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->offset = sg->offset;
  68         walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
  69         walk->offset = offset_in_page(walk->offset);
  70         walk->entrylen = sg->length;
  71
  72         if (walk->entrylen > walk->total)
  73                 walk->entrylen = walk->total;
  74         walk->total -= walk->entrylen;
  75
  76         return hash_walk_next(walk);
  77 }
  78
  79 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
  80 {
  81         unsigned int alignmask = walk->alignmask;
  82         unsigned int nbytes = walk->entrylen;
  83
  84         walk->data -= walk->offset;
  85
  86         if (nbytes && walk->offset & alignmask && !err) {
  87                 walk->offset = ALIGN(walk->offset, alignmask + 1);
  88                 walk->data += walk->offset;
  89
  90                 nbytes = min(nbytes,
  91                              ((unsigned int)(PAGE_SIZE)) - walk->offset);
  92                 walk->entrylen -= nbytes;
  93
  94                 return nbytes;
  95         }
  96
  97         kunmap_atomic(walk->data);
  98         crypto_yield(walk->flags);
  99
 100         if (err)
 101                 return err;
 102
 103         if (nbytes) {
 104                 walk->offset = 0;
 105                 walk->pg++;
 106                 return hash_walk_next(walk);
 107         }
 108
 109         if (!walk->total)
 110                 return 0;
 111
 112         walk->sg = scatterwalk_sg_next(walk->sg);
 113
 114         return hash_walk_new_entry(walk);
 115 }
 116 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
 117
 118 int crypto_hash_walk_first(struct ahash_request *req,
 119                            struct crypto_hash_walk *walk)
 120 {
 121         walk->total = req->nbytes;
 122
 123         if (!walk->total)
 124                 return 0;
 125
 126         walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
 127         walk->sg = req->src;
 128         walk->flags = req->base.flags;
 129
 130         return hash_walk_new_entry(walk);
 131 }
 132 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
 133
 134 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
 135                                   struct crypto_hash_walk *walk,
 136                                   struct scatterlist *sg, unsigned int len)
 137 {
 138         walk->total = len;
 139
 140         if (!walk->total)
 141                 return 0;
 142
 143         walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
 144         walk->sg = sg;
 145         walk->flags = hdesc->flags;
 146
 147         return hash_walk_new_entry(walk);
 148 }
 149
 150 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
 151                                 unsigned int keylen)
 152 {
 153         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 154         int ret;
 155         u8 *buffer, *alignbuffer;
 156         unsigned long absize;
 157
 158         absize = keylen + alignmask;
 159         buffer = kmalloc(absize, GFP_KERNEL);
 160         if (!buffer)
 161                 return -ENOMEM;
 162
 163         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 164         memcpy(alignbuffer, key, keylen);
 165         ret = tfm->setkey(tfm, alignbuffer, keylen);
 166         kzfree(buffer);
 167         return ret;
 168 }
 169
 170 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 171                         unsigned int keylen)
 172 {
 173         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 174
 175         if ((unsigned long)key & alignmask)
 176                 return ahash_setkey_unaligned(tfm, key, keylen);
 177
 178         return tfm->setkey(tfm, key, keylen);
 179 }
 180 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
 181
 182 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 183                           unsigned int keylen)
 184 {
 185         return -ENOSYS;
 186 }
 187
 188 static inline unsigned int ahash_align_buffer_size(unsigned len,
 189                                                    unsigned long mask)
 190 {
 191         return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
 192 }
 193
 194 static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
 195 {
 196         struct ahash_request_priv *priv = req->priv;
 197
 198         if (err == -EINPROGRESS)
 199                 return;
 200
 201         if (!err)
 202                 memcpy(priv->result, req->result,
 203                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 204
 205         kzfree(priv);
 206 }
 207
 208 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
 209 {
 210         struct ahash_request *areq = req->data;
 211         struct ahash_request_priv *priv = areq->priv;
 212         crypto_completion_t complete = priv->complete;
 213         void *data = priv->data;
 214
 215         ahash_op_unaligned_finish(areq, err);
 216
 217         complete(data, err);
 218 }
 219
 220 static int ahash_op_unaligned(struct ahash_request *req,
 221                               int (*op)(struct ahash_request *))
 222 {
 223         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 224         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 225         unsigned int ds = crypto_ahash_digestsize(tfm);
 226         struct ahash_request_priv *priv;
 227         int err;
 228
 229         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 230                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 231                        GFP_KERNEL : GFP_ATOMIC);
 232         if (!priv)
 233                 return -ENOMEM;
 234
 235         priv->result = req->result;
 236         priv->complete = req->base.complete;
 237         priv->data = req->base.data;
 238
 239         req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
 240         req->base.complete = ahash_op_unaligned_done;
 241         req->base.data = req;
 242         req->priv = priv;
 243
 244         err = op(req);
 245         ahash_op_unaligned_finish(req, err);
 246
 247         return err;
 248 }
 249
 250 static int crypto_ahash_op(struct ahash_request *req,
 251                            int (*op)(struct ahash_request *))
 252 {
 253         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 254         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 255
 256         if ((unsigned long)req->result & alignmask)
 257                 return ahash_op_unaligned(req, op);
 258
 259         return op(req);
 260 }
 261
 262 int crypto_ahash_final(struct ahash_request *req)
 263 {
 264         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
 265 }
 266 EXPORT_SYMBOL_GPL(crypto_ahash_final);
 267
 268 int crypto_ahash_finup(struct ahash_request *req)
 269 {
 270         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
 271 }
 272 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
 273
 274 int crypto_ahash_digest(struct ahash_request *req)
 275 {
 276         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
 277 }
 278 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
 279
 280 static void ahash_def_finup_finish2(struct ahash_request *req, int err)
 281 {
 282         struct ahash_request_priv *priv = req->priv;
 283
 284         if (err == -EINPROGRESS)
 285                 return;
 286
 287         if (!err)
 288                 memcpy(priv->result, req->result,
 289                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
 290
 291         kzfree(priv);
 292 }
 293
 294 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
 295 {
 296         struct ahash_request *areq = req->data;
 297         struct ahash_request_priv *priv = areq->priv;
 298         crypto_completion_t complete = priv->complete;
 299         void *data = priv->data;
 300
 301         ahash_def_finup_finish2(areq, err);
 302
 303         complete(data, err);
 304 }
 305
 306 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
 307 {
 308         if (err)
 309                 goto out;
 310
 311         req->base.complete = ahash_def_finup_done2;
 312         req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 313         err = crypto_ahash_reqtfm(req)->final(req);
 314
 315 out:
 316         ahash_def_finup_finish2(req, err);
 317         return err;
 318 }
 319
 320 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
 321 {
 322         struct ahash_request *areq = req->data;
 323         struct ahash_request_priv *priv = areq->priv;
 324         crypto_completion_t complete = priv->complete;
 325         void *data = priv->data;
 326
 327         err = ahash_def_finup_finish1(areq, err);
 328
 329         complete(data, err);
 330 }
 331
 332 static int ahash_def_finup(struct ahash_request *req)
 333 {
 334         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 335         unsigned long alignmask = crypto_ahash_alignmask(tfm);
 336         unsigned int ds = crypto_ahash_digestsize(tfm);
 337         struct ahash_request_priv *priv;
 338
 339         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
 340                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 341                        GFP_KERNEL : GFP_ATOMIC);
 342         if (!priv)
 343                 return -ENOMEM;
 344
 345         priv->result = req->result;
 346         priv->complete = req->base.complete;
 347         priv->data = req->base.data;
 348
 349         req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
 350         req->base.complete = ahash_def_finup_done1;
 351         req->base.data = req;
 352         req->priv = priv;
 353
 354         return ahash_def_finup_finish1(req, tfm->update(req));
 355 }
 356
 357 static int ahash_no_export(struct ahash_request *req, void *out)
 358 {
 359         return -ENOSYS;
 360 }
 361
 362 static int ahash_no_import(struct ahash_request *req, const void *in)
 363 {
 364         return -ENOSYS;
 365 }
 366
 367 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 368 {
 369         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 370         struct ahash_alg *alg = crypto_ahash_alg(hash);
 371
 372         hash->setkey = ahash_nosetkey;
 373         hash->has_setkey = false;
 374         hash->export = ahash_no_export;
 375         hash->import = ahash_no_import;
 376
 377         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 378                 return crypto_init_shash_ops_async(tfm);
 379
 380         hash->init = alg->init;
 381         hash->update = alg->update;
 382         hash->final = alg->final;
 383         hash->finup = alg->finup ?: ahash_def_finup;
 384         hash->digest = alg->digest;
 385
 386         if (alg->setkey) {
 387                 hash->setkey = alg->setkey;
 388                 hash->has_setkey = true;
 389         }
 390         if (alg->export)
 391                 hash->export = alg->export;
 392         if (alg->import)
 393                 hash->import = alg->import;
 394
 395         return 0;
 396 }
 397
 398 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
 399 {
 400         if (alg->cra_type == &crypto_ahash_type)
 401                 return alg->cra_ctxsize;
 402
 403         return sizeof(struct crypto_shash *);
 404 }
 405
 406 #ifdef CONFIG_NET
 407 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 408 {
 409         struct crypto_report_hash rhash;
 410
 411         strncpy(rhash.type, "ahash", sizeof(rhash.type));
 412
 413         rhash.blocksize = alg->cra_blocksize;
 414         rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
 415
 416         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
 417                     sizeof(struct crypto_report_hash), &rhash))
 418                 goto nla_put_failure;
 419         return 0;
 420
 421 nla_put_failure:
 422         return -EMSGSIZE;
 423 }
 424 #else
 425 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
 426 {
 427         return -ENOSYS;
 428 }
 429 #endif
 430
 431 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 432         __attribute__ ((unused));
 433 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 434 {
 435         seq_printf(m, "type         : ahash\n");
 436         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 437                                              "yes" : "no");
 438         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 439         seq_printf(m, "digestsize   : %u\n",
 440                    __crypto_hash_alg_common(alg)->digestsize);
 441 }
 442
 443 const struct crypto_type crypto_ahash_type = {
 444         .extsize = crypto_ahash_extsize,
 445         .init_tfm = crypto_ahash_init_tfm,
 446 #ifdef CONFIG_PROC_FS
 447         .show = crypto_ahash_show,
 448 #endif
 449         .report = crypto_ahash_report,
 450         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 451         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 452         .type = CRYPTO_ALG_TYPE_AHASH,
 453         .tfmsize = offsetof(struct crypto_ahash, base),
 454 };
 455 EXPORT_SYMBOL_GPL(crypto_ahash_type);
 456
 457 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 458                                         u32 mask)
 459 {
 460         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 461 }
 462 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
 463
 464 static int ahash_prepare_alg(struct ahash_alg *alg)
 465 {
 466         struct crypto_alg *base = &alg->halg.base;
 467
 468         if (alg->halg.digestsize > PAGE_SIZE / 8 ||
 469             alg->halg.statesize > PAGE_SIZE / 8 ||
 470             alg->halg.statesize == 0)
 471                 return -EINVAL;
 472
 473         base->cra_type = &crypto_ahash_type;
 474         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 475         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
 476
 477         return 0;
 478 }
 479
 480 int crypto_register_ahash(struct ahash_alg *alg)
 481 {
 482         struct crypto_alg *base = &alg->halg.base;
 483         int err;
 484
 485         err = ahash_prepare_alg(alg);
 486         if (err)
 487                 return err;
 488
 489         return crypto_register_alg(base);
 490 }
 491 EXPORT_SYMBOL_GPL(crypto_register_ahash);
 492
 493 int crypto_unregister_ahash(struct ahash_alg *alg)
 494 {
 495         return crypto_unregister_alg(&alg->halg.base);
 496 }
 497 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
 498
 499 int ahash_register_instance(struct crypto_template *tmpl,
 500                             struct ahash_instance *inst)
 501 {
 502         int err;
 503
 504         err = ahash_prepare_alg(&inst->alg);
 505         if (err)
 506                 return err;
 507
 508         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 509 }
 510 EXPORT_SYMBOL_GPL(ahash_register_instance);
 511
 512 void ahash_free_instance(struct crypto_instance *inst)
 513 {
 514         crypto_drop_spawn(crypto_instance_ctx(inst));
 515         kfree(ahash_instance(inst));
 516 }
 517 EXPORT_SYMBOL_GPL(ahash_free_instance);
 518
 519 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
 520                             struct hash_alg_common *alg,
 521                             struct crypto_instance *inst)
 522 {
 523         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 524                                   &crypto_ahash_type);
 525 }
 526 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
 527
 528 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 529 {
 530         struct crypto_alg *alg;
 531
 532         alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
 533         return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
 534 }
 535 EXPORT_SYMBOL_GPL(ahash_attr_alg);
 536
 537 MODULE_LICENSE("GPL");
 538 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");