1 /*
2 * Copyright 1999-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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 "../x509/x509_local.h" /* for x509_signing_allowed() */
17 #include "internal/tsan_assist.h"
18
19 static void x509v3_cache_extensions(X509 *x);
20
21 static int check_ssl_ca(const X509 *x);
22 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
23 int ca);
24 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
25 int ca);
26 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
27 int ca);
28 static int purpose_smime(const X509 *x, int ca);
29 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
30 int ca);
31 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
32 int ca);
33 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
34 int ca);
35 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
36 int ca);
37 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
38 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
39
40 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
41 static void xptable_free(X509_PURPOSE *p);
42
43 static X509_PURPOSE xstandard[] = {
44 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
45 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
46 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
47 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
48 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
49 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
50 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
51 "S/MIME signing", "smimesign", NULL},
52 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
53 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
54 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
55 "CRL signing", "crlsign", NULL},
56 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any",
57 NULL},
58 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
59 "OCSP helper", "ocsphelper", NULL},
60 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
61 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
62 NULL},
63 };
64
65 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
66
67 static STACK_OF(X509_PURPOSE) *xptable = NULL;
68
xp_cmp(const X509_PURPOSE * const * a,const X509_PURPOSE * const * b)69 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
70 {
71 return (*a)->purpose - (*b)->purpose;
72 }
73
74 /*
75 * As much as I'd like to make X509_check_purpose use a "const" X509* I
76 * really can't because it does recalculate hashes and do other non-const
77 * things.
78 */
X509_check_purpose(X509 * x,int id,int ca)79 int X509_check_purpose(X509 *x, int id, int ca)
80 {
81 int idx;
82 const X509_PURPOSE *pt;
83
84 x509v3_cache_extensions(x);
85 if (x->ex_flags & EXFLAG_INVALID)
86 return -1;
87
88 /* Return if side-effect only call */
89 if (id == -1)
90 return 1;
91 idx = X509_PURPOSE_get_by_id(id);
92 if (idx == -1)
93 return -1;
94 pt = X509_PURPOSE_get0(idx);
95 return pt->check_purpose(pt, x, ca);
96 }
97
X509_PURPOSE_set(int * p,int purpose)98 int X509_PURPOSE_set(int *p, int purpose)
99 {
100 if (X509_PURPOSE_get_by_id(purpose) == -1) {
101 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
102 return 0;
103 }
104 *p = purpose;
105 return 1;
106 }
107
X509_PURPOSE_get_count(void)108 int X509_PURPOSE_get_count(void)
109 {
110 if (!xptable)
111 return X509_PURPOSE_COUNT;
112 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
113 }
114
X509_PURPOSE_get0(int idx)115 X509_PURPOSE *X509_PURPOSE_get0(int idx)
116 {
117 if (idx < 0)
118 return NULL;
119 if (idx < (int)X509_PURPOSE_COUNT)
120 return xstandard + idx;
121 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
122 }
123
X509_PURPOSE_get_by_sname(const char * sname)124 int X509_PURPOSE_get_by_sname(const char *sname)
125 {
126 int i;
127 X509_PURPOSE *xptmp;
128 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
129 xptmp = X509_PURPOSE_get0(i);
130 if (strcmp(xptmp->sname, sname) == 0)
131 return i;
132 }
133 return -1;
134 }
135
X509_PURPOSE_get_by_id(int purpose)136 int X509_PURPOSE_get_by_id(int purpose)
137 {
138 X509_PURPOSE tmp;
139 int idx;
140
141 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
142 return purpose - X509_PURPOSE_MIN;
143 if (xptable == NULL)
144 return -1;
145 tmp.purpose = purpose;
146 idx = sk_X509_PURPOSE_find(xptable, &tmp);
147 if (idx < 0)
148 return -1;
149 return idx + X509_PURPOSE_COUNT;
150 }
151
X509_PURPOSE_add(int id,int trust,int flags,int (* ck)(const X509_PURPOSE *,const X509 *,int),const char * name,const char * sname,void * arg)152 int X509_PURPOSE_add(int id, int trust, int flags,
153 int (*ck) (const X509_PURPOSE *, const X509 *, int),
154 const char *name, const char *sname, void *arg)
155 {
156 int idx;
157 X509_PURPOSE *ptmp;
158 /*
159 * This is set according to what we change: application can't set it
160 */
161 flags &= ~X509_PURPOSE_DYNAMIC;
162 /* This will always be set for application modified trust entries */
163 flags |= X509_PURPOSE_DYNAMIC_NAME;
164 /* Get existing entry if any */
165 idx = X509_PURPOSE_get_by_id(id);
166 /* Need a new entry */
167 if (idx == -1) {
168 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
169 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
170 return 0;
171 }
172 ptmp->flags = X509_PURPOSE_DYNAMIC;
173 } else
174 ptmp = X509_PURPOSE_get0(idx);
175
176 /* OPENSSL_free existing name if dynamic */
177 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
178 OPENSSL_free(ptmp->name);
179 OPENSSL_free(ptmp->sname);
180 }
181 /* dup supplied name */
182 ptmp->name = OPENSSL_strdup(name);
183 ptmp->sname = OPENSSL_strdup(sname);
184 if (!ptmp->name || !ptmp->sname) {
185 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
186 goto err;
187 }
188 /* Keep the dynamic flag of existing entry */
189 ptmp->flags &= X509_PURPOSE_DYNAMIC;
190 /* Set all other flags */
191 ptmp->flags |= flags;
192
193 ptmp->purpose = id;
194 ptmp->trust = trust;
195 ptmp->check_purpose = ck;
196 ptmp->usr_data = arg;
197
198 /* If its a new entry manage the dynamic table */
199 if (idx == -1) {
200 if (xptable == NULL
201 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
202 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
203 goto err;
204 }
205 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
206 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
207 goto err;
208 }
209 }
210 return 1;
211 err:
212 if (idx == -1) {
213 OPENSSL_free(ptmp->name);
214 OPENSSL_free(ptmp->sname);
215 OPENSSL_free(ptmp);
216 }
217 return 0;
218 }
219
xptable_free(X509_PURPOSE * p)220 static void xptable_free(X509_PURPOSE *p)
221 {
222 if (!p)
223 return;
224 if (p->flags & X509_PURPOSE_DYNAMIC) {
225 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
226 OPENSSL_free(p->name);
227 OPENSSL_free(p->sname);
228 }
229 OPENSSL_free(p);
230 }
231 }
232
X509_PURPOSE_cleanup(void)233 void X509_PURPOSE_cleanup(void)
234 {
235 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
236 xptable = NULL;
237 }
238
X509_PURPOSE_get_id(const X509_PURPOSE * xp)239 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
240 {
241 return xp->purpose;
242 }
243
X509_PURPOSE_get0_name(const X509_PURPOSE * xp)244 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
245 {
246 return xp->name;
247 }
248
X509_PURPOSE_get0_sname(const X509_PURPOSE * xp)249 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
250 {
251 return xp->sname;
252 }
253
X509_PURPOSE_get_trust(const X509_PURPOSE * xp)254 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
255 {
256 return xp->trust;
257 }
258
nid_cmp(const int * a,const int * b)259 static int nid_cmp(const int *a, const int *b)
260 {
261 return *a - *b;
262 }
263
264 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
265 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
266
X509_supported_extension(X509_EXTENSION * ex)267 int X509_supported_extension(X509_EXTENSION *ex)
268 {
269 /*
270 * This table is a list of the NIDs of supported extensions: that is
271 * those which are used by the verify process. If an extension is
272 * critical and doesn't appear in this list then the verify process will
273 * normally reject the certificate. The list must be kept in numerical
274 * order because it will be searched using bsearch.
275 */
276
277 static const int supported_nids[] = {
278 NID_netscape_cert_type, /* 71 */
279 NID_key_usage, /* 83 */
280 NID_subject_alt_name, /* 85 */
281 NID_basic_constraints, /* 87 */
282 NID_certificate_policies, /* 89 */
283 NID_crl_distribution_points, /* 103 */
284 NID_ext_key_usage, /* 126 */
285 #ifndef OPENSSL_NO_RFC3779
286 NID_sbgp_ipAddrBlock, /* 290 */
287 NID_sbgp_autonomousSysNum, /* 291 */
288 #endif
289 NID_policy_constraints, /* 401 */
290 NID_proxyCertInfo, /* 663 */
291 NID_name_constraints, /* 666 */
292 NID_policy_mappings, /* 747 */
293 NID_inhibit_any_policy /* 748 */
294 };
295
296 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
297
298 if (ex_nid == NID_undef)
299 return 0;
300
301 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
302 return 1;
303 return 0;
304 }
305
setup_dp(X509 * x,DIST_POINT * dp)306 static int setup_dp(X509 *x, DIST_POINT *dp)
307 {
308 X509_NAME *iname = NULL;
309 int i;
310
311 if (dp->reasons) {
312 if (dp->reasons->length > 0)
313 dp->dp_reasons = dp->reasons->data[0];
314 if (dp->reasons->length > 1)
315 dp->dp_reasons |= (dp->reasons->data[1] << 8);
316 dp->dp_reasons &= CRLDP_ALL_REASONS;
317 } else
318 dp->dp_reasons = CRLDP_ALL_REASONS;
319 if (!dp->distpoint || (dp->distpoint->type != 1))
320 return 1;
321 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
322 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
323 if (gen->type == GEN_DIRNAME) {
324 iname = gen->d.directoryName;
325 break;
326 }
327 }
328 if (!iname)
329 iname = X509_get_issuer_name(x);
330
331 return DIST_POINT_set_dpname(dp->distpoint, iname);
332 }
333
setup_crldp(X509 * x)334 static int setup_crldp(X509 *x)
335 {
336 int i;
337
338 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
339 if (x->crldp == NULL && i != -1)
340 return 0;
341 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
342 if (!setup_dp(x, sk_DIST_POINT_value(x->crldp, i)))
343 return 0;
344 }
345 return 1;
346 }
347
348 /* Check that issuer public key algorithm matches subject signature algorithm */
check_sig_alg_match(const EVP_PKEY * pkey,const X509 * subject)349 static int check_sig_alg_match(const EVP_PKEY *pkey, const X509 *subject)
350 {
351 int pkey_sig_nid, subj_sig_nid;
352
353 if (pkey == NULL)
354 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
355 if (OBJ_find_sigid_algs(EVP_PKEY_base_id(pkey),
356 NULL, &pkey_sig_nid) == 0)
357 pkey_sig_nid = EVP_PKEY_base_id(pkey);
358 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
359 NULL, &subj_sig_nid) == 0)
360 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
361 if (pkey_sig_nid != EVP_PKEY_type(subj_sig_nid))
362 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
363 return X509_V_OK;
364 }
365
366 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
367 #define ku_reject(x, usage) \
368 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
369 #define xku_reject(x, usage) \
370 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
371 #define ns_reject(x, usage) \
372 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
373
x509v3_cache_extensions(X509 * x)374 static void x509v3_cache_extensions(X509 *x)
375 {
376 BASIC_CONSTRAINTS *bs;
377 PROXY_CERT_INFO_EXTENSION *pci;
378 ASN1_BIT_STRING *usage;
379 ASN1_BIT_STRING *ns;
380 EXTENDED_KEY_USAGE *extusage;
381 X509_EXTENSION *ex;
382 int i;
383
384 #ifdef tsan_ld_acq
385 /* fast lock-free check, see end of the function for details. */
386 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
387 return;
388 #endif
389
390 CRYPTO_THREAD_write_lock(x->lock);
391 if (x->ex_flags & EXFLAG_SET) {
392 CRYPTO_THREAD_unlock(x->lock);
393 return;
394 }
395
396 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
397 x->ex_flags |= (EXFLAG_NO_FINGERPRINT | EXFLAG_INVALID);
398
399 /* V1 should mean no extensions ... */
400 if (!X509_get_version(x))
401 x->ex_flags |= EXFLAG_V1;
402 /* Handle basic constraints */
403 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) {
404 if (bs->ca)
405 x->ex_flags |= EXFLAG_CA;
406 if (bs->pathlen) {
407 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
408 x->ex_flags |= EXFLAG_INVALID;
409 x->ex_pathlen = 0;
410 } else {
411 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
412 if (!bs->ca && x->ex_pathlen != 0) {
413 x->ex_flags |= EXFLAG_INVALID;
414 x->ex_pathlen = 0;
415 }
416 }
417 } else
418 x->ex_pathlen = -1;
419 BASIC_CONSTRAINTS_free(bs);
420 x->ex_flags |= EXFLAG_BCONS;
421 } else if (i != -1) {
422 x->ex_flags |= EXFLAG_INVALID;
423 }
424 /* Handle proxy certificates */
425 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) {
426 if (x->ex_flags & EXFLAG_CA
427 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
428 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
429 x->ex_flags |= EXFLAG_INVALID;
430 }
431 if (pci->pcPathLengthConstraint) {
432 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
433 } else
434 x->ex_pcpathlen = -1;
435 PROXY_CERT_INFO_EXTENSION_free(pci);
436 x->ex_flags |= EXFLAG_PROXY;
437 } else if (i != -1) {
438 x->ex_flags |= EXFLAG_INVALID;
439 }
440 /* Handle key usage */
441 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) {
442 if (usage->length > 0) {
443 x->ex_kusage = usage->data[0];
444 if (usage->length > 1)
445 x->ex_kusage |= usage->data[1] << 8;
446 } else
447 x->ex_kusage = 0;
448 x->ex_flags |= EXFLAG_KUSAGE;
449 ASN1_BIT_STRING_free(usage);
450 } else if (i != -1) {
451 x->ex_flags |= EXFLAG_INVALID;
452 }
453 x->ex_xkusage = 0;
454 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) {
455 x->ex_flags |= EXFLAG_XKUSAGE;
456 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
457 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
458 case NID_server_auth:
459 x->ex_xkusage |= XKU_SSL_SERVER;
460 break;
461
462 case NID_client_auth:
463 x->ex_xkusage |= XKU_SSL_CLIENT;
464 break;
465
466 case NID_email_protect:
467 x->ex_xkusage |= XKU_SMIME;
468 break;
469
470 case NID_code_sign:
471 x->ex_xkusage |= XKU_CODE_SIGN;
472 break;
473
474 case NID_ms_sgc:
475 case NID_ns_sgc:
476 x->ex_xkusage |= XKU_SGC;
477 break;
478
479 case NID_OCSP_sign:
480 x->ex_xkusage |= XKU_OCSP_SIGN;
481 break;
482
483 case NID_time_stamp:
484 x->ex_xkusage |= XKU_TIMESTAMP;
485 break;
486
487 case NID_dvcs:
488 x->ex_xkusage |= XKU_DVCS;
489 break;
490
491 case NID_anyExtendedKeyUsage:
492 x->ex_xkusage |= XKU_ANYEKU;
493 break;
494 }
495 }
496 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
497 } else if (i != -1) {
498 x->ex_flags |= EXFLAG_INVALID;
499 }
500
501 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) {
502 if (ns->length > 0)
503 x->ex_nscert = ns->data[0];
504 else
505 x->ex_nscert = 0;
506 x->ex_flags |= EXFLAG_NSCERT;
507 ASN1_BIT_STRING_free(ns);
508 } else if (i != -1) {
509 x->ex_flags |= EXFLAG_INVALID;
510 }
511 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
512 if (x->skid == NULL && i != -1)
513 x->ex_flags |= EXFLAG_INVALID;
514 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
515 if (x->akid == NULL && i != -1)
516 x->ex_flags |= EXFLAG_INVALID;
517 /* Does subject name match issuer ? */
518 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
519 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
520 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
521 /* .. and the signature alg matches the PUBKEY alg: */
522 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
523 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
524 }
525 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
526 if (x->altname == NULL && i != -1)
527 x->ex_flags |= EXFLAG_INVALID;
528 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
529 if (x->nc == NULL && i != -1)
530 x->ex_flags |= EXFLAG_INVALID;
531 if (!setup_crldp(x))
532 x->ex_flags |= EXFLAG_INVALID;
533
534 #ifndef OPENSSL_NO_RFC3779
535 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
536 if (x->rfc3779_addr == NULL && i != -1)
537 x->ex_flags |= EXFLAG_INVALID;
538 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
539 if (x->rfc3779_asid == NULL && i != -1)
540 x->ex_flags |= EXFLAG_INVALID;
541 #endif
542 for (i = 0; i < X509_get_ext_count(x); i++) {
543 ex = X509_get_ext(x, i);
544 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
545 == NID_freshest_crl)
546 x->ex_flags |= EXFLAG_FRESHEST;
547 if (!X509_EXTENSION_get_critical(ex))
548 continue;
549 if (!X509_supported_extension(ex)) {
550 x->ex_flags |= EXFLAG_CRITICAL;
551 break;
552 }
553 }
554 x509_init_sig_info(x);
555 x->ex_flags |= EXFLAG_SET;
556 #ifdef tsan_st_rel
557 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
558 /*
559 * Above store triggers fast lock-free check in the beginning of the
560 * function. But one has to ensure that the structure is "stable", i.e.
561 * all stores are visible on all processors. Hence the release fence.
562 */
563 #endif
564 CRYPTO_THREAD_unlock(x->lock);
565 }
566
567 /*-
568 * CA checks common to all purposes
569 * return codes:
570 * 0 not a CA
571 * 1 is a CA
572 * 2 Only possible in older versions of openSSL when basicConstraints are absent
573 * new versions will not return this value. May be a CA
574 * 3 basicConstraints absent but self signed V1.
575 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
576 * 5 Netscape specific CA Flags present
577 */
578
check_ca(const X509 * x)579 static int check_ca(const X509 *x)
580 {
581 /* keyUsage if present should allow cert signing */
582 if (ku_reject(x, KU_KEY_CERT_SIGN))
583 return 0;
584 if (x->ex_flags & EXFLAG_BCONS) {
585 if (x->ex_flags & EXFLAG_CA)
586 return 1;
587 /* If basicConstraints says not a CA then say so */
588 else
589 return 0;
590 } else {
591 /* we support V1 roots for... uh, I don't really know why. */
592 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
593 return 3;
594 /*
595 * If key usage present it must have certSign so tolerate it
596 */
597 else if (x->ex_flags & EXFLAG_KUSAGE)
598 return 4;
599 /* Older certificates could have Netscape-specific CA types */
600 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
601 return 5;
602 /* can this still be regarded a CA certificate? I doubt it */
603 return 0;
604 }
605 }
606
X509_set_proxy_flag(X509 * x)607 void X509_set_proxy_flag(X509 *x)
608 {
609 x->ex_flags |= EXFLAG_PROXY;
610 }
611
X509_set_proxy_pathlen(X509 * x,long l)612 void X509_set_proxy_pathlen(X509 *x, long l)
613 {
614 x->ex_pcpathlen = l;
615 }
616
X509_check_ca(X509 * x)617 int X509_check_ca(X509 *x)
618 {
619 x509v3_cache_extensions(x);
620
621 return check_ca(x);
622 }
623
624 /* Check SSL CA: common checks for SSL client and server */
check_ssl_ca(const X509 * x)625 static int check_ssl_ca(const X509 *x)
626 {
627 int ca_ret;
628 ca_ret = check_ca(x);
629 if (!ca_ret)
630 return 0;
631 /* check nsCertType if present */
632 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
633 return ca_ret;
634 else
635 return 0;
636 }
637
check_purpose_ssl_client(const X509_PURPOSE * xp,const X509 * x,int ca)638 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
639 int ca)
640 {
641 if (xku_reject(x, XKU_SSL_CLIENT))
642 return 0;
643 if (ca)
644 return check_ssl_ca(x);
645 /* We need to do digital signatures or key agreement */
646 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
647 return 0;
648 /* nsCertType if present should allow SSL client use */
649 if (ns_reject(x, NS_SSL_CLIENT))
650 return 0;
651 return 1;
652 }
653
654 /*
655 * Key usage needed for TLS/SSL server: digital signature, encipherment or
656 * key agreement. The ssl code can check this more thoroughly for individual
657 * key types.
658 */
659 #define KU_TLS \
660 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
661
check_purpose_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)662 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
663 int ca)
664 {
665 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
666 return 0;
667 if (ca)
668 return check_ssl_ca(x);
669
670 if (ns_reject(x, NS_SSL_SERVER))
671 return 0;
672 if (ku_reject(x, KU_TLS))
673 return 0;
674
675 return 1;
676
677 }
678
check_purpose_ns_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)679 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
680 int ca)
681 {
682 int ret;
683 ret = check_purpose_ssl_server(xp, x, ca);
684 if (!ret || ca)
685 return ret;
686 /* We need to encipher or Netscape complains */
687 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
688 return 0;
689 return ret;
690 }
691
692 /* common S/MIME checks */
purpose_smime(const X509 * x,int ca)693 static int purpose_smime(const X509 *x, int ca)
694 {
695 if (xku_reject(x, XKU_SMIME))
696 return 0;
697 if (ca) {
698 int ca_ret;
699 ca_ret = check_ca(x);
700 if (!ca_ret)
701 return 0;
702 /* check nsCertType if present */
703 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
704 return ca_ret;
705 else
706 return 0;
707 }
708 if (x->ex_flags & EXFLAG_NSCERT) {
709 if (x->ex_nscert & NS_SMIME)
710 return 1;
711 /* Workaround for some buggy certificates */
712 if (x->ex_nscert & NS_SSL_CLIENT)
713 return 2;
714 return 0;
715 }
716 return 1;
717 }
718
check_purpose_smime_sign(const X509_PURPOSE * xp,const X509 * x,int ca)719 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
720 int ca)
721 {
722 int ret;
723 ret = purpose_smime(x, ca);
724 if (!ret || ca)
725 return ret;
726 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
727 return 0;
728 return ret;
729 }
730
check_purpose_smime_encrypt(const X509_PURPOSE * xp,const X509 * x,int ca)731 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
732 int ca)
733 {
734 int ret;
735 ret = purpose_smime(x, ca);
736 if (!ret || ca)
737 return ret;
738 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
739 return 0;
740 return ret;
741 }
742
check_purpose_crl_sign(const X509_PURPOSE * xp,const X509 * x,int ca)743 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
744 int ca)
745 {
746 if (ca) {
747 int ca_ret;
748 if ((ca_ret = check_ca(x)) != 2)
749 return ca_ret;
750 else
751 return 0;
752 }
753 if (ku_reject(x, KU_CRL_SIGN))
754 return 0;
755 return 1;
756 }
757
758 /*
759 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
760 * is valid. Additional checks must be made on the chain.
761 */
762
ocsp_helper(const X509_PURPOSE * xp,const X509 * x,int ca)763 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
764 {
765 /*
766 * Must be a valid CA. Should we really support the "I don't know" value
767 * (2)?
768 */
769 if (ca)
770 return check_ca(x);
771 /* leaf certificate is checked in OCSP_verify() */
772 return 1;
773 }
774
check_purpose_timestamp_sign(const X509_PURPOSE * xp,const X509 * x,int ca)775 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
776 int ca)
777 {
778 int i_ext;
779
780 /* If ca is true we must return if this is a valid CA certificate. */
781 if (ca)
782 return check_ca(x);
783
784 /*
785 * Check the optional key usage field:
786 * if Key Usage is present, it must be one of digitalSignature
787 * and/or nonRepudiation (other values are not consistent and shall
788 * be rejected).
789 */
790 if ((x->ex_flags & EXFLAG_KUSAGE)
791 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
792 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
793 return 0;
794
795 /* Only time stamp key usage is permitted and it's required. */
796 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
797 return 0;
798
799 /* Extended Key Usage MUST be critical */
800 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
801 if (i_ext >= 0) {
802 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
803 if (!X509_EXTENSION_get_critical(ext))
804 return 0;
805 }
806
807 return 1;
808 }
809
no_check(const X509_PURPOSE * xp,const X509 * x,int ca)810 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
811 {
812 return 1;
813 }
814
815 /*-
816 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
817 * according to the B<keyUsage> field of I<issuer> if present
818 * depending on any proxyCertInfo extension of I<subject>.
819 * Returns 0 for OK, or positive for reason for rejection
820 * where reason codes match those for X509_verify_cert().
821 */
x509_signing_allowed(const X509 * issuer,const X509 * subject)822 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
823 {
824 if (subject->ex_flags & EXFLAG_PROXY) {
825 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
826 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
827 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
828 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
829 return X509_V_OK;
830 }
831
832 /*-
833 * Various checks to see if one certificate issued the second.
834 * This can be used to prune a set of possible issuer certificates
835 * which have been looked up using some simple method such as by
836 * subject name.
837 * These are:
838 * 1. Check issuer_name(subject) == subject_name(issuer)
839 * 2. If akid(subject) exists check it matches issuer
840 * 3. Check that issuer public key algorithm matches subject signature algorithm
841 * 4. If key_usage(issuer) exists check it supports certificate signing
842 * returns 0 for OK, positive for reason for mismatch, reasons match
843 * codes for X509_verify_cert()
844 */
845
X509_check_issued(X509 * issuer,X509 * subject)846 int X509_check_issued(X509 *issuer, X509 *subject)
847 {
848 int ret;
849
850 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
851 return ret;
852 return x509_signing_allowed(issuer, subject);
853 }
854
855 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
x509_likely_issued(X509 * issuer,X509 * subject)856 int x509_likely_issued(X509 *issuer, X509 *subject)
857 {
858 if (X509_NAME_cmp(X509_get_subject_name(issuer),
859 X509_get_issuer_name(subject)))
860 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
861
862 x509v3_cache_extensions(issuer);
863 if (issuer->ex_flags & EXFLAG_INVALID)
864 return X509_V_ERR_UNSPECIFIED;
865 x509v3_cache_extensions(subject);
866 if (subject->ex_flags & EXFLAG_INVALID)
867 return X509_V_ERR_UNSPECIFIED;
868
869 if (subject->akid) {
870 int ret = X509_check_akid(issuer, subject->akid);
871 if (ret != X509_V_OK)
872 return ret;
873 }
874
875 /* check if the subject signature alg matches the issuer's PUBKEY alg */
876 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
877 }
878
X509_check_akid(X509 * issuer,AUTHORITY_KEYID * akid)879 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
880 {
881
882 if (!akid)
883 return X509_V_OK;
884
885 /* Check key ids (if present) */
886 if (akid->keyid && issuer->skid &&
887 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
888 return X509_V_ERR_AKID_SKID_MISMATCH;
889 /* Check serial number */
890 if (akid->serial &&
891 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
892 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
893 /* Check issuer name */
894 if (akid->issuer) {
895 /*
896 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
897 * GeneralName. So look for a DirName. There may be more than one but
898 * we only take any notice of the first.
899 */
900 GENERAL_NAMES *gens;
901 GENERAL_NAME *gen;
902 X509_NAME *nm = NULL;
903 int i;
904 gens = akid->issuer;
905 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
906 gen = sk_GENERAL_NAME_value(gens, i);
907 if (gen->type == GEN_DIRNAME) {
908 nm = gen->d.dirn;
909 break;
910 }
911 }
912 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
913 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
914 }
915 return X509_V_OK;
916 }
917
X509_get_extension_flags(X509 * x)918 uint32_t X509_get_extension_flags(X509 *x)
919 {
920 /* Call for side-effect of computing hash and caching extensions */
921 X509_check_purpose(x, -1, -1);
922 return x->ex_flags;
923 }
924
X509_get_key_usage(X509 * x)925 uint32_t X509_get_key_usage(X509 *x)
926 {
927 /* Call for side-effect of computing hash and caching extensions */
928 if (X509_check_purpose(x, -1, -1) != 1)
929 return 0;
930 if (x->ex_flags & EXFLAG_KUSAGE)
931 return x->ex_kusage;
932 return UINT32_MAX;
933 }
934
X509_get_extended_key_usage(X509 * x)935 uint32_t X509_get_extended_key_usage(X509 *x)
936 {
937 /* Call for side-effect of computing hash and caching extensions */
938 if (X509_check_purpose(x, -1, -1) != 1)
939 return 0;
940 if (x->ex_flags & EXFLAG_XKUSAGE)
941 return x->ex_xkusage;
942 return UINT32_MAX;
943 }
944
X509_get0_subject_key_id(X509 * x)945 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
946 {
947 /* Call for side-effect of computing hash and caching extensions */
948 if (X509_check_purpose(x, -1, -1) != 1)
949 return NULL;
950 return x->skid;
951 }
952
X509_get0_authority_key_id(X509 * x)953 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
954 {
955 /* Call for side-effect of computing hash and caching extensions */
956 if (X509_check_purpose(x, -1, -1) != 1)
957 return NULL;
958 return (x->akid != NULL ? x->akid->keyid : NULL);
959 }
960
X509_get0_authority_issuer(X509 * x)961 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
962 {
963 /* Call for side-effect of computing hash and caching extensions */
964 if (X509_check_purpose(x, -1, -1) != 1)
965 return NULL;
966 return (x->akid != NULL ? x->akid->issuer : NULL);
967 }
968
X509_get0_authority_serial(X509 * x)969 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
970 {
971 /* Call for side-effect of computing hash and caching extensions */
972 if (X509_check_purpose(x, -1, -1) != 1)
973 return NULL;
974 return (x->akid != NULL ? x->akid->serial : NULL);
975 }
976
X509_get_pathlen(X509 * x)977 long X509_get_pathlen(X509 *x)
978 {
979 /* Called for side effect of caching extensions */
980 if (X509_check_purpose(x, -1, -1) != 1
981 || (x->ex_flags & EXFLAG_BCONS) == 0)
982 return -1;
983 return x->ex_pathlen;
984 }
985
X509_get_proxy_pathlen(X509 * x)986 long X509_get_proxy_pathlen(X509 *x)
987 {
988 /* Called for side effect of caching extensions */
989 if (X509_check_purpose(x, -1, -1) != 1
990 || (x->ex_flags & EXFLAG_PROXY) == 0)
991 return -1;
992 return x->ex_pcpathlen;
993 }
994