summaryrefslogtreecommitdiff
path: root/src/prime.c
blob: 4c4efd3440135936ea8f9508ed5c29e672d25ad0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
 * 2010  Free Software Foundation, Inc.
 *
 * This file is part of GnuTLS.
 *
 * GnuTLS is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuTLS is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include <config.h>

#ifdef ENABLE_PKI

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <gnutls/gnutls.h>
#include <certtool-common.h>

/* Generates Diffie-Hellman parameters (a prime and a generator
 * of the group). Exports them in PKCS #3 format. Used by certtool.
 */

extern FILE *outfile;
extern FILE *infile;

static int cparams = 0;

/* If how is zero then the included parameters are used.
 */
int
generate_prime (int how)
{
  unsigned int i;
  int ret;
  gnutls_dh_params_t dh_params;
  gnutls_datum_t p, g;
  int bits = get_bits (GNUTLS_PK_DH);

  gnutls_dh_params_init (&dh_params);

  fprintf (stderr, "Generating DH parameters...");

  if (how != 0)
    {
      ret = gnutls_dh_params_generate2 (dh_params, bits);
      if (ret < 0)
        {
          fprintf (stderr, "Error generating parameters: %s\n",
                   gnutls_strerror (ret));
          exit (1);
        }

      ret = gnutls_dh_params_export_raw (dh_params, &p, &g, NULL);
      if (ret < 0)
        {
          fprintf (stderr, "Error exporting parameters: %s\n",
                   gnutls_strerror (ret));
          exit (1);
        }
    }
  else
    {
#ifdef ENABLE_SRP
      if (bits <= 1024)
        {
          p = gnutls_srp_1024_group_prime;
          g = gnutls_srp_1024_group_generator;
        }
      else if (bits <= 1536)
        {
          p = gnutls_srp_1536_group_prime;
          g = gnutls_srp_1536_group_generator;
        }
      else
        {
          p = gnutls_srp_2048_group_prime;
          g = gnutls_srp_2048_group_generator;
        }

      ret = gnutls_dh_params_import_raw (dh_params, &p, &g);
      if (ret < 0)
        {
          fprintf (stderr, "Error exporting parameters: %s\n",
                   gnutls_strerror (ret));
          exit (1);
        }
#else
      fprintf (stderr, "Parameters unavailable as SRP disabled.\n");
#endif
    }

  if (cparams)
    {

      fprintf (outfile, "/* generator */\n");
      fprintf (outfile, "\nconst uint8 g[%d] = { ", g.size);

      for (i = 0; i < g.size; i++)
        {
          if (i % 7 == 0)
            fprintf (outfile, "\n\t");
          fprintf (outfile, "0x%.2x", g.data[i]);
          if (i != g.size - 1)
            fprintf (outfile, ", ");
        }

      fprintf (outfile, "\n};\n\n");
    }
  else
    {
      fprintf (outfile, "\nGenerator: ");

      for (i = 0; i < g.size; i++)
        {
          if (i != 0 && i % 12 == 0)
            fprintf (outfile, "\n\t");
          else if (i != 0 && i != g.size)
            fprintf (outfile, ":");

          fprintf (outfile, "%.2x", g.data[i]);
        }

      fprintf (outfile, "\n\n");
    }

  /* print prime */

  if (cparams)
    {
      fprintf (outfile, "/* prime - %d bits */\n", p.size * 8);
      fprintf (outfile, "\nconst uint8 prime[%d] = { ", p.size);

      for (i = 0; i < p.size; i++)
        {
          if (i % 7 == 0)
            fprintf (outfile, "\n\t");
          fprintf (outfile, "0x%.2x", p.data[i]);
          if (i != p.size - 1)
            fprintf (outfile, ", ");
        }

      fprintf (outfile, "\n};\n");
    }
  else
    {
      fprintf (outfile, "Prime: ");

      for (i = 0; i < p.size; i++)
        {
          if (i != 0 && i % 12 == 0)
            fprintf (outfile, "\n\t");
          else if (i != 0 && i != p.size)
            fprintf (outfile, ":");
          fprintf (outfile, "%.2x", p.data[i]);
        }

      fprintf (outfile, "\n\n");

    }

  if (!cparams)
    {                           /* generate a PKCS#3 structure */

      size_t len = buffer_size;

      ret = gnutls_dh_params_export_pkcs3 (dh_params, GNUTLS_X509_FMT_PEM,
                                           buffer, &len);

      if (ret == 0)
        {
          fprintf (outfile, "\n%s", buffer);
        }
      else
        {
          fprintf (stderr, "Error: %s\n", gnutls_strerror (ret));
        }

    }

  return 0;
}

#endif