lib/crypto/gnutls_weak_crypto.c

   1 /*
   2  * Copyright (c) 2019      Andreas Schneider <asn@samba.org>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "includes.h"
  19 #include "lib/crypto/gnutls_helpers.h"
  20
  21 #include <gnutls/crypto.h>
  22 #include <gnutls/gnutls.h>
  23
  24 bool samba_gnutls_weak_crypto_allowed(void)
  25 {
  26         gnutls_cipher_hd_t cipher_hnd = NULL;
  27         gnutls_datum_t key = {
  28                 .data = discard_const_p(unsigned char, "SystemLibraryDTC"),
  29                 .size = 16,
  30         };
  31         int rc;
  32
  33         /*
  34          * If we can't initialize RC4 then weak crypto is not allowed.
  35          */
  36         rc = gnutls_cipher_init(&cipher_hnd,
  37                                 GNUTLS_CIPHER_ARCFOUR_128,
  38                                 &key,
  39                                 NULL);
  40         if (rc == GNUTLS_E_UNWANTED_ALGORITHM) {
  41                 return false;
  42         }
  43
  44         gnutls_cipher_deinit(cipher_hnd);
  45
  46         return true;
  47 }