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1 /***************************************************************************/ | |
2 /* */ | |
3 /* t1parse.c */ | |
4 /* */ | |
5 /* Type 1 parser (body). */ | |
6 /* */ | |
7 /* Copyright 1996-2005, 2008, 2009, 2012, 2013 by */ | |
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ | |
9 /* */ | |
10 /* This file is part of the FreeType project, and may only be used, */ | |
11 /* modified, and distributed under the terms of the FreeType project */ | |
12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ | |
13 /* this file you indicate that you have read the license and */ | |
14 /* understand and accept it fully. */ | |
15 /* */ | |
16 /***************************************************************************/ | |
17 | |
18 | |
19 /*************************************************************************/ | |
20 /* */ | |
21 /* The Type 1 parser is in charge of the following: */ | |
22 /* */ | |
23 /* - provide an implementation of a growing sequence of objects called */ | |
24 /* a `T1_Table' (used to build various tables needed by the loader). */ | |
25 /* */ | |
26 /* - opening .pfb and .pfa files to extract their top-level and private */ | |
27 /* dictionaries. */ | |
28 /* */ | |
29 /* - read numbers, arrays & strings from any dictionary. */ | |
30 /* */ | |
31 /* See `t1load.c' to see how data is loaded from the font file. */ | |
32 /* */ | |
33 /*************************************************************************/ | |
34 | |
35 | |
36 #include "../../include/ft2build.h" | |
37 #include "../../include/freetype/internal/ftdebug.h" | |
38 #include "../../include/freetype/internal/ftstream.h" | |
39 #include "../../include/freetype/internal/psaux.h" | |
40 | |
41 #include "t1parse.h" | |
42 | |
43 #include "t1errors.h" | |
44 | |
45 | |
46 /*************************************************************************/ | |
47 /* */ | |
48 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ | |
49 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ | |
50 /* messages during execution. */ | |
51 /* */ | |
52 #undef FT_COMPONENT | |
53 #define FT_COMPONENT trace_t1parse | |
54 | |
55 | |
56 /*************************************************************************/ | |
57 /*************************************************************************/ | |
58 /*************************************************************************/ | |
59 /***** *****/ | |
60 /***** INPUT STREAM PARSER *****/ | |
61 /***** *****/ | |
62 /*************************************************************************/ | |
63 /*************************************************************************/ | |
64 /*************************************************************************/ | |
65 | |
66 | |
67 /* see Adobe Technical Note 5040.Download_Fonts.pdf */ | |
68 | |
69 static FT_Error | |
70 read_pfb_tag( FT_Stream stream, | |
71 FT_UShort *atag, | |
72 FT_ULong *asize ) | |
73 { | |
74 FT_Error error; | |
75 FT_UShort tag; | |
76 FT_ULong size; | |
77 | |
78 | |
79 *atag = 0; | |
80 *asize = 0; | |
81 | |
82 if ( !FT_READ_USHORT( tag ) ) | |
83 { | |
84 if ( tag == 0x8001U || tag == 0x8002U ) | |
85 { | |
86 if ( !FT_READ_ULONG_LE( size ) ) | |
87 *asize = size; | |
88 } | |
89 | |
90 *atag = tag; | |
91 } | |
92 | |
93 return error; | |
94 } | |
95 | |
96 | |
97 static FT_Error | |
98 check_type1_format( FT_Stream stream, | |
99 const char* header_string, | |
100 size_t header_length ) | |
101 { | |
102 FT_Error error; | |
103 FT_UShort tag; | |
104 FT_ULong dummy; | |
105 | |
106 | |
107 if ( FT_STREAM_SEEK( 0 ) ) | |
108 goto Exit; | |
109 | |
110 error = read_pfb_tag( stream, &tag, &dummy ); | |
111 if ( error ) | |
112 goto Exit; | |
113 | |
114 /* We assume that the first segment in a PFB is always encoded as */ | |
115 /* text. This might be wrong (and the specification doesn't insist */ | |
116 /* on that), but we have never seen a counterexample. */ | |
117 if ( tag != 0x8001U && FT_STREAM_SEEK( 0 ) ) | |
118 goto Exit; | |
119 | |
120 if ( !FT_FRAME_ENTER( header_length ) ) | |
121 { | |
122 error = FT_Err_Ok; | |
123 | |
124 if ( ft_memcmp( stream->cursor, header_string, header_length ) != 0 ) | |
125 error = FT_THROW( Unknown_File_Format ); | |
126 | |
127 FT_FRAME_EXIT(); | |
128 } | |
129 | |
130 Exit: | |
131 return error; | |
132 } | |
133 | |
134 | |
135 FT_LOCAL_DEF( FT_Error ) | |
136 T1_New_Parser( T1_Parser parser, | |
137 FT_Stream stream, | |
138 FT_Memory memory, | |
139 PSAux_Service psaux ) | |
140 { | |
141 FT_Error error; | |
142 FT_UShort tag; | |
143 FT_ULong size; | |
144 | |
145 | |
146 psaux->ps_parser_funcs->init( &parser->root, 0, 0, memory ); | |
147 | |
148 parser->stream = stream; | |
149 parser->base_len = 0; | |
150 parser->base_dict = 0; | |
151 parser->private_len = 0; | |
152 parser->private_dict = 0; | |
153 parser->in_pfb = 0; | |
154 parser->in_memory = 0; | |
155 parser->single_block = 0; | |
156 | |
157 /* check the header format */ | |
158 error = check_type1_format( stream, "%!PS-AdobeFont", 14 ); | |
159 if ( error ) | |
160 { | |
161 if ( FT_ERR_NEQ( error, Unknown_File_Format ) ) | |
162 goto Exit; | |
163 | |
164 error = check_type1_format( stream, "%!FontType", 10 ); | |
165 if ( error ) | |
166 { | |
167 FT_TRACE2(( " not a Type 1 font\n" )); | |
168 goto Exit; | |
169 } | |
170 } | |
171 | |
172 /******************************************************************/ | |
173 /* */ | |
174 /* Here a short summary of what is going on: */ | |
175 /* */ | |
176 /* When creating a new Type 1 parser, we try to locate and load */ | |
177 /* the base dictionary if this is possible (i.e., for PFB */ | |
178 /* files). Otherwise, we load the whole font into memory. */ | |
179 /* */ | |
180 /* When `loading' the base dictionary, we only setup pointers */ | |
181 /* in the case of a memory-based stream. Otherwise, we */ | |
182 /* allocate and load the base dictionary in it. */ | |
183 /* */ | |
184 /* parser->in_pfb is set if we are in a binary (`.pfb') font. */ | |
185 /* parser->in_memory is set if we have a memory stream. */ | |
186 /* */ | |
187 | |
188 /* try to compute the size of the base dictionary; */ | |
189 /* look for a Postscript binary file tag, i.e., 0x8001 */ | |
190 if ( FT_STREAM_SEEK( 0L ) ) | |
191 goto Exit; | |
192 | |
193 error = read_pfb_tag( stream, &tag, &size ); | |
194 if ( error ) | |
195 goto Exit; | |
196 | |
197 if ( tag != 0x8001U ) | |
198 { | |
199 /* assume that this is a PFA file for now; an error will */ | |
200 /* be produced later when more things are checked */ | |
201 if ( FT_STREAM_SEEK( 0L ) ) | |
202 goto Exit; | |
203 size = stream->size; | |
204 } | |
205 else | |
206 parser->in_pfb = 1; | |
207 | |
208 /* now, try to load `size' bytes of the `base' dictionary we */ | |
209 /* found previously */ | |
210 | |
211 /* if it is a memory-based resource, set up pointers */ | |
212 if ( !stream->read ) | |
213 { | |
214 parser->base_dict = (FT_Byte*)stream->base + stream->pos; | |
215 parser->base_len = size; | |
216 parser->in_memory = 1; | |
217 | |
218 /* check that the `size' field is valid */ | |
219 if ( FT_STREAM_SKIP( size ) ) | |
220 goto Exit; | |
221 } | |
222 else | |
223 { | |
224 /* read segment in memory -- this is clumsy, but so does the format */ | |
225 if ( FT_ALLOC( parser->base_dict, size ) || | |
226 FT_STREAM_READ( parser->base_dict, size ) ) | |
227 goto Exit; | |
228 parser->base_len = size; | |
229 } | |
230 | |
231 parser->root.base = parser->base_dict; | |
232 parser->root.cursor = parser->base_dict; | |
233 parser->root.limit = parser->root.cursor + parser->base_len; | |
234 | |
235 Exit: | |
236 if ( error && !parser->in_memory ) | |
237 FT_FREE( parser->base_dict ); | |
238 | |
239 return error; | |
240 } | |
241 | |
242 | |
243 FT_LOCAL_DEF( void ) | |
244 T1_Finalize_Parser( T1_Parser parser ) | |
245 { | |
246 FT_Memory memory = parser->root.memory; | |
247 | |
248 | |
249 /* always free the private dictionary */ | |
250 FT_FREE( parser->private_dict ); | |
251 | |
252 /* free the base dictionary only when we have a disk stream */ | |
253 if ( !parser->in_memory ) | |
254 FT_FREE( parser->base_dict ); | |
255 | |
256 parser->root.funcs.done( &parser->root ); | |
257 } | |
258 | |
259 | |
260 FT_LOCAL_DEF( FT_Error ) | |
261 T1_Get_Private_Dict( T1_Parser parser, | |
262 PSAux_Service psaux ) | |
263 { | |
264 FT_Stream stream = parser->stream; | |
265 FT_Memory memory = parser->root.memory; | |
266 FT_Error error = FT_Err_Ok; | |
267 FT_ULong size; | |
268 | |
269 | |
270 if ( parser->in_pfb ) | |
271 { | |
272 /* in the case of the PFB format, the private dictionary can be */ | |
273 /* made of several segments. We thus first read the number of */ | |
274 /* segments to compute the total size of the private dictionary */ | |
275 /* then re-read them into memory. */ | |
276 FT_Long start_pos = FT_STREAM_POS(); | |
277 FT_UShort tag; | |
278 | |
279 | |
280 parser->private_len = 0; | |
281 for (;;) | |
282 { | |
283 error = read_pfb_tag( stream, &tag, &size ); | |
284 if ( error ) | |
285 goto Fail; | |
286 | |
287 if ( tag != 0x8002U ) | |
288 break; | |
289 | |
290 parser->private_len += size; | |
291 | |
292 if ( FT_STREAM_SKIP( size ) ) | |
293 goto Fail; | |
294 } | |
295 | |
296 /* Check that we have a private dictionary there */ | |
297 /* and allocate private dictionary buffer */ | |
298 if ( parser->private_len == 0 ) | |
299 { | |
300 FT_ERROR(( "T1_Get_Private_Dict:" | |
301 " invalid private dictionary section\n" )); | |
302 error = FT_THROW( Invalid_File_Format ); | |
303 goto Fail; | |
304 } | |
305 | |
306 if ( FT_STREAM_SEEK( start_pos ) || | |
307 FT_ALLOC( parser->private_dict, parser->private_len ) ) | |
308 goto Fail; | |
309 | |
310 parser->private_len = 0; | |
311 for (;;) | |
312 { | |
313 error = read_pfb_tag( stream, &tag, &size ); | |
314 if ( error || tag != 0x8002U ) | |
315 { | |
316 error = FT_Err_Ok; | |
317 break; | |
318 } | |
319 | |
320 if ( FT_STREAM_READ( parser->private_dict + parser->private_len, | |
321 size ) ) | |
322 goto Fail; | |
323 | |
324 parser->private_len += size; | |
325 } | |
326 } | |
327 else | |
328 { | |
329 /* We have already `loaded' the whole PFA font file into memory; */ | |
330 /* if this is a memory resource, allocate a new block to hold */ | |
331 /* the private dict. Otherwise, simply overwrite into the base */ | |
332 /* dictionary block in the heap. */ | |
333 | |
334 /* first of all, look at the `eexec' keyword */ | |
335 FT_Byte* cur = parser->base_dict; | |
336 FT_Byte* limit = cur + parser->base_len; | |
337 FT_Byte c; | |
338 | |
339 | |
340 Again: | |
341 for (;;) | |
342 { | |
343 c = cur[0]; | |
344 if ( c == 'e' && cur + 9 < limit ) /* 9 = 5 letters for `eexec' + */ | |
345 /* whitespace + 4 chars */ | |
346 { | |
347 if ( cur[1] == 'e' && | |
348 cur[2] == 'x' && | |
349 cur[3] == 'e' && | |
350 cur[4] == 'c' ) | |
351 break; | |
352 } | |
353 cur++; | |
354 if ( cur >= limit ) | |
355 { | |
356 FT_ERROR(( "T1_Get_Private_Dict:" | |
357 " could not find `eexec' keyword\n" )); | |
358 error = FT_THROW( Invalid_File_Format ); | |
359 goto Exit; | |
360 } | |
361 } | |
362 | |
363 /* check whether `eexec' was real -- it could be in a comment */ | |
364 /* or string (as e.g. in u003043t.gsf from ghostscript) */ | |
365 | |
366 parser->root.cursor = parser->base_dict; | |
367 /* set limit to `eexec' + whitespace + 4 characters */ | |
368 parser->root.limit = cur + 10; | |
369 | |
370 cur = parser->root.cursor; | |
371 limit = parser->root.limit; | |
372 | |
373 while ( cur < limit ) | |
374 { | |
375 if ( *cur == 'e' && ft_strncmp( (char*)cur, "eexec", 5 ) == 0 ) | |
376 goto Found; | |
377 | |
378 T1_Skip_PS_Token( parser ); | |
379 if ( parser->root.error ) | |
380 break; | |
381 T1_Skip_Spaces ( parser ); | |
382 cur = parser->root.cursor; | |
383 } | |
384 | |
385 /* we haven't found the correct `eexec'; go back and continue */ | |
386 /* searching */ | |
387 | |
388 cur = limit; | |
389 limit = parser->base_dict + parser->base_len; | |
390 goto Again; | |
391 | |
392 /* now determine where to write the _encrypted_ binary private */ | |
393 /* dictionary. We overwrite the base dictionary for disk-based */ | |
394 /* resources and allocate a new block otherwise */ | |
395 | |
396 Found: | |
397 parser->root.limit = parser->base_dict + parser->base_len; | |
398 | |
399 T1_Skip_PS_Token( parser ); | |
400 cur = parser->root.cursor; | |
401 limit = parser->root.limit; | |
402 | |
403 /* according to the Type1 spec, the first cipher byte must not be */ | |
404 /* an ASCII whitespace character code (blank, tab, carriage return */ | |
405 /* or line feed). We have seen Type 1 fonts with two line feed */ | |
406 /* characters... So skip now all whitespace character codes. */ | |
407 while ( cur < limit && | |
408 ( *cur == ' ' || | |
409 *cur == '\t' || | |
410 *cur == '\r' || | |
411 *cur == '\n' ) ) | |
412 ++cur; | |
413 if ( cur >= limit ) | |
414 { | |
415 FT_ERROR(( "T1_Get_Private_Dict:" | |
416 " `eexec' not properly terminated\n" )); | |
417 error = FT_THROW( Invalid_File_Format ); | |
418 goto Exit; | |
419 } | |
420 | |
421 size = (FT_ULong)( parser->base_len - ( cur - parser->base_dict ) ); | |
422 | |
423 if ( parser->in_memory ) | |
424 { | |
425 /* note that we allocate one more byte to put a terminating `0' */ | |
426 if ( FT_ALLOC( parser->private_dict, size + 1 ) ) | |
427 goto Fail; | |
428 parser->private_len = size; | |
429 } | |
430 else | |
431 { | |
432 parser->single_block = 1; | |
433 parser->private_dict = parser->base_dict; | |
434 parser->private_len = size; | |
435 parser->base_dict = 0; | |
436 parser->base_len = 0; | |
437 } | |
438 | |
439 /* now determine whether the private dictionary is encoded in binary */ | |
440 /* or hexadecimal ASCII format -- decode it accordingly */ | |
441 | |
442 /* we need to access the next 4 bytes (after the final whitespace */ | |
443 /* following the `eexec' keyword); if they all are hexadecimal */ | |
444 /* digits, then we have a case of ASCII storage */ | |
445 | |
446 if ( cur + 3 < limit && | |
447 ft_isxdigit( cur[0] ) && ft_isxdigit( cur[1] ) && | |
448 ft_isxdigit( cur[2] ) && ft_isxdigit( cur[3] ) ) | |
449 { | |
450 /* ASCII hexadecimal encoding */ | |
451 FT_Long len; | |
452 | |
453 | |
454 parser->root.cursor = cur; | |
455 (void)psaux->ps_parser_funcs->to_bytes( &parser->root, | |
456 parser->private_dict, | |
457 parser->private_len, | |
458 &len, | |
459 0 ); | |
460 parser->private_len = len; | |
461 | |
462 /* put a safeguard */ | |
463 parser->private_dict[len] = '\0'; | |
464 } | |
465 else | |
466 /* binary encoding -- copy the private dict */ | |
467 FT_MEM_MOVE( parser->private_dict, cur, size ); | |
468 } | |
469 | |
470 /* we now decrypt the encoded binary private dictionary */ | |
471 psaux->t1_decrypt( parser->private_dict, parser->private_len, 55665U ); | |
472 | |
473 if ( parser->private_len < 4 ) | |
474 { | |
475 FT_ERROR(( "T1_Get_Private_Dict:" | |
476 " invalid private dictionary section\n" )); | |
477 error = FT_THROW( Invalid_File_Format ); | |
478 goto Fail; | |
479 } | |
480 | |
481 /* replace the four random bytes at the beginning with whitespace */ | |
482 parser->private_dict[0] = ' '; | |
483 parser->private_dict[1] = ' '; | |
484 parser->private_dict[2] = ' '; | |
485 parser->private_dict[3] = ' '; | |
486 | |
487 parser->root.base = parser->private_dict; | |
488 parser->root.cursor = parser->private_dict; | |
489 parser->root.limit = parser->root.cursor + parser->private_len; | |
490 | |
491 Fail: | |
492 Exit: | |
493 return error; | |
494 } | |
495 | |
496 | |
497 /* END */ | |
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