library/asn1parse.c - security/mbedtls - Rivoreo Source Code Repositories

 /*
  *  Generic ASN.1 parsing
  *
  *  Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
  *
  *  This file is part of mbed TLS (https://polarssl.org)
  *
  *  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.
  */

 #if !defined(POLARSSL_CONFIG_FILE)
 #include "polarssl/config.h"
 #else
 #include POLARSSL_CONFIG_FILE
 #endif

 #if defined(POLARSSL_ASN1_PARSE_C)

 #include "polarssl/asn1.h"

 #if defined(POLARSSL_BIGNUM_C)
 #include "polarssl/bignum.h"
 #endif

 #if defined(POLARSSL_PLATFORM_C)
 #include "polarssl/platform.h"
 #else
 #define polarssl_malloc     malloc
 #define polarssl_free       free
 #endif

 #include <string.h>
 #include <stdlib.h>

 /* Implementation that should never be optimized out by the compiler */
 static void polarssl_zeroize( void *v, size_t n ) {
     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
 }

 /*
  * 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)-- < 2 || *(*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 = polarssl_malloc(
                  sizeof( asn1_sequence ) );

             if( cur->next == NULL )
                 return( POLARSSL_ERR_ASN1_MALLOC_FAILED );

             memset( cur->next, 0, sizeof( asn1_sequence ) );

             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 );

     if( ( end - *p ) < 1 )
         return( POLARSSL_ERR_ASN1_OUT_OF_DATA );

     alg->tag = **p;
     end = *p + len;

     if( ( ret = asn1_get_tag( p, end, &alg->len, ASN1_OID ) ) != 0 )
         return( ret );

     alg->p = *p;
     *p += alg->len;

     if( *p == end )
     {
         polarssl_zeroize( params, sizeof(asn1_buf) );
         return( 0 );
     }

     params->tag = **p;
     (*p)++;

     if( ( ret = asn1_get_len( p, end, &params->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( &params, 0, sizeof(asn1_buf) );

     if( ( ret = asn1_get_alg( p, end, alg, &params ) ) != 0 )
         return( ret );

     if( ( params.tag != ASN1_NULL && params.tag != 0 ) || params.len != 0 )
         return( POLARSSL_ERR_ASN1_INVALID_DATA );

     return( 0 );
 }

 void asn1_free_named_data( asn1_named_data *cur )
 {
     if( cur == NULL )
         return;

     polarssl_free( cur->oid.p );
     polarssl_free( cur->val.p );

     polarssl_zeroize( cur, sizeof( asn1_named_data ) );
 }

 void asn1_free_named_data_list( asn1_named_data **head )
 {
     asn1_named_data *cur;

     while( ( cur = *head ) != NULL )
     {
         *head = cur->next;
         asn1_free_named_data( cur );
         polarssl_free( cur );
     }
 }

 asn1_named_data *asn1_find_named_data( 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 /* POLARSSL_ASN1_PARSE_C */
	/*
	* Generic ASN.1 parsing
	*
	* Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
	*
	* This file is part of mbed TLS (https://polarssl.org)
	*
	* 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.
	*/

	#if !defined(POLARSSL_CONFIG_FILE)
	#include "polarssl/config.h"
	#else
	#include POLARSSL_CONFIG_FILE
	#endif

	#if defined(POLARSSL_ASN1_PARSE_C)

	#include "polarssl/asn1.h"

	#if defined(POLARSSL_BIGNUM_C)
	#include "polarssl/bignum.h"
	#endif

	#if defined(POLARSSL_PLATFORM_C)
	#include "polarssl/platform.h"
	#else
	#define polarssl_malloc malloc
	#define polarssl_free free
	#endif

	#include <string.h>
	#include <stdlib.h>

	/* Implementation that should never be optimized out by the compiler */
	static void polarssl_zeroize( void *v, size_t n ) {
	volatile unsigned char p = v; while( n-- ) p++ = 0;
	}

	/*
	* 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)-- < 2 \|\| (*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 = polarssl_malloc(
	sizeof( asn1_sequence ) );

	if( cur->next == NULL )
	return( POLARSSL_ERR_ASN1_MALLOC_FAILED );

	memset( cur->next, 0, sizeof( asn1_sequence ) );

	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 );

	if( ( end - *p ) < 1 )
	return( POLARSSL_ERR_ASN1_OUT_OF_DATA );

	alg->tag = **p;
	end = *p + len;

	if( ( ret = asn1_get_tag( p, end, &alg->len, ASN1_OID ) ) != 0 )
	return( ret );

	alg->p = *p;
	*p += alg->len;

	if( *p == end )
	{
	polarssl_zeroize( params, sizeof(asn1_buf) );
	return( 0 );
	}

	params->tag = **p;
	(*p)++;

	if( ( ret = asn1_get_len( p, end, &params->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( &params, 0, sizeof(asn1_buf) );

	if( ( ret = asn1_get_alg( p, end, alg, &params ) ) != 0 )
	return( ret );

	if( ( params.tag != ASN1_NULL && params.tag != 0 ) \|\| params.len != 0 )
	return( POLARSSL_ERR_ASN1_INVALID_DATA );

	return( 0 );
	}

	void asn1_free_named_data( asn1_named_data *cur )
	{
	if( cur == NULL )
	return;

	polarssl_free( cur->oid.p );
	polarssl_free( cur->val.p );

	polarssl_zeroize( cur, sizeof( asn1_named_data ) );
	}

	void asn1_free_named_data_list( asn1_named_data **head )
	{
	asn1_named_data *cur;

	while( ( cur = *head ) != NULL )
	{
	*head = cur->next;
	asn1_free_named_data( cur );
	polarssl_free( cur );
	}
	}

	asn1_named_data asn1_find_named_data( 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 /* POLARSSL_ASN1_PARSE_C */