393 lines
9.2 KiB
C
393 lines
9.2 KiB
C
/*
|
|
* Generic ASN.1 parsing
|
|
*
|
|
* 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)
|
|
*/
|
|
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "mbedtls/config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_ASN1_PARSE_C)
|
|
|
|
#include "mbedtls/asn1.h"
|
|
|
|
#include <string.h>
|
|
|
|
#if defined(MBEDTLS_BIGNUM_C)
|
|
#include "mbedtls/bignum.h"
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_PLATFORM_C)
|
|
#include "mbedtls/platform.h"
|
|
#else
|
|
#include <stdlib.h>
|
|
#define mbedtls_calloc calloc
|
|
#define mbedtls_free free
|
|
#endif
|
|
|
|
/* Implementation that should never be optimized out by the compiler */
|
|
static void mbedtls_zeroize( void *v, size_t n ) {
|
|
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
|
|
}
|
|
|
|
/*
|
|
* ASN.1 DER decoding routines
|
|
*/
|
|
int mbedtls_asn1_get_len( unsigned char **p,
|
|
const unsigned char *end,
|
|
size_t *len )
|
|
{
|
|
if( ( end - *p ) < 1 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
if( ( **p & 0x80 ) == 0 )
|
|
*len = *(*p)++;
|
|
else
|
|
{
|
|
switch( **p & 0x7F )
|
|
{
|
|
case 1:
|
|
if( ( end - *p ) < 2 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = (*p)[1];
|
|
(*p) += 2;
|
|
break;
|
|
|
|
case 2:
|
|
if( ( end - *p ) < 3 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = ( (size_t)(*p)[1] << 8 ) | (*p)[2];
|
|
(*p) += 3;
|
|
break;
|
|
|
|
case 3:
|
|
if( ( end - *p ) < 4 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = ( (size_t)(*p)[1] << 16 ) |
|
|
( (size_t)(*p)[2] << 8 ) | (*p)[3];
|
|
(*p) += 4;
|
|
break;
|
|
|
|
case 4:
|
|
if( ( end - *p ) < 5 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = ( (size_t)(*p)[1] << 24 ) | ( (size_t)(*p)[2] << 16 ) |
|
|
( (size_t)(*p)[3] << 8 ) | (*p)[4];
|
|
(*p) += 5;
|
|
break;
|
|
|
|
default:
|
|
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
|
|
}
|
|
}
|
|
|
|
if( *len > (size_t) ( end - *p ) )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_asn1_get_tag( unsigned char **p,
|
|
const unsigned char *end,
|
|
size_t *len, int tag )
|
|
{
|
|
if( ( end - *p ) < 1 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
if( **p != tag )
|
|
return( MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
|
|
|
|
(*p)++;
|
|
|
|
return( mbedtls_asn1_get_len( p, end, len ) );
|
|
}
|
|
|
|
int mbedtls_asn1_get_bool( unsigned char **p,
|
|
const unsigned char *end,
|
|
int *val )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_BOOLEAN ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( len != 1 )
|
|
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
|
|
|
|
*val = ( **p != 0 ) ? 1 : 0;
|
|
(*p)++;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_asn1_get_int( unsigned char **p,
|
|
const unsigned char *end,
|
|
int *val )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( len == 0 || len > sizeof( int ) || ( **p & 0x80 ) != 0 )
|
|
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
|
|
|
|
*val = 0;
|
|
|
|
while( len-- > 0 )
|
|
{
|
|
*val = ( *val << 8 ) | **p;
|
|
(*p)++;
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_BIGNUM_C)
|
|
int mbedtls_asn1_get_mpi( unsigned char **p,
|
|
const unsigned char *end,
|
|
mbedtls_mpi *X )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_INTEGER ) ) != 0 )
|
|
return( ret );
|
|
|
|
ret = mbedtls_mpi_read_binary( X, *p, len );
|
|
|
|
*p += len;
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_BIGNUM_C */
|
|
|
|
int mbedtls_asn1_get_bitstring( unsigned char **p, const unsigned char *end,
|
|
mbedtls_asn1_bitstring *bs)
|
|
{
|
|
int ret;
|
|
|
|
/* Certificate type is a single byte bitstring */
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &bs->len, MBEDTLS_ASN1_BIT_STRING ) ) != 0 )
|
|
return( ret );
|
|
|
|
/* Check length, subtract one for actual bit string length */
|
|
if( bs->len < 1 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
bs->len -= 1;
|
|
|
|
/* Get number of unused bits, ensure unused bits <= 7 */
|
|
bs->unused_bits = **p;
|
|
if( bs->unused_bits > 7 )
|
|
return( MBEDTLS_ERR_ASN1_INVALID_LENGTH );
|
|
(*p)++;
|
|
|
|
/* Get actual bitstring */
|
|
bs->p = *p;
|
|
*p += bs->len;
|
|
|
|
if( *p != end )
|
|
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Get a bit string without unused bits
|
|
*/
|
|
int mbedtls_asn1_get_bitstring_null( unsigned char **p, const unsigned char *end,
|
|
size_t *len )
|
|
{
|
|
int ret;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, len, MBEDTLS_ASN1_BIT_STRING ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( (*len)-- < 2 || *(*p)++ != 0 )
|
|
return( MBEDTLS_ERR_ASN1_INVALID_DATA );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
|
|
*/
|
|
int mbedtls_asn1_get_sequence_of( unsigned char **p,
|
|
const unsigned char *end,
|
|
mbedtls_asn1_sequence *cur,
|
|
int tag)
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
mbedtls_asn1_buf *buf;
|
|
|
|
/* Get main sequence tag */
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
|
|
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( *p + len != end )
|
|
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
while( *p < end )
|
|
{
|
|
buf = &(cur->buf);
|
|
buf->tag = **p;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &buf->len, tag ) ) != 0 )
|
|
return( ret );
|
|
|
|
buf->p = *p;
|
|
*p += buf->len;
|
|
|
|
/* Allocate and assign next pointer */
|
|
if( *p < end )
|
|
{
|
|
cur->next = (mbedtls_asn1_sequence*)mbedtls_calloc( 1,
|
|
sizeof( mbedtls_asn1_sequence ) );
|
|
|
|
if( cur->next == NULL )
|
|
return( MBEDTLS_ERR_ASN1_ALLOC_FAILED );
|
|
|
|
cur = cur->next;
|
|
}
|
|
}
|
|
|
|
/* Set final sequence entry's next pointer to NULL */
|
|
cur->next = NULL;
|
|
|
|
if( *p != end )
|
|
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_asn1_get_alg( unsigned char **p,
|
|
const unsigned char *end,
|
|
mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
|
|
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( ( end - *p ) < 1 )
|
|
return( MBEDTLS_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
alg->tag = **p;
|
|
end = *p + len;
|
|
|
|
if( ( ret = mbedtls_asn1_get_tag( p, end, &alg->len, MBEDTLS_ASN1_OID ) ) != 0 )
|
|
return( ret );
|
|
|
|
alg->p = *p;
|
|
*p += alg->len;
|
|
|
|
if( *p == end )
|
|
{
|
|
mbedtls_zeroize( params, sizeof(mbedtls_asn1_buf) );
|
|
return( 0 );
|
|
}
|
|
|
|
params->tag = **p;
|
|
(*p)++;
|
|
|
|
if( ( ret = mbedtls_asn1_get_len( p, end, ¶ms->len ) ) != 0 )
|
|
return( ret );
|
|
|
|
params->p = *p;
|
|
*p += params->len;
|
|
|
|
if( *p != end )
|
|
return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_asn1_get_alg_null( unsigned char **p,
|
|
const unsigned char *end,
|
|
mbedtls_asn1_buf *alg )
|
|
{
|
|
int ret;
|
|
mbedtls_asn1_buf params;
|
|
|
|
memset( ¶ms, 0, sizeof(mbedtls_asn1_buf) );
|
|
|
|
if( ( ret = mbedtls_asn1_get_alg( p, end, alg, ¶ms ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( ( params.tag != MBEDTLS_ASN1_NULL && params.tag != 0 ) || params.len != 0 )
|
|
return( MBEDTLS_ERR_ASN1_INVALID_DATA );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
void mbedtls_asn1_free_named_data( mbedtls_asn1_named_data *cur )
|
|
{
|
|
if( cur == NULL )
|
|
return;
|
|
|
|
mbedtls_free( cur->oid.p );
|
|
mbedtls_free( cur->val.p );
|
|
|
|
mbedtls_zeroize( cur, sizeof( mbedtls_asn1_named_data ) );
|
|
}
|
|
|
|
void mbedtls_asn1_free_named_data_list( mbedtls_asn1_named_data **head )
|
|
{
|
|
mbedtls_asn1_named_data *cur;
|
|
|
|
while( ( cur = *head ) != NULL )
|
|
{
|
|
*head = cur->next;
|
|
mbedtls_asn1_free_named_data( cur );
|
|
mbedtls_free( cur );
|
|
}
|
|
}
|
|
|
|
mbedtls_asn1_named_data *mbedtls_asn1_find_named_data( mbedtls_asn1_named_data *list,
|
|
const char *oid, size_t len )
|
|
{
|
|
while( list != NULL )
|
|
{
|
|
if( list->oid.len == len &&
|
|
memcmp( list->oid.p, oid, len ) == 0 )
|
|
{
|
|
break;
|
|
}
|
|
|
|
list = list->next;
|
|
}
|
|
|
|
return( list );
|
|
}
|
|
|
|
#endif /* MBEDTLS_ASN1_PARSE_C */
|