/**************************************************************************** * * gxvmort1.c * * TrueTypeGX/AAT mort table validation * body for type1 (Contextual Substitution) subtable. * * 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" /************************************************************************** * * 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 typedef struct GXV_mort_subtable_type1_StateOptRec_ { FT_UShort substitutionTable; FT_UShort substitutionTable_length; } GXV_mort_subtable_type1_StateOptRec, *GXV_mort_subtable_type1_StateOptRecData; #define GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE \ ( GXV_STATETABLE_HEADER_SIZE + 2 ) static void gxv_mort_subtable_type1_substitutionTable_load( FT_Bytes table, FT_Bytes limit, GXV_Validator gxvalid ) { FT_Bytes p = table; GXV_mort_subtable_type1_StateOptRecData optdata = (GXV_mort_subtable_type1_StateOptRecData)gxvalid->statetable.optdata; GXV_LIMIT_CHECK( 2 ); optdata->substitutionTable = FT_NEXT_USHORT( p ); } static void gxv_mort_subtable_type1_subtable_setup( FT_UShort table_size, FT_UShort classTable, FT_UShort stateArray, FT_UShort entryTable, FT_UShort* classTable_length_p, FT_UShort* stateArray_length_p, FT_UShort* entryTable_length_p, GXV_Validator gxvalid ) { FT_UShort o[4]; FT_UShort *l[4]; FT_UShort buff[5]; GXV_mort_subtable_type1_StateOptRecData optdata = (GXV_mort_subtable_type1_StateOptRecData)gxvalid->statetable.optdata; o[0] = classTable; o[1] = stateArray; o[2] = entryTable; o[3] = optdata->substitutionTable; l[0] = classTable_length_p; l[1] = stateArray_length_p; l[2] = entryTable_length_p; l[3] = &( optdata->substitutionTable_length ); gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, gxvalid ); } static void gxv_mort_subtable_type1_offset_to_subst_validate( FT_Short wordOffset, const FT_String* tag, FT_Byte state, GXV_Validator gxvalid ) { FT_UShort substTable; FT_UShort substTable_limit; FT_UNUSED( tag ); FT_UNUSED( state ); substTable = ((GXV_mort_subtable_type1_StateOptRec *) (gxvalid->statetable.optdata))->substitutionTable; substTable_limit = (FT_UShort)( substTable + ((GXV_mort_subtable_type1_StateOptRec *) (gxvalid->statetable.optdata))->substitutionTable_length ); gxvalid->min_gid = (FT_UShort)( ( substTable - wordOffset * 2 ) / 2 ); gxvalid->max_gid = (FT_UShort)( ( substTable_limit - wordOffset * 2 ) / 2 ); gxvalid->max_gid = (FT_UShort)( FT_MAX( gxvalid->max_gid, gxvalid->face->num_glyphs ) ); /* XXX: check range? */ /* TODO: min_gid & max_gid comparison with ClassTable contents */ } static void gxv_mort_subtable_type1_entry_validate( FT_Byte state, FT_UShort flags, GXV_StateTable_GlyphOffsetCPtr glyphOffset_p, FT_Bytes table, FT_Bytes limit, GXV_Validator gxvalid ) { #ifdef GXV_LOAD_UNUSED_VARS FT_UShort setMark; FT_UShort dontAdvance; #endif FT_UShort reserved; FT_Short markOffset; FT_Short currentOffset; FT_UNUSED( table ); FT_UNUSED( limit ); #ifdef GXV_LOAD_UNUSED_VARS setMark = (FT_UShort)( flags >> 15 ); dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 ); #endif reserved = (FT_UShort)( flags & 0x3FFF ); markOffset = (FT_Short)( glyphOffset_p->ul >> 16 ); currentOffset = (FT_Short)( glyphOffset_p->ul ); if ( 0 < reserved ) { GXV_TRACE(( " non-zero bits found in reserved range\n" )); GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); } gxv_mort_subtable_type1_offset_to_subst_validate( markOffset, "markOffset", state, gxvalid ); gxv_mort_subtable_type1_offset_to_subst_validate( currentOffset, "currentOffset", state, gxvalid ); } static void gxv_mort_subtable_type1_substTable_validate( FT_Bytes table, FT_Bytes limit, GXV_Validator gxvalid ) { FT_Bytes p = table; FT_UShort num_gids = (FT_UShort)( ((GXV_mort_subtable_type1_StateOptRec *) (gxvalid->statetable.optdata))->substitutionTable_length / 2 ); FT_UShort i; GXV_NAME_ENTER( "validating contents of substitutionTable" ); for ( i = 0; i < num_gids; i++ ) { FT_UShort dst_gid; GXV_LIMIT_CHECK( 2 ); dst_gid = FT_NEXT_USHORT( p ); if ( dst_gid >= 0xFFFFU ) continue; if ( dst_gid < gxvalid->min_gid || gxvalid->max_gid < dst_gid ) { GXV_TRACE(( "substTable include a strange gid[%d]=%d >" " out of define range (%d..%d)\n", i, dst_gid, gxvalid->min_gid, gxvalid->max_gid )); GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID ); } } GXV_EXIT; } /* * subtable for Contextual glyph substitution is a modified StateTable. * In addition to classTable, stateArray, and entryTable, the field * `substitutionTable' is added. */ FT_LOCAL_DEF( void ) gxv_mort_subtable_type1_validate( FT_Bytes table, FT_Bytes limit, GXV_Validator gxvalid ) { FT_Bytes p = table; GXV_mort_subtable_type1_StateOptRec st_rec; GXV_NAME_ENTER( "mort chain subtable type1 (Contextual Glyph Subst)" ); GXV_LIMIT_CHECK( GXV_MORT_SUBTABLE_TYPE1_HEADER_SIZE ); gxvalid->statetable.optdata = &st_rec; gxvalid->statetable.optdata_load_func = gxv_mort_subtable_type1_substitutionTable_load; gxvalid->statetable.subtable_setup_func = gxv_mort_subtable_type1_subtable_setup; gxvalid->statetable.entry_glyphoffset_fmt = GXV_GLYPHOFFSET_ULONG; gxvalid->statetable.entry_validate_func = gxv_mort_subtable_type1_entry_validate; gxv_StateTable_validate( p, limit, gxvalid ); gxv_mort_subtable_type1_substTable_validate( table + st_rec.substitutionTable, table + st_rec.substitutionTable + st_rec.substitutionTable_length, gxvalid ); GXV_EXIT; } /* END */