1 /****************************************************************************
2 *
3 * otvmath.c
4 *
5 * OpenType MATH table validation (body).
6 *
7 * Copyright (C) 2007-2023 by
8 * David Turner, Robert Wilhelm, and Werner Lemberg.
9 *
10 * Written by George Williams.
11 *
12 * This file is part of the FreeType project, and may only be used,
13 * modified, and distributed under the terms of the FreeType project
14 * license, LICENSE.TXT. By continuing to use, modify, or distribute
15 * this file you indicate that you have read the license and
16 * understand and accept it fully.
17 *
18 */
19
20
21 #include "otvalid.h"
22 #include "otvcommn.h"
23 #include "otvgpos.h"
24
25
26 /**************************************************************************
27 *
28 * The macro FT_COMPONENT is used in trace mode. It is an implicit
29 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
30 * messages during execution.
31 */
32 #undef FT_COMPONENT
33 #define FT_COMPONENT otvmath
34
35
36
37 /*************************************************************************/
38 /*************************************************************************/
39 /***** *****/
40 /***** MATH TYPOGRAPHIC CONSTANTS *****/
41 /***** *****/
42 /*************************************************************************/
43 /*************************************************************************/
44
45 static void
46 otv_MathConstants_validate( FT_Bytes table,
47 OTV_Validator otvalid )
48 {
49 FT_Bytes p = table;
50 FT_UInt i;
51 FT_UInt table_size;
52
53 OTV_OPTIONAL_TABLE( DeviceTableOffset );
54
55
56 OTV_NAME_ENTER( "MathConstants" );
57
58 /* 56 constants, 51 have device tables */
59 OTV_LIMIT_CHECK( 2 * ( 56 + 51 ) );
60 table_size = 2 * ( 56 + 51 );
61
62 p += 4 * 2; /* First 4 constants have no device tables */
63 for ( i = 0; i < 51; i++ )
64 {
65 p += 2; /* skip the value */
66 OTV_OPTIONAL_OFFSET( DeviceTableOffset );
67 OTV_SIZE_CHECK( DeviceTableOffset );
68 if ( DeviceTableOffset )
69 otv_Device_validate( table + DeviceTableOffset, otvalid );
70 }
71
72 OTV_EXIT;
73 }
74
75
76 /*************************************************************************/
77 /*************************************************************************/
78 /***** *****/
79 /***** MATH ITALICS CORRECTION *****/
80 /***** MATH TOP ACCENT ATTACHMENT *****/
81 /***** *****/
82 /*************************************************************************/
83 /*************************************************************************/
84
85 static void
86 otv_MathItalicsCorrectionInfo_validate( FT_Bytes table,
87 OTV_Validator otvalid,
88 FT_Int isItalic )
89 {
90 FT_Bytes p = table;
91 FT_UInt i, cnt, table_size;
92
93 OTV_OPTIONAL_TABLE( Coverage );
94 OTV_OPTIONAL_TABLE( DeviceTableOffset );
95
96 FT_UNUSED( isItalic ); /* only used if tracing is active */
97
98
99 OTV_NAME_ENTER( isItalic ? "MathItalicsCorrectionInfo"
100 : "MathTopAccentAttachment" );
101
102 OTV_LIMIT_CHECK( 4 );
103
104 OTV_OPTIONAL_OFFSET( Coverage );
105 cnt = FT_NEXT_USHORT( p );
106
107 OTV_LIMIT_CHECK( 4 * cnt );
108 table_size = 4 + 4 * cnt;
109
110 OTV_SIZE_CHECK( Coverage );
111 otv_Coverage_validate( table + Coverage, otvalid, (FT_Int)cnt );
112
113 for ( i = 0; i < cnt; i++ )
114 {
115 p += 2; /* Skip the value */
116 OTV_OPTIONAL_OFFSET( DeviceTableOffset );
117 OTV_SIZE_CHECK( DeviceTableOffset );
118 if ( DeviceTableOffset )
119 otv_Device_validate( table + DeviceTableOffset, otvalid );
120 }
121
122 OTV_EXIT;
123 }
124
125
126 /*************************************************************************/
127 /*************************************************************************/
128 /***** *****/
129 /***** MATH KERNING *****/
130 /***** *****/
131 /*************************************************************************/
132 /*************************************************************************/
133
134 static void
135 otv_MathKern_validate( FT_Bytes table,
136 OTV_Validator otvalid )
137 {
138 FT_Bytes p = table;
139 FT_UInt i, cnt, table_size;
140
141 OTV_OPTIONAL_TABLE( DeviceTableOffset );
142
143
144 /* OTV_NAME_ENTER( "MathKern" ); */
145
146 OTV_LIMIT_CHECK( 2 );
147
148 cnt = FT_NEXT_USHORT( p );
149
150 OTV_LIMIT_CHECK( 4 * cnt + 2 );
151 table_size = 4 + 4 * cnt;
152
153 /* Heights */
154 for ( i = 0; i < cnt; i++ )
155 {
156 p += 2; /* Skip the value */
157 OTV_OPTIONAL_OFFSET( DeviceTableOffset );
158 OTV_SIZE_CHECK( DeviceTableOffset );
159 if ( DeviceTableOffset )
160 otv_Device_validate( table + DeviceTableOffset, otvalid );
161 }
162
163 /* One more Kerning value */
164 for ( i = 0; i < cnt + 1; i++ )
165 {
166 p += 2; /* Skip the value */
167 OTV_OPTIONAL_OFFSET( DeviceTableOffset );
168 OTV_SIZE_CHECK( DeviceTableOffset );
169 if ( DeviceTableOffset )
170 otv_Device_validate( table + DeviceTableOffset, otvalid );
171 }
172
173 OTV_EXIT;
174 }
175
176
177 static void
178 otv_MathKernInfo_validate( FT_Bytes table,
179 OTV_Validator otvalid )
180 {
181 FT_Bytes p = table;
182 FT_UInt i, j, cnt, table_size;
183
184 OTV_OPTIONAL_TABLE( Coverage );
185 OTV_OPTIONAL_TABLE( MKRecordOffset );
186
187
188 OTV_NAME_ENTER( "MathKernInfo" );
189
190 OTV_LIMIT_CHECK( 4 );
191
192 OTV_OPTIONAL_OFFSET( Coverage );
193 cnt = FT_NEXT_USHORT( p );
194
195 OTV_LIMIT_CHECK( 8 * cnt );
196 table_size = 4 + 8 * cnt;
197
198 OTV_SIZE_CHECK( Coverage );
199 otv_Coverage_validate( table + Coverage, otvalid, (FT_Int)cnt );
200
201 for ( i = 0; i < cnt; i++ )
202 {
203 for ( j = 0; j < 4; j++ )
204 {
205 OTV_OPTIONAL_OFFSET( MKRecordOffset );
206 OTV_SIZE_CHECK( MKRecordOffset );
207 if ( MKRecordOffset )
208 otv_MathKern_validate( table + MKRecordOffset, otvalid );
209 }
210 }
211
212 OTV_EXIT;
213 }
214
215
216 /*************************************************************************/
217 /*************************************************************************/
218 /***** *****/
219 /***** MATH GLYPH INFO *****/
220 /***** *****/
221 /*************************************************************************/
222 /*************************************************************************/
223
224 static void
225 otv_MathGlyphInfo_validate( FT_Bytes table,
226 OTV_Validator otvalid )
227 {
228 FT_Bytes p = table;
229 FT_UInt MathItalicsCorrectionInfo, MathTopAccentAttachment;
230 FT_UInt ExtendedShapeCoverage, MathKernInfo;
231
232
233 OTV_NAME_ENTER( "MathGlyphInfo" );
234
235 OTV_LIMIT_CHECK( 8 );
236
237 MathItalicsCorrectionInfo = FT_NEXT_USHORT( p );
238 MathTopAccentAttachment = FT_NEXT_USHORT( p );
239 ExtendedShapeCoverage = FT_NEXT_USHORT( p );
240 MathKernInfo = FT_NEXT_USHORT( p );
241
242 if ( MathItalicsCorrectionInfo )
243 otv_MathItalicsCorrectionInfo_validate(
244 table + MathItalicsCorrectionInfo, otvalid, TRUE );
245
246 /* Italic correction and Top Accent Attachment have the same format */
247 if ( MathTopAccentAttachment )
248 otv_MathItalicsCorrectionInfo_validate(
249 table + MathTopAccentAttachment, otvalid, FALSE );
250
251 if ( ExtendedShapeCoverage )
252 {
253 OTV_NAME_ENTER( "ExtendedShapeCoverage" );
254 otv_Coverage_validate( table + ExtendedShapeCoverage, otvalid, -1 );
255 OTV_EXIT;
256 }
257
258 if ( MathKernInfo )
259 otv_MathKernInfo_validate( table + MathKernInfo, otvalid );
260
261 OTV_EXIT;
262 }
263
264
265 /*************************************************************************/
266 /*************************************************************************/
267 /***** *****/
268 /***** MATH GLYPH CONSTRUCTION *****/
269 /***** *****/
270 /*************************************************************************/
271 /*************************************************************************/
272
273 static void
274 otv_GlyphAssembly_validate( FT_Bytes table,
275 OTV_Validator otvalid )
276 {
277 FT_Bytes p = table;
278 FT_UInt pcnt, table_size;
279 FT_UInt i;
280
281 OTV_OPTIONAL_TABLE( DeviceTableOffset );
282
283
284 /* OTV_NAME_ENTER( "GlyphAssembly" ); */
285
286 OTV_LIMIT_CHECK( 6 );
287
288 p += 2; /* Skip the Italics Correction value */
289 OTV_OPTIONAL_OFFSET( DeviceTableOffset );
290 pcnt = FT_NEXT_USHORT( p );
291
292 OTV_LIMIT_CHECK( 8 * pcnt );
293 table_size = 6 + 8 * pcnt;
294
295 OTV_SIZE_CHECK( DeviceTableOffset );
296 if ( DeviceTableOffset )
297 otv_Device_validate( table + DeviceTableOffset, otvalid );
298
299 for ( i = 0; i < pcnt; i++ )
300 {
301 FT_UInt gid;
302
303
304 gid = FT_NEXT_USHORT( p );
305 if ( gid >= otvalid->glyph_count )
306 FT_INVALID_GLYPH_ID;
307 p += 2*4; /* skip the Start, End, Full, and Flags fields */
308 }
309
310 /* OTV_EXIT; */
311 }
312
313
314 static void
315 otv_MathGlyphConstruction_validate( FT_Bytes table,
316 OTV_Validator otvalid )
317 {
318 FT_Bytes p = table;
319 FT_UInt vcnt, table_size;
320 FT_UInt i;
321
322 OTV_OPTIONAL_TABLE( GlyphAssembly );
323
324
325 /* OTV_NAME_ENTER( "MathGlyphConstruction" ); */
326
327 OTV_LIMIT_CHECK( 4 );
328
329 OTV_OPTIONAL_OFFSET( GlyphAssembly );
330 vcnt = FT_NEXT_USHORT( p );
331
332 OTV_LIMIT_CHECK( 4 * vcnt );
333 table_size = 4 + 4 * vcnt;
334
335 for ( i = 0; i < vcnt; i++ )
336 {
337 FT_UInt gid;
338
339
340 gid = FT_NEXT_USHORT( p );
341 if ( gid >= otvalid->glyph_count )
342 FT_INVALID_GLYPH_ID;
343 p += 2; /* skip the size */
344 }
345
346 OTV_SIZE_CHECK( GlyphAssembly );
347 if ( GlyphAssembly )
348 otv_GlyphAssembly_validate( table+GlyphAssembly, otvalid );
349
350 /* OTV_EXIT; */
351 }
352
353
354 static void
355 otv_MathVariants_validate( FT_Bytes table,
356 OTV_Validator otvalid )
357 {
358 FT_Bytes p = table;
359 FT_UInt vcnt, hcnt, i, table_size;
360
361 OTV_OPTIONAL_TABLE( VCoverage );
362 OTV_OPTIONAL_TABLE( HCoverage );
363 OTV_OPTIONAL_TABLE( Offset );
364
365
366 OTV_NAME_ENTER( "MathVariants" );
367
368 OTV_LIMIT_CHECK( 10 );
369
370 p += 2; /* Skip the MinConnectorOverlap constant */
371 OTV_OPTIONAL_OFFSET( VCoverage );
372 OTV_OPTIONAL_OFFSET( HCoverage );
373 vcnt = FT_NEXT_USHORT( p );
374 hcnt = FT_NEXT_USHORT( p );
375
376 OTV_LIMIT_CHECK( 2 * vcnt + 2 * hcnt );
377 table_size = 10 + 2 * vcnt + 2 * hcnt;
378
379 OTV_SIZE_CHECK( VCoverage );
380 if ( VCoverage )
381 otv_Coverage_validate( table + VCoverage, otvalid, (FT_Int)vcnt );
382
383 OTV_SIZE_CHECK( HCoverage );
384 if ( HCoverage )
385 otv_Coverage_validate( table + HCoverage, otvalid, (FT_Int)hcnt );
386
387 for ( i = 0; i < vcnt; i++ )
388 {
389 OTV_OPTIONAL_OFFSET( Offset );
390 OTV_SIZE_CHECK( Offset );
391 otv_MathGlyphConstruction_validate( table + Offset, otvalid );
392 }
393
394 for ( i = 0; i < hcnt; i++ )
395 {
396 OTV_OPTIONAL_OFFSET( Offset );
397 OTV_SIZE_CHECK( Offset );
398 otv_MathGlyphConstruction_validate( table + Offset, otvalid );
399 }
400
401 OTV_EXIT;
402 }
403
404
405 /*************************************************************************/
406 /*************************************************************************/
407 /***** *****/
408 /***** MATH TABLE *****/
409 /***** *****/
410 /*************************************************************************/
411 /*************************************************************************/
412
413 /* sets otvalid->glyph_count */
414
415 FT_LOCAL_DEF( void )
416 otv_MATH_validate( FT_Bytes table,
417 FT_UInt glyph_count,
418 FT_Validator ftvalid )
419 {
420 OTV_ValidatorRec otvalidrec;
421 OTV_Validator otvalid = &otvalidrec;
422 FT_Bytes p = table;
423 FT_UInt MathConstants, MathGlyphInfo, MathVariants;
424
425
426 otvalid->root = ftvalid;
427
428 FT_TRACE3(( "validating MATH table\n" ));
429 OTV_INIT;
430
431 OTV_LIMIT_CHECK( 10 );
432
433 if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */
434 FT_INVALID_FORMAT;
435
436 MathConstants = FT_NEXT_USHORT( p );
437 MathGlyphInfo = FT_NEXT_USHORT( p );
438 MathVariants = FT_NEXT_USHORT( p );
439
440 otvalid->glyph_count = glyph_count;
441
442 otv_MathConstants_validate( table + MathConstants,
443 otvalid );
444 otv_MathGlyphInfo_validate( table + MathGlyphInfo,
445 otvalid );
446 otv_MathVariants_validate ( table + MathVariants,
447 otvalid );
448
449 FT_TRACE4(( "\n" ));
450 }
451
452
453 /* END */