xref: /optee_os/lib/libmbedtls/mbedtls/library/x509_crt.c (revision 5b25c76ac40f830867e3d60800120ffd7874e8dc)
1 // SPDX-License-Identifier: Apache-2.0
2 /*
3  *  X.509 certificate parsing and verification
4  *
5  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
6  *
7  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
8  *  not use this file except in compliance with the License.
9  *  You may obtain a copy of the License at
10  *
11  *  http://www.apache.org/licenses/LICENSE-2.0
12  *
13  *  Unless required by applicable law or agreed to in writing, software
14  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  *  See the License for the specific language governing permissions and
17  *  limitations under the License.
18  *
19  *  This file is part of mbed TLS (https://tls.mbed.org)
20  */
21 /*
22  *  The ITU-T X.509 standard defines a certificate format for PKI.
23  *
24  *  http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
25  *  http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
26  *  http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
27  *
28  *  http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
29  *  http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
30  *
31  *  [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf
32  */
33 
34 #if !defined(MBEDTLS_CONFIG_FILE)
35 #include "mbedtls/config.h"
36 #else
37 #include MBEDTLS_CONFIG_FILE
38 #endif
39 
40 #if defined(MBEDTLS_X509_CRT_PARSE_C)
41 
42 #include "mbedtls/x509_crt.h"
43 #include "mbedtls/oid.h"
44 #include "mbedtls/platform_util.h"
45 
46 #include <string.h>
47 
48 #if defined(MBEDTLS_PEM_PARSE_C)
49 #include "mbedtls/pem.h"
50 #endif
51 
52 #if defined(MBEDTLS_PLATFORM_C)
53 #include "mbedtls/platform.h"
54 #else
55 #include <stdio.h>
56 #include <stdlib.h>
57 #define mbedtls_free       free
58 #define mbedtls_calloc    calloc
59 #define mbedtls_snprintf   snprintf
60 #endif
61 
62 #if defined(MBEDTLS_THREADING_C)
63 #include "mbedtls/threading.h"
64 #endif
65 
66 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
67 #include <windows.h>
68 #else
69 #include <time.h>
70 #endif
71 
72 #if defined(MBEDTLS_FS_IO)
73 #include <stdio.h>
74 #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
75 #include <sys/types.h>
76 #include <sys/stat.h>
77 #include <dirent.h>
78 #endif /* !_WIN32 || EFIX64 || EFI32 */
79 #endif
80 
81 /*
82  * Item in a verification chain: cert and flags for it
83  */
84 typedef struct {
85     mbedtls_x509_crt *crt;
86     uint32_t flags;
87 } x509_crt_verify_chain_item;
88 
89 /*
90  * Max size of verification chain: end-entity + intermediates + trusted root
91  */
92 #define X509_MAX_VERIFY_CHAIN_SIZE    ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )
93 
94 /*
95  * Default profile
96  */
97 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
98 {
99 #if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
100     /* Allow SHA-1 (weak, but still safe in controlled environments) */
101     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
102 #endif
103     /* Only SHA-2 hashes */
104     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
105     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
106     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
107     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
108     0xFFFFFFF, /* Any PK alg    */
109     0xFFFFFFF, /* Any curve     */
110     2048,
111 };
112 
113 /*
114  * Next-default profile
115  */
116 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next =
117 {
118     /* Hashes from SHA-256 and above */
119     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
120     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
121     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
122     0xFFFFFFF, /* Any PK alg    */
123 #if defined(MBEDTLS_ECP_C)
124     /* Curves at or above 128-bit security level */
125     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
126     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ) |
127     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP521R1 ) |
128     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP256R1 ) |
129     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP384R1 ) |
130     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP512R1 ) |
131     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256K1 ),
132 #else
133     0,
134 #endif
135     2048,
136 };
137 
138 /*
139  * NSA Suite B Profile
140  */
141 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb =
142 {
143     /* Only SHA-256 and 384 */
144     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
145     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ),
146     /* Only ECDSA */
147     MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECDSA ) |
148     MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECKEY ),
149 #if defined(MBEDTLS_ECP_C)
150     /* Only NIST P-256 and P-384 */
151     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
152     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ),
153 #else
154     0,
155 #endif
156     0,
157 };
158 
159 /*
160  * Check md_alg against profile
161  * Return 0 if md_alg is acceptable for this profile, -1 otherwise
162  */
163 static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile,
164                                       mbedtls_md_type_t md_alg )
165 {
166     if( md_alg == MBEDTLS_MD_NONE )
167         return( -1 );
168 
169     if( ( profile->allowed_mds & MBEDTLS_X509_ID_FLAG( md_alg ) ) != 0 )
170         return( 0 );
171 
172     return( -1 );
173 }
174 
175 /*
176  * Check pk_alg against profile
177  * Return 0 if pk_alg is acceptable for this profile, -1 otherwise
178  */
179 static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile,
180                                       mbedtls_pk_type_t pk_alg )
181 {
182     if( pk_alg == MBEDTLS_PK_NONE )
183         return( -1 );
184 
185     if( ( profile->allowed_pks & MBEDTLS_X509_ID_FLAG( pk_alg ) ) != 0 )
186         return( 0 );
187 
188     return( -1 );
189 }
190 
191 /*
192  * Check key against profile
193  * Return 0 if pk is acceptable for this profile, -1 otherwise
194  */
195 static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile,
196                                    const mbedtls_pk_context *pk )
197 {
198     const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type( pk );
199 
200 #if defined(MBEDTLS_RSA_C)
201     if( pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS )
202     {
203         if( mbedtls_pk_get_bitlen( pk ) >= profile->rsa_min_bitlen )
204             return( 0 );
205 
206         return( -1 );
207     }
208 #endif
209 
210 #if defined(MBEDTLS_ECP_C)
211     if( pk_alg == MBEDTLS_PK_ECDSA ||
212         pk_alg == MBEDTLS_PK_ECKEY ||
213         pk_alg == MBEDTLS_PK_ECKEY_DH )
214     {
215         const mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id;
216 
217         if( gid == MBEDTLS_ECP_DP_NONE )
218             return( -1 );
219 
220         if( ( profile->allowed_curves & MBEDTLS_X509_ID_FLAG( gid ) ) != 0 )
221             return( 0 );
222 
223         return( -1 );
224     }
225 #endif
226 
227     return( -1 );
228 }
229 
230 /*
231  * Like memcmp, but case-insensitive and always returns -1 if different
232  */
233 static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
234 {
235     size_t i;
236     unsigned char diff;
237     const unsigned char *n1 = s1, *n2 = s2;
238 
239     for( i = 0; i < len; i++ )
240     {
241         diff = n1[i] ^ n2[i];
242 
243         if( diff == 0 )
244             continue;
245 
246         if( diff == 32 &&
247             ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
248               ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
249         {
250             continue;
251         }
252 
253         return( -1 );
254     }
255 
256     return( 0 );
257 }
258 
259 /*
260  * Return 0 if name matches wildcard, -1 otherwise
261  */
262 static int x509_check_wildcard( const char *cn, const mbedtls_x509_buf *name )
263 {
264     size_t i;
265     size_t cn_idx = 0, cn_len = strlen( cn );
266 
267     /* We can't have a match if there is no wildcard to match */
268     if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' )
269         return( -1 );
270 
271     for( i = 0; i < cn_len; ++i )
272     {
273         if( cn[i] == '.' )
274         {
275             cn_idx = i;
276             break;
277         }
278     }
279 
280     if( cn_idx == 0 )
281         return( -1 );
282 
283     if( cn_len - cn_idx == name->len - 1 &&
284         x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 )
285     {
286         return( 0 );
287     }
288 
289     return( -1 );
290 }
291 
292 /*
293  * Compare two X.509 strings, case-insensitive, and allowing for some encoding
294  * variations (but not all).
295  *
296  * Return 0 if equal, -1 otherwise.
297  */
298 static int x509_string_cmp( const mbedtls_x509_buf *a, const mbedtls_x509_buf *b )
299 {
300     if( a->tag == b->tag &&
301         a->len == b->len &&
302         memcmp( a->p, b->p, b->len ) == 0 )
303     {
304         return( 0 );
305     }
306 
307     if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
308         ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
309         a->len == b->len &&
310         x509_memcasecmp( a->p, b->p, b->len ) == 0 )
311     {
312         return( 0 );
313     }
314 
315     return( -1 );
316 }
317 
318 /*
319  * Compare two X.509 Names (aka rdnSequence).
320  *
321  * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
322  * we sometimes return unequal when the full algorithm would return equal,
323  * but never the other way. (In particular, we don't do Unicode normalisation
324  * or space folding.)
325  *
326  * Return 0 if equal, -1 otherwise.
327  */
328 static int x509_name_cmp( const mbedtls_x509_name *a, const mbedtls_x509_name *b )
329 {
330     /* Avoid recursion, it might not be optimised by the compiler */
331     while( a != NULL || b != NULL )
332     {
333         if( a == NULL || b == NULL )
334             return( -1 );
335 
336         /* type */
337         if( a->oid.tag != b->oid.tag ||
338             a->oid.len != b->oid.len ||
339             memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
340         {
341             return( -1 );
342         }
343 
344         /* value */
345         if( x509_string_cmp( &a->val, &b->val ) != 0 )
346             return( -1 );
347 
348         /* structure of the list of sets */
349         if( a->next_merged != b->next_merged )
350             return( -1 );
351 
352         a = a->next;
353         b = b->next;
354     }
355 
356     /* a == NULL == b */
357     return( 0 );
358 }
359 
360 /*
361  * Reset (init or clear) a verify_chain
362  */
363 static void x509_crt_verify_chain_reset(
364     mbedtls_x509_crt_verify_chain *ver_chain )
365 {
366     size_t i;
367 
368     for( i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++ )
369     {
370         ver_chain->items[i].crt = NULL;
371         ver_chain->items[i].flags = (uint32_t) -1;
372     }
373 
374     ver_chain->len = 0;
375 }
376 
377 /*
378  *  Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
379  */
380 static int x509_get_version( unsigned char **p,
381                              const unsigned char *end,
382                              int *ver )
383 {
384     int ret;
385     size_t len;
386 
387     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
388             MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) != 0 )
389     {
390         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
391         {
392             *ver = 0;
393             return( 0 );
394         }
395 
396         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
397     }
398 
399     end = *p + len;
400 
401     if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
402         return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
403 
404     if( *p != end )
405         return( MBEDTLS_ERR_X509_INVALID_VERSION +
406                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
407 
408     return( 0 );
409 }
410 
411 /*
412  *  Validity ::= SEQUENCE {
413  *       notBefore      Time,
414  *       notAfter       Time }
415  */
416 static int x509_get_dates( unsigned char **p,
417                            const unsigned char *end,
418                            mbedtls_x509_time *from,
419                            mbedtls_x509_time *to )
420 {
421     int ret;
422     size_t len;
423 
424     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
425             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
426         return( MBEDTLS_ERR_X509_INVALID_DATE + ret );
427 
428     end = *p + len;
429 
430     if( ( ret = mbedtls_x509_get_time( p, end, from ) ) != 0 )
431         return( ret );
432 
433     if( ( ret = mbedtls_x509_get_time( p, end, to ) ) != 0 )
434         return( ret );
435 
436     if( *p != end )
437         return( MBEDTLS_ERR_X509_INVALID_DATE +
438                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
439 
440     return( 0 );
441 }
442 
443 /*
444  * X.509 v2/v3 unique identifier (not parsed)
445  */
446 static int x509_get_uid( unsigned char **p,
447                          const unsigned char *end,
448                          mbedtls_x509_buf *uid, int n )
449 {
450     int ret;
451 
452     if( *p == end )
453         return( 0 );
454 
455     uid->tag = **p;
456 
457     if( ( ret = mbedtls_asn1_get_tag( p, end, &uid->len,
458             MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n ) ) != 0 )
459     {
460         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
461             return( 0 );
462 
463         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
464     }
465 
466     uid->p = *p;
467     *p += uid->len;
468 
469     return( 0 );
470 }
471 
472 static int x509_get_basic_constraints( unsigned char **p,
473                                        const unsigned char *end,
474                                        int *ca_istrue,
475                                        int *max_pathlen )
476 {
477     int ret;
478     size_t len;
479 
480     /*
481      * BasicConstraints ::= SEQUENCE {
482      *      cA                      BOOLEAN DEFAULT FALSE,
483      *      pathLenConstraint       INTEGER (0..MAX) OPTIONAL }
484      */
485     *ca_istrue = 0; /* DEFAULT FALSE */
486     *max_pathlen = 0; /* endless */
487 
488     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
489             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
490         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
491 
492     if( *p == end )
493         return( 0 );
494 
495     if( ( ret = mbedtls_asn1_get_bool( p, end, ca_istrue ) ) != 0 )
496     {
497         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
498             ret = mbedtls_asn1_get_int( p, end, ca_istrue );
499 
500         if( ret != 0 )
501             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
502 
503         if( *ca_istrue != 0 )
504             *ca_istrue = 1;
505     }
506 
507     if( *p == end )
508         return( 0 );
509 
510     if( ( ret = mbedtls_asn1_get_int( p, end, max_pathlen ) ) != 0 )
511         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
512 
513     if( *p != end )
514         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
515                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
516 
517     (*max_pathlen)++;
518 
519     return( 0 );
520 }
521 
522 static int x509_get_ns_cert_type( unsigned char **p,
523                                        const unsigned char *end,
524                                        unsigned char *ns_cert_type)
525 {
526     int ret;
527     mbedtls_x509_bitstring bs = { 0, 0, NULL };
528 
529     if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
530         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
531 
532     if( bs.len != 1 )
533         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
534                 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
535 
536     /* Get actual bitstring */
537     *ns_cert_type = *bs.p;
538     return( 0 );
539 }
540 
541 static int x509_get_key_usage( unsigned char **p,
542                                const unsigned char *end,
543                                unsigned int *key_usage)
544 {
545     int ret;
546     size_t i;
547     mbedtls_x509_bitstring bs = { 0, 0, NULL };
548 
549     if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
550         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
551 
552     if( bs.len < 1 )
553         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
554                 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
555 
556     /* Get actual bitstring */
557     *key_usage = 0;
558     for( i = 0; i < bs.len && i < sizeof( unsigned int ); i++ )
559     {
560         *key_usage |= (unsigned int) bs.p[i] << (8*i);
561     }
562 
563     return( 0 );
564 }
565 
566 /*
567  * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
568  *
569  * KeyPurposeId ::= OBJECT IDENTIFIER
570  */
571 static int x509_get_ext_key_usage( unsigned char **p,
572                                const unsigned char *end,
573                                mbedtls_x509_sequence *ext_key_usage)
574 {
575     int ret;
576 
577     if( ( ret = mbedtls_asn1_get_sequence_of( p, end, ext_key_usage, MBEDTLS_ASN1_OID ) ) != 0 )
578         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
579 
580     /* Sequence length must be >= 1 */
581     if( ext_key_usage->buf.p == NULL )
582         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
583                 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
584 
585     return( 0 );
586 }
587 
588 /*
589  * SubjectAltName ::= GeneralNames
590  *
591  * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
592  *
593  * GeneralName ::= CHOICE {
594  *      otherName                       [0]     OtherName,
595  *      rfc822Name                      [1]     IA5String,
596  *      dNSName                         [2]     IA5String,
597  *      x400Address                     [3]     ORAddress,
598  *      directoryName                   [4]     Name,
599  *      ediPartyName                    [5]     EDIPartyName,
600  *      uniformResourceIdentifier       [6]     IA5String,
601  *      iPAddress                       [7]     OCTET STRING,
602  *      registeredID                    [8]     OBJECT IDENTIFIER }
603  *
604  * OtherName ::= SEQUENCE {
605  *      type-id    OBJECT IDENTIFIER,
606  *      value      [0] EXPLICIT ANY DEFINED BY type-id }
607  *
608  * EDIPartyName ::= SEQUENCE {
609  *      nameAssigner            [0]     DirectoryString OPTIONAL,
610  *      partyName               [1]     DirectoryString }
611  *
612  * NOTE: we only parse and use dNSName at this point.
613  */
614 static int x509_get_subject_alt_name( unsigned char **p,
615                                       const unsigned char *end,
616                                       mbedtls_x509_sequence *subject_alt_name )
617 {
618     int ret;
619     size_t len, tag_len;
620     mbedtls_asn1_buf *buf;
621     unsigned char tag;
622     mbedtls_asn1_sequence *cur = subject_alt_name;
623 
624     /* Get main sequence tag */
625     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
626             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
627         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
628 
629     if( *p + len != end )
630         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
631                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
632 
633     while( *p < end )
634     {
635         if( ( end - *p ) < 1 )
636             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
637                     MBEDTLS_ERR_ASN1_OUT_OF_DATA );
638 
639         tag = **p;
640         (*p)++;
641         if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 )
642             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
643 
644         if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) !=
645                 MBEDTLS_ASN1_CONTEXT_SPECIFIC )
646         {
647             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
648                     MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
649         }
650 
651         /* Skip everything but DNS name */
652         if( tag != ( MBEDTLS_ASN1_CONTEXT_SPECIFIC | 2 ) )
653         {
654             *p += tag_len;
655             continue;
656         }
657 
658         /* Allocate and assign next pointer */
659         if( cur->buf.p != NULL )
660         {
661             if( cur->next != NULL )
662                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
663 
664             cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) );
665 
666             if( cur->next == NULL )
667                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
668                         MBEDTLS_ERR_ASN1_ALLOC_FAILED );
669 
670             cur = cur->next;
671         }
672 
673         buf = &(cur->buf);
674         buf->tag = tag;
675         buf->p = *p;
676         buf->len = tag_len;
677         *p += buf->len;
678     }
679 
680     /* Set final sequence entry's next pointer to NULL */
681     cur->next = NULL;
682 
683     if( *p != end )
684         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
685                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
686 
687     return( 0 );
688 }
689 
690 /*
691  * X.509 v3 extensions
692  *
693  */
694 static int x509_get_crt_ext( unsigned char **p,
695                              const unsigned char *end,
696                              mbedtls_x509_crt *crt )
697 {
698     int ret;
699     size_t len;
700     unsigned char *end_ext_data, *end_ext_octet;
701 
702     if( *p == end )
703         return( 0 );
704 
705     if( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
706         return( ret );
707 
708     end = crt->v3_ext.p + crt->v3_ext.len;
709     while( *p < end )
710     {
711         /*
712          * Extension  ::=  SEQUENCE  {
713          *      extnID      OBJECT IDENTIFIER,
714          *      critical    BOOLEAN DEFAULT FALSE,
715          *      extnValue   OCTET STRING  }
716          */
717         mbedtls_x509_buf extn_oid = {0, 0, NULL};
718         int is_critical = 0; /* DEFAULT FALSE */
719         int ext_type = 0;
720 
721         if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
722                 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
723             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
724 
725         end_ext_data = *p + len;
726 
727         /* Get extension ID */
728         if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &extn_oid.len,
729                                           MBEDTLS_ASN1_OID ) ) != 0 )
730             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
731 
732         extn_oid.tag = MBEDTLS_ASN1_OID;
733         extn_oid.p = *p;
734         *p += extn_oid.len;
735 
736         /* Get optional critical */
737         if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
738             ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
739             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
740 
741         /* Data should be octet string type */
742         if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
743                 MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
744             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
745 
746         end_ext_octet = *p + len;
747 
748         if( end_ext_octet != end_ext_data )
749             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
750                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
751 
752         /*
753          * Detect supported extensions
754          */
755         ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type );
756 
757         if( ret != 0 )
758         {
759             /* No parser found, skip extension */
760             *p = end_ext_octet;
761 
762 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
763             if( is_critical )
764             {
765                 /* Data is marked as critical: fail */
766                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
767                         MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
768             }
769 #endif
770             continue;
771         }
772 
773         /* Forbid repeated extensions */
774         if( ( crt->ext_types & ext_type ) != 0 )
775             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
776 
777         crt->ext_types |= ext_type;
778 
779         switch( ext_type )
780         {
781         case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
782             /* Parse basic constraints */
783             if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
784                     &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
785                 return( ret );
786             break;
787 
788         case MBEDTLS_X509_EXT_KEY_USAGE:
789             /* Parse key usage */
790             if( ( ret = x509_get_key_usage( p, end_ext_octet,
791                     &crt->key_usage ) ) != 0 )
792                 return( ret );
793             break;
794 
795         case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
796             /* Parse extended key usage */
797             if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
798                     &crt->ext_key_usage ) ) != 0 )
799                 return( ret );
800             break;
801 
802         case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
803             /* Parse subject alt name */
804             if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
805                     &crt->subject_alt_names ) ) != 0 )
806                 return( ret );
807             break;
808 
809         case MBEDTLS_X509_EXT_NS_CERT_TYPE:
810             /* Parse netscape certificate type */
811             if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
812                     &crt->ns_cert_type ) ) != 0 )
813                 return( ret );
814             break;
815 
816         default:
817             return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
818         }
819     }
820 
821     if( *p != end )
822         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
823                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
824 
825     return( 0 );
826 }
827 
828 /*
829  * Parse and fill a single X.509 certificate in DER format
830  */
831 static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *buf,
832                                     size_t buflen )
833 {
834     int ret;
835     size_t len;
836     unsigned char *p, *end, *crt_end;
837     mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
838 
839     memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) );
840     memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) );
841     memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) );
842 
843     /*
844      * Check for valid input
845      */
846     if( crt == NULL || buf == NULL )
847         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
848 
849     // Use the original buffer until we figure out actual length
850     p = (unsigned char*) buf;
851     len = buflen;
852     end = p + len;
853 
854     /*
855      * Certificate  ::=  SEQUENCE  {
856      *      tbsCertificate       TBSCertificate,
857      *      signatureAlgorithm   AlgorithmIdentifier,
858      *      signatureValue       BIT STRING  }
859      */
860     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
861             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
862     {
863         mbedtls_x509_crt_free( crt );
864         return( MBEDTLS_ERR_X509_INVALID_FORMAT );
865     }
866 
867     if( len > (size_t) ( end - p ) )
868     {
869         mbedtls_x509_crt_free( crt );
870         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
871                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
872     }
873     crt_end = p + len;
874 
875     // Create and populate a new buffer for the raw field
876     crt->raw.len = crt_end - buf;
877     crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
878     if( p == NULL )
879         return( MBEDTLS_ERR_X509_ALLOC_FAILED );
880 
881     memcpy( p, buf, crt->raw.len );
882 
883     // Direct pointers to the new buffer
884     p += crt->raw.len - len;
885     end = crt_end = p + len;
886 
887     /*
888      * TBSCertificate  ::=  SEQUENCE  {
889      */
890     crt->tbs.p = p;
891 
892     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
893             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
894     {
895         mbedtls_x509_crt_free( crt );
896         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
897     }
898 
899     end = p + len;
900     crt->tbs.len = end - crt->tbs.p;
901 
902     /*
903      * Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
904      *
905      * CertificateSerialNumber  ::=  INTEGER
906      *
907      * signature            AlgorithmIdentifier
908      */
909     if( ( ret = x509_get_version(  &p, end, &crt->version  ) ) != 0 ||
910         ( ret = mbedtls_x509_get_serial(   &p, end, &crt->serial   ) ) != 0 ||
911         ( ret = mbedtls_x509_get_alg(      &p, end, &crt->sig_oid,
912                                             &sig_params1 ) ) != 0 )
913     {
914         mbedtls_x509_crt_free( crt );
915         return( ret );
916     }
917 
918     if( crt->version < 0 || crt->version > 2 )
919     {
920         mbedtls_x509_crt_free( crt );
921         return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
922     }
923 
924     crt->version++;
925 
926     if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1,
927                                   &crt->sig_md, &crt->sig_pk,
928                                   &crt->sig_opts ) ) != 0 )
929     {
930         mbedtls_x509_crt_free( crt );
931         return( ret );
932     }
933 
934     /*
935      * issuer               Name
936      */
937     crt->issuer_raw.p = p;
938 
939     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
940             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
941     {
942         mbedtls_x509_crt_free( crt );
943         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
944     }
945 
946     if( ( ret = mbedtls_x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
947     {
948         mbedtls_x509_crt_free( crt );
949         return( ret );
950     }
951 
952     crt->issuer_raw.len = p - crt->issuer_raw.p;
953 
954     /*
955      * Validity ::= SEQUENCE {
956      *      notBefore      Time,
957      *      notAfter       Time }
958      *
959      */
960     if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
961                                          &crt->valid_to ) ) != 0 )
962     {
963         mbedtls_x509_crt_free( crt );
964         return( ret );
965     }
966 
967     /*
968      * subject              Name
969      */
970     crt->subject_raw.p = p;
971 
972     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
973             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
974     {
975         mbedtls_x509_crt_free( crt );
976         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
977     }
978 
979     if( len && ( ret = mbedtls_x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
980     {
981         mbedtls_x509_crt_free( crt );
982         return( ret );
983     }
984 
985     crt->subject_raw.len = p - crt->subject_raw.p;
986 
987     /*
988      * SubjectPublicKeyInfo
989      */
990     if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
991     {
992         mbedtls_x509_crt_free( crt );
993         return( ret );
994     }
995 
996     /*
997      *  issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
998      *                       -- If present, version shall be v2 or v3
999      *  subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL,
1000      *                       -- If present, version shall be v2 or v3
1001      *  extensions      [3]  EXPLICIT Extensions OPTIONAL
1002      *                       -- If present, version shall be v3
1003      */
1004     if( crt->version == 2 || crt->version == 3 )
1005     {
1006         ret = x509_get_uid( &p, end, &crt->issuer_id,  1 );
1007         if( ret != 0 )
1008         {
1009             mbedtls_x509_crt_free( crt );
1010             return( ret );
1011         }
1012     }
1013 
1014     if( crt->version == 2 || crt->version == 3 )
1015     {
1016         ret = x509_get_uid( &p, end, &crt->subject_id,  2 );
1017         if( ret != 0 )
1018         {
1019             mbedtls_x509_crt_free( crt );
1020             return( ret );
1021         }
1022     }
1023 
1024 #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
1025     if( crt->version == 3 )
1026 #endif
1027     {
1028         ret = x509_get_crt_ext( &p, end, crt );
1029         if( ret != 0 )
1030         {
1031             mbedtls_x509_crt_free( crt );
1032             return( ret );
1033         }
1034     }
1035 
1036     if( p != end )
1037     {
1038         mbedtls_x509_crt_free( crt );
1039         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1040                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1041     }
1042 
1043     end = crt_end;
1044 
1045     /*
1046      *  }
1047      *  -- end of TBSCertificate
1048      *
1049      *  signatureAlgorithm   AlgorithmIdentifier,
1050      *  signatureValue       BIT STRING
1051      */
1052     if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 )
1053     {
1054         mbedtls_x509_crt_free( crt );
1055         return( ret );
1056     }
1057 
1058     if( crt->sig_oid.len != sig_oid2.len ||
1059         memcmp( crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len ) != 0 ||
1060         sig_params1.len != sig_params2.len ||
1061         ( sig_params1.len != 0 &&
1062           memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
1063     {
1064         mbedtls_x509_crt_free( crt );
1065         return( MBEDTLS_ERR_X509_SIG_MISMATCH );
1066     }
1067 
1068     if( ( ret = mbedtls_x509_get_sig( &p, end, &crt->sig ) ) != 0 )
1069     {
1070         mbedtls_x509_crt_free( crt );
1071         return( ret );
1072     }
1073 
1074     if( p != end )
1075     {
1076         mbedtls_x509_crt_free( crt );
1077         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1078                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1079     }
1080 
1081     return( 0 );
1082 }
1083 
1084 /*
1085  * Parse one X.509 certificate in DER format from a buffer and add them to a
1086  * chained list
1087  */
1088 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
1089                         size_t buflen )
1090 {
1091     int ret;
1092     mbedtls_x509_crt *crt = chain, *prev = NULL;
1093 
1094     /*
1095      * Check for valid input
1096      */
1097     if( crt == NULL || buf == NULL )
1098         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1099 
1100     while( crt->version != 0 && crt->next != NULL )
1101     {
1102         prev = crt;
1103         crt = crt->next;
1104     }
1105 
1106     /*
1107      * Add new certificate on the end of the chain if needed.
1108      */
1109     if( crt->version != 0 && crt->next == NULL )
1110     {
1111         crt->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
1112 
1113         if( crt->next == NULL )
1114             return( MBEDTLS_ERR_X509_ALLOC_FAILED );
1115 
1116         prev = crt;
1117         mbedtls_x509_crt_init( crt->next );
1118         crt = crt->next;
1119     }
1120 
1121     if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
1122     {
1123         if( prev )
1124             prev->next = NULL;
1125 
1126         if( crt != chain )
1127             mbedtls_free( crt );
1128 
1129         return( ret );
1130     }
1131 
1132     return( 0 );
1133 }
1134 
1135 /*
1136  * Parse one or more PEM certificates from a buffer and add them to the chained
1137  * list
1138  */
1139 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen )
1140 {
1141 #if defined(MBEDTLS_PEM_PARSE_C)
1142     int success = 0, first_error = 0, total_failed = 0;
1143     int buf_format = MBEDTLS_X509_FORMAT_DER;
1144 #endif
1145 
1146     /*
1147      * Check for valid input
1148      */
1149     if( chain == NULL || buf == NULL )
1150         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1151 
1152     /*
1153      * Determine buffer content. Buffer contains either one DER certificate or
1154      * one or more PEM certificates.
1155      */
1156 #if defined(MBEDTLS_PEM_PARSE_C)
1157     if( buflen != 0 && buf[buflen - 1] == '\0' &&
1158         strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
1159     {
1160         buf_format = MBEDTLS_X509_FORMAT_PEM;
1161     }
1162 
1163     if( buf_format == MBEDTLS_X509_FORMAT_DER )
1164         return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1165 #else
1166     return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1167 #endif
1168 
1169 #if defined(MBEDTLS_PEM_PARSE_C)
1170     if( buf_format == MBEDTLS_X509_FORMAT_PEM )
1171     {
1172         int ret;
1173         mbedtls_pem_context pem;
1174 
1175         /* 1 rather than 0 since the terminating NULL byte is counted in */
1176         while( buflen > 1 )
1177         {
1178             size_t use_len;
1179             mbedtls_pem_init( &pem );
1180 
1181             /* If we get there, we know the string is null-terminated */
1182             ret = mbedtls_pem_read_buffer( &pem,
1183                            "-----BEGIN CERTIFICATE-----",
1184                            "-----END CERTIFICATE-----",
1185                            buf, NULL, 0, &use_len );
1186 
1187             if( ret == 0 )
1188             {
1189                 /*
1190                  * Was PEM encoded
1191                  */
1192                 buflen -= use_len;
1193                 buf += use_len;
1194             }
1195             else if( ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA )
1196             {
1197                 return( ret );
1198             }
1199             else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1200             {
1201                 mbedtls_pem_free( &pem );
1202 
1203                 /*
1204                  * PEM header and footer were found
1205                  */
1206                 buflen -= use_len;
1207                 buf += use_len;
1208 
1209                 if( first_error == 0 )
1210                     first_error = ret;
1211 
1212                 total_failed++;
1213                 continue;
1214             }
1215             else
1216                 break;
1217 
1218             ret = mbedtls_x509_crt_parse_der( chain, pem.buf, pem.buflen );
1219 
1220             mbedtls_pem_free( &pem );
1221 
1222             if( ret != 0 )
1223             {
1224                 /*
1225                  * Quit parsing on a memory error
1226                  */
1227                 if( ret == MBEDTLS_ERR_X509_ALLOC_FAILED )
1228                     return( ret );
1229 
1230                 if( first_error == 0 )
1231                     first_error = ret;
1232 
1233                 total_failed++;
1234                 continue;
1235             }
1236 
1237             success = 1;
1238         }
1239     }
1240 
1241     if( success )
1242         return( total_failed );
1243     else if( first_error )
1244         return( first_error );
1245     else
1246         return( MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT );
1247 #endif /* MBEDTLS_PEM_PARSE_C */
1248 }
1249 
1250 #if defined(MBEDTLS_FS_IO)
1251 /*
1252  * Load one or more certificates and add them to the chained list
1253  */
1254 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path )
1255 {
1256     int ret;
1257     size_t n;
1258     unsigned char *buf;
1259 
1260     if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
1261         return( ret );
1262 
1263     ret = mbedtls_x509_crt_parse( chain, buf, n );
1264 
1265     mbedtls_platform_zeroize( buf, n );
1266     mbedtls_free( buf );
1267 
1268     return( ret );
1269 }
1270 
1271 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
1272 {
1273     int ret = 0;
1274 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
1275     int w_ret;
1276     WCHAR szDir[MAX_PATH];
1277     char filename[MAX_PATH];
1278     char *p;
1279     size_t len = strlen( path );
1280 
1281     WIN32_FIND_DATAW file_data;
1282     HANDLE hFind;
1283 
1284     if( len > MAX_PATH - 3 )
1285         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1286 
1287     memset( szDir, 0, sizeof(szDir) );
1288     memset( filename, 0, MAX_PATH );
1289     memcpy( filename, path, len );
1290     filename[len++] = '\\';
1291     p = filename + len;
1292     filename[len++] = '*';
1293 
1294     w_ret = MultiByteToWideChar( CP_ACP, 0, filename, (int)len, szDir,
1295                                  MAX_PATH - 3 );
1296     if( w_ret == 0 )
1297         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1298 
1299     hFind = FindFirstFileW( szDir, &file_data );
1300     if( hFind == INVALID_HANDLE_VALUE )
1301         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1302 
1303     len = MAX_PATH - len;
1304     do
1305     {
1306         memset( p, 0, len );
1307 
1308         if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
1309             continue;
1310 
1311         w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
1312                                      lstrlenW( file_data.cFileName ),
1313                                      p, (int) len - 1,
1314                                      NULL, NULL );
1315         if( w_ret == 0 )
1316         {
1317             ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1318             goto cleanup;
1319         }
1320 
1321         w_ret = mbedtls_x509_crt_parse_file( chain, filename );
1322         if( w_ret < 0 )
1323             ret++;
1324         else
1325             ret += w_ret;
1326     }
1327     while( FindNextFileW( hFind, &file_data ) != 0 );
1328 
1329     if( GetLastError() != ERROR_NO_MORE_FILES )
1330         ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1331 
1332 cleanup:
1333     FindClose( hFind );
1334 #else /* _WIN32 */
1335     int t_ret;
1336     int snp_ret;
1337     struct stat sb;
1338     struct dirent *entry;
1339     char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
1340     DIR *dir = opendir( path );
1341 
1342     if( dir == NULL )
1343         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1344 
1345 #if defined(MBEDTLS_THREADING_C)
1346     if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 )
1347     {
1348         closedir( dir );
1349         return( ret );
1350     }
1351 #endif /* MBEDTLS_THREADING_C */
1352 
1353     while( ( entry = readdir( dir ) ) != NULL )
1354     {
1355         snp_ret = mbedtls_snprintf( entry_name, sizeof entry_name,
1356                                     "%s/%s", path, entry->d_name );
1357 
1358         if( snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name )
1359         {
1360             ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
1361             goto cleanup;
1362         }
1363         else if( stat( entry_name, &sb ) == -1 )
1364         {
1365             ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1366             goto cleanup;
1367         }
1368 
1369         if( !S_ISREG( sb.st_mode ) )
1370             continue;
1371 
1372         // Ignore parse errors
1373         //
1374         t_ret = mbedtls_x509_crt_parse_file( chain, entry_name );
1375         if( t_ret < 0 )
1376             ret++;
1377         else
1378             ret += t_ret;
1379     }
1380 
1381 cleanup:
1382     closedir( dir );
1383 
1384 #if defined(MBEDTLS_THREADING_C)
1385     if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 )
1386         ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1387 #endif /* MBEDTLS_THREADING_C */
1388 
1389 #endif /* _WIN32 */
1390 
1391     return( ret );
1392 }
1393 #endif /* MBEDTLS_FS_IO */
1394 
1395 static int x509_info_subject_alt_name( char **buf, size_t *size,
1396                                        const mbedtls_x509_sequence *subject_alt_name )
1397 {
1398     size_t i;
1399     size_t n = *size;
1400     char *p = *buf;
1401     const mbedtls_x509_sequence *cur = subject_alt_name;
1402     const char *sep = "";
1403     size_t sep_len = 0;
1404 
1405     while( cur != NULL )
1406     {
1407         if( cur->buf.len + sep_len >= n )
1408         {
1409             *p = '\0';
1410             return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
1411         }
1412 
1413         n -= cur->buf.len + sep_len;
1414         for( i = 0; i < sep_len; i++ )
1415             *p++ = sep[i];
1416         for( i = 0; i < cur->buf.len; i++ )
1417             *p++ = cur->buf.p[i];
1418 
1419         sep = ", ";
1420         sep_len = 2;
1421 
1422         cur = cur->next;
1423     }
1424 
1425     *p = '\0';
1426 
1427     *size = n;
1428     *buf = p;
1429 
1430     return( 0 );
1431 }
1432 
1433 #define PRINT_ITEM(i)                           \
1434     {                                           \
1435         ret = mbedtls_snprintf( p, n, "%s" i, sep );    \
1436         MBEDTLS_X509_SAFE_SNPRINTF;                        \
1437         sep = ", ";                             \
1438     }
1439 
1440 #define CERT_TYPE(type,name)                    \
1441     if( ns_cert_type & (type) )                 \
1442         PRINT_ITEM( name );
1443 
1444 static int x509_info_cert_type( char **buf, size_t *size,
1445                                 unsigned char ns_cert_type )
1446 {
1447     int ret;
1448     size_t n = *size;
1449     char *p = *buf;
1450     const char *sep = "";
1451 
1452     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT,         "SSL Client" );
1453     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER,         "SSL Server" );
1454     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL,              "Email" );
1455     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING,     "Object Signing" );
1456     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED,           "Reserved" );
1457     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA,             "SSL CA" );
1458     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA,           "Email CA" );
1459     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA,  "Object Signing CA" );
1460 
1461     *size = n;
1462     *buf = p;
1463 
1464     return( 0 );
1465 }
1466 
1467 #define KEY_USAGE(code,name)    \
1468     if( key_usage & (code) )    \
1469         PRINT_ITEM( name );
1470 
1471 static int x509_info_key_usage( char **buf, size_t *size,
1472                                 unsigned int key_usage )
1473 {
1474     int ret;
1475     size_t n = *size;
1476     char *p = *buf;
1477     const char *sep = "";
1478 
1479     KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE,    "Digital Signature" );
1480     KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION,      "Non Repudiation" );
1481     KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT,     "Key Encipherment" );
1482     KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT,    "Data Encipherment" );
1483     KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT,        "Key Agreement" );
1484     KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN,        "Key Cert Sign" );
1485     KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN,             "CRL Sign" );
1486     KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY,        "Encipher Only" );
1487     KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY,        "Decipher Only" );
1488 
1489     *size = n;
1490     *buf = p;
1491 
1492     return( 0 );
1493 }
1494 
1495 static int x509_info_ext_key_usage( char **buf, size_t *size,
1496                                     const mbedtls_x509_sequence *extended_key_usage )
1497 {
1498     int ret;
1499     const char *desc;
1500     size_t n = *size;
1501     char *p = *buf;
1502     const mbedtls_x509_sequence *cur = extended_key_usage;
1503     const char *sep = "";
1504 
1505     while( cur != NULL )
1506     {
1507         if( mbedtls_oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
1508             desc = "???";
1509 
1510         ret = mbedtls_snprintf( p, n, "%s%s", sep, desc );
1511         MBEDTLS_X509_SAFE_SNPRINTF;
1512 
1513         sep = ", ";
1514 
1515         cur = cur->next;
1516     }
1517 
1518     *size = n;
1519     *buf = p;
1520 
1521     return( 0 );
1522 }
1523 
1524 /*
1525  * Return an informational string about the certificate.
1526  */
1527 #define BEFORE_COLON    18
1528 #define BC              "18"
1529 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
1530                    const mbedtls_x509_crt *crt )
1531 {
1532     int ret;
1533     size_t n;
1534     char *p;
1535     char key_size_str[BEFORE_COLON];
1536 
1537     p = buf;
1538     n = size;
1539 
1540     if( NULL == crt )
1541     {
1542         ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" );
1543         MBEDTLS_X509_SAFE_SNPRINTF;
1544 
1545         return( (int) ( size - n ) );
1546     }
1547 
1548     ret = mbedtls_snprintf( p, n, "%scert. version     : %d\n",
1549                                prefix, crt->version );
1550     MBEDTLS_X509_SAFE_SNPRINTF;
1551     ret = mbedtls_snprintf( p, n, "%sserial number     : ",
1552                                prefix );
1553     MBEDTLS_X509_SAFE_SNPRINTF;
1554 
1555     ret = mbedtls_x509_serial_gets( p, n, &crt->serial );
1556     MBEDTLS_X509_SAFE_SNPRINTF;
1557 
1558     ret = mbedtls_snprintf( p, n, "\n%sissuer name       : ", prefix );
1559     MBEDTLS_X509_SAFE_SNPRINTF;
1560     ret = mbedtls_x509_dn_gets( p, n, &crt->issuer  );
1561     MBEDTLS_X509_SAFE_SNPRINTF;
1562 
1563     ret = mbedtls_snprintf( p, n, "\n%ssubject name      : ", prefix );
1564     MBEDTLS_X509_SAFE_SNPRINTF;
1565     ret = mbedtls_x509_dn_gets( p, n, &crt->subject );
1566     MBEDTLS_X509_SAFE_SNPRINTF;
1567 
1568     ret = mbedtls_snprintf( p, n, "\n%sissued  on        : " \
1569                    "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1570                    crt->valid_from.year, crt->valid_from.mon,
1571                    crt->valid_from.day,  crt->valid_from.hour,
1572                    crt->valid_from.min,  crt->valid_from.sec );
1573     MBEDTLS_X509_SAFE_SNPRINTF;
1574 
1575     ret = mbedtls_snprintf( p, n, "\n%sexpires on        : " \
1576                    "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1577                    crt->valid_to.year, crt->valid_to.mon,
1578                    crt->valid_to.day,  crt->valid_to.hour,
1579                    crt->valid_to.min,  crt->valid_to.sec );
1580     MBEDTLS_X509_SAFE_SNPRINTF;
1581 
1582     ret = mbedtls_snprintf( p, n, "\n%ssigned using      : ", prefix );
1583     MBEDTLS_X509_SAFE_SNPRINTF;
1584 
1585     ret = mbedtls_x509_sig_alg_gets( p, n, &crt->sig_oid, crt->sig_pk,
1586                              crt->sig_md, crt->sig_opts );
1587     MBEDTLS_X509_SAFE_SNPRINTF;
1588 
1589     /* Key size */
1590     if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON,
1591                                       mbedtls_pk_get_name( &crt->pk ) ) ) != 0 )
1592     {
1593         return( ret );
1594     }
1595 
1596     ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
1597                           (int) mbedtls_pk_get_bitlen( &crt->pk ) );
1598     MBEDTLS_X509_SAFE_SNPRINTF;
1599 
1600     /*
1601      * Optional extensions
1602      */
1603 
1604     if( crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS )
1605     {
1606         ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
1607                         crt->ca_istrue ? "true" : "false" );
1608         MBEDTLS_X509_SAFE_SNPRINTF;
1609 
1610         if( crt->max_pathlen > 0 )
1611         {
1612             ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
1613             MBEDTLS_X509_SAFE_SNPRINTF;
1614         }
1615     }
1616 
1617     if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
1618     {
1619         ret = mbedtls_snprintf( p, n, "\n%ssubject alt name  : ", prefix );
1620         MBEDTLS_X509_SAFE_SNPRINTF;
1621 
1622         if( ( ret = x509_info_subject_alt_name( &p, &n,
1623                                             &crt->subject_alt_names ) ) != 0 )
1624             return( ret );
1625     }
1626 
1627     if( crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE )
1628     {
1629         ret = mbedtls_snprintf( p, n, "\n%scert. type        : ", prefix );
1630         MBEDTLS_X509_SAFE_SNPRINTF;
1631 
1632         if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
1633             return( ret );
1634     }
1635 
1636     if( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE )
1637     {
1638         ret = mbedtls_snprintf( p, n, "\n%skey usage         : ", prefix );
1639         MBEDTLS_X509_SAFE_SNPRINTF;
1640 
1641         if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
1642             return( ret );
1643     }
1644 
1645     if( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE )
1646     {
1647         ret = mbedtls_snprintf( p, n, "\n%sext key usage     : ", prefix );
1648         MBEDTLS_X509_SAFE_SNPRINTF;
1649 
1650         if( ( ret = x509_info_ext_key_usage( &p, &n,
1651                                              &crt->ext_key_usage ) ) != 0 )
1652             return( ret );
1653     }
1654 
1655     ret = mbedtls_snprintf( p, n, "\n" );
1656     MBEDTLS_X509_SAFE_SNPRINTF;
1657 
1658     return( (int) ( size - n ) );
1659 }
1660 
1661 struct x509_crt_verify_string {
1662     int code;
1663     const char *string;
1664 };
1665 
1666 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
1667     { MBEDTLS_X509_BADCERT_EXPIRED,       "The certificate validity has expired" },
1668     { MBEDTLS_X509_BADCERT_REVOKED,       "The certificate has been revoked (is on a CRL)" },
1669     { MBEDTLS_X509_BADCERT_CN_MISMATCH,   "The certificate Common Name (CN) does not match with the expected CN" },
1670     { MBEDTLS_X509_BADCERT_NOT_TRUSTED,   "The certificate is not correctly signed by the trusted CA" },
1671     { MBEDTLS_X509_BADCRL_NOT_TRUSTED,    "The CRL is not correctly signed by the trusted CA" },
1672     { MBEDTLS_X509_BADCRL_EXPIRED,        "The CRL is expired" },
1673     { MBEDTLS_X509_BADCERT_MISSING,       "Certificate was missing" },
1674     { MBEDTLS_X509_BADCERT_SKIP_VERIFY,   "Certificate verification was skipped" },
1675     { MBEDTLS_X509_BADCERT_OTHER,         "Other reason (can be used by verify callback)" },
1676     { MBEDTLS_X509_BADCERT_FUTURE,        "The certificate validity starts in the future" },
1677     { MBEDTLS_X509_BADCRL_FUTURE,         "The CRL is from the future" },
1678     { MBEDTLS_X509_BADCERT_KEY_USAGE,     "Usage does not match the keyUsage extension" },
1679     { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
1680     { MBEDTLS_X509_BADCERT_NS_CERT_TYPE,  "Usage does not match the nsCertType extension" },
1681     { MBEDTLS_X509_BADCERT_BAD_MD,        "The certificate is signed with an unacceptable hash." },
1682     { MBEDTLS_X509_BADCERT_BAD_PK,        "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1683     { MBEDTLS_X509_BADCERT_BAD_KEY,       "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
1684     { MBEDTLS_X509_BADCRL_BAD_MD,         "The CRL is signed with an unacceptable hash." },
1685     { MBEDTLS_X509_BADCRL_BAD_PK,         "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1686     { MBEDTLS_X509_BADCRL_BAD_KEY,        "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
1687     { 0, NULL }
1688 };
1689 
1690 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
1691                           uint32_t flags )
1692 {
1693     int ret;
1694     const struct x509_crt_verify_string *cur;
1695     char *p = buf;
1696     size_t n = size;
1697 
1698     for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
1699     {
1700         if( ( flags & cur->code ) == 0 )
1701             continue;
1702 
1703         ret = mbedtls_snprintf( p, n, "%s%s\n", prefix, cur->string );
1704         MBEDTLS_X509_SAFE_SNPRINTF;
1705         flags ^= cur->code;
1706     }
1707 
1708     if( flags != 0 )
1709     {
1710         ret = mbedtls_snprintf( p, n, "%sUnknown reason "
1711                                        "(this should not happen)\n", prefix );
1712         MBEDTLS_X509_SAFE_SNPRINTF;
1713     }
1714 
1715     return( (int) ( size - n ) );
1716 }
1717 
1718 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1719 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
1720                                       unsigned int usage )
1721 {
1722     unsigned int usage_must, usage_may;
1723     unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
1724                           | MBEDTLS_X509_KU_DECIPHER_ONLY;
1725 
1726     if( ( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) == 0 )
1727         return( 0 );
1728 
1729     usage_must = usage & ~may_mask;
1730 
1731     if( ( ( crt->key_usage & ~may_mask ) & usage_must ) != usage_must )
1732         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1733 
1734     usage_may = usage & may_mask;
1735 
1736     if( ( ( crt->key_usage & may_mask ) | usage_may ) != usage_may )
1737         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1738 
1739     return( 0 );
1740 }
1741 #endif
1742 
1743 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
1744 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
1745                                        const char *usage_oid,
1746                                        size_t usage_len )
1747 {
1748     const mbedtls_x509_sequence *cur;
1749 
1750     /* Extension is not mandatory, absent means no restriction */
1751     if( ( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 )
1752         return( 0 );
1753 
1754     /*
1755      * Look for the requested usage (or wildcard ANY) in our list
1756      */
1757     for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
1758     {
1759         const mbedtls_x509_buf *cur_oid = &cur->buf;
1760 
1761         if( cur_oid->len == usage_len &&
1762             memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
1763         {
1764             return( 0 );
1765         }
1766 
1767         if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) == 0 )
1768             return( 0 );
1769     }
1770 
1771     return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1772 }
1773 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
1774 
1775 #if defined(MBEDTLS_X509_CRL_PARSE_C)
1776 /*
1777  * Return 1 if the certificate is revoked, or 0 otherwise.
1778  */
1779 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl )
1780 {
1781     const mbedtls_x509_crl_entry *cur = &crl->entry;
1782 
1783     while( cur != NULL && cur->serial.len != 0 )
1784     {
1785         if( crt->serial.len == cur->serial.len &&
1786             memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
1787         {
1788             if( mbedtls_x509_time_is_past( &cur->revocation_date ) )
1789                 return( 1 );
1790         }
1791 
1792         cur = cur->next;
1793     }
1794 
1795     return( 0 );
1796 }
1797 
1798 /*
1799  * Check that the given certificate is not revoked according to the CRL.
1800  * Skip validation if no CRL for the given CA is present.
1801  */
1802 static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
1803                                mbedtls_x509_crl *crl_list,
1804                                const mbedtls_x509_crt_profile *profile )
1805 {
1806     int flags = 0;
1807     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1808     const mbedtls_md_info_t *md_info;
1809 
1810     if( ca == NULL )
1811         return( flags );
1812 
1813     while( crl_list != NULL )
1814     {
1815         if( crl_list->version == 0 ||
1816             x509_name_cmp( &crl_list->issuer, &ca->subject ) != 0 )
1817         {
1818             crl_list = crl_list->next;
1819             continue;
1820         }
1821 
1822         /*
1823          * Check if the CA is configured to sign CRLs
1824          */
1825 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1826         if( mbedtls_x509_crt_check_key_usage( ca,
1827                                               MBEDTLS_X509_KU_CRL_SIGN ) != 0 )
1828         {
1829             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1830             break;
1831         }
1832 #endif
1833 
1834         /*
1835          * Check if CRL is correctly signed by the trusted CA
1836          */
1837         if( x509_profile_check_md_alg( profile, crl_list->sig_md ) != 0 )
1838             flags |= MBEDTLS_X509_BADCRL_BAD_MD;
1839 
1840         if( x509_profile_check_pk_alg( profile, crl_list->sig_pk ) != 0 )
1841             flags |= MBEDTLS_X509_BADCRL_BAD_PK;
1842 
1843         md_info = mbedtls_md_info_from_type( crl_list->sig_md );
1844         if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 )
1845         {
1846             /* Note: this can't happen except after an internal error */
1847             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1848             break;
1849         }
1850 
1851         if( x509_profile_check_key( profile, &ca->pk ) != 0 )
1852             flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
1853 
1854         if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
1855                            crl_list->sig_md, hash, mbedtls_md_get_size( md_info ),
1856                            crl_list->sig.p, crl_list->sig.len ) != 0 )
1857         {
1858             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1859             break;
1860         }
1861 
1862         /*
1863          * Check for validity of CRL (Do not drop out)
1864          */
1865         if( mbedtls_x509_time_is_past( &crl_list->next_update ) )
1866             flags |= MBEDTLS_X509_BADCRL_EXPIRED;
1867 
1868         if( mbedtls_x509_time_is_future( &crl_list->this_update ) )
1869             flags |= MBEDTLS_X509_BADCRL_FUTURE;
1870 
1871         /*
1872          * Check if certificate is revoked
1873          */
1874         if( mbedtls_x509_crt_is_revoked( crt, crl_list ) )
1875         {
1876             flags |= MBEDTLS_X509_BADCERT_REVOKED;
1877             break;
1878         }
1879 
1880         crl_list = crl_list->next;
1881     }
1882 
1883     return( flags );
1884 }
1885 #endif /* MBEDTLS_X509_CRL_PARSE_C */
1886 
1887 /*
1888  * Check the signature of a certificate by its parent
1889  */
1890 static int x509_crt_check_signature( const mbedtls_x509_crt *child,
1891                                      mbedtls_x509_crt *parent,
1892                                      mbedtls_x509_crt_restart_ctx *rs_ctx )
1893 {
1894     const mbedtls_md_info_t *md_info;
1895     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1896 
1897     md_info = mbedtls_md_info_from_type( child->sig_md );
1898     if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
1899     {
1900         /* Note: this can't happen except after an internal error */
1901         return( -1 );
1902     }
1903 
1904     /* Skip expensive computation on obvious mismatch */
1905     if( ! mbedtls_pk_can_do( &parent->pk, child->sig_pk ) )
1906         return( -1 );
1907 
1908 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
1909     if( rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA )
1910     {
1911         return( mbedtls_pk_verify_restartable( &parent->pk,
1912                     child->sig_md, hash, mbedtls_md_get_size( md_info ),
1913                     child->sig.p, child->sig.len, &rs_ctx->pk ) );
1914     }
1915 #else
1916     (void) rs_ctx;
1917 #endif
1918 
1919     return( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
1920                 child->sig_md, hash, mbedtls_md_get_size( md_info ),
1921                 child->sig.p, child->sig.len ) );
1922 }
1923 
1924 /*
1925  * Check if 'parent' is a suitable parent (signing CA) for 'child'.
1926  * Return 0 if yes, -1 if not.
1927  *
1928  * top means parent is a locally-trusted certificate
1929  */
1930 static int x509_crt_check_parent( const mbedtls_x509_crt *child,
1931                                   const mbedtls_x509_crt *parent,
1932                                   int top )
1933 {
1934     int need_ca_bit;
1935 
1936     /* Parent must be the issuer */
1937     if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
1938         return( -1 );
1939 
1940     /* Parent must have the basicConstraints CA bit set as a general rule */
1941     need_ca_bit = 1;
1942 
1943     /* Exception: v1/v2 certificates that are locally trusted. */
1944     if( top && parent->version < 3 )
1945         need_ca_bit = 0;
1946 
1947     if( need_ca_bit && ! parent->ca_istrue )
1948         return( -1 );
1949 
1950 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1951     if( need_ca_bit &&
1952         mbedtls_x509_crt_check_key_usage( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
1953     {
1954         return( -1 );
1955     }
1956 #endif
1957 
1958     return( 0 );
1959 }
1960 
1961 /*
1962  * Find a suitable parent for child in candidates, or return NULL.
1963  *
1964  * Here suitable is defined as:
1965  *  1. subject name matches child's issuer
1966  *  2. if necessary, the CA bit is set and key usage allows signing certs
1967  *  3. for trusted roots, the signature is correct
1968  *     (for intermediates, the signature is checked and the result reported)
1969  *  4. pathlen constraints are satisfied
1970  *
1971  * If there's a suitable candidate which is also time-valid, return the first
1972  * such. Otherwise, return the first suitable candidate (or NULL if there is
1973  * none).
1974  *
1975  * The rationale for this rule is that someone could have a list of trusted
1976  * roots with two versions on the same root with different validity periods.
1977  * (At least one user reported having such a list and wanted it to just work.)
1978  * The reason we don't just require time-validity is that generally there is
1979  * only one version, and if it's expired we want the flags to state that
1980  * rather than NOT_TRUSTED, as would be the case if we required it here.
1981  *
1982  * The rationale for rule 3 (signature for trusted roots) is that users might
1983  * have two versions of the same CA with different keys in their list, and the
1984  * way we select the correct one is by checking the signature (as we don't
1985  * rely on key identifier extensions). (This is one way users might choose to
1986  * handle key rollover, another relies on self-issued certs, see [SIRO].)
1987  *
1988  * Arguments:
1989  *  - [in] child: certificate for which we're looking for a parent
1990  *  - [in] candidates: chained list of potential parents
1991  *  - [out] r_parent: parent found (or NULL)
1992  *  - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0
1993  *  - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
1994  *         of the chain, 0 otherwise
1995  *  - [in] path_cnt: number of intermediates seen so far
1996  *  - [in] self_cnt: number of self-signed intermediates seen so far
1997  *         (will never be greater than path_cnt)
1998  *  - [in-out] rs_ctx: context for restarting operations
1999  *
2000  * Return value:
2001  *  - 0 on success
2002  *  - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2003  */
2004 static int x509_crt_find_parent_in(
2005                         mbedtls_x509_crt *child,
2006                         mbedtls_x509_crt *candidates,
2007                         mbedtls_x509_crt **r_parent,
2008                         int *r_signature_is_good,
2009                         int top,
2010                         unsigned path_cnt,
2011                         unsigned self_cnt,
2012                         mbedtls_x509_crt_restart_ctx *rs_ctx )
2013 {
2014     int ret;
2015     mbedtls_x509_crt *parent, *fallback_parent;
2016     int signature_is_good, fallback_signature_is_good;
2017 
2018 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2019     /* did we have something in progress? */
2020     if( rs_ctx != NULL && rs_ctx->parent != NULL )
2021     {
2022         /* restore saved state */
2023         parent = rs_ctx->parent;
2024         fallback_parent = rs_ctx->fallback_parent;
2025         fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
2026 
2027         /* clear saved state */
2028         rs_ctx->parent = NULL;
2029         rs_ctx->fallback_parent = NULL;
2030         rs_ctx->fallback_signature_is_good = 0;
2031 
2032         /* resume where we left */
2033         goto check_signature;
2034     }
2035 #endif
2036 
2037     fallback_parent = NULL;
2038     fallback_signature_is_good = 0;
2039 
2040     for( parent = candidates; parent != NULL; parent = parent->next )
2041     {
2042         /* basic parenting skills (name, CA bit, key usage) */
2043         if( x509_crt_check_parent( child, parent, top ) != 0 )
2044             continue;
2045 
2046         /* +1 because stored max_pathlen is 1 higher that the actual value */
2047         if( parent->max_pathlen > 0 &&
2048             (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt )
2049         {
2050             continue;
2051         }
2052 
2053         /* Signature */
2054 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2055 check_signature:
2056 #endif
2057         ret = x509_crt_check_signature( child, parent, rs_ctx );
2058 
2059 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2060         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2061         {
2062             /* save state */
2063             rs_ctx->parent = parent;
2064             rs_ctx->fallback_parent = fallback_parent;
2065             rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
2066 
2067             return( ret );
2068         }
2069 #else
2070         (void) ret;
2071 #endif
2072 
2073         signature_is_good = ret == 0;
2074         if( top && ! signature_is_good )
2075             continue;
2076 
2077         /* optional time check */
2078         if( mbedtls_x509_time_is_past( &parent->valid_to ) ||
2079             mbedtls_x509_time_is_future( &parent->valid_from ) )
2080         {
2081             if( fallback_parent == NULL )
2082             {
2083                 fallback_parent = parent;
2084                 fallback_signature_is_good = signature_is_good;
2085             }
2086 
2087             continue;
2088         }
2089 
2090         *r_parent = parent;
2091         *r_signature_is_good = signature_is_good;
2092 
2093         break;
2094     }
2095 
2096     if( parent == NULL )
2097     {
2098         *r_parent = fallback_parent;
2099         *r_signature_is_good = fallback_signature_is_good;
2100     }
2101 
2102     return( 0 );
2103 }
2104 
2105 /*
2106  * Find a parent in trusted CAs or the provided chain, or return NULL.
2107  *
2108  * Searches in trusted CAs first, and return the first suitable parent found
2109  * (see find_parent_in() for definition of suitable).
2110  *
2111  * Arguments:
2112  *  - [in] child: certificate for which we're looking for a parent, followed
2113  *         by a chain of possible intermediates
2114  *  - [in] trust_ca: list of locally trusted certificates
2115  *  - [out] parent: parent found (or NULL)
2116  *  - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0
2117  *  - [out] signature_is_good: 1 if child signature by parent is valid, or 0
2118  *  - [in] path_cnt: number of links in the chain so far (EE -> ... -> child)
2119  *  - [in] self_cnt: number of self-signed certs in the chain so far
2120  *         (will always be no greater than path_cnt)
2121  *  - [in-out] rs_ctx: context for restarting operations
2122  *
2123  * Return value:
2124  *  - 0 on success
2125  *  - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2126  */
2127 static int x509_crt_find_parent(
2128                         mbedtls_x509_crt *child,
2129                         mbedtls_x509_crt *trust_ca,
2130                         mbedtls_x509_crt **parent,
2131                         int *parent_is_trusted,
2132                         int *signature_is_good,
2133                         unsigned path_cnt,
2134                         unsigned self_cnt,
2135                         mbedtls_x509_crt_restart_ctx *rs_ctx )
2136 {
2137     int ret;
2138     mbedtls_x509_crt *search_list;
2139 
2140     *parent_is_trusted = 1;
2141 
2142 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2143     /* restore then clear saved state if we have some stored */
2144     if( rs_ctx != NULL && rs_ctx->parent_is_trusted != -1 )
2145     {
2146         *parent_is_trusted = rs_ctx->parent_is_trusted;
2147         rs_ctx->parent_is_trusted = -1;
2148     }
2149 #endif
2150 
2151     while( 1 ) {
2152         search_list = *parent_is_trusted ? trust_ca : child->next;
2153 
2154         ret = x509_crt_find_parent_in( child, search_list,
2155                                        parent, signature_is_good,
2156                                        *parent_is_trusted,
2157                                        path_cnt, self_cnt, rs_ctx );
2158 
2159 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2160         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2161         {
2162             /* save state */
2163             rs_ctx->parent_is_trusted = *parent_is_trusted;
2164             return( ret );
2165         }
2166 #else
2167         (void) ret;
2168 #endif
2169 
2170         /* stop here if found or already in second iteration */
2171         if( *parent != NULL || *parent_is_trusted == 0 )
2172             break;
2173 
2174         /* prepare second iteration */
2175         *parent_is_trusted = 0;
2176     }
2177 
2178     /* extra precaution against mistakes in the caller */
2179     if( *parent == NULL )
2180     {
2181         *parent_is_trusted = 0;
2182         *signature_is_good = 0;
2183     }
2184 
2185     return( 0 );
2186 }
2187 
2188 /*
2189  * Check if an end-entity certificate is locally trusted
2190  *
2191  * Currently we require such certificates to be self-signed (actually only
2192  * check for self-issued as self-signatures are not checked)
2193  */
2194 static int x509_crt_check_ee_locally_trusted(
2195                     mbedtls_x509_crt *crt,
2196                     mbedtls_x509_crt *trust_ca )
2197 {
2198     mbedtls_x509_crt *cur;
2199 
2200     /* must be self-issued */
2201     if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 )
2202         return( -1 );
2203 
2204     /* look for an exact match with trusted cert */
2205     for( cur = trust_ca; cur != NULL; cur = cur->next )
2206     {
2207         if( crt->raw.len == cur->raw.len &&
2208             memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 )
2209         {
2210             return( 0 );
2211         }
2212     }
2213 
2214     /* too bad */
2215     return( -1 );
2216 }
2217 
2218 /*
2219  * Build and verify a certificate chain
2220  *
2221  * Given a peer-provided list of certificates EE, C1, ..., Cn and
2222  * a list of trusted certs R1, ... Rp, try to build and verify a chain
2223  *      EE, Ci1, ... Ciq [, Rj]
2224  * such that every cert in the chain is a child of the next one,
2225  * jumping to a trusted root as early as possible.
2226  *
2227  * Verify that chain and return it with flags for all issues found.
2228  *
2229  * Special cases:
2230  * - EE == Rj -> return a one-element list containing it
2231  * - EE, Ci1, ..., Ciq cannot be continued with a trusted root
2232  *   -> return that chain with NOT_TRUSTED set on Ciq
2233  *
2234  * Tests for (aspects of) this function should include at least:
2235  * - trusted EE
2236  * - EE -> trusted root
2237  * - EE -> intermediate CA -> trusted root
2238  * - if relevant: EE untrusted
2239  * - if relevant: EE -> intermediate, untrusted
2240  * with the aspect under test checked at each relevant level (EE, int, root).
2241  * For some aspects longer chains are required, but usually length 2 is
2242  * enough (but length 1 is not in general).
2243  *
2244  * Arguments:
2245  *  - [in] crt: the cert list EE, C1, ..., Cn
2246  *  - [in] trust_ca: the trusted list R1, ..., Rp
2247  *  - [in] ca_crl, profile: as in verify_with_profile()
2248  *  - [out] ver_chain: the built and verified chain
2249  *      Only valid when return value is 0, may contain garbage otherwise!
2250  *      Restart note: need not be the same when calling again to resume.
2251  *  - [in-out] rs_ctx: context for restarting operations
2252  *
2253  * Return value:
2254  *  - non-zero if the chain could not be fully built and examined
2255  *  - 0 is the chain was successfully built and examined,
2256  *      even if it was found to be invalid
2257  */
2258 static int x509_crt_verify_chain(
2259                 mbedtls_x509_crt *crt,
2260                 mbedtls_x509_crt *trust_ca,
2261                 mbedtls_x509_crl *ca_crl,
2262                 const mbedtls_x509_crt_profile *profile,
2263                 mbedtls_x509_crt_verify_chain *ver_chain,
2264                 mbedtls_x509_crt_restart_ctx *rs_ctx )
2265 {
2266     /* Don't initialize any of those variables here, so that the compiler can
2267      * catch potential issues with jumping ahead when restarting */
2268     int ret;
2269     uint32_t *flags;
2270     mbedtls_x509_crt_verify_chain_item *cur;
2271     mbedtls_x509_crt *child;
2272     mbedtls_x509_crt *parent;
2273     int parent_is_trusted;
2274     int child_is_trusted;
2275     int signature_is_good;
2276     unsigned self_cnt;
2277 
2278 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2279     /* resume if we had an operation in progress */
2280     if( rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent )
2281     {
2282         /* restore saved state */
2283         *ver_chain = rs_ctx->ver_chain; /* struct copy */
2284         self_cnt = rs_ctx->self_cnt;
2285 
2286         /* restore derived state */
2287         cur = &ver_chain->items[ver_chain->len - 1];
2288         child = cur->crt;
2289         flags = &cur->flags;
2290 
2291         goto find_parent;
2292     }
2293 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2294 
2295     child = crt;
2296     self_cnt = 0;
2297     parent_is_trusted = 0;
2298     child_is_trusted = 0;
2299 
2300     while( 1 ) {
2301         /* Add certificate to the verification chain */
2302         cur = &ver_chain->items[ver_chain->len];
2303         cur->crt = child;
2304         cur->flags = 0;
2305         ver_chain->len++;
2306         flags = &cur->flags;
2307 
2308         /* Check time-validity (all certificates) */
2309         if( mbedtls_x509_time_is_past( &child->valid_to ) )
2310             *flags |= MBEDTLS_X509_BADCERT_EXPIRED;
2311 
2312         if( mbedtls_x509_time_is_future( &child->valid_from ) )
2313             *flags |= MBEDTLS_X509_BADCERT_FUTURE;
2314 
2315         /* Stop here for trusted roots (but not for trusted EE certs) */
2316         if( child_is_trusted )
2317             return( 0 );
2318 
2319         /* Check signature algorithm: MD & PK algs */
2320         if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 )
2321             *flags |= MBEDTLS_X509_BADCERT_BAD_MD;
2322 
2323         if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 )
2324             *flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2325 
2326         /* Special case: EE certs that are locally trusted */
2327         if( ver_chain->len == 1 &&
2328             x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 )
2329         {
2330             return( 0 );
2331         }
2332 
2333 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2334 find_parent:
2335 #endif
2336         /* Look for a parent in trusted CAs or up the chain */
2337         ret = x509_crt_find_parent( child, trust_ca, &parent,
2338                                        &parent_is_trusted, &signature_is_good,
2339                                        ver_chain->len - 1, self_cnt, rs_ctx );
2340 
2341 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2342         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2343         {
2344             /* save state */
2345             rs_ctx->in_progress = x509_crt_rs_find_parent;
2346             rs_ctx->self_cnt = self_cnt;
2347             rs_ctx->ver_chain = *ver_chain; /* struct copy */
2348 
2349             return( ret );
2350         }
2351 #else
2352         (void) ret;
2353 #endif
2354 
2355         /* No parent? We're done here */
2356         if( parent == NULL )
2357         {
2358             *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2359             return( 0 );
2360         }
2361 
2362         /* Count intermediate self-issued (not necessarily self-signed) certs.
2363          * These can occur with some strategies for key rollover, see [SIRO],
2364          * and should be excluded from max_pathlen checks. */
2365         if( ver_chain->len != 1 &&
2366             x509_name_cmp( &child->issuer, &child->subject ) == 0 )
2367         {
2368             self_cnt++;
2369         }
2370 
2371         /* path_cnt is 0 for the first intermediate CA,
2372          * and if parent is trusted it's not an intermediate CA */
2373         if( ! parent_is_trusted &&
2374             ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
2375         {
2376             /* return immediately to avoid overflow the chain array */
2377             return( MBEDTLS_ERR_X509_FATAL_ERROR );
2378         }
2379 
2380         /* signature was checked while searching parent */
2381         if( ! signature_is_good )
2382             *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2383 
2384         /* check size of signing key */
2385         if( x509_profile_check_key( profile, &parent->pk ) != 0 )
2386             *flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2387 
2388 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2389         /* Check trusted CA's CRL for the given crt */
2390         *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile );
2391 #else
2392         (void) ca_crl;
2393 #endif
2394 
2395         /* prepare for next iteration */
2396         child = parent;
2397         parent = NULL;
2398         child_is_trusted = parent_is_trusted;
2399         signature_is_good = 0;
2400     }
2401 }
2402 
2403 /*
2404  * Check for CN match
2405  */
2406 static int x509_crt_check_cn( const mbedtls_x509_buf *name,
2407                               const char *cn, size_t cn_len )
2408 {
2409     /* try exact match */
2410     if( name->len == cn_len &&
2411         x509_memcasecmp( cn, name->p, cn_len ) == 0 )
2412     {
2413         return( 0 );
2414     }
2415 
2416     /* try wildcard match */
2417     if( x509_check_wildcard( cn, name ) == 0 )
2418     {
2419         return( 0 );
2420     }
2421 
2422     return( -1 );
2423 }
2424 
2425 /*
2426  * Verify the requested CN - only call this if cn is not NULL!
2427  */
2428 static void x509_crt_verify_name( const mbedtls_x509_crt *crt,
2429                                   const char *cn,
2430                                   uint32_t *flags )
2431 {
2432     const mbedtls_x509_name *name;
2433     const mbedtls_x509_sequence *cur;
2434     size_t cn_len = strlen( cn );
2435 
2436     if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
2437     {
2438         for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next )
2439         {
2440             if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 )
2441                 break;
2442         }
2443 
2444         if( cur == NULL )
2445             *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2446     }
2447     else
2448     {
2449         for( name = &crt->subject; name != NULL; name = name->next )
2450         {
2451             if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 &&
2452                 x509_crt_check_cn( &name->val, cn, cn_len ) == 0 )
2453             {
2454                 break;
2455             }
2456         }
2457 
2458         if( name == NULL )
2459             *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2460     }
2461 }
2462 
2463 /*
2464  * Merge the flags for all certs in the chain, after calling callback
2465  */
2466 static int x509_crt_merge_flags_with_cb(
2467            uint32_t *flags,
2468            const mbedtls_x509_crt_verify_chain *ver_chain,
2469            int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2470            void *p_vrfy )
2471 {
2472     int ret;
2473     unsigned i;
2474     uint32_t cur_flags;
2475     const mbedtls_x509_crt_verify_chain_item *cur;
2476 
2477     for( i = ver_chain->len; i != 0; --i )
2478     {
2479         cur = &ver_chain->items[i-1];
2480         cur_flags = cur->flags;
2481 
2482         if( NULL != f_vrfy )
2483             if( ( ret = f_vrfy( p_vrfy, cur->crt, (int) i-1, &cur_flags ) ) != 0 )
2484                 return( ret );
2485 
2486         *flags |= cur_flags;
2487     }
2488 
2489     return( 0 );
2490 }
2491 
2492 /*
2493  * Verify the certificate validity (default profile, not restartable)
2494  */
2495 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
2496                      mbedtls_x509_crt *trust_ca,
2497                      mbedtls_x509_crl *ca_crl,
2498                      const char *cn, uint32_t *flags,
2499                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2500                      void *p_vrfy )
2501 {
2502     return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
2503                 &mbedtls_x509_crt_profile_default, cn, flags,
2504                 f_vrfy, p_vrfy, NULL ) );
2505 }
2506 
2507 /*
2508  * Verify the certificate validity (user-chosen profile, not restartable)
2509  */
2510 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
2511                      mbedtls_x509_crt *trust_ca,
2512                      mbedtls_x509_crl *ca_crl,
2513                      const mbedtls_x509_crt_profile *profile,
2514                      const char *cn, uint32_t *flags,
2515                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2516                      void *p_vrfy )
2517 {
2518     return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
2519                 profile, cn, flags, f_vrfy, p_vrfy, NULL ) );
2520 }
2521 
2522 /*
2523  * Verify the certificate validity, with profile, restartable version
2524  *
2525  * This function:
2526  *  - checks the requested CN (if any)
2527  *  - checks the type and size of the EE cert's key,
2528  *    as that isn't done as part of chain building/verification currently
2529  *  - builds and verifies the chain
2530  *  - then calls the callback and merges the flags
2531  */
2532 int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt,
2533                      mbedtls_x509_crt *trust_ca,
2534                      mbedtls_x509_crl *ca_crl,
2535                      const mbedtls_x509_crt_profile *profile,
2536                      const char *cn, uint32_t *flags,
2537                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2538                      void *p_vrfy,
2539                      mbedtls_x509_crt_restart_ctx *rs_ctx )
2540 {
2541     int ret;
2542     mbedtls_pk_type_t pk_type;
2543     mbedtls_x509_crt_verify_chain ver_chain;
2544     uint32_t ee_flags;
2545 
2546     *flags = 0;
2547     ee_flags = 0;
2548     x509_crt_verify_chain_reset( &ver_chain );
2549 
2550     if( profile == NULL )
2551     {
2552         ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
2553         goto exit;
2554     }
2555 
2556     /* check name if requested */
2557     if( cn != NULL )
2558         x509_crt_verify_name( crt, cn, &ee_flags );
2559 
2560     /* Check the type and size of the key */
2561     pk_type = mbedtls_pk_get_type( &crt->pk );
2562 
2563     if( x509_profile_check_pk_alg( profile, pk_type ) != 0 )
2564         ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2565 
2566     if( x509_profile_check_key( profile, &crt->pk ) != 0 )
2567         ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2568 
2569     /* Check the chain */
2570     ret = x509_crt_verify_chain( crt, trust_ca, ca_crl, profile,
2571                                  &ver_chain, rs_ctx );
2572 
2573     if( ret != 0 )
2574         goto exit;
2575 
2576     /* Merge end-entity flags */
2577     ver_chain.items[0].flags |= ee_flags;
2578 
2579     /* Build final flags, calling callback on the way if any */
2580     ret = x509_crt_merge_flags_with_cb( flags, &ver_chain, f_vrfy, p_vrfy );
2581 
2582 exit:
2583 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2584     if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
2585         mbedtls_x509_crt_restart_free( rs_ctx );
2586 #endif
2587 
2588     /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
2589      * the SSL module for authmode optional, but non-zero return from the
2590      * callback means a fatal error so it shouldn't be ignored */
2591     if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
2592         ret = MBEDTLS_ERR_X509_FATAL_ERROR;
2593 
2594     if( ret != 0 )
2595     {
2596         *flags = (uint32_t) -1;
2597         return( ret );
2598     }
2599 
2600     if( *flags != 0 )
2601         return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
2602 
2603     return( 0 );
2604 }
2605 
2606 /*
2607  * Initialize a certificate chain
2608  */
2609 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt )
2610 {
2611     memset( crt, 0, sizeof(mbedtls_x509_crt) );
2612 }
2613 
2614 /*
2615  * Unallocate all certificate data
2616  */
2617 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
2618 {
2619     mbedtls_x509_crt *cert_cur = crt;
2620     mbedtls_x509_crt *cert_prv;
2621     mbedtls_x509_name *name_cur;
2622     mbedtls_x509_name *name_prv;
2623     mbedtls_x509_sequence *seq_cur;
2624     mbedtls_x509_sequence *seq_prv;
2625 
2626     if( crt == NULL )
2627         return;
2628 
2629     do
2630     {
2631         mbedtls_pk_free( &cert_cur->pk );
2632 
2633 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
2634         mbedtls_free( cert_cur->sig_opts );
2635 #endif
2636 
2637         name_cur = cert_cur->issuer.next;
2638         while( name_cur != NULL )
2639         {
2640             name_prv = name_cur;
2641             name_cur = name_cur->next;
2642             mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2643             mbedtls_free( name_prv );
2644         }
2645 
2646         name_cur = cert_cur->subject.next;
2647         while( name_cur != NULL )
2648         {
2649             name_prv = name_cur;
2650             name_cur = name_cur->next;
2651             mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2652             mbedtls_free( name_prv );
2653         }
2654 
2655         seq_cur = cert_cur->ext_key_usage.next;
2656         while( seq_cur != NULL )
2657         {
2658             seq_prv = seq_cur;
2659             seq_cur = seq_cur->next;
2660             mbedtls_platform_zeroize( seq_prv,
2661                                       sizeof( mbedtls_x509_sequence ) );
2662             mbedtls_free( seq_prv );
2663         }
2664 
2665         seq_cur = cert_cur->subject_alt_names.next;
2666         while( seq_cur != NULL )
2667         {
2668             seq_prv = seq_cur;
2669             seq_cur = seq_cur->next;
2670             mbedtls_platform_zeroize( seq_prv,
2671                                       sizeof( mbedtls_x509_sequence ) );
2672             mbedtls_free( seq_prv );
2673         }
2674 
2675         if( cert_cur->raw.p != NULL )
2676         {
2677             mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
2678             mbedtls_free( cert_cur->raw.p );
2679         }
2680 
2681         cert_cur = cert_cur->next;
2682     }
2683     while( cert_cur != NULL );
2684 
2685     cert_cur = crt;
2686     do
2687     {
2688         cert_prv = cert_cur;
2689         cert_cur = cert_cur->next;
2690 
2691         mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) );
2692         if( cert_prv != crt )
2693             mbedtls_free( cert_prv );
2694     }
2695     while( cert_cur != NULL );
2696 }
2697 
2698 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2699 /*
2700  * Initialize a restart context
2701  */
2702 void mbedtls_x509_crt_restart_init( mbedtls_x509_crt_restart_ctx *ctx )
2703 {
2704     mbedtls_pk_restart_init( &ctx->pk );
2705 
2706     ctx->parent = NULL;
2707     ctx->fallback_parent = NULL;
2708     ctx->fallback_signature_is_good = 0;
2709 
2710     ctx->parent_is_trusted = -1;
2711 
2712     ctx->in_progress = x509_crt_rs_none;
2713     ctx->self_cnt = 0;
2714     x509_crt_verify_chain_reset( &ctx->ver_chain );
2715 }
2716 
2717 /*
2718  * Free the components of a restart context
2719  */
2720 void mbedtls_x509_crt_restart_free( mbedtls_x509_crt_restart_ctx *ctx )
2721 {
2722     if( ctx == NULL )
2723         return;
2724 
2725     mbedtls_pk_restart_free( &ctx->pk );
2726     mbedtls_x509_crt_restart_init( ctx );
2727 }
2728 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2729 
2730 #endif /* MBEDTLS_X509_CRT_PARSE_C */
2731