library/asn1parse.c - mirror/mbed-tls - TrustedFirmware Git Browser

 /*
  *  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 = 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_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, &params->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( &params, 0, sizeof(mbedtls_asn1_buf) );

     if( ( ret = mbedtls_asn1_get_alg( p, end, alg, &params ) ) != 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 */
	/*
	* 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 = 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_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, &params->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( &params, 0, sizeof(mbedtls_asn1_buf) );

	if( ( ret = mbedtls_asn1_get_alg( p, end, alg, &params ) ) != 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 */