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 "crypto/pbkdf.h"
  23 #include "gcrypt.h"
  24
  25 bool qcrypto_pbkdf2_supports(QCryptoHashAlgorithm hash)
  26 {
  27     switch (hash) {
  28     case QCRYPTO_HASH_ALG_MD5:
  29     case QCRYPTO_HASH_ALG_SHA1:
  30     case QCRYPTO_HASH_ALG_SHA256:
  31         return true;
  32     default:
  33         return false;
  34     }
  35 }
  36
  37 int qcrypto_pbkdf2(QCryptoHashAlgorithm hash,
  38                    const uint8_t *key, size_t nkey,
  39                    const uint8_t *salt, size_t nsalt,
  40                    unsigned int iterations,
  41                    uint8_t *out, size_t nout,
  42                    Error **errp)
  43 {
  44     static const int hash_map[QCRYPTO_HASH_ALG__MAX] = {
  45         [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5,
  46         [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1,
  47         [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256,
  48     };
  49     int ret;
  50
  51     if (hash >= G_N_ELEMENTS(hash_map) ||
  52         hash_map[hash] == GCRY_MD_NONE) {
  53         error_setg(errp, "Unexpected hash algorithm %d", hash);
  54         return -1;
  55     }
  56
  57     ret = gcry_kdf_derive(key, nkey, GCRY_KDF_PBKDF2,
  58                           hash_map[hash],
  59                           salt, nsalt, iterations,
  60                           nout, out);
  61     if (ret != 0) {
  62         error_setg(errp, "Cannot derive password: %s",
  63                    gcry_strerror(ret));
  64         return -1;
  65     }
  66
  67     return 0;
  68 }