fuck! don't perform ssl handshake for blocked hosts!
[mediator.git] / src / libpolarssl / x509_crt.c
blobb94f2132228b123dd71282cc0d7fcdfb0dff0876
1 /*
2 * X.509 certificate parsing and verification
4 * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
6 * This file is part of mbed TLS (https://tls.mbed.org)
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 * The ITU-T X.509 standard defines a certificate format for PKI.
25 * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
26 * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
27 * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
29 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
30 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
33 #if !defined(POLARSSL_CONFIG_FILE)
34 #include "polarssl/config.h"
35 #else
36 #include POLARSSL_CONFIG_FILE
37 #endif
39 #if defined(POLARSSL_X509_CRT_PARSE_C)
41 #include "polarssl/x509_crt.h"
42 #include "polarssl/oid.h"
44 #include <stdio.h>
45 #include <string.h>
47 #if defined(POLARSSL_PEM_PARSE_C)
48 #include "polarssl/pem.h"
49 #endif
51 #if defined(POLARSSL_PLATFORM_C)
52 #include "polarssl/platform.h"
53 #else
54 #include <stdlib.h>
55 #define polarssl_free free
56 #define polarssl_malloc malloc
57 #define polarssl_snprintf snprintf
58 #endif
60 #if defined(POLARSSL_THREADING_C)
61 #include "polarssl/threading.h"
62 #endif
64 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
65 #include <windows.h>
66 #else
67 #include <time.h>
68 #endif
70 #if defined(POLARSSL_FS_IO)
71 #include <stdio.h>
72 #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
73 #include <sys/types.h>
74 #include <sys/stat.h>
75 #include <dirent.h>
76 #endif /* !_WIN32 || EFIX64 || EFI32 */
77 #endif
79 /* Implementation that should never be optimized out by the compiler */
80 static void polarssl_zeroize( void *v, size_t n ) {
81 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
85 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
87 static int x509_get_version( unsigned char **p,
88 const unsigned char *end,
89 int *ver )
91 int ret;
92 size_t len;
94 if( ( ret = asn1_get_tag( p, end, &len,
95 ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 0 ) ) != 0 )
97 if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
99 *ver = 0;
100 return( 0 );
103 return( ret );
106 end = *p + len;
108 if( ( ret = asn1_get_int( p, end, ver ) ) != 0 )
109 return( POLARSSL_ERR_X509_INVALID_VERSION + ret );
111 if( *p != end )
112 return( POLARSSL_ERR_X509_INVALID_VERSION +
113 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
115 return( 0 );
119 * Validity ::= SEQUENCE {
120 * notBefore Time,
121 * notAfter Time }
123 static int x509_get_dates( unsigned char **p,
124 const unsigned char *end,
125 x509_time *from,
126 x509_time *to )
128 int ret;
129 size_t len;
131 if( ( ret = asn1_get_tag( p, end, &len,
132 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
133 return( POLARSSL_ERR_X509_INVALID_DATE + ret );
135 end = *p + len;
137 if( ( ret = x509_get_time( p, end, from ) ) != 0 )
138 return( ret );
140 if( ( ret = x509_get_time( p, end, to ) ) != 0 )
141 return( ret );
143 if( *p != end )
144 return( POLARSSL_ERR_X509_INVALID_DATE +
145 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
147 return( 0 );
151 * X.509 v2/v3 unique identifier (not parsed)
153 static int x509_get_uid( unsigned char **p,
154 const unsigned char *end,
155 x509_buf *uid, int n )
157 int ret;
159 if( *p == end )
160 return( 0 );
162 uid->tag = **p;
164 if( ( ret = asn1_get_tag( p, end, &uid->len,
165 ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | n ) ) != 0 )
167 if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
168 return( 0 );
170 return( ret );
173 uid->p = *p;
174 *p += uid->len;
176 return( 0 );
179 static int x509_get_basic_constraints( unsigned char **p,
180 const unsigned char *end,
181 int *ca_istrue,
182 int *max_pathlen )
184 int ret;
185 size_t len;
188 * BasicConstraints ::= SEQUENCE {
189 * cA BOOLEAN DEFAULT FALSE,
190 * pathLenConstraint INTEGER (0..MAX) OPTIONAL }
192 *ca_istrue = 0; /* DEFAULT FALSE */
193 *max_pathlen = 0; /* endless */
195 if( ( ret = asn1_get_tag( p, end, &len,
196 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
197 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
199 if( *p == end )
200 return( 0 );
202 if( ( ret = asn1_get_bool( p, end, ca_istrue ) ) != 0 )
204 if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
205 ret = asn1_get_int( p, end, ca_istrue );
207 if( ret != 0 )
208 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
210 if( *ca_istrue != 0 )
211 *ca_istrue = 1;
214 if( *p == end )
215 return( 0 );
217 if( ( ret = asn1_get_int( p, end, max_pathlen ) ) != 0 )
218 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
220 if( *p != end )
221 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
222 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
224 (*max_pathlen)++;
226 return( 0 );
229 static int x509_get_ns_cert_type( unsigned char **p,
230 const unsigned char *end,
231 unsigned char *ns_cert_type)
233 int ret;
234 x509_bitstring bs = { 0, 0, NULL };
236 if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 )
237 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
239 if( bs.len != 1 )
240 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
241 POLARSSL_ERR_ASN1_INVALID_LENGTH );
243 /* Get actual bitstring */
244 *ns_cert_type = *bs.p;
245 return( 0 );
248 static int x509_get_key_usage( unsigned char **p,
249 const unsigned char *end,
250 unsigned char *key_usage)
252 int ret;
253 x509_bitstring bs = { 0, 0, NULL };
255 if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 )
256 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
258 if( bs.len < 1 )
259 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
260 POLARSSL_ERR_ASN1_INVALID_LENGTH );
262 /* Get actual bitstring */
263 *key_usage = *bs.p;
264 return( 0 );
268 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
270 * KeyPurposeId ::= OBJECT IDENTIFIER
272 static int x509_get_ext_key_usage( unsigned char **p,
273 const unsigned char *end,
274 x509_sequence *ext_key_usage)
276 int ret;
278 if( ( ret = asn1_get_sequence_of( p, end, ext_key_usage, ASN1_OID ) ) != 0 )
279 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
281 /* Sequence length must be >= 1 */
282 if( ext_key_usage->buf.p == NULL )
283 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
284 POLARSSL_ERR_ASN1_INVALID_LENGTH );
286 return( 0 );
290 * SubjectAltName ::= GeneralNames
292 * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
294 * GeneralName ::= CHOICE {
295 * otherName [0] OtherName,
296 * rfc822Name [1] IA5String,
297 * dNSName [2] IA5String,
298 * x400Address [3] ORAddress,
299 * directoryName [4] Name,
300 * ediPartyName [5] EDIPartyName,
301 * uniformResourceIdentifier [6] IA5String,
302 * iPAddress [7] OCTET STRING,
303 * registeredID [8] OBJECT IDENTIFIER }
305 * OtherName ::= SEQUENCE {
306 * type-id OBJECT IDENTIFIER,
307 * value [0] EXPLICIT ANY DEFINED BY type-id }
309 * EDIPartyName ::= SEQUENCE {
310 * nameAssigner [0] DirectoryString OPTIONAL,
311 * partyName [1] DirectoryString }
313 * NOTE: we only parse and use dNSName at this point.
315 static int x509_get_subject_alt_name( unsigned char **p,
316 const unsigned char *end,
317 x509_sequence *subject_alt_name )
319 int ret;
320 size_t len, tag_len;
321 asn1_buf *buf;
322 unsigned char tag;
323 asn1_sequence *cur = subject_alt_name;
325 /* Get main sequence tag */
326 if( ( ret = asn1_get_tag( p, end, &len,
327 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
328 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
330 if( *p + len != end )
331 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
332 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
334 while( *p < end )
336 if( ( end - *p ) < 1 )
337 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
338 POLARSSL_ERR_ASN1_OUT_OF_DATA );
340 tag = **p;
341 (*p)++;
342 if( ( ret = asn1_get_len( p, end, &tag_len ) ) != 0 )
343 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
345 if( ( tag & ASN1_CONTEXT_SPECIFIC ) != ASN1_CONTEXT_SPECIFIC )
346 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
347 POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
349 /* Skip everything but DNS name */
350 if( tag != ( ASN1_CONTEXT_SPECIFIC | 2 ) )
352 *p += tag_len;
353 continue;
356 /* Allocate and assign next pointer */
357 if( cur->buf.p != NULL )
359 if( cur->next != NULL )
360 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS );
362 cur->next = polarssl_malloc( sizeof( asn1_sequence ) );
364 if( cur->next == NULL )
365 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
366 POLARSSL_ERR_ASN1_MALLOC_FAILED );
368 memset( cur->next, 0, sizeof( asn1_sequence ) );
369 cur = cur->next;
372 buf = &(cur->buf);
373 buf->tag = tag;
374 buf->p = *p;
375 buf->len = tag_len;
376 *p += buf->len;
379 /* Set final sequence entry's next pointer to NULL */
380 cur->next = NULL;
382 if( *p != end )
383 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
384 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
386 return( 0 );
390 * X.509 v3 extensions
392 * TODO: Perform all of the basic constraints tests required by the RFC
393 * TODO: Set values for undetected extensions to a sane default?
396 static int x509_get_crt_ext( unsigned char **p,
397 const unsigned char *end,
398 x509_crt *crt )
400 int ret;
401 size_t len;
402 unsigned char *end_ext_data, *end_ext_octet;
404 if( ( ret = x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
406 if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
407 return( 0 );
409 return( ret );
412 while( *p < end )
415 * Extension ::= SEQUENCE {
416 * extnID OBJECT IDENTIFIER,
417 * critical BOOLEAN DEFAULT FALSE,
418 * extnValue OCTET STRING }
420 x509_buf extn_oid = {0, 0, NULL};
421 int is_critical = 0; /* DEFAULT FALSE */
422 int ext_type = 0;
424 if( ( ret = asn1_get_tag( p, end, &len,
425 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
426 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
428 end_ext_data = *p + len;
430 /* Get extension ID */
431 extn_oid.tag = **p;
433 if( ( ret = asn1_get_tag( p, end, &extn_oid.len, ASN1_OID ) ) != 0 )
434 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
436 extn_oid.p = *p;
437 *p += extn_oid.len;
439 if( ( end - *p ) < 1 )
440 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
441 POLARSSL_ERR_ASN1_OUT_OF_DATA );
443 /* Get optional critical */
444 if( ( ret = asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
445 ( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) )
446 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
448 /* Data should be octet string type */
449 if( ( ret = asn1_get_tag( p, end_ext_data, &len,
450 ASN1_OCTET_STRING ) ) != 0 )
451 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
453 end_ext_octet = *p + len;
455 if( end_ext_octet != end_ext_data )
456 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
457 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
460 * Detect supported extensions
462 ret = oid_get_x509_ext_type( &extn_oid, &ext_type );
464 if( ret != 0 )
466 /* No parser found, skip extension */
467 *p = end_ext_octet;
469 #if !defined(POLARSSL_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
470 if( is_critical )
472 /* Data is marked as critical: fail */
473 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
474 POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
476 #endif
477 continue;
480 /* Forbid repeated extensions */
481 if( ( crt->ext_types & ext_type ) != 0 )
482 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS );
484 crt->ext_types |= ext_type;
486 switch( ext_type )
488 case EXT_BASIC_CONSTRAINTS:
489 /* Parse basic constraints */
490 if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
491 &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
492 return( ret );
493 break;
495 case EXT_KEY_USAGE:
496 /* Parse key usage */
497 if( ( ret = x509_get_key_usage( p, end_ext_octet,
498 &crt->key_usage ) ) != 0 )
499 return( ret );
500 break;
502 case EXT_EXTENDED_KEY_USAGE:
503 /* Parse extended key usage */
504 if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
505 &crt->ext_key_usage ) ) != 0 )
506 return( ret );
507 break;
509 case EXT_SUBJECT_ALT_NAME:
510 /* Parse subject alt name */
511 if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
512 &crt->subject_alt_names ) ) != 0 )
513 return( ret );
514 break;
516 case EXT_NS_CERT_TYPE:
517 /* Parse netscape certificate type */
518 if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
519 &crt->ns_cert_type ) ) != 0 )
520 return( ret );
521 break;
523 default:
524 return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
528 if( *p != end )
529 return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
530 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
532 return( 0 );
536 * Parse and fill a single X.509 certificate in DER format
538 static int x509_crt_parse_der_core( x509_crt *crt, const unsigned char *buf,
539 size_t buflen )
541 int ret;
542 size_t len;
543 unsigned char *p, *end, *crt_end;
544 x509_buf sig_params1, sig_params2;
546 memset( &sig_params1, 0, sizeof( x509_buf ) );
547 memset( &sig_params2, 0, sizeof( x509_buf ) );
550 * Check for valid input
552 if( crt == NULL || buf == NULL )
553 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
555 p = polarssl_malloc( len = buflen );
557 if( p == NULL )
558 return( POLARSSL_ERR_X509_MALLOC_FAILED );
560 memcpy( p, buf, buflen );
562 crt->raw.p = p;
563 crt->raw.len = len;
564 end = p + len;
567 * Certificate ::= SEQUENCE {
568 * tbsCertificate TBSCertificate,
569 * signatureAlgorithm AlgorithmIdentifier,
570 * signatureValue BIT STRING }
572 if( ( ret = asn1_get_tag( &p, end, &len,
573 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
575 x509_crt_free( crt );
576 return( POLARSSL_ERR_X509_INVALID_FORMAT );
579 if( len > (size_t) ( end - p ) )
581 x509_crt_free( crt );
582 return( POLARSSL_ERR_X509_INVALID_FORMAT +
583 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
585 crt_end = p + len;
588 * TBSCertificate ::= SEQUENCE {
590 crt->tbs.p = p;
592 if( ( ret = asn1_get_tag( &p, end, &len,
593 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
595 x509_crt_free( crt );
596 return( POLARSSL_ERR_X509_INVALID_FORMAT + ret );
599 end = p + len;
600 crt->tbs.len = end - crt->tbs.p;
603 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
605 * CertificateSerialNumber ::= INTEGER
607 * signature AlgorithmIdentifier
609 if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 ||
610 ( ret = x509_get_serial( &p, end, &crt->serial ) ) != 0 ||
611 ( ret = x509_get_alg( &p, end, &crt->sig_oid1,
612 &sig_params1 ) ) != 0 )
614 x509_crt_free( crt );
615 return( ret );
618 crt->version++;
620 if( crt->version > 3 )
622 x509_crt_free( crt );
623 return( POLARSSL_ERR_X509_UNKNOWN_VERSION );
626 if( ( ret = x509_get_sig_alg( &crt->sig_oid1, &sig_params1,
627 &crt->sig_md, &crt->sig_pk,
628 &crt->sig_opts ) ) != 0 )
630 x509_crt_free( crt );
631 return( ret );
635 * issuer Name
637 crt->issuer_raw.p = p;
639 if( ( ret = asn1_get_tag( &p, end, &len,
640 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
642 x509_crt_free( crt );
643 return( POLARSSL_ERR_X509_INVALID_FORMAT + ret );
646 if( ( ret = x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
648 x509_crt_free( crt );
649 return( ret );
652 crt->issuer_raw.len = p - crt->issuer_raw.p;
655 * Validity ::= SEQUENCE {
656 * notBefore Time,
657 * notAfter Time }
660 if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
661 &crt->valid_to ) ) != 0 )
663 x509_crt_free( crt );
664 return( ret );
668 * subject Name
670 crt->subject_raw.p = p;
672 if( ( ret = asn1_get_tag( &p, end, &len,
673 ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
675 x509_crt_free( crt );
676 return( POLARSSL_ERR_X509_INVALID_FORMAT + ret );
679 if( len && ( ret = x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
681 x509_crt_free( crt );
682 return( ret );
685 crt->subject_raw.len = p - crt->subject_raw.p;
688 * SubjectPublicKeyInfo
690 if( ( ret = pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
692 x509_crt_free( crt );
693 return( ret );
697 * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
698 * -- If present, version shall be v2 or v3
699 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
700 * -- If present, version shall be v2 or v3
701 * extensions [3] EXPLICIT Extensions OPTIONAL
702 * -- If present, version shall be v3
704 if( crt->version == 2 || crt->version == 3 )
706 ret = x509_get_uid( &p, end, &crt->issuer_id, 1 );
707 if( ret != 0 )
709 x509_crt_free( crt );
710 return( ret );
714 if( crt->version == 2 || crt->version == 3 )
716 ret = x509_get_uid( &p, end, &crt->subject_id, 2 );
717 if( ret != 0 )
719 x509_crt_free( crt );
720 return( ret );
724 #if !defined(POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3)
725 if( crt->version == 3 )
727 #endif
728 ret = x509_get_crt_ext( &p, end, crt );
729 if( ret != 0 )
731 x509_crt_free( crt );
732 return( ret );
734 #if !defined(POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3)
736 #endif
738 if( p != end )
740 x509_crt_free( crt );
741 return( POLARSSL_ERR_X509_INVALID_FORMAT +
742 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
745 end = crt_end;
749 * -- end of TBSCertificate
751 * signatureAlgorithm AlgorithmIdentifier,
752 * signatureValue BIT STRING
754 if( ( ret = x509_get_alg( &p, end, &crt->sig_oid2, &sig_params2 ) ) != 0 )
756 x509_crt_free( crt );
757 return( ret );
760 if( crt->sig_oid1.len != crt->sig_oid2.len ||
761 memcmp( crt->sig_oid1.p, crt->sig_oid2.p, crt->sig_oid1.len ) != 0 ||
762 sig_params1.len != sig_params2.len ||
763 ( sig_params1.len != 0 &&
764 memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
766 x509_crt_free( crt );
767 return( POLARSSL_ERR_X509_SIG_MISMATCH );
770 if( ( ret = x509_get_sig( &p, end, &crt->sig ) ) != 0 )
772 x509_crt_free( crt );
773 return( ret );
776 if( p != end )
778 x509_crt_free( crt );
779 return( POLARSSL_ERR_X509_INVALID_FORMAT +
780 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
783 return( 0 );
787 * Parse one X.509 certificate in DER format from a buffer and add them to a
788 * chained list
790 int x509_crt_parse_der( x509_crt *chain, const unsigned char *buf,
791 size_t buflen )
793 int ret;
794 x509_crt *crt = chain, *prev = NULL;
797 * Check for valid input
799 if( crt == NULL || buf == NULL )
800 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
802 while( crt->version != 0 && crt->next != NULL )
804 prev = crt;
805 crt = crt->next;
809 * Add new certificate on the end of the chain if needed.
811 if( crt->version != 0 && crt->next == NULL )
813 crt->next = polarssl_malloc( sizeof( x509_crt ) );
815 if( crt->next == NULL )
816 return( POLARSSL_ERR_X509_MALLOC_FAILED );
818 prev = crt;
819 x509_crt_init( crt->next );
820 crt = crt->next;
823 if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
825 if( prev )
826 prev->next = NULL;
828 if( crt != chain )
829 polarssl_free( crt );
831 return( ret );
834 return( 0 );
838 * Parse one or more PEM certificates from a buffer and add them to the chained
839 * list
841 int x509_crt_parse( x509_crt *chain, const unsigned char *buf, size_t buflen )
843 int success = 0, first_error = 0, total_failed = 0;
844 int buf_format = X509_FORMAT_DER;
847 * Check for valid input
849 if( chain == NULL || buf == NULL )
850 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
853 * Determine buffer content. Buffer contains either one DER certificate or
854 * one or more PEM certificates.
856 #if defined(POLARSSL_PEM_PARSE_C)
857 if( strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
858 buf_format = X509_FORMAT_PEM;
859 #endif
861 if( buf_format == X509_FORMAT_DER )
862 return x509_crt_parse_der( chain, buf, buflen );
864 #if defined(POLARSSL_PEM_PARSE_C)
865 if( buf_format == X509_FORMAT_PEM )
867 int ret;
868 pem_context pem;
870 while( buflen > 0 )
872 size_t use_len;
873 pem_init( &pem );
875 ret = pem_read_buffer( &pem,
876 "-----BEGIN CERTIFICATE-----",
877 "-----END CERTIFICATE-----",
878 buf, NULL, 0, &use_len );
880 if( ret == 0 )
883 * Was PEM encoded
885 buflen -= use_len;
886 buf += use_len;
888 else if( ret == POLARSSL_ERR_PEM_BAD_INPUT_DATA )
890 return( ret );
892 else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
894 pem_free( &pem );
897 * PEM header and footer were found
899 buflen -= use_len;
900 buf += use_len;
902 if( first_error == 0 )
903 first_error = ret;
905 total_failed++;
906 continue;
908 else
909 break;
911 ret = x509_crt_parse_der( chain, pem.buf, pem.buflen );
913 pem_free( &pem );
915 if( ret != 0 )
918 * Quit parsing on a memory error
920 if( ret == POLARSSL_ERR_X509_MALLOC_FAILED )
921 return( ret );
923 if( first_error == 0 )
924 first_error = ret;
926 total_failed++;
927 continue;
930 success = 1;
933 #endif /* POLARSSL_PEM_PARSE_C */
935 if( success )
936 return( total_failed );
937 else if( first_error )
938 return( first_error );
939 else
940 return( POLARSSL_ERR_X509_CERT_UNKNOWN_FORMAT );
943 #if defined(POLARSSL_FS_IO)
945 * Load one or more certificates and add them to the chained list
947 int x509_crt_parse_file( x509_crt *chain, const char *path )
949 int ret;
950 size_t n;
951 unsigned char *buf;
953 if( ( ret = pk_load_file( path, &buf, &n ) ) != 0 )
954 return( ret );
956 ret = x509_crt_parse( chain, buf, n );
958 polarssl_zeroize( buf, n + 1 );
959 polarssl_free( buf );
961 return( ret );
964 #if defined(POLARSSL_THREADING_PTHREAD)
965 static threading_mutex_t readdir_mutex = PTHREAD_MUTEX_INITIALIZER;
966 #endif
968 int x509_crt_parse_path( x509_crt *chain, const char *path )
970 int ret = 0;
971 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
972 int w_ret;
973 WCHAR szDir[MAX_PATH];
974 char filename[MAX_PATH];
975 char *p;
976 int len = (int) strlen( path );
978 WIN32_FIND_DATAW file_data;
979 HANDLE hFind;
981 if( len > MAX_PATH - 3 )
982 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
984 memset( szDir, 0, sizeof(szDir) );
985 memset( filename, 0, MAX_PATH );
986 memcpy( filename, path, len );
987 filename[len++] = '\\';
988 p = filename + len;
989 filename[len++] = '*';
991 w_ret = MultiByteToWideChar( CP_ACP, 0, filename, len, szDir,
992 MAX_PATH - 3 );
993 if( w_ret == 0 )
994 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
996 hFind = FindFirstFileW( szDir, &file_data );
997 if( hFind == INVALID_HANDLE_VALUE )
998 return( POLARSSL_ERR_X509_FILE_IO_ERROR );
1000 len = MAX_PATH - len;
1003 memset( p, 0, len );
1005 if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
1006 continue;
1008 w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
1009 lstrlenW( file_data.cFileName ),
1010 p, len - 1,
1011 NULL, NULL );
1012 if( w_ret == 0 )
1013 return( POLARSSL_ERR_X509_FILE_IO_ERROR );
1015 w_ret = x509_crt_parse_file( chain, filename );
1016 if( w_ret < 0 )
1017 ret++;
1018 else
1019 ret += w_ret;
1021 while( FindNextFileW( hFind, &file_data ) != 0 );
1023 if( GetLastError() != ERROR_NO_MORE_FILES )
1024 ret = POLARSSL_ERR_X509_FILE_IO_ERROR;
1026 FindClose( hFind );
1027 #else /* _WIN32 */
1028 int t_ret;
1029 struct stat sb;
1030 struct dirent *entry;
1031 char entry_name[255];
1032 DIR *dir = opendir( path );
1034 if( dir == NULL )
1035 return( POLARSSL_ERR_X509_FILE_IO_ERROR );
1037 #if defined(POLARSSL_THREADING_PTHREAD)
1038 if( ( ret = polarssl_mutex_lock( &readdir_mutex ) ) != 0 )
1039 return( ret );
1040 #endif
1042 while( ( entry = readdir( dir ) ) != NULL )
1044 polarssl_snprintf( entry_name, sizeof entry_name, "%s/%s", path, entry->d_name );
1046 if( stat( entry_name, &sb ) == -1 )
1048 closedir( dir );
1049 ret = POLARSSL_ERR_X509_FILE_IO_ERROR;
1050 goto cleanup;
1053 if( !S_ISREG( sb.st_mode ) )
1054 continue;
1056 // Ignore parse errors
1058 t_ret = x509_crt_parse_file( chain, entry_name );
1059 if( t_ret < 0 )
1060 ret++;
1061 else
1062 ret += t_ret;
1064 closedir( dir );
1066 cleanup:
1067 #if defined(POLARSSL_THREADING_PTHREAD)
1068 if( polarssl_mutex_unlock( &readdir_mutex ) != 0 )
1069 ret = POLARSSL_ERR_THREADING_MUTEX_ERROR;
1070 #endif
1072 #endif /* _WIN32 */
1074 return( ret );
1076 #endif /* POLARSSL_FS_IO */
1078 #if defined(_MSC_VER) && !defined snprintf && !defined(EFIX64) && \
1079 !defined(EFI32)
1080 #include <stdarg.h>
1082 #if !defined vsnprintf
1083 #define vsnprintf _vsnprintf
1084 #endif // vsnprintf
1087 * Windows _snprintf and _vsnprintf are not compatible to linux versions.
1088 * Result value is not size of buffer needed, but -1 if no fit is possible.
1090 * This fuction tries to 'fix' this by at least suggesting enlarging the
1091 * size by 20.
1093 static int compat_snprintf( char *str, size_t size, const char *format, ... )
1095 va_list ap;
1096 int res = -1;
1098 va_start( ap, format );
1100 res = vsnprintf( str, size, format, ap );
1102 va_end( ap );
1104 // No quick fix possible
1105 if( res < 0 )
1106 return( (int) size + 20 );
1108 return( res );
1111 #define snprintf compat_snprintf
1112 #endif /* _MSC_VER && !snprintf && !EFIX64 && !EFI32 */
1114 #define POLARSSL_ERR_DEBUG_BUF_TOO_SMALL -2
1116 #define SAFE_SNPRINTF() \
1118 if( ret == -1 ) \
1119 return( -1 ); \
1121 if( (unsigned int) ret > n ) { \
1122 p[n - 1] = '\0'; \
1123 return( POLARSSL_ERR_DEBUG_BUF_TOO_SMALL ); \
1126 n -= (unsigned int) ret; \
1127 p += (unsigned int) ret; \
1130 static int x509_info_subject_alt_name( char **buf, size_t *size,
1131 const x509_sequence *subject_alt_name )
1133 size_t i;
1134 size_t n = *size;
1135 char *p = *buf;
1136 const x509_sequence *cur = subject_alt_name;
1137 const char *sep = "";
1138 size_t sep_len = 0;
1140 while( cur != NULL )
1142 if( cur->buf.len + sep_len >= n )
1144 *p = '\0';
1145 return( POLARSSL_ERR_DEBUG_BUF_TOO_SMALL );
1148 n -= cur->buf.len + sep_len;
1149 for( i = 0; i < sep_len; i++ )
1150 *p++ = sep[i];
1151 for( i = 0; i < cur->buf.len; i++ )
1152 *p++ = cur->buf.p[i];
1154 sep = ", ";
1155 sep_len = 2;
1157 cur = cur->next;
1160 *p = '\0';
1162 *size = n;
1163 *buf = p;
1165 return( 0 );
1168 #define PRINT_ITEM(i) \
1170 ret = polarssl_snprintf( p, n, "%s" i, sep ); \
1171 SAFE_SNPRINTF(); \
1172 sep = ", "; \
1175 #define CERT_TYPE(type,name) \
1176 if( ns_cert_type & type ) \
1177 PRINT_ITEM( name );
1179 static int x509_info_cert_type( char **buf, size_t *size,
1180 unsigned char ns_cert_type )
1182 int ret;
1183 size_t n = *size;
1184 char *p = *buf;
1185 const char *sep = "";
1187 CERT_TYPE( NS_CERT_TYPE_SSL_CLIENT, "SSL Client" );
1188 CERT_TYPE( NS_CERT_TYPE_SSL_SERVER, "SSL Server" );
1189 CERT_TYPE( NS_CERT_TYPE_EMAIL, "Email" );
1190 CERT_TYPE( NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing" );
1191 CERT_TYPE( NS_CERT_TYPE_RESERVED, "Reserved" );
1192 CERT_TYPE( NS_CERT_TYPE_SSL_CA, "SSL CA" );
1193 CERT_TYPE( NS_CERT_TYPE_EMAIL_CA, "Email CA" );
1194 CERT_TYPE( NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA" );
1196 *size = n;
1197 *buf = p;
1199 return( 0 );
1202 #define KEY_USAGE(code,name) \
1203 if( key_usage & code ) \
1204 PRINT_ITEM( name );
1206 static int x509_info_key_usage( char **buf, size_t *size,
1207 unsigned char key_usage )
1209 int ret;
1210 size_t n = *size;
1211 char *p = *buf;
1212 const char *sep = "";
1214 KEY_USAGE( KU_DIGITAL_SIGNATURE, "Digital Signature" );
1215 KEY_USAGE( KU_NON_REPUDIATION, "Non Repudiation" );
1216 KEY_USAGE( KU_KEY_ENCIPHERMENT, "Key Encipherment" );
1217 KEY_USAGE( KU_DATA_ENCIPHERMENT, "Data Encipherment" );
1218 KEY_USAGE( KU_KEY_AGREEMENT, "Key Agreement" );
1219 KEY_USAGE( KU_KEY_CERT_SIGN, "Key Cert Sign" );
1220 KEY_USAGE( KU_CRL_SIGN, "CRL Sign" );
1222 *size = n;
1223 *buf = p;
1225 return( 0 );
1228 static int x509_info_ext_key_usage( char **buf, size_t *size,
1229 const x509_sequence *extended_key_usage )
1231 int ret;
1232 const char *desc;
1233 size_t n = *size;
1234 char *p = *buf;
1235 const x509_sequence *cur = extended_key_usage;
1236 const char *sep = "";
1238 while( cur != NULL )
1240 if( oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
1241 desc = "???";
1243 ret = polarssl_snprintf( p, n, "%s%s", sep, desc );
1244 SAFE_SNPRINTF();
1246 sep = ", ";
1248 cur = cur->next;
1251 *size = n;
1252 *buf = p;
1254 return( 0 );
1258 * Return an informational string about the certificate.
1260 #define BEFORE_COLON 18
1261 #define BC "18"
1262 int x509_crt_info( char *buf, size_t size, const char *prefix,
1263 const x509_crt *crt )
1265 int ret;
1266 size_t n;
1267 char *p;
1268 char key_size_str[BEFORE_COLON];
1270 p = buf;
1271 n = size;
1273 ret = polarssl_snprintf( p, n, "%scert. version : %d\n",
1274 prefix, crt->version );
1275 SAFE_SNPRINTF();
1276 ret = polarssl_snprintf( p, n, "%sserial number : ",
1277 prefix );
1278 SAFE_SNPRINTF();
1280 ret = x509_serial_gets( p, n, &crt->serial );
1281 SAFE_SNPRINTF();
1283 ret = polarssl_snprintf( p, n, "\n%sissuer name : ", prefix );
1284 SAFE_SNPRINTF();
1285 ret = x509_dn_gets( p, n, &crt->issuer );
1286 SAFE_SNPRINTF();
1288 ret = polarssl_snprintf( p, n, "\n%ssubject name : ", prefix );
1289 SAFE_SNPRINTF();
1290 ret = x509_dn_gets( p, n, &crt->subject );
1291 SAFE_SNPRINTF();
1293 ret = polarssl_snprintf( p, n, "\n%sissued on : " \
1294 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1295 crt->valid_from.year, crt->valid_from.mon,
1296 crt->valid_from.day, crt->valid_from.hour,
1297 crt->valid_from.min, crt->valid_from.sec );
1298 SAFE_SNPRINTF();
1300 ret = polarssl_snprintf( p, n, "\n%sexpires on : " \
1301 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1302 crt->valid_to.year, crt->valid_to.mon,
1303 crt->valid_to.day, crt->valid_to.hour,
1304 crt->valid_to.min, crt->valid_to.sec );
1305 SAFE_SNPRINTF();
1307 ret = polarssl_snprintf( p, n, "\n%ssigned using : ", prefix );
1308 SAFE_SNPRINTF();
1310 ret = x509_sig_alg_gets( p, n, &crt->sig_oid1, crt->sig_pk,
1311 crt->sig_md, crt->sig_opts );
1312 SAFE_SNPRINTF();
1314 /* Key size */
1315 if( ( ret = x509_key_size_helper( key_size_str, BEFORE_COLON,
1316 pk_get_name( &crt->pk ) ) ) != 0 )
1318 return( ret );
1321 ret = polarssl_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
1322 (int) pk_get_size( &crt->pk ) );
1323 SAFE_SNPRINTF();
1326 * Optional extensions
1329 if( crt->ext_types & EXT_BASIC_CONSTRAINTS )
1331 ret = polarssl_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
1332 crt->ca_istrue ? "true" : "false" );
1333 SAFE_SNPRINTF();
1335 if( crt->max_pathlen > 0 )
1337 ret = polarssl_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
1338 SAFE_SNPRINTF();
1342 if( crt->ext_types & EXT_SUBJECT_ALT_NAME )
1344 ret = polarssl_snprintf( p, n, "\n%ssubject alt name : ", prefix );
1345 SAFE_SNPRINTF();
1347 if( ( ret = x509_info_subject_alt_name( &p, &n,
1348 &crt->subject_alt_names ) ) != 0 )
1349 return( ret );
1352 if( crt->ext_types & EXT_NS_CERT_TYPE )
1354 ret = polarssl_snprintf( p, n, "\n%scert. type : ", prefix );
1355 SAFE_SNPRINTF();
1357 if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
1358 return( ret );
1361 if( crt->ext_types & EXT_KEY_USAGE )
1363 ret = polarssl_snprintf( p, n, "\n%skey usage : ", prefix );
1364 SAFE_SNPRINTF();
1366 if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
1367 return( ret );
1370 if( crt->ext_types & EXT_EXTENDED_KEY_USAGE )
1372 ret = polarssl_snprintf( p, n, "\n%sext key usage : ", prefix );
1373 SAFE_SNPRINTF();
1375 if( ( ret = x509_info_ext_key_usage( &p, &n,
1376 &crt->ext_key_usage ) ) != 0 )
1377 return( ret );
1380 ret = polarssl_snprintf( p, n, "\n" );
1381 SAFE_SNPRINTF();
1383 return( (int) ( size - n ) );
1386 struct x509_crt_verify_string {
1387 int code;
1388 const char *string;
1391 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
1392 { BADCERT_EXPIRED, "The certificate validity has expired" },
1393 { BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)" },
1394 { BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN" },
1395 { BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA" },
1396 { BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA" },
1397 { BADCRL_EXPIRED, "The CRL is expired" },
1398 { BADCERT_MISSING, "Certificate was missing" },
1399 { BADCERT_SKIP_VERIFY, "Certificate verification was skipped" },
1400 { BADCERT_OTHER, "Other reason (can be used by verify callback)" },
1401 { BADCERT_FUTURE, "The certificate validity starts in the future" },
1402 { BADCRL_FUTURE, "The CRL is from the future" },
1403 { BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension" },
1404 { BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
1405 { BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension" },
1406 { 0, NULL }
1409 int x509_crt_verify_info( char *buf, size_t size, const char *prefix,
1410 int flags )
1412 int ret;
1413 const struct x509_crt_verify_string *cur;
1414 char *p = buf;
1415 size_t n = size;
1417 for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
1419 if( ( flags & cur->code ) == 0 )
1420 continue;
1422 ret = polarssl_snprintf( p, n, "%s%s\n", prefix, cur->string );
1423 SAFE_SNPRINTF();
1424 flags ^= cur->code;
1427 if( flags != 0 )
1429 ret = polarssl_snprintf( p, n, "%sUnknown reason "
1430 "(this should not happen)\n", prefix );
1431 SAFE_SNPRINTF();
1434 return( (int) ( size - n ) );
1437 #if defined(POLARSSL_X509_CHECK_KEY_USAGE)
1438 int x509_crt_check_key_usage( const x509_crt *crt, int usage )
1440 if( ( crt->ext_types & EXT_KEY_USAGE ) != 0 &&
1441 ( crt->key_usage & usage ) != usage )
1442 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
1444 return( 0 );
1446 #endif
1448 #if defined(POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE)
1449 int x509_crt_check_extended_key_usage( const x509_crt *crt,
1450 const char *usage_oid,
1451 size_t usage_len )
1453 const x509_sequence *cur;
1455 /* Extension is not mandatory, absent means no restriction */
1456 if( ( crt->ext_types & EXT_EXTENDED_KEY_USAGE ) == 0 )
1457 return( 0 );
1460 * Look for the requested usage (or wildcard ANY) in our list
1462 for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
1464 const x509_buf *cur_oid = &cur->buf;
1466 if( cur_oid->len == usage_len &&
1467 memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
1469 return( 0 );
1472 if( OID_CMP( OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) )
1473 return( 0 );
1476 return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
1478 #endif /* POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE */
1480 #if defined(POLARSSL_X509_CRL_PARSE_C)
1482 * Return 1 if the certificate is revoked, or 0 otherwise.
1484 int x509_crt_revoked( const x509_crt *crt, const x509_crl *crl )
1486 const x509_crl_entry *cur = &crl->entry;
1488 while( cur != NULL && cur->serial.len != 0 )
1490 if( crt->serial.len == cur->serial.len &&
1491 memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
1493 if( x509_time_expired( &cur->revocation_date ) )
1494 return( 1 );
1497 cur = cur->next;
1500 return( 0 );
1504 * Check that the given certificate is valid according to the CRL.
1506 static int x509_crt_verifycrl( x509_crt *crt, x509_crt *ca,
1507 x509_crl *crl_list)
1509 int flags = 0;
1510 unsigned char hash[POLARSSL_MD_MAX_SIZE];
1511 const md_info_t *md_info;
1513 if( ca == NULL )
1514 return( flags );
1517 * TODO: What happens if no CRL is present?
1518 * Suggestion: Revocation state should be unknown if no CRL is present.
1519 * For backwards compatibility this is not yet implemented.
1522 while( crl_list != NULL )
1524 if( crl_list->version == 0 ||
1525 crl_list->issuer_raw.len != ca->subject_raw.len ||
1526 memcmp( crl_list->issuer_raw.p, ca->subject_raw.p,
1527 crl_list->issuer_raw.len ) != 0 )
1529 crl_list = crl_list->next;
1530 continue;
1534 * Check if the CA is configured to sign CRLs
1536 #if defined(POLARSSL_X509_CHECK_KEY_USAGE)
1537 if( x509_crt_check_key_usage( ca, KU_CRL_SIGN ) != 0 )
1539 flags |= BADCRL_NOT_TRUSTED;
1540 break;
1542 #endif
1545 * Check if CRL is correctly signed by the trusted CA
1547 md_info = md_info_from_type( crl_list->sig_md );
1548 if( md_info == NULL )
1551 * Cannot check 'unknown' hash
1553 flags |= BADCRL_NOT_TRUSTED;
1554 break;
1557 md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash );
1559 if( pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
1560 crl_list->sig_md, hash, md_info->size,
1561 crl_list->sig.p, crl_list->sig.len ) != 0 )
1563 flags |= BADCRL_NOT_TRUSTED;
1564 break;
1568 * Check for validity of CRL (Do not drop out)
1570 if( x509_time_expired( &crl_list->next_update ) )
1571 flags |= BADCRL_EXPIRED;
1573 if( x509_time_future( &crl_list->this_update ) )
1574 flags |= BADCRL_FUTURE;
1577 * Check if certificate is revoked
1579 if( x509_crt_revoked( crt, crl_list ) )
1581 flags |= BADCERT_REVOKED;
1582 break;
1585 crl_list = crl_list->next;
1587 return( flags );
1589 #endif /* POLARSSL_X509_CRL_PARSE_C */
1592 * Like memcmp, but case-insensitive and always returns -1 if different
1594 static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
1596 size_t i;
1597 unsigned char diff;
1598 const unsigned char *n1 = s1, *n2 = s2;
1600 for( i = 0; i < len; i++ )
1602 diff = n1[i] ^ n2[i];
1604 if( diff == 0 )
1605 continue;
1607 if( diff == 32 &&
1608 ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
1609 ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
1611 continue;
1614 return( -1 );
1617 return( 0 );
1621 * Return 1 if match, 0 if not
1622 * TODO: inverted return value!
1624 static int x509_wildcard_verify( const char *cn, x509_buf *name )
1626 size_t i;
1627 size_t cn_idx = 0, cn_len = strlen( cn );
1629 if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' )
1630 return( 0 );
1632 for( i = 0; i < cn_len; ++i )
1634 if( cn[i] == '.' )
1636 cn_idx = i;
1637 break;
1641 if( cn_idx == 0 )
1642 return( 0 );
1644 if( cn_len - cn_idx == name->len - 1 &&
1645 x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 )
1647 return( 1 );
1650 return( 0 );
1654 * Compare two X.509 strings, case-insensitive, and allowing for some encoding
1655 * variations (but not all).
1657 * Return 0 if equal, -1 otherwise.
1659 static int x509_string_cmp( const x509_buf *a, const x509_buf *b )
1661 if( a->tag == b->tag &&
1662 a->len == b->len &&
1663 memcmp( a->p, b->p, b->len ) == 0 )
1665 return( 0 );
1668 if( ( a->tag == ASN1_UTF8_STRING || a->tag == ASN1_PRINTABLE_STRING ) &&
1669 ( b->tag == ASN1_UTF8_STRING || b->tag == ASN1_PRINTABLE_STRING ) &&
1670 a->len == b->len &&
1671 x509_memcasecmp( a->p, b->p, b->len ) == 0 )
1673 return( 0 );
1676 return( -1 );
1680 * Compare two X.509 Names (aka rdnSequence).
1682 * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
1683 * we sometimes return unequal when the full algorithm would return equal,
1684 * but never the other way. (In particular, we don't do Unicode normalisation
1685 * or space folding.)
1687 * Return 0 if equal, -1 otherwise.
1689 static int x509_name_cmp( const x509_name *a, const x509_name *b )
1691 /* Avoid recursion, it might not be optimised by the compiler */
1692 while( a != NULL || b != NULL )
1694 if( a == NULL || b == NULL )
1695 return( -1 );
1697 /* type */
1698 if( a->oid.tag != b->oid.tag ||
1699 a->oid.len != b->oid.len ||
1700 memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
1702 return( -1 );
1705 /* value */
1706 if( x509_string_cmp( &a->val, &b->val ) != 0 )
1707 return( -1 );
1709 /* structure of the list of sets */
1710 if( a->next_merged != b->next_merged )
1711 return( -1 );
1713 a = a->next;
1714 b = b->next;
1717 /* a == NULL == b */
1718 return( 0 );
1722 * Check if 'parent' is a suitable parent (signing CA) for 'child'.
1723 * Return 0 if yes, -1 if not.
1725 * top means parent is a locally-trusted certificate
1726 * bottom means child is the end entity cert
1728 static int x509_crt_check_parent( const x509_crt *child,
1729 const x509_crt *parent,
1730 int top, int bottom )
1732 int need_ca_bit;
1734 /* Parent must be the issuer */
1735 if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
1736 return( -1 );
1738 /* Parent must have the basicConstraints CA bit set as a general rule */
1739 need_ca_bit = 1;
1741 /* Exception: v1/v2 certificates that are locally trusted. */
1742 if( top && parent->version < 3 )
1743 need_ca_bit = 0;
1745 /* Exception: self-signed end-entity certs that are locally trusted. */
1746 if( top && bottom &&
1747 child->raw.len == parent->raw.len &&
1748 memcmp( child->raw.p, parent->raw.p, child->raw.len ) == 0 )
1750 need_ca_bit = 0;
1753 if( need_ca_bit && ! parent->ca_istrue )
1754 return( -1 );
1756 #if defined(POLARSSL_X509_CHECK_KEY_USAGE)
1757 if( need_ca_bit &&
1758 x509_crt_check_key_usage( parent, KU_KEY_CERT_SIGN ) != 0 )
1760 return( -1 );
1762 #endif
1764 return( 0 );
1767 static int x509_crt_verify_top(
1768 x509_crt *child, x509_crt *trust_ca,
1769 x509_crl *ca_crl, int path_cnt, int *flags,
1770 int (*f_vrfy)(void *, x509_crt *, int, int *),
1771 void *p_vrfy )
1773 int ret;
1774 int ca_flags = 0, check_path_cnt;
1775 unsigned char hash[POLARSSL_MD_MAX_SIZE];
1776 const md_info_t *md_info;
1778 if( x509_time_expired( &child->valid_to ) )
1779 *flags |= BADCERT_EXPIRED;
1781 if( x509_time_future( &child->valid_from ) )
1782 *flags |= BADCERT_FUTURE;
1785 * Child is the top of the chain. Check against the trust_ca list.
1787 *flags |= BADCERT_NOT_TRUSTED;
1789 md_info = md_info_from_type( child->sig_md );
1790 if( md_info == NULL )
1793 * Cannot check 'unknown', no need to try any CA
1795 trust_ca = NULL;
1797 else
1798 md( md_info, child->tbs.p, child->tbs.len, hash );
1800 for( /* trust_ca */ ; trust_ca != NULL; trust_ca = trust_ca->next )
1802 if( x509_crt_check_parent( child, trust_ca, 1, path_cnt == 0 ) != 0 )
1803 continue;
1805 check_path_cnt = path_cnt + 1;
1808 * Reduce check_path_cnt to check against if top of the chain is
1809 * the same as the trusted CA
1811 if( child->subject_raw.len == trust_ca->subject_raw.len &&
1812 memcmp( child->subject_raw.p, trust_ca->subject_raw.p,
1813 child->issuer_raw.len ) == 0 )
1815 check_path_cnt--;
1818 if( trust_ca->max_pathlen > 0 &&
1819 trust_ca->max_pathlen < check_path_cnt )
1821 continue;
1824 if( pk_verify_ext( child->sig_pk, child->sig_opts, &trust_ca->pk,
1825 child->sig_md, hash, md_info->size,
1826 child->sig.p, child->sig.len ) != 0 )
1828 continue;
1832 * Top of chain is signed by a trusted CA
1834 *flags &= ~BADCERT_NOT_TRUSTED;
1835 break;
1839 * If top of chain is not the same as the trusted CA send a verify request
1840 * to the callback for any issues with validity and CRL presence for the
1841 * trusted CA certificate.
1843 if( trust_ca != NULL &&
1844 ( child->subject_raw.len != trust_ca->subject_raw.len ||
1845 memcmp( child->subject_raw.p, trust_ca->subject_raw.p,
1846 child->issuer_raw.len ) != 0 ) )
1848 #if defined(POLARSSL_X509_CRL_PARSE_C)
1849 /* Check trusted CA's CRL for the chain's top crt */
1850 *flags |= x509_crt_verifycrl( child, trust_ca, ca_crl );
1851 #else
1852 ((void) ca_crl);
1853 #endif
1855 if( x509_time_expired( &trust_ca->valid_to ) )
1856 ca_flags |= BADCERT_EXPIRED;
1858 if( x509_time_future( &trust_ca->valid_from ) )
1859 ca_flags |= BADCERT_FUTURE;
1861 if( NULL != f_vrfy )
1863 if( ( ret = f_vrfy( p_vrfy, trust_ca, path_cnt + 1,
1864 &ca_flags ) ) != 0 )
1866 return( ret );
1871 /* Call callback on top cert */
1872 if( NULL != f_vrfy )
1874 if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 )
1875 return( ret );
1878 *flags |= ca_flags;
1880 return( 0 );
1883 static int x509_crt_verify_child(
1884 x509_crt *child, x509_crt *parent, x509_crt *trust_ca,
1885 x509_crl *ca_crl, int path_cnt, int *flags,
1886 int (*f_vrfy)(void *, x509_crt *, int, int *),
1887 void *p_vrfy )
1889 int ret;
1890 int parent_flags = 0;
1891 unsigned char hash[POLARSSL_MD_MAX_SIZE];
1892 x509_crt *grandparent;
1893 const md_info_t *md_info;
1895 /* path_cnt is 0 for the first intermediate CA */
1896 if( 1 + path_cnt > POLARSSL_X509_MAX_INTERMEDIATE_CA )
1898 *flags |= BADCERT_NOT_TRUSTED;
1899 return( POLARSSL_ERR_X509_CERT_VERIFY_FAILED );
1902 if( x509_time_expired( &child->valid_to ) )
1903 *flags |= BADCERT_EXPIRED;
1905 if( x509_time_future( &child->valid_from ) )
1906 *flags |= BADCERT_FUTURE;
1908 md_info = md_info_from_type( child->sig_md );
1909 if( md_info == NULL )
1912 * Cannot check 'unknown' hash
1914 *flags |= BADCERT_NOT_TRUSTED;
1916 else
1918 md( md_info, child->tbs.p, child->tbs.len, hash );
1920 if( pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
1921 child->sig_md, hash, md_info->size,
1922 child->sig.p, child->sig.len ) != 0 )
1924 *flags |= BADCERT_NOT_TRUSTED;
1928 #if defined(POLARSSL_X509_CRL_PARSE_C)
1929 /* Check trusted CA's CRL for the given crt */
1930 *flags |= x509_crt_verifycrl(child, parent, ca_crl);
1931 #endif
1933 /* Look for a grandparent upwards the chain */
1934 for( grandparent = parent->next;
1935 grandparent != NULL;
1936 grandparent = grandparent->next )
1938 if( x509_crt_check_parent( parent, grandparent,
1939 0, path_cnt == 0 ) == 0 )
1940 break;
1943 /* Is our parent part of the chain or at the top? */
1944 if( grandparent != NULL )
1946 ret = x509_crt_verify_child( parent, grandparent, trust_ca, ca_crl,
1947 path_cnt + 1, &parent_flags, f_vrfy, p_vrfy );
1948 if( ret != 0 )
1949 return( ret );
1951 else
1953 ret = x509_crt_verify_top( parent, trust_ca, ca_crl,
1954 path_cnt + 1, &parent_flags, f_vrfy, p_vrfy );
1955 if( ret != 0 )
1956 return( ret );
1959 /* child is verified to be a child of the parent, call verify callback */
1960 if( NULL != f_vrfy )
1961 if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 )
1962 return( ret );
1964 *flags |= parent_flags;
1966 return( 0 );
1970 * Verify the certificate validity
1972 int x509_crt_verify( x509_crt *crt,
1973 x509_crt *trust_ca,
1974 x509_crl *ca_crl,
1975 const char *cn, int *flags,
1976 int (*f_vrfy)(void *, x509_crt *, int, int *),
1977 void *p_vrfy )
1979 size_t cn_len;
1980 int ret;
1981 int pathlen = 0;
1982 x509_crt *parent;
1983 x509_name *name;
1984 x509_sequence *cur = NULL;
1986 *flags = 0;
1988 if( cn != NULL )
1990 name = &crt->subject;
1991 cn_len = strlen( cn );
1993 if( crt->ext_types & EXT_SUBJECT_ALT_NAME )
1995 cur = &crt->subject_alt_names;
1997 while( cur != NULL )
1999 if( cur->buf.len == cn_len &&
2000 x509_memcasecmp( cn, cur->buf.p, cn_len ) == 0 )
2001 break;
2003 if( cur->buf.len > 2 &&
2004 memcmp( cur->buf.p, "*.", 2 ) == 0 &&
2005 x509_wildcard_verify( cn, &cur->buf ) )
2006 break;
2008 cur = cur->next;
2011 if( cur == NULL )
2012 *flags |= BADCERT_CN_MISMATCH;
2014 else
2016 while( name != NULL )
2018 if( OID_CMP( OID_AT_CN, &name->oid ) )
2020 if( name->val.len == cn_len &&
2021 x509_memcasecmp( name->val.p, cn, cn_len ) == 0 )
2022 break;
2024 if( name->val.len > 2 &&
2025 memcmp( name->val.p, "*.", 2 ) == 0 &&
2026 x509_wildcard_verify( cn, &name->val ) )
2027 break;
2030 name = name->next;
2033 if( name == NULL )
2034 *flags |= BADCERT_CN_MISMATCH;
2038 /* Look for a parent upwards the chain */
2039 for( parent = crt->next; parent != NULL; parent = parent->next )
2041 if( x509_crt_check_parent( crt, parent, 0, pathlen == 0 ) == 0 )
2042 break;
2045 /* Are we part of the chain or at the top? */
2046 if( parent != NULL )
2048 ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl,
2049 pathlen, flags, f_vrfy, p_vrfy );
2050 if( ret != 0 )
2051 return( ret );
2053 else
2055 ret = x509_crt_verify_top( crt, trust_ca, ca_crl,
2056 pathlen, flags, f_vrfy, p_vrfy );
2057 if( ret != 0 )
2058 return( ret );
2061 if( *flags != 0 )
2062 return( POLARSSL_ERR_X509_CERT_VERIFY_FAILED );
2064 return( 0 );
2068 * Initialize a certificate chain
2070 void x509_crt_init( x509_crt *crt )
2072 memset( crt, 0, sizeof(x509_crt) );
2076 * Unallocate all certificate data
2078 void x509_crt_free( x509_crt *crt )
2080 x509_crt *cert_cur = crt;
2081 x509_crt *cert_prv;
2082 x509_name *name_cur;
2083 x509_name *name_prv;
2084 x509_sequence *seq_cur;
2085 x509_sequence *seq_prv;
2087 if( crt == NULL )
2088 return;
2092 pk_free( &cert_cur->pk );
2094 #if defined(POLARSSL_X509_RSASSA_PSS_SUPPORT)
2095 polarssl_free( cert_cur->sig_opts );
2096 #endif
2098 name_cur = cert_cur->issuer.next;
2099 while( name_cur != NULL )
2101 name_prv = name_cur;
2102 name_cur = name_cur->next;
2103 polarssl_zeroize( name_prv, sizeof( x509_name ) );
2104 polarssl_free( name_prv );
2107 name_cur = cert_cur->subject.next;
2108 while( name_cur != NULL )
2110 name_prv = name_cur;
2111 name_cur = name_cur->next;
2112 polarssl_zeroize( name_prv, sizeof( x509_name ) );
2113 polarssl_free( name_prv );
2116 seq_cur = cert_cur->ext_key_usage.next;
2117 while( seq_cur != NULL )
2119 seq_prv = seq_cur;
2120 seq_cur = seq_cur->next;
2121 polarssl_zeroize( seq_prv, sizeof( x509_sequence ) );
2122 polarssl_free( seq_prv );
2125 seq_cur = cert_cur->subject_alt_names.next;
2126 while( seq_cur != NULL )
2128 seq_prv = seq_cur;
2129 seq_cur = seq_cur->next;
2130 polarssl_zeroize( seq_prv, sizeof( x509_sequence ) );
2131 polarssl_free( seq_prv );
2134 if( cert_cur->raw.p != NULL )
2136 polarssl_zeroize( cert_cur->raw.p, cert_cur->raw.len );
2137 polarssl_free( cert_cur->raw.p );
2140 cert_cur = cert_cur->next;
2142 while( cert_cur != NULL );
2144 cert_cur = crt;
2147 cert_prv = cert_cur;
2148 cert_cur = cert_cur->next;
2150 polarssl_zeroize( cert_prv, sizeof( x509_crt ) );
2151 if( cert_prv != crt )
2152 polarssl_free( cert_prv );
2154 while( cert_cur != NULL );
2157 #endif /* POLARSSL_X509_CRT_PARSE_C */