1 /*
2 * X.509 certificate parsing and verification
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0
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 /*
20 * The ITU-T X.509 standard defines a certificate format for PKI.
21 *
22 * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
23 * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
24 * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
25 *
26 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
27 * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
28 *
29 * [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf
30 */
31
32 #include "common.h"
33
34 #if defined(MBEDTLS_X509_CRT_PARSE_C)
35
36 #include "mbedtls/x509_crt.h"
37 #include "mbedtls/error.h"
38 #include "mbedtls/oid.h"
39 #include "mbedtls/platform_util.h"
40
41 #include <string.h>
42
43 #if defined(MBEDTLS_PEM_PARSE_C)
44 #include "mbedtls/pem.h"
45 #endif
46
47 #if defined(MBEDTLS_USE_PSA_CRYPTO)
48 #include "psa/crypto.h"
49 #include "mbedtls/psa_util.h"
50 #endif /* MBEDTLS_USE_PSA_CRYPTO */
51 #include "hash_info.h"
52
53 #include "mbedtls/platform.h"
54
55 #if defined(MBEDTLS_THREADING_C)
56 #include "mbedtls/threading.h"
57 #endif
58
59 #if defined(MBEDTLS_HAVE_TIME)
60 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
61 #include <windows.h>
62 #else
63 #include <time.h>
64 #endif
65 #endif
66
67 #if defined(MBEDTLS_FS_IO)
68 #include <stdio.h>
69 #if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
70 #include <sys/types.h>
71 #include <sys/stat.h>
72 #if defined(__MBED__)
73 #include <platform/mbed_retarget.h>
74 #else
75 #include <dirent.h>
76 #endif /* __MBED__ */
77 #include <errno.h>
78 #endif /* !_WIN32 || EFIX64 || EFI32 */
79 #endif
80
81 /*
82 * Item in a verification chain: cert and flags for it
83 */
84 typedef struct {
85 mbedtls_x509_crt *crt;
86 uint32_t flags;
87 } x509_crt_verify_chain_item;
88
89 /*
90 * Max size of verification chain: end-entity + intermediates + trusted root
91 */
92 #define X509_MAX_VERIFY_CHAIN_SIZE (MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2)
93
94 /* Default profile. Do not remove items unless there are serious security
95 * concerns. */
96 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
97 {
98 /* Hashes from SHA-256 and above. Note that this selection
99 * should be aligned with ssl_preset_default_hashes in ssl_tls.c. */
100 MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) |
101 MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384) |
102 MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA512),
103 0xFFFFFFF, /* Any PK alg */
104 #if defined(MBEDTLS_ECP_C)
105 /* Curves at or above 128-bit security level. Note that this selection
106 * should be aligned with ssl_preset_default_curves in ssl_tls.c. */
107 MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256R1) |
108 MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP384R1) |
109 MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP521R1) |
110 MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP256R1) |
111 MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP384R1) |
112 MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP512R1) |
113 0,
114 #else
115 0,
116 #endif
117 2048,
118 };
119
120 /* Next-generation profile. Currently identical to the default, but may
121 * be tightened at any time. */
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 * Empty / all-forbidden profile
167 */
168 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none =
169 {
170 0,
171 0,
172 0,
173 (uint32_t) -1,
174 };
175
176 /*
177 * Check md_alg against profile
178 * Return 0 if md_alg is acceptable for this profile, -1 otherwise
179 */
x509_profile_check_md_alg(const mbedtls_x509_crt_profile * profile,mbedtls_md_type_t md_alg)180 static int x509_profile_check_md_alg(const mbedtls_x509_crt_profile *profile,
181 mbedtls_md_type_t md_alg)
182 {
183 if (md_alg == MBEDTLS_MD_NONE) {
184 return -1;
185 }
186
187 if ((profile->allowed_mds & MBEDTLS_X509_ID_FLAG(md_alg)) != 0) {
188 return 0;
189 }
190
191 return -1;
192 }
193
194 /*
195 * Check pk_alg against profile
196 * Return 0 if pk_alg is acceptable for this profile, -1 otherwise
197 */
x509_profile_check_pk_alg(const mbedtls_x509_crt_profile * profile,mbedtls_pk_type_t pk_alg)198 static int x509_profile_check_pk_alg(const mbedtls_x509_crt_profile *profile,
199 mbedtls_pk_type_t pk_alg)
200 {
201 if (pk_alg == MBEDTLS_PK_NONE) {
202 return -1;
203 }
204
205 if ((profile->allowed_pks & MBEDTLS_X509_ID_FLAG(pk_alg)) != 0) {
206 return 0;
207 }
208
209 return -1;
210 }
211
212 /*
213 * Check key against profile
214 * Return 0 if pk is acceptable for this profile, -1 otherwise
215 */
x509_profile_check_key(const mbedtls_x509_crt_profile * profile,const mbedtls_pk_context * pk)216 static int x509_profile_check_key(const mbedtls_x509_crt_profile *profile,
217 const mbedtls_pk_context *pk)
218 {
219 const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type(pk);
220
221 #if defined(MBEDTLS_RSA_C)
222 if (pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS) {
223 if (mbedtls_pk_get_bitlen(pk) >= profile->rsa_min_bitlen) {
224 return 0;
225 }
226
227 return -1;
228 }
229 #endif
230
231 #if defined(MBEDTLS_ECP_C)
232 if (pk_alg == MBEDTLS_PK_ECDSA ||
233 pk_alg == MBEDTLS_PK_ECKEY ||
234 pk_alg == MBEDTLS_PK_ECKEY_DH) {
235 const mbedtls_ecp_group_id gid = mbedtls_pk_ec(*pk)->grp.id;
236
237 if (gid == MBEDTLS_ECP_DP_NONE) {
238 return -1;
239 }
240
241 if ((profile->allowed_curves & MBEDTLS_X509_ID_FLAG(gid)) != 0) {
242 return 0;
243 }
244
245 return -1;
246 }
247 #endif
248
249 return -1;
250 }
251
252 /*
253 * Like memcmp, but case-insensitive and always returns -1 if different
254 */
x509_memcasecmp(const void * s1,const void * s2,size_t len)255 static int x509_memcasecmp(const void *s1, const void *s2, size_t len)
256 {
257 size_t i;
258 unsigned char diff;
259 const unsigned char *n1 = s1, *n2 = s2;
260
261 for (i = 0; i < len; i++) {
262 diff = n1[i] ^ n2[i];
263
264 if (diff == 0) {
265 continue;
266 }
267
268 if (diff == 32 &&
269 ((n1[i] >= 'a' && n1[i] <= 'z') ||
270 (n1[i] >= 'A' && n1[i] <= 'Z'))) {
271 continue;
272 }
273
274 return -1;
275 }
276
277 return 0;
278 }
279
280 /*
281 * Return 0 if name matches wildcard, -1 otherwise
282 */
x509_check_wildcard(const char * cn,const mbedtls_x509_buf * name)283 static int x509_check_wildcard(const char *cn, const mbedtls_x509_buf *name)
284 {
285 size_t i;
286 size_t cn_idx = 0, cn_len = strlen(cn);
287
288 /* We can't have a match if there is no wildcard to match */
289 if (name->len < 3 || name->p[0] != '*' || name->p[1] != '.') {
290 return -1;
291 }
292
293 for (i = 0; i < cn_len; ++i) {
294 if (cn[i] == '.') {
295 cn_idx = i;
296 break;
297 }
298 }
299
300 if (cn_idx == 0) {
301 return -1;
302 }
303
304 if (cn_len - cn_idx == name->len - 1 &&
305 x509_memcasecmp(name->p + 1, cn + cn_idx, name->len - 1) == 0) {
306 return 0;
307 }
308
309 return -1;
310 }
311
312 /*
313 * Compare two X.509 strings, case-insensitive, and allowing for some encoding
314 * variations (but not all).
315 *
316 * Return 0 if equal, -1 otherwise.
317 */
x509_string_cmp(const mbedtls_x509_buf * a,const mbedtls_x509_buf * b)318 static int x509_string_cmp(const mbedtls_x509_buf *a, const mbedtls_x509_buf *b)
319 {
320 if (a->tag == b->tag &&
321 a->len == b->len &&
322 memcmp(a->p, b->p, b->len) == 0) {
323 return 0;
324 }
325
326 if ((a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING) &&
327 (b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING) &&
328 a->len == b->len &&
329 x509_memcasecmp(a->p, b->p, b->len) == 0) {
330 return 0;
331 }
332
333 return -1;
334 }
335
336 /*
337 * Compare two X.509 Names (aka rdnSequence).
338 *
339 * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
340 * we sometimes return unequal when the full algorithm would return equal,
341 * but never the other way. (In particular, we don't do Unicode normalisation
342 * or space folding.)
343 *
344 * Return 0 if equal, -1 otherwise.
345 */
x509_name_cmp(const mbedtls_x509_name * a,const mbedtls_x509_name * b)346 static int x509_name_cmp(const mbedtls_x509_name *a, const mbedtls_x509_name *b)
347 {
348 /* Avoid recursion, it might not be optimised by the compiler */
349 while (a != NULL || b != NULL) {
350 if (a == NULL || b == NULL) {
351 return -1;
352 }
353
354 /* type */
355 if (a->oid.tag != b->oid.tag ||
356 a->oid.len != b->oid.len ||
357 memcmp(a->oid.p, b->oid.p, b->oid.len) != 0) {
358 return -1;
359 }
360
361 /* value */
362 if (x509_string_cmp(&a->val, &b->val) != 0) {
363 return -1;
364 }
365
366 /* structure of the list of sets */
367 if (a->next_merged != b->next_merged) {
368 return -1;
369 }
370
371 a = a->next;
372 b = b->next;
373 }
374
375 /* a == NULL == b */
376 return 0;
377 }
378
379 /*
380 * Reset (init or clear) a verify_chain
381 */
x509_crt_verify_chain_reset(mbedtls_x509_crt_verify_chain * ver_chain)382 static void x509_crt_verify_chain_reset(
383 mbedtls_x509_crt_verify_chain *ver_chain)
384 {
385 size_t i;
386
387 for (i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++) {
388 ver_chain->items[i].crt = NULL;
389 ver_chain->items[i].flags = (uint32_t) -1;
390 }
391
392 ver_chain->len = 0;
393
394 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
395 ver_chain->trust_ca_cb_result = NULL;
396 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
397 }
398
399 /*
400 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
401 */
x509_get_version(unsigned char ** p,const unsigned char * end,int * ver)402 static int x509_get_version(unsigned char **p,
403 const unsigned char *end,
404 int *ver)
405 {
406 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
407 size_t len;
408
409 if ((ret = mbedtls_asn1_get_tag(p, end, &len,
410 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED |
411 0)) != 0) {
412 if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
413 *ver = 0;
414 return 0;
415 }
416
417 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
418 }
419
420 end = *p + len;
421
422 if ((ret = mbedtls_asn1_get_int(p, end, ver)) != 0) {
423 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION, ret);
424 }
425
426 if (*p != end) {
427 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION,
428 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
429 }
430
431 return 0;
432 }
433
434 /*
435 * Validity ::= SEQUENCE {
436 * notBefore Time,
437 * notAfter Time }
438 */
x509_get_dates(unsigned char ** p,const unsigned char * end,mbedtls_x509_time * from,mbedtls_x509_time * to)439 static int x509_get_dates(unsigned char **p,
440 const unsigned char *end,
441 mbedtls_x509_time *from,
442 mbedtls_x509_time *to)
443 {
444 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
445 size_t len;
446
447 if ((ret = mbedtls_asn1_get_tag(p, end, &len,
448 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
449 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE, ret);
450 }
451
452 end = *p + len;
453
454 if ((ret = mbedtls_x509_get_time(p, end, from)) != 0) {
455 return ret;
456 }
457
458 if ((ret = mbedtls_x509_get_time(p, end, to)) != 0) {
459 return ret;
460 }
461
462 if (*p != end) {
463 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE,
464 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
465 }
466
467 return 0;
468 }
469
470 /*
471 * X.509 v2/v3 unique identifier (not parsed)
472 */
x509_get_uid(unsigned char ** p,const unsigned char * end,mbedtls_x509_buf * uid,int n)473 static int x509_get_uid(unsigned char **p,
474 const unsigned char *end,
475 mbedtls_x509_buf *uid, int n)
476 {
477 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
478
479 if (*p == end) {
480 return 0;
481 }
482
483 uid->tag = **p;
484
485 if ((ret = mbedtls_asn1_get_tag(p, end, &uid->len,
486 MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED |
487 n)) != 0) {
488 if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
489 return 0;
490 }
491
492 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
493 }
494
495 uid->p = *p;
496 *p += uid->len;
497
498 return 0;
499 }
500
x509_get_basic_constraints(unsigned char ** p,const unsigned char * end,int * ca_istrue,int * max_pathlen)501 static int x509_get_basic_constraints(unsigned char **p,
502 const unsigned char *end,
503 int *ca_istrue,
504 int *max_pathlen)
505 {
506 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
507 size_t len;
508
509 /*
510 * BasicConstraints ::= SEQUENCE {
511 * cA BOOLEAN DEFAULT FALSE,
512 * pathLenConstraint INTEGER (0..MAX) OPTIONAL }
513 */
514 *ca_istrue = 0; /* DEFAULT FALSE */
515 *max_pathlen = 0; /* endless */
516
517 if ((ret = mbedtls_asn1_get_tag(p, end, &len,
518 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
519 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
520 }
521
522 if (*p == end) {
523 return 0;
524 }
525
526 if ((ret = mbedtls_asn1_get_bool(p, end, ca_istrue)) != 0) {
527 if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
528 ret = mbedtls_asn1_get_int(p, end, ca_istrue);
529 }
530
531 if (ret != 0) {
532 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
533 }
534
535 if (*ca_istrue != 0) {
536 *ca_istrue = 1;
537 }
538 }
539
540 if (*p == end) {
541 return 0;
542 }
543
544 if ((ret = mbedtls_asn1_get_int(p, end, max_pathlen)) != 0) {
545 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
546 }
547
548 if (*p != end) {
549 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
550 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
551 }
552
553 /* Do not accept max_pathlen equal to INT_MAX to avoid a signed integer
554 * overflow, which is an undefined behavior. */
555 if (*max_pathlen == INT_MAX) {
556 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
557 MBEDTLS_ERR_ASN1_INVALID_LENGTH);
558 }
559
560 (*max_pathlen)++;
561
562 return 0;
563 }
564
565 /*
566 * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
567 *
568 * KeyPurposeId ::= OBJECT IDENTIFIER
569 */
x509_get_ext_key_usage(unsigned char ** p,const unsigned char * end,mbedtls_x509_sequence * ext_key_usage)570 static int x509_get_ext_key_usage(unsigned char **p,
571 const unsigned char *end,
572 mbedtls_x509_sequence *ext_key_usage)
573 {
574 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
575
576 if ((ret = mbedtls_asn1_get_sequence_of(p, end, ext_key_usage, MBEDTLS_ASN1_OID)) != 0) {
577 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
578 }
579
580 /* Sequence length must be >= 1 */
581 if (ext_key_usage->buf.p == NULL) {
582 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
583 MBEDTLS_ERR_ASN1_INVALID_LENGTH);
584 }
585
586 return 0;
587 }
588
589 /*
590 * id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 }
591 *
592 * anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 }
593 *
594 * certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
595 *
596 * PolicyInformation ::= SEQUENCE {
597 * policyIdentifier CertPolicyId,
598 * policyQualifiers SEQUENCE SIZE (1..MAX) OF
599 * PolicyQualifierInfo OPTIONAL }
600 *
601 * CertPolicyId ::= OBJECT IDENTIFIER
602 *
603 * PolicyQualifierInfo ::= SEQUENCE {
604 * policyQualifierId PolicyQualifierId,
605 * qualifier ANY DEFINED BY policyQualifierId }
606 *
607 * -- policyQualifierIds for Internet policy qualifiers
608 *
609 * id-qt OBJECT IDENTIFIER ::= { id-pkix 2 }
610 * id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 }
611 * id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 }
612 *
613 * PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice )
614 *
615 * Qualifier ::= CHOICE {
616 * cPSuri CPSuri,
617 * userNotice UserNotice }
618 *
619 * CPSuri ::= IA5String
620 *
621 * UserNotice ::= SEQUENCE {
622 * noticeRef NoticeReference OPTIONAL,
623 * explicitText DisplayText OPTIONAL }
624 *
625 * NoticeReference ::= SEQUENCE {
626 * organization DisplayText,
627 * noticeNumbers SEQUENCE OF INTEGER }
628 *
629 * DisplayText ::= CHOICE {
630 * ia5String IA5String (SIZE (1..200)),
631 * visibleString VisibleString (SIZE (1..200)),
632 * bmpString BMPString (SIZE (1..200)),
633 * utf8String UTF8String (SIZE (1..200)) }
634 *
635 * NOTE: we only parse and use anyPolicy without qualifiers at this point
636 * as defined in RFC 5280.
637 */
x509_get_certificate_policies(unsigned char ** p,const unsigned char * end,mbedtls_x509_sequence * certificate_policies)638 static int x509_get_certificate_policies(unsigned char **p,
639 const unsigned char *end,
640 mbedtls_x509_sequence *certificate_policies)
641 {
642 int ret, parse_ret = 0;
643 size_t len;
644 mbedtls_asn1_buf *buf;
645 mbedtls_asn1_sequence *cur = certificate_policies;
646
647 /* Get main sequence tag */
648 ret = mbedtls_asn1_get_tag(p, end, &len,
649 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE);
650 if (ret != 0) {
651 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
652 }
653
654 if (*p + len != end) {
655 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
656 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
657 }
658
659 /*
660 * Cannot be an empty sequence.
661 */
662 if (len == 0) {
663 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
664 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
665 }
666
667 while (*p < end) {
668 mbedtls_x509_buf policy_oid;
669 const unsigned char *policy_end;
670
671 /*
672 * Get the policy sequence
673 */
674 if ((ret = mbedtls_asn1_get_tag(p, end, &len,
675 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
676 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
677 }
678
679 policy_end = *p + len;
680
681 if ((ret = mbedtls_asn1_get_tag(p, policy_end, &len,
682 MBEDTLS_ASN1_OID)) != 0) {
683 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
684 }
685
686 policy_oid.tag = MBEDTLS_ASN1_OID;
687 policy_oid.len = len;
688 policy_oid.p = *p;
689
690 /*
691 * Only AnyPolicy is currently supported when enforcing policy.
692 */
693 if (MBEDTLS_OID_CMP(MBEDTLS_OID_ANY_POLICY, &policy_oid) != 0) {
694 /*
695 * Set the parsing return code but continue parsing, in case this
696 * extension is critical.
697 */
698 parse_ret = MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE;
699 }
700
701 /* Allocate and assign next pointer */
702 if (cur->buf.p != NULL) {
703 if (cur->next != NULL) {
704 return MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
705 }
706
707 cur->next = mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));
708
709 if (cur->next == NULL) {
710 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
711 MBEDTLS_ERR_ASN1_ALLOC_FAILED);
712 }
713
714 cur = cur->next;
715 }
716
717 buf = &(cur->buf);
718 buf->tag = policy_oid.tag;
719 buf->p = policy_oid.p;
720 buf->len = policy_oid.len;
721
722 *p += len;
723
724 /*
725 * If there is an optional qualifier, then *p < policy_end
726 * Check the Qualifier len to verify it doesn't exceed policy_end.
727 */
728 if (*p < policy_end) {
729 if ((ret = mbedtls_asn1_get_tag(p, policy_end, &len,
730 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) !=
731 0) {
732 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
733 }
734 /*
735 * Skip the optional policy qualifiers.
736 */
737 *p += len;
738 }
739
740 if (*p != policy_end) {
741 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
742 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
743 }
744 }
745
746 /* Set final sequence entry's next pointer to NULL */
747 cur->next = NULL;
748
749 if (*p != end) {
750 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
751 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
752 }
753
754 return parse_ret;
755 }
756
757 /*
758 * X.509 v3 extensions
759 *
760 */
x509_get_crt_ext(unsigned char ** p,const unsigned char * end,mbedtls_x509_crt * crt,mbedtls_x509_crt_ext_cb_t cb,void * p_ctx)761 static int x509_get_crt_ext(unsigned char **p,
762 const unsigned char *end,
763 mbedtls_x509_crt *crt,
764 mbedtls_x509_crt_ext_cb_t cb,
765 void *p_ctx)
766 {
767 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
768 size_t len;
769 unsigned char *end_ext_data, *start_ext_octet, *end_ext_octet;
770
771 if (*p == end) {
772 return 0;
773 }
774
775 if ((ret = mbedtls_x509_get_ext(p, end, &crt->v3_ext, 3)) != 0) {
776 return ret;
777 }
778
779 end = crt->v3_ext.p + crt->v3_ext.len;
780 while (*p < end) {
781 /*
782 * Extension ::= SEQUENCE {
783 * extnID OBJECT IDENTIFIER,
784 * critical BOOLEAN DEFAULT FALSE,
785 * extnValue OCTET STRING }
786 */
787 mbedtls_x509_buf extn_oid = { 0, 0, NULL };
788 int is_critical = 0; /* DEFAULT FALSE */
789 int ext_type = 0;
790
791 if ((ret = mbedtls_asn1_get_tag(p, end, &len,
792 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
793 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
794 }
795
796 end_ext_data = *p + len;
797
798 /* Get extension ID */
799 if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &extn_oid.len,
800 MBEDTLS_ASN1_OID)) != 0) {
801 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
802 }
803
804 extn_oid.tag = MBEDTLS_ASN1_OID;
805 extn_oid.p = *p;
806 *p += extn_oid.len;
807
808 /* Get optional critical */
809 if ((ret = mbedtls_asn1_get_bool(p, end_ext_data, &is_critical)) != 0 &&
810 (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) {
811 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
812 }
813
814 /* Data should be octet string type */
815 if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len,
816 MBEDTLS_ASN1_OCTET_STRING)) != 0) {
817 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
818 }
819
820 start_ext_octet = *p;
821 end_ext_octet = *p + len;
822
823 if (end_ext_octet != end_ext_data) {
824 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
825 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
826 }
827
828 /*
829 * Detect supported extensions
830 */
831 ret = mbedtls_oid_get_x509_ext_type(&extn_oid, &ext_type);
832
833 if (ret != 0) {
834 /* Give the callback (if any) a chance to handle the extension */
835 if (cb != NULL) {
836 ret = cb(p_ctx, crt, &extn_oid, is_critical, *p, end_ext_octet);
837 if (ret != 0 && is_critical) {
838 return ret;
839 }
840 *p = end_ext_octet;
841 continue;
842 }
843
844 /* No parser found, skip extension */
845 *p = end_ext_octet;
846
847 if (is_critical) {
848 /* Data is marked as critical: fail */
849 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
850 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
851 }
852 continue;
853 }
854
855 /* Forbid repeated extensions */
856 if ((crt->ext_types & ext_type) != 0) {
857 return MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
858 }
859
860 crt->ext_types |= ext_type;
861
862 switch (ext_type) {
863 case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
864 /* Parse basic constraints */
865 if ((ret = x509_get_basic_constraints(p, end_ext_octet,
866 &crt->ca_istrue, &crt->max_pathlen)) != 0) {
867 return ret;
868 }
869 break;
870
871 case MBEDTLS_X509_EXT_KEY_USAGE:
872 /* Parse key usage */
873 if ((ret = mbedtls_x509_get_key_usage(p, end_ext_octet,
874 &crt->key_usage)) != 0) {
875 return ret;
876 }
877 break;
878
879 case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
880 /* Parse extended key usage */
881 if ((ret = x509_get_ext_key_usage(p, end_ext_octet,
882 &crt->ext_key_usage)) != 0) {
883 return ret;
884 }
885 break;
886
887 case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
888 /* Parse subject alt name */
889 if ((ret = mbedtls_x509_get_subject_alt_name(p, end_ext_octet,
890 &crt->subject_alt_names)) != 0) {
891 return ret;
892 }
893 break;
894
895 case MBEDTLS_X509_EXT_NS_CERT_TYPE:
896 /* Parse netscape certificate type */
897 if ((ret = mbedtls_x509_get_ns_cert_type(p, end_ext_octet,
898 &crt->ns_cert_type)) != 0) {
899 return ret;
900 }
901 break;
902
903 case MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES:
904 /* Parse certificate policies type */
905 if ((ret = x509_get_certificate_policies(p, end_ext_octet,
906 &crt->certificate_policies)) != 0) {
907 /* Give the callback (if any) a chance to handle the extension
908 * if it contains unsupported policies */
909 if (ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE && cb != NULL &&
910 cb(p_ctx, crt, &extn_oid, is_critical,
911 start_ext_octet, end_ext_octet) == 0) {
912 break;
913 }
914
915 if (is_critical) {
916 return ret;
917 } else
918 /*
919 * If MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE is returned, then we
920 * cannot interpret or enforce the policy. However, it is up to
921 * the user to choose how to enforce the policies,
922 * unless the extension is critical.
923 */
924 if (ret != MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE) {
925 return ret;
926 }
927 }
928 break;
929
930 default:
931 /*
932 * If this is a non-critical extension, which the oid layer
933 * supports, but there isn't an x509 parser for it,
934 * skip the extension.
935 */
936 if (is_critical) {
937 return MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE;
938 } else {
939 *p = end_ext_octet;
940 }
941 }
942 }
943
944 if (*p != end) {
945 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
946 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
947 }
948
949 return 0;
950 }
951
952 /*
953 * Parse and fill a single X.509 certificate in DER format
954 */
x509_crt_parse_der_core(mbedtls_x509_crt * crt,const unsigned char * buf,size_t buflen,int make_copy,mbedtls_x509_crt_ext_cb_t cb,void * p_ctx)955 static int x509_crt_parse_der_core(mbedtls_x509_crt *crt,
956 const unsigned char *buf,
957 size_t buflen,
958 int make_copy,
959 mbedtls_x509_crt_ext_cb_t cb,
960 void *p_ctx)
961 {
962 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
963 size_t len;
964 unsigned char *p, *end, *crt_end;
965 mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
966
967 memset(&sig_params1, 0, sizeof(mbedtls_x509_buf));
968 memset(&sig_params2, 0, sizeof(mbedtls_x509_buf));
969 memset(&sig_oid2, 0, sizeof(mbedtls_x509_buf));
970
971 /*
972 * Check for valid input
973 */
974 if (crt == NULL || buf == NULL) {
975 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
976 }
977
978 /* Use the original buffer until we figure out actual length. */
979 p = (unsigned char *) buf;
980 len = buflen;
981 end = p + len;
982
983 /*
984 * Certificate ::= SEQUENCE {
985 * tbsCertificate TBSCertificate,
986 * signatureAlgorithm AlgorithmIdentifier,
987 * signatureValue BIT STRING }
988 */
989 if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
990 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
991 mbedtls_x509_crt_free(crt);
992 return MBEDTLS_ERR_X509_INVALID_FORMAT;
993 }
994
995 end = crt_end = p + len;
996 crt->raw.len = crt_end - buf;
997 if (make_copy != 0) {
998 /* Create and populate a new buffer for the raw field. */
999 crt->raw.p = p = mbedtls_calloc(1, crt->raw.len);
1000 if (crt->raw.p == NULL) {
1001 return MBEDTLS_ERR_X509_ALLOC_FAILED;
1002 }
1003
1004 memcpy(crt->raw.p, buf, crt->raw.len);
1005 crt->own_buffer = 1;
1006
1007 p += crt->raw.len - len;
1008 end = crt_end = p + len;
1009 } else {
1010 crt->raw.p = (unsigned char *) buf;
1011 crt->own_buffer = 0;
1012 }
1013
1014 /*
1015 * TBSCertificate ::= SEQUENCE {
1016 */
1017 crt->tbs.p = p;
1018
1019 if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
1020 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
1021 mbedtls_x509_crt_free(crt);
1022 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
1023 }
1024
1025 end = p + len;
1026 crt->tbs.len = end - crt->tbs.p;
1027
1028 /*
1029 * Version ::= INTEGER { v1(0), v2(1), v3(2) }
1030 *
1031 * CertificateSerialNumber ::= INTEGER
1032 *
1033 * signature AlgorithmIdentifier
1034 */
1035 if ((ret = x509_get_version(&p, end, &crt->version)) != 0 ||
1036 (ret = mbedtls_x509_get_serial(&p, end, &crt->serial)) != 0 ||
1037 (ret = mbedtls_x509_get_alg(&p, end, &crt->sig_oid,
1038 &sig_params1)) != 0) {
1039 mbedtls_x509_crt_free(crt);
1040 return ret;
1041 }
1042
1043 if (crt->version < 0 || crt->version > 2) {
1044 mbedtls_x509_crt_free(crt);
1045 return MBEDTLS_ERR_X509_UNKNOWN_VERSION;
1046 }
1047
1048 crt->version++;
1049
1050 if ((ret = mbedtls_x509_get_sig_alg(&crt->sig_oid, &sig_params1,
1051 &crt->sig_md, &crt->sig_pk,
1052 &crt->sig_opts)) != 0) {
1053 mbedtls_x509_crt_free(crt);
1054 return ret;
1055 }
1056
1057 /*
1058 * issuer Name
1059 */
1060 crt->issuer_raw.p = p;
1061
1062 if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
1063 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
1064 mbedtls_x509_crt_free(crt);
1065 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
1066 }
1067
1068 if ((ret = mbedtls_x509_get_name(&p, p + len, &crt->issuer)) != 0) {
1069 mbedtls_x509_crt_free(crt);
1070 return ret;
1071 }
1072
1073 crt->issuer_raw.len = p - crt->issuer_raw.p;
1074
1075 /*
1076 * Validity ::= SEQUENCE {
1077 * notBefore Time,
1078 * notAfter Time }
1079 *
1080 */
1081 if ((ret = x509_get_dates(&p, end, &crt->valid_from,
1082 &crt->valid_to)) != 0) {
1083 mbedtls_x509_crt_free(crt);
1084 return ret;
1085 }
1086
1087 /*
1088 * subject Name
1089 */
1090 crt->subject_raw.p = p;
1091
1092 if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
1093 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
1094 mbedtls_x509_crt_free(crt);
1095 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
1096 }
1097
1098 if (len && (ret = mbedtls_x509_get_name(&p, p + len, &crt->subject)) != 0) {
1099 mbedtls_x509_crt_free(crt);
1100 return ret;
1101 }
1102
1103 crt->subject_raw.len = p - crt->subject_raw.p;
1104
1105 /*
1106 * SubjectPublicKeyInfo
1107 */
1108 crt->pk_raw.p = p;
1109 if ((ret = mbedtls_pk_parse_subpubkey(&p, end, &crt->pk)) != 0) {
1110 mbedtls_x509_crt_free(crt);
1111 return ret;
1112 }
1113 crt->pk_raw.len = p - crt->pk_raw.p;
1114
1115 /*
1116 * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
1117 * -- If present, version shall be v2 or v3
1118 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
1119 * -- If present, version shall be v2 or v3
1120 * extensions [3] EXPLICIT Extensions OPTIONAL
1121 * -- If present, version shall be v3
1122 */
1123 if (crt->version == 2 || crt->version == 3) {
1124 ret = x509_get_uid(&p, end, &crt->issuer_id, 1);
1125 if (ret != 0) {
1126 mbedtls_x509_crt_free(crt);
1127 return ret;
1128 }
1129 }
1130
1131 if (crt->version == 2 || crt->version == 3) {
1132 ret = x509_get_uid(&p, end, &crt->subject_id, 2);
1133 if (ret != 0) {
1134 mbedtls_x509_crt_free(crt);
1135 return ret;
1136 }
1137 }
1138
1139 if (crt->version == 3) {
1140 ret = x509_get_crt_ext(&p, end, crt, cb, p_ctx);
1141 if (ret != 0) {
1142 mbedtls_x509_crt_free(crt);
1143 return ret;
1144 }
1145 }
1146
1147 if (p != end) {
1148 mbedtls_x509_crt_free(crt);
1149 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,
1150 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
1151 }
1152
1153 end = crt_end;
1154
1155 /*
1156 * }
1157 * -- end of TBSCertificate
1158 *
1159 * signatureAlgorithm AlgorithmIdentifier,
1160 * signatureValue BIT STRING
1161 */
1162 if ((ret = mbedtls_x509_get_alg(&p, end, &sig_oid2, &sig_params2)) != 0) {
1163 mbedtls_x509_crt_free(crt);
1164 return ret;
1165 }
1166
1167 if (crt->sig_oid.len != sig_oid2.len ||
1168 memcmp(crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len) != 0 ||
1169 sig_params1.tag != sig_params2.tag ||
1170 sig_params1.len != sig_params2.len ||
1171 (sig_params1.len != 0 &&
1172 memcmp(sig_params1.p, sig_params2.p, sig_params1.len) != 0)) {
1173 mbedtls_x509_crt_free(crt);
1174 return MBEDTLS_ERR_X509_SIG_MISMATCH;
1175 }
1176
1177 if ((ret = mbedtls_x509_get_sig(&p, end, &crt->sig)) != 0) {
1178 mbedtls_x509_crt_free(crt);
1179 return ret;
1180 }
1181
1182 if (p != end) {
1183 mbedtls_x509_crt_free(crt);
1184 return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,
1185 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
1186 }
1187
1188 return 0;
1189 }
1190
1191 /*
1192 * Parse one X.509 certificate in DER format from a buffer and add them to a
1193 * chained list
1194 */
mbedtls_x509_crt_parse_der_internal(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen,int make_copy,mbedtls_x509_crt_ext_cb_t cb,void * p_ctx)1195 static int mbedtls_x509_crt_parse_der_internal(mbedtls_x509_crt *chain,
1196 const unsigned char *buf,
1197 size_t buflen,
1198 int make_copy,
1199 mbedtls_x509_crt_ext_cb_t cb,
1200 void *p_ctx)
1201 {
1202 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1203 mbedtls_x509_crt *crt = chain, *prev = NULL;
1204
1205 /*
1206 * Check for valid input
1207 */
1208 if (crt == NULL || buf == NULL) {
1209 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1210 }
1211
1212 while (crt->version != 0 && crt->next != NULL) {
1213 prev = crt;
1214 crt = crt->next;
1215 }
1216
1217 /*
1218 * Add new certificate on the end of the chain if needed.
1219 */
1220 if (crt->version != 0 && crt->next == NULL) {
1221 crt->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crt));
1222
1223 if (crt->next == NULL) {
1224 return MBEDTLS_ERR_X509_ALLOC_FAILED;
1225 }
1226
1227 prev = crt;
1228 mbedtls_x509_crt_init(crt->next);
1229 crt = crt->next;
1230 }
1231
1232 ret = x509_crt_parse_der_core(crt, buf, buflen, make_copy, cb, p_ctx);
1233 if (ret != 0) {
1234 if (prev) {
1235 prev->next = NULL;
1236 }
1237
1238 if (crt != chain) {
1239 mbedtls_free(crt);
1240 }
1241
1242 return ret;
1243 }
1244
1245 return 0;
1246 }
1247
mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen)1248 int mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain,
1249 const unsigned char *buf,
1250 size_t buflen)
1251 {
1252 return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, 0, NULL, NULL);
1253 }
1254
mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen,int make_copy,mbedtls_x509_crt_ext_cb_t cb,void * p_ctx)1255 int mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt *chain,
1256 const unsigned char *buf,
1257 size_t buflen,
1258 int make_copy,
1259 mbedtls_x509_crt_ext_cb_t cb,
1260 void *p_ctx)
1261 {
1262 return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, make_copy, cb, p_ctx);
1263 }
1264
mbedtls_x509_crt_parse_der(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen)1265 int mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain,
1266 const unsigned char *buf,
1267 size_t buflen)
1268 {
1269 return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, 1, NULL, NULL);
1270 }
1271
1272 /*
1273 * Parse one or more PEM certificates from a buffer and add them to the chained
1274 * list
1275 */
mbedtls_x509_crt_parse(mbedtls_x509_crt * chain,const unsigned char * buf,size_t buflen)1276 int mbedtls_x509_crt_parse(mbedtls_x509_crt *chain,
1277 const unsigned char *buf,
1278 size_t buflen)
1279 {
1280 #if defined(MBEDTLS_PEM_PARSE_C)
1281 int success = 0, first_error = 0, total_failed = 0;
1282 int buf_format = MBEDTLS_X509_FORMAT_DER;
1283 #endif
1284
1285 /*
1286 * Check for valid input
1287 */
1288 if (chain == NULL || buf == NULL) {
1289 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1290 }
1291
1292 /*
1293 * Determine buffer content. Buffer contains either one DER certificate or
1294 * one or more PEM certificates.
1295 */
1296 #if defined(MBEDTLS_PEM_PARSE_C)
1297 if (buflen != 0 && buf[buflen - 1] == '\0' &&
1298 strstr((const char *) buf, "-----BEGIN CERTIFICATE-----") != NULL) {
1299 buf_format = MBEDTLS_X509_FORMAT_PEM;
1300 }
1301
1302 if (buf_format == MBEDTLS_X509_FORMAT_DER) {
1303 return mbedtls_x509_crt_parse_der(chain, buf, buflen);
1304 }
1305 #else
1306 return mbedtls_x509_crt_parse_der(chain, buf, buflen);
1307 #endif
1308
1309 #if defined(MBEDTLS_PEM_PARSE_C)
1310 if (buf_format == MBEDTLS_X509_FORMAT_PEM) {
1311 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1312 mbedtls_pem_context pem;
1313
1314 /* 1 rather than 0 since the terminating NULL byte is counted in */
1315 while (buflen > 1) {
1316 size_t use_len;
1317 mbedtls_pem_init(&pem);
1318
1319 /* If we get there, we know the string is null-terminated */
1320 ret = mbedtls_pem_read_buffer(&pem,
1321 "-----BEGIN CERTIFICATE-----",
1322 "-----END CERTIFICATE-----",
1323 buf, NULL, 0, &use_len);
1324
1325 if (ret == 0) {
1326 /*
1327 * Was PEM encoded
1328 */
1329 buflen -= use_len;
1330 buf += use_len;
1331 } else if (ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA) {
1332 return ret;
1333 } else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
1334 mbedtls_pem_free(&pem);
1335
1336 /*
1337 * PEM header and footer were found
1338 */
1339 buflen -= use_len;
1340 buf += use_len;
1341
1342 if (first_error == 0) {
1343 first_error = ret;
1344 }
1345
1346 total_failed++;
1347 continue;
1348 } else {
1349 break;
1350 }
1351
1352 ret = mbedtls_x509_crt_parse_der(chain, pem.buf, pem.buflen);
1353
1354 mbedtls_pem_free(&pem);
1355
1356 if (ret != 0) {
1357 /*
1358 * Quit parsing on a memory error
1359 */
1360 if (ret == MBEDTLS_ERR_X509_ALLOC_FAILED) {
1361 return ret;
1362 }
1363
1364 if (first_error == 0) {
1365 first_error = ret;
1366 }
1367
1368 total_failed++;
1369 continue;
1370 }
1371
1372 success = 1;
1373 }
1374 }
1375
1376 if (success) {
1377 return total_failed;
1378 } else if (first_error) {
1379 return first_error;
1380 } else {
1381 return MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT;
1382 }
1383 #endif /* MBEDTLS_PEM_PARSE_C */
1384 }
1385
1386 #if defined(MBEDTLS_FS_IO)
1387 /*
1388 * Load one or more certificates and add them to the chained list
1389 */
mbedtls_x509_crt_parse_file(mbedtls_x509_crt * chain,const char * path)1390 int mbedtls_x509_crt_parse_file(mbedtls_x509_crt *chain, const char *path)
1391 {
1392 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1393 size_t n;
1394 unsigned char *buf;
1395
1396 if ((ret = mbedtls_pk_load_file(path, &buf, &n)) != 0) {
1397 return ret;
1398 }
1399
1400 ret = mbedtls_x509_crt_parse(chain, buf, n);
1401
1402 mbedtls_platform_zeroize(buf, n);
1403 mbedtls_free(buf);
1404
1405 return ret;
1406 }
1407
mbedtls_x509_crt_parse_path(mbedtls_x509_crt * chain,const char * path)1408 int mbedtls_x509_crt_parse_path(mbedtls_x509_crt *chain, const char *path)
1409 {
1410 int ret = 0;
1411 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
1412 int w_ret;
1413 WCHAR szDir[MAX_PATH];
1414 char filename[MAX_PATH];
1415 char *p;
1416 size_t len = strlen(path);
1417
1418 WIN32_FIND_DATAW file_data;
1419 HANDLE hFind;
1420
1421 if (len > MAX_PATH - 3) {
1422 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1423 }
1424
1425 memset(szDir, 0, sizeof(szDir));
1426 memset(filename, 0, MAX_PATH);
1427 memcpy(filename, path, len);
1428 filename[len++] = '\\';
1429 p = filename + len;
1430 filename[len++] = '*';
1431
1432 w_ret = MultiByteToWideChar(CP_ACP, 0, filename, (int) len, szDir,
1433 MAX_PATH - 3);
1434 if (w_ret == 0) {
1435 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1436 }
1437
1438 hFind = FindFirstFileW(szDir, &file_data);
1439 if (hFind == INVALID_HANDLE_VALUE) {
1440 return MBEDTLS_ERR_X509_FILE_IO_ERROR;
1441 }
1442
1443 len = MAX_PATH - len;
1444 do {
1445 memset(p, 0, len);
1446
1447 if (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
1448 continue;
1449 }
1450
1451 w_ret = WideCharToMultiByte(CP_ACP, 0, file_data.cFileName,
1452 -1,
1453 p, (int) len,
1454 NULL, NULL);
1455 if (w_ret == 0) {
1456 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1457 goto cleanup;
1458 }
1459
1460 w_ret = mbedtls_x509_crt_parse_file(chain, filename);
1461 if (w_ret < 0) {
1462 ret++;
1463 } else {
1464 ret += w_ret;
1465 }
1466 } while (FindNextFileW(hFind, &file_data) != 0);
1467
1468 if (GetLastError() != ERROR_NO_MORE_FILES) {
1469 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1470 }
1471
1472 cleanup:
1473 FindClose(hFind);
1474 #else /* _WIN32 */
1475 int t_ret;
1476 int snp_ret;
1477 struct stat sb;
1478 struct dirent *entry;
1479 char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
1480 DIR *dir = opendir(path);
1481
1482 if (dir == NULL) {
1483 return MBEDTLS_ERR_X509_FILE_IO_ERROR;
1484 }
1485
1486 #if defined(MBEDTLS_THREADING_C)
1487 if ((ret = mbedtls_mutex_lock(&mbedtls_threading_readdir_mutex)) != 0) {
1488 closedir(dir);
1489 return ret;
1490 }
1491 #endif /* MBEDTLS_THREADING_C */
1492
1493 memset(&sb, 0, sizeof(sb));
1494
1495 while ((entry = readdir(dir)) != NULL) {
1496 snp_ret = mbedtls_snprintf(entry_name, sizeof(entry_name),
1497 "%s/%s", path, entry->d_name);
1498
1499 if (snp_ret < 0 || (size_t) snp_ret >= sizeof(entry_name)) {
1500 ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
1501 goto cleanup;
1502 } else if (stat(entry_name, &sb) == -1) {
1503 if (errno == ENOENT) {
1504 /* Broken symbolic link - ignore this entry.
1505 stat(2) will return this error for either (a) a dangling
1506 symlink or (b) a missing file.
1507 Given that we have just obtained the filename from readdir,
1508 assume that it does exist and therefore treat this as a
1509 dangling symlink. */
1510 continue;
1511 } else {
1512 /* Some other file error; report the error. */
1513 ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
1514 goto cleanup;
1515 }
1516 }
1517
1518 if (!S_ISREG(sb.st_mode)) {
1519 continue;
1520 }
1521
1522 // Ignore parse errors
1523 //
1524 t_ret = mbedtls_x509_crt_parse_file(chain, entry_name);
1525 if (t_ret < 0) {
1526 ret++;
1527 } else {
1528 ret += t_ret;
1529 }
1530 }
1531
1532 cleanup:
1533 closedir(dir);
1534
1535 #if defined(MBEDTLS_THREADING_C)
1536 if (mbedtls_mutex_unlock(&mbedtls_threading_readdir_mutex) != 0) {
1537 ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
1538 }
1539 #endif /* MBEDTLS_THREADING_C */
1540
1541 #endif /* _WIN32 */
1542
1543 return ret;
1544 }
1545 #endif /* MBEDTLS_FS_IO */
1546
1547 #if !defined(MBEDTLS_X509_REMOVE_INFO)
x509_info_ext_key_usage(char ** buf,size_t * size,const mbedtls_x509_sequence * extended_key_usage)1548 static int x509_info_ext_key_usage(char **buf, size_t *size,
1549 const mbedtls_x509_sequence *extended_key_usage)
1550 {
1551 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1552 const char *desc;
1553 size_t n = *size;
1554 char *p = *buf;
1555 const mbedtls_x509_sequence *cur = extended_key_usage;
1556 const char *sep = "";
1557
1558 while (cur != NULL) {
1559 if (mbedtls_oid_get_extended_key_usage(&cur->buf, &desc) != 0) {
1560 desc = "???";
1561 }
1562
1563 ret = mbedtls_snprintf(p, n, "%s%s", sep, desc);
1564 MBEDTLS_X509_SAFE_SNPRINTF;
1565
1566 sep = ", ";
1567
1568 cur = cur->next;
1569 }
1570
1571 *size = n;
1572 *buf = p;
1573
1574 return 0;
1575 }
1576
x509_info_cert_policies(char ** buf,size_t * size,const mbedtls_x509_sequence * certificate_policies)1577 static int x509_info_cert_policies(char **buf, size_t *size,
1578 const mbedtls_x509_sequence *certificate_policies)
1579 {
1580 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1581 const char *desc;
1582 size_t n = *size;
1583 char *p = *buf;
1584 const mbedtls_x509_sequence *cur = certificate_policies;
1585 const char *sep = "";
1586
1587 while (cur != NULL) {
1588 if (mbedtls_oid_get_certificate_policies(&cur->buf, &desc) != 0) {
1589 desc = "???";
1590 }
1591
1592 ret = mbedtls_snprintf(p, n, "%s%s", sep, desc);
1593 MBEDTLS_X509_SAFE_SNPRINTF;
1594
1595 sep = ", ";
1596
1597 cur = cur->next;
1598 }
1599
1600 *size = n;
1601 *buf = p;
1602
1603 return 0;
1604 }
1605
1606 /*
1607 * Return an informational string about the certificate.
1608 */
1609 #define BEFORE_COLON 18
1610 #define BC "18"
mbedtls_x509_crt_info(char * buf,size_t size,const char * prefix,const mbedtls_x509_crt * crt)1611 int mbedtls_x509_crt_info(char *buf, size_t size, const char *prefix,
1612 const mbedtls_x509_crt *crt)
1613 {
1614 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1615 size_t n;
1616 char *p;
1617 char key_size_str[BEFORE_COLON];
1618
1619 p = buf;
1620 n = size;
1621
1622 if (NULL == crt) {
1623 ret = mbedtls_snprintf(p, n, "\nCertificate is uninitialised!\n");
1624 MBEDTLS_X509_SAFE_SNPRINTF;
1625
1626 return (int) (size - n);
1627 }
1628
1629 ret = mbedtls_snprintf(p, n, "%scert. version : %d\n",
1630 prefix, crt->version);
1631 MBEDTLS_X509_SAFE_SNPRINTF;
1632 ret = mbedtls_snprintf(p, n, "%sserial number : ",
1633 prefix);
1634 MBEDTLS_X509_SAFE_SNPRINTF;
1635
1636 ret = mbedtls_x509_serial_gets(p, n, &crt->serial);
1637 MBEDTLS_X509_SAFE_SNPRINTF;
1638
1639 ret = mbedtls_snprintf(p, n, "\n%sissuer name : ", prefix);
1640 MBEDTLS_X509_SAFE_SNPRINTF;
1641 ret = mbedtls_x509_dn_gets(p, n, &crt->issuer);
1642 MBEDTLS_X509_SAFE_SNPRINTF;
1643
1644 ret = mbedtls_snprintf(p, n, "\n%ssubject name : ", prefix);
1645 MBEDTLS_X509_SAFE_SNPRINTF;
1646 ret = mbedtls_x509_dn_gets(p, n, &crt->subject);
1647 MBEDTLS_X509_SAFE_SNPRINTF;
1648
1649 ret = mbedtls_snprintf(p, n, "\n%sissued on : " \
1650 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1651 crt->valid_from.year, crt->valid_from.mon,
1652 crt->valid_from.day, crt->valid_from.hour,
1653 crt->valid_from.min, crt->valid_from.sec);
1654 MBEDTLS_X509_SAFE_SNPRINTF;
1655
1656 ret = mbedtls_snprintf(p, n, "\n%sexpires on : " \
1657 "%04d-%02d-%02d %02d:%02d:%02d", prefix,
1658 crt->valid_to.year, crt->valid_to.mon,
1659 crt->valid_to.day, crt->valid_to.hour,
1660 crt->valid_to.min, crt->valid_to.sec);
1661 MBEDTLS_X509_SAFE_SNPRINTF;
1662
1663 ret = mbedtls_snprintf(p, n, "\n%ssigned using : ", prefix);
1664 MBEDTLS_X509_SAFE_SNPRINTF;
1665
1666 ret = mbedtls_x509_sig_alg_gets(p, n, &crt->sig_oid, crt->sig_pk,
1667 crt->sig_md, crt->sig_opts);
1668 MBEDTLS_X509_SAFE_SNPRINTF;
1669
1670 /* Key size */
1671 if ((ret = mbedtls_x509_key_size_helper(key_size_str, BEFORE_COLON,
1672 mbedtls_pk_get_name(&crt->pk))) != 0) {
1673 return ret;
1674 }
1675
1676 ret = mbedtls_snprintf(p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
1677 (int) mbedtls_pk_get_bitlen(&crt->pk));
1678 MBEDTLS_X509_SAFE_SNPRINTF;
1679
1680 /*
1681 * Optional extensions
1682 */
1683
1684 if (crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS) {
1685 ret = mbedtls_snprintf(p, n, "\n%sbasic constraints : CA=%s", prefix,
1686 crt->ca_istrue ? "true" : "false");
1687 MBEDTLS_X509_SAFE_SNPRINTF;
1688
1689 if (crt->max_pathlen > 0) {
1690 ret = mbedtls_snprintf(p, n, ", max_pathlen=%d", crt->max_pathlen - 1);
1691 MBEDTLS_X509_SAFE_SNPRINTF;
1692 }
1693 }
1694
1695 if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) {
1696 ret = mbedtls_snprintf(p, n, "\n%ssubject alt name :", prefix);
1697 MBEDTLS_X509_SAFE_SNPRINTF;
1698
1699 if ((ret = mbedtls_x509_info_subject_alt_name(&p, &n,
1700 &crt->subject_alt_names,
1701 prefix)) != 0) {
1702 return ret;
1703 }
1704 }
1705
1706 if (crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE) {
1707 ret = mbedtls_snprintf(p, n, "\n%scert. type : ", prefix);
1708 MBEDTLS_X509_SAFE_SNPRINTF;
1709
1710 if ((ret = mbedtls_x509_info_cert_type(&p, &n, crt->ns_cert_type)) != 0) {
1711 return ret;
1712 }
1713 }
1714
1715 if (crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE) {
1716 ret = mbedtls_snprintf(p, n, "\n%skey usage : ", prefix);
1717 MBEDTLS_X509_SAFE_SNPRINTF;
1718
1719 if ((ret = mbedtls_x509_info_key_usage(&p, &n, crt->key_usage)) != 0) {
1720 return ret;
1721 }
1722 }
1723
1724 if (crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE) {
1725 ret = mbedtls_snprintf(p, n, "\n%sext key usage : ", prefix);
1726 MBEDTLS_X509_SAFE_SNPRINTF;
1727
1728 if ((ret = x509_info_ext_key_usage(&p, &n,
1729 &crt->ext_key_usage)) != 0) {
1730 return ret;
1731 }
1732 }
1733
1734 if (crt->ext_types & MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES) {
1735 ret = mbedtls_snprintf(p, n, "\n%scertificate policies : ", prefix);
1736 MBEDTLS_X509_SAFE_SNPRINTF;
1737
1738 if ((ret = x509_info_cert_policies(&p, &n,
1739 &crt->certificate_policies)) != 0) {
1740 return ret;
1741 }
1742 }
1743
1744 ret = mbedtls_snprintf(p, n, "\n");
1745 MBEDTLS_X509_SAFE_SNPRINTF;
1746
1747 return (int) (size - n);
1748 }
1749
1750 struct x509_crt_verify_string {
1751 int code;
1752 const char *string;
1753 };
1754
1755 #define X509_CRT_ERROR_INFO(err, err_str, info) { err, info },
1756 static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
1757 MBEDTLS_X509_CRT_ERROR_INFO_LIST
1758 { 0, NULL }
1759 };
1760 #undef X509_CRT_ERROR_INFO
1761
mbedtls_x509_crt_verify_info(char * buf,size_t size,const char * prefix,uint32_t flags)1762 int mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix,
1763 uint32_t flags)
1764 {
1765 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1766 const struct x509_crt_verify_string *cur;
1767 char *p = buf;
1768 size_t n = size;
1769
1770 for (cur = x509_crt_verify_strings; cur->string != NULL; cur++) {
1771 if ((flags & cur->code) == 0) {
1772 continue;
1773 }
1774
1775 ret = mbedtls_snprintf(p, n, "%s%s\n", prefix, cur->string);
1776 MBEDTLS_X509_SAFE_SNPRINTF;
1777 flags ^= cur->code;
1778 }
1779
1780 if (flags != 0) {
1781 ret = mbedtls_snprintf(p, n, "%sUnknown reason "
1782 "(this should not happen)\n", prefix);
1783 MBEDTLS_X509_SAFE_SNPRINTF;
1784 }
1785
1786 return (int) (size - n);
1787 }
1788 #endif /* MBEDTLS_X509_REMOVE_INFO */
1789
mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt * crt,unsigned int usage)1790 int mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt *crt,
1791 unsigned int usage)
1792 {
1793 unsigned int usage_must, usage_may;
1794 unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
1795 | MBEDTLS_X509_KU_DECIPHER_ONLY;
1796
1797 if ((crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE) == 0) {
1798 return 0;
1799 }
1800
1801 usage_must = usage & ~may_mask;
1802
1803 if (((crt->key_usage & ~may_mask) & usage_must) != usage_must) {
1804 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1805 }
1806
1807 usage_may = usage & may_mask;
1808
1809 if (((crt->key_usage & may_mask) | usage_may) != usage_may) {
1810 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1811 }
1812
1813 return 0;
1814 }
1815
mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt * crt,const char * usage_oid,size_t usage_len)1816 int mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt *crt,
1817 const char *usage_oid,
1818 size_t usage_len)
1819 {
1820 const mbedtls_x509_sequence *cur;
1821
1822 /* Extension is not mandatory, absent means no restriction */
1823 if ((crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE) == 0) {
1824 return 0;
1825 }
1826
1827 /*
1828 * Look for the requested usage (or wildcard ANY) in our list
1829 */
1830 for (cur = &crt->ext_key_usage; cur != NULL; cur = cur->next) {
1831 const mbedtls_x509_buf *cur_oid = &cur->buf;
1832
1833 if (cur_oid->len == usage_len &&
1834 memcmp(cur_oid->p, usage_oid, usage_len) == 0) {
1835 return 0;
1836 }
1837
1838 if (MBEDTLS_OID_CMP(MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid) == 0) {
1839 return 0;
1840 }
1841 }
1842
1843 return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
1844 }
1845
1846 #if defined(MBEDTLS_X509_CRL_PARSE_C)
1847 /*
1848 * Return 1 if the certificate is revoked, or 0 otherwise.
1849 */
mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt * crt,const mbedtls_x509_crl * crl)1850 int mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl)
1851 {
1852 const mbedtls_x509_crl_entry *cur = &crl->entry;
1853
1854 while (cur != NULL && cur->serial.len != 0) {
1855 if (crt->serial.len == cur->serial.len &&
1856 memcmp(crt->serial.p, cur->serial.p, crt->serial.len) == 0) {
1857 return 1;
1858 }
1859
1860 cur = cur->next;
1861 }
1862
1863 return 0;
1864 }
1865
1866 /*
1867 * Check that the given certificate is not revoked according to the CRL.
1868 * Skip validation if no CRL for the given CA is present.
1869 */
x509_crt_verifycrl(mbedtls_x509_crt * crt,mbedtls_x509_crt * ca,mbedtls_x509_crl * crl_list,const mbedtls_x509_crt_profile * profile)1870 static int x509_crt_verifycrl(mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
1871 mbedtls_x509_crl *crl_list,
1872 const mbedtls_x509_crt_profile *profile)
1873 {
1874 int flags = 0;
1875 unsigned char hash[MBEDTLS_HASH_MAX_SIZE];
1876 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1877 psa_algorithm_t psa_algorithm;
1878 #else
1879 const mbedtls_md_info_t *md_info;
1880 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1881 size_t hash_length;
1882
1883 if (ca == NULL) {
1884 return flags;
1885 }
1886
1887 while (crl_list != NULL) {
1888 if (crl_list->version == 0 ||
1889 x509_name_cmp(&crl_list->issuer, &ca->subject) != 0) {
1890 crl_list = crl_list->next;
1891 continue;
1892 }
1893
1894 /*
1895 * Check if the CA is configured to sign CRLs
1896 */
1897 if (mbedtls_x509_crt_check_key_usage(ca,
1898 MBEDTLS_X509_KU_CRL_SIGN) != 0) {
1899 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1900 break;
1901 }
1902
1903 /*
1904 * Check if CRL is correctly signed by the trusted CA
1905 */
1906 if (x509_profile_check_md_alg(profile, crl_list->sig_md) != 0) {
1907 flags |= MBEDTLS_X509_BADCRL_BAD_MD;
1908 }
1909
1910 if (x509_profile_check_pk_alg(profile, crl_list->sig_pk) != 0) {
1911 flags |= MBEDTLS_X509_BADCRL_BAD_PK;
1912 }
1913
1914 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1915 psa_algorithm = mbedtls_hash_info_psa_from_md(crl_list->sig_md);
1916 if (psa_hash_compute(psa_algorithm,
1917 crl_list->tbs.p,
1918 crl_list->tbs.len,
1919 hash,
1920 sizeof(hash),
1921 &hash_length) != PSA_SUCCESS) {
1922 /* Note: this can't happen except after an internal error */
1923 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1924 break;
1925 }
1926 #else
1927 md_info = mbedtls_md_info_from_type(crl_list->sig_md);
1928 hash_length = mbedtls_md_get_size(md_info);
1929 if (mbedtls_md(md_info,
1930 crl_list->tbs.p,
1931 crl_list->tbs.len,
1932 hash) != 0) {
1933 /* Note: this can't happen except after an internal error */
1934 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1935 break;
1936 }
1937 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1938
1939 if (x509_profile_check_key(profile, &ca->pk) != 0) {
1940 flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
1941 }
1942
1943 if (mbedtls_pk_verify_ext(crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
1944 crl_list->sig_md, hash, hash_length,
1945 crl_list->sig.p, crl_list->sig.len) != 0) {
1946 flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
1947 break;
1948 }
1949
1950 /*
1951 * Check for validity of CRL (Do not drop out)
1952 */
1953 if (mbedtls_x509_time_is_past(&crl_list->next_update)) {
1954 flags |= MBEDTLS_X509_BADCRL_EXPIRED;
1955 }
1956
1957 if (mbedtls_x509_time_is_future(&crl_list->this_update)) {
1958 flags |= MBEDTLS_X509_BADCRL_FUTURE;
1959 }
1960
1961 /*
1962 * Check if certificate is revoked
1963 */
1964 if (mbedtls_x509_crt_is_revoked(crt, crl_list)) {
1965 flags |= MBEDTLS_X509_BADCERT_REVOKED;
1966 break;
1967 }
1968
1969 crl_list = crl_list->next;
1970 }
1971
1972 return flags;
1973 }
1974 #endif /* MBEDTLS_X509_CRL_PARSE_C */
1975
1976 /*
1977 * Check the signature of a certificate by its parent
1978 */
x509_crt_check_signature(const mbedtls_x509_crt * child,mbedtls_x509_crt * parent,mbedtls_x509_crt_restart_ctx * rs_ctx)1979 static int x509_crt_check_signature(const mbedtls_x509_crt *child,
1980 mbedtls_x509_crt *parent,
1981 mbedtls_x509_crt_restart_ctx *rs_ctx)
1982 {
1983 size_t hash_len;
1984 unsigned char hash[MBEDTLS_HASH_MAX_SIZE];
1985 #if !defined(MBEDTLS_USE_PSA_CRYPTO)
1986 const mbedtls_md_info_t *md_info;
1987 md_info = mbedtls_md_info_from_type(child->sig_md);
1988 hash_len = mbedtls_md_get_size(md_info);
1989
1990 /* Note: hash errors can happen only after an internal error */
1991 if (mbedtls_md(md_info, child->tbs.p, child->tbs.len, hash) != 0) {
1992 return -1;
1993 }
1994 #else
1995 psa_algorithm_t hash_alg = mbedtls_hash_info_psa_from_md(child->sig_md);
1996 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
1997
1998 status = psa_hash_compute(hash_alg,
1999 child->tbs.p,
2000 child->tbs.len,
2001 hash,
2002 sizeof(hash),
2003 &hash_len);
2004 if (status != PSA_SUCCESS) {
2005 return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
2006 }
2007
2008 #endif /* MBEDTLS_USE_PSA_CRYPTO */
2009 /* Skip expensive computation on obvious mismatch */
2010 if (!mbedtls_pk_can_do(&parent->pk, child->sig_pk)) {
2011 return -1;
2012 }
2013
2014 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2015 if (rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA) {
2016 return mbedtls_pk_verify_restartable(&parent->pk,
2017 child->sig_md, hash, hash_len,
2018 child->sig.p, child->sig.len, &rs_ctx->pk);
2019 }
2020 #else
2021 (void) rs_ctx;
2022 #endif
2023
2024 return mbedtls_pk_verify_ext(child->sig_pk, child->sig_opts, &parent->pk,
2025 child->sig_md, hash, hash_len,
2026 child->sig.p, child->sig.len);
2027 }
2028
2029 /*
2030 * Check if 'parent' is a suitable parent (signing CA) for 'child'.
2031 * Return 0 if yes, -1 if not.
2032 *
2033 * top means parent is a locally-trusted certificate
2034 */
x509_crt_check_parent(const mbedtls_x509_crt * child,const mbedtls_x509_crt * parent,int top)2035 static int x509_crt_check_parent(const mbedtls_x509_crt *child,
2036 const mbedtls_x509_crt *parent,
2037 int top)
2038 {
2039 int need_ca_bit;
2040
2041 /* Parent must be the issuer */
2042 if (x509_name_cmp(&child->issuer, &parent->subject) != 0) {
2043 return -1;
2044 }
2045
2046 /* Parent must have the basicConstraints CA bit set as a general rule */
2047 need_ca_bit = 1;
2048
2049 /* Exception: v1/v2 certificates that are locally trusted. */
2050 if (top && parent->version < 3) {
2051 need_ca_bit = 0;
2052 }
2053
2054 if (need_ca_bit && !parent->ca_istrue) {
2055 return -1;
2056 }
2057
2058 if (need_ca_bit &&
2059 mbedtls_x509_crt_check_key_usage(parent, MBEDTLS_X509_KU_KEY_CERT_SIGN) != 0) {
2060 return -1;
2061 }
2062
2063 return 0;
2064 }
2065
2066 /*
2067 * Find a suitable parent for child in candidates, or return NULL.
2068 *
2069 * Here suitable is defined as:
2070 * 1. subject name matches child's issuer
2071 * 2. if necessary, the CA bit is set and key usage allows signing certs
2072 * 3. for trusted roots, the signature is correct
2073 * (for intermediates, the signature is checked and the result reported)
2074 * 4. pathlen constraints are satisfied
2075 *
2076 * If there's a suitable candidate which is also time-valid, return the first
2077 * such. Otherwise, return the first suitable candidate (or NULL if there is
2078 * none).
2079 *
2080 * The rationale for this rule is that someone could have a list of trusted
2081 * roots with two versions on the same root with different validity periods.
2082 * (At least one user reported having such a list and wanted it to just work.)
2083 * The reason we don't just require time-validity is that generally there is
2084 * only one version, and if it's expired we want the flags to state that
2085 * rather than NOT_TRUSTED, as would be the case if we required it here.
2086 *
2087 * The rationale for rule 3 (signature for trusted roots) is that users might
2088 * have two versions of the same CA with different keys in their list, and the
2089 * way we select the correct one is by checking the signature (as we don't
2090 * rely on key identifier extensions). (This is one way users might choose to
2091 * handle key rollover, another relies on self-issued certs, see [SIRO].)
2092 *
2093 * Arguments:
2094 * - [in] child: certificate for which we're looking for a parent
2095 * - [in] candidates: chained list of potential parents
2096 * - [out] r_parent: parent found (or NULL)
2097 * - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0
2098 * - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
2099 * of the chain, 0 otherwise
2100 * - [in] path_cnt: number of intermediates seen so far
2101 * - [in] self_cnt: number of self-signed intermediates seen so far
2102 * (will never be greater than path_cnt)
2103 * - [in-out] rs_ctx: context for restarting operations
2104 *
2105 * Return value:
2106 * - 0 on success
2107 * - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2108 */
x509_crt_find_parent_in(mbedtls_x509_crt * child,mbedtls_x509_crt * candidates,mbedtls_x509_crt ** r_parent,int * r_signature_is_good,int top,unsigned path_cnt,unsigned self_cnt,mbedtls_x509_crt_restart_ctx * rs_ctx)2109 static int x509_crt_find_parent_in(
2110 mbedtls_x509_crt *child,
2111 mbedtls_x509_crt *candidates,
2112 mbedtls_x509_crt **r_parent,
2113 int *r_signature_is_good,
2114 int top,
2115 unsigned path_cnt,
2116 unsigned self_cnt,
2117 mbedtls_x509_crt_restart_ctx *rs_ctx)
2118 {
2119 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2120 mbedtls_x509_crt *parent, *fallback_parent;
2121 int signature_is_good = 0, fallback_signature_is_good;
2122
2123 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2124 /* did we have something in progress? */
2125 if (rs_ctx != NULL && rs_ctx->parent != NULL) {
2126 /* restore saved state */
2127 parent = rs_ctx->parent;
2128 fallback_parent = rs_ctx->fallback_parent;
2129 fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
2130
2131 /* clear saved state */
2132 rs_ctx->parent = NULL;
2133 rs_ctx->fallback_parent = NULL;
2134 rs_ctx->fallback_signature_is_good = 0;
2135
2136 /* resume where we left */
2137 goto check_signature;
2138 }
2139 #endif
2140
2141 fallback_parent = NULL;
2142 fallback_signature_is_good = 0;
2143
2144 for (parent = candidates; parent != NULL; parent = parent->next) {
2145 /* basic parenting skills (name, CA bit, key usage) */
2146 if (x509_crt_check_parent(child, parent, top) != 0) {
2147 continue;
2148 }
2149
2150 /* +1 because stored max_pathlen is 1 higher that the actual value */
2151 if (parent->max_pathlen > 0 &&
2152 (size_t) parent->max_pathlen < 1 + path_cnt - self_cnt) {
2153 continue;
2154 }
2155
2156 /* Signature */
2157 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2158 check_signature:
2159 #endif
2160 ret = x509_crt_check_signature(child, parent, rs_ctx);
2161
2162 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2163 if (rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) {
2164 /* save state */
2165 rs_ctx->parent = parent;
2166 rs_ctx->fallback_parent = fallback_parent;
2167 rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
2168
2169 return ret;
2170 }
2171 #else
2172 (void) ret;
2173 #endif
2174
2175 signature_is_good = ret == 0;
2176 if (top && !signature_is_good) {
2177 continue;
2178 }
2179
2180 /* optional time check */
2181 if (mbedtls_x509_time_is_past(&parent->valid_to) ||
2182 mbedtls_x509_time_is_future(&parent->valid_from)) {
2183 if (fallback_parent == NULL) {
2184 fallback_parent = parent;
2185 fallback_signature_is_good = signature_is_good;
2186 }
2187
2188 continue;
2189 }
2190
2191 *r_parent = parent;
2192 *r_signature_is_good = signature_is_good;
2193
2194 break;
2195 }
2196
2197 if (parent == NULL) {
2198 *r_parent = fallback_parent;
2199 *r_signature_is_good = fallback_signature_is_good;
2200 }
2201
2202 return 0;
2203 }
2204
2205 /*
2206 * Find a parent in trusted CAs or the provided chain, or return NULL.
2207 *
2208 * Searches in trusted CAs first, and return the first suitable parent found
2209 * (see find_parent_in() for definition of suitable).
2210 *
2211 * Arguments:
2212 * - [in] child: certificate for which we're looking for a parent, followed
2213 * by a chain of possible intermediates
2214 * - [in] trust_ca: list of locally trusted certificates
2215 * - [out] parent: parent found (or NULL)
2216 * - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0
2217 * - [out] signature_is_good: 1 if child signature by parent is valid, or 0
2218 * - [in] path_cnt: number of links in the chain so far (EE -> ... -> child)
2219 * - [in] self_cnt: number of self-signed certs in the chain so far
2220 * (will always be no greater than path_cnt)
2221 * - [in-out] rs_ctx: context for restarting operations
2222 *
2223 * Return value:
2224 * - 0 on success
2225 * - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
2226 */
x509_crt_find_parent(mbedtls_x509_crt * child,mbedtls_x509_crt * trust_ca,mbedtls_x509_crt ** parent,int * parent_is_trusted,int * signature_is_good,unsigned path_cnt,unsigned self_cnt,mbedtls_x509_crt_restart_ctx * rs_ctx)2227 static int x509_crt_find_parent(
2228 mbedtls_x509_crt *child,
2229 mbedtls_x509_crt *trust_ca,
2230 mbedtls_x509_crt **parent,
2231 int *parent_is_trusted,
2232 int *signature_is_good,
2233 unsigned path_cnt,
2234 unsigned self_cnt,
2235 mbedtls_x509_crt_restart_ctx *rs_ctx)
2236 {
2237 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2238 mbedtls_x509_crt *search_list;
2239
2240 *parent_is_trusted = 1;
2241
2242 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2243 /* restore then clear saved state if we have some stored */
2244 if (rs_ctx != NULL && rs_ctx->parent_is_trusted != -1) {
2245 *parent_is_trusted = rs_ctx->parent_is_trusted;
2246 rs_ctx->parent_is_trusted = -1;
2247 }
2248 #endif
2249
2250 while (1) {
2251 search_list = *parent_is_trusted ? trust_ca : child->next;
2252
2253 ret = x509_crt_find_parent_in(child, search_list,
2254 parent, signature_is_good,
2255 *parent_is_trusted,
2256 path_cnt, self_cnt, rs_ctx);
2257
2258 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2259 if (rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) {
2260 /* save state */
2261 rs_ctx->parent_is_trusted = *parent_is_trusted;
2262 return ret;
2263 }
2264 #else
2265 (void) ret;
2266 #endif
2267
2268 /* stop here if found or already in second iteration */
2269 if (*parent != NULL || *parent_is_trusted == 0) {
2270 break;
2271 }
2272
2273 /* prepare second iteration */
2274 *parent_is_trusted = 0;
2275 }
2276
2277 /* extra precaution against mistakes in the caller */
2278 if (*parent == NULL) {
2279 *parent_is_trusted = 0;
2280 *signature_is_good = 0;
2281 }
2282
2283 return 0;
2284 }
2285
2286 /*
2287 * Check if an end-entity certificate is locally trusted
2288 *
2289 * Currently we require such certificates to be self-signed (actually only
2290 * check for self-issued as self-signatures are not checked)
2291 */
x509_crt_check_ee_locally_trusted(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca)2292 static int x509_crt_check_ee_locally_trusted(
2293 mbedtls_x509_crt *crt,
2294 mbedtls_x509_crt *trust_ca)
2295 {
2296 mbedtls_x509_crt *cur;
2297
2298 /* must be self-issued */
2299 if (x509_name_cmp(&crt->issuer, &crt->subject) != 0) {
2300 return -1;
2301 }
2302
2303 /* look for an exact match with trusted cert */
2304 for (cur = trust_ca; cur != NULL; cur = cur->next) {
2305 if (crt->raw.len == cur->raw.len &&
2306 memcmp(crt->raw.p, cur->raw.p, crt->raw.len) == 0) {
2307 return 0;
2308 }
2309 }
2310
2311 /* too bad */
2312 return -1;
2313 }
2314
2315 /*
2316 * Build and verify a certificate chain
2317 *
2318 * Given a peer-provided list of certificates EE, C1, ..., Cn and
2319 * a list of trusted certs R1, ... Rp, try to build and verify a chain
2320 * EE, Ci1, ... Ciq [, Rj]
2321 * such that every cert in the chain is a child of the next one,
2322 * jumping to a trusted root as early as possible.
2323 *
2324 * Verify that chain and return it with flags for all issues found.
2325 *
2326 * Special cases:
2327 * - EE == Rj -> return a one-element list containing it
2328 * - EE, Ci1, ..., Ciq cannot be continued with a trusted root
2329 * -> return that chain with NOT_TRUSTED set on Ciq
2330 *
2331 * Tests for (aspects of) this function should include at least:
2332 * - trusted EE
2333 * - EE -> trusted root
2334 * - EE -> intermediate CA -> trusted root
2335 * - if relevant: EE untrusted
2336 * - if relevant: EE -> intermediate, untrusted
2337 * with the aspect under test checked at each relevant level (EE, int, root).
2338 * For some aspects longer chains are required, but usually length 2 is
2339 * enough (but length 1 is not in general).
2340 *
2341 * Arguments:
2342 * - [in] crt: the cert list EE, C1, ..., Cn
2343 * - [in] trust_ca: the trusted list R1, ..., Rp
2344 * - [in] ca_crl, profile: as in verify_with_profile()
2345 * - [out] ver_chain: the built and verified chain
2346 * Only valid when return value is 0, may contain garbage otherwise!
2347 * Restart note: need not be the same when calling again to resume.
2348 * - [in-out] rs_ctx: context for restarting operations
2349 *
2350 * Return value:
2351 * - non-zero if the chain could not be fully built and examined
2352 * - 0 is the chain was successfully built and examined,
2353 * even if it was found to be invalid
2354 */
x509_crt_verify_chain(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,mbedtls_x509_crt_ca_cb_t f_ca_cb,void * p_ca_cb,const mbedtls_x509_crt_profile * profile,mbedtls_x509_crt_verify_chain * ver_chain,mbedtls_x509_crt_restart_ctx * rs_ctx)2355 static int x509_crt_verify_chain(
2356 mbedtls_x509_crt *crt,
2357 mbedtls_x509_crt *trust_ca,
2358 mbedtls_x509_crl *ca_crl,
2359 mbedtls_x509_crt_ca_cb_t f_ca_cb,
2360 void *p_ca_cb,
2361 const mbedtls_x509_crt_profile *profile,
2362 mbedtls_x509_crt_verify_chain *ver_chain,
2363 mbedtls_x509_crt_restart_ctx *rs_ctx)
2364 {
2365 /* Don't initialize any of those variables here, so that the compiler can
2366 * catch potential issues with jumping ahead when restarting */
2367 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2368 uint32_t *flags;
2369 mbedtls_x509_crt_verify_chain_item *cur;
2370 mbedtls_x509_crt *child;
2371 mbedtls_x509_crt *parent;
2372 int parent_is_trusted;
2373 int child_is_trusted;
2374 int signature_is_good;
2375 unsigned self_cnt;
2376 mbedtls_x509_crt *cur_trust_ca = NULL;
2377
2378 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2379 /* resume if we had an operation in progress */
2380 if (rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent) {
2381 /* restore saved state */
2382 *ver_chain = rs_ctx->ver_chain; /* struct copy */
2383 self_cnt = rs_ctx->self_cnt;
2384
2385 /* restore derived state */
2386 cur = &ver_chain->items[ver_chain->len - 1];
2387 child = cur->crt;
2388 flags = &cur->flags;
2389
2390 goto find_parent;
2391 }
2392 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2393
2394 child = crt;
2395 self_cnt = 0;
2396 parent_is_trusted = 0;
2397 child_is_trusted = 0;
2398
2399 while (1) {
2400 /* Add certificate to the verification chain */
2401 cur = &ver_chain->items[ver_chain->len];
2402 cur->crt = child;
2403 cur->flags = 0;
2404 ver_chain->len++;
2405 flags = &cur->flags;
2406
2407 /* Check time-validity (all certificates) */
2408 if (mbedtls_x509_time_is_past(&child->valid_to)) {
2409 *flags |= MBEDTLS_X509_BADCERT_EXPIRED;
2410 }
2411
2412 if (mbedtls_x509_time_is_future(&child->valid_from)) {
2413 *flags |= MBEDTLS_X509_BADCERT_FUTURE;
2414 }
2415
2416 /* Stop here for trusted roots (but not for trusted EE certs) */
2417 if (child_is_trusted) {
2418 return 0;
2419 }
2420
2421 /* Check signature algorithm: MD & PK algs */
2422 if (x509_profile_check_md_alg(profile, child->sig_md) != 0) {
2423 *flags |= MBEDTLS_X509_BADCERT_BAD_MD;
2424 }
2425
2426 if (x509_profile_check_pk_alg(profile, child->sig_pk) != 0) {
2427 *flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2428 }
2429
2430 /* Special case: EE certs that are locally trusted */
2431 if (ver_chain->len == 1 &&
2432 x509_crt_check_ee_locally_trusted(child, trust_ca) == 0) {
2433 return 0;
2434 }
2435
2436 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2437 find_parent:
2438 #endif
2439
2440 /* Obtain list of potential trusted signers from CA callback,
2441 * or use statically provided list. */
2442 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
2443 if (f_ca_cb != NULL) {
2444 mbedtls_x509_crt_free(ver_chain->trust_ca_cb_result);
2445 mbedtls_free(ver_chain->trust_ca_cb_result);
2446 ver_chain->trust_ca_cb_result = NULL;
2447
2448 ret = f_ca_cb(p_ca_cb, child, &ver_chain->trust_ca_cb_result);
2449 if (ret != 0) {
2450 return MBEDTLS_ERR_X509_FATAL_ERROR;
2451 }
2452
2453 cur_trust_ca = ver_chain->trust_ca_cb_result;
2454 } else
2455 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
2456 {
2457 ((void) f_ca_cb);
2458 ((void) p_ca_cb);
2459 cur_trust_ca = trust_ca;
2460 }
2461
2462 /* Look for a parent in trusted CAs or up the chain */
2463 ret = x509_crt_find_parent(child, cur_trust_ca, &parent,
2464 &parent_is_trusted, &signature_is_good,
2465 ver_chain->len - 1, self_cnt, rs_ctx);
2466
2467 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2468 if (rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) {
2469 /* save state */
2470 rs_ctx->in_progress = x509_crt_rs_find_parent;
2471 rs_ctx->self_cnt = self_cnt;
2472 rs_ctx->ver_chain = *ver_chain; /* struct copy */
2473
2474 return ret;
2475 }
2476 #else
2477 (void) ret;
2478 #endif
2479
2480 /* No parent? We're done here */
2481 if (parent == NULL) {
2482 *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2483 return 0;
2484 }
2485
2486 /* Count intermediate self-issued (not necessarily self-signed) certs.
2487 * These can occur with some strategies for key rollover, see [SIRO],
2488 * and should be excluded from max_pathlen checks. */
2489 if (ver_chain->len != 1 &&
2490 x509_name_cmp(&child->issuer, &child->subject) == 0) {
2491 self_cnt++;
2492 }
2493
2494 /* path_cnt is 0 for the first intermediate CA,
2495 * and if parent is trusted it's not an intermediate CA */
2496 if (!parent_is_trusted &&
2497 ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA) {
2498 /* return immediately to avoid overflow the chain array */
2499 return MBEDTLS_ERR_X509_FATAL_ERROR;
2500 }
2501
2502 /* signature was checked while searching parent */
2503 if (!signature_is_good) {
2504 *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
2505 }
2506
2507 /* check size of signing key */
2508 if (x509_profile_check_key(profile, &parent->pk) != 0) {
2509 *flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2510 }
2511
2512 #if defined(MBEDTLS_X509_CRL_PARSE_C)
2513 /* Check trusted CA's CRL for the given crt */
2514 *flags |= x509_crt_verifycrl(child, parent, ca_crl, profile);
2515 #else
2516 (void) ca_crl;
2517 #endif
2518
2519 /* prepare for next iteration */
2520 child = parent;
2521 parent = NULL;
2522 child_is_trusted = parent_is_trusted;
2523 signature_is_good = 0;
2524 }
2525 }
2526
2527 /*
2528 * Check for CN match
2529 */
x509_crt_check_cn(const mbedtls_x509_buf * name,const char * cn,size_t cn_len)2530 static int x509_crt_check_cn(const mbedtls_x509_buf *name,
2531 const char *cn, size_t cn_len)
2532 {
2533 /* try exact match */
2534 if (name->len == cn_len &&
2535 x509_memcasecmp(cn, name->p, cn_len) == 0) {
2536 return 0;
2537 }
2538
2539 /* try wildcard match */
2540 if (x509_check_wildcard(cn, name) == 0) {
2541 return 0;
2542 }
2543
2544 return -1;
2545 }
2546
2547 /*
2548 * Check for SAN match, see RFC 5280 Section 4.2.1.6
2549 */
x509_crt_check_san(const mbedtls_x509_buf * name,const char * cn,size_t cn_len)2550 static int x509_crt_check_san(const mbedtls_x509_buf *name,
2551 const char *cn, size_t cn_len)
2552 {
2553 const unsigned char san_type = (unsigned char) name->tag &
2554 MBEDTLS_ASN1_TAG_VALUE_MASK;
2555
2556 /* dNSName */
2557 if (san_type == MBEDTLS_X509_SAN_DNS_NAME) {
2558 return x509_crt_check_cn(name, cn, cn_len);
2559 }
2560
2561 /* (We may handle other types here later.) */
2562
2563 /* Unrecognized type */
2564 return -1;
2565 }
2566
2567 /*
2568 * Verify the requested CN - only call this if cn is not NULL!
2569 */
x509_crt_verify_name(const mbedtls_x509_crt * crt,const char * cn,uint32_t * flags)2570 static void x509_crt_verify_name(const mbedtls_x509_crt *crt,
2571 const char *cn,
2572 uint32_t *flags)
2573 {
2574 const mbedtls_x509_name *name;
2575 const mbedtls_x509_sequence *cur;
2576 size_t cn_len = strlen(cn);
2577
2578 if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) {
2579 for (cur = &crt->subject_alt_names; cur != NULL; cur = cur->next) {
2580 if (x509_crt_check_san(&cur->buf, cn, cn_len) == 0) {
2581 break;
2582 }
2583 }
2584
2585 if (cur == NULL) {
2586 *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2587 }
2588 } else {
2589 for (name = &crt->subject; name != NULL; name = name->next) {
2590 if (MBEDTLS_OID_CMP(MBEDTLS_OID_AT_CN, &name->oid) == 0 &&
2591 x509_crt_check_cn(&name->val, cn, cn_len) == 0) {
2592 break;
2593 }
2594 }
2595
2596 if (name == NULL) {
2597 *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
2598 }
2599 }
2600 }
2601
2602 /*
2603 * Merge the flags for all certs in the chain, after calling callback
2604 */
x509_crt_merge_flags_with_cb(uint32_t * flags,const mbedtls_x509_crt_verify_chain * ver_chain,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2605 static int x509_crt_merge_flags_with_cb(
2606 uint32_t *flags,
2607 const mbedtls_x509_crt_verify_chain *ver_chain,
2608 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2609 void *p_vrfy)
2610 {
2611 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2612 unsigned i;
2613 uint32_t cur_flags;
2614 const mbedtls_x509_crt_verify_chain_item *cur;
2615
2616 for (i = ver_chain->len; i != 0; --i) {
2617 cur = &ver_chain->items[i-1];
2618 cur_flags = cur->flags;
2619
2620 if (NULL != f_vrfy) {
2621 if ((ret = f_vrfy(p_vrfy, cur->crt, (int) i-1, &cur_flags)) != 0) {
2622 return ret;
2623 }
2624 }
2625
2626 *flags |= cur_flags;
2627 }
2628
2629 return 0;
2630 }
2631
2632 /*
2633 * Verify the certificate validity, with profile, restartable version
2634 *
2635 * This function:
2636 * - checks the requested CN (if any)
2637 * - checks the type and size of the EE cert's key,
2638 * as that isn't done as part of chain building/verification currently
2639 * - builds and verifies the chain
2640 * - then calls the callback and merges the flags
2641 *
2642 * The parameters pairs `trust_ca`, `ca_crl` and `f_ca_cb`, `p_ca_cb`
2643 * are mutually exclusive: If `f_ca_cb != NULL`, it will be used by the
2644 * verification routine to search for trusted signers, and CRLs will
2645 * be disabled. Otherwise, `trust_ca` will be used as the static list
2646 * of trusted signers, and `ca_crl` will be use as the static list
2647 * of CRLs.
2648 */
x509_crt_verify_restartable_ca_cb(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,mbedtls_x509_crt_ca_cb_t f_ca_cb,void * p_ca_cb,const mbedtls_x509_crt_profile * profile,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy,mbedtls_x509_crt_restart_ctx * rs_ctx)2649 static int x509_crt_verify_restartable_ca_cb(mbedtls_x509_crt *crt,
2650 mbedtls_x509_crt *trust_ca,
2651 mbedtls_x509_crl *ca_crl,
2652 mbedtls_x509_crt_ca_cb_t f_ca_cb,
2653 void *p_ca_cb,
2654 const mbedtls_x509_crt_profile *profile,
2655 const char *cn, uint32_t *flags,
2656 int (*f_vrfy)(void *,
2657 mbedtls_x509_crt *,
2658 int,
2659 uint32_t *),
2660 void *p_vrfy,
2661 mbedtls_x509_crt_restart_ctx *rs_ctx)
2662 {
2663 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2664 mbedtls_pk_type_t pk_type;
2665 mbedtls_x509_crt_verify_chain ver_chain;
2666 uint32_t ee_flags;
2667
2668 *flags = 0;
2669 ee_flags = 0;
2670 x509_crt_verify_chain_reset(&ver_chain);
2671
2672 if (profile == NULL) {
2673 ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
2674 goto exit;
2675 }
2676
2677 /* check name if requested */
2678 if (cn != NULL) {
2679 x509_crt_verify_name(crt, cn, &ee_flags);
2680 }
2681
2682 /* Check the type and size of the key */
2683 pk_type = mbedtls_pk_get_type(&crt->pk);
2684
2685 if (x509_profile_check_pk_alg(profile, pk_type) != 0) {
2686 ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
2687 }
2688
2689 if (x509_profile_check_key(profile, &crt->pk) != 0) {
2690 ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
2691 }
2692
2693 /* Check the chain */
2694 ret = x509_crt_verify_chain(crt, trust_ca, ca_crl,
2695 f_ca_cb, p_ca_cb, profile,
2696 &ver_chain, rs_ctx);
2697
2698 if (ret != 0) {
2699 goto exit;
2700 }
2701
2702 /* Merge end-entity flags */
2703 ver_chain.items[0].flags |= ee_flags;
2704
2705 /* Build final flags, calling callback on the way if any */
2706 ret = x509_crt_merge_flags_with_cb(flags, &ver_chain, f_vrfy, p_vrfy);
2707
2708 exit:
2709
2710 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
2711 mbedtls_x509_crt_free(ver_chain.trust_ca_cb_result);
2712 mbedtls_free(ver_chain.trust_ca_cb_result);
2713 ver_chain.trust_ca_cb_result = NULL;
2714 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
2715
2716 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2717 if (rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS) {
2718 mbedtls_x509_crt_restart_free(rs_ctx);
2719 }
2720 #endif
2721
2722 /* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
2723 * the SSL module for authmode optional, but non-zero return from the
2724 * callback means a fatal error so it shouldn't be ignored */
2725 if (ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED) {
2726 ret = MBEDTLS_ERR_X509_FATAL_ERROR;
2727 }
2728
2729 if (ret != 0) {
2730 *flags = (uint32_t) -1;
2731 return ret;
2732 }
2733
2734 if (*flags != 0) {
2735 return MBEDTLS_ERR_X509_CERT_VERIFY_FAILED;
2736 }
2737
2738 return 0;
2739 }
2740
2741
2742 /*
2743 * Verify the certificate validity (default profile, not restartable)
2744 */
mbedtls_x509_crt_verify(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2745 int mbedtls_x509_crt_verify(mbedtls_x509_crt *crt,
2746 mbedtls_x509_crt *trust_ca,
2747 mbedtls_x509_crl *ca_crl,
2748 const char *cn, uint32_t *flags,
2749 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2750 void *p_vrfy)
2751 {
2752 return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl,
2753 NULL, NULL,
2754 &mbedtls_x509_crt_profile_default,
2755 cn, flags,
2756 f_vrfy, p_vrfy, NULL);
2757 }
2758
2759 /*
2760 * Verify the certificate validity (user-chosen profile, not restartable)
2761 */
mbedtls_x509_crt_verify_with_profile(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const mbedtls_x509_crt_profile * profile,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2762 int mbedtls_x509_crt_verify_with_profile(mbedtls_x509_crt *crt,
2763 mbedtls_x509_crt *trust_ca,
2764 mbedtls_x509_crl *ca_crl,
2765 const mbedtls_x509_crt_profile *profile,
2766 const char *cn, uint32_t *flags,
2767 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2768 void *p_vrfy)
2769 {
2770 return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl,
2771 NULL, NULL,
2772 profile, cn, flags,
2773 f_vrfy, p_vrfy, NULL);
2774 }
2775
2776 #if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
2777 /*
2778 * Verify the certificate validity (user-chosen profile, CA callback,
2779 * not restartable).
2780 */
mbedtls_x509_crt_verify_with_ca_cb(mbedtls_x509_crt * crt,mbedtls_x509_crt_ca_cb_t f_ca_cb,void * p_ca_cb,const mbedtls_x509_crt_profile * profile,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy)2781 int mbedtls_x509_crt_verify_with_ca_cb(mbedtls_x509_crt *crt,
2782 mbedtls_x509_crt_ca_cb_t f_ca_cb,
2783 void *p_ca_cb,
2784 const mbedtls_x509_crt_profile *profile,
2785 const char *cn, uint32_t *flags,
2786 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2787 void *p_vrfy)
2788 {
2789 return x509_crt_verify_restartable_ca_cb(crt, NULL, NULL,
2790 f_ca_cb, p_ca_cb,
2791 profile, cn, flags,
2792 f_vrfy, p_vrfy, NULL);
2793 }
2794 #endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
2795
mbedtls_x509_crt_verify_restartable(mbedtls_x509_crt * crt,mbedtls_x509_crt * trust_ca,mbedtls_x509_crl * ca_crl,const mbedtls_x509_crt_profile * profile,const char * cn,uint32_t * flags,int (* f_vrfy)(void *,mbedtls_x509_crt *,int,uint32_t *),void * p_vrfy,mbedtls_x509_crt_restart_ctx * rs_ctx)2796 int mbedtls_x509_crt_verify_restartable(mbedtls_x509_crt *crt,
2797 mbedtls_x509_crt *trust_ca,
2798 mbedtls_x509_crl *ca_crl,
2799 const mbedtls_x509_crt_profile *profile,
2800 const char *cn, uint32_t *flags,
2801 int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
2802 void *p_vrfy,
2803 mbedtls_x509_crt_restart_ctx *rs_ctx)
2804 {
2805 return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl,
2806 NULL, NULL,
2807 profile, cn, flags,
2808 f_vrfy, p_vrfy, rs_ctx);
2809 }
2810
2811
2812 /*
2813 * Initialize a certificate chain
2814 */
mbedtls_x509_crt_init(mbedtls_x509_crt * crt)2815 void mbedtls_x509_crt_init(mbedtls_x509_crt *crt)
2816 {
2817 memset(crt, 0, sizeof(mbedtls_x509_crt));
2818 }
2819
2820 /*
2821 * Unallocate all certificate data
2822 */
mbedtls_x509_crt_free(mbedtls_x509_crt * crt)2823 void mbedtls_x509_crt_free(mbedtls_x509_crt *crt)
2824 {
2825 mbedtls_x509_crt *cert_cur = crt;
2826 mbedtls_x509_crt *cert_prv;
2827
2828 while (cert_cur != NULL) {
2829 mbedtls_pk_free(&cert_cur->pk);
2830
2831 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
2832 mbedtls_free(cert_cur->sig_opts);
2833 #endif
2834
2835 mbedtls_asn1_free_named_data_list_shallow(cert_cur->issuer.next);
2836 mbedtls_asn1_free_named_data_list_shallow(cert_cur->subject.next);
2837 mbedtls_asn1_sequence_free(cert_cur->ext_key_usage.next);
2838 mbedtls_asn1_sequence_free(cert_cur->subject_alt_names.next);
2839 mbedtls_asn1_sequence_free(cert_cur->certificate_policies.next);
2840
2841 if (cert_cur->raw.p != NULL && cert_cur->own_buffer) {
2842 mbedtls_platform_zeroize(cert_cur->raw.p, cert_cur->raw.len);
2843 mbedtls_free(cert_cur->raw.p);
2844 }
2845
2846 cert_prv = cert_cur;
2847 cert_cur = cert_cur->next;
2848
2849 mbedtls_platform_zeroize(cert_prv, sizeof(mbedtls_x509_crt));
2850 if (cert_prv != crt) {
2851 mbedtls_free(cert_prv);
2852 }
2853 }
2854 }
2855
2856 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
2857 /*
2858 * Initialize a restart context
2859 */
mbedtls_x509_crt_restart_init(mbedtls_x509_crt_restart_ctx * ctx)2860 void mbedtls_x509_crt_restart_init(mbedtls_x509_crt_restart_ctx *ctx)
2861 {
2862 mbedtls_pk_restart_init(&ctx->pk);
2863
2864 ctx->parent = NULL;
2865 ctx->fallback_parent = NULL;
2866 ctx->fallback_signature_is_good = 0;
2867
2868 ctx->parent_is_trusted = -1;
2869
2870 ctx->in_progress = x509_crt_rs_none;
2871 ctx->self_cnt = 0;
2872 x509_crt_verify_chain_reset(&ctx->ver_chain);
2873 }
2874
2875 /*
2876 * Free the components of a restart context
2877 */
mbedtls_x509_crt_restart_free(mbedtls_x509_crt_restart_ctx * ctx)2878 void mbedtls_x509_crt_restart_free(mbedtls_x509_crt_restart_ctx *ctx)
2879 {
2880 if (ctx == NULL) {
2881 return;
2882 }
2883
2884 mbedtls_pk_restart_free(&ctx->pk);
2885 mbedtls_x509_crt_restart_init(ctx);
2886 }
2887 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
2888
2889 #endif /* MBEDTLS_X509_CRT_PARSE_C */
2890