LXR qemu/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 "qapi/error.h"
  23#include "crypto/pbkdf.h"
  24#include "gcrypt.h"
  25
  26bool 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
  38int 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}
  70