xref: /openbsd-src/lib/libcrypto/dh/dh_lib.c (revision f6aab3d83b51b91c24247ad2c2573574de475a82)
1 /* $OpenBSD: dh_lib.c,v 1.41 2023/08/13 12:09:14 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 #include <limits.h>
60 #include <stdio.h>
61 
62 #include <openssl/opensslconf.h>
63 
64 #include <openssl/bn.h>
65 #include <openssl/dh.h>
66 #include <openssl/err.h>
67 
68 #ifndef OPENSSL_NO_ENGINE
69 #include <openssl/engine.h>
70 #endif
71 
72 #include "dh_local.h"
73 
74 static const DH_METHOD *default_DH_method = NULL;
75 
76 void
77 DH_set_default_method(const DH_METHOD *meth)
78 {
79 	default_DH_method = meth;
80 }
81 LCRYPTO_ALIAS(DH_set_default_method);
82 
83 const DH_METHOD *
84 DH_get_default_method(void)
85 {
86 	if (!default_DH_method)
87 		default_DH_method = DH_OpenSSL();
88 	return default_DH_method;
89 }
90 LCRYPTO_ALIAS(DH_get_default_method);
91 
92 int
93 DH_set_method(DH *dh, const DH_METHOD *meth)
94 {
95 	/*
96 	 * NB: The caller is specifically setting a method, so it's not up to us
97 	 * to deal with which ENGINE it comes from.
98 	 */
99 	const DH_METHOD *mtmp;
100 
101 	mtmp = dh->meth;
102 	if (mtmp->finish)
103 		mtmp->finish(dh);
104 #ifndef OPENSSL_NO_ENGINE
105 	ENGINE_finish(dh->engine);
106 	dh->engine = NULL;
107 #endif
108 	dh->meth = meth;
109 	if (meth->init)
110 		meth->init(dh);
111 	return 1;
112 }
113 LCRYPTO_ALIAS(DH_set_method);
114 
115 DH *
116 DH_new(void)
117 {
118 	return DH_new_method(NULL);
119 }
120 LCRYPTO_ALIAS(DH_new);
121 
122 DH *
123 DH_new_method(ENGINE *engine)
124 {
125 	DH *dh;
126 
127 	if ((dh = calloc(1, sizeof(*dh))) == NULL) {
128 		DHerror(ERR_R_MALLOC_FAILURE);
129 		goto err;
130 	}
131 
132 	dh->meth = DH_get_default_method();
133 	dh->flags = dh->meth->flags & ~DH_FLAG_NON_FIPS_ALLOW;
134 	dh->references = 1;
135 
136 #ifndef OPENSSL_NO_ENGINE
137 	if (engine != NULL) {
138 		if (!ENGINE_init(engine)) {
139 			DHerror(ERR_R_ENGINE_LIB);
140 			goto err;
141 		}
142 		dh->engine = engine;
143 	} else
144 		dh->engine = ENGINE_get_default_DH();
145 	if (dh->engine != NULL) {
146 		if ((dh->meth = ENGINE_get_DH(dh->engine)) == NULL) {
147 			DHerror(ERR_R_ENGINE_LIB);
148 			goto err;
149 		}
150 		dh->flags = dh->meth->flags & ~DH_FLAG_NON_FIPS_ALLOW;
151 	}
152 #endif
153 
154 	if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, dh, &dh->ex_data))
155 		goto err;
156 	if (dh->meth->init != NULL && !dh->meth->init(dh))
157 		goto err;
158 
159 	return dh;
160 
161  err:
162 	DH_free(dh);
163 
164 	return NULL;
165 }
166 LCRYPTO_ALIAS(DH_new_method);
167 
168 void
169 DH_free(DH *r)
170 {
171 	int i;
172 
173 	if (r == NULL)
174 		return;
175 	i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
176 	if (i > 0)
177 		return;
178 
179 	if (r->meth != NULL && r->meth->finish != NULL)
180 		r->meth->finish(r);
181 #ifndef OPENSSL_NO_ENGINE
182 	ENGINE_finish(r->engine);
183 #endif
184 
185 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
186 
187 	BN_free(r->p);
188 	BN_free(r->g);
189 	BN_free(r->q);
190 	BN_free(r->j);
191 	free(r->seed);
192 	BN_free(r->counter);
193 	BN_free(r->pub_key);
194 	BN_free(r->priv_key);
195 	free(r);
196 }
197 LCRYPTO_ALIAS(DH_free);
198 
199 int
200 DH_up_ref(DH *r)
201 {
202 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
203 
204 	return i > 1 ? 1 : 0;
205 }
206 LCRYPTO_ALIAS(DH_up_ref);
207 
208 int
209 DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
210     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
211 {
212 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp, new_func,
213 	    dup_func, free_func);
214 }
215 LCRYPTO_ALIAS(DH_get_ex_new_index);
216 
217 int
218 DH_set_ex_data(DH *d, int idx, void *arg)
219 {
220 	return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
221 }
222 LCRYPTO_ALIAS(DH_set_ex_data);
223 
224 void *
225 DH_get_ex_data(DH *d, int idx)
226 {
227 	return CRYPTO_get_ex_data(&d->ex_data, idx);
228 }
229 LCRYPTO_ALIAS(DH_get_ex_data);
230 
231 int
232 DH_size(const DH *dh)
233 {
234 	return BN_num_bytes(dh->p);
235 }
236 LCRYPTO_ALIAS(DH_size);
237 
238 int
239 DH_bits(const DH *dh)
240 {
241 	return BN_num_bits(dh->p);
242 }
243 LCRYPTO_ALIAS(DH_bits);
244 
245 int
246 DH_security_bits(const DH *dh)
247 {
248 	int N = -1;
249 
250 	if (dh->q != NULL)
251 		N = BN_num_bits(dh->q);
252 	else if (dh->length > 0)
253 		N = dh->length;
254 
255 	return BN_security_bits(BN_num_bits(dh->p), N);
256 }
257 LCRYPTO_ALIAS(DH_security_bits);
258 
259 ENGINE *
260 DH_get0_engine(DH *dh)
261 {
262 	return dh->engine;
263 }
264 LCRYPTO_ALIAS(DH_get0_engine);
265 
266 void
267 DH_get0_pqg(const DH *dh, const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
268 {
269 	if (p != NULL)
270 		*p = dh->p;
271 	if (q != NULL)
272 		*q = dh->q;
273 	if (g != NULL)
274 		*g = dh->g;
275 }
276 LCRYPTO_ALIAS(DH_get0_pqg);
277 
278 int
279 DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
280 {
281 	if ((dh->p == NULL && p == NULL) || (dh->g == NULL && g == NULL))
282 		return 0;
283 
284 	if (p != NULL) {
285 		BN_free(dh->p);
286 		dh->p = p;
287 	}
288 	if (q != NULL) {
289 		BN_free(dh->q);
290 		dh->q = q;
291 		dh->length = BN_num_bits(dh->q);
292 	}
293 	if (g != NULL) {
294 		BN_free(dh->g);
295 		dh->g = g;
296 	}
297 
298 	return 1;
299 }
300 LCRYPTO_ALIAS(DH_set0_pqg);
301 
302 void
303 DH_get0_key(const DH *dh, const BIGNUM **pub_key, const BIGNUM **priv_key)
304 {
305 	if (pub_key != NULL)
306 		*pub_key = dh->pub_key;
307 	if (priv_key != NULL)
308 		*priv_key = dh->priv_key;
309 }
310 LCRYPTO_ALIAS(DH_get0_key);
311 
312 int
313 DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key)
314 {
315 	if (pub_key != NULL) {
316 		BN_free(dh->pub_key);
317 		dh->pub_key = pub_key;
318 	}
319 	if (priv_key != NULL) {
320 		BN_free(dh->priv_key);
321 		dh->priv_key = priv_key;
322 	}
323 
324 	return 1;
325 }
326 LCRYPTO_ALIAS(DH_set0_key);
327 
328 const BIGNUM *
329 DH_get0_p(const DH *dh)
330 {
331 	return dh->p;
332 }
333 LCRYPTO_ALIAS(DH_get0_p);
334 
335 const BIGNUM *
336 DH_get0_q(const DH *dh)
337 {
338 	return dh->q;
339 }
340 LCRYPTO_ALIAS(DH_get0_q);
341 
342 const BIGNUM *
343 DH_get0_g(const DH *dh)
344 {
345 	return dh->g;
346 }
347 LCRYPTO_ALIAS(DH_get0_g);
348 
349 const BIGNUM *
350 DH_get0_priv_key(const DH *dh)
351 {
352 	return dh->priv_key;
353 }
354 LCRYPTO_ALIAS(DH_get0_priv_key);
355 
356 const BIGNUM *
357 DH_get0_pub_key(const DH *dh)
358 {
359 	return dh->pub_key;
360 }
361 LCRYPTO_ALIAS(DH_get0_pub_key);
362 
363 void
364 DH_clear_flags(DH *dh, int flags)
365 {
366 	dh->flags &= ~flags;
367 }
368 LCRYPTO_ALIAS(DH_clear_flags);
369 
370 int
371 DH_test_flags(const DH *dh, int flags)
372 {
373 	return dh->flags & flags;
374 }
375 LCRYPTO_ALIAS(DH_test_flags);
376 
377 void
378 DH_set_flags(DH *dh, int flags)
379 {
380 	dh->flags |= flags;
381 }
382 LCRYPTO_ALIAS(DH_set_flags);
383 
384 long
385 DH_get_length(const DH *dh)
386 {
387 	return dh->length;
388 }
389 LCRYPTO_ALIAS(DH_get_length);
390 
391 int
392 DH_set_length(DH *dh, long length)
393 {
394 	if (length < 0 || length > INT_MAX)
395 		return 0;
396 
397 	dh->length = length;
398 	return 1;
399 }
400 LCRYPTO_ALIAS(DH_set_length);
401