xref: /openbsd/lib/libcrypto/x509/x509_trs.c (revision b518871a)
1 /* $OpenBSD: x509_trs.c,v 1.58 2024/08/31 10:12:23 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 
61 #include <openssl/asn1.h>
62 #include <openssl/objects.h>
63 #include <openssl/x509.h>
64 #include <openssl/x509v3.h>
65 
66 #include "x509_internal.h"
67 #include "x509_local.h"
68 
69 static int
trust_if_self_signed(const X509 * x)70 trust_if_self_signed(const X509 *x)
71 {
72 	/* Extensions already cached in X509_check_trust(). */
73 	if ((x->ex_flags & EXFLAG_SS) != 0)
74 		return X509_TRUST_TRUSTED;
75 
76 	return X509_TRUST_UNTRUSTED;
77 }
78 
79 static int
trust_was_set(const X509 * x)80 trust_was_set(const X509 *x)
81 {
82 	return x->aux != NULL && (x->aux->trust != NULL ||
83 	    x->aux->reject != NULL);
84 }
85 
86 static int
obj_trust(int id,const X509 * x)87 obj_trust(int id, const X509 *x)
88 {
89 	const X509_CERT_AUX *aux;
90 	ASN1_OBJECT *obj;
91 	int i, nid;
92 
93 	if ((aux = x->aux) == NULL)
94 		return X509_TRUST_UNTRUSTED;
95 
96 	for (i = 0; i < sk_ASN1_OBJECT_num(aux->reject); i++) {
97 		obj = sk_ASN1_OBJECT_value(aux->reject, i);
98 		nid = OBJ_obj2nid(obj);
99 		if (nid == id || nid == NID_anyExtendedKeyUsage)
100 			return X509_TRUST_REJECTED;
101 	}
102 
103 	for (i = 0; i < sk_ASN1_OBJECT_num(aux->trust); i++) {
104 		obj = sk_ASN1_OBJECT_value(aux->trust, i);
105 		nid = OBJ_obj2nid(obj);
106 		if (nid == id || nid == NID_anyExtendedKeyUsage)
107 			return X509_TRUST_TRUSTED;
108 	}
109 
110 	return X509_TRUST_UNTRUSTED;
111 }
112 
113 static int
nid_from_trust_id(int trust_id)114 nid_from_trust_id(int trust_id)
115 {
116 	OPENSSL_assert(trust_id == 0 ||
117 	    (trust_id >= X509_TRUST_MIN && trust_id <= X509_TRUST_MAX));
118 
119 	switch (trust_id) {
120 	case X509_TRUST_COMPAT:
121 		return NID_undef;
122 	case X509_TRUST_SSL_CLIENT:
123 		return NID_client_auth;
124 	case X509_TRUST_SSL_SERVER:
125 		return NID_server_auth;
126 	case X509_TRUST_EMAIL:
127 		return NID_email_protect;
128 	case X509_TRUST_OBJECT_SIGN:
129 		return NID_code_sign;
130 	case X509_TRUST_OCSP_SIGN:
131 		return NID_OCSP_sign;
132 	case X509_TRUST_OCSP_REQUEST:
133 		return NID_ad_OCSP;
134 	case X509_TRUST_TSA:
135 		return NID_time_stamp;
136 	default:
137 		return NID_undef;
138 	}
139 }
140 
141 int
X509_check_trust(X509 * x,int trust_id,int flags)142 X509_check_trust(X509 *x, int trust_id, int flags)
143 {
144 	int rv;
145 
146 	/* Call early so the trust handlers don't need to modify the certs. */
147 	if (!x509v3_cache_extensions(x))
148 		return X509_TRUST_UNTRUSTED;
149 
150 	if (trust_id == X509_TRUST_ACCEPT_ALL)
151 		return 1;
152 
153 	switch (trust_id) {
154 	case X509_TRUST_COMPAT:
155 		return trust_if_self_signed(x);
156 	case X509_TRUST_EMAIL:
157 	case X509_TRUST_OBJECT_SIGN:
158 	case X509_TRUST_SSL_SERVER:
159 	case X509_TRUST_SSL_CLIENT:
160 	case X509_TRUST_TSA:
161 		if (trust_was_set(x))
162 			return obj_trust(nid_from_trust_id(trust_id), x);
163 		return trust_if_self_signed(x);
164 	case X509_TRUST_OCSP_SIGN:
165 	case X509_TRUST_OCSP_REQUEST:
166 		return obj_trust(nid_from_trust_id(trust_id), x);
167 	default:
168 		rv = obj_trust(NID_anyExtendedKeyUsage, x);
169 		if (rv != X509_TRUST_UNTRUSTED)
170 			return rv;
171 		return trust_if_self_signed(x);
172 	}
173 }
174