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b75ffb5061
mbedtls/library/x509_crt.c
Hanno Becker b75ffb5061 Don't perform binary comparison of CRL issuer and CA subject 
Previously, when checking whether a CRT was revoked through
one of the configured CRLs, the library would only consider
those CRLs whose `issuer` field binary-matches the `subject`
field of the CA that has issued the CRT in question. If those
fields were not binary equivalent, the corresponding CRL was
discarded.

This is not in line with RFC 5280, which demands that the
comparison should be format- and case-insensitive. For example:

- If the same string is once encoded as a `PrintableString` and
  another time as a `UTF8String`, they should compare equal.
- If two strings differ only in their choice of upper and lower case
  letters, they should compare equal.

This commit fixes this by using the dedicated x509_name_cmp()
function to compare the CRL issuer with the CA subject.

Fixes #1784.
2018-11-05 11:54:06 +00:00

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/*
* X.509 certificate parsing and verification
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* 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.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* 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
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#include "mbedtls/x509_crt.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include <stdio.h>
#include <string.h>
#if defined(MBEDTLS_PEM_PARSE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_free free
#define mbedtls_calloc calloc
#define mbedtls_snprintf snprintf
#endif
#if defined(MBEDTLS_THREADING_C)
#include "mbedtls/threading.h"
#endif
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
#include <windows.h>
#else
#include <time.h>
#endif
#if defined(MBEDTLS_FS_IO)
#include <stdio.h>
#if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.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
*/
const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
{
#if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
/* Allow SHA-1 (weak, but still safe in controlled environments) */
MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
#endif
/* Only SHA-2 hashes */
MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
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 */
0xFFFFFFF, /* Any curve */
2048,
};
/*
* Next-default profile
*/
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,
};
/*
* 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 = -1;
}
ver_chain->len = 0;
}
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
static int x509_get_version( unsigned char **p,
const unsigned char *end,
int *ver )
{
int ret;
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( ret );
}
end = *p + len;
if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_VERSION + ret );
if( *p != end )
return( 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;
size_t len;
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( 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_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;
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( 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;
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_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_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_ERR_X509_INVALID_EXTENSIONS + ret );
if( *p != end )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
(*max_pathlen)++;
return( 0 );
}
static int x509_get_ns_cert_type( unsigned char **p,
const unsigned char *end,
unsigned char *ns_cert_type)
{
int ret;
mbedtls_x509_bitstring bs = { 0, 0, NULL };
if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
if( bs.len != 1 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_INVALID_LENGTH );
/* Get actual bitstring */
*ns_cert_type = *bs.p;
return( 0 );
}
static int x509_get_key_usage( unsigned char **p,
const unsigned char *end,
unsigned int *key_usage)
{
int ret;
size_t i;
mbedtls_x509_bitstring bs = { 0, 0, NULL };
if( ( ret = mbedtls_asn1_get_bitstring( p, end, &bs ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
if( bs.len < 1 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_INVALID_LENGTH );
/* Get actual bitstring */
*key_usage = 0;
for( i = 0; i < bs.len && i < sizeof( unsigned int ); i++ )
{
*key_usage |= (unsigned int) bs.p[i] << (8*i);
}
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;
if( ( ret = mbedtls_asn1_get_sequence_of( p, end, ext_key_usage, MBEDTLS_ASN1_OID ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
/* Sequence length must be >= 1 */
if( ext_key_usage->buf.p == NULL )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_INVALID_LENGTH );
return( 0 );
}
/*
* SubjectAltName ::= GeneralNames
*
* GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
*
* GeneralName ::= CHOICE {
* otherName [0] OtherName,
* rfc822Name [1] IA5String,
* dNSName [2] IA5String,
* x400Address [3] ORAddress,
* directoryName [4] Name,
* ediPartyName [5] EDIPartyName,
* uniformResourceIdentifier [6] IA5String,
* iPAddress [7] OCTET STRING,
* registeredID [8] OBJECT IDENTIFIER }
*
* OtherName ::= SEQUENCE {
* type-id OBJECT IDENTIFIER,
* value [0] EXPLICIT ANY DEFINED BY type-id }
*
* EDIPartyName ::= SEQUENCE {
* nameAssigner [0] DirectoryString OPTIONAL,
* partyName [1] DirectoryString }
*
* NOTE: we only parse and use dNSName at this point.
*/
static int x509_get_subject_alt_name( unsigned char **p,
const unsigned char *end,
mbedtls_x509_sequence *subject_alt_name )
{
int ret;
size_t len, tag_len;
mbedtls_asn1_buf *buf;
unsigned char tag;
mbedtls_asn1_sequence *cur = subject_alt_name;
/* Get main sequence tag */
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
if( *p + len != end )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
while( *p < end )
{
if( ( end - *p ) < 1 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_OUT_OF_DATA );
tag = **p;
(*p)++;
if( ( ret = mbedtls_asn1_get_len( p, end, &tag_len ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
if( ( tag & MBEDTLS_ASN1_TAG_CLASS_MASK ) !=
MBEDTLS_ASN1_CONTEXT_SPECIFIC )
{
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
}
/* Skip everything but DNS name */
if( tag != ( MBEDTLS_ASN1_CONTEXT_SPECIFIC | 2 ) )
{
*p += tag_len;
continue;
}
/* 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_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_ALLOC_FAILED );
cur = cur->next;
}
buf = &(cur->buf);
buf->tag = tag;
buf->p = *p;
buf->len = tag_len;
*p += buf->len;
}
/* Set final sequence entry's next pointer to NULL */
cur->next = NULL;
if( *p != end )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
/*
* X.509 v3 extensions
*
*/
static int x509_get_crt_ext( unsigned char **p,
const unsigned char *end,
mbedtls_x509_crt *crt )
{
int ret;
size_t len;
unsigned char *end_ext_data, *end_ext_octet;
if( ( ret = mbedtls_x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
{
if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
return( 0 );
return( ret );
}
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_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_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_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_ERR_X509_INVALID_EXTENSIONS + ret );
end_ext_octet = *p + len;
if( end_ext_octet != end_ext_data )
return( 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 )
{
/* No parser found, skip extension */
*p = end_ext_octet;
#if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
if( is_critical )
{
/* Data is marked as critical: fail */
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
}
#endif
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 = 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 = 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 = x509_get_ns_cert_type( p, end_ext_octet,
&crt->ns_cert_type ) ) != 0 )
return( ret );
break;
default:
return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
}
}
if( *p != end )
return( 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 ret;
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 );
}
if( len > (size_t) ( end - p ) )
{
mbedtls_x509_crt_free( crt );
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
crt_end = p + len;
// Create and populate a new buffer for the raw field
crt->raw.len = crt_end - buf;
crt->raw.p = p = mbedtls_calloc( 1, crt->raw.len );
if( p == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
memcpy( p, buf, crt->raw.len );
// Direct pointers to the new buffer
p += crt->raw.len - len;
end = crt_end = p + len;
/*
* 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_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_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_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
*/
if( ( ret = mbedtls_pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
{
mbedtls_x509_crt_free( crt );
return( ret );
}
/*
* 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 !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
if( crt->version == 3 )
#endif
{
ret = x509_get_crt_ext( &p, end, crt );
if( ret != 0 )
{
mbedtls_x509_crt_free( crt );
return( ret );
}
}
if( p != end )
{
mbedtls_x509_crt_free( crt );
return( 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.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_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
*/
int mbedtls_x509_crt_parse_der( mbedtls_x509_crt *chain, const unsigned char *buf,
size_t buflen )
{
int ret;
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;
}
if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
{
if( prev )
prev->next = NULL;
if( crt != chain )
mbedtls_free( crt );
return( ret );
}
return( 0 );
}
/*
* 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_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;
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,
lstrlenW( file_data.cFileName ),
p, (int) len - 1,
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 */
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 )
{
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 */
static int x509_info_subject_alt_name( char **buf, size_t *size,
const mbedtls_x509_sequence *subject_alt_name )
{
size_t i;
size_t n = *size;
char *p = *buf;
const mbedtls_x509_sequence *cur = subject_alt_name;
const char *sep = "";
size_t sep_len = 0;
while( cur != NULL )
{
if( cur->buf.len + sep_len >= n )
{
*p = '\0';
return( MBEDTLS_ERR_X509_BUFFER_TOO_SMALL );
}
n -= cur->buf.len + sep_len;
for( i = 0; i < sep_len; i++ )
*p++ = sep[i];
for( i = 0; i < cur->buf.len; i++ )
*p++ = cur->buf.p[i];
sep = ", ";
sep_len = 2;
cur = cur->next;
}
*p = '\0';
*size = n;
*buf = p;
return( 0 );
}
#define PRINT_ITEM(i) \
{ \
ret = mbedtls_snprintf( p, n, "%s" i, sep ); \
MBEDTLS_X509_SAFE_SNPRINTF; \
sep = ", "; \
}
#define CERT_TYPE(type,name) \
if( ns_cert_type & type ) \
PRINT_ITEM( name );
static int x509_info_cert_type( char **buf, size_t *size,
unsigned char ns_cert_type )
{
int ret;
size_t n = *size;
char *p = *buf;
const char *sep = "";
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT, "SSL Client" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER, "SSL Server" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL, "Email" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_RESERVED, "Reserved" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_SSL_CA, "SSL CA" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA, "Email CA" );
CERT_TYPE( MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA" );
*size = n;
*buf = p;
return( 0 );
}
#define KEY_USAGE(code,name) \
if( key_usage & code ) \
PRINT_ITEM( name );
static int x509_info_key_usage( char **buf, size_t *size,
unsigned int key_usage )
{
int ret;
size_t n = *size;
char *p = *buf;
const char *sep = "";
KEY_USAGE( MBEDTLS_X509_KU_DIGITAL_SIGNATURE, "Digital Signature" );
KEY_USAGE( MBEDTLS_X509_KU_NON_REPUDIATION, "Non Repudiation" );
KEY_USAGE( MBEDTLS_X509_KU_KEY_ENCIPHERMENT, "Key Encipherment" );
KEY_USAGE( MBEDTLS_X509_KU_DATA_ENCIPHERMENT, "Data Encipherment" );
KEY_USAGE( MBEDTLS_X509_KU_KEY_AGREEMENT, "Key Agreement" );
KEY_USAGE( MBEDTLS_X509_KU_KEY_CERT_SIGN, "Key Cert Sign" );
KEY_USAGE( MBEDTLS_X509_KU_CRL_SIGN, "CRL Sign" );
KEY_USAGE( MBEDTLS_X509_KU_ENCIPHER_ONLY, "Encipher Only" );
KEY_USAGE( MBEDTLS_X509_KU_DECIPHER_ONLY, "Decipher Only" );
*size = n;
*buf = p;
return( 0 );
}
static int x509_info_ext_key_usage( char **buf, size_t *size,
const mbedtls_x509_sequence *extended_key_usage )
{
int ret;
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 );
}
/*
* 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;
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 = x509_info_subject_alt_name( &p, &n,
&crt->subject_alt_names ) ) != 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 = 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 = 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 );
}
ret = mbedtls_snprintf( p, n, "\n" );
MBEDTLS_X509_SAFE_SNPRINTF;
return( (int) ( size - n ) );
}
struct x509_crt_verify_string {
int code;
const char *string;
};
static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
{ MBEDTLS_X509_BADCERT_EXPIRED, "The certificate validity has expired" },
{ MBEDTLS_X509_BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)" },
{ MBEDTLS_X509_BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN" },
{ MBEDTLS_X509_BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA" },
{ MBEDTLS_X509_BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA" },
{ MBEDTLS_X509_BADCRL_EXPIRED, "The CRL is expired" },
{ MBEDTLS_X509_BADCERT_MISSING, "Certificate was missing" },
{ MBEDTLS_X509_BADCERT_SKIP_VERIFY, "Certificate verification was skipped" },
{ MBEDTLS_X509_BADCERT_OTHER, "Other reason (can be used by verify callback)" },
{ MBEDTLS_X509_BADCERT_FUTURE, "The certificate validity starts in the future" },
{ MBEDTLS_X509_BADCRL_FUTURE, "The CRL is from the future" },
{ MBEDTLS_X509_BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension" },
{ MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
{ MBEDTLS_X509_BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension" },
{ MBEDTLS_X509_BADCERT_BAD_MD, "The certificate is signed with an unacceptable hash." },
{ MBEDTLS_X509_BADCERT_BAD_PK, "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
{ MBEDTLS_X509_BADCERT_BAD_KEY, "The certificate is signed with an unacceptable key (eg bad curve, RSA too short)." },
{ MBEDTLS_X509_BADCRL_BAD_MD, "The CRL is signed with an unacceptable hash." },
{ MBEDTLS_X509_BADCRL_BAD_PK, "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA)." },
{ MBEDTLS_X509_BADCRL_BAD_KEY, "The CRL is signed with an unacceptable key (eg bad curve, RSA too short)." },
{ 0, NULL }
};
int mbedtls_x509_crt_verify_info( char *buf, size_t size, const char *prefix,
uint32_t flags )
{
int ret;
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 ) );
}
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
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 );
}
#endif
#if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
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 );
}
#endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
#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 )
{
if( mbedtls_x509_time_is_past( &cur->revocation_date ) )
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_MD_MAX_SIZE];
const mbedtls_md_info_t *md_info;
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 defined(MBEDTLS_X509_CHECK_KEY_USAGE)
if( mbedtls_x509_crt_check_key_usage( ca,
MBEDTLS_X509_KU_CRL_SIGN ) != 0 )
{
flags |= MBEDTLS_X509_BADCRL_NOT_TRUSTED;
break;
}
#endif
/*
* 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;
md_info = mbedtls_md_info_from_type( crl_list->sig_md );
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;
}
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, mbedtls_md_get_size( md_info ),
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 )
{
const mbedtls_md_info_t *md_info;
unsigned char hash[MBEDTLS_MD_MAX_SIZE];
md_info = mbedtls_md_info_from_type( child->sig_md );
if( mbedtls_md( md_info, child->tbs.p, child->tbs.len, hash ) != 0 )
{
/* Note: this can't happen except after an internal error */
return( -1 );
}
/* 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, mbedtls_md_get_size( md_info ),
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, mbedtls_md_get_size( md_info ),
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 defined(MBEDTLS_X509_CHECK_KEY_USAGE)
if( need_ca_bit &&
mbedtls_x509_crt_check_key_usage( parent, MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
{
return( -1 );
}
#endif
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_x509_crt *parent, *fallback_parent;
int signature_is_good, 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;
}
break;
}
if( parent != NULL )
{
*r_parent = parent;
*r_signature_is_good = signature_is_good;
}
else
{
*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_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 -> intermedate 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,
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;
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;
#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
/* Look for a parent in trusted CAs or up the chain */
ret = x509_crt_find_parent( child, 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 );
}
/*
* 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_cn( &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;
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 (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( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
&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( mbedtls_x509_crt_verify_restartable( crt, trust_ca, ca_crl,
profile, cn, flags, f_vrfy, p_vrfy, NULL ) );
}
/*
* 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
*/
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 )
{
int ret;
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, 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_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 );
}
/*
* 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;
mbedtls_x509_name *name_cur;
mbedtls_x509_name *name_prv;
mbedtls_x509_sequence *seq_cur;
mbedtls_x509_sequence *seq_prv;
if( crt == NULL )
return;
do
{
mbedtls_pk_free( &cert_cur->pk );
#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
mbedtls_free( cert_cur->sig_opts );
#endif
name_cur = cert_cur->issuer.next;
while( name_cur != NULL )
{
name_prv = name_cur;
name_cur = name_cur->next;
mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
mbedtls_free( name_prv );
}
name_cur = cert_cur->subject.next;
while( name_cur != NULL )
{
name_prv = name_cur;
name_cur = name_cur->next;
mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
mbedtls_free( name_prv );
}
seq_cur = cert_cur->ext_key_usage.next;
while( seq_cur != NULL )
{
seq_prv = seq_cur;
seq_cur = seq_cur->next;
mbedtls_platform_zeroize( seq_prv,
sizeof( mbedtls_x509_sequence ) );
mbedtls_free( seq_prv );
}
seq_cur = cert_cur->subject_alt_names.next;
while( seq_cur != NULL )
{
seq_prv = seq_cur;
seq_cur = seq_cur->next;
mbedtls_platform_zeroize( seq_prv,
sizeof( mbedtls_x509_sequence ) );
mbedtls_free( seq_prv );
}
if( cert_cur->raw.p != NULL )
{
mbedtls_platform_zeroize( cert_cur->raw.p, cert_cur->raw.len );
mbedtls_free( cert_cur->raw.p );
}
cert_cur = cert_cur->next;
}
while( cert_cur != NULL );
cert_cur = crt;
do
{
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 );
}
while( cert_cur != NULL );
}
#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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