/****************************************************************************
*
* gxvtrak.c
*
* TrueTypeGX/AAT trak table validation (body).
*
* Copyright (C) 2004-2022 by
* suzuki toshiya, Masatake YAMATO, Red Hat K.K.,
* David Turner, Robert Wilhelm, and Werner Lemberg.
*
* This file is part of the FreeType project, and may only be used,
* modified, and distributed under the terms of the FreeType project
* license, LICENSE.TXT. By continuing to use, modify, or distribute
* this file you indicate that you have read the license and
* understand and accept it fully.
*
*/
/****************************************************************************
*
* gxvalid is derived from both gxlayout module and otvalid module.
* Development of gxlayout is supported by the Information-technology
* Promotion Agency(IPA), Japan.
*
*/
#include "gxvalid.h"
#include "gxvcommn.h"
/**************************************************************************
*
* The macro FT_COMPONENT is used in trace mode. It is an implicit
* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
* messages during execution.
*/
#undef FT_COMPONENT
#define FT_COMPONENT gxvtrak
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** Data and Types *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* referred track table format specification:
* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6trak.html
* last update was 1996.
* ----------------------------------------------
* [MINIMUM HEADER]: GXV_TRAK_SIZE_MIN
* version (fixed: 32bit) = 0x00010000
* format (uint16: 16bit) = 0 is only defined (1996)
* horizOffset (uint16: 16bit)
* vertOffset (uint16: 16bit)
* reserved (uint16: 16bit) = 0
* ----------------------------------------------
* [VARIABLE BODY]:
* horizData
* header ( 2 + 2 + 4
* trackTable + nTracks * ( 4 + 2 + 2 )
* sizeTable + nSizes * 4 )
* ----------------------------------------------
* vertData
* header ( 2 + 2 + 4
* trackTable + nTracks * ( 4 + 2 + 2 )
* sizeTable + nSizes * 4 )
* ----------------------------------------------
*/
typedef struct GXV_trak_DataRec_
{
FT_UShort trackValueOffset_min;
FT_UShort trackValueOffset_max;
} GXV_trak_DataRec, *GXV_trak_Data;
#define GXV_TRAK_DATA( FIELD ) GXV_TABLE_DATA( trak, FIELD )
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** UTILITY FUNCTIONS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
gxv_trak_trackTable_validate( FT_Bytes table,
FT_Bytes limit,
FT_UShort nTracks,
GXV_Validator gxvalid )
{
FT_Bytes p = table;
FT_Fixed track, t;
FT_UShort nameIndex;
FT_UShort offset;
FT_UShort i, j;
GXV_NAME_ENTER( "trackTable" );
GXV_TRAK_DATA( trackValueOffset_min ) = 0xFFFFU;
GXV_TRAK_DATA( trackValueOffset_max ) = 0x0000;
GXV_LIMIT_CHECK( nTracks * ( 4 + 2 + 2 ) );
for ( i = 0; i < nTracks; i++ )
{
p = table + i * ( 4 + 2 + 2 );
track = FT_NEXT_LONG( p );
nameIndex = FT_NEXT_USHORT( p );
offset = FT_NEXT_USHORT( p );
if ( offset < GXV_TRAK_DATA( trackValueOffset_min ) )
GXV_TRAK_DATA( trackValueOffset_min ) = offset;
if ( offset > GXV_TRAK_DATA( trackValueOffset_max ) )
GXV_TRAK_DATA( trackValueOffset_max ) = offset;
gxv_sfntName_validate( nameIndex, 256, 32767, gxvalid );
for ( j = i; j < nTracks; j++ )
{
p = table + j * ( 4 + 2 + 2 );
t = FT_NEXT_LONG( p );
if ( t == track )
GXV_TRACE(( "duplicated entries found for track value 0x%lx\n",
track ));
}
}
gxvalid->subtable_length = (FT_ULong)( p - table );
GXV_EXIT;
}
static void
gxv_trak_trackData_validate( FT_Bytes table,
FT_Bytes limit,
GXV_Validator gxvalid )
{
FT_Bytes p = table;
FT_UShort nTracks;
FT_UShort nSizes;
FT_ULong sizeTableOffset;
GXV_ODTECT( 4, odtect );
GXV_ODTECT_INIT( odtect );
GXV_NAME_ENTER( "trackData" );
/* read the header of trackData */
GXV_LIMIT_CHECK( 2 + 2 + 4 );
nTracks = FT_NEXT_USHORT( p );
nSizes = FT_NEXT_USHORT( p );
sizeTableOffset = FT_NEXT_ULONG( p );
gxv_odtect_add_range( table, (FT_ULong)( p - table ),
"trackData header", odtect );
/* validate trackTable */
gxv_trak_trackTable_validate( p, limit, nTracks, gxvalid );
gxv_odtect_add_range( p, gxvalid->subtable_length,
"trackTable", odtect );
/* sizeTable is array of FT_Fixed, don't check contents */
p = gxvalid->root->base + sizeTableOffset;
GXV_LIMIT_CHECK( nSizes * 4 );
gxv_odtect_add_range( p, nSizes * 4, "sizeTable", odtect );
/* validate trackValueOffet */
p = gxvalid->root->base + GXV_TRAK_DATA( trackValueOffset_min );
if ( limit - p < nTracks * nSizes * 2 )
GXV_TRACE(( "too short trackValue array\n" ));
p = gxvalid->root->base + GXV_TRAK_DATA( trackValueOffset_max );
GXV_LIMIT_CHECK( nSizes * 2 );
gxv_odtect_add_range( gxvalid->root->base
+ GXV_TRAK_DATA( trackValueOffset_min ),
GXV_TRAK_DATA( trackValueOffset_max )
- GXV_TRAK_DATA( trackValueOffset_min )
+ nSizes * 2,
"trackValue array", odtect );
gxv_odtect_validate( odtect, gxvalid );
GXV_EXIT;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** trak TABLE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL_DEF( void )
gxv_trak_validate( FT_Bytes table,
FT_Face face,
FT_Validator ftvalid )
{
FT_Bytes p = table;
FT_Bytes limit = 0;
GXV_ValidatorRec gxvalidrec;
GXV_Validator gxvalid = &gxvalidrec;
GXV_trak_DataRec trakrec;
GXV_trak_Data trak = &trakrec;
FT_ULong version;
FT_UShort format;
FT_UShort horizOffset;
FT_UShort vertOffset;
FT_UShort reserved;
GXV_ODTECT( 3, odtect );
GXV_ODTECT_INIT( odtect );
gxvalid->root = ftvalid;
gxvalid->table_data = trak;
gxvalid->face = face;
limit = gxvalid->root->limit;
FT_TRACE3(( "validating `trak' table\n" ));
GXV_INIT;
GXV_LIMIT_CHECK( 4 + 2 + 2 + 2 + 2 );
version = FT_NEXT_ULONG( p );
format = FT_NEXT_USHORT( p );
horizOffset = FT_NEXT_USHORT( p );
vertOffset = FT_NEXT_USHORT( p );
reserved = FT_NEXT_USHORT( p );
GXV_TRACE(( " (version = 0x%08lx)\n", version ));
GXV_TRACE(( " (format = 0x%04x)\n", format ));
GXV_TRACE(( " (horizOffset = 0x%04x)\n", horizOffset ));
GXV_TRACE(( " (vertOffset = 0x%04x)\n", vertOffset ));
GXV_TRACE(( " (reserved = 0x%04x)\n", reserved ));
/* Version 1.0 (always:1996) */
if ( version != 0x00010000UL )
FT_INVALID_FORMAT;
/* format 0 (always:1996) */
if ( format != 0x0000 )
FT_INVALID_FORMAT;
GXV_32BIT_ALIGNMENT_VALIDATE( horizOffset );
GXV_32BIT_ALIGNMENT_VALIDATE( vertOffset );
/* Reserved Fixed Value (always) */
if ( reserved != 0x0000 )
FT_INVALID_DATA;
/* validate trackData */
if ( 0 < horizOffset )
{
gxv_trak_trackData_validate( table + horizOffset, limit, gxvalid );
gxv_odtect_add_range( table + horizOffset, gxvalid->subtable_length,
"horizJustData", odtect );
}
if ( 0 < vertOffset )
{
gxv_trak_trackData_validate( table + vertOffset, limit, gxvalid );
gxv_odtect_add_range( table + vertOffset, gxvalid->subtable_length,
"vertJustData", odtect );
}
gxv_odtect_validate( odtect, gxvalid );
FT_TRACE4(( "\n" ));
}
/* END */
