xref: /optee_os/lib/libmbedtls/mbedtls/library/x509_crt.c (revision 5a913ee74d3c71af2a2860ce8a4e7aeab2916f9b)
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 = -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( 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( 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( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
703     {
704         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
705             return( 0 );
706 
707         return( ret );
708     }
709 
710     while( *p < end )
711     {
712         /*
713          * Extension  ::=  SEQUENCE  {
714          *      extnID      OBJECT IDENTIFIER,
715          *      critical    BOOLEAN DEFAULT FALSE,
716          *      extnValue   OCTET STRING  }
717          */
718         mbedtls_x509_buf extn_oid = {0, 0, NULL};
719         int is_critical = 0; /* DEFAULT FALSE */
720         int ext_type = 0;
721 
722         if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
723                 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
724             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
725 
726         end_ext_data = *p + len;
727 
728         /* Get extension ID */
729         if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &extn_oid.len,
730                                           MBEDTLS_ASN1_OID ) ) != 0 )
731             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
732 
733         extn_oid.tag = MBEDTLS_ASN1_OID;
734         extn_oid.p = *p;
735         *p += extn_oid.len;
736 
737         /* Get optional critical */
738         if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
739             ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
740             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
741 
742         /* Data should be octet string type */
743         if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
744                 MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
745             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
746 
747         end_ext_octet = *p + len;
748 
749         if( end_ext_octet != end_ext_data )
750             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
751                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
752 
753         /*
754          * Detect supported extensions
755          */
756         ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type );
757 
758         if( ret != 0 )
759         {
760             /* No parser found, skip extension */
761             *p = end_ext_octet;
762 
763 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
764             if( is_critical )
765             {
766                 /* Data is marked as critical: fail */
767                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
768                         MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
769             }
770 #endif
771             continue;
772         }
773 
774         /* Forbid repeated extensions */
775         if( ( crt->ext_types & ext_type ) != 0 )
776             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
777 
778         crt->ext_types |= ext_type;
779 
780         switch( ext_type )
781         {
782         case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
783             /* Parse basic constraints */
784             if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
785                     &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
786                 return( ret );
787             break;
788 
789         case MBEDTLS_X509_EXT_KEY_USAGE:
790             /* Parse key usage */
791             if( ( ret = x509_get_key_usage( p, end_ext_octet,
792                     &crt->key_usage ) ) != 0 )
793                 return( ret );
794             break;
795 
796         case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
797             /* Parse extended key usage */
798             if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
799                     &crt->ext_key_usage ) ) != 0 )
800                 return( ret );
801             break;
802 
803         case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
804             /* Parse subject alt name */
805             if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
806                     &crt->subject_alt_names ) ) != 0 )
807                 return( ret );
808             break;
809 
810         case MBEDTLS_X509_EXT_NS_CERT_TYPE:
811             /* Parse netscape certificate type */
812             if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
813                     &crt->ns_cert_type ) ) != 0 )
814                 return( ret );
815             break;
816 
817         default:
818             return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
819         }
820     }
821 
822     if( *p != end )
823         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
824                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
825 
826     return( 0 );
827 }
828 
829 /*
830  * Parse and fill a single X.509 certificate in DER format
831  */
832 static int x509_crt_parse_der_core( mbedtls_x509_crt *crt, const unsigned char *buf,
833                                     size_t buflen )
834 {
835     int ret;
836     size_t len;
837     unsigned char *p, *end, *crt_end;
838     mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
839 
840     memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) );
841     memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) );
842     memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) );
843 
844     /*
845      * Check for valid input
846      */
847     if( crt == NULL || buf == NULL )
848         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
849 
850     // Use the original buffer until we figure out actual length
851     p = (unsigned char*) buf;
852     len = buflen;
853     end = p + len;
854 
855     /*
856      * Certificate  ::=  SEQUENCE  {
857      *      tbsCertificate       TBSCertificate,
858      *      signatureAlgorithm   AlgorithmIdentifier,
859      *      signatureValue       BIT STRING  }
860      */
861     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
862             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
863     {
864         mbedtls_x509_crt_free( crt );
865         return( MBEDTLS_ERR_X509_INVALID_FORMAT );
866     }
867 
868     if( len > (size_t) ( end - p ) )
869     {
870         mbedtls_x509_crt_free( crt );
871         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
872                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
873     }
874     crt_end = p + len;
875 
876     // Create and populate a new buffer for the raw field
877     crt->raw.len = crt_end - buf;
878     crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
879     if( p == NULL )
880         return( MBEDTLS_ERR_X509_ALLOC_FAILED );
881 
882     memcpy( p, buf, crt->raw.len );
883 
884     // Direct pointers to the new buffer
885     p += crt->raw.len - len;
886     end = crt_end = p + len;
887 
888     /*
889      * TBSCertificate  ::=  SEQUENCE  {
890      */
891     crt->tbs.p = p;
892 
893     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
894             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
895     {
896         mbedtls_x509_crt_free( crt );
897         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
898     }
899 
900     end = p + len;
901     crt->tbs.len = end - crt->tbs.p;
902 
903     /*
904      * Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
905      *
906      * CertificateSerialNumber  ::=  INTEGER
907      *
908      * signature            AlgorithmIdentifier
909      */
910     if( ( ret = x509_get_version(  &p, end, &crt->version  ) ) != 0 ||
911         ( ret = mbedtls_x509_get_serial(   &p, end, &crt->serial   ) ) != 0 ||
912         ( ret = mbedtls_x509_get_alg(      &p, end, &crt->sig_oid,
913                                             &sig_params1 ) ) != 0 )
914     {
915         mbedtls_x509_crt_free( crt );
916         return( ret );
917     }
918 
919     if( crt->version < 0 || crt->version > 2 )
920     {
921         mbedtls_x509_crt_free( crt );
922         return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
923     }
924 
925     crt->version++;
926 
927     if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1,
928                                   &crt->sig_md, &crt->sig_pk,
929                                   &crt->sig_opts ) ) != 0 )
930     {
931         mbedtls_x509_crt_free( crt );
932         return( ret );
933     }
934 
935     /*
936      * issuer               Name
937      */
938     crt->issuer_raw.p = p;
939 
940     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
941             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
942     {
943         mbedtls_x509_crt_free( crt );
944         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
945     }
946 
947     if( ( ret = mbedtls_x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
948     {
949         mbedtls_x509_crt_free( crt );
950         return( ret );
951     }
952 
953     crt->issuer_raw.len = p - crt->issuer_raw.p;
954 
955     /*
956      * Validity ::= SEQUENCE {
957      *      notBefore      Time,
958      *      notAfter       Time }
959      *
960      */
961     if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
962                                          &crt->valid_to ) ) != 0 )
963     {
964         mbedtls_x509_crt_free( crt );
965         return( ret );
966     }
967 
968     /*
969      * subject              Name
970      */
971     crt->subject_raw.p = p;
972 
973     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
974             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
975     {
976         mbedtls_x509_crt_free( crt );
977         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
978     }
979 
980     if( len && ( ret = mbedtls_x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
981     {
982         mbedtls_x509_crt_free( crt );
983         return( ret );
984     }
985 
986     crt->subject_raw.len = p - crt->subject_raw.p;
987 
988     /*
989      * SubjectPublicKeyInfo
990      */
991     if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
992     {
993         mbedtls_x509_crt_free( crt );
994         return( ret );
995     }
996 
997     /*
998      *  issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
999      *                       -- If present, version shall be v2 or v3
1000      *  subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL,
1001      *                       -- If present, version shall be v2 or v3
1002      *  extensions      [3]  EXPLICIT Extensions OPTIONAL
1003      *                       -- If present, version shall be v3
1004      */
1005     if( crt->version == 2 || crt->version == 3 )
1006     {
1007         ret = x509_get_uid( &p, end, &crt->issuer_id,  1 );
1008         if( ret != 0 )
1009         {
1010             mbedtls_x509_crt_free( crt );
1011             return( ret );
1012         }
1013     }
1014 
1015     if( crt->version == 2 || crt->version == 3 )
1016     {
1017         ret = x509_get_uid( &p, end, &crt->subject_id,  2 );
1018         if( ret != 0 )
1019         {
1020             mbedtls_x509_crt_free( crt );
1021             return( ret );
1022         }
1023     }
1024 
1025 #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
1026     if( crt->version == 3 )
1027 #endif
1028     {
1029         ret = x509_get_crt_ext( &p, end, crt );
1030         if( ret != 0 )
1031         {
1032             mbedtls_x509_crt_free( crt );
1033             return( ret );
1034         }
1035     }
1036 
1037     if( p != end )
1038     {
1039         mbedtls_x509_crt_free( crt );
1040         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1041                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1042     }
1043 
1044     end = crt_end;
1045 
1046     /*
1047      *  }
1048      *  -- end of TBSCertificate
1049      *
1050      *  signatureAlgorithm   AlgorithmIdentifier,
1051      *  signatureValue       BIT STRING
1052      */
1053     if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 )
1054     {
1055         mbedtls_x509_crt_free( crt );
1056         return( ret );
1057     }
1058 
1059     if( crt->sig_oid.len != sig_oid2.len ||
1060         memcmp( crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len ) != 0 ||
1061         sig_params1.len != sig_params2.len ||
1062         ( sig_params1.len != 0 &&
1063           memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
1064     {
1065         mbedtls_x509_crt_free( crt );
1066         return( MBEDTLS_ERR_X509_SIG_MISMATCH );
1067     }
1068 
1069     if( ( ret = mbedtls_x509_get_sig( &p, end, &crt->sig ) ) != 0 )
1070     {
1071         mbedtls_x509_crt_free( crt );
1072         return( ret );
1073     }
1074 
1075     if( p != end )
1076     {
1077         mbedtls_x509_crt_free( crt );
1078         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1079                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1080     }
1081 
1082     return( 0 );
1083 }
1084 
1085 /*
1086  * Parse one X.509 certificate in DER format from a buffer and add them to a
1087  * chained list
1088  */
1089 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
1090                         size_t buflen )
1091 {
1092     int ret;
1093     mbedtls_x509_crt *crt = chain, *prev = NULL;
1094 
1095     /*
1096      * Check for valid input
1097      */
1098     if( crt == NULL || buf == NULL )
1099         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1100 
1101     while( crt->version != 0 && crt->next != NULL )
1102     {
1103         prev = crt;
1104         crt = crt->next;
1105     }
1106 
1107     /*
1108      * Add new certificate on the end of the chain if needed.
1109      */
1110     if( crt->version != 0 && crt->next == NULL )
1111     {
1112         crt->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
1113 
1114         if( crt->next == NULL )
1115             return( MBEDTLS_ERR_X509_ALLOC_FAILED );
1116 
1117         prev = crt;
1118         mbedtls_x509_crt_init( crt->next );
1119         crt = crt->next;
1120     }
1121 
1122     if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
1123     {
1124         if( prev )
1125             prev->next = NULL;
1126 
1127         if( crt != chain )
1128             mbedtls_free( crt );
1129 
1130         return( ret );
1131     }
1132 
1133     return( 0 );
1134 }
1135 
1136 /*
1137  * Parse one or more PEM certificates from a buffer and add them to the chained
1138  * list
1139  */
1140 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen )
1141 {
1142 #if defined(MBEDTLS_PEM_PARSE_C)
1143     int success = 0, first_error = 0, total_failed = 0;
1144     int buf_format = MBEDTLS_X509_FORMAT_DER;
1145 #endif
1146 
1147     /*
1148      * Check for valid input
1149      */
1150     if( chain == NULL || buf == NULL )
1151         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1152 
1153     /*
1154      * Determine buffer content. Buffer contains either one DER certificate or
1155      * one or more PEM certificates.
1156      */
1157 #if defined(MBEDTLS_PEM_PARSE_C)
1158     if( buflen != 0 && buf[buflen - 1] == '\0' &&
1159         strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
1160     {
1161         buf_format = MBEDTLS_X509_FORMAT_PEM;
1162     }
1163 
1164     if( buf_format == MBEDTLS_X509_FORMAT_DER )
1165         return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1166 #else
1167     return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1168 #endif
1169 
1170 #if defined(MBEDTLS_PEM_PARSE_C)
1171     if( buf_format == MBEDTLS_X509_FORMAT_PEM )
1172     {
1173         int ret;
1174         mbedtls_pem_context pem;
1175 
1176         /* 1 rather than 0 since the terminating NULL byte is counted in */
1177         while( buflen > 1 )
1178         {
1179             size_t use_len;
1180             mbedtls_pem_init( &pem );
1181 
1182             /* If we get there, we know the string is null-terminated */
1183             ret = mbedtls_pem_read_buffer( &pem,
1184                            "-----BEGIN CERTIFICATE-----",
1185                            "-----END CERTIFICATE-----",
1186                            buf, NULL, 0, &use_len );
1187 
1188             if( ret == 0 )
1189             {
1190                 /*
1191                  * Was PEM encoded
1192                  */
1193                 buflen -= use_len;
1194                 buf += use_len;
1195             }
1196             else if( ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA )
1197             {
1198                 return( ret );
1199             }
1200             else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1201             {
1202                 mbedtls_pem_free( &pem );
1203 
1204                 /*
1205                  * PEM header and footer were found
1206                  */
1207                 buflen -= use_len;
1208                 buf += use_len;
1209 
1210                 if( first_error == 0 )
1211                     first_error = ret;
1212 
1213                 total_failed++;
1214                 continue;
1215             }
1216             else
1217                 break;
1218 
1219             ret = mbedtls_x509_crt_parse_der( chain, pem.buf, pem.buflen );
1220 
1221             mbedtls_pem_free( &pem );
1222 
1223             if( ret != 0 )
1224             {
1225                 /*
1226                  * Quit parsing on a memory error
1227                  */
1228                 if( ret == MBEDTLS_ERR_X509_ALLOC_FAILED )
1229                     return( ret );
1230 
1231                 if( first_error == 0 )
1232                     first_error = ret;
1233 
1234                 total_failed++;
1235                 continue;
1236             }
1237 
1238             success = 1;
1239         }
1240     }
1241 
1242     if( success )
1243         return( total_failed );
1244     else if( first_error )
1245         return( first_error );
1246     else
1247         return( MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT );
1248 #endif /* MBEDTLS_PEM_PARSE_C */
1249 }
1250 
1251 #if defined(MBEDTLS_FS_IO)
1252 /*
1253  * Load one or more certificates and add them to the chained list
1254  */
1255 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path )
1256 {
1257     int ret;
1258     size_t n;
1259     unsigned char *buf;
1260 
1261     if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
1262         return( ret );
1263 
1264     ret = mbedtls_x509_crt_parse( chain, buf, n );
1265 
1266     mbedtls_platform_zeroize( buf, n );
1267     mbedtls_free( buf );
1268 
1269     return( ret );
1270 }
1271 
1272 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
1273 {
1274     int ret = 0;
1275 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
1276     int w_ret;
1277     WCHAR szDir[MAX_PATH];
1278     char filename[MAX_PATH];
1279     char *p;
1280     size_t len = strlen( path );
1281 
1282     WIN32_FIND_DATAW file_data;
1283     HANDLE hFind;
1284 
1285     if( len > MAX_PATH - 3 )
1286         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1287 
1288     memset( szDir, 0, sizeof(szDir) );
1289     memset( filename, 0, MAX_PATH );
1290     memcpy( filename, path, len );
1291     filename[len++] = '\\';
1292     p = filename + len;
1293     filename[len++] = '*';
1294 
1295     w_ret = MultiByteToWideChar( CP_ACP, 0, filename, (int)len, szDir,
1296                                  MAX_PATH - 3 );
1297     if( w_ret == 0 )
1298         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1299 
1300     hFind = FindFirstFileW( szDir, &file_data );
1301     if( hFind == INVALID_HANDLE_VALUE )
1302         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1303 
1304     len = MAX_PATH - len;
1305     do
1306     {
1307         memset( p, 0, len );
1308 
1309         if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
1310             continue;
1311 
1312         w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
1313                                      lstrlenW( file_data.cFileName ),
1314                                      p, (int) len - 1,
1315                                      NULL, NULL );
1316         if( w_ret == 0 )
1317         {
1318             ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1319             goto cleanup;
1320         }
1321 
1322         w_ret = mbedtls_x509_crt_parse_file( chain, filename );
1323         if( w_ret < 0 )
1324             ret++;
1325         else
1326             ret += w_ret;
1327     }
1328     while( FindNextFileW( hFind, &file_data ) != 0 );
1329 
1330     if( GetLastError() != ERROR_NO_MORE_FILES )
1331         ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1332 
1333 cleanup:
1334     FindClose( hFind );
1335 #else /* _WIN32 */
1336     int t_ret;
1337     int snp_ret;
1338     struct stat sb;
1339     struct dirent *entry;
1340     char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
1341     DIR *dir = opendir( path );
1342 
1343     if( dir == NULL )
1344         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1345 
1346 #if defined(MBEDTLS_THREADING_C)
1347     if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 )
1348     {
1349         closedir( dir );
1350         return( ret );
1351     }
1352 #endif /* MBEDTLS_THREADING_C */
1353 
1354     while( ( entry = readdir( dir ) ) != NULL )
1355     {
1356         snp_ret = mbedtls_snprintf( entry_name, sizeof entry_name,
1357                                     "%s/%s", path, entry->d_name );
1358 
1359         if( snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name )
1360         {
1361             ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
1362             goto cleanup;
1363         }
1364         else if( stat( entry_name, &sb ) == -1 )
1365         {
1366             ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1367             goto cleanup;
1368         }
1369 
1370         if( !S_ISREG( sb.st_mode ) )
1371             continue;
1372 
1373         // Ignore parse errors
1374         //
1375         t_ret = mbedtls_x509_crt_parse_file( chain, entry_name );
1376         if( t_ret < 0 )
1377             ret++;
1378         else
1379             ret += t_ret;
1380     }
1381 
1382 cleanup:
1383     closedir( dir );
1384 
1385 #if defined(MBEDTLS_THREADING_C)
1386     if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 )
1387         ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1388 #endif /* MBEDTLS_THREADING_C */
1389 
1390 #endif /* _WIN32 */
1391 
1392     return( ret );
1393 }
1394 #endif /* MBEDTLS_FS_IO */
1395 
1396 static int x509_info_subject_alt_name( char **buf, size_t *size,
1397                                        const mbedtls_x509_sequence *subject_alt_name )
1398 {
1399     size_t i;
1400     size_t n = *size;
1401     char *p = *buf;
1402     const mbedtls_x509_sequence *cur = subject_alt_name;
1403     const char *sep = "";
1404     size_t sep_len = 0;
1405 
1406     while( cur != NULL )
1407     {
1408         if( cur->buf.len + sep_len >= n )
1409         {
1410             *p = '\0';
1411             return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
1412         }
1413 
1414         n -= cur->buf.len + sep_len;
1415         for( i = 0; i < sep_len; i++ )
1416             *p++ = sep[i];
1417         for( i = 0; i < cur->buf.len; i++ )
1418             *p++ = cur->buf.p[i];
1419 
1420         sep = ", ";
1421         sep_len = 2;
1422 
1423         cur = cur->next;
1424     }
1425 
1426     *p = '\0';
1427 
1428     *size = n;
1429     *buf = p;
1430 
1431     return( 0 );
1432 }
1433 
1434 #define PRINT_ITEM(i)                           \
1435     {                                           \
1436         ret = mbedtls_snprintf( p, n, "%s" i, sep );    \
1437         MBEDTLS_X509_SAFE_SNPRINTF;                        \
1438         sep = ", ";                             \
1439     }
1440 
1441 #define CERT_TYPE(type,name)                    \
1442     if( ns_cert_type & type )                   \
1443         PRINT_ITEM( name );
1444 
1445 static int x509_info_cert_type( char **buf, size_t *size,
1446                                 unsigned char ns_cert_type )
1447 {
1448     int ret;
1449     size_t n = *size;
1450     char *p = *buf;
1451     const char *sep = "";
1452 
1453     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT,         "SSL Client" );
1454     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER,         "SSL Server" );
1455     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL,              "Email" );
1456     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING,     "Object Signing" );
1457     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED,           "Reserved" );
1458     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA,             "SSL CA" );
1459     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA,           "Email CA" );
1460     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA,  "Object Signing CA" );
1461 
1462     *size = n;
1463     *buf = p;
1464 
1465     return( 0 );
1466 }
1467 
1468 #define KEY_USAGE(code,name)    \
1469     if( key_usage & code )      \
1470         PRINT_ITEM( name );
1471 
1472 static int x509_info_key_usage( char **buf, size_t *size,
1473                                 unsigned int key_usage )
1474 {
1475     int ret;
1476     size_t n = *size;
1477     char *p = *buf;
1478     const char *sep = "";
1479 
1480     KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE,    "Digital Signature" );
1481     KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION,      "Non Repudiation" );
1482     KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT,     "Key Encipherment" );
1483     KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT,    "Data Encipherment" );
1484     KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT,        "Key Agreement" );
1485     KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN,        "Key Cert Sign" );
1486     KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN,             "CRL Sign" );
1487     KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY,        "Encipher Only" );
1488     KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY,        "Decipher Only" );
1489 
1490     *size = n;
1491     *buf = p;
1492 
1493     return( 0 );
1494 }
1495 
1496 static int x509_info_ext_key_usage( char **buf, size_t *size,
1497                                     const mbedtls_x509_sequence *extended_key_usage )
1498 {
1499     int ret;
1500     const char *desc;
1501     size_t n = *size;
1502     char *p = *buf;
1503     const mbedtls_x509_sequence *cur = extended_key_usage;
1504     const char *sep = "";
1505 
1506     while( cur != NULL )
1507     {
1508         if( mbedtls_oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
1509             desc = "???";
1510 
1511         ret = mbedtls_snprintf( p, n, "%s%s", sep, desc );
1512         MBEDTLS_X509_SAFE_SNPRINTF;
1513 
1514         sep = ", ";
1515 
1516         cur = cur->next;
1517     }
1518 
1519     *size = n;
1520     *buf = p;
1521 
1522     return( 0 );
1523 }
1524 
1525 /*
1526  * Return an informational string about the certificate.
1527  */
1528 #define BEFORE_COLON    18
1529 #define BC              "18"
1530 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
1531                    const mbedtls_x509_crt *crt )
1532 {
1533     int ret;
1534     size_t n;
1535     char *p;
1536     char key_size_str[BEFORE_COLON];
1537 
1538     p = buf;
1539     n = size;
1540 
1541     if( NULL == crt )
1542     {
1543         ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" );
1544         MBEDTLS_X509_SAFE_SNPRINTF;
1545 
1546         return( (int) ( size - n ) );
1547     }
1548 
1549     ret = mbedtls_snprintf( p, n, "%scert. version     : %d\n",
1550                                prefix, crt->version );
1551     MBEDTLS_X509_SAFE_SNPRINTF;
1552     ret = mbedtls_snprintf( p, n, "%sserial number     : ",
1553                                prefix );
1554     MBEDTLS_X509_SAFE_SNPRINTF;
1555 
1556     ret = mbedtls_x509_serial_gets( p, n, &crt->serial );
1557     MBEDTLS_X509_SAFE_SNPRINTF;
1558 
1559     ret = mbedtls_snprintf( p, n, "\n%sissuer name       : ", prefix );
1560     MBEDTLS_X509_SAFE_SNPRINTF;
1561     ret = mbedtls_x509_dn_gets( p, n, &crt->issuer  );
1562     MBEDTLS_X509_SAFE_SNPRINTF;
1563 
1564     ret = mbedtls_snprintf( p, n, "\n%ssubject name      : ", prefix );
1565     MBEDTLS_X509_SAFE_SNPRINTF;
1566     ret = mbedtls_x509_dn_gets( p, n, &crt->subject );
1567     MBEDTLS_X509_SAFE_SNPRINTF;
1568 
1569     ret = mbedtls_snprintf( p, n, "\n%sissued  on        : " \
1570                    "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1571                    crt->valid_from.year, crt->valid_from.mon,
1572                    crt->valid_from.day,  crt->valid_from.hour,
1573                    crt->valid_from.min,  crt->valid_from.sec );
1574     MBEDTLS_X509_SAFE_SNPRINTF;
1575 
1576     ret = mbedtls_snprintf( p, n, "\n%sexpires on        : " \
1577                    "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1578                    crt->valid_to.year, crt->valid_to.mon,
1579                    crt->valid_to.day,  crt->valid_to.hour,
1580                    crt->valid_to.min,  crt->valid_to.sec );
1581     MBEDTLS_X509_SAFE_SNPRINTF;
1582 
1583     ret = mbedtls_snprintf( p, n, "\n%ssigned using      : ", prefix );
1584     MBEDTLS_X509_SAFE_SNPRINTF;
1585 
1586     ret = mbedtls_x509_sig_alg_gets( p, n, &crt->sig_oid, crt->sig_pk,
1587                              crt->sig_md, crt->sig_opts );
1588     MBEDTLS_X509_SAFE_SNPRINTF;
1589 
1590     /* Key size */
1591     if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON,
1592                                       mbedtls_pk_get_name( &crt->pk ) ) ) != 0 )
1593     {
1594         return( ret );
1595     }
1596 
1597     ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
1598                           (int) mbedtls_pk_get_bitlen( &crt->pk ) );
1599     MBEDTLS_X509_SAFE_SNPRINTF;
1600 
1601     /*
1602      * Optional extensions
1603      */
1604 
1605     if( crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS )
1606     {
1607         ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
1608                         crt->ca_istrue ? "true" : "false" );
1609         MBEDTLS_X509_SAFE_SNPRINTF;
1610 
1611         if( crt->max_pathlen > 0 )
1612         {
1613             ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
1614             MBEDTLS_X509_SAFE_SNPRINTF;
1615         }
1616     }
1617 
1618     if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
1619     {
1620         ret = mbedtls_snprintf( p, n, "\n%ssubject alt name  : ", prefix );
1621         MBEDTLS_X509_SAFE_SNPRINTF;
1622 
1623         if( ( ret = x509_info_subject_alt_name( &p, &n,
1624                                             &crt->subject_alt_names ) ) != 0 )
1625             return( ret );
1626     }
1627 
1628     if( crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE )
1629     {
1630         ret = mbedtls_snprintf( p, n, "\n%scert. type        : ", prefix );
1631         MBEDTLS_X509_SAFE_SNPRINTF;
1632 
1633         if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
1634             return( ret );
1635     }
1636 
1637     if( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE )
1638     {
1639         ret = mbedtls_snprintf( p, n, "\n%skey usage         : ", prefix );
1640         MBEDTLS_X509_SAFE_SNPRINTF;
1641 
1642         if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
1643             return( ret );
1644     }
1645 
1646     if( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE )
1647     {
1648         ret = mbedtls_snprintf( p, n, "\n%sext key usage     : ", prefix );
1649         MBEDTLS_X509_SAFE_SNPRINTF;
1650 
1651         if( ( ret = x509_info_ext_key_usage( &p, &n,
1652                                              &crt->ext_key_usage ) ) != 0 )
1653             return( ret );
1654     }
1655 
1656     ret = mbedtls_snprintf( p, n, "\n" );
1657     MBEDTLS_X509_SAFE_SNPRINTF;
1658 
1659     return( (int) ( size - n ) );
1660 }
1661 
1662 struct x509_crt_verify_string {
1663     int code;
1664     const char *string;
1665 };
1666 
1667 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
1668     { MBEDTLS_X509_BADCERT_EXPIRED,       "The certificate validity has expired" },
1669     { MBEDTLS_X509_BADCERT_REVOKED,       "The certificate has been revoked (is on a CRL)" },
1670     { MBEDTLS_X509_BADCERT_CN_MISMATCH,   "The certificate Common Name (CN) does not match with the expected CN" },
1671     { MBEDTLS_X509_BADCERT_NOT_TRUSTED,   "The certificate is not correctly signed by the trusted CA" },
1672     { MBEDTLS_X509_BADCRL_NOT_TRUSTED,    "The CRL is not correctly signed by the trusted CA" },
1673     { MBEDTLS_X509_BADCRL_EXPIRED,        "The CRL is expired" },
1674     { MBEDTLS_X509_BADCERT_MISSING,       "Certificate was missing" },
1675     { MBEDTLS_X509_BADCERT_SKIP_VERIFY,   "Certificate verification was skipped" },
1676     { MBEDTLS_X509_BADCERT_OTHER,         "Other reason (can be used by verify callback)" },
1677     { MBEDTLS_X509_BADCERT_FUTURE,        "The certificate validity starts in the future" },
1678     { MBEDTLS_X509_BADCRL_FUTURE,         "The CRL is from the future" },
1679     { MBEDTLS_X509_BADCERT_KEY_USAGE,     "Usage does not match the keyUsage extension" },
1680     { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
1681     { MBEDTLS_X509_BADCERT_NS_CERT_TYPE,  "Usage does not match the nsCertType extension" },
1682     { MBEDTLS_X509_BADCERT_BAD_MD,        "The certificate is signed with an unacceptable hash." },
1683     { MBEDTLS_X509_BADCERT_BAD_PK,        "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1684     { MBEDTLS_X509_BADCERT_BAD_KEY,       "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
1685     { MBEDTLS_X509_BADCRL_BAD_MD,         "The CRL is signed with an unacceptable hash." },
1686     { MBEDTLS_X509_BADCRL_BAD_PK,         "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
1687     { MBEDTLS_X509_BADCRL_BAD_KEY,        "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
1688     { 0, NULL }
1689 };
1690 
1691 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
1692                           uint32_t flags )
1693 {
1694     int ret;
1695     const struct x509_crt_verify_string *cur;
1696     char *p = buf;
1697     size_t n = size;
1698 
1699     for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
1700     {
1701         if( ( flags & cur->code ) == 0 )
1702             continue;
1703 
1704         ret = mbedtls_snprintf( p, n, "%s%s\n", prefix, cur->string );
1705         MBEDTLS_X509_SAFE_SNPRINTF;
1706         flags ^= cur->code;
1707     }
1708 
1709     if( flags != 0 )
1710     {
1711         ret = mbedtls_snprintf( p, n, "%sUnknown reason "
1712                                        "(this should not happen)\n", prefix );
1713         MBEDTLS_X509_SAFE_SNPRINTF;
1714     }
1715 
1716     return( (int) ( size - n ) );
1717 }
1718 
1719 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1720 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
1721                                       unsigned int usage )
1722 {
1723     unsigned int usage_must, usage_may;
1724     unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
1725                           | MBEDTLS_X509_KU_DECIPHER_ONLY;
1726 
1727     if( ( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) == 0 )
1728         return( 0 );
1729 
1730     usage_must = usage & ~may_mask;
1731 
1732     if( ( ( crt->key_usage & ~may_mask ) & usage_must ) != usage_must )
1733         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1734 
1735     usage_may = usage & may_mask;
1736 
1737     if( ( ( crt->key_usage & may_mask ) | usage_may ) != usage_may )
1738         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1739 
1740     return( 0 );
1741 }
1742 #endif
1743 
1744 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
1745 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
1746                                        const char *usage_oid,
1747                                        size_t usage_len )
1748 {
1749     const mbedtls_x509_sequence *cur;
1750 
1751     /* Extension is not mandatory, absent means no restriction */
1752     if( ( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 )
1753         return( 0 );
1754 
1755     /*
1756      * Look for the requested usage (or wildcard ANY) in our list
1757      */
1758     for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
1759     {
1760         const mbedtls_x509_buf *cur_oid = &cur->buf;
1761 
1762         if( cur_oid->len == usage_len &&
1763             memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
1764         {
1765             return( 0 );
1766         }
1767 
1768         if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) == 0 )
1769             return( 0 );
1770     }
1771 
1772     return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1773 }
1774 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
1775 
1776 #if defined(MBEDTLS_X509_CRL_PARSE_C)
1777 /*
1778  * Return 1 if the certificate is revoked, or 0 otherwise.
1779  */
1780 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl )
1781 {
1782     const mbedtls_x509_crl_entry *cur = &crl->entry;
1783 
1784     while( cur != NULL && cur->serial.len != 0 )
1785     {
1786         if( crt->serial.len == cur->serial.len &&
1787             memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
1788         {
1789             if( mbedtls_x509_time_is_past( &cur->revocation_date ) )
1790                 return( 1 );
1791         }
1792 
1793         cur = cur->next;
1794     }
1795 
1796     return( 0 );
1797 }
1798 
1799 /*
1800  * Check that the given certificate is not revoked according to the CRL.
1801  * Skip validation if no CRL for the given CA is present.
1802  */
1803 static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
1804                                mbedtls_x509_crl *crl_list,
1805                                const mbedtls_x509_crt_profile *profile )
1806 {
1807     int flags = 0;
1808     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1809     const mbedtls_md_info_t *md_info;
1810 
1811     if( ca == NULL )
1812         return( flags );
1813 
1814     while( crl_list != NULL )
1815     {
1816         if( crl_list->version == 0 ||
1817             x509_name_cmp( &crl_list->issuer, &ca->subject ) != 0 )
1818         {
1819             crl_list = crl_list->next;
1820             continue;
1821         }
1822 
1823         /*
1824          * Check if the CA is configured to sign CRLs
1825          */
1826 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1827         if( mbedtls_x509_crt_check_key_usage( ca,
1828                                               MBEDTLS_X509_KU_CRL_SIGN ) != 0 )
1829         {
1830             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1831             break;
1832         }
1833 #endif
1834 
1835         /*
1836          * Check if CRL is correctly signed by the trusted CA
1837          */
1838         if( x509_profile_check_md_alg( profile, crl_list->sig_md ) != 0 )
1839             flags |= MBEDTLS_X509_BADCRL_BAD_MD;
1840 
1841         if( x509_profile_check_pk_alg( profile, crl_list->sig_pk ) != 0 )
1842             flags |= MBEDTLS_X509_BADCRL_BAD_PK;
1843 
1844         md_info = mbedtls_md_info_from_type( crl_list->sig_md );
1845         if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 )
1846         {
1847             /* Note: this can't happen except after an internal error */
1848             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1849             break;
1850         }
1851 
1852         if( x509_profile_check_key( profile, &ca->pk ) != 0 )
1853             flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
1854 
1855         if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
1856                            crl_list->sig_md, hash, mbedtls_md_get_size( md_info ),
1857                            crl_list->sig.p, crl_list->sig.len ) != 0 )
1858         {
1859             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1860             break;
1861         }
1862 
1863         /*
1864          * Check for validity of CRL (Do not drop out)
1865          */
1866         if( mbedtls_x509_time_is_past( &crl_list->next_update ) )
1867             flags |= MBEDTLS_X509_BADCRL_EXPIRED;
1868 
1869         if( mbedtls_x509_time_is_future( &crl_list->this_update ) )
1870             flags |= MBEDTLS_X509_BADCRL_FUTURE;
1871 
1872         /*
1873          * Check if certificate is revoked
1874          */
1875         if( mbedtls_x509_crt_is_revoked( crt, crl_list ) )
1876         {
1877             flags |= MBEDTLS_X509_BADCERT_REVOKED;
1878             break;
1879         }
1880 
1881         crl_list = crl_list->next;
1882     }
1883 
1884     return( flags );
1885 }
1886 #endif /* MBEDTLS_X509_CRL_PARSE_C */
1887 
1888 /*
1889  * Check the signature of a certificate by its parent
1890  */
1891 static int x509_crt_check_signature( const mbedtls_x509_crt *child,
1892                                      mbedtls_x509_crt *parent,
1893                                      mbedtls_x509_crt_restart_ctx *rs_ctx )
1894 {
1895     const mbedtls_md_info_t *md_info;
1896     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
1897 
1898     md_info = mbedtls_md_info_from_type( child->sig_md );
1899     if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
1900     {
1901         /* Note: this can't happen except after an internal error */
1902         return( -1 );
1903     }
1904 
1905     /* Skip expensive computation on obvious mismatch */
1906     if( ! mbedtls_pk_can_do( &parent->pk, child->sig_pk ) )
1907         return( -1 );
1908 
1909 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
1910     if( rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA )
1911     {
1912         return( mbedtls_pk_verify_restartable( &parent->pk,
1913                     child->sig_md, hash, mbedtls_md_get_size( md_info ),
1914                     child->sig.p, child->sig.len, &rs_ctx->pk ) );
1915     }
1916 #else
1917     (void) rs_ctx;
1918 #endif
1919 
1920     return( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
1921                 child->sig_md, hash, mbedtls_md_get_size( md_info ),
1922                 child->sig.p, child->sig.len ) );
1923 }
1924 
1925 /*
1926  * Check if 'parent' is a suitable parent (signing CA) for 'child'.
1927  * Return 0 if yes, -1 if not.
1928  *
1929  * top means parent is a locally-trusted certificate
1930  */
1931 static int x509_crt_check_parent( const mbedtls_x509_crt *child,
1932                                   const mbedtls_x509_crt *parent,
1933                                   int top )
1934 {
1935     int need_ca_bit;
1936 
1937     /* Parent must be the issuer */
1938     if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
1939         return( -1 );
1940 
1941     /* Parent must have the basicConstraints CA bit set as a general rule */
1942     need_ca_bit = 1;
1943 
1944     /* Exception: v1/v2 certificates that are locally trusted. */
1945     if( top && parent->version < 3 )
1946         need_ca_bit = 0;
1947 
1948     if( need_ca_bit && ! parent->ca_istrue )
1949         return( -1 );
1950 
1951 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
1952     if( need_ca_bit &&
1953         mbedtls_x509_crt_check_key_usage( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
1954     {
1955         return( -1 );
1956     }
1957 #endif
1958 
1959     return( 0 );
1960 }
1961 
1962 /*
1963  * Find a suitable parent for child in candidates, or return NULL.
1964  *
1965  * Here suitable is defined as:
1966  *  1. subject name matches child's issuer
1967  *  2. if necessary, the CA bit is set and key usage allows signing certs
1968  *  3. for trusted roots, the signature is correct
1969  *     (for intermediates, the signature is checked and the result reported)
1970  *  4. pathlen constraints are satisfied
1971  *
1972  * If there's a suitable candidate which is also time-valid, return the first
1973  * such. Otherwise, return the first suitable candidate (or NULL if there is
1974  * none).
1975  *
1976  * The rationale for this rule is that someone could have a list of trusted
1977  * roots with two versions on the same root with different validity periods.
1978  * (At least one user reported having such a list and wanted it to just work.)
1979  * The reason we don't just require time-validity is that generally there is
1980  * only one version, and if it's expired we want the flags to state that
1981  * rather than NOT_TRUSTED, as would be the case if we required it here.
1982  *
1983  * The rationale for rule 3 (signature for trusted roots) is that users might
1984  * have two versions of the same CA with different keys in their list, and the
1985  * way we select the correct one is by checking the signature (as we don't
1986  * rely on key identifier extensions). (This is one way users might choose to
1987  * handle key rollover, another relies on self-issued certs, see [SIRO].)
1988  *
1989  * Arguments:
1990  *  - [in] child: certificate for which we're looking for a parent
1991  *  - [in] candidates: chained list of potential parents
1992  *  - [out] r_parent: parent found (or NULL)
1993  *  - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0
1994  *  - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
1995  *         of the chain, 0 otherwise
1996  *  - [in] path_cnt: number of intermediates seen so far
1997  *  - [in] self_cnt: number of self-signed intermediates seen so far
1998  *         (will never be greater than path_cnt)
1999  *  - [in-out] rs_ctx: context for restarting operations
2000  *
2001  * Return value:
2002  *  - 0 on success
2003  *  - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2004  */
2005 static int x509_crt_find_parent_in(
2006                         mbedtls_x509_crt *child,
2007                         mbedtls_x509_crt *candidates,
2008                         mbedtls_x509_crt **r_parent,
2009                         int *r_signature_is_good,
2010                         int top,
2011                         unsigned path_cnt,
2012                         unsigned self_cnt,
2013                         mbedtls_x509_crt_restart_ctx *rs_ctx )
2014 {
2015     int ret;
2016     mbedtls_x509_crt *parent, *fallback_parent;
2017     int signature_is_good, fallback_signature_is_good;
2018 
2019 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2020     /* did we have something in progress? */
2021     if( rs_ctx != NULL && rs_ctx->parent != NULL )
2022     {
2023         /* restore saved state */
2024         parent = rs_ctx->parent;
2025         fallback_parent = rs_ctx->fallback_parent;
2026         fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
2027 
2028         /* clear saved state */
2029         rs_ctx->parent = NULL;
2030         rs_ctx->fallback_parent = NULL;
2031         rs_ctx->fallback_signature_is_good = 0;
2032 
2033         /* resume where we left */
2034         goto check_signature;
2035     }
2036 #endif
2037 
2038     fallback_parent = NULL;
2039     fallback_signature_is_good = 0;
2040 
2041     for( parent = candidates; parent != NULL; parent = parent->next )
2042     {
2043         /* basic parenting skills (name, CA bit, key usage) */
2044         if( x509_crt_check_parent( child, parent, top ) != 0 )
2045             continue;
2046 
2047         /* +1 because stored max_pathlen is 1 higher that the actual value */
2048         if( parent->max_pathlen > 0 &&
2049             (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt )
2050         {
2051             continue;
2052         }
2053 
2054         /* Signature */
2055 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2056 check_signature:
2057 #endif
2058         ret = x509_crt_check_signature( child, parent, rs_ctx );
2059 
2060 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2061         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2062         {
2063             /* save state */
2064             rs_ctx->parent = parent;
2065             rs_ctx->fallback_parent = fallback_parent;
2066             rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
2067 
2068             return( ret );
2069         }
2070 #else
2071         (void) ret;
2072 #endif
2073 
2074         signature_is_good = ret == 0;
2075         if( top && ! signature_is_good )
2076             continue;
2077 
2078         /* optional time check */
2079         if( mbedtls_x509_time_is_past( &parent->valid_to ) ||
2080             mbedtls_x509_time_is_future( &parent->valid_from ) )
2081         {
2082             if( fallback_parent == NULL )
2083             {
2084                 fallback_parent = parent;
2085                 fallback_signature_is_good = signature_is_good;
2086             }
2087 
2088             continue;
2089         }
2090 
2091         break;
2092     }
2093 
2094     if( parent != NULL )
2095     {
2096         *r_parent = parent;
2097         *r_signature_is_good = signature_is_good;
2098     }
2099     else
2100     {
2101         *r_parent = fallback_parent;
2102         *r_signature_is_good = fallback_signature_is_good;
2103     }
2104 
2105     return( 0 );
2106 }
2107 
2108 /*
2109  * Find a parent in trusted CAs or the provided chain, or return NULL.
2110  *
2111  * Searches in trusted CAs first, and return the first suitable parent found
2112  * (see find_parent_in() for definition of suitable).
2113  *
2114  * Arguments:
2115  *  - [in] child: certificate for which we're looking for a parent, followed
2116  *         by a chain of possible intermediates
2117  *  - [in] trust_ca: list of locally trusted certificates
2118  *  - [out] parent: parent found (or NULL)
2119  *  - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0
2120  *  - [out] signature_is_good: 1 if child signature by parent is valid, or 0
2121  *  - [in] path_cnt: number of links in the chain so far (EE -> ... -> child)
2122  *  - [in] self_cnt: number of self-signed certs in the chain so far
2123  *         (will always be no greater than path_cnt)
2124  *  - [in-out] rs_ctx: context for restarting operations
2125  *
2126  * Return value:
2127  *  - 0 on success
2128  *  - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2129  */
2130 static int x509_crt_find_parent(
2131                         mbedtls_x509_crt *child,
2132                         mbedtls_x509_crt *trust_ca,
2133                         mbedtls_x509_crt **parent,
2134                         int *parent_is_trusted,
2135                         int *signature_is_good,
2136                         unsigned path_cnt,
2137                         unsigned self_cnt,
2138                         mbedtls_x509_crt_restart_ctx *rs_ctx )
2139 {
2140     int ret;
2141     mbedtls_x509_crt *search_list;
2142 
2143     *parent_is_trusted = 1;
2144 
2145 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2146     /* restore then clear saved state if we have some stored */
2147     if( rs_ctx != NULL && rs_ctx->parent_is_trusted != -1 )
2148     {
2149         *parent_is_trusted = rs_ctx->parent_is_trusted;
2150         rs_ctx->parent_is_trusted = -1;
2151     }
2152 #endif
2153 
2154     while( 1 ) {
2155         search_list = *parent_is_trusted ? trust_ca : child->next;
2156 
2157         ret = x509_crt_find_parent_in( child, search_list,
2158                                        parent, signature_is_good,
2159                                        *parent_is_trusted,
2160                                        path_cnt, self_cnt, rs_ctx );
2161 
2162 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2163         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2164         {
2165             /* save state */
2166             rs_ctx->parent_is_trusted = *parent_is_trusted;
2167             return( ret );
2168         }
2169 #else
2170         (void) ret;
2171 #endif
2172 
2173         /* stop here if found or already in second iteration */
2174         if( *parent != NULL || *parent_is_trusted == 0 )
2175             break;
2176 
2177         /* prepare second iteration */
2178         *parent_is_trusted = 0;
2179     }
2180 
2181     /* extra precaution against mistakes in the caller */
2182     if( *parent == NULL )
2183     {
2184         *parent_is_trusted = 0;
2185         *signature_is_good = 0;
2186     }
2187 
2188     return( 0 );
2189 }
2190 
2191 /*
2192  * Check if an end-entity certificate is locally trusted
2193  *
2194  * Currently we require such certificates to be self-signed (actually only
2195  * check for self-issued as self-signatures are not checked)
2196  */
2197 static int x509_crt_check_ee_locally_trusted(
2198                     mbedtls_x509_crt *crt,
2199                     mbedtls_x509_crt *trust_ca )
2200 {
2201     mbedtls_x509_crt *cur;
2202 
2203     /* must be self-issued */
2204     if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 )
2205         return( -1 );
2206 
2207     /* look for an exact match with trusted cert */
2208     for( cur = trust_ca; cur != NULL; cur = cur->next )
2209     {
2210         if( crt->raw.len == cur->raw.len &&
2211             memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 )
2212         {
2213             return( 0 );
2214         }
2215     }
2216 
2217     /* too bad */
2218     return( -1 );
2219 }
2220 
2221 /*
2222  * Build and verify a certificate chain
2223  *
2224  * Given a peer-provided list of certificates EE, C1, ..., Cn and
2225  * a list of trusted certs R1, ... Rp, try to build and verify a chain
2226  *      EE, Ci1, ... Ciq [, Rj]
2227  * such that every cert in the chain is a child of the next one,
2228  * jumping to a trusted root as early as possible.
2229  *
2230  * Verify that chain and return it with flags for all issues found.
2231  *
2232  * Special cases:
2233  * - EE == Rj -> return a one-element list containing it
2234  * - EE, Ci1, ..., Ciq cannot be continued with a trusted root
2235  *   -> return that chain with NOT_TRUSTED set on Ciq
2236  *
2237  * Tests for (aspects of) this function should include at least:
2238  * - trusted EE
2239  * - EE -> trusted root
2240  * - EE -> intermedate CA -> trusted root
2241  * - if relevant: EE untrusted
2242  * - if relevant: EE -> intermediate, untrusted
2243  * with the aspect under test checked at each relevant level (EE, int, root).
2244  * For some aspects longer chains are required, but usually length 2 is
2245  * enough (but length 1 is not in general).
2246  *
2247  * Arguments:
2248  *  - [in] crt: the cert list EE, C1, ..., Cn
2249  *  - [in] trust_ca: the trusted list R1, ..., Rp
2250  *  - [in] ca_crl, profile: as in verify_with_profile()
2251  *  - [out] ver_chain: the built and verified chain
2252  *      Only valid when return value is 0, may contain garbage otherwise!
2253  *      Restart note: need not be the same when calling again to resume.
2254  *  - [in-out] rs_ctx: context for restarting operations
2255  *
2256  * Return value:
2257  *  - non-zero if the chain could not be fully built and examined
2258  *  - 0 is the chain was successfully built and examined,
2259  *      even if it was found to be invalid
2260  */
2261 static int x509_crt_verify_chain(
2262                 mbedtls_x509_crt *crt,
2263                 mbedtls_x509_crt *trust_ca,
2264                 mbedtls_x509_crl *ca_crl,
2265                 const mbedtls_x509_crt_profile *profile,
2266                 mbedtls_x509_crt_verify_chain *ver_chain,
2267                 mbedtls_x509_crt_restart_ctx *rs_ctx )
2268 {
2269     /* Don't initialize any of those variables here, so that the compiler can
2270      * catch potential issues with jumping ahead when restarting */
2271     int ret;
2272     uint32_t *flags;
2273     mbedtls_x509_crt_verify_chain_item *cur;
2274     mbedtls_x509_crt *child;
2275     mbedtls_x509_crt *parent;
2276     int parent_is_trusted;
2277     int child_is_trusted;
2278     int signature_is_good;
2279     unsigned self_cnt;
2280 
2281 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2282     /* resume if we had an operation in progress */
2283     if( rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent )
2284     {
2285         /* restore saved state */
2286         *ver_chain = rs_ctx->ver_chain; /* struct copy */
2287         self_cnt = rs_ctx->self_cnt;
2288 
2289         /* restore derived state */
2290         cur = &ver_chain->items[ver_chain->len - 1];
2291         child = cur->crt;
2292         flags = &cur->flags;
2293 
2294         goto find_parent;
2295     }
2296 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2297 
2298     child = crt;
2299     self_cnt = 0;
2300     parent_is_trusted = 0;
2301     child_is_trusted = 0;
2302 
2303     while( 1 ) {
2304         /* Add certificate to the verification chain */
2305         cur = &ver_chain->items[ver_chain->len];
2306         cur->crt = child;
2307         cur->flags = 0;
2308         ver_chain->len++;
2309         flags = &cur->flags;
2310 
2311         /* Check time-validity (all certificates) */
2312         if( mbedtls_x509_time_is_past( &child->valid_to ) )
2313             *flags |= MBEDTLS_X509_BADCERT_EXPIRED;
2314 
2315         if( mbedtls_x509_time_is_future( &child->valid_from ) )
2316             *flags |= MBEDTLS_X509_BADCERT_FUTURE;
2317 
2318         /* Stop here for trusted roots (but not for trusted EE certs) */
2319         if( child_is_trusted )
2320             return( 0 );
2321 
2322         /* Check signature algorithm: MD & PK algs */
2323         if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 )
2324             *flags |= MBEDTLS_X509_BADCERT_BAD_MD;
2325 
2326         if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 )
2327             *flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2328 
2329         /* Special case: EE certs that are locally trusted */
2330         if( ver_chain->len == 1 &&
2331             x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 )
2332         {
2333             return( 0 );
2334         }
2335 
2336 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2337 find_parent:
2338 #endif
2339         /* Look for a parent in trusted CAs or up the chain */
2340         ret = x509_crt_find_parent( child, trust_ca, &parent,
2341                                        &parent_is_trusted, &signature_is_good,
2342                                        ver_chain->len - 1, self_cnt, rs_ctx );
2343 
2344 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2345         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2346         {
2347             /* save state */
2348             rs_ctx->in_progress = x509_crt_rs_find_parent;
2349             rs_ctx->self_cnt = self_cnt;
2350             rs_ctx->ver_chain = *ver_chain; /* struct copy */
2351 
2352             return( ret );
2353         }
2354 #else
2355         (void) ret;
2356 #endif
2357 
2358         /* No parent? We're done here */
2359         if( parent == NULL )
2360         {
2361             *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2362             return( 0 );
2363         }
2364 
2365         /* Count intermediate self-issued (not necessarily self-signed) certs.
2366          * These can occur with some strategies for key rollover, see [SIRO],
2367          * and should be excluded from max_pathlen checks. */
2368         if( ver_chain->len != 1 &&
2369             x509_name_cmp( &child->issuer, &child->subject ) == 0 )
2370         {
2371             self_cnt++;
2372         }
2373 
2374         /* path_cnt is 0 for the first intermediate CA,
2375          * and if parent is trusted it's not an intermediate CA */
2376         if( ! parent_is_trusted &&
2377             ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
2378         {
2379             /* return immediately to avoid overflow the chain array */
2380             return( MBEDTLS_ERR_X509_FATAL_ERROR );
2381         }
2382 
2383         /* signature was checked while searching parent */
2384         if( ! signature_is_good )
2385             *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2386 
2387         /* check size of signing key */
2388         if( x509_profile_check_key( profile, &parent->pk ) != 0 )
2389             *flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2390 
2391 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2392         /* Check trusted CA's CRL for the given crt */
2393         *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile );
2394 #else
2395         (void) ca_crl;
2396 #endif
2397 
2398         /* prepare for next iteration */
2399         child = parent;
2400         parent = NULL;
2401         child_is_trusted = parent_is_trusted;
2402         signature_is_good = 0;
2403     }
2404 }
2405 
2406 /*
2407  * Check for CN match
2408  */
2409 static int x509_crt_check_cn( const mbedtls_x509_buf *name,
2410                               const char *cn, size_t cn_len )
2411 {
2412     /* try exact match */
2413     if( name->len == cn_len &&
2414         x509_memcasecmp( cn, name->p, cn_len ) == 0 )
2415     {
2416         return( 0 );
2417     }
2418 
2419     /* try wildcard match */
2420     if( x509_check_wildcard( cn, name ) == 0 )
2421     {
2422         return( 0 );
2423     }
2424 
2425     return( -1 );
2426 }
2427 
2428 /*
2429  * Verify the requested CN - only call this if cn is not NULL!
2430  */
2431 static void x509_crt_verify_name( const mbedtls_x509_crt *crt,
2432                                   const char *cn,
2433                                   uint32_t *flags )
2434 {
2435     const mbedtls_x509_name *name;
2436     const mbedtls_x509_sequence *cur;
2437     size_t cn_len = strlen( cn );
2438 
2439     if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
2440     {
2441         for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next )
2442         {
2443             if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 )
2444                 break;
2445         }
2446 
2447         if( cur == NULL )
2448             *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2449     }
2450     else
2451     {
2452         for( name = &crt->subject; name != NULL; name = name->next )
2453         {
2454             if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 &&
2455                 x509_crt_check_cn( &name->val, cn, cn_len ) == 0 )
2456             {
2457                 break;
2458             }
2459         }
2460 
2461         if( name == NULL )
2462             *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2463     }
2464 }
2465 
2466 /*
2467  * Merge the flags for all certs in the chain, after calling callback
2468  */
2469 static int x509_crt_merge_flags_with_cb(
2470            uint32_t *flags,
2471            const mbedtls_x509_crt_verify_chain *ver_chain,
2472            int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2473            void *p_vrfy )
2474 {
2475     int ret;
2476     unsigned i;
2477     uint32_t cur_flags;
2478     const mbedtls_x509_crt_verify_chain_item *cur;
2479 
2480     for( i = ver_chain->len; i != 0; --i )
2481     {
2482         cur = &ver_chain->items[i-1];
2483         cur_flags = cur->flags;
2484 
2485         if( NULL != f_vrfy )
2486             if( ( ret = f_vrfy( p_vrfy, cur->crt, (int) i-1, &cur_flags ) ) != 0 )
2487                 return( ret );
2488 
2489         *flags |= cur_flags;
2490     }
2491 
2492     return( 0 );
2493 }
2494 
2495 /*
2496  * Verify the certificate validity (default profile, not restartable)
2497  */
2498 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
2499                      mbedtls_x509_crt *trust_ca,
2500                      mbedtls_x509_crl *ca_crl,
2501                      const char *cn, uint32_t *flags,
2502                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2503                      void *p_vrfy )
2504 {
2505     return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
2506                 &mbedtls_x509_crt_profile_default, cn, flags,
2507                 f_vrfy, p_vrfy, NULL ) );
2508 }
2509 
2510 /*
2511  * Verify the certificate validity (user-chosen profile, not restartable)
2512  */
2513 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
2514                      mbedtls_x509_crt *trust_ca,
2515                      mbedtls_x509_crl *ca_crl,
2516                      const mbedtls_x509_crt_profile *profile,
2517                      const char *cn, uint32_t *flags,
2518                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2519                      void *p_vrfy )
2520 {
2521     return( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
2522                 profile, cn, flags, f_vrfy, p_vrfy, NULL ) );
2523 }
2524 
2525 /*
2526  * Verify the certificate validity, with profile, restartable version
2527  *
2528  * This function:
2529  *  - checks the requested CN (if any)
2530  *  - checks the type and size of the EE cert's key,
2531  *    as that isn't done as part of chain building/verification currently
2532  *  - builds and verifies the chain
2533  *  - then calls the callback and merges the flags
2534  */
2535 int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt,
2536                      mbedtls_x509_crt *trust_ca,
2537                      mbedtls_x509_crl *ca_crl,
2538                      const mbedtls_x509_crt_profile *profile,
2539                      const char *cn, uint32_t *flags,
2540                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2541                      void *p_vrfy,
2542                      mbedtls_x509_crt_restart_ctx *rs_ctx )
2543 {
2544     int ret;
2545     mbedtls_pk_type_t pk_type;
2546     mbedtls_x509_crt_verify_chain ver_chain;
2547     uint32_t ee_flags;
2548 
2549     *flags = 0;
2550     ee_flags = 0;
2551     x509_crt_verify_chain_reset( &ver_chain );
2552 
2553     if( profile == NULL )
2554     {
2555         ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
2556         goto exit;
2557     }
2558 
2559     /* check name if requested */
2560     if( cn != NULL )
2561         x509_crt_verify_name( crt, cn, &ee_flags );
2562 
2563     /* Check the type and size of the key */
2564     pk_type = mbedtls_pk_get_type( &crt->pk );
2565 
2566     if( x509_profile_check_pk_alg( profile, pk_type ) != 0 )
2567         ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2568 
2569     if( x509_profile_check_key( profile, &crt->pk ) != 0 )
2570         ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2571 
2572     /* Check the chain */
2573     ret = x509_crt_verify_chain( crt, trust_ca, ca_crl, profile,
2574                                  &ver_chain, rs_ctx );
2575 
2576     if( ret != 0 )
2577         goto exit;
2578 
2579     /* Merge end-entity flags */
2580     ver_chain.items[0].flags |= ee_flags;
2581 
2582     /* Build final flags, calling callback on the way if any */
2583     ret = x509_crt_merge_flags_with_cb( flags, &ver_chain, f_vrfy, p_vrfy );
2584 
2585 exit:
2586 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2587     if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
2588         mbedtls_x509_crt_restart_free( rs_ctx );
2589 #endif
2590 
2591     /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
2592      * the SSL module for authmode optional, but non-zero return from the
2593      * callback means a fatal error so it shouldn't be ignored */
2594     if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
2595         ret = MBEDTLS_ERR_X509_FATAL_ERROR;
2596 
2597     if( ret != 0 )
2598     {
2599         *flags = (uint32_t) -1;
2600         return( ret );
2601     }
2602 
2603     if( *flags != 0 )
2604         return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
2605 
2606     return( 0 );
2607 }
2608 
2609 /*
2610  * Initialize a certificate chain
2611  */
2612 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt )
2613 {
2614     memset( crt, 0, sizeof(mbedtls_x509_crt) );
2615 }
2616 
2617 /*
2618  * Unallocate all certificate data
2619  */
2620 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
2621 {
2622     mbedtls_x509_crt *cert_cur = crt;
2623     mbedtls_x509_crt *cert_prv;
2624     mbedtls_x509_name *name_cur;
2625     mbedtls_x509_name *name_prv;
2626     mbedtls_x509_sequence *seq_cur;
2627     mbedtls_x509_sequence *seq_prv;
2628 
2629     if( crt == NULL )
2630         return;
2631 
2632     do
2633     {
2634         mbedtls_pk_free( &cert_cur->pk );
2635 
2636 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
2637         mbedtls_free( cert_cur->sig_opts );
2638 #endif
2639 
2640         name_cur = cert_cur->issuer.next;
2641         while( name_cur != NULL )
2642         {
2643             name_prv = name_cur;
2644             name_cur = name_cur->next;
2645             mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2646             mbedtls_free( name_prv );
2647         }
2648 
2649         name_cur = cert_cur->subject.next;
2650         while( name_cur != NULL )
2651         {
2652             name_prv = name_cur;
2653             name_cur = name_cur->next;
2654             mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
2655             mbedtls_free( name_prv );
2656         }
2657 
2658         seq_cur = cert_cur->ext_key_usage.next;
2659         while( seq_cur != NULL )
2660         {
2661             seq_prv = seq_cur;
2662             seq_cur = seq_cur->next;
2663             mbedtls_platform_zeroize( seq_prv,
2664                                       sizeof( mbedtls_x509_sequence ) );
2665             mbedtls_free( seq_prv );
2666         }
2667 
2668         seq_cur = cert_cur->subject_alt_names.next;
2669         while( seq_cur != NULL )
2670         {
2671             seq_prv = seq_cur;
2672             seq_cur = seq_cur->next;
2673             mbedtls_platform_zeroize( seq_prv,
2674                                       sizeof( mbedtls_x509_sequence ) );
2675             mbedtls_free( seq_prv );
2676         }
2677 
2678         if( cert_cur->raw.p != NULL )
2679         {
2680             mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
2681             mbedtls_free( cert_cur->raw.p );
2682         }
2683 
2684         cert_cur = cert_cur->next;
2685     }
2686     while( cert_cur != NULL );
2687 
2688     cert_cur = crt;
2689     do
2690     {
2691         cert_prv = cert_cur;
2692         cert_cur = cert_cur->next;
2693 
2694         mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) );
2695         if( cert_prv != crt )
2696             mbedtls_free( cert_prv );
2697     }
2698     while( cert_cur != NULL );
2699 }
2700 
2701 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2702 /*
2703  * Initialize a restart context
2704  */
2705 void mbedtls_x509_crt_restart_init( mbedtls_x509_crt_restart_ctx *ctx )
2706 {
2707     mbedtls_pk_restart_init( &ctx->pk );
2708 
2709     ctx->parent = NULL;
2710     ctx->fallback_parent = NULL;
2711     ctx->fallback_signature_is_good = 0;
2712 
2713     ctx->parent_is_trusted = -1;
2714 
2715     ctx->in_progress = x509_crt_rs_none;
2716     ctx->self_cnt = 0;
2717     x509_crt_verify_chain_reset( &ctx->ver_chain );
2718 }
2719 
2720 /*
2721  * Free the components of a restart context
2722  */
2723 void mbedtls_x509_crt_restart_free( mbedtls_x509_crt_restart_ctx *ctx )
2724 {
2725     if( ctx == NULL )
2726         return;
2727 
2728     mbedtls_pk_restart_free( &ctx->pk );
2729     mbedtls_x509_crt_restart_init( ctx );
2730 }
2731 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2732 
2733 #endif /* MBEDTLS_X509_CRT_PARSE_C */
2734