1/****************************************************************************
2 *
3 * cidparse.c
4 *
5 * CID-keyed Type1 parser (body).
6 *
7 * Copyright (C) 1996-2019 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#include <ft2build.h>
20#include FT_INTERNAL_DEBUG_H
21#include FT_INTERNAL_OBJECTS_H
22#include FT_INTERNAL_STREAM_H
23
24#include "cidparse.h"
25
26#include "ciderrs.h"
27
28
29 /**************************************************************************
30 *
31 * The macro FT_COMPONENT is used in trace mode. It is an implicit
32 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
33 * messages during execution.
34 */
35#undef FT_COMPONENT
36#define FT_COMPONENT cidparse
37
38
39 /*************************************************************************/
40 /*************************************************************************/
41 /*************************************************************************/
42 /***** *****/
43 /***** INPUT STREAM PARSER *****/
44 /***** *****/
45 /*************************************************************************/
46 /*************************************************************************/
47 /*************************************************************************/
48
49
50#define STARTDATA "StartData"
51#define STARTDATA_LEN ( sizeof ( STARTDATA ) - 1 )
52#define SFNTS "/sfnts"
53#define SFNTS_LEN ( sizeof ( SFNTS ) - 1 )
54
55
56 FT_LOCAL_DEF( FT_Error )
57 cid_parser_new( CID_Parser* parser,
58 FT_Stream stream,
59 FT_Memory memory,
60 PSAux_Service psaux )
61 {
62 FT_Error error;
63 FT_ULong base_offset, offset, ps_len;
64 FT_Byte *cur, *limit;
65 FT_Byte *arg1, *arg2;
66
67
68 FT_ZERO( parser );
69 psaux->ps_parser_funcs->init( &parser->root, 0, 0, memory );
70
71 parser->stream = stream;
72
73 base_offset = FT_STREAM_POS();
74
75 /* first of all, check the font format in the header */
76 if ( FT_FRAME_ENTER( 31 ) )
77 goto Exit;
78
79 if ( ft_strncmp( (char *)stream->cursor,
80 "%!PS-Adobe-3.0 Resource-CIDFont", 31 ) )
81 {
82 FT_TRACE2(( " not a CID-keyed font\n" ));
83 error = FT_THROW( Unknown_File_Format );
84 }
85
86 FT_FRAME_EXIT();
87 if ( error )
88 goto Exit;
89
90 Again:
91 /* now, read the rest of the file until we find */
92 /* `StartData' or `/sfnts' */
93 {
94 /*
95 * The algorithm is as follows (omitting the case with less than 256
96 * bytes to fill for simplicity).
97 *
98 * 1. Fill the buffer with 256 + STARTDATA_LEN bytes.
99 *
100 * 2. Search for the STARTDATA and SFNTS strings at positions
101 * buffer[0], buffer[1], ...,
102 * buffer[255 + STARTDATA_LEN - SFNTS_LEN].
103 *
104 * 3. Move the last STARTDATA_LEN bytes to buffer[0].
105 *
106 * 4. Fill the buffer with 256 bytes, starting at STARTDATA_LEN.
107 *
108 * 5. Repeat with step 2.
109 *
110 */
111 FT_Byte buffer[256 + STARTDATA_LEN + 1];
112
113 /* values for the first loop */
114 FT_ULong read_len = 256 + STARTDATA_LEN;
115 FT_ULong read_offset = 0;
116 FT_Byte* p = buffer;
117
118
119 for ( offset = FT_STREAM_POS(); ; offset += 256 )
120 {
121 FT_ULong stream_len;
122
123
124 stream_len = stream->size - FT_STREAM_POS();
125
126 read_len = FT_MIN( read_len, stream_len );
127 if ( FT_STREAM_READ( p, read_len ) )
128 goto Exit;
129
130 /* ensure that we do not compare with data beyond the buffer */
131 p[read_len] = '\0';
132
133 limit = p + read_len - SFNTS_LEN;
134
135 for ( p = buffer; p < limit; p++ )
136 {
137 if ( p[0] == 'S' &&
138 ft_strncmp( (char*)p, STARTDATA, STARTDATA_LEN ) == 0 )
139 {
140 /* save offset of binary data after `StartData' */
141 offset += (FT_ULong)( p - buffer ) + STARTDATA_LEN + 1;
142 goto Found;
143 }
144 else if ( p[1] == 's' &&
145 ft_strncmp( (char*)p, SFNTS, SFNTS_LEN ) == 0 )
146 {
147 offset += (FT_ULong)( p - buffer ) + SFNTS_LEN + 1;
148 goto Found;
149 }
150 }
151
152 if ( read_offset + read_len < STARTDATA_LEN )
153 {
154 FT_TRACE2(( "cid_parser_new: no `StartData' keyword found\n" ));
155 error = FT_THROW( Invalid_File_Format );
156 goto Exit;
157 }
158
159 FT_MEM_MOVE( buffer,
160 buffer + read_offset + read_len - STARTDATA_LEN,
161 STARTDATA_LEN );
162
163 /* values for the next loop */
164 read_len = 256;
165 read_offset = STARTDATA_LEN;
166 p = buffer + read_offset;
167 }
168 }
169
170 Found:
171 /* We have found the start of the binary data or the `/sfnts' token. */
172 /* Now rewind and extract the frame corresponding to this PostScript */
173 /* section. */
174
175 ps_len = offset - base_offset;
176 if ( FT_STREAM_SEEK( base_offset ) ||
177 FT_FRAME_EXTRACT( ps_len, parser->postscript ) )
178 goto Exit;
179
180 parser->data_offset = offset;
181 parser->postscript_len = ps_len;
182 parser->root.base = parser->postscript;
183 parser->root.cursor = parser->postscript;
184 parser->root.limit = parser->root.cursor + ps_len;
185 parser->num_dict = -1;
186
187 /* Finally, we check whether `StartData' or `/sfnts' was real -- */
188 /* it could be in a comment or string. We also get the arguments */
189 /* of `StartData' to find out whether the data is represented in */
190 /* binary or hex format. */
191
192 arg1 = parser->root.cursor;
193 cid_parser_skip_PS_token( parser );
194 cid_parser_skip_spaces ( parser );
195 arg2 = parser->root.cursor;
196 cid_parser_skip_PS_token( parser );
197 cid_parser_skip_spaces ( parser );
198
199 limit = parser->root.limit;
200 cur = parser->root.cursor;
201
202 while ( cur <= limit - SFNTS_LEN )
203 {
204 if ( parser->root.error )
205 {
206 error = parser->root.error;
207 goto Exit;
208 }
209
210 if ( cur[0] == 'S' &&
211 cur <= limit - STARTDATA_LEN &&
212 ft_strncmp( (char*)cur, STARTDATA, STARTDATA_LEN ) == 0 )
213 {
214 if ( ft_strncmp( (char*)arg1, "(Hex)", 5 ) == 0 )
215 {
216 FT_Long tmp = ft_strtol( (const char *)arg2, NULL, 10 );
217
218
219 if ( tmp < 0 )
220 {
221 FT_ERROR(( "cid_parser_new: invalid length of hex data\n" ));
222 error = FT_THROW( Invalid_File_Format );
223 }
224 else
225 parser->binary_length = (FT_ULong)tmp;
226 }
227
228 goto Exit;
229 }
230 else if ( cur[1] == 's' &&
231 ft_strncmp( (char*)cur, SFNTS, SFNTS_LEN ) == 0 )
232 {
233 FT_TRACE2(( "cid_parser_new: cannot handle Type 11 fonts\n" ));
234 error = FT_THROW( Unknown_File_Format );
235 goto Exit;
236 }
237
238 cid_parser_skip_PS_token( parser );
239 cid_parser_skip_spaces ( parser );
240 arg1 = arg2;
241 arg2 = cur;
242 cur = parser->root.cursor;
243 }
244
245 /* we haven't found the correct `StartData'; go back and continue */
246 /* searching */
247 FT_FRAME_RELEASE( parser->postscript );
248 if ( !FT_STREAM_SEEK( offset ) )
249 goto Again;
250
251 Exit:
252 return error;
253 }
254
255
256#undef STARTDATA
257#undef STARTDATA_LEN
258#undef SFNTS
259#undef SFNTS_LEN
260
261
262 FT_LOCAL_DEF( void )
263 cid_parser_done( CID_Parser* parser )
264 {
265 /* always free the private dictionary */
266 if ( parser->postscript )
267 {
268 FT_Stream stream = parser->stream;
269
270
271 FT_FRAME_RELEASE( parser->postscript );
272 }
273 parser->root.funcs.done( &parser->root );
274 }
275
276
277/* END */
278