xref: /openbsd-src/lib/libcrypto/x509/x509_trs.c (revision 3374c67d44f9b75b98444cbf63020f777792342e)
1 /* $OpenBSD: x509_trs.c,v 1.30 2022/11/26 16:08:55 tb Exp $ */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3  * project 1999.
4  */
5 /* ====================================================================
6  * Copyright (c) 1999 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 #include <string.h>
61 
62 #include <openssl/err.h>
63 #include <openssl/x509v3.h>
64 
65 #include "x509_local.h"
66 
67 static int tr_cmp(const X509_TRUST * const *a, const X509_TRUST * const *b);
68 static void trtable_free(X509_TRUST *p);
69 
70 static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags);
71 static int trust_1oid(X509_TRUST *trust, X509 *x, int flags);
72 static int trust_compat(X509_TRUST *trust, X509 *x, int flags);
73 
74 static int obj_trust(int id, X509 *x, int flags);
75 static int (*default_trust)(int id, X509 *x, int flags) = obj_trust;
76 
77 /* WARNING: the following table should be kept in order of trust
78  * and without any gaps so we can just subtract the minimum trust
79  * value to get an index into the table
80  */
81 
82 static X509_TRUST trstandard[] = {
83 	{X509_TRUST_COMPAT, 0, trust_compat, "compatible", 0, NULL},
84 	{X509_TRUST_SSL_CLIENT, 0, trust_1oidany, "SSL Client", NID_client_auth, NULL},
85 	{X509_TRUST_SSL_SERVER, 0, trust_1oidany, "SSL Server", NID_server_auth, NULL},
86 	{X509_TRUST_EMAIL, 0, trust_1oidany, "S/MIME email", NID_email_protect, NULL},
87 	{X509_TRUST_OBJECT_SIGN, 0, trust_1oidany, "Object Signer", NID_code_sign, NULL},
88 	{X509_TRUST_OCSP_SIGN, 0, trust_1oid, "OCSP responder", NID_OCSP_sign, NULL},
89 	{X509_TRUST_OCSP_REQUEST, 0, trust_1oid, "OCSP request", NID_ad_OCSP, NULL},
90 	{X509_TRUST_TSA, 0, trust_1oidany, "TSA server", NID_time_stamp, NULL}
91 };
92 
93 #define X509_TRUST_COUNT	(sizeof(trstandard)/sizeof(X509_TRUST))
94 
95 static STACK_OF(X509_TRUST) *trtable = NULL;
96 
97 static int
98 tr_cmp(const X509_TRUST * const *a, const X509_TRUST * const *b)
99 {
100 	return (*a)->trust - (*b)->trust;
101 }
102 
103 int
104 (*X509_TRUST_set_default(int (*trust)(int , X509 *, int)))(int, X509 *, int)
105 {
106 	int (*oldtrust)(int , X509 *, int);
107 
108 	oldtrust = default_trust;
109 	default_trust = trust;
110 	return oldtrust;
111 }
112 LCRYPTO_ALIAS(X509_TRUST_set_default)
113 
114 int
115 X509_check_trust(X509 *x, int id, int flags)
116 {
117 	X509_TRUST *pt;
118 	int idx;
119 
120 	if (id == -1)
121 		return 1;
122 	/*
123 	 * XXX beck/jsing This enables self signed certs to be trusted for
124 	 * an unspecified id/trust flag value (this is NOT the
125 	 * X509_TRUST_DEFAULT), which was the longstanding
126 	 * openssl behaviour. boringssl does not have this behaviour.
127 	 *
128 	 * This should be revisited, but changing the default "not default"
129 	 * may break things.
130 	 */
131 	if (id == 0) {
132 		int rv;
133 		rv = obj_trust(NID_anyExtendedKeyUsage, x, 0);
134 		if (rv != X509_TRUST_UNTRUSTED)
135 			return rv;
136 		return trust_compat(NULL, x, 0);
137 	}
138 	idx = X509_TRUST_get_by_id(id);
139 	if (idx == -1)
140 		return default_trust(id, x, flags);
141 	pt = X509_TRUST_get0(idx);
142 	return pt->check_trust(pt, x, flags);
143 }
144 LCRYPTO_ALIAS(X509_check_trust)
145 
146 int
147 X509_TRUST_get_count(void)
148 {
149 	if (!trtable)
150 		return X509_TRUST_COUNT;
151 	return sk_X509_TRUST_num(trtable) + X509_TRUST_COUNT;
152 }
153 LCRYPTO_ALIAS(X509_TRUST_get_count)
154 
155 X509_TRUST *
156 X509_TRUST_get0(int idx)
157 {
158 	if (idx < 0)
159 		return NULL;
160 	if (idx < (int)X509_TRUST_COUNT)
161 		return trstandard + idx;
162 	return sk_X509_TRUST_value(trtable, idx - X509_TRUST_COUNT);
163 }
164 LCRYPTO_ALIAS(X509_TRUST_get0)
165 
166 int
167 X509_TRUST_get_by_id(int id)
168 {
169 	X509_TRUST tmp;
170 	int idx;
171 
172 	if ((id >= X509_TRUST_MIN) && (id <= X509_TRUST_MAX))
173 		return id - X509_TRUST_MIN;
174 	tmp.trust = id;
175 	if (!trtable)
176 		return -1;
177 	idx = sk_X509_TRUST_find(trtable, &tmp);
178 	if (idx == -1)
179 		return -1;
180 	return idx + X509_TRUST_COUNT;
181 }
182 LCRYPTO_ALIAS(X509_TRUST_get_by_id)
183 
184 int
185 X509_TRUST_set(int *t, int trust)
186 {
187 	if (X509_TRUST_get_by_id(trust) == -1) {
188 		X509error(X509_R_INVALID_TRUST);
189 		return 0;
190 	}
191 	*t = trust;
192 	return 1;
193 }
194 LCRYPTO_ALIAS(X509_TRUST_set)
195 
196 int
197 X509_TRUST_add(int id, int flags, int (*ck)(X509_TRUST *, X509 *, int),
198     const char *name, int arg1, void *arg2)
199 {
200 	int idx;
201 	X509_TRUST *trtmp;
202 	char *name_dup;
203 
204 	/* This is set according to what we change: application can't set it */
205 	flags &= ~X509_TRUST_DYNAMIC;
206 	/* This will always be set for application modified trust entries */
207 	flags |= X509_TRUST_DYNAMIC_NAME;
208 	/* Get existing entry if any */
209 	idx = X509_TRUST_get_by_id(id);
210 	/* Need a new entry */
211 	if (idx == -1) {
212 		if (!(trtmp = malloc(sizeof(X509_TRUST)))) {
213 			X509error(ERR_R_MALLOC_FAILURE);
214 			return 0;
215 		}
216 		trtmp->flags = X509_TRUST_DYNAMIC;
217 	} else {
218 		trtmp = X509_TRUST_get0(idx);
219 		if (trtmp == NULL) {
220 			X509error(X509_R_INVALID_TRUST);
221 			return 0;
222 		}
223 	}
224 
225 	if ((name_dup = strdup(name)) == NULL)
226 		goto err;
227 
228 	/* free existing name if dynamic */
229 	if (trtmp->flags & X509_TRUST_DYNAMIC_NAME)
230 		free(trtmp->name);
231 	/* dup supplied name */
232 	trtmp->name = name_dup;
233 	/* Keep the dynamic flag of existing entry */
234 	trtmp->flags &= X509_TRUST_DYNAMIC;
235 	/* Set all other flags */
236 	trtmp->flags |= flags;
237 
238 	trtmp->trust = id;
239 	trtmp->check_trust = ck;
240 	trtmp->arg1 = arg1;
241 	trtmp->arg2 = arg2;
242 
243 	/* If it's a new entry, manage the dynamic table */
244 	if (idx == -1) {
245 		if (trtable == NULL &&
246 		    (trtable = sk_X509_TRUST_new(tr_cmp)) == NULL)
247 			goto err;
248 		if (sk_X509_TRUST_push(trtable, trtmp) == 0)
249 			goto err;
250 	}
251 	return 1;
252 
253 err:
254 	free(name_dup);
255 	if (idx == -1)
256 		free(trtmp);
257 	X509error(ERR_R_MALLOC_FAILURE);
258 	return 0;
259 }
260 LCRYPTO_ALIAS(X509_TRUST_add)
261 
262 static void
263 trtable_free(X509_TRUST *p)
264 {
265 	if (!p)
266 		return;
267 	if (p->flags & X509_TRUST_DYNAMIC) {
268 		if (p->flags & X509_TRUST_DYNAMIC_NAME)
269 			free(p->name);
270 		free(p);
271 	}
272 }
273 
274 void
275 X509_TRUST_cleanup(void)
276 {
277 	sk_X509_TRUST_pop_free(trtable, trtable_free);
278 	trtable = NULL;
279 }
280 LCRYPTO_ALIAS(X509_TRUST_cleanup)
281 
282 int
283 X509_TRUST_get_flags(const X509_TRUST *xp)
284 {
285 	return xp->flags;
286 }
287 LCRYPTO_ALIAS(X509_TRUST_get_flags)
288 
289 char *
290 X509_TRUST_get0_name(const X509_TRUST *xp)
291 {
292 	return xp->name;
293 }
294 LCRYPTO_ALIAS(X509_TRUST_get0_name)
295 
296 int
297 X509_TRUST_get_trust(const X509_TRUST *xp)
298 {
299 	return xp->trust;
300 }
301 LCRYPTO_ALIAS(X509_TRUST_get_trust)
302 
303 static int
304 trust_1oidany(X509_TRUST *trust, X509 *x, int flags)
305 {
306 	if (x->aux && (x->aux->trust || x->aux->reject))
307 		return obj_trust(trust->arg1, x, flags);
308 	/* we don't have any trust settings: for compatibility
309 	 * we return trusted if it is self signed
310 	 */
311 	return trust_compat(trust, x, flags);
312 }
313 
314 static int
315 trust_1oid(X509_TRUST *trust, X509 *x, int flags)
316 {
317 	if (x->aux)
318 		return obj_trust(trust->arg1, x, flags);
319 	return X509_TRUST_UNTRUSTED;
320 }
321 
322 static int
323 trust_compat(X509_TRUST *trust, X509 *x, int flags)
324 {
325 	X509_check_purpose(x, -1, 0);
326 	if (x->ex_flags & EXFLAG_SS)
327 		return X509_TRUST_TRUSTED;
328 	else
329 		return X509_TRUST_UNTRUSTED;
330 }
331 
332 static int
333 obj_trust(int id, X509 *x, int flags)
334 {
335 	ASN1_OBJECT *obj;
336 	int i, nid;
337 	X509_CERT_AUX *ax;
338 
339 	ax = x->aux;
340 	if (!ax)
341 		return X509_TRUST_UNTRUSTED;
342 	if (ax->reject) {
343 		for (i = 0; i < sk_ASN1_OBJECT_num(ax->reject); i++) {
344 			obj = sk_ASN1_OBJECT_value(ax->reject, i);
345 			nid = OBJ_obj2nid(obj);
346 			if (nid == id || nid == NID_anyExtendedKeyUsage)
347 				return X509_TRUST_REJECTED;
348 		}
349 	}
350 	if (ax->trust) {
351 		for (i = 0; i < sk_ASN1_OBJECT_num(ax->trust); i++) {
352 			obj = sk_ASN1_OBJECT_value(ax->trust, i);
353 			nid = OBJ_obj2nid(obj);
354 			if (nid == id || nid == NID_anyExtendedKeyUsage)
355 				return X509_TRUST_TRUSTED;
356 		}
357 	}
358 	return X509_TRUST_UNTRUSTED;
359 }
360