Bug Summary

File:src/dh.c
Location:line 198, column 11
Description:Value stored to 'bits' is never read

Annotated Source Code

1/*
2 * Copyright (C) 2001-2012 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuTLS.
5 *
6 * GnuTLS is free software: you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuTLS is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see
18 * <http://www.gnu.org/licenses/>.
19 */
20
21#include <config.h>
22
23#ifdef ENABLE_PKI1
24
25#include <stdio.h>
26#include <string.h>
27#include <stdlib.h>
28#include <unistd.h>
29#include <gnutls/gnutls.h>
30#include <read-file.h>
31#include <certtool-common.h>
32
33/* Generates Diffie-Hellman parameters (a prime and a generator
34 * of the group). Exports them in PKCS #3 format. Used by certtool.
35 */
36
37extern FILE *outfile;
38extern FILE *infile;
39
40static void
41print_dh_info (gnutls_datum_t * p, gnutls_datum_t * g, unsigned int q_bits)
42{
43int i;
44
45 fprintf (outfile, "\nGenerator (%d bits): ", g->size*8);
46
47 for (i = 0; i < g->size; i++)
48 {
49 if (i != 0 && i % 12 == 0)
50 fprintf (outfile, "\n\t");
51 else if (i != 0 && i != g->size)
52 fprintf (outfile, ":");
53
54 fprintf (outfile, "%.2x", g->data[i]);
55 }
56
57 fprintf (outfile, "\n\n");
58
59 /* print prime */
60
61 fprintf (outfile, "Prime (%d bits):", p->size*8);
62
63 for (i = 0; i < p->size; i++)
64 {
65 if (i % 12 == 0)
66 fprintf (outfile, "\n\t");
67 else if (i != 0 && i != p->size)
68 fprintf (outfile, ":");
69 fprintf (outfile, "%.2x", p->data[i]);
70 }
71
72 if (q_bits > 0)
73 fprintf (outfile, "\n\nRecommended key length: %d bits\n", q_bits);
74 fprintf (outfile, "\n");
75
76}
77
78void dh_info (common_info_st * ci)
79{
80 gnutls_datum_t params;
81 size_t size;
82 int ret;
83 gnutls_dh_params_t dh_params;
84 gnutls_datum_t p, g;
85 unsigned int q_bits = 0;
86
87 if (gnutls_dh_params_init (&dh_params) < 0)
88 {
89 fprintf (stderrstderr, "Error in dh parameter initialization\n");
90 exit (1);
91 }
92
93 params.data = fread_file_gnutls_fread_file (infile, &size);
94 params.size = size;
95
96 ret =
97 gnutls_dh_params_import_pkcs3 (dh_params, &params, GNUTLS_X509_FMT_PEM);
98 if (ret < 0)
99 {
100 fprintf (stderrstderr, "Error parsing dh params: %s\n", gnutls_strerror (ret));
101 exit (1);
102 }
103
104 ret = gnutls_dh_params_export_raw (dh_params, &p, &g, &q_bits);
105 if (ret < 0)
106 {
107 fprintf (stderrstderr, "Error exporting parameters: %s\n",
108 gnutls_strerror (ret));
109 exit (1);
110 }
111
112 print_dh_info (&p, &g, q_bits);
113
114 { /* generate a PKCS#3 structure */
115 size_t len = buffer_size;
116
117 ret = gnutls_dh_params_export_pkcs3 (dh_params, GNUTLS_X509_FMT_PEM,
118 buffer, &len);
119
120 if (ret == 0)
121 {
122 fprintf (outfile, "\n%s", buffer);
123 }
124 else
125 {
126 fprintf (stderrstderr, "Error: %s\n", gnutls_strerror (ret));
127 }
128
129 }
130
131 gnutls_dh_params_deinit(dh_params);
132}
133
134/* If how is zero then the included parameters are used.
135 */
136int
137generate_prime (int how, common_info_st * info)
138{
139 int ret;
140 gnutls_dh_params_t dh_params;
141 gnutls_datum_t p, g;
142 int bits = get_bits (GNUTLS_PK_DH, info->bits, info->sec_param);
143 unsigned int q_bits = 0;
144
145 gnutls_dh_params_init (&dh_params);
146
147 if (how != 0)
148 {
149 fprintf (stderrstderr, "Generating DH parameters (%d bits)...\n", bits);
150 fprintf (stderrstderr, "(might take long time)\n");
151 }
152 else
153 fprintf (stderrstderr, "Retrieving DH parameters...\n");
154
155 if (how != 0)
156 {
157 ret = gnutls_dh_params_generate2 (dh_params, bits);
158 if (ret < 0)
159 {
160 fprintf (stderrstderr, "Error generating parameters: %s\n",
161 gnutls_strerror (ret));
162 exit (1);
163 }
164
165 ret = gnutls_dh_params_export_raw (dh_params, &p, &g, &q_bits);
166 if (ret < 0)
167 {
168 fprintf (stderrstderr, "Error exporting parameters: %s\n",
169 gnutls_strerror (ret));
170 exit (1);
171 }
172 }
173 else
174 {
175#ifdef ENABLE_SRP1
176 if (bits <= 1024)
177 {
178 p = gnutls_srp_1024_group_prime;
179 g = gnutls_srp_1024_group_generator;
180 bits = 1024;
181 }
182 else if (bits <= 1536)
183 {
184 p = gnutls_srp_1536_group_prime;
185 g = gnutls_srp_1536_group_generator;
186 bits = 1536;
187 }
188 else if (bits <= 2048)
189 {
190 p = gnutls_srp_2048_group_prime;
191 g = gnutls_srp_2048_group_generator;
192 bits = 2048;
193 }
194 else if (bits <= 3072)
195 {
196 p = gnutls_srp_3072_group_prime;
197 g = gnutls_srp_3072_group_generator;
198 bits = 3072;
Value stored to 'bits' is never read
199 }
200 else
201 {
202 p = gnutls_srp_4096_group_prime;
203 g = gnutls_srp_4096_group_generator;
204 bits = 4096;
205 }
206
207 ret = gnutls_dh_params_import_raw (dh_params, &p, &g);
208 if (ret < 0)
209 {
210 fprintf (stderrstderr, "Error exporting parameters: %s\n",
211 gnutls_strerror (ret));
212 exit (1);
213 }
214#else
215 fprintf (stderrstderr, "Parameters unavailable as SRP is disabled.\n");
216 exit (1);
217#endif
218 }
219
220 print_dh_info (&p, &g, q_bits);
221
222 { /* generate a PKCS#3 structure */
223 size_t len = buffer_size;
224
225 ret = gnutls_dh_params_export_pkcs3 (dh_params, GNUTLS_X509_FMT_PEM,
226 buffer, &len);
227
228 if (ret == 0)
229 {
230 fprintf (outfile, "\n%s", buffer);
231 }
232 else
233 {
234 fprintf (stderrstderr, "Error: %s\n", gnutls_strerror (ret));
235 }
236
237 }
238
239 gnutls_dh_params_deinit(dh_params);
240
241 return 0;
242}
243
244#endif