blob: 43bb9770fec0f6a37a9f17a9a53a31ff2a22e569 [file] [log] [blame]
/*
* 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/x509_internal.h"
#include "mbedtls/oid.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/platform.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 <stdio.h>
#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
#if !defined(MBEDTLS_X509_ON_DEMAND_PARSING)
static void x509_buf_to_buf_raw( mbedtls_x509_buf_raw *dst,
mbedtls_x509_buf const *src )
{
dst->p = src->p;
dst->len = src->len;
}
static void x509_buf_raw_to_buf( mbedtls_x509_buf *dst,
mbedtls_x509_buf_raw const *src )
{
dst->p = src->p;
dst->len = src->len;
}
#endif /* MBEDTLS_X509_ON_DEMAND_PARSING */
static int x509_crt_parse_frame( unsigned char *start,
unsigned char *end,
mbedtls_x509_crt_frame *frame );
static int x509_crt_subject_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_name *subject );
static int x509_crt_issuer_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_name *issuer );
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
static int x509_crt_subject_alt_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_sequence *subject_alt );
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
static int x509_crt_ext_key_usage_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_sequence *ext_key_usage );
static int mbedtls_x509_crt_flush_cache_pk( mbedtls_x509_crt const *crt )
{
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &crt->cache->pk_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif
#if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \
defined(MBEDTLS_THREADING_C)
/* Can only free the PK context if nobody is using it.
* If MBEDTLS_X509_ALWAYS_FLUSH is set, nested uses
* of xxx_acquire() are prohibited, and no reference
* counting is needed. Also, notice that the code-path
* below is safe if the cache isn't filled. */
if( crt->cache->pk_readers == 0 )
#endif /* !MBEDTLS_X509_ALWAYS_FLUSH ||
MBEDTLS_THREADING_C */
{
#if !defined(MBEDTLS_X509_ON_DEMAND_PARSING)
/* The cache holds a shallow copy of the PK context
* in the legacy struct, so don't free PK context. */
mbedtls_free( crt->cache->pk );
#else
mbedtls_pk_free( crt->cache->pk );
mbedtls_free( crt->cache->pk );
#endif /* MBEDTLS_X509_ON_DEMAND_PARSING */
crt->cache->pk = NULL;
}
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &crt->cache->pk_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif
return( 0 );
}
static int mbedtls_x509_crt_flush_cache_frame( mbedtls_x509_crt const *crt )
{
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &crt->cache->frame_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif
#if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \
defined(MBEDTLS_THREADING_C)
/* Can only free the PK context if nobody is using it.
* If MBEDTLS_X509_ALWAYS_FLUSH is set, nested uses
* of xxx_acquire() are prohibited, and no reference
* counting is needed. Also, notice that the code-path
* below is safe if the cache isn't filled. */
if( crt->cache->frame_readers == 0 )
#endif /* !MBEDTLS_X509_ALWAYS_FLUSH ||
MBEDTLS_THREADING_C */
{
mbedtls_free( crt->cache->frame );
crt->cache->frame = NULL;
}
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &crt->cache->frame_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif
return( 0 );
}
int mbedtls_x509_crt_flush_cache( mbedtls_x509_crt const *crt )
{
int ret;
ret = mbedtls_x509_crt_flush_cache_frame( crt );
if( ret != 0 )
return( ret );
ret = mbedtls_x509_crt_flush_cache_pk( crt );
if( ret != 0 )
return( ret );
return( 0 );
}
static int x509_crt_frame_parse_ext( mbedtls_x509_crt_frame *frame );
static int mbedtls_x509_crt_cache_provide_frame( mbedtls_x509_crt const *crt )
{
mbedtls_x509_crt_cache *cache = crt->cache;
mbedtls_x509_crt_frame *frame;
if( cache->frame != NULL )
{
#if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \
defined(MBEDTLS_THREADING_C)
return( 0 );
#else
/* If MBEDTLS_X509_ALWAYS_FLUSH is set, we don't
* allow nested uses of acquire. */
return( MBEDTLS_ERR_X509_FATAL_ERROR );
#endif
}
frame = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt_frame ) );
if( frame == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
cache->frame = frame;
#if defined(MBEDTLS_X509_ON_DEMAND_PARSING)
/* This would work with !MBEDTLS_X509_ON_DEMAND_PARSING, too,
* but is inefficient compared to copying the respective fields
* from the legacy mbedtls_x509_crt. */
return( x509_crt_parse_frame( crt->raw.p,
crt->raw.p + crt->raw.len,
frame ) );
#else /* MBEDTLS_X509_ON_DEMAND_PARSING */
/* Make sure all extension related fields are properly initialized. */
frame->ca_istrue = 0;
frame->max_pathlen = 0;
frame->ext_types = 0;
frame->version = crt->version;
frame->sig_md = crt->sig_md;
frame->sig_pk = crt->sig_pk;
#if !defined(MBEDTLS_X509_CRT_REMOVE_TIME)
frame->valid_from = crt->valid_from;
frame->valid_to = crt->valid_to;
#endif /* !MBEDTLS_X509_CRT_REMOVE_TIME */
x509_buf_to_buf_raw( &frame->raw, &crt->raw );
x509_buf_to_buf_raw( &frame->tbs, &crt->tbs );
x509_buf_to_buf_raw( &frame->serial, &crt->serial );
x509_buf_to_buf_raw( &frame->pubkey_raw, &crt->pk_raw );
x509_buf_to_buf_raw( &frame->issuer_raw, &crt->issuer_raw );
x509_buf_to_buf_raw( &frame->subject_raw, &crt->subject_raw );
#if !defined(MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID)
x509_buf_to_buf_raw( &frame->subject_id, &crt->subject_id );
x509_buf_to_buf_raw( &frame->issuer_id, &crt->issuer_id );
#endif /* !MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID */
x509_buf_to_buf_raw( &frame->sig, &crt->sig );
x509_buf_to_buf_raw( &frame->v3_ext, &crt->v3_ext );
/* The legacy CRT structure doesn't explicitly contain
* the `AlgorithmIdentifier` bounds; however, those can
* be inferred from the surrounding (mandatory) `SerialNumber`
* and `Issuer` fields. */
frame->sig_alg.p = crt->serial.p + crt->serial.len;
frame->sig_alg.len = crt->issuer_raw.p - frame->sig_alg.p;
return( x509_crt_frame_parse_ext( frame ) );
#endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */
}
static int mbedtls_x509_crt_cache_provide_pk( mbedtls_x509_crt const *crt )
{
mbedtls_x509_crt_cache *cache = crt->cache;
mbedtls_pk_context *pk;
if( cache->pk != NULL )
{
#if !defined(MBEDTLS_X509_ALWAYS_FLUSH) || \
defined(MBEDTLS_THREADING_C)
return( 0 );
#else
/* If MBEDTLS_X509_ALWAYS_FLUSH is set, we don't
* allow nested uses of acquire. */
return( MBEDTLS_ERR_X509_FATAL_ERROR );
#endif
}
pk = mbedtls_calloc( 1, sizeof( mbedtls_pk_context ) );
if( pk == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
cache->pk = pk;
#if !defined(MBEDTLS_X509_ON_DEMAND_PARSING)
*pk = crt->pk;
return( 0 );
#else
{
mbedtls_x509_buf_raw pk_raw = cache->pk_raw;
return( mbedtls_pk_parse_subpubkey( &pk_raw.p,
pk_raw.p + pk_raw.len,
pk ) );
}
#endif /* MBEDTLS_X509_ON_DEMAND_PARSING */
}
static void x509_crt_cache_init( mbedtls_x509_crt_cache *cache )
{
memset( cache, 0, sizeof( *cache ) );
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init( &cache->frame_mutex );
mbedtls_mutex_init( &cache->pk_mutex );
#endif
}
static void x509_crt_cache_clear_pk( mbedtls_x509_crt_cache *cache )
{
#if !defined(MBEDTLS_X509_ON_DEMAND_PARSING)
/* The cache holds a shallow copy of the PK context
* in the legacy struct, so don't free PK context. */
mbedtls_free( cache->pk );
#else
mbedtls_pk_free( cache->pk );
mbedtls_free( cache->pk );
#endif /* MBEDTLS_X509_ON_DEMAND_PARSING */
cache->pk = NULL;
}
static void x509_crt_cache_clear_frame( mbedtls_x509_crt_cache *cache )
{
mbedtls_free( cache->frame );
cache->frame = NULL;
}
static void x509_crt_cache_free( mbedtls_x509_crt_cache *cache )
{
if( cache == NULL )
return;
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_free( &cache->frame_mutex );
mbedtls_mutex_free( &cache->pk_mutex );
#endif
x509_crt_cache_clear_frame( cache );
x509_crt_cache_clear_pk( cache );
mbedtls_platform_memset( cache, 0, sizeof( *cache ) );
}
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
int mbedtls_x509_crt_get_subject_alt_names( mbedtls_x509_crt const *crt,
mbedtls_x509_sequence **subj_alt )
{
int ret;
mbedtls_x509_crt_frame const *frame;
mbedtls_x509_sequence *seq;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( ret );
seq = mbedtls_calloc( 1, sizeof( mbedtls_x509_sequence ) );
if( seq == NULL )
ret = MBEDTLS_ERR_X509_ALLOC_FAILED;
else
ret = x509_crt_subject_alt_from_frame( frame, seq );
mbedtls_x509_crt_frame_release( crt );
*subj_alt = seq;
return( ret );
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
int mbedtls_x509_crt_get_ext_key_usage( mbedtls_x509_crt const *crt,
mbedtls_x509_sequence **ext_key_usage )
{
int ret;
mbedtls_x509_crt_frame const *frame;
mbedtls_x509_sequence *seq;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( ret );
seq = mbedtls_calloc( 1, sizeof( mbedtls_x509_sequence ) );
if( seq == NULL )
ret = MBEDTLS_ERR_X509_ALLOC_FAILED;
else
ret = x509_crt_ext_key_usage_from_frame( frame, seq );
mbedtls_x509_crt_frame_release( crt );
*ext_key_usage = seq;
return( ret );
}
int mbedtls_x509_crt_get_subject( mbedtls_x509_crt const *crt,
mbedtls_x509_name **subject )
{
int ret;
mbedtls_x509_crt_frame const *frame;
mbedtls_x509_name *name;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( ret );
name = mbedtls_calloc( 1, sizeof( mbedtls_x509_name ) );
if( name == NULL )
ret = MBEDTLS_ERR_X509_ALLOC_FAILED;
else
ret = x509_crt_subject_from_frame( frame, name );
mbedtls_x509_crt_frame_release( crt );
*subject = name;
return( ret );
}
int mbedtls_x509_crt_get_issuer( mbedtls_x509_crt const *crt,
mbedtls_x509_name **issuer )
{
int ret;
mbedtls_x509_crt_frame const *frame;
mbedtls_x509_name *name;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( ret );
name = mbedtls_calloc( 1, sizeof( mbedtls_x509_name ) );
if( name == NULL )
ret = MBEDTLS_ERR_X509_ALLOC_FAILED;
else
ret = x509_crt_issuer_from_frame( frame, name );
mbedtls_x509_crt_frame_release( crt );
*issuer = name;
return( ret );
}
int mbedtls_x509_crt_get_frame( mbedtls_x509_crt const *crt,
mbedtls_x509_crt_frame *dst )
{
int ret;
mbedtls_x509_crt_frame const *frame;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( ret );
*dst = *frame;
mbedtls_x509_crt_frame_release( crt );
return( 0 );
}
int mbedtls_x509_crt_get_pk( mbedtls_x509_crt const *crt,
mbedtls_pk_context *dst )
{
#if !defined(MBEDTLS_X509_ON_DEMAND_PARSING)
mbedtls_x509_buf_raw pk_raw = crt->cache->pk_raw;
return( mbedtls_pk_parse_subpubkey( &pk_raw.p,
pk_raw.p + pk_raw.len,
dst ) );
#else /* !MBEDTLS_X509_ON_DEMAND_PARSING */
int ret;
mbedtls_pk_context *pk;
ret = mbedtls_x509_crt_pk_acquire( crt, &pk );
if( ret != 0 )
return( ret );
/* Move PK from CRT cache to destination pointer
* to avoid a copy. */
*dst = *pk;
mbedtls_free( crt->cache->pk );
crt->cache->pk = NULL;
mbedtls_x509_crt_pk_release( crt );
return( 0 );
#endif /* MBEDTLS_X509_ON_DEMAND_PARSING */
}
/*
* 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_USE_TINYCRYPT)
MBEDTLS_X509_ID_FLAG( MBEDTLS_UECC_DP_SECP256R1 ),
#elif 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_USE_TINYCRYPT)
MBEDTLS_X509_ID_FLAG( MBEDTLS_UECC_DP_SECP256R1 ),
#elif 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_USE_TINYCRYPT)
if( pk_alg == MBEDTLS_PK_ECKEY )
{
if( ( profile->allowed_curves & MBEDTLS_UECC_DP_SECP256R1 ) != 0 )
return( 0 );
return( -1 );
}
#endif /* MBEDTLS_USE_TINYCRYPT */
#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 );
}
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
/*
* Return 0 if name matches wildcard, -1 otherwise
*/
static int x509_check_wildcard( char const *cn,
size_t cn_len,
unsigned char const *buf,
size_t buf_len )
{
size_t i;
size_t cn_idx = 0;
/* We can't have a match if there is no wildcard to match */
if( buf_len < 3 || buf[0] != '*' || buf[1] != '.' )
return( -1 );
for( i = 0; i < cn_len; ++i )
{
if( cn[i] == '.' )
{
cn_idx = i;
break;
}
}
if( cn_idx == 0 )
return( -1 );
if( mbedtls_x509_memcasecmp( buf + 1, cn + cn_idx,
buf_len - 1, cn_len - cn_idx ) == 0 )
{
return( 0 );
}
return( -1 );
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
/*
* 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( MBEDTLS_ERR_X509_INVALID_FORMAT + 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 );
}
#if !defined(MBEDTLS_X509_CRT_REMOVE_TIME)
/*
* 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 );
}
#else /* !MBEDTLS_X509_CRT_REMOVE_TIME */
static int x509_skip_dates( unsigned char **p,
const unsigned char *end )
{
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 );
/* skip contents of the sequence */
*p += len;
return( 0 );
}
#endif /* MBEDTLS_X509_CRT_REMOVE_TIME */
#if !defined(MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID)
/*
* X.509 v2/v3 unique identifier (not parsed)
*/
static int x509_get_uid( unsigned char **p,
const unsigned char *end,
mbedtls_x509_buf_raw *uid, int n )
{
int ret;
if( *p == end )
return( 0 );
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_ERR_X509_INVALID_FORMAT + ret );
}
uid->p = *p;
*p += uid->len;
return( 0 );
}
#else /* !MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID */
static int x509_skip_uid( unsigned char **p,
const unsigned char *end,
int n )
{
int ret;
size_t len;
if( *p == end )
return( 0 );
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | n ) ) != 0 )
{
if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
return( 0 );
return( MBEDTLS_ERR_X509_INVALID_FORMAT + ret );
}
*p += len;
return( 0 );
}
#endif /* MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID */
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( 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( 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( ret );
if( *p != end )
return( 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_ERR_ASN1_INVALID_LENGTH );
(*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( ret );
if( bs.len != 1 )
return( 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,
uint16_t *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( ret );
if( bs.len < 1 )
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
/* Get actual bitstring */
*key_usage = 0;
for( i = 0; i < bs.len && i < sizeof( *key_usage ); i++ )
{
*key_usage |= (uint16_t) bs.p[i] << ( 8*i );
}
return( 0 );
}
static int asn1_build_sequence_cb( void *ctx,
int tag,
unsigned char *data,
size_t data_len )
{
mbedtls_asn1_sequence **cur_ptr = (mbedtls_asn1_sequence **) ctx;
mbedtls_asn1_sequence *cur = *cur_ptr;
/* Allocate and assign next pointer */
if( cur->buf.p != NULL )
{
cur->next = mbedtls_calloc( 1, sizeof( mbedtls_asn1_sequence ) );
if( cur->next == NULL )
return( MBEDTLS_ERR_ASN1_ALLOC_FAILED );
cur = cur->next;
}
cur->buf.tag = tag;
cur->buf.p = data;
cur->buf.len = data_len;
*cur_ptr = cur;
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)
{
return( mbedtls_asn1_traverse_sequence_of( p, end,
0xFF, MBEDTLS_ASN1_OID,
0, 0,
asn1_build_sequence_cb,
(void *) &ext_key_usage ) );
}
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
/*
* 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 )
{
return( mbedtls_asn1_traverse_sequence_of( &p, end,
MBEDTLS_ASN1_TAG_CLASS_MASK,
MBEDTLS_ASN1_CONTEXT_SPECIFIC,
MBEDTLS_ASN1_TAG_VALUE_MASK,
2 /* SubjectAlt DNS */,
asn1_build_sequence_cb,
(void *) &subject_alt_name ) );
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
/*
* X.509 v3 extensions
*
*/
static int x509_crt_get_ext_cb( void *ctx,
int tag,
unsigned char *p,
size_t ext_len )
{
int ret;
mbedtls_x509_crt_frame *frame = (mbedtls_x509_crt_frame *) ctx;
size_t len;
unsigned char *end, *end_ext_octet;
mbedtls_x509_buf extn_oid = { 0, 0, NULL };
int is_critical = 0; /* DEFAULT FALSE */
int ext_type = 0;
((void) tag);
/*
* Extension ::= SEQUENCE {
* extnID OBJECT IDENTIFIER,
* critical BOOLEAN DEFAULT FALSE,
* extnValue OCTET STRING }
*/
end = p + ext_len;
/* Get extension ID */
if( ( ret = mbedtls_asn1_get_tag( &p, end, &extn_oid.len,
MBEDTLS_ASN1_OID ) ) != 0 )
goto err;
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, &is_critical ) ) != 0 &&
( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
goto err;
/* Data should be octet string type */
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
goto err;
end_ext_octet = p + len;
if( end_ext_octet != end )
{
ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
goto err;
}
/*
* Detect supported extensions
*/
ret = mbedtls_oid_get_x509_ext_type( &extn_oid, &ext_type );
if( ret != 0 )
{
#if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
if( is_critical )
{
/* Data is marked as critical: fail */
ret = MBEDTLS_ERR_ASN1_UNEXPECTED_TAG;
goto err;
}
#endif /* MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION */
return( 0 );
}
/* Forbid repeated extensions */
if( ( frame->ext_types & ext_type ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS );
frame->ext_types |= ext_type;
switch( ext_type )
{
case MBEDTLS_X509_EXT_BASIC_CONSTRAINTS:
{
int ca_istrue;
int max_pathlen;
/* Parse basic constraints */
ret = x509_get_basic_constraints( &p, end_ext_octet,
&ca_istrue,
&max_pathlen );
if( ret != 0 )
goto err;
frame->ca_istrue = ca_istrue;
frame->max_pathlen = max_pathlen;
break;
}
case MBEDTLS_X509_EXT_KEY_USAGE:
/* Parse key usage */
ret = x509_get_key_usage( &p, end_ext_octet,
&frame->key_usage );
if( ret != 0 )
goto err;
break;
case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
/* Copy reference to raw subject alt name data. */
frame->subject_alt_raw.p = p;
frame->subject_alt_raw.len = end_ext_octet - p;
ret = mbedtls_asn1_traverse_sequence_of( &p, end_ext_octet,
MBEDTLS_ASN1_TAG_CLASS_MASK,
MBEDTLS_ASN1_CONTEXT_SPECIFIC,
MBEDTLS_ASN1_TAG_VALUE_MASK,
2 /* SubjectAlt DNS */,
NULL, NULL );
if( ret != 0 )
goto err;
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
break;
case MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE:
/* Parse extended key usage */
frame->ext_key_usage_raw.p = p;
frame->ext_key_usage_raw.len = end_ext_octet - p;
if( frame->ext_key_usage_raw.len == 0 )
{
ret = MBEDTLS_ERR_ASN1_INVALID_LENGTH;
goto err;
}
/* Check structural sanity of extension. */
ret = mbedtls_asn1_traverse_sequence_of( &p, end_ext_octet,
0xFF, MBEDTLS_ASN1_OID,
0, 0, NULL, NULL );
if( ret != 0 )
goto err;
break;
case MBEDTLS_X509_EXT_NS_CERT_TYPE:
/* Parse netscape certificate type */
ret = x509_get_ns_cert_type( &p, end_ext_octet,
&frame->ns_cert_type );
if( ret != 0 )
goto err;
break;
default:
/*
* If this is a non-critical extension, which the oid layer
* supports, but there isn't an X.509 parser for it,
* skip the extension.
*/
#if !defined(MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
if( is_critical )
return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
#endif
p = end_ext_octet;
}
return( 0 );
err:
return( ret );
}
static int x509_crt_frame_parse_ext( mbedtls_x509_crt_frame *frame )
{
int ret;
unsigned char *p = frame->v3_ext.p;
unsigned char *end = p + frame->v3_ext.len;
if( p == end )
return( 0 );
ret = mbedtls_asn1_traverse_sequence_of( &p, end,
0xFF, MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED,
0, 0, x509_crt_get_ext_cb, frame );
if( ret == MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE )
return( ret );
if( ret == MBEDTLS_ERR_X509_INVALID_EXTENSIONS )
return( ret );
if( ret != 0 )
ret += MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
return( ret );
}
static int x509_crt_parse_frame( unsigned char *start,
unsigned char *end,
mbedtls_x509_crt_frame *frame )
{
int ret;
unsigned char *p;
size_t len;
mbedtls_x509_buf tmp;
unsigned char *tbs_start;
mbedtls_x509_buf outer_sig_alg;
size_t inner_sig_alg_len;
unsigned char *inner_sig_alg_start;
mbedtls_platform_memset( frame, 0, sizeof( *frame ) );
/*
* Certificate ::= SEQUENCE {
* tbsCertificate TBSCertificate,
* signatureAlgorithm AlgorithmIdentifier,
* signatureValue BIT STRING
* }
*
*/
p = start;
frame->raw.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERR_X509_INVALID_FORMAT );
}
/* NOTE: We are currently not checking that the `Certificate`
* structure spans the entire buffer. */
end = p + len;
frame->raw.len = end - frame->raw.p;
/*
* TBSCertificate ::= SEQUENCE { ...
*/
frame->tbs.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( ret + MBEDTLS_ERR_X509_INVALID_FORMAT );
}
tbs_start = p;
/* Breadth-first parsing: Jump over TBS for now. */
p += len;
frame->tbs.len = p - frame->tbs.p;
/*
* AlgorithmIdentifier ::= SEQUENCE { ...
*/
outer_sig_alg.p = p;
if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
{
return( MBEDTLS_ERR_X509_INVALID_ALG + ret );
}
p += len;
outer_sig_alg.len = p - outer_sig_alg.p;
/*
* signatureValue BIT STRING
*/
ret = mbedtls_x509_get_sig( &p, end, &tmp );
if( ret != 0 )
return( ret );
frame->sig.p = tmp.p;
frame->sig.len = tmp.len;
/* Check that we consumed the entire `Certificate` structure. */
if( p != end )
{
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
/* Parse TBSCertificate structure
*
* TBSCertificate ::= SEQUENCE {
* version [0] EXPLICIT Version DEFAULT v1,
* serialNumber CertificateSerialNumber,
* signature AlgorithmIdentifier,
* issuer Name,
* validity Validity,
* subject Name,
* subjectPublicKeyInfo SubjectPublicKeyInfo,
* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
* -- If present, version MUST be v2 or v3
* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
* -- If present, version MUST be v2 or v3
* extensions [3] EXPLICIT Extensions OPTIONAL
* -- If present, version MUST be v3
* }
*/
end = frame->tbs.p + frame->tbs.len;
p = tbs_start;
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
{
int version;
ret = x509_get_version( &p, end, &version );
if( ret != 0 )
return( ret );
if( version < 0 || version > 2 )
return( MBEDTLS_ERR_X509_UNKNOWN_VERSION );
frame->version = version + 1;
}
/*
* CertificateSerialNumber ::= INTEGER
*/
ret = mbedtls_x509_get_serial( &p, end, &tmp );
if( ret != 0 )
return( ret );
frame->serial.p = tmp.p;
frame->serial.len = tmp.len;
/*
* signature AlgorithmIdentifier
*/
inner_sig_alg_start = p;
ret = mbedtls_x509_get_sig_alg_raw( &p, end, &frame->sig_md,
&frame->sig_pk, NULL );
if( ret != 0 )
return( ret );
inner_sig_alg_len = p - inner_sig_alg_start;
frame->sig_alg.p = inner_sig_alg_start;
frame->sig_alg.len = inner_sig_alg_len;
/* Consistency check:
* Inner and outer AlgorithmIdentifier structures must coincide:
*
* Quoting RFC 5280, Section 4.1.1.2:
* This field MUST contain the same algorithm identifier as the
* signature field in the sequence tbsCertificate (Section 4.1.2.3).
*/
if( outer_sig_alg.len != inner_sig_alg_len ||
mbedtls_platform_memcmp( outer_sig_alg.p, inner_sig_alg_start, inner_sig_alg_len ) != 0 )
{
return( MBEDTLS_ERR_X509_SIG_MISMATCH );
}
/*
* issuer Name
*
* Name ::= CHOICE { -- only one possibility for now --
* rdnSequence RDNSequence }
*
* RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
*/
frame->issuer_raw.p = p;
ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE );
if( ret != 0 )
return( ret + MBEDTLS_ERR_X509_INVALID_FORMAT );
p += len;
frame->issuer_raw.len = p - frame->issuer_raw.p;
/* Comparing the raw buffer to itself amounts to structural validation. */
ret = mbedtls_x509_name_cmp_raw( &frame->issuer_raw,
&frame->issuer_raw,
NULL, NULL );
if( ret != 0 )
return( ret );
/*
* Validity ::= SEQUENCE { ...
*/
#if !defined(MBEDTLS_X509_CRT_REMOVE_TIME)
ret = x509_get_dates( &p, end, &frame->valid_from, &frame->valid_to );
if( ret != 0 )
return( ret );
#else /* !MBEDTLS_X509_CRT_REMOVE_TIME */
ret = x509_skip_dates( &p, end );
if( ret != 0 )
return( ret );
#endif /* MBEDTLS_X509_CRT_REMOVE_TIME */
/*
* subject Name
*
* Name ::= CHOICE { -- only one possibility for now --
* rdnSequence RDNSequence }
*
* RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
*/
frame->subject_raw.p = p;
ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE );
if( ret != 0 )
return( ret + MBEDTLS_ERR_X509_INVALID_FORMAT );
p += len;
frame->subject_raw.len = p - frame->subject_raw.p;
/* Comparing the raw buffer to itself amounts to structural validation. */
ret = mbedtls_x509_name_cmp_raw( &frame->subject_raw,
&frame->subject_raw,
NULL, NULL );
if( ret != 0 )
return( ret );
/*
* SubjectPublicKeyInfo
*/
frame->pubkey_raw.p = p;
ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE );
if( ret != 0 )
return( ret + MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
p += len;
frame->pubkey_raw.len = p - frame->pubkey_raw.p;
if( frame->version != 1 )
{
#if !defined(MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID)
/*
* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
* -- If present, version shall be v2 or v3
*/
ret = x509_get_uid( &p, end, &frame->issuer_id, 1 /* implicit tag */ );
if( ret != 0 )
return( ret );
/*
* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
* -- If present, version shall be v2 or v3
*/
ret = x509_get_uid( &p, end, &frame->subject_id, 2 /* implicit tag */ );
if( ret != 0 )
return( ret );
#else /* !MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID */
ret = x509_skip_uid( &p, end, 1 /* implicit tag */ );
if( ret != 0 )
return( ret );
ret = x509_skip_uid( &p, end, 2 /* implicit tag */ );
if( ret != 0 )
return( ret );
#endif /* MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID */
}
/*
* extensions [3] EXPLICIT Extensions OPTIONAL
* -- If present, version shall be v3
*/
#if !defined(MBEDTLS_X509_ALLOW_EXTENSIONS_NON_V3)
if( frame->version == 3 )
#endif
{
if( p != end )
{
ret = mbedtls_asn1_get_tag( &p, end, &len,
MBEDTLS_ASN1_CONTEXT_SPECIFIC |
MBEDTLS_ASN1_CONSTRUCTED | 3 );
if( len == 0 )
ret = MBEDTLS_ERR_ASN1_OUT_OF_DATA;
if( ret != 0 )
return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS + ret );
frame->v3_ext.p = p;
frame->v3_ext.len = len;
p += len;
}
ret = x509_crt_frame_parse_ext( frame );
if( ret != 0 )
return( ret );
}
/* Wrapup: Check that we consumed the entire `TBSCertificate` structure. */
if( p != end )
{
return( MBEDTLS_ERR_X509_INVALID_FORMAT +
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
}
return( 0 );
}
static int x509_crt_subject_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_name *subject )
{
return( mbedtls_x509_get_name( frame->subject_raw.p,
frame->subject_raw.len,
subject ) );
}
static int x509_crt_issuer_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_name *issuer )
{
return( mbedtls_x509_get_name( frame->issuer_raw.p,
frame->issuer_raw.len,
issuer ) );
}
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
static int x509_crt_subject_alt_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_sequence *subject_alt )
{
int ret;
unsigned char *p = frame->subject_alt_raw.p;
unsigned char *end = p + frame->subject_alt_raw.len;
mbedtls_platform_memset( subject_alt, 0, sizeof( *subject_alt ) );
if( ( frame->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME ) == 0 )
return( 0 );
ret = x509_get_subject_alt_name( p, end, subject_alt );
if( ret != 0 )
ret += MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
return( ret );
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
static int x509_crt_ext_key_usage_from_frame( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_sequence *ext_key_usage )
{
int ret;
unsigned char *p = frame->ext_key_usage_raw.p;
unsigned char *end = p + frame->ext_key_usage_raw.len;
mbedtls_platform_memset( ext_key_usage, 0, sizeof( *ext_key_usage ) );
if( ( frame->ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) == 0 )
return( 0 );
ret = x509_get_ext_key_usage( &p, end, ext_key_usage );
if( ret != 0 )
{
ret += MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
return( ret );
}
return( 0 );
}
#if !defined(MBEDTLS_X509_ON_DEMAND_PARSING)
static int x509_crt_pk_from_frame( mbedtls_x509_crt_frame *frame,
mbedtls_pk_context *pk )
{
unsigned char *p = frame->pubkey_raw.p;
unsigned char *end = p + frame->pubkey_raw.len;
return( mbedtls_pk_parse_subpubkey( &p, end, pk ) );
}
#endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */
/*
* 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 )
{
int ret;
mbedtls_x509_crt_frame *frame;
mbedtls_x509_crt_cache *cache;
if( crt == NULL || buf == NULL )
return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
if( make_copy == 0 )
{
crt->raw.p = (unsigned char*) buf;
crt->raw.len = buflen;
crt->own_buffer = 0;
}
else
{
/* Call mbedtls_calloc with buflen + 1 in order to avoid potential
* return of NULL in case of length 0 certificates, which we want
* to cleanly fail with MBEDTLS_ERR_X509_INVALID_FORMAT in the
* core parsing routine, but not here. */
crt->raw.p = mbedtls_calloc( 1, buflen + 1 );
if( crt->raw.p == NULL )
return( MBEDTLS_ERR_X509_ALLOC_FAILED );
crt->raw.len = buflen;
mbedtls_platform_memcpy( crt->raw.p, buf, buflen );
crt->own_buffer = 1;
}
cache = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt_cache ) );
if( cache == NULL )
{
ret = MBEDTLS_ERR_X509_ALLOC_FAILED;
goto exit;
}
crt->cache = cache;
x509_crt_cache_init( cache );
#if defined(MBEDTLS_X509_ON_DEMAND_PARSING)
ret = mbedtls_x509_crt_cache_provide_frame( crt );
if( ret != 0 )
goto exit;
frame = crt->cache->frame;
#else /* MBEDTLS_X509_ON_DEMAND_PARSING */
frame = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt_frame ) );
if( frame == NULL )
{
ret = MBEDTLS_ERR_X509_ALLOC_FAILED;
goto exit;
}
cache->frame = frame;
ret = x509_crt_parse_frame( crt->raw.p,
crt->raw.p + crt->raw.len,
frame );
if( ret != 0 )
goto exit;
/* Copy frame to legacy CRT structure -- that's inefficient, but if
* memory matters, the new CRT structure should be used anyway. */
x509_buf_raw_to_buf( &crt->tbs, &frame->tbs );
x509_buf_raw_to_buf( &crt->serial, &frame->serial );
x509_buf_raw_to_buf( &crt->issuer_raw, &frame->issuer_raw );
x509_buf_raw_to_buf( &crt->subject_raw, &frame->subject_raw );
#if !defined(MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID)
x509_buf_raw_to_buf( &crt->issuer_id, &frame->issuer_id );
x509_buf_raw_to_buf( &crt->subject_id, &frame->subject_id );
#endif /* !MBEDTLS_X509_CRT_REMOVE_SUBJECT_ISSUER_ID */
x509_buf_raw_to_buf( &crt->pk_raw, &frame->pubkey_raw );
x509_buf_raw_to_buf( &crt->sig, &frame->sig );
x509_buf_raw_to_buf( &crt->v3_ext, &frame->v3_ext );
#if !defined(MBEDTLS_X509_CRT_REMOVE_TIME)
crt->valid_from = frame->valid_from;
crt->valid_to = frame->valid_to;
#endif /* !MBEDTLS_X509_CRT_REMOVE_TIME */
crt->version = frame->version;
crt->ca_istrue = frame->ca_istrue;
crt->max_pathlen = frame->max_pathlen;
crt->ext_types = frame->ext_types;
crt->key_usage = frame->key_usage;
crt->ns_cert_type = frame->ns_cert_type;
/*
* Obtain the remaining fields from the frame.
*/
{
/* sig_oid: Previously, needed for convenience in
* mbedtls_x509_crt_info(), now pure legacy burden. */
unsigned char *tmp = frame->sig_alg.p;
unsigned char *end = tmp + frame->sig_alg.len;
mbedtls_x509_buf sig_oid, sig_params;
ret = mbedtls_x509_get_alg( &tmp, end,
&sig_oid, &sig_params );
if( ret != 0 )
{
/* This should never happen, because we check
* the sanity of the AlgorithmIdentifier structure
* during frame parsing. */
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto exit;
}
crt->sig_oid = sig_oid;
/* Signature parameters */
tmp = frame->sig_alg.p;
ret = mbedtls_x509_get_sig_alg_raw( &tmp, end,
&crt->sig_md, &crt->sig_pk,
&crt->sig_opts );
if( ret != 0 )
{
/* Again, this should never happen. */
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto exit;
}
}
ret = x509_crt_pk_from_frame( frame, &crt->pk );
if( ret != 0 )
goto exit;
ret = x509_crt_subject_from_frame( frame, &crt->subject );
if( ret != 0 )
goto exit;
ret = x509_crt_issuer_from_frame( frame, &crt->issuer );
if( ret != 0 )
goto exit;
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
ret = x509_crt_subject_alt_from_frame( frame, &crt->subject_alt_names );
if( ret != 0 )
goto exit;
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
ret = x509_crt_ext_key_usage_from_frame( frame, &crt->ext_key_usage );
if( ret != 0 )
goto exit;
#endif /* !MBEDTLS_X509_ON_DEMAND_PARSING */
/* Currently, we accept DER encoded CRTs with trailing garbage
* and promise to not account for the garbage in the `raw` field.
*
* Note that this means that `crt->raw.len` is not necessarily the
* full size of the heap buffer allocated at `crt->raw.p` in case
* of copy-mode, but this is not a problem: freeing the buffer doesn't
* need the size, and the garbage data doesn't need zeroization. */
crt->raw.len = frame->raw.len;
cache->pk_raw = frame->pubkey_raw;
/* Free the frame before parsing the public key to
* keep peak RAM usage low. This is slightly inefficient
* because the frame will need to be parsed again on the
* first usage of the CRT, but that seems acceptable.
* As soon as the frame gets used multiple times, it
* will be cached by default. */
x509_crt_cache_clear_frame( crt->cache );
/* The cache just references the PK structure from the legacy
* implementation, so set up the latter first before setting up
* the cache.
*
* We're not actually using the parsed PK context here;
* we just parse it to check that it's well-formed. */
ret = mbedtls_x509_crt_cache_provide_pk( crt );
if( ret != 0 )
goto exit;
x509_crt_cache_clear_pk( crt->cache );
exit:
if( ret != 0 )
mbedtls_x509_crt_free( crt );
return( ret );
}
/*
* 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 )
{
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->raw.p != NULL && crt->next != NULL )
{
prev = crt;
crt = crt->next;
}
/*
* Add new certificate on the end of the chain if needed.
*/
if( crt->raw.p != NULL && 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, make_copy ) ) != 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 ) );
}
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 ) );
}
/*
* 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 );
mbedtls_platform_memset( szDir, 0, sizeof(szDir) );
mbedtls_platform_memset( filename, 0, MAX_PATH );
mbedtls_platform_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
{
mbedtls_platform_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 */
typedef struct mbedtls_x509_crt_sig_info
{
mbedtls_md_type_t sig_md;
mbedtls_pk_type_t sig_pk;
void *sig_opts;
size_t crt_hash_len;
mbedtls_x509_buf_raw sig;
mbedtls_x509_buf_raw issuer_raw;
uint8_t crt_hash[MBEDTLS_MD_MAX_SIZE];
} mbedtls_x509_crt_sig_info;
static void x509_crt_free_sig_info( mbedtls_x509_crt_sig_info *info )
{
#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
mbedtls_free( info->sig_opts );
#else
((void) info);
#endif /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */
}
static int x509_crt_get_sig_info( mbedtls_x509_crt_frame const *frame,
mbedtls_x509_crt_sig_info *info )
{
mbedtls_md_handle_t md_info;
md_info = mbedtls_md_info_from_type( frame->sig_md );
if( mbedtls_md( md_info, frame->tbs.p, frame->tbs.len,
info->crt_hash ) != 0 )
{
/* Note: this can't happen except after an internal error */
return( -1 );
}
info->crt_hash_len = mbedtls_md_get_size( md_info );
/* Make sure that this function leaves the target structure
* ready to be freed, regardless of success of failure. */
info->sig_opts = NULL;
#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
{
int ret;
unsigned char *alg_start = frame->sig_alg.p;
unsigned char *alg_end = alg_start + frame->sig_alg.len;
/* Get signature options -- currently only
* necessary for RSASSA-PSS. */
ret = mbedtls_x509_get_sig_alg_raw( &alg_start, alg_end, &info->sig_md,
&info->sig_pk, &info->sig_opts );
if( ret != 0 )
{
/* Note: this can't happen except after an internal error */
return( -1 );
}
}
#else /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */
info->sig_md = frame->sig_md;
info->sig_pk = frame->sig_pk;
#endif /* !MBEDTLS_X509_RSASSA_PSS_SUPPORT */
info->issuer_raw = frame->issuer_raw;
info->sig = frame->sig;
return( 0 );
}
#if !defined(MBEDTLS_X509_REMOVE_INFO)
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
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 );
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
#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_CRT 18
#define BC_CRT "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_CRT];
mbedtls_x509_crt_frame frame;
mbedtls_pk_context pk;
mbedtls_x509_name *issuer = NULL, *subject = NULL;
mbedtls_x509_sequence *ext_key_usage = NULL;
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
mbedtls_x509_sequence *subject_alt_names = NULL;
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
mbedtls_x509_crt_sig_info sig_info;
p = buf;
n = size;
memset( &sig_info, 0, sizeof( mbedtls_x509_crt_sig_info ) );
mbedtls_pk_init( &pk );
if( NULL == crt )
{
ret = mbedtls_snprintf( p, n, "\nCertificate is uninitialised!\n" );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
return( (int) ( size - n ) );
}
ret = mbedtls_x509_crt_get_frame( crt, &frame );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
ret = mbedtls_x509_crt_get_subject( crt, &subject );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
ret = mbedtls_x509_crt_get_issuer( crt, &issuer );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
ret = mbedtls_x509_crt_get_subject_alt_names( crt, &subject_alt_names );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
ret = mbedtls_x509_crt_get_ext_key_usage( crt, &ext_key_usage );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
ret = mbedtls_x509_crt_get_pk( crt, &pk );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
ret = x509_crt_get_sig_info( &frame, &sig_info );
if( ret != 0 )
{
ret = MBEDTLS_ERR_X509_FATAL_ERROR;
goto cleanup;
}
ret = mbedtls_snprintf( p, n, "%scert. version : %d\n",
prefix, frame.version );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
{
mbedtls_x509_buf serial;
serial.p = frame.serial.p;
serial.len = frame.serial.len;
ret = mbedtls_snprintf( p, n, "%sserial number : ",
prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = mbedtls_x509_serial_gets( p, n, &serial );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
}
ret = mbedtls_snprintf( p, n, "\n%sissuer name : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = mbedtls_x509_dn_gets( p, n, issuer );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = mbedtls_snprintf( p, n, "\n%ssubject name : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = mbedtls_x509_dn_gets( p, n, subject );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
#if !defined(MBEDTLS_X509_CRT_REMOVE_TIME)
ret = mbedtls_snprintf( p, n, "\n%sissued on : " \
"%04d-%02d-%02d %02d:%02d:%02d", prefix,
frame.valid_from.year, frame.valid_from.mon,
frame.valid_from.day, frame.valid_from.hour,
frame.valid_from.min, frame.valid_from.sec );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = mbedtls_snprintf( p, n, "\n%sexpires on : " \
"%04d-%02d-%02d %02d:%02d:%02d", prefix,
frame.valid_to.year, frame.valid_to.mon,
frame.valid_to.day, frame.valid_to.hour,
frame.valid_to.min, frame.valid_to.sec );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
#endif /* MBEDTLS_X509_CRT_REMOVE_TIME */
ret = mbedtls_snprintf( p, n, "\n%ssigned using : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = mbedtls_x509_sig_alg_gets( p, n, sig_info.sig_pk,
sig_info.sig_md, sig_info.sig_opts );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
/* Key size */
if( ( ret = mbedtls_x509_key_size_helper( key_size_str, BEFORE_COLON_CRT,
mbedtls_pk_get_name( &pk ) ) ) != 0 )
{
return( ret );
}
ret = mbedtls_snprintf( p, n, "\n%s%-" BC_CRT "s: %d bits", prefix, key_size_str,
(int) mbedtls_pk_get_bitlen( &pk ) );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
/*
* Optional extensions
*/
if( frame.ext_types & MBEDTLS_X509_EXT_BASIC_CONSTRAINTS )
{
ret = mbedtls_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
frame.ca_istrue ? "true" : "false" );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
if( frame.max_pathlen > 0 )
{
ret = mbedtls_snprintf( p, n, ", max_pathlen=%d", frame.max_pathlen - 1 );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
}
}
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
if( frame.ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME )
{
ret = mbedtls_snprintf( p, n, "\n%ssubject alt name : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
if( ( ret = x509_info_subject_alt_name( &p, &n,
subject_alt_names ) ) != 0 )
return( ret );
}
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
if( frame.ext_types & MBEDTLS_X509_EXT_NS_CERT_TYPE )
{
ret = mbedtls_snprintf( p, n, "\n%scert. type : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
if( ( ret = x509_info_cert_type( &p, &n, frame.ns_cert_type ) ) != 0 )
return( ret );
}
if( frame.ext_types & MBEDTLS_X509_EXT_KEY_USAGE )
{
ret = mbedtls_snprintf( p, n, "\n%skey usage : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
if( ( ret = x509_info_key_usage( &p, &n, frame.key_usage ) ) != 0 )
return( ret );
}
if( frame.ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE )
{
ret = mbedtls_snprintf( p, n, "\n%sext key usage : ", prefix );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
if( ( ret = x509_info_ext_key_usage( &p, &n,
ext_key_usage ) ) != 0 )
return( ret );
}
ret = mbedtls_snprintf( p, n, "\n" );
MBEDTLS_X509_SAFE_SNPRINTF_WITH_CLEANUP;
ret = (int) ( size - n );
cleanup:
x509_crt_free_sig_info( &sig_info );
mbedtls_pk_free( &pk );
mbedtls_x509_name_free( issuer );
mbedtls_x509_name_free( subject );
mbedtls_x509_sequence_free( ext_key_usage );
#if !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
mbedtls_x509_sequence_free( subject_alt_names );
#endif /* !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
return( ret );
}
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 ) );
}
#endif /* !MBEDTLS_X509_REMOVE_INFO */
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
static int x509_crt_check_key_usage_frame( const mbedtls_x509_crt_frame *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_key_usage( const mbedtls_x509_crt *crt,
unsigned int usage )
{
int ret;
mbedtls_x509_crt_frame const *frame;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( MBEDTLS_ERR_X509_FATAL_ERROR );
ret = x509_crt_check_key_usage_frame( frame, usage );
mbedtls_x509_crt_frame_release( crt );
return( ret );
}
#endif
#if defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
typedef struct
{
const char *oid;
size_t oid_len;
} x509_crt_check_ext_key_usage_cb_ctx_t;
static int x509_crt_check_ext_key_usage_cb( void *ctx,
int tag,
unsigned char *data,
size_t data_len )
{
x509_crt_check_ext_key_usage_cb_ctx_t *cb_ctx =
(x509_crt_check_ext_key_usage_cb_ctx_t *) ctx;
((void) tag);
if( MBEDTLS_OID_CMP_RAW( MBEDTLS_OID_ANY_EXTENDED_KEY_USAGE,
data, data_len ) == 0 )
{
return( 1 );
}
if( data_len == cb_ctx->oid_len && mbedtls_platform_memcmp( data, cb_ctx->oid,
data_len ) == 0 )
{
return( 1 );
}
return( 0 );
}
int mbedtls_x509_crt_check_extended_key_usage( const mbedtls_x509_crt *crt,
const char *usage_oid,
size_t usage_len )
{
int ret;
mbedtls_x509_crt_frame const *frame;
unsigned ext_types;
unsigned char *p, *end;
x509_crt_check_ext_key_usage_cb_ctx_t cb_ctx = { usage_oid, usage_len };
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( MBEDTLS_ERR_X509_FATAL_ERROR );
/* Extension is not mandatory, absent means no restriction */
ext_types = frame->ext_types;
if( ( ext_types & MBEDTLS_X509_EXT_EXTENDED_KEY_USAGE ) != 0 )
{
p = frame->ext_key_usage_raw.p;
end = p + frame->ext_key_usage_raw.len;
ret = mbedtls_asn1_traverse_sequence_of( &p, end,
0xFF, MBEDTLS_ASN1_OID, 0, 0,
x509_crt_check_ext_key_usage_cb,
&cb_ctx );
if( ret == 1 )
ret = 0;
else
ret = MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
mbedtls_x509_crt_frame_release( crt );
return( ret );
}
#endif /* MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE */
#if defined(MBEDTLS_X509_CRL_PARSE_C)
/*
* Return 1 if the certificate is revoked, or 0 otherwise.
*/
static int x509_serial_is_revoked( unsigned char const *serial,
size_t serial_len,
const mbedtls_x509_crl *crl )
{
const mbedtls_x509_crl_entry *cur = &crl->entry;
while( cur != NULL && cur->serial.len != 0 )
{
if( serial_len == cur->serial.len &&
mbedtls_platform_memcmp( serial, cur->serial.p, serial_len ) == 0 )
{
if( mbedtls_x509_time_is_past( &cur->revocation_date ) )
return( 1 );
}
cur = cur->next;
}
return( 0 );
}
int mbedtls_x509_crt_is_revoked( const mbedtls_x509_crt *crt,
const mbedtls_x509_crl *crl )
{
int ret;
mbedtls_x509_crt_frame const *frame;
ret = mbedtls_x509_crt_frame_acquire( crt, &frame );
if( ret != 0 )
return( MBEDTLS_ERR_X509_FATAL_ERROR );
ret = x509_serial_is_revoked( frame->serial.p,
frame->serial.len,
crl );
mbedtls_x509_crt_frame_release( crt );
return( ret );
}
/*
* 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( unsigned char *crt_serial,
size_t crt_serial_len,
mbedtls_x509_crt *ca_crt,
mbedtls_x509_crl *crl_list,
const mbedtls_x509_crt_profile *profile )
{
int ret;
int flags = 0;
unsigned char hash[MBEDTLS_MD_MAX_SIZE];
mbedtls_md_handle_t md_info;
mbedtls_x509_buf_raw ca_subject;
mbedtls_pk_context *pk;
int can_sign;
if( ca_crt == NULL )
return( flags );
{
mbedtls_x509_crt_frame const *ca;
ret = mbedtls_x509_crt_frame_acquire( ca_crt, &ca );
if( ret != 0 )
return( MBEDTLS_X509_BADCRL_NOT_TRUSTED );
ca_subject = ca->subject_raw;
can_sign = 0;
if( x509_crt_check_key_usage_frame( ca,
MBEDTLS_X509_KU_CRL_SIGN ) == 0 )
{
can_sign = 1;
}
mbedtls_x509_crt_frame_release( ca_crt );
}
ret = mbedtls_x509_crt_pk_acquire( ca_crt, &pk );
if( ret != 0 )
return( MBEDTLS_X509_BADCRL_NOT_TRUSTED );
while( crl_list != NULL )
{
if( crl_list->version == 0 ||
mbedtls_x509_name_cmp_raw( &crl_list->issuer_raw,
&ca_subject, NULL, NULL ) != 0 )
{
crl_list = crl_list->next;
continue;
}
/*
* Check if the CA is configured to sign CRLs
*/
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
if( !can_sign )
{
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, pk ) != 0 )
flags |= MBEDTLS_X509_BADCERT_BAD_KEY;
if( mbedtls_pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, 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( x509_serial_is_revoked( crt_serial, crt_serial_len,
crl_list ) )
{
flags |= MBEDTLS_X509_BADCERT_REVOKED;
break;
}
crl_list = crl_list->next;
}
mbedtls_x509_crt_pk_release( ca_crt );
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_sig_info *sig_info,
mbedtls_x509_crt *parent,
mbedtls_x509_crt_restart_ctx *rs_ctx )
{
int ret;
mbedtls_pk_context *pk;
ret = mbedtls_x509_crt_pk_acquire( parent, &pk );
if( ret != 0 )
return( MBEDTLS_ERR_X509_FATAL_ERROR );
/* Skip expensive computation on obvious mismatch */
if( ! mbedtls_pk_can_do( pk, sig_info->sig_pk ) )
{
ret = -1;
goto exit;
}
#if !( defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE) )
((void) rs_ctx);
#else
if( rs_ctx != NULL && sig_info->sig_pk == MBEDTLS_PK_ECDSA )
{
ret = mbedtls_pk_verify_restartable( pk,
sig_info->sig_md,
sig_info->crt_hash, sig_info->crt_hash_len,
sig_info->sig.p, sig_info->sig.len,
&rs_ctx->pk );
}
else
#endif
{
ret = mbedtls_pk_verify_ext( sig_info->sig_pk,
sig_info->sig_opts,
pk,
sig_info->sig_md,
sig_info->crt_hash, sig_info->crt_hash_len,
sig_info->sig.p, sig_info->sig.len );
}
exit:
mbedtls_x509_crt_pk_release( parent );
return( ret );
}
/*
* 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_sig_info *sig_info,
const mbedtls_x509_crt_frame *parent,
int top )
{
int need_ca_bit;
/* Parent must be the issuer */
if( mbedtls_x509_name_cmp_raw( &sig_info->issuer_raw,
&parent->subject_raw,
NULL, NULL ) != 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 &&
x509_crt_check_key_usage_frame( parent,
MBEDTLS_X509_KU_KEY_CERT_SIGN ) != 0 )
{
return( -1 );
}
#endif
return( 0 );
}
/* This value is different enough from 0 that it's hard for an active physical
* attacker to reach it just by flipping a few bits. */
#define X509_SIGNATURE_IS_GOOD 0x7f5a5a5a
/*
* 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: set to X509_SIGNATURE_IS_GOOD if
* child signature by parent is valid, or to 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 or MBEDTLS_ERR_PLATFORM_FAULT_DETECTED otherwise
*/
static int x509_crt_find_parent_in(
mbedtls_x509_crt_sig_info const *child_sig,
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;
volatile int ret_fi = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
mbedtls_x509_crt *parent_crt;
int signature_is_good = 0;
#if defined(MBEDTLS_HAVE_TIME_DATE)
mbedtls_x509_crt *fallback_parent;
int fallback_signature_is_good;
#endif /* MBEDTLS_HAVE_TIME_DATE */
#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_crt = rs_ctx->parent;
#if defined(MBEDTLS_HAVE_TIME_DATE)
fallback_parent = rs_ctx->fallback_parent;
fallback_signature_is_good = rs_ctx->fallback_signature_is_good;
#endif /* MBEDTLS_HAVE_TIME_DATE */
/* clear saved state */
rs_ctx->parent = NULL;
#if defined(MBEDTLS_HAVE_TIME_DATE)
rs_ctx->fallback_parent = NULL;
rs_ctx->fallback_signature_is_good = 0;
#endif /* MBEDTLS_HAVE_TIME_DATE */
/* resume where we left */
goto check_signature;
}
#endif
#if defined(MBEDTLS_HAVE_TIME_DATE)
fallback_parent = NULL;
fallback_signature_is_good = 0;
#endif /* MBEDTLS_HAVE_TIME_DATE */
for( parent_crt = candidates; parent_crt != NULL;
parent_crt = parent_crt->next )
{
int parent_valid, parent_match, path_len_ok;
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
check_signature:
#endif
parent_valid = parent_match = path_len_ok = 0;
{
mbedtls_x509_crt_frame const *parent;
ret = mbedtls_x509_crt_frame_acquire( parent_crt, &parent );
if( ret != 0 )
return( MBEDTLS_ERR_X509_FATAL_ERROR );
#if !defined(MBEDTLS_X509_CRT_REMOVE_TIME)
if( !mbedtls_x509_time_is_past( &parent->valid_to ) &&
!mbedtls_x509_time_is_future( &parent->valid_from ) )
#endif /* !MBEDTLS_X509_CRT_REMOVE_TIME */
{
parent_valid = 1;
}
/* basic parenting skills (name, CA bit, key usage) */
if( x509_crt_check_parent( child_sig, parent, top ) == 0 )
parent_match = 1;
/* +1 because the stored max_pathlen is 1 higher
* than the actual value */
if( !( parent->max_pathlen > 0 &&
(size_t) parent->max_pathlen < 1 + path_cnt - self_cnt ) )
{
path_len_ok = 1;
}
mbedtls_x509_crt_frame_release( parent_crt );
}
if( parent_match == 0 || path_len_ok == 0 )
continue;
/* Signature */
ret_fi = x509_crt_check_signature( child_sig, parent_crt, rs_ctx );
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
if( rs_ctx != NULL && ret_fi == MBEDTLS_ERR_ECP_IN_PROGRESS )
{
/* save state */
rs_ctx->parent = parent_crt;
#if defined(MBEDTLS_HAVE_TIME_DATE)
rs_ctx->fallback_parent = fallback_parent;
rs_ctx->fallback_signature_is_good = fallback_signature_is_good;
#endif /* MBEDTLS_HAVE_TIME_DATE */
return( ret_fi );
}
#endif
if( ret_fi == 0 )
{
mbedtls_platform_random_delay();
if( ret_fi == 0 )
signature_is_good = X509_SIGNATURE_IS_GOOD;
else
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
}
if( top && ! signature_is_good )
continue;
/* optional time check */
if( !parent_valid )
{
#if defined(MBEDTLS_HAVE_TIME_DATE)
if( fallback_parent == NULL )
{
fallback_parent = parent_crt;
fallback_signature_is_good = signature_is_good;
}
#endif /* MBEDTLS_HAVE_TIME_DATE */
continue;
}
*r_parent = parent_crt;
*r_signature_is_good = signature_is_good;
break;
}
if( parent_crt == NULL )
{
#if defined(MBEDTLS_HAVE_TIME_DATE)
*r_parent = fallback_parent;
*r_signature_is_good = fallback_signature_is_good;
#else /* MBEDTLS_HAVE_TIME_DATE */
*r_parent = NULL;
#endif /* !MBEDTLS_HAVE_TIME_DATE */
}
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_sig_info const *child_sig,
mbedtls_x509_crt *rest,
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 : rest;
ret = x509_crt_find_parent_in( child_sig, 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