crypto/ahash.c

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