xref: /optee_os/lib/libmbedtls/mbedtls/library/x509_crt.c (revision 11fa71b9ddb429088f325cfda430183003ccd1db)
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/error.h"
44 #include "mbedtls/oid.h"
45 #include "mbedtls/platform_util.h"
46 
47 #include <string.h>
48 
49 #if defined(MBEDTLS_PEM_PARSE_C)
50 #include "mbedtls/pem.h"
51 #endif
52 
53 #if defined(MBEDTLS_USE_PSA_CRYPTO)
54 #include "psa/crypto.h"
55 #include "mbedtls/psa_util.h"
56 #endif
57 
58 #if defined(MBEDTLS_PLATFORM_C)
59 #include "mbedtls/platform.h"
60 #else
61 #include <stdio.h>
62 #include <stdlib.h>
63 #define mbedtls_free       free
64 #define mbedtls_calloc    calloc
65 #define mbedtls_snprintf   snprintf
66 #endif
67 
68 #if defined(MBEDTLS_THREADING_C)
69 #include "mbedtls/threading.h"
70 #endif
71 
72 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
73 #include <windows.h>
74 #else
75 #include <time.h>
76 #endif
77 
78 #if defined(MBEDTLS_FS_IO)
79 #include <stdio.h>
80 #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
81 #include <sys/types.h>
82 #include <sys/stat.h>
83 #include <dirent.h>
84 #endif /* !_WIN32 || EFIX64 || EFI32 */
85 #endif
86 
87 /*
88  * Item in a verification chain: cert and flags for it
89  */
90 typedef struct {
91     mbedtls_x509_crt *crt;
92     uint32_t flags;
93 } x509_crt_verify_chain_item;
94 
95 /*
96  * Max size of verification chain: end-entity + intermediates + trusted root
97  */
98 #define X509_MAX_VERIFY_CHAIN_SIZE    ( MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2 )
99 
100 /*
101  * Default profile
102  */
103 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
104 {
105 #if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
106     /* Allow SHA-1 (weak, but still safe in controlled environments) */
107     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
108 #endif
109     /* Only SHA-2 hashes */
110     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
111     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
112     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
113     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
114     0xFFFFFFF, /* Any PK alg    */
115     0xFFFFFFF, /* Any curve     */
116     2048,
117 };
118 
119 /*
120  * Next-default profile
121  */
122 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next =
123 {
124     /* Hashes from SHA-256 and above */
125     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
126     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
127     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
128     0xFFFFFFF, /* Any PK alg    */
129 #if defined(MBEDTLS_ECP_C)
130     /* Curves at or above 128-bit security level */
131     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
132     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ) |
133     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP521R1 ) |
134     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP256R1 ) |
135     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP384R1 ) |
136     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_BP512R1 ) |
137     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256K1 ),
138 #else
139     0,
140 #endif
141     2048,
142 };
143 
144 /*
145  * NSA Suite B Profile
146  */
147 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb =
148 {
149     /* Only SHA-256 and 384 */
150     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
151     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ),
152     /* Only ECDSA */
153     MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECDSA ) |
154     MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_ECKEY ),
155 #if defined(MBEDTLS_ECP_C)
156     /* Only NIST P-256 and P-384 */
157     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP256R1 ) |
158     MBEDTLS_X509_ID_FLAG( MBEDTLS_ECP_DP_SECP384R1 ),
159 #else
160     0,
161 #endif
162     0,
163 };
164 
165 /*
166  * Check md_alg against profile
167  * Return 0 if md_alg is acceptable for this profile, -1 otherwise
168  */
169 static int x509_profile_check_md_alg( const mbedtls_x509_crt_profile *profile,
170                                       mbedtls_md_type_t md_alg )
171 {
172     if( md_alg == MBEDTLS_MD_NONE )
173         return( -1 );
174 
175     if( ( profile->allowed_mds & MBEDTLS_X509_ID_FLAG( md_alg ) ) != 0 )
176         return( 0 );
177 
178     return( -1 );
179 }
180 
181 /*
182  * Check pk_alg against profile
183  * Return 0 if pk_alg is acceptable for this profile, -1 otherwise
184  */
185 static int x509_profile_check_pk_alg( const mbedtls_x509_crt_profile *profile,
186                                       mbedtls_pk_type_t pk_alg )
187 {
188     if( pk_alg == MBEDTLS_PK_NONE )
189         return( -1 );
190 
191     if( ( profile->allowed_pks & MBEDTLS_X509_ID_FLAG( pk_alg ) ) != 0 )
192         return( 0 );
193 
194     return( -1 );
195 }
196 
197 /*
198  * Check key against profile
199  * Return 0 if pk is acceptable for this profile, -1 otherwise
200  */
201 static int x509_profile_check_key( const mbedtls_x509_crt_profile *profile,
202                                    const mbedtls_pk_context *pk )
203 {
204     const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type( pk );
205 
206 #if defined(MBEDTLS_RSA_C)
207     if( pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS )
208     {
209         if( mbedtls_pk_get_bitlen( pk ) >= profile->rsa_min_bitlen )
210             return( 0 );
211 
212         return( -1 );
213     }
214 #endif
215 
216 #if defined(MBEDTLS_ECP_C)
217     if( pk_alg == MBEDTLS_PK_ECDSA ||
218         pk_alg == MBEDTLS_PK_ECKEY ||
219         pk_alg == MBEDTLS_PK_ECKEY_DH )
220     {
221         const mbedtls_ecp_group_id gid = mbedtls_pk_ec( *pk )->grp.id;
222 
223         if( gid == MBEDTLS_ECP_DP_NONE )
224             return( -1 );
225 
226         if( ( profile->allowed_curves & MBEDTLS_X509_ID_FLAG( gid ) ) != 0 )
227             return( 0 );
228 
229         return( -1 );
230     }
231 #endif
232 
233     return( -1 );
234 }
235 
236 /*
237  * Like memcmp, but case-insensitive and always returns -1 if different
238  */
239 static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
240 {
241     size_t i;
242     unsigned char diff;
243     const unsigned char *n1 = s1, *n2 = s2;
244 
245     for( i = 0; i < len; i++ )
246     {
247         diff = n1[i] ^ n2[i];
248 
249         if( diff == 0 )
250             continue;
251 
252         if( diff == 32 &&
253             ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
254               ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
255         {
256             continue;
257         }
258 
259         return( -1 );
260     }
261 
262     return( 0 );
263 }
264 
265 /*
266  * Return 0 if name matches wildcard, -1 otherwise
267  */
268 static int x509_check_wildcard( const char *cn, const mbedtls_x509_buf *name )
269 {
270     size_t i;
271     size_t cn_idx = 0, cn_len = strlen( cn );
272 
273     /* We can't have a match if there is no wildcard to match */
274     if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' )
275         return( -1 );
276 
277     for( i = 0; i < cn_len; ++i )
278     {
279         if( cn[i] == '.' )
280         {
281             cn_idx = i;
282             break;
283         }
284     }
285 
286     if( cn_idx == 0 )
287         return( -1 );
288 
289     if( cn_len - cn_idx == name->len - 1 &&
290         x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 )
291     {
292         return( 0 );
293     }
294 
295     return( -1 );
296 }
297 
298 /*
299  * Compare two X.509 strings, case-insensitive, and allowing for some encoding
300  * variations (but not all).
301  *
302  * Return 0 if equal, -1 otherwise.
303  */
304 static int x509_string_cmp( const mbedtls_x509_buf *a, const mbedtls_x509_buf *b )
305 {
306     if( a->tag == b->tag &&
307         a->len == b->len &&
308         memcmp( a->p, b->p, b->len ) == 0 )
309     {
310         return( 0 );
311     }
312 
313     if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
314         ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
315         a->len == b->len &&
316         x509_memcasecmp( a->p, b->p, b->len ) == 0 )
317     {
318         return( 0 );
319     }
320 
321     return( -1 );
322 }
323 
324 /*
325  * Compare two X.509 Names (aka rdnSequence).
326  *
327  * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
328  * we sometimes return unequal when the full algorithm would return equal,
329  * but never the other way. (In particular, we don't do Unicode normalisation
330  * or space folding.)
331  *
332  * Return 0 if equal, -1 otherwise.
333  */
334 static int x509_name_cmp( const mbedtls_x509_name *a, const mbedtls_x509_name *b )
335 {
336     /* Avoid recursion, it might not be optimised by the compiler */
337     while( a != NULL || b != NULL )
338     {
339         if( a == NULL || b == NULL )
340             return( -1 );
341 
342         /* type */
343         if( a->oid.tag != b->oid.tag ||
344             a->oid.len != b->oid.len ||
345             memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
346         {
347             return( -1 );
348         }
349 
350         /* value */
351         if( x509_string_cmp( &a->val, &b->val ) != 0 )
352             return( -1 );
353 
354         /* structure of the list of sets */
355         if( a->next_merged != b->next_merged )
356             return( -1 );
357 
358         a = a->next;
359         b = b->next;
360     }
361 
362     /* a == NULL == b */
363     return( 0 );
364 }
365 
366 /*
367  * Reset (init or clear) a verify_chain
368  */
369 static void x509_crt_verify_chain_reset(
370     mbedtls_x509_crt_verify_chain *ver_chain )
371 {
372     size_t i;
373 
374     for( i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++ )
375     {
376         ver_chain->items[i].crt = NULL;
377         ver_chain->items[i].flags = (uint32_t) -1;
378     }
379 
380     ver_chain->len = 0;
381 
382 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
383     ver_chain->trust_ca_cb_result = NULL;
384 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
385 }
386 
387 /*
388  *  Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
389  */
390 static int x509_get_version( unsigned char **p,
391                              const unsigned char *end,
392                              int *ver )
393 {
394     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
395     size_t len;
396 
397     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
398             MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) != 0 )
399     {
400         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
401         {
402             *ver = 0;
403             return( 0 );
404         }
405 
406         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
407     }
408 
409     end = *p + len;
410 
411     if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
412         return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
413 
414     if( *p != end )
415         return( MBEDTLS_ERR_X509_INVALID_VERSION +
416                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
417 
418     return( 0 );
419 }
420 
421 /*
422  *  Validity ::= SEQUENCE {
423  *       notBefore      Time,
424  *       notAfter       Time }
425  */
426 static int x509_get_dates( unsigned char **p,
427                            const unsigned char *end,
428                            mbedtls_x509_time *from,
429                            mbedtls_x509_time *to )
430 {
431     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
432     size_t len;
433 
434     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
435             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
436         return( MBEDTLS_ERR_X509_INVALID_DATE + ret );
437 
438     end = *p + len;
439 
440     if( ( ret = mbedtls_x509_get_time( p, end, from ) ) != 0 )
441         return( ret );
442 
443     if( ( ret = mbedtls_x509_get_time( p, end, to ) ) != 0 )
444         return( ret );
445 
446     if( *p != end )
447         return( MBEDTLS_ERR_X509_INVALID_DATE +
448                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
449 
450     return( 0 );
451 }
452 
453 /*
454  * X.509 v2/v3 unique identifier (not parsed)
455  */
456 static int x509_get_uid( unsigned char **p,
457                          const unsigned char *end,
458                          mbedtls_x509_buf *uid, int n )
459 {
460     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
461 
462     if( *p == end )
463         return( 0 );
464 
465     uid->tag = **p;
466 
467     if( ( ret = mbedtls_asn1_get_tag( p, end, &uid->len,
468             MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n ) ) != 0 )
469     {
470         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
471             return( 0 );
472 
473         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
474     }
475 
476     uid->p = *p;
477     *p += uid->len;
478 
479     return( 0 );
480 }
481 
482 static int x509_get_basic_constraints( unsigned char **p,
483                                        const unsigned char *end,
484                                        int *ca_istrue,
485                                        int *max_pathlen )
486 {
487     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
488     size_t len;
489 
490     /*
491      * BasicConstraints ::= SEQUENCE {
492      *      cA                      BOOLEAN DEFAULT FALSE,
493      *      pathLenConstraint       INTEGER (0..MAX) OPTIONAL }
494      */
495     *ca_istrue = 0; /* DEFAULT FALSE */
496     *max_pathlen = 0; /* endless */
497 
498     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
499             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
500         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
501 
502     if( *p == end )
503         return( 0 );
504 
505     if( ( ret = mbedtls_asn1_get_bool( p, end, ca_istrue ) ) != 0 )
506     {
507         if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
508             ret = mbedtls_asn1_get_int( p, end, ca_istrue );
509 
510         if( ret != 0 )
511             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
512 
513         if( *ca_istrue != 0 )
514             *ca_istrue = 1;
515     }
516 
517     if( *p == end )
518         return( 0 );
519 
520     if( ( ret = mbedtls_asn1_get_int( p, end, max_pathlen ) ) != 0 )
521         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
522 
523     if( *p != end )
524         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
525                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
526 
527     (*max_pathlen)++;
528 
529     return( 0 );
530 }
531 
532 static int x509_get_ns_cert_type( unsigned char **p,
533                                        const unsigned char *end,
534                                        unsigned char *ns_cert_type)
535 {
536     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
537     mbedtls_x509_bitstring bs = { 0, 0, NULL };
538 
539     if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
540         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
541 
542     if( bs.len != 1 )
543         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
544                 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
545 
546     /* Get actual bitstring */
547     *ns_cert_type = *bs.p;
548     return( 0 );
549 }
550 
551 static int x509_get_key_usage( unsigned char **p,
552                                const unsigned char *end,
553                                unsigned int *key_usage)
554 {
555     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
556     size_t i;
557     mbedtls_x509_bitstring bs = { 0, 0, NULL };
558 
559     if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
560         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
561 
562     if( bs.len < 1 )
563         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
564                 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
565 
566     /* Get actual bitstring */
567     *key_usage = 0;
568     for( i = 0; i < bs.len && i < sizeof( unsigned int ); i++ )
569     {
570         *key_usage |= (unsigned int) bs.p[i] << (8*i);
571     }
572 
573     return( 0 );
574 }
575 
576 /*
577  * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
578  *
579  * KeyPurposeId ::= OBJECT IDENTIFIER
580  */
581 static int x509_get_ext_key_usage( unsigned char **p,
582                                const unsigned char *end,
583                                mbedtls_x509_sequence *ext_key_usage)
584 {
585     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
586 
587     if( ( ret = mbedtls_asn1_get_sequence_of( p, end, ext_key_usage, MBEDTLS_ASN1_OID ) ) != 0 )
588         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
589 
590     /* Sequence length must be >= 1 */
591     if( ext_key_usage->buf.p == NULL )
592         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
593                 MBEDTLS_ERR_ASN1_INVALID_LENGTH );
594 
595     return( 0 );
596 }
597 
598 /*
599  * SubjectAltName ::= GeneralNames
600  *
601  * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
602  *
603  * GeneralName ::= CHOICE {
604  *      otherName                       [0]     OtherName,
605  *      rfc822Name                      [1]     IA5String,
606  *      dNSName                         [2]     IA5String,
607  *      x400Address                     [3]     ORAddress,
608  *      directoryName                   [4]     Name,
609  *      ediPartyName                    [5]     EDIPartyName,
610  *      uniformResourceIdentifier       [6]     IA5String,
611  *      iPAddress                       [7]     OCTET STRING,
612  *      registeredID                    [8]     OBJECT IDENTIFIER }
613  *
614  * OtherName ::= SEQUENCE {
615  *      type-id    OBJECT IDENTIFIER,
616  *      value      [0] EXPLICIT ANY DEFINED BY type-id }
617  *
618  * EDIPartyName ::= SEQUENCE {
619  *      nameAssigner            [0]     DirectoryString OPTIONAL,
620  *      partyName               [1]     DirectoryString }
621  *
622  * NOTE: we list all types, but only use dNSName and otherName
623  * of type HwModuleName, as defined in RFC 4108, at this point.
624  */
625 static int x509_get_subject_alt_name( unsigned char **p,
626                                       const unsigned char *end,
627                                       mbedtls_x509_sequence *subject_alt_name )
628 {
629     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
630     size_t len, tag_len;
631     mbedtls_asn1_buf *buf;
632     unsigned char tag;
633     mbedtls_asn1_sequence *cur = subject_alt_name;
634 
635     /* Get main sequence tag */
636     if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
637             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
638         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
639 
640     if( *p + len != end )
641         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
642                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
643 
644     while( *p < end )
645     {
646         mbedtls_x509_subject_alternative_name dummy_san_buf;
647         memset( &dummy_san_buf, 0, sizeof( dummy_san_buf ) );
648 
649         if( ( end - *p ) < 1 )
650             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
651                     MBEDTLS_ERR_ASN1_OUT_OF_DATA );
652 
653         tag = **p;
654         (*p)++;
655         if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 )
656             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
657 
658         if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) !=
659                 MBEDTLS_ASN1_CONTEXT_SPECIFIC )
660         {
661             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
662                     MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
663         }
664 
665         /*
666          * Check that the SAN are structured correct.
667          */
668         ret = mbedtls_x509_parse_subject_alt_name( &(cur->buf), &dummy_san_buf );
669         /*
670          * In case the extension is malformed, return an error,
671          * and clear the allocated sequences.
672          */
673         if( ret != 0 && ret != MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE )
674         {
675             mbedtls_x509_sequence *seq_cur = subject_alt_name->next;
676             mbedtls_x509_sequence *seq_prv;
677             while( seq_cur != NULL )
678             {
679                 seq_prv = seq_cur;
680                 seq_cur = seq_cur->next;
681                 mbedtls_platform_zeroize( seq_prv,
682                                           sizeof( mbedtls_x509_sequence ) );
683                 mbedtls_free( seq_prv );
684             }
685             subject_alt_name->next = NULL;
686             return( ret );
687         }
688 
689         /* Allocate and assign next pointer */
690         if( cur->buf.p != NULL )
691         {
692             if( cur->next != NULL )
693                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
694 
695             cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) );
696 
697             if( cur->next == NULL )
698                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
699                         MBEDTLS_ERR_ASN1_ALLOC_FAILED );
700 
701             cur = cur->next;
702         }
703 
704         buf = &(cur->buf);
705         buf->tag = tag;
706         buf->p = *p;
707         buf->len = tag_len;
708         *p += buf->len;
709     }
710 
711     /* Set final sequence entry's next pointer to NULL */
712     cur->next = NULL;
713 
714     if( *p != end )
715         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
716                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
717 
718     return( 0 );
719 }
720 
721 /*
722  * id-ce-certificatePolicies OBJECT IDENTIFIER ::=  { id-ce 32 }
723  *
724  * anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 }
725  *
726  * certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
727  *
728  * PolicyInformation ::= SEQUENCE {
729  *     policyIdentifier   CertPolicyId,
730  *     policyQualifiers   SEQUENCE SIZE (1..MAX) OF
731  *                             PolicyQualifierInfo OPTIONAL }
732  *
733  * CertPolicyId ::= OBJECT IDENTIFIER
734  *
735  * PolicyQualifierInfo ::= SEQUENCE {
736  *      policyQualifierId  PolicyQualifierId,
737  *      qualifier          ANY DEFINED BY policyQualifierId }
738  *
739  * -- policyQualifierIds for Internet policy qualifiers
740  *
741  * id-qt          OBJECT IDENTIFIER ::=  { id-pkix 2 }
742  * id-qt-cps      OBJECT IDENTIFIER ::=  { id-qt 1 }
743  * id-qt-unotice  OBJECT IDENTIFIER ::=  { id-qt 2 }
744  *
745  * PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice )
746  *
747  * Qualifier ::= CHOICE {
748  *      cPSuri           CPSuri,
749  *      userNotice       UserNotice }
750  *
751  * CPSuri ::= IA5String
752  *
753  * UserNotice ::= SEQUENCE {
754  *      noticeRef        NoticeReference OPTIONAL,
755  *      explicitText     DisplayText OPTIONAL }
756  *
757  * NoticeReference ::= SEQUENCE {
758  *      organization     DisplayText,
759  *      noticeNumbers    SEQUENCE OF INTEGER }
760  *
761  * DisplayText ::= CHOICE {
762  *      ia5String        IA5String      (SIZE (1..200)),
763  *      visibleString    VisibleString  (SIZE (1..200)),
764  *      bmpString        BMPString      (SIZE (1..200)),
765  *      utf8String       UTF8String     (SIZE (1..200)) }
766  *
767  * NOTE: we only parse and use anyPolicy without qualifiers at this point
768  * as defined in RFC 5280.
769  */
770 static int x509_get_certificate_policies( unsigned char **p,
771                                           const unsigned char *end,
772                                           mbedtls_x509_sequence *certificate_policies )
773 {
774     int ret, parse_ret = 0;
775     size_t len;
776     mbedtls_asn1_buf *buf;
777     mbedtls_asn1_sequence *cur = certificate_policies;
778 
779     /* Get main sequence tag */
780     ret = mbedtls_asn1_get_tag( p, end, &len,
781                              MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE );
782     if( ret != 0 )
783         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
784 
785     if( *p + len != end )
786         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
787                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
788 
789     /*
790      * Cannot be an empty sequence.
791      */
792     if( len == 0 )
793         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
794                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
795 
796     while( *p < end )
797     {
798         mbedtls_x509_buf policy_oid;
799         const unsigned char *policy_end;
800 
801         /*
802          * Get the policy sequence
803          */
804         if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
805                 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
806             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
807 
808         policy_end = *p + len;
809 
810         if( ( ret = mbedtls_asn1_get_tag( p, policy_end, &len,
811                                           MBEDTLS_ASN1_OID ) ) != 0 )
812             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
813 
814         policy_oid.tag = MBEDTLS_ASN1_OID;
815         policy_oid.len = len;
816         policy_oid.p = *p;
817 
818         /*
819          * Only AnyPolicy is currently supported when enforcing policy.
820          */
821         if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_POLICY, &policy_oid ) != 0 )
822         {
823             /*
824              * Set the parsing return code but continue parsing, in case this
825              * extension is critical and MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION
826              * is configured.
827              */
828             parse_ret = MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE;
829         }
830 
831         /* Allocate and assign next pointer */
832         if( cur->buf.p != NULL )
833         {
834             if( cur->next != NULL )
835                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
836 
837             cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) );
838 
839             if( cur->next == NULL )
840                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
841                         MBEDTLS_ERR_ASN1_ALLOC_FAILED );
842 
843             cur = cur->next;
844         }
845 
846         buf = &( cur->buf );
847         buf->tag = policy_oid.tag;
848         buf->p = policy_oid.p;
849         buf->len = policy_oid.len;
850 
851         *p += len;
852 
853        /*
854         * If there is an optional qualifier, then *p < policy_end
855         * Check the Qualifier len to verify it doesn't exceed policy_end.
856         */
857         if( *p < policy_end )
858         {
859             if( ( ret = mbedtls_asn1_get_tag( p, policy_end, &len,
860                      MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
861                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
862             /*
863              * Skip the optional policy qualifiers.
864              */
865             *p += len;
866         }
867 
868         if( *p != policy_end )
869             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
870                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
871     }
872 
873     /* Set final sequence entry's next pointer to NULL */
874     cur->next = NULL;
875 
876     if( *p != end )
877         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
878                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
879 
880     return( parse_ret );
881 }
882 
883 /*
884  * X.509 v3 extensions
885  *
886  */
887 static int x509_get_crt_ext( unsigned char **p,
888                              const unsigned char *end,
889                              mbedtls_x509_crt *crt )
890 {
891     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
892     size_t len;
893     unsigned char *end_ext_data, *end_ext_octet;
894 
895     if( *p == end )
896         return( 0 );
897 
898     if( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
899         return( ret );
900 
901     end = crt->v3_ext.p + crt->v3_ext.len;
902     while( *p < end )
903     {
904         /*
905          * Extension  ::=  SEQUENCE  {
906          *      extnID      OBJECT IDENTIFIER,
907          *      critical    BOOLEAN DEFAULT FALSE,
908          *      extnValue   OCTET STRING  }
909          */
910         mbedtls_x509_buf extn_oid = {0, 0, NULL};
911         int is_critical = 0; /* DEFAULT FALSE */
912         int ext_type = 0;
913 
914         if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
915                 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
916             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
917 
918         end_ext_data = *p + len;
919 
920         /* Get extension ID */
921         if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &extn_oid.len,
922                                           MBEDTLS_ASN1_OID ) ) != 0 )
923             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
924 
925         extn_oid.tag = MBEDTLS_ASN1_OID;
926         extn_oid.p = *p;
927         *p += extn_oid.len;
928 
929         /* Get optional critical */
930         if( ( ret = mbedtls_asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
931             ( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
932             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
933 
934         /* Data should be octet string type */
935         if( ( ret = mbedtls_asn1_get_tag( p, end_ext_data, &len,
936                 MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
937             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
938 
939         end_ext_octet = *p + len;
940 
941         if( end_ext_octet != end_ext_data )
942             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
943                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
944 
945         /*
946          * Detect supported extensions
947          */
948         ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type );
949 
950         if( ret != 0 )
951         {
952             /* No parser found, skip extension */
953             *p = end_ext_octet;
954 
955 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
956             if( is_critical )
957             {
958                 /* Data is marked as critical: fail */
959                 return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
960                         MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
961             }
962 #endif
963             continue;
964         }
965 
966         /* Forbid repeated extensions */
967         if( ( crt->ext_types & ext_type ) != 0 )
968             return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
969 
970         crt->ext_types |= ext_type;
971 
972         switch( ext_type )
973         {
974         case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
975             /* Parse basic constraints */
976             if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
977                     &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
978                 return( ret );
979             break;
980 
981         case MBEDTLS_X509_EXT_KEY_USAGE:
982             /* Parse key usage */
983             if( ( ret = x509_get_key_usage( p, end_ext_octet,
984                     &crt->key_usage ) ) != 0 )
985                 return( ret );
986             break;
987 
988         case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
989             /* Parse extended key usage */
990             if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
991                     &crt->ext_key_usage ) ) != 0 )
992                 return( ret );
993             break;
994 
995         case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
996             /* Parse subject alt name */
997             if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
998                     &crt->subject_alt_names ) ) != 0 )
999                 return( ret );
1000             break;
1001 
1002         case MBEDTLS_X509_EXT_NS_CERT_TYPE:
1003             /* Parse netscape certificate type */
1004             if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
1005                     &crt->ns_cert_type ) ) != 0 )
1006                 return( ret );
1007             break;
1008 
1009         case MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES:
1010             /* Parse certificate policies type */
1011             if( ( ret = x509_get_certificate_policies( p, end_ext_octet,
1012                     &crt->certificate_policies ) ) != 0 )
1013             {
1014 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
1015                 if( is_critical )
1016                     return( ret );
1017                 else
1018 #endif
1019                 /*
1020                  * If MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE is returned, then we
1021                  * cannot interpret or enforce the policy. However, it is up to
1022                  * the user to choose how to enforce the policies,
1023                  * unless the extension is critical.
1024                  */
1025                 if( ret != MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE )
1026                     return( ret );
1027             }
1028             break;
1029 
1030         default:
1031             /*
1032              * If this is a non-critical extension, which the oid layer
1033              * supports, but there isn't an x509 parser for it,
1034              * skip the extension.
1035              */
1036 #if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
1037             if( is_critical )
1038                 return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
1039             else
1040 #endif
1041                 *p = end_ext_octet;
1042         }
1043     }
1044 
1045     if( *p != end )
1046         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
1047                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1048 
1049     return( 0 );
1050 }
1051 
1052 /*
1053  * Parse and fill a single X.509 certificate in DER format
1054  */
1055 static int x509_crt_parse_der_core( mbedtls_x509_crt *crt,
1056                                     const unsigned char *buf,
1057                                     size_t buflen,
1058                                     int make_copy )
1059 {
1060     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1061     size_t len;
1062     unsigned char *p, *end, *crt_end;
1063     mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
1064 
1065     memset( &sig_params1, 0, sizeof( mbedtls_x509_buf ) );
1066     memset( &sig_params2, 0, sizeof( mbedtls_x509_buf ) );
1067     memset( &sig_oid2, 0, sizeof( mbedtls_x509_buf ) );
1068 
1069     /*
1070      * Check for valid input
1071      */
1072     if( crt == NULL || buf == NULL )
1073         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1074 
1075     /* Use the original buffer until we figure out actual length. */
1076     p = (unsigned char*) buf;
1077     len = buflen;
1078     end = p + len;
1079 
1080     /*
1081      * Certificate  ::=  SEQUENCE  {
1082      *      tbsCertificate       TBSCertificate,
1083      *      signatureAlgorithm   AlgorithmIdentifier,
1084      *      signatureValue       BIT STRING  }
1085      */
1086     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1087             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1088     {
1089         mbedtls_x509_crt_free( crt );
1090         return( MBEDTLS_ERR_X509_INVALID_FORMAT );
1091     }
1092 
1093     end = crt_end = p + len;
1094     crt->raw.len = crt_end - buf;
1095     if( make_copy != 0 )
1096     {
1097         /* Create and populate a new buffer for the raw field. */
1098         crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
1099         if( crt->raw.p == NULL )
1100             return( MBEDTLS_ERR_X509_ALLOC_FAILED );
1101 
1102         memcpy( crt->raw.p, buf, crt->raw.len );
1103         crt->own_buffer = 1;
1104 
1105         p += crt->raw.len - len;
1106         end = crt_end = p + len;
1107     }
1108     else
1109     {
1110         crt->raw.p = (unsigned char*) buf;
1111         crt->own_buffer = 0;
1112     }
1113 
1114     /*
1115      * TBSCertificate  ::=  SEQUENCE  {
1116      */
1117     crt->tbs.p = p;
1118 
1119     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1120             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1121     {
1122         mbedtls_x509_crt_free( crt );
1123         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
1124     }
1125 
1126     end = p + len;
1127     crt->tbs.len = end - crt->tbs.p;
1128 
1129     /*
1130      * Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
1131      *
1132      * CertificateSerialNumber  ::=  INTEGER
1133      *
1134      * signature            AlgorithmIdentifier
1135      */
1136     if( ( ret = x509_get_version(  &p, end, &crt->version  ) ) != 0 ||
1137         ( ret = mbedtls_x509_get_serial(   &p, end, &crt->serial   ) ) != 0 ||
1138         ( ret = mbedtls_x509_get_alg(      &p, end, &crt->sig_oid,
1139                                             &sig_params1 ) ) != 0 )
1140     {
1141         mbedtls_x509_crt_free( crt );
1142         return( ret );
1143     }
1144 
1145     if( crt->version < 0 || crt->version > 2 )
1146     {
1147         mbedtls_x509_crt_free( crt );
1148         return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
1149     }
1150 
1151     crt->version++;
1152 
1153     if( ( ret = mbedtls_x509_get_sig_alg( &crt->sig_oid, &sig_params1,
1154                                   &crt->sig_md, &crt->sig_pk,
1155                                   &crt->sig_opts ) ) != 0 )
1156     {
1157         mbedtls_x509_crt_free( crt );
1158         return( ret );
1159     }
1160 
1161     /*
1162      * issuer               Name
1163      */
1164     crt->issuer_raw.p = p;
1165 
1166     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1167             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1168     {
1169         mbedtls_x509_crt_free( crt );
1170         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
1171     }
1172 
1173     if( ( ret = mbedtls_x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
1174     {
1175         mbedtls_x509_crt_free( crt );
1176         return( ret );
1177     }
1178 
1179     crt->issuer_raw.len = p - crt->issuer_raw.p;
1180 
1181     /*
1182      * Validity ::= SEQUENCE {
1183      *      notBefore      Time,
1184      *      notAfter       Time }
1185      *
1186      */
1187     if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
1188                                          &crt->valid_to ) ) != 0 )
1189     {
1190         mbedtls_x509_crt_free( crt );
1191         return( ret );
1192     }
1193 
1194     /*
1195      * subject              Name
1196      */
1197     crt->subject_raw.p = p;
1198 
1199     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1200             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1201     {
1202         mbedtls_x509_crt_free( crt );
1203         return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
1204     }
1205 
1206     if( len && ( ret = mbedtls_x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
1207     {
1208         mbedtls_x509_crt_free( crt );
1209         return( ret );
1210     }
1211 
1212     crt->subject_raw.len = p - crt->subject_raw.p;
1213 
1214     /*
1215      * SubjectPublicKeyInfo
1216      */
1217     crt->pk_raw.p = p;
1218     if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
1219     {
1220         mbedtls_x509_crt_free( crt );
1221         return( ret );
1222     }
1223     crt->pk_raw.len = p - crt->pk_raw.p;
1224 
1225     /*
1226      *  issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
1227      *                       -- If present, version shall be v2 or v3
1228      *  subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL,
1229      *                       -- If present, version shall be v2 or v3
1230      *  extensions      [3]  EXPLICIT Extensions OPTIONAL
1231      *                       -- If present, version shall be v3
1232      */
1233     if( crt->version == 2 || crt->version == 3 )
1234     {
1235         ret = x509_get_uid( &p, end, &crt->issuer_id,  1 );
1236         if( ret != 0 )
1237         {
1238             mbedtls_x509_crt_free( crt );
1239             return( ret );
1240         }
1241     }
1242 
1243     if( crt->version == 2 || crt->version == 3 )
1244     {
1245         ret = x509_get_uid( &p, end, &crt->subject_id,  2 );
1246         if( ret != 0 )
1247         {
1248             mbedtls_x509_crt_free( crt );
1249             return( ret );
1250         }
1251     }
1252 
1253 #if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
1254     if( crt->version == 3 )
1255 #endif
1256     {
1257         ret = x509_get_crt_ext( &p, end, crt );
1258         if( ret != 0 )
1259         {
1260             mbedtls_x509_crt_free( crt );
1261             return( ret );
1262         }
1263     }
1264 
1265     if( p != end )
1266     {
1267         mbedtls_x509_crt_free( crt );
1268         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1269                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1270     }
1271 
1272     end = crt_end;
1273 
1274     /*
1275      *  }
1276      *  -- end of TBSCertificate
1277      *
1278      *  signatureAlgorithm   AlgorithmIdentifier,
1279      *  signatureValue       BIT STRING
1280      */
1281     if( ( ret = mbedtls_x509_get_alg( &p, end, &sig_oid2, &sig_params2 ) ) != 0 )
1282     {
1283         mbedtls_x509_crt_free( crt );
1284         return( ret );
1285     }
1286 
1287     if( crt->sig_oid.len != sig_oid2.len ||
1288         memcmp( crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len ) != 0 ||
1289         sig_params1.len != sig_params2.len ||
1290         ( sig_params1.len != 0 &&
1291           memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
1292     {
1293         mbedtls_x509_crt_free( crt );
1294         return( MBEDTLS_ERR_X509_SIG_MISMATCH );
1295     }
1296 
1297     if( ( ret = mbedtls_x509_get_sig( &p, end, &crt->sig ) ) != 0 )
1298     {
1299         mbedtls_x509_crt_free( crt );
1300         return( ret );
1301     }
1302 
1303     if( p != end )
1304     {
1305         mbedtls_x509_crt_free( crt );
1306         return( MBEDTLS_ERR_X509_INVALID_FORMAT +
1307                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1308     }
1309 
1310     return( 0 );
1311 }
1312 
1313 /*
1314  * Parse one X.509 certificate in DER format from a buffer and add them to a
1315  * chained list
1316  */
1317 static int mbedtls_x509_crt_parse_der_internal( mbedtls_x509_crt *chain,
1318                                                 const unsigned char *buf,
1319                                                 size_t buflen,
1320                                                 int make_copy )
1321 {
1322     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1323     mbedtls_x509_crt *crt = chain, *prev = NULL;
1324 
1325     /*
1326      * Check for valid input
1327      */
1328     if( crt == NULL || buf == NULL )
1329         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1330 
1331     while( crt->version != 0 && crt->next != NULL )
1332     {
1333         prev = crt;
1334         crt = crt->next;
1335     }
1336 
1337     /*
1338      * Add new certificate on the end of the chain if needed.
1339      */
1340     if( crt->version != 0 && crt->next == NULL )
1341     {
1342         crt->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) );
1343 
1344         if( crt->next == NULL )
1345             return( MBEDTLS_ERR_X509_ALLOC_FAILED );
1346 
1347         prev = crt;
1348         mbedtls_x509_crt_init( crt->next );
1349         crt = crt->next;
1350     }
1351 
1352     if( ( ret = x509_crt_parse_der_core( crt, buf, buflen, make_copy ) ) != 0 )
1353     {
1354         if( prev )
1355             prev->next = NULL;
1356 
1357         if( crt != chain )
1358             mbedtls_free( crt );
1359 
1360         return( ret );
1361     }
1362 
1363     return( 0 );
1364 }
1365 
1366 int mbedtls_x509_crt_parse_der_nocopy( mbedtls_x509_crt *chain,
1367                                        const unsigned char *buf,
1368                                        size_t buflen )
1369 {
1370     return( mbedtls_x509_crt_parse_der_internal( chain, buf, buflen, 0 ) );
1371 }
1372 
1373 int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain,
1374                                 const unsigned char *buf,
1375                                 size_t buflen )
1376 {
1377     return( mbedtls_x509_crt_parse_der_internal( chain, buf, buflen, 1 ) );
1378 }
1379 
1380 /*
1381  * Parse one or more PEM certificates from a buffer and add them to the chained
1382  * list
1383  */
1384 int mbedtls_x509_crt_parse( mbedtls_x509_crt *chain,
1385                             const unsigned char *buf,
1386                             size_t buflen )
1387 {
1388 #if defined(MBEDTLS_PEM_PARSE_C)
1389     int success = 0, first_error = 0, total_failed = 0;
1390     int buf_format = MBEDTLS_X509_FORMAT_DER;
1391 #endif
1392 
1393     /*
1394      * Check for valid input
1395      */
1396     if( chain == NULL || buf == NULL )
1397         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1398 
1399     /*
1400      * Determine buffer content. Buffer contains either one DER certificate or
1401      * one or more PEM certificates.
1402      */
1403 #if defined(MBEDTLS_PEM_PARSE_C)
1404     if( buflen != 0 && buf[buflen - 1] == '\0' &&
1405         strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
1406     {
1407         buf_format = MBEDTLS_X509_FORMAT_PEM;
1408     }
1409 
1410     if( buf_format == MBEDTLS_X509_FORMAT_DER )
1411         return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1412 #else
1413     return mbedtls_x509_crt_parse_der( chain, buf, buflen );
1414 #endif
1415 
1416 #if defined(MBEDTLS_PEM_PARSE_C)
1417     if( buf_format == MBEDTLS_X509_FORMAT_PEM )
1418     {
1419         int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1420         mbedtls_pem_context pem;
1421 
1422         /* 1 rather than 0 since the terminating NULL byte is counted in */
1423         while( buflen > 1 )
1424         {
1425             size_t use_len;
1426             mbedtls_pem_init( &pem );
1427 
1428             /* If we get there, we know the string is null-terminated */
1429             ret = mbedtls_pem_read_buffer( &pem,
1430                            "-----BEGIN CERTIFICATE-----",
1431                            "-----END CERTIFICATE-----",
1432                            buf, NULL, 0, &use_len );
1433 
1434             if( ret == 0 )
1435             {
1436                 /*
1437                  * Was PEM encoded
1438                  */
1439                 buflen -= use_len;
1440                 buf += use_len;
1441             }
1442             else if( ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA )
1443             {
1444                 return( ret );
1445             }
1446             else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
1447             {
1448                 mbedtls_pem_free( &pem );
1449 
1450                 /*
1451                  * PEM header and footer were found
1452                  */
1453                 buflen -= use_len;
1454                 buf += use_len;
1455 
1456                 if( first_error == 0 )
1457                     first_error = ret;
1458 
1459                 total_failed++;
1460                 continue;
1461             }
1462             else
1463                 break;
1464 
1465             ret = mbedtls_x509_crt_parse_der( chain, pem.buf, pem.buflen );
1466 
1467             mbedtls_pem_free( &pem );
1468 
1469             if( ret != 0 )
1470             {
1471                 /*
1472                  * Quit parsing on a memory error
1473                  */
1474                 if( ret == MBEDTLS_ERR_X509_ALLOC_FAILED )
1475                     return( ret );
1476 
1477                 if( first_error == 0 )
1478                     first_error = ret;
1479 
1480                 total_failed++;
1481                 continue;
1482             }
1483 
1484             success = 1;
1485         }
1486     }
1487 
1488     if( success )
1489         return( total_failed );
1490     else if( first_error )
1491         return( first_error );
1492     else
1493         return( MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT );
1494 #endif /* MBEDTLS_PEM_PARSE_C */
1495 }
1496 
1497 #if defined(MBEDTLS_FS_IO)
1498 /*
1499  * Load one or more certificates and add them to the chained list
1500  */
1501 int mbedtls_x509_crt_parse_file( mbedtls_x509_crt *chain, const char *path )
1502 {
1503     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1504     size_t n;
1505     unsigned char *buf;
1506 
1507     if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
1508         return( ret );
1509 
1510     ret = mbedtls_x509_crt_parse( chain, buf, n );
1511 
1512     mbedtls_platform_zeroize( buf, n );
1513     mbedtls_free( buf );
1514 
1515     return( ret );
1516 }
1517 
1518 int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
1519 {
1520     int ret = 0;
1521 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
1522     int w_ret;
1523     WCHAR szDir[MAX_PATH];
1524     char filename[MAX_PATH];
1525     char *p;
1526     size_t len = strlen( path );
1527 
1528     WIN32_FIND_DATAW file_data;
1529     HANDLE hFind;
1530 
1531     if( len > MAX_PATH - 3 )
1532         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1533 
1534     memset( szDir, 0, sizeof(szDir) );
1535     memset( filename, 0, MAX_PATH );
1536     memcpy( filename, path, len );
1537     filename[len++] = '\\';
1538     p = filename + len;
1539     filename[len++] = '*';
1540 
1541     w_ret = MultiByteToWideChar( CP_ACP, 0, filename, (int)len, szDir,
1542                                  MAX_PATH - 3 );
1543     if( w_ret == 0 )
1544         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1545 
1546     hFind = FindFirstFileW( szDir, &file_data );
1547     if( hFind == INVALID_HANDLE_VALUE )
1548         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1549 
1550     len = MAX_PATH - len;
1551     do
1552     {
1553         memset( p, 0, len );
1554 
1555         if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
1556             continue;
1557 
1558         w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
1559                                      lstrlenW( file_data.cFileName ),
1560                                      p, (int) len - 1,
1561                                      NULL, NULL );
1562         if( w_ret == 0 )
1563         {
1564             ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1565             goto cleanup;
1566         }
1567 
1568         w_ret = mbedtls_x509_crt_parse_file( chain, filename );
1569         if( w_ret < 0 )
1570             ret++;
1571         else
1572             ret += w_ret;
1573     }
1574     while( FindNextFileW( hFind, &file_data ) != 0 );
1575 
1576     if( GetLastError() != ERROR_NO_MORE_FILES )
1577         ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1578 
1579 cleanup:
1580     FindClose( hFind );
1581 #else /* _WIN32 */
1582     int t_ret;
1583     int snp_ret;
1584     struct stat sb;
1585     struct dirent *entry;
1586     char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
1587     DIR *dir = opendir( path );
1588 
1589     if( dir == NULL )
1590         return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
1591 
1592 #if defined(MBEDTLS_THREADING_C)
1593     if( ( ret = mbedtls_mutex_lock( &mbedtls_threading_readdir_mutex ) ) != 0 )
1594     {
1595         closedir( dir );
1596         return( ret );
1597     }
1598 #endif /* MBEDTLS_THREADING_C */
1599 
1600     while( ( entry = readdir( dir ) ) != NULL )
1601     {
1602         snp_ret = mbedtls_snprintf( entry_name, sizeof entry_name,
1603                                     "%s/%s", path, entry->d_name );
1604 
1605         if( snp_ret < 0 || (size_t)snp_ret >= sizeof entry_name )
1606         {
1607             ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
1608             goto cleanup;
1609         }
1610         else if( stat( entry_name, &sb ) == -1 )
1611         {
1612             ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1613             goto cleanup;
1614         }
1615 
1616         if( !S_ISREG( sb.st_mode ) )
1617             continue;
1618 
1619         // Ignore parse errors
1620         //
1621         t_ret = mbedtls_x509_crt_parse_file( chain, entry_name );
1622         if( t_ret < 0 )
1623             ret++;
1624         else
1625             ret += t_ret;
1626     }
1627 
1628 cleanup:
1629     closedir( dir );
1630 
1631 #if defined(MBEDTLS_THREADING_C)
1632     if( mbedtls_mutex_unlock( &mbedtls_threading_readdir_mutex ) != 0 )
1633         ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1634 #endif /* MBEDTLS_THREADING_C */
1635 
1636 #endif /* _WIN32 */
1637 
1638     return( ret );
1639 }
1640 #endif /* MBEDTLS_FS_IO */
1641 
1642 /*
1643  * OtherName ::= SEQUENCE {
1644  *      type-id    OBJECT IDENTIFIER,
1645  *      value      [0] EXPLICIT ANY DEFINED BY type-id }
1646  *
1647  * HardwareModuleName ::= SEQUENCE {
1648  *                           hwType OBJECT IDENTIFIER,
1649  *                           hwSerialNum OCTET STRING }
1650  *
1651  * NOTE: we currently only parse and use otherName of type HwModuleName,
1652  * as defined in RFC 4108.
1653  */
1654 static int x509_get_other_name( const mbedtls_x509_buf *subject_alt_name,
1655                                 mbedtls_x509_san_other_name *other_name )
1656 {
1657     int ret = 0;
1658     size_t len;
1659     unsigned char *p = subject_alt_name->p;
1660     const unsigned char *end = p + subject_alt_name->len;
1661     mbedtls_x509_buf cur_oid;
1662 
1663     if( ( subject_alt_name->tag &
1664         ( MBEDTLS_ASN1_TAG_CLASS_MASK | MBEDTLS_ASN1_TAG_VALUE_MASK ) ) !=
1665         ( MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_OTHER_NAME ) )
1666     {
1667         /*
1668          * The given subject alternative name is not of type "othername".
1669          */
1670         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
1671     }
1672 
1673     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1674                                       MBEDTLS_ASN1_OID ) ) != 0 )
1675         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
1676 
1677     cur_oid.tag = MBEDTLS_ASN1_OID;
1678     cur_oid.p = p;
1679     cur_oid.len = len;
1680 
1681     /*
1682      * Only HwModuleName is currently supported.
1683      */
1684     if( MBEDTLS_OID_CMP( MBEDTLS_OID_ON_HW_MODULE_NAME, &cur_oid ) != 0 )
1685     {
1686         return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
1687     }
1688 
1689     if( p + len >= end )
1690     {
1691         mbedtls_platform_zeroize( other_name, sizeof( *other_name ) );
1692         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
1693                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1694     }
1695     p += len;
1696     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1697             MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 )
1698         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
1699 
1700     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1701                      MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
1702        return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
1703 
1704     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OID ) ) != 0 )
1705         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
1706 
1707     other_name->value.hardware_module_name.oid.tag = MBEDTLS_ASN1_OID;
1708     other_name->value.hardware_module_name.oid.p = p;
1709     other_name->value.hardware_module_name.oid.len = len;
1710 
1711     if( p + len >= end )
1712     {
1713         mbedtls_platform_zeroize( other_name, sizeof( *other_name ) );
1714         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
1715                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1716     }
1717     p += len;
1718     if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
1719                                       MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
1720         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
1721 
1722     other_name->value.hardware_module_name.val.tag = MBEDTLS_ASN1_OCTET_STRING;
1723     other_name->value.hardware_module_name.val.p = p;
1724     other_name->value.hardware_module_name.val.len = len;
1725     p += len;
1726     if( p != end )
1727     {
1728         mbedtls_platform_zeroize( other_name,
1729                                   sizeof( *other_name ) );
1730         return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
1731                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
1732     }
1733     return( 0 );
1734 }
1735 
1736 static int x509_info_subject_alt_name( char **buf, size_t *size,
1737                                        const mbedtls_x509_sequence
1738                                                     *subject_alt_name,
1739                                        const char *prefix )
1740 {
1741     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1742     size_t n = *size;
1743     char *p = *buf;
1744     const mbedtls_x509_sequence *cur = subject_alt_name;
1745     mbedtls_x509_subject_alternative_name san;
1746     int parse_ret;
1747 
1748     while( cur != NULL )
1749     {
1750         memset( &san, 0, sizeof( san ) );
1751         parse_ret = mbedtls_x509_parse_subject_alt_name( &cur->buf, &san );
1752         if( parse_ret != 0 )
1753         {
1754             if( parse_ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE )
1755             {
1756                 ret = mbedtls_snprintf( p, n, "\n%s    <unsupported>", prefix );
1757                 MBEDTLS_X509_SAFE_SNPRINTF;
1758             }
1759             else
1760             {
1761                 ret = mbedtls_snprintf( p, n, "\n%s    <malformed>", prefix );
1762                 MBEDTLS_X509_SAFE_SNPRINTF;
1763             }
1764             cur = cur->next;
1765             continue;
1766         }
1767 
1768         switch( san.type )
1769         {
1770             /*
1771              * otherName
1772              */
1773             case MBEDTLS_X509_SAN_OTHER_NAME:
1774             {
1775                 mbedtls_x509_san_other_name *other_name = &san.san.other_name;
1776 
1777                 ret = mbedtls_snprintf( p, n, "\n%s    otherName :", prefix );
1778                 MBEDTLS_X509_SAFE_SNPRINTF;
1779 
1780                 if( MBEDTLS_OID_CMP( MBEDTLS_OID_ON_HW_MODULE_NAME,
1781                                      &other_name->value.hardware_module_name.oid ) != 0 )
1782                 {
1783                     ret = mbedtls_snprintf( p, n, "\n%s        hardware module name :", prefix );
1784                     MBEDTLS_X509_SAFE_SNPRINTF;
1785                     ret = mbedtls_snprintf( p, n, "\n%s            hardware type          : ", prefix );
1786                     MBEDTLS_X509_SAFE_SNPRINTF;
1787 
1788                     ret = mbedtls_oid_get_numeric_string( p, n, &other_name->value.hardware_module_name.oid );
1789                     MBEDTLS_X509_SAFE_SNPRINTF;
1790 
1791                     ret = mbedtls_snprintf( p, n, "\n%s            hardware serial number : ", prefix );
1792                     MBEDTLS_X509_SAFE_SNPRINTF;
1793 
1794                     if( other_name->value.hardware_module_name.val.len >= n )
1795                     {
1796                         *p = '\0';
1797                         return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
1798                     }
1799 
1800                     memcpy( p, other_name->value.hardware_module_name.val.p,
1801                             other_name->value.hardware_module_name.val.len );
1802                     p += other_name->value.hardware_module_name.val.len;
1803 
1804                     n -= other_name->value.hardware_module_name.val.len;
1805 
1806                 }/* MBEDTLS_OID_ON_HW_MODULE_NAME */
1807             }
1808             break;
1809 
1810             /*
1811              * dNSName
1812              */
1813             case MBEDTLS_X509_SAN_DNS_NAME:
1814             {
1815                 ret = mbedtls_snprintf( p, n, "\n%s    dNSName : ", prefix );
1816                 MBEDTLS_X509_SAFE_SNPRINTF;
1817                 if( san.san.unstructured_name.len >= n )
1818                 {
1819                     *p = '\0';
1820                     return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
1821                 }
1822 
1823                 memcpy( p, san.san.unstructured_name.p, san.san.unstructured_name.len );
1824                 p += san.san.unstructured_name.len;
1825                 n -= san.san.unstructured_name.len;
1826             }
1827             break;
1828 
1829             /*
1830              * Type not supported, skip item.
1831              */
1832             default:
1833                 ret = mbedtls_snprintf( p, n, "\n%s    <unsupported>", prefix );
1834                 MBEDTLS_X509_SAFE_SNPRINTF;
1835                 break;
1836         }
1837 
1838         cur = cur->next;
1839     }
1840 
1841     *p = '\0';
1842 
1843     *size = n;
1844     *buf = p;
1845 
1846     return( 0 );
1847 }
1848 
1849 int mbedtls_x509_parse_subject_alt_name( const mbedtls_x509_buf *san_buf,
1850                                          mbedtls_x509_subject_alternative_name *san )
1851 {
1852     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1853     switch( san_buf->tag &
1854             ( MBEDTLS_ASN1_TAG_CLASS_MASK |
1855               MBEDTLS_ASN1_TAG_VALUE_MASK ) )
1856     {
1857         /*
1858          * otherName
1859          */
1860         case( MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_OTHER_NAME ):
1861         {
1862             mbedtls_x509_san_other_name other_name;
1863 
1864             ret = x509_get_other_name( san_buf, &other_name );
1865             if( ret != 0 )
1866                 return( ret );
1867 
1868             memset( san, 0, sizeof( mbedtls_x509_subject_alternative_name ) );
1869             san->type = MBEDTLS_X509_SAN_OTHER_NAME;
1870             memcpy( &san->san.other_name,
1871                     &other_name, sizeof( other_name ) );
1872 
1873         }
1874         break;
1875 
1876         /*
1877          * dNSName
1878          */
1879         case( MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_DNS_NAME ):
1880         {
1881             memset( san, 0, sizeof( mbedtls_x509_subject_alternative_name ) );
1882             san->type = MBEDTLS_X509_SAN_DNS_NAME;
1883 
1884             memcpy( &san->san.unstructured_name,
1885                     san_buf, sizeof( *san_buf ) );
1886 
1887         }
1888         break;
1889 
1890         /*
1891          * Type not supported
1892          */
1893         default:
1894             return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
1895     }
1896     return( 0 );
1897 }
1898 
1899 #define PRINT_ITEM(i)                           \
1900     {                                           \
1901         ret = mbedtls_snprintf( p, n, "%s" i, sep );    \
1902         MBEDTLS_X509_SAFE_SNPRINTF;                        \
1903         sep = ", ";                             \
1904     }
1905 
1906 #define CERT_TYPE(type,name)                    \
1907     if( ns_cert_type & (type) )                 \
1908         PRINT_ITEM( name );
1909 
1910 static int x509_info_cert_type( char **buf, size_t *size,
1911                                 unsigned char ns_cert_type )
1912 {
1913     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1914     size_t n = *size;
1915     char *p = *buf;
1916     const char *sep = "";
1917 
1918     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT,         "SSL Client" );
1919     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER,         "SSL Server" );
1920     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL,              "Email" );
1921     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING,     "Object Signing" );
1922     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED,           "Reserved" );
1923     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA,             "SSL CA" );
1924     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA,           "Email CA" );
1925     CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA,  "Object Signing CA" );
1926 
1927     *size = n;
1928     *buf = p;
1929 
1930     return( 0 );
1931 }
1932 
1933 #define KEY_USAGE(code,name)    \
1934     if( key_usage & (code) )    \
1935         PRINT_ITEM( name );
1936 
1937 static int x509_info_key_usage( char **buf, size_t *size,
1938                                 unsigned int key_usage )
1939 {
1940     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1941     size_t n = *size;
1942     char *p = *buf;
1943     const char *sep = "";
1944 
1945     KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE,    "Digital Signature" );
1946     KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION,      "Non Repudiation" );
1947     KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT,     "Key Encipherment" );
1948     KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT,    "Data Encipherment" );
1949     KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT,        "Key Agreement" );
1950     KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN,        "Key Cert Sign" );
1951     KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN,             "CRL Sign" );
1952     KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY,        "Encipher Only" );
1953     KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY,        "Decipher Only" );
1954 
1955     *size = n;
1956     *buf = p;
1957 
1958     return( 0 );
1959 }
1960 
1961 static int x509_info_ext_key_usage( char **buf, size_t *size,
1962                                     const mbedtls_x509_sequence *extended_key_usage )
1963 {
1964     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1965     const char *desc;
1966     size_t n = *size;
1967     char *p = *buf;
1968     const mbedtls_x509_sequence *cur = extended_key_usage;
1969     const char *sep = "";
1970 
1971     while( cur != NULL )
1972     {
1973         if( mbedtls_oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
1974             desc = "???";
1975 
1976         ret = mbedtls_snprintf( p, n, "%s%s", sep, desc );
1977         MBEDTLS_X509_SAFE_SNPRINTF;
1978 
1979         sep = ", ";
1980 
1981         cur = cur->next;
1982     }
1983 
1984     *size = n;
1985     *buf = p;
1986 
1987     return( 0 );
1988 }
1989 
1990 static int x509_info_cert_policies( char **buf, size_t *size,
1991                                     const mbedtls_x509_sequence *certificate_policies )
1992 {
1993     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1994     const char *desc;
1995     size_t n = *size;
1996     char *p = *buf;
1997     const mbedtls_x509_sequence *cur = certificate_policies;
1998     const char *sep = "";
1999 
2000     while( cur != NULL )
2001     {
2002         if( mbedtls_oid_get_certificate_policies( &cur->buf, &desc ) != 0 )
2003             desc = "???";
2004 
2005         ret = mbedtls_snprintf( p, n, "%s%s", sep, desc );
2006         MBEDTLS_X509_SAFE_SNPRINTF;
2007 
2008         sep = ", ";
2009 
2010         cur = cur->next;
2011     }
2012 
2013     *size = n;
2014     *buf = p;
2015 
2016     return( 0 );
2017 }
2018 
2019 /*
2020  * Return an informational string about the certificate.
2021  */
2022 #define BEFORE_COLON    18
2023 #define BC              "18"
2024 int mbedtls_x509_crt_info( char *buf, size_t size, const char *prefix,
2025                    const mbedtls_x509_crt *crt )
2026 {
2027     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2028     size_t n;
2029     char *p;
2030     char key_size_str[BEFORE_COLON];
2031 
2032     p = buf;
2033     n = size;
2034 
2035     if( NULL == crt )
2036     {
2037         ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" );
2038         MBEDTLS_X509_SAFE_SNPRINTF;
2039 
2040         return( (int) ( size - n ) );
2041     }
2042 
2043     ret = mbedtls_snprintf( p, n, "%scert. version     : %d\n",
2044                                prefix, crt->version );
2045     MBEDTLS_X509_SAFE_SNPRINTF;
2046     ret = mbedtls_snprintf( p, n, "%sserial number     : ",
2047                                prefix );
2048     MBEDTLS_X509_SAFE_SNPRINTF;
2049 
2050     ret = mbedtls_x509_serial_gets( p, n, &crt->serial );
2051     MBEDTLS_X509_SAFE_SNPRINTF;
2052 
2053     ret = mbedtls_snprintf( p, n, "\n%sissuer name       : ", prefix );
2054     MBEDTLS_X509_SAFE_SNPRINTF;
2055     ret = mbedtls_x509_dn_gets( p, n, &crt->issuer  );
2056     MBEDTLS_X509_SAFE_SNPRINTF;
2057 
2058     ret = mbedtls_snprintf( p, n, "\n%ssubject name      : ", prefix );
2059     MBEDTLS_X509_SAFE_SNPRINTF;
2060     ret = mbedtls_x509_dn_gets( p, n, &crt->subject );
2061     MBEDTLS_X509_SAFE_SNPRINTF;
2062 
2063     ret = mbedtls_snprintf( p, n, "\n%sissued  on        : " \
2064                    "%04d-%02d-%02d %02d:%02d:%02d", prefix,
2065                    crt->valid_from.year, crt->valid_from.mon,
2066                    crt->valid_from.day,  crt->valid_from.hour,
2067                    crt->valid_from.min,  crt->valid_from.sec );
2068     MBEDTLS_X509_SAFE_SNPRINTF;
2069 
2070     ret = mbedtls_snprintf( p, n, "\n%sexpires on        : " \
2071                    "%04d-%02d-%02d %02d:%02d:%02d", prefix,
2072                    crt->valid_to.year, crt->valid_to.mon,
2073                    crt->valid_to.day,  crt->valid_to.hour,
2074                    crt->valid_to.min,  crt->valid_to.sec );
2075     MBEDTLS_X509_SAFE_SNPRINTF;
2076 
2077     ret = mbedtls_snprintf( p, n, "\n%ssigned using      : ", prefix );
2078     MBEDTLS_X509_SAFE_SNPRINTF;
2079 
2080     ret = mbedtls_x509_sig_alg_gets( p, n, &crt->sig_oid, crt->sig_pk,
2081                              crt->sig_md, crt->sig_opts );
2082     MBEDTLS_X509_SAFE_SNPRINTF;
2083 
2084     /* Key size */
2085     if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON,
2086                                       mbedtls_pk_get_name( &crt->pk ) ) ) != 0 )
2087     {
2088         return( ret );
2089     }
2090 
2091     ret = mbedtls_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
2092                           (int) mbedtls_pk_get_bitlen( &crt->pk ) );
2093     MBEDTLS_X509_SAFE_SNPRINTF;
2094 
2095     /*
2096      * Optional extensions
2097      */
2098 
2099     if( crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS )
2100     {
2101         ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
2102                         crt->ca_istrue ? "true" : "false" );
2103         MBEDTLS_X509_SAFE_SNPRINTF;
2104 
2105         if( crt->max_pathlen > 0 )
2106         {
2107             ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
2108             MBEDTLS_X509_SAFE_SNPRINTF;
2109         }
2110     }
2111 
2112     if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
2113     {
2114         ret = mbedtls_snprintf( p, n, "\n%ssubject alt name  :", prefix );
2115         MBEDTLS_X509_SAFE_SNPRINTF;
2116 
2117         if( ( ret = x509_info_subject_alt_name( &p, &n,
2118                                                 &crt->subject_alt_names,
2119                                                 prefix ) ) != 0 )
2120             return( ret );
2121     }
2122 
2123     if( crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE )
2124     {
2125         ret = mbedtls_snprintf( p, n, "\n%scert. type        : ", prefix );
2126         MBEDTLS_X509_SAFE_SNPRINTF;
2127 
2128         if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
2129             return( ret );
2130     }
2131 
2132     if( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE )
2133     {
2134         ret = mbedtls_snprintf( p, n, "\n%skey usage         : ", prefix );
2135         MBEDTLS_X509_SAFE_SNPRINTF;
2136 
2137         if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
2138             return( ret );
2139     }
2140 
2141     if( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE )
2142     {
2143         ret = mbedtls_snprintf( p, n, "\n%sext key usage     : ", prefix );
2144         MBEDTLS_X509_SAFE_SNPRINTF;
2145 
2146         if( ( ret = x509_info_ext_key_usage( &p, &n,
2147                                              &crt->ext_key_usage ) ) != 0 )
2148             return( ret );
2149     }
2150 
2151     if( crt->ext_types & MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES )
2152     {
2153         ret = mbedtls_snprintf( p, n, "\n%scertificate policies : ", prefix );
2154         MBEDTLS_X509_SAFE_SNPRINTF;
2155 
2156         if( ( ret = x509_info_cert_policies( &p, &n,
2157                                              &crt->certificate_policies ) ) != 0 )
2158             return( ret );
2159     }
2160 
2161     ret = mbedtls_snprintf( p, n, "\n" );
2162     MBEDTLS_X509_SAFE_SNPRINTF;
2163 
2164     return( (int) ( size - n ) );
2165 }
2166 
2167 struct x509_crt_verify_string {
2168     int code;
2169     const char *string;
2170 };
2171 
2172 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
2173     { MBEDTLS_X509_BADCERT_EXPIRED,       "The certificate validity has expired" },
2174     { MBEDTLS_X509_BADCERT_REVOKED,       "The certificate has been revoked (is on a CRL)" },
2175     { MBEDTLS_X509_BADCERT_CN_MISMATCH,   "The certificate Common Name (CN) does not match with the expected CN" },
2176     { MBEDTLS_X509_BADCERT_NOT_TRUSTED,   "The certificate is not correctly signed by the trusted CA" },
2177     { MBEDTLS_X509_BADCRL_NOT_TRUSTED,    "The CRL is not correctly signed by the trusted CA" },
2178     { MBEDTLS_X509_BADCRL_EXPIRED,        "The CRL is expired" },
2179     { MBEDTLS_X509_BADCERT_MISSING,       "Certificate was missing" },
2180     { MBEDTLS_X509_BADCERT_SKIP_VERIFY,   "Certificate verification was skipped" },
2181     { MBEDTLS_X509_BADCERT_OTHER,         "Other reason (can be used by verify callback)" },
2182     { MBEDTLS_X509_BADCERT_FUTURE,        "The certificate validity starts in the future" },
2183     { MBEDTLS_X509_BADCRL_FUTURE,         "The CRL is from the future" },
2184     { MBEDTLS_X509_BADCERT_KEY_USAGE,     "Usage does not match the keyUsage extension" },
2185     { MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
2186     { MBEDTLS_X509_BADCERT_NS_CERT_TYPE,  "Usage does not match the nsCertType extension" },
2187     { MBEDTLS_X509_BADCERT_BAD_MD,        "The certificate is signed with an unacceptable hash." },
2188     { MBEDTLS_X509_BADCERT_BAD_PK,        "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
2189     { MBEDTLS_X509_BADCERT_BAD_KEY,       "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
2190     { MBEDTLS_X509_BADCRL_BAD_MD,         "The CRL is signed with an unacceptable hash." },
2191     { MBEDTLS_X509_BADCRL_BAD_PK,         "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
2192     { MBEDTLS_X509_BADCRL_BAD_KEY,        "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
2193     { 0, NULL }
2194 };
2195 
2196 int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
2197                           uint32_t flags )
2198 {
2199     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2200     const struct x509_crt_verify_string *cur;
2201     char *p = buf;
2202     size_t n = size;
2203 
2204     for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
2205     {
2206         if( ( flags & cur->code ) == 0 )
2207             continue;
2208 
2209         ret = mbedtls_snprintf( p, n, "%s%s\n", prefix, cur->string );
2210         MBEDTLS_X509_SAFE_SNPRINTF;
2211         flags ^= cur->code;
2212     }
2213 
2214     if( flags != 0 )
2215     {
2216         ret = mbedtls_snprintf( p, n, "%sUnknown reason "
2217                                        "(this should not happen)\n", prefix );
2218         MBEDTLS_X509_SAFE_SNPRINTF;
2219     }
2220 
2221     return( (int) ( size - n ) );
2222 }
2223 
2224 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
2225 int mbedtls_x509_crt_check_key_usage( const mbedtls_x509_crt *crt,
2226                                       unsigned int usage )
2227 {
2228     unsigned int usage_must, usage_may;
2229     unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
2230                           | MBEDTLS_X509_KU_DECIPHER_ONLY;
2231 
2232     if( ( crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE ) == 0 )
2233         return( 0 );
2234 
2235     usage_must = usage & ~may_mask;
2236 
2237     if( ( ( crt->key_usage & ~may_mask ) & usage_must ) != usage_must )
2238         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
2239 
2240     usage_may = usage & may_mask;
2241 
2242     if( ( ( crt->key_usage & may_mask ) | usage_may ) != usage_may )
2243         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
2244 
2245     return( 0 );
2246 }
2247 #endif
2248 
2249 #if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
2250 int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
2251                                        const char *usage_oid,
2252                                        size_t usage_len )
2253 {
2254     const mbedtls_x509_sequence *cur;
2255 
2256     /* Extension is not mandatory, absent means no restriction */
2257     if( ( crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 )
2258         return( 0 );
2259 
2260     /*
2261      * Look for the requested usage (or wildcard ANY) in our list
2262      */
2263     for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
2264     {
2265         const mbedtls_x509_buf *cur_oid = &cur->buf;
2266 
2267         if( cur_oid->len == usage_len &&
2268             memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
2269         {
2270             return( 0 );
2271         }
2272 
2273         if( MBEDTLS_OID_CMP( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) == 0 )
2274             return( 0 );
2275     }
2276 
2277     return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
2278 }
2279 #endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
2280 
2281 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2282 /*
2283  * Return 1 if the certificate is revoked, or 0 otherwise.
2284  */
2285 int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl )
2286 {
2287     const mbedtls_x509_crl_entry *cur = &crl->entry;
2288 
2289     while( cur != NULL && cur->serial.len != 0 )
2290     {
2291         if( crt->serial.len == cur->serial.len &&
2292             memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
2293         {
2294             if( mbedtls_x509_time_is_past( &cur->revocation_date ) )
2295                 return( 1 );
2296         }
2297 
2298         cur = cur->next;
2299     }
2300 
2301     return( 0 );
2302 }
2303 
2304 /*
2305  * Check that the given certificate is not revoked according to the CRL.
2306  * Skip validation if no CRL for the given CA is present.
2307  */
2308 static int x509_crt_verifycrl( mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
2309                                mbedtls_x509_crl *crl_list,
2310                                const mbedtls_x509_crt_profile *profile )
2311 {
2312     int flags = 0;
2313     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
2314     const mbedtls_md_info_t *md_info;
2315 
2316     if( ca == NULL )
2317         return( flags );
2318 
2319     while( crl_list != NULL )
2320     {
2321         if( crl_list->version == 0 ||
2322             x509_name_cmp( &crl_list->issuer, &ca->subject ) != 0 )
2323         {
2324             crl_list = crl_list->next;
2325             continue;
2326         }
2327 
2328         /*
2329          * Check if the CA is configured to sign CRLs
2330          */
2331 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
2332         if( mbedtls_x509_crt_check_key_usage( ca,
2333                                               MBEDTLS_X509_KU_CRL_SIGN ) != 0 )
2334         {
2335             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
2336             break;
2337         }
2338 #endif
2339 
2340         /*
2341          * Check if CRL is correctly signed by the trusted CA
2342          */
2343         if( x509_profile_check_md_alg( profile, crl_list->sig_md ) != 0 )
2344             flags |= MBEDTLS_X509_BADCRL_BAD_MD;
2345 
2346         if( x509_profile_check_pk_alg( profile, crl_list->sig_pk ) != 0 )
2347             flags |= MBEDTLS_X509_BADCRL_BAD_PK;
2348 
2349         md_info = mbedtls_md_info_from_type( crl_list->sig_md );
2350         if( mbedtls_md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash ) != 0 )
2351         {
2352             /* Note: this can't happen except after an internal error */
2353             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
2354             break;
2355         }
2356 
2357         if( x509_profile_check_key( profile, &ca->pk ) != 0 )
2358             flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2359 
2360         if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
2361                            crl_list->sig_md, hash, mbedtls_md_get_size( md_info ),
2362                            crl_list->sig.p, crl_list->sig.len ) != 0 )
2363         {
2364             flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
2365             break;
2366         }
2367 
2368         /*
2369          * Check for validity of CRL (Do not drop out)
2370          */
2371         if( mbedtls_x509_time_is_past( &crl_list->next_update ) )
2372             flags |= MBEDTLS_X509_BADCRL_EXPIRED;
2373 
2374         if( mbedtls_x509_time_is_future( &crl_list->this_update ) )
2375             flags |= MBEDTLS_X509_BADCRL_FUTURE;
2376 
2377         /*
2378          * Check if certificate is revoked
2379          */
2380         if( mbedtls_x509_crt_is_revoked( crt, crl_list ) )
2381         {
2382             flags |= MBEDTLS_X509_BADCERT_REVOKED;
2383             break;
2384         }
2385 
2386         crl_list = crl_list->next;
2387     }
2388 
2389     return( flags );
2390 }
2391 #endif /* MBEDTLS_X509_CRL_PARSE_C */
2392 
2393 /*
2394  * Check the signature of a certificate by its parent
2395  */
2396 static int x509_crt_check_signature( const mbedtls_x509_crt *child,
2397                                      mbedtls_x509_crt *parent,
2398                                      mbedtls_x509_crt_restart_ctx *rs_ctx )
2399 {
2400     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
2401     size_t hash_len;
2402 #if !defined(MBEDTLS_USE_PSA_CRYPTO)
2403     const mbedtls_md_info_t *md_info;
2404     md_info = mbedtls_md_info_from_type( child->sig_md );
2405     hash_len = mbedtls_md_get_size( md_info );
2406 
2407     /* Note: hash errors can happen only after an internal error */
2408     if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
2409         return( -1 );
2410 #else
2411     psa_hash_operation_t hash_operation = PSA_HASH_OPERATION_INIT;
2412     psa_algorithm_t hash_alg = mbedtls_psa_translate_md( child->sig_md );
2413 
2414     if( psa_hash_setup( &hash_operation, hash_alg ) != PSA_SUCCESS )
2415         return( -1 );
2416 
2417     if( psa_hash_update( &hash_operation, child->tbs.p, child->tbs.len )
2418         != PSA_SUCCESS )
2419     {
2420         return( -1 );
2421     }
2422 
2423     if( psa_hash_finish( &hash_operation, hash, sizeof( hash ), &hash_len )
2424         != PSA_SUCCESS )
2425     {
2426         return( -1 );
2427     }
2428 #endif /* MBEDTLS_USE_PSA_CRYPTO */
2429     /* Skip expensive computation on obvious mismatch */
2430     if( ! mbedtls_pk_can_do( &parent->pk, child->sig_pk ) )
2431         return( -1 );
2432 
2433 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2434     if( rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA )
2435     {
2436         return( mbedtls_pk_verify_restartable( &parent->pk,
2437                     child->sig_md, hash, hash_len,
2438                     child->sig.p, child->sig.len, &rs_ctx->pk ) );
2439     }
2440 #else
2441     (void) rs_ctx;
2442 #endif
2443 
2444     return( mbedtls_pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
2445                 child->sig_md, hash, hash_len,
2446                 child->sig.p, child->sig.len ) );
2447 }
2448 
2449 /*
2450  * Check if 'parent' is a suitable parent (signing CA) for 'child'.
2451  * Return 0 if yes, -1 if not.
2452  *
2453  * top means parent is a locally-trusted certificate
2454  */
2455 static int x509_crt_check_parent( const mbedtls_x509_crt *child,
2456                                   const mbedtls_x509_crt *parent,
2457                                   int top )
2458 {
2459     int need_ca_bit;
2460 
2461     /* Parent must be the issuer */
2462     if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
2463         return( -1 );
2464 
2465     /* Parent must have the basicConstraints CA bit set as a general rule */
2466     need_ca_bit = 1;
2467 
2468     /* Exception: v1/v2 certificates that are locally trusted. */
2469     if( top && parent->version < 3 )
2470         need_ca_bit = 0;
2471 
2472     if( need_ca_bit && ! parent->ca_istrue )
2473         return( -1 );
2474 
2475 #if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
2476     if( need_ca_bit &&
2477         mbedtls_x509_crt_check_key_usage( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
2478     {
2479         return( -1 );
2480     }
2481 #endif
2482 
2483     return( 0 );
2484 }
2485 
2486 /*
2487  * Find a suitable parent for child in candidates, or return NULL.
2488  *
2489  * Here suitable is defined as:
2490  *  1. subject name matches child's issuer
2491  *  2. if necessary, the CA bit is set and key usage allows signing certs
2492  *  3. for trusted roots, the signature is correct
2493  *     (for intermediates, the signature is checked and the result reported)
2494  *  4. pathlen constraints are satisfied
2495  *
2496  * If there's a suitable candidate which is also time-valid, return the first
2497  * such. Otherwise, return the first suitable candidate (or NULL if there is
2498  * none).
2499  *
2500  * The rationale for this rule is that someone could have a list of trusted
2501  * roots with two versions on the same root with different validity periods.
2502  * (At least one user reported having such a list and wanted it to just work.)
2503  * The reason we don't just require time-validity is that generally there is
2504  * only one version, and if it's expired we want the flags to state that
2505  * rather than NOT_TRUSTED, as would be the case if we required it here.
2506  *
2507  * The rationale for rule 3 (signature for trusted roots) is that users might
2508  * have two versions of the same CA with different keys in their list, and the
2509  * way we select the correct one is by checking the signature (as we don't
2510  * rely on key identifier extensions). (This is one way users might choose to
2511  * handle key rollover, another relies on self-issued certs, see [SIRO].)
2512  *
2513  * Arguments:
2514  *  - [in] child: certificate for which we're looking for a parent
2515  *  - [in] candidates: chained list of potential parents
2516  *  - [out] r_parent: parent found (or NULL)
2517  *  - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0
2518  *  - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
2519  *         of the chain, 0 otherwise
2520  *  - [in] path_cnt: number of intermediates seen so far
2521  *  - [in] self_cnt: number of self-signed intermediates seen so far
2522  *         (will never be greater than path_cnt)
2523  *  - [in-out] rs_ctx: context for restarting operations
2524  *
2525  * Return value:
2526  *  - 0 on success
2527  *  - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2528  */
2529 static int x509_crt_find_parent_in(
2530                         mbedtls_x509_crt *child,
2531                         mbedtls_x509_crt *candidates,
2532                         mbedtls_x509_crt **r_parent,
2533                         int *r_signature_is_good,
2534                         int top,
2535                         unsigned path_cnt,
2536                         unsigned self_cnt,
2537                         mbedtls_x509_crt_restart_ctx *rs_ctx )
2538 {
2539     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2540     mbedtls_x509_crt *parent, *fallback_parent;
2541     int signature_is_good = 0, fallback_signature_is_good;
2542 
2543 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2544     /* did we have something in progress? */
2545     if( rs_ctx != NULL && rs_ctx->parent != NULL )
2546     {
2547         /* restore saved state */
2548         parent = rs_ctx->parent;
2549         fallback_parent = rs_ctx->fallback_parent;
2550         fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
2551 
2552         /* clear saved state */
2553         rs_ctx->parent = NULL;
2554         rs_ctx->fallback_parent = NULL;
2555         rs_ctx->fallback_signature_is_good = 0;
2556 
2557         /* resume where we left */
2558         goto check_signature;
2559     }
2560 #endif
2561 
2562     fallback_parent = NULL;
2563     fallback_signature_is_good = 0;
2564 
2565     for( parent = candidates; parent != NULL; parent = parent->next )
2566     {
2567         /* basic parenting skills (name, CA bit, key usage) */
2568         if( x509_crt_check_parent( child, parent, top ) != 0 )
2569             continue;
2570 
2571         /* +1 because stored max_pathlen is 1 higher that the actual value */
2572         if( parent->max_pathlen > 0 &&
2573             (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt )
2574         {
2575             continue;
2576         }
2577 
2578         /* Signature */
2579 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2580 check_signature:
2581 #endif
2582         ret = x509_crt_check_signature( child, parent, rs_ctx );
2583 
2584 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2585         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2586         {
2587             /* save state */
2588             rs_ctx->parent = parent;
2589             rs_ctx->fallback_parent = fallback_parent;
2590             rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
2591 
2592             return( ret );
2593         }
2594 #else
2595         (void) ret;
2596 #endif
2597 
2598         signature_is_good = ret == 0;
2599         if( top && ! signature_is_good )
2600             continue;
2601 
2602         /* optional time check */
2603         if( mbedtls_x509_time_is_past( &parent->valid_to ) ||
2604             mbedtls_x509_time_is_future( &parent->valid_from ) )
2605         {
2606             if( fallback_parent == NULL )
2607             {
2608                 fallback_parent = parent;
2609                 fallback_signature_is_good = signature_is_good;
2610             }
2611 
2612             continue;
2613         }
2614 
2615         *r_parent = parent;
2616         *r_signature_is_good = signature_is_good;
2617 
2618         break;
2619     }
2620 
2621     if( parent == NULL )
2622     {
2623         *r_parent = fallback_parent;
2624         *r_signature_is_good = fallback_signature_is_good;
2625     }
2626 
2627     return( 0 );
2628 }
2629 
2630 /*
2631  * Find a parent in trusted CAs or the provided chain, or return NULL.
2632  *
2633  * Searches in trusted CAs first, and return the first suitable parent found
2634  * (see find_parent_in() for definition of suitable).
2635  *
2636  * Arguments:
2637  *  - [in] child: certificate for which we're looking for a parent, followed
2638  *         by a chain of possible intermediates
2639  *  - [in] trust_ca: list of locally trusted certificates
2640  *  - [out] parent: parent found (or NULL)
2641  *  - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0
2642  *  - [out] signature_is_good: 1 if child signature by parent is valid, or 0
2643  *  - [in] path_cnt: number of links in the chain so far (EE -> ... -> child)
2644  *  - [in] self_cnt: number of self-signed certs in the chain so far
2645  *         (will always be no greater than path_cnt)
2646  *  - [in-out] rs_ctx: context for restarting operations
2647  *
2648  * Return value:
2649  *  - 0 on success
2650  *  - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2651  */
2652 static int x509_crt_find_parent(
2653                         mbedtls_x509_crt *child,
2654                         mbedtls_x509_crt *trust_ca,
2655                         mbedtls_x509_crt **parent,
2656                         int *parent_is_trusted,
2657                         int *signature_is_good,
2658                         unsigned path_cnt,
2659                         unsigned self_cnt,
2660                         mbedtls_x509_crt_restart_ctx *rs_ctx )
2661 {
2662     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2663     mbedtls_x509_crt *search_list;
2664 
2665     *parent_is_trusted = 1;
2666 
2667 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2668     /* restore then clear saved state if we have some stored */
2669     if( rs_ctx != NULL && rs_ctx->parent_is_trusted != -1 )
2670     {
2671         *parent_is_trusted = rs_ctx->parent_is_trusted;
2672         rs_ctx->parent_is_trusted = -1;
2673     }
2674 #endif
2675 
2676     while( 1 ) {
2677         search_list = *parent_is_trusted ? trust_ca : child->next;
2678 
2679         ret = x509_crt_find_parent_in( child, search_list,
2680                                        parent, signature_is_good,
2681                                        *parent_is_trusted,
2682                                        path_cnt, self_cnt, rs_ctx );
2683 
2684 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2685         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2686         {
2687             /* save state */
2688             rs_ctx->parent_is_trusted = *parent_is_trusted;
2689             return( ret );
2690         }
2691 #else
2692         (void) ret;
2693 #endif
2694 
2695         /* stop here if found or already in second iteration */
2696         if( *parent != NULL || *parent_is_trusted == 0 )
2697             break;
2698 
2699         /* prepare second iteration */
2700         *parent_is_trusted = 0;
2701     }
2702 
2703     /* extra precaution against mistakes in the caller */
2704     if( *parent == NULL )
2705     {
2706         *parent_is_trusted = 0;
2707         *signature_is_good = 0;
2708     }
2709 
2710     return( 0 );
2711 }
2712 
2713 /*
2714  * Check if an end-entity certificate is locally trusted
2715  *
2716  * Currently we require such certificates to be self-signed (actually only
2717  * check for self-issued as self-signatures are not checked)
2718  */
2719 static int x509_crt_check_ee_locally_trusted(
2720                     mbedtls_x509_crt *crt,
2721                     mbedtls_x509_crt *trust_ca )
2722 {
2723     mbedtls_x509_crt *cur;
2724 
2725     /* must be self-issued */
2726     if( x509_name_cmp( &crt->issuer, &crt->subject ) != 0 )
2727         return( -1 );
2728 
2729     /* look for an exact match with trusted cert */
2730     for( cur = trust_ca; cur != NULL; cur = cur->next )
2731     {
2732         if( crt->raw.len == cur->raw.len &&
2733             memcmp( crt->raw.p, cur->raw.p, crt->raw.len ) == 0 )
2734         {
2735             return( 0 );
2736         }
2737     }
2738 
2739     /* too bad */
2740     return( -1 );
2741 }
2742 
2743 /*
2744  * Build and verify a certificate chain
2745  *
2746  * Given a peer-provided list of certificates EE, C1, ..., Cn and
2747  * a list of trusted certs R1, ... Rp, try to build and verify a chain
2748  *      EE, Ci1, ... Ciq [, Rj]
2749  * such that every cert in the chain is a child of the next one,
2750  * jumping to a trusted root as early as possible.
2751  *
2752  * Verify that chain and return it with flags for all issues found.
2753  *
2754  * Special cases:
2755  * - EE == Rj -> return a one-element list containing it
2756  * - EE, Ci1, ..., Ciq cannot be continued with a trusted root
2757  *   -> return that chain with NOT_TRUSTED set on Ciq
2758  *
2759  * Tests for (aspects of) this function should include at least:
2760  * - trusted EE
2761  * - EE -> trusted root
2762  * - EE -> intermediate CA -> trusted root
2763  * - if relevant: EE untrusted
2764  * - if relevant: EE -> intermediate, untrusted
2765  * with the aspect under test checked at each relevant level (EE, int, root).
2766  * For some aspects longer chains are required, but usually length 2 is
2767  * enough (but length 1 is not in general).
2768  *
2769  * Arguments:
2770  *  - [in] crt: the cert list EE, C1, ..., Cn
2771  *  - [in] trust_ca: the trusted list R1, ..., Rp
2772  *  - [in] ca_crl, profile: as in verify_with_profile()
2773  *  - [out] ver_chain: the built and verified chain
2774  *      Only valid when return value is 0, may contain garbage otherwise!
2775  *      Restart note: need not be the same when calling again to resume.
2776  *  - [in-out] rs_ctx: context for restarting operations
2777  *
2778  * Return value:
2779  *  - non-zero if the chain could not be fully built and examined
2780  *  - 0 is the chain was successfully built and examined,
2781  *      even if it was found to be invalid
2782  */
2783 static int x509_crt_verify_chain(
2784                 mbedtls_x509_crt *crt,
2785                 mbedtls_x509_crt *trust_ca,
2786                 mbedtls_x509_crl *ca_crl,
2787                 mbedtls_x509_crt_ca_cb_t f_ca_cb,
2788                 void *p_ca_cb,
2789                 const mbedtls_x509_crt_profile *profile,
2790                 mbedtls_x509_crt_verify_chain *ver_chain,
2791                 mbedtls_x509_crt_restart_ctx *rs_ctx )
2792 {
2793     /* Don't initialize any of those variables here, so that the compiler can
2794      * catch potential issues with jumping ahead when restarting */
2795     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2796     uint32_t *flags;
2797     mbedtls_x509_crt_verify_chain_item *cur;
2798     mbedtls_x509_crt *child;
2799     mbedtls_x509_crt *parent;
2800     int parent_is_trusted;
2801     int child_is_trusted;
2802     int signature_is_good;
2803     unsigned self_cnt;
2804     mbedtls_x509_crt *cur_trust_ca = NULL;
2805 
2806 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2807     /* resume if we had an operation in progress */
2808     if( rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent )
2809     {
2810         /* restore saved state */
2811         *ver_chain = rs_ctx->ver_chain; /* struct copy */
2812         self_cnt = rs_ctx->self_cnt;
2813 
2814         /* restore derived state */
2815         cur = &ver_chain->items[ver_chain->len - 1];
2816         child = cur->crt;
2817         flags = &cur->flags;
2818 
2819         goto find_parent;
2820     }
2821 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2822 
2823     child = crt;
2824     self_cnt = 0;
2825     parent_is_trusted = 0;
2826     child_is_trusted = 0;
2827 
2828     while( 1 ) {
2829         /* Add certificate to the verification chain */
2830         cur = &ver_chain->items[ver_chain->len];
2831         cur->crt = child;
2832         cur->flags = 0;
2833         ver_chain->len++;
2834         flags = &cur->flags;
2835 
2836         /* Check time-validity (all certificates) */
2837         if( mbedtls_x509_time_is_past( &child->valid_to ) )
2838             *flags |= MBEDTLS_X509_BADCERT_EXPIRED;
2839 
2840         if( mbedtls_x509_time_is_future( &child->valid_from ) )
2841             *flags |= MBEDTLS_X509_BADCERT_FUTURE;
2842 
2843         /* Stop here for trusted roots (but not for trusted EE certs) */
2844         if( child_is_trusted )
2845             return( 0 );
2846 
2847         /* Check signature algorithm: MD & PK algs */
2848         if( x509_profile_check_md_alg( profile, child->sig_md ) != 0 )
2849             *flags |= MBEDTLS_X509_BADCERT_BAD_MD;
2850 
2851         if( x509_profile_check_pk_alg( profile, child->sig_pk ) != 0 )
2852             *flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2853 
2854         /* Special case: EE certs that are locally trusted */
2855         if( ver_chain->len == 1 &&
2856             x509_crt_check_ee_locally_trusted( child, trust_ca ) == 0 )
2857         {
2858             return( 0 );
2859         }
2860 
2861 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2862 find_parent:
2863 #endif
2864 
2865         /* Obtain list of potential trusted signers from CA callback,
2866          * or use statically provided list. */
2867 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
2868         if( f_ca_cb != NULL )
2869         {
2870             mbedtls_x509_crt_free( ver_chain->trust_ca_cb_result );
2871             mbedtls_free( ver_chain->trust_ca_cb_result );
2872             ver_chain->trust_ca_cb_result = NULL;
2873 
2874             ret = f_ca_cb( p_ca_cb, child, &ver_chain->trust_ca_cb_result );
2875             if( ret != 0 )
2876                 return( MBEDTLS_ERR_X509_FATAL_ERROR );
2877 
2878             cur_trust_ca = ver_chain->trust_ca_cb_result;
2879         }
2880         else
2881 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
2882         {
2883             ((void) f_ca_cb);
2884             ((void) p_ca_cb);
2885             cur_trust_ca = trust_ca;
2886         }
2887 
2888         /* Look for a parent in trusted CAs or up the chain */
2889         ret = x509_crt_find_parent( child, cur_trust_ca, &parent,
2890                                        &parent_is_trusted, &signature_is_good,
2891                                        ver_chain->len - 1, self_cnt, rs_ctx );
2892 
2893 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2894         if( rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2895         {
2896             /* save state */
2897             rs_ctx->in_progress = x509_crt_rs_find_parent;
2898             rs_ctx->self_cnt = self_cnt;
2899             rs_ctx->ver_chain = *ver_chain; /* struct copy */
2900 
2901             return( ret );
2902         }
2903 #else
2904         (void) ret;
2905 #endif
2906 
2907         /* No parent? We're done here */
2908         if( parent == NULL )
2909         {
2910             *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2911             return( 0 );
2912         }
2913 
2914         /* Count intermediate self-issued (not necessarily self-signed) certs.
2915          * These can occur with some strategies for key rollover, see [SIRO],
2916          * and should be excluded from max_pathlen checks. */
2917         if( ver_chain->len != 1 &&
2918             x509_name_cmp( &child->issuer, &child->subject ) == 0 )
2919         {
2920             self_cnt++;
2921         }
2922 
2923         /* path_cnt is 0 for the first intermediate CA,
2924          * and if parent is trusted it's not an intermediate CA */
2925         if( ! parent_is_trusted &&
2926             ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA )
2927         {
2928             /* return immediately to avoid overflow the chain array */
2929             return( MBEDTLS_ERR_X509_FATAL_ERROR );
2930         }
2931 
2932         /* signature was checked while searching parent */
2933         if( ! signature_is_good )
2934             *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2935 
2936         /* check size of signing key */
2937         if( x509_profile_check_key( profile, &parent->pk ) != 0 )
2938             *flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2939 
2940 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2941         /* Check trusted CA's CRL for the given crt */
2942         *flags |= x509_crt_verifycrl( child, parent, ca_crl, profile );
2943 #else
2944         (void) ca_crl;
2945 #endif
2946 
2947         /* prepare for next iteration */
2948         child = parent;
2949         parent = NULL;
2950         child_is_trusted = parent_is_trusted;
2951         signature_is_good = 0;
2952     }
2953 }
2954 
2955 /*
2956  * Check for CN match
2957  */
2958 static int x509_crt_check_cn( const mbedtls_x509_buf *name,
2959                               const char *cn, size_t cn_len )
2960 {
2961     /* try exact match */
2962     if( name->len == cn_len &&
2963         x509_memcasecmp( cn, name->p, cn_len ) == 0 )
2964     {
2965         return( 0 );
2966     }
2967 
2968     /* try wildcard match */
2969     if( x509_check_wildcard( cn, name ) == 0 )
2970     {
2971         return( 0 );
2972     }
2973 
2974     return( -1 );
2975 }
2976 
2977 /*
2978  * Verify the requested CN - only call this if cn is not NULL!
2979  */
2980 static void x509_crt_verify_name( const mbedtls_x509_crt *crt,
2981                                   const char *cn,
2982                                   uint32_t *flags )
2983 {
2984     const mbedtls_x509_name *name;
2985     const mbedtls_x509_sequence *cur;
2986     size_t cn_len = strlen( cn );
2987 
2988     if( crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
2989     {
2990         for( cur = &crt->subject_alt_names; cur != NULL; cur = cur->next )
2991         {
2992             if( x509_crt_check_cn( &cur->buf, cn, cn_len ) == 0 )
2993                 break;
2994         }
2995 
2996         if( cur == NULL )
2997             *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2998     }
2999     else
3000     {
3001         for( name = &crt->subject; name != NULL; name = name->next )
3002         {
3003             if( MBEDTLS_OID_CMP( MBEDTLS_OID_AT_CN, &name->oid ) == 0 &&
3004                 x509_crt_check_cn( &name->val, cn, cn_len ) == 0 )
3005             {
3006                 break;
3007             }
3008         }
3009 
3010         if( name == NULL )
3011             *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
3012     }
3013 }
3014 
3015 /*
3016  * Merge the flags for all certs in the chain, after calling callback
3017  */
3018 static int x509_crt_merge_flags_with_cb(
3019            uint32_t *flags,
3020            const mbedtls_x509_crt_verify_chain *ver_chain,
3021            int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
3022            void *p_vrfy )
3023 {
3024     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3025     unsigned i;
3026     uint32_t cur_flags;
3027     const mbedtls_x509_crt_verify_chain_item *cur;
3028 
3029     for( i = ver_chain->len; i != 0; --i )
3030     {
3031         cur = &ver_chain->items[i-1];
3032         cur_flags = cur->flags;
3033 
3034         if( NULL != f_vrfy )
3035             if( ( ret = f_vrfy( p_vrfy, cur->crt, (int) i-1, &cur_flags ) ) != 0 )
3036                 return( ret );
3037 
3038         *flags |= cur_flags;
3039     }
3040 
3041     return( 0 );
3042 }
3043 
3044 /*
3045  * Verify the certificate validity, with profile, restartable version
3046  *
3047  * This function:
3048  *  - checks the requested CN (if any)
3049  *  - checks the type and size of the EE cert's key,
3050  *    as that isn't done as part of chain building/verification currently
3051  *  - builds and verifies the chain
3052  *  - then calls the callback and merges the flags
3053  *
3054  * The parameters pairs `trust_ca`, `ca_crl` and `f_ca_cb`, `p_ca_cb`
3055  * are mutually exclusive: If `f_ca_cb != NULL`, it will be used by the
3056  * verification routine to search for trusted signers, and CRLs will
3057  * be disabled. Otherwise, `trust_ca` will be used as the static list
3058  * of trusted signers, and `ca_crl` will be use as the static list
3059  * of CRLs.
3060  */
3061 static int x509_crt_verify_restartable_ca_cb( mbedtls_x509_crt *crt,
3062                      mbedtls_x509_crt *trust_ca,
3063                      mbedtls_x509_crl *ca_crl,
3064                      mbedtls_x509_crt_ca_cb_t f_ca_cb,
3065                      void *p_ca_cb,
3066                      const mbedtls_x509_crt_profile *profile,
3067                      const char *cn, uint32_t *flags,
3068                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
3069                      void *p_vrfy,
3070                      mbedtls_x509_crt_restart_ctx *rs_ctx )
3071 {
3072     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3073     mbedtls_pk_type_t pk_type;
3074     mbedtls_x509_crt_verify_chain ver_chain;
3075     uint32_t ee_flags;
3076 
3077     *flags = 0;
3078     ee_flags = 0;
3079     x509_crt_verify_chain_reset( &ver_chain );
3080 
3081     if( profile == NULL )
3082     {
3083         ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
3084         goto exit;
3085     }
3086 
3087     /* check name if requested */
3088     if( cn != NULL )
3089         x509_crt_verify_name( crt, cn, &ee_flags );
3090 
3091     /* Check the type and size of the key */
3092     pk_type = mbedtls_pk_get_type( &crt->pk );
3093 
3094     if( x509_profile_check_pk_alg( profile, pk_type ) != 0 )
3095         ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
3096 
3097     if( x509_profile_check_key( profile, &crt->pk ) != 0 )
3098         ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
3099 
3100     /* Check the chain */
3101     ret = x509_crt_verify_chain( crt, trust_ca, ca_crl,
3102                                  f_ca_cb, p_ca_cb, profile,
3103                                  &ver_chain, rs_ctx );
3104 
3105     if( ret != 0 )
3106         goto exit;
3107 
3108     /* Merge end-entity flags */
3109     ver_chain.items[0].flags |= ee_flags;
3110 
3111     /* Build final flags, calling callback on the way if any */
3112     ret = x509_crt_merge_flags_with_cb( flags, &ver_chain, f_vrfy, p_vrfy );
3113 
3114 exit:
3115 
3116 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
3117     mbedtls_x509_crt_free( ver_chain.trust_ca_cb_result );
3118     mbedtls_free( ver_chain.trust_ca_cb_result );
3119     ver_chain.trust_ca_cb_result = NULL;
3120 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
3121 
3122 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
3123     if( rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
3124         mbedtls_x509_crt_restart_free( rs_ctx );
3125 #endif
3126 
3127     /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
3128      * the SSL module for authmode optional, but non-zero return from the
3129      * callback means a fatal error so it shouldn't be ignored */
3130     if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
3131         ret = MBEDTLS_ERR_X509_FATAL_ERROR;
3132 
3133     if( ret != 0 )
3134     {
3135         *flags = (uint32_t) -1;
3136         return( ret );
3137     }
3138 
3139     if( *flags != 0 )
3140         return( MBEDTLS_ERR_X509_CERT_VERIFY_FAILED );
3141 
3142     return( 0 );
3143 }
3144 
3145 
3146 /*
3147  * Verify the certificate validity (default profile, not restartable)
3148  */
3149 int mbedtls_x509_crt_verify( mbedtls_x509_crt *crt,
3150                      mbedtls_x509_crt *trust_ca,
3151                      mbedtls_x509_crl *ca_crl,
3152                      const char *cn, uint32_t *flags,
3153                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
3154                      void *p_vrfy )
3155 {
3156     return( x509_crt_verify_restartable_ca_cb( crt, trust_ca, ca_crl,
3157                                          NULL, NULL,
3158                                          &mbedtls_x509_crt_profile_default,
3159                                          cn, flags,
3160                                          f_vrfy, p_vrfy, NULL ) );
3161 }
3162 
3163 /*
3164  * Verify the certificate validity (user-chosen profile, not restartable)
3165  */
3166 int mbedtls_x509_crt_verify_with_profile( mbedtls_x509_crt *crt,
3167                      mbedtls_x509_crt *trust_ca,
3168                      mbedtls_x509_crl *ca_crl,
3169                      const mbedtls_x509_crt_profile *profile,
3170                      const char *cn, uint32_t *flags,
3171                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
3172                      void *p_vrfy )
3173 {
3174     return( x509_crt_verify_restartable_ca_cb( crt, trust_ca, ca_crl,
3175                                                  NULL, NULL,
3176                                                  profile, cn, flags,
3177                                                  f_vrfy, p_vrfy, NULL ) );
3178 }
3179 
3180 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
3181 /*
3182  * Verify the certificate validity (user-chosen profile, CA callback,
3183  *                                  not restartable).
3184  */
3185 int mbedtls_x509_crt_verify_with_ca_cb( mbedtls_x509_crt *crt,
3186                      mbedtls_x509_crt_ca_cb_t f_ca_cb,
3187                      void *p_ca_cb,
3188                      const mbedtls_x509_crt_profile *profile,
3189                      const char *cn, uint32_t *flags,
3190                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
3191                      void *p_vrfy )
3192 {
3193     return( x509_crt_verify_restartable_ca_cb( crt, NULL, NULL,
3194                                                  f_ca_cb, p_ca_cb,
3195                                                  profile, cn, flags,
3196                                                  f_vrfy, p_vrfy, NULL ) );
3197 }
3198 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
3199 
3200 int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt,
3201                      mbedtls_x509_crt *trust_ca,
3202                      mbedtls_x509_crl *ca_crl,
3203                      const mbedtls_x509_crt_profile *profile,
3204                      const char *cn, uint32_t *flags,
3205                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
3206                      void *p_vrfy,
3207                      mbedtls_x509_crt_restart_ctx *rs_ctx )
3208 {
3209     return( x509_crt_verify_restartable_ca_cb( crt, trust_ca, ca_crl,
3210                                                  NULL, NULL,
3211                                                  profile, cn, flags,
3212                                                  f_vrfy, p_vrfy, rs_ctx ) );
3213 }
3214 
3215 
3216 /*
3217  * Initialize a certificate chain
3218  */
3219 void mbedtls_x509_crt_init( mbedtls_x509_crt *crt )
3220 {
3221     memset( crt, 0, sizeof(mbedtls_x509_crt) );
3222 }
3223 
3224 /*
3225  * Unallocate all certificate data
3226  */
3227 void mbedtls_x509_crt_free( mbedtls_x509_crt *crt )
3228 {
3229     mbedtls_x509_crt *cert_cur = crt;
3230     mbedtls_x509_crt *cert_prv;
3231     mbedtls_x509_name *name_cur;
3232     mbedtls_x509_name *name_prv;
3233     mbedtls_x509_sequence *seq_cur;
3234     mbedtls_x509_sequence *seq_prv;
3235 
3236     if( crt == NULL )
3237         return;
3238 
3239     do
3240     {
3241         mbedtls_pk_free( &cert_cur->pk );
3242 
3243 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
3244         mbedtls_free( cert_cur->sig_opts );
3245 #endif
3246 
3247         name_cur = cert_cur->issuer.next;
3248         while( name_cur != NULL )
3249         {
3250             name_prv = name_cur;
3251             name_cur = name_cur->next;
3252             mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
3253             mbedtls_free( name_prv );
3254         }
3255 
3256         name_cur = cert_cur->subject.next;
3257         while( name_cur != NULL )
3258         {
3259             name_prv = name_cur;
3260             name_cur = name_cur->next;
3261             mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
3262             mbedtls_free( name_prv );
3263         }
3264 
3265         seq_cur = cert_cur->ext_key_usage.next;
3266         while( seq_cur != NULL )
3267         {
3268             seq_prv = seq_cur;
3269             seq_cur = seq_cur->next;
3270             mbedtls_platform_zeroize( seq_prv,
3271                                       sizeof( mbedtls_x509_sequence ) );
3272             mbedtls_free( seq_prv );
3273         }
3274 
3275         seq_cur = cert_cur->subject_alt_names.next;
3276         while( seq_cur != NULL )
3277         {
3278             seq_prv = seq_cur;
3279             seq_cur = seq_cur->next;
3280             mbedtls_platform_zeroize( seq_prv,
3281                                       sizeof( mbedtls_x509_sequence ) );
3282             mbedtls_free( seq_prv );
3283         }
3284 
3285         seq_cur = cert_cur->certificate_policies.next;
3286         while( seq_cur != NULL )
3287         {
3288             seq_prv = seq_cur;
3289             seq_cur = seq_cur->next;
3290             mbedtls_platform_zeroize( seq_prv,
3291                                       sizeof( mbedtls_x509_sequence ) );
3292             mbedtls_free( seq_prv );
3293         }
3294 
3295         if( cert_cur->raw.p != NULL && cert_cur->own_buffer )
3296         {
3297             mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
3298             mbedtls_free( cert_cur->raw.p );
3299         }
3300 
3301         cert_cur = cert_cur->next;
3302     }
3303     while( cert_cur != NULL );
3304 
3305     cert_cur = crt;
3306     do
3307     {
3308         cert_prv = cert_cur;
3309         cert_cur = cert_cur->next;
3310 
3311         mbedtls_platform_zeroize( cert_prv, sizeof( mbedtls_x509_crt ) );
3312         if( cert_prv != crt )
3313             mbedtls_free( cert_prv );
3314     }
3315     while( cert_cur != NULL );
3316 }
3317 
3318 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
3319 /*
3320  * Initialize a restart context
3321  */
3322 void mbedtls_x509_crt_restart_init( mbedtls_x509_crt_restart_ctx *ctx )
3323 {
3324     mbedtls_pk_restart_init( &ctx->pk );
3325 
3326     ctx->parent = NULL;
3327     ctx->fallback_parent = NULL;
3328     ctx->fallback_signature_is_good = 0;
3329 
3330     ctx->parent_is_trusted = -1;
3331 
3332     ctx->in_progress = x509_crt_rs_none;
3333     ctx->self_cnt = 0;
3334     x509_crt_verify_chain_reset( &ctx->ver_chain );
3335 }
3336 
3337 /*
3338  * Free the components of a restart context
3339  */
3340 void mbedtls_x509_crt_restart_free( mbedtls_x509_crt_restart_ctx *ctx )
3341 {
3342     if( ctx == NULL )
3343         return;
3344 
3345     mbedtls_pk_restart_free( &ctx->pk );
3346     mbedtls_x509_crt_restart_init( ctx );
3347 }
3348 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
3349 
3350 #endif /* MBEDTLS_X509_CRT_PARSE_C */
3351