/**************************************************************************** * * gxvmort.c * * TrueTypeGX/AAT mort table validation (body). * * Copyright (C) 2005-2023 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 "gxvmort.h" #include "gxvfeat.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 gxvmort static void gxv_mort_feature_validate( GXV_mort_feature f, GXV_Validator gxvalid ) { if ( f->featureType >= gxv_feat_registry_length ) { GXV_TRACE(( "featureType %d is out of registered range, " "setting %d is unchecked\n", f->featureType, f->featureSetting )); GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); } else if ( !gxv_feat_registry[f->featureType].existence ) { GXV_TRACE(( "featureType %d is within registered area " "but undefined, setting %d is unchecked\n", f->featureType, f->featureSetting )); GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); } else { FT_Byte nSettings_max; /* nSettings in gxvfeat.c is halved for exclusive on/off settings */ nSettings_max = gxv_feat_registry[f->featureType].nSettings; if ( gxv_feat_registry[f->featureType].exclusive ) nSettings_max = (FT_Byte)( 2 * nSettings_max ); GXV_TRACE(( "featureType %d is registered", f->featureType )); GXV_TRACE(( "setting %d", f->featureSetting )); if ( f->featureSetting > nSettings_max ) { GXV_TRACE(( "out of defined range %d", nSettings_max )); GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); } GXV_TRACE(( "\n" )); } /* TODO: enableFlags must be unique value in specified chain? */ } /* * nFeatureFlags is typed to FT_ULong to accept that in * mort (typed FT_UShort) and morx (typed FT_ULong). */ FT_LOCAL_DEF( void ) gxv_mort_featurearray_validate( FT_Bytes table, FT_Bytes limit, FT_ULong nFeatureFlags, GXV_Validator gxvalid ) { FT_Bytes p = table; FT_ULong i; GXV_mort_featureRec f = GXV_MORT_FEATURE_OFF; GXV_NAME_ENTER( "mort feature list" ); for ( i = 0; i < nFeatureFlags; i++ ) { GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 ); f.featureType = FT_NEXT_USHORT( p ); f.featureSetting = FT_NEXT_USHORT( p ); f.enableFlags = FT_NEXT_ULONG( p ); f.disableFlags = FT_NEXT_ULONG( p ); gxv_mort_feature_validate( &f, gxvalid ); } if ( !IS_GXV_MORT_FEATURE_OFF( f ) ) FT_INVALID_DATA; gxvalid->subtable_length = (FT_ULong)( p - table ); GXV_EXIT; } FT_LOCAL_DEF( void ) gxv_mort_coverage_validate( FT_UShort coverage, GXV_Validator gxvalid ) { FT_UNUSED( gxvalid ); FT_UNUSED( coverage ); #ifdef FT_DEBUG_LEVEL_TRACE if ( coverage & 0x8000U ) GXV_TRACE(( " this subtable is for vertical text only\n" )); else GXV_TRACE(( " this subtable is for horizontal text only\n" )); if ( coverage & 0x4000 ) GXV_TRACE(( " this subtable is applied to glyph array " "in descending order\n" )); else GXV_TRACE(( " this subtable is applied to glyph array " "in ascending order\n" )); if ( coverage & 0x2000 ) GXV_TRACE(( " this subtable is forcibly applied to " "vertical/horizontal text\n" )); if ( coverage & 0x1FF8 ) GXV_TRACE(( " coverage has non-zero bits in reserved area\n" )); #endif } static void gxv_mort_subtables_validate( FT_Bytes table, FT_Bytes limit, FT_UShort nSubtables, GXV_Validator gxvalid ) { FT_Bytes p = table; GXV_Validate_Func fmt_funcs_table[] = { gxv_mort_subtable_type0_validate, /* 0 */ gxv_mort_subtable_type1_validate, /* 1 */ gxv_mort_subtable_type2_validate, /* 2 */ NULL, /* 3 */ gxv_mort_subtable_type4_validate, /* 4 */ gxv_mort_subtable_type5_validate, /* 5 */ }; FT_UShort i; GXV_NAME_ENTER( "subtables in a chain" ); for ( i = 0; i < nSubtables; i++ ) { GXV_Validate_Func func; FT_UShort length; FT_UShort coverage; #ifdef GXV_LOAD_UNUSED_VARS FT_ULong subFeatureFlags; #endif FT_UInt type; FT_UInt rest; GXV_LIMIT_CHECK( 2 + 2 + 4 ); length = FT_NEXT_USHORT( p ); coverage = FT_NEXT_USHORT( p ); #ifdef GXV_LOAD_UNUSED_VARS subFeatureFlags = FT_NEXT_ULONG( p ); #else p += 4; #endif GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n", i + 1, nSubtables, length )); type = coverage & 0x0007; rest = length - ( 2 + 2 + 4 ); GXV_LIMIT_CHECK( rest ); gxv_mort_coverage_validate( coverage, gxvalid ); if ( type > 5 ) FT_INVALID_FORMAT; func = fmt_funcs_table[type]; if ( !func ) GXV_TRACE(( "morx type %d is reserved\n", type )); func( p, p + rest, gxvalid ); p += rest; /* TODO: validate subFeatureFlags */ } gxvalid->subtable_length = (FT_ULong)( p - table ); GXV_EXIT; } static void gxv_mort_chain_validate( FT_Bytes table, FT_Bytes limit, GXV_Validator gxvalid ) { FT_Bytes p = table; #ifdef GXV_LOAD_UNUSED_VARS FT_ULong defaultFlags; #endif FT_ULong chainLength; FT_UShort nFeatureFlags; FT_UShort nSubtables; GXV_NAME_ENTER( "mort chain header" ); GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 ); #ifdef GXV_LOAD_UNUSED_VARS defaultFlags = FT_NEXT_ULONG( p ); #else p += 4; #endif chainLength = FT_NEXT_ULONG( p ); nFeatureFlags = FT_NEXT_USHORT( p ); nSubtables = FT_NEXT_USHORT( p ); gxv_mort_featurearray_validate( p, table + chainLength, nFeatureFlags, gxvalid ); p += gxvalid->subtable_length; gxv_mort_subtables_validate( p, table + chainLength, nSubtables, gxvalid ); gxvalid->subtable_length = chainLength; /* TODO: validate defaultFlags */ GXV_EXIT; } FT_LOCAL_DEF( void ) gxv_mort_validate( FT_Bytes table, FT_Face face, FT_Validator ftvalid ) { GXV_ValidatorRec gxvalidrec; GXV_Validator gxvalid = &gxvalidrec; FT_Bytes p = table; FT_Bytes limit = 0; FT_ULong version; FT_ULong nChains; FT_ULong i; gxvalid->root = ftvalid; gxvalid->face = face; limit = gxvalid->root->limit; FT_TRACE3(( "validating `mort' table\n" )); GXV_INIT; GXV_LIMIT_CHECK( 4 + 4 ); version = FT_NEXT_ULONG( p ); nChains = FT_NEXT_ULONG( p ); if (version != 0x00010000UL) FT_INVALID_FORMAT; for ( i = 0; i < nChains; i++ ) { GXV_TRACE(( "validating chain %lu/%lu\n", i + 1, nChains )); GXV_32BIT_ALIGNMENT_VALIDATE( p - table ); gxv_mort_chain_validate( p, limit, gxvalid ); p += gxvalid->subtable_length; } FT_TRACE4(( "\n" )); } /* END */