xref: /openbsd/usr.bin/openssl/gendh.c (revision 5af055cd)
1 /* $OpenBSD: gendh.c,v 1.7 2015/10/17 15:00:11 doug Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 #include <openssl/opensslconf.h>
60 
61 /* Until the key-gen callbacks are modified to use newer prototypes, we allow
62  * deprecated functions for openssl-internal code */
63 #ifdef OPENSSL_NO_DEPRECATED
64 #undef OPENSSL_NO_DEPRECATED
65 #endif
66 
67 #ifndef OPENSSL_NO_DH
68 
69 #include <sys/types.h>
70 #include <sys/stat.h>
71 
72 #include <limits.h>
73 #include <stdio.h>
74 #include <string.h>
75 
76 #include "apps.h"
77 
78 #include <openssl/bio.h>
79 #include <openssl/bn.h>
80 #include <openssl/dh.h>
81 #include <openssl/err.h>
82 #include <openssl/pem.h>
83 #include <openssl/x509.h>
84 
85 #define DEFBITS	512
86 
87 static int dh_cb(int p, int n, BN_GENCB * cb);
88 
89 static struct {
90 	int g;
91 	char *outfile;
92 } gendh_config;
93 
94 static struct option gendh_options[] = {
95 	{
96 		.name = "2",
97 		.desc = "Generate DH parameters with a generator value of 2 "
98 		    "(default)",
99 		.type = OPTION_VALUE,
100 		.value = 2,
101 		.opt.value = &gendh_config.g,
102 	},
103 	{
104 		.name = "5",
105 		.desc = "Generate DH parameters with a generator value of 5",
106 		.type = OPTION_VALUE,
107 		.value = 5,
108 		.opt.value = &gendh_config.g,
109 	},
110 	{
111 		.name = "out",
112 		.argname = "file",
113 		.desc = "Output file (default stdout)",
114 		.type = OPTION_ARG,
115 		.opt.arg = &gendh_config.outfile,
116 	},
117 	{ NULL },
118 };
119 
120 static void
121 gendh_usage(void)
122 {
123 	fprintf(stderr,
124 	    "usage: gendh [-2 | -5] [-out file] [numbits]\n\n");
125 	options_usage(gendh_options);
126 }
127 
128 int
129 gendh_main(int argc, char **argv)
130 {
131 	BN_GENCB cb;
132 	DH *dh = NULL;
133 	int ret = 1, numbits = DEFBITS;
134 	BIO *out = NULL;
135 	char *strbits = NULL;
136 
137 	if (single_execution) {
138 		if (pledge("stdio rpath wpath cpath", NULL) == -1) {
139 			perror("pledge");
140 			exit(1);
141 		}
142 	}
143 
144 	BN_GENCB_set(&cb, dh_cb, bio_err);
145 
146 	memset(&gendh_config, 0, sizeof(gendh_config));
147 
148 	gendh_config.g = 2;
149 
150 	if (options_parse(argc, argv, gendh_options, &strbits, NULL) != 0) {
151 		gendh_usage();
152 		goto end;
153 	}
154 
155 	if (strbits != NULL) {
156 		const char *errstr;
157 		numbits = strtonum(strbits, 0, INT_MAX, &errstr);
158 		if (errstr) {
159 			fprintf(stderr, "Invalid number of bits: %s\n", errstr);
160 			goto end;
161 		}
162 	}
163 
164 	out = BIO_new(BIO_s_file());
165 	if (out == NULL) {
166 		ERR_print_errors(bio_err);
167 		goto end;
168 	}
169 	if (gendh_config.outfile == NULL) {
170 		BIO_set_fp(out, stdout, BIO_NOCLOSE);
171 	} else {
172 		if (BIO_write_filename(out, gendh_config.outfile) <= 0) {
173 			perror(gendh_config.outfile);
174 			goto end;
175 		}
176 	}
177 
178 	BIO_printf(bio_err, "Generating DH parameters, %d bit long safe prime,"
179 	    " generator %d\n", numbits, gendh_config.g);
180 	BIO_printf(bio_err, "This is going to take a long time\n");
181 
182 	if (((dh = DH_new()) == NULL) ||
183 	    !DH_generate_parameters_ex(dh, numbits, gendh_config.g, &cb))
184 		goto end;
185 
186 	if (!PEM_write_bio_DHparams(out, dh))
187 		goto end;
188 	ret = 0;
189 end:
190 	if (ret != 0)
191 		ERR_print_errors(bio_err);
192 	if (out != NULL)
193 		BIO_free_all(out);
194 	if (dh != NULL)
195 		DH_free(dh);
196 
197 	return (ret);
198 }
199 
200 static int
201 dh_cb(int p, int n, BN_GENCB * cb)
202 {
203 	char c = '*';
204 
205 	if (p == 0)
206 		c = '.';
207 	if (p == 1)
208 		c = '+';
209 	if (p == 2)
210 		c = '*';
211 	if (p == 3)
212 		c = '\n';
213 	BIO_write(cb->arg, &c, 1);
214 	(void) BIO_flush(cb->arg);
215 	return 1;
216 }
217 #endif
218