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 static const struct crypto_type crypto_shash_type;
  22
  23 static inline struct crypto_shash *__crypto_shash_cast(struct crypto_tfm *tfm)
  24 {
  25         return container_of(tfm, struct crypto_shash, base);
  26 }
  27
  28 #include "internal.h"
  29
  30 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
  31                                   unsigned int keylen)
  32 {
  33         struct shash_alg *shash = crypto_shash_alg(tfm);
  34         unsigned long alignmask = crypto_shash_alignmask(tfm);
  35         unsigned long absize;
  36         u8 *buffer, *alignbuffer;
  37         int err;
  38
  39         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
  40         buffer = kmalloc(absize, GFP_KERNEL);
  41         if (!buffer)
  42                 return -ENOMEM;
  43
  44         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  45         memcpy(alignbuffer, key, keylen);
  46         err = shash->setkey(tfm, alignbuffer, keylen);
  47         memset(alignbuffer, 0, keylen);
  48         kfree(buffer);
  49         return err;
  50 }
  51
  52 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
  53                         unsigned int keylen)
  54 {
  55         struct shash_alg *shash = crypto_shash_alg(tfm);
  56         unsigned long alignmask = crypto_shash_alignmask(tfm);
  57
  58         if ((unsigned long)key & alignmask)
  59                 return shash_setkey_unaligned(tfm, key, keylen);
  60
  61         return shash->setkey(tfm, key, keylen);
  62 }
  63 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
  64
  65 static inline unsigned int shash_align_buffer_size(unsigned len,
  66                                                    unsigned long mask)
  67 {
  68         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
  69 }
  70
  71 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
  72                                   unsigned int len)
  73 {
  74         struct crypto_shash *tfm = desc->tfm;
  75         struct shash_alg *shash = crypto_shash_alg(tfm);
  76         unsigned long alignmask = crypto_shash_alignmask(tfm);
  77         unsigned int unaligned_len = alignmask + 1 -
  78                                      ((unsigned long)data & alignmask);
  79         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
  80                 __attribute__ ((aligned));
  81
  82         memcpy(buf, data, unaligned_len);
  83
  84         return shash->update(desc, buf, unaligned_len) ?:
  85                shash->update(desc, data + unaligned_len, len - unaligned_len);
  86 }
  87
  88 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
  89                         unsigned int len)
  90 {
  91         struct crypto_shash *tfm = desc->tfm;
  92         struct shash_alg *shash = crypto_shash_alg(tfm);
  93         unsigned long alignmask = crypto_shash_alignmask(tfm);
  94
  95         if ((unsigned long)data & alignmask)
  96                 return shash_update_unaligned(desc, data, len);
  97
  98         return shash->update(desc, data, len);
  99 }
 100 EXPORT_SYMBOL_GPL(crypto_shash_update);
 101
 102 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 103 {
 104         struct crypto_shash *tfm = desc->tfm;
 105         unsigned long alignmask = crypto_shash_alignmask(tfm);
 106         struct shash_alg *shash = crypto_shash_alg(tfm);
 107         unsigned int ds = crypto_shash_digestsize(tfm);
 108         u8 buf[shash_align_buffer_size(ds, alignmask)]
 109                 __attribute__ ((aligned));
 110         int err;
 111
 112         err = shash->final(desc, buf);
 113         memcpy(out, buf, ds);
 114         return err;
 115 }
 116
 117 int crypto_shash_final(struct shash_desc *desc, u8 *out)
 118 {
 119         struct crypto_shash *tfm = desc->tfm;
 120         struct shash_alg *shash = crypto_shash_alg(tfm);
 121         unsigned long alignmask = crypto_shash_alignmask(tfm);
 122
 123         if ((unsigned long)out & alignmask)
 124                 return shash_final_unaligned(desc, out);
 125
 126         return shash->final(desc, out);
 127 }
 128 EXPORT_SYMBOL_GPL(crypto_shash_final);
 129
 130 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
 131                                  unsigned int len, u8 *out)
 132 {
 133         return crypto_shash_update(desc, data, len) ?:
 134                crypto_shash_final(desc, out);
 135 }
 136
 137 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
 138                        unsigned int len, u8 *out)
 139 {
 140         struct crypto_shash *tfm = desc->tfm;
 141         struct shash_alg *shash = crypto_shash_alg(tfm);
 142         unsigned long alignmask = crypto_shash_alignmask(tfm);
 143
 144         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 145             !shash->finup)
 146                 return shash_finup_unaligned(desc, data, len, out);
 147
 148         return shash->finup(desc, data, len, out);
 149 }
 150 EXPORT_SYMBOL_GPL(crypto_shash_finup);
 151
 152 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
 153                                   unsigned int len, u8 *out)
 154 {
 155         return crypto_shash_init(desc) ?:
 156                crypto_shash_update(desc, data, len) ?:
 157                crypto_shash_final(desc, out);
 158 }
 159
 160 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
 161                         unsigned int len, u8 *out)
 162 {
 163         struct crypto_shash *tfm = desc->tfm;
 164         struct shash_alg *shash = crypto_shash_alg(tfm);
 165         unsigned long alignmask = crypto_shash_alignmask(tfm);
 166
 167         if (((unsigned long)data | (unsigned long)out) & alignmask ||
 168             !shash->digest)
 169                 return shash_digest_unaligned(desc, data, len, out);
 170
 171         return shash->digest(desc, data, len, out);
 172 }
 173 EXPORT_SYMBOL_GPL(crypto_shash_digest);
 174
 175 int crypto_shash_import(struct shash_desc *desc, const u8 *in)
 176 {
 177         struct crypto_shash *tfm = desc->tfm;
 178         struct shash_alg *alg = crypto_shash_alg(tfm);
 179
 180         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
 181
 182         if (alg->reinit)
 183                 alg->reinit(desc);
 184
 185         return 0;
 186 }
 187 EXPORT_SYMBOL_GPL(crypto_shash_import);
 188
 189 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 190                               unsigned int keylen)
 191 {
 192         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
 193
 194         return crypto_shash_setkey(*ctx, key, keylen);
 195 }
 196
 197 static int shash_async_init(struct ahash_request *req)
 198 {
 199         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 200         struct shash_desc *desc = ahash_request_ctx(req);
 201
 202         desc->tfm = *ctx;
 203         desc->flags = req->base.flags;
 204
 205         return crypto_shash_init(desc);
 206 }
 207
 208 static int shash_async_update(struct ahash_request *req)
 209 {
 210         struct shash_desc *desc = ahash_request_ctx(req);
 211         struct crypto_hash_walk walk;
 212         int nbytes;
 213
 214         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
 215              nbytes = crypto_hash_walk_done(&walk, nbytes))
 216                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
 217
 218         return nbytes;
 219 }
 220
 221 static int shash_async_final(struct ahash_request *req)
 222 {
 223         return crypto_shash_final(ahash_request_ctx(req), req->result);
 224 }
 225
 226 static int shash_async_digest(struct ahash_request *req)
 227 {
 228         struct scatterlist *sg = req->src;
 229         unsigned int offset = sg->offset;
 230         unsigned int nbytes = req->nbytes;
 231         int err;
 232
 233         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
 234                 struct crypto_shash **ctx =
 235                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
 236                 struct shash_desc *desc = ahash_request_ctx(req);
 237                 void *data;
 238
 239                 desc->tfm = *ctx;
 240                 desc->flags = req->base.flags;
 241
 242                 data = crypto_kmap(sg_page(sg), 0);
 243                 err = crypto_shash_digest(desc, data + offset, nbytes,
 244                                           req->result);
 245                 crypto_kunmap(data, 0);
 246                 crypto_yield(desc->flags);
 247                 goto out;
 248         }
 249
 250         err = shash_async_init(req);
 251         if (err)
 252                 goto out;
 253
 254         err = shash_async_update(req);
 255         if (err)
 256                 goto out;
 257
 258         err = shash_async_final(req);
 259
 260 out:
 261         return err;
 262 }
 263
 264 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
 265 {
 266         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 267
 268         crypto_free_shash(*ctx);
 269 }
 270
 271 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
 272 {
 273         struct crypto_alg *calg = tfm->__crt_alg;
 274         struct shash_alg *alg = __crypto_shash_alg(calg);
 275         struct ahash_tfm *crt = &tfm->crt_ahash;
 276         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
 277         struct crypto_shash *shash;
 278
 279         if (!crypto_mod_get(calg))
 280                 return -EAGAIN;
 281
 282         shash = __crypto_shash_cast(crypto_create_tfm(
 283                 calg, &crypto_shash_type));
 284         if (IS_ERR(shash)) {
 285                 crypto_mod_put(calg);
 286                 return PTR_ERR(shash);
 287         }
 288
 289         *ctx = shash;
 290         tfm->exit = crypto_exit_shash_ops_async;
 291
 292         crt->init = shash_async_init;
 293         crt->update = shash_async_update;
 294         crt->final  = shash_async_final;
 295         crt->digest = shash_async_digest;
 296         crt->setkey = shash_async_setkey;
 297
 298         crt->digestsize = alg->digestsize;
 299         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
 300
 301         return 0;
 302 }
 303
 304 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 305 {
 306         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 307         case CRYPTO_ALG_TYPE_AHASH_MASK:
 308                 return crypto_init_shash_ops_async(tfm);
 309         }
 310
 311         return -EINVAL;
 312 }
 313
 314 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
 315                                          u32 mask)
 316 {
 317         switch (mask & CRYPTO_ALG_TYPE_MASK) {
 318         case CRYPTO_ALG_TYPE_AHASH_MASK:
 319                 return sizeof(struct crypto_shash *);
 320         }
 321
 322         return 0;
 323 }
 324
 325 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
 326                                  const struct crypto_type *frontend)
 327 {
 328         if (frontend->type != CRYPTO_ALG_TYPE_SHASH)
 329                 return -EINVAL;
 330         return 0;
 331 }
 332
 333 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
 334                                          const struct crypto_type *frontend)
 335 {
 336         return alg->cra_ctxsize;
 337 }
 338
 339 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 340         __attribute__ ((unused));
 341 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
 342 {
 343         struct shash_alg *salg = __crypto_shash_alg(alg);
 344
 345         seq_printf(m, "type         : shash\n");
 346         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 347         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
 348         seq_printf(m, "descsize     : %u\n", salg->descsize);
 349 }
 350
 351 static const struct crypto_type crypto_shash_type = {
 352         .ctxsize = crypto_shash_ctxsize,
 353         .extsize = crypto_shash_extsize,
 354         .init = crypto_init_shash_ops,
 355         .init_tfm = crypto_shash_init_tfm,
 356 #ifdef CONFIG_PROC_FS
 357         .show = crypto_shash_show,
 358 #endif
 359         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 360         .maskset = CRYPTO_ALG_TYPE_MASK,
 361         .type = CRYPTO_ALG_TYPE_SHASH,
 362         .tfmsize = offsetof(struct crypto_shash, base),
 363 };
 364
 365 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 366                                         u32 mask)
 367 {
 368         return __crypto_shash_cast(
 369                 crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask));
 370 }
 371 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 372
 373 int crypto_register_shash(struct shash_alg *alg)
 374 {
 375         struct crypto_alg *base = &alg->base;
 376
 377         if (alg->digestsize > PAGE_SIZE / 8 ||
 378             alg->descsize > PAGE_SIZE / 8)
 379                 return -EINVAL;
 380
 381         base->cra_type = &crypto_shash_type;
 382         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 383         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
 384
 385         return crypto_register_alg(base);
 386 }
 387 EXPORT_SYMBOL_GPL(crypto_register_shash);
 388
 389 int crypto_unregister_shash(struct shash_alg *alg)
 390 {
 391         return crypto_unregister_alg(&alg->base);
 392 }
 393 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
 394
 395 MODULE_LICENSE("GPL");
 396 MODULE_DESCRIPTION("Synchronous cryptographic hash type");