2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
5 /* ====================================================================
6 * Copyright (c) 1999-2004 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>
64 static void x509v3_cache_extensions(X509 *x);
66 static int check_ssl_ca(const X509 *x);
67 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca);
68 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
69 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
70 static int purpose_smime(const X509 *x, int ca);
71 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
72 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca);
73 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
74 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
75 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
77 static int xp_cmp(const X509_PURPOSE * const *a,
78 const X509_PURPOSE * const *b);
79 static void xptable_free(X509_PURPOSE *p);
81 static X509_PURPOSE xstandard[] = {
82 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
83 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
84 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
85 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
86 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
87 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
88 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
89 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", 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_set(int *p, int purpose)
125 if(X509_PURPOSE_get_by_id(purpose) == -1) {
126 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
133 int X509_PURPOSE_get_count(void)
135 if(!xptable) return X509_PURPOSE_COUNT;
136 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
139 X509_PURPOSE * X509_PURPOSE_get0(int idx)
141 if(idx < 0) return NULL;
142 if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
143 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
146 int X509_PURPOSE_get_by_sname(char *sname)
150 for(i = 0; i < X509_PURPOSE_get_count(); i++) {
151 xptmp = X509_PURPOSE_get0(i);
152 if(!strcmp(xptmp->sname, sname)) return i;
157 int X509_PURPOSE_get_by_id(int purpose)
161 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
162 return purpose - X509_PURPOSE_MIN;
163 tmp.purpose = purpose;
164 if(!xptable) return -1;
165 idx = sk_X509_PURPOSE_find(xptable, &tmp);
166 if(idx == -1) return -1;
167 return idx + X509_PURPOSE_COUNT;
170 int X509_PURPOSE_add(int id, int trust, int flags,
171 int (*ck)(const X509_PURPOSE *, const X509 *, int),
172 char *name, char *sname, void *arg)
176 /* This is set according to what we change: application can't set it */
177 flags &= ~X509_PURPOSE_DYNAMIC;
178 /* This will always be set for application modified trust entries */
179 flags |= X509_PURPOSE_DYNAMIC_NAME;
180 /* Get existing entry if any */
181 idx = X509_PURPOSE_get_by_id(id);
182 /* Need a new entry */
184 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
185 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
188 ptmp->flags = X509_PURPOSE_DYNAMIC;
189 } else ptmp = X509_PURPOSE_get0(idx);
191 /* OPENSSL_free existing name if dynamic */
192 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
193 OPENSSL_free(ptmp->name);
194 OPENSSL_free(ptmp->sname);
196 /* dup supplied name */
197 ptmp->name = BUF_strdup(name);
198 ptmp->sname = BUF_strdup(sname);
199 if(!ptmp->name || !ptmp->sname) {
200 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
203 /* Keep the dynamic flag of existing entry */
204 ptmp->flags &= X509_PURPOSE_DYNAMIC;
205 /* Set all other flags */
206 ptmp->flags |= flags;
210 ptmp->check_purpose = ck;
211 ptmp->usr_data = arg;
213 /* If its a new entry manage the dynamic table */
215 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
216 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
219 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
220 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
227 static void xptable_free(X509_PURPOSE *p)
230 if (p->flags & X509_PURPOSE_DYNAMIC)
232 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
233 OPENSSL_free(p->name);
234 OPENSSL_free(p->sname);
240 void X509_PURPOSE_cleanup(void)
243 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
244 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
248 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
253 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
258 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
263 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
268 static int nid_cmp(int *a, int *b)
273 int X509_supported_extension(X509_EXTENSION *ex)
275 /* This table is a list of the NIDs of supported extensions:
276 * that is those which are used by the verify process. If
277 * an extension is critical and doesn't appear in this list
278 * then the verify process will normally reject the certificate.
279 * The list must be kept in numerical order because it will be
280 * searched using bsearch.
283 static int supported_nids[] = {
284 NID_netscape_cert_type, /* 71 */
285 NID_key_usage, /* 83 */
286 NID_subject_alt_name, /* 85 */
287 NID_basic_constraints, /* 87 */
288 NID_ext_key_usage, /* 126 */
289 NID_proxyCertInfo /* 661 */
294 ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
296 if (ex_nid == NID_undef)
299 if (OBJ_bsearch((char *)&ex_nid, (char *)supported_nids,
300 sizeof(supported_nids)/sizeof(int), sizeof(int),
301 (int (*)(const void *, const void *))nid_cmp))
307 static void x509v3_cache_extensions(X509 *x)
309 BASIC_CONSTRAINTS *bs;
310 PROXY_CERT_INFO_EXTENSION *pci;
311 ASN1_BIT_STRING *usage;
313 EXTENDED_KEY_USAGE *extusage;
317 if(x->ex_flags & EXFLAG_SET) return;
318 #ifndef OPENSSL_NO_SHA
319 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
321 /* Does subject name match issuer ? */
322 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
323 x->ex_flags |= EXFLAG_SS;
324 /* V1 should mean no extensions ... */
325 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
326 /* Handle basic constraints */
327 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
328 if(bs->ca) x->ex_flags |= EXFLAG_CA;
330 if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
332 x->ex_flags |= EXFLAG_INVALID;
334 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
335 } else x->ex_pathlen = -1;
336 BASIC_CONSTRAINTS_free(bs);
337 x->ex_flags |= EXFLAG_BCONS;
339 /* Handle proxy certificates */
340 if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
341 if (x->ex_flags & EXFLAG_CA
342 || X509_get_ext_by_NID(x, NID_subject_alt_name, 0) >= 0
343 || X509_get_ext_by_NID(x, NID_issuer_alt_name, 0) >= 0) {
344 x->ex_flags |= EXFLAG_INVALID;
346 if (pci->pcPathLengthConstraint) {
348 ASN1_INTEGER_get(pci->pcPathLengthConstraint);
349 } else x->ex_pcpathlen = -1;
350 PROXY_CERT_INFO_EXTENSION_free(pci);
351 x->ex_flags |= EXFLAG_PROXY;
353 /* Handle key usage */
354 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
355 if(usage->length > 0) {
356 x->ex_kusage = usage->data[0];
357 if(usage->length > 1)
358 x->ex_kusage |= usage->data[1] << 8;
359 } else x->ex_kusage = 0;
360 x->ex_flags |= EXFLAG_KUSAGE;
361 ASN1_BIT_STRING_free(usage);
364 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
365 x->ex_flags |= EXFLAG_XKUSAGE;
366 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
367 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
368 case NID_server_auth:
369 x->ex_xkusage |= XKU_SSL_SERVER;
372 case NID_client_auth:
373 x->ex_xkusage |= XKU_SSL_CLIENT;
376 case NID_email_protect:
377 x->ex_xkusage |= XKU_SMIME;
381 x->ex_xkusage |= XKU_CODE_SIGN;
386 x->ex_xkusage |= XKU_SGC;
390 x->ex_xkusage |= XKU_OCSP_SIGN;
394 x->ex_xkusage |= XKU_TIMESTAMP;
398 x->ex_xkusage |= XKU_DVCS;
402 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
405 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
406 if(ns->length > 0) x->ex_nscert = ns->data[0];
407 else x->ex_nscert = 0;
408 x->ex_flags |= EXFLAG_NSCERT;
409 ASN1_BIT_STRING_free(ns);
411 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
412 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
413 for (i = 0; i < X509_get_ext_count(x); i++)
415 ex = X509_get_ext(x, i);
416 if (!X509_EXTENSION_get_critical(ex))
418 if (!X509_supported_extension(ex))
420 x->ex_flags |= EXFLAG_CRITICAL;
424 x->ex_flags |= EXFLAG_SET;
427 /* CA checks common to all purposes
431 * 2 basicConstraints absent so "maybe" a CA
432 * 3 basicConstraints absent but self signed V1.
433 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
436 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
437 #define ku_reject(x, usage) \
438 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
439 #define xku_reject(x, usage) \
440 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
441 #define ns_reject(x, usage) \
442 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
444 static int check_ca(const X509 *x)
446 /* keyUsage if present should allow cert signing */
447 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
448 if(x->ex_flags & EXFLAG_BCONS) {
449 if(x->ex_flags & EXFLAG_CA) return 1;
450 /* If basicConstraints says not a CA then say so */
453 /* we support V1 roots for... uh, I don't really know why. */
454 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
455 /* If key usage present it must have certSign so tolerate it */
456 else if (x->ex_flags & EXFLAG_KUSAGE) return 4;
457 /* Older certificates could have Netscape-specific CA types */
458 else if (x->ex_flags & EXFLAG_NSCERT
459 && x->ex_nscert & NS_ANY_CA) return 5;
460 /* can this still be regarded a CA certificate? I doubt it */
465 int X509_check_ca(X509 *x)
467 if(!(x->ex_flags & EXFLAG_SET)) {
468 CRYPTO_w_lock(CRYPTO_LOCK_X509);
469 x509v3_cache_extensions(x);
470 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
476 /* Check SSL CA: common checks for SSL client and server */
477 static int check_ssl_ca(const X509 *x)
480 ca_ret = check_ca(x);
481 if(!ca_ret) return 0;
482 /* check nsCertType if present */
483 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret;
488 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
490 if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
491 if(ca) return check_ssl_ca(x);
492 /* We need to do digital signatures with it */
493 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
494 /* nsCertType if present should allow SSL client use */
495 if(ns_reject(x, NS_SSL_CLIENT)) return 0;
499 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
501 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
502 if(ca) return check_ssl_ca(x);
504 if(ns_reject(x, NS_SSL_SERVER)) return 0;
505 /* Now as for keyUsage: we'll at least need to sign OR encipher */
506 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
512 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
515 ret = check_purpose_ssl_server(xp, x, ca);
516 if(!ret || ca) return ret;
517 /* We need to encipher or Netscape complains */
518 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
522 /* common S/MIME checks */
523 static int purpose_smime(const X509 *x, int ca)
525 if(xku_reject(x,XKU_SMIME)) return 0;
528 ca_ret = check_ca(x);
529 if(!ca_ret) return 0;
530 /* check nsCertType if present */
531 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret;
534 if(x->ex_flags & EXFLAG_NSCERT) {
535 if(x->ex_nscert & NS_SMIME) return 1;
536 /* Workaround for some buggy certificates */
537 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
543 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
546 ret = purpose_smime(x, ca);
547 if(!ret || ca) return ret;
548 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
552 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
555 ret = purpose_smime(x, ca);
556 if(!ret || ca) return ret;
557 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
561 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
565 if((ca_ret = check_ca(x)) != 2) return ca_ret;
568 if(ku_reject(x, KU_CRL_SIGN)) return 0;
572 /* OCSP helper: this is *not* a full OCSP check. It just checks that
573 * each CA is valid. Additional checks must be made on the chain.
576 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
578 /* Must be a valid CA. Should we really support the "I don't know"
580 if(ca) return check_ca(x);
581 /* leaf certificate is checked in OCSP_verify() */
585 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
590 /* Various checks to see if one certificate issued the second.
591 * This can be used to prune a set of possible issuer certificates
592 * which have been looked up using some simple method such as by
595 * 1. Check issuer_name(subject) == subject_name(issuer)
596 * 2. If akid(subject) exists check it matches issuer
597 * 3. If key_usage(issuer) exists check it supports certificate signing
598 * returns 0 for OK, positive for reason for mismatch, reasons match
599 * codes for X509_verify_cert()
602 int X509_check_issued(X509 *issuer, X509 *subject)
604 if(X509_NAME_cmp(X509_get_subject_name(issuer),
605 X509_get_issuer_name(subject)))
606 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
607 x509v3_cache_extensions(issuer);
608 x509v3_cache_extensions(subject);
610 /* Check key ids (if present) */
611 if(subject->akid->keyid && issuer->skid &&
612 ASN1_OCTET_STRING_cmp(subject->akid->keyid, issuer->skid) )
613 return X509_V_ERR_AKID_SKID_MISMATCH;
614 /* Check serial number */
615 if(subject->akid->serial &&
616 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer),
617 subject->akid->serial))
618 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
619 /* Check issuer name */
620 if(subject->akid->issuer) {
621 /* Ugh, for some peculiar reason AKID includes
622 * SEQUENCE OF GeneralName. So look for a DirName.
623 * There may be more than one but we only take any
624 * notice of the first.
628 X509_NAME *nm = NULL;
630 gens = subject->akid->issuer;
631 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
632 gen = sk_GENERAL_NAME_value(gens, i);
633 if(gen->type == GEN_DIRNAME) {
638 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
639 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
642 if(subject->ex_flags & EXFLAG_PROXY)
644 if(ku_reject(issuer, KU_DIGITAL_SIGNATURE))
645 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
647 else if(ku_reject(issuer, KU_KEY_CERT_SIGN))
648 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;