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mbedtls/library/x509_crt.c
Tom Cosgrove b96c309395 Don't use lstrlenW() on Windows 
The lstrlenW() function isn't available to UWP apps, and isn't necessary, since
when given -1, WideCharToMultiByte() will process the terminating null character
itself (and the length returned by the function includes this character).

Resolves #2994

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
2023-02-10 12:52:13 +00:00

2889 lines
87 KiB
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/*
* X.509 certificate parsing and verification
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* The ITU-T X.509 standard defines a certificate format for PKI.
*
* http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
* http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
* http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
*
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
*
* [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf
*/
#include "common.h"
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#include "mbedtls/x509_crt.h"
#include "mbedtls/error.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#if defined(MBEDTLS_PEM_PARSE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "mbedtls/psa_util.h"
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#include "hash_info.h"
#include "mbedtls/platform.h"
#if defined(MBEDTLS_THREADING_C)
#include "mbedtls/threading.h"
#endif
#if defined(MBEDTLS_HAVE_TIME)
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
#include <windows.h>
#else
#include <time.h>
#endif
#endif
#if defined(MBEDTLS_FS_IO)
#include <stdio.h>
#if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
#include <sys/types.h>
#include <sys/stat.h>
#if defined(__MBED__)
#include <platform/mbed_retarget.h>
#else
#include <dirent.h>
#endif /* __MBED__ */
#include <errno.h>
#endif /* !_WIN32 || EFIX64 || EFI32 */
#endif
/*
* Item in a verification chain: cert and flags for it
*/
typedef struct {
mbedtls_x509_crt *crt;
uint32_t flags;
} x509_crt_verify_chain_item;
/*
* Max size of verification chain: end-entity + intermediates + trusted root
*/
#define X509_MAX_VERIFY_CHAIN_SIZE (MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2)
/* Default profile. Do not remove items unless there are serious security
* concerns. */
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
{
/* Hashes from SHA-256 and above. Note that this selection
* should be aligned with ssl_preset_default_hashes in ssl_tls.c. */
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA512),
0xFFFFFFF, /* Any PK alg */
#if defined(MBEDTLS_ECP_C)
/* Curves at or above 128-bit security level. Note that this selection
* should be aligned with ssl_preset_default_curves in ssl_tls.c. */
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP384R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP521R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP256R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP384R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP512R1) |
0,
#else
0,
#endif
2048,
};
/* Next-generation profile. Currently identical to the default, but may
* be tightened at any time. */
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next =
{
/* Hashes from SHA-256 and above. */
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA512),
0xFFFFFFF, /* Any PK alg */
#if defined(MBEDTLS_ECP_C)
/* Curves at or above 128-bit security level. */
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP384R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP521R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP256R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP384R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_BP512R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256K1),
#else
0,
#endif
2048,
};
/*
* NSA Suite B Profile
*/
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb =
{
/* Only SHA-256 and 384 */
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA256) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_MD_SHA384),
/* Only ECDSA */
MBEDTLS_X509_ID_FLAG(MBEDTLS_PK_ECDSA) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_PK_ECKEY),
#if defined(MBEDTLS_ECP_C)
/* Only NIST P-256 and P-384 */
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP256R1) |
MBEDTLS_X509_ID_FLAG(MBEDTLS_ECP_DP_SECP384R1),
#else
0,
#endif
0,
};
/*
* Empty / all-forbidden profile
*/
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none =
{
0,
0,
0,
(uint32_t) -1,
};
/*
* Check md_alg against profile
* Return 0 if md_alg is acceptable for this profile, -1 otherwise
*/
static int x509_profile_check_md_alg(const mbedtls_x509_crt_profile *profile,
mbedtls_md_type_t md_alg)
{
if (md_alg == MBEDTLS_MD_NONE) {
return -1;
}
if ((profile->allowed_mds & MBEDTLS_X509_ID_FLAG(md_alg)) != 0) {
return 0;
}
return -1;
}
/*
* Check pk_alg against profile
* Return 0 if pk_alg is acceptable for this profile, -1 otherwise
*/
static int x509_profile_check_pk_alg(const mbedtls_x509_crt_profile *profile,
mbedtls_pk_type_t pk_alg)
{
if (pk_alg == MBEDTLS_PK_NONE) {
return -1;
}
if ((profile->allowed_pks & MBEDTLS_X509_ID_FLAG(pk_alg)) != 0) {
return 0;
}
return -1;
}
/*
* Check key against profile
* Return 0 if pk is acceptable for this profile, -1 otherwise
*/
static int x509_profile_check_key(const mbedtls_x509_crt_profile *profile,
const mbedtls_pk_context *pk)
{
const mbedtls_pk_type_t pk_alg = mbedtls_pk_get_type(pk);
#if defined(MBEDTLS_RSA_C)
if (pk_alg == MBEDTLS_PK_RSA || pk_alg == MBEDTLS_PK_RSASSA_PSS) {
if (mbedtls_pk_get_bitlen(pk) >= profile->rsa_min_bitlen) {
return 0;
}
return -1;
}
#endif
#if defined(MBEDTLS_ECP_C)
if (pk_alg == MBEDTLS_PK_ECDSA ||
pk_alg == MBEDTLS_PK_ECKEY ||
pk_alg == MBEDTLS_PK_ECKEY_DH) {
const mbedtls_ecp_group_id gid = mbedtls_pk_ec(*pk)->grp.id;
if (gid == MBEDTLS_ECP_DP_NONE) {
return -1;
}
if ((profile->allowed_curves & MBEDTLS_X509_ID_FLAG(gid)) != 0) {
return 0;
}
return -1;
}
#endif
return -1;
}
/*
* Like memcmp, but case-insensitive and always returns -1 if different
*/
static int x509_memcasecmp(const void *s1, const void *s2, size_t len)
{
size_t i;
unsigned char diff;
const unsigned char *n1 = s1, *n2 = s2;
for (i = 0; i < len; i++) {
diff = n1[i] ^ n2[i];
if (diff == 0) {
continue;
}
if (diff == 32 &&
((n1[i] >= 'a' && n1[i] <= 'z') ||
(n1[i] >= 'A' && n1[i] <= 'Z'))) {
continue;
}
return -1;
}
return 0;
}
/*
* Return 0 if name matches wildcard, -1 otherwise
*/
static int x509_check_wildcard(const char *cn, const mbedtls_x509_buf *name)
{
size_t i;
size_t cn_idx = 0, cn_len = strlen(cn);
/* We can't have a match if there is no wildcard to match */
if (name->len < 3 || name->p[0] != '*' || name->p[1] != '.') {
return -1;
}
for (i = 0; i < cn_len; ++i) {
if (cn[i] == '.') {
cn_idx = i;
break;
}
}
if (cn_idx == 0) {
return -1;
}
if (cn_len - cn_idx == name->len - 1 &&
x509_memcasecmp(name->p + 1, cn + cn_idx, name->len - 1) == 0) {
return 0;
}
return -1;
}
/*
* Compare two X.509 strings, case-insensitive, and allowing for some encoding
* variations (but not all).
*
* Return 0 if equal, -1 otherwise.
*/
static int x509_string_cmp(const mbedtls_x509_buf *a, const mbedtls_x509_buf *b)
{
if (a->tag == b->tag &&
a->len == b->len &&
memcmp(a->p, b->p, b->len) == 0) {
return 0;
}
if ((a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING) &&
(b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING) &&
a->len == b->len &&
x509_memcasecmp(a->p, b->p, b->len) == 0) {
return 0;
}
return -1;
}
/*
* Compare two X.509 Names (aka rdnSequence).
*
* See RFC 5280 section 7.1, though we don't implement the whole algorithm:
* we sometimes return unequal when the full algorithm would return equal,
* but never the other way. (In particular, we don't do Unicode normalisation
* or space folding.)
*
* Return 0 if equal, -1 otherwise.
*/
static int x509_name_cmp(const mbedtls_x509_name *a, const mbedtls_x509_name *b)
{
/* Avoid recursion, it might not be optimised by the compiler */
while (a != NULL || b != NULL) {
if (a == NULL || b == NULL) {
return -1;
}
/* type */
if (a->oid.tag != b->oid.tag ||
a->oid.len != b->oid.len ||
memcmp(a->oid.p, b->oid.p, b->oid.len) != 0) {
return -1;
}
/* value */
if (x509_string_cmp(&a->val, &b->val) != 0) {
return -1;
}
/* structure of the list of sets */
if (a->next_merged != b->next_merged) {
return -1;
}
a = a->next;
b = b->next;
}
/* a == NULL == b */
return 0;
}
/*
* Reset (init or clear) a verify_chain
*/
static void x509_crt_verify_chain_reset(
mbedtls_x509_crt_verify_chain *ver_chain)
{
size_t i;
for (i = 0; i < MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE; i++) {
ver_chain->items[i].crt = NULL;
ver_chain->items[i].flags = (uint32_t) -1;
}
ver_chain->len = 0;
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
ver_chain->trust_ca_cb_result = NULL;
#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
}
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
static int x509_get_version(unsigned char **p,
const unsigned char *end,
int *ver)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED |
0)) != 0) {
if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
*ver = 0;
return 0;
}
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
}
end = *p + len;
if ((ret = mbedtls_asn1_get_int(p, end, ver)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION, ret);
}
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return 0;
}
/*
* Validity ::= SEQUENCE {
* notBefore Time,
* notAfter Time }
*/
static int x509_get_dates(unsigned char **p,
const unsigned char *end,
mbedtls_x509_time *from,
mbedtls_x509_time *to)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE, ret);
}
end = *p + len;
if ((ret = mbedtls_x509_get_time(p, end, from)) != 0) {
return ret;
}
if ((ret = mbedtls_x509_get_time(p, end, to)) != 0) {
return ret;
}
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return 0;
}
/*
* X.509 v2/v3 unique identifier (not parsed)
*/
static int x509_get_uid(unsigned char **p,
const unsigned char *end,
mbedtls_x509_buf *uid, int n)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if (*p == end) {
return 0;
}
uid->tag = **p;
if ((ret = mbedtls_asn1_get_tag(p, end, &uid->len,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED |
n)) != 0) {
if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
return 0;
}
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
}
uid->p = *p;
*p += uid->len;
return 0;
}
static int x509_get_basic_constraints(unsigned char **p,
const unsigned char *end,
int *ca_istrue,
int *max_pathlen)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
/*
* BasicConstraints ::= SEQUENCE {
* cA BOOLEAN DEFAULT FALSE,
* pathLenConstraint INTEGER (0..MAX) OPTIONAL }
*/
*ca_istrue = 0; /* DEFAULT FALSE */
*max_pathlen = 0; /* endless */
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
if (*p == end) {
return 0;
}
if ((ret = mbedtls_asn1_get_bool(p, end, ca_istrue)) != 0) {
if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {
ret = mbedtls_asn1_get_int(p, end, ca_istrue);
}
if (ret != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
if (*ca_istrue != 0) {
*ca_istrue = 1;
}
}
if (*p == end) {
return 0;
}
if ((ret = mbedtls_asn1_get_int(p, end, max_pathlen)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
/* Do not accept max_pathlen equal to INT_MAX to avoid a signed integer
* overflow, which is an undefined behavior. */
if (*max_pathlen == INT_MAX) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_INVALID_LENGTH);
}
(*max_pathlen)++;
return 0;
}
/*
* ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
*
* KeyPurposeId ::= OBJECT IDENTIFIER
*/
static int x509_get_ext_key_usage(unsigned char **p,
const unsigned char *end,
mbedtls_x509_sequence *ext_key_usage)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if ((ret = mbedtls_asn1_get_sequence_of(p, end, ext_key_usage, MBEDTLS_ASN1_OID)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
/* Sequence length must be >= 1 */
if (ext_key_usage->buf.p == NULL) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_INVALID_LENGTH);
}
return 0;
}
/*
* id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 }
*
* anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 }
*
* certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
*
* PolicyInformation ::= SEQUENCE {
* policyIdentifier CertPolicyId,
* policyQualifiers SEQUENCE SIZE (1..MAX) OF
* PolicyQualifierInfo OPTIONAL }
*
* CertPolicyId ::= OBJECT IDENTIFIER
*
* PolicyQualifierInfo ::= SEQUENCE {
* policyQualifierId PolicyQualifierId,
* qualifier ANY DEFINED BY policyQualifierId }
*
* -- policyQualifierIds for Internet policy qualifiers
*
* id-qt OBJECT IDENTIFIER ::= { id-pkix 2 }
* id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 }
* id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 }
*
* PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice )
*
* Qualifier ::= CHOICE {
* cPSuri CPSuri,
* userNotice UserNotice }
*
* CPSuri ::= IA5String
*
* UserNotice ::= SEQUENCE {
* noticeRef NoticeReference OPTIONAL,
* explicitText DisplayText OPTIONAL }
*
* NoticeReference ::= SEQUENCE {
* organization DisplayText,
* noticeNumbers SEQUENCE OF INTEGER }
*
* DisplayText ::= CHOICE {
* ia5String IA5String (SIZE (1..200)),
* visibleString VisibleString (SIZE (1..200)),
* bmpString BMPString (SIZE (1..200)),
* utf8String UTF8String (SIZE (1..200)) }
*
* NOTE: we only parse and use anyPolicy without qualifiers at this point
* as defined in RFC 5280.
*/
static int x509_get_certificate_policies(unsigned char **p,
const unsigned char *end,
mbedtls_x509_sequence *certificate_policies)
{
int ret, parse_ret = 0;
size_t len;
mbedtls_asn1_buf *buf;
mbedtls_asn1_sequence *cur = certificate_policies;
/* Get main sequence tag */
ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE);
if (ret != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
if (*p + len != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
/*
* Cannot be an empty sequence.
*/
if (len == 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
while (*p < end) {
mbedtls_x509_buf policy_oid;
const unsigned char *policy_end;
/*
* Get the policy sequence
*/
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
policy_end = *p + len;
if ((ret = mbedtls_asn1_get_tag(p, policy_end, &len,
MBEDTLS_ASN1_OID)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
policy_oid.tag = MBEDTLS_ASN1_OID;
policy_oid.len = len;
policy_oid.p = *p;
/*
* Only AnyPolicy is currently supported when enforcing policy.
*/
if (MBEDTLS_OID_CMP(MBEDTLS_OID_ANY_POLICY, &policy_oid) != 0) {
/*
* Set the parsing return code but continue parsing, in case this
* extension is critical.
*/
parse_ret = MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE;
}
/* Allocate and assign next pointer */
if (cur->buf.p != NULL) {
if (cur->next != NULL) {
return MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
}
cur->next = mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));
if (cur->next == NULL) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_ALLOC_FAILED);
}
cur = cur->next;
}
buf = &(cur->buf);
buf->tag = policy_oid.tag;
buf->p = policy_oid.p;
buf->len = policy_oid.len;
*p += len;
/*
* If there is an optional qualifier, then *p < policy_end
* Check the Qualifier len to verify it doesn't exceed policy_end.
*/
if (*p < policy_end) {
if ((ret = mbedtls_asn1_get_tag(p, policy_end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) !=
0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
/*
* Skip the optional policy qualifiers.
*/
*p += len;
}
if (*p != policy_end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
}
/* Set final sequence entry's next pointer to NULL */
cur->next = NULL;
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return parse_ret;
}
/*
* X.509 v3 extensions
*
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
unsigned char *end_ext_data, *start_ext_octet, *end_ext_octet;
if (*p == end) {
return 0;
}
if ((ret = mbedtls_x509_get_ext(p, end, &crt->v3_ext, 3)) != 0) {
return ret;
}
end = crt->v3_ext.p + crt->v3_ext.len;
while (*p < end) {
/*
* Extension ::= SEQUENCE {
* extnID OBJECT IDENTIFIER,
* critical BOOLEAN DEFAULT FALSE,
* extnValue OCTET STRING }
*/
mbedtls_x509_buf extn_oid = { 0, 0, NULL };
int is_critical = 0; /* DEFAULT FALSE */
int ext_type = 0;
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
end_ext_data = *p + len;
/* Get extension ID */
if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &extn_oid.len,
MBEDTLS_ASN1_OID)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
extn_oid.tag = MBEDTLS_ASN1_OID;
extn_oid.p = *p;
*p += extn_oid.len;
/* Get optional critical */
if ((ret = mbedtls_asn1_get_bool(p, end_ext_data, &is_critical)) != 0 &&
(ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
/* Data should be octet string type */
if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len,
MBEDTLS_ASN1_OCTET_STRING)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
}
start_ext_octet = *p;
end_ext_octet = *p + len;
if (end_ext_octet != end_ext_data) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
/*
* Detect supported extensions
*/
ret = mbedtls_oid_get_x509_ext_type(&extn_oid, &ext_type);
if (ret != 0) {
/* Give the callback (if any) a chance to handle the extension */
if (cb != NULL) {
ret = cb(p_ctx, crt, &extn_oid, is_critical, *p, end_ext_octet);
if (ret != 0 && is_critical) {
return ret;
}
*p = end_ext_octet;
continue;
}
/* No parser found, skip extension */
*p = end_ext_octet;
if (is_critical) {
/* Data is marked as critical: fail */
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
}
continue;
}
/* Forbid repeated extensions */
if ((crt->ext_types & ext_type) != 0) {
return MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
}
crt->ext_types |= ext_type;
switch (ext_type) {
case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
/* Parse basic constraints */
if ((ret = x509_get_basic_constraints(p, end_ext_octet,
&crt->ca_istrue, &crt->max_pathlen)) != 0) {
return ret;
}
break;
case MBEDTLS_X509_EXT_KEY_USAGE:
/* Parse key usage */
if ((ret = mbedtls_x509_get_key_usage(p, end_ext_octet,
&crt->key_usage)) != 0) {
return ret;
}
break;
case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
/* Parse extended key usage */
if ((ret = x509_get_ext_key_usage(p, end_ext_octet,
&crt->ext_key_usage)) != 0) {
return ret;
}
break;
case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
/* Parse subject alt name */
if ((ret = mbedtls_x509_get_subject_alt_name(p, end_ext_octet,
&crt->subject_alt_names)) != 0) {
return ret;
}
break;
case MBEDTLS_X509_EXT_NS_CERT_TYPE:
/* Parse netscape certificate type */
if ((ret = mbedtls_x509_get_ns_cert_type(p, end_ext_octet,
&crt->ns_cert_type)) != 0) {
return ret;
}
break;
case MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES:
/* Parse certificate policies type */
if ((ret = x509_get_certificate_policies(p, end_ext_octet,
&crt->certificate_policies)) != 0) {
/* Give the callback (if any) a chance to handle the extension
* if it contains unsupported policies */
if (ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE && cb != NULL &&
cb(p_ctx, crt, &extn_oid, is_critical,
start_ext_octet, end_ext_octet) == 0) {
break;
}
if (is_critical) {
return ret;
} else
/*
* If MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE is returned, then we
* cannot interpret or enforce the policy. However, it is up to
* the user to choose how to enforce the policies,
* unless the extension is critical.
*/
if (ret != MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE) {
return ret;
}
}
break;
default:
/*
* If this is a non-critical extension, which the oid layer
* supports, but there isn't an x509 parser for it,
* skip the extension.
*/
if (is_critical) {
return MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE;
} else {
*p = end_ext_octet;
}
}
}
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return 0;
}
/*
* Parse and fill a single X.509 certificate in DER format
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
unsigned char *p, *end, *crt_end;
mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;
memset(&sig_params1, 0, sizeof(mbedtls_x509_buf));
memset(&sig_params2, 0, sizeof(mbedtls_x509_buf));
memset(&sig_oid2, 0, sizeof(mbedtls_x509_buf));
/*
* Check for valid input
*/
if (crt == NULL || buf == NULL) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
/* Use the original buffer until we figure out actual length. */
p = (unsigned char *) buf;
len = buflen;
end = p + len;
/*
* Certificate ::= SEQUENCE {
* tbsCertificate TBSCertificate,
* signatureAlgorithm AlgorithmIdentifier,
* signatureValue BIT STRING }
*/
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERR_X509_INVALID_FORMAT;
}
end = crt_end = p + len;
crt->raw.len = crt_end - buf;
if (make_copy != 0) {
/* Create and populate a new buffer for the raw field. */
crt->raw.p = p = mbedtls_calloc(1, crt->raw.len);
if (crt->raw.p == NULL) {
return MBEDTLS_ERR_X509_ALLOC_FAILED;
}
memcpy(crt->raw.p, buf, crt->raw.len);
crt->own_buffer = 1;
p += crt->raw.len - len;
end = crt_end = p + len;
} else {
crt->raw.p = (unsigned char *) buf;
crt->own_buffer = 0;
}
/*
* TBSCertificate ::= SEQUENCE {
*/
crt->tbs.p = p;
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
}
end = p + len;
crt->tbs.len = end - crt->tbs.p;
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*
* CertificateSerialNumber ::= INTEGER
*
* signature AlgorithmIdentifier
*/
if ((ret = x509_get_version(&p, end, &crt->version)) != 0 ||
(ret = mbedtls_x509_get_serial(&p, end, &crt->serial)) != 0 ||
(ret = mbedtls_x509_get_alg(&p, end, &crt->sig_oid,
&sig_params1)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
if (crt->version < 0 || crt->version > 2) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERR_X509_UNKNOWN_VERSION;
}
crt->version++;
if ((ret = mbedtls_x509_get_sig_alg(&crt->sig_oid, &sig_params1,
&crt->sig_md, &crt->sig_pk,
&crt->sig_opts)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
/*
* issuer Name
*/
crt->issuer_raw.p = p;
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
}
if ((ret = mbedtls_x509_get_name(&p, p + len, &crt->issuer)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
crt->issuer_raw.len = p - crt->issuer_raw.p;
/*
* Validity ::= SEQUENCE {
* notBefore Time,
* notAfter Time }
*
*/
if ((ret = x509_get_dates(&p, end, &crt->valid_from,
&crt->valid_to)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
/*
* subject Name
*/
crt->subject_raw.p = p;
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);
}
if (len && (ret = mbedtls_x509_get_name(&p, p + len, &crt->subject)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
crt->subject_raw.len = p - crt->subject_raw.p;
/*
* SubjectPublicKeyInfo
*/
crt->pk_raw.p = p;
if ((ret = mbedtls_pk_parse_subpubkey(&p, end, &crt->pk)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
crt->pk_raw.len = p - crt->pk_raw.p;
/*
* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
* -- If present, version shall be v2 or v3
* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
* -- If present, version shall be v2 or v3
* extensions [3] EXPLICIT Extensions OPTIONAL
* -- If present, version shall be v3
*/
if (crt->version == 2 || crt->version == 3) {
ret = x509_get_uid(&p, end, &crt->issuer_id, 1);
if (ret != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
}
if (crt->version == 2 || crt->version == 3) {
ret = x509_get_uid(&p, end, &crt->subject_id, 2);
if (ret != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
}
if (crt->version == 3) {
ret = x509_get_crt_ext(&p, end, crt, cb, p_ctx);
if (ret != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
}
if (p != end) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
end = crt_end;
/*
* }
* -- end of TBSCertificate
*
* signatureAlgorithm AlgorithmIdentifier,
* signatureValue BIT STRING
*/
if ((ret = mbedtls_x509_get_alg(&p, end, &sig_oid2, &sig_params2)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
if (crt->sig_oid.len != sig_oid2.len ||
memcmp(crt->sig_oid.p, sig_oid2.p, crt->sig_oid.len) != 0 ||
sig_params1.tag != sig_params2.tag ||
sig_params1.len != sig_params2.len ||
(sig_params1.len != 0 &&
memcmp(sig_params1.p, sig_params2.p, sig_params1.len) != 0)) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERR_X509_SIG_MISMATCH;
}
if ((ret = mbedtls_x509_get_sig(&p, end, &crt->sig)) != 0) {
mbedtls_x509_crt_free(crt);
return ret;
}
if (p != end) {
mbedtls_x509_crt_free(crt);
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return 0;
}
/*
* Parse one X.509 certificate in DER format from a buffer and add them to a
* chained list
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_x509_crt *crt = chain, *prev = NULL;
/*
* Check for valid input
*/
if (crt == NULL || buf == NULL) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
while (crt->version != 0 && crt->next != NULL) {
prev = crt;
crt = crt->next;
}
/*
* Add new certificate on the end of the chain if needed.
*/
if (crt->version != 0 && crt->next == NULL) {
crt->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crt));
if (crt->next == NULL) {
return MBEDTLS_ERR_X509_ALLOC_FAILED;
}
prev = crt;
mbedtls_x509_crt_init(crt->next);
crt = crt->next;
}
ret = x509_crt_parse_der_core(crt, buf, buflen, make_copy, cb, p_ctx);
if (ret != 0) {
if (prev) {
prev->next = NULL;
}
if (crt != chain) {
mbedtls_free(crt);
}
return ret;
}
return 0;
}
int mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain,
const unsigned char *buf,
size_t buflen)
{
return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, 0, NULL, NULL);
}
int 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)
{
return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, make_copy, cb, p_ctx);
}
int mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain,
const unsigned char *buf,
size_t buflen)
{
return mbedtls_x509_crt_parse_der_internal(chain, buf, buflen, 1, NULL, NULL);
}
/*
* Parse one or more PEM certificates from a buffer and add them to the chained
* list
*/
int mbedtls_x509_crt_parse(mbedtls_x509_crt *chain,
const unsigned char *buf,
size_t buflen)
{
#if defined(MBEDTLS_PEM_PARSE_C)
int success = 0, first_error = 0, total_failed = 0;
int buf_format = MBEDTLS_X509_FORMAT_DER;
#endif
/*
* Check for valid input
*/
if (chain == NULL || buf == NULL) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
/*
* Determine buffer content. Buffer contains either one DER certificate or
* one or more PEM certificates.
*/
#if defined(MBEDTLS_PEM_PARSE_C)
if (buflen != 0 && buf[buflen - 1] == '\0' &&
strstr((const char *) buf, "-----BEGIN CERTIFICATE-----") != NULL) {
buf_format = MBEDTLS_X509_FORMAT_PEM;
}
if (buf_format == MBEDTLS_X509_FORMAT_DER) {
return mbedtls_x509_crt_parse_der(chain, buf, buflen);
}
#else
return mbedtls_x509_crt_parse_der(chain, buf, buflen);
#endif
#if defined(MBEDTLS_PEM_PARSE_C)
if (buf_format == MBEDTLS_X509_FORMAT_PEM) {
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_pem_context pem;
/* 1 rather than 0 since the terminating NULL byte is counted in */
while (buflen > 1) {
size_t use_len;
mbedtls_pem_init(&pem);
/* If we get there, we know the string is null-terminated */
ret = mbedtls_pem_read_buffer(&pem,
"-----BEGIN CERTIFICATE-----",
"-----END CERTIFICATE-----",
buf, NULL, 0, &use_len);
if (ret == 0) {
/*
* Was PEM encoded
*/
buflen -= use_len;
buf += use_len;
} else if (ret == MBEDTLS_ERR_PEM_BAD_INPUT_DATA) {
return ret;
} else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
mbedtls_pem_free(&pem);
/*
* PEM header and footer were found
*/
buflen -= use_len;
buf += use_len;
if (first_error == 0) {
first_error = ret;
}
total_failed++;
continue;
} else {
break;
}
ret = mbedtls_x509_crt_parse_der(chain, pem.buf, pem.buflen);
mbedtls_pem_free(&pem);
if (ret != 0) {
/*
* Quit parsing on a memory error
*/
if (ret == MBEDTLS_ERR_X509_ALLOC_FAILED) {
return ret;
}
if (first_error == 0) {
first_error = ret;
}
total_failed++;
continue;
}
success = 1;
}
}
if (success) {
return total_failed;
} else if (first_error) {
return first_error;
} else {
return MBEDTLS_ERR_X509_CERT_UNKNOWN_FORMAT;
}
#endif /* MBEDTLS_PEM_PARSE_C */
}
#if defined(MBEDTLS_FS_IO)
/*
* Load one or more certificates and add them to the chained list
*/
int mbedtls_x509_crt_parse_file(mbedtls_x509_crt *chain, const char *path)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
unsigned char *buf;
if ((ret = mbedtls_pk_load_file(path, &buf, &n)) != 0) {
return ret;
}
ret = mbedtls_x509_crt_parse(chain, buf, n);
mbedtls_platform_zeroize(buf, n);
mbedtls_free(buf);
return ret;
}
int mbedtls_x509_crt_parse_path(mbedtls_x509_crt *chain, const char *path)
{
int ret = 0;
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
int w_ret;
WCHAR szDir[MAX_PATH];
char filename[MAX_PATH];
char *p;
size_t len = strlen(path);
WIN32_FIND_DATAW file_data;
HANDLE hFind;
if (len > MAX_PATH - 3) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
memset(szDir, 0, sizeof(szDir));
memset(filename, 0, MAX_PATH);
memcpy(filename, path, len);
filename[len++] = '\\';
p = filename + len;
filename[len++] = '*';
w_ret = MultiByteToWideChar(CP_ACP, 0, filename, (int) len, szDir,
MAX_PATH - 3);
if (w_ret == 0) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
hFind = FindFirstFileW(szDir, &file_data);
if (hFind == INVALID_HANDLE_VALUE) {
return MBEDTLS_ERR_X509_FILE_IO_ERROR;
}
len = MAX_PATH - len;
do {
memset(p, 0, len);
if (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
continue;
}
w_ret = WideCharToMultiByte(CP_ACP, 0, file_data.cFileName,
-1,
p, (int) len,
NULL, NULL);
if (w_ret == 0) {
ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
goto cleanup;
}
w_ret = mbedtls_x509_crt_parse_file(chain, filename);
if (w_ret < 0) {
ret++;
} else {
ret += w_ret;
}
} while (FindNextFileW(hFind, &file_data) != 0);
if (GetLastError() != ERROR_NO_MORE_FILES) {
ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
}
cleanup:
FindClose(hFind);
#else /* _WIN32 */
int t_ret;
int snp_ret;
struct stat sb;
struct dirent *entry;
char entry_name[MBEDTLS_X509_MAX_FILE_PATH_LEN];
DIR *dir = opendir(path);
if (dir == NULL) {
return MBEDTLS_ERR_X509_FILE_IO_ERROR;
}
#if defined(MBEDTLS_THREADING_C)
if ((ret = mbedtls_mutex_lock(&mbedtls_threading_readdir_mutex)) != 0) {
closedir(dir);
return ret;
}
#endif /* MBEDTLS_THREADING_C */
memset(&sb, 0, sizeof(sb));
while ((entry = readdir(dir)) != NULL) {
snp_ret = mbedtls_snprintf(entry_name, sizeof(entry_name),
"%s/%s", path, entry->d_name);
if (snp_ret < 0 || (size_t) snp_ret >= sizeof(entry_name)) {
ret = MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
goto cleanup;
} else if (stat(entry_name, &sb) == -1) {
if (errno == ENOENT) {
/* Broken symbolic link - ignore this entry.
stat(2) will return this error for either (a) a dangling
symlink or (b) a missing file.
Given that we have just obtained the filename from readdir,
assume that it does exist and therefore treat this as a
dangling symlink. */
continue;
} else {
/* Some other file error; report the error. */
ret = MBEDTLS_ERR_X509_FILE_IO_ERROR;
goto cleanup;
}
}
if (!S_ISREG(sb.st_mode)) {
continue;
}
// Ignore parse errors
//
t_ret = mbedtls_x509_crt_parse_file(chain, entry_name);
if (t_ret < 0) {
ret++;
} else {
ret += t_ret;
}
}
cleanup:
closedir(dir);
#if defined(MBEDTLS_THREADING_C)
if (mbedtls_mutex_unlock(&mbedtls_threading_readdir_mutex) != 0) {
ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
}
#endif /* MBEDTLS_THREADING_C */
#endif /* _WIN32 */
return ret;
}
#endif /* MBEDTLS_FS_IO */
#if !defined(MBEDTLS_X509_REMOVE_INFO)
static int x509_info_ext_key_usage(char **buf, size_t *size,
const mbedtls_x509_sequence *extended_key_usage)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const char *desc;
size_t n = *size;
char *p = *buf;
const mbedtls_x509_sequence *cur = extended_key_usage;
const char *sep = "";
while (cur != NULL) {
if (mbedtls_oid_get_extended_key_usage(&cur->buf, &desc) != 0) {
desc = "???";
}
ret = mbedtls_snprintf(p, n, "%s%s", sep, desc);
MBEDTLS_X509_SAFE_SNPRINTF;
sep = ", ";
cur = cur->next;
}
*size = n;
*buf = p;
return 0;
}
static int x509_info_cert_policies(char **buf, size_t *size,
const mbedtls_x509_sequence *certificate_policies)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const char *desc;
size_t n = *size;
char *p = *buf;
const mbedtls_x509_sequence *cur = certificate_policies;
const char *sep = "";
while (cur != NULL) {
if (mbedtls_oid_get_certificate_policies(&cur->buf, &desc) != 0) {
desc = "???";
}
ret = mbedtls_snprintf(p, n, "%s%s", sep, desc);
MBEDTLS_X509_SAFE_SNPRINTF;
sep = ", ";
cur = cur->next;
}
*size = n;
*buf = p;
return 0;
}
/*
* Return an informational string about the certificate.
*/
#define BEFORE_COLON 18
#define BC "18"
int mbedtls_x509_crt_info(char *buf, size_t size, const char *prefix,
const mbedtls_x509_crt *crt)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t n;
char *p;
char key_size_str[BEFORE_COLON];
p = buf;
n = size;
if (NULL == crt) {
ret = mbedtls_snprintf(p, n, "\nCertificate is uninitialised!\n");
MBEDTLS_X509_SAFE_SNPRINTF;
return (int) (size - n);
}
ret = mbedtls_snprintf(p, n, "%scert. version : %d\n",
prefix, crt->version);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf(p, n, "%sserial number : ",
prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_serial_gets(p, n, &crt->serial);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf(p, n, "\n%sissuer name : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_dn_gets(p, n, &crt->issuer);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf(p, n, "\n%ssubject name : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_dn_gets(p, n, &crt->subject);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf(p, n, "\n%sissued on : " \
"%04d-%02d-%02d %02d:%02d:%02d", prefix,
crt->valid_from.year, crt->valid_from.mon,
crt->valid_from.day, crt->valid_from.hour,
crt->valid_from.min, crt->valid_from.sec);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf(p, n, "\n%sexpires on : " \
"%04d-%02d-%02d %02d:%02d:%02d", prefix,
crt->valid_to.year, crt->valid_to.mon,
crt->valid_to.day, crt->valid_to.hour,
crt->valid_to.min, crt->valid_to.sec);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_snprintf(p, n, "\n%ssigned using : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
ret = mbedtls_x509_sig_alg_gets(p, n, &crt->sig_oid, crt->sig_pk,
crt->sig_md, crt->sig_opts);
MBEDTLS_X509_SAFE_SNPRINTF;
/* Key size */
if ((ret = mbedtls_x509_key_size_helper(key_size_str, BEFORE_COLON,
mbedtls_pk_get_name(&crt->pk))) != 0) {
return ret;
}
ret = mbedtls_snprintf(p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
(int) mbedtls_pk_get_bitlen(&crt->pk));
MBEDTLS_X509_SAFE_SNPRINTF;
/*
* Optional extensions
*/
if (crt->ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS) {
ret = mbedtls_snprintf(p, n, "\n%sbasic constraints : CA=%s", prefix,
crt->ca_istrue ? "true" : "false");
MBEDTLS_X509_SAFE_SNPRINTF;
if (crt->max_pathlen > 0) {
ret = mbedtls_snprintf(p, n, ", max_pathlen=%d", crt->max_pathlen - 1);
MBEDTLS_X509_SAFE_SNPRINTF;
}
}
if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) {
ret = mbedtls_snprintf(p, n, "\n%ssubject alt name :", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
if ((ret = mbedtls_x509_info_subject_alt_name(&p, &n,
&crt->subject_alt_names,
prefix)) != 0) {
return ret;
}
}
if (crt->ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE) {
ret = mbedtls_snprintf(p, n, "\n%scert. type : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
if ((ret = mbedtls_x509_info_cert_type(&p, &n, crt->ns_cert_type)) != 0) {
return ret;
}
}
if (crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE) {
ret = mbedtls_snprintf(p, n, "\n%skey usage : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
if ((ret = mbedtls_x509_info_key_usage(&p, &n, crt->key_usage)) != 0) {
return ret;
}
}
if (crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE) {
ret = mbedtls_snprintf(p, n, "\n%sext key usage : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
if ((ret = x509_info_ext_key_usage(&p, &n,
&crt->ext_key_usage)) != 0) {
return ret;
}
}
if (crt->ext_types & MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES) {
ret = mbedtls_snprintf(p, n, "\n%scertificate policies : ", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
if ((ret = x509_info_cert_policies(&p, &n,
&crt->certificate_policies)) != 0) {
return ret;
}
}
ret = mbedtls_snprintf(p, n, "\n");
MBEDTLS_X509_SAFE_SNPRINTF;
return (int) (size - n);
}
struct x509_crt_verify_string {
int code;
const char *string;
};
#define X509_CRT_ERROR_INFO(err, err_str, info) { err, info },
static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
MBEDTLS_X509_CRT_ERROR_INFO_LIST
{ 0, NULL }
};
#undef X509_CRT_ERROR_INFO
int mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix,
uint32_t flags)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const struct x509_crt_verify_string *cur;
char *p = buf;
size_t n = size;
for (cur = x509_crt_verify_strings; cur->string != NULL; cur++) {
if ((flags & cur->code) == 0) {
continue;
}
ret = mbedtls_snprintf(p, n, "%s%s\n", prefix, cur->string);
MBEDTLS_X509_SAFE_SNPRINTF;
flags ^= cur->code;
}
if (flags != 0) {
ret = mbedtls_snprintf(p, n, "%sUnknown reason "
"(this should not happen)\n", prefix);
MBEDTLS_X509_SAFE_SNPRINTF;
}
return (int) (size - n);
}
#endif /* MBEDTLS_X509_REMOVE_INFO */
int mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt *crt,
unsigned int usage)
{
unsigned int usage_must, usage_may;
unsigned int may_mask = MBEDTLS_X509_KU_ENCIPHER_ONLY
| MBEDTLS_X509_KU_DECIPHER_ONLY;
if ((crt->ext_types & MBEDTLS_X509_EXT_KEY_USAGE) == 0) {
return 0;
}
usage_must = usage & ~may_mask;
if (((crt->key_usage & ~may_mask) & usage_must) != usage_must) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
usage_may = usage & may_mask;
if (((crt->key_usage & may_mask) | usage_may) != usage_may) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
return 0;
}
int mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt *crt,
const char *usage_oid,
size_t usage_len)
{
const mbedtls_x509_sequence *cur;
/* Extension is not mandatory, absent means no restriction */
if ((crt->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE) == 0) {
return 0;
}
/*
* Look for the requested usage (or wildcard ANY) in our list
*/
for (cur = &crt->ext_key_usage; cur != NULL; cur = cur->next) {
const mbedtls_x509_buf *cur_oid = &cur->buf;
if (cur_oid->len == usage_len &&
memcmp(cur_oid->p, usage_oid, usage_len) == 0) {
return 0;
}
if (MBEDTLS_OID_CMP(MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE, cur_oid) == 0) {
return 0;
}
}
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
#if defined(MBEDTLS_X509_CRL_PARSE_C)
/*
* Return 1 if the certificate is revoked, or 0 otherwise.
*/
int mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl)
{
const mbedtls_x509_crl_entry *cur = &crl->entry;
while (cur != NULL && cur->serial.len != 0) {
if (crt->serial.len == cur->serial.len &&
memcmp(crt->serial.p, cur->serial.p, crt->serial.len) == 0) {
return 1;
}
cur = cur->next;
}
return 0;
}
/*
* Check that the given certificate is not revoked according to the CRL.
* Skip validation if no CRL for the given CA is present.
*/
static int x509_crt_verifycrl(mbedtls_x509_crt *crt, mbedtls_x509_crt *ca,
mbedtls_x509_crl *crl_list,
const mbedtls_x509_crt_profile *profile)
{
int flags = 0;
unsigned char hash[MBEDTLS_HASH_MAX_SIZE];
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_algorithm_t psa_algorithm;
#else
const mbedtls_md_info_t *md_info;
#endif /* MBEDTLS_USE_PSA_CRYPTO */
size_t hash_length;
if (ca == NULL) {
return flags;
}
while (crl_list != NULL) {
if (crl_list->version == 0 ||
x509_name_cmp(&crl_list->issuer, &ca->subject) != 0) {
crl_list = crl_list->next;
continue;
}
/*
* Check if the CA is configured to sign CRLs
*/
if (mbedtls_x509_crt_check_key_usage(ca,
MBEDTLS_X509_KU_CRL_SIGN) != 0) {
flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
break;
}
/*
* Check if CRL is correctly signed by the trusted CA
*/
if (x509_profile_check_md_alg(profile, crl_list->sig_md) != 0) {
flags |= MBEDTLS_X509_BADCRL_BAD_MD;
}
if (x509_profile_check_pk_alg(profile, crl_list->sig_pk) != 0) {
flags |= MBEDTLS_X509_BADCRL_BAD_PK;
}
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_algorithm = mbedtls_hash_info_psa_from_md(crl_list->sig_md);
if (psa_hash_compute(psa_algorithm,
crl_list->tbs.p,
crl_list->tbs.len,
hash,
sizeof(hash),
&hash_length) != PSA_SUCCESS) {
/* Note: this can't happen except after an internal error */
flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
break;
}
#else
md_info = mbedtls_md_info_from_type(crl_list->sig_md);
hash_length = mbedtls_md_get_size(md_info);
if (mbedtls_md(md_info,
crl_list->tbs.p,
crl_list->tbs.len,
hash) != 0) {
/* Note: this can't happen except after an internal error */
flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
break;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
if (x509_profile_check_key(profile, &ca->pk) != 0) {
flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
}
if (mbedtls_pk_verify_ext(crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
crl_list->sig_md, hash, hash_length,
crl_list->sig.p, crl_list->sig.len) != 0) {
flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
break;
}
/*
* Check for validity of CRL (Do not drop out)
*/
if (mbedtls_x509_time_is_past(&crl_list->next_update)) {
flags |= MBEDTLS_X509_BADCRL_EXPIRED;
}
if (mbedtls_x509_time_is_future(&crl_list->this_update)) {
flags |= MBEDTLS_X509_BADCRL_FUTURE;
}
/*
* Check if certificate is revoked
*/
if (mbedtls_x509_crt_is_revoked(crt, crl_list)) {
flags |= MBEDTLS_X509_BADCERT_REVOKED;
break;
}
crl_list = crl_list->next;
}
return flags;
}
#endif /* MBEDTLS_X509_CRL_PARSE_C */
/*
* Check the signature of a certificate by its parent
*/
static int x509_crt_check_signature(const mbedtls_x509_crt *child,
mbedtls_x509_crt *parent,
mbedtls_x509_crt_restart_ctx *rs_ctx)
{
size_t hash_len;
unsigned char hash[MBEDTLS_HASH_MAX_SIZE];
#if !defined(MBEDTLS_USE_PSA_CRYPTO)
const mbedtls_md_info_t *md_info;
md_info = mbedtls_md_info_from_type(child->sig_md);
hash_len = mbedtls_md_get_size(md_info);
/* Note: hash errors can happen only after an internal error */
if (mbedtls_md(md_info, child->tbs.p, child->tbs.len, hash) != 0) {
return -1;
}
#else
psa_algorithm_t hash_alg = mbedtls_hash_info_psa_from_md(child->sig_md);
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
status = psa_hash_compute(hash_alg,
child->tbs.p,
child->tbs.len,
hash,
sizeof(hash),
&hash_len);
if (status != PSA_SUCCESS) {
return MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
/* Skip expensive computation on obvious mismatch */
if (!mbedtls_pk_can_do(&parent->pk, child->sig_pk)) {
return -1;
}
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
if (rs_ctx != NULL && child->sig_pk == MBEDTLS_PK_ECDSA) {
return mbedtls_pk_verify_restartable(&parent->pk,
child->sig_md, hash, hash_len,
child->sig.p, child->sig.len, &rs_ctx->pk);
}
#else
(void) rs_ctx;
#endif
return mbedtls_pk_verify_ext(child->sig_pk, child->sig_opts, &parent->pk,
child->sig_md, hash, hash_len,
child->sig.p, child->sig.len);
}
/*
* Check if 'parent' is a suitable parent (signing CA) for 'child'.
* Return 0 if yes, -1 if not.
*
* top means parent is a locally-trusted certificate
*/
static int x509_crt_check_parent(const mbedtls_x509_crt *child,
const mbedtls_x509_crt *parent,
int top)
{
int need_ca_bit;
/* Parent must be the issuer */
if (x509_name_cmp(&child->issuer, &parent->subject) != 0) {
return -1;
}
/* Parent must have the basicConstraints CA bit set as a general rule */
need_ca_bit = 1;
/* Exception: v1/v2 certificates that are locally trusted. */
if (top && parent->version < 3) {
need_ca_bit = 0;
}
if (need_ca_bit && !parent->ca_istrue) {
return -1;
}
if (need_ca_bit &&
mbedtls_x509_crt_check_key_usage(parent, MBEDTLS_X509_KU_KEY_CERT_SIGN) != 0) {
return -1;
}
return 0;
}
/*
* Find a suitable parent for child in candidates, or return NULL.
*
* Here suitable is defined as:
* 1. subject name matches child's issuer
* 2. if necessary, the CA bit is set and key usage allows signing certs
* 3. for trusted roots, the signature is correct
* (for intermediates, the signature is checked and the result reported)
* 4. pathlen constraints are satisfied
*
* If there's a suitable candidate which is also time-valid, return the first
* such. Otherwise, return the first suitable candidate (or NULL if there is
* none).
*
* The rationale for this rule is that someone could have a list of trusted
* roots with two versions on the same root with different validity periods.
* (At least one user reported having such a list and wanted it to just work.)
* The reason we don't just require time-validity is that generally there is
* only one version, and if it's expired we want the flags to state that
* rather than NOT_TRUSTED, as would be the case if we required it here.
*
* The rationale for rule 3 (signature for trusted roots) is that users might
* have two versions of the same CA with different keys in their list, and the
* way we select the correct one is by checking the signature (as we don't
* rely on key identifier extensions). (This is one way users might choose to
* handle key rollover, another relies on self-issued certs, see [SIRO].)
*
* Arguments:
* - [in] child: certificate for which we're looking for a parent
* - [in] candidates: chained list of potential parents
* - [out] r_parent: parent found (or NULL)
* - [out] r_signature_is_good: 1 if child signature by parent is valid, or 0
* - [in] top: 1 if candidates consists of trusted roots, ie we're at the top
* of the chain, 0 otherwise
* - [in] path_cnt: number of intermediates seen so far
* - [in] self_cnt: number of self-signed intermediates seen so far
* (will never be greater than path_cnt)
* - [in-out] rs_ctx: context for restarting operations
*
* Return value:
* - 0 on success
* - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_x509_crt *parent, *fallback_parent;
int signature_is_good = 0, fallback_signature_is_good;
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/* did we have something in progress? */
if (rs_ctx != NULL && rs_ctx->parent != NULL) {
/* restore saved state */
parent = rs_ctx->parent;
fallback_parent = rs_ctx->fallback_parent;
fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
/* clear saved state */
rs_ctx->parent = NULL;
rs_ctx->fallback_parent = NULL;
rs_ctx->fallback_signature_is_good = 0;
/* resume where we left */
goto check_signature;
}
#endif
fallback_parent = NULL;
fallback_signature_is_good = 0;
for (parent = candidates; parent != NULL; parent = parent->next) {
/* basic parenting skills (name, CA bit, key usage) */
if (x509_crt_check_parent(child, parent, top) != 0) {
continue;
}
/* +1 because stored max_pathlen is 1 higher that the actual value */
if (parent->max_pathlen > 0 &&
(size_t) parent->max_pathlen < 1 + path_cnt - self_cnt) {
continue;
}
/* Signature */
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
check_signature:
#endif
ret = x509_crt_check_signature(child, parent, rs_ctx);
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
if (rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) {
/* save state */
rs_ctx->parent = parent;
rs_ctx->fallback_parent = fallback_parent;
rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
return ret;
}
#else
(void) ret;
#endif
signature_is_good = ret == 0;
if (top && !signature_is_good) {
continue;
}
/* optional time check */
if (mbedtls_x509_time_is_past(&parent->valid_to) ||
mbedtls_x509_time_is_future(&parent->valid_from)) {
if (fallback_parent == NULL) {
fallback_parent = parent;
fallback_signature_is_good = signature_is_good;
}
continue;
}
*r_parent = parent;
*r_signature_is_good = signature_is_good;
break;
}
if (parent == NULL) {
*r_parent = fallback_parent;
*r_signature_is_good = fallback_signature_is_good;
}
return 0;
}
/*
* Find a parent in trusted CAs or the provided chain, or return NULL.
*
* Searches in trusted CAs first, and return the first suitable parent found
* (see find_parent_in() for definition of suitable).
*
* Arguments:
* - [in] child: certificate for which we're looking for a parent, followed
* by a chain of possible intermediates
* - [in] trust_ca: list of locally trusted certificates
* - [out] parent: parent found (or NULL)
* - [out] parent_is_trusted: 1 if returned `parent` is trusted, or 0
* - [out] signature_is_good: 1 if child signature by parent is valid, or 0
* - [in] path_cnt: number of links in the chain so far (EE -> ... -> child)
* - [in] self_cnt: number of self-signed certs in the chain so far
* (will always be no greater than path_cnt)
* - [in-out] rs_ctx: context for restarting operations
*
* Return value:
* - 0 on success
* - MBEDTLS_ERR_ECP_IN_PROGRESS otherwise
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_x509_crt *search_list;
*parent_is_trusted = 1;
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/* restore then clear saved state if we have some stored */
if (rs_ctx != NULL && rs_ctx->parent_is_trusted != -1) {
*parent_is_trusted = rs_ctx->parent_is_trusted;
rs_ctx->parent_is_trusted = -1;
}
#endif
while (1) {
search_list = *parent_is_trusted ? trust_ca : child->next;
ret = x509_crt_find_parent_in(child, search_list,
parent, signature_is_good,
*parent_is_trusted,
path_cnt, self_cnt, rs_ctx);
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
if (rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) {
/* save state */
rs_ctx->parent_is_trusted = *parent_is_trusted;
return ret;
}
#else
(void) ret;
#endif
/* stop here if found or already in second iteration */
if (*parent != NULL || *parent_is_trusted == 0) {
break;
}
/* prepare second iteration */
*parent_is_trusted = 0;
}
/* extra precaution against mistakes in the caller */
if (*parent == NULL) {
*parent_is_trusted = 0;
*signature_is_good = 0;
}
return 0;
}
/*
* Check if an end-entity certificate is locally trusted
*
* Currently we require such certificates to be self-signed (actually only
* check for self-issued as self-signatures are not checked)
*/
static int x509_crt_check_ee_locally_trusted(
mbedtls_x509_crt *crt,
mbedtls_x509_crt *trust_ca)
{
mbedtls_x509_crt *cur;
/* must be self-issued */
if (x509_name_cmp(&crt->issuer, &crt->subject) != 0) {
return -1;
}
/* look for an exact match with trusted cert */
for (cur = trust_ca; cur != NULL; cur = cur->next) {
if (crt->raw.len == cur->raw.len &&
memcmp(crt->raw.p, cur->raw.p, crt->raw.len) == 0) {
return 0;
}
}
/* too bad */
return -1;
}
/*
* Build and verify a certificate chain
*
* Given a peer-provided list of certificates EE, C1, ..., Cn and
* a list of trusted certs R1, ... Rp, try to build and verify a chain
* EE, Ci1, ... Ciq [, Rj]
* such that every cert in the chain is a child of the next one,
* jumping to a trusted root as early as possible.
*
* Verify that chain and return it with flags for all issues found.
*
* Special cases:
* - EE == Rj -> return a one-element list containing it
* - EE, Ci1, ..., Ciq cannot be continued with a trusted root
* -> return that chain with NOT_TRUSTED set on Ciq
*
* Tests for (aspects of) this function should include at least:
* - trusted EE
* - EE -> trusted root
* - EE -> intermediate CA -> trusted root
* - if relevant: EE untrusted
* - if relevant: EE -> intermediate, untrusted
* with the aspect under test checked at each relevant level (EE, int, root).
* For some aspects longer chains are required, but usually length 2 is
* enough (but length 1 is not in general).
*
* Arguments:
* - [in] crt: the cert list EE, C1, ..., Cn
* - [in] trust_ca: the trusted list R1, ..., Rp
* - [in] ca_crl, profile: as in verify_with_profile()
* - [out] ver_chain: the built and verified chain
* Only valid when return value is 0, may contain garbage otherwise!
* Restart note: need not be the same when calling again to resume.
* - [in-out] rs_ctx: context for restarting operations
*
* Return value:
* - non-zero if the chain could not be fully built and examined
* - 0 is the chain was successfully built and examined,
* even if it was found to be invalid
*/
static int 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)
{
/* Don't initialize any of those variables here, so that the compiler can
* catch potential issues with jumping ahead when restarting */
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
uint32_t *flags;
mbedtls_x509_crt_verify_chain_item *cur;
mbedtls_x509_crt *child;
mbedtls_x509_crt *parent;
int parent_is_trusted;
int child_is_trusted;
int signature_is_good;
unsigned self_cnt;
mbedtls_x509_crt *cur_trust_ca = NULL;
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/* resume if we had an operation in progress */
if (rs_ctx != NULL && rs_ctx->in_progress == x509_crt_rs_find_parent) {
/* restore saved state */
*ver_chain = rs_ctx->ver_chain; /* struct copy */
self_cnt = rs_ctx->self_cnt;
/* restore derived state */
cur = &ver_chain->items[ver_chain->len - 1];
child = cur->crt;
flags = &cur->flags;
goto find_parent;
}
#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
child = crt;
self_cnt = 0;
parent_is_trusted = 0;
child_is_trusted = 0;
while (1) {
/* Add certificate to the verification chain */
cur = &ver_chain->items[ver_chain->len];
cur->crt = child;
cur->flags = 0;
ver_chain->len++;
flags = &cur->flags;
/* Check time-validity (all certificates) */
if (mbedtls_x509_time_is_past(&child->valid_to)) {
*flags |= MBEDTLS_X509_BADCERT_EXPIRED;
}
if (mbedtls_x509_time_is_future(&child->valid_from)) {
*flags |= MBEDTLS_X509_BADCERT_FUTURE;
}
/* Stop here for trusted roots (but not for trusted EE certs) */
if (child_is_trusted) {
return 0;
}
/* Check signature algorithm: MD & PK algs */
if (x509_profile_check_md_alg(profile, child->sig_md) != 0) {
*flags |= MBEDTLS_X509_BADCERT_BAD_MD;
}
if (x509_profile_check_pk_alg(profile, child->sig_pk) != 0) {
*flags |= MBEDTLS_X509_BADCERT_BAD_PK;
}
/* Special case: EE certs that are locally trusted */
if (ver_chain->len == 1 &&
x509_crt_check_ee_locally_trusted(child, trust_ca) == 0) {
return 0;
}
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
find_parent:
#endif
/* Obtain list of potential trusted signers from CA callback,
* or use statically provided list. */
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
if (f_ca_cb != NULL) {
mbedtls_x509_crt_free(ver_chain->trust_ca_cb_result);
mbedtls_free(ver_chain->trust_ca_cb_result);
ver_chain->trust_ca_cb_result = NULL;
ret = f_ca_cb(p_ca_cb, child, &ver_chain->trust_ca_cb_result);
if (ret != 0) {
return MBEDTLS_ERR_X509_FATAL_ERROR;
}
cur_trust_ca = ver_chain->trust_ca_cb_result;
} else
#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
{
((void) f_ca_cb);
((void) p_ca_cb);
cur_trust_ca = trust_ca;
}
/* Look for a parent in trusted CAs or up the chain */
ret = x509_crt_find_parent(child, cur_trust_ca, &parent,
&parent_is_trusted, &signature_is_good,
ver_chain->len - 1, self_cnt, rs_ctx);
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
if (rs_ctx != NULL && ret == MBEDTLS_ERR_ECP_IN_PROGRESS) {
/* save state */
rs_ctx->in_progress = x509_crt_rs_find_parent;
rs_ctx->self_cnt = self_cnt;
rs_ctx->ver_chain = *ver_chain; /* struct copy */
return ret;
}
#else
(void) ret;
#endif
/* No parent? We're done here */
if (parent == NULL) {
*flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
return 0;
}
/* Count intermediate self-issued (not necessarily self-signed) certs.
* These can occur with some strategies for key rollover, see [SIRO],
* and should be excluded from max_pathlen checks. */
if (ver_chain->len != 1 &&
x509_name_cmp(&child->issuer, &child->subject) == 0) {
self_cnt++;
}
/* path_cnt is 0 for the first intermediate CA,
* and if parent is trusted it's not an intermediate CA */
if (!parent_is_trusted &&
ver_chain->len > MBEDTLS_X509_MAX_INTERMEDIATE_CA) {
/* return immediately to avoid overflow the chain array */
return MBEDTLS_ERR_X509_FATAL_ERROR;
}
/* signature was checked while searching parent */
if (!signature_is_good) {
*flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED;
}
/* check size of signing key */
if (x509_profile_check_key(profile, &parent->pk) != 0) {
*flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
}
#if defined(MBEDTLS_X509_CRL_PARSE_C)
/* Check trusted CA's CRL for the given crt */
*flags |= x509_crt_verifycrl(child, parent, ca_crl, profile);
#else
(void) ca_crl;
#endif
/* prepare for next iteration */
child = parent;
parent = NULL;
child_is_trusted = parent_is_trusted;
signature_is_good = 0;
}
}
/*
* Check for CN match
*/
static int x509_crt_check_cn(const mbedtls_x509_buf *name,
const char *cn, size_t cn_len)
{
/* try exact match */
if (name->len == cn_len &&
x509_memcasecmp(cn, name->p, cn_len) == 0) {
return 0;
}
/* try wildcard match */
if (x509_check_wildcard(cn, name) == 0) {
return 0;
}
return -1;
}
/*
* Check for SAN match, see RFC 5280 Section 4.2.1.6
*/
static int x509_crt_check_san(const mbedtls_x509_buf *name,
const char *cn, size_t cn_len)
{
const unsigned char san_type = (unsigned char) name->tag &
MBEDTLS_ASN1_TAG_VALUE_MASK;
/* dNSName */
if (san_type == MBEDTLS_X509_SAN_DNS_NAME) {
return x509_crt_check_cn(name, cn, cn_len);
}
/* (We may handle other types here later.) */
/* Unrecognized type */
return -1;
}
/*
* Verify the requested CN - only call this if cn is not NULL!
*/
static void x509_crt_verify_name(const mbedtls_x509_crt *crt,
const char *cn,
uint32_t *flags)
{
const mbedtls_x509_name *name;
const mbedtls_x509_sequence *cur;
size_t cn_len = strlen(cn);
if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) {
for (cur = &crt->subject_alt_names; cur != NULL; cur = cur->next) {
if (x509_crt_check_san(&cur->buf, cn, cn_len) == 0) {
break;
}
}
if (cur == NULL) {
*flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
}
} else {
for (name = &crt->subject; name != NULL; name = name->next) {
if (MBEDTLS_OID_CMP(MBEDTLS_OID_AT_CN, &name->oid) == 0 &&
x509_crt_check_cn(&name->val, cn, cn_len) == 0) {
break;
}
}
if (name == NULL) {
*flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH;
}
}
}
/*
* Merge the flags for all certs in the chain, after calling callback
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned i;
uint32_t cur_flags;
const mbedtls_x509_crt_verify_chain_item *cur;
for (i = ver_chain->len; i != 0; --i) {
cur = &ver_chain->items[i-1];
cur_flags = cur->flags;
if (NULL != f_vrfy) {
if ((ret = f_vrfy(p_vrfy, cur->crt, (int) i-1, &cur_flags)) != 0) {
return ret;
}
}
*flags |= cur_flags;
}
return 0;
}
/*
* Verify the certificate validity, with profile, restartable version
*
* This function:
* - checks the requested CN (if any)
* - checks the type and size of the EE cert's key,
* as that isn't done as part of chain building/verification currently
* - builds and verifies the chain
* - then calls the callback and merges the flags
*
* The parameters pairs `trust_ca`, `ca_crl` and `f_ca_cb`, `p_ca_cb`
* are mutually exclusive: If `f_ca_cb != NULL`, it will be used by the
* verification routine to search for trusted signers, and CRLs will
* be disabled. Otherwise, `trust_ca` will be used as the static list
* of trusted signers, and `ca_crl` will be use as the static list
* of CRLs.
*/
static int 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)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_pk_type_t pk_type;
mbedtls_x509_crt_verify_chain ver_chain;
uint32_t ee_flags;
*flags = 0;
ee_flags = 0;
x509_crt_verify_chain_reset(&ver_chain);
if (profile == NULL) {
ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
goto exit;
}
/* check name if requested */
if (cn != NULL) {
x509_crt_verify_name(crt, cn, &ee_flags);
}
/* Check the type and size of the key */
pk_type = mbedtls_pk_get_type(&crt->pk);
if (x509_profile_check_pk_alg(profile, pk_type) != 0) {
ee_flags |= MBEDTLS_X509_BADCERT_BAD_PK;
}
if (x509_profile_check_key(profile, &crt->pk) != 0) {
ee_flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
}
/* Check the chain */
ret = x509_crt_verify_chain(crt, trust_ca, ca_crl,
f_ca_cb, p_ca_cb, profile,
&ver_chain, rs_ctx);
if (ret != 0) {
goto exit;
}
/* Merge end-entity flags */
ver_chain.items[0].flags |= ee_flags;
/* Build final flags, calling callback on the way if any */
ret = x509_crt_merge_flags_with_cb(flags, &ver_chain, f_vrfy, p_vrfy);
exit:
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
mbedtls_x509_crt_free(ver_chain.trust_ca_cb_result);
mbedtls_free(ver_chain.trust_ca_cb_result);
ver_chain.trust_ca_cb_result = NULL;
#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
if (rs_ctx != NULL && ret != MBEDTLS_ERR_ECP_IN_PROGRESS) {
mbedtls_x509_crt_restart_free(rs_ctx);
}
#endif
/* prevent misuse of the vrfy callback - VERIFY_FAILED would be ignored by
* the SSL module for authmode optional, but non-zero return from the
* callback means a fatal error so it shouldn't be ignored */
if (ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED) {
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
}
if (ret != 0) {
*flags = (uint32_t) -1;
return ret;
}
if (*flags != 0) {
return MBEDTLS_ERR_X509_CERT_VERIFY_FAILED;
}
return 0;
}
/*
* Verify the certificate validity (default profile, not restartable)
*/
int 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)
{
return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl,
NULL, NULL,
&mbedtls_x509_crt_profile_default,
cn, flags,
f_vrfy, p_vrfy, NULL);
}
/*
* Verify the certificate validity (user-chosen profile, not restartable)
*/
int 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)
{
return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl,
NULL, NULL,
profile, cn, flags,
f_vrfy, p_vrfy, NULL);
}
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
/*
* Verify the certificate validity (user-chosen profile, CA callback,
* not restartable).
*/
int 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)
{
return x509_crt_verify_restartable_ca_cb(crt, NULL, NULL,
f_ca_cb, p_ca_cb,
profile, cn, flags,
f_vrfy, p_vrfy, NULL);
}
#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
int 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)
{
return x509_crt_verify_restartable_ca_cb(crt, trust_ca, ca_crl,
NULL, NULL,
profile, cn, flags,
f_vrfy, p_vrfy, rs_ctx);
}
/*
* Initialize a certificate chain
*/
void mbedtls_x509_crt_init(mbedtls_x509_crt *crt)
{
memset(crt, 0, sizeof(mbedtls_x509_crt));
}
/*
* Unallocate all certificate data
*/
void mbedtls_x509_crt_free(mbedtls_x509_crt *crt)
{
mbedtls_x509_crt *cert_cur = crt;
mbedtls_x509_crt *cert_prv;
while (cert_cur != NULL) {
mbedtls_pk_free(&cert_cur->pk);
#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
mbedtls_free(cert_cur->sig_opts);
#endif
mbedtls_asn1_free_named_data_list_shallow(cert_cur->issuer.next);
mbedtls_asn1_free_named_data_list_shallow(cert_cur->subject.next);
mbedtls_asn1_sequence_free(cert_cur->ext_key_usage.next);
mbedtls_asn1_sequence_free(cert_cur->subject_alt_names.next);
mbedtls_asn1_sequence_free(cert_cur->certificate_policies.next);
if (cert_cur->raw.p != NULL && cert_cur->own_buffer) {
mbedtls_platform_zeroize(cert_cur->raw.p, cert_cur->raw.len);
mbedtls_free(cert_cur->raw.p);
}
cert_prv = cert_cur;
cert_cur = cert_cur->next;
mbedtls_platform_zeroize(cert_prv, sizeof(mbedtls_x509_crt));
if (cert_prv != crt) {
mbedtls_free(cert_prv);
}
}
}
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
/*
* Initialize a restart context
*/
void mbedtls_x509_crt_restart_init(mbedtls_x509_crt_restart_ctx *ctx)
{
mbedtls_pk_restart_init(&ctx->pk);
ctx->parent = NULL;
ctx->fallback_parent = NULL;
ctx->fallback_signature_is_good = 0;
ctx->parent_is_trusted = -1;
ctx->in_progress = x509_crt_rs_none;
ctx->self_cnt = 0;
x509_crt_verify_chain_reset(&ctx->ver_chain);
}
/*
* Free the components of a restart context
*/
void mbedtls_x509_crt_restart_free(mbedtls_x509_crt_restart_ctx *ctx)
{
if (ctx == NULL) {
return;
}
mbedtls_pk_restart_free(&ctx->pk);
mbedtls_x509_crt_restart_init(ctx);
}
#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
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