1/*
2 * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <stdio.h>
11#include "internal/cryptlib.h"
12#include <openssl/x509v3.h>
13#include "crypto/x509.h"
14
15static int tr_cmp(const X509_TRUST *const *a, const X509_TRUST *const *b);
16static void trtable_free(X509_TRUST *p);
17
18static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags);
19static int trust_1oid(X509_TRUST *trust, X509 *x, int flags);
20static int trust_compat(X509_TRUST *trust, X509 *x, int flags);
21
22static int obj_trust(int id, X509 *x, int flags);
23static int (*default_trust) (int id, X509 *x, int flags) = obj_trust;
24
25/*
26 * WARNING: the following table should be kept in order of trust and without
27 * any gaps so we can just subtract the minimum trust value to get an index
28 * into the table
29 */
30
31static X509_TRUST trstandard[] = {
32 {X509_TRUST_COMPAT, 0, trust_compat, "compatible", 0, NULL},
33 {X509_TRUST_SSL_CLIENT, 0, trust_1oidany, "SSL Client", NID_client_auth,
34 NULL},
35 {X509_TRUST_SSL_SERVER, 0, trust_1oidany, "SSL Server", NID_server_auth,
36 NULL},
37 {X509_TRUST_EMAIL, 0, trust_1oidany, "S/MIME email", NID_email_protect,
38 NULL},
39 {X509_TRUST_OBJECT_SIGN, 0, trust_1oidany, "Object Signer", NID_code_sign,
40 NULL},
41 {X509_TRUST_OCSP_SIGN, 0, trust_1oid, "OCSP responder", NID_OCSP_sign,
42 NULL},
43 {X509_TRUST_OCSP_REQUEST, 0, trust_1oid, "OCSP request", NID_ad_OCSP,
44 NULL},
45 {X509_TRUST_TSA, 0, trust_1oidany, "TSA server", NID_time_stamp, NULL}
46};
47
48#define X509_TRUST_COUNT OSSL_NELEM(trstandard)
49
50static STACK_OF(X509_TRUST) *trtable = NULL;
51
52static int tr_cmp(const X509_TRUST *const *a, const X509_TRUST *const *b)
53{
54 return (*a)->trust - (*b)->trust;
55}
56
57int (*X509_TRUST_set_default(int (*trust) (int, X509 *, int))) (int, X509 *,
58 int) {
59 int (*oldtrust) (int, X509 *, int);
60 oldtrust = default_trust;
61 default_trust = trust;
62 return oldtrust;
63}
64
65int X509_check_trust(X509 *x, int id, int flags)
66{
67 X509_TRUST *pt;
68 int idx;
69
70 /* We get this as a default value */
71 if (id == X509_TRUST_DEFAULT)
72 return obj_trust(NID_anyExtendedKeyUsage, x,
73 flags | X509_TRUST_DO_SS_COMPAT);
74 idx = X509_TRUST_get_by_id(id);
75 if (idx == -1)
76 return default_trust(id, x, flags);
77 pt = X509_TRUST_get0(idx);
78 return pt->check_trust(pt, x, flags);
79}
80
81int X509_TRUST_get_count(void)
82{
83 if (!trtable)
84 return X509_TRUST_COUNT;
85 return sk_X509_TRUST_num(trtable) + X509_TRUST_COUNT;
86}
87
88X509_TRUST *X509_TRUST_get0(int idx)
89{
90 if (idx < 0)
91 return NULL;
92 if (idx < (int)X509_TRUST_COUNT)
93 return trstandard + idx;
94 return sk_X509_TRUST_value(trtable, idx - X509_TRUST_COUNT);
95}
96
97int X509_TRUST_get_by_id(int id)
98{
99 X509_TRUST tmp;
100 int idx;
101
102 if ((id >= X509_TRUST_MIN) && (id <= X509_TRUST_MAX))
103 return id - X509_TRUST_MIN;
104 if (trtable == NULL)
105 return -1;
106 tmp.trust = id;
107 idx = sk_X509_TRUST_find(trtable, &tmp);
108 if (idx < 0)
109 return -1;
110 return idx + X509_TRUST_COUNT;
111}
112
113int X509_TRUST_set(int *t, int trust)
114{
115 if (X509_TRUST_get_by_id(trust) == -1) {
116 X509err(X509_F_X509_TRUST_SET, X509_R_INVALID_TRUST);
117 return 0;
118 }
119 *t = trust;
120 return 1;
121}
122
123int X509_TRUST_add(int id, int flags, int (*ck) (X509_TRUST *, X509 *, int),
124 const char *name, int arg1, void *arg2)
125{
126 int idx;
127 X509_TRUST *trtmp;
128 /*
129 * This is set according to what we change: application can't set it
130 */
131 flags &= ~X509_TRUST_DYNAMIC;
132 /* This will always be set for application modified trust entries */
133 flags |= X509_TRUST_DYNAMIC_NAME;
134 /* Get existing entry if any */
135 idx = X509_TRUST_get_by_id(id);
136 /* Need a new entry */
137 if (idx == -1) {
138 if ((trtmp = OPENSSL_malloc(sizeof(*trtmp))) == NULL) {
139 X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
140 return 0;
141 }
142 trtmp->flags = X509_TRUST_DYNAMIC;
143 } else
144 trtmp = X509_TRUST_get0(idx);
145
146 /* OPENSSL_free existing name if dynamic */
147 if (trtmp->flags & X509_TRUST_DYNAMIC_NAME)
148 OPENSSL_free(trtmp->name);
149 /* dup supplied name */
150 if ((trtmp->name = OPENSSL_strdup(name)) == NULL) {
151 X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
152 goto err;
153 }
154 /* Keep the dynamic flag of existing entry */
155 trtmp->flags &= X509_TRUST_DYNAMIC;
156 /* Set all other flags */
157 trtmp->flags |= flags;
158
159 trtmp->trust = id;
160 trtmp->check_trust = ck;
161 trtmp->arg1 = arg1;
162 trtmp->arg2 = arg2;
163
164 /* If its a new entry manage the dynamic table */
165 if (idx == -1) {
166 if (trtable == NULL
167 && (trtable = sk_X509_TRUST_new(tr_cmp)) == NULL) {
168 X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
169 goto err;;
170 }
171 if (!sk_X509_TRUST_push(trtable, trtmp)) {
172 X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
173 goto err;
174 }
175 }
176 return 1;
177 err:
178 if (idx == -1) {
179 OPENSSL_free(trtmp->name);
180 OPENSSL_free(trtmp);
181 }
182 return 0;
183}
184
185static void trtable_free(X509_TRUST *p)
186{
187 if (p == NULL)
188 return;
189 if (p->flags & X509_TRUST_DYNAMIC) {
190 if (p->flags & X509_TRUST_DYNAMIC_NAME)
191 OPENSSL_free(p->name);
192 OPENSSL_free(p);
193 }
194}
195
196void X509_TRUST_cleanup(void)
197{
198 sk_X509_TRUST_pop_free(trtable, trtable_free);
199 trtable = NULL;
200}
201
202int X509_TRUST_get_flags(const X509_TRUST *xp)
203{
204 return xp->flags;
205}
206
207char *X509_TRUST_get0_name(const X509_TRUST *xp)
208{
209 return xp->name;
210}
211
212int X509_TRUST_get_trust(const X509_TRUST *xp)
213{
214 return xp->trust;
215}
216
217static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags)
218{
219 /*
220 * Declare the chain verified if the desired trust OID is not rejected in
221 * any auxiliary trust info for this certificate, and the OID is either
222 * expressly trusted, or else either "anyEKU" is trusted, or the
223 * certificate is self-signed.
224 */
225 flags |= X509_TRUST_DO_SS_COMPAT | X509_TRUST_OK_ANY_EKU;
226 return obj_trust(trust->arg1, x, flags);
227}
228
229static int trust_1oid(X509_TRUST *trust, X509 *x, int flags)
230{
231 /*
232 * Declare the chain verified only if the desired trust OID is not
233 * rejected and is expressly trusted. Neither "anyEKU" nor "compat"
234 * trust in self-signed certificates apply.
235 */
236 flags &= ~(X509_TRUST_DO_SS_COMPAT | X509_TRUST_OK_ANY_EKU);
237 return obj_trust(trust->arg1, x, flags);
238}
239
240static int trust_compat(X509_TRUST *trust, X509 *x, int flags)
241{
242 /* Call for side-effect of computing hash and caching extensions */
243 X509_check_purpose(x, -1, 0);
244 if ((flags & X509_TRUST_NO_SS_COMPAT) == 0 && x->ex_flags & EXFLAG_SS)
245 return X509_TRUST_TRUSTED;
246 else
247 return X509_TRUST_UNTRUSTED;
248}
249
250static int obj_trust(int id, X509 *x, int flags)
251{
252 X509_CERT_AUX *ax = x->aux;
253 int i;
254
255 if (ax && ax->reject) {
256 for (i = 0; i < sk_ASN1_OBJECT_num(ax->reject); i++) {
257 ASN1_OBJECT *obj = sk_ASN1_OBJECT_value(ax->reject, i);
258 int nid = OBJ_obj2nid(obj);
259
260 if (nid == id || (nid == NID_anyExtendedKeyUsage &&
261 (flags & X509_TRUST_OK_ANY_EKU)))
262 return X509_TRUST_REJECTED;
263 }
264 }
265
266 if (ax && ax->trust) {
267 for (i = 0; i < sk_ASN1_OBJECT_num(ax->trust); i++) {
268 ASN1_OBJECT *obj = sk_ASN1_OBJECT_value(ax->trust, i);
269 int nid = OBJ_obj2nid(obj);
270
271 if (nid == id || (nid == NID_anyExtendedKeyUsage &&
272 (flags & X509_TRUST_OK_ANY_EKU)))
273 return X509_TRUST_TRUSTED;
274 }
275 /*
276 * Reject when explicit trust EKU are set and none match.
277 *
278 * Returning untrusted is enough for for full chains that end in
279 * self-signed roots, because when explicit trust is specified it
280 * suppresses the default blanket trust of self-signed objects.
281 *
282 * But for partial chains, this is not enough, because absent a similar
283 * trust-self-signed policy, non matching EKUs are indistinguishable
284 * from lack of EKU constraints.
285 *
286 * Therefore, failure to match any trusted purpose must trigger an
287 * explicit reject.
288 */
289 return X509_TRUST_REJECTED;
290 }
291
292 if ((flags & X509_TRUST_DO_SS_COMPAT) == 0)
293 return X509_TRUST_UNTRUSTED;
294
295 /*
296 * Not rejected, and there is no list of accepted uses, try compat.
297 */
298 return trust_compat(NULL, x, flags);
299}
300