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_SHA224:
  32     case QCRYPTO_HASH_ALG_SHA256:
  33     case QCRYPTO_HASH_ALG_SHA384:
  34     case QCRYPTO_HASH_ALG_SHA512:
  35     case QCRYPTO_HASH_ALG_RIPEMD160:
  36         return true;
  37     default:
  38         return false;
  39     }
  40 }
  41
  42 int qcrypto_pbkdf2(QCryptoHashAlgorithm hash,
  43                    const uint8_t *key, size_t nkey,
  44                    const uint8_t *salt, size_t nsalt,
  45                    uint64_t iterations,
  46                    uint8_t *out, size_t nout,
  47                    Error **errp)
  48 {
  49     static const int hash_map[QCRYPTO_HASH_ALG__MAX] = {
  50         [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5,
  51         [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1,
  52         [QCRYPTO_HASH_ALG_SHA224] = GCRY_MD_SHA224,
  53         [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256,
  54         [QCRYPTO_HASH_ALG_SHA384] = GCRY_MD_SHA384,
  55         [QCRYPTO_HASH_ALG_SHA512] = GCRY_MD_SHA512,
  56         [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MD_RMD160,
  57     };
  58     int ret;
  59
  60     if (iterations > ULONG_MAX) {
  61         error_setg_errno(errp, ERANGE,
  62                          "PBKDF iterations %llu must be less than %lu",
  63                          (long long unsigned)iterations, ULONG_MAX);
  64         return -1;
  65     }
  66
  67     if (hash >= G_N_ELEMENTS(hash_map) ||
  68         hash_map[hash] == GCRY_MD_NONE) {
  69         error_setg_errno(errp, ENOSYS,
  70                          "PBKDF does not support hash algorithm %s",
  71                          QCryptoHashAlgorithm_str(hash));
  72         return -1;
  73     }
  74
  75     ret = gcry_kdf_derive(key, nkey, GCRY_KDF_PBKDF2,
  76                           hash_map[hash],
  77                           salt, nsalt, iterations,
  78                           nout, out);
  79     if (ret != 0) {
  80         error_setg(errp, "Cannot derive password: %s",
  81                    gcry_strerror(ret));
  82         return -1;
  83     }
  84
  85     return 0;
  86 }