xref: /openbsd-src/lib/libcrypto/x509/x509_vfy.c (revision 24bb5fcea3ed904bc467217bdaadb5dfc618d5bf)
1 /* $OpenBSD: x509_vfy.c,v 1.86 2021/02/25 17:29:22 tb Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 #include <errno.h>
60 #include <stdio.h>
61 #include <string.h>
62 #include <time.h>
63 #include <unistd.h>
64 
65 #include <openssl/opensslconf.h>
66 
67 #include <openssl/asn1.h>
68 #include <openssl/buffer.h>
69 #include <openssl/crypto.h>
70 #include <openssl/err.h>
71 #include <openssl/evp.h>
72 #include <openssl/lhash.h>
73 #include <openssl/objects.h>
74 #include <openssl/x509.h>
75 #include <openssl/x509v3.h>
76 #include "asn1_locl.h"
77 #include "vpm_int.h"
78 #include "x509_internal.h"
79 #include "x509_lcl.h"
80 #include "x509_internal.h"
81 
82 /* CRL score values */
83 
84 /* No unhandled critical extensions */
85 
86 #define CRL_SCORE_NOCRITICAL	0x100
87 
88 /* certificate is within CRL scope */
89 
90 #define CRL_SCORE_SCOPE		0x080
91 
92 /* CRL times valid */
93 
94 #define CRL_SCORE_TIME		0x040
95 
96 /* Issuer name matches certificate */
97 
98 #define CRL_SCORE_ISSUER_NAME	0x020
99 
100 /* If this score or above CRL is probably valid */
101 
102 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
103 
104 /* CRL issuer is certificate issuer */
105 
106 #define CRL_SCORE_ISSUER_CERT	0x018
107 
108 /* CRL issuer is on certificate path */
109 
110 #define CRL_SCORE_SAME_PATH	0x008
111 
112 /* CRL issuer matches CRL AKID */
113 
114 #define CRL_SCORE_AKID		0x004
115 
116 /* Have a delta CRL with valid times */
117 
118 #define CRL_SCORE_TIME_DELTA	0x002
119 
120 static int null_callback(int ok, X509_STORE_CTX *e);
121 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
122 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x,
123     int allow_expired);
124 static int check_chain_extensions(X509_STORE_CTX *ctx);
125 static int check_name_constraints(X509_STORE_CTX *ctx);
126 static int check_trust(X509_STORE_CTX *ctx);
127 static int check_revocation(X509_STORE_CTX *ctx);
128 static int check_cert(X509_STORE_CTX *ctx, STACK_OF(X509) *chain, int depth);
129 static int check_policy(X509_STORE_CTX *ctx);
130 
131 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
132     unsigned int *preasons, X509_CRL *crl, X509 *x);
133 static int get_crl_delta(X509_STORE_CTX *ctx,
134     X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
135 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pcrl_score,
136     X509_CRL *base, STACK_OF(X509_CRL) *crls);
137 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
138     int *pcrl_score);
139 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
140     unsigned int *preasons);
141 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
142 static int check_crl_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *cert_path,
143     STACK_OF(X509) *crl_path);
144 static int X509_cmp_time_internal(const ASN1_TIME *ctm, time_t *cmp_time,
145     int clamp_notafter);
146 
147 static int internal_verify(X509_STORE_CTX *ctx);
148 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x);
149 
150 int ASN1_time_tm_clamp_notafter(struct tm *tm);
151 
152 static int
153 null_callback(int ok, X509_STORE_CTX *e)
154 {
155 	return ok;
156 }
157 
158 #if 0
159 static int
160 x509_subject_cmp(X509 **a, X509 **b)
161 {
162 	return X509_subject_name_cmp(*a, *b);
163 }
164 #endif
165 
166 /* Return 1 if a certificate is self signed */
167 static int
168 cert_self_signed(X509 *x)
169 {
170 	X509_check_purpose(x, -1, 0);
171 	if (x->ex_flags & EXFLAG_SS)
172 		return 1;
173 	else
174 		return 0;
175 }
176 
177 static int
178 check_id_error(X509_STORE_CTX *ctx, int errcode)
179 {
180 	ctx->error = errcode;
181 	ctx->current_cert = ctx->cert;
182 	ctx->error_depth = 0;
183 	return ctx->verify_cb(0, ctx);
184 }
185 
186 static int
187 check_hosts(X509 *x, X509_VERIFY_PARAM_ID *id)
188 {
189 	size_t i, n;
190 	char *name;
191 
192 	n = sk_OPENSSL_STRING_num(id->hosts);
193 	free(id->peername);
194 	id->peername = NULL;
195 
196 	for (i = 0; i < n; ++i) {
197 		name = sk_OPENSSL_STRING_value(id->hosts, i);
198 		if (X509_check_host(x, name, strlen(name), id->hostflags,
199 		    &id->peername) > 0)
200 			return 1;
201 	}
202 	return n == 0;
203 }
204 
205 static int
206 check_id(X509_STORE_CTX *ctx)
207 {
208 	X509_VERIFY_PARAM *vpm = ctx->param;
209 	X509_VERIFY_PARAM_ID *id = vpm->id;
210 	X509 *x = ctx->cert;
211 
212 	if (id->hosts && check_hosts(x, id) <= 0) {
213 		if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
214 			return 0;
215 	}
216 	if (id->email != NULL && X509_check_email(x, id->email, id->emaillen, 0)
217 	    <= 0) {
218 		if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
219 			return 0;
220 	}
221 	if (id->ip != NULL && X509_check_ip(x, id->ip, id->iplen, 0) <= 0) {
222 		if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
223 			return 0;
224 	}
225 	return 1;
226 }
227 
228 int
229 x509_vfy_check_id(X509_STORE_CTX *ctx) {
230 	return check_id(ctx);
231 }
232 
233 /*
234  * This is the effectively broken legacy OpenSSL chain builder. It
235  * might find an unvalidated chain and leave it sitting in
236  * ctx->chain. It does not correctly handle many cases where multiple
237  * chains could exist.
238  *
239  * Oh no.. I know a dirty word...
240  * Oooooooh..
241  */
242 static int
243 X509_verify_cert_legacy_build_chain(X509_STORE_CTX *ctx, int *bad, int *out_ok)
244 {
245 	X509 *x, *xtmp, *xtmp2, *chain_ss = NULL;
246 	int bad_chain = 0;
247 	X509_VERIFY_PARAM *param = ctx->param;
248 	int ok = 0, ret = 0;
249 	int depth, i;
250 	int num, j, retry, trust;
251 	int (*cb) (int xok, X509_STORE_CTX *xctx);
252 	STACK_OF(X509) *sktmp = NULL;
253 
254 	cb = ctx->verify_cb;
255 
256 	/*
257 	 * First we make sure the chain we are going to build is
258 	 * present and that the first entry is in place.
259 	 */
260 	ctx->chain = sk_X509_new_null();
261 	if (ctx->chain == NULL || !sk_X509_push(ctx->chain, ctx->cert)) {
262 		X509error(ERR_R_MALLOC_FAILURE);
263 		ctx->error = X509_V_ERR_OUT_OF_MEM;
264 		goto end;
265 	}
266 	X509_up_ref(ctx->cert);
267 	ctx->last_untrusted = 1;
268 
269 	/* We use a temporary STACK so we can chop and hack at it */
270 	if (ctx->untrusted != NULL &&
271 	    (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
272 		X509error(ERR_R_MALLOC_FAILURE);
273 		ctx->error = X509_V_ERR_OUT_OF_MEM;
274 		goto end;
275 	}
276 
277 	num = sk_X509_num(ctx->chain);
278 	x = sk_X509_value(ctx->chain, num - 1);
279 	depth = param->depth;
280 
281 	for (;;) {
282 		/* If we have enough, we break */
283 		/* FIXME: If this happens, we should take
284 		 * note of it and, if appropriate, use the
285 		 * X509_V_ERR_CERT_CHAIN_TOO_LONG error code
286 		 * later.
287 		 */
288 		if (depth < num)
289 			break;
290 		/* If we are self signed, we break */
291 		if (cert_self_signed(x))
292 			break;
293 		/*
294 		 * If asked see if we can find issuer in trusted store first
295 		 */
296 		if (ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) {
297 			ok = ctx->get_issuer(&xtmp, ctx, x);
298 			if (ok < 0) {
299 				ctx->error = X509_V_ERR_STORE_LOOKUP;
300 				goto end;
301 			}
302 			/*
303 			 * If successful for now free up cert so it
304 			 * will be picked up again later.
305 			 */
306 			if (ok > 0) {
307 				X509_free(xtmp);
308 				break;
309 			}
310 		}
311 		/* If we were passed a cert chain, use it first */
312 		if (ctx->untrusted != NULL) {
313 			/*
314 			 * If we do not find a non-expired untrusted cert, peek
315 			 * ahead and see if we can satisify this from the trusted
316 			 * store. If not, see if we have an expired untrusted cert.
317 			 */
318 			xtmp = find_issuer(ctx, sktmp, x, 0);
319 			if (xtmp == NULL &&
320 			    !(ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)) {
321 				ok = ctx->get_issuer(&xtmp, ctx, x);
322 				if (ok < 0) {
323 					ctx->error = X509_V_ERR_STORE_LOOKUP;
324 					goto end;
325 				}
326 				if (ok > 0) {
327 					X509_free(xtmp);
328 					break;
329 				}
330 				xtmp = find_issuer(ctx, sktmp, x, 1);
331 			}
332 			if (xtmp != NULL) {
333 				if (!sk_X509_push(ctx->chain, xtmp)) {
334 					X509error(ERR_R_MALLOC_FAILURE);
335 					ctx->error = X509_V_ERR_OUT_OF_MEM;
336 					ok = 0;
337 					goto end;
338 				}
339 				X509_up_ref(xtmp);
340 				(void)sk_X509_delete_ptr(sktmp, xtmp);
341 				ctx->last_untrusted++;
342 				x = xtmp;
343 				num++;
344 				/*
345 				 * reparse the full chain for the next one
346 				 */
347 				continue;
348 			}
349 		}
350 		break;
351 	}
352 	/* Remember how many untrusted certs we have */
353 	j = num;
354 
355 	/*
356 	 * At this point, chain should contain a list of untrusted
357 	 * certificates.  We now need to add at least one trusted one,
358 	 * if possible, otherwise we complain.
359 	 */
360 
361 	do {
362 		/*
363 		 * Examine last certificate in chain and see if it is
364 		 * self signed.
365 		 */
366 		i = sk_X509_num(ctx->chain);
367 		x = sk_X509_value(ctx->chain, i - 1);
368 		if (cert_self_signed(x)) {
369 			/* we have a self signed certificate */
370 			if (i == 1) {
371 				/*
372 				 * We have a single self signed
373 				 * certificate: see if we can find it
374 				 * in the store. We must have an exact
375 				 * match to avoid possible
376 				 * impersonation.
377 				 */
378 				ok = ctx->get_issuer(&xtmp, ctx, x);
379 				if ((ok <= 0) || X509_cmp(x, xtmp)) {
380 					ctx->error = X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT;
381 					ctx->current_cert = x;
382 					ctx->error_depth = i - 1;
383 					if (ok == 1)
384 						X509_free(xtmp);
385 					bad_chain = 1;
386 					ok = cb(0, ctx);
387 					if (!ok)
388 						goto end;
389 				} else {
390 					/*
391 					 * We have a match: replace
392 					 * certificate with store
393 					 * version so we get any trust
394 					 * settings.
395 					 */
396 					X509_free(x);
397 					x = xtmp;
398 					(void)sk_X509_set(ctx->chain, i - 1, x);
399 					ctx->last_untrusted = 0;
400 				}
401 			} else {
402 				/*
403 				 * extract and save self signed
404 				 * certificate for later use
405 				 */
406 				chain_ss = sk_X509_pop(ctx->chain);
407 				ctx->last_untrusted--;
408 				num--;
409 				j--;
410 				x = sk_X509_value(ctx->chain, num - 1);
411 			}
412 		}
413 		/* We now lookup certs from the certificate store */
414 		for (;;) {
415 			/* If we have enough, we break */
416 			if (depth < num)
417 				break;
418 			/* If we are self signed, we break */
419 			if (cert_self_signed(x))
420 				break;
421 			ok = ctx->get_issuer(&xtmp, ctx, x);
422 
423 			if (ok < 0) {
424 				ctx->error = X509_V_ERR_STORE_LOOKUP;
425 				goto end;
426 			}
427 			if (ok == 0)
428 				break;
429 			x = xtmp;
430 			if (!sk_X509_push(ctx->chain, x)) {
431 				X509_free(xtmp);
432 				X509error(ERR_R_MALLOC_FAILURE);
433 				ctx->error = X509_V_ERR_OUT_OF_MEM;
434 				ok = 0;
435 				goto end;
436 			}
437 			num++;
438 		}
439 
440 		/* we now have our chain, lets check it... */
441 		trust = check_trust(ctx);
442 
443 		/* If explicitly rejected error */
444 		if (trust == X509_TRUST_REJECTED) {
445 			ok = 0;
446 			goto end;
447 		}
448 		/*
449 		 * If it's not explicitly trusted then check if there
450 		 * is an alternative chain that could be used. We only
451 		 * do this if we haven't already checked via
452 		 * TRUSTED_FIRST and the user hasn't switched off
453 		 * alternate chain checking
454 		 */
455 		retry = 0;
456 		if (trust != X509_TRUST_TRUSTED &&
457 		    !(ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) &&
458 		    !(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) {
459 			while (j-- > 1) {
460 				xtmp2 = sk_X509_value(ctx->chain, j - 1);
461 				ok = ctx->get_issuer(&xtmp, ctx, xtmp2);
462 				if (ok < 0)
463 					goto end;
464 				/* Check if we found an alternate chain */
465 				if (ok > 0) {
466 					/*
467 					 * Free up the found cert
468 					 * we'll add it again later
469 					 */
470 					X509_free(xtmp);
471 					/*
472 					 * Dump all the certs above
473 					 * this point - we've found an
474 					 * alternate chain
475 					 */
476 					while (num > j) {
477 						xtmp = sk_X509_pop(ctx->chain);
478 						X509_free(xtmp);
479 						num--;
480 					}
481 					ctx->last_untrusted = sk_X509_num(ctx->chain);
482 					retry = 1;
483 					break;
484 				}
485 			}
486 		}
487 	} while (retry);
488 
489 	/*
490 	 * If not explicitly trusted then indicate error unless it's a single
491 	 * self signed certificate in which case we've indicated an error already
492 	 * and set bad_chain == 1
493 	 */
494 	if (trust != X509_TRUST_TRUSTED && !bad_chain) {
495 		if ((chain_ss == NULL) || !ctx->check_issued(ctx, x, chain_ss)) {
496 			if (ctx->last_untrusted >= num)
497 				ctx->error = X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY;
498 			else
499 				ctx->error = X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT;
500 			ctx->current_cert = x;
501 		} else {
502 			if (!sk_X509_push(ctx->chain, chain_ss)) {
503 				X509error(ERR_R_MALLOC_FAILURE);
504 				ctx->error = X509_V_ERR_OUT_OF_MEM;
505 				ok = 0;
506 				goto end;
507 			}
508 			num++;
509 			ctx->last_untrusted = num;
510 			ctx->current_cert = chain_ss;
511 			ctx->error = X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN;
512 			chain_ss = NULL;
513 		}
514 
515 		ctx->error_depth = num - 1;
516 		bad_chain = 1;
517 		ok = cb(0, ctx);
518 		if (!ok)
519 			goto end;
520 	}
521 
522 	ret = 1;
523  end:
524 	sk_X509_free(sktmp);
525 	X509_free(chain_ss);
526 	*bad = bad_chain;
527 	*out_ok = ok;
528 
529 	return ret;
530 }
531 
532 static int
533 X509_verify_cert_legacy(X509_STORE_CTX *ctx)
534 {
535 	int ok = 0, bad_chain;
536 
537 	ctx->error = X509_V_OK; /* Initialize to OK */
538 
539 	if (!X509_verify_cert_legacy_build_chain(ctx, &bad_chain, &ok))
540 		goto end;
541 
542 	/* We have the chain complete: now we need to check its purpose */
543 	ok = check_chain_extensions(ctx);
544 	if (!ok)
545 		goto end;
546 
547 	/* Check name constraints */
548 	ok = check_name_constraints(ctx);
549 	if (!ok)
550 		goto end;
551 
552 	ok = check_id(ctx);
553 	if (!ok)
554 		goto end;
555 
556 	/*
557 	 * Check revocation status: we do this after copying parameters because
558 	 * they may be needed for CRL signature verification.
559 	 */
560 	ok = ctx->check_revocation(ctx);
561 	if (!ok)
562 		goto end;
563 
564 	/* At this point, we have a chain and need to verify it */
565 	if (ctx->verify != NULL)
566 		ok = ctx->verify(ctx);
567 	else
568 		ok = internal_verify(ctx);
569 	if (!ok)
570 		goto end;
571 
572 	/* If we get this far evaluate policies */
573 	if (!bad_chain && (ctx->param->flags & X509_V_FLAG_POLICY_CHECK))
574 		ok = ctx->check_policy(ctx);
575 
576  end:
577 	/* Safety net, error returns must set ctx->error */
578 	if (ok <= 0 && ctx->error == X509_V_OK)
579 		ctx->error = X509_V_ERR_UNSPECIFIED;
580 
581 	return ok;
582 }
583 
584 int
585 X509_verify_cert(X509_STORE_CTX *ctx)
586 {
587 	STACK_OF(X509) *roots = NULL;
588 	struct x509_verify_ctx *vctx = NULL;
589 	int chain_count = 0;
590 
591 	if (ctx->cert == NULL) {
592 		X509error(X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
593 		ctx->error = X509_V_ERR_INVALID_CALL;
594 		return -1;
595 	}
596 	if (ctx->chain != NULL) {
597 		/*
598 		 * This X509_STORE_CTX has already been used to verify
599 		 * a cert. We cannot do another one.
600 		 */
601 		X509error(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
602 		ctx->error = X509_V_ERR_INVALID_CALL;
603 		return -1;
604 	}
605 	if (ctx->param->id->poisoned) {
606 		/*
607 		 * This X509_STORE_CTX had failures setting
608 		 * up verify parameters. We can not use it.
609 		 */
610 		X509error(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
611 		ctx->error = X509_V_ERR_INVALID_CALL;
612 		return -1;
613 	}
614 	if (ctx->error != X509_V_ERR_INVALID_CALL) {
615 		/*
616 		 * This X509_STORE_CTX has not been properly initialized.
617 		 */
618 		X509error(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
619 		ctx->error = X509_V_ERR_INVALID_CALL;
620 		return -1;
621 	}
622 
623 	/*
624 	 * If flags request legacy, use the legacy verifier. If we
625 	 * requested "no alt chains" from the age of hammer pants, use
626 	 * the legacy verifier because the multi chain verifier really
627 	 * does find all the "alt chains".
628 	 *
629 	 * XXX deprecate the NO_ALT_CHAINS flag?
630 	 */
631 	if ((ctx->param->flags & X509_V_FLAG_LEGACY_VERIFY) ||
632 	    (ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS))
633 		return X509_verify_cert_legacy(ctx);
634 
635 	/* Use the modern multi-chain verifier from x509_verify_cert */
636 
637 	/* Find our trusted roots */
638 	ctx->error = X509_V_ERR_OUT_OF_MEM;
639 
640 	if (ctx->get_issuer == get_issuer_sk) {
641 		/*
642 		 * We are using the trusted stack method. so
643 		 * the roots are in the aptly named "ctx->other_ctx"
644 		 * pointer. (It could have been called "al")
645 		 */
646 		if ((roots = X509_chain_up_ref(ctx->other_ctx)) == NULL)
647 			return -1;
648 	} else {
649 		/*
650 		 * We have a X509_STORE and need to pull out the roots.
651 		 * Don't look Ethel...
652 		 */
653 		STACK_OF(X509_OBJECT) *objs;
654 		size_t i, good = 1;
655 
656 		if ((roots = sk_X509_new_null()) == NULL)
657 			return -1;
658 
659 		CRYPTO_w_lock(CRYPTO_LOCK_X509_STORE);
660 		if ((objs = X509_STORE_get0_objects(ctx->ctx)) == NULL)
661 			good = 0;
662 		for (i = 0; good && i < sk_X509_OBJECT_num(objs); i++) {
663 			X509_OBJECT *obj;
664 			X509 *root;
665 			obj = sk_X509_OBJECT_value(objs, i);
666 			if (obj->type != X509_LU_X509)
667 				continue;
668 			root = obj->data.x509;
669 			if (X509_up_ref(root) == 0)
670 				good = 0;
671 			if (sk_X509_push(roots, root) == 0) {
672 				X509_free(root);
673 				good = 0;
674 			}
675 		}
676 		CRYPTO_w_unlock(CRYPTO_LOCK_X509_STORE);
677 
678 		if (!good) {
679 			sk_X509_pop_free(roots, X509_free);
680 			return -1;
681 		}
682 	}
683 
684 	if ((vctx = x509_verify_ctx_new_from_xsc(ctx, roots)) != NULL) {
685 		ctx->error = X509_V_OK; /* Initialize to OK */
686 		chain_count = x509_verify(vctx, NULL, NULL);
687 	}
688 	x509_verify_ctx_free(vctx);
689 
690 	sk_X509_pop_free(roots, X509_free);
691 
692 	/* if we succeed we have a chain in ctx->chain */
693 	return (chain_count > 0 && ctx->chain != NULL);
694 }
695 
696 /* Given a STACK_OF(X509) find the issuer of cert (if any)
697  */
698 
699 static X509 *
700 find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x,
701     int allow_expired)
702 {
703 	int i;
704 	X509 *issuer, *rv = NULL;
705 
706 	for (i = 0; i < sk_X509_num(sk); i++) {
707 		issuer = sk_X509_value(sk, i);
708 		if (ctx->check_issued(ctx, x, issuer)) {
709 			if (x509_check_cert_time(ctx, issuer, -1))
710 				return issuer;
711 			if (allow_expired)
712 				rv = issuer;
713 		}
714 	}
715 	return rv;
716 }
717 
718 /* Given a possible certificate and issuer check them */
719 
720 static int
721 check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
722 {
723 	int ret;
724 
725 	ret = X509_check_issued(issuer, x);
726 	if (ret == X509_V_OK)
727 		return 1;
728 	/* If we haven't asked for issuer errors don't set ctx */
729 	if (!(ctx->param->flags & X509_V_FLAG_CB_ISSUER_CHECK))
730 		return 0;
731 
732 	ctx->error = ret;
733 	ctx->current_cert = x;
734 	ctx->current_issuer = issuer;
735 	return ctx->verify_cb(0, ctx);
736 }
737 
738 /* Alternative lookup method: look from a STACK stored in other_ctx */
739 
740 static int
741 get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
742 {
743 	*issuer = find_issuer(ctx, ctx->other_ctx, x, 1);
744 	if (*issuer) {
745 		CRYPTO_add(&(*issuer)->references, 1, CRYPTO_LOCK_X509);
746 		return 1;
747 	} else
748 		return 0;
749 }
750 
751 /* Check a certificate chains extensions for consistency
752  * with the supplied purpose
753  */
754 
755 int
756 x509_vfy_check_chain_extensions(X509_STORE_CTX *ctx)
757 {
758 #ifdef OPENSSL_NO_CHAIN_VERIFY
759 	return 1;
760 #else
761 	int i, ok = 0, must_be_ca, plen = 0;
762 	X509 *x;
763 	int (*cb)(int xok, X509_STORE_CTX *xctx);
764 	int proxy_path_length = 0;
765 	int purpose;
766 	int allow_proxy_certs;
767 
768 	cb = ctx->verify_cb;
769 
770 	/* must_be_ca can have 1 of 3 values:
771 	   -1: we accept both CA and non-CA certificates, to allow direct
772 	       use of self-signed certificates (which are marked as CA).
773 	   0:  we only accept non-CA certificates.  This is currently not
774 	       used, but the possibility is present for future extensions.
775 	   1:  we only accept CA certificates.  This is currently used for
776 	       all certificates in the chain except the leaf certificate.
777 	*/
778 	must_be_ca = -1;
779 
780 	/* CRL path validation */
781 	if (ctx->parent) {
782 		allow_proxy_certs = 0;
783 		purpose = X509_PURPOSE_CRL_SIGN;
784 	} else {
785 		allow_proxy_certs =
786 		    !!(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
787 		purpose = ctx->param->purpose;
788 	}
789 
790 	/* Check all untrusted certificates */
791 	for (i = 0; i < ctx->last_untrusted; i++) {
792 		int ret;
793 		x = sk_X509_value(ctx->chain, i);
794 		if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) &&
795 		    (x->ex_flags & EXFLAG_CRITICAL)) {
796 			ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;
797 			ctx->error_depth = i;
798 			ctx->current_cert = x;
799 			ok = cb(0, ctx);
800 			if (!ok)
801 				goto end;
802 		}
803 		if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) {
804 			ctx->error = X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED;
805 			ctx->error_depth = i;
806 			ctx->current_cert = x;
807 			ok = cb(0, ctx);
808 			if (!ok)
809 				goto end;
810 		}
811 		ret = X509_check_ca(x);
812 		switch (must_be_ca) {
813 		case -1:
814 			if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) &&
815 			    (ret != 1) && (ret != 0)) {
816 				ret = 0;
817 				ctx->error = X509_V_ERR_INVALID_CA;
818 			} else
819 				ret = 1;
820 			break;
821 		case 0:
822 			if (ret != 0) {
823 				ret = 0;
824 				ctx->error = X509_V_ERR_INVALID_NON_CA;
825 			} else
826 				ret = 1;
827 			break;
828 		default:
829 			if ((ret == 0) ||
830 			    ((ctx->param->flags & X509_V_FLAG_X509_STRICT) &&
831 			    (ret != 1))) {
832 				ret = 0;
833 				ctx->error = X509_V_ERR_INVALID_CA;
834 			} else
835 				ret = 1;
836 			break;
837 		}
838 		if (ret == 0) {
839 			ctx->error_depth = i;
840 			ctx->current_cert = x;
841 			ok = cb(0, ctx);
842 			if (!ok)
843 				goto end;
844 		}
845 		if (ctx->param->purpose > 0) {
846 			ret = X509_check_purpose(x, purpose, must_be_ca > 0);
847 			if ((ret == 0) ||
848 			    ((ctx->param->flags & X509_V_FLAG_X509_STRICT) &&
849 			    (ret != 1))) {
850 				ctx->error = X509_V_ERR_INVALID_PURPOSE;
851 				ctx->error_depth = i;
852 				ctx->current_cert = x;
853 				ok = cb(0, ctx);
854 				if (!ok)
855 					goto end;
856 			}
857 		}
858 		/* Check pathlen if not self issued */
859 		if ((i > 1) && !(x->ex_flags & EXFLAG_SI) &&
860 		    (x->ex_pathlen != -1) &&
861 		    (plen > (x->ex_pathlen + proxy_path_length + 1))) {
862 			ctx->error = X509_V_ERR_PATH_LENGTH_EXCEEDED;
863 			ctx->error_depth = i;
864 			ctx->current_cert = x;
865 			ok = cb(0, ctx);
866 			if (!ok)
867 				goto end;
868 		}
869 		/* Increment path length if not self issued */
870 		if (!(x->ex_flags & EXFLAG_SI))
871 			plen++;
872 		/* If this certificate is a proxy certificate, the next
873 		   certificate must be another proxy certificate or a EE
874 		   certificate.  If not, the next certificate must be a
875 		   CA certificate.  */
876 		if (x->ex_flags & EXFLAG_PROXY) {
877 			if (x->ex_pcpathlen != -1 && i > x->ex_pcpathlen) {
878 				ctx->error =
879 				    X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED;
880 				ctx->error_depth = i;
881 				ctx->current_cert = x;
882 				ok = cb(0, ctx);
883 				if (!ok)
884 					goto end;
885 			}
886 			proxy_path_length++;
887 			must_be_ca = 0;
888 		} else
889 			must_be_ca = 1;
890 	}
891 	ok = 1;
892 
893 end:
894 	return ok;
895 #endif
896 }
897 
898 static int
899 check_chain_extensions(X509_STORE_CTX *ctx) {
900 	return x509_vfy_check_chain_extensions(ctx);
901 }
902 
903 static int
904 check_name_constraints(X509_STORE_CTX *ctx)
905 {
906 	if (!x509_constraints_chain(ctx->chain, &ctx->error,
907 	    &ctx->error_depth)) {
908 		ctx->current_cert = sk_X509_value(ctx->chain, ctx->error_depth);
909 		if (!ctx->verify_cb(0, ctx))
910 			return 0;
911 	}
912 	return 1;
913 }
914 
915 /* Given a certificate try and find an exact match in the store */
916 
917 static X509 *
918 lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
919 {
920 	STACK_OF(X509) *certs;
921 	X509 *xtmp = NULL;
922 	size_t i;
923 
924 	/* Lookup all certs with matching subject name */
925 	certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
926 	if (certs == NULL)
927 		return NULL;
928 
929 	/* Look for exact match */
930 	for (i = 0; i < sk_X509_num(certs); i++) {
931 		xtmp = sk_X509_value(certs, i);
932 		if (!X509_cmp(xtmp, x))
933 			break;
934 	}
935 
936 	if (i < sk_X509_num(certs))
937 		X509_up_ref(xtmp);
938 	else
939 		xtmp = NULL;
940 
941 	sk_X509_pop_free(certs, X509_free);
942 	return xtmp;
943 }
944 
945 static int
946 check_trust(X509_STORE_CTX *ctx)
947 {
948 	size_t i;
949 	int ok;
950 	X509 *x = NULL;
951 	int (*cb) (int xok, X509_STORE_CTX *xctx);
952 
953 	cb = ctx->verify_cb;
954 	/* Check all trusted certificates in chain */
955 	for (i = ctx->last_untrusted; i < sk_X509_num(ctx->chain); i++) {
956 		x = sk_X509_value(ctx->chain, i);
957 		ok = X509_check_trust(x, ctx->param->trust, 0);
958 
959 		/* If explicitly trusted return trusted */
960 		if (ok == X509_TRUST_TRUSTED)
961 			return X509_TRUST_TRUSTED;
962 		/*
963 		 * If explicitly rejected notify callback and reject if not
964 		 * overridden.
965 		 */
966 		if (ok == X509_TRUST_REJECTED) {
967 			ctx->error_depth = i;
968 			ctx->current_cert = x;
969 			ctx->error = X509_V_ERR_CERT_REJECTED;
970 			ok = cb(0, ctx);
971 			if (!ok)
972 				return X509_TRUST_REJECTED;
973 		}
974 	}
975 	/*
976 	 * If we accept partial chains and have at least one trusted certificate
977 	 * return success.
978 	 */
979 	if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
980 		X509 *mx;
981 		if (ctx->last_untrusted < (int)sk_X509_num(ctx->chain))
982 			return X509_TRUST_TRUSTED;
983 		x = sk_X509_value(ctx->chain, 0);
984 		mx = lookup_cert_match(ctx, x);
985 		if (mx) {
986 			(void)sk_X509_set(ctx->chain, 0, mx);
987 			X509_free(x);
988 			ctx->last_untrusted = 0;
989 			return X509_TRUST_TRUSTED;
990 		}
991 	}
992 
993 	/*
994 	 * If no trusted certs in chain at all return untrusted and allow
995 	 * standard (no issuer cert) etc errors to be indicated.
996 	 */
997 	return X509_TRUST_UNTRUSTED;
998 }
999 
1000 int
1001 x509_vfy_check_trust(X509_STORE_CTX *ctx)
1002 {
1003 	return check_trust(ctx);
1004 }
1005 
1006 static int
1007 check_revocation(X509_STORE_CTX *ctx)
1008 {
1009 	int i, last, ok;
1010 
1011 	if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
1012 		return 1;
1013 	if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
1014 		last = sk_X509_num(ctx->chain) - 1;
1015 	else {
1016 		/* If checking CRL paths this isn't the EE certificate */
1017 		if (ctx->parent)
1018 			return 1;
1019 		last = 0;
1020 	}
1021 	for (i = 0; i <= last; i++) {
1022 		ok = check_cert(ctx, ctx->chain, i);
1023 		if (!ok)
1024 			return ok;
1025 	}
1026 	return 1;
1027 }
1028 
1029 int
1030 x509_vfy_check_revocation(X509_STORE_CTX *ctx)
1031 {
1032 	return check_revocation(ctx);
1033 }
1034 
1035 static int
1036 check_cert(X509_STORE_CTX *ctx, STACK_OF(X509) *chain, int depth)
1037 {
1038 	X509_CRL *crl = NULL, *dcrl = NULL;
1039 	X509 *x;
1040 	int ok = 0, cnum;
1041 	unsigned int last_reasons;
1042 
1043 	cnum = ctx->error_depth = depth;
1044 	x = sk_X509_value(chain, cnum);
1045 	ctx->current_cert = x;
1046 	ctx->current_issuer = NULL;
1047 	ctx->current_crl_score = 0;
1048 	ctx->current_reasons = 0;
1049 	while (ctx->current_reasons != CRLDP_ALL_REASONS) {
1050 		last_reasons = ctx->current_reasons;
1051 		/* Try to retrieve relevant CRL */
1052 		if (ctx->get_crl)
1053 			ok = ctx->get_crl(ctx, &crl, x);
1054 		else
1055 			ok = get_crl_delta(ctx, &crl, &dcrl, x);
1056 		/* If error looking up CRL, nothing we can do except
1057 		 * notify callback
1058 		 */
1059 		if (!ok) {
1060 			ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
1061 			ok = ctx->verify_cb(0, ctx);
1062 			goto err;
1063 		}
1064 		ctx->current_crl = crl;
1065 		ok = ctx->check_crl(ctx, crl);
1066 		if (!ok)
1067 			goto err;
1068 
1069 		if (dcrl) {
1070 			ok = ctx->check_crl(ctx, dcrl);
1071 			if (!ok)
1072 				goto err;
1073 			ok = ctx->cert_crl(ctx, dcrl, x);
1074 			if (!ok)
1075 				goto err;
1076 		} else
1077 			ok = 1;
1078 
1079 		/* Don't look in full CRL if delta reason is removefromCRL */
1080 		if (ok != 2) {
1081 			ok = ctx->cert_crl(ctx, crl, x);
1082 			if (!ok)
1083 				goto err;
1084 		}
1085 
1086 		ctx->current_crl = NULL;
1087 		X509_CRL_free(crl);
1088 		X509_CRL_free(dcrl);
1089 		crl = NULL;
1090 		dcrl = NULL;
1091 		/* If reasons not updated we wont get anywhere by
1092 		 * another iteration, so exit loop.
1093 		 */
1094 		if (last_reasons == ctx->current_reasons) {
1095 			ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
1096 			ok = ctx->verify_cb(0, ctx);
1097 			goto err;
1098 		}
1099 	}
1100 
1101 err:
1102 	ctx->current_crl = NULL;
1103 	X509_CRL_free(crl);
1104 	X509_CRL_free(dcrl);
1105 	return ok;
1106 }
1107 
1108 /* Check CRL times against values in X509_STORE_CTX */
1109 
1110 static int
1111 check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
1112 {
1113 	time_t *ptime = NULL;
1114 	int i;
1115 
1116 	if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1117 		return (1);
1118 
1119 	if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1120 		ptime = &ctx->param->check_time;
1121 
1122 	if (notify)
1123 		ctx->current_crl = crl;
1124 
1125 	i = X509_cmp_time(X509_CRL_get_lastUpdate(crl), ptime);
1126 	if (i == 0) {
1127 		if (!notify)
1128 			return 0;
1129 		ctx->error = X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD;
1130 		if (!ctx->verify_cb(0, ctx))
1131 			return 0;
1132 	}
1133 
1134 	if (i > 0) {
1135 		if (!notify)
1136 			return 0;
1137 		ctx->error = X509_V_ERR_CRL_NOT_YET_VALID;
1138 		if (!ctx->verify_cb(0, ctx))
1139 			return 0;
1140 	}
1141 
1142 	if (X509_CRL_get_nextUpdate(crl)) {
1143 		i = X509_cmp_time(X509_CRL_get_nextUpdate(crl), ptime);
1144 
1145 		if (i == 0) {
1146 			if (!notify)
1147 				return 0;
1148 			ctx->error = X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
1149 			if (!ctx->verify_cb(0, ctx))
1150 				return 0;
1151 		}
1152 		/* Ignore expiry of base CRL is delta is valid */
1153 		if ((i < 0) &&
1154 		    !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
1155 			if (!notify)
1156 				return 0;
1157 			ctx->error = X509_V_ERR_CRL_HAS_EXPIRED;
1158 			if (!ctx->verify_cb(0, ctx))
1159 				return 0;
1160 		}
1161 	}
1162 
1163 	if (notify)
1164 		ctx->current_crl = NULL;
1165 
1166 	return 1;
1167 }
1168 
1169 static int
1170 get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
1171     X509 **pissuer, int *pscore, unsigned int *preasons,
1172     STACK_OF(X509_CRL) *crls)
1173 {
1174 	int i, crl_score, best_score = *pscore;
1175 	unsigned int reasons, best_reasons = 0;
1176 	X509 *x = ctx->current_cert;
1177 	X509_CRL *crl, *best_crl = NULL;
1178 	X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
1179 
1180 	for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1181 		crl = sk_X509_CRL_value(crls, i);
1182 		reasons = *preasons;
1183 		crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
1184 
1185 		if (crl_score > best_score) {
1186 			best_crl = crl;
1187 			best_crl_issuer = crl_issuer;
1188 			best_score = crl_score;
1189 			best_reasons = reasons;
1190 		}
1191 	}
1192 
1193 	if (best_crl) {
1194 		if (*pcrl)
1195 			X509_CRL_free(*pcrl);
1196 		*pcrl = best_crl;
1197 		*pissuer = best_crl_issuer;
1198 		*pscore = best_score;
1199 		*preasons = best_reasons;
1200 		CRYPTO_add(&best_crl->references, 1, CRYPTO_LOCK_X509_CRL);
1201 		if (*pdcrl) {
1202 			X509_CRL_free(*pdcrl);
1203 			*pdcrl = NULL;
1204 		}
1205 		get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
1206 	}
1207 
1208 	if (best_score >= CRL_SCORE_VALID)
1209 		return 1;
1210 
1211 	return 0;
1212 }
1213 
1214 /* Compare two CRL extensions for delta checking purposes. They should be
1215  * both present or both absent. If both present all fields must be identical.
1216  */
1217 
1218 static int
1219 crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
1220 {
1221 	ASN1_OCTET_STRING *exta, *extb;
1222 	int i;
1223 
1224 	i = X509_CRL_get_ext_by_NID(a, nid, -1);
1225 	if (i >= 0) {
1226 		/* Can't have multiple occurrences */
1227 		if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
1228 			return 0;
1229 		exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
1230 	} else
1231 		exta = NULL;
1232 
1233 	i = X509_CRL_get_ext_by_NID(b, nid, -1);
1234 
1235 	if (i >= 0) {
1236 		if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
1237 			return 0;
1238 		extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
1239 	} else
1240 		extb = NULL;
1241 
1242 	if (!exta && !extb)
1243 		return 1;
1244 
1245 	if (!exta || !extb)
1246 		return 0;
1247 
1248 	if (ASN1_OCTET_STRING_cmp(exta, extb))
1249 		return 0;
1250 
1251 	return 1;
1252 }
1253 
1254 /* See if a base and delta are compatible */
1255 
1256 static int
1257 check_delta_base(X509_CRL *delta, X509_CRL *base)
1258 {
1259 	/* Delta CRL must be a delta */
1260 	if (!delta->base_crl_number)
1261 		return 0;
1262 	/* Base must have a CRL number */
1263 	if (!base->crl_number)
1264 		return 0;
1265 	/* Issuer names must match */
1266 	if (X509_NAME_cmp(X509_CRL_get_issuer(base),
1267 	    X509_CRL_get_issuer(delta)))
1268 		return 0;
1269 	/* AKID and IDP must match */
1270 	if (!crl_extension_match(delta, base, NID_authority_key_identifier))
1271 		return 0;
1272 	if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
1273 		return 0;
1274 	/* Delta CRL base number must not exceed Full CRL number. */
1275 	if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
1276 		return 0;
1277 	/* Delta CRL number must exceed full CRL number */
1278 	if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
1279 		return 1;
1280 	return 0;
1281 }
1282 
1283 /* For a given base CRL find a delta... maybe extend to delta scoring
1284  * or retrieve a chain of deltas...
1285  */
1286 
1287 static void
1288 get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore, X509_CRL *base,
1289     STACK_OF(X509_CRL) *crls)
1290 {
1291 	X509_CRL *delta;
1292 	int i;
1293 
1294 	if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
1295 		return;
1296 	if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
1297 		return;
1298 	for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1299 		delta = sk_X509_CRL_value(crls, i);
1300 		if (check_delta_base(delta, base)) {
1301 			if (check_crl_time(ctx, delta, 0))
1302 				*pscore |= CRL_SCORE_TIME_DELTA;
1303 			CRYPTO_add(&delta->references, 1, CRYPTO_LOCK_X509_CRL);
1304 			*dcrl = delta;
1305 			return;
1306 		}
1307 	}
1308 	*dcrl = NULL;
1309 }
1310 
1311 /* For a given CRL return how suitable it is for the supplied certificate 'x'.
1312  * The return value is a mask of several criteria.
1313  * If the issuer is not the certificate issuer this is returned in *pissuer.
1314  * The reasons mask is also used to determine if the CRL is suitable: if
1315  * no new reasons the CRL is rejected, otherwise reasons is updated.
1316  */
1317 
1318 static int
1319 get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, unsigned int *preasons,
1320     X509_CRL *crl, X509 *x)
1321 {
1322 	int crl_score = 0;
1323 	unsigned int tmp_reasons = *preasons, crl_reasons;
1324 
1325 	/* First see if we can reject CRL straight away */
1326 
1327 	/* Invalid IDP cannot be processed */
1328 	if (crl->idp_flags & IDP_INVALID)
1329 		return 0;
1330 	/* Reason codes or indirect CRLs need extended CRL support */
1331 	if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
1332 		if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
1333 			return 0;
1334 	} else if (crl->idp_flags & IDP_REASONS) {
1335 		/* If no new reasons reject */
1336 		if (!(crl->idp_reasons & ~tmp_reasons))
1337 			return 0;
1338 	}
1339 	/* Don't process deltas at this stage */
1340 	else if (crl->base_crl_number)
1341 		return 0;
1342 	/* If issuer name doesn't match certificate need indirect CRL */
1343 	if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
1344 		if (!(crl->idp_flags & IDP_INDIRECT))
1345 			return 0;
1346 	} else
1347 		crl_score |= CRL_SCORE_ISSUER_NAME;
1348 
1349 	if (!(crl->flags & EXFLAG_CRITICAL))
1350 		crl_score |= CRL_SCORE_NOCRITICAL;
1351 
1352 	/* Check expiry */
1353 	if (check_crl_time(ctx, crl, 0))
1354 		crl_score |= CRL_SCORE_TIME;
1355 
1356 	/* Check authority key ID and locate certificate issuer */
1357 	crl_akid_check(ctx, crl, pissuer, &crl_score);
1358 
1359 	/* If we can't locate certificate issuer at this point forget it */
1360 
1361 	if (!(crl_score & CRL_SCORE_AKID))
1362 		return 0;
1363 
1364 	/* Check cert for matching CRL distribution points */
1365 
1366 	if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
1367 		/* If no new reasons reject */
1368 		if (!(crl_reasons & ~tmp_reasons))
1369 			return 0;
1370 		tmp_reasons |= crl_reasons;
1371 		crl_score |= CRL_SCORE_SCOPE;
1372 	}
1373 
1374 	*preasons = tmp_reasons;
1375 
1376 	return crl_score;
1377 }
1378 
1379 static void
1380 crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
1381     int *pcrl_score)
1382 {
1383 	X509 *crl_issuer = NULL;
1384 	X509_NAME *cnm = X509_CRL_get_issuer(crl);
1385 	int cidx = ctx->error_depth;
1386 	int i;
1387 
1388 	if (cidx != sk_X509_num(ctx->chain) - 1)
1389 		cidx++;
1390 
1391 	crl_issuer = sk_X509_value(ctx->chain, cidx);
1392 
1393 	if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1394 		if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
1395 			*pcrl_score |= CRL_SCORE_AKID|CRL_SCORE_ISSUER_CERT;
1396 			*pissuer = crl_issuer;
1397 			return;
1398 		}
1399 	}
1400 
1401 	for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) {
1402 		crl_issuer = sk_X509_value(ctx->chain, cidx);
1403 		if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1404 			continue;
1405 		if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1406 			*pcrl_score |= CRL_SCORE_AKID|CRL_SCORE_SAME_PATH;
1407 			*pissuer = crl_issuer;
1408 			return;
1409 		}
1410 	}
1411 
1412 	/* Anything else needs extended CRL support */
1413 
1414 	if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
1415 		return;
1416 
1417 	/* Otherwise the CRL issuer is not on the path. Look for it in the
1418 	 * set of untrusted certificates.
1419 	 */
1420 	for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
1421 		crl_issuer = sk_X509_value(ctx->untrusted, i);
1422 		if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1423 			continue;
1424 		if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1425 			*pissuer = crl_issuer;
1426 			*pcrl_score |= CRL_SCORE_AKID;
1427 			return;
1428 		}
1429 	}
1430 }
1431 
1432 /* Check the path of a CRL issuer certificate. This creates a new
1433  * X509_STORE_CTX and populates it with most of the parameters from the
1434  * parent. This could be optimised somewhat since a lot of path checking
1435  * will be duplicated by the parent, but this will rarely be used in
1436  * practice.
1437  */
1438 
1439 static int
1440 check_crl_path(X509_STORE_CTX *ctx, X509 *x)
1441 {
1442 	X509_STORE_CTX crl_ctx;
1443 	int ret;
1444 
1445 	/* Don't allow recursive CRL path validation */
1446 	if (ctx->parent)
1447 		return 0;
1448 	if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted)) {
1449 		ret = -1;
1450 		goto err;
1451 	}
1452 
1453 	crl_ctx.crls = ctx->crls;
1454 	/* Copy verify params across */
1455 	X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
1456 
1457 	crl_ctx.parent = ctx;
1458 	crl_ctx.verify_cb = ctx->verify_cb;
1459 
1460 	/* Verify CRL issuer */
1461 	ret = X509_verify_cert(&crl_ctx);
1462 
1463 	if (ret <= 0)
1464 		goto err;
1465 
1466 	/* Check chain is acceptable */
1467 	ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
1468 
1469 err:
1470 	X509_STORE_CTX_cleanup(&crl_ctx);
1471 	return ret;
1472 }
1473 
1474 /* RFC3280 says nothing about the relationship between CRL path
1475  * and certificate path, which could lead to situations where a
1476  * certificate could be revoked or validated by a CA not authorised
1477  * to do so. RFC5280 is more strict and states that the two paths must
1478  * end in the same trust anchor, though some discussions remain...
1479  * until this is resolved we use the RFC5280 version
1480  */
1481 
1482 static int
1483 check_crl_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *cert_path,
1484     STACK_OF(X509) *crl_path)
1485 {
1486 	X509 *cert_ta, *crl_ta;
1487 
1488 	cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
1489 	crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
1490 	if (!X509_cmp(cert_ta, crl_ta))
1491 		return 1;
1492 	return 0;
1493 }
1494 
1495 /* Check for match between two dist point names: three separate cases.
1496  * 1. Both are relative names and compare X509_NAME types.
1497  * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
1498  * 3. Both are full names and compare two GENERAL_NAMES.
1499  * 4. One is NULL: automatic match.
1500  */
1501 
1502 static int
1503 idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
1504 {
1505 	X509_NAME *nm = NULL;
1506 	GENERAL_NAMES *gens = NULL;
1507 	GENERAL_NAME *gena, *genb;
1508 	int i, j;
1509 
1510 	if (!a || !b)
1511 		return 1;
1512 	if (a->type == 1) {
1513 		if (!a->dpname)
1514 			return 0;
1515 		/* Case 1: two X509_NAME */
1516 		if (b->type == 1) {
1517 			if (!b->dpname)
1518 				return 0;
1519 			if (!X509_NAME_cmp(a->dpname, b->dpname))
1520 				return 1;
1521 			else
1522 				return 0;
1523 		}
1524 		/* Case 2: set name and GENERAL_NAMES appropriately */
1525 		nm = a->dpname;
1526 		gens = b->name.fullname;
1527 	} else if (b->type == 1) {
1528 		if (!b->dpname)
1529 			return 0;
1530 		/* Case 2: set name and GENERAL_NAMES appropriately */
1531 		gens = a->name.fullname;
1532 		nm = b->dpname;
1533 	}
1534 
1535 	/* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
1536 	if (nm) {
1537 		for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1538 			gena = sk_GENERAL_NAME_value(gens, i);
1539 			if (gena->type != GEN_DIRNAME)
1540 				continue;
1541 			if (!X509_NAME_cmp(nm, gena->d.directoryName))
1542 				return 1;
1543 		}
1544 		return 0;
1545 	}
1546 
1547 	/* Else case 3: two GENERAL_NAMES */
1548 
1549 	for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
1550 		gena = sk_GENERAL_NAME_value(a->name.fullname, i);
1551 		for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
1552 			genb = sk_GENERAL_NAME_value(b->name.fullname, j);
1553 			if (!GENERAL_NAME_cmp(gena, genb))
1554 				return 1;
1555 		}
1556 	}
1557 
1558 	return 0;
1559 }
1560 
1561 static int
1562 crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
1563 {
1564 	int i;
1565 	X509_NAME *nm = X509_CRL_get_issuer(crl);
1566 
1567 	/* If no CRLissuer return is successful iff don't need a match */
1568 	if (!dp->CRLissuer)
1569 		return !!(crl_score & CRL_SCORE_ISSUER_NAME);
1570 	for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
1571 		GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
1572 		if (gen->type != GEN_DIRNAME)
1573 			continue;
1574 		if (!X509_NAME_cmp(gen->d.directoryName, nm))
1575 			return 1;
1576 	}
1577 	return 0;
1578 }
1579 
1580 /* Check CRLDP and IDP */
1581 
1582 static int
1583 crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, unsigned int *preasons)
1584 {
1585 	int i;
1586 
1587 	if (crl->idp_flags & IDP_ONLYATTR)
1588 		return 0;
1589 	if (x->ex_flags & EXFLAG_CA) {
1590 		if (crl->idp_flags & IDP_ONLYUSER)
1591 			return 0;
1592 	} else {
1593 		if (crl->idp_flags & IDP_ONLYCA)
1594 			return 0;
1595 	}
1596 	*preasons = crl->idp_reasons;
1597 	for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
1598 		DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
1599 		if (crldp_check_crlissuer(dp, crl, crl_score)) {
1600 			if (!crl->idp ||
1601 			    idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
1602 				*preasons &= dp->dp_reasons;
1603 				return 1;
1604 			}
1605 		}
1606 	}
1607 	if ((!crl->idp || !crl->idp->distpoint) &&
1608 	    (crl_score & CRL_SCORE_ISSUER_NAME))
1609 		return 1;
1610 	return 0;
1611 }
1612 
1613 /* Retrieve CRL corresponding to current certificate.
1614  * If deltas enabled try to find a delta CRL too
1615  */
1616 
1617 static int
1618 get_crl_delta(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
1619 {
1620 	int ok;
1621 	X509 *issuer = NULL;
1622 	int crl_score = 0;
1623 	unsigned int reasons;
1624 	X509_CRL *crl = NULL, *dcrl = NULL;
1625 	STACK_OF(X509_CRL) *skcrl;
1626 	X509_NAME *nm = X509_get_issuer_name(x);
1627 
1628 	reasons = ctx->current_reasons;
1629 	ok = get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons,
1630 	    ctx->crls);
1631 	if (ok)
1632 		goto done;
1633 
1634 	/* Lookup CRLs from store */
1635 	skcrl = ctx->lookup_crls(ctx, nm);
1636 
1637 	/* If no CRLs found and a near match from get_crl_sk use that */
1638 	if (!skcrl && crl)
1639 		goto done;
1640 
1641 	get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
1642 
1643 	sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
1644 
1645 done:
1646 
1647 	/* If we got any kind of CRL use it and return success */
1648 	if (crl) {
1649 		ctx->current_issuer = issuer;
1650 		ctx->current_crl_score = crl_score;
1651 		ctx->current_reasons = reasons;
1652 		*pcrl = crl;
1653 		*pdcrl = dcrl;
1654 		return 1;
1655 	}
1656 
1657 	return 0;
1658 }
1659 
1660 /* Check CRL validity */
1661 static int
1662 check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
1663 {
1664 	X509 *issuer = NULL;
1665 	EVP_PKEY *ikey = NULL;
1666 	int ok = 0, chnum, cnum;
1667 
1668 	cnum = ctx->error_depth;
1669 	chnum = sk_X509_num(ctx->chain) - 1;
1670 	/* if we have an alternative CRL issuer cert use that */
1671 	if (ctx->current_issuer) {
1672 		issuer = ctx->current_issuer;
1673 	} else if (cnum < chnum) {
1674 		/*
1675 		 * Else find CRL issuer: if not last certificate then issuer
1676 		 * is next certificate in chain.
1677 		 */
1678 		issuer = sk_X509_value(ctx->chain, cnum + 1);
1679 	} else {
1680 		issuer = sk_X509_value(ctx->chain, chnum);
1681 		/* If not self signed, can't check signature */
1682 		if (!ctx->check_issued(ctx, issuer, issuer)) {
1683 			ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER;
1684 			ok = ctx->verify_cb(0, ctx);
1685 			if (!ok)
1686 				goto err;
1687 		}
1688 	}
1689 
1690 	if (issuer) {
1691 		/* Skip most tests for deltas because they have already
1692 		 * been done
1693 		 */
1694 		if (!crl->base_crl_number) {
1695 			/* Check for cRLSign bit if keyUsage present */
1696 			if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
1697 			    !(issuer->ex_kusage & KU_CRL_SIGN)) {
1698 				ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;
1699 				ok = ctx->verify_cb(0, ctx);
1700 				if (!ok)
1701 					goto err;
1702 			}
1703 
1704 			if (!(ctx->current_crl_score & CRL_SCORE_SCOPE)) {
1705 				ctx->error = X509_V_ERR_DIFFERENT_CRL_SCOPE;
1706 				ok = ctx->verify_cb(0, ctx);
1707 				if (!ok)
1708 					goto err;
1709 			}
1710 
1711 			if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH)) {
1712 				if (check_crl_path(ctx,
1713 				    ctx->current_issuer) <= 0) {
1714 					ctx->error = X509_V_ERR_CRL_PATH_VALIDATION_ERROR;
1715 					ok = ctx->verify_cb(0, ctx);
1716 					if (!ok)
1717 						goto err;
1718 				}
1719 			}
1720 
1721 			if (crl->idp_flags & IDP_INVALID) {
1722 				ctx->error = X509_V_ERR_INVALID_EXTENSION;
1723 				ok = ctx->verify_cb(0, ctx);
1724 				if (!ok)
1725 					goto err;
1726 			}
1727 
1728 
1729 		}
1730 
1731 		if (!(ctx->current_crl_score & CRL_SCORE_TIME)) {
1732 			ok = check_crl_time(ctx, crl, 1);
1733 			if (!ok)
1734 				goto err;
1735 		}
1736 
1737 		/* Attempt to get issuer certificate public key */
1738 		ikey = X509_get_pubkey(issuer);
1739 
1740 		if (!ikey) {
1741 			ctx->error = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
1742 			ok = ctx->verify_cb(0, ctx);
1743 			if (!ok)
1744 				goto err;
1745 		} else {
1746 			/* Verify CRL signature */
1747 			if (X509_CRL_verify(crl, ikey) <= 0) {
1748 				ctx->error = X509_V_ERR_CRL_SIGNATURE_FAILURE;
1749 				ok = ctx->verify_cb(0, ctx);
1750 				if (!ok)
1751 					goto err;
1752 			}
1753 		}
1754 	}
1755 
1756 	ok = 1;
1757 
1758 err:
1759 	EVP_PKEY_free(ikey);
1760 	return ok;
1761 }
1762 
1763 /* Check certificate against CRL */
1764 static int
1765 cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
1766 {
1767 	int ok;
1768 	X509_REVOKED *rev;
1769 
1770 	/* The rules changed for this... previously if a CRL contained
1771 	 * unhandled critical extensions it could still be used to indicate
1772 	 * a certificate was revoked. This has since been changed since
1773 	 * critical extension can change the meaning of CRL entries.
1774 	 */
1775 	if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) &&
1776 	    (crl->flags & EXFLAG_CRITICAL)) {
1777 		ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
1778 		ok = ctx->verify_cb(0, ctx);
1779 		if (!ok)
1780 			return 0;
1781 	}
1782 	/* Look for serial number of certificate in CRL
1783 	 * If found make sure reason is not removeFromCRL.
1784 	 */
1785 	if (X509_CRL_get0_by_cert(crl, &rev, x)) {
1786 		if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
1787 			return 2;
1788 		ctx->error = X509_V_ERR_CERT_REVOKED;
1789 		ok = ctx->verify_cb(0, ctx);
1790 		if (!ok)
1791 			return 0;
1792 	}
1793 
1794 	return 1;
1795 }
1796 
1797 int
1798 x509_vfy_check_policy(X509_STORE_CTX *ctx)
1799 {
1800 	int ret;
1801 
1802 	if (ctx->parent)
1803 		return 1;
1804 
1805 	/* X509_policy_check always allocates a new tree. */
1806 	X509_policy_tree_free(ctx->tree);
1807 	ctx->tree = NULL;
1808 
1809 	ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
1810 	    ctx->param->policies, ctx->param->flags);
1811 	if (ret == 0) {
1812 		X509error(ERR_R_MALLOC_FAILURE);
1813 		return 0;
1814 	}
1815 	/* Invalid or inconsistent extensions */
1816 	if (ret == -1) {
1817 		/* Locate certificates with bad extensions and notify
1818 		 * callback.
1819 		 */
1820 		X509 *x;
1821 		int i;
1822 		for (i = 1; i < sk_X509_num(ctx->chain); i++) {
1823 			x = sk_X509_value(ctx->chain, i);
1824 			if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
1825 				continue;
1826 			ctx->current_cert = x;
1827 			ctx->error = X509_V_ERR_INVALID_POLICY_EXTENSION;
1828 			if (!ctx->verify_cb(0, ctx))
1829 				return 0;
1830 		}
1831 		return 1;
1832 	}
1833 	if (ret == -2) {
1834 		ctx->current_cert = NULL;
1835 		ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
1836 		return ctx->verify_cb(0, ctx);
1837 	}
1838 
1839 	if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
1840 		ctx->current_cert = NULL;
1841 		ctx->error = X509_V_OK;
1842 		if (!ctx->verify_cb(2, ctx))
1843 			return 0;
1844 	}
1845 
1846 	return 1;
1847 }
1848 
1849 static int
1850 check_policy(X509_STORE_CTX *ctx)
1851 {
1852 	return x509_vfy_check_policy(ctx);
1853 }
1854 
1855 /*
1856  * Inform the verify callback of an error.
1857  *
1858  * If x is not NULL it is the error cert, otherwise use the chain cert
1859  * at depth.
1860  *
1861  * If err is not X509_V_OK, that's the error value, otherwise leave
1862  * unchanged (presumably set by the caller).
1863  *
1864  * Returns 0 to abort verification with an error, non-zero to continue.
1865  */
1866 static int
1867 verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
1868 {
1869 	ctx->error_depth = depth;
1870 	ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
1871 	if (err != X509_V_OK)
1872 		ctx->error = err;
1873 	return ctx->verify_cb(0, ctx);
1874 }
1875 
1876 /*
1877  * Check certificate validity times.
1878  *
1879  * If depth >= 0, invoke verification callbacks on error, otherwise just return
1880  * the validation status.
1881  *
1882  * Return 1 on success, 0 otherwise.
1883  */
1884 int
1885 x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth)
1886 {
1887 	time_t *ptime;
1888 	int i;
1889 
1890 	if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1891 		ptime = &ctx->param->check_time;
1892 	else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1893 		return 1;
1894 	else
1895 		ptime = NULL;
1896 
1897 	i = X509_cmp_time(X509_get_notBefore(x), ptime);
1898 	if (i >= 0 && depth < 0)
1899 		return 0;
1900 	if (i == 0 && !verify_cb_cert(ctx, x, depth,
1901 	    X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD))
1902 		return 0;
1903 	if (i > 0 && !verify_cb_cert(ctx, x, depth,
1904 	    X509_V_ERR_CERT_NOT_YET_VALID))
1905 		return 0;
1906 
1907 	i = X509_cmp_time_internal(X509_get_notAfter(x), ptime, 1);
1908 	if (i <= 0 && depth < 0)
1909 		return 0;
1910 	if (i == 0 && !verify_cb_cert(ctx, x, depth,
1911 	    X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD))
1912 		return 0;
1913 	if (i < 0 && !verify_cb_cert(ctx, x, depth,
1914 	    X509_V_ERR_CERT_HAS_EXPIRED))
1915 		return 0;
1916 	return 1;
1917 }
1918 
1919 static int
1920 internal_verify(X509_STORE_CTX *ctx)
1921 {
1922 	int n = sk_X509_num(ctx->chain) - 1;
1923 	X509 *xi = sk_X509_value(ctx->chain, n);
1924 	X509 *xs;
1925 
1926 	if (ctx->check_issued(ctx, xi, xi))
1927 		xs = xi;
1928 	else {
1929 		if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
1930 			xs = xi;
1931 			goto check_cert;
1932 		}
1933 		if (n <= 0)
1934 			return verify_cb_cert(ctx, xi, 0,
1935 			    X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
1936 		n--;
1937 		ctx->error_depth = n;
1938 		xs = sk_X509_value(ctx->chain, n);
1939 	}
1940 
1941 	/*
1942 	 * Do not clear ctx->error=0, it must be "sticky", only the
1943 	 * user's callback is allowed to reset errors (at its own
1944 	 * peril).
1945 	 */
1946 	while (n >= 0) {
1947 
1948 		/*
1949 		 * Skip signature check for self signed certificates
1950 		 * unless explicitly asked for.  It doesn't add any
1951 		 * security and just wastes time.  If the issuer's
1952 		 * public key is unusable, report the issuer
1953 		 * certificate and its depth (rather than the depth of
1954 		 * the subject).
1955 		 */
1956 		if (xs != xi ||
1957 		    (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)) {
1958 			EVP_PKEY *pkey;
1959 			if ((pkey = X509_get_pubkey(xi)) == NULL) {
1960 				if (!verify_cb_cert(ctx, xi, xi != xs ? n+1 : n,
1961 				    X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
1962 					return 0;
1963 			} else if (X509_verify(xs, pkey) <= 0) {
1964 				if (!verify_cb_cert(ctx, xs, n,
1965 				    X509_V_ERR_CERT_SIGNATURE_FAILURE)) {
1966 					EVP_PKEY_free(pkey);
1967 					return 0;
1968 				}
1969 			}
1970 			EVP_PKEY_free(pkey);
1971 		}
1972 check_cert:
1973 		/* Calls verify callback as needed */
1974 		if (!x509_check_cert_time(ctx, xs, n))
1975 			return 0;
1976 
1977 		/*
1978 		 * Signal success at this depth.  However, the
1979 		 * previous error (if any) is retained.
1980 		 */
1981 		ctx->current_issuer = xi;
1982 		ctx->current_cert = xs;
1983 		ctx->error_depth = n;
1984 		if (!ctx->verify_cb(1, ctx))
1985 			return 0;
1986 
1987 		if (--n >= 0) {
1988 			xi = xs;
1989 			xs = sk_X509_value(ctx->chain, n);
1990 		}
1991 	}
1992 	return 1;
1993 }
1994 
1995 int
1996 X509_cmp_current_time(const ASN1_TIME *ctm)
1997 {
1998 	return X509_cmp_time(ctm, NULL);
1999 }
2000 
2001 /*
2002  * Compare a possibly unvalidated ASN1_TIME string against a time_t
2003  * using RFC 5280 rules for the time string. If *cmp_time is NULL
2004  * the current system time is used.
2005  *
2006  * XXX NOTE that unlike what you expect a "cmp" function to do in C,
2007  * XXX this one is "special", and returns 0 for error.
2008  *
2009  * Returns:
2010  * -1 if the ASN1_time is earlier than OR the same as *cmp_time.
2011  * 1 if the ASN1_time is later than *cmp_time.
2012  * 0 on error.
2013  */
2014 static int
2015 X509_cmp_time_internal(const ASN1_TIME *ctm, time_t *cmp_time, int clamp_notafter)
2016 {
2017 	time_t compare;
2018 	struct tm tm1, tm2;
2019 	int ret = 0;
2020 
2021 	if (cmp_time == NULL)
2022 		compare = time(NULL);
2023 	else
2024 		compare = *cmp_time;
2025 
2026 	memset(&tm1, 0, sizeof(tm1));
2027 
2028 	if (!x509_verify_asn1_time_to_tm(ctm, &tm1, clamp_notafter))
2029 		goto out; /* invalid time */
2030 
2031 	if (gmtime_r(&compare, &tm2) == NULL)
2032 		goto out;
2033 
2034 	ret = ASN1_time_tm_cmp(&tm1, &tm2);
2035 	if (ret == 0)
2036 		ret = -1; /* 0 is used for error, so map same to less than */
2037  out:
2038 	return (ret);
2039 }
2040 
2041 int
2042 X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
2043 {
2044 	return X509_cmp_time_internal(ctm, cmp_time, 0);
2045 }
2046 
2047 
2048 ASN1_TIME *
2049 X509_gmtime_adj(ASN1_TIME *s, long adj)
2050 {
2051 	return X509_time_adj(s, adj, NULL);
2052 }
2053 
2054 ASN1_TIME *
2055 X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_time)
2056 {
2057 	return X509_time_adj_ex(s, 0, offset_sec, in_time);
2058 }
2059 
2060 ASN1_TIME *
2061 X509_time_adj_ex(ASN1_TIME *s, int offset_day, long offset_sec, time_t *in_time)
2062 {
2063 	time_t t;
2064 	if (in_time == NULL)
2065 		t = time(NULL);
2066 	else
2067 		t = *in_time;
2068 
2069 	return ASN1_TIME_adj(s, t, offset_day, offset_sec);
2070 }
2071 
2072 int
2073 X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
2074 {
2075 	EVP_PKEY *ktmp = NULL, *ktmp2;
2076 	int i, j;
2077 
2078 	if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
2079 		return 1;
2080 
2081 	for (i = 0; i < sk_X509_num(chain); i++) {
2082 		ktmp = X509_get_pubkey(sk_X509_value(chain, i));
2083 		if (ktmp == NULL) {
2084 			X509error(X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
2085 			return 0;
2086 		}
2087 		if (!EVP_PKEY_missing_parameters(ktmp))
2088 			break;
2089 		else {
2090 			EVP_PKEY_free(ktmp);
2091 			ktmp = NULL;
2092 		}
2093 	}
2094 	if (ktmp == NULL) {
2095 		X509error(X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
2096 		return 0;
2097 	}
2098 
2099 	/* first, populate the other certs */
2100 	for (j = i - 1; j >= 0; j--) {
2101 		ktmp2 = X509_get_pubkey(sk_X509_value(chain, j));
2102 		EVP_PKEY_copy_parameters(ktmp2, ktmp);
2103 		EVP_PKEY_free(ktmp2);
2104 	}
2105 
2106 	if (pkey != NULL)
2107 		EVP_PKEY_copy_parameters(pkey, ktmp);
2108 	EVP_PKEY_free(ktmp);
2109 	return 1;
2110 }
2111 
2112 int
2113 X509_STORE_CTX_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
2114     CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
2115 {
2116 	/* This function is (usually) called only once, by
2117 	 * SSL_get_ex_data_X509_STORE_CTX_idx (ssl/ssl_cert.c). */
2118 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_X509_STORE_CTX,
2119 	    argl, argp, new_func, dup_func, free_func);
2120 }
2121 
2122 int
2123 X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
2124 {
2125 	return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
2126 }
2127 
2128 void *
2129 X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx)
2130 {
2131 	return CRYPTO_get_ex_data(&ctx->ex_data, idx);
2132 }
2133 
2134 int
2135 X509_STORE_CTX_get_error(X509_STORE_CTX *ctx)
2136 {
2137 	return ctx->error;
2138 }
2139 
2140 void
2141 X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
2142 {
2143 	ctx->error = err;
2144 }
2145 
2146 int
2147 X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx)
2148 {
2149 	return ctx->error_depth;
2150 }
2151 
2152 X509 *
2153 X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx)
2154 {
2155 	return ctx->current_cert;
2156 }
2157 
2158 STACK_OF(X509) *
2159 X509_STORE_CTX_get_chain(X509_STORE_CTX *ctx)
2160 {
2161 	return ctx->chain;
2162 }
2163 
2164 STACK_OF(X509) *
2165 X509_STORE_CTX_get0_chain(X509_STORE_CTX *xs)
2166 {
2167 	return xs->chain;
2168 }
2169 
2170 STACK_OF(X509) *
2171 X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx)
2172 {
2173 	int i;
2174 	X509 *x;
2175 	STACK_OF(X509) *chain;
2176 
2177 	if (!ctx->chain || !(chain = sk_X509_dup(ctx->chain)))
2178 		return NULL;
2179 	for (i = 0; i < sk_X509_num(chain); i++) {
2180 		x = sk_X509_value(chain, i);
2181 		CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
2182 	}
2183 	return chain;
2184 }
2185 
2186 X509 *
2187 X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx)
2188 {
2189 	return ctx->current_issuer;
2190 }
2191 
2192 X509_CRL *
2193 X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx)
2194 {
2195 	return ctx->current_crl;
2196 }
2197 
2198 X509_STORE_CTX *
2199 X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx)
2200 {
2201 	return ctx->parent;
2202 }
2203 
2204 X509_STORE *
2205 X509_STORE_CTX_get0_store(X509_STORE_CTX *xs)
2206 {
2207 	return xs->ctx;
2208 }
2209 
2210 void
2211 X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
2212 {
2213 	ctx->cert = x;
2214 }
2215 
2216 void
2217 X509_STORE_CTX_set_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2218 {
2219 	ctx->untrusted = sk;
2220 }
2221 
2222 void
2223 X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
2224 {
2225 	ctx->crls = sk;
2226 }
2227 
2228 int
2229 X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
2230 {
2231 	return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
2232 }
2233 
2234 int
2235 X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
2236 {
2237 	return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
2238 }
2239 
2240 /* This function is used to set the X509_STORE_CTX purpose and trust
2241  * values. This is intended to be used when another structure has its
2242  * own trust and purpose values which (if set) will be inherited by
2243  * the ctx. If they aren't set then we will usually have a default
2244  * purpose in mind which should then be used to set the trust value.
2245  * An example of this is SSL use: an SSL structure will have its own
2246  * purpose and trust settings which the application can set: if they
2247  * aren't set then we use the default of SSL client/server.
2248  */
2249 
2250 int
2251 X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
2252     int purpose, int trust)
2253 {
2254 	int idx;
2255 
2256 	/* If purpose not set use default */
2257 	if (!purpose)
2258 		purpose = def_purpose;
2259 	/* If we have a purpose then check it is valid */
2260 	if (purpose) {
2261 		X509_PURPOSE *ptmp;
2262 		idx = X509_PURPOSE_get_by_id(purpose);
2263 		if (idx == -1) {
2264 			X509error(X509_R_UNKNOWN_PURPOSE_ID);
2265 			return 0;
2266 		}
2267 		ptmp = X509_PURPOSE_get0(idx);
2268 		if (ptmp->trust == X509_TRUST_DEFAULT) {
2269 			idx = X509_PURPOSE_get_by_id(def_purpose);
2270 			if (idx == -1) {
2271 				X509error(X509_R_UNKNOWN_PURPOSE_ID);
2272 				return 0;
2273 			}
2274 			ptmp = X509_PURPOSE_get0(idx);
2275 		}
2276 		/* If trust not set then get from purpose default */
2277 		if (!trust)
2278 			trust = ptmp->trust;
2279 	}
2280 	if (trust) {
2281 		idx = X509_TRUST_get_by_id(trust);
2282 		if (idx == -1) {
2283 			X509error(X509_R_UNKNOWN_TRUST_ID);
2284 			return 0;
2285 		}
2286 	}
2287 
2288 	if (purpose && !ctx->param->purpose)
2289 		ctx->param->purpose = purpose;
2290 	if (trust && !ctx->param->trust)
2291 		ctx->param->trust = trust;
2292 	return 1;
2293 }
2294 
2295 X509_STORE_CTX *
2296 X509_STORE_CTX_new(void)
2297 {
2298 	X509_STORE_CTX *ctx;
2299 
2300 	ctx = calloc(1, sizeof(X509_STORE_CTX));
2301 	if (!ctx) {
2302 		X509error(ERR_R_MALLOC_FAILURE);
2303 		return NULL;
2304 	}
2305 	return ctx;
2306 }
2307 
2308 void
2309 X509_STORE_CTX_free(X509_STORE_CTX *ctx)
2310 {
2311 	if (ctx == NULL)
2312 		return;
2313 
2314 	X509_STORE_CTX_cleanup(ctx);
2315 	free(ctx);
2316 }
2317 
2318 int
2319 X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
2320     STACK_OF(X509) *chain)
2321 {
2322 	int param_ret = 1;
2323 
2324 	/*
2325 	 * Make sure everything is initialized properly even in case of an
2326 	 * early return due to an error.
2327 	 *
2328 	 * While this 'ctx' can be reused, X509_STORE_CTX_cleanup() will have
2329 	 * freed everything and memset ex_data anyway.  This also allows us
2330 	 * to safely use X509_STORE_CTX variables from the stack which will
2331 	 * have uninitialized data.
2332 	 */
2333 	memset(ctx, 0, sizeof(*ctx));
2334 
2335 	/*
2336 	 * Start with this set to not valid - it will be set to valid
2337 	 * in X509_verify_cert.
2338 	 */
2339 	ctx->error = X509_V_ERR_INVALID_CALL;
2340 
2341 	/*
2342 	 * Set values other than 0.  Keep this in the same order as
2343 	 * X509_STORE_CTX except for values that may fail.  All fields that
2344 	 * may fail should go last to make sure 'ctx' is as consistent as
2345 	 * possible even on early exits.
2346 	 */
2347 	ctx->ctx = store;
2348 	ctx->cert = x509;
2349 	ctx->untrusted = chain;
2350 
2351 	if (store && store->verify)
2352 		ctx->verify = store->verify;
2353 	else
2354 		ctx->verify = internal_verify;
2355 
2356 	if (store && store->verify_cb)
2357 		ctx->verify_cb = store->verify_cb;
2358 	else
2359 		ctx->verify_cb = null_callback;
2360 
2361 	if (store && store->get_issuer)
2362 		ctx->get_issuer = store->get_issuer;
2363 	else
2364 		ctx->get_issuer = X509_STORE_CTX_get1_issuer;
2365 
2366 	if (store && store->check_issued)
2367 		ctx->check_issued = store->check_issued;
2368 	else
2369 		ctx->check_issued = check_issued;
2370 
2371 	if (store && store->check_revocation)
2372 		ctx->check_revocation = store->check_revocation;
2373 	else
2374 		ctx->check_revocation = check_revocation;
2375 
2376 	if (store && store->get_crl)
2377 		ctx->get_crl = store->get_crl;
2378 	else
2379 		ctx->get_crl = NULL;
2380 
2381 	if (store && store->check_crl)
2382 		ctx->check_crl = store->check_crl;
2383 	else
2384 		ctx->check_crl = check_crl;
2385 
2386 	if (store && store->cert_crl)
2387 		ctx->cert_crl = store->cert_crl;
2388 	else
2389 		ctx->cert_crl = cert_crl;
2390 
2391 	ctx->check_policy = check_policy;
2392 
2393 	if (store && store->lookup_certs)
2394 		ctx->lookup_certs = store->lookup_certs;
2395 	else
2396 		ctx->lookup_certs = X509_STORE_get1_certs;
2397 
2398 	if (store && store->lookup_crls)
2399 		ctx->lookup_crls = store->lookup_crls;
2400 	else
2401 		ctx->lookup_crls = X509_STORE_get1_crls;
2402 
2403 	if (store && store->cleanup)
2404 		ctx->cleanup = store->cleanup;
2405 	else
2406 		ctx->cleanup = NULL;
2407 
2408 	ctx->param = X509_VERIFY_PARAM_new();
2409 	if (!ctx->param) {
2410 		X509error(ERR_R_MALLOC_FAILURE);
2411 		return 0;
2412 	}
2413 
2414 	/* Inherit callbacks and flags from X509_STORE if not set
2415 	 * use defaults.
2416 	 */
2417 	if (store)
2418 		param_ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
2419 	else
2420 		ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT|X509_VP_FLAG_ONCE;
2421 
2422 	if (param_ret)
2423 		param_ret = X509_VERIFY_PARAM_inherit(ctx->param,
2424 		    X509_VERIFY_PARAM_lookup("default"));
2425 
2426 	if (param_ret == 0) {
2427 		X509error(ERR_R_MALLOC_FAILURE);
2428 		return 0;
2429 	}
2430 
2431 	if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
2432 	    &(ctx->ex_data)) == 0) {
2433 		X509error(ERR_R_MALLOC_FAILURE);
2434 		return 0;
2435 	}
2436 	return 1;
2437 }
2438 
2439 /* Set alternative lookup method: just a STACK of trusted certificates.
2440  * This avoids X509_STORE nastiness where it isn't needed.
2441  */
2442 
2443 void
2444 X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2445 {
2446 	ctx->other_ctx = sk;
2447 	ctx->get_issuer = get_issuer_sk;
2448 }
2449 
2450 void
2451 X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2452 {
2453 	X509_STORE_CTX_trusted_stack(ctx, sk);
2454 }
2455 
2456 void
2457 X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
2458 {
2459 	if (ctx->cleanup)
2460 		ctx->cleanup(ctx);
2461 	if (ctx->param != NULL) {
2462 		if (ctx->parent == NULL)
2463 			X509_VERIFY_PARAM_free(ctx->param);
2464 		ctx->param = NULL;
2465 	}
2466 	if (ctx->tree != NULL) {
2467 		X509_policy_tree_free(ctx->tree);
2468 		ctx->tree = NULL;
2469 	}
2470 	if (ctx->chain != NULL) {
2471 		sk_X509_pop_free(ctx->chain, X509_free);
2472 		ctx->chain = NULL;
2473 	}
2474 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX,
2475 	    ctx, &(ctx->ex_data));
2476 	memset(&ctx->ex_data, 0, sizeof(CRYPTO_EX_DATA));
2477 }
2478 
2479 void
2480 X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
2481 {
2482 	X509_VERIFY_PARAM_set_depth(ctx->param, depth);
2483 }
2484 
2485 void
2486 X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
2487 {
2488 	X509_VERIFY_PARAM_set_flags(ctx->param, flags);
2489 }
2490 
2491 void
2492 X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, time_t t)
2493 {
2494 	X509_VERIFY_PARAM_set_time(ctx->param, t);
2495 }
2496 
2497 void
2498 X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
2499     int (*verify_cb)(int, X509_STORE_CTX *))
2500 {
2501 	ctx->verify_cb = verify_cb;
2502 }
2503 
2504 X509 *
2505 X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx)
2506 {
2507 	return ctx->cert;
2508 }
2509 
2510 STACK_OF(X509) *
2511 X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx)
2512 {
2513 	return ctx->untrusted;
2514 }
2515 
2516 void
2517 X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2518 {
2519 	ctx->untrusted = sk;
2520 }
2521 
2522 X509_POLICY_TREE *
2523 X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx)
2524 {
2525 	return ctx->tree;
2526 }
2527 
2528 int
2529 X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx)
2530 {
2531 	return ctx->explicit_policy;
2532 }
2533 
2534 int
2535 X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
2536 {
2537 	const X509_VERIFY_PARAM *param;
2538 	param = X509_VERIFY_PARAM_lookup(name);
2539 	if (!param)
2540 		return 0;
2541 	return X509_VERIFY_PARAM_inherit(ctx->param, param);
2542 }
2543 
2544 X509_VERIFY_PARAM *
2545 X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx)
2546 {
2547 	return ctx->param;
2548 }
2549 
2550 void
2551 X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
2552 {
2553 	if (ctx->param)
2554 		X509_VERIFY_PARAM_free(ctx->param);
2555 	ctx->param = param;
2556 }
2557