1 /* $OpenBSD: dhparam.c,v 1.14 2022/01/14 09:22:50 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 struct {
135 	int C;
136 	int check;
137 	int dsaparam;
138 	int g;
139 	char *infile;
140 	int informat;
141 	int noout;
142 	char *outfile;
143 	int outformat;
144 	int text;
145 } dhparam_config;
146 
147 static const struct option dhparam_options[] = {
148 	{
149 		.name = "2",
150 		.desc = "Generate DH parameters with a generator value of 2 "
151 		    "(default)",
152 		.type = OPTION_VALUE,
153 		.opt.value = &dhparam_config.g,
154 		.value = 2,
155 	},
156 	{
157 		.name = "5",
158 		.desc = "Generate DH parameters with a generator value of 5",
159 		.type = OPTION_VALUE,
160 		.opt.value = &dhparam_config.g,
161 		.value = 5,
162 	},
163 	{
164 		.name = "C",
165 		.desc = "Convert DH parameters into C code",
166 		.type = OPTION_FLAG,
167 		.opt.flag = &dhparam_config.C,
168 	},
169 	{
170 		.name = "check",
171 		.desc = "Check the DH parameters",
172 		.type = OPTION_FLAG,
173 		.opt.flag = &dhparam_config.check,
174 	},
175 	{
176 		.name = "dsaparam",
177 		.desc = "Read or generate DSA parameters and convert to DH",
178 		.type = OPTION_FLAG,
179 		.opt.flag = &dhparam_config.dsaparam,
180 	},
181 	{
182 		.name = "in",
183 		.argname = "file",
184 		.desc = "Input file (default stdin)",
185 		.type = OPTION_ARG,
186 		.opt.arg = &dhparam_config.infile,
187 	},
188 	{
189 		.name = "inform",
190 		.argname = "format",
191 		.desc = "Input format (DER or PEM (default))",
192 		.type = OPTION_ARG_FORMAT,
193 		.opt.value = &dhparam_config.informat,
194 	},
195 	{
196 		.name = "noout",
197 		.desc = "Do not output encoded version of DH parameters",
198 		.type = OPTION_FLAG,
199 		.opt.flag = &dhparam_config.noout,
200 	},
201 	{
202 		.name = "out",
203 		.argname = "file",
204 		.desc = "Output file (default stdout)",
205 		.type = OPTION_ARG,
206 		.opt.arg = &dhparam_config.outfile,
207 	},
208 	{
209 		.name = "outform",
210 		.argname = "format",
211 		.desc = "Output format (DER or PEM (default))",
212 		.type = OPTION_ARG_FORMAT,
213 		.opt.value = &dhparam_config.outformat,
214 	},
215 	{
216 		.name = "text",
217 		.desc = "Print DH parameters in plain text",
218 		.type = OPTION_FLAG,
219 		.opt.flag = &dhparam_config.text,
220 	},
221 	{ NULL },
222 };
223 
224 static void
225 dhparam_usage()
226 {
227 	fprintf(stderr,
228 	    "usage: dhparam [-2 | -5] [-C] [-check] [-dsaparam]\n"
229 	    "    [-in file] [-inform DER | PEM] [-noout] [-out file]\n"
230 	    "    [-outform DER | PEM] [-text] [numbits]\n\n");
231 	options_usage(dhparam_options);
232 }
233 
234 static int dh_cb(int p, int n, BN_GENCB *cb);
235 
236 int
237 dhparam_main(int argc, char **argv)
238 {
239 	BIO *in = NULL, *out = NULL;
240 	BN_GENCB *cb = NULL;
241 	char *num_bits = NULL;
242 	DH *dh = NULL;
243 	int num = 0;
244 	int ret = 1;
245 	int i;
246 
247 	if (single_execution) {
248 		if (pledge("stdio cpath wpath rpath", NULL) == -1) {
249 			perror("pledge");
250 			exit(1);
251 		}
252 	}
253 
254 	memset(&dhparam_config, 0, sizeof(dhparam_config));
255 
256 	dhparam_config.informat = FORMAT_PEM;
257 	dhparam_config.outformat = FORMAT_PEM;
258 
259 	if (options_parse(argc, argv, dhparam_options, &num_bits, NULL) != 0) {
260 		dhparam_usage();
261 		return (1);
262 	}
263 
264 	if (num_bits != NULL) {
265 		if(sscanf(num_bits, "%d", &num) == 0 || num <= 0) {
266 			BIO_printf(bio_err, "invalid number of bits: %s\n",
267 			    num_bits);
268 			return (1);
269 		}
270 	}
271 
272 	if (dhparam_config.g && !num)
273 		num = DEFBITS;
274 
275 	if (dhparam_config.dsaparam) {
276 		if (dhparam_config.g) {
277 			BIO_printf(bio_err, "generator may not be chosen for DSA parameters\n");
278 			goto end;
279 		}
280 	} else {
281 		/* DH parameters */
282 		if (num && !dhparam_config.g)
283 			dhparam_config.g = 2;
284 	}
285 
286 	if (num) {
287 		if ((cb = BN_GENCB_new()) == NULL) {
288 			BIO_printf(bio_err,
289 			    "Error allocating BN_GENCB object\n");
290 			goto end;
291 		}
292 
293 		BN_GENCB_set(cb, dh_cb, bio_err);
294 		if (dhparam_config.dsaparam) {
295 			DSA *dsa = DSA_new();
296 
297 			BIO_printf(bio_err, "Generating DSA parameters, %d bit long prime\n", num);
298 			if (!dsa || !DSA_generate_parameters_ex(dsa, num,
299 				NULL, 0, NULL, NULL, cb)) {
300 				DSA_free(dsa);
301 				ERR_print_errors(bio_err);
302 				goto end;
303 			}
304 			dh = DSA_dup_DH(dsa);
305 			DSA_free(dsa);
306 			if (dh == NULL) {
307 				ERR_print_errors(bio_err);
308 				goto end;
309 			}
310 		} else {
311 			dh = DH_new();
312 			BIO_printf(bio_err, "Generating DH parameters, %d bit long safe prime, generator %d\n", num, dhparam_config.g);
313 			BIO_printf(bio_err, "This is going to take a long time\n");
314 			if (!dh || !DH_generate_parameters_ex(dh, num, dhparam_config.g, cb)) {
315 				ERR_print_errors(bio_err);
316 				goto end;
317 			}
318 		}
319 	} else {
320 
321 		in = BIO_new(BIO_s_file());
322 		if (in == NULL) {
323 			ERR_print_errors(bio_err);
324 			goto end;
325 		}
326 		if (dhparam_config.infile == NULL)
327 			BIO_set_fp(in, stdin, BIO_NOCLOSE);
328 		else {
329 			if (BIO_read_filename(in, dhparam_config.infile) <= 0) {
330 				perror(dhparam_config.infile);
331 				goto end;
332 			}
333 		}
334 
335 		if (dhparam_config.informat != FORMAT_ASN1 &&
336 		    dhparam_config.informat != FORMAT_PEM) {
337 			BIO_printf(bio_err, "bad input format specified\n");
338 			goto end;
339 		}
340 		if (dhparam_config.dsaparam) {
341 			DSA *dsa;
342 
343 			if (dhparam_config.informat == FORMAT_ASN1)
344 				dsa = d2i_DSAparams_bio(in, NULL);
345 			else	/* informat == FORMAT_PEM */
346 				dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL);
347 
348 			if (dsa == NULL) {
349 				BIO_printf(bio_err, "unable to load DSA parameters\n");
350 				ERR_print_errors(bio_err);
351 				goto end;
352 			}
353 			dh = DSA_dup_DH(dsa);
354 			DSA_free(dsa);
355 			if (dh == NULL) {
356 				ERR_print_errors(bio_err);
357 				goto end;
358 			}
359 		} else
360 		{
361 			if (dhparam_config.informat == FORMAT_ASN1)
362 				dh = d2i_DHparams_bio(in, NULL);
363 			else	/* informat == FORMAT_PEM */
364 				dh = PEM_read_bio_DHparams(in, NULL, NULL, NULL);
365 
366 			if (dh == NULL) {
367 				BIO_printf(bio_err, "unable to load DH parameters\n");
368 				ERR_print_errors(bio_err);
369 				goto end;
370 			}
371 		}
372 
373 		/* dh != NULL */
374 	}
375 
376 	out = BIO_new(BIO_s_file());
377 	if (out == NULL) {
378 		ERR_print_errors(bio_err);
379 		goto end;
380 	}
381 	if (dhparam_config.outfile == NULL) {
382 		BIO_set_fp(out, stdout, BIO_NOCLOSE);
383 	} else {
384 		if (BIO_write_filename(out, dhparam_config.outfile) <= 0) {
385 			perror(dhparam_config.outfile);
386 			goto end;
387 		}
388 	}
389 
390 
391 	if (dhparam_config.text) {
392 		DHparams_print(out, dh);
393 	}
394 	if (dhparam_config.check) {
395 		if (!DH_check(dh, &i)) {
396 			ERR_print_errors(bio_err);
397 			goto end;
398 		}
399 		if (i & DH_CHECK_P_NOT_PRIME)
400 			printf("p value is not prime\n");
401 		if (i & DH_CHECK_P_NOT_SAFE_PRIME)
402 			printf("p value is not a safe prime\n");
403 		if (i & DH_UNABLE_TO_CHECK_GENERATOR)
404 			printf("unable to check the generator value\n");
405 		if (i & DH_NOT_SUITABLE_GENERATOR)
406 			printf("the g value is not a generator\n");
407 		if (i == 0)
408 			printf("DH parameters appear to be ok.\n");
409 	}
410 	if (dhparam_config.C) {
411 		unsigned char *data;
412 		int len, l, bits;
413 
414 		len = BN_num_bytes(DH_get0_p(dh));
415 		bits = BN_num_bits(DH_get0_p(dh));
416 		data = malloc(len);
417 		if (data == NULL) {
418 			perror("malloc");
419 			goto end;
420 		}
421 		printf("#ifndef HEADER_DH_H\n"
422 		    "#include <openssl/dh.h>\n"
423 		    "#endif\n");
424 		printf("DH *get_dh%d()\n\t{\n", bits);
425 
426 		l = BN_bn2bin(DH_get0_p(dh), data);
427 		printf("\tstatic unsigned char dh%d_p[] = {", bits);
428 		for (i = 0; i < l; i++) {
429 			if ((i % 12) == 0)
430 				printf("\n\t\t");
431 			printf("0x%02X, ", data[i]);
432 		}
433 		printf("\n\t\t};\n");
434 
435 		l = BN_bn2bin(DH_get0_g(dh), data);
436 		printf("\tstatic unsigned char dh%d_g[] = {", bits);
437 		for (i = 0; i < l; i++) {
438 			if ((i % 12) == 0)
439 				printf("\n\t\t");
440 			printf("0x%02X, ", data[i]);
441 		}
442 		printf("\n\t\t};\n");
443 
444 		printf("\tDH *dh;\n");
445 		printf("\tBIGNUM *p = NULL, *g = NULL;\n\n");
446 		printf("\tif ((dh = DH_new()) == NULL) return(NULL);\n");
447 		printf("\tp = BN_bin2bn(dh%d_p, sizeof(dh%d_p), NULL);\n",
448 		    bits, bits);
449 		printf("\tg = BN_bin2bn(dh%d_g, sizeof(dh%d_g), NULL);\n",
450 		    bits, bits);
451 		printf("\tif (p == NULL || g == NULL)\n");
452 		printf("\t\t{ BN_free(p); BN_free(g); DH_free(dh); return(NULL); }\n");
453 		printf("\tDH_set0_pqg(dh, p, NULL, g);\n");
454 		if (DH_get_length(dh) > 0)
455 			printf("\tDH_set_length(dh, %ld);\n", DH_get_length(dh));
456 		printf("\treturn(dh);\n\t}\n");
457 		free(data);
458 	}
459 	if (!dhparam_config.noout) {
460 		if (dhparam_config.outformat == FORMAT_ASN1)
461 			i = i2d_DHparams_bio(out, dh);
462 		else if (dhparam_config.outformat == FORMAT_PEM)
463 			i = PEM_write_bio_DHparams(out, dh);
464 		else {
465 			BIO_printf(bio_err, "bad output format specified for outfile\n");
466 			goto end;
467 		}
468 		if (!i) {
469 			BIO_printf(bio_err, "unable to write DH parameters\n");
470 			ERR_print_errors(bio_err);
471 			goto end;
472 		}
473 	}
474 	ret = 0;
475 
476  end:
477 	BIO_free(in);
478 	BIO_free_all(out);
479 	BN_GENCB_free(cb);
480 	DH_free(dh);
481 
482 	return (ret);
483 }
484 
485 /* dh_cb is identical to dsa_cb in apps/dsaparam.c */
486 static int
487 dh_cb(int p, int n, BN_GENCB *cb)
488 {
489 	char c = '*';
490 
491 	if (p == 0)
492 		c = '.';
493 	if (p == 1)
494 		c = '+';
495 	if (p == 2)
496 		c = '*';
497 	if (p == 3)
498 		c = '\n';
499 	BIO_write(BN_GENCB_get_arg(cb), &c, 1);
500 	(void) BIO_flush(BN_GENCB_get_arg(cb));
501 	return 1;
502 }
503 
504 #endif
505