        }
 492
 493        return 0;
 494
 495err:
 496        for (--i; i >= 0; --i)
 497                crypto_unregister_shash(&algs[i]);
 498
 499        return ret;
 500}
 501EXPORT_SYMBOL_GPL(crypto_register_shashes);
 502
 503int crypto_unregister_shashes(struct shash_alg *algs, int count)
 504{
 505        int i, ret;
 506
 507        for (i = count - 1; i >= 0; --i) {
 508                ret = crypto_unregister_shash(&algs[i]);
 509                if (ret)
 510                        pr_err("Failed to unregister %s %s: %d\n",
 511                               algs[i].base.cra_driver_name,
 512                               algs[i].base.cra_name, ret);
 513        }
 514
 515        return 0;
 516}
 517EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 518
 519int shash_register_instance(struct crypto_template *tmpl,
 520                            struct shash_instance *inst)
 521{
 522        int err;
 523
 524        err = shash_prepare_alg(&inst->alg);
 525        if (err)
 526                return err;
 527
 528        return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 529}
 530EXPORT_SYMBOL_GPL(shash_register_instance);
 531
 532void shash_free_instance(struct crypto_instance *inst)
 533{
 534        crypto_drop_spawn(crypto_instance_ctx(inst));
 535        kfree(shash_instance(inst));
 536}
 537EXPORT_SYMBOL_GPL(shash_free_instance);
 538
 539int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 540                            struct shash_alg *alg,
 541                            struct crypto_instance *inst)
 542{
 543        return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 544                                  &crypto_shash_type);
 545}
 546EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 547
 548struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 549{
 550        struct crypto_alg *alg;
 551
 552        alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 553        return IS_ERR(alg) ? ERR_CAST(alg) :
 554               container_of(alg, struct shash_alg, base);
 555}
 556EXPORT_SYMBOL_GPL(shash_attr_alg);
 557
 558MODULE_LICENSE("GPL");
 559MODULE_DESCRIPTION("Synchronous cryptographic hash type");
 560