344 lines
7.7 KiB
C
344 lines
7.7 KiB
C
/*
|
|
* Generic ASN.1 parsing
|
|
*
|
|
* Copyright (C) 2006-2013, Brainspark B.V.
|
|
*
|
|
* This file is part of PolarSSL (http://www.polarssl.org)
|
|
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
|
|
*
|
|
* All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include "polarssl/config.h"
|
|
|
|
#if defined(POLARSSL_ASN1_PARSE_C)
|
|
|
|
#include "polarssl/asn1.h"
|
|
|
|
#if defined(POLARSSL_BIGNUM_C)
|
|
#include "polarssl/bignum.h"
|
|
#endif
|
|
|
|
#if defined(POLARSSL_MEMORY_C)
|
|
#include "polarssl/memory.h"
|
|
#else
|
|
#define polarssl_malloc malloc
|
|
#define polarssl_free free
|
|
#endif
|
|
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
|
|
/*
|
|
* ASN.1 DER decoding routines
|
|
*/
|
|
int asn1_get_len( unsigned char **p,
|
|
const unsigned char *end,
|
|
size_t *len )
|
|
{
|
|
if( ( end - *p ) < 1 )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
if( ( **p & 0x80 ) == 0 )
|
|
*len = *(*p)++;
|
|
else
|
|
{
|
|
switch( **p & 0x7F )
|
|
{
|
|
case 1:
|
|
if( ( end - *p ) < 2 )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = (*p)[1];
|
|
(*p) += 2;
|
|
break;
|
|
|
|
case 2:
|
|
if( ( end - *p ) < 3 )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = ( (*p)[1] << 8 ) | (*p)[2];
|
|
(*p) += 3;
|
|
break;
|
|
|
|
case 3:
|
|
if( ( end - *p ) < 4 )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = ( (*p)[1] << 16 ) | ( (*p)[2] << 8 ) | (*p)[3];
|
|
(*p) += 4;
|
|
break;
|
|
|
|
case 4:
|
|
if( ( end - *p ) < 5 )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
*len = ( (*p)[1] << 24 ) | ( (*p)[2] << 16 ) | ( (*p)[3] << 8 ) | (*p)[4];
|
|
(*p) += 5;
|
|
break;
|
|
|
|
default:
|
|
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
|
|
}
|
|
}
|
|
|
|
if( *len > (size_t) ( end - *p ) )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int asn1_get_tag( unsigned char **p,
|
|
const unsigned char *end,
|
|
size_t *len, int tag )
|
|
{
|
|
if( ( end - *p ) < 1 )
|
|
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
|
|
|
|
if( **p != tag )
|
|
return( POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
|
|
|
|
(*p)++;
|
|
|
|
return( asn1_get_len( p, end, len ) );
|
|
}
|
|
|
|
int asn1_get_bool( unsigned char **p,
|
|
const unsigned char *end,
|
|
int *val )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = asn1_get_tag( p, end, &len, ASN1_BOOLEAN ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( len != 1 )
|
|
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
|
|
|
|
*val = ( **p != 0 ) ? 1 : 0;
|
|
(*p)++;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int asn1_get_int( unsigned char **p,
|
|
const unsigned char *end,
|
|
int *val )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( len > sizeof( int ) || ( **p & 0x80 ) != 0 )
|
|
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
|
|
|
|
*val = 0;
|
|
|
|
while( len-- > 0 )
|
|
{
|
|
*val = ( *val << 8 ) | **p;
|
|
(*p)++;
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(POLARSSL_BIGNUM_C)
|
|
int asn1_get_mpi( unsigned char **p,
|
|
const unsigned char *end,
|
|
mpi *X )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
|
|
return( ret );
|
|
|
|
ret = mpi_read_binary( X, *p, len );
|
|
|
|
*p += len;
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* POLARSSL_BIGNUM_C */
|
|
|
|
int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
|
|
asn1_bitstring *bs)
|
|
{
|
|
int ret;
|
|
|
|
/* Certificate type is a single byte bitstring */
|
|
if( ( ret = asn1_get_tag( p, end, &bs->len, ASN1_BIT_STRING ) ) != 0 )
|
|
return( ret );
|
|
|
|
/* Check length, subtract one for actual bit string length */
|
|
if ( bs->len < 1 )
|
|
return( POLARSSL_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( POLARSSL_ERR_ASN1_INVALID_LENGTH );
|
|
(*p)++;
|
|
|
|
/* Get actual bitstring */
|
|
bs->p = *p;
|
|
*p += bs->len;
|
|
|
|
if( *p != end )
|
|
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Get a bit string without unused bits
|
|
*/
|
|
int asn1_get_bitstring_null( unsigned char **p, const unsigned char *end,
|
|
size_t *len )
|
|
{
|
|
int ret;
|
|
|
|
if( ( ret = asn1_get_tag( p, end, len, ASN1_BIT_STRING ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( --*len < 1 || *(*p)++ != 0 )
|
|
return( POLARSSL_ERR_ASN1_INVALID_DATA );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
|
|
*/
|
|
int asn1_get_sequence_of( unsigned char **p,
|
|
const unsigned char *end,
|
|
asn1_sequence *cur,
|
|
int tag)
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
asn1_buf *buf;
|
|
|
|
/* Get main sequence tag */
|
|
if( ( ret = asn1_get_tag( p, end, &len,
|
|
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( *p + len != end )
|
|
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
while( *p < end )
|
|
{
|
|
buf = &(cur->buf);
|
|
buf->tag = **p;
|
|
|
|
if( ( ret = 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 = (asn1_sequence *) polarssl_malloc(
|
|
sizeof( asn1_sequence ) );
|
|
|
|
if( cur->next == NULL )
|
|
return( POLARSSL_ERR_ASN1_MALLOC_FAILED );
|
|
|
|
cur = cur->next;
|
|
}
|
|
}
|
|
|
|
/* Set final sequence entry's next pointer to NULL */
|
|
cur->next = NULL;
|
|
|
|
if( *p != end )
|
|
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int asn1_get_alg( unsigned char **p,
|
|
const unsigned char *end,
|
|
asn1_buf *alg, asn1_buf *params )
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
|
|
if( ( ret = asn1_get_tag( p, end, &len,
|
|
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
|
|
return( ret );
|
|
|
|
end = *p + len;
|
|
alg->tag = **p;
|
|
|
|
if( ( ret = asn1_get_tag( p, end, &alg->len, ASN1_OID ) ) != 0 )
|
|
return( ret );
|
|
|
|
alg->p = *p;
|
|
*p += alg->len;
|
|
|
|
if( *p == end )
|
|
{
|
|
memset( params, 0, sizeof(asn1_buf) );
|
|
return( 0 );
|
|
}
|
|
|
|
params->tag = **p;
|
|
(*p)++;
|
|
|
|
if( ( ret = asn1_get_len( p, end, ¶ms->len ) ) != 0 )
|
|
return( ret );
|
|
|
|
params->p = *p;
|
|
*p += params->len;
|
|
|
|
if( *p != end )
|
|
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
int asn1_get_alg_null( unsigned char **p,
|
|
const unsigned char *end,
|
|
asn1_buf *alg )
|
|
{
|
|
int ret;
|
|
asn1_buf params;
|
|
|
|
memset( ¶ms, 0, sizeof(asn1_buf) );
|
|
|
|
if( ( ret = asn1_get_alg( p, end, alg, ¶ms ) ) != 0 )
|
|
return( ret );
|
|
|
|
if( ( params.tag != ASN1_NULL && params.tag != 0 ) || params.len != 0 )
|
|
return( POLARSSL_ERR_ASN1_INVALID_DATA );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#endif
|