Change the trust and purpose code so it doesn't need init
[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 };
86
87 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
88
89 IMPLEMENT_STACK_OF(X509_PURPOSE)
90
91 static STACK_OF(X509_PURPOSE) *xptable = NULL;
92
93 static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b)
94 {
95         return (*a)->purpose - (*b)->purpose;
96 }
97
98 int X509_check_purpose(X509 *x, int id, int ca)
99 {
100         int idx;
101         X509_PURPOSE *pt;
102         if(!(x->ex_flags & EXFLAG_SET)) {
103                 CRYPTO_w_lock(CRYPTO_LOCK_X509);
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         if(!xptable) return X509_PURPOSE_COUNT;
117         return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
118 }
119
120 X509_PURPOSE * X509_PURPOSE_iget(int idx)
121 {
122         if(idx < 0) return NULL;
123         if(idx < X509_PURPOSE_COUNT) return xstandard + idx;
124         return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
125 }
126
127 int X509_PURPOSE_get_by_sname(char *sname)
128 {
129         int i;
130         X509_PURPOSE *xptmp;
131         for(i = 0; i < X509_PURPOSE_get_count(); i++) {
132                 xptmp = X509_PURPOSE_iget(i);
133                 if(!strcmp(xptmp->sname, sname)) return i;
134         }
135         return -1;
136 }
137
138
139 int X509_PURPOSE_get_by_id(int purpose)
140 {
141         X509_PURPOSE tmp;
142         int idx;
143         if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
144                 return purpose - X509_PURPOSE_MIN;
145         tmp.purpose = purpose;
146         if(!xptable) return -1;
147         idx = sk_X509_PURPOSE_find(xptable, &tmp);
148         if(idx == -1) return -1;
149         return idx + X509_PURPOSE_COUNT;
150 }
151
152 int X509_PURPOSE_add(int id, int trust, int flags,
153                         int (*ck)(X509_PURPOSE *, X509 *, int),
154                                         char *name, char *sname, void *arg)
155 {
156         int idx;
157         X509_PURPOSE *ptmp;
158         /* This is set according to what we change: application can't set it */
159         flags &= ~X509_PURPOSE_DYNAMIC;
160         /* This will always be set for application modified trust entries */
161         flags |= X509_PURPOSE_DYNAMIC_NAME;
162         /* Get existing entry if any */
163         idx = X509_PURPOSE_get_by_id(id);
164         /* Need a new entry */
165         if(idx == -1) {
166                 if(!(ptmp = Malloc(sizeof(X509_PURPOSE)))) {
167                         X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
168                         return 0;
169                 }
170                 ptmp->flags = X509_PURPOSE_DYNAMIC;
171         } else ptmp = X509_PURPOSE_iget(idx);
172
173         /* Free existing name if dynamic */
174         if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
175                 Free(ptmp->name);
176                 Free(ptmp->sname);
177         }
178         /* dup supplied name */
179         ptmp->name = BUF_strdup(name);
180         ptmp->sname = BUF_strdup(sname);
181         if(!ptmp->name || !ptmp->sname) {
182                 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
183                 return 0;
184         }
185         /* Keep the dynamic flag of existing entry */
186         ptmp->flags &= X509_PURPOSE_DYNAMIC;
187         /* Set all other flags */
188         ptmp->flags |= flags;
189
190         ptmp->purpose = id;
191         ptmp->trust = trust;
192         ptmp->check_purpose = ck;
193         ptmp->usr_data = arg;
194
195         /* If its a new entry manage the dynamic table */
196         if(idx == -1) {
197                 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
198                         X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
199                         return 0;
200                 }
201                 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
202                         X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
203                         return 0;
204                 }
205         }
206         return 1;
207 }
208
209 static void xptable_free(X509_PURPOSE *p)
210         {
211         if(!p) return;
212         if (p->flags & X509_PURPOSE_DYNAMIC) 
213                 {
214                 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
215                         Free(p->name);
216                         Free(p->sname);
217                 }
218                 Free(p);
219                 }
220         }
221
222 void X509_PURPOSE_cleanup(void)
223 {
224         int i;
225         sk_X509_PURPOSE_pop_free(xptable, xptable_free);
226         for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
227         xptable = NULL;
228 }
229
230 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
231 {
232         return xp->purpose;
233 }
234
235 char *X509_PURPOSE_iget_name(X509_PURPOSE *xp)
236 {
237         return xp->name;
238 }
239
240 char *X509_PURPOSE_iget_sname(X509_PURPOSE *xp)
241 {
242         return xp->sname;
243 }
244
245 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
246 {
247         return xp->trust;
248 }
249
250 static void x509v3_cache_extensions(X509 *x)
251 {
252         BASIC_CONSTRAINTS *bs;
253         ASN1_BIT_STRING *usage;
254         ASN1_BIT_STRING *ns;
255         STACK_OF(ASN1_OBJECT) *extusage;
256         int i;
257         if(x->ex_flags & EXFLAG_SET) return;
258         X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
259         /* Does subject name match issuer ? */
260         if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
261                          x->ex_flags |= EXFLAG_SS;
262         /* V1 should mean no extensions ... */
263         if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
264         /* Handle basic constraints */
265         if((bs=X509V3_X509_get_d2i(x, NID_basic_constraints, NULL, NULL))) {
266                 if(bs->ca) x->ex_flags |= EXFLAG_CA;
267                 if(bs->pathlen) {
268                         if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
269                                                 || !bs->ca) {
270                                 x->ex_flags |= EXFLAG_INVALID;
271                                 x->ex_pathlen = 0;
272                         } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
273                 } else x->ex_pathlen = -1;
274                 BASIC_CONSTRAINTS_free(bs);
275                 x->ex_flags |= EXFLAG_BCONS;
276         }
277         /* Handle key usage */
278         if((usage=X509V3_X509_get_d2i(x, NID_key_usage, NULL, NULL))) {
279                 if(usage->length > 0) {
280                         x->ex_kusage = usage->data[0];
281                         if(usage->length > 1) 
282                                 x->ex_kusage |= usage->data[1] << 8;
283                 } else x->ex_kusage = 0;
284                 x->ex_flags |= EXFLAG_KUSAGE;
285                 ASN1_BIT_STRING_free(usage);
286         }
287         x->ex_xkusage = 0;
288         if((extusage=X509V3_X509_get_d2i(x, NID_ext_key_usage, NULL, NULL))) {
289                 x->ex_flags |= EXFLAG_XKUSAGE;
290                 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
291                         switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
292                                 case NID_server_auth:
293                                 x->ex_xkusage |= XKU_SSL_SERVER;
294                                 break;
295
296                                 case NID_client_auth:
297                                 x->ex_xkusage |= XKU_SSL_CLIENT;
298                                 break;
299
300                                 case NID_email_protect:
301                                 x->ex_xkusage |= XKU_SMIME;
302                                 break;
303
304                                 case NID_code_sign:
305                                 x->ex_xkusage |= XKU_CODE_SIGN;
306                                 break;
307
308                                 case NID_ms_sgc:
309                                 case NID_ns_sgc:
310                                 x->ex_xkusage |= XKU_SGC;
311                         }
312                 }
313                 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
314         }
315
316         if((ns=X509V3_X509_get_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
317                 if(ns->length > 0) x->ex_nscert = ns->data[0];
318                 else x->ex_nscert = 0;
319                 x->ex_flags |= EXFLAG_NSCERT;
320                 ASN1_BIT_STRING_free(ns);
321         }
322         x->ex_flags |= EXFLAG_SET;
323 }
324
325 /* CA checks common to all purposes
326  * return codes:
327  * 0 not a CA
328  * 1 is a CA
329  * 2 basicConstraints absent so "maybe" a CA
330  * 3 basicConstraints absent but self signed V1.
331  */
332
333 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
334 #define ku_reject(x, usage) \
335         (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
336 #define xku_reject(x, usage) \
337         (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
338 #define ns_reject(x, usage) \
339         (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
340
341 static int ca_check(X509 *x)
342 {
343         /* keyUsage if present should allow cert signing */
344         if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
345         if(x->ex_flags & EXFLAG_BCONS) {
346                 if(x->ex_flags & EXFLAG_CA) return 1;
347                 /* If basicConstraints says not a CA then say so */
348                 else return 0;
349         } else {
350                 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
351                 else return 2;
352         }
353 }
354
355
356 static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca)
357 {
358         if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
359         if(ca) {
360                 int ca_ret;
361                 ca_ret = ca_check(x);
362                 if(!ca_ret) return 0;
363                 /* check nsCertType if present */
364                 if(x->ex_flags & EXFLAG_NSCERT) {
365                         if(x->ex_nscert & NS_SSL_CA) return ca_ret;
366                         return 0;
367                 }
368                 if(ca_ret != 2) return ca_ret;
369                 else return 0;
370         }
371         /* We need to do digital signatures with it */
372         if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
373         /* nsCertType if present should allow SSL client use */ 
374         if(ns_reject(x, NS_SSL_CLIENT)) return 0;
375         return 1;
376 }
377
378 static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
379 {
380         if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
381         /* Otherwise same as SSL client for a CA */
382         if(ca) return check_purpose_ssl_client(xp, x, 1);
383
384         if(ns_reject(x, NS_SSL_SERVER)) return 0;
385         /* Now as for keyUsage: we'll at least need to sign OR encipher */
386         if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
387         
388         return 1;
389
390 }
391
392 static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
393 {
394         int ret;
395         ret = check_purpose_ssl_server(xp, x, ca);
396         if(!ret || ca) return ret;
397         /* We need to encipher or Netscape complains */
398         if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
399         return ret;
400 }
401
402 /* common S/MIME checks */
403 static int purpose_smime(X509 *x, int ca)
404 {
405         if(xku_reject(x,XKU_SMIME)) return 0;
406         if(ca) {
407                 int ca_ret;
408                 ca_ret = ca_check(x);
409                 if(!ca_ret) return 0;
410                 /* check nsCertType if present */
411                 if(x->ex_flags & EXFLAG_NSCERT) {
412                         if(x->ex_nscert & NS_SMIME_CA) return ca_ret;
413                         return 0;
414                 }
415                 if(ca_ret != 2) return ca_ret;
416                 else return 0;
417         }
418         if(x->ex_flags & EXFLAG_NSCERT) {
419                 if(x->ex_nscert & NS_SMIME) return 1;
420                 /* Workaround for some buggy certificates */
421                 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
422                 return 0;
423         }
424         return 1;
425 }
426
427 static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca)
428 {
429         int ret;
430         ret = purpose_smime(x, ca);
431         if(!ret || ca) return ret;
432         if(ku_reject(x, KU_DIGITAL_SIGNATURE)) return 0;
433         return ret;
434 }
435
436 static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca)
437 {
438         int ret;
439         ret = purpose_smime(x, ca);
440         if(!ret || ca) return ret;
441         if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
442         return ret;
443 }
444
445 static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca)
446 {
447         if(ca) {
448                 int ca_ret;
449                 if((ca_ret = ca_check(x)) != 2) return ca_ret;
450                 else return 0;
451         }
452         if(ku_reject(x, KU_CRL_SIGN)) return 0;
453         return 1;
454 }