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 = kmap_atomic(walk->pg);
  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         kunmap_atomic(walk->data);
  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         areq->base.complete = complete;
 217         areq->base.data = data;
 218
 219         complete(&areq->base, err);
 220 }
 221
 222 static int ahash_op_unaligned(struct ahash_request *req,
 223                               int (*op)(struct ahash_request *))
 224 {
 225         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 226         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 227         unsigned int ds = crypto_ahash_digestsize(tfm);
 228         struct ahash_request_priv *priv;
 229         int err;
 230
 231         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 232                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 233                        GFP_KERNEL : GFP_ATOMIC);
 234         if (!priv)
 235                 return -ENOMEM;
 236
 237         priv->result = req->result;
 238         priv->complete = req->base.complete;
 239         priv->data = req->base.data;
 240
 241         req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
 242         req->base.complete = ahash_op_unaligned_done;
 243         req->base.data = req;
 244         req->priv = priv;
 245
 246         err = op(req);
 247         ahash_op_unaligned_finish(req, err);
 248
 249         return err;
 250 }
 251
 252 static int crypto_ahash_op(struct ahash_request *req,
 253                            int (*op)(struct ahash_request *))
 254 {
 255         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 256         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 257
 258         if ((unsigned long)req->result & alignmask)
 259                 return ahash_op_unaligned(req, op);
 260
 261         return op(req);
 262 }
 263
 264 int crypto_ahash_final(struct ahash_request *req)
 265 {
 266         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
 267 }
 268 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 269
 270 int crypto_ahash_finup(struct ahash_request *req)
 271 {
 272         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
 273 }
 274 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 275
 276 int crypto_ahash_digest(struct ahash_request *req)
 277 {
 278         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
 279 }
 280 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 281
 282 static void ahash_def_finup_finish2(struct ahash_request *req, int err)
 283 {
 284         struct ahash_request_priv *priv = req->priv;
 285
 286         if (err == -EINPROGRESS)
 287                 return;
 288
 289         if (!err)
 290                 memcpy(priv->result, req->result,
 291                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 292
 293         kzfree(priv);
 294 }
 295
 296 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
 297 {
 298         struct ahash_request *areq = req->data;
 299         struct ahash_request_priv *priv = areq->priv;
 300         crypto_completion_t complete = priv->complete;
 301         void *data = priv->data;
 302
 303         ahash_def_finup_finish2(areq, err);
 304
 305         complete(data, err);
 306 }
 307
 308 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
 309 {
 310         if (err)
 311                 goto out;
 312
 313         req->base.complete = ahash_def_finup_done2;
 314         req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 315         err = crypto_ahash_reqtfm(req)->final(req);
 316
 317 out:
 318         ahash_def_finup_finish2(req, err);
 319         return err;
 320 }
 321
 322 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
 323 {
 324         struct ahash_request *areq = req->data;
 325         struct ahash_request_priv *priv = areq->priv;
 326         crypto_completion_t complete = priv->complete;
 327         void *data = priv->data;
 328
 329         err = ahash_def_finup_finish1(areq, err);
 330
 331         complete(data, err);
 332 }
 333
 334 static int ahash_def_finup(struct ahash_request *req)
 335 {
 336         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 337         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 338         unsigned int ds = crypto_ahash_digestsize(tfm);
 339         struct ahash_request_priv *priv;
 340
 341         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 342                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 343                        GFP_KERNEL : GFP_ATOMIC);
 344         if (!priv)
 345                 return -ENOMEM;
 346
 347         priv->result = req->result;
 348         priv->complete = req->base.complete;
 349         priv->data = req->base.data;
 350
 351         req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
 352         req->base.complete = ahash_def_finup_done1;
 353         req->base.data = req;
 354         req->priv = priv;
 355
 356         return ahash_def_finup_finish1(req, tfm->update(req));
 357 }
 358
 359 static int ahash_no_export(struct ahash_request *req, void *out)
 360 {
 361         return -ENOSYS;
 362 }
 363
 364 static int ahash_no_import(struct ahash_request *req, const void *in)
 365 {
 366         return -ENOSYS;
 367 }
 368
 369 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 370 {
 371         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 372         struct ahash_alg *alg = crypto_ahash_alg(hash);
 373
 374         hash->setkey = ahash_nosetkey;
 375         hash->export = ahash_no_export;
 376         hash->import = ahash_no_import;
 377
 378         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 379                 return crypto_init_shash_ops_async(tfm);
 380
 381         hash->init = alg->init;
 382         hash->update = alg->update;
 383         hash->final = alg->final;
 384         hash->finup = alg->finup ?: ahash_def_finup;
 385         hash->digest = alg->digest;
 386
 387         if (alg->setkey)
 388                 hash->setkey = alg->setkey;
 389         if (alg->export)
 390                 hash->export = alg->export;
 391         if (alg->import)
 392                 hash->import = alg->import;
 393
 394         return 0;
 395 }
 396
 397 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
 398 {
 399         if (alg->cra_type == &crypto_ahash_type)
 400                 return alg->cra_ctxsize;
 401
 402         return sizeof(struct crypto_shash *);
 403 }
 404
 405 #ifdef CONFIG_NET
 406 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 407 {
 408         struct crypto_report_hash rhash;
 409
 410         strncpy(rhash.type, "ahash", sizeof(rhash.type));
 411
 412         rhash.blocksize = alg->cra_blocksize;
 413         rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
 414
 415         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 416                     sizeof(struct crypto_report_hash), &rhash))
 417                 goto nla_put_failure;
 418         return 0;
 419
 420 nla_put_failure:
 421         return -EMSGSIZE;
 422 }
 423 #else
 424 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 425 {
 426         return -ENOSYS;
 427 }
 428 #endif
 429
 430 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 431         __attribute__ ((unused));
 432 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 433 {
 434         seq_printf(m, "type         : ahash\n");
 435         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 436                                              "yes" : "no");
 437         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 438         seq_printf(m, "digestsize   : %u\n",
 439                    __crypto_hash_alg_common(alg)->digestsize);
 440 }
 441
 442 const struct crypto_type crypto_ahash_type = {
 443         .extsize = crypto_ahash_extsize,
 444         .init_tfm = crypto_ahash_init_tfm,
 445 #ifdef CONFIG_PROC_FS
 446         .show = crypto_ahash_show,
 447 #endif
 448         .report = crypto_ahash_report,
 449         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 450         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 451         .type = CRYPTO_ALG_TYPE_AHASH,
 452         .tfmsize = offsetof(struct crypto_ahash, base),
 453 };
 454 EXPORT_SYMBOL_GPL(crypto_ahash_type);
 455
 456 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 457                                         u32 mask)
 458 {
 459         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 460 }
 461 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 462
 463 static int ahash_prepare_alg(struct ahash_alg *alg)
 464 {
 465         struct crypto_alg *base = &alg->halg.base;
 466
 467         if (alg->halg.digestsize > PAGE_SIZE / 8 ||
 468             alg->halg.statesize > PAGE_SIZE / 8)
 469                 return -EINVAL;
 470
 471         base->cra_type = &crypto_ahash_type;
 472         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 473         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 474
 475         return 0;
 476 }
 477
 478 int crypto_register_ahash(struct ahash_alg *alg)
 479 {
 480         struct crypto_alg *base = &alg->halg.base;
 481         int err;
 482
 483         err = ahash_prepare_alg(alg);
 484         if (err)
 485                 return err;
 486
 487         return crypto_register_alg(base);
 488 }
 489 EXPORT_SYMBOL_GPL(crypto_register_ahash);
 490
 491 int crypto_unregister_ahash(struct ahash_alg *alg)
 492 {
 493         return crypto_unregister_alg(&alg->halg.base);
 494 }
 495 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 496
 497 int ahash_register_instance(struct crypto_template *tmpl,
 498                             struct ahash_instance *inst)
 499 {
 500         int err;
 501
 502         err = ahash_prepare_alg(&inst->alg);
 503         if (err)
 504                 return err;
 505
 506         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 507 }
 508 EXPORT_SYMBOL_GPL(ahash_register_instance);
 509
 510 void ahash_free_instance(struct crypto_instance *inst)
 511 {
 512         crypto_drop_spawn(crypto_instance_ctx(inst));
 513         kfree(ahash_instance(inst));
 514 }
 515 EXPORT_SYMBOL_GPL(ahash_free_instance);
 516
 517 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
 518                             struct hash_alg_common *alg,
 519                             struct crypto_instance *inst)
 520 {
 521         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 522                                   &crypto_ahash_type);
 523 }
 524 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
 525
 526 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 527 {
 528         struct crypto_alg *alg;
 529
 530         alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
 531         return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
 532 }
 533 EXPORT_SYMBOL_GPL(ahash_attr_alg);
 534
 535 MODULE_LICENSE("GPL");
 536 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");