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                 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
  60 static 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
  76 int 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 }
 113 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
 114
 115 int 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 }
 129 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
 130
 131 int 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
 147 static 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
 167 int 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 }
 177 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 178
 179 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 180                           unsigned int keylen)
 181 {
 182         return -ENOSYS;
 183 }
 184
 185 static 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
 191 static 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
 205 static 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
 217 static 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
 247 static 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
 259 int crypto_ahash_final(struct ahash_request *req)
 260 {
 261         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
 262 }
 263 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 264
 265 int crypto_ahash_finup(struct ahash_request *req)
 266 {
 267         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
 268 }
 269 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 270
 271 int crypto_ahash_digest(struct ahash_request *req)
 272 {
 273         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
 274 }
 275 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 276
 277 static 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
 291 static 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
 303 static 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
 312 out:
 313         ahash_def_finup_finish2(req, err);
 314         return err;
 315 }
 316
 317 static 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
 329 static 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
 354 static int ahash_no_export(struct ahash_request *req, void *out)
 355 {
 356         return -ENOSYS;
 357 }
 358
 359 static int ahash_no_import(struct ahash_request *req, const void *in)
 360 {
 361         return -ENOSYS;
 362 }
 363
 364 static 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
 392 static 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
 400 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 401         __attribute__ ((unused));
 402 static 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
 412 const 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 };
 423 EXPORT_SYMBOL_GPL(crypto_ahash_type);
 424
 425 struct 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 }
 430 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 431
 432 static 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
 447 int 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 }
 458 EXPORT_SYMBOL_GPL(crypto_register_ahash);
 459
 460 int crypto_unregister_ahash(struct ahash_alg *alg)
 461 {
 462         return crypto_unregister_alg(&alg->halg.base);
 463 }
 464 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 465
 466 int 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 }
 477 EXPORT_SYMBOL_GPL(ahash_register_instance);
 478
 479 void ahash_free_instance(struct crypto_instance *inst)
 480 {
 481         crypto_drop_spawn(crypto_instance_ctx(inst));
 482         kfree(ahash_instance(inst));
 483 }
 484 EXPORT_SYMBOL_GPL(ahash_free_instance);
 485
 486 int 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 }
 493 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
 494
 495 struct 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 }
 502 EXPORT_SYMBOL_GPL(ahash_attr_alg);
 503
 504 MODULE_LICENSE("GPL");
 505 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");