| /**************************************************************************** |
| * |
| * gxvprop.c |
| * |
| * TrueTypeGX/AAT prop table validation (body). |
| * |
| * Copyright (C) 2004-2021 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%08lx\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 %ld 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 */ |
