1 /*
2  * Copyright © 2018 Adobe Inc.
3  *
4  *  This is part of HarfBuzz, a text shaping library.
5  *
6  * Permission is hereby granted, without written agreement and without
7  * license or royalty fees, to use, copy, modify, and distribute this
8  * software and its documentation for any purpose, provided that the
9  * above copyright notice and the following two paragraphs appear in
10  * all copies of this software.
11  *
12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16  * DAMAGE.
17  *
18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23  *
24  * Adobe Author(s): Michiharu Ariza
25  */
26 
27 #ifndef HB_OT_CFF2_TABLE_HH
28 #define HB_OT_CFF2_TABLE_HH
29 
30 #include "hb-ot-head-table.hh"
31 #include "hb-ot-cff-common.hh"
32 #include "hb-subset-cff2.hh"
33 
34 namespace CFF {
35 
36 /*
37  * CFF2 -- Compact Font Format (CFF) Version 2
38  * https://docs.microsoft.com/en-us/typography/opentype/spec/cff2
39  */
40 #define HB_OT_TAG_cff2 HB_TAG('C','F','F','2')
41 
42 typedef CFFIndex<HBUINT32>  CFF2Index;
43 template <typename Type> struct CFF2IndexOf : CFFIndexOf<HBUINT32, Type> {};
44 
45 typedef CFF2Index         CFF2CharStrings;
46 typedef FDArray<HBUINT32> CFF2FDArray;
47 typedef Subrs<HBUINT32>   CFF2Subrs;
48 
49 typedef FDSelect3_4<HBUINT32, HBUINT16> FDSelect4;
50 typedef FDSelect3_4_Range<HBUINT32, HBUINT16> FDSelect4_Range;
51 
52 struct CFF2FDSelect
53 {
serializeCFF::CFF2FDSelect54   bool serialize (hb_serialize_context_t *c, const CFF2FDSelect &src, unsigned int num_glyphs)
55   {
56     TRACE_SERIALIZE (this);
57     unsigned int size = src.get_size (num_glyphs);
58     CFF2FDSelect *dest = c->allocate_size<CFF2FDSelect> (size);
59     if (unlikely (dest == nullptr)) return_trace (false);
60     memcpy (dest, &src, size);
61     return_trace (true);
62   }
63 
calculate_serialized_sizeCFF::CFF2FDSelect64   unsigned int calculate_serialized_size (unsigned int num_glyphs) const
65   { return get_size (num_glyphs); }
66 
get_sizeCFF::CFF2FDSelect67   unsigned int get_size (unsigned int num_glyphs) const
68   {
69     switch (format)
70     {
71     case 0: return format.static_size + u.format0.get_size (num_glyphs);
72     case 3: return format.static_size + u.format3.get_size ();
73     case 4: return format.static_size + u.format4.get_size ();
74     default:return 0;
75     }
76   }
77 
get_fdCFF::CFF2FDSelect78   hb_codepoint_t get_fd (hb_codepoint_t glyph) const
79   {
80     if (this == &Null (CFF2FDSelect))
81       return 0;
82 
83     switch (format)
84     {
85     case 0: return u.format0.get_fd (glyph);
86     case 3: return u.format3.get_fd (glyph);
87     case 4: return u.format4.get_fd (glyph);
88     default:return 0;
89     }
90   }
91 
sanitizeCFF::CFF2FDSelect92   bool sanitize (hb_sanitize_context_t *c, unsigned int fdcount) const
93   {
94     TRACE_SANITIZE (this);
95     if (unlikely (!c->check_struct (this)))
96       return_trace (false);
97 
98     switch (format)
99     {
100     case 0: return_trace (u.format0.sanitize (c, fdcount));
101     case 3: return_trace (u.format3.sanitize (c, fdcount));
102     case 4: return_trace (u.format4.sanitize (c, fdcount));
103     default:return_trace (false);
104     }
105   }
106 
107   HBUINT8	format;
108   union {
109   FDSelect0	format0;
110   FDSelect3	format3;
111   FDSelect4	format4;
112   } u;
113   public:
114   DEFINE_SIZE_MIN (2);
115 };
116 
117 struct CFF2VariationStore
118 {
sanitizeCFF::CFF2VariationStore119   bool sanitize (hb_sanitize_context_t *c) const
120   {
121     TRACE_SANITIZE (this);
122     return_trace (likely (c->check_struct (this)) && c->check_range (&varStore, size) && varStore.sanitize (c));
123   }
124 
serializeCFF::CFF2VariationStore125   bool serialize (hb_serialize_context_t *c, const CFF2VariationStore *varStore)
126   {
127     TRACE_SERIALIZE (this);
128     unsigned int size_ = varStore->get_size ();
129     CFF2VariationStore *dest = c->allocate_size<CFF2VariationStore> (size_);
130     if (unlikely (dest == nullptr)) return_trace (false);
131     memcpy (dest, varStore, size_);
132     return_trace (true);
133   }
134 
get_sizeCFF::CFF2VariationStore135   unsigned int get_size () const { return HBUINT16::static_size + size; }
136 
137   HBUINT16	size;
138   VariationStore  varStore;
139 
140   DEFINE_SIZE_MIN (2 + VariationStore::min_size);
141 };
142 
143 struct cff2_top_dict_values_t : top_dict_values_t<>
144 {
initCFF::cff2_top_dict_values_t145   void init ()
146   {
147     top_dict_values_t<>::init ();
148     vstoreOffset = 0;
149     FDSelectOffset = 0;
150   }
finiCFF::cff2_top_dict_values_t151   void fini () { top_dict_values_t<>::fini (); }
152 
calculate_serialized_sizeCFF::cff2_top_dict_values_t153   unsigned int calculate_serialized_size () const
154   {
155     unsigned int size = 0;
156     for (unsigned int i = 0; i < get_count (); i++)
157     {
158       op_code_t op = get_value (i).op;
159       switch (op)
160       {
161 	case OpCode_vstore:
162 	case OpCode_FDSelect:
163 	  size += OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (op);
164 	  break;
165 	default:
166 	  size += top_dict_values_t<>::calculate_serialized_op_size (get_value (i));
167 	  break;
168       }
169     }
170     return size;
171   }
172 
173   unsigned int  vstoreOffset;
174   unsigned int  FDSelectOffset;
175 };
176 
177 struct cff2_top_dict_opset_t : top_dict_opset_t<>
178 {
process_opCFF::cff2_top_dict_opset_t179   static void process_op (op_code_t op, num_interp_env_t& env, cff2_top_dict_values_t& dictval)
180   {
181     switch (op) {
182       case OpCode_FontMatrix:
183 	{
184 	  dict_val_t val;
185 	  val.init ();
186 	  dictval.add_op (op, env.str_ref);
187 	  env.clear_args ();
188 	}
189 	break;
190 
191       case OpCode_vstore:
192 	dictval.vstoreOffset = env.argStack.pop_uint ();
193 	env.clear_args ();
194 	break;
195       case OpCode_FDSelect:
196 	dictval.FDSelectOffset = env.argStack.pop_uint ();
197 	env.clear_args ();
198 	break;
199 
200       default:
201 	SUPER::process_op (op, env, dictval);
202 	/* Record this operand below if stack is empty, otherwise done */
203 	if (!env.argStack.is_empty ()) return;
204     }
205 
206     if (unlikely (env.in_error ())) return;
207 
208     dictval.add_op (op, env.str_ref);
209   }
210 
211   typedef top_dict_opset_t<> SUPER;
212 };
213 
214 struct cff2_font_dict_values_t : dict_values_t<op_str_t>
215 {
initCFF::cff2_font_dict_values_t216   void init ()
217   {
218     dict_values_t<op_str_t>::init ();
219     privateDictInfo.init ();
220   }
finiCFF::cff2_font_dict_values_t221   void fini () { dict_values_t<op_str_t>::fini (); }
222 
223   table_info_t    privateDictInfo;
224 };
225 
226 struct cff2_font_dict_opset_t : dict_opset_t
227 {
process_opCFF::cff2_font_dict_opset_t228   static void process_op (op_code_t op, num_interp_env_t& env, cff2_font_dict_values_t& dictval)
229   {
230     switch (op) {
231       case OpCode_Private:
232 	dictval.privateDictInfo.offset = env.argStack.pop_uint ();
233 	dictval.privateDictInfo.size = env.argStack.pop_uint ();
234 	env.clear_args ();
235 	break;
236 
237       default:
238 	SUPER::process_op (op, env);
239 	if (!env.argStack.is_empty ())
240 	  return;
241     }
242 
243     if (unlikely (env.in_error ())) return;
244 
245     dictval.add_op (op, env.str_ref);
246   }
247 
248   private:
249   typedef dict_opset_t SUPER;
250 };
251 
252 template <typename VAL>
253 struct cff2_private_dict_values_base_t : dict_values_t<VAL>
254 {
initCFF::cff2_private_dict_values_base_t255   void init ()
256   {
257     dict_values_t<VAL>::init ();
258     subrsOffset = 0;
259     localSubrs = &Null(CFF2Subrs);
260     ivs = 0;
261   }
finiCFF::cff2_private_dict_values_base_t262   void fini () { dict_values_t<VAL>::fini (); }
263 
calculate_serialized_sizeCFF::cff2_private_dict_values_base_t264   unsigned int calculate_serialized_size () const
265   {
266     unsigned int size = 0;
267     for (unsigned int i = 0; i < dict_values_t<VAL>::get_count; i++)
268       if (dict_values_t<VAL>::get_value (i).op == OpCode_Subrs)
269 	size += OpCode_Size (OpCode_shortint) + 2 + OpCode_Size (OpCode_Subrs);
270       else
271 	size += dict_values_t<VAL>::get_value (i).str.length;
272     return size;
273   }
274 
275   unsigned int      subrsOffset;
276   const CFF2Subrs   *localSubrs;
277   unsigned int      ivs;
278 };
279 
280 typedef cff2_private_dict_values_base_t<op_str_t> cff2_private_dict_values_subset_t;
281 typedef cff2_private_dict_values_base_t<num_dict_val_t> cff2_private_dict_values_t;
282 
283 struct cff2_priv_dict_interp_env_t : num_interp_env_t
284 {
initCFF::cff2_priv_dict_interp_env_t285   void init (const byte_str_t &str)
286   {
287     num_interp_env_t::init (str);
288     ivs = 0;
289     seen_vsindex = false;
290   }
291 
process_vsindexCFF::cff2_priv_dict_interp_env_t292   void process_vsindex ()
293   {
294     if (likely (!seen_vsindex))
295     {
296       set_ivs (argStack.pop_uint ());
297     }
298     seen_vsindex = true;
299   }
300 
get_ivsCFF::cff2_priv_dict_interp_env_t301   unsigned int get_ivs () const { return ivs; }
set_ivsCFF::cff2_priv_dict_interp_env_t302   void	 set_ivs (unsigned int ivs_) { ivs = ivs_; }
303 
304   protected:
305   unsigned int  ivs;
306   bool	  seen_vsindex;
307 };
308 
309 struct cff2_private_dict_opset_t : dict_opset_t
310 {
process_opCFF::cff2_private_dict_opset_t311   static void process_op (op_code_t op, cff2_priv_dict_interp_env_t& env, cff2_private_dict_values_t& dictval)
312   {
313     num_dict_val_t val;
314     val.init ();
315 
316     switch (op) {
317       case OpCode_StdHW:
318       case OpCode_StdVW:
319       case OpCode_BlueScale:
320       case OpCode_BlueShift:
321       case OpCode_BlueFuzz:
322       case OpCode_ExpansionFactor:
323       case OpCode_LanguageGroup:
324 	val.single_val = env.argStack.pop_num ();
325 	env.clear_args ();
326 	break;
327       case OpCode_BlueValues:
328       case OpCode_OtherBlues:
329       case OpCode_FamilyBlues:
330       case OpCode_FamilyOtherBlues:
331       case OpCode_StemSnapH:
332       case OpCode_StemSnapV:
333 	env.clear_args ();
334 	break;
335       case OpCode_Subrs:
336 	dictval.subrsOffset = env.argStack.pop_uint ();
337 	env.clear_args ();
338 	break;
339       case OpCode_vsindexdict:
340 	env.process_vsindex ();
341 	dictval.ivs = env.get_ivs ();
342 	env.clear_args ();
343 	break;
344       case OpCode_blenddict:
345 	break;
346 
347       default:
348 	dict_opset_t::process_op (op, env);
349 	if (!env.argStack.is_empty ()) return;
350 	break;
351     }
352 
353     if (unlikely (env.in_error ())) return;
354 
355     dictval.add_op (op, env.str_ref, val);
356   }
357 };
358 
359 struct cff2_private_dict_opset_subset_t : dict_opset_t
360 {
process_opCFF::cff2_private_dict_opset_subset_t361   static void process_op (op_code_t op, cff2_priv_dict_interp_env_t& env, cff2_private_dict_values_subset_t& dictval)
362   {
363     switch (op) {
364       case OpCode_BlueValues:
365       case OpCode_OtherBlues:
366       case OpCode_FamilyBlues:
367       case OpCode_FamilyOtherBlues:
368       case OpCode_StdHW:
369       case OpCode_StdVW:
370       case OpCode_BlueScale:
371       case OpCode_BlueShift:
372       case OpCode_BlueFuzz:
373       case OpCode_StemSnapH:
374       case OpCode_StemSnapV:
375       case OpCode_LanguageGroup:
376       case OpCode_ExpansionFactor:
377 	env.clear_args ();
378 	break;
379 
380       case OpCode_blenddict:
381 	env.clear_args ();
382 	return;
383 
384       case OpCode_Subrs:
385 	dictval.subrsOffset = env.argStack.pop_uint ();
386 	env.clear_args ();
387 	break;
388 
389       default:
390 	SUPER::process_op (op, env);
391 	if (!env.argStack.is_empty ()) return;
392 	break;
393     }
394 
395     if (unlikely (env.in_error ())) return;
396 
397     dictval.add_op (op, env.str_ref);
398   }
399 
400   private:
401   typedef dict_opset_t SUPER;
402 };
403 
404 typedef dict_interpreter_t<cff2_top_dict_opset_t, cff2_top_dict_values_t> cff2_top_dict_interpreter_t;
405 typedef dict_interpreter_t<cff2_font_dict_opset_t, cff2_font_dict_values_t> cff2_font_dict_interpreter_t;
406 
407 } /* namespace CFF */
408 
409 namespace OT {
410 
411 using namespace CFF;
412 
413 struct cff2
414 {
415   static constexpr hb_tag_t tableTag = HB_OT_TAG_cff2;
416 
sanitizeOT::cff2417   bool sanitize (hb_sanitize_context_t *c) const
418   {
419     TRACE_SANITIZE (this);
420     return_trace (c->check_struct (this) &&
421 		  likely (version.major == 2));
422   }
423 
424   template <typename PRIVOPSET, typename PRIVDICTVAL>
425   struct accelerator_templ_t
426   {
initOT::cff2::accelerator_templ_t427     void init (hb_face_t *face)
428     {
429       topDict.init ();
430       fontDicts.init ();
431       privateDicts.init ();
432 
433       this->blob = sc.reference_table<cff2> (face);
434 
435       /* setup for run-time santization */
436       sc.init (this->blob);
437       sc.start_processing ();
438 
439       const OT::cff2 *cff2 = this->blob->template as<OT::cff2> ();
440 
441       if (cff2 == &Null(OT::cff2))
442       { fini (); return; }
443 
444       { /* parse top dict */
445 	byte_str_t topDictStr (cff2 + cff2->topDict, cff2->topDictSize);
446 	if (unlikely (!topDictStr.sanitize (&sc))) { fini (); return; }
447 	cff2_top_dict_interpreter_t top_interp;
448 	top_interp.env.init (topDictStr);
449 	topDict.init ();
450 	if (unlikely (!top_interp.interpret (topDict))) { fini (); return; }
451       }
452 
453       globalSubrs = &StructAtOffset<CFF2Subrs> (cff2, cff2->topDict + cff2->topDictSize);
454       varStore = &StructAtOffsetOrNull<CFF2VariationStore> (cff2, topDict.vstoreOffset);
455       charStrings = &StructAtOffsetOrNull<CFF2CharStrings> (cff2, topDict.charStringsOffset);
456       fdArray = &StructAtOffsetOrNull<CFF2FDArray> (cff2, topDict.FDArrayOffset);
457       fdSelect = &StructAtOffsetOrNull<CFF2FDSelect> (cff2, topDict.FDSelectOffset);
458 
459       if (((varStore != &Null(CFF2VariationStore)) && unlikely (!varStore->sanitize (&sc))) ||
460 	  (charStrings == &Null(CFF2CharStrings)) || unlikely (!charStrings->sanitize (&sc)) ||
461 	  (globalSubrs == &Null(CFF2Subrs)) || unlikely (!globalSubrs->sanitize (&sc)) ||
462 	  (fdArray == &Null(CFF2FDArray)) || unlikely (!fdArray->sanitize (&sc)) ||
463 	  (((fdSelect != &Null(CFF2FDSelect)) && unlikely (!fdSelect->sanitize (&sc, fdArray->count)))))
464       { fini (); return; }
465 
466       num_glyphs = charStrings->count;
467       if (num_glyphs != sc.get_num_glyphs ())
468       { fini (); return; }
469 
470       fdCount = fdArray->count;
471       privateDicts.resize (fdCount);
472 
473       /* parse font dicts and gather private dicts */
474       for (unsigned int i = 0; i < fdCount; i++)
475       {
476 	const byte_str_t fontDictStr = (*fdArray)[i];
477 	if (unlikely (!fontDictStr.sanitize (&sc))) { fini (); return; }
478 	cff2_font_dict_values_t  *font;
479 	cff2_font_dict_interpreter_t font_interp;
480 	font_interp.env.init (fontDictStr);
481 	font = fontDicts.push ();
482 	if (unlikely (font == &Crap(cff2_font_dict_values_t))) { fini (); return; }
483 	font->init ();
484 	if (unlikely (!font_interp.interpret (*font))) { fini (); return; }
485 
486 	const byte_str_t privDictStr (StructAtOffsetOrNull<UnsizedByteStr> (cff2, font->privateDictInfo.offset), font->privateDictInfo.size);
487 	if (unlikely (!privDictStr.sanitize (&sc))) { fini (); return; }
488 	dict_interpreter_t<PRIVOPSET, PRIVDICTVAL, cff2_priv_dict_interp_env_t>  priv_interp;
489 	priv_interp.env.init(privDictStr);
490 	privateDicts[i].init ();
491 	if (unlikely (!priv_interp.interpret (privateDicts[i]))) { fini (); return; }
492 
493 	privateDicts[i].localSubrs = &StructAtOffsetOrNull<CFF2Subrs> (&privDictStr[0], privateDicts[i].subrsOffset);
494 	if (privateDicts[i].localSubrs != &Null(CFF2Subrs) &&
495 	  unlikely (!privateDicts[i].localSubrs->sanitize (&sc)))
496 	{ fini (); return; }
497       }
498     }
499 
finiOT::cff2::accelerator_templ_t500     void fini ()
501     {
502       sc.end_processing ();
503       topDict.fini ();
504       fontDicts.fini_deep ();
505       privateDicts.fini_deep ();
506       hb_blob_destroy (blob);
507       blob = nullptr;
508     }
509 
is_validOT::cff2::accelerator_templ_t510     bool is_valid () const { return blob != nullptr; }
511 
512     protected:
513     hb_blob_t			*blob;
514     hb_sanitize_context_t	sc;
515 
516     public:
517     cff2_top_dict_values_t	topDict;
518     const CFF2Subrs		*globalSubrs;
519     const CFF2VariationStore	*varStore;
520     const CFF2CharStrings	*charStrings;
521     const CFF2FDArray		*fdArray;
522     const CFF2FDSelect		*fdSelect;
523     unsigned int		fdCount;
524 
525     hb_vector_t<cff2_font_dict_values_t>     fontDicts;
526     hb_vector_t<PRIVDICTVAL>  privateDicts;
527 
528     unsigned int	      num_glyphs;
529   };
530 
531   struct accelerator_t : accelerator_templ_t<cff2_private_dict_opset_t, cff2_private_dict_values_t>
532   {
533     HB_INTERNAL bool get_extents (hb_font_t *font,
534 				  hb_codepoint_t glyph,
535 				  hb_glyph_extents_t *extents) const;
536   };
537 
538   typedef accelerator_templ_t<cff2_private_dict_opset_subset_t, cff2_private_dict_values_subset_t> accelerator_subset_t;
539 
subsetOT::cff2540   bool subset (hb_subset_plan_t *plan) const
541   {
542     hb_blob_t *cff2_prime = nullptr;
543 
544     bool success = true;
545     if (hb_subset_cff2 (plan, &cff2_prime)) {
546       success = success && plan->add_table (HB_OT_TAG_cff2, cff2_prime);
547       hb_blob_t *head_blob = hb_sanitize_context_t().reference_table<head> (plan->source);
548       success = success && head_blob && plan->add_table (HB_OT_TAG_head, head_blob);
549       hb_blob_destroy (head_blob);
550     } else {
551       success = false;
552     }
553     hb_blob_destroy (cff2_prime);
554 
555     return success;
556   }
557 
558   public:
559   FixedVersion<HBUINT8>		version;	/* Version of CFF2 table. set to 0x0200u */
560   NNOffsetTo<TopDict, HBUINT8>	topDict;	/* headerSize = Offset to Top DICT. */
561   HBUINT16			topDictSize;	/* Top DICT size */
562 
563   public:
564   DEFINE_SIZE_STATIC (5);
565 };
566 
567 struct cff2_accelerator_t : cff2::accelerator_t {};
568 } /* namespace OT */
569 
570 #endif /* HB_OT_CFF2_TABLE_HH */
571