1 /**************************************************************************** 2 * 3 * gxvmort.c 4 * 5 * TrueTypeGX/AAT mort table validation (body). 6 * 7 * Copyright (C) 2005-2020 by 8 * suzuki toshiya, Masatake YAMATO, Red Hat K.K., 9 * David Turner, Robert Wilhelm, and Werner Lemberg. 10 * 11 * This file is part of the FreeType project, and may only be used, 12 * modified, and distributed under the terms of the FreeType project 13 * license, LICENSE.TXT. By continuing to use, modify, or distribute 14 * this file you indicate that you have read the license and 15 * understand and accept it fully. 16 * 17 */ 18 19 /**************************************************************************** 20 * 21 * gxvalid is derived from both gxlayout module and otvalid module. 22 * Development of gxlayout is supported by the Information-technology 23 * Promotion Agency(IPA), Japan. 24 * 25 */ 26 27 28 #include "gxvmort.h" 29 #include "gxvfeat.h" 30 31 32 /************************************************************************** 33 * 34 * The macro FT_COMPONENT is used in trace mode. It is an implicit 35 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log 36 * messages during execution. 37 */ 38 #undef FT_COMPONENT 39 #define FT_COMPONENT gxvmort 40 41 42 static void gxv_mort_feature_validate(GXV_mort_feature f,GXV_Validator gxvalid)43 gxv_mort_feature_validate( GXV_mort_feature f, 44 GXV_Validator gxvalid ) 45 { 46 if ( f->featureType >= gxv_feat_registry_length ) 47 { 48 GXV_TRACE(( "featureType %d is out of registered range, " 49 "setting %d is unchecked\n", 50 f->featureType, f->featureSetting )); 51 GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); 52 } 53 else if ( !gxv_feat_registry[f->featureType].existence ) 54 { 55 GXV_TRACE(( "featureType %d is within registered area " 56 "but undefined, setting %d is unchecked\n", 57 f->featureType, f->featureSetting )); 58 GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); 59 } 60 else 61 { 62 FT_Byte nSettings_max; 63 64 65 /* nSettings in gxvfeat.c is halved for exclusive on/off settings */ 66 nSettings_max = gxv_feat_registry[f->featureType].nSettings; 67 if ( gxv_feat_registry[f->featureType].exclusive ) 68 nSettings_max = (FT_Byte)( 2 * nSettings_max ); 69 70 GXV_TRACE(( "featureType %d is registered", f->featureType )); 71 GXV_TRACE(( "setting %d", f->featureSetting )); 72 73 if ( f->featureSetting > nSettings_max ) 74 { 75 GXV_TRACE(( "out of defined range %d", nSettings_max )); 76 GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); 77 } 78 GXV_TRACE(( "\n" )); 79 } 80 81 /* TODO: enableFlags must be unique value in specified chain? */ 82 } 83 84 85 /* 86 * nFeatureFlags is typed to FT_ULong to accept that in 87 * mort (typed FT_UShort) and morx (typed FT_ULong). 88 */ 89 FT_LOCAL_DEF( void ) gxv_mort_featurearray_validate(FT_Bytes table,FT_Bytes limit,FT_ULong nFeatureFlags,GXV_Validator gxvalid)90 gxv_mort_featurearray_validate( FT_Bytes table, 91 FT_Bytes limit, 92 FT_ULong nFeatureFlags, 93 GXV_Validator gxvalid ) 94 { 95 FT_Bytes p = table; 96 FT_ULong i; 97 98 GXV_mort_featureRec f = GXV_MORT_FEATURE_OFF; 99 100 101 GXV_NAME_ENTER( "mort feature list" ); 102 for ( i = 0; i < nFeatureFlags; i++ ) 103 { 104 GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 ); 105 f.featureType = FT_NEXT_USHORT( p ); 106 f.featureSetting = FT_NEXT_USHORT( p ); 107 f.enableFlags = FT_NEXT_ULONG( p ); 108 f.disableFlags = FT_NEXT_ULONG( p ); 109 110 gxv_mort_feature_validate( &f, gxvalid ); 111 } 112 113 if ( !IS_GXV_MORT_FEATURE_OFF( f ) ) 114 FT_INVALID_DATA; 115 116 gxvalid->subtable_length = (FT_ULong)( p - table ); 117 GXV_EXIT; 118 } 119 120 121 FT_LOCAL_DEF( void ) gxv_mort_coverage_validate(FT_UShort coverage,GXV_Validator gxvalid)122 gxv_mort_coverage_validate( FT_UShort coverage, 123 GXV_Validator gxvalid ) 124 { 125 FT_UNUSED( gxvalid ); 126 FT_UNUSED( coverage ); 127 128 #ifdef FT_DEBUG_LEVEL_TRACE 129 if ( coverage & 0x8000U ) 130 GXV_TRACE(( " this subtable is for vertical text only\n" )); 131 else 132 GXV_TRACE(( " this subtable is for horizontal text only\n" )); 133 134 if ( coverage & 0x4000 ) 135 GXV_TRACE(( " this subtable is applied to glyph array " 136 "in descending order\n" )); 137 else 138 GXV_TRACE(( " this subtable is applied to glyph array " 139 "in ascending order\n" )); 140 141 if ( coverage & 0x2000 ) 142 GXV_TRACE(( " this subtable is forcibly applied to " 143 "vertical/horizontal text\n" )); 144 145 if ( coverage & 0x1FF8 ) 146 GXV_TRACE(( " coverage has non-zero bits in reserved area\n" )); 147 #endif 148 } 149 150 151 static void gxv_mort_subtables_validate(FT_Bytes table,FT_Bytes limit,FT_UShort nSubtables,GXV_Validator gxvalid)152 gxv_mort_subtables_validate( FT_Bytes table, 153 FT_Bytes limit, 154 FT_UShort nSubtables, 155 GXV_Validator gxvalid ) 156 { 157 FT_Bytes p = table; 158 159 GXV_Validate_Func fmt_funcs_table[] = 160 { 161 gxv_mort_subtable_type0_validate, /* 0 */ 162 gxv_mort_subtable_type1_validate, /* 1 */ 163 gxv_mort_subtable_type2_validate, /* 2 */ 164 NULL, /* 3 */ 165 gxv_mort_subtable_type4_validate, /* 4 */ 166 gxv_mort_subtable_type5_validate, /* 5 */ 167 168 }; 169 170 FT_UShort i; 171 172 173 GXV_NAME_ENTER( "subtables in a chain" ); 174 175 for ( i = 0; i < nSubtables; i++ ) 176 { 177 GXV_Validate_Func func; 178 179 FT_UShort length; 180 FT_UShort coverage; 181 #ifdef GXV_LOAD_UNUSED_VARS 182 FT_ULong subFeatureFlags; 183 #endif 184 FT_UInt type; 185 FT_UInt rest; 186 187 188 GXV_LIMIT_CHECK( 2 + 2 + 4 ); 189 length = FT_NEXT_USHORT( p ); 190 coverage = FT_NEXT_USHORT( p ); 191 #ifdef GXV_LOAD_UNUSED_VARS 192 subFeatureFlags = FT_NEXT_ULONG( p ); 193 #else 194 p += 4; 195 #endif 196 197 GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n", 198 i + 1, nSubtables, length )); 199 type = coverage & 0x0007; 200 rest = length - ( 2 + 2 + 4 ); 201 202 GXV_LIMIT_CHECK( rest ); 203 gxv_mort_coverage_validate( coverage, gxvalid ); 204 205 if ( type > 5 ) 206 FT_INVALID_FORMAT; 207 208 func = fmt_funcs_table[type]; 209 if ( !func ) 210 GXV_TRACE(( "morx type %d is reserved\n", type )); 211 212 func( p, p + rest, gxvalid ); 213 214 p += rest; 215 /* TODO: validate subFeatureFlags */ 216 } 217 218 gxvalid->subtable_length = (FT_ULong)( p - table ); 219 220 GXV_EXIT; 221 } 222 223 224 static void gxv_mort_chain_validate(FT_Bytes table,FT_Bytes limit,GXV_Validator gxvalid)225 gxv_mort_chain_validate( FT_Bytes table, 226 FT_Bytes limit, 227 GXV_Validator gxvalid ) 228 { 229 FT_Bytes p = table; 230 #ifdef GXV_LOAD_UNUSED_VARS 231 FT_ULong defaultFlags; 232 #endif 233 FT_ULong chainLength; 234 FT_UShort nFeatureFlags; 235 FT_UShort nSubtables; 236 237 238 GXV_NAME_ENTER( "mort chain header" ); 239 240 GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 ); 241 #ifdef GXV_LOAD_UNUSED_VARS 242 defaultFlags = FT_NEXT_ULONG( p ); 243 #else 244 p += 4; 245 #endif 246 chainLength = FT_NEXT_ULONG( p ); 247 nFeatureFlags = FT_NEXT_USHORT( p ); 248 nSubtables = FT_NEXT_USHORT( p ); 249 250 gxv_mort_featurearray_validate( p, table + chainLength, 251 nFeatureFlags, gxvalid ); 252 p += gxvalid->subtable_length; 253 gxv_mort_subtables_validate( p, table + chainLength, nSubtables, gxvalid ); 254 gxvalid->subtable_length = chainLength; 255 256 /* TODO: validate defaultFlags */ 257 GXV_EXIT; 258 } 259 260 261 FT_LOCAL_DEF( void ) gxv_mort_validate(FT_Bytes table,FT_Face face,FT_Validator ftvalid)262 gxv_mort_validate( FT_Bytes table, 263 FT_Face face, 264 FT_Validator ftvalid ) 265 { 266 GXV_ValidatorRec gxvalidrec; 267 GXV_Validator gxvalid = &gxvalidrec; 268 FT_Bytes p = table; 269 FT_Bytes limit = 0; 270 FT_ULong version; 271 FT_ULong nChains; 272 FT_ULong i; 273 274 275 gxvalid->root = ftvalid; 276 gxvalid->face = face; 277 limit = gxvalid->root->limit; 278 279 FT_TRACE3(( "validating `mort' table\n" )); 280 GXV_INIT; 281 282 GXV_LIMIT_CHECK( 4 + 4 ); 283 version = FT_NEXT_ULONG( p ); 284 nChains = FT_NEXT_ULONG( p ); 285 286 if (version != 0x00010000UL) 287 FT_INVALID_FORMAT; 288 289 for ( i = 0; i < nChains; i++ ) 290 { 291 GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains )); 292 GXV_32BIT_ALIGNMENT_VALIDATE( p - table ); 293 gxv_mort_chain_validate( p, limit, gxvalid ); 294 p += gxvalid->subtable_length; 295 } 296 297 FT_TRACE4(( "\n" )); 298 } 299 300 301 /* END */ 302