1 /****************************************************************************
2 *
3 * gxvkern.c
4 *
5 * TrueTypeGX/AAT kern table validation (body).
6 *
7 * Copyright (C) 2004-2023 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 "gxvalid.h"
29 #include "gxvcommn.h"
30
31 #include <freetype/ftsnames.h>
32 #include <freetype/internal/services/svgxval.h>
33
34
35 /**************************************************************************
36 *
37 * The macro FT_COMPONENT is used in trace mode. It is an implicit
38 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
39 * messages during execution.
40 */
41 #undef FT_COMPONENT
42 #define FT_COMPONENT gxvkern
43
44
45 /*************************************************************************/
46 /*************************************************************************/
47 /***** *****/
48 /***** Data and Types *****/
49 /***** *****/
50 /*************************************************************************/
51 /*************************************************************************/
52
53 typedef enum GXV_kern_Version_
54 {
55 KERN_VERSION_CLASSIC = 0x0000,
56 KERN_VERSION_NEW = 0x0001
57
58 } GXV_kern_Version;
59
60
61 typedef enum GXV_kern_Dialect_
62 {
63 KERN_DIALECT_UNKNOWN = 0,
64 KERN_DIALECT_MS = FT_VALIDATE_MS,
65 KERN_DIALECT_APPLE = FT_VALIDATE_APPLE,
66 KERN_DIALECT_ANY = FT_VALIDATE_CKERN
67
68 } GXV_kern_Dialect;
69
70
71 typedef struct GXV_kern_DataRec_
72 {
73 GXV_kern_Version version;
74 void *subtable_data;
75 GXV_kern_Dialect dialect_request;
76
77 } GXV_kern_DataRec, *GXV_kern_Data;
78
79
80 #define GXV_KERN_DATA( field ) GXV_TABLE_DATA( kern, field )
81
82 #define KERN_IS_CLASSIC( gxvalid ) \
83 ( KERN_VERSION_CLASSIC == GXV_KERN_DATA( version ) )
84 #define KERN_IS_NEW( gxvalid ) \
85 ( KERN_VERSION_NEW == GXV_KERN_DATA( version ) )
86
87 #define KERN_DIALECT( gxvalid ) \
88 GXV_KERN_DATA( dialect_request )
89 #define KERN_ALLOWS_MS( gxvalid ) \
90 ( KERN_DIALECT( gxvalid ) & KERN_DIALECT_MS )
91 #define KERN_ALLOWS_APPLE( gxvalid ) \
92 ( KERN_DIALECT( gxvalid ) & KERN_DIALECT_APPLE )
93
94 #define GXV_KERN_HEADER_SIZE ( KERN_IS_NEW( gxvalid ) ? 8 : 4 )
95 #define GXV_KERN_SUBTABLE_HEADER_SIZE ( KERN_IS_NEW( gxvalid ) ? 8 : 6 )
96
97
98 /*************************************************************************/
99 /*************************************************************************/
100 /***** *****/
101 /***** SUBTABLE VALIDATORS *****/
102 /***** *****/
103 /*************************************************************************/
104 /*************************************************************************/
105
106
107 /* ============================= format 0 ============================== */
108
109 static void
110 gxv_kern_subtable_fmt0_pairs_validate( FT_Bytes table,
111 FT_Bytes limit,
112 FT_UShort nPairs,
113 GXV_Validator gxvalid )
114 {
115 FT_Bytes p = table;
116 FT_UShort i;
117
118 FT_UShort last_gid_left = 0;
119 FT_UShort last_gid_right = 0;
120
121 FT_UNUSED( limit );
122
123
124 GXV_NAME_ENTER( "kern format 0 pairs" );
125
126 for ( i = 0; i < nPairs; i++ )
127 {
128 FT_UShort gid_left;
129 FT_UShort gid_right;
130 #ifdef GXV_LOAD_UNUSED_VARS
131 FT_Short kernValue;
132 #endif
133
134
135 /* left */
136 gid_left = FT_NEXT_USHORT( p );
137 gxv_glyphid_validate( gid_left, gxvalid );
138
139 /* right */
140 gid_right = FT_NEXT_USHORT( p );
141 gxv_glyphid_validate( gid_right, gxvalid );
142
143 /* Pairs of left and right GIDs must be unique and sorted. */
144 GXV_TRACE(( "left gid = %u, right gid = %u\n", gid_left, gid_right ));
145 if ( gid_left == last_gid_left )
146 {
147 if ( last_gid_right < gid_right )
148 last_gid_right = gid_right;
149 else
150 FT_INVALID_DATA;
151 }
152 else if ( last_gid_left < gid_left )
153 {
154 last_gid_left = gid_left;
155 last_gid_right = gid_right;
156 }
157 else
158 FT_INVALID_DATA;
159
160 /* skip the kern value */
161 #ifdef GXV_LOAD_UNUSED_VARS
162 kernValue = FT_NEXT_SHORT( p );
163 #else
164 p += 2;
165 #endif
166 }
167
168 GXV_EXIT;
169 }
170
171 static void
172 gxv_kern_subtable_fmt0_validate( FT_Bytes table,
173 FT_Bytes limit,
174 GXV_Validator gxvalid )
175 {
176 FT_Bytes p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
177
178 FT_UShort nPairs;
179 FT_UShort unitSize;
180
181
182 GXV_NAME_ENTER( "kern subtable format 0" );
183
184 unitSize = 2 + 2 + 2;
185 nPairs = 0;
186
187 /* nPairs, searchRange, entrySelector, rangeShift */
188 GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
189 gxv_BinSrchHeader_validate( p, limit, &unitSize, &nPairs, gxvalid );
190 p += 2 + 2 + 2 + 2;
191
192 gxv_kern_subtable_fmt0_pairs_validate( p, limit, nPairs, gxvalid );
193
194 GXV_EXIT;
195 }
196
197
198 /* ============================= format 1 ============================== */
199
200
201 typedef struct GXV_kern_fmt1_StateOptRec_
202 {
203 FT_UShort valueTable;
204 FT_UShort valueTable_length;
205
206 } GXV_kern_fmt1_StateOptRec, *GXV_kern_fmt1_StateOptRecData;
207
208
209 static void
210 gxv_kern_subtable_fmt1_valueTable_load( FT_Bytes table,
211 FT_Bytes limit,
212 GXV_Validator gxvalid )
213 {
214 FT_Bytes p = table;
215 GXV_kern_fmt1_StateOptRecData optdata =
216 (GXV_kern_fmt1_StateOptRecData)gxvalid->statetable.optdata;
217
218
219 GXV_LIMIT_CHECK( 2 );
220 optdata->valueTable = FT_NEXT_USHORT( p );
221 }
222
223
224 /*
225 * passed tables_size covers whole StateTable, including kern fmt1 header
226 */
227 static void
228 gxv_kern_subtable_fmt1_subtable_setup( FT_UShort table_size,
229 FT_UShort classTable,
230 FT_UShort stateArray,
231 FT_UShort entryTable,
232 FT_UShort* classTable_length_p,
233 FT_UShort* stateArray_length_p,
234 FT_UShort* entryTable_length_p,
235 GXV_Validator gxvalid )
236 {
237 FT_UShort o[4];
238 FT_UShort *l[4];
239 FT_UShort buff[5];
240
241 GXV_kern_fmt1_StateOptRecData optdata =
242 (GXV_kern_fmt1_StateOptRecData)gxvalid->statetable.optdata;
243
244
245 o[0] = classTable;
246 o[1] = stateArray;
247 o[2] = entryTable;
248 o[3] = optdata->valueTable;
249 l[0] = classTable_length_p;
250 l[1] = stateArray_length_p;
251 l[2] = entryTable_length_p;
252 l[3] = &(optdata->valueTable_length);
253
254 gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, gxvalid );
255 }
256
257
258 /*
259 * passed table & limit are of whole StateTable, not including subtables
260 */
261 static void
262 gxv_kern_subtable_fmt1_entry_validate(
263 FT_Byte state,
264 FT_UShort flags,
265 GXV_StateTable_GlyphOffsetCPtr glyphOffset_p,
266 FT_Bytes table,
267 FT_Bytes limit,
268 GXV_Validator gxvalid )
269 {
270 #ifdef GXV_LOAD_UNUSED_VARS
271 FT_UShort push;
272 FT_UShort dontAdvance;
273 #endif
274 FT_UShort valueOffset;
275 #ifdef GXV_LOAD_UNUSED_VARS
276 FT_UShort kernAction;
277 FT_UShort kernValue;
278 #endif
279
280 FT_UNUSED( state );
281 FT_UNUSED( glyphOffset_p );
282
283
284 #ifdef GXV_LOAD_UNUSED_VARS
285 push = (FT_UShort)( ( flags >> 15 ) & 1 );
286 dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 );
287 #endif
288 valueOffset = (FT_UShort)( flags & 0x3FFF );
289
290 {
291 GXV_kern_fmt1_StateOptRecData vt_rec =
292 (GXV_kern_fmt1_StateOptRecData)gxvalid->statetable.optdata;
293 FT_Bytes p;
294
295
296 if ( valueOffset < vt_rec->valueTable )
297 FT_INVALID_OFFSET;
298
299 p = table + valueOffset;
300 limit = table + vt_rec->valueTable + vt_rec->valueTable_length;
301
302 GXV_LIMIT_CHECK( 2 + 2 );
303 #ifdef GXV_LOAD_UNUSED_VARS
304 kernAction = FT_NEXT_USHORT( p );
305 kernValue = FT_NEXT_USHORT( p );
306 #endif
307 }
308 }
309
310
311 static void
312 gxv_kern_subtable_fmt1_validate( FT_Bytes table,
313 FT_Bytes limit,
314 GXV_Validator gxvalid )
315 {
316 FT_Bytes p = table;
317 GXV_kern_fmt1_StateOptRec vt_rec;
318
319
320 GXV_NAME_ENTER( "kern subtable format 1" );
321
322 gxvalid->statetable.optdata =
323 &vt_rec;
324 gxvalid->statetable.optdata_load_func =
325 gxv_kern_subtable_fmt1_valueTable_load;
326 gxvalid->statetable.subtable_setup_func =
327 gxv_kern_subtable_fmt1_subtable_setup;
328 gxvalid->statetable.entry_glyphoffset_fmt =
329 GXV_GLYPHOFFSET_NONE;
330 gxvalid->statetable.entry_validate_func =
331 gxv_kern_subtable_fmt1_entry_validate;
332
333 gxv_StateTable_validate( p, limit, gxvalid );
334
335 GXV_EXIT;
336 }
337
338
339 /* ================ Data for Class-Based Subtables 2, 3 ================ */
340
341 typedef enum GXV_kern_ClassSpec_
342 {
343 GXV_KERN_CLS_L = 0,
344 GXV_KERN_CLS_R
345
346 } GXV_kern_ClassSpec;
347
348
349 /* ============================= format 2 ============================== */
350
351 /* ---------------------- format 2 specific data ----------------------- */
352
353 typedef struct GXV_kern_subtable_fmt2_DataRec_
354 {
355 FT_UShort rowWidth;
356 FT_UShort array;
357 FT_UShort offset_min[2];
358 FT_UShort offset_max[2];
359 const FT_String* class_tag[2];
360 GXV_odtect_Range odtect;
361
362 } GXV_kern_subtable_fmt2_DataRec, *GXV_kern_subtable_fmt2_Data;
363
364
365 #define GXV_KERN_FMT2_DATA( field ) \
366 ( ( (GXV_kern_subtable_fmt2_DataRec *) \
367 ( GXV_KERN_DATA( subtable_data ) ) )->field )
368
369
370 /* -------------------------- utility functions ----------------------- */
371
372 static void
373 gxv_kern_subtable_fmt2_clstbl_validate( FT_Bytes table,
374 FT_Bytes limit,
375 GXV_kern_ClassSpec spec,
376 GXV_Validator gxvalid )
377 {
378 const FT_String* tag = GXV_KERN_FMT2_DATA( class_tag[spec] );
379 GXV_odtect_Range odtect = GXV_KERN_FMT2_DATA( odtect );
380
381 FT_Bytes p = table;
382 FT_UShort firstGlyph;
383 FT_UShort nGlyphs;
384
385
386 GXV_NAME_ENTER( "kern format 2 classTable" );
387
388 GXV_LIMIT_CHECK( 2 + 2 );
389 firstGlyph = FT_NEXT_USHORT( p );
390 nGlyphs = FT_NEXT_USHORT( p );
391 GXV_TRACE(( " %s firstGlyph=%d, nGlyphs=%d\n",
392 tag, firstGlyph, nGlyphs ));
393
394 gxv_glyphid_validate( firstGlyph, gxvalid );
395 gxv_glyphid_validate( (FT_UShort)( firstGlyph + nGlyphs - 1 ), gxvalid );
396
397 gxv_array_getlimits_ushort( p, p + ( 2 * nGlyphs ),
398 &( GXV_KERN_FMT2_DATA( offset_min[spec] ) ),
399 &( GXV_KERN_FMT2_DATA( offset_max[spec] ) ),
400 gxvalid );
401
402 gxv_odtect_add_range( table, 2 * nGlyphs, tag, odtect );
403
404 GXV_EXIT;
405 }
406
407
408 static void
409 gxv_kern_subtable_fmt2_validate( FT_Bytes table,
410 FT_Bytes limit,
411 GXV_Validator gxvalid )
412 {
413 GXV_ODTECT( 3, odtect );
414 GXV_kern_subtable_fmt2_DataRec fmt2_rec =
415 { 0, 0, { 0, 0 }, { 0, 0 }, { "leftClass", "rightClass" }, NULL };
416
417 FT_Bytes p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
418 FT_UShort leftOffsetTable;
419 FT_UShort rightOffsetTable;
420
421
422 GXV_NAME_ENTER( "kern subtable format 2" );
423
424 GXV_ODTECT_INIT( odtect );
425 fmt2_rec.odtect = odtect;
426 GXV_KERN_DATA( subtable_data ) = &fmt2_rec;
427
428 GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
429 GXV_KERN_FMT2_DATA( rowWidth ) = FT_NEXT_USHORT( p );
430 leftOffsetTable = FT_NEXT_USHORT( p );
431 rightOffsetTable = FT_NEXT_USHORT( p );
432 GXV_KERN_FMT2_DATA( array ) = FT_NEXT_USHORT( p );
433
434 GXV_TRACE(( "rowWidth = %d\n", GXV_KERN_FMT2_DATA( rowWidth ) ));
435
436
437 GXV_LIMIT_CHECK( leftOffsetTable );
438 GXV_LIMIT_CHECK( rightOffsetTable );
439 GXV_LIMIT_CHECK( GXV_KERN_FMT2_DATA( array ) );
440
441 gxv_kern_subtable_fmt2_clstbl_validate( table + leftOffsetTable, limit,
442 GXV_KERN_CLS_L, gxvalid );
443
444 gxv_kern_subtable_fmt2_clstbl_validate( table + rightOffsetTable, limit,
445 GXV_KERN_CLS_R, gxvalid );
446
447 if ( GXV_KERN_FMT2_DATA( offset_min[GXV_KERN_CLS_L] ) +
448 GXV_KERN_FMT2_DATA( offset_min[GXV_KERN_CLS_R] )
449 < GXV_KERN_FMT2_DATA( array ) )
450 FT_INVALID_OFFSET;
451
452 gxv_odtect_add_range( table + GXV_KERN_FMT2_DATA( array ),
453 GXV_KERN_FMT2_DATA( offset_max[GXV_KERN_CLS_L] )
454 + GXV_KERN_FMT2_DATA( offset_max[GXV_KERN_CLS_R] )
455 - GXV_KERN_FMT2_DATA( array ),
456 "array", odtect );
457
458 gxv_odtect_validate( odtect, gxvalid );
459
460 GXV_EXIT;
461 }
462
463
464 /* ============================= format 3 ============================== */
465
466 static void
467 gxv_kern_subtable_fmt3_validate( FT_Bytes table,
468 FT_Bytes limit,
469 GXV_Validator gxvalid )
470 {
471 FT_Bytes p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
472 FT_UShort glyphCount;
473 FT_Byte kernValueCount;
474 FT_Byte leftClassCount;
475 FT_Byte rightClassCount;
476 FT_Byte flags;
477
478
479 GXV_NAME_ENTER( "kern subtable format 3" );
480
481 GXV_LIMIT_CHECK( 2 + 1 + 1 + 1 + 1 );
482 glyphCount = FT_NEXT_USHORT( p );
483 kernValueCount = FT_NEXT_BYTE( p );
484 leftClassCount = FT_NEXT_BYTE( p );
485 rightClassCount = FT_NEXT_BYTE( p );
486 flags = FT_NEXT_BYTE( p );
487
488 if ( gxvalid->face->num_glyphs != glyphCount )
489 {
490 GXV_TRACE(( "maxGID=%ld, but glyphCount=%d\n",
491 gxvalid->face->num_glyphs, glyphCount ));
492 GXV_SET_ERR_IF_PARANOID( FT_INVALID_GLYPH_ID );
493 }
494
495 if ( flags != 0 )
496 GXV_TRACE(( "kern subtable fmt3 has nonzero value"
497 " (%d) in unused flag\n", flags ));
498 /*
499 * just skip kernValue[kernValueCount]
500 */
501 GXV_LIMIT_CHECK( 2 * kernValueCount );
502 p += 2 * kernValueCount;
503
504 /*
505 * check leftClass[gid] < leftClassCount
506 */
507 {
508 FT_Byte min, max;
509
510
511 GXV_LIMIT_CHECK( glyphCount );
512 gxv_array_getlimits_byte( p, p + glyphCount, &min, &max, gxvalid );
513 p += gxvalid->subtable_length;
514
515 if ( leftClassCount < max )
516 FT_INVALID_DATA;
517 }
518
519 /*
520 * check rightClass[gid] < rightClassCount
521 */
522 {
523 FT_Byte min, max;
524
525
526 GXV_LIMIT_CHECK( glyphCount );
527 gxv_array_getlimits_byte( p, p + glyphCount, &min, &max, gxvalid );
528 p += gxvalid->subtable_length;
529
530 if ( rightClassCount < max )
531 FT_INVALID_DATA;
532 }
533
534 /*
535 * check kernIndex[i, j] < kernValueCount
536 */
537 {
538 FT_UShort i, j;
539
540
541 for ( i = 0; i < leftClassCount; i++ )
542 {
543 for ( j = 0; j < rightClassCount; j++ )
544 {
545 GXV_LIMIT_CHECK( 1 );
546 if ( kernValueCount < FT_NEXT_BYTE( p ) )
547 FT_INVALID_OFFSET;
548 }
549 }
550 }
551
552 gxvalid->subtable_length = (FT_ULong)( p - table );
553
554 GXV_EXIT;
555 }
556
557
558 static FT_Bool
559 gxv_kern_coverage_new_apple_validate( FT_UShort coverage,
560 FT_UShort* format,
561 GXV_Validator gxvalid )
562 {
563 /* new Apple-dialect */
564 #ifdef GXV_LOAD_TRACE_VARS
565 FT_Bool kernVertical;
566 FT_Bool kernCrossStream;
567 FT_Bool kernVariation;
568 #endif
569
570 FT_UNUSED( gxvalid );
571
572
573 /* reserved bits = 0 */
574 if ( coverage & 0x1FFC )
575 return FALSE;
576
577 #ifdef GXV_LOAD_TRACE_VARS
578 kernVertical = FT_BOOL( ( coverage >> 15 ) & 1 );
579 kernCrossStream = FT_BOOL( ( coverage >> 14 ) & 1 );
580 kernVariation = FT_BOOL( ( coverage >> 13 ) & 1 );
581 #endif
582
583 *format = (FT_UShort)( coverage & 0x0003 );
584
585 GXV_TRACE(( "new Apple-dialect: "
586 "horizontal=%d, cross-stream=%d, variation=%d, format=%d\n",
587 !kernVertical, kernCrossStream, kernVariation, *format ));
588
589 GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" ));
590
591 return TRUE;
592 }
593
594
595 static FT_Bool
596 gxv_kern_coverage_classic_apple_validate( FT_UShort coverage,
597 FT_UShort* format,
598 GXV_Validator gxvalid )
599 {
600 /* classic Apple-dialect */
601 #ifdef GXV_LOAD_TRACE_VARS
602 FT_Bool horizontal;
603 FT_Bool cross_stream;
604 #endif
605
606
607 /* check expected flags, but don't check if MS-dialect is impossible */
608 if ( !( coverage & 0xFD00 ) && KERN_ALLOWS_MS( gxvalid ) )
609 return FALSE;
610
611 /* reserved bits = 0 */
612 if ( coverage & 0x02FC )
613 return FALSE;
614
615 #ifdef GXV_LOAD_TRACE_VARS
616 horizontal = FT_BOOL( ( coverage >> 15 ) & 1 );
617 cross_stream = FT_BOOL( ( coverage >> 13 ) & 1 );
618 #endif
619
620 *format = (FT_UShort)( coverage & 0x0003 );
621
622 GXV_TRACE(( "classic Apple-dialect: "
623 "horizontal=%d, cross-stream=%d, format=%d\n",
624 horizontal, cross_stream, *format ));
625
626 /* format 1 requires GX State Machine, too new for classic */
627 if ( *format == 1 )
628 return FALSE;
629
630 GXV_TRACE(( "kerning values in Apple format subtable are ignored\n" ));
631
632 return TRUE;
633 }
634
635
636 static FT_Bool
637 gxv_kern_coverage_classic_microsoft_validate( FT_UShort coverage,
638 FT_UShort* format,
639 GXV_Validator gxvalid )
640 {
641 /* classic Microsoft-dialect */
642 #ifdef GXV_LOAD_TRACE_VARS
643 FT_Bool horizontal;
644 FT_Bool minimum;
645 FT_Bool cross_stream;
646 FT_Bool override;
647 #endif
648
649 FT_UNUSED( gxvalid );
650
651
652 /* reserved bits = 0 */
653 if ( coverage & 0xFDF0 )
654 return FALSE;
655
656 #ifdef GXV_LOAD_TRACE_VARS
657 horizontal = FT_BOOL( coverage & 1 );
658 minimum = FT_BOOL( ( coverage >> 1 ) & 1 );
659 cross_stream = FT_BOOL( ( coverage >> 2 ) & 1 );
660 override = FT_BOOL( ( coverage >> 3 ) & 1 );
661 #endif
662
663 *format = (FT_UShort)( ( coverage >> 8 ) & 0x0003 );
664
665 GXV_TRACE(( "classic Microsoft-dialect: "
666 "horizontal=%d, minimum=%d, cross-stream=%d, "
667 "override=%d, format=%d\n",
668 horizontal, minimum, cross_stream, override, *format ));
669
670 if ( *format == 2 )
671 GXV_TRACE((
672 "kerning values in Microsoft format 2 subtable are ignored\n" ));
673
674 return TRUE;
675 }
676
677
678 /*************************************************************************/
679 /*************************************************************************/
680 /***** *****/
681 /***** MAIN *****/
682 /***** *****/
683 /*************************************************************************/
684 /*************************************************************************/
685
686 static GXV_kern_Dialect
687 gxv_kern_coverage_validate( FT_UShort coverage,
688 FT_UShort* format,
689 GXV_Validator gxvalid )
690 {
691 GXV_kern_Dialect result = KERN_DIALECT_UNKNOWN;
692
693
694 GXV_NAME_ENTER( "validating coverage" );
695
696 GXV_TRACE(( "interpret coverage 0x%04x by Apple style\n", coverage ));
697
698 if ( KERN_IS_NEW( gxvalid ) )
699 {
700 if ( gxv_kern_coverage_new_apple_validate( coverage,
701 format,
702 gxvalid ) )
703 {
704 result = KERN_DIALECT_APPLE;
705 goto Exit;
706 }
707 }
708
709 if ( KERN_IS_CLASSIC( gxvalid ) && KERN_ALLOWS_APPLE( gxvalid ) )
710 {
711 if ( gxv_kern_coverage_classic_apple_validate( coverage,
712 format,
713 gxvalid ) )
714 {
715 result = KERN_DIALECT_APPLE;
716 goto Exit;
717 }
718 }
719
720 if ( KERN_IS_CLASSIC( gxvalid ) && KERN_ALLOWS_MS( gxvalid ) )
721 {
722 if ( gxv_kern_coverage_classic_microsoft_validate( coverage,
723 format,
724 gxvalid ) )
725 {
726 result = KERN_DIALECT_MS;
727 goto Exit;
728 }
729 }
730
731 GXV_TRACE(( "cannot interpret coverage, broken kern subtable\n" ));
732
733 Exit:
734 GXV_EXIT;
735 return result;
736 }
737
738
739 static void
740 gxv_kern_subtable_validate( FT_Bytes table,
741 FT_Bytes limit,
742 GXV_Validator gxvalid )
743 {
744 FT_Bytes p = table;
745 #ifdef GXV_LOAD_TRACE_VARS
746 FT_UShort version = 0; /* MS only: subtable version, unused */
747 #endif
748 FT_ULong length; /* MS: 16bit, Apple: 32bit */
749 FT_UShort coverage;
750 #ifdef GXV_LOAD_TRACE_VARS
751 FT_UShort tupleIndex = 0; /* Apple only */
752 #endif
753 FT_UShort u16[2];
754 FT_UShort format = 255; /* subtable format */
755
756
757 GXV_NAME_ENTER( "kern subtable" );
758
759 GXV_LIMIT_CHECK( 2 + 2 + 2 );
760 u16[0] = FT_NEXT_USHORT( p ); /* Apple: length_hi MS: version */
761 u16[1] = FT_NEXT_USHORT( p ); /* Apple: length_lo MS: length */
762 coverage = FT_NEXT_USHORT( p );
763
764 switch ( gxv_kern_coverage_validate( coverage, &format, gxvalid ) )
765 {
766 case KERN_DIALECT_MS:
767 #ifdef GXV_LOAD_TRACE_VARS
768 version = u16[0];
769 #endif
770 length = u16[1];
771 #ifdef GXV_LOAD_TRACE_VARS
772 tupleIndex = 0;
773 #endif
774 GXV_TRACE(( "Subtable version = %d\n", version ));
775 GXV_TRACE(( "Subtable length = %lu\n", length ));
776 break;
777
778 case KERN_DIALECT_APPLE:
779 #ifdef GXV_LOAD_TRACE_VARS
780 version = 0;
781 #endif
782 length = ( (FT_ULong)u16[0] << 16 ) + u16[1];
783 #ifdef GXV_LOAD_TRACE_VARS
784 tupleIndex = 0;
785 #endif
786 GXV_TRACE(( "Subtable length = %lu\n", length ));
787
788 if ( KERN_IS_NEW( gxvalid ) )
789 {
790 GXV_LIMIT_CHECK( 2 );
791 #ifdef GXV_LOAD_TRACE_VARS
792 tupleIndex = FT_NEXT_USHORT( p );
793 #else
794 p += 2;
795 #endif
796 GXV_TRACE(( "Subtable tupleIndex = %d\n", tupleIndex ));
797 }
798 break;
799
800 default:
801 length = u16[1];
802 GXV_TRACE(( "cannot detect subtable dialect, "
803 "just skip %lu byte\n", length ));
804 goto Exit;
805 }
806
807 /* formats 1, 2, 3 require the position of the start of this subtable */
808 if ( format == 0 )
809 gxv_kern_subtable_fmt0_validate( table, table + length, gxvalid );
810 else if ( format == 1 )
811 gxv_kern_subtable_fmt1_validate( table, table + length, gxvalid );
812 else if ( format == 2 )
813 gxv_kern_subtable_fmt2_validate( table, table + length, gxvalid );
814 else if ( format == 3 )
815 gxv_kern_subtable_fmt3_validate( table, table + length, gxvalid );
816 else
817 FT_INVALID_DATA;
818
819 Exit:
820 gxvalid->subtable_length = length;
821 GXV_EXIT;
822 }
823
824
825 /*************************************************************************/
826 /*************************************************************************/
827 /***** *****/
828 /***** kern TABLE *****/
829 /***** *****/
830 /*************************************************************************/
831 /*************************************************************************/
832
833 static void
834 gxv_kern_validate_generic( FT_Bytes table,
835 FT_Face face,
836 FT_Bool classic_only,
837 GXV_kern_Dialect dialect_request,
838 FT_Validator ftvalid )
839 {
840 GXV_ValidatorRec gxvalidrec;
841 GXV_Validator gxvalid = &gxvalidrec;
842
843 GXV_kern_DataRec kernrec;
844 GXV_kern_Data kern = &kernrec;
845
846 FT_Bytes p = table;
847 FT_Bytes limit = 0;
848
849 FT_ULong nTables = 0;
850 FT_UInt i;
851
852
853 gxvalid->root = ftvalid;
854 gxvalid->table_data = kern;
855 gxvalid->face = face;
856
857 FT_TRACE3(( "validating `kern' table\n" ));
858 GXV_INIT;
859 KERN_DIALECT( gxvalid ) = dialect_request;
860
861 GXV_LIMIT_CHECK( 2 );
862 GXV_KERN_DATA( version ) = (GXV_kern_Version)FT_NEXT_USHORT( p );
863 GXV_TRACE(( "version 0x%04x (higher 16bit)\n",
864 GXV_KERN_DATA( version ) ));
865
866 if ( 0x0001 < GXV_KERN_DATA( version ) )
867 FT_INVALID_FORMAT;
868 else if ( KERN_IS_CLASSIC( gxvalid ) )
869 {
870 GXV_LIMIT_CHECK( 2 );
871 nTables = FT_NEXT_USHORT( p );
872 }
873 else if ( KERN_IS_NEW( gxvalid ) )
874 {
875 if ( classic_only )
876 FT_INVALID_FORMAT;
877
878 if ( 0x0000 != FT_NEXT_USHORT( p ) )
879 FT_INVALID_FORMAT;
880
881 GXV_LIMIT_CHECK( 4 );
882 nTables = FT_NEXT_ULONG( p );
883 }
884
885 for ( i = 0; i < nTables; i++ )
886 {
887 GXV_TRACE(( "validating subtable %d/%lu\n", i, nTables ));
888 /* p should be 32bit-aligned? */
889 gxv_kern_subtable_validate( p, 0, gxvalid );
890 p += gxvalid->subtable_length;
891 }
892
893 FT_TRACE4(( "\n" ));
894 }
895
896
897 FT_LOCAL_DEF( void )
898 gxv_kern_validate( FT_Bytes table,
899 FT_Face face,
900 FT_Validator ftvalid )
901 {
902 gxv_kern_validate_generic( table, face, 0, KERN_DIALECT_ANY, ftvalid );
903 }
904
905
906 FT_LOCAL_DEF( void )
907 gxv_kern_validate_classic( FT_Bytes table,
908 FT_Face face,
909 FT_Int dialect_flags,
910 FT_Validator ftvalid )
911 {
912 GXV_kern_Dialect dialect_request;
913
914
915 dialect_request = (GXV_kern_Dialect)dialect_flags;
916 gxv_kern_validate_generic( table, face, 1, dialect_request, ftvalid );
917 }
918
919
920 /* END */