linux/crypto/ahash.c
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   1/*
   2 * Asynchronous Cryptographic Hash operations.
   3 *
   4 * This is the asynchronous version of hash.c with notification of
   5 * completion via a callback.
   6 *
   7 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the Free
  11 * Software Foundation; either version 2 of the License, or (at your option)
  12 * any later version.
  13 *
  14 */
  15
  16#include <crypto/internal/hash.h>
  17#include <crypto/scatterwalk.h>
  18#include <linux/err.h>
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/sched.h>
  22#include <linux/slab.h>
  23#include <linux/seq_file.h>
  24#include <linux/cryptouser.h>
  25#include <net/netlink.h>
  26
  27#include "internal.h"
  28
  29struct ahash_request_priv {
  30        crypto_completion_t complete;
  31        void *data;
  32        u8 *result;
  33        void *ubuf[] CRYPTO_MINALIGN_ATTR;
  34};
  35
  36static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
  37{
  38        return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
  39                            halg);
  40}
  41
  42static int hash_walk_next(struct crypto_hash_walk *walk)
  43{
  44        unsigned int alignmask = walk->alignmask;
  45        unsigned int offset = walk->offset;
  46        unsigned int nbytes = min(walk->entrylen,
  47                                  ((unsigned int)(PAGE_SIZE)) - offset);
  48
  49        walk->data = kmap_atomic(walk->pg);
  50        walk->data += offset;
  51
  52        if (offset & alignmask) {
  53                unsigned int unaligned = alignmask + 1 - (offset & alignmask);
  54                if (nbytes > unaligned)
  55                        nbytes = unaligned;
  56        }
  57
  58        walk->entrylen -= nbytes;
  59        return nbytes;
  60}
  61
  62static int hash_walk_new_entry(struct crypto_hash_walk *walk)
  63{
  64        struct scatterlist *sg;
  65
  66        sg = walk->sg;
  67        walk->pg = sg_page(sg);
  68        walk->offset = sg->offset;
  69        walk->entrylen = sg->length;
  70
  71        if (walk->entrylen > walk->total)
  72                walk->entrylen = walk->total;
  73        walk->total -= walk->entrylen;
  74
  75        return hash_walk_next(walk);
  76}
  77
  78int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
  79{
  80        unsigned int alignmask = walk->alignmask;
  81        unsigned int nbytes = walk->entrylen;
  82
  83        walk->data -= walk->offset;
  84
  85        if (nbytes && walk->offset & alignmask && !err) {
  86                walk->offset = ALIGN(walk->offset, alignmask + 1);
  87                walk->data += walk->offset;
  88
  89                nbytes = min(nbytes,
  90                             ((unsigned int)(PAGE_SIZE)) - walk->offset);
  91                walk->entrylen -= nbytes;
  92
  93                return nbytes;
  94        }
  95
  96        kunmap_atomic(walk->data);
  97        crypto_yield(walk->flags);
  98
  99        if (err)
 100                return err;
 101
 102        if (nbytes) {
 103                walk->offset = 0;
 104                walk->pg++;
 105                return hash_walk_next(walk);
 106        }
 107
 108        if (!walk->total)
 109                return 0;
 110
 111        walk->sg = scatterwalk_sg_next(walk->sg);
 112
 113        return hash_walk_new_entry(walk);
 114}
 115EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
 116
 117int crypto_hash_walk_first(struct ahash_request *req,
 118                           struct crypto_hash_walk *walk)
 119{
 120        walk->total = req->nbytes;
 121
 122        if (!walk->total)
 123                return 0;
 124
 125        walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
 126        walk->sg = req->src;
 127        walk->flags = req->base.flags;
 128
 129        return hash_walk_new_entry(walk);
 130}
 131EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
 132
 133int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
 134                                  struct crypto_hash_walk *walk,
 135                                  struct scatterlist *sg, unsigned int len)
 136{
 137        walk->total = len;
 138
 139        if (!walk->total)
 140                return 0;
 141
 142        walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
 143        walk->sg = sg;
 144        walk->flags = hdesc->flags;
 145
 146        return hash_walk_new_entry(walk);
 147}
 148
 149static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
 150                                unsigned int keylen)
 151{
 152        unsigned long alignmask = crypto_ahash_alignmask(tfm);
 153        int ret;
 154        u8 *buffer, *alignbuffer;
 155        unsigned long absize;
 156
 157        absize = keylen + alignmask;
 158        buffer = kmalloc(absize, GFP_KERNEL);
 159        if (!buffer)
 160                return -ENOMEM;
 161
 162        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 163        memcpy(alignbuffer, key, keylen);
 164        ret = tfm->setkey(tfm, alignbuffer, keylen);
 165        kzfree(buffer);
 166        return ret;
 167}
 168
 169int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 170                        unsigned int keylen)
 171{
 172        unsigned long alignmask = crypto_ahash_alignmask(tfm);
 173
 174        if ((unsigned long)key & alignmask)
 175                return ahash_setkey_unaligned(tfm, key, keylen);
 176
 177        return tfm->setkey(tfm, key, keylen);
 178}
 179EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 180
 181static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 182                          unsigned int keylen)
 183{
 184        return -ENOSYS;
 185}
 186
 187static inline unsigned int ahash_align_buffer_size(unsigned len,
 188                                                   unsigned long mask)
 189{
 190        return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
 191}
 192
 193static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
 194{
 195        struct ahash_request_priv *priv = req->priv;
 196
 197        if (err == -EINPROGRESS)
 198                return;
 199
 200        if (!err)
 201                memcpy(priv->result, req->result,
 202                       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 203
 204        kzfree(priv);
 205}
 206
 207static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
 208{
 209        struct ahash_request *areq = req->data;
 210        struct ahash_request_priv *priv = areq->priv;
 211        crypto_completion_t complete = priv->complete;
 212        void *data = priv->data;
 213
 214        ahash_op_unaligned_finish(areq, err);
 215
 216        complete(data, err);
 217}
 218
 219static int ahash_op_unaligned(struct ahash_request *req,
 220                              int (*op)(struct ahash_request *))
 221{
 222        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 223        unsigned long alignmask = crypto_ahash_alignmask(tfm);
 224        unsigned int ds = crypto_ahash_digestsize(tfm);
 225        struct ahash_request_priv *priv;
 226        int err;
 227
 228        priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 229                       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 230                       GFP_KERNEL : GFP_ATOMIC);
 231        if (!priv)
 232                return -ENOMEM;
 233
 234        priv->result = req->result;
 235        priv->complete = req->base.complete;
 236        priv->data = req->base.data;
 237
 238        req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
 239        req->base.complete = ahash_op_unaligned_done;
 240        req->base.data = req;
 241        req->priv = priv;
 242
 243        err = op(req);
 244        ahash_op_unaligned_finish(req, err);
 245
 246        return err;
 247}
 248
 249static int crypto_ahash_op(struct ahash_request *req,
 250                           int (*op)(struct ahash_request *))
 251{
 252        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 253        unsigned long alignmask = crypto_ahash_alignmask(tfm);
 254
 255        if ((unsigned long)req->result & alignmask)
 256                return ahash_op_unaligned(req, op);
 257
 258        return op(req);
 259}
 260
 261int crypto_ahash_final(struct ahash_request *req)
 262{
 263        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
 264}
 265EXPORT_SYMBOL_GPL(crypto_ahash_final);
 266
 267int crypto_ahash_finup(struct ahash_request *req)
 268{
 269        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
 270}
 271EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 272
 273int crypto_ahash_digest(struct ahash_request *req)
 274{
 275        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
 276}
 277EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 278
 279static void ahash_def_finup_finish2(struct ahash_request *req, int err)
 280{
 281        struct ahash_request_priv *priv = req->priv;
 282
 283        if (err == -EINPROGRESS)
 284                return;
 285
 286        if (!err)
 287                memcpy(priv->result, req->result,
 288                       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 289
 290        kzfree(priv);
 291}
 292
 293static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
 294{
 295        struct ahash_request *areq = req->data;
 296        struct ahash_request_priv *priv = areq->priv;
 297        crypto_completion_t complete = priv->complete;
 298        void *data = priv->data;
 299
 300        ahash_def_finup_finish2(areq, err);
 301
 302        complete(data, err);
 303}
 304
 305static int ahash_def_finup_finish1(struct ahash_request *req, int err)
 306{
 307        if (err)
 308                goto out;
 309
 310        req->base.complete = ahash_def_finup_done2;
 311        req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 312        err = crypto_ahash_reqtfm(req)->final(req);
 313
 314out:
 315        ahash_def_finup_finish2(req, err);
 316        return err;
 317}
 318
 319static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
 320{
 321        struct ahash_request *areq = req->data;
 322        struct ahash_request_priv *priv = areq->priv;
 323        crypto_completion_t complete = priv->complete;
 324        void *data = priv->data;
 325
 326        err = ahash_def_finup_finish1(areq, err);
 327
 328        complete(data, err);
 329}
 330
 331static int ahash_def_finup(struct ahash_request *req)
 332{
 333        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 334        unsigned long alignmask = crypto_ahash_alignmask(tfm);
 335        unsigned int ds = crypto_ahash_digestsize(tfm);
 336        struct ahash_request_priv *priv;
 337
 338        priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 339                       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 340                       GFP_KERNEL : GFP_ATOMIC);
 341        if (!priv)
 342                return -ENOMEM;
 343
 344        priv->result = req->result;
 345        priv->complete = req->base.complete;
 346        priv->data = req->base.data;
 347
 348        req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
 349        req->base.complete = ahash_def_finup_done1;
 350        req->base.data = req;
 351        req->priv = priv;
 352
 353        return ahash_def_finup_finish1(req, tfm->update(req));
 354}
 355
 356static int ahash_no_export(struct ahash_request *req, void *out)
 357{
 358        return -ENOSYS;
 359}
 360
 361static int ahash_no_import(struct ahash_request *req, const void *in)
 362{
 363        return -ENOSYS;
 364}
 365
 366static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 367{
 368        struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 369        struct ahash_alg *alg = crypto_ahash_alg(hash);
 370
 371        hash->setkey = ahash_nosetkey;
 372        hash->export = ahash_no_export;
 373        hash->import = ahash_no_import;
 374
 375        if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 376                return crypto_init_shash_ops_async(tfm);
 377
 378        hash->init = alg->init;
 379        hash->update = alg->update;
 380        hash->final = alg->final;
 381        hash->finup = alg->finup ?: ahash_def_finup;
 382        hash->digest = alg->digest;
 383
 384        if (alg->setkey)
 385                hash->setkey = alg->setkey;
 386        if (alg->export)
 387                hash->export = alg->export;
 388        if (alg->import)
 389                hash->import = alg->import;
 390
 391        return 0;
 392}
 393
 394static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
 395{
 396        if (alg->cra_type == &crypto_ahash_type)
 397                return alg->cra_ctxsize;
 398
 399        return sizeof(struct crypto_shash *);
 400}
 401
 402#ifdef CONFIG_NET
 403static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 404{
 405        struct crypto_report_hash rhash;
 406
 407        snprintf(rhash.type, CRYPTO_MAX_ALG_NAME, "%s", "ahash");
 408
 409        rhash.blocksize = alg->cra_blocksize;
 410        rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
 411
 412        if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 413                    sizeof(struct crypto_report_hash), &rhash))
 414                goto nla_put_failure;
 415        return 0;
 416
 417nla_put_failure:
 418        return -EMSGSIZE;
 419}
 420#else
 421static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 422{
 423        return -ENOSYS;
 424}
 425#endif
 426
 427static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 428        __attribute__ ((unused));
 429static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 430{
 431        seq_printf(m, "type         : ahash\n");
 432        seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 433                                             "yes" : "no");
 434        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 435        seq_printf(m, "digestsize   : %u\n",
 436                   __crypto_hash_alg_common(alg)->digestsize);
 437}
 438
 439const struct crypto_type crypto_ahash_type = {
 440        .extsize = crypto_ahash_extsize,
 441        .init_tfm = crypto_ahash_init_tfm,
 442#ifdef CONFIG_PROC_FS
 443        .show = crypto_ahash_show,
 444#endif
 445        .report = crypto_ahash_report,
 446        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 447        .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 448        .type = CRYPTO_ALG_TYPE_AHASH,
 449        .tfmsize = offsetof(struct crypto_ahash, base),
 450};
 451EXPORT_SYMBOL_GPL(crypto_ahash_type);
 452
 453struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 454                                        u32 mask)
 455{
 456        return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 457}
 458EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 459
 460static int ahash_prepare_alg(struct ahash_alg *alg)
 461{
 462        struct crypto_alg *base = &alg->halg.base;
 463
 464        if (alg->halg.digestsize > PAGE_SIZE / 8 ||
 465            alg->halg.statesize > PAGE_SIZE / 8)
 466                return -EINVAL;
 467
 468        base->cra_type = &crypto_ahash_type;
 469        base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 470        base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 471
 472        return 0;
 473}
 474
 475int crypto_register_ahash(struct ahash_alg *alg)
 476{
 477        struct crypto_alg *base = &alg->halg.base;
 478        int err;
 479
 480        err = ahash_prepare_alg(alg);
 481        if (err)
 482                return err;
 483
 484        return crypto_register_alg(base);
 485}
 486EXPORT_SYMBOL_GPL(crypto_register_ahash);
 487
 488int crypto_unregister_ahash(struct ahash_alg *alg)
 489{
 490        return crypto_unregister_alg(&alg->halg.base);
 491}
 492EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 493
 494int ahash_register_instance(struct crypto_template *tmpl,
 495                            struct ahash_instance *inst)
 496{
 497        int err;
 498
 499        err = ahash_prepare_alg(&inst->alg);
 500        if (err)
 501                return err;
 502
 503        return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 504}
 505EXPORT_SYMBOL_GPL(ahash_register_instance);
 506
 507void ahash_free_instance(struct crypto_instance *inst)
 508{
 509        crypto_drop_spawn(crypto_instance_ctx(inst));
 510        kfree(ahash_instance(inst));
 511}
 512EXPORT_SYMBOL_GPL(ahash_free_instance);
 513
 514int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
 515                            struct hash_alg_common *alg,
 516                            struct crypto_instance *inst)
 517{
 518        return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 519                                  &crypto_ahash_type);
 520}
 521EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
 522
 523struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 524{
 525        struct crypto_alg *alg;
 526
 527        alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
 528        return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
 529}
 530EXPORT_SYMBOL_GPL(ahash_attr_alg);
 531
 532MODULE_LICENSE("GPL");
 533MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
 534
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