1/*
2 * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include <stdio.h>
11#include "internal/cryptlib.h"
12#include "internal/numbers.h"
13#include <openssl/x509v3.h>
14#include <openssl/x509_vfy.h>
15#include "crypto/x509.h"
16#include "internal/tsan_assist.h"
17
18static void x509v3_cache_extensions(X509 *x);
19
20static int check_ssl_ca(const X509 *x);
21static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
22 int ca);
23static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
24 int ca);
25static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
26 int ca);
27static int purpose_smime(const X509 *x, int ca);
28static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
29 int ca);
30static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
31 int ca);
32static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
33 int ca);
34static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
35 int ca);
36static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
37static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
38
39static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
40static void xptable_free(X509_PURPOSE *p);
41
42static X509_PURPOSE xstandard[] = {
43 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
44 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
45 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
46 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
47 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
48 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
49 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
50 "S/MIME signing", "smimesign", NULL},
51 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
52 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
53 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
54 "CRL signing", "crlsign", NULL},
55 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any",
56 NULL},
57 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
58 "OCSP helper", "ocsphelper", NULL},
59 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
60 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
61 NULL},
62};
63
64#define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
65
66static STACK_OF(X509_PURPOSE) *xptable = NULL;
67
68static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
69{
70 return (*a)->purpose - (*b)->purpose;
71}
72
73/*
74 * As much as I'd like to make X509_check_purpose use a "const" X509* I
75 * really can't because it does recalculate hashes and do other non-const
76 * things.
77 */
78int X509_check_purpose(X509 *x, int id, int ca)
79{
80 int idx;
81 const X509_PURPOSE *pt;
82
83 x509v3_cache_extensions(x);
84
85 /* Return if side-effect only call */
86 if (id == -1)
87 return 1;
88 idx = X509_PURPOSE_get_by_id(id);
89 if (idx == -1)
90 return -1;
91 pt = X509_PURPOSE_get0(idx);
92 return pt->check_purpose(pt, x, ca);
93}
94
95int X509_PURPOSE_set(int *p, int purpose)
96{
97 if (X509_PURPOSE_get_by_id(purpose) == -1) {
98 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
99 return 0;
100 }
101 *p = purpose;
102 return 1;
103}
104
105int X509_PURPOSE_get_count(void)
106{
107 if (!xptable)
108 return X509_PURPOSE_COUNT;
109 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
110}
111
112X509_PURPOSE *X509_PURPOSE_get0(int idx)
113{
114 if (idx < 0)
115 return NULL;
116 if (idx < (int)X509_PURPOSE_COUNT)
117 return xstandard + idx;
118 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
119}
120
121int X509_PURPOSE_get_by_sname(const char *sname)
122{
123 int i;
124 X509_PURPOSE *xptmp;
125 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
126 xptmp = X509_PURPOSE_get0(i);
127 if (strcmp(xptmp->sname, sname) == 0)
128 return i;
129 }
130 return -1;
131}
132
133int X509_PURPOSE_get_by_id(int purpose)
134{
135 X509_PURPOSE tmp;
136 int idx;
137
138 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
139 return purpose - X509_PURPOSE_MIN;
140 if (xptable == NULL)
141 return -1;
142 tmp.purpose = purpose;
143 idx = sk_X509_PURPOSE_find(xptable, &tmp);
144 if (idx < 0)
145 return -1;
146 return idx + X509_PURPOSE_COUNT;
147}
148
149int X509_PURPOSE_add(int id, int trust, int flags,
150 int (*ck) (const X509_PURPOSE *, const X509 *, int),
151 const char *name, const char *sname, void *arg)
152{
153 int idx;
154 X509_PURPOSE *ptmp;
155 /*
156 * This is set according to what we change: application can't set it
157 */
158 flags &= ~X509_PURPOSE_DYNAMIC;
159 /* This will always be set for application modified trust entries */
160 flags |= X509_PURPOSE_DYNAMIC_NAME;
161 /* Get existing entry if any */
162 idx = X509_PURPOSE_get_by_id(id);
163 /* Need a new entry */
164 if (idx == -1) {
165 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
166 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
167 return 0;
168 }
169 ptmp->flags = X509_PURPOSE_DYNAMIC;
170 } else
171 ptmp = X509_PURPOSE_get0(idx);
172
173 /* OPENSSL_free existing name if dynamic */
174 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
175 OPENSSL_free(ptmp->name);
176 OPENSSL_free(ptmp->sname);
177 }
178 /* dup supplied name */
179 ptmp->name = OPENSSL_strdup(name);
180 ptmp->sname = OPENSSL_strdup(sname);
181 if (ptmp->name == NULL|| ptmp->sname == NULL) {
182 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
183 goto err;
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 == NULL
198 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
199 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
200 goto err;
201 }
202 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
203 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
204 goto err;
205 }
206 }
207 return 1;
208 err:
209 if (idx == -1) {
210 OPENSSL_free(ptmp->name);
211 OPENSSL_free(ptmp->sname);
212 OPENSSL_free(ptmp);
213 }
214 return 0;
215}
216
217static void xptable_free(X509_PURPOSE *p)
218{
219 if (p == NULL)
220 return;
221 if (p->flags & X509_PURPOSE_DYNAMIC) {
222 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
223 OPENSSL_free(p->name);
224 OPENSSL_free(p->sname);
225 }
226 OPENSSL_free(p);
227 }
228}
229
230void X509_PURPOSE_cleanup(void)
231{
232 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
233 xptable = NULL;
234}
235
236int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
237{
238 return xp->purpose;
239}
240
241char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
242{
243 return xp->name;
244}
245
246char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
247{
248 return xp->sname;
249}
250
251int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
252{
253 return xp->trust;
254}
255
256static int nid_cmp(const int *a, const int *b)
257{
258 return *a - *b;
259}
260
261DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
262IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
263
264int X509_supported_extension(X509_EXTENSION *ex)
265{
266 /*
267 * This table is a list of the NIDs of supported extensions: that is
268 * those which are used by the verify process. If an extension is
269 * critical and doesn't appear in this list then the verify process will
270 * normally reject the certificate. The list must be kept in numerical
271 * order because it will be searched using bsearch.
272 */
273
274 static const int supported_nids[] = {
275 NID_netscape_cert_type, /* 71 */
276 NID_key_usage, /* 83 */
277 NID_subject_alt_name, /* 85 */
278 NID_basic_constraints, /* 87 */
279 NID_certificate_policies, /* 89 */
280 NID_crl_distribution_points, /* 103 */
281 NID_ext_key_usage, /* 126 */
282#ifndef OPENSSL_NO_RFC3779
283 NID_sbgp_ipAddrBlock, /* 290 */
284 NID_sbgp_autonomousSysNum, /* 291 */
285#endif
286 NID_policy_constraints, /* 401 */
287 NID_proxyCertInfo, /* 663 */
288 NID_name_constraints, /* 666 */
289 NID_policy_mappings, /* 747 */
290 NID_inhibit_any_policy /* 748 */
291 };
292
293 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
294
295 if (ex_nid == NID_undef)
296 return 0;
297
298 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
299 return 1;
300 return 0;
301}
302
303static void setup_dp(X509 *x, DIST_POINT *dp)
304{
305 X509_NAME *iname = NULL;
306 int i;
307 if (dp->reasons) {
308 if (dp->reasons->length > 0)
309 dp->dp_reasons = dp->reasons->data[0];
310 if (dp->reasons->length > 1)
311 dp->dp_reasons |= (dp->reasons->data[1] << 8);
312 dp->dp_reasons &= CRLDP_ALL_REASONS;
313 } else
314 dp->dp_reasons = CRLDP_ALL_REASONS;
315 if (!dp->distpoint || (dp->distpoint->type != 1))
316 return;
317 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
318 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
319 if (gen->type == GEN_DIRNAME) {
320 iname = gen->d.directoryName;
321 break;
322 }
323 }
324 if (!iname)
325 iname = X509_get_issuer_name(x);
326
327 DIST_POINT_set_dpname(dp->distpoint, iname);
328
329}
330
331static void setup_crldp(X509 *x)
332{
333 int i;
334 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
335 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
336 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
337}
338
339#define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
340#define ku_reject(x, usage) \
341 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
342#define xku_reject(x, usage) \
343 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
344#define ns_reject(x, usage) \
345 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
346
347static void x509v3_cache_extensions(X509 *x)
348{
349 BASIC_CONSTRAINTS *bs;
350 PROXY_CERT_INFO_EXTENSION *pci;
351 ASN1_BIT_STRING *usage;
352 ASN1_BIT_STRING *ns;
353 EXTENDED_KEY_USAGE *extusage;
354 X509_EXTENSION *ex;
355 int i;
356
357#ifdef tsan_ld_acq
358 /* fast lock-free check, see end of the function for details. */
359 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
360 return;
361#endif
362
363 CRYPTO_THREAD_write_lock(x->lock);
364 if (x->ex_flags & EXFLAG_SET) {
365 CRYPTO_THREAD_unlock(x->lock);
366 return;
367 }
368
369 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
370 /* V1 should mean no extensions ... */
371 if (!X509_get_version(x))
372 x->ex_flags |= EXFLAG_V1;
373 /* Handle basic constraints */
374 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
375 if (bs->ca)
376 x->ex_flags |= EXFLAG_CA;
377 if (bs->pathlen) {
378 if ((bs->pathlen->type == V_ASN1_NEG_INTEGER)
379 || !bs->ca) {
380 x->ex_flags |= EXFLAG_INVALID;
381 x->ex_pathlen = 0;
382 } else
383 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
384 } else
385 x->ex_pathlen = -1;
386 BASIC_CONSTRAINTS_free(bs);
387 x->ex_flags |= EXFLAG_BCONS;
388 }
389 /* Handle proxy certificates */
390 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
391 if (x->ex_flags & EXFLAG_CA
392 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
393 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
394 x->ex_flags |= EXFLAG_INVALID;
395 }
396 if (pci->pcPathLengthConstraint) {
397 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
398 } else
399 x->ex_pcpathlen = -1;
400 PROXY_CERT_INFO_EXTENSION_free(pci);
401 x->ex_flags |= EXFLAG_PROXY;
402 }
403 /* Handle key usage */
404 if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
405 if (usage->length > 0) {
406 x->ex_kusage = usage->data[0];
407 if (usage->length > 1)
408 x->ex_kusage |= usage->data[1] << 8;
409 } else
410 x->ex_kusage = 0;
411 x->ex_flags |= EXFLAG_KUSAGE;
412 ASN1_BIT_STRING_free(usage);
413 }
414 x->ex_xkusage = 0;
415 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
416 x->ex_flags |= EXFLAG_XKUSAGE;
417 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
418 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
419 case NID_server_auth:
420 x->ex_xkusage |= XKU_SSL_SERVER;
421 break;
422
423 case NID_client_auth:
424 x->ex_xkusage |= XKU_SSL_CLIENT;
425 break;
426
427 case NID_email_protect:
428 x->ex_xkusage |= XKU_SMIME;
429 break;
430
431 case NID_code_sign:
432 x->ex_xkusage |= XKU_CODE_SIGN;
433 break;
434
435 case NID_ms_sgc:
436 case NID_ns_sgc:
437 x->ex_xkusage |= XKU_SGC;
438 break;
439
440 case NID_OCSP_sign:
441 x->ex_xkusage |= XKU_OCSP_SIGN;
442 break;
443
444 case NID_time_stamp:
445 x->ex_xkusage |= XKU_TIMESTAMP;
446 break;
447
448 case NID_dvcs:
449 x->ex_xkusage |= XKU_DVCS;
450 break;
451
452 case NID_anyExtendedKeyUsage:
453 x->ex_xkusage |= XKU_ANYEKU;
454 break;
455 }
456 }
457 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
458 }
459
460 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
461 if (ns->length > 0)
462 x->ex_nscert = ns->data[0];
463 else
464 x->ex_nscert = 0;
465 x->ex_flags |= EXFLAG_NSCERT;
466 ASN1_BIT_STRING_free(ns);
467 }
468 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
469 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
470 /* Does subject name match issuer ? */
471 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
472 x->ex_flags |= EXFLAG_SI;
473 /* If SKID matches AKID also indicate self signed */
474 if (X509_check_akid(x, x->akid) == X509_V_OK &&
475 !ku_reject(x, KU_KEY_CERT_SIGN))
476 x->ex_flags |= EXFLAG_SS;
477 }
478 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
479 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
480 if (!x->nc && (i != -1))
481 x->ex_flags |= EXFLAG_INVALID;
482 setup_crldp(x);
483
484#ifndef OPENSSL_NO_RFC3779
485 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL);
486 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum,
487 NULL, NULL);
488#endif
489 for (i = 0; i < X509_get_ext_count(x); i++) {
490 ex = X509_get_ext(x, i);
491 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
492 == NID_freshest_crl)
493 x->ex_flags |= EXFLAG_FRESHEST;
494 if (!X509_EXTENSION_get_critical(ex))
495 continue;
496 if (!X509_supported_extension(ex)) {
497 x->ex_flags |= EXFLAG_CRITICAL;
498 break;
499 }
500 }
501 x509_init_sig_info(x);
502 x->ex_flags |= EXFLAG_SET;
503#ifdef tsan_st_rel
504 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
505 /*
506 * Above store triggers fast lock-free check in the beginning of the
507 * function. But one has to ensure that the structure is "stable", i.e.
508 * all stores are visible on all processors. Hence the release fence.
509 */
510#endif
511 CRYPTO_THREAD_unlock(x->lock);
512}
513
514/*-
515 * CA checks common to all purposes
516 * return codes:
517 * 0 not a CA
518 * 1 is a CA
519 * 2 basicConstraints absent so "maybe" a CA
520 * 3 basicConstraints absent but self signed V1.
521 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
522 */
523
524static int check_ca(const X509 *x)
525{
526 /* keyUsage if present should allow cert signing */
527 if (ku_reject(x, KU_KEY_CERT_SIGN))
528 return 0;
529 if (x->ex_flags & EXFLAG_BCONS) {
530 if (x->ex_flags & EXFLAG_CA)
531 return 1;
532 /* If basicConstraints says not a CA then say so */
533 else
534 return 0;
535 } else {
536 /* we support V1 roots for... uh, I don't really know why. */
537 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
538 return 3;
539 /*
540 * If key usage present it must have certSign so tolerate it
541 */
542 else if (x->ex_flags & EXFLAG_KUSAGE)
543 return 4;
544 /* Older certificates could have Netscape-specific CA types */
545 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
546 return 5;
547 /* can this still be regarded a CA certificate? I doubt it */
548 return 0;
549 }
550}
551
552void X509_set_proxy_flag(X509 *x)
553{
554 x->ex_flags |= EXFLAG_PROXY;
555}
556
557void X509_set_proxy_pathlen(X509 *x, long l)
558{
559 x->ex_pcpathlen = l;
560}
561
562int X509_check_ca(X509 *x)
563{
564 x509v3_cache_extensions(x);
565
566 return check_ca(x);
567}
568
569/* Check SSL CA: common checks for SSL client and server */
570static int check_ssl_ca(const X509 *x)
571{
572 int ca_ret;
573 ca_ret = check_ca(x);
574 if (!ca_ret)
575 return 0;
576 /* check nsCertType if present */
577 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
578 return ca_ret;
579 else
580 return 0;
581}
582
583static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
584 int ca)
585{
586 if (xku_reject(x, XKU_SSL_CLIENT))
587 return 0;
588 if (ca)
589 return check_ssl_ca(x);
590 /* We need to do digital signatures or key agreement */
591 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
592 return 0;
593 /* nsCertType if present should allow SSL client use */
594 if (ns_reject(x, NS_SSL_CLIENT))
595 return 0;
596 return 1;
597}
598
599/*
600 * Key usage needed for TLS/SSL server: digital signature, encipherment or
601 * key agreement. The ssl code can check this more thoroughly for individual
602 * key types.
603 */
604#define KU_TLS \
605 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
606
607static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
608 int ca)
609{
610 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
611 return 0;
612 if (ca)
613 return check_ssl_ca(x);
614
615 if (ns_reject(x, NS_SSL_SERVER))
616 return 0;
617 if (ku_reject(x, KU_TLS))
618 return 0;
619
620 return 1;
621
622}
623
624static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
625 int ca)
626{
627 int ret;
628 ret = check_purpose_ssl_server(xp, x, ca);
629 if (!ret || ca)
630 return ret;
631 /* We need to encipher or Netscape complains */
632 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
633 return 0;
634 return ret;
635}
636
637/* common S/MIME checks */
638static int purpose_smime(const X509 *x, int ca)
639{
640 if (xku_reject(x, XKU_SMIME))
641 return 0;
642 if (ca) {
643 int ca_ret;
644 ca_ret = check_ca(x);
645 if (!ca_ret)
646 return 0;
647 /* check nsCertType if present */
648 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
649 return ca_ret;
650 else
651 return 0;
652 }
653 if (x->ex_flags & EXFLAG_NSCERT) {
654 if (x->ex_nscert & NS_SMIME)
655 return 1;
656 /* Workaround for some buggy certificates */
657 if (x->ex_nscert & NS_SSL_CLIENT)
658 return 2;
659 return 0;
660 }
661 return 1;
662}
663
664static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
665 int ca)
666{
667 int ret;
668 ret = purpose_smime(x, ca);
669 if (!ret || ca)
670 return ret;
671 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
672 return 0;
673 return ret;
674}
675
676static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
677 int ca)
678{
679 int ret;
680 ret = purpose_smime(x, ca);
681 if (!ret || ca)
682 return ret;
683 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
684 return 0;
685 return ret;
686}
687
688static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
689 int ca)
690{
691 if (ca) {
692 int ca_ret;
693 if ((ca_ret = check_ca(x)) != 2)
694 return ca_ret;
695 else
696 return 0;
697 }
698 if (ku_reject(x, KU_CRL_SIGN))
699 return 0;
700 return 1;
701}
702
703/*
704 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
705 * is valid. Additional checks must be made on the chain.
706 */
707
708static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
709{
710 /*
711 * Must be a valid CA. Should we really support the "I don't know" value
712 * (2)?
713 */
714 if (ca)
715 return check_ca(x);
716 /* leaf certificate is checked in OCSP_verify() */
717 return 1;
718}
719
720static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
721 int ca)
722{
723 int i_ext;
724
725 /* If ca is true we must return if this is a valid CA certificate. */
726 if (ca)
727 return check_ca(x);
728
729 /*
730 * Check the optional key usage field:
731 * if Key Usage is present, it must be one of digitalSignature
732 * and/or nonRepudiation (other values are not consistent and shall
733 * be rejected).
734 */
735 if ((x->ex_flags & EXFLAG_KUSAGE)
736 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
737 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
738 return 0;
739
740 /* Only time stamp key usage is permitted and it's required. */
741 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
742 return 0;
743
744 /* Extended Key Usage MUST be critical */
745 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
746 if (i_ext >= 0) {
747 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
748 if (!X509_EXTENSION_get_critical(ext))
749 return 0;
750 }
751
752 return 1;
753}
754
755static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
756{
757 return 1;
758}
759
760/*-
761 * Various checks to see if one certificate issued the second.
762 * This can be used to prune a set of possible issuer certificates
763 * which have been looked up using some simple method such as by
764 * subject name.
765 * These are:
766 * 1. Check issuer_name(subject) == subject_name(issuer)
767 * 2. If akid(subject) exists, check that it matches issuer
768 * 3. Check that issuer public key algorithm matches subject signature algorithm
769 * 4. If key_usage(issuer) exists, check that it supports certificate signing
770 * returns 0 for OK, positive for reason for mismatch, reasons match
771 * codes for X509_verify_cert()
772 */
773
774int X509_check_issued(X509 *issuer, X509 *subject)
775{
776 if (X509_NAME_cmp(X509_get_subject_name(issuer),
777 X509_get_issuer_name(subject)))
778 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
779
780 x509v3_cache_extensions(issuer);
781 x509v3_cache_extensions(subject);
782
783 if (subject->akid) {
784 int ret = X509_check_akid(issuer, subject->akid);
785 if (ret != X509_V_OK)
786 return ret;
787 }
788
789 {
790 /*
791 * Check if the subject signature algorithm matches the issuer's PUBKEY
792 * algorithm
793 */
794 EVP_PKEY *i_pkey = X509_get0_pubkey(issuer);
795 X509_ALGOR *s_algor = &subject->cert_info.signature;
796 int s_pknid = NID_undef, s_mdnid = NID_undef;
797
798 if (i_pkey == NULL)
799 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
800
801 if (!OBJ_find_sigid_algs(OBJ_obj2nid(s_algor->algorithm),
802 &s_mdnid, &s_pknid)
803 || EVP_PKEY_type(s_pknid) != EVP_PKEY_base_id(i_pkey))
804 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
805 }
806
807 if (subject->ex_flags & EXFLAG_PROXY) {
808 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
809 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
810 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
811 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
812 return X509_V_OK;
813}
814
815int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
816{
817
818 if (!akid)
819 return X509_V_OK;
820
821 /* Check key ids (if present) */
822 if (akid->keyid && issuer->skid &&
823 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
824 return X509_V_ERR_AKID_SKID_MISMATCH;
825 /* Check serial number */
826 if (akid->serial &&
827 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
828 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
829 /* Check issuer name */
830 if (akid->issuer) {
831 /*
832 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
833 * GeneralName. So look for a DirName. There may be more than one but
834 * we only take any notice of the first.
835 */
836 GENERAL_NAMES *gens;
837 GENERAL_NAME *gen;
838 X509_NAME *nm = NULL;
839 int i;
840 gens = akid->issuer;
841 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
842 gen = sk_GENERAL_NAME_value(gens, i);
843 if (gen->type == GEN_DIRNAME) {
844 nm = gen->d.dirn;
845 break;
846 }
847 }
848 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
849 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
850 }
851 return X509_V_OK;
852}
853
854uint32_t X509_get_extension_flags(X509 *x)
855{
856 /* Call for side-effect of computing hash and caching extensions */
857 X509_check_purpose(x, -1, -1);
858 return x->ex_flags;
859}
860
861uint32_t X509_get_key_usage(X509 *x)
862{
863 /* Call for side-effect of computing hash and caching extensions */
864 X509_check_purpose(x, -1, -1);
865 if (x->ex_flags & EXFLAG_KUSAGE)
866 return x->ex_kusage;
867 return UINT32_MAX;
868}
869
870uint32_t X509_get_extended_key_usage(X509 *x)
871{
872 /* Call for side-effect of computing hash and caching extensions */
873 X509_check_purpose(x, -1, -1);
874 if (x->ex_flags & EXFLAG_XKUSAGE)
875 return x->ex_xkusage;
876 return UINT32_MAX;
877}
878
879const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
880{
881 /* Call for side-effect of computing hash and caching extensions */
882 X509_check_purpose(x, -1, -1);
883 return x->skid;
884}
885
886const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
887{
888 /* Call for side-effect of computing hash and caching extensions */
889 X509_check_purpose(x, -1, -1);
890 return (x->akid != NULL ? x->akid->keyid : NULL);
891}
892
893const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
894{
895 /* Call for side-effect of computing hash and caching extensions */
896 X509_check_purpose(x, -1, -1);
897 return (x->akid != NULL ? x->akid->issuer : NULL);
898}
899
900const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
901{
902 /* Call for side-effect of computing hash and caching extensions */
903 X509_check_purpose(x, -1, -1);
904 return (x->akid != NULL ? x->akid->serial : NULL);
905}
906
907long X509_get_pathlen(X509 *x)
908{
909 /* Called for side effect of caching extensions */
910 if (X509_check_purpose(x, -1, -1) != 1
911 || (x->ex_flags & EXFLAG_BCONS) == 0)
912 return -1;
913 return x->ex_pathlen;
914}
915
916long X509_get_proxy_pathlen(X509 *x)
917{
918 /* Called for side effect of caching extensions */
919 if (X509_check_purpose(x, -1, -1) != 1
920 || (x->ex_flags & EXFLAG_PROXY) == 0)
921 return -1;
922 return x->ex_pcpathlen;
923}
924