Edit
kc3-lang/freetype/src/gxvalid/gxvprop.c
Werner Lemberg
- src/gxvalid/gxvprop.c
-
/**************************************************************************** * * gxvprop.c * * TrueTypeGX/AAT prop table validation (body). * * Copyright (C) 2004-2020 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 gxvprop /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** Data and Types *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ #define GXV_PROP_HEADER_SIZE ( 4 + 2 + 2 ) #define GXV_PROP_SIZE_MIN GXV_PROP_HEADER_SIZE typedef struct GXV_prop_DataRec_ { FT_Fixed version; } GXV_prop_DataRec, *GXV_prop_Data; #define GXV_PROP_DATA( field ) GXV_TABLE_DATA( prop, field ) #define GXV_PROP_FLOATER 0x8000U #define GXV_PROP_USE_COMPLEMENTARY_BRACKET 0x1000U #define GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET 0x0F00U #define GXV_PROP_ATTACHING_TO_RIGHT 0x0080U #define GXV_PROP_RESERVED 0x0060U #define GXV_PROP_DIRECTIONALITY_CLASS 0x001FU /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** UTILITY FUNCTIONS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void gxv_prop_zero_advance_validate( FT_UShort gid, GXV_Validator gxvalid ) { FT_Face face; FT_Error error; FT_GlyphSlot glyph; GXV_NAME_ENTER( "zero advance" ); face = gxvalid->face; error = FT_Load_Glyph( face, gid, FT_LOAD_IGNORE_TRANSFORM ); if ( error ) FT_INVALID_GLYPH_ID; glyph = face->glyph; if ( glyph->advance.x != (FT_Pos)0 || glyph->advance.y != (FT_Pos)0 ) { GXV_TRACE(( " found non-zero advance in zero-advance glyph\n" )); FT_INVALID_DATA; } GXV_EXIT; } /* Pass 0 as GLYPH to check the default property */ static void gxv_prop_property_validate( FT_UShort property, FT_UShort glyph, GXV_Validator gxvalid ) { if ( glyph != 0 && ( property & GXV_PROP_FLOATER ) ) gxv_prop_zero_advance_validate( glyph, gxvalid ); if ( property & GXV_PROP_USE_COMPLEMENTARY_BRACKET ) { FT_UShort offset; char complement; offset = (FT_UShort)( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET ); if ( offset == 0 ) { GXV_TRACE(( " found zero offset to property\n" )); FT_INVALID_OFFSET; } complement = (char)( offset >> 8 ); if ( complement & 0x08 ) { /* Top bit is set: negative */ /* Calculate the absolute offset */ complement = (char)( ( complement & 0x07 ) + 1 ); /* The gid for complement must be greater than 0 */ if ( glyph <= complement ) { GXV_TRACE(( " found non-positive glyph complement\n" )); FT_INVALID_DATA; } } else { /* The gid for complement must be the face. */ gxv_glyphid_validate( (FT_UShort)( glyph + complement ), gxvalid ); } } else { if ( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET ) GXV_TRACE(( "glyph %d cannot have complementary bracketing\n", glyph )); } /* this is introduced in version 2.0 */ if ( property & GXV_PROP_ATTACHING_TO_RIGHT ) { if ( GXV_PROP_DATA( version ) == 0x00010000UL ) { GXV_TRACE(( " found older version (1.0) in new version table\n" )); FT_INVALID_DATA; } } if ( property & GXV_PROP_RESERVED ) { GXV_TRACE(( " found non-zero bits in reserved bits\n" )); FT_INVALID_DATA; } if ( ( property & GXV_PROP_DIRECTIONALITY_CLASS ) > 11 ) { /* TODO: Too restricted. Use the validation level. */ if ( GXV_PROP_DATA( version ) == 0x00010000UL || GXV_PROP_DATA( version ) == 0x00020000UL ) { GXV_TRACE(( " found too old version in directionality class\n" )); FT_INVALID_DATA; } } } static void gxv_prop_LookupValue_validate( FT_UShort glyph, GXV_LookupValueCPtr value_p, GXV_Validator gxvalid ) { gxv_prop_property_validate( value_p->u, glyph, gxvalid ); } /* +===============+ --------+ | lookup header | | +===============+ | | BinSrchHeader | | +===============+ | | lastGlyph[0] | | +---------------+ | | firstGlyph[0] | | head of lookup table +---------------+ | + | offset[0] | -> | offset [byte] +===============+ | + | lastGlyph[1] | | (glyphID - firstGlyph) * 2 [byte] +---------------+ | | firstGlyph[1] | | +---------------+ | | offset[1] | | +===============+ | | ... | | 16bit value array | +===============+ | | value | <-------+ ... */ static GXV_LookupValueDesc gxv_prop_LookupFmt4_transit( FT_UShort relative_gindex, GXV_LookupValueCPtr base_value_p, FT_Bytes lookuptbl_limit, GXV_Validator gxvalid ) { FT_Bytes p; FT_Bytes limit; FT_UShort offset; GXV_LookupValueDesc value; /* XXX: check range? */ offset = (FT_UShort)( base_value_p->u + relative_gindex * sizeof ( FT_UShort ) ); p = gxvalid->lookuptbl_head + offset; limit = lookuptbl_limit; GXV_LIMIT_CHECK ( 2 ); value.u = FT_NEXT_USHORT( p ); return value; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** prop TABLE *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_LOCAL_DEF( void ) gxv_prop_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_prop_DataRec proprec; GXV_prop_Data prop = &proprec; FT_Fixed version; FT_UShort format; FT_UShort defaultProp; gxvalid->root = ftvalid; gxvalid->table_data = prop; gxvalid->face = face; FT_TRACE3(( "validating `prop' table\n" )); GXV_INIT; GXV_LIMIT_CHECK( 4 + 2 + 2 ); version = FT_NEXT_LONG( p ); format = FT_NEXT_USHORT( p ); defaultProp = FT_NEXT_USHORT( p ); GXV_TRACE(( " version 0x%08x\n", version )); GXV_TRACE(( " format 0x%04x\n", format )); GXV_TRACE(( " defaultProp 0x%04x\n", defaultProp )); /* only versions 1.0, 2.0, 3.0 are defined (1996) */ if ( version != 0x00010000UL && version != 0x00020000UL && version != 0x00030000UL ) { GXV_TRACE(( " found unknown version\n" )); FT_INVALID_FORMAT; } /* only formats 0x0000, 0x0001 are defined (1996) */ if ( format > 1 ) { GXV_TRACE(( " found unknown format\n" )); FT_INVALID_FORMAT; } gxv_prop_property_validate( defaultProp, 0, gxvalid ); if ( format == 0 ) { FT_TRACE3(( "(format 0, no per-glyph properties, " "remaining %d bytes are skipped)", limit - p )); goto Exit; } /* format == 1 */ GXV_PROP_DATA( version ) = version; gxvalid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED; gxvalid->lookupval_func = gxv_prop_LookupValue_validate; gxvalid->lookupfmt4_trans = gxv_prop_LookupFmt4_transit; gxv_LookupTable_validate( p, limit, gxvalid ); Exit: FT_TRACE4(( "\n" )); } /* END */