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