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
  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] = 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 }