xref: /openbsd-src/usr.bin/openssl/dhparam.c (revision a9d90585ca40c280201dda70d6b331b26701653a)
1 /* $OpenBSD: dhparam.c,v 1.19 2025/01/19 10:24:17 tb 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  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  *
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  *
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in
70  *    the documentation and/or other materials provided with the
71  *    distribution.
72  *
73  * 3. All advertising materials mentioning features or use of this
74  *    software must display the following acknowledgment:
75  *    "This product includes software developed by the OpenSSL Project
76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77  *
78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79  *    endorse or promote products derived from this software without
80  *    prior written permission. For written permission, please contact
81  *    openssl-core@openssl.org.
82  *
83  * 5. Products derived from this software may not be called "OpenSSL"
84  *    nor may "OpenSSL" appear in their names without prior written
85  *    permission of the OpenSSL Project.
86  *
87  * 6. Redistributions of any form whatsoever must retain the following
88  *    acknowledgment:
89  *    "This product includes software developed by the OpenSSL Project
90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91  *
92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103  * OF THE POSSIBILITY OF SUCH DAMAGE.
104  * ====================================================================
105  *
106  * This product includes cryptographic software written by Eric Young
107  * (eay@cryptsoft.com).  This product includes software written by Tim
108  * Hudson (tjh@cryptsoft.com).
109  *
110  */
111 
112 #include <openssl/opensslconf.h>	/* for OPENSSL_NO_DH */
113 
114 #ifndef OPENSSL_NO_DH
115 
116 #include <stdio.h>
117 #include <stdlib.h>
118 #include <string.h>
119 #include <time.h>
120 
121 #include "apps.h"
122 
123 #include <openssl/bio.h>
124 #include <openssl/bn.h>
125 #include <openssl/err.h>
126 #include <openssl/dh.h>
127 #include <openssl/pem.h>
128 #include <openssl/x509.h>
129 
130 #include <openssl/dsa.h>
131 
132 #define DEFBITS	2048
133 
134 static struct {
135 	int check;
136 	int dsaparam;
137 	int g;
138 	char *infile;
139 	int informat;
140 	int noout;
141 	char *outfile;
142 	int outformat;
143 	int text;
144 } cfg;
145 
146 static const struct option dhparam_options[] = {
147 	{
148 		.name = "2",
149 		.desc = "Generate DH parameters with a generator value of 2 "
150 		    "(default)",
151 		.type = OPTION_VALUE,
152 		.opt.value = &cfg.g,
153 		.value = 2,
154 	},
155 	{
156 		.name = "5",
157 		.desc = "Generate DH parameters with a generator value of 5",
158 		.type = OPTION_VALUE,
159 		.opt.value = &cfg.g,
160 		.value = 5,
161 	},
162 	{
163 		.name = "check",
164 		.desc = "Check the DH parameters",
165 		.type = OPTION_FLAG,
166 		.opt.flag = &cfg.check,
167 	},
168 	{
169 		.name = "dsaparam",
170 		.desc = "Read or generate DSA parameters and convert to DH",
171 		.type = OPTION_FLAG,
172 		.opt.flag = &cfg.dsaparam,
173 	},
174 	{
175 		.name = "in",
176 		.argname = "file",
177 		.desc = "Input file (default stdin)",
178 		.type = OPTION_ARG,
179 		.opt.arg = &cfg.infile,
180 	},
181 	{
182 		.name = "inform",
183 		.argname = "format",
184 		.desc = "Input format (DER or PEM (default))",
185 		.type = OPTION_ARG_FORMAT,
186 		.opt.value = &cfg.informat,
187 	},
188 	{
189 		.name = "noout",
190 		.desc = "Do not output encoded version of DH parameters",
191 		.type = OPTION_FLAG,
192 		.opt.flag = &cfg.noout,
193 	},
194 	{
195 		.name = "out",
196 		.argname = "file",
197 		.desc = "Output file (default stdout)",
198 		.type = OPTION_ARG,
199 		.opt.arg = &cfg.outfile,
200 	},
201 	{
202 		.name = "outform",
203 		.argname = "format",
204 		.desc = "Output format (DER or PEM (default))",
205 		.type = OPTION_ARG_FORMAT,
206 		.opt.value = &cfg.outformat,
207 	},
208 	{
209 		.name = "text",
210 		.desc = "Print DH parameters in plain text",
211 		.type = OPTION_FLAG,
212 		.opt.flag = &cfg.text,
213 	},
214 	{ NULL },
215 };
216 
217 static void
218 dhparam_usage(void)
219 {
220 	fprintf(stderr,
221 	    "usage: dhparam [-2 | -5] [-check] [-dsaparam]\n"
222 	    "    [-in file] [-inform DER | PEM] [-noout] [-out file]\n"
223 	    "    [-outform DER | PEM] [-text] [numbits]\n\n");
224 	options_usage(dhparam_options);
225 }
226 
227 static int dh_cb(int p, int n, BN_GENCB *cb);
228 
229 int
230 dhparam_main(int argc, char **argv)
231 {
232 	BIO *in = NULL, *out = NULL;
233 	BN_GENCB *cb = NULL;
234 	char *num_bits = NULL;
235 	DH *dh = NULL;
236 	int num = 0;
237 	int ret = 1;
238 	int i;
239 
240 	if (pledge("stdio cpath wpath rpath", NULL) == -1) {
241 		perror("pledge");
242 		exit(1);
243 	}
244 
245 	memset(&cfg, 0, sizeof(cfg));
246 
247 	cfg.informat = FORMAT_PEM;
248 	cfg.outformat = FORMAT_PEM;
249 
250 	if (options_parse(argc, argv, dhparam_options, &num_bits, NULL) != 0) {
251 		dhparam_usage();
252 		return (1);
253 	}
254 
255 	if (num_bits != NULL) {
256 		if(sscanf(num_bits, "%d", &num) == 0 || num <= 0) {
257 			BIO_printf(bio_err, "invalid number of bits: %s\n",
258 			    num_bits);
259 			return (1);
260 		}
261 	}
262 
263 	if (cfg.g && !num)
264 		num = DEFBITS;
265 
266 	if (cfg.dsaparam) {
267 		if (cfg.g) {
268 			BIO_printf(bio_err, "generator may not be chosen for DSA parameters\n");
269 			goto end;
270 		}
271 	} else {
272 		/* DH parameters */
273 		if (num && !cfg.g)
274 			cfg.g = 2;
275 	}
276 
277 	if (num) {
278 		if ((cb = BN_GENCB_new()) == NULL) {
279 			BIO_printf(bio_err,
280 			    "Error allocating BN_GENCB object\n");
281 			goto end;
282 		}
283 
284 		BN_GENCB_set(cb, dh_cb, bio_err);
285 		if (cfg.dsaparam) {
286 			DSA *dsa = DSA_new();
287 
288 			BIO_printf(bio_err, "Generating DSA parameters, %d bit long prime\n", num);
289 			if (!dsa || !DSA_generate_parameters_ex(dsa, num,
290 				NULL, 0, NULL, NULL, cb)) {
291 				DSA_free(dsa);
292 				ERR_print_errors(bio_err);
293 				goto end;
294 			}
295 			dh = DSA_dup_DH(dsa);
296 			DSA_free(dsa);
297 			if (dh == NULL) {
298 				ERR_print_errors(bio_err);
299 				goto end;
300 			}
301 		} else {
302 			dh = DH_new();
303 			BIO_printf(bio_err, "Generating DH parameters, %d bit long safe prime, generator %d\n", num, cfg.g);
304 			BIO_printf(bio_err, "This is going to take a long time\n");
305 			if (!dh || !DH_generate_parameters_ex(dh, num, cfg.g, cb)) {
306 				ERR_print_errors(bio_err);
307 				goto end;
308 			}
309 		}
310 	} else {
311 
312 		in = BIO_new(BIO_s_file());
313 		if (in == NULL) {
314 			ERR_print_errors(bio_err);
315 			goto end;
316 		}
317 		if (cfg.infile == NULL)
318 			BIO_set_fp(in, stdin, BIO_NOCLOSE);
319 		else {
320 			if (BIO_read_filename(in, cfg.infile) <= 0) {
321 				perror(cfg.infile);
322 				goto end;
323 			}
324 		}
325 
326 		if (cfg.informat != FORMAT_ASN1 &&
327 		    cfg.informat != FORMAT_PEM) {
328 			BIO_printf(bio_err, "bad input format specified\n");
329 			goto end;
330 		}
331 		if (cfg.dsaparam) {
332 			DSA *dsa;
333 
334 			if (cfg.informat == FORMAT_ASN1)
335 				dsa = d2i_DSAparams_bio(in, NULL);
336 			else	/* informat == FORMAT_PEM */
337 				dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL);
338 
339 			if (dsa == NULL) {
340 				BIO_printf(bio_err, "unable to load DSA parameters\n");
341 				ERR_print_errors(bio_err);
342 				goto end;
343 			}
344 			dh = DSA_dup_DH(dsa);
345 			DSA_free(dsa);
346 			if (dh == NULL) {
347 				ERR_print_errors(bio_err);
348 				goto end;
349 			}
350 		} else
351 		{
352 			if (cfg.informat == FORMAT_ASN1)
353 				dh = d2i_DHparams_bio(in, NULL);
354 			else	/* informat == FORMAT_PEM */
355 				dh = PEM_read_bio_DHparams(in, NULL, NULL, NULL);
356 
357 			if (dh == NULL) {
358 				BIO_printf(bio_err, "unable to load DH parameters\n");
359 				ERR_print_errors(bio_err);
360 				goto end;
361 			}
362 		}
363 
364 		/* dh != NULL */
365 	}
366 
367 	out = BIO_new(BIO_s_file());
368 	if (out == NULL) {
369 		ERR_print_errors(bio_err);
370 		goto end;
371 	}
372 	if (cfg.outfile == NULL) {
373 		BIO_set_fp(out, stdout, BIO_NOCLOSE);
374 	} else {
375 		if (BIO_write_filename(out, cfg.outfile) <= 0) {
376 			perror(cfg.outfile);
377 			goto end;
378 		}
379 	}
380 
381 
382 	if (cfg.text) {
383 		DHparams_print(out, dh);
384 	}
385 	if (cfg.check) {
386 		if (!DH_check(dh, &i)) {
387 			ERR_print_errors(bio_err);
388 			goto end;
389 		}
390 		if (i & DH_CHECK_P_NOT_PRIME)
391 			printf("p value is not prime\n");
392 		if (i & DH_CHECK_P_NOT_SAFE_PRIME)
393 			printf("p value is not a safe prime\n");
394 		if (i & DH_UNABLE_TO_CHECK_GENERATOR)
395 			printf("unable to check the generator value\n");
396 		if (i & DH_NOT_SUITABLE_GENERATOR)
397 			printf("the g value is not a generator\n");
398 		if (i == 0)
399 			printf("DH parameters appear to be ok.\n");
400 	}
401 	if (!cfg.noout) {
402 		if (cfg.outformat == FORMAT_ASN1)
403 			i = i2d_DHparams_bio(out, dh);
404 		else if (cfg.outformat == FORMAT_PEM)
405 			i = PEM_write_bio_DHparams(out, dh);
406 		else {
407 			BIO_printf(bio_err, "bad output format specified for outfile\n");
408 			goto end;
409 		}
410 		if (!i) {
411 			BIO_printf(bio_err, "unable to write DH parameters\n");
412 			ERR_print_errors(bio_err);
413 			goto end;
414 		}
415 	}
416 	ret = 0;
417 
418  end:
419 	BIO_free(in);
420 	BIO_free_all(out);
421 	BN_GENCB_free(cb);
422 	DH_free(dh);
423 
424 	return (ret);
425 }
426 
427 /* dh_cb is identical to dsa_cb in apps/dsaparam.c */
428 static int
429 dh_cb(int p, int n, BN_GENCB *cb)
430 {
431 	char c = '*';
432 
433 	if (p == 0)
434 		c = '.';
435 	if (p == 1)
436 		c = '+';
437 	if (p == 2)
438 		c = '*';
439 	if (p == 3)
440 		c = '\n';
441 	BIO_write(BN_GENCB_get_arg(cb), &c, 1);
442 	(void) BIO_flush(BN_GENCB_get_arg(cb));
443 	return 1;
444 }
445 
446 #endif
447