1 /***************************************************************************/
5 /* Type 1 parser (body). */
7 /* Copyright 1996-2018 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
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. */
16 /***************************************************************************/
19 /*************************************************************************/
21 /* The Type 1 parser is in charge of the following: */
23 /* - provide an implementation of a growing sequence of objects called */
24 /* a `T1_Table' (used to build various tables needed by the loader). */
26 /* - opening .pfb and .pfa files to extract their top-level and private */
29 /* - read numbers, arrays & strings from any dictionary. */
31 /* See `t1load.c' to see how data is loaded from the font file. */
33 /*************************************************************************/
37 #include FT_INTERNAL_DEBUG_H
38 #include FT_INTERNAL_STREAM_H
39 #include FT_INTERNAL_POSTSCRIPT_AUX_H
46 /*************************************************************************/
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. */
53 #define FT_COMPONENT trace_t1parse
56 /*************************************************************************/
57 /*************************************************************************/
58 /*************************************************************************/
60 /***** INPUT STREAM PARSER *****/
62 /*************************************************************************/
63 /*************************************************************************/
64 /*************************************************************************/
67 /* see Adobe Technical Note 5040.Download_Fonts.pdf */
70 read_pfb_tag( FT_Stream stream
,
82 if ( !FT_READ_USHORT( tag
) )
84 if ( tag
== 0x8001U
|| tag
== 0x8002U
)
86 if ( !FT_READ_ULONG_LE( size
) )
98 check_type1_format( FT_Stream stream
,
99 const char* header_string
,
100 size_t header_length
)
107 if ( FT_STREAM_SEEK( 0 ) )
110 error
= read_pfb_tag( stream
, &tag
, &dummy
);
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 ) )
120 if ( !FT_FRAME_ENTER( header_length
) )
124 if ( ft_memcmp( stream
->cursor
, header_string
, header_length
) != 0 )
125 error
= FT_THROW( Unknown_File_Format
);
135 FT_LOCAL_DEF( FT_Error
)
136 T1_New_Parser( T1_Parser parser
,
139 PSAux_Service psaux
)
146 psaux
->ps_parser_funcs
->init( &parser
->root
, NULL
, NULL
, memory
);
148 parser
->stream
= stream
;
149 parser
->base_len
= 0;
150 parser
->base_dict
= NULL
;
151 parser
->private_len
= 0;
152 parser
->private_dict
= NULL
;
154 parser
->in_memory
= 0;
155 parser
->single_block
= 0;
157 /* check the header format */
158 error
= check_type1_format( stream
, "%!PS-AdobeFont", 14 );
161 if ( FT_ERR_NEQ( error
, Unknown_File_Format
) )
164 error
= check_type1_format( stream
, "%!FontType", 10 );
167 FT_TRACE2(( " not a Type 1 font\n" ));
172 /******************************************************************/
174 /* Here a short summary of what is going on: */
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. */
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. */
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. */
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 ) )
193 error
= read_pfb_tag( stream
, &tag
, &size
);
197 if ( tag
!= 0x8001U
)
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 ) )
208 /* now, try to load `size' bytes of the `base' dictionary we */
209 /* found previously */
211 /* if it is a memory-based resource, set up pointers */
214 parser
->base_dict
= (FT_Byte
*)stream
->base
+ stream
->pos
;
215 parser
->base_len
= size
;
216 parser
->in_memory
= 1;
218 /* check that the `size' field is valid */
219 if ( FT_STREAM_SKIP( size
) )
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
) )
228 parser
->base_len
= size
;
231 parser
->root
.base
= parser
->base_dict
;
232 parser
->root
.cursor
= parser
->base_dict
;
233 parser
->root
.limit
= parser
->root
.cursor
+ parser
->base_len
;
236 if ( error
&& !parser
->in_memory
)
237 FT_FREE( parser
->base_dict
);
244 T1_Finalize_Parser( T1_Parser parser
)
246 FT_Memory memory
= parser
->root
.memory
;
249 /* always free the private dictionary */
250 FT_FREE( parser
->private_dict
);
252 /* free the base dictionary only when we have a disk stream */
253 if ( !parser
->in_memory
)
254 FT_FREE( parser
->base_dict
);
256 parser
->root
.funcs
.done( &parser
->root
);
260 FT_LOCAL_DEF( FT_Error
)
261 T1_Get_Private_Dict( T1_Parser parser
,
262 PSAux_Service psaux
)
264 FT_Stream stream
= parser
->stream
;
265 FT_Memory memory
= parser
->root
.memory
;
266 FT_Error error
= FT_Err_Ok
;
270 if ( parser
->in_pfb
)
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_ULong start_pos
= FT_STREAM_POS();
280 parser
->private_len
= 0;
283 error
= read_pfb_tag( stream
, &tag
, &size
);
287 if ( tag
!= 0x8002U
)
290 parser
->private_len
+= size
;
292 if ( FT_STREAM_SKIP( size
) )
296 /* Check that we have a private dictionary there */
297 /* and allocate private dictionary buffer */
298 if ( parser
->private_len
== 0 )
300 FT_ERROR(( "T1_Get_Private_Dict:"
301 " invalid private dictionary section\n" ));
302 error
= FT_THROW( Invalid_File_Format
);
306 if ( FT_STREAM_SEEK( start_pos
) ||
307 FT_ALLOC( parser
->private_dict
, parser
->private_len
) )
310 parser
->private_len
= 0;
313 error
= read_pfb_tag( stream
, &tag
, &size
);
314 if ( error
|| tag
!= 0x8002U
)
320 if ( FT_STREAM_READ( parser
->private_dict
+ parser
->private_len
,
324 parser
->private_len
+= size
;
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. */
334 /* first of all, look at the `eexec' keyword */
335 FT_Byte
* cur
= parser
->base_dict
;
336 FT_Byte
* limit
= cur
+ parser
->base_len
;
344 if ( cur
[0] == 'e' &&
345 cur
+ 9 < limit
) /* 9 = 5 letters for `eexec' + */
346 /* whitespace + 4 chars */
348 if ( cur
[1] == 'e' &&
357 FT_ERROR(( "T1_Get_Private_Dict:"
358 " could not find `eexec' keyword\n" ));
359 error
= FT_THROW( Invalid_File_Format
);
364 /* check whether `eexec' was real -- it could be in a comment */
365 /* or string (as e.g. in u003043t.gsf from ghostscript) */
367 parser
->root
.cursor
= parser
->base_dict
;
368 /* set limit to `eexec' + whitespace + 4 characters */
369 parser
->root
.limit
= cur
+ 10;
371 cur
= parser
->root
.cursor
;
372 limit
= parser
->root
.limit
;
374 while ( cur
< limit
)
376 if ( cur
[0] == 'e' &&
379 if ( cur
[1] == 'e' &&
386 T1_Skip_PS_Token( parser
);
387 if ( parser
->root
.error
)
389 T1_Skip_Spaces ( parser
);
390 cur
= parser
->root
.cursor
;
393 /* we haven't found the correct `eexec'; go back and continue */
397 limit
= parser
->base_dict
+ parser
->base_len
;
401 FT_ERROR(( "T1_Get_Private_Dict:"
402 " premature end in private dictionary\n" ));
403 error
= FT_THROW( Invalid_File_Format
);
409 /* now determine where to write the _encrypted_ binary private */
410 /* dictionary. We overwrite the base dictionary for disk-based */
411 /* resources and allocate a new block otherwise */
414 parser
->root
.limit
= parser
->base_dict
+ parser
->base_len
;
416 T1_Skip_PS_Token( parser
);
417 cur
= parser
->root
.cursor
;
418 limit
= parser
->root
.limit
;
420 /* According to the Type 1 spec, the first cipher byte must not be */
421 /* an ASCII whitespace character code (blank, tab, carriage return */
422 /* or line feed). We have seen Type 1 fonts with two line feed */
423 /* characters... So skip now all whitespace character codes. */
425 /* On the other hand, Adobe's Type 1 parser handles fonts just */
426 /* fine that are violating this limitation, so we add a heuristic */
427 /* test to stop at \r only if it is not used for EOL. */
429 pos_lf
= ft_memchr( cur
, '\n', (size_t)( limit
- cur
) );
430 test_cr
= FT_BOOL( !pos_lf
||
431 pos_lf
> ft_memchr( cur
,
433 (size_t)( limit
- cur
) ) );
435 while ( cur
< limit
&&
438 (test_cr
&& *cur
== '\r' ) ||
443 FT_ERROR(( "T1_Get_Private_Dict:"
444 " `eexec' not properly terminated\n" ));
445 error
= FT_THROW( Invalid_File_Format
);
449 size
= parser
->base_len
- (FT_ULong
)( cur
- parser
->base_dict
);
451 if ( parser
->in_memory
)
453 /* note that we allocate one more byte to put a terminating `0' */
454 if ( FT_ALLOC( parser
->private_dict
, size
+ 1 ) )
456 parser
->private_len
= size
;
460 parser
->single_block
= 1;
461 parser
->private_dict
= parser
->base_dict
;
462 parser
->private_len
= size
;
463 parser
->base_dict
= NULL
;
464 parser
->base_len
= 0;
467 /* now determine whether the private dictionary is encoded in binary */
468 /* or hexadecimal ASCII format -- decode it accordingly */
470 /* we need to access the next 4 bytes (after the final whitespace */
471 /* following the `eexec' keyword); if they all are hexadecimal */
472 /* digits, then we have a case of ASCII storage */
474 if ( cur
+ 3 < limit
&&
475 ft_isxdigit( cur
[0] ) && ft_isxdigit( cur
[1] ) &&
476 ft_isxdigit( cur
[2] ) && ft_isxdigit( cur
[3] ) )
478 /* ASCII hexadecimal encoding */
482 parser
->root
.cursor
= cur
;
483 (void)psaux
->ps_parser_funcs
->to_bytes( &parser
->root
,
484 parser
->private_dict
,
488 parser
->private_len
= len
;
490 /* put a safeguard */
491 parser
->private_dict
[len
] = '\0';
494 /* binary encoding -- copy the private dict */
495 FT_MEM_MOVE( parser
->private_dict
, cur
, size
);
498 /* we now decrypt the encoded binary private dictionary */
499 psaux
->t1_decrypt( parser
->private_dict
, parser
->private_len
, 55665U );
501 if ( parser
->private_len
< 4 )
503 FT_ERROR(( "T1_Get_Private_Dict:"
504 " invalid private dictionary section\n" ));
505 error
= FT_THROW( Invalid_File_Format
);
509 /* replace the four random bytes at the beginning with whitespace */
510 parser
->private_dict
[0] = ' ';
511 parser
->private_dict
[1] = ' ';
512 parser
->private_dict
[2] = ' ';
513 parser
->private_dict
[3] = ' ';
515 parser
->root
.base
= parser
->private_dict
;
516 parser
->root
.cursor
= parser
->private_dict
;
517 parser
->root
.limit
= parser
->root
.cursor
+ parser
->private_len
;