library/asn1write.c - mirror/mbed-crypto - TrustedFirmware Git Browser

 /*
  * ASN.1 buffer writing functionality
  *
  *  Copyright (C) 2006-2012, 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_WRITE_C)

 #include "polarssl/asn1write.h"

 #if defined(POLARSSL_MEMORY_C)
 #include "polarssl/memory.h"
 #else
 #include <stdlib.h>
 #define polarssl_malloc     malloc
 #define polarssl_free       free
 #endif

 int asn1_write_len( unsigned char **p, unsigned char *start, size_t len )
 {
     if( len < 0x80 )
     {
         if( *p - start < 1 )
             return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

         *--(*p) = (unsigned char) len;
         return( 1 );
     }

     if( len <= 0xFF )
     {
         if( *p - start < 2 )
             return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

         *--(*p) = (unsigned char) len;
         *--(*p) = 0x81;
         return( 2 );
     }

     if( *p - start < 3 )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     // We assume we never have lengths larger than 65535 bytes
     //
     *--(*p) = len % 256;
     *--(*p) = ( len / 256 ) % 256;
     *--(*p) = 0x82;

     return( 3 );
 }

 int asn1_write_tag( unsigned char **p, unsigned char *start, unsigned char tag )
 {
     if( *p - start < 1 )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     *--(*p) = tag;

     return( 1 );
 }

 int asn1_write_raw_buffer( unsigned char **p, unsigned char *start,
                            const unsigned char *buf, size_t size )
 {
     size_t len = 0;

     if( *p - start < (int) size )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     len = size;
     (*p) -= len;
     memcpy( *p, buf, len );

     return( (int) len );
 }

 #if defined(POLARSSL_BIGNUM_C)
 int asn1_write_mpi( unsigned char **p, unsigned char *start, mpi *X )
 {
     int ret;
     size_t len = 0;

     // Write the MPI
     //
     len = mpi_size( X );

     if( *p - start < (int) len )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     (*p) -= len;
     mpi_write_binary( X, *p, len );

     // DER format assumes 2s complement for numbers, so the leftmost bit
     // should be 0 for positive numbers and 1 for negative numbers.
     //
     if ( X->s ==1 && **p & 0x80 )
     {
         if( *p - start < 1 )
             return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

         *--(*p) = 0x00;
         len += 1;
     }

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_INTEGER ) );

     return( (int) len );
 }
 #endif /* POLARSSL_BIGNUM_C */

 int asn1_write_null( unsigned char **p, unsigned char *start )
 {
     int ret;
     size_t len = 0;

     // Write NULL
     //
     ASN1_CHK_ADD( len, asn1_write_len( p, start, 0) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_NULL ) );

     return( (int) len );
 }

 int asn1_write_oid( unsigned char **p, unsigned char *start,
                     const char *oid, size_t oid_len )
 {
     int ret;
     size_t len = 0;

     ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
                                   (const unsigned char *) oid, oid_len ) );
     ASN1_CHK_ADD( len , asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len , asn1_write_tag( p, start, ASN1_OID ) );

     return( (int) len );
 }

 int asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start,
                                      const char *oid, size_t oid_len,
                                      size_t par_len )
 {
     int ret;
     size_t len = 0;

     if( par_len == 0 )
         ASN1_CHK_ADD( len, asn1_write_null( p, start ) );
     else
         len += par_len;

     ASN1_CHK_ADD( len, asn1_write_oid( p, start, oid, oid_len ) );

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start,
                                        ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );

     return( (int) len );
 }

 int asn1_write_bool( unsigned char **p, unsigned char *start, int boolean )
 {
     int ret;
     size_t len = 0;

     if( *p - start < 1 )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     *--(*p) = (boolean) ? 1 : 0;
     len++;

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BOOLEAN ) );

     return( (int) len );
 }

 int asn1_write_int( unsigned char **p, unsigned char *start, int val )
 {
     int ret;
     size_t len = 0;

     // TODO negative values and values larger than 128
     // DER format assumes 2s complement for numbers, so the leftmost bit
     // should be 0 for positive numbers and 1 for negative numbers.
     //
     if( *p - start < 1 )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     len += 1;
     *--(*p) = val;

     if ( val > 0 && **p & 0x80 )
     {
         if( *p - start < 1 )
             return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

         *--(*p) = 0x00;
         len += 1;
     }

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_INTEGER ) );

     return( (int) len );
 }

 int asn1_write_printable_string( unsigned char **p, unsigned char *start,
                                  const char *text, size_t text_len )
 {
     int ret;
     size_t len = 0;

     ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
                   (const unsigned char *) text, text_len ) );

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_PRINTABLE_STRING ) );

     return( (int) len );
 }

 int asn1_write_ia5_string( unsigned char **p, unsigned char *start,
                            const char *text, size_t text_len )
 {
     int ret;
     size_t len = 0;

     ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
                   (const unsigned char *) text, text_len ) );

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_IA5_STRING ) );

     return( (int) len );
 }

 int asn1_write_bitstring( unsigned char **p, unsigned char *start,
                           const unsigned char *buf, size_t bits )
 {
     int ret;
     size_t len = 0, size;

     size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 );

     // Calculate byte length
     //
     if( *p - start < (int) size + 1 )
         return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

     len = size + 1;
     (*p) -= size;
     memcpy( *p, buf, size );

     // Write unused bits
     //
     *--(*p) = (unsigned char) (size * 8 - bits);

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) );

     return( (int) len );
 }

 int asn1_write_octet_string( unsigned char **p, unsigned char *start,
                              const unsigned char *buf, size_t size )
 {
     int ret;
     size_t len = 0;

     ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, buf, size ) );

     ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
     ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OCTET_STRING ) );

     return( (int) len );
 }

 asn1_named_data *asn1_store_named_data( asn1_named_data **head,
                                         const char *oid, size_t oid_len,
                                         const unsigned char *val,
                                         size_t val_len )
 {
     asn1_named_data *cur;

     if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
     {
         // Add new entry if not present yet based on OID
         //
         if( ( cur = polarssl_malloc( sizeof(asn1_named_data) ) ) == NULL )
             return( NULL );

         memset( cur, 0, sizeof(asn1_named_data) );

         cur->oid.len = oid_len;
         cur->oid.p = polarssl_malloc( oid_len );
         if( cur->oid.p == NULL )
         {
             polarssl_free( cur );
             return( NULL );
         }

         cur->val.len = val_len;
         cur->val.p = polarssl_malloc( val_len );
         if( cur->val.p == NULL )
         {
             polarssl_free( cur->oid.p );
             polarssl_free( cur );
             return( NULL );
         }

         memcpy( cur->oid.p, oid, oid_len );

         cur->next = *head;
         *head = cur;
     }
     else if( cur->val.len < val_len )
     {
         // Enlarge existing value buffer if needed
         //
         polarssl_free( cur->val.p );
         cur->val.p = NULL;

         cur->val.len = val_len;
         cur->val.p = polarssl_malloc( val_len );
         if( cur->val.p == NULL )
         {
             polarssl_free( cur->oid.p );
             polarssl_free( cur );
             return( NULL );
         }
     }

     if( val != NULL )
         memcpy( cur->val.p, val, val_len );

     return( cur );
 }
 #endif
	/*
	* ASN.1 buffer writing functionality
	*
	* Copyright (C) 2006-2012, 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_WRITE_C)

	#include "polarssl/asn1write.h"

	#if defined(POLARSSL_MEMORY_C)
	#include "polarssl/memory.h"
	#else
	#include <stdlib.h>
	#define polarssl_malloc malloc
	#define polarssl_free free
	#endif

	int asn1_write_len( unsigned char *p, unsigned char start, size_t len )
	{
	if( len < 0x80 )
	{
	if( *p - start < 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	--(p) = (unsigned char) len;
	return( 1 );
	}

	if( len <= 0xFF )
	{
	if( *p - start < 2 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	--(p) = (unsigned char) len;
	--(p) = 0x81;
	return( 2 );
	}

	if( *p - start < 3 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	// We assume we never have lengths larger than 65535 bytes
	//
	--(p) = len % 256;
	--(p) = ( len / 256 ) % 256;
	--(p) = 0x82;

	return( 3 );
	}

	int asn1_write_tag( unsigned char *p, unsigned char start, unsigned char tag )
	{
	if( *p - start < 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	--(p) = tag;

	return( 1 );
	}

	int asn1_write_raw_buffer( unsigned char *p, unsigned char start,
	const unsigned char *buf, size_t size )
	{
	size_t len = 0;

	if( *p - start < (int) size )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	len = size;
	(*p) -= len;
	memcpy( *p, buf, len );

	return( (int) len );
	}

	#if defined(POLARSSL_BIGNUM_C)
	int asn1_write_mpi( unsigned char *p, unsigned char start, mpi *X )
	{
	int ret;
	size_t len = 0;

	// Write the MPI
	//
	len = mpi_size( X );

	if( *p - start < (int) len )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	(*p) -= len;
	mpi_write_binary( X, *p, len );

	// DER format assumes 2s complement for numbers, so the leftmost bit
	// should be 0 for positive numbers and 1 for negative numbers.
	//
	if ( X->s ==1 && **p & 0x80 )
	{
	if( *p - start < 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	--(p) = 0x00;
	len += 1;
	}

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_INTEGER ) );

	return( (int) len );
	}
	#endif /* POLARSSL_BIGNUM_C */

	int asn1_write_null( unsigned char *p, unsigned char start )
	{
	int ret;
	size_t len = 0;

	// Write NULL
	//
	ASN1_CHK_ADD( len, asn1_write_len( p, start, 0) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_NULL ) );

	return( (int) len );
	}

	int asn1_write_oid( unsigned char *p, unsigned char start,
	const char *oid, size_t oid_len )
	{
	int ret;
	size_t len = 0;

	ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
	(const unsigned char *) oid, oid_len ) );
	ASN1_CHK_ADD( len , asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len , asn1_write_tag( p, start, ASN1_OID ) );

	return( (int) len );
	}

	int asn1_write_algorithm_identifier( unsigned char *p, unsigned char start,
	const char *oid, size_t oid_len,
	size_t par_len )
	{
	int ret;
	size_t len = 0;

	if( par_len == 0 )
	ASN1_CHK_ADD( len, asn1_write_null( p, start ) );
	else
	len += par_len;

	ASN1_CHK_ADD( len, asn1_write_oid( p, start, oid, oid_len ) );

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start,
	ASN1_CONSTRUCTED \| ASN1_SEQUENCE ) );

	return( (int) len );
	}

	int asn1_write_bool( unsigned char *p, unsigned char start, int boolean )
	{
	int ret;
	size_t len = 0;

	if( *p - start < 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	--(p) = (boolean) ? 1 : 0;
	len++;

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BOOLEAN ) );

	return( (int) len );
	}

	int asn1_write_int( unsigned char *p, unsigned char start, int val )
	{
	int ret;
	size_t len = 0;

	// TODO negative values and values larger than 128
	// DER format assumes 2s complement for numbers, so the leftmost bit
	// should be 0 for positive numbers and 1 for negative numbers.
	//
	if( *p - start < 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	len += 1;
	--(p) = val;

	if ( val > 0 && **p & 0x80 )
	{
	if( *p - start < 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	--(p) = 0x00;
	len += 1;
	}

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_INTEGER ) );

	return( (int) len );
	}

	int asn1_write_printable_string( unsigned char *p, unsigned char start,
	const char *text, size_t text_len )
	{
	int ret;
	size_t len = 0;

	ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
	(const unsigned char *) text, text_len ) );

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_PRINTABLE_STRING ) );

	return( (int) len );
	}

	int asn1_write_ia5_string( unsigned char *p, unsigned char start,
	const char *text, size_t text_len )
	{
	int ret;
	size_t len = 0;

	ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
	(const unsigned char *) text, text_len ) );

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_IA5_STRING ) );

	return( (int) len );
	}

	int asn1_write_bitstring( unsigned char *p, unsigned char start,
	const unsigned char *buf, size_t bits )
	{
	int ret;
	size_t len = 0, size;

	size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 );

	// Calculate byte length
	//
	if( *p - start < (int) size + 1 )
	return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );

	len = size + 1;
	(*p) -= size;
	memcpy( *p, buf, size );

	// Write unused bits
	//
	--(p) = (unsigned char) (size * 8 - bits);

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) );

	return( (int) len );
	}

	int asn1_write_octet_string( unsigned char *p, unsigned char start,
	const unsigned char *buf, size_t size )
	{
	int ret;
	size_t len = 0;

	ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start, buf, size ) );

	ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
	ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_OCTET_STRING ) );

	return( (int) len );
	}

	asn1_named_data asn1_store_named_data( asn1_named_data *head,
	const char *oid, size_t oid_len,
	const unsigned char *val,
	size_t val_len )
	{
	asn1_named_data *cur;

	if( ( cur = asn1_find_named_data( *head, oid, oid_len ) ) == NULL )
	{
	// Add new entry if not present yet based on OID
	//
	if( ( cur = polarssl_malloc( sizeof(asn1_named_data) ) ) == NULL )
	return( NULL );

	memset( cur, 0, sizeof(asn1_named_data) );

	cur->oid.len = oid_len;
	cur->oid.p = polarssl_malloc( oid_len );
	if( cur->oid.p == NULL )
	{
	polarssl_free( cur );
	return( NULL );
	}

	cur->val.len = val_len;
	cur->val.p = polarssl_malloc( val_len );
	if( cur->val.p == NULL )
	{
	polarssl_free( cur->oid.p );
	polarssl_free( cur );
	return( NULL );
	}

	memcpy( cur->oid.p, oid, oid_len );

	cur->next = *head;
	*head = cur;
	}
	else if( cur->val.len < val_len )
	{
	// Enlarge existing value buffer if needed
	//
	polarssl_free( cur->val.p );
	cur->val.p = NULL;

	cur->val.len = val_len;
	cur->val.p = polarssl_malloc( val_len );
	if( cur->val.p == NULL )
	{
	polarssl_free( cur->oid.p );
	polarssl_free( cur );
	return( NULL );
	}
	}

	if( val != NULL )
	memcpy( cur->val.p, val, val_len );

	return( cur );
	}
	#endif