crypto/shash.c

   1 /*
   2  * Synchronous Cryptographic Hash operations.
   3  *
   4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <crypto/scatterwalk.h>
  14 #include <crypto/internal/hash.h>
  15 #include <linux/err.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/seq_file.h>
  20
  21 #include "internal.h"
  22
  23 static const struct crypto_type crypto_shash_type;
  24
  25 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  26                                   unsigned int keylen)
  27 {
  28         struct shash_alg *shash = crypto_shash_alg(tfm);
  29         unsigned long alignmask = crypto_shash_alignmask(tfm);
  30         unsigned long absize;
  31         u8 *buffer, *alignbuffer;
  32         int err;
  33
  34         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  35         buffer = kmalloc(absize, GFP_KERNEL);
  36         if (!buffer)
  37                 return -ENOMEM;
  38
  39         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  40         memcpy(alignbuffer, key, keylen);
  41         err = shash->setkey(tfm, alignbuffer, keylen);
  42         memset(alignbuffer, 0, keylen);
  43         kfree(buffer);
  44         return err;
  45 }
  46
  47 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  48                         unsigned int keylen)
  49 {
  50         struct shash_alg *shash = crypto_shash_alg(tfm);
  51         unsigned long alignmask = crypto_shash_alignmask(tfm);
  52
  53         if (!shash->setkey)
  54                 return -ENOSYS;
  55
  56         if ((unsigned long)key & alignmask)
  57                 return shash_setkey_unaligned(tfm, key, keylen);
  58
  59         return shash->setkey(tfm, key, keylen);
  60 }
  61 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  62
  63 static inline unsigned int shash_align_buffer_size(unsigned len,
  64                                                    unsigned long mask)
  65 {
  66         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  67 }
  68
  69 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  70                                   unsigned int len)
  71 {
  72         struct crypto_shash *tfm = desc->tfm;
  73         struct shash_alg *shash = crypto_shash_alg(tfm);
  74         unsigned long alignmask = crypto_shash_alignmask(tfm);
  75         unsigned int unaligned_len = alignmask + 1 -
  76                                      ((unsigned long)data & alignmask);
  77         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  78                 __attribute__ ((aligned));
  79
  80         memcpy(buf, data, unaligned_len);
  81
  82         return shash->update(desc, buf, unaligned_len) ?:
  83                shash->update(desc, data + unaligned_len, len - unaligned_len);
  84 }
  85
  86 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  87                         unsigned int len)
  88 {
  89         struct crypto_shash *tfm = desc->tfm;
  90         struct shash_alg *shash = crypto_shash_alg(tfm);
  91         unsigned long alignmask = crypto_shash_alignmask(tfm);
  92
  93         if ((unsigned long)data & alignmask)
  94                 return shash_update_unaligned(desc, data, len);
  95
  96         return shash->update(desc, data, len);
  97 }
  98 EXPORT_SYMBOL_GPL(crypto_shash_update);
  99
 100 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 101 {
 102         struct crypto_shash *tfm = desc->tfm;
 103         unsigned long alignmask = crypto_shash_alignmask(tfm);
 104         struct shash_alg *shash = crypto_shash_alg(tfm);
 105         unsigned int ds = crypto_shash_digestsize(tfm);
 106         u8 buf[shash_align_buffer_size(ds, alignmask)]
 107                 __attribute__ ((aligned));
 108         int err;
 109
 110         err = shash->final(desc, buf);
 111         memcpy(out, buf, ds);
 112         return err;
 113 }
 114
 115 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 116 {
 117         struct crypto_shash *tfm = desc->tfm;
 118         struct shash_alg *shash = crypto_shash_alg(tfm);
 119         unsigned long alignmask = crypto_shash_alignmask(tfm);
 120
 121         if ((unsigned long)out & alignmask)
 122                 return shash_final_unaligned(desc, out);
 123
 124         return shash->final(desc, out);
 125 }
 126 EXPORT_SYMBOL_GPL(crypto_shash_final);
 127
 128 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 129                                  unsigned int len, u8 *out)
 130 {
 131         return crypto_shash_update(desc, data, len) ?:
 132                crypto_shash_final(desc, out);
 133 }
 134
 135 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 136                        unsigned int len, u8 *out)
 137 {
 138         struct crypto_shash *tfm = desc->tfm;
 139         struct shash_alg *shash = crypto_shash_alg(tfm);
 140         unsigned long alignmask = crypto_shash_alignmask(tfm);
 141
 142         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 143             !shash->finup)
 144                 return shash_finup_unaligned(desc, data, len, out);
 145
 146         return shash->finup(desc, data, len, out);
 147 }
 148 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 149
 150 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 151                                   unsigned int len, u8 *out)
 152 {
 153         return crypto_shash_init(desc) ?:
 154                crypto_shash_update(desc, data, len) ?:
 155                crypto_shash_final(desc, out);
 156 }
 157
 158 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 159                         unsigned int len, u8 *out)
 160 {
 161         struct crypto_shash *tfm = desc->tfm;
 162         struct shash_alg *shash = crypto_shash_alg(tfm);
 163         unsigned long alignmask = crypto_shash_alignmask(tfm);
 164
 165         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 166             !shash->digest)
 167                 return shash_digest_unaligned(desc, data, len, out);
 168
 169         return shash->digest(desc, data, len, out);
 170 }
 171 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 172
 173 int crypto_shash_import(struct shash_desc *desc, const u8 *in)
 174 {
 175         struct crypto_shash *tfm = desc->tfm;
 176         struct shash_alg *alg = crypto_shash_alg(tfm);
 177
 178         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
 179
 180         if (alg->reinit)
 181                 alg->reinit(desc);
 182
 183         return 0;
 184 }
 185 EXPORT_SYMBOL_GPL(crypto_shash_import);
 186
 187 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 188                               unsigned int keylen)
 189 {
 190         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 191
 192         return crypto_shash_setkey(*ctx, key, keylen);
 193 }
 194
 195 static int shash_async_init(struct ahash_request *req)
 196 {
 197         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 198         struct shash_desc *desc = ahash_request_ctx(req);
 199
 200         desc->tfm = *ctx;
 201         desc->flags = req->base.flags;
 202
 203         return crypto_shash_init(desc);
 204 }
 205
 206 static int shash_async_update(struct ahash_request *req)
 207 {
 208         struct shash_desc *desc = ahash_request_ctx(req);
 209         struct crypto_hash_walk walk;
 210         int nbytes;
 211
 212         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 213              nbytes = crypto_hash_walk_done(&walk, nbytes))
 214                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 215
 216         return nbytes;
 217 }
 218
 219 static int shash_async_final(struct ahash_request *req)
 220 {
 221         return crypto_shash_final(ahash_request_ctx(req), req->result);
 222 }
 223
 224 static int shash_async_digest(struct ahash_request *req)
 225 {
 226         struct scatterlist *sg = req->src;
 227         unsigned int offset = sg->offset;
 228         unsigned int nbytes = req->nbytes;
 229         int err;
 230
 231         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 232                 struct crypto_shash **ctx =
 233                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 234                 struct shash_desc *desc = ahash_request_ctx(req);
 235                 void *data;
 236
 237                 desc->tfm = *ctx;
 238                 desc->flags = req->base.flags;
 239
 240                 data = crypto_kmap(sg_page(sg), 0);
 241                 err = crypto_shash_digest(desc, data + offset, nbytes,
 242                                           req->result);
 243                 crypto_kunmap(data, 0);
 244                 crypto_yield(desc->flags);
 245                 goto out;
 246         }
 247
 248         err = shash_async_init(req);
 249         if (err)
 250                 goto out;
 251
 252         err = shash_async_update(req);
 253         if (err)
 254                 goto out;
 255
 256         err = shash_async_final(req);
 257
 258 out:
 259         return err;
 260 }
 261
 262 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 263 {
 264         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 265
 266         crypto_free_shash(*ctx);
 267 }
 268
 269 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 270 {
 271         struct crypto_alg *calg = tfm->__crt_alg;
 272         struct shash_alg *alg = __crypto_shash_alg(calg);
 273         struct ahash_tfm *crt = &tfm->crt_ahash;
 274         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 275         struct crypto_shash *shash;
 276
 277         if (!crypto_mod_get(calg))
 278                 return -EAGAIN;
 279
 280         shash = crypto_create_tfm(calg, &crypto_shash_type);
 281         if (IS_ERR(shash)) {
 282                 crypto_mod_put(calg);
 283                 return PTR_ERR(shash);
 284         }
 285
 286         *ctx = shash;
 287         tfm->exit = crypto_exit_shash_ops_async;
 288
 289         crt->init = shash_async_init;
 290         crt->update = shash_async_update;
 291         crt->final  = shash_async_final;
 292         crt->digest = shash_async_digest;
 293         crt->setkey = shash_async_setkey;
 294
 295         crt->digestsize = alg->digestsize;
 296         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 297
 298         return 0;
 299 }
 300
 301 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
 302                                unsigned int keylen)
 303 {
 304         struct shash_desc *desc = crypto_hash_ctx(tfm);
 305
 306         return crypto_shash_setkey(desc->tfm, key, keylen);
 307 }
 308
 309 static int shash_compat_init(struct hash_desc *hdesc)
 310 {
 311         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 312
 313         desc->flags = hdesc->flags;
 314
 315         return crypto_shash_init(desc);
 316 }
 317
 318 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
 319                                unsigned int len)
 320 {
 321         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 322         struct crypto_hash_walk walk;
 323         int nbytes;
 324
 325         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
 326              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
 327                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 328
 329         return nbytes;
 330 }
 331
 332 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
 333 {
 334         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
 335 }
 336
 337 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
 338                                unsigned int nbytes, u8 *out)
 339 {
 340         unsigned int offset = sg->offset;
 341         int err;
 342
 343         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 344                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
 345                 void *data;
 346
 347                 desc->flags = hdesc->flags;
 348
 349                 data = crypto_kmap(sg_page(sg), 0);
 350                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
 351                 crypto_kunmap(data, 0);
 352                 crypto_yield(desc->flags);
 353                 goto out;
 354         }
 355
 356         err = shash_compat_init(hdesc);
 357         if (err)
 358                 goto out;
 359
 360         err = shash_compat_update(hdesc, sg, nbytes);
 361         if (err)
 362                 goto out;
 363
 364         err = shash_compat_final(hdesc, out);
 365
 366 out:
 367         return err;
 368 }
 369
 370 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
 371 {
 372         struct shash_desc *desc= crypto_tfm_ctx(tfm);
 373
 374         crypto_free_shash(desc->tfm);
 375 }
 376
 377 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
 378 {
 379         struct hash_tfm *crt = &tfm->crt_hash;
 380         struct crypto_alg *calg = tfm->__crt_alg;
 381         struct shash_alg *alg = __crypto_shash_alg(calg);
 382         struct shash_desc *desc = crypto_tfm_ctx(tfm);
 383         struct crypto_shash *shash;
 384
 385         if (!crypto_mod_get(calg))
 386                 return -EAGAIN;
 387
 388         shash = crypto_create_tfm(calg, &crypto_shash_type);
 389         if (IS_ERR(shash)) {
 390                 crypto_mod_put(calg);
 391                 return PTR_ERR(shash);
 392         }
 393
 394         desc->tfm = shash;
 395         tfm->exit = crypto_exit_shash_ops_compat;
 396
 397         crt->init = shash_compat_init;
 398         crt->update = shash_compat_update;
 399         crt->final  = shash_compat_final;
 400         crt->digest = shash_compat_digest;
 401         crt->setkey = shash_compat_setkey;
 402
 403         crt->digestsize = alg->digestsize;
 404
 405         return 0;
 406 }
 407
 408 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 409 {
 410         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 411         case CRYPTO_ALG_TYPE_HASH_MASK:
 412                 return crypto_init_shash_ops_compat(tfm);
 413         case CRYPTO_ALG_TYPE_AHASH_MASK:
 414                 return crypto_init_shash_ops_async(tfm);
 415         }
 416
 417         return -EINVAL;
 418 }
 419
 420 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 421                                          u32 mask)
 422 {
 423         struct shash_alg *salg = __crypto_shash_alg(alg);
 424
 425         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 426         case CRYPTO_ALG_TYPE_HASH_MASK:
 427                 return sizeof(struct shash_desc) + salg->descsize;
 428         case CRYPTO_ALG_TYPE_AHASH_MASK:
 429                 return sizeof(struct crypto_shash *);
 430         }
 431
 432         return 0;
 433 }
 434
 435 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 436                                  const struct crypto_type *frontend)
 437 {
 438         return 0;
 439 }
 440
 441 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 442                                          const struct crypto_type *frontend)
 443 {
 444         return alg->cra_ctxsize;
 445 }
 446
 447 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 448         __attribute__ ((unused));
 449 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 450 {
 451         struct shash_alg *salg = __crypto_shash_alg(alg);
 452
 453         seq_printf(m, "type         : shash\n");
 454         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 455         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 456         seq_printf(m, "descsize     : %u\n", salg->descsize);
 457 }
 458
 459 static const struct crypto_type crypto_shash_type = {
 460         .ctxsize = crypto_shash_ctxsize,
 461         .extsize = crypto_shash_extsize,
 462         .init = crypto_init_shash_ops,
 463         .init_tfm = crypto_shash_init_tfm,
 464 #ifdef CONFIG_PROC_FS
 465         .show = crypto_shash_show,
 466 #endif
 467         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 468         .maskset = CRYPTO_ALG_TYPE_MASK,
 469         .type = CRYPTO_ALG_TYPE_SHASH,
 470         .tfmsize = offsetof(struct crypto_shash, base),
 471 };
 472
 473 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 474                                         u32 mask)
 475 {
 476         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
 477 }
 478 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 479
 480 int crypto_register_shash(struct shash_alg *alg)
 481 {
 482         struct crypto_alg *base = &alg->base;
 483
 484         if (alg->digestsize > PAGE_SIZE / 8 ||
 485             alg->descsize > PAGE_SIZE / 8)
 486                 return -EINVAL;
 487
 488         base->cra_type = &crypto_shash_type;
 489         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 490         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 491
 492         return crypto_register_alg(base);
 493 }
 494 EXPORT_SYMBOL_GPL(crypto_register_shash);
 495
 496 int crypto_unregister_shash(struct shash_alg *alg)
 497 {
 498         return crypto_unregister_alg(&alg->base);
 499 }
 500 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 501
 502 MODULE_LICENSE("GPL");
 503 MODULE_DESCRIPTION("Synchronous cryptographic hash type");