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#include <linux/compiler.h>
  23
  24#include "internal.h"
  25
  26static const struct crypto_type crypto_shash_type;
  27
  28int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
  29                    unsigned int keylen)
  30{
  31        return -ENOSYS;
  32}
  33EXPORT_SYMBOL_GPL(shash_no_setkey);
  34
  35static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  36                                  unsigned int keylen)
  37{
  38        struct shash_alg *shash = crypto_shash_alg(tfm);
  39        unsigned long alignmask = crypto_shash_alignmask(tfm);
  40        unsigned long absize;
  41        u8 *buffer, *alignbuffer;
  42        int err;
  43
  44        absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
  45        buffer = kmalloc(absize, GFP_ATOMIC);
  46        if (!buffer)
  47                return -ENOMEM;
  48
  49        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  50        memcpy(alignbuffer, key, keylen);
  51        err = shash->setkey(tfm, alignbuffer, keylen);
  52        kzfree(buffer);
  53        return err;
  54}
  55
  56int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  57                        unsigned int keylen)
  58{
  59        struct shash_alg *shash = crypto_shash_alg(tfm);
  60        unsigned long alignmask = crypto_shash_alignmask(tfm);
  61        int err;
  62
  63        if ((unsigned long)key & alignmask)
  64                err = shash_setkey_unaligned(tfm, key, keylen);
  65        else
  66                err = shash->setkey(tfm, key, keylen);
  67
  68        if (err)
  69                return err;
  70
  71        crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  72        return 0;
  73}
  74EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  75
  76static inline unsigned int shash_align_buffer_size(unsigned len,
  77                                                   unsigned long mask)
  78{
  79        typedef u8 __aligned_largest u8_aligned;
  80        return len + (mask & ~(__alignof__(u8_aligned) - 1));
  81}
  82
  83static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  84                                  unsigned int len)
  85{
  86        struct crypto_shash *tfm = desc->tfm;
  87        struct shash_alg *shash = crypto_shash_alg(tfm);
  88        unsigned long alignmask = crypto_shash_alignmask(tfm);
  89        unsigned int unaligned_len = alignmask + 1 -
  90                                     ((unsigned long)data & alignmask);
  91        u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
  92                __aligned_largest;
  93        u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
  94        int err;
  95
  96        if (unaligned_len > len)
  97                unaligned_len = len;
  98
  99        memcpy(buf, data, unaligned_len);
 100        err = shash->update(desc, buf, unaligned_len);
 101        memset(buf, 0, unaligned_len);
 102
 103        return err ?:
 104               shash->update(desc, data + unaligned_len, len - unaligned_len);
 105}
 106
 107int crypto_shash_update(struct shash_desc *desc, const u8 *data,
 108                        unsigned int len)
 109{
 110        struct crypto_shash *tfm = desc->tfm;
 111        struct shash_alg *shash = crypto_shash_alg(tfm);
 112        unsigned long alignmask = crypto_shash_alignmask(tfm);
 113
 114        if ((unsigned long)data & alignmask)
 115                return shash_update_unaligned(desc, data, len);
 116
 117        return shash->update(desc, data, len);
 118}
 119EXPORT_SYMBOL_GPL(crypto_shash_update);
 120
 121static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 122{
 123        struct crypto_shash *tfm = desc->tfm;
 124        unsigned long alignmask = crypto_shash_alignmask(tfm);
 125        struct shash_alg *shash = crypto_shash_alg(tfm);
 126        unsigned int ds = crypto_shash_digestsize(tfm);
 127        u8 ubuf[shash_align_buffer_size(ds, alignmask)]
 128                __aligned_largest;
 129        u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 130        int err;
 131
 132        err = shash->final(desc, buf);
 133        if (err)
 134                goto out;
 135
 136        memcpy(out, buf, ds);
 137
 138out:
 139        memset(buf, 0, ds);
 140        return err;
 141}
 142
 143int crypto_shash_final(struct shash_desc *desc, u8 *out)
 144{
 145        struct crypto_shash *tfm = desc->tfm;
 146        struct shash_alg *shash = crypto_shash_alg(tfm);
 147        unsigned long alignmask = crypto_shash_alignmask(tfm);
 148
 149        if ((unsigned long)out & alignmask)
 150                return shash_final_unaligned(desc, out);
 151
 152        return shash->final(desc, out);
 153}
 154EXPORT_SYMBOL_GPL(crypto_shash_final);
 155
 156static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 157                                 unsigned int len, u8 *out)
 158{
 159        return crypto_shash_update(desc, data, len) ?:
 160               crypto_shash_final(desc, out);
 161}
 162
 163int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 164                       unsigned int len, u8 *out)
 165{
 166        struct crypto_shash *tfm = desc->tfm;
 167        struct shash_alg *shash = crypto_shash_alg(tfm);
 168        unsigned long alignmask = crypto_shash_alignmask(tfm);
 169
 170        if (((unsigned long)data | (unsigned long)out) & alignmask)
 171                return shash_finup_unaligned(desc, data, len, out);
 172
 173        return shash->finup(desc, data, len, out);
 174}
 175EXPORT_SYMBOL_GPL(crypto_shash_finup);
 176
 177static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 178                                  unsigned int len, u8 *out)
 179{
 180        return crypto_shash_init(desc) ?:
 181               crypto_shash_finup(desc, data, len, out);
 182}
 183
 184int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 185                        unsigned int len, u8 *out)
 186{
 187        struct crypto_shash *tfm = desc->tfm;
 188        struct shash_alg *shash = crypto_shash_alg(tfm);
 189        unsigned long alignmask = crypto_shash_alignmask(tfm);
 190
 191        if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
 192                return -ENOKEY;
 193
 194        if (((unsigned long)data | (unsigned long)out) & alignmask)
 195                return shash_digest_unaligned(desc, data, len, out);
 196
 197        return shash->digest(desc, data, len, out);
 198}
 199EXPORT_SYMBOL_GPL(crypto_shash_digest);
 200
 201static int shash_default_export(struct shash_desc *desc, void *out)
 202{
 203        memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
 204        return 0;
 205}
 206
 207static int shash_default_import(struct shash_desc *desc, const void *in)
 208{
 209        memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
 210        return 0;
 211}
 212
 213static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 214                              unsigned int keylen)
 215{
 216        struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 217
 218        return crypto_shash_setkey(*ctx, key, keylen);
 219}
 220
 221static int shash_async_init(struct ahash_request *req)
 222{
 223        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 224        struct shash_desc *desc = ahash_request_ctx(req);
 225
 226        desc->tfm = *ctx;
 227        desc->flags = req->base.flags;
 228
 229        return crypto_shash_init(desc);
 230}
 231
 232int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
 233{
 234        struct crypto_hash_walk walk;
 235        int nbytes;
 236
 237        for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 238             nbytes = crypto_hash_walk_done(&walk, nbytes))
 239                nbytes = crypto_shash_update(desc, walk.data, nbytes);
 240
 241        return nbytes;
 242}
 243EXPORT_SYMBOL_GPL(shash_ahash_update);
 244
 245static int shash_async_update(struct ahash_request *req)
 246{
 247        return shash_ahash_update(req, ahash_request_ctx(req));
 248}
 249
 250static int shash_async_final(struct ahash_request *req)
 251{
 252        return crypto_shash_final(ahash_request_ctx(req), req->result);
 253}
 254
 255int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
 256{
 257        struct crypto_hash_walk walk;
 258        int nbytes;
 259
 260        nbytes = crypto_hash_walk_first(req, &walk);
 261        if (!nbytes)
 262                return crypto_shash_final(desc, req->result);
 263
 264        do {
 265                nbytes = crypto_hash_walk_last(&walk) ?
 266                         crypto_shash_finup(desc, walk.data, nbytes,
 267                                            req->result) :
 268                         crypto_shash_update(desc, walk.data, nbytes);
 269                nbytes = crypto_hash_walk_done(&walk, nbytes);
 270        } while (nbytes > 0);
 271
 272        return nbytes;
 273}
 274EXPORT_SYMBOL_GPL(shash_ahash_finup);
 275
 276static int shash_async_finup(struct ahash_request *req)
 277{
 278        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 279        struct shash_desc *desc = ahash_request_ctx(req);
 280
 281        desc->tfm = *ctx;
 282        desc->flags = req->base.flags;
 283
 284        return shash_ahash_finup(req, desc);
 285}
 286
 287int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 288{
 289        unsigned int nbytes = req->nbytes;
 290        struct scatterlist *sg;
 291        unsigned int offset;
 292        int err;
 293
 294        if (nbytes &&
 295            (sg = req->src, offset = sg->offset,
 296             nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 297                void *data;
 298
 299                data = kmap_atomic(sg_page(sg));
 300                err = crypto_shash_digest(desc, data + offset, nbytes,
 301                                          req->result);
 302                kunmap_atomic(data);
 303                crypto_yield(desc->flags);
 304        } else
 305                err = crypto_shash_init(desc) ?:
 306                      shash_ahash_finup(req, desc);
 307
 308        return err;
 309}
 310EXPORT_SYMBOL_GPL(shash_ahash_digest);
 311
 312static int shash_async_digest(struct ahash_request *req)
 313{
 314        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 315        struct shash_desc *desc = ahash_request_ctx(req);
 316
 317        desc->tfm = *ctx;
 318        desc->flags = req->base.flags;
 319
 320        return shash_ahash_digest(req, desc);
 321}
 322
 323static int shash_async_export(struct ahash_request *req, void *out)
 324{
 325        return crypto_shash_export(ahash_request_ctx(req), out);
 326}
 327
 328static int shash_async_import(struct ahash_request *req, const void *in)
 329{
 330        struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 331        struct shash_desc *desc = ahash_request_ctx(req);
 332
 333        desc->tfm = *ctx;
 334        desc->flags = req->base.flags;
 335
 336        return crypto_shash_import(desc, in);
 337}
 338
 339static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 340{
 341        struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 342
 343        crypto_free_shash(*ctx);
 344}
 345
 346int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 347{
 348        struct crypto_alg *calg = tfm->__crt_alg;
 349        struct shash_alg *alg = __crypto_shash_alg(calg);
 350        struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 351        struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 352        struct crypto_shash *shash;
 353
 354        if (!crypto_mod_get(calg))
 355                return -EAGAIN;
 356
 357        shash = crypto_create_tfm(calg, &crypto_shash_type);
 358        if (IS_ERR(shash)) {
 359                crypto_mod_put(calg);
 360                return PTR_ERR(shash);
 361        }
 362
 363        *ctx = shash;
 364        tfm->exit = crypto_exit_shash_ops_async;
 365
 366        crt->init = shash_async_init;
 367        crt->update = shash_async_update;
 368        crt->final = shash_async_final;
 369        crt->finup = shash_async_finup;
 370        crt->digest = shash_async_digest;
 371        crt->setkey = shash_async_setkey;
 372
 373        crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
 374                                    CRYPTO_TFM_NEED_KEY);
 375
 376        if (alg->export)
 377                crt->export = shash_async_export;
 378        if (alg->import)
 379                crt->import = shash_async_import;
 380
 381        crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 382
 383        return 0;
 384}
 385
 386static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
 387{
 388        struct crypto_shash *hash = __crypto_shash_cast(tfm);
 389        struct shash_alg *alg = crypto_shash_alg(hash);
 390
 391        hash->descsize = alg->descsize;
 392
 393        if (crypto_shash_alg_has_setkey(alg) &&
 394            !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
 395                crypto_shash_set_flags(hash, CRYPTO_TFM_NEED_KEY);
 396
 397        return 0;
 398}
 399
 400#ifdef CONFIG_NET
 401static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 402{
 403        struct crypto_report_hash rhash;
 404        struct shash_alg *salg = __crypto_shash_alg(alg);
 405
 406        strncpy(rhash.type, "shash", sizeof(rhash.type));
 407
 408        rhash.blocksize = alg->cra_blocksize;
 409        rhash.digestsize = salg->digestsize;
 410
 411        if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 412                    sizeof(struct crypto_report_hash), &rhash))
 413                goto nla_put_failure;
 414        return 0;
 415
 416nla_put_failure:
 417        return -EMSGSIZE;
 418}
 419#else
 420static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
 421{
 422        return -ENOSYS;
 423}
 424#endif
 425
 426static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 427        __maybe_unused;
 428static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 429{
 430        struct shash_alg *salg = __crypto_shash_alg(alg);
 431
 432        seq_printf(m, "type         : shash\n");
 433        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 434        seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 435}
 436
 437static const struct crypto_type crypto_shash_type = {
 438        .extsize = crypto_alg_extsize,
 439        .init_tfm = crypto_shash_init_tfm,
 440#ifdef CONFIG_PROC_FS
 441        .show = crypto_shash_show,
 442#endif
 443        .report = crypto_shash_report,
 444        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 445        .maskset = CRYPTO_ALG_TYPE_MASK,
 446        .type = CRYPTO_ALG_TYPE_SHASH,
 447        .tfmsize = offsetof(struct crypto_shash, base),
 448};
 449
 450struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 451                                        u32 mask)
 452{
 453        return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 454}
 455EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 456
 457static int shash_prepare_alg(struct shash_alg *alg)
 458{
 459        struct crypto_alg *base = &alg->base;
 460
 461        if (alg->digestsize > PAGE_SIZE / 8 ||
 462            alg->descsize > PAGE_SIZE / 8 ||
 463            alg->statesize > PAGE_SIZE / 8)
 464                return -EINVAL;
 465
 466        base->cra_type = &crypto_shash_type;
 467        base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 468        base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 469
 470        if (!alg->finup)
 471                alg->finup = shash_finup_unaligned;
 472        if (!alg->digest)
 473                alg->digest = shash_digest_unaligned;
 474        if (!alg->export) {
 475                alg->export = shash_default_export;
 476                alg->import = shash_default_import;
 477                alg->statesize = alg->descsize;
 478        }
 479        if (!alg->setkey)
 480                alg->setkey = shash_no_setkey;
 481
 482        return 0;
 483}
 484
 485int crypto_register_shash(struct shash_alg *alg)
 486{
 487        struct crypto_alg *base = &alg->base;
 488        int err;
 489
 490        err = shash_prepare_alg(alg);
 491        if (err)
 492                return err;
 493
 494        return crypto_register_alg(base);
 495}
 496EXPORT_SYMBOL_GPL(crypto_register_shash);
 497
 498int crypto_unregister_shash(struct shash_alg *alg)
 499{
 500        return crypto_unregister_alg(&alg->base);
 501}
 502EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 503
 504int crypto_register_shashes(struct shash_alg *algs, int count)
 505{
 506        int i, ret;
 507
 508        for (i = 0; i < count; i++) {
 509                ret = crypto_register_shash(&algs[i]);
 510                if (ret)
 511                        goto err;
 512        }
 513
 514        return 0;
 515
 516err:
 517        for (--i; i >= 0; --i)
 518                crypto_unregister_shash(&algs[i]);
 519
 520        return ret;
 521}
 522EXPORT_SYMBOL_GPL(crypto_register_shashes);
 523
 524int crypto_unregister_shashes(struct shash_alg *algs, int count)
 525{
 526        int i, ret;
 527
 528        for (i = count - 1; i >= 0; --i) {
 529                ret = crypto_unregister_shash(&algs[i]);
 530                if (ret)
 531                        pr_err("Failed to unregister %s %s: %d\n",
 532                               algs[i].base.cra_driver_name,
 533                               algs[i].base.cra_name, ret);
 534        }
 535
 536        return 0;
 537}
 538EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
 539
 540int shash_register_instance(struct crypto_template *tmpl,
 541                            struct shash_instance *inst)
 542{
 543        int err;
 544
 545        err = shash_prepare_alg(&inst->alg);
 546        if (err)
 547                return err;
 548
 549        return crypto_register_instance(tmpl, shash_crypto_instance(inst));
 550}
 551EXPORT_SYMBOL_GPL(shash_register_instance);
 552
 553void shash_free_instance(struct crypto_instance *inst)
 554{
 555        crypto_drop_spawn(crypto_instance_ctx(inst));
 556        kfree(shash_instance(inst));
 557}
 558EXPORT_SYMBOL_GPL(shash_free_instance);
 559
 560int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
 561                            struct shash_alg *alg,
 562                            struct crypto_instance *inst)
 563{
 564        return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 565                                  &crypto_shash_type);
 566}
 567EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
 568
 569struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 570{
 571        struct crypto_alg *alg;
 572
 573        alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
 574        return IS_ERR(alg) ? ERR_CAST(alg) :
 575               container_of(alg, struct shash_alg, base);
 576}
 577EXPORT_SYMBOL_GPL(shash_attr_alg);
 578
 579MODULE_LICENSE("GPL");
 580MODULE_DESCRIPTION("Synchronous cryptographic hash type");
 581