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- Extracted ASN.1 parsing code from the X.509 parsing code. Added new module.

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This commit is contained in:
Paul Bakker 2011-11-10 14:43:23 +00:00
parent b125ed8fc6
commit efc302964c
8 changed files with 526 additions and 293 deletions
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221
library/x509parse.c
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@ -1,7 +1,7 @@
/*
* X.509 certificate and private key decoding
*
* Copyright (C) 2006-2010, Brainspark B.V.
* Copyright (C) 2006-2011, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@ -39,6 +39,7 @@
#if defined(POLARSSL_X509_PARSE_C)
#include "polarssl/x509.h"
#include "polarssl/asn1.h"
#include "polarssl/pem.h"
#include "polarssl/des.h"
#include "polarssl/md2.h"
@ -57,224 +58,6 @@
#include <stdio.h>
#endif
/*
* ASN.1 DER decoding routines
*/
static 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 );
}
static 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 ) );
}
static 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 );
}
static 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 );
}
static 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 );
}
static int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
x509_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;
}
/*
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
*/
static int asn1_get_sequence_of( unsigned char **p,
const unsigned char *end,
x509_sequence *cur,
int tag)
{
int ret;
size_t len;
x509_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 = (x509_sequence *) malloc(
sizeof( x509_sequence ) );
if( cur->next == NULL )
return( 1 );
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 );
}
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/