lib/crypto/gnutls_arcfour_confounded_md5.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Wrapper for gnutls hash and encryption functions
   4
   5    Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009-2019
   7    Copyright (c) Andreas Schneider <asn@samba.org> 2019
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 */
  23
  24 /*
  25  * This (arcfour over data with a key combined from two imputs, one
  26  * the key another the confounder), is a common pattern in pre-AES
  27  * windows cryptography
  28  *
  29  * Some protocols put the confounder first, others second so both
  30  * parameters are named key_input here.
  31  *
  32  */
  33
  34 #include "includes.h"
  35 #include "lib/util/data_blob.h"
  36 #include <gnutls/gnutls.h>
  37 #include <gnutls/crypto.h>
  38 #include "gnutls_helpers.h"
  39 #include "lib/util/memory.h"
  40
  41 int samba_gnutls_arcfour_confounded_md5(const DATA_BLOB *key_input1,
  42                                         const DATA_BLOB *key_input2,
  43                                         DATA_BLOB *data,
  44                                         enum samba_gnutls_direction encrypt)
  45 {
  46         int rc;
  47         gnutls_hash_hd_t hash_hnd = NULL;
  48         uint8_t confounded_key[16];
  49         gnutls_cipher_hd_t cipher_hnd = NULL;
  50         gnutls_datum_t confounded_key_datum = {
  51                 .data = confounded_key,
  52                 .size = sizeof(confounded_key),
  53         };
  54
  55         rc = gnutls_hash_init(&hash_hnd, GNUTLS_DIG_MD5);
  56         if (rc < 0) {
  57                 return rc;
  58         }
  59         rc = gnutls_hash(hash_hnd, key_input1->data, key_input1->length);
  60         if (rc < 0) {
  61                 gnutls_hash_deinit(hash_hnd, NULL);
  62                 return rc;
  63         }
  64         rc = gnutls_hash(hash_hnd, key_input2->data, key_input2->length);
  65         if (rc < 0) {
  66                 gnutls_hash_deinit(hash_hnd, NULL);
  67                 return rc;
  68         }
  69
  70         gnutls_hash_deinit(hash_hnd, confounded_key);
  71
  72         rc = gnutls_cipher_init(&cipher_hnd,
  73                                 GNUTLS_CIPHER_ARCFOUR_128,
  74                                 &confounded_key_datum,
  75                                 NULL);
  76         if (rc < 0) {
  77                 return rc;
  78         }
  79
  80         if (encrypt == SAMBA_GNUTLS_ENCRYPT) {
  81                 rc = gnutls_cipher_encrypt(cipher_hnd,
  82                                            data->data,
  83                                            data->length);
  84         } else {
  85                 rc = gnutls_cipher_decrypt(cipher_hnd,
  86                                            data->data,
  87                                            data->length);
  88         }
  89         gnutls_cipher_deinit(cipher_hnd);
  90         ZERO_ARRAY(confounded_key);
  91
  92         return rc;
  93 }