1 /*
2 * X.509 certificate parsing and verification
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 *
7 * This file is provided under the Apache License 2.0, or the
8 * GNU General Public License v2.0 or later.
9 *
10 * **********
11 * Apache License 2.0:
12 *
13 * Licensed under the Apache License, Version 2.0 (the "License"); you may
14 * not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
16 *
17 * http://www.apache.org/licenses/LICENSE-2.0
18 *
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
24 *
25 * **********
26 *
27 * **********
28 * GNU General Public License v2.0 or later:
29 *
30 * This program is free software; you can redistribute it and/or modify
31 * it under the terms of the GNU General Public License as published by
32 * the Free Software Foundation; either version 2 of the License, or
33 * (at your option) any later version.
34 *
35 * This program is distributed in the hope that it will be useful,
36 * but WITHOUT ANY WARRANTY; without even the implied warranty of
37 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
38 * GNU General Public License for more details.
39 *
40 * You should have received a copy of the GNU General Public License along
41 * with this program; if not, write to the Free Software Foundation, Inc.,
42 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
43 *
44 * **********
45 */
46 /*
47 * The ITU-T X.509 standard defines a certificate format for PKI.
48 *
49 * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
50 * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
51 * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
52 *
53 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
54 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
55 *
56 * [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf
57 */
58
59 #if !defined(MBEDTLS_CONFIG_FILE)
60 #include "mbedtls/config.h"
61 #else
62 #include MBEDTLS_CONFIG_FILE
63 #endif
64
65 #if defined(MBEDTLS_X509_CRT_PARSE_C)
66
67 #include "mbedtls/x509_crt.h"
68 #include "mbedtls/oid.h"
69 #include "mbedtls/platform_util.h"
70
71 #include <string.h>
72
73 #if defined(MBEDTLS_PEM_PARSE_C)
74 #include "mbedtls/pem.h"
75 #endif
76
77 #if defined(MBEDTLS_PLATFORM_C)
78 #include "mbedtls/platform.h"
79 #else
80 #include <stdio.h>
81 #include <stdlib.h>
82 #define mbedtls_free free
83 #define mbedtls_calloc calloc
84 #define mbedtls_snprintf snprintf
85 #endif
86
87 #if defined(MBEDTLS_THREADING_C)
88 #include "mbedtls/threading.h"
89 #endif
90
91 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
92 #include <windows.h>
93 #if defined(_MSC_VER) && _MSC_VER <= 1600
94 /* Visual Studio 2010 and earlier issue a warning when both <stdint.h> and
95 * <intsafe.h> are included, as they redefine a number of <TYPE>_MAX constants.
96 * These constants are guaranteed to be the same, though, so we suppress the
97 * warning when including intsafe.h.
98 */
99 #pragma warning( push )
100 #pragma warning( disable : 4005 )
101 #endif
102 #include <intsafe.h>
103 #if defined(_MSC_VER) && _MSC_VER <= 1600
104 #pragma warning( pop )
105 #endif
106 #else
107 #include <time.h>
108 #endif
109
110 #if defined(MBEDTLS_FS_IO)
111 #include <stdio.h>
112 #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
113 #include <sys/types.h>
114 #include <sys/stat.h>
115 #include <dirent.h>
116 #endif /* !_WIN32 || EFIX64 || EFI32 */
117 #endif
118
119 /*
120 * Item in a verification chain: cert and flags for it
121 */
122 typedef struct {
123 mbedtls_x509_crt *crt;
124 uint32_t flags;
125 } x509_crt_verify_chain_item;
126
127 /*
128 * Max size of verification chain: end-entity + intermediates + trusted root
129 */
130 #define X509_MAX_VERIFY_CHAIN_SIZE ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )
131
132 /*
133 * Default profile
134 */
135 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
136 {
137 #if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
138 /* Allow SHA-1 (weak, but still safe in controlled environments) */
139 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
140 #endif
141 /* Only SHA-2 hashes */
142 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
143 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
144 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
145 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
146 0xFFFFFFF, /* Any PK alg */
147 0xFFFFFFF, /* Any curve */
148 2048,
149 };
150
151 /*
152 * Next-default profile
153 */
154 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next =
155 {
156 /* Hashes from SHA-256 and above */
157 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
158 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
159 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
160 0xFFFFFFF, /* Any PK alg */
161 #if defined(MBEDTLS_ECP_C)
162 /* Curves at or above 128-bit security level */
163 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
164 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ) |
165 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP521R1 ) |
166 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP256R1 ) |
167 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP384R1 ) |
168 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP512R1 ) |
169 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256K1 ),
170 #else
171 0,
172 #endif
173 2048,
174 };
175
176 /*
177 * NSA Suite B Profile
178 */
179 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb =
180 {
181 /* Only SHA-256 and 384 */
182 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
183 MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ),
184 /* Only ECDSA */
185 MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECDSA ) |
186 MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECKEY ),
187 #if defined(MBEDTLS_ECP_C)
188 /* Only NIST P-256 and P-384 */
189 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
190 MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ),
191 #else
192 0,
193 #endif
194 0,
195 };
196
197 /*
198 * Check md_alg against profile
199 * Return 0 if md_alg is acceptable for this profile, -1 otherwise
200 */
x509_profile_check_md_alg(const mbedtls_x509_crt_profile * profile,mbedtls_md_type_t md_alg)201 static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile,
202 mbedtls_md_type_t md_alg )
203 {
204 if( md_alg == MBEDTLS_MD_NONE )
205 return( -1 );
206
207 if( ( profile->allowed_mds & MBEDTLS_X509_ID_FLAG( md_alg ) ) != 0 )
208 return( 0 );
209
210 return( -1 );
211 }
212
213 /*
214 * Check pk_alg against profile
215 * Return 0 if pk_alg is acceptable for this profile, -1 otherwise
216 */
x509_profile_check_pk_alg(const mbedtls_x509_crt_profile * profile,mbedtls_pk_type_t pk_alg)217 static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile,
218 mbedtls_pk_type_t pk_alg )
219 {
220 if( pk_alg == MBEDTLS_PK_NONE )
221 return( -1 );
222
223 if( ( profile->allowed_pks & MBEDTLS_X509_ID_FLAG( pk_alg ) ) != 0 )
224 return( 0 );
225
226 return( -1 );
227 }
228
229 /*
230 * Check key against profile
231 * Return 0 if pk is acceptable for this profile, -1 otherwise
232 */
x509_profile_check_key(const mbedtls_x509_crt_profile * profile,const mbedtls_pk_context * pk)233 static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile,
234 const mbedtls_pk_context *pk )
235 {
236 const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type( pk );
237
238 #if defined(MBEDTLS_RSA_C)
239 if( pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS )
240 {
241 if( mbedtls_pk_get_bitlen( pk ) >= profile->rsa_min_bitlen )
242 return( 0 );
243
244 return( -1 );
245 }
246 #endif
247
248 #if defined(MBEDTLS_ECP_C)
249 if( pk_alg == MBEDTLS_PK_ECDSA ||
250 pk_alg == MBEDTLS_PK_ECKEY ||
251 pk_alg == MBEDTLS_PK_ECKEY_DH )
252 {
253 const mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id;
254
255 if( gid == MBEDTLS_ECP_DP_NONE )
256 return( -1 );
257
258 if( ( profile->allowed_curves & MBEDTLS_X509_ID_FLAG( gid ) ) != 0 )
259 return( 0 );
260
261 return( -1 );
262 }
263 #endif
264
265 return( -1 );
266 }
267
268 /*
269 * Like memcmp, but case-insensitive and always returns -1 if different
270 */
x509_memcasecmp(const void * s1,const void * s2,size_t len)271 static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
272 {
273 size_t i;
274 unsigned char diff;
275 const unsigned char *n1 = s1, *n2 = s2;
276
277 for( i = 0; i < len; i++ )
278 {
279 diff = n1[i] ^ n2[i];
280
281 if( diff == 0 )
282 continue;
283
284 if( diff == 32 &&
285 ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
286 ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
287 {
288 continue;
289 }
290
291 return( -1 );
292 }
293
294 return( 0 );
295 }
296
297 /*
298 * Return 0 if name matches wildcard, -1 otherwise
299 */
x509_check_wildcard(const char * cn,const mbedtls_x509_buf * name)300 static int x509_check_wildcard( const char *cn, const mbedtls_x509_buf *name )
301 {
302 size_t i;
303 size_t cn_idx = 0, cn_len = strlen( cn );
304
305 /* We can't have a match if there is no wildcard to match */
306 if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' )
307 return( -1 );
308
309 for( i = 0; i < cn_len; ++i )
310 {
311 if( cn[i] == '.' )
312 {
313 cn_idx = i;
314 break;
315 }
316 }
317
318 if( cn_idx == 0 )
319 return( -1 );
320
321 if( cn_len - cn_idx == name->len - 1 &&
322 x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 )
323 {
324 return( 0 );
325 }
326
327 return( -1 );
328 }
329
330 /*
331 * Compare two X.509 strings, case-insensitive, and allowing for some encoding
332 * variations (but not all).
333 *
334 * Return 0 if equal, -1 otherwise.
335 */
x509_string_cmp(const mbedtls_x509_buf * a,const mbedtls_x509_buf * b)336 static int x509_string_cmp( const mbedtls_x509_buf *a, const mbedtls_x509_buf *b )
337 {
338 if( a->tag == b->tag &&
339 a->len == b->len &&
340 memcmp( a->p, b->p, b->len ) == 0 )
341 {
342 return( 0 );
343 }
344
345 if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
346 ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
347 a->len == b->len &&
348 x509_memcasecmp( a->p, b->p, b->len ) == 0 )
349 {
350 return( 0 );
351 }
352
353 return( -1 );
354 }
355
356 /*
357 * Compare two X.509 Names (aka rdnSequence).
358 *
359 * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
360 * we sometimes return unequal when the full algorithm would return equal,
361 * but never the other way. (In particular, we don't do Unicode normalisation
362 * or space folding.)
363 *
364 * Return 0 if equal, -1 otherwise.
365 */
x509_name_cmp(const mbedtls_x509_name * a,const mbedtls_x509_name * b)366 static int x509_name_cmp( const mbedtls_x509_name *a, const mbedtls_x509_name *b )
367 {
368 /* Avoid recursion, it might not be optimised by the compiler */
369 while( a != NULL || b != NULL )
370 {
371 if( a == NULL || b == NULL )
372 return( -1 );
373
374 /* type */
375 if( a->oid.tag != b->oid.tag ||
376 a->oid.len != b->oid.len ||
377 memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
378 {
379 return( -1 );
380 }
381
382 /* value */
383 if( x509_string_cmp( &a->val, &b->val ) != 0 )
384 return( -1 );
385
386 /* structure of the list of sets */
387 if( a->next_merged != b->next_merged )
388 return( -1 );
389
390 a = a->next;
391 b = b->next;
392 }
393
394 /* a == NULL == b */
395 return( 0 );
396 }
397
398 /*
399 * Reset (init or clear) a verify_chain
400 */
x509_crt_verify_chain_reset(mbedtls_x509_crt_verify_chain * ver_chain)401 static void x509_crt_verify_chain_reset(
402 mbedtls_x509_crt_verify_chain *ver_chain )
403 {
404 size_t i;
405
406 for( i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++ )
407 {
408 ver_chain->items[i].crt = NULL;
409 ver_chain->items[i].flags = (uint32_t) -1;
410 }
411
412 ver_chain->len = 0;
413 }
414
415 /*
416 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
417 */
x509_get_version(unsigned char ** p,const unsigned char * end,int * ver)418 static int x509_get_version( unsigned char **p,
419 const unsigned char *end,
420 int *ver )
421 {
422 int ret;
423 size_t len;
424
425 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
426 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) != 0 )
427 {
428 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
429 {
430 *ver = 0;
431 return( 0 );
432 }
433
434 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
435 }
436
437 end = *p + len;
438
439 if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
440 return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
441
442 if( *p != end )
443 return( MBEDTLS_ERR_X509_INVALID_VERSION +
444 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
445
446 return( 0 );
447 }
448
449 /*
450 * Validity ::= SEQUENCE {
451 * notBefore Time,
452 * notAfter Time }
453 */
x509_get_dates(unsigned char ** p,const unsigned char * end,mbedtls_x509_time * from,mbedtls_x509_time * to)454 static int x509_get_dates( unsigned char **p,
455 const unsigned char *end,
456 mbedtls_x509_time *from,
457 mbedtls_x509_time *to )
458 {
459 int ret;
460 size_t len;
461
462 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
463 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
464 return( MBEDTLS_ERR_X509_INVALID_DATE + ret );
465
466 end = *p + len;
467
468 if( ( ret = mbedtls_x509_get_time( p, end, from ) ) != 0 )
469 return( ret );
470
471 if( ( ret = mbedtls_x509_get_time( p, end, to ) ) != 0 )
472 return( ret );
473
474 if( *p != end )
475 return( MBEDTLS_ERR_X509_INVALID_DATE +
476 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
477
478 return( 0 );
479 }
480
481 /*
482 * X.509 v2/v3 unique identifier (not parsed)
483 */
x509_get_uid(unsigned char ** p,const unsigned char * end,mbedtls_x509_buf * uid,int n)484 static int x509_get_uid( unsigned char **p,
485 const unsigned char *end,
486 mbedtls_x509_buf *uid, int n )
487 {
488 int ret;
489
490 if( *p == end )
491 return( 0 );
492
493 uid->tag = **p;
494
495 if( ( ret = mbedtls_asn1_get_tag( p, end, &uid->len,
496 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n ) ) != 0 )
497 {
498 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
499 return( 0 );
500
501 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
502 }
503
504 uid->p = *p;
505 *p += uid->len;
506
507 return( 0 );
508 }
509
x509_get_basic_constraints(unsigned char ** p,const unsigned char * end,int * ca_istrue,int * max_pathlen)510 static int x509_get_basic_constraints( unsigned char **p,
511 const unsigned char *end,
512 int *ca_istrue,
513 int *max_pathlen )
514 {
515 int ret;
516 size_t len;
517
518 /*
519 * BasicConstraints ::= SEQUENCE {
520 * cA BOOLEAN DEFAULT FALSE,
521 * pathLenConstraint INTEGER (0..MAX) OPTIONAL }
522 */
523 *ca_istrue = 0; /* DEFAULT FALSE */
524 *max_pathlen = 0; /* endless */
525
526 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
527 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
528 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
529
530 if( *p == end )
531 return( 0 );
532
533 if( ( ret = mbedtls_asn1_get_bool( p, end, ca_istrue ) ) != 0 )
534 {
535 if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
536 ret = mbedtls_asn1_get_int( p, end, ca_istrue );
537
538 if( ret != 0 )
539 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
540
541 if( *ca_istrue != 0 )
542 *ca_istrue = 1;
543 }
544
545 if( *p == end )
546 return( 0 );
547
548 if( ( ret = mbedtls_asn1_get_int( p, end, max_pathlen ) ) != 0 )
549 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
550
551 if( *p != end )
552 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
553 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
554
555 /* Do not accept max_pathlen equal to INT_MAX to avoid a signed integer
556 * overflow, which is an undefined behavior. */
557 if( *max_pathlen == INT_MAX )
558 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
559 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
560
561 (*max_pathlen)++;
562
563 return( 0 );
564 }
565
x509_get_ns_cert_type(unsigned char ** p,const unsigned char * end,unsigned char * ns_cert_type)566 static int x509_get_ns_cert_type( unsigned char **p,
567 const unsigned char *end,
568 unsigned char *ns_cert_type)
569 {
570 int ret;
571 mbedtls_x509_bitstring bs = { 0, 0, NULL };
572
573 if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
574 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
575
576 if( bs.len != 1 )
577 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
578 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
579
580 /* Get actual bitstring */
581 *ns_cert_type = *bs.p;
582 return( 0 );
583 }
584
x509_get_key_usage(unsigned char ** p,const unsigned char * end,unsigned int * key_usage)585 static int x509_get_key_usage( unsigned char **p,
586 const unsigned char *end,
587 unsigned int *key_usage)
588 {
589 int ret;
590 size_t i;
591 mbedtls_x509_bitstring bs = { 0, 0, NULL };
592
593 if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
594 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
595
596 if( bs.len < 1 )
597 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
598 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
599
600 /* Get actual bitstring */
601 *key_usage = 0;
602 for( i = 0; i < bs.len && i < sizeof( unsigned int ); i++ )
603 {
604 *key_usage |= (unsigned int) bs.p[i] << (8*i);
605 }
606
607 return( 0 );
608 }
609
610 /*
611 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
612 *
613 * KeyPurposeId ::= OBJECT IDENTIFIER
614 */
x509_get_ext_key_usage(unsigned char ** p,const unsigned char * end,mbedtls_x509_sequence * ext_key_usage)615 static int x509_get_ext_key_usage( unsigned char **p,
616 const unsigned char *end,
617 mbedtls_x509_sequence *ext_key_usage)
618 {
619 int ret;
620
621 if( ( ret = mbedtls_asn1_get_sequence_of( p, end, ext_key_usage, MBEDTLS_ASN1_OID ) ) != 0 )
622 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
623
624 /* Sequence length must be >= 1 */
625 if( ext_key_usage->buf.p == NULL )
626 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
627 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
628
629 return( 0 );
630 }
631
632 /*
633 * SubjectAltName ::= GeneralNames
634 *
635 * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
636 *
637 * GeneralName ::= CHOICE {
638 * otherName [0] OtherName,
639 * rfc822Name [1] IA5String,
640 * dNSName [2] IA5String,
641 * x400Address [3] ORAddress,
642 * directoryName [4] Name,
643 * ediPartyName [5] EDIPartyName,
644 * uniformResourceIdentifier [6] IA5String,
645 * iPAddress [7] OCTET STRING,
646 * registeredID [8] OBJECT IDENTIFIER }
647 *
648 * OtherName ::= SEQUENCE {
649 * type-id OBJECT IDENTIFIER,
650 * value [0] EXPLICIT ANY DEFINED BY type-id }
651 *
652 * EDIPartyName ::= SEQUENCE {
653 * nameAssigner [0] DirectoryString OPTIONAL,
654 * partyName [1] DirectoryString }
655 *
656 * NOTE: we only parse and use dNSName at this point.
657 */
x509_get_subject_alt_name(unsigned char ** p,const unsigned char * end,mbedtls_x509_sequence * subject_alt_name)658 static int x509_get_subject_alt_name( unsigned char **p,
659 const unsigned char *end,
660 mbedtls_x509_sequence *subject_alt_name )
661 {
662 int ret;
663 size_t len, tag_len;
664 mbedtls_asn1_buf *buf;
665 unsigned char tag;
666 mbedtls_asn1_sequence *cur = subject_alt_name;
667
668 /* Get main sequence tag */
669 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
670 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
671 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
672
673 if( *p + len != end )
674 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
675 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
676
677 while( *p < end )
678 {
679 if( ( end - *p ) < 1 )
680 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
681 MBEDTLS_ERR_ASN1_OUT_OF_DATA );
682
683 tag = **p;
684 (*p)++;
685 if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 )
686 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
687
688 if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) !=
689 MBEDTLS_ASN1_CONTEXT_SPECIFIC )
690 {
691 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
692 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
693 }
694
695 /* Skip everything but DNS name */
696 if( tag != ( MBEDTLS_ASN1_CONTEXT_SPECIFIC | 2 ) )
697 {
698 *p += tag_len;
699 continue;
700 }
701
702 /* Allocate and assign next pointer */
703 if( cur->buf.p != NULL )
704 {
705 if( cur->next != NULL )
706 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
707
708 cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) );
709
710 if( cur->next == NULL )
711 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
712 MBEDTLS_ERR_ASN1_ALLOC_FAILED );
713
714 cur = cur->next;
715 }
716
717 buf = &(cur->buf);
718 buf->tag = tag;
719 buf->p = *p;
720 buf->len = tag_len;
721 *p += buf->len;
722 }
723
724 /* Set final sequence entry's next pointer to NULL */
725 cur->next = NULL;
726
727 if( *p != end )
728 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
729 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
730
731 return( 0 );
732 }
733
734 /*
735 * X.509 v3 extensions
736 *
737 */
x509_get_crt_ext(unsigned char ** p,const unsigned char * end,mbedtls_x509_crt * crt)738 static int x509_get_crt_ext( unsigned char **p,
739 const unsigned char *end,
740 mbedtls_x509_crt *crt )
741 {
742 int ret;
743 size_t len;
744 unsigned char *end_ext_data, *end_ext_octet;
745
746 if( *p == end )
747 return( 0 );
748
749 if( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
750 return( ret );
751
752 end = crt->v3_ext.p + crt->v3_ext.len;
753 while( *p < end )
754 {
755 /*
756 * Extension ::= SEQUENCE {
757 * extnID OBJECT IDENTIFIER,
758 * critical BOOLEAN DEFAULT FALSE,
759 * extnValue OCTET STRING }
760 */
761 mbedtls_x509_buf extn_oid = {0, 0, NULL};
762 int is_critical = 0; /* DEFAULT FALSE */
763 int ext_type = 0;
764
765 if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
766 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
767 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
768
769 end_ext_data = *p + len;
770
771 /* Get extension ID */
772 if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &extn_oid.len,
773 MBEDTLS_ASN1_OID ) ) != 0 )
774 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
775
776 extn_oid.tag = MBEDTLS_ASN1_OID;
777 extn_oid.p = *p;
778 *p += extn_oid.len;
779
780 /* Get optional critical */
781 if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
782 ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
783 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
784
785 /* Data should be octet string type */
786 if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
787 MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
788 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
789
790 end_ext_octet = *p + len;
791
792 if( end_ext_octet != end_ext_data )
793 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
794 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
795
796 /*
797 * Detect supported extensions
798 */
799 ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type );
800
801 if( ret != 0 )
802 {
803 /* No parser found, skip extension */
804 *p = end_ext_octet;
805
806 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
807 if( is_critical )
808 {
809 /* Data is marked as critical: fail */
810 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
811 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
812 }
813 #endif
814 continue;
815 }
816
817 /* Forbid repeated extensions */
818 if( ( crt->ext_types & ext_type ) != 0 )
819 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
820
821 crt->ext_types |= ext_type;
822
823 switch( ext_type )
824 {
825 case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
826 /* Parse basic constraints */
827 if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
828 &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
829 return( ret );
830 break;
831
832 case MBEDTLS_X509_EXT_KEY_USAGE:
833 /* Parse key usage */
834 if( ( ret = x509_get_key_usage( p, end_ext_octet,
835 &crt->key_usage ) ) != 0 )
836 return( ret );
837 break;
838
839 case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
840 /* Parse extended key usage */
841 if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
842 &crt->ext_key_usage ) ) != 0 )
843 return( ret );
844 break;
845
846 case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
847 /* Parse subject alt name */
848 if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
849 &crt->subject_alt_names ) ) != 0 )
850 return( ret );
851 break;
852
853 case MBEDTLS_X509_EXT_NS_CERT_TYPE:
854 /* Parse netscape certificate type */
855 if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
856 &crt->ns_cert_type ) ) != 0 )
857 return( ret );
858 break;
859
860 default:
861 return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
862 }
863 }
864
865 if( *p != end )
866 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
867 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
868
869 return( 0 );
870 }
871
872 /*
873 * Parse and fill a single X.509 certificate in DER format
874 */
x509_crt_parse_der_core(mbedtls_x509_crt * crt,const unsigned char * buf,size_t buflen)875 static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *buf,
876 size_t buflen )
877 {
878 int ret;
879 size_t len;
880 unsigned char *p, *end, *crt_end;
881 mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
882
883 memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) );
884 memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) );
885 memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) );
886
887 /*
888 * Check for valid input
889 */
890 if( crt == NULL || buf == NULL )
891 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
892
893 // Use the original buffer until we figure out actual length
894 p = (unsigned char*) buf;
895 len = buflen;
896 end = p + len;
897
898 /*
899 * Certificate ::= SEQUENCE {
900 * tbsCertificate TBSCertificate,
901 * signatureAlgorithm AlgorithmIdentifier,
902 * signatureValue BIT STRING }
903 */
904 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
905 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
906 {
907 mbedtls_x509_crt_free( crt );
908 return( MBEDTLS_ERR_X509_INVALID_FORMAT );
909 }
910
911 if( len > (size_t) ( end - p ) )
912 {
913 mbedtls_x509_crt_free( crt );
914 return( MBEDTLS_ERR_X509_INVALID_FORMAT +
915 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
916 }
917 crt_end = p + len;
918
919 // Create and populate a new buffer for the raw field
920 crt->raw.len = crt_end - buf;
921 crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
922 if( p == NULL )
923 return( MBEDTLS_ERR_X509_ALLOC_FAILED );
924
925 memcpy( p, buf, crt->raw.len );
926
927 // Direct pointers to the new buffer
928 p += crt->raw.len - len;
929 end = crt_end = p + len;
930
931 /*
932 * TBSCertificate ::= SEQUENCE {
933 */
934 crt->tbs.p = p;
935
936 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
937 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
938 {
939 mbedtls_x509_crt_free( crt );
940 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
941 }
942
943 end = p + len;
944 crt->tbs.len = end - crt->tbs.p;
945
946 /*
947 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
948 *
949 * CertificateSerialNumber ::= INTEGER
950 *
951 * signature AlgorithmIdentifier
952 */
953 if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 ||
954 ( ret = mbedtls_x509_get_serial( &p, end, &crt->serial ) ) != 0 ||
955 ( ret = mbedtls_x509_get_alg( &p, end, &crt->sig_oid,
956 &sig_params1 ) ) != 0 )
957 {
958 mbedtls_x509_crt_free( crt );
959 return( ret );
960 }
961
962 if( crt->version < 0 || crt->version > 2 )
963 {
964 mbedtls_x509_crt_free( crt );
965 return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
966 }
967
968 crt->version++;
969
970 if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1,
971 &crt->sig_md, &crt->sig_pk,
972 &crt->sig_opts ) ) != 0 )
973 {
974 mbedtls_x509_crt_free( crt );
975 return( ret );
976 }
977
978 /*
979 * issuer Name
980 */
981 crt->issuer_raw.p = p;
982
983 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
984 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
985 {
986 mbedtls_x509_crt_free( crt );
987 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
988 }
989
990 if( ( ret = mbedtls_x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
991 {
992 mbedtls_x509_crt_free( crt );
993 return( ret );
994 }
995
996 crt->issuer_raw.len = p - crt->issuer_raw.p;
997
998 /*
999 * Validity ::= SEQUENCE {
1000 * notBefore Time,
1001 * notAfter Time }
1002 *
1003 */
1004 if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
1005 &crt->valid_to ) ) != 0 )
1006 {
1007 mbedtls_x509_crt_free( crt );
1008 return( ret );
1009 }
1010
1011 /*
1012 * subject Name
1013 */
1014 crt->subject_raw.p = p;
1015
1016 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1017 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1018 {
1019 mbedtls_x509_crt_free( crt );
1020 return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
1021 }
1022
1023 if( len && ( ret = mbedtls_x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
1024 {
1025 mbedtls_x509_crt_free( crt );
1026 return( ret );
1027 }
1028
1029 crt->subject_raw.len = p - crt->subject_raw.p;
1030
1031 /*
1032 * SubjectPublicKeyInfo
1033 */
1034 if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
1035 {
1036 mbedtls_x509_crt_free( crt );
1037 return( ret );
1038 }
1039
1040 /*
1041 * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
1042 * -- If present, version shall be v2 or v3
1043 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
1044 * -- If present, version shall be v2 or v3
1045 * extensions [3] EXPLICIT Extensions OPTIONAL
1046 * -- If present, version shall be v3
1047 */
1048 if( crt->version == 2 || crt->version == 3 )
1049 {
1050 ret = x509_get_uid( &p, end, &crt->issuer_id, 1 );
1051 if( ret != 0 )
1052 {
1053 mbedtls_x509_crt_free( crt );
1054 return( ret );
1055 }
1056 }
1057
1058 if( crt->version == 2 || crt->version == 3 )
1059 {
1060 ret = x509_get_uid( &p, end, &crt->subject_id, 2 );
1061 if( ret != 0 )
1062 {
1063 mbedtls_x509_crt_free( crt );
1064 return( ret );
1065 }
1066 }
1067
1068 #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
1069 if( crt->version == 3 )
1070 #endif
1071 {
1072 ret = x509_get_crt_ext( &p, end, crt );
1073 if( ret != 0 )
1074 {
1075 mbedtls_x509_crt_free( crt );
1076 return( ret );
1077 }
1078 }
1079
1080 if( p != end )
1081 {
1082 mbedtls_x509_crt_free( crt );
1083 return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1084 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1085 }
1086
1087 end = crt_end;
1088
1089 /*
1090 * }
1091 * -- end of TBSCertificate
1092 *
1093 * signatureAlgorithm AlgorithmIdentifier,
1094 * signatureValue BIT STRING
1095 */
1096 if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 )
1097 {
1098 mbedtls_x509_crt_free( crt );
1099 return( ret );
1100 }
1101
1102 if( crt->sig_oid.len != sig_oid2.len ||
1103 memcmp( crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len ) != 0 ||
1104 sig_params1.len != sig_params2.len ||
1105 ( sig_params1.len != 0 &&
1106 memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
1107 {
1108 mbedtls_x509_crt_free( crt );
1109 return( MBEDTLS_ERR_X509_SIG_MISMATCH );
1110 }
1111
1112 if( ( ret = mbedtls_x509_get_sig( &p, end, &crt->sig ) ) != 0 )
1113 {
1114 mbedtls_x509_crt_free( crt );
1115 return( ret );
1116 }
1117
1118 if( p != end )
1119 {
1120 mbedtls_x509_crt_free( crt );
1121 return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1122 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1123 }
1124
1125 return( 0 );
1126 }
1127
1128 /*
1129 * Parse one X.509 certificate in DER format from a buffer and add them to a
1130 * chained list
1131 */
mbedtls_x509_crt_parse_der(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen)1132 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
1133 size_t buflen )
1134 {
1135 int ret;
1136 mbedtls_x509_crt *crt = chain, *prev = NULL;
1137
1138 /*
1139 * Check for valid input
1140 */
1141 if( crt == NULL || buf == NULL )
1142 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1143
1144 while( crt->version != 0 && crt->next != NULL )
1145 {
1146 prev = crt;
1147 crt = crt->next;
1148 }
1149
1150 /*
1151 * Add new certificate on the end of the chain if needed.
1152 */
1153 if( crt->version != 0 && crt->next == NULL )
1154 {
1155 crt->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
1156
1157 if( crt->next == NULL )
1158 return( MBEDTLS_ERR_X509_ALLOC_FAILED );
1159
1160 prev = crt;
1161 mbedtls_x509_crt_init( crt->next );
1162 crt = crt->next;
1163 }
1164
1165 if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
1166 {
1167 if( prev )
1168 prev->next = NULL;
1169
1170 if( crt != chain )
1171 mbedtls_free( crt );
1172
1173 return( ret );
1174 }
1175
1176 return( 0 );
1177 }
1178
1179 /*
1180 * Parse one or more PEM certificates from a buffer and add them to the chained
1181 * list
1182 */
mbedtls_x509_crt_parse(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen)1183 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen )
1184 {
1185 #if defined(MBEDTLS_PEM_PARSE_C)
1186 int success = 0, first_error = 0, total_failed = 0;
1187 int buf_format = MBEDTLS_X509_FORMAT_DER;
1188 #endif
1189
1190 /*
1191 * Check for valid input
1192 */
1193 if( chain == NULL || buf == NULL )
1194 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1195
1196 /*
1197 * Determine buffer content. Buffer contains either one DER certificate or
1198 * one or more PEM certificates.
1199 */
1200 #if defined(MBEDTLS_PEM_PARSE_C)
1201 if( buflen != 0 && buf[buflen - 1] == '\0' &&
1202 strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
1203 {
1204 buf_format = MBEDTLS_X509_FORMAT_PEM;
1205 }
1206
1207 if( buf_format == MBEDTLS_X509_FORMAT_DER )
1208 return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1209 #else
1210 return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1211 #endif
1212
1213 #if defined(MBEDTLS_PEM_PARSE_C)
1214 if( buf_format == MBEDTLS_X509_FORMAT_PEM )
1215 {
1216 int ret;
1217 mbedtls_pem_context pem;
1218
1219 /* 1 rather than 0 since the terminating NULL byte is counted in */
1220 while( buflen > 1 )
1221 {
1222 size_t use_len;
1223 mbedtls_pem_init( &pem );
1224
1225 /* If we get there, we know the string is null-terminated */
1226 ret = mbedtls_pem_read_buffer( &pem,
1227 "-----BEGIN CERTIFICATE-----",
1228 "-----END CERTIFICATE-----",
1229 buf, NULL, 0, &use_len );
1230
1231 if( ret == 0 )
1232 {
1233 /*
1234 * Was PEM encoded
1235 */
1236 buflen -= use_len;
1237 buf += use_len;
1238 }
1239 else if( ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA )
1240 {
1241 return( ret );
1242 }
1243 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1244 {
1245 mbedtls_pem_free( &pem );
1246
1247 /*
1248 * PEM header and footer were found
1249 */
1250 buflen -= use_len;
1251 buf += use_len;
1252
1253 if( first_error == 0 )
1254 first_error = ret;
1255
1256 total_failed++;
1257 continue;
1258 }
1259 else
1260 break;
1261
1262 ret = mbedtls_x509_crt_parse_der( chain, pem.buf, pem.buflen );
1263
1264 mbedtls_pem_free( &pem );
1265
1266 if( ret != 0 )
1267 {
1268 /*
1269 * Quit parsing on a memory error
1270 */
1271 if( ret == MBEDTLS_ERR_X509_ALLOC_FAILED )
1272 return( ret );
1273
1274 if( first_error == 0 )
1275 first_error = ret;
1276
1277 total_failed++;
1278 continue;
1279 }
1280
1281 success = 1;
1282 }
1283 }
1284
1285 if( success )
1286 return( total_failed );
1287 else if( first_error )
1288 return( first_error );
1289 else
1290 return( MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT );
1291 #endif /* MBEDTLS_PEM_PARSE_C */
1292 }
1293
1294 #if defined(MBEDTLS_FS_IO)
1295 /*
1296 * Load one or more certificates and add them to the chained list
1297 */
mbedtls_x509_crt_parse_file(mbedtls_x509_crt * chain,const char * path)1298 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path )
1299 {
1300 int ret;
1301 size_t n;
1302 unsigned char *buf;
1303
1304 if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
1305 return( ret );
1306
1307 ret = mbedtls_x509_crt_parse( chain, buf, n );
1308
1309 mbedtls_platform_zeroize( buf, n );
1310 mbedtls_free( buf );
1311
1312 return( ret );
1313 }
1314
mbedtls_x509_crt_parse_path(mbedtls_x509_crt * chain,const char * path)1315 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
1316 {
1317 int ret = 0;
1318 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
1319 int w_ret;
1320 WCHAR szDir[MAX_PATH];
1321 char filename[MAX_PATH];
1322 char *p;
1323 size_t len = strlen( path );
1324 int lengthAsInt = 0;
1325
1326 WIN32_FIND_DATAW file_data;
1327 HANDLE hFind;
1328
1329 if( len > MAX_PATH - 3 )
1330 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1331
1332 memset( szDir, 0, sizeof(szDir) );
1333 memset( filename, 0, MAX_PATH );
1334 memcpy( filename, path, len );
1335 filename[len++] = '\\';
1336 p = filename + len;
1337 filename[len++] = '*';
1338
1339 if ( FAILED ( SizeTToInt( len, &lengthAsInt ) ) )
1340 return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1341
1342 /*
1343 * Note this function uses the code page CP_ACP, and assumes the incoming
1344 * string is encoded in ANSI, before translating it into Unicode. If the
1345 * incoming string were changed to be UTF-8, then the length check needs to
1346 * change to check the number of characters, not the number of bytes, in the
1347 * incoming string are less than MAX_PATH to avoid a buffer overrun with
1348 * MultiByteToWideChar().
1349 */
1350 w_ret = MultiByteToWideChar( CP_ACP, 0, filename, lengthAsInt, szDir,
1351 MAX_PATH - 3 );
1352 if( w_ret == 0 )
1353 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1354
1355 hFind = FindFirstFileW( szDir, &file_data );
1356 if( hFind == INVALID_HANDLE_VALUE )
1357 return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1358
1359 len = MAX_PATH - len;
1360 do
1361 {
1362 memset( p, 0, len );
1363
1364 if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
1365 continue;
1366
1367 if ( FAILED( SizeTToInt( wcslen( file_data.cFileName ), &lengthAsInt ) ) )
1368 return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1369
1370 w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
1371 lengthAsInt,
1372 p, (int) len - 1,
1373 NULL, NULL );
1374 if( w_ret == 0 )
1375 {
1376 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1377 goto cleanup;
1378 }
1379
1380 w_ret = mbedtls_x509_crt_parse_file( chain, filename );
1381 if( w_ret < 0 )
1382 ret++;
1383 else
1384 ret += w_ret;
1385 }
1386 while( FindNextFileW( hFind, &file_data ) != 0 );
1387
1388 if( GetLastError() != ERROR_NO_MORE_FILES )
1389 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1390
1391 cleanup:
1392 FindClose( hFind );
1393 #else /* _WIN32 */
1394 int t_ret;
1395 int snp_ret;
1396 struct stat sb;
1397 struct dirent *entry;
1398 char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
1399 DIR *dir = opendir( path );
1400
1401 if( dir == NULL )
1402 return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1403
1404 #if defined(MBEDTLS_THREADING_C)
1405 if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 )
1406 {
1407 closedir( dir );
1408 return( ret );
1409 }
1410 #endif /* MBEDTLS_THREADING_C */
1411
1412 while( ( entry = readdir( dir ) ) != NULL )
1413 {
1414 snp_ret = mbedtls_snprintf( entry_name, sizeof entry_name,
1415 "%s/%s", path, entry->d_name );
1416
1417 if( snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name )
1418 {
1419 ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
1420 goto cleanup;
1421 }
1422 else if( stat( entry_name, &sb ) == -1 )
1423 {
1424 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1425 goto cleanup;
1426 }
1427
1428 if( !S_ISREG( sb.st_mode ) )
1429 continue;
1430
1431 // Ignore parse errors
1432 //
1433 t_ret = mbedtls_x509_crt_parse_file( chain, entry_name );
1434 if( t_ret < 0 )
1435 ret++;
1436 else
1437 ret += t_ret;
1438 }
1439
1440 cleanup:
1441 closedir( dir );
1442
1443 #if defined(MBEDTLS_THREADING_C)
1444 if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 )
1445 ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1446 #endif /* MBEDTLS_THREADING_C */
1447
1448 #endif /* _WIN32 */
1449
1450 return( ret );
1451 }
1452 #endif /* MBEDTLS_FS_IO */
1453
x509_info_subject_alt_name(char ** buf,size_t * size,const mbedtls_x509_sequence * subject_alt_name)1454 static int x509_info_subject_alt_name( char **buf, size_t *size,
1455 const mbedtls_x509_sequence *subject_alt_name )
1456 {
1457 size_t i;
1458 size_t n = *size;
1459 char *p = *buf;
1460 const mbedtls_x509_sequence *cur = subject_alt_name;
1461 const char *sep = "";
1462 size_t sep_len = 0;
1463
1464 while( cur != NULL )
1465 {
1466 if( cur->buf.len + sep_len >= n )
1467 {
1468 *p = '\0';
1469 return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
1470 }
1471
1472 n -= cur->buf.len + sep_len;
1473 for( i = 0; i < sep_len; i++ )
1474 *p++ = sep[i];
1475 for( i = 0; i < cur->buf.len; i++ )
1476 *p++ = cur->buf.p[i];
1477
1478 sep = ", ";
1479 sep_len = 2;
1480
1481 cur = cur->next;
1482 }
1483
1484 *p = '\0';
1485
1486 *size = n;
1487 *buf = p;
1488
1489 return( 0 );
1490 }
1491
1492 #define PRINT_ITEM(i) \
1493 { \
1494 ret = mbedtls_snprintf( p, n, "%s" i, sep ); \
1495 MBEDTLS_X509_SAFE_SNPRINTF; \
1496 sep = ", "; \
1497 }
1498
1499 #define CERT_TYPE(type,name) \
1500 if( ns_cert_type & (type) ) \
1501 PRINT_ITEM( name );
1502
x509_info_cert_type(char ** buf,size_t * size,unsigned char ns_cert_type)1503 static int x509_info_cert_type( char **buf, size_t *size,
1504 unsigned char ns_cert_type )
1505 {
1506 int ret;
1507 size_t n = *size;
1508 char *p = *buf;
1509 const char *sep = "";
1510
1511 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT, "SSL Client" );
1512 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER, "SSL Server" );
1513 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL, "Email" );
1514 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing" );
1515 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED, "Reserved" );
1516 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA, "SSL CA" );
1517 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA, "Email CA" );
1518 CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA" );
1519
1520 *size = n;
1521 *buf = p;
1522
1523 return( 0 );
1524 }
1525
1526 #define KEY_USAGE(code,name) \
1527 if( key_usage & (code) ) \
1528 PRINT_ITEM( name );
1529
x509_info_key_usage(char ** buf,size_t * size,unsigned int key_usage)1530 static int x509_info_key_usage( char **buf, size_t *size,
1531 unsigned int key_usage )
1532 {
1533 int ret;
1534 size_t n = *size;
1535 char *p = *buf;
1536 const char *sep = "";
1537
1538 KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE, "Digital Signature" );
1539 KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION, "Non Repudiation" );
1540 KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT, "Key Encipherment" );
1541 KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT, "Data Encipherment" );
1542 KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT, "Key Agreement" );
1543 KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN, "Key Cert Sign" );
1544 KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN, "CRL Sign" );
1545 KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY, "Encipher Only" );
1546 KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY, "Decipher Only" );
1547
1548 *size = n;
1549 *buf = p;
1550
1551 return( 0 );
1552 }
1553
x509_info_ext_key_usage(char ** buf,size_t * size,const mbedtls_x509_sequence * extended_key_usage)1554 static int x509_info_ext_key_usage( char **buf, size_t *size,
1555 const mbedtls_x509_sequence *extended_key_usage )
1556 {
1557 int ret;
1558 const char *desc;
1559 size_t n = *size;
1560 char *p = *buf;
1561 const mbedtls_x509_sequence *cur = extended_key_usage;
1562 const char *sep = "";
1563
1564 while( cur != NULL )
1565 {
1566 if( mbedtls_oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
1567 desc = "???";
1568
1569 ret = mbedtls_snprintf( p, n, "%s%s", sep, desc );
1570 MBEDTLS_X509_SAFE_SNPRINTF;
1571
1572 sep = ", ";
1573
1574 cur = cur->next;
1575 }
1576
1577 *size = n;
1578 *buf = p;
1579
1580 return( 0 );
1581 }
1582
1583 /*
1584 * Return an informational string about the certificate.
1585 */
1586 #define BEFORE_COLON 18
1587 #define BC "18"
mbedtls_x509_crt_info(char * buf,size_t size,const char * prefix,const mbedtls_x509_crt * crt)1588 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
1589 const mbedtls_x509_crt *crt )
1590 {
1591 int ret;
1592 size_t n;
1593 char *p;
1594 char key_size_str[BEFORE_COLON];
1595
1596 p = buf;
1597 n = size;
1598
1599 if( NULL == crt )
1600 {
1601 ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" );
1602 MBEDTLS_X509_SAFE_SNPRINTF;
1603
1604 return( (int) ( size - n ) );
1605 }
1606
1607 ret = mbedtls_snprintf( p, n, "%scert. version : %d\n",
1608 prefix, crt->version );
1609 MBEDTLS_X509_SAFE_SNPRINTF;
1610 ret = mbedtls_snprintf( p, n, "%sserial number : ",
1611 prefix );
1612 MBEDTLS_X509_SAFE_SNPRINTF;
1613
1614 ret = mbedtls_x509_serial_gets( p, n, &crt->serial );
1615 MBEDTLS_X509_SAFE_SNPRINTF;
1616
1617 ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix );
1618 MBEDTLS_X509_SAFE_SNPRINTF;
1619 ret = mbedtls_x509_dn_gets( p, n, &crt->issuer );
1620 MBEDTLS_X509_SAFE_SNPRINTF;
1621
1622 ret = mbedtls_snprintf( p, n, "\n%ssubject name : ", prefix );
1623 MBEDTLS_X509_SAFE_SNPRINTF;
1624 ret = mbedtls_x509_dn_gets( p, n, &crt->subject );
1625 MBEDTLS_X509_SAFE_SNPRINTF;
1626
1627 ret = mbedtls_snprintf( p, n, "\n%sissued on : " \
1628 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1629 crt->valid_from.year, crt->valid_from.mon,
1630 crt->valid_from.day, crt->valid_from.hour,
1631 crt->valid_from.min, crt->valid_from.sec );
1632 MBEDTLS_X509_SAFE_SNPRINTF;
1633
1634 ret = mbedtls_snprintf( p, n, "\n%sexpires on : " \
1635 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1636 crt->valid_to.year, crt->valid_to.mon,
1637 crt->valid_to.day, crt->valid_to.hour,
1638 crt->valid_to.min, crt->valid_to.sec );
1639 MBEDTLS_X509_SAFE_SNPRINTF;
1640
1641 ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix );
1642 MBEDTLS_X509_SAFE_SNPRINTF;
1643
1644 ret = mbedtls_x509_sig_alg_gets( p, n, &crt->sig_oid, crt->sig_pk,
1645 crt->sig_md, crt->sig_opts );
1646 MBEDTLS_X509_SAFE_SNPRINTF;
1647
1648 /* Key size */
1649 if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON,
1650 mbedtls_pk_get_name( &crt->pk ) ) ) != 0 )
1651 {
1652 return( ret );
1653 }
1654
1655 ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
1656 (int) mbedtls_pk_get_bitlen( &crt->pk ) );
1657 MBEDTLS_X509_SAFE_SNPRINTF;
1658
1659 /*
1660 * Optional extensions
1661 */
1662
1663 if( crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS )
1664 {
1665 ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
1666 crt->ca_istrue ? "true" : "false" );
1667 MBEDTLS_X509_SAFE_SNPRINTF;
1668
1669 if( crt->max_pathlen > 0 )
1670 {
1671 ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
1672 MBEDTLS_X509_SAFE_SNPRINTF;
1673 }
1674 }
1675
1676 if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
1677 {
1678 ret = mbedtls_snprintf( p, n, "\n%ssubject alt name : ", prefix );
1679 MBEDTLS_X509_SAFE_SNPRINTF;
1680
1681 if( ( ret = x509_info_subject_alt_name( &p, &n,
1682 &crt->subject_alt_names ) ) != 0 )
1683 return( ret );
1684 }
1685
1686 if( crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE )
1687 {
1688 ret = mbedtls_snprintf( p, n, "\n%scert. type : ", prefix );
1689 MBEDTLS_X509_SAFE_SNPRINTF;
1690
1691 if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
1692 return( ret );
1693 }
1694
1695 if( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE )
1696 {
1697 ret = mbedtls_snprintf( p, n, "\n%skey usage : ", prefix );
1698 MBEDTLS_X509_SAFE_SNPRINTF;
1699
1700 if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
1701 return( ret );
1702 }
1703
1704 if( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE )
1705 {
1706 ret = mbedtls_snprintf( p, n, "\n%sext key usage : ", prefix );
1707 MBEDTLS_X509_SAFE_SNPRINTF;
1708
1709 if( ( ret = x509_info_ext_key_usage( &p, &n,
1710 &crt->ext_key_usage ) ) != 0 )
1711 return( ret );
1712 }
1713
1714 ret = mbedtls_snprintf( p, n, "\n" );
1715 MBEDTLS_X509_SAFE_SNPRINTF;
1716
1717 return( (int) ( size - n ) );
1718 }
1719
1720 struct x509_crt_verify_string {
1721 int code;
1722 const char *string;
1723 };
1724
1725 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
1726 { MBEDTLS_X509_BADCERT_EXPIRED, "The certificate validity has expired" },
1727 { MBEDTLS_X509_BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)" },
1728 { MBEDTLS_X509_BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN" },
1729 { MBEDTLS_X509_BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA" },
1730 { MBEDTLS_X509_BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA" },
1731 { MBEDTLS_X509_BADCRL_EXPIRED, "The CRL is expired" },
1732 { MBEDTLS_X509_BADCERT_MISSING, "Certificate was missing" },
1733 { MBEDTLS_X509_BADCERT_SKIP_VERIFY, "Certificate verification was skipped" },
1734 { MBEDTLS_X509_BADCERT_OTHER, "Other reason (can be used by verify callback)" },
1735 { MBEDTLS_X509_BADCERT_FUTURE, "The certificate validity starts in the future" },
1736 { MBEDTLS_X509_BADCRL_FUTURE, "The CRL is from the future" },
1737 { MBEDTLS_X509_BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension" },
1738 { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
1739 { MBEDTLS_X509_BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension" },
1740 { MBEDTLS_X509_BADCERT_BAD_MD, "The certificate is signed with an unacceptable hash." },
1741 { MBEDTLS_X509_BADCERT_BAD_PK, "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1742 { MBEDTLS_X509_BADCERT_BAD_KEY, "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
1743 { MBEDTLS_X509_BADCRL_BAD_MD, "The CRL is signed with an unacceptable hash." },
1744 { MBEDTLS_X509_BADCRL_BAD_PK, "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1745 { MBEDTLS_X509_BADCRL_BAD_KEY, "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
1746 { 0, NULL }
1747 };
1748
mbedtls_x509_crt_verify_info(char * buf,size_t size,const char * prefix,uint32_t flags)1749 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
1750 uint32_t flags )
1751 {
1752 int ret;
1753 const struct x509_crt_verify_string *cur;
1754 char *p = buf;
1755 size_t n = size;
1756
1757 for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
1758 {
1759 if( ( flags & cur->code ) == 0 )
1760 continue;
1761
1762 ret = mbedtls_snprintf( p, n, "%s%s\n", prefix, cur->string );
1763 MBEDTLS_X509_SAFE_SNPRINTF;
1764 flags ^= cur->code;
1765 }
1766
1767 if( flags != 0 )
1768 {
1769 ret = mbedtls_snprintf( p, n, "%sUnknown reason "
1770 "(this should not happen)\n", prefix );
1771 MBEDTLS_X509_SAFE_SNPRINTF;
1772 }
1773
1774 return( (int) ( size - n ) );
1775 }
1776
1777 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt * crt,unsigned int usage)1778 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
1779 unsigned int usage )
1780 {
1781 unsigned int usage_must, usage_may;
1782 unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
1783 | MBEDTLS_X509_KU_DECIPHER_ONLY;
1784
1785 if( ( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) == 0 )
1786 return( 0 );
1787
1788 usage_must = usage & ~may_mask;
1789
1790 if( ( ( crt->key_usage & ~may_mask ) & usage_must ) != usage_must )
1791 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1792
1793 usage_may = usage & may_mask;
1794
1795 if( ( ( crt->key_usage & may_mask ) | usage_may ) != usage_may )
1796 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1797
1798 return( 0 );
1799 }
1800 #endif
1801
1802 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt * crt,const char * usage_oid,size_t usage_len)1803 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
1804 const char *usage_oid,
1805 size_t usage_len )
1806 {
1807 const mbedtls_x509_sequence *cur;
1808
1809 /* Extension is not mandatory, absent means no restriction */
1810 if( ( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 )
1811 return( 0 );
1812
1813 /*
1814 * Look for the requested usage (or wildcard ANY) in our list
1815 */
1816 for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
1817 {
1818 const mbedtls_x509_buf *cur_oid = &cur->buf;
1819
1820 if( cur_oid->len == usage_len &&
1821 memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
1822 {
1823 return( 0 );
1824 }
1825
1826 if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) == 0 )
1827 return( 0 );
1828 }
1829
1830 return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1831 }
1832 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
1833
1834 #if defined(MBEDTLS_X509_CRL_PARSE_C)
1835 /*
1836 * Return 1 if the certificate is revoked, or 0 otherwise.
1837 */
mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt * crt,const mbedtls_x509_crl * crl)1838 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl )
1839 {
1840 const mbedtls_x509_crl_entry *cur = &crl->entry;
1841
1842 while( cur != NULL && cur->serial.len != 0 )
1843 {
1844 if( crt->serial.len == cur->serial.len &&
1845 memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
1846 {
1847 return( 1 );
1848 }
1849
1850 cur = cur->next;
1851 }
1852
1853 return( 0 );
1854 }
1855
1856 /*
1857 * Check that the given certificate is not revoked according to the CRL.
1858 * Skip validation if no CRL for the given CA is present.
1859 */
x509_crt_verifycrl(mbedtls_x509_crt * crt,mbedtls_x509_crt * ca,mbedtls_x509_crl * crl_list,const mbedtls_x509_crt_profile * profile)1860 static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
1861 mbedtls_x509_crl *crl_list,
1862 const mbedtls_x509_crt_profile *profile )
1863 {
1864 int flags = 0;
1865 unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1866 const mbedtls_md_info_t *md_info;
1867
1868 if( ca == NULL )
1869 return( flags );
1870
1871 while( crl_list != NULL )
1872 {
1873 if( crl_list->version == 0 ||
1874 x509_name_cmp( &crl_list->issuer, &ca->subject ) != 0 )
1875 {
1876 crl_list = crl_list->next;
1877 continue;
1878 }
1879
1880 /*
1881 * Check if the CA is configured to sign CRLs
1882 */
1883 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1884 if( mbedtls_x509_crt_check_key_usage( ca,
1885 MBEDTLS_X509_KU_CRL_SIGN ) != 0 )
1886 {
1887 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1888 break;
1889 }
1890 #endif
1891
1892 /*
1893 * Check if CRL is correctly signed by the trusted CA
1894 */
1895 if( x509_profile_check_md_alg( profile, crl_list->sig_md ) != 0 )
1896 flags |= MBEDTLS_X509_BADCRL_BAD_MD;
1897
1898 if( x509_profile_check_pk_alg( profile, crl_list->sig_pk ) != 0 )
1899 flags |= MBEDTLS_X509_BADCRL_BAD_PK;
1900
1901 md_info = mbedtls_md_info_from_type( crl_list->sig_md );
1902 if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 )
1903 {
1904 /* Note: this can't happen except after an internal error */
1905 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1906 break;
1907 }
1908
1909 if( x509_profile_check_key( profile, &ca->pk ) != 0 )
1910 flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
1911
1912 if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
1913 crl_list->sig_md, hash, mbedtls_md_get_size( md_info ),
1914 crl_list->sig.p, crl_list->sig.len ) != 0 )
1915 {
1916 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1917 break;
1918 }
1919
1920 /*
1921 * Check for validity of CRL (Do not drop out)
1922 */
1923 if( mbedtls_x509_time_is_past( &crl_list->next_update ) )
1924 flags |= MBEDTLS_X509_BADCRL_EXPIRED;
1925
1926 if( mbedtls_x509_time_is_future( &crl_list->this_update ) )
1927 flags |= MBEDTLS_X509_BADCRL_FUTURE;
1928
1929 /*
1930 * Check if certificate is revoked
1931 */
1932 if( mbedtls_x509_crt_is_revoked( crt, crl_list ) )
1933 {
1934 flags |= MBEDTLS_X509_BADCERT_REVOKED;
1935 break;
1936 }
1937
1938 crl_list = crl_list->next;
1939 }
1940
1941 return( flags );
1942 }
1943 #endif /* MBEDTLS_X509_CRL_PARSE_C */
1944
1945 /*
1946 * Check the signature of a certificate by its parent
1947 */
x509_crt_check_signature(const mbedtls_x509_crt * child,mbedtls_x509_crt * parent,mbedtls_x509_crt_restart_ctx * rs_ctx)1948 static int x509_crt_check_signature( const mbedtls_x509_crt *child,
1949 mbedtls_x509_crt *parent,
1950 mbedtls_x509_crt_restart_ctx *rs_ctx )
1951 {
1952 const mbedtls_md_info_t *md_info;
1953 unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1954
1955 md_info = mbedtls_md_info_from_type( child->sig_md );
1956 if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
1957 {
1958 /* Note: this can't happen except after an internal error */
1959 return( -1 );
1960 }
1961
1962 /* Skip expensive computation on obvious mismatch */
1963 if( ! mbedtls_pk_can_do( &parent->pk, child->sig_pk ) )
1964 return( -1 );
1965
1966 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
1967 if( rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA )
1968 {
1969 return( mbedtls_pk_verify_restartable( &parent->pk,
1970 child->sig_md, hash, mbedtls_md_get_size( md_info ),
1971 child->sig.p, child->sig.len, &rs_ctx->pk ) );
1972 }
1973 #else
1974 (void) rs_ctx;
1975 #endif
1976
1977 return( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
1978 child->sig_md, hash, mbedtls_md_get_size( md_info ),
1979 child->sig.p, child->sig.len ) );
1980 }
1981
1982 /*
1983 * Check if 'parent' is a suitable parent (signing CA) for 'child'.
1984 * Return 0 if yes, -1 if not.
1985 *
1986 * top means parent is a locally-trusted certificate
1987 */
x509_crt_check_parent(const mbedtls_x509_crt * child,const mbedtls_x509_crt * parent,int top)1988 static int x509_crt_check_parent( const mbedtls_x509_crt *child,
1989 const mbedtls_x509_crt *parent,
1990 int top )
1991 {
1992 int need_ca_bit;
1993
1994 /* Parent must be the issuer */
1995 if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
1996 return( -1 );
1997
1998 /* Parent must have the basicConstraints CA bit set as a general rule */
1999 need_ca_bit = 1;
2000
2001 /* Exception: v1/v2 certificates that are locally trusted. */
2002 if( top && parent->version < 3 )
2003 need_ca_bit = 0;
2004
2005 if( need_ca_bit && ! parent->ca_istrue )
2006 return( -1 );
2007
2008 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
2009 if( need_ca_bit &&
2010 mbedtls_x509_crt_check_key_usage( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
2011 {
2012 return( -1 );
2013 }
2014 #endif
2015
2016 return( 0 );
2017 }
2018
2019 /*
2020 * Find a suitable parent for child in candidates, or return NULL.
2021 *
2022 * Here suitable is defined as:
2023 * 1. subject name matches child's issuer
2024 * 2. if necessary, the CA bit is set and key usage allows signing certs
2025 * 3. for trusted roots, the signature is correct
2026 * (for intermediates, the signature is checked and the result reported)
2027 * 4. pathlen constraints are satisfied
2028 *
2029 * If there's a suitable candidate which is also time-valid, return the first
2030 * such. Otherwise, return the first suitable candidate (or NULL if there is
2031 * none).
2032 *
2033 * The rationale for this rule is that someone could have a list of trusted
2034 * roots with two versions on the same root with different validity periods.
2035 * (At least one user reported having such a list and wanted it to just work.)
2036 * The reason we don't just require time-validity is that generally there is
2037 * only one version, and if it's expired we want the flags to state that
2038 * rather than NOT_TRUSTED, as would be the case if we required it here.
2039 *
2040 * The rationale for rule 3 (signature for trusted roots) is that users might
2041 * have two versions of the same CA with different keys in their list, and the
2042 * way we select the correct one is by checking the signature (as we don't
2043 * rely on key identifier extensions). (This is one way users might choose to
2044 * handle key rollover, another relies on self-issued certs, see [SIRO].)
2045 *
2046 * Arguments:
2047 * - [in] child: certificate for which we're looking for a parent
2048 * - [in] candidates: chained list of potential parents
2049 * - [out] r_parent: parent found (or NULL)
2050 * - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0
2051 * - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
2052 * of the chain, 0 otherwise
2053 * - [in] path_cnt: number of intermediates seen so far
2054 * - [in] self_cnt: number of self-signed intermediates seen so far
2055 * (will never be greater than path_cnt)
2056 * - [in-out] rs_ctx: context for restarting operations
2057 *
2058 * Return value:
2059 * - 0 on success
2060 * - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2061 */
x509_crt_find_parent_in(mbedtls_x509_crt * child,mbedtls_x509_crt * candidates,mbedtls_x509_crt ** r_parent,int * r_signature_is_good,int top,unsigned path_cnt,unsigned self_cnt,mbedtls_x509_crt_restart_ctx * rs_ctx)2062 static int x509_crt_find_parent_in(
2063 mbedtls_x509_crt *child,
2064 mbedtls_x509_crt *candidates,
2065 mbedtls_x509_crt **r_parent,
2066 int *r_signature_is_good,
2067 int top,
2068 unsigned path_cnt,
2069 unsigned self_cnt,
2070 mbedtls_x509_crt_restart_ctx *rs_ctx )
2071 {
2072 int ret;
2073 mbedtls_x509_crt *parent, *fallback_parent;
2074 int signature_is_good, fallback_signature_is_good;
2075
2076 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2077 /* did we have something in progress? */
2078 if( rs_ctx != NULL && rs_ctx->parent != NULL )
2079 {
2080 /* restore saved state */
2081 parent = rs_ctx->parent;
2082 fallback_parent = rs_ctx->fallback_parent;
2083 fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
2084
2085 /* clear saved state */
2086 rs_ctx->parent = NULL;
2087 rs_ctx->fallback_parent = NULL;
2088 rs_ctx->fallback_signature_is_good = 0;
2089
2090 /* resume where we left */
2091 goto check_signature;
2092 }
2093 #endif
2094
2095 fallback_parent = NULL;
2096 fallback_signature_is_good = 0;
2097
2098 for( parent = candidates; parent != NULL; parent = parent->next )
2099 {
2100 /* basic parenting skills (name, CA bit, key usage) */
2101 if( x509_crt_check_parent( child, parent, top ) != 0 )
2102 continue;
2103
2104 /* +1 because stored max_pathlen is 1 higher that the actual value */
2105 if( parent->max_pathlen > 0 &&
2106 (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt )
2107 {
2108 continue;
2109 }
2110
2111 /* Signature */
2112 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2113 check_signature:
2114 #endif
2115 ret = x509_crt_check_signature( child, parent, rs_ctx );
2116
2117 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2118 if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2119 {
2120 /* save state */
2121 rs_ctx->parent = parent;
2122 rs_ctx->fallback_parent = fallback_parent;
2123 rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
2124
2125 return( ret );
2126 }
2127 #else
2128 (void) ret;
2129 #endif
2130
2131 signature_is_good = ret == 0;
2132 if( top && ! signature_is_good )
2133 continue;
2134
2135 /* optional time check */
2136 if( mbedtls_x509_time_is_past( &parent->valid_to ) ||
2137 mbedtls_x509_time_is_future( &parent->valid_from ) )
2138 {
2139 if( fallback_parent == NULL )
2140 {
2141 fallback_parent = parent;
2142 fallback_signature_is_good = signature_is_good;
2143 }
2144
2145 continue;
2146 }
2147
2148 *r_parent = parent;
2149 *r_signature_is_good = signature_is_good;
2150
2151 break;
2152 }
2153
2154 if( parent == NULL )
2155 {
2156 *r_parent = fallback_parent;
2157 *r_signature_is_good = fallback_signature_is_good;
2158 }
2159
2160 return( 0 );
2161 }
2162
2163 /*
2164 * Find a parent in trusted CAs or the provided chain, or return NULL.
2165 *
2166 * Searches in trusted CAs first, and return the first suitable parent found
2167 * (see find_parent_in() for definition of suitable).
2168 *
2169 * Arguments:
2170 * - [in] child: certificate for which we're looking for a parent, followed
2171 * by a chain of possible intermediates
2172 * - [in] trust_ca: list of locally trusted certificates
2173 * - [out] parent: parent found (or NULL)
2174 * - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0
2175 * - [out] signature_is_good: 1 if child signature by parent is valid, or 0
2176 * - [in] path_cnt: number of links in the chain so far (EE -> ... -> child)
2177 * - [in] self_cnt: number of self-signed certs in the chain so far
2178 * (will always be no greater than path_cnt)
2179 * - [in-out] rs_ctx: context for restarting operations
2180 *
2181 * Return value:
2182 * - 0 on success
2183 * - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2184 */
x509_crt_find_parent(mbedtls_x509_crt * child,mbedtls_x509_crt * trust_ca,mbedtls_x509_crt ** parent,int * parent_is_trusted,int * signature_is_good,unsigned path_cnt,unsigned self_cnt,mbedtls_x509_crt_restart_ctx * rs_ctx)2185 static int x509_crt_find_parent(
2186 mbedtls_x509_crt *child,
2187 mbedtls_x509_crt *trust_ca,
2188 mbedtls_x509_crt **parent,
2189 int *parent_is_trusted,
2190 int *signature_is_good,
2191 unsigned path_cnt,
2192 unsigned self_cnt,
2193 mbedtls_x509_crt_restart_ctx *rs_ctx )
2194 {
2195 int ret;
2196 mbedtls_x509_crt *search_list;
2197
2198 *parent_is_trusted = 1;
2199
2200 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2201 /* restore then clear saved state if we have some stored */
2202 if( rs_ctx != NULL && rs_ctx->parent_is_trusted != -1 )
2203 {
2204 *parent_is_trusted = rs_ctx->parent_is_trusted;
2205 rs_ctx->parent_is_trusted = -1;
2206 }
2207 #endif
2208
2209 while( 1 ) {
2210 search_list = *parent_is_trusted ? trust_ca : child->next;
2211
2212 ret = x509_crt_find_parent_in( child, search_list,
2213 parent, signature_is_good,
2214 *parent_is_trusted,
2215 path_cnt, self_cnt, rs_ctx );
2216
2217 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2218 if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2219 {
2220 /* save state */
2221 rs_ctx->parent_is_trusted = *parent_is_trusted;
2222 return( ret );
2223 }
2224 #else
2225 (void) ret;
2226 #endif
2227
2228 /* stop here if found or already in second iteration */
2229 if( *parent != NULL || *parent_is_trusted == 0 )
2230 break;
2231
2232 /* prepare second iteration */
2233 *parent_is_trusted = 0;
2234 }
2235
2236 /* extra precaution against mistakes in the caller */
2237 if( *parent == NULL )
2238 {
2239 *parent_is_trusted = 0;
2240 *signature_is_good = 0;
2241 }
2242
2243 return( 0 );
2244 }
2245
2246 /*
2247 * Check if an end-entity certificate is locally trusted
2248 *
2249 * Currently we require such certificates to be self-signed (actually only
2250 * check for self-issued as self-signatures are not checked)
2251 */
x509_crt_check_ee_locally_trusted(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca)2252 static int x509_crt_check_ee_locally_trusted(
2253 mbedtls_x509_crt *crt,
2254 mbedtls_x509_crt *trust_ca )
2255 {
2256 mbedtls_x509_crt *cur;
2257
2258 /* must be self-issued */
2259 if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 )
2260 return( -1 );
2261
2262 /* look for an exact match with trusted cert */
2263 for( cur = trust_ca; cur != NULL; cur = cur->next )
2264 {
2265 if( crt->raw.len == cur->raw.len &&
2266 memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 )
2267 {
2268 return( 0 );
2269 }
2270 }
2271
2272 /* too bad */
2273 return( -1 );
2274 }
2275
2276 /*
2277 * Build and verify a certificate chain
2278 *
2279 * Given a peer-provided list of certificates EE, C1, ..., Cn and
2280 * a list of trusted certs R1, ... Rp, try to build and verify a chain
2281 * EE, Ci1, ... Ciq [, Rj]
2282 * such that every cert in the chain is a child of the next one,
2283 * jumping to a trusted root as early as possible.
2284 *
2285 * Verify that chain and return it with flags for all issues found.
2286 *
2287 * Special cases:
2288 * - EE == Rj -> return a one-element list containing it
2289 * - EE, Ci1, ..., Ciq cannot be continued with a trusted root
2290 * -> return that chain with NOT_TRUSTED set on Ciq
2291 *
2292 * Tests for (aspects of) this function should include at least:
2293 * - trusted EE
2294 * - EE -> trusted root
2295 * - EE -> intermediate CA -> trusted root
2296 * - if relevant: EE untrusted
2297 * - if relevant: EE -> intermediate, untrusted
2298 * with the aspect under test checked at each relevant level (EE, int, root).
2299 * For some aspects longer chains are required, but usually length 2 is
2300 * enough (but length 1 is not in general).
2301 *
2302 * Arguments:
2303 * - [in] crt: the cert list EE, C1, ..., Cn
2304 * - [in] trust_ca: the trusted list R1, ..., Rp
2305 * - [in] ca_crl, profile: as in verify_with_profile()
2306 * - [out] ver_chain: the built and verified chain
2307 * Only valid when return value is 0, may contain garbage otherwise!
2308 * Restart note: need not be the same when calling again to resume.
2309 * - [in-out] rs_ctx: context for restarting operations
2310 *
2311 * Return value:
2312 * - non-zero if the chain could not be fully built and examined
2313 * - 0 is the chain was successfully built and examined,
2314 * even if it was found to be invalid
2315 */
x509_crt_verify_chain(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const mbedtls_x509_crt_profile * profile,mbedtls_x509_crt_verify_chain * ver_chain,mbedtls_x509_crt_restart_ctx * rs_ctx)2316 static int x509_crt_verify_chain(
2317 mbedtls_x509_crt *crt,
2318 mbedtls_x509_crt *trust_ca,
2319 mbedtls_x509_crl *ca_crl,
2320 const mbedtls_x509_crt_profile *profile,
2321 mbedtls_x509_crt_verify_chain *ver_chain,
2322 mbedtls_x509_crt_restart_ctx *rs_ctx )
2323 {
2324 /* Don't initialize any of those variables here, so that the compiler can
2325 * catch potential issues with jumping ahead when restarting */
2326 int ret;
2327 uint32_t *flags;
2328 mbedtls_x509_crt_verify_chain_item *cur;
2329 mbedtls_x509_crt *child;
2330 mbedtls_x509_crt *parent;
2331 int parent_is_trusted;
2332 int child_is_trusted;
2333 int signature_is_good;
2334 unsigned self_cnt;
2335
2336 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2337 /* resume if we had an operation in progress */
2338 if( rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent )
2339 {
2340 /* restore saved state */
2341 *ver_chain = rs_ctx->ver_chain; /* struct copy */
2342 self_cnt = rs_ctx->self_cnt;
2343
2344 /* restore derived state */
2345 cur = &ver_chain->items[ver_chain->len - 1];
2346 child = cur->crt;
2347 flags = &cur->flags;
2348
2349 goto find_parent;
2350 }
2351 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2352
2353 child = crt;
2354 self_cnt = 0;
2355 parent_is_trusted = 0;
2356 child_is_trusted = 0;
2357
2358 while( 1 ) {
2359 /* Add certificate to the verification chain */
2360 cur = &ver_chain->items[ver_chain->len];
2361 cur->crt = child;
2362 cur->flags = 0;
2363 ver_chain->len++;
2364 flags = &cur->flags;
2365
2366 /* Check time-validity (all certificates) */
2367 if( mbedtls_x509_time_is_past( &child->valid_to ) )
2368 *flags |= MBEDTLS_X509_BADCERT_EXPIRED;
2369
2370 if( mbedtls_x509_time_is_future( &child->valid_from ) )
2371 *flags |= MBEDTLS_X509_BADCERT_FUTURE;
2372
2373 /* Stop here for trusted roots (but not for trusted EE certs) */
2374 if( child_is_trusted )
2375 return( 0 );
2376
2377 /* Check signature algorithm: MD & PK algs */
2378 if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 )
2379 *flags |= MBEDTLS_X509_BADCERT_BAD_MD;
2380
2381 if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 )
2382 *flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2383
2384 /* Special case: EE certs that are locally trusted */
2385 if( ver_chain->len == 1 &&
2386 x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 )
2387 {
2388 return( 0 );
2389 }
2390
2391 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2392 find_parent:
2393 #endif
2394 /* Look for a parent in trusted CAs or up the chain */
2395 ret = x509_crt_find_parent( child, trust_ca, &parent,
2396 &parent_is_trusted, &signature_is_good,
2397 ver_chain->len - 1, self_cnt, rs_ctx );
2398
2399 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2400 if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2401 {
2402 /* save state */
2403 rs_ctx->in_progress = x509_crt_rs_find_parent;
2404 rs_ctx->self_cnt = self_cnt;
2405 rs_ctx->ver_chain = *ver_chain; /* struct copy */
2406
2407 return( ret );
2408 }
2409 #else
2410 (void) ret;
2411 #endif
2412
2413 /* No parent? We're done here */
2414 if( parent == NULL )
2415 {
2416 *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2417 return( 0 );
2418 }
2419
2420 /* Count intermediate self-issued (not necessarily self-signed) certs.
2421 * These can occur with some strategies for key rollover, see [SIRO],
2422 * and should be excluded from max_pathlen checks. */
2423 if( ver_chain->len != 1 &&
2424 x509_name_cmp( &child->issuer, &child->subject ) == 0 )
2425 {
2426 self_cnt++;
2427 }
2428
2429 /* path_cnt is 0 for the first intermediate CA,
2430 * and if parent is trusted it's not an intermediate CA */
2431 if( ! parent_is_trusted &&
2432 ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
2433 {
2434 /* return immediately to avoid overflow the chain array */
2435 return( MBEDTLS_ERR_X509_FATAL_ERROR );
2436 }
2437
2438 /* signature was checked while searching parent */
2439 if( ! signature_is_good )
2440 *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2441
2442 /* check size of signing key */
2443 if( x509_profile_check_key( profile, &parent->pk ) != 0 )
2444 *flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2445
2446 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2447 /* Check trusted CA's CRL for the given crt */
2448 *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile );
2449 #else
2450 (void) ca_crl;
2451 #endif
2452
2453 /* prepare for next iteration */
2454 child = parent;
2455 parent = NULL;
2456 child_is_trusted = parent_is_trusted;
2457 signature_is_good = 0;
2458 }
2459 }
2460
2461 /*
2462 * Check for CN match
2463 */
x509_crt_check_cn(const mbedtls_x509_buf * name,const char * cn,size_t cn_len)2464 static int x509_crt_check_cn( const mbedtls_x509_buf *name,
2465 const char *cn, size_t cn_len )
2466 {
2467 /* try exact match */
2468 if( name->len == cn_len &&
2469 x509_memcasecmp( cn, name->p, cn_len ) == 0 )
2470 {
2471 return( 0 );
2472 }
2473
2474 /* try wildcard match */
2475 if( x509_check_wildcard( cn, name ) == 0 )
2476 {
2477 return( 0 );
2478 }
2479
2480 return( -1 );
2481 }
2482
2483 /*
2484 * Verify the requested CN - only call this if cn is not NULL!
2485 */
x509_crt_verify_name(const mbedtls_x509_crt * crt,const char * cn,uint32_t * flags)2486 static void x509_crt_verify_name( const mbedtls_x509_crt *crt,
2487 const char *cn,
2488 uint32_t *flags )
2489 {
2490 const mbedtls_x509_name *name;
2491 const mbedtls_x509_sequence *cur;
2492 size_t cn_len = strlen( cn );
2493
2494 if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
2495 {
2496 for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next )
2497 {
2498 if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 )
2499 break;
2500 }
2501
2502 if( cur == NULL )
2503 *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2504 }
2505 else
2506 {
2507 for( name = &crt->subject; name != NULL; name = name->next )
2508 {
2509 if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 &&
2510 x509_crt_check_cn( &name->val, cn, cn_len ) == 0 )
2511 {
2512 break;
2513 }
2514 }
2515
2516 if( name == NULL )
2517 *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2518 }
2519 }
2520
2521 /*
2522 * Merge the flags for all certs in the chain, after calling callback
2523 */
x509_crt_merge_flags_with_cb(uint32_t * flags,const mbedtls_x509_crt_verify_chain * ver_chain,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2524 static int x509_crt_merge_flags_with_cb(
2525 uint32_t *flags,
2526 const mbedtls_x509_crt_verify_chain *ver_chain,
2527 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2528 void *p_vrfy )
2529 {
2530 int ret;
2531 unsigned i;
2532 uint32_t cur_flags;
2533 const mbedtls_x509_crt_verify_chain_item *cur;
2534
2535 for( i = ver_chain->len; i != 0; --i )
2536 {
2537 cur = &ver_chain->items[i-1];
2538 cur_flags = cur->flags;
2539
2540 if( NULL != f_vrfy )
2541 if( ( ret = f_vrfy( p_vrfy, cur->crt, (int) i-1, &cur_flags ) ) != 0 )
2542 return( ret );
2543
2544 *flags |= cur_flags;
2545 }
2546
2547 return( 0 );
2548 }
2549
2550 /*
2551 * Verify the certificate validity (default profile, not restartable)
2552 */
mbedtls_x509_crt_verify(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2553 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
2554 mbedtls_x509_crt *trust_ca,
2555 mbedtls_x509_crl *ca_crl,
2556 const char *cn, uint32_t *flags,
2557 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2558 void *p_vrfy )
2559 {
2560 return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
2561 &mbedtls_x509_crt_profile_default, cn, flags,
2562 f_vrfy, p_vrfy, NULL ) );
2563 }
2564
2565 /*
2566 * Verify the certificate validity (user-chosen profile, not restartable)
2567 */
mbedtls_x509_crt_verify_with_profile(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const mbedtls_x509_crt_profile * profile,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2568 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
2569 mbedtls_x509_crt *trust_ca,
2570 mbedtls_x509_crl *ca_crl,
2571 const mbedtls_x509_crt_profile *profile,
2572 const char *cn, uint32_t *flags,
2573 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2574 void *p_vrfy )
2575 {
2576 return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
2577 profile, cn, flags, f_vrfy, p_vrfy, NULL ) );
2578 }
2579
2580 /*
2581 * Verify the certificate validity, with profile, restartable version
2582 *
2583 * This function:
2584 * - checks the requested CN (if any)
2585 * - checks the type and size of the EE cert's key,
2586 * as that isn't done as part of chain building/verification currently
2587 * - builds and verifies the chain
2588 * - then calls the callback and merges the flags
2589 */
mbedtls_x509_crt_verify_restartable(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const mbedtls_x509_crt_profile * profile,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy,mbedtls_x509_crt_restart_ctx * rs_ctx)2590 int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt,
2591 mbedtls_x509_crt *trust_ca,
2592 mbedtls_x509_crl *ca_crl,
2593 const mbedtls_x509_crt_profile *profile,
2594 const char *cn, uint32_t *flags,
2595 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2596 void *p_vrfy,
2597 mbedtls_x509_crt_restart_ctx *rs_ctx )
2598 {
2599 int ret;
2600 mbedtls_pk_type_t pk_type;
2601 mbedtls_x509_crt_verify_chain ver_chain;
2602 uint32_t ee_flags;
2603
2604 *flags = 0;
2605 ee_flags = 0;
2606 x509_crt_verify_chain_reset( &ver_chain );
2607
2608 if( profile == NULL )
2609 {
2610 ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
2611 goto exit;
2612 }
2613
2614 /* check name if requested */
2615 if( cn != NULL )
2616 x509_crt_verify_name( crt, cn, &ee_flags );
2617
2618 /* Check the type and size of the key */
2619 pk_type = mbedtls_pk_get_type( &crt->pk );
2620
2621 if( x509_profile_check_pk_alg( profile, pk_type ) != 0 )
2622 ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2623
2624 if( x509_profile_check_key( profile, &crt->pk ) != 0 )
2625 ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2626
2627 /* Check the chain */
2628 ret = x509_crt_verify_chain( crt, trust_ca, ca_crl, profile,
2629 &ver_chain, rs_ctx );
2630
2631 if( ret != 0 )
2632 goto exit;
2633
2634 /* Merge end-entity flags */
2635 ver_chain.items[0].flags |= ee_flags;
2636
2637 /* Build final flags, calling callback on the way if any */
2638 ret = x509_crt_merge_flags_with_cb( flags, &ver_chain, f_vrfy, p_vrfy );
2639
2640 exit:
2641 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2642 if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
2643 mbedtls_x509_crt_restart_free( rs_ctx );
2644 #endif
2645
2646 /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
2647 * the SSL module for authmode optional, but non-zero return from the
2648 * callback means a fatal error so it shouldn't be ignored */
2649 if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
2650 ret = MBEDTLS_ERR_X509_FATAL_ERROR;
2651
2652 if( ret != 0 )
2653 {
2654 *flags = (uint32_t) -1;
2655 return( ret );
2656 }
2657
2658 if( *flags != 0 )
2659 return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
2660
2661 return( 0 );
2662 }
2663
2664 /*
2665 * Initialize a certificate chain
2666 */
mbedtls_x509_crt_init(mbedtls_x509_crt * crt)2667 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt )
2668 {
2669 memset( crt, 0, sizeof(mbedtls_x509_crt) );
2670 }
2671
2672 /*
2673 * Unallocate all certificate data
2674 */
mbedtls_x509_crt_free(mbedtls_x509_crt * crt)2675 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
2676 {
2677 mbedtls_x509_crt *cert_cur = crt;
2678 mbedtls_x509_crt *cert_prv;
2679 mbedtls_x509_name *name_cur;
2680 mbedtls_x509_name *name_prv;
2681 mbedtls_x509_sequence *seq_cur;
2682 mbedtls_x509_sequence *seq_prv;
2683
2684 if( crt == NULL )
2685 return;
2686
2687 do
2688 {
2689 mbedtls_pk_free( &cert_cur->pk );
2690
2691 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
2692 mbedtls_free( cert_cur->sig_opts );
2693 #endif
2694
2695 name_cur = cert_cur->issuer.next;
2696 while( name_cur != NULL )
2697 {
2698 name_prv = name_cur;
2699 name_cur = name_cur->next;
2700 mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2701 mbedtls_free( name_prv );
2702 }
2703
2704 name_cur = cert_cur->subject.next;
2705 while( name_cur != NULL )
2706 {
2707 name_prv = name_cur;
2708 name_cur = name_cur->next;
2709 mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2710 mbedtls_free( name_prv );
2711 }
2712
2713 seq_cur = cert_cur->ext_key_usage.next;
2714 while( seq_cur != NULL )
2715 {
2716 seq_prv = seq_cur;
2717 seq_cur = seq_cur->next;
2718 mbedtls_platform_zeroize( seq_prv,
2719 sizeof( mbedtls_x509_sequence ) );
2720 mbedtls_free( seq_prv );
2721 }
2722
2723 seq_cur = cert_cur->subject_alt_names.next;
2724 while( seq_cur != NULL )
2725 {
2726 seq_prv = seq_cur;
2727 seq_cur = seq_cur->next;
2728 mbedtls_platform_zeroize( seq_prv,
2729 sizeof( mbedtls_x509_sequence ) );
2730 mbedtls_free( seq_prv );
2731 }
2732
2733 if( cert_cur->raw.p != NULL )
2734 {
2735 mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
2736 mbedtls_free( cert_cur->raw.p );
2737 }
2738
2739 cert_cur = cert_cur->next;
2740 }
2741 while( cert_cur != NULL );
2742
2743 cert_cur = crt;
2744 do
2745 {
2746 cert_prv = cert_cur;
2747 cert_cur = cert_cur->next;
2748
2749 mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) );
2750 if( cert_prv != crt )
2751 mbedtls_free( cert_prv );
2752 }
2753 while( cert_cur != NULL );
2754 }
2755
2756 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2757 /*
2758 * Initialize a restart context
2759 */
mbedtls_x509_crt_restart_init(mbedtls_x509_crt_restart_ctx * ctx)2760 void mbedtls_x509_crt_restart_init( mbedtls_x509_crt_restart_ctx *ctx )
2761 {
2762 mbedtls_pk_restart_init( &ctx->pk );
2763
2764 ctx->parent = NULL;
2765 ctx->fallback_parent = NULL;
2766 ctx->fallback_signature_is_good = 0;
2767
2768 ctx->parent_is_trusted = -1;
2769
2770 ctx->in_progress = x509_crt_rs_none;
2771 ctx->self_cnt = 0;
2772 x509_crt_verify_chain_reset( &ctx->ver_chain );
2773 }
2774
2775 /*
2776 * Free the components of a restart context
2777 */
mbedtls_x509_crt_restart_free(mbedtls_x509_crt_restart_ctx * ctx)2778 void mbedtls_x509_crt_restart_free( mbedtls_x509_crt_restart_ctx *ctx )
2779 {
2780 if( ctx == NULL )
2781 return;
2782
2783 mbedtls_pk_restart_free( &ctx->pk );
2784 mbedtls_x509_crt_restart_init( ctx );
2785 }
2786 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2787
2788 #endif /* MBEDTLS_X509_CRT_PARSE_C */
2789