lib/auth_anon.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation
   3  *
   4  * Author: Nikos Mavrogiannopoulos
   5  *
   6  * This file is part of GNUTLS.
   7  *
   8  * The GNUTLS library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 2.1 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  21  * USA
  22  *
  23  */
  24
  25 /* This file contains the Anonymous Diffie Hellman key exchange part of
  26  * the anonymous authentication. The functions here are used in the
  27  * handshake.
  28  */
  29
  30 #include <gnutls_int.h>
  31
  32 #ifdef ENABLE_ANON
  33
  34 #include "gnutls_auth_int.h"
  35 #include "gnutls_errors.h"
  36 #include "gnutls_dh.h"
  37 #include "auth_anon.h"
  38 #include "gnutls_num.h"
  39 #include "gnutls_mpi.h"
  40 #include <gnutls_state.h>
  41 #include <auth_dh_common.h>
  42
  43 static int gen_anon_server_kx (gnutls_session_t, opaque **);
  44 static int proc_anon_client_kx (gnutls_session_t, opaque *, size_t);
  45 static int proc_anon_server_kx (gnutls_session_t, opaque *, size_t);
  46
  47 const mod_auth_st anon_auth_struct = {
  48   "ANON",
  49   NULL,
  50   NULL,
  51   gen_anon_server_kx,
  52   _gnutls_gen_dh_common_client_kx,      /* this can be shared */
  53   NULL,
  54   NULL,
  55
  56   NULL,
  57   NULL,                         /* certificate */
  58   proc_anon_server_kx,
  59   proc_anon_client_kx,
  60   NULL,
  61   NULL
  62 };
  63
  64 static int
  65 gen_anon_server_kx (gnutls_session_t session, opaque ** data)
  66 {
  67   mpi_t g, p;
  68   const mpi_t *mpis;
  69   int ret;
  70   gnutls_dh_params_t dh_params;
  71   gnutls_anon_server_credentials_t cred;
  72
  73   cred = (gnutls_anon_server_credentials_t)
  74     _gnutls_get_cred (session->key, GNUTLS_CRD_ANON, NULL);
  75   if (cred == NULL)
  76     {
  77       gnutls_assert ();
  78       return GNUTLS_E_INSUFFICIENT_CREDENTIALS;
  79     }
  80
  81   dh_params =
  82     _gnutls_get_dh_params (cred->dh_params, cred->params_func, session);
  83   mpis = _gnutls_dh_params_to_mpi (dh_params);
  84   if (mpis == NULL)
  85     {
  86       gnutls_assert ();
  87       return GNUTLS_E_NO_TEMPORARY_DH_PARAMS;
  88     }
  89
  90   p = mpis[0];
  91   g = mpis[1];
  92
  93   if ((ret =
  94        _gnutls_auth_info_set (session, GNUTLS_CRD_ANON,
  95                               sizeof (anon_auth_info_st), 1)) < 0)
  96     {
  97       gnutls_assert ();
  98       return ret;
  99     }
 100
 101   _gnutls_dh_set_group (session, g, p);
 102
 103   ret = _gnutls_dh_common_print_server_kx (session, g, p, data, 0);
 104   if (ret < 0)
 105     {
 106       gnutls_assert ();
 107     }
 108
 109   return ret;
 110 }
 111
 112
 113 static int
 114 proc_anon_client_kx (gnutls_session_t session, opaque * data,
 115                      size_t _data_size)
 116 {
 117   gnutls_anon_server_credentials_t cred;
 118   int bits;
 119   int ret;
 120   mpi_t p, g;
 121   gnutls_dh_params_t dh_params;
 122   const mpi_t *mpis;
 123
 124   bits = _gnutls_dh_get_allowed_prime_bits (session);
 125
 126   cred = (gnutls_anon_server_credentials_t)
 127     _gnutls_get_cred (session->key, GNUTLS_CRD_ANON, NULL);
 128   if (cred == NULL)
 129     {
 130       gnutls_assert ();
 131       return GNUTLS_E_INSUFFICIENT_CREDENTIALS;
 132     }
 133
 134   dh_params =
 135     _gnutls_get_dh_params (cred->dh_params, cred->params_func, session);
 136   mpis = _gnutls_dh_params_to_mpi (dh_params);
 137   if (mpis == NULL)
 138     {
 139       gnutls_assert ();
 140       return GNUTLS_E_NO_TEMPORARY_DH_PARAMS;
 141     }
 142
 143   p = mpis[0];
 144   g = mpis[1];
 145
 146   ret = _gnutls_proc_dh_common_client_kx (session, data, _data_size, g, p);
 147
 148   return ret;
 149
 150 }
 151
 152 int
 153 proc_anon_server_kx (gnutls_session_t session, opaque * data,
 154                      size_t _data_size)
 155 {
 156
 157   int ret;
 158
 159   /* set auth_info */
 160   if ((ret =
 161        _gnutls_auth_info_set (session, GNUTLS_CRD_ANON,
 162                               sizeof (anon_auth_info_st), 1)) < 0)
 163     {
 164       gnutls_assert ();
 165       return ret;
 166     }
 167
 168   ret = _gnutls_proc_dh_common_server_kx (session, data, _data_size, 0);
 169   if (ret < 0)
 170     {
 171       gnutls_assert ();
 172       return ret;
 173     }
 174
 175   return 0;
 176 }
 177
 178 #endif /* ENABLE_ANON */