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>
62 #include <openssl/x509_vfy.h>
65 static void x509v3_cache_extensions(X509 *x);
67 static int ca_check(const X509 *x);
68 static int check_ssl_ca(const X509 *x);
69 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca);
70 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
71 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
72 static int purpose_smime(const X509 *x, int ca);
73 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
74 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca);
75 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
76 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
78 static int xp_cmp(const X509_PURPOSE * const *a,
79 const X509_PURPOSE * const *b);
80 static void xptable_free(X509_PURPOSE *p);
82 static X509_PURPOSE xstandard[] = {
83 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
84 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
85 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
86 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
87 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
88 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
89 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
92 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
94 IMPLEMENT_STACK_OF(X509_PURPOSE)
96 static STACK_OF(X509_PURPOSE) *xptable = NULL;
98 static int xp_cmp(const X509_PURPOSE * const *a,
99 const X509_PURPOSE * const *b)
101 return (*a)->purpose - (*b)->purpose;
104 /* As much as I'd like to make X509_check_purpose use a "const" X509*
105 * I really can't because it does recalculate hashes and do other non-const
107 int X509_check_purpose(X509 *x, int id, int ca)
110 const X509_PURPOSE *pt;
111 if(!(x->ex_flags & EXFLAG_SET)) {
112 CRYPTO_w_lock(CRYPTO_LOCK_X509);
113 x509v3_cache_extensions(x);
114 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
116 if(id == -1) return 1;
117 idx = X509_PURPOSE_get_by_id(id);
118 if(idx == -1) return -1;
119 pt = X509_PURPOSE_get0(idx);
120 return pt->check_purpose(pt, x, ca);
123 int X509_PURPOSE_get_count(void)
125 if(!xptable) return X509_PURPOSE_COUNT;
126 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
129 X509_PURPOSE * X509_PURPOSE_get0(int idx)
131 if(idx < 0) return NULL;
132 if(idx < X509_PURPOSE_COUNT) return xstandard + idx;
133 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
136 int X509_PURPOSE_get_by_sname(char *sname)
140 for(i = 0; i < X509_PURPOSE_get_count(); i++) {
141 xptmp = X509_PURPOSE_get0(i);
142 if(!strcmp(xptmp->sname, sname)) return i;
148 int X509_PURPOSE_get_by_id(int purpose)
152 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
153 return purpose - X509_PURPOSE_MIN;
154 tmp.purpose = purpose;
155 if(!xptable) return -1;
156 idx = sk_X509_PURPOSE_find(xptable, &tmp);
157 if(idx == -1) return -1;
158 return idx + X509_PURPOSE_COUNT;
161 int X509_PURPOSE_add(int id, int trust, int flags,
162 int (*ck)(const X509_PURPOSE *, const X509 *, int),
163 char *name, char *sname, void *arg)
167 /* This is set according to what we change: application can't set it */
168 flags &= ~X509_PURPOSE_DYNAMIC;
169 /* This will always be set for application modified trust entries */
170 flags |= X509_PURPOSE_DYNAMIC_NAME;
171 /* Get existing entry if any */
172 idx = X509_PURPOSE_get_by_id(id);
173 /* Need a new entry */
175 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
176 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
179 ptmp->flags = X509_PURPOSE_DYNAMIC;
180 } else ptmp = X509_PURPOSE_get0(idx);
182 /* OPENSSL_free existing name if dynamic */
183 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
184 OPENSSL_free(ptmp->name);
185 OPENSSL_free(ptmp->sname);
187 /* dup supplied name */
188 ptmp->name = BUF_strdup(name);
189 ptmp->sname = BUF_strdup(sname);
190 if(!ptmp->name || !ptmp->sname) {
191 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
194 /* Keep the dynamic flag of existing entry */
195 ptmp->flags &= X509_PURPOSE_DYNAMIC;
196 /* Set all other flags */
197 ptmp->flags |= flags;
201 ptmp->check_purpose = ck;
202 ptmp->usr_data = arg;
204 /* If its a new entry manage the dynamic table */
206 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
207 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
210 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
211 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
218 static void xptable_free(X509_PURPOSE *p)
221 if (p->flags & X509_PURPOSE_DYNAMIC)
223 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
224 OPENSSL_free(p->name);
225 OPENSSL_free(p->sname);
231 void X509_PURPOSE_cleanup(void)
234 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
235 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
239 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
244 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
249 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
254 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
259 static void x509v3_cache_extensions(X509 *x)
261 BASIC_CONSTRAINTS *bs;
262 ASN1_BIT_STRING *usage;
264 STACK_OF(ASN1_OBJECT) *extusage;
267 if(x->ex_flags & EXFLAG_SET) return;
269 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
271 /* Does subject name match issuer ? */
272 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
273 x->ex_flags |= EXFLAG_SS;
274 /* V1 should mean no extensions ... */
275 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
276 /* Handle basic constraints */
277 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
278 if(bs->ca) x->ex_flags |= EXFLAG_CA;
280 if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
282 x->ex_flags |= EXFLAG_INVALID;
284 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
285 } else x->ex_pathlen = -1;
286 BASIC_CONSTRAINTS_free(bs);
287 x->ex_flags |= EXFLAG_BCONS;
289 /* Handle key usage */
290 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
291 if(usage->length > 0) {
292 x->ex_kusage = usage->data[0];
293 if(usage->length > 1)
294 x->ex_kusage |= usage->data[1] << 8;
295 } else x->ex_kusage = 0;
296 x->ex_flags |= EXFLAG_KUSAGE;
297 ASN1_BIT_STRING_free(usage);
300 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
301 x->ex_flags |= EXFLAG_XKUSAGE;
302 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
303 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
304 case NID_server_auth:
305 x->ex_xkusage |= XKU_SSL_SERVER;
308 case NID_client_auth:
309 x->ex_xkusage |= XKU_SSL_CLIENT;
312 case NID_email_protect:
313 x->ex_xkusage |= XKU_SMIME;
317 x->ex_xkusage |= XKU_CODE_SIGN;
322 x->ex_xkusage |= XKU_SGC;
325 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
328 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
329 if(ns->length > 0) x->ex_nscert = ns->data[0];
330 else x->ex_nscert = 0;
331 x->ex_flags |= EXFLAG_NSCERT;
332 ASN1_BIT_STRING_free(ns);
334 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
335 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
336 x->ex_flags |= EXFLAG_SET;
339 /* CA checks common to all purposes
343 * 2 basicConstraints absent so "maybe" a CA
344 * 3 basicConstraints absent but self signed V1.
347 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
348 #define ku_reject(x, usage) \
349 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
350 #define xku_reject(x, usage) \
351 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
352 #define ns_reject(x, usage) \
353 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
355 static int ca_check(const X509 *x)
357 /* keyUsage if present should allow cert signing */
358 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
359 if(x->ex_flags & EXFLAG_BCONS) {
360 if(x->ex_flags & EXFLAG_CA) return 1;
361 /* If basicConstraints says not a CA then say so */
364 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
365 /* If key usage present it must have certSign so tolerate it */
366 else if (x->ex_flags & EXFLAG_KUSAGE) return 3;
371 /* Check SSL CA: common checks for SSL client and server */
372 static int check_ssl_ca(const X509 *x)
375 ca_ret = ca_check(x);
376 if(!ca_ret) return 0;
377 /* check nsCertType if present */
378 if(x->ex_flags & EXFLAG_NSCERT) {
379 if(x->ex_nscert & NS_SSL_CA) return ca_ret;
382 if(ca_ret != 2) return ca_ret;
387 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
389 if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
390 if(ca) return check_ssl_ca(x);
391 /* We need to do digital signatures with it */
392 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
393 /* nsCertType if present should allow SSL client use */
394 if(ns_reject(x, NS_SSL_CLIENT)) return 0;
398 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
400 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
401 if(ca) return check_ssl_ca(x);
403 if(ns_reject(x, NS_SSL_SERVER)) return 0;
404 /* Now as for keyUsage: we'll at least need to sign OR encipher */
405 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
411 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
414 ret = check_purpose_ssl_server(xp, x, ca);
415 if(!ret || ca) return ret;
416 /* We need to encipher or Netscape complains */
417 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
421 /* common S/MIME checks */
422 static int purpose_smime(const X509 *x, int ca)
424 if(xku_reject(x,XKU_SMIME)) return 0;
427 ca_ret = ca_check(x);
428 if(!ca_ret) return 0;
429 /* check nsCertType if present */
430 if(x->ex_flags & EXFLAG_NSCERT) {
431 if(x->ex_nscert & NS_SMIME_CA) return ca_ret;
434 if(ca_ret != 2) return ca_ret;
437 if(x->ex_flags & EXFLAG_NSCERT) {
438 if(x->ex_nscert & NS_SMIME) return 1;
439 /* Workaround for some buggy certificates */
440 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
446 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
449 ret = purpose_smime(x, ca);
450 if(!ret || ca) return ret;
451 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
455 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
458 ret = purpose_smime(x, ca);
459 if(!ret || ca) return ret;
460 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
464 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
468 if((ca_ret = ca_check(x)) != 2) return ca_ret;
471 if(ku_reject(x, KU_CRL_SIGN)) return 0;
475 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
480 /* Various checks to see if one certificate issued the second.
481 * This can be used to prune a set of possible issuer certificates
482 * which have been looked up using some simple method such as by
485 * 1. Check issuer_name(subject) == subject_name(issuer)
486 * 2. If akid(subject) exists check it matches issuer
487 * 3. If key_usage(issuer) exists check it supports certificate signing
488 * returns 0 for OK, positive for reason for mismatch, reasons match
489 * codes for X509_verify_cert()
492 int X509_check_issued(X509 *issuer, X509 *subject)
494 if(X509_NAME_cmp(X509_get_subject_name(issuer),
495 X509_get_issuer_name(subject)))
496 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
497 x509v3_cache_extensions(issuer);
498 x509v3_cache_extensions(subject);
500 /* Check key ids (if present) */
501 if(subject->akid->keyid && issuer->skid &&
502 ASN1_OCTET_STRING_cmp(subject->akid->keyid, issuer->skid) )
503 return X509_V_ERR_AKID_SKID_MISMATCH;
504 /* Check serial number */
505 if(subject->akid->serial &&
506 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer),
507 subject->akid->serial))
508 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
509 /* Check issuer name */
510 if(subject->akid->issuer) {
511 /* Ugh, for some peculiar reason AKID includes
512 * SEQUENCE OF GeneralName. So look for a DirName.
513 * There may be more than one but we only take any
514 * notice of the first.
516 STACK_OF(GENERAL_NAME) *gens;
518 X509_NAME *nm = NULL;
520 gens = subject->akid->issuer;
521 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
522 gen = sk_GENERAL_NAME_value(gens, i);
523 if(gen->type == GEN_DIRNAME) {
528 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
529 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
532 if(ku_reject(issuer, KU_KEY_CERT_SIGN)) return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;