1 /* $OpenBSD: dh_ameth.c,v 1.42 2025/01/17 05:04:25 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2006.
4 */
5 /* ====================================================================
6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59 #include <stdio.h>
60
61 #include <openssl/asn1.h>
62 #include <openssl/bn.h>
63 #include <openssl/dh.h>
64 #include <openssl/err.h>
65 #include <openssl/x509.h>
66
67 #include "asn1_local.h"
68 #include "bn_local.h"
69 #include "dh_local.h"
70 #include "evp_local.h"
71
72 static void
dh_free(EVP_PKEY * pkey)73 dh_free(EVP_PKEY *pkey)
74 {
75 DH_free(pkey->pkey.dh);
76 }
77
78 static int
dh_pub_decode(EVP_PKEY * pkey,X509_PUBKEY * pubkey)79 dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
80 {
81 X509_ALGOR *algor;
82 int ptype;
83 const void *pval;
84 const ASN1_STRING *astr;
85 const unsigned char *key, *params, *p;
86 int key_len, params_len;
87 ASN1_INTEGER *aint = NULL;
88 DH *dh = NULL;
89 int ret = 0;
90
91 if (!X509_PUBKEY_get0_param(NULL, &key, &key_len, &algor, pubkey))
92 goto err;
93 X509_ALGOR_get0(NULL, &ptype, &pval, algor);
94
95 if (ptype != V_ASN1_SEQUENCE) {
96 DHerror(DH_R_PARAMETER_ENCODING_ERROR);
97 goto err;
98 }
99
100 astr = pval;
101 params = astr->data;
102 params_len = astr->length;
103
104 p = params;
105 if ((dh = d2i_DHparams(NULL, &p, params_len)) == NULL) {
106 DHerror(DH_R_DECODE_ERROR);
107 goto err;
108 }
109 p = key;
110 if ((aint = d2i_ASN1_INTEGER(NULL, &p, key_len)) == NULL) {
111 DHerror(DH_R_DECODE_ERROR);
112 goto err;
113 }
114 BN_free(dh->pub_key);
115 if ((dh->pub_key = ASN1_INTEGER_to_BN(aint, NULL)) == NULL) {
116 DHerror(DH_R_BN_DECODE_ERROR);
117 goto err;
118 }
119
120 if (!EVP_PKEY_assign_DH(pkey, dh))
121 goto err;
122 dh = NULL;
123
124 ret = 1;
125
126 err:
127 ASN1_INTEGER_free(aint);
128 DH_free(dh);
129
130 return ret;
131 }
132
133 static int
dh_pub_encode(X509_PUBKEY * pk,const EVP_PKEY * pkey)134 dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
135 {
136 const DH *dh = pkey->pkey.dh;
137 ASN1_STRING *astr = NULL;
138 int ptype = V_ASN1_SEQUENCE;
139 ASN1_INTEGER *aint = NULL;
140 ASN1_OBJECT *aobj;
141 unsigned char *params = NULL, *key = NULL;
142 int params_len = 0, key_len = 0;
143 int ret = 0;
144
145 if ((params_len = i2d_DHparams(dh, ¶ms)) <= 0) {
146 DHerror(ERR_R_MALLOC_FAILURE);
147 params_len = 0;
148 goto err;
149 }
150 if ((astr = ASN1_STRING_new()) == NULL) {
151 DHerror(ERR_R_MALLOC_FAILURE);
152 goto err;
153 }
154 ASN1_STRING_set0(astr, params, params_len);
155 params = NULL;
156 params_len = 0;
157
158 if ((aint = BN_to_ASN1_INTEGER(dh->pub_key, NULL)) == NULL)
159 goto err;
160 if ((key_len = i2d_ASN1_INTEGER(aint, &key)) <= 0) {
161 DHerror(ERR_R_MALLOC_FAILURE);
162 key_len = 0;
163 goto err;
164 }
165
166 if ((aobj = OBJ_nid2obj(EVP_PKEY_DH)) == NULL)
167 goto err;
168 if (!X509_PUBKEY_set0_param(pk, aobj, ptype, astr, key, key_len))
169 goto err;
170 astr = NULL;
171 key = NULL;
172 key_len = 0;
173
174 ret = 1;
175
176 err:
177 ASN1_STRING_free(astr);
178 ASN1_INTEGER_free(aint);
179 freezero(params, params_len);
180 freezero(key, key_len);
181
182 return ret;
183 }
184
185 /*
186 * PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in
187 * that the AlgorithmIdentifier contains the parameters, the private key
188 * is explicitly included and the pubkey must be recalculated.
189 */
190
191 static int
dh_priv_decode(EVP_PKEY * pkey,const PKCS8_PRIV_KEY_INFO * p8)192 dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
193 {
194 const X509_ALGOR *algor;
195 int ptype;
196 const void *pval;
197 const ASN1_STRING *astr;
198 const unsigned char *key, *params, *p;
199 int key_len, params_len;
200 ASN1_INTEGER *aint = NULL;
201 DH *dh = NULL;
202 int ret = 0;
203
204 if (!PKCS8_pkey_get0(NULL, &key, &key_len, &algor, p8))
205 goto err;
206 X509_ALGOR_get0(NULL, &ptype, &pval, algor);
207
208 if (ptype != V_ASN1_SEQUENCE) {
209 DHerror(DH_R_PARAMETER_ENCODING_ERROR);
210 goto err;
211 }
212
213 astr = pval;
214 params = astr->data;
215 params_len = astr->length;
216
217 p = params;
218 if ((dh = d2i_DHparams(NULL, &p, params_len)) == NULL) {
219 DHerror(DH_R_DECODE_ERROR);
220 goto err;
221 }
222 p = key;
223 if ((aint = d2i_ASN1_INTEGER(NULL, &p, key_len)) == NULL) {
224 DHerror(DH_R_DECODE_ERROR);
225 goto err;
226 }
227 BN_free(dh->priv_key);
228 if ((dh->priv_key = ASN1_INTEGER_to_BN(aint, NULL)) == NULL) {
229 DHerror(DH_R_BN_DECODE_ERROR);
230 goto err;
231 }
232 if (!DH_generate_key(dh))
233 goto err;
234
235 if (!EVP_PKEY_assign_DH(pkey, dh))
236 goto err;
237 dh = NULL;
238
239 ret = 1;
240
241 err:
242 ASN1_INTEGER_free(aint);
243 DH_free(dh);
244
245 return ret;
246 }
247
248 static int
dh_priv_encode(PKCS8_PRIV_KEY_INFO * p8,const EVP_PKEY * pkey)249 dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
250 {
251 const DH *dh = pkey->pkey.dh;
252 ASN1_STRING *astr = NULL;
253 int ptype = V_ASN1_SEQUENCE;
254 ASN1_INTEGER *aint = NULL;
255 ASN1_OBJECT *aobj;
256 unsigned char *params = NULL, *key = NULL;
257 int params_len = 0, key_len = 0;
258 int ret = 0;
259
260 if ((params_len = i2d_DHparams(dh, ¶ms)) <= 0) {
261 DHerror(ERR_R_MALLOC_FAILURE);
262 params_len = 0;
263 goto err;
264 }
265 if ((astr = ASN1_STRING_type_new(V_ASN1_SEQUENCE)) == NULL) {
266 DHerror(ERR_R_MALLOC_FAILURE);
267 goto err;
268 }
269 ASN1_STRING_set0(astr, params, params_len);
270 params = NULL;
271 params_len = 0;
272
273 if ((aint = BN_to_ASN1_INTEGER(dh->priv_key, NULL)) == NULL) {
274 DHerror(DH_R_BN_ERROR);
275 goto err;
276 }
277 if ((key_len = i2d_ASN1_INTEGER(aint, &key)) <= 0) {
278 DHerror(ERR_R_MALLOC_FAILURE);
279 key_len = 0;
280 goto err;
281 }
282
283 if ((aobj = OBJ_nid2obj(NID_dhKeyAgreement)) == NULL)
284 goto err;
285 if (!PKCS8_pkey_set0(p8, aobj, 0, ptype, astr, key, key_len))
286 goto err;
287 astr = NULL;
288 key = NULL;
289 key_len = 0;
290
291 ret = 1;
292
293 err:
294 ASN1_STRING_free(astr);
295 ASN1_INTEGER_free(aint);
296 freezero(params, params_len);
297 freezero(key, key_len);
298
299 return ret;
300 }
301
302 static int
dh_param_decode(EVP_PKEY * pkey,const unsigned char ** params,int params_len)303 dh_param_decode(EVP_PKEY *pkey, const unsigned char **params, int params_len)
304 {
305 DH *dh = NULL;
306 int ret = 0;
307
308 if ((dh = d2i_DHparams(NULL, params, params_len)) == NULL) {
309 DHerror(ERR_R_DH_LIB);
310 goto err;
311 }
312 if (!EVP_PKEY_assign_DH(pkey, dh))
313 goto err;
314 dh = NULL;
315
316 ret = 1;
317
318 err:
319 DH_free(dh);
320
321 return ret;
322 }
323
324 static int
dh_param_encode(const EVP_PKEY * pkey,unsigned char ** params)325 dh_param_encode(const EVP_PKEY *pkey, unsigned char **params)
326 {
327 return i2d_DHparams(pkey->pkey.dh, params);
328 }
329
330 static int
do_dh_print(BIO * bp,const DH * x,int indent,ASN1_PCTX * ctx,int ptype)331 do_dh_print(BIO *bp, const DH *x, int indent, ASN1_PCTX *ctx, int ptype)
332 {
333 int reason = ERR_R_BUF_LIB, ret = 0;
334 const char *ktype = NULL;
335 BIGNUM *priv_key, *pub_key;
336
337 if (ptype == 2)
338 priv_key = x->priv_key;
339 else
340 priv_key = NULL;
341
342 if (ptype > 0)
343 pub_key = x->pub_key;
344 else
345 pub_key = NULL;
346
347 if (ptype == 2)
348 ktype = "PKCS#3 DH Private-Key";
349 else if (ptype == 1)
350 ktype = "PKCS#3 DH Public-Key";
351 else
352 ktype = "PKCS#3 DH Parameters";
353
354 if (x->p == NULL) {
355 reason = ERR_R_PASSED_NULL_PARAMETER;
356 goto err;
357 }
358
359 if (!BIO_indent(bp, indent, 128))
360 goto err;
361 if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
362 goto err;
363 indent += 4;
364
365 if (!bn_printf(bp, priv_key, indent, "private-key:"))
366 goto err;
367 if (!bn_printf(bp, pub_key, indent, "public-key:"))
368 goto err;
369
370 if (!bn_printf(bp, x->p, indent, "prime:"))
371 goto err;
372 if (!bn_printf(bp, x->g, indent, "generator:"))
373 goto err;
374 if (x->length != 0) {
375 if (!BIO_indent(bp, indent, 128))
376 goto err;
377 if (BIO_printf(bp, "recommended-private-length: %d bits\n",
378 (int)x->length) <= 0)
379 goto err;
380 }
381
382 ret = 1;
383 if (0) {
384 err:
385 DHerror(reason);
386 }
387 return(ret);
388 }
389
390 static int
dh_size(const EVP_PKEY * pkey)391 dh_size(const EVP_PKEY *pkey)
392 {
393 return DH_size(pkey->pkey.dh);
394 }
395
396 static int
dh_bits(const EVP_PKEY * pkey)397 dh_bits(const EVP_PKEY *pkey)
398 {
399 return BN_num_bits(pkey->pkey.dh->p);
400 }
401
402 static int
dh_security_bits(const EVP_PKEY * pkey)403 dh_security_bits(const EVP_PKEY *pkey)
404 {
405 return DH_security_bits(pkey->pkey.dh);
406 }
407
408 static int
dh_cmp_parameters(const EVP_PKEY * a,const EVP_PKEY * b)409 dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
410 {
411 if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
412 BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
413 return 0;
414 else
415 return 1;
416 }
417
418 static int
dh_copy_parameters(EVP_PKEY * to,const EVP_PKEY * from)419 dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
420 {
421 BIGNUM *a;
422
423 if ((a = BN_dup(from->pkey.dh->p)) == NULL)
424 return 0;
425 BN_free(to->pkey.dh->p);
426 to->pkey.dh->p = a;
427
428 if ((a = BN_dup(from->pkey.dh->g)) == NULL)
429 return 0;
430 BN_free(to->pkey.dh->g);
431 to->pkey.dh->g = a;
432
433 return 1;
434 }
435
436 static int
dh_missing_parameters(const EVP_PKEY * pkey)437 dh_missing_parameters(const EVP_PKEY *pkey)
438 {
439 const DH *dh = pkey->pkey.dh;
440
441 return dh->p == NULL || dh->g == NULL;
442 }
443
444 static int
dh_pub_cmp(const EVP_PKEY * a,const EVP_PKEY * b)445 dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
446 {
447 if (dh_cmp_parameters(a, b) == 0)
448 return 0;
449 if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
450 return 0;
451 else
452 return 1;
453 }
454
455 static int
dh_param_print(BIO * bp,const EVP_PKEY * pkey,int indent,ASN1_PCTX * ctx)456 dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent, ASN1_PCTX *ctx)
457 {
458 return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 0);
459 }
460
461 static int
dh_public_print(BIO * bp,const EVP_PKEY * pkey,int indent,ASN1_PCTX * ctx)462 dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent, ASN1_PCTX *ctx)
463 {
464 return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 1);
465 }
466
467 static int
dh_private_print(BIO * bp,const EVP_PKEY * pkey,int indent,ASN1_PCTX * ctx)468 dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent, ASN1_PCTX *ctx)
469 {
470 return do_dh_print(bp, pkey->pkey.dh, indent, ctx, 2);
471 }
472
473 int
DHparams_print(BIO * bp,const DH * x)474 DHparams_print(BIO *bp, const DH *x)
475 {
476 return do_dh_print(bp, x, 4, NULL, 0);
477 }
478 LCRYPTO_ALIAS(DHparams_print);
479
480 int
DHparams_print_fp(FILE * fp,const DH * x)481 DHparams_print_fp(FILE *fp, const DH *x)
482 {
483 BIO *b;
484 int ret;
485
486 if ((b = BIO_new(BIO_s_file())) == NULL) {
487 DHerror(ERR_R_BUF_LIB);
488 return 0;
489 }
490
491 BIO_set_fp(b, fp, BIO_NOCLOSE);
492 ret = DHparams_print(b, x);
493 BIO_free(b);
494
495 return ret;
496 }
497 LCRYPTO_ALIAS(DHparams_print_fp);
498
499 const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
500 .base_method = &dh_asn1_meth,
501 .pkey_id = EVP_PKEY_DH,
502
503 .pem_str = "DH",
504 .info = "OpenSSL PKCS#3 DH method",
505
506 .pub_decode = dh_pub_decode,
507 .pub_encode = dh_pub_encode,
508 .pub_cmp = dh_pub_cmp,
509 .pub_print = dh_public_print,
510
511 .priv_decode = dh_priv_decode,
512 .priv_encode = dh_priv_encode,
513 .priv_print = dh_private_print,
514
515 .pkey_size = dh_size,
516 .pkey_bits = dh_bits,
517 .pkey_security_bits = dh_security_bits,
518
519 .param_decode = dh_param_decode,
520 .param_encode = dh_param_encode,
521 .param_missing = dh_missing_parameters,
522 .param_copy = dh_copy_parameters,
523 .param_cmp = dh_cmp_parameters,
524 .param_print = dh_param_print,
525
526 .pkey_free = dh_free,
527 };
528