Add part of chain verify SSL support code: not complete or doing anything
[openssl.git] / crypto / x509v3 / v3_purp.c
1 /* v3_purp.c */
2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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 "cryptlib.h"
61 #include <openssl/x509v3.h>
62
63
64 static void x509v3_cache_extensions(X509 *x);
65
66 static int ca_check(X509 *x);
67 static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca);
68 static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca);
69 static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca);
70 static int purpose_smime(X509 *x, int ca);
71 static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca);
72 static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca);
73 static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca);
74
75 static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b);
76 static void xptable_free(X509_PURPOSE *p);
77
78 static X509_PURPOSE xstandard[] = {
79         {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
80         {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
81         {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
82         {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
83         {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
84         {X509_PURPOSE_CRL_SIGN, X509_TRUST_ANY, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
85         {-1, 0, 0, NULL, NULL, NULL, NULL}
86 };
87
88 IMPLEMENT_STACK_OF(X509_PURPOSE)
89
90 static STACK_OF(X509_PURPOSE) *xptable = NULL;
91
92 static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b)
93 {
94         return (*a)->purpose - (*b)->purpose;
95 }
96
97 int X509_check_purpose(X509 *x, int id, int ca)
98 {
99         int idx;
100         X509_PURPOSE *pt;
101         if(!(x->ex_flags & EXFLAG_SET)) {
102                 CRYPTO_w_lock(CRYPTO_LOCK_X509);
103                 X509_init();
104                 x509v3_cache_extensions(x);
105                 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
106         }
107         if(id == -1) return 1;
108         idx = X509_PURPOSE_get_by_id(id);
109         if(idx == -1) return -1;
110         pt = sk_X509_PURPOSE_value(xptable, idx);
111         return pt->check_purpose(pt, x,ca);
112 }
113
114 int X509_PURPOSE_get_count(void)
115 {
116         return sk_X509_PURPOSE_num(xptable);
117 }
118
119 X509_PURPOSE * X509_PURPOSE_iget(int idx)
120 {
121         return sk_X509_PURPOSE_value(xptable, idx);
122 }
123
124 int X509_PURPOSE_get_by_sname(char *sname)
125 {
126         int i;
127         X509_PURPOSE *xptmp;
128         for(i = 0; i < sk_X509_PURPOSE_num(xptable); i++) {
129                 xptmp = sk_X509_PURPOSE_value(xptable, i);
130                 if(!strcmp(xptmp->sname, sname)) return i;
131         }
132         return -1;
133 }
134
135
136 int X509_PURPOSE_get_by_id(int purpose)
137 {
138         X509_PURPOSE tmp;
139         tmp.purpose = purpose;
140         if(!xptable) return -1;
141         return sk_X509_PURPOSE_find(xptable, &tmp);
142 }
143
144 int X509_PURPOSE_add(X509_PURPOSE *xp)
145 {
146         int idx;
147         if(!xptable)
148                 {
149                 xptable = sk_X509_PURPOSE_new(xp_cmp);
150                 if (!xptable) 
151                         {
152                         X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
153                         return 0;
154                         }
155                 }
156                         
157         idx = X509_PURPOSE_get_by_id(xp->purpose);
158         if(idx != -1) {
159                 xptable_free(sk_X509_PURPOSE_value(xptable, idx));
160                 sk_X509_PURPOSE_set(xptable, idx, xp);
161         } else {
162                 if (!sk_X509_PURPOSE_push(xptable, xp)) {
163                         X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
164                         return 0;
165                 }
166         }
167         return 1;
168 }
169
170 static void xptable_free(X509_PURPOSE *p)
171         {
172         if(!p) return;
173         if (p->flags & X509_PURPOSE_DYNAMIC) 
174                 {
175                 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
176                         Free(p->name);
177                         Free(p->sname);
178                 }
179                 Free(p);
180                 }
181         }
182
183 void X509_PURPOSE_cleanup(void)
184 {
185         sk_X509_PURPOSE_pop_free(xptable, xptable_free);
186         xptable = NULL;
187 }
188
189 void X509_PURPOSE_add_standard(void)
190 {
191         X509_PURPOSE *xp;
192         for(xp = xstandard; xp->name; xp++) X509_PURPOSE_add(xp);
193 }
194
195 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
196 {
197         return xp->purpose;
198 }
199
200 char *X509_PURPOSE_iget_name(X509_PURPOSE *xp)
201 {
202         return xp->name;
203 }
204
205 char *X509_PURPOSE_iget_sname(X509_PURPOSE *xp)
206 {
207         return xp->sname;
208 }
209
210 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
211 {
212         return xp->trust;
213 }
214
215 static void x509v3_cache_extensions(X509 *x)
216 {
217         BASIC_CONSTRAINTS *bs;
218         ASN1_BIT_STRING *usage;
219         ASN1_BIT_STRING *ns;
220         STACK_OF(ASN1_OBJECT) *extusage;
221         int i;
222         if(x->ex_flags & EXFLAG_SET) return;
223         X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
224         /* Does subject name match issuer ? */
225         if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
226                          x->ex_flags |= EXFLAG_SS;
227         /* V1 should mean no extensions ... */
228         if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
229         /* Handle basic constraints */
230         if((bs=X509V3_X509_get_d2i(x, NID_basic_constraints, NULL, NULL))) {
231                 if(bs->ca) x->ex_flags |= EXFLAG_CA;
232                 if(bs->pathlen) {
233                         if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
234                                                 || !bs->ca) {
235                                 x->ex_flags |= EXFLAG_INVALID;
236                                 x->ex_pathlen = 0;
237                         } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
238                 } else x->ex_pathlen = -1;
239                 BASIC_CONSTRAINTS_free(bs);
240                 x->ex_flags |= EXFLAG_BCONS;
241         }
242         /* Handle key usage */
243         if((usage=X509V3_X509_get_d2i(x, NID_key_usage, NULL, NULL))) {
244                 if(usage->length > 0) {
245                         x->ex_kusage = usage->data[0];
246                         if(usage->length > 1) 
247                                 x->ex_kusage |= usage->data[1] << 8;
248                 } else x->ex_kusage = 0;
249                 x->ex_flags |= EXFLAG_KUSAGE;
250                 ASN1_BIT_STRING_free(usage);
251         }
252         x->ex_xkusage = 0;
253         if((extusage=X509V3_X509_get_d2i(x, NID_ext_key_usage, NULL, NULL))) {
254                 x->ex_flags |= EXFLAG_XKUSAGE;
255                 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
256                         switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
257                                 case NID_server_auth:
258                                 x->ex_xkusage |= XKU_SSL_SERVER;
259                                 break;
260
261                                 case NID_client_auth:
262                                 x->ex_xkusage |= XKU_SSL_CLIENT;
263                                 break;
264
265                                 case NID_email_protect:
266                                 x->ex_xkusage |= XKU_SMIME;
267                                 break;
268
269                                 case NID_code_sign:
270                                 x->ex_xkusage |= XKU_CODE_SIGN;
271                                 break;
272
273                                 case NID_ms_sgc:
274                                 case NID_ns_sgc:
275                                 x->ex_xkusage |= XKU_SGC;
276                         }
277                 }
278                 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
279         }
280
281         if((ns=X509V3_X509_get_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
282                 if(ns->length > 0) x->ex_nscert = ns->data[0];
283                 else x->ex_nscert = 0;
284                 x->ex_flags |= EXFLAG_NSCERT;
285                 ASN1_BIT_STRING_free(ns);
286         }
287         x->ex_flags |= EXFLAG_SET;
288 }
289
290 /* CA checks common to all purposes
291  * return codes:
292  * 0 not a CA
293  * 1 is a CA
294  * 2 basicConstraints absent so "maybe" a CA
295  * 3 basicConstraints absent but self signed V1.
296  */
297
298 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
299 #define ku_reject(x, usage) \
300         (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
301 #define xku_reject(x, usage) \
302         (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
303 #define ns_reject(x, usage) \
304         (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
305
306 static int ca_check(X509 *x)
307 {
308         /* keyUsage if present should allow cert signing */
309         if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
310         if(x->ex_flags & EXFLAG_BCONS) {
311                 if(x->ex_flags & EXFLAG_CA) return 1;
312                 /* If basicConstraints says not a CA then say so */
313                 else return 0;
314         } else {
315                 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
316                 else return 2;
317         }
318 }
319
320
321 static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca)
322 {
323         if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
324         if(ca) {
325                 int ca_ret;
326                 ca_ret = ca_check(x);
327                 if(!ca_ret) return 0;
328                 /* check nsCertType if present */
329                 if(x->ex_flags & EXFLAG_NSCERT) {
330                         if(x->ex_nscert & NS_SSL_CA) return ca_ret;
331                         return 0;
332                 }
333                 if(ca_ret != 2) return ca_ret;
334                 else return 0;
335         }
336         /* We need to do digital signatures with it */
337         if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
338         /* nsCertType if present should allow SSL client use */ 
339         if(ns_reject(x, NS_SSL_CLIENT)) return 0;
340         return 1;
341 }
342
343 static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
344 {
345         if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
346         /* Otherwise same as SSL client for a CA */
347         if(ca) return check_purpose_ssl_client(xp, x, 1);
348
349         if(ns_reject(x, NS_SSL_SERVER)) return 0;
350         /* Now as for keyUsage: we'll at least need to sign OR encipher */
351         if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
352         
353         return 1;
354
355 }
356
357 static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
358 {
359         int ret;
360         ret = check_purpose_ssl_server(xp, x, ca);
361         if(!ret || ca) return ret;
362         /* We need to encipher or Netscape complains */
363         if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
364         return ret;
365 }
366
367 /* common S/MIME checks */
368 static int purpose_smime(X509 *x, int ca)
369 {
370         if(xku_reject(x,XKU_SMIME)) return 0;
371         if(ca) {
372                 int ca_ret;
373                 ca_ret = ca_check(x);
374                 if(!ca_ret) return 0;
375                 /* check nsCertType if present */
376                 if(x->ex_flags & EXFLAG_NSCERT) {
377                         if(x->ex_nscert & NS_SMIME_CA) return ca_ret;
378                         return 0;
379                 }
380                 if(ca_ret != 2) return ca_ret;
381                 else return 0;
382         }
383         if(x->ex_flags & EXFLAG_NSCERT) {
384                 if(x->ex_nscert & NS_SMIME) return 1;
385                 /* Workaround for some buggy certificates */
386                 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
387                 return 0;
388         }
389         return 1;
390 }
391
392 static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca)
393 {
394         int ret;
395         ret = purpose_smime(x, ca);
396         if(!ret || ca) return ret;
397         if(ku_reject(x, KU_DIGITAL_SIGNATURE)) return 0;
398         return ret;
399 }
400
401 static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca)
402 {
403         int ret;
404         ret = purpose_smime(x, ca);
405         if(!ret || ca) return ret;
406         if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
407         return ret;
408 }
409
410 static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca)
411 {
412         if(ca) {
413                 int ca_ret;
414                 if((ca_ret = ca_check(x)) != 2) return ca_ret;
415                 else return 0;
416         }
417         if(ku_reject(x, KU_CRL_SIGN)) return 0;
418         return 1;
419 }