2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
5 /* ====================================================================
6 * Copyright (c) 1999 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
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).
61 #include <openssl/x509v3.h>
64 static int x509_purpose_get_idx(int id);
65 void x509v3_cache_extensions(X509 *x);
67 static int ca_check(X509 *x);
68 static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca);
69 static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca);
70 static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca);
71 static int purpose_smime(X509 *x, int ca);
72 static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca);
73 static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca);
74 static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca);
76 static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b);
78 static X509_PURPOSE xstandard[] = {
79 {1, check_purpose_ssl_client, "SSL client", NULL},
80 {2, check_purpose_ssl_server, "SSL server", NULL},
81 {3, check_purpose_ns_ssl_server, "Netscape SSL server", NULL},
82 {4, check_purpose_smime_sign, "S/MIME signing", NULL},
83 {5, check_purpose_smime_encrypt, "S/MIME encryption", NULL},
84 {6, check_purpose_crl_sign, "CRL signing", NULL},
85 {-1, NULL, NULL, NULL}
88 IMPLEMENT_STACK_OF(X509_PURPOSE)
90 static STACK_OF(X509_PURPOSE) *xptable;
92 static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b)
94 return (*a)->purpose_id - (*b)->purpose_id;
97 int X509_check_purpose(X509 *x, int id, int ca)
101 if(!(x->ex_flags & EXFLAG_SET)) {
102 CRYPTO_w_lock(CRYPTO_LOCK_X509);
103 x509v3_cache_extensions(x);
104 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
106 idx = x509_purpose_get_idx(id);
107 if(idx == -1) return -1;
108 pt = sk_X509_PURPOSE_value(xptable, idx);
109 return pt->check_purpose(pt, x,ca);
115 static int x509_purpose_get_idx(int id)
119 if(!xptable) return -1;
120 return sk_X509_PURPOSE_find(xptable, &tmp);
123 int X509_PURPOSE_add(X509_PURPOSE *xp)
126 if(!xptable) xptable = sk_X509_PURPOSE_new(xp_cmp);
127 idx = x509_purpose_get_idx(xp->purpose_id);
128 if(idx != -1) sk_X509_PURPOSE_set(xptable, idx, xp);
129 else sk_X509_PURPOSE_push(xptable, xp);
133 void X509_PURPOSE_add_standard(void)
136 for(xp = xstandard; xp->purpose_name; xp++)
137 X509_PURPOSE_add(xp);
140 int X509_PURPOSE_enum(int (*efunc)(X509_PURPOSE *, void *), void *usr)
144 if(!xptable) return 0;
145 for(i = 0; i < sk_X509_PURPOSE_num(xptable); i++) {
146 xp = sk_X509_PURPOSE_value(xptable, i);
147 if(!efunc(xp, usr)) return i;
153 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
155 return xp->purpose_id;
158 char *X509_PURPOSE_get_name(X509_PURPOSE *xp)
160 return xp->purpose_name;
163 void x509v3_cache_extensions(X509 *x)
165 BASIC_CONSTRAINTS *bs;
166 ASN1_BIT_STRING *usage;
168 STACK_OF(ASN1_OBJECT) *extusage;
170 if(x->ex_flags & EXFLAG_SET) return;
171 /* Does subject name match issuer ? */
172 if(X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
173 x->ex_flags |= EXFLAG_SS;
174 /* V1 should mean no extensions ... */
175 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
176 /* Handle basic constraints */
177 if((bs=X509V3_X509_get_d2i(x, NID_basic_constraints, NULL, NULL))) {
178 if(bs->ca) x->ex_flags |= EXFLAG_CA;
180 if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
182 x->ex_flags |= EXFLAG_INVALID;
184 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
185 } else x->ex_pathlen = -1;
186 BASIC_CONSTRAINTS_free(bs);
187 x->ex_flags |= EXFLAG_BCONS;
189 /* Handle key usage */
190 if((usage=X509V3_X509_get_d2i(x, NID_key_usage, NULL, NULL))) {
191 if(usage->length > 0) {
192 x->ex_kusage = usage->data[0];
193 if(usage->length > 1)
194 x->ex_kusage |= usage->data[1] << 8;
195 } else x->ex_kusage = 0;
196 x->ex_flags |= EXFLAG_KUSAGE;
197 ASN1_BIT_STRING_free(usage);
200 if((extusage=X509V3_X509_get_d2i(x, NID_ext_key_usage, NULL, NULL))) {
201 x->ex_flags |= EXFLAG_XKUSAGE;
202 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
203 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
204 case NID_server_auth:
205 x->ex_xkusage |= XKU_SSL_SERVER;
208 case NID_client_auth:
209 x->ex_xkusage |= XKU_SSL_CLIENT;
212 case NID_email_protect:
213 x->ex_xkusage |= XKU_SMIME;
217 x->ex_xkusage |= XKU_CODE_SIGN;
222 x->ex_xkusage |= XKU_SGC;
225 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
228 if((ns=X509V3_X509_get_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
229 if(ns->length > 0) x->ex_nscert = ns->data[0];
230 else x->ex_nscert = 0;
231 x->ex_flags |= EXFLAG_NSCERT;
232 ASN1_BIT_STRING_free(ns);
234 x->ex_flags |= EXFLAG_SET;
237 /* CA checks common to all purposes
241 * 2 basicConstraints absent so "maybe" a CA
242 * 3 basicConstraints absent but self signed V1.
245 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
246 #define ku_reject(x, usage) \
247 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
248 #define xku_reject(x, usage) \
249 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
250 #define ns_reject(x, usage) \
251 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
253 static int ca_check(X509 *x)
255 /* keyUsage if present should allow cert signing */
256 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
257 if(x->ex_flags & EXFLAG_BCONS) {
258 if(x->ex_flags & EXFLAG_CA) return 1;
259 /* If basicConstraints says not a CA then say so */
262 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
268 static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca)
270 if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
273 ca_ret = ca_check(x);
274 if(!ca_ret) return 0;
275 /* check nsCertType if present */
276 if(x->ex_flags & EXFLAG_NSCERT) {
277 if(x->ex_nscert & NS_SSL_CA) return ca_ret;
280 if(ca_ret != 2) return ca_ret;
283 /* We need to do digital signatures with it */
284 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
285 /* nsCertType if present should allow SSL client use */
286 if(ns_reject(x, NS_SSL_CLIENT)) return 0;
290 static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
292 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
293 /* Otherwise same as SSL client for a CA */
294 if(ca) return check_purpose_ssl_client(xp, x, 1);
296 if(ns_reject(x, NS_SSL_SERVER)) return 0;
297 /* Now as for keyUsage: we'll at least need to sign OR encipher */
298 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
304 static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
307 ret = check_purpose_ssl_server(xp, x, ca);
308 if(!ret || ca) return ret;
309 /* We need to encipher or Netscape complains */
310 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
314 /* common S/MIME checks */
315 static int purpose_smime(X509 *x, int ca)
317 if(xku_reject(x,XKU_SMIME)) return 0;
320 ca_ret = ca_check(x);
321 if(!ca_ret) return 0;
322 /* check nsCertType if present */
323 if(x->ex_flags & EXFLAG_NSCERT) {
324 if(x->ex_nscert & NS_SMIME_CA) return ca_ret;
327 if(ca_ret != 2) return ca_ret;
330 if(x->ex_flags & EXFLAG_NSCERT) {
331 if(x->ex_nscert & NS_SMIME) return 1;
332 /* Workaround for some buggy certificates */
333 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
339 static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca)
342 ret = purpose_smime(x, ca);
343 if(!ret || ca) return ret;
344 if(ku_reject(x, KU_DIGITAL_SIGNATURE)) return 0;
348 static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca)
351 ret = purpose_smime(x, ca);
352 if(!ret || ca) return ret;
353 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
357 static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca)
361 if((ca_ret = ca_check(x)) != 2) return ca_ret;
364 if(ku_reject(x, KU_CRL_SIGN)) return 0;