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