src/prime.c

   1 /*
   2  * Copyright (C) 2004,2005,2007 Free Software Foundation
   3  * Copyright (C) 2001,2002,2003 Nikos Mavrogiannopoulos
   4  *
   5  * This file is part of GNUTLS.
   6  *
   7  * GNUTLS is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * GNUTLS is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22
  23 #ifdef ENABLE_PKI
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <gnutls/gnutls.h>
  30
  31 /* Generates Diffie Hellman parameters (a prime and a generator
  32  * of the group). Exports them in PKCS #3 format. Used by certtool.
  33  */
  34
  35 extern FILE *outfile;
  36 extern FILE *infile;
  37 extern unsigned char buffer[];
  38 extern const int buffer_size;
  39
  40 static int cparams = 0;
  41
  42 /* If how is zero then the included parameters are used.
  43  */
  44 int
  45 generate_prime (int bits, int how)
  46 {
  47   unsigned int i;
  48   int ret;
  49   gnutls_dh_params_t dh_params;
  50   gnutls_datum_t p, g;
  51
  52   gnutls_dh_params_init (&dh_params);
  53
  54   fprintf (stderr, "Generating DH parameters...");
  55
  56   if (how != 0)
  57     {
  58       ret = gnutls_dh_params_generate2 (dh_params, bits);
  59       if (ret < 0)
  60         {
  61           fprintf (stderr, "Error generating parameters: %s\n",
  62                    gnutls_strerror (ret));
  63           exit (1);
  64         }
  65
  66       ret = gnutls_dh_params_export_raw (dh_params, &p, &g, NULL);
  67       if (ret < 0)
  68         {
  69           fprintf (stderr, "Error exporting parameters: %s\n",
  70                    gnutls_strerror (ret));
  71           exit (1);
  72         }
  73     }
  74   else
  75     {
  76 #ifdef ENABLE_SRP
  77       if (bits <= 1024)
  78         {
  79           p = gnutls_srp_1024_group_prime;
  80           g = gnutls_srp_1024_group_generator;
  81         }
  82       else if (bits <= 1536)
  83         {
  84           p = gnutls_srp_1536_group_prime;
  85           g = gnutls_srp_1536_group_generator;
  86         }
  87       else
  88         {
  89           p = gnutls_srp_2048_group_prime;
  90           g = gnutls_srp_2048_group_generator;
  91         }
  92
  93       ret = gnutls_dh_params_import_raw (dh_params, &p, &g);
  94       if (ret < 0)
  95         {
  96           fprintf (stderr, "Error exporting parameters: %s\n",
  97                    gnutls_strerror (ret));
  98           exit (1);
  99         }
 100 #else
 101       fprintf (stderr, "Parameters unavailable as SRP disabled.\n");
 102 #endif
 103     }
 104
 105   if (cparams)
 106     {
 107
 108       fprintf (outfile, "/* generator */\n");
 109       fprintf (outfile, "\nconst uint8 g[%d] = { ", g.size);
 110
 111       for (i = 0; i < g.size; i++)
 112         {
 113           if (i % 7 == 0)
 114             fprintf (outfile, "\n\t");
 115           fprintf (outfile, "0x%.2x", g.data[i]);
 116           if (i != g.size - 1)
 117             fprintf (outfile, ", ");
 118         }
 119
 120       fprintf (outfile, "\n};\n\n");
 121     }
 122   else
 123     {
 124       fprintf (outfile, "\nGenerator: ");
 125
 126       for (i = 0; i < g.size; i++)
 127         {
 128           if (i != 0 && i % 12 == 0)
 129             fprintf (outfile, "\n\t");
 130           else if (i != 0 && i != g.size)
 131             fprintf (outfile, ":");
 132
 133           fprintf (outfile, "%.2x", g.data[i]);
 134         }
 135
 136       fprintf (outfile, "\n\n");
 137     }
 138
 139   /* print prime */
 140
 141   if (cparams)
 142     {
 143       fprintf (outfile, "/* prime - %d bits */\n", p.size * 8);
 144       fprintf (outfile, "\nconst uint8 prime[%d] = { ", p.size);
 145
 146       for (i = 0; i < p.size; i++)
 147         {
 148           if (i % 7 == 0)
 149             fprintf (outfile, "\n\t");
 150           fprintf (outfile, "0x%.2x", p.data[i]);
 151           if (i != p.size - 1)
 152             fprintf (outfile, ", ");
 153         }
 154
 155       fprintf (outfile, "\n};\n");
 156     }
 157   else
 158     {
 159       fprintf (outfile, "Prime: ");
 160
 161       for (i = 0; i < p.size; i++)
 162         {
 163           if (i != 0 && i % 12 == 0)
 164             fprintf (outfile, "\n\t");
 165           else if (i != 0 && i != p.size)
 166             fprintf (outfile, ":");
 167           fprintf (outfile, "%.2x", p.data[i]);
 168         }
 169
 170       fprintf (outfile, "\n\n");
 171
 172     }
 173
 174   if (!cparams)
 175     {                           /* generate a PKCS#3 structure */
 176
 177       int ret;
 178       size_t len = buffer_size;
 179
 180       ret = gnutls_dh_params_export_pkcs3 (dh_params, GNUTLS_X509_FMT_PEM,
 181                                            buffer, &len);
 182
 183       if (ret == 0)
 184         {
 185           fprintf (outfile, "\n%s", buffer);
 186         }
 187       else
 188         {
 189           fprintf (stderr, "Error: %s\n", gnutls_strerror (ret));
 190         }
 191
 192     }
 193
 194   return 0;
 195 }
 196
 197 #endif