LXR qemu/crypto/pbkdf-gnutls.c

   1/*
   2 * QEMU Crypto PBKDF support (Password-Based Key Derivation Function)
   3 *
   4 * Copyright (c) 2021 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 2.1 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 <gnutls/crypto.h>
  23#include "qapi/error.h"
  24#include "crypto/pbkdf.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_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
  42int 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] = GNUTLS_DIG_MD5,
  51        [QCRYPTO_HASH_ALG_SHA1] = GNUTLS_DIG_SHA1,
  52        [QCRYPTO_HASH_ALG_SHA224] = GNUTLS_DIG_SHA224,
  53        [QCRYPTO_HASH_ALG_SHA256] = GNUTLS_DIG_SHA256,
  54        [QCRYPTO_HASH_ALG_SHA384] = GNUTLS_DIG_SHA384,
  55        [QCRYPTO_HASH_ALG_SHA512] = GNUTLS_DIG_SHA512,
  56        [QCRYPTO_HASH_ALG_RIPEMD160] = GNUTLS_DIG_RMD160,
  57    };
  58    int ret;
  59    const gnutls_datum_t gkey = { (unsigned char *)key, nkey };
  60    const gnutls_datum_t gsalt = { (unsigned char *)salt, nsalt };
  61
  62    if (iterations > ULONG_MAX) {
  63        error_setg_errno(errp, ERANGE,
  64                         "PBKDF iterations %llu must be less than %lu",
  65                         (long long unsigned)iterations, ULONG_MAX);
  66        return -1;
  67    }
  68
  69    if (hash >= G_N_ELEMENTS(hash_map) ||
  70        hash_map[hash] == GNUTLS_DIG_UNKNOWN) {
  71        error_setg_errno(errp, ENOSYS,
  72                         "PBKDF does not support hash algorithm %s",
  73                         QCryptoHashAlgorithm_str(hash));
  74        return -1;
  75    }
  76
  77    ret = gnutls_pbkdf2(hash_map[hash],
  78                        &gkey,
  79                        &gsalt,
  80                        iterations,
  81                        out,
  82                        nout);
  83    if (ret != 0) {
  84        error_setg(errp, "Cannot derive password: %s",
  85                   gnutls_strerror(ret));
  86        return -1;
  87    }
  88
  89    return 0;
  90}
  91