crypto/pbkdf-gcrypt.c

   1 /*
   2  * QEMU Crypto PBKDF support (Password-Based Key Derivation Function)
   3  *
   4  * Copyright (c) 2015-2016 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include <gcrypt.h>
  23 #include "qapi/error.h"
  24 #include "crypto/pbkdf.h"
  25
  26 bool qcrypto_pbkdf2_supports(QCryptoHashAlgorithm hash)
  27 {
  28     switch (hash) {
  29     case QCRYPTO_HASH_ALG_MD5:
  30     case QCRYPTO_HASH_ALG_SHA1:
  31     case QCRYPTO_HASH_ALG_SHA256:
  32         return true;
  33     default:
  34         return false;
  35     }
  36 }
  37
  38 int qcrypto_pbkdf2(QCryptoHashAlgorithm hash,
  39                    const uint8_t *key, size_t nkey,
  40                    const uint8_t *salt, size_t nsalt,
  41                    unsigned int iterations,
  42                    uint8_t *out, size_t nout,
  43                    Error **errp)
  44 {
  45     static const int hash_map[QCRYPTO_HASH_ALG__MAX] = {
  46         [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5,
  47         [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1,
  48         [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256,
  49     };
  50     int ret;
  51
  52     if (hash >= G_N_ELEMENTS(hash_map) ||
  53         hash_map[hash] == GCRY_MD_NONE) {
  54         error_setg(errp, "Unexpected hash algorithm %d", hash);
  55         return -1;
  56     }
  57
  58     ret = gcry_kdf_derive(key, nkey, GCRY_KDF_PBKDF2,
  59                           hash_map[hash],
  60                           salt, nsalt, iterations,
  61                           nout, out);
  62     if (ret != 0) {
  63         error_setg(errp, "Cannot derive password: %s",
  64                    gcry_strerror(ret));
  65         return -1;
  66     }
  67
  68     return 0;
  69 }