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move from polarssl to mbedtls (#708)
[proxmark3-svn] / common / mbedtls / x509_crt.c
1 /*
2 * X.509 certificate parsing and verification
3 *
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: GPL-2.0
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * This file is part of mbed TLS (https://tls.mbed.org)
22 */
23 /*
24 * The ITU-T X.509 standard defines a certificate format for PKI.
25 *
26 * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
27 * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
28 * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
29 *
30 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
31 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
32 *
33 * [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf
34 */
35
36 #if !defined(MBEDTLS_CONFIG_FILE)
37 #include "mbedtls/config.h"
38 #else
39 #include MBEDTLS_CONFIG_FILE
40 #endif
41
42 #if defined(MBEDTLS_X509_CRT_PARSE_C)
43
44 #include "mbedtls/x509_crt.h"
45 #include "mbedtls/oid.h"
46 #include "mbedtls/platform_util.h"
47
48 #include <stdio.h>
49 #include <string.h>
50
51 #if defined(MBEDTLS_PEM_PARSE_C)
52 #include "mbedtls/pem.h"
53 #endif
54
55 #if defined(MBEDTLS_PLATFORM_C)
56 #include "mbedtls/platform.h"
57 #else
58 #include <stdlib.h>
59 #define mbedtls_free free
60 #define mbedtls_calloc calloc
61 #define mbedtls_snprintf snprintf
62 #endif
63
64 #if defined(MBEDTLS_THREADING_C)
65 #include "mbedtls/threading.h"
66 #endif
67
68 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
69 #include <windows.h>
70 #else
71 #include <time.h>
72 #endif
73
74 #if defined(MBEDTLS_FS_IO)
75 #include <stdio.h>
76 #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
77 #include <sys/types.h>
78 #include <sys/stat.h>
79 #include <dirent.h>
80 #endif /* !_WIN32 || EFIX64 || EFI32 */
81 #endif
82
83 /*
84 * Item in a verification chain: cert and flags for it
85 */
86 typedef struct {
87 mbedtls_x509_crt *crt;
88 uint32_t flags;
89 } x509_crt_verify_chain_item;
90
91 /*
92 * Max size of verification chain: end-entity + intermediates + trusted root
93 */
94 #define X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )
95
96 /*
97 * Default profile
98 */
99 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
100 {
101 #if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
102 /* Allow SHA-1 (weak, but still safe in controlled environments) */
103 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
104 #endif
105 /* Only SHA-2 hashes */
106 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
107 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
108 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
109 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
110 0xFFFFFFF, /* Any PK alg */
111 0xFFFFFFF, /* Any curve */
112 2048,
113 };
114
115 /*
116 * Next-default profile
117 */
118 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next =
119 {
120 /* Hashes from SHA-256 and above */
121 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
122 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
123 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
124 0xFFFFFFF, /* Any PK alg */
125 #if defined(MBEDTLS_ECP_C)
126 /* Curves at or above 128-bit security level */
127 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
128 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ) |
129 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP521R1 ) |
130 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP256R1 ) |
131 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP384R1 ) |
132 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP512R1 ) |
133 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256K1 ),
134 #else
135 0,
136 #endif
137 2048,
138 };
139
140 /*
141 * NSA Suite B Profile
142 */
143 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb =
144 {
145 /* Only SHA-256 and 384 */
146 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
147 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ),
148 /* Only ECDSA */
149 MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECDSA ) |
150 MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECKEY ),
151 #if defined(MBEDTLS_ECP_C)
152 /* Only NIST P-256 and P-384 */
153 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
154 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ),
155 #else
156 0,
157 #endif
158 0,
159 };
160
161 /*
162 * Check md_alg against profile
163 * Return 0 if md_alg is acceptable for this profile, -1 otherwise
164 */
165 static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile,
166 mbedtls_md_type_t md_alg )
167 {
168 if( md_alg == MBEDTLS_MD_NONE )
169 return( -1 );
170
171 if( ( profile->allowed_mds & MBEDTLS_X509_ID_FLAG( md_alg ) ) != 0 )
172 return( 0 );
173
174 return( -1 );
175 }
176
177 /*
178 * Check pk_alg against profile
179 * Return 0 if pk_alg is acceptable for this profile, -1 otherwise
180 */
181 static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile,
182 mbedtls_pk_type_t pk_alg )
183 {
184 if( pk_alg == MBEDTLS_PK_NONE )
185 return( -1 );
186
187 if( ( profile->allowed_pks & MBEDTLS_X509_ID_FLAG( pk_alg ) ) != 0 )
188 return( 0 );
189
190 return( -1 );
191 }
192
193 /*
194 * Check key against profile
195 * Return 0 if pk is acceptable for this profile, -1 otherwise
196 */
197 static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile,
198 const mbedtls_pk_context *pk )
199 {
200 const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type( pk );
201
202 #if defined(MBEDTLS_RSA_C)
203 if( pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS )
204 {
205 if( mbedtls_pk_get_bitlen( pk ) >= profile->rsa_min_bitlen )
206 return( 0 );
207
208 return( -1 );
209 }
210 #endif
211
212 #if defined(MBEDTLS_ECP_C)
213 if( pk_alg == MBEDTLS_PK_ECDSA ||
214 pk_alg == MBEDTLS_PK_ECKEY ||
215 pk_alg == MBEDTLS_PK_ECKEY_DH )
216 {
217 const mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id;
218
219 if( gid == MBEDTLS_ECP_DP_NONE )
220 return( -1 );
221
222 if( ( profile->allowed_curves & MBEDTLS_X509_ID_FLAG( gid ) ) != 0 )
223 return( 0 );
224
225 return( -1 );
226 }
227 #endif
228
229 return( -1 );
230 }
231
232 /*
233 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
234 */
235 static int x509_get_version( unsigned char **p,
236 const unsigned char *end,
237 int *ver )
238 {
239 int ret;
240 size_t len;
241
242 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
243 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) != 0 )
244 {
245 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
246 {
247 *ver = 0;
248 return( 0 );
249 }
250
251 return( ret );
252 }
253
254 end = *p + len;
255
256 if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
257 return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
258
259 if( *p != end )
260 return( MBEDTLS_ERR_X509_INVALID_VERSION +
261 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
262
263 return( 0 );
264 }
265
266 /*
267 * Validity ::= SEQUENCE {
268 * notBefore Time,
269 * notAfter Time }
270 */
271 static int x509_get_dates( unsigned char **p,
272 const unsigned char *end,
273 mbedtls_x509_time *from,
274 mbedtls_x509_time *to )
275 {
276 int ret;
277 size_t len;
278
279 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
280 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
281 return( MBEDTLS_ERR_X509_INVALID_DATE + ret );
282
283 end = *p + len;
284
285 if( ( ret = mbedtls_x509_get_time( p, end, from ) ) != 0 )
286 return( ret );
287
288 if( ( ret = mbedtls_x509_get_time( p, end, to ) ) != 0 )
289 return( ret );
290
291 if( *p != end )
292 return( MBEDTLS_ERR_X509_INVALID_DATE +
293 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
294
295 return( 0 );
296 }
297
298 /*
299 * X.509 v2/v3 unique identifier (not parsed)
300 */
301 static int x509_get_uid( unsigned char **p,
302 const unsigned char *end,
303 mbedtls_x509_buf *uid, int n )
304 {
305 int ret;
306
307 if( *p == end )
308 return( 0 );
309
310 uid->tag = **p;
311
312 if( ( ret = mbedtls_asn1_get_tag( p, end, &uid->len,
313 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n ) ) != 0 )
314 {
315 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
316 return( 0 );
317
318 return( ret );
319 }
320
321 uid->p = *p;
322 *p += uid->len;
323
324 return( 0 );
325 }
326
327 static int x509_get_basic_constraints( unsigned char **p,
328 const unsigned char *end,
329 int *ca_istrue,
330 int *max_pathlen )
331 {
332 int ret;
333 size_t len;
334
335 /*
336 * BasicConstraints ::= SEQUENCE {
337 * cA BOOLEAN DEFAULT FALSE,
338 * pathLenConstraint INTEGER (0..MAX) OPTIONAL }
339 */
340 *ca_istrue = 0; /* DEFAULT FALSE */
341 *max_pathlen = 0; /* endless */
342
343 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
344 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
345 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
346
347 if( *p == end )
348 return( 0 );
349
350 if( ( ret = mbedtls_asn1_get_bool( p, end, ca_istrue ) ) != 0 )
351 {
352 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
353 ret = mbedtls_asn1_get_int( p, end, ca_istrue );
354
355 if( ret != 0 )
356 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
357
358 if( *ca_istrue != 0 )
359 *ca_istrue = 1;
360 }
361
362 if( *p == end )
363 return( 0 );
364
365 if( ( ret = mbedtls_asn1_get_int( p, end, max_pathlen ) ) != 0 )
366 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
367
368 if( *p != end )
369 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
370 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
371
372 (*max_pathlen)++;
373
374 return( 0 );
375 }
376
377 static int x509_get_ns_cert_type( unsigned char **p,
378 const unsigned char *end,
379 unsigned char *ns_cert_type)
380 {
381 int ret;
382 mbedtls_x509_bitstring bs = { 0, 0, NULL };
383
384 if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
385 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
386
387 if( bs.len != 1 )
388 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
389 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
390
391 /* Get actual bitstring */
392 *ns_cert_type = *bs.p;
393 return( 0 );
394 }
395
396 static int x509_get_key_usage( unsigned char **p,
397 const unsigned char *end,
398 unsigned int *key_usage)
399 {
400 int ret;
401 size_t i;
402 mbedtls_x509_bitstring bs = { 0, 0, NULL };
403
404 if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
405 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
406
407 if( bs.len < 1 )
408 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
409 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
410
411 /* Get actual bitstring */
412 *key_usage = 0;
413 for( i = 0; i < bs.len && i < sizeof( unsigned int ); i++ )
414 {
415 *key_usage |= (unsigned int) bs.p[i] << (8*i);
416 }
417
418 return( 0 );
419 }
420
421 /*
422 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
423 *
424 * KeyPurposeId ::= OBJECT IDENTIFIER
425 */
426 static int x509_get_ext_key_usage( unsigned char **p,
427 const unsigned char *end,
428 mbedtls_x509_sequence *ext_key_usage)
429 {
430 int ret;
431
432 if( ( ret = mbedtls_asn1_get_sequence_of( p, end, ext_key_usage, MBEDTLS_ASN1_OID ) ) != 0 )
433 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
434
435 /* Sequence length must be >= 1 */
436 if( ext_key_usage->buf.p == NULL )
437 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
438 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
439
440 return( 0 );
441 }
442
443 /*
444 * SubjectAltName ::= GeneralNames
445 *
446 * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
447 *
448 * GeneralName ::= CHOICE {
449 * otherName [0] OtherName,
450 * rfc822Name [1] IA5String,
451 * dNSName [2] IA5String,
452 * x400Address [3] ORAddress,
453 * directoryName [4] Name,
454 * ediPartyName [5] EDIPartyName,
455 * uniformResourceIdentifier [6] IA5String,
456 * iPAddress [7] OCTET STRING,
457 * registeredID [8] OBJECT IDENTIFIER }
458 *
459 * OtherName ::= SEQUENCE {
460 * type-id OBJECT IDENTIFIER,
461 * value [0] EXPLICIT ANY DEFINED BY type-id }
462 *
463 * EDIPartyName ::= SEQUENCE {
464 * nameAssigner [0] DirectoryString OPTIONAL,
465 * partyName [1] DirectoryString }
466 *
467 * NOTE: we only parse and use dNSName at this point.
468 */
469 static int x509_get_subject_alt_name( unsigned char **p,
470 const unsigned char *end,
471 mbedtls_x509_sequence *subject_alt_name )
472 {
473 int ret;
474 size_t len, tag_len;
475 mbedtls_asn1_buf *buf;
476 unsigned char tag;
477 mbedtls_asn1_sequence *cur = subject_alt_name;
478
479 /* Get main sequence tag */
480 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
481 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
482 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
483
484 if( *p + len != end )
485 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
486 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
487
488 while( *p < end )
489 {
490 if( ( end - *p ) < 1 )
491 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
492 MBEDTLS_ERR_ASN1_OUT_OF_DATA );
493
494 tag = **p;
495 (*p)++;
496 if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 )
497 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
498
499 if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) !=
500 MBEDTLS_ASN1_CONTEXT_SPECIFIC )
501 {
502 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
503 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
504 }
505
506 /* Skip everything but DNS name */
507 if( tag != ( MBEDTLS_ASN1_CONTEXT_SPECIFIC | 2 ) )
508 {
509 *p += tag_len;
510 continue;
511 }
512
513 /* Allocate and assign next pointer */
514 if( cur->buf.p != NULL )
515 {
516 if( cur->next != NULL )
517 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
518
519 cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) );
520
521 if( cur->next == NULL )
522 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
523 MBEDTLS_ERR_ASN1_ALLOC_FAILED );
524
525 cur = cur->next;
526 }
527
528 buf = &(cur->buf);
529 buf->tag = tag;
530 buf->p = *p;
531 buf->len = tag_len;
532 *p += buf->len;
533 }
534
535 /* Set final sequence entry's next pointer to NULL */
536 cur->next = NULL;
537
538 if( *p != end )
539 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
540 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
541
542 return( 0 );
543 }
544
545 /*
546 * X.509 v3 extensions
547 *
548 */
549 static int x509_get_crt_ext( unsigned char **p,
550 const unsigned char *end,
551 mbedtls_x509_crt *crt )
552 {
553 int ret;
554 size_t len;
555 unsigned char *end_ext_data, *end_ext_octet;
556
557 if( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
558 {
559 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
560 return( 0 );
561
562 return( ret );
563 }
564
565 while( *p < end )
566 {
567 /*
568 * Extension ::= SEQUENCE {
569 * extnID OBJECT IDENTIFIER,
570 * critical BOOLEAN DEFAULT FALSE,
571 * extnValue OCTET STRING }
572 */
573 mbedtls_x509_buf extn_oid = {0, 0, NULL};
574 int is_critical = 0; /* DEFAULT FALSE */
575 int ext_type = 0;
576
577 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
578 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
579 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
580
581 end_ext_data = *p + len;
582
583 /* Get extension ID */
584 if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &extn_oid.len,
585 MBEDTLS_ASN1_OID ) ) != 0 )
586 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
587
588 extn_oid.tag = MBEDTLS_ASN1_OID;
589 extn_oid.p = *p;
590 *p += extn_oid.len;
591
592 /* Get optional critical */
593 if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
594 ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
595 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
596
597 /* Data should be octet string type */
598 if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
599 MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
600 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
601
602 end_ext_octet = *p + len;
603
604 if( end_ext_octet != end_ext_data )
605 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
606 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
607
608 /*
609 * Detect supported extensions
610 */
611 ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type );
612
613 if( ret != 0 )
614 {
615 /* No parser found, skip extension */
616 *p = end_ext_octet;
617
618 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
619 if( is_critical )
620 {
621 /* Data is marked as critical: fail */
622 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
623 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
624 }
625 #endif
626 continue;
627 }
628
629 /* Forbid repeated extensions */
630 if( ( crt->ext_types & ext_type ) != 0 )
631 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
632
633 crt->ext_types |= ext_type;
634
635 switch( ext_type )
636 {
637 case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
638 /* Parse basic constraints */
639 if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
640 &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
641 return( ret );
642 break;
643
644 case MBEDTLS_X509_EXT_KEY_USAGE:
645 /* Parse key usage */
646 if( ( ret = x509_get_key_usage( p, end_ext_octet,
647 &crt->key_usage ) ) != 0 )
648 return( ret );
649 break;
650
651 case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
652 /* Parse extended key usage */
653 if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
654 &crt->ext_key_usage ) ) != 0 )
655 return( ret );
656 break;
657
658 case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
659 /* Parse subject alt name */
660 if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
661 &crt->subject_alt_names ) ) != 0 )
662 return( ret );
663 break;
664
665 case MBEDTLS_X509_EXT_NS_CERT_TYPE:
666 /* Parse netscape certificate type */
667 if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
668 &crt->ns_cert_type ) ) != 0 )
669 return( ret );
670 break;
671
672 default:
673 return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
674 }
675 }
676
677 if( *p != end )
678 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
679 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
680
681 return( 0 );
682 }
683
684 /*
685 * Parse and fill a single X.509 certificate in DER format
686 */
687 static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *buf,
688 size_t buflen )
689 {
690 int ret;
691 size_t len;
692 unsigned char *p, *end, *crt_end;
693 mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
694
695 memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) );
696 memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) );
697 memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) );
698
699 /*
700 * Check for valid input
701 */
702 if( crt == NULL || buf == NULL )
703 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
704
705 // Use the original buffer until we figure out actual length
706 p = (unsigned char*) buf;
707 len = buflen;
708 end = p + len;
709
710 /*
711 * Certificate ::= SEQUENCE {
712 * tbsCertificate TBSCertificate,
713 * signatureAlgorithm AlgorithmIdentifier,
714 * signatureValue BIT STRING }
715 */
716 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
717 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
718 {
719 mbedtls_x509_crt_free( crt );
720 return( MBEDTLS_ERR_X509_INVALID_FORMAT );
721 }
722
723 if( len > (size_t) ( end - p ) )
724 {
725 mbedtls_x509_crt_free( crt );
726 return( MBEDTLS_ERR_X509_INVALID_FORMAT +
727 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
728 }
729 crt_end = p + len;
730
731 // Create and populate a new buffer for the raw field
732 crt->raw.len = crt_end - buf;
733 crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
734 if( p == NULL )
735 return( MBEDTLS_ERR_X509_ALLOC_FAILED );
736
737 memcpy( p, buf, crt->raw.len );
738
739 // Direct pointers to the new buffer
740 p += crt->raw.len - len;
741 end = crt_end = p + len;
742
743 /*
744 * TBSCertificate ::= SEQUENCE {
745 */
746 crt->tbs.p = p;
747
748 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
749 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
750 {
751 mbedtls_x509_crt_free( crt );
752 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
753 }
754
755 end = p + len;
756 crt->tbs.len = end - crt->tbs.p;
757
758 /*
759 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
760 *
761 * CertificateSerialNumber ::= INTEGER
762 *
763 * signature AlgorithmIdentifier
764 */
765 if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 ||
766 ( ret = mbedtls_x509_get_serial( &p, end, &crt->serial ) ) != 0 ||
767 ( ret = mbedtls_x509_get_alg( &p, end, &crt->sig_oid,
768 &sig_params1 ) ) != 0 )
769 {
770 mbedtls_x509_crt_free( crt );
771 return( ret );
772 }
773
774 if( crt->version < 0 || crt->version > 2 )
775 {
776 mbedtls_x509_crt_free( crt );
777 return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
778 }
779
780 crt->version++;
781
782 if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1,
783 &crt->sig_md, &crt->sig_pk,
784 &crt->sig_opts ) ) != 0 )
785 {
786 mbedtls_x509_crt_free( crt );
787 return( ret );
788 }
789
790 /*
791 * issuer Name
792 */
793 crt->issuer_raw.p = p;
794
795 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
796 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
797 {
798 mbedtls_x509_crt_free( crt );
799 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
800 }
801
802 if( ( ret = mbedtls_x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
803 {
804 mbedtls_x509_crt_free( crt );
805 return( ret );
806 }
807
808 crt->issuer_raw.len = p - crt->issuer_raw.p;
809
810 /*
811 * Validity ::= SEQUENCE {
812 * notBefore Time,
813 * notAfter Time }
814 *
815 */
816 if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
817 &crt->valid_to ) ) != 0 )
818 {
819 mbedtls_x509_crt_free( crt );
820 return( ret );
821 }
822
823 /*
824 * subject Name
825 */
826 crt->subject_raw.p = p;
827
828 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
829 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
830 {
831 mbedtls_x509_crt_free( crt );
832 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
833 }
834
835 if( len && ( ret = mbedtls_x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
836 {
837 mbedtls_x509_crt_free( crt );
838 return( ret );
839 }
840
841 crt->subject_raw.len = p - crt->subject_raw.p;
842
843 /*
844 * SubjectPublicKeyInfo
845 */
846 if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
847 {
848 mbedtls_x509_crt_free( crt );
849 return( ret );
850 }
851
852 /*
853 * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
854 * -- If present, version shall be v2 or v3
855 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
856 * -- If present, version shall be v2 or v3
857 * extensions [3] EXPLICIT Extensions OPTIONAL
858 * -- If present, version shall be v3
859 */
860 if( crt->version == 2 || crt->version == 3 )
861 {
862 ret = x509_get_uid( &p, end, &crt->issuer_id, 1 );
863 if( ret != 0 )
864 {
865 mbedtls_x509_crt_free( crt );
866 return( ret );
867 }
868 }
869
870 if( crt->version == 2 || crt->version == 3 )
871 {
872 ret = x509_get_uid( &p, end, &crt->subject_id, 2 );
873 if( ret != 0 )
874 {
875 mbedtls_x509_crt_free( crt );
876 return( ret );
877 }
878 }
879
880 #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
881 if( crt->version == 3 )
882 #endif
883 {
884 ret = x509_get_crt_ext( &p, end, crt );
885 if( ret != 0 )
886 {
887 mbedtls_x509_crt_free( crt );
888 return( ret );
889 }
890 }
891
892 if( p != end )
893 {
894 mbedtls_x509_crt_free( crt );
895 return( MBEDTLS_ERR_X509_INVALID_FORMAT +
896 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
897 }
898
899 end = crt_end;
900
901 /*
902 * }
903 * -- end of TBSCertificate
904 *
905 * signatureAlgorithm AlgorithmIdentifier,
906 * signatureValue BIT STRING
907 */
908 if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 )
909 {
910 mbedtls_x509_crt_free( crt );
911 return( ret );
912 }
913
914 if( crt->sig_oid.len != sig_oid2.len ||
915 memcmp( crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len ) != 0 ||
916 sig_params1.len != sig_params2.len ||
917 ( sig_params1.len != 0 &&
918 memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
919 {
920 mbedtls_x509_crt_free( crt );
921 return( MBEDTLS_ERR_X509_SIG_MISMATCH );
922 }
923
924 if( ( ret = mbedtls_x509_get_sig( &p, end, &crt->sig ) ) != 0 )
925 {
926 mbedtls_x509_crt_free( crt );
927 return( ret );
928 }
929
930 if( p != end )
931 {
932 mbedtls_x509_crt_free( crt );
933 return( MBEDTLS_ERR_X509_INVALID_FORMAT +
934 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
935 }
936
937 return( 0 );
938 }
939
940 /*
941 * Parse one X.509 certificate in DER format from a buffer and add them to a
942 * chained list
943 */
944 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
945 size_t buflen )
946 {
947 int ret;
948 mbedtls_x509_crt *crt = chain, *prev = NULL;
949
950 /*
951 * Check for valid input
952 */
953 if( crt == NULL || buf == NULL )
954 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
955
956 while( crt->version != 0 && crt->next != NULL )
957 {
958 prev = crt;
959 crt = crt->next;
960 }
961
962 /*
963 * Add new certificate on the end of the chain if needed.
964 */
965 if( crt->version != 0 && crt->next == NULL )
966 {
967 crt->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
968
969 if( crt->next == NULL )
970 return( MBEDTLS_ERR_X509_ALLOC_FAILED );
971
972 prev = crt;
973 mbedtls_x509_crt_init( crt->next );
974 crt = crt->next;
975 }
976
977 if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
978 {
979 if( prev )
980 prev->next = NULL;
981
982 if( crt != chain )
983 mbedtls_free( crt );
984
985 return( ret );
986 }
987
988 return( 0 );
989 }
990
991 /*
992 * Parse one or more PEM certificates from a buffer and add them to the chained
993 * list
994 */
995 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen )
996 {
997 #if defined(MBEDTLS_PEM_PARSE_C)
998 int success = 0, first_error = 0, total_failed = 0;
999 int buf_format = MBEDTLS_X509_FORMAT_DER;
1000 #endif
1001
1002 /*
1003 * Check for valid input
1004 */
1005 if( chain == NULL || buf == NULL )
1006 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1007
1008 /*
1009 * Determine buffer content. Buffer contains either one DER certificate or
1010 * one or more PEM certificates.
1011 */
1012 #if defined(MBEDTLS_PEM_PARSE_C)
1013 if( buflen != 0 && buf[buflen - 1] == '\0' &&
1014 strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
1015 {
1016 buf_format = MBEDTLS_X509_FORMAT_PEM;
1017 }
1018
1019 if( buf_format == MBEDTLS_X509_FORMAT_DER )
1020 return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1021 #else
1022 return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1023 #endif
1024
1025 #if defined(MBEDTLS_PEM_PARSE_C)
1026 if( buf_format == MBEDTLS_X509_FORMAT_PEM )
1027 {
1028 int ret;
1029 mbedtls_pem_context pem;
1030
1031 /* 1 rather than 0 since the terminating NULL byte is counted in */
1032 while( buflen > 1 )
1033 {
1034 size_t use_len;
1035 mbedtls_pem_init( &pem );
1036
1037 /* If we get there, we know the string is null-terminated */
1038 ret = mbedtls_pem_read_buffer( &pem,
1039 "-----BEGIN CERTIFICATE-----",
1040 "-----END CERTIFICATE-----",
1041 buf, NULL, 0, &use_len );
1042
1043 if( ret == 0 )
1044 {
1045 /*
1046 * Was PEM encoded
1047 */
1048 buflen -= use_len;
1049 buf += use_len;
1050 }
1051 else if( ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA )
1052 {
1053 return( ret );
1054 }
1055 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1056 {
1057 mbedtls_pem_free( &pem );
1058
1059 /*
1060 * PEM header and footer were found
1061 */
1062 buflen -= use_len;
1063 buf += use_len;
1064
1065 if( first_error == 0 )
1066 first_error = ret;
1067
1068 total_failed++;
1069 continue;
1070 }
1071 else
1072 break;
1073
1074 ret = mbedtls_x509_crt_parse_der( chain, pem.buf, pem.buflen );
1075
1076 mbedtls_pem_free( &pem );
1077
1078 if( ret != 0 )
1079 {
1080 /*
1081 * Quit parsing on a memory error
1082 */
1083 if( ret == MBEDTLS_ERR_X509_ALLOC_FAILED )
1084 return( ret );
1085
1086 if( first_error == 0 )
1087 first_error = ret;
1088
1089 total_failed++;
1090 continue;
1091 }
1092
1093 success = 1;
1094 }
1095 }
1096
1097 if( success )
1098 return( total_failed );
1099 else if( first_error )
1100 return( first_error );
1101 else
1102 return( MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT );
1103 #endif /* MBEDTLS_PEM_PARSE_C */
1104 }
1105
1106 #if defined(MBEDTLS_FS_IO)
1107 /*
1108 * Load one or more certificates and add them to the chained list
1109 */
1110 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path )
1111 {
1112 int ret;
1113 size_t n;
1114 unsigned char *buf;
1115
1116 if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
1117 return( ret );
1118
1119 ret = mbedtls_x509_crt_parse( chain, buf, n );
1120
1121 mbedtls_platform_zeroize( buf, n );
1122 mbedtls_free( buf );
1123
1124 return( ret );
1125 }
1126
1127 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
1128 {
1129 int ret = 0;
1130 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
1131 int w_ret;
1132 WCHAR szDir[MAX_PATH];
1133 char filename[MAX_PATH];
1134 char *p;
1135 size_t len = strlen( path );
1136
1137 WIN32_FIND_DATAW file_data;
1138 HANDLE hFind;
1139
1140 if( len > MAX_PATH - 3 )
1141 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1142
1143 memset( szDir, 0, sizeof(szDir) );
1144 memset( filename, 0, MAX_PATH );
1145 memcpy( filename, path, len );
1146 filename[len++] = '\\';
1147 p = filename + len;
1148 filename[len++] = '*';
1149
1150 w_ret = MultiByteToWideChar( CP_ACP, 0, filename, (int)len, szDir,
1151 MAX_PATH - 3 );
1152 if( w_ret == 0 )
1153 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1154
1155 hFind = FindFirstFileW( szDir, &file_data );
1156 if( hFind == INVALID_HANDLE_VALUE )
1157 return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1158
1159 len = MAX_PATH - len;
1160 do
1161 {
1162 memset( p, 0, len );
1163
1164 if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
1165 continue;
1166
1167 w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
1168 lstrlenW( file_data.cFileName ),
1169 p, (int) len - 1,
1170 NULL, NULL );
1171 if( w_ret == 0 )
1172 {
1173 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1174 goto cleanup;
1175 }
1176
1177 w_ret = mbedtls_x509_crt_parse_file( chain, filename );
1178 if( w_ret < 0 )
1179 ret++;
1180 else
1181 ret += w_ret;
1182 }
1183 while( FindNextFileW( hFind, &file_data ) != 0 );
1184
1185 if( GetLastError() != ERROR_NO_MORE_FILES )
1186 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1187
1188 cleanup:
1189 FindClose( hFind );
1190 #else /* _WIN32 */
1191 int t_ret;
1192 int snp_ret;
1193 struct stat sb;
1194 struct dirent *entry;
1195 char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
1196 DIR *dir = opendir( path );
1197
1198 if( dir == NULL )
1199 return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1200
1201 #if defined(MBEDTLS_THREADING_C)
1202 if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 )
1203 {
1204 closedir( dir );
1205 return( ret );
1206 }
1207 #endif /* MBEDTLS_THREADING_C */
1208
1209 while( ( entry = readdir( dir ) ) != NULL )
1210 {
1211 snp_ret = mbedtls_snprintf( entry_name, sizeof entry_name,
1212 "%s/%s", path, entry->d_name );
1213
1214 if( snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name )
1215 {
1216 ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
1217 goto cleanup;
1218 }
1219 else if( stat( entry_name, &sb ) == -1 )
1220 {
1221 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1222 goto cleanup;
1223 }
1224
1225 if( !S_ISREG( sb.st_mode ) )
1226 continue;
1227
1228 // Ignore parse errors
1229 //
1230 t_ret = mbedtls_x509_crt_parse_file( chain, entry_name );
1231 if( t_ret < 0 )
1232 ret++;
1233 else
1234 ret += t_ret;
1235 }
1236
1237 cleanup:
1238 closedir( dir );
1239
1240 #if defined(MBEDTLS_THREADING_C)
1241 if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 )
1242 ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1243 #endif /* MBEDTLS_THREADING_C */
1244
1245 #endif /* _WIN32 */
1246
1247 return( ret );
1248 }
1249 #endif /* MBEDTLS_FS_IO */
1250
1251 static int x509_info_subject_alt_name( char **buf, size_t *size,
1252 const mbedtls_x509_sequence *subject_alt_name )
1253 {
1254 size_t i;
1255 size_t n = *size;
1256 char *p = *buf;
1257 const mbedtls_x509_sequence *cur = subject_alt_name;
1258 const char *sep = "";
1259 size_t sep_len = 0;
1260
1261 while( cur != NULL )
1262 {
1263 if( cur->buf.len + sep_len >= n )
1264 {
1265 *p = '\0';
1266 return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
1267 }
1268
1269 n -= cur->buf.len + sep_len;
1270 for( i = 0; i < sep_len; i++ )
1271 *p++ = sep[i];
1272 for( i = 0; i < cur->buf.len; i++ )
1273 *p++ = cur->buf.p[i];
1274
1275 sep = ", ";
1276 sep_len = 2;
1277
1278 cur = cur->next;
1279 }
1280
1281 *p = '\0';
1282
1283 *size = n;
1284 *buf = p;
1285
1286 return( 0 );
1287 }
1288
1289 #define PRINT_ITEM(i) \
1290 { \
1291 ret = mbedtls_snprintf( p, n, "%s" i, sep ); \
1292 MBEDTLS_X509_SAFE_SNPRINTF; \
1293 sep = ", "; \
1294 }
1295
1296 #define CERT_TYPE(type,name) \
1297 if( ns_cert_type & type ) \
1298 PRINT_ITEM( name );
1299
1300 static int x509_info_cert_type( char **buf, size_t *size,
1301 unsigned char ns_cert_type )
1302 {
1303 int ret;
1304 size_t n = *size;
1305 char *p = *buf;
1306 const char *sep = "";
1307
1308 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT, "SSL Client" );
1309 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER, "SSL Server" );
1310 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL, "Email" );
1311 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing" );
1312 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED, "Reserved" );
1313 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA, "SSL CA" );
1314 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA, "Email CA" );
1315 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA" );
1316
1317 *size = n;
1318 *buf = p;
1319
1320 return( 0 );
1321 }
1322
1323 #define KEY_USAGE(code,name) \
1324 if( key_usage & code ) \
1325 PRINT_ITEM( name );
1326
1327 static int x509_info_key_usage( char **buf, size_t *size,
1328 unsigned int key_usage )
1329 {
1330 int ret;
1331 size_t n = *size;
1332 char *p = *buf;
1333 const char *sep = "";
1334
1335 KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE, "Digital Signature" );
1336 KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION, "Non Repudiation" );
1337 KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT, "Key Encipherment" );
1338 KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT, "Data Encipherment" );
1339 KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT, "Key Agreement" );
1340 KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN, "Key Cert Sign" );
1341 KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN, "CRL Sign" );
1342 KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY, "Encipher Only" );
1343 KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY, "Decipher Only" );
1344
1345 *size = n;
1346 *buf = p;
1347
1348 return( 0 );
1349 }
1350
1351 static int x509_info_ext_key_usage( char **buf, size_t *size,
1352 const mbedtls_x509_sequence *extended_key_usage )
1353 {
1354 int ret;
1355 const char *desc;
1356 size_t n = *size;
1357 char *p = *buf;
1358 const mbedtls_x509_sequence *cur = extended_key_usage;
1359 const char *sep = "";
1360
1361 while( cur != NULL )
1362 {
1363 if( mbedtls_oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
1364 desc = "???";
1365
1366 ret = mbedtls_snprintf( p, n, "%s%s", sep, desc );
1367 MBEDTLS_X509_SAFE_SNPRINTF;
1368
1369 sep = ", ";
1370
1371 cur = cur->next;
1372 }
1373
1374 *size = n;
1375 *buf = p;
1376
1377 return( 0 );
1378 }
1379
1380 /*
1381 * Return an informational string about the certificate.
1382 */
1383 #define BEFORE_COLON 18
1384 #define BC "18"
1385 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
1386 const mbedtls_x509_crt *crt )
1387 {
1388 int ret;
1389 size_t n;
1390 char *p;
1391 char key_size_str[BEFORE_COLON];
1392
1393 p = buf;
1394 n = size;
1395
1396 if( NULL == crt )
1397 {
1398 ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" );
1399 MBEDTLS_X509_SAFE_SNPRINTF;
1400
1401 return( (int) ( size - n ) );
1402 }
1403
1404 ret = mbedtls_snprintf( p, n, "%scert. version : %d\n",
1405 prefix, crt->version );
1406 MBEDTLS_X509_SAFE_SNPRINTF;
1407 ret = mbedtls_snprintf( p, n, "%sserial number : ",
1408 prefix );
1409 MBEDTLS_X509_SAFE_SNPRINTF;
1410
1411 ret = mbedtls_x509_serial_gets( p, n, &crt->serial );
1412 MBEDTLS_X509_SAFE_SNPRINTF;
1413
1414 ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix );
1415 MBEDTLS_X509_SAFE_SNPRINTF;
1416 ret = mbedtls_x509_dn_gets( p, n, &crt->issuer );
1417 MBEDTLS_X509_SAFE_SNPRINTF;
1418
1419 ret = mbedtls_snprintf( p, n, "\n%ssubject name : ", prefix );
1420 MBEDTLS_X509_SAFE_SNPRINTF;
1421 ret = mbedtls_x509_dn_gets( p, n, &crt->subject );
1422 MBEDTLS_X509_SAFE_SNPRINTF;
1423
1424 ret = mbedtls_snprintf( p, n, "\n%sissued on : " \
1425 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1426 crt->valid_from.year, crt->valid_from.mon,
1427 crt->valid_from.day, crt->valid_from.hour,
1428 crt->valid_from.min, crt->valid_from.sec );
1429 MBEDTLS_X509_SAFE_SNPRINTF;
1430
1431 ret = mbedtls_snprintf( p, n, "\n%sexpires on : " \
1432 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1433 crt->valid_to.year, crt->valid_to.mon,
1434 crt->valid_to.day, crt->valid_to.hour,
1435 crt->valid_to.min, crt->valid_to.sec );
1436 MBEDTLS_X509_SAFE_SNPRINTF;
1437
1438 ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix );
1439 MBEDTLS_X509_SAFE_SNPRINTF;
1440
1441 ret = mbedtls_x509_sig_alg_gets( p, n, &crt->sig_oid, crt->sig_pk,
1442 crt->sig_md, crt->sig_opts );
1443 MBEDTLS_X509_SAFE_SNPRINTF;
1444
1445 /* Key size */
1446 if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON,
1447 mbedtls_pk_get_name( &crt->pk ) ) ) != 0 )
1448 {
1449 return( ret );
1450 }
1451
1452 ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
1453 (int) mbedtls_pk_get_bitlen( &crt->pk ) );
1454 MBEDTLS_X509_SAFE_SNPRINTF;
1455
1456 /*
1457 * Optional extensions
1458 */
1459
1460 if( crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS )
1461 {
1462 ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
1463 crt->ca_istrue ? "true" : "false" );
1464 MBEDTLS_X509_SAFE_SNPRINTF;
1465
1466 if( crt->max_pathlen > 0 )
1467 {
1468 ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
1469 MBEDTLS_X509_SAFE_SNPRINTF;
1470 }
1471 }
1472
1473 if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
1474 {
1475 ret = mbedtls_snprintf( p, n, "\n%ssubject alt name : ", prefix );
1476 MBEDTLS_X509_SAFE_SNPRINTF;
1477
1478 if( ( ret = x509_info_subject_alt_name( &p, &n,
1479 &crt->subject_alt_names ) ) != 0 )
1480 return( ret );
1481 }
1482
1483 if( crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE )
1484 {
1485 ret = mbedtls_snprintf( p, n, "\n%scert. type : ", prefix );
1486 MBEDTLS_X509_SAFE_SNPRINTF;
1487
1488 if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
1489 return( ret );
1490 }
1491
1492 if( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE )
1493 {
1494 ret = mbedtls_snprintf( p, n, "\n%skey usage : ", prefix );
1495 MBEDTLS_X509_SAFE_SNPRINTF;
1496
1497 if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
1498 return( ret );
1499 }
1500
1501 if( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE )
1502 {
1503 ret = mbedtls_snprintf( p, n, "\n%sext key usage : ", prefix );
1504 MBEDTLS_X509_SAFE_SNPRINTF;
1505
1506 if( ( ret = x509_info_ext_key_usage( &p, &n,
1507 &crt->ext_key_usage ) ) != 0 )
1508 return( ret );
1509 }
1510
1511 ret = mbedtls_snprintf( p, n, "\n" );
1512 MBEDTLS_X509_SAFE_SNPRINTF;
1513
1514 return( (int) ( size - n ) );
1515 }
1516
1517 struct x509_crt_verify_string {
1518 int code;
1519 const char *string;
1520 };
1521
1522 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
1523 { MBEDTLS_X509_BADCERT_EXPIRED, "The certificate validity has expired" },
1524 { MBEDTLS_X509_BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)" },
1525 { MBEDTLS_X509_BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN" },
1526 { MBEDTLS_X509_BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA" },
1527 { MBEDTLS_X509_BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA" },
1528 { MBEDTLS_X509_BADCRL_EXPIRED, "The CRL is expired" },
1529 { MBEDTLS_X509_BADCERT_MISSING, "Certificate was missing" },
1530 { MBEDTLS_X509_BADCERT_SKIP_VERIFY, "Certificate verification was skipped" },
1531 { MBEDTLS_X509_BADCERT_OTHER, "Other reason (can be used by verify callback)" },
1532 { MBEDTLS_X509_BADCERT_FUTURE, "The certificate validity starts in the future" },
1533 { MBEDTLS_X509_BADCRL_FUTURE, "The CRL is from the future" },
1534 { MBEDTLS_X509_BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension" },
1535 { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
1536 { MBEDTLS_X509_BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension" },
1537 { MBEDTLS_X509_BADCERT_BAD_MD, "The certificate is signed with an unacceptable hash." },
1538 { MBEDTLS_X509_BADCERT_BAD_PK, "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1539 { MBEDTLS_X509_BADCERT_BAD_KEY, "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
1540 { MBEDTLS_X509_BADCRL_BAD_MD, "The CRL is signed with an unacceptable hash." },
1541 { MBEDTLS_X509_BADCRL_BAD_PK, "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1542 { MBEDTLS_X509_BADCRL_BAD_KEY, "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
1543 { 0, NULL }
1544 };
1545
1546 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
1547 uint32_t flags )
1548 {
1549 int ret;
1550 const struct x509_crt_verify_string *cur;
1551 char *p = buf;
1552 size_t n = size;
1553
1554 for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
1555 {
1556 if( ( flags & cur->code ) == 0 )
1557 continue;
1558
1559 ret = mbedtls_snprintf( p, n, "%s%s\n", prefix, cur->string );
1560 MBEDTLS_X509_SAFE_SNPRINTF;
1561 flags ^= cur->code;
1562 }
1563
1564 if( flags != 0 )
1565 {
1566 ret = mbedtls_snprintf( p, n, "%sUnknown reason "
1567 "(this should not happen)\n", prefix );
1568 MBEDTLS_X509_SAFE_SNPRINTF;
1569 }
1570
1571 return( (int) ( size - n ) );
1572 }
1573
1574 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1575 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
1576 unsigned int usage )
1577 {
1578 unsigned int usage_must, usage_may;
1579 unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
1580 | MBEDTLS_X509_KU_DECIPHER_ONLY;
1581
1582 if( ( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) == 0 )
1583 return( 0 );
1584
1585 usage_must = usage & ~may_mask;
1586
1587 if( ( ( crt->key_usage & ~may_mask ) & usage_must ) != usage_must )
1588 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1589
1590 usage_may = usage & may_mask;
1591
1592 if( ( ( crt->key_usage & may_mask ) | usage_may ) != usage_may )
1593 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1594
1595 return( 0 );
1596 }
1597 #endif
1598
1599 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
1600 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
1601 const char *usage_oid,
1602 size_t usage_len )
1603 {
1604 const mbedtls_x509_sequence *cur;
1605
1606 /* Extension is not mandatory, absent means no restriction */
1607 if( ( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 )
1608 return( 0 );
1609
1610 /*
1611 * Look for the requested usage (or wildcard ANY) in our list
1612 */
1613 for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
1614 {
1615 const mbedtls_x509_buf *cur_oid = &cur->buf;
1616
1617 if( cur_oid->len == usage_len &&
1618 memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
1619 {
1620 return( 0 );
1621 }
1622
1623 if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) == 0 )
1624 return( 0 );
1625 }
1626
1627 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1628 }
1629 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
1630
1631 #if defined(MBEDTLS_X509_CRL_PARSE_C)
1632 /*
1633 * Return 1 if the certificate is revoked, or 0 otherwise.
1634 */
1635 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl )
1636 {
1637 const mbedtls_x509_crl_entry *cur = &crl->entry;
1638
1639 while( cur != NULL && cur->serial.len != 0 )
1640 {
1641 if( crt->serial.len == cur->serial.len &&
1642 memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
1643 {
1644 if( mbedtls_x509_time_is_past( &cur->revocation_date ) )
1645 return( 1 );
1646 }
1647
1648 cur = cur->next;
1649 }
1650
1651 return( 0 );
1652 }
1653
1654 /*
1655 * Check that the given certificate is not revoked according to the CRL.
1656 * Skip validation if no CRL for the given CA is present.
1657 */
1658 static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
1659 mbedtls_x509_crl *crl_list,
1660 const mbedtls_x509_crt_profile *profile )
1661 {
1662 int flags = 0;
1663 unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1664 const mbedtls_md_info_t *md_info;
1665
1666 if( ca == NULL )
1667 return( flags );
1668
1669 while( crl_list != NULL )
1670 {
1671 if( crl_list->version == 0 ||
1672 crl_list->issuer_raw.len != ca->subject_raw.len ||
1673 memcmp( crl_list->issuer_raw.p, ca->subject_raw.p,
1674 crl_list->issuer_raw.len ) != 0 )
1675 {
1676 crl_list = crl_list->next;
1677 continue;
1678 }
1679
1680 /*
1681 * Check if the CA is configured to sign CRLs
1682 */
1683 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1684 if( mbedtls_x509_crt_check_key_usage( ca, MBEDTLS_X509_KU_CRL_SIGN ) != 0 )
1685 {
1686 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1687 break;
1688 }
1689 #endif
1690
1691 /*
1692 * Check if CRL is correctly signed by the trusted CA
1693 */
1694 if( x509_profile_check_md_alg( profile, crl_list->sig_md ) != 0 )
1695 flags |= MBEDTLS_X509_BADCRL_BAD_MD;
1696
1697 if( x509_profile_check_pk_alg( profile, crl_list->sig_pk ) != 0 )
1698 flags |= MBEDTLS_X509_BADCRL_BAD_PK;
1699
1700 md_info = mbedtls_md_info_from_type( crl_list->sig_md );
1701 if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 )
1702 {
1703 /* Note: this can't happen except after an internal error */
1704 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1705 break;
1706 }
1707
1708 if( x509_profile_check_key( profile, &ca->pk ) != 0 )
1709 flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
1710
1711 if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
1712 crl_list->sig_md, hash, mbedtls_md_get_size( md_info ),
1713 crl_list->sig.p, crl_list->sig.len ) != 0 )
1714 {
1715 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1716 break;
1717 }
1718
1719 /*
1720 * Check for validity of CRL (Do not drop out)
1721 */
1722 if( mbedtls_x509_time_is_past( &crl_list->next_update ) )
1723 flags |= MBEDTLS_X509_BADCRL_EXPIRED;
1724
1725 if( mbedtls_x509_time_is_future( &crl_list->this_update ) )
1726 flags |= MBEDTLS_X509_BADCRL_FUTURE;
1727
1728 /*
1729 * Check if certificate is revoked
1730 */
1731 if( mbedtls_x509_crt_is_revoked( crt, crl_list ) )
1732 {
1733 flags |= MBEDTLS_X509_BADCERT_REVOKED;
1734 break;
1735 }
1736
1737 crl_list = crl_list->next;
1738 }
1739
1740 return( flags );
1741 }
1742 #endif /* MBEDTLS_X509_CRL_PARSE_C */
1743
1744 /*
1745 * Like memcmp, but case-insensitive and always returns -1 if different
1746 */
1747 static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
1748 {
1749 size_t i;
1750 unsigned char diff;
1751 const unsigned char *n1 = s1, *n2 = s2;
1752
1753 for( i = 0; i < len; i++ )
1754 {
1755 diff = n1[i] ^ n2[i];
1756
1757 if( diff == 0 )
1758 continue;
1759
1760 if( diff == 32 &&
1761 ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
1762 ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
1763 {
1764 continue;
1765 }
1766
1767 return( -1 );
1768 }
1769
1770 return( 0 );
1771 }
1772
1773 /*
1774 * Return 0 if name matches wildcard, -1 otherwise
1775 */
1776 static int x509_check_wildcard( const char *cn, const mbedtls_x509_buf *name )
1777 {
1778 size_t i;
1779 size_t cn_idx = 0, cn_len = strlen( cn );
1780
1781 /* We can't have a match if there is no wildcard to match */
1782 if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' )
1783 return( -1 );
1784
1785 for( i = 0; i < cn_len; ++i )
1786 {
1787 if( cn[i] == '.' )
1788 {
1789 cn_idx = i;
1790 break;
1791 }
1792 }
1793
1794 if( cn_idx == 0 )
1795 return( -1 );
1796
1797 if( cn_len - cn_idx == name->len - 1 &&
1798 x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 )
1799 {
1800 return( 0 );
1801 }
1802
1803 return( -1 );
1804 }
1805
1806 /*
1807 * Compare two X.509 strings, case-insensitive, and allowing for some encoding
1808 * variations (but not all).
1809 *
1810 * Return 0 if equal, -1 otherwise.
1811 */
1812 static int x509_string_cmp( const mbedtls_x509_buf *a, const mbedtls_x509_buf *b )
1813 {
1814 if( a->tag == b->tag &&
1815 a->len == b->len &&
1816 memcmp( a->p, b->p, b->len ) == 0 )
1817 {
1818 return( 0 );
1819 }
1820
1821 if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
1822 ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
1823 a->len == b->len &&
1824 x509_memcasecmp( a->p, b->p, b->len ) == 0 )
1825 {
1826 return( 0 );
1827 }
1828
1829 return( -1 );
1830 }
1831
1832 /*
1833 * Compare two X.509 Names (aka rdnSequence).
1834 *
1835 * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
1836 * we sometimes return unequal when the full algorithm would return equal,
1837 * but never the other way. (In particular, we don't do Unicode normalisation
1838 * or space folding.)
1839 *
1840 * Return 0 if equal, -1 otherwise.
1841 */
1842 static int x509_name_cmp( const mbedtls_x509_name *a, const mbedtls_x509_name *b )
1843 {
1844 /* Avoid recursion, it might not be optimised by the compiler */
1845 while( a != NULL || b != NULL )
1846 {
1847 if( a == NULL || b == NULL )
1848 return( -1 );
1849
1850 /* type */
1851 if( a->oid.tag != b->oid.tag ||
1852 a->oid.len != b->oid.len ||
1853 memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
1854 {
1855 return( -1 );
1856 }
1857
1858 /* value */
1859 if( x509_string_cmp( &a->val, &b->val ) != 0 )
1860 return( -1 );
1861
1862 /* structure of the list of sets */
1863 if( a->next_merged != b->next_merged )
1864 return( -1 );
1865
1866 a = a->next;
1867 b = b->next;
1868 }
1869
1870 /* a == NULL == b */
1871 return( 0 );
1872 }
1873
1874 /*
1875 * Check the signature of a certificate by its parent
1876 */
1877 static int x509_crt_check_signature( const mbedtls_x509_crt *child,
1878 mbedtls_x509_crt *parent )
1879 {
1880 const mbedtls_md_info_t *md_info;
1881 unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1882
1883 md_info = mbedtls_md_info_from_type( child->sig_md );
1884 if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
1885 {
1886 /* Note: this can't happen except after an internal error */
1887 return( -1 );
1888 }
1889
1890 if( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
1891 child->sig_md, hash, mbedtls_md_get_size( md_info ),
1892 child->sig.p, child->sig.len ) != 0 )
1893 {
1894 return( -1 );
1895 }
1896
1897 return( 0 );
1898 }
1899
1900 /*
1901 * Check if 'parent' is a suitable parent (signing CA) for 'child'.
1902 * Return 0 if yes, -1 if not.
1903 *
1904 * top means parent is a locally-trusted certificate
1905 */
1906 static int x509_crt_check_parent( const mbedtls_x509_crt *child,
1907 const mbedtls_x509_crt *parent,
1908 int top )
1909 {
1910 int need_ca_bit;
1911
1912 /* Parent must be the issuer */
1913 if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
1914 return( -1 );
1915
1916 /* Parent must have the basicConstraints CA bit set as a general rule */
1917 need_ca_bit = 1;
1918
1919 /* Exception: v1/v2 certificates that are locally trusted. */
1920 if( top && parent->version < 3 )
1921 need_ca_bit = 0;
1922
1923 if( need_ca_bit && ! parent->ca_istrue )
1924 return( -1 );
1925
1926 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1927 if( need_ca_bit &&
1928 mbedtls_x509_crt_check_key_usage( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
1929 {
1930 return( -1 );
1931 }
1932 #endif
1933
1934 return( 0 );
1935 }
1936
1937 /*
1938 * Find a suitable parent for child in candidates, or return NULL.
1939 *
1940 * Here suitable is defined as:
1941 * 1. subject name matches child's issuer
1942 * 2. if necessary, the CA bit is set and key usage allows signing certs
1943 * 3. for trusted roots, the signature is correct
1944 * 4. pathlen constraints are satisfied
1945 *
1946 * If there's a suitable candidate which is also time-valid, return the first
1947 * such. Otherwise, return the first suitable candidate (or NULL if there is
1948 * none).
1949 *
1950 * The rationale for this rule is that someone could have a list of trusted
1951 * roots with two versions on the same root with different validity periods.
1952 * (At least one user reported having such a list and wanted it to just work.)
1953 * The reason we don't just require time-validity is that generally there is
1954 * only one version, and if it's expired we want the flags to state that
1955 * rather than NOT_TRUSTED, as would be the case if we required it here.
1956 *
1957 * The rationale for rule 3 (signature for trusted roots) is that users might
1958 * have two versions of the same CA with different keys in their list, and the
1959 * way we select the correct one is by checking the signature (as we don't
1960 * rely on key identifier extensions). (This is one way users might choose to
1961 * handle key rollover, another relies on self-issued certs, see [SIRO].)
1962 *
1963 * Arguments:
1964 * - [in] child: certificate for which we're looking for a parent
1965 * - [in] candidates: chained list of potential parents
1966 * - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
1967 * of the chain, 0 otherwise
1968 * - [in] path_cnt: number of intermediates seen so far
1969 * - [in] self_cnt: number of self-signed intermediates seen so far
1970 * (will never be greater than path_cnt)
1971 *
1972 * Return value:
1973 * - the first suitable parent found (see above regarding time-validity)
1974 * - NULL if no suitable parent was found
1975 */
1976 static mbedtls_x509_crt *x509_crt_find_parent_in( mbedtls_x509_crt *child,
1977 mbedtls_x509_crt *candidates,
1978 int top,
1979 size_t path_cnt,
1980 size_t self_cnt )
1981 {
1982 mbedtls_x509_crt *parent, *badtime_parent = NULL;
1983
1984 for( parent = candidates; parent != NULL; parent = parent->next )
1985 {
1986 /* basic parenting skills (name, CA bit, key usage) */
1987 if( x509_crt_check_parent( child, parent, top ) != 0 )
1988 continue;
1989
1990 /* +1 because stored max_pathlen is 1 higher that the actual value */
1991 if( parent->max_pathlen > 0 &&
1992 (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt )
1993 {
1994 continue;
1995 }
1996
1997 /* Signature */
1998 if( top && x509_crt_check_signature( child, parent ) != 0 )
1999 {
2000 continue;
2001 }
2002
2003 /* optional time check */
2004 if( mbedtls_x509_time_is_past( &parent->valid_to ) ||
2005 mbedtls_x509_time_is_future( &parent->valid_from ) )
2006 {
2007 if( badtime_parent == NULL )
2008 badtime_parent = parent;
2009
2010 continue;
2011 }
2012
2013 break;
2014 }
2015
2016 if( parent == NULL )
2017 parent = badtime_parent;
2018
2019 return( parent );
2020 }
2021
2022 /*
2023 * Find a parent in trusted CAs or the provided chain, or return NULL.
2024 *
2025 * Searches in trusted CAs first, and return the first suitable parent found
2026 * (see find_parent_in() for definition of suitable).
2027 *
2028 * Arguments:
2029 * - [in] child: certificate for which we're looking for a parent, followed
2030 * by a chain of possible intermediates
2031 * - [in] trust_ca: locally trusted CAs
2032 * - [out] 1 if parent was found in trust_ca, 0 if found in provided chain
2033 * - [in] path_cnt: number of intermediates seen so far
2034 * - [in] self_cnt: number of self-signed intermediates seen so far
2035 * (will always be no greater than path_cnt)
2036 *
2037 * Return value:
2038 * - the first suitable parent found (see find_parent_in() for "suitable")
2039 * - NULL if no suitable parent was found
2040 */
2041 static mbedtls_x509_crt *x509_crt_find_parent( mbedtls_x509_crt *child,
2042 mbedtls_x509_crt *trust_ca,
2043 int *parent_is_trusted,
2044 size_t path_cnt,
2045 size_t self_cnt )
2046 {
2047 mbedtls_x509_crt *parent;
2048
2049 /* Look for a parent in trusted CAs */
2050 *parent_is_trusted = 1;
2051 parent = x509_crt_find_parent_in( child, trust_ca, 1, path_cnt, self_cnt );
2052
2053 if( parent != NULL )
2054 return( parent );
2055
2056 /* Look for a parent upwards the chain */
2057 *parent_is_trusted = 0;
2058 return( x509_crt_find_parent_in( child, child->next, 0, path_cnt, self_cnt ) );
2059 }
2060
2061 /*
2062 * Check if an end-entity certificate is locally trusted
2063 *
2064 * Currently we require such certificates to be self-signed (actually only
2065 * check for self-issued as self-signatures are not checked)
2066 */
2067 static int x509_crt_check_ee_locally_trusted(
2068 mbedtls_x509_crt *crt,
2069 mbedtls_x509_crt *trust_ca )
2070 {
2071 mbedtls_x509_crt *cur;
2072
2073 /* must be self-issued */
2074 if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 )
2075 return( -1 );
2076
2077 /* look for an exact match with trusted cert */
2078 for( cur = trust_ca; cur != NULL; cur = cur->next )
2079 {
2080 if( crt->raw.len == cur->raw.len &&
2081 memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 )
2082 {
2083 return( 0 );
2084 }
2085 }
2086
2087 /* too bad */
2088 return( -1 );
2089 }
2090
2091 /*
2092 * Build and verify a certificate chain
2093 *
2094 * Given a peer-provided list of certificates EE, C1, ..., Cn and
2095 * a list of trusted certs R1, ... Rp, try to build and verify a chain
2096 * EE, Ci1, ... Ciq [, Rj]
2097 * such that every cert in the chain is a child of the next one,
2098 * jumping to a trusted root as early as possible.
2099 *
2100 * Verify that chain and return it with flags for all issues found.
2101 *
2102 * Special cases:
2103 * - EE == Rj -> return a one-element list containing it
2104 * - EE, Ci1, ..., Ciq cannot be continued with a trusted root
2105 * -> return that chain with NOT_TRUSTED set on Ciq
2106 *
2107 * Arguments:
2108 * - [in] crt: the cert list EE, C1, ..., Cn
2109 * - [in] trust_ca: the trusted list R1, ..., Rp
2110 * - [in] ca_crl, profile: as in verify_with_profile()
2111 * - [out] ver_chain, chain_len: the built and verified chain
2112 *
2113 * Return value:
2114 * - non-zero if the chain could not be fully built and examined
2115 * - 0 is the chain was successfully built and examined,
2116 * even if it was found to be invalid
2117 */
2118 static int x509_crt_verify_chain(
2119 mbedtls_x509_crt *crt,
2120 mbedtls_x509_crt *trust_ca,
2121 mbedtls_x509_crl *ca_crl,
2122 const mbedtls_x509_crt_profile *profile,
2123 x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE],
2124 size_t *chain_len )
2125 {
2126 uint32_t *flags;
2127 mbedtls_x509_crt *child;
2128 mbedtls_x509_crt *parent;
2129 int parent_is_trusted = 0;
2130 int child_is_trusted = 0;
2131 size_t self_cnt = 0;
2132
2133 child = crt;
2134 *chain_len = 0;
2135
2136 while( 1 ) {
2137 /* Add certificate to the verification chain */
2138 ver_chain[*chain_len].crt = child;
2139 flags = &ver_chain[*chain_len].flags;
2140 ++*chain_len;
2141
2142 /* Check time-validity (all certificates) */
2143 if( mbedtls_x509_time_is_past( &child->valid_to ) )
2144 *flags |= MBEDTLS_X509_BADCERT_EXPIRED;
2145
2146 if( mbedtls_x509_time_is_future( &child->valid_from ) )
2147 *flags |= MBEDTLS_X509_BADCERT_FUTURE;
2148
2149 /* Stop here for trusted roots (but not for trusted EE certs) */
2150 if( child_is_trusted )
2151 return( 0 );
2152
2153 /* Check signature algorithm: MD & PK algs */
2154 if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 )
2155 *flags |= MBEDTLS_X509_BADCERT_BAD_MD;
2156
2157 if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 )
2158 *flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2159
2160 /* Special case: EE certs that are locally trusted */
2161 if( *chain_len == 1 &&
2162 x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 )
2163 {
2164 return( 0 );
2165 }
2166
2167 /* Look for a parent in trusted CAs or up the chain */
2168 parent = x509_crt_find_parent( child, trust_ca, &parent_is_trusted,
2169 *chain_len - 1, self_cnt );
2170
2171 /* No parent? We're done here */
2172 if( parent == NULL )
2173 {
2174 *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2175 return( 0 );
2176 }
2177
2178 /* Count intermediate self-issued (not necessarily self-signed) certs.
2179 * These can occur with some strategies for key rollover, see [SIRO],
2180 * and should be excluded from max_pathlen checks. */
2181 if( *chain_len != 1 &&
2182 x509_name_cmp( &child->issuer, &child->subject ) == 0 )
2183 {
2184 self_cnt++;
2185 }
2186
2187 /* path_cnt is 0 for the first intermediate CA,
2188 * and if parent is trusted it's not an intermediate CA */
2189 if( ! parent_is_trusted &&
2190 *chain_len > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
2191 {
2192 /* return immediately to avoid overflow the chain array */
2193 return( MBEDTLS_ERR_X509_FATAL_ERROR );
2194 }
2195
2196 /* if parent is trusted, the signature was checked by find_parent() */
2197 if( ! parent_is_trusted && x509_crt_check_signature( child, parent ) != 0 )
2198 *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2199
2200 /* check size of signing key */
2201 if( x509_profile_check_key( profile, &parent->pk ) != 0 )
2202 *flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2203
2204 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2205 /* Check trusted CA's CRL for the given crt */
2206 *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile );
2207 #else
2208 (void) ca_crl;
2209 #endif
2210
2211 /* prepare for next iteration */
2212 child = parent;
2213 parent = NULL;
2214 child_is_trusted = parent_is_trusted;
2215 }
2216 }
2217
2218 /*
2219 * Check for CN match
2220 */
2221 static int x509_crt_check_cn( const mbedtls_x509_buf *name,
2222 const char *cn, size_t cn_len )
2223 {
2224 /* try exact match */
2225 if( name->len == cn_len &&
2226 x509_memcasecmp( cn, name->p, cn_len ) == 0 )
2227 {
2228 return( 0 );
2229 }
2230
2231 /* try wildcard match */
2232 if( x509_check_wildcard( cn, name ) == 0 )
2233 {
2234 return( 0 );
2235 }
2236
2237 return( -1 );
2238 }
2239
2240 /*
2241 * Verify the requested CN - only call this if cn is not NULL!
2242 */
2243 static void x509_crt_verify_name( const mbedtls_x509_crt *crt,
2244 const char *cn,
2245 uint32_t *flags )
2246 {
2247 const mbedtls_x509_name *name;
2248 const mbedtls_x509_sequence *cur;
2249 size_t cn_len = strlen( cn );
2250
2251 if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
2252 {
2253 for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next )
2254 {
2255 if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 )
2256 break;
2257 }
2258
2259 if( cur == NULL )
2260 *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2261 }
2262 else
2263 {
2264 for( name = &crt->subject; name != NULL; name = name->next )
2265 {
2266 if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 &&
2267 x509_crt_check_cn( &name->val, cn, cn_len ) == 0 )
2268 {
2269 break;
2270 }
2271 }
2272
2273 if( name == NULL )
2274 *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2275 }
2276 }
2277
2278 /*
2279 * Merge the flags for all certs in the chain, after calling callback
2280 */
2281 static int x509_crt_merge_flags_with_cb(
2282 uint32_t *flags,
2283 x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE],
2284 size_t chain_len,
2285 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2286 void *p_vrfy )
2287 {
2288 int ret;
2289 size_t i;
2290 uint32_t cur_flags;
2291
2292 for( i = chain_len; i != 0; --i )
2293 {
2294 cur_flags = ver_chain[i-1].flags;
2295
2296 if( NULL != f_vrfy )
2297 if( ( ret = f_vrfy( p_vrfy, ver_chain[i-1].crt, (int) i-1, &cur_flags ) ) != 0 )
2298 return( ret );
2299
2300 *flags |= cur_flags;
2301 }
2302
2303 return( 0 );
2304 }
2305
2306 /*
2307 * Verify the certificate validity
2308 */
2309 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
2310 mbedtls_x509_crt *trust_ca,
2311 mbedtls_x509_crl *ca_crl,
2312 const char *cn, uint32_t *flags,
2313 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2314 void *p_vrfy )
2315 {
2316 return( mbedtls_x509_crt_verify_with_profile( crt, trust_ca, ca_crl,
2317 &mbedtls_x509_crt_profile_default, cn, flags, f_vrfy, p_vrfy ) );
2318 }
2319
2320 /*
2321 * Verify the certificate validity, with profile
2322 *
2323 * This function:
2324 * - checks the requested CN (if any)
2325 * - checks the type and size of the EE cert's key,
2326 * as that isn't done as part of chain building/verification currently
2327 * - builds and verifies the chain
2328 * - then calls the callback and merges the flags
2329 */
2330 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
2331 mbedtls_x509_crt *trust_ca,
2332 mbedtls_x509_crl *ca_crl,
2333 const mbedtls_x509_crt_profile *profile,
2334 const char *cn, uint32_t *flags,
2335 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2336 void *p_vrfy )
2337 {
2338 int ret;
2339 mbedtls_pk_type_t pk_type;
2340 x509_crt_verify_chain_item ver_chain[X509_MAX_VERIFY_CHAIN_SIZE];
2341 size_t chain_len;
2342 uint32_t *ee_flags = &ver_chain[0].flags;
2343
2344 *flags = 0;
2345 memset( ver_chain, 0, sizeof( ver_chain ) );
2346 chain_len = 0;
2347
2348 if( profile == NULL )
2349 {
2350 ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
2351 goto exit;
2352 }
2353
2354 /* check name if requested */
2355 if( cn != NULL )
2356 x509_crt_verify_name( crt, cn, ee_flags );
2357
2358 /* Check the type and size of the key */
2359 pk_type = mbedtls_pk_get_type( &crt->pk );
2360
2361 if( x509_profile_check_pk_alg( profile, pk_type ) != 0 )
2362 *ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2363
2364 if( x509_profile_check_key( profile, &crt->pk ) != 0 )
2365 *ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2366
2367 /* Check the chain */
2368 ret = x509_crt_verify_chain( crt, trust_ca, ca_crl, profile,
2369 ver_chain, &chain_len );
2370 if( ret != 0 )
2371 goto exit;
2372
2373 /* Build final flags, calling callback on the way if any */
2374 ret = x509_crt_merge_flags_with_cb( flags,
2375 ver_chain, chain_len, f_vrfy, p_vrfy );
2376
2377 exit:
2378 /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
2379 * the SSL module for authmode optional, but non-zero return from the
2380 * callback means a fatal error so it shouldn't be ignored */
2381 if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
2382 ret = MBEDTLS_ERR_X509_FATAL_ERROR;
2383
2384 if( ret != 0 )
2385 {
2386 *flags = (uint32_t) -1;
2387 return( ret );
2388 }
2389
2390 if( *flags != 0 )
2391 return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
2392
2393 return( 0 );
2394 }
2395
2396 /*
2397 * Initialize a certificate chain
2398 */
2399 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt )
2400 {
2401 memset( crt, 0, sizeof(mbedtls_x509_crt) );
2402 }
2403
2404 /*
2405 * Unallocate all certificate data
2406 */
2407 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
2408 {
2409 mbedtls_x509_crt *cert_cur = crt;
2410 mbedtls_x509_crt *cert_prv;
2411 mbedtls_x509_name *name_cur;
2412 mbedtls_x509_name *name_prv;
2413 mbedtls_x509_sequence *seq_cur;
2414 mbedtls_x509_sequence *seq_prv;
2415
2416 if( crt == NULL )
2417 return;
2418
2419 do
2420 {
2421 mbedtls_pk_free( &cert_cur->pk );
2422
2423 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
2424 mbedtls_free( cert_cur->sig_opts );
2425 #endif
2426
2427 name_cur = cert_cur->issuer.next;
2428 while( name_cur != NULL )
2429 {
2430 name_prv = name_cur;
2431 name_cur = name_cur->next;
2432 mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2433 mbedtls_free( name_prv );
2434 }
2435
2436 name_cur = cert_cur->subject.next;
2437 while( name_cur != NULL )
2438 {
2439 name_prv = name_cur;
2440 name_cur = name_cur->next;
2441 mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2442 mbedtls_free( name_prv );
2443 }
2444
2445 seq_cur = cert_cur->ext_key_usage.next;
2446 while( seq_cur != NULL )
2447 {
2448 seq_prv = seq_cur;
2449 seq_cur = seq_cur->next;
2450 mbedtls_platform_zeroize( seq_prv,
2451 sizeof( mbedtls_x509_sequence ) );
2452 mbedtls_free( seq_prv );
2453 }
2454
2455 seq_cur = cert_cur->subject_alt_names.next;
2456 while( seq_cur != NULL )
2457 {
2458 seq_prv = seq_cur;
2459 seq_cur = seq_cur->next;
2460 mbedtls_platform_zeroize( seq_prv,
2461 sizeof( mbedtls_x509_sequence ) );
2462 mbedtls_free( seq_prv );
2463 }
2464
2465 if( cert_cur->raw.p != NULL )
2466 {
2467 mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
2468 mbedtls_free( cert_cur->raw.p );
2469 }
2470
2471 cert_cur = cert_cur->next;
2472 }
2473 while( cert_cur != NULL );
2474
2475 cert_cur = crt;
2476 do
2477 {
2478 cert_prv = cert_cur;
2479 cert_cur = cert_cur->next;
2480
2481 mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) );
2482 if( cert_prv != crt )
2483 mbedtls_free( cert_prv );
2484 }
2485 while( cert_cur != NULL );
2486 }
2487
2488 #endif /* MBEDTLS_X509_CRT_PARSE_C */
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