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 #include <linux/cryptouser.h>
  25 #include <net/netlink.h>
  26
  27 #include "internal.h"
  28
  29 struct ahash_request_priv {
  30         crypto_completion_t complete;
  31         void *data;
  32         u8 *result;
  33         void *ubuf[] CRYPTO_MINALIGN_ATTR;
  34 };
  35
  36 static 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
  42 static 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 = crypto_kmap(walk->pg, 0);
  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
  62 static 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
  78 int 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         crypto_kunmap(walk->data, 0);
  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 }
 115 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
 116
 117 int 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 }
 131 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
 132
 133 int 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
 149 static 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
 169 int 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 }
 179 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 180
 181 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 182                           unsigned int keylen)
 183 {
 184         return -ENOSYS;
 185 }
 186
 187 static 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
 193 static 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
 207 static 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
 219 static 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
 249 static 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
 261 int crypto_ahash_final(struct ahash_request *req)
 262 {
 263         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
 264 }
 265 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 266
 267 int crypto_ahash_finup(struct ahash_request *req)
 268 {
 269         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
 270 }
 271 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 272
 273 int crypto_ahash_digest(struct ahash_request *req)
 274 {
 275         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
 276 }
 277 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 278
 279 static 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
 293 static 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
 305 static 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
 314 out:
 315         ahash_def_finup_finish2(req, err);
 316         return err;
 317 }
 318
 319 static 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
 331 static 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
 356 static int ahash_no_export(struct ahash_request *req, void *out)
 357 {
 358         return -ENOSYS;
 359 }
 360
 361 static int ahash_no_import(struct ahash_request *req, const void *in)
 362 {
 363         return -ENOSYS;
 364 }
 365
 366 static 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
 394 static 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 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 403 {
 404         struct crypto_report_hash rhash;
 405
 406         snprintf(rhash.type, CRYPTO_MAX_ALG_NAME, "%s", "ahash");
 407
 408         rhash.blocksize = alg->cra_blocksize;
 409         rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
 410
 411         NLA_PUT(skb, CRYPTOCFGA_REPORT_HASH,
 412                 sizeof(struct crypto_report_hash), &rhash);
 413
 414         return 0;
 415
 416 nla_put_failure:
 417         return -EMSGSIZE;
 418 }
 419
 420 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 421         __attribute__ ((unused));
 422 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 423 {
 424         seq_printf(m, "type         : ahash\n");
 425         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 426                                              "yes" : "no");
 427         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 428         seq_printf(m, "digestsize   : %u\n",
 429                    __crypto_hash_alg_common(alg)->digestsize);
 430 }
 431
 432 const struct crypto_type crypto_ahash_type = {
 433         .extsize = crypto_ahash_extsize,
 434         .init_tfm = crypto_ahash_init_tfm,
 435 #ifdef CONFIG_PROC_FS
 436         .show = crypto_ahash_show,
 437 #endif
 438         .report = crypto_ahash_report,
 439         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 440         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 441         .type = CRYPTO_ALG_TYPE_AHASH,
 442         .tfmsize = offsetof(struct crypto_ahash, base),
 443 };
 444 EXPORT_SYMBOL_GPL(crypto_ahash_type);
 445
 446 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 447                                         u32 mask)
 448 {
 449         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 450 }
 451 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 452
 453 static int ahash_prepare_alg(struct ahash_alg *alg)
 454 {
 455         struct crypto_alg *base = &alg->halg.base;
 456
 457         if (alg->halg.digestsize > PAGE_SIZE / 8 ||
 458             alg->halg.statesize > PAGE_SIZE / 8)
 459                 return -EINVAL;
 460
 461         base->cra_type = &crypto_ahash_type;
 462         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 463         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 464
 465         return 0;
 466 }
 467
 468 int crypto_register_ahash(struct ahash_alg *alg)
 469 {
 470         struct crypto_alg *base = &alg->halg.base;
 471         int err;
 472
 473         err = ahash_prepare_alg(alg);
 474         if (err)
 475                 return err;
 476
 477         return crypto_register_alg(base);
 478 }
 479 EXPORT_SYMBOL_GPL(crypto_register_ahash);
 480
 481 int crypto_unregister_ahash(struct ahash_alg *alg)
 482 {
 483         return crypto_unregister_alg(&alg->halg.base);
 484 }
 485 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 486
 487 int ahash_register_instance(struct crypto_template *tmpl,
 488                             struct ahash_instance *inst)
 489 {
 490         int err;
 491
 492         err = ahash_prepare_alg(&inst->alg);
 493         if (err)
 494                 return err;
 495
 496         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 497 }
 498 EXPORT_SYMBOL_GPL(ahash_register_instance);
 499
 500 void ahash_free_instance(struct crypto_instance *inst)
 501 {
 502         crypto_drop_spawn(crypto_instance_ctx(inst));
 503         kfree(ahash_instance(inst));
 504 }
 505 EXPORT_SYMBOL_GPL(ahash_free_instance);
 506
 507 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
 508                             struct hash_alg_common *alg,
 509                             struct crypto_instance *inst)
 510 {
 511         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 512                                   &crypto_ahash_type);
 513 }
 514 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
 515
 516 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 517 {
 518         struct crypto_alg *alg;
 519
 520         alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
 521         return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
 522 }
 523 EXPORT_SYMBOL_GPL(ahash_attr_alg);
 524
 525 MODULE_LICENSE("GPL");
 526 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");