1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
//========================================================================
//
// Parser.cc
//
// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================
#include <aconf.h>
#ifdef USE_GCC_PRAGMAS
#pragma implementation
#endif
#include <stddef.h>
#include "Object.h"
#include "Array.h"
#include "Dict.h"
#include "Parser.h"
#include "XRef.h"
#include "Error.h"
#ifndef NO_DECRYPTION
#include "Decrypt.h"
#endif
Parser::Parser(XRef *xrefA, Lexer *lexerA) {
xref = xrefA;
lexer = lexerA;
inlineImg = 0;
lexer->getObj(&buf1);
lexer->getObj(&buf2);
}
Parser::~Parser() {
buf1.free();
buf2.free();
delete lexer;
}
#ifndef NO_DECRYPTION
Object *Parser::getObj(Object *obj,
Guchar *fileKey, int keyLength,
int objNum, int objGen) {
#else
Object *Parser::getObj(Object *obj) {
#endif
char *key;
Stream *str;
Object obj2;
int num;
#ifndef NO_DECRYPTION
Decrypt *decrypt;
GString *s;
char *p;
int i;
#endif
// refill buffer after inline image data
if (inlineImg == 2) {
buf1.free();
buf2.free();
lexer->getObj(&buf1);
lexer->getObj(&buf2);
inlineImg = 0;
}
// array
if (buf1.isCmd("[")) {
shift();
obj->initArray(xref);
while (!buf1.isCmd("]") && !buf1.isEOF())
#ifndef NO_DECRYPTION
obj->arrayAdd(getObj(&obj2, fileKey, keyLength, objNum, objGen));
#else
obj->arrayAdd(getObj(&obj2));
#endif
if (buf1.isEOF())
error(getPos(), "End of file inside array");
shift();
// dictionary or stream
} else if (buf1.isCmd("<<")) {
shift();
obj->initDict(xref);
while (!buf1.isCmd(">>") && !buf1.isEOF()) {
if (!buf1.isName()) {
error(getPos(), "Dictionary key must be a name object");
shift();
} else {
key = copyString(buf1.getName());
shift();
if (buf1.isEOF() || buf1.isError()) {
gfree(key);
break;
}
#ifndef NO_DECRYPTION
obj->dictAdd(key, getObj(&obj2, fileKey, keyLength, objNum, objGen));
#else
obj->dictAdd(key, getObj(&obj2));
#endif
}
}
if (buf1.isEOF())
error(getPos(), "End of file inside dictionary");
if (buf2.isCmd("stream")) {
if ((str = makeStream(obj))) {
obj->initStream(str);
#ifndef NO_DECRYPTION
if (fileKey) {
str->getBaseStream()->doDecryption(fileKey, keyLength,
objNum, objGen);
}
#endif
} else {
obj->free();
obj->initError();
}
} else {
shift();
}
// indirect reference or integer
} else if (buf1.isInt()) {
num = buf1.getInt();
shift();
if (buf1.isInt() && buf2.isCmd("R")) {
obj->initRef(num, buf1.getInt());
shift();
shift();
} else {
obj->initInt(num);
}
#ifndef NO_DECRYPTION
// string
} else if (buf1.isString() && fileKey) {
buf1.copy(obj);
s = obj->getString();
decrypt = new Decrypt(fileKey, keyLength, objNum, objGen);
for (i = 0, p = obj->getString()->getCString();
i < s->getLength();
++i, ++p) {
*p = decrypt->decryptByte(*p);
}
delete decrypt;
shift();
#endif
// simple object
} else {
buf1.copy(obj);
shift();
}
return obj;
}
Stream *Parser::makeStream(Object *dict) {
Object obj;
Stream *str;
Guint pos, endPos, length;
// get stream start position
lexer->skipToNextLine();
pos = lexer->getPos();
// get length
dict->dictLookup("Length", &obj);
if (obj.isInt()) {
length = (Guint)obj.getInt();
obj.free();
} else {
error(getPos(), "Bad 'Length' attribute in stream");
obj.free();
return NULL;
}
// check for length in damaged file
if (xref && xref->getStreamEnd(pos, &endPos)) {
length = endPos - pos;
}
// in badly damaged PDF files, we can run off the end of the input
// stream immediately after the "stream" token
if (!lexer->getStream()) {
return NULL;
}
// make base stream
str = lexer->getStream()->getBaseStream()->makeSubStream(pos, gTrue,
length, dict);
// get filters
str = str->addFilters(dict);
// skip over stream data
lexer->setPos(pos + length);
// refill token buffers and check for 'endstream'
shift(); // kill '>>'
shift(); // kill 'stream'
if (buf1.isCmd("endstream")) {
shift();
} else {
error(getPos(), "Missing 'endstream'");
str->ignoreLength();
}
return str;
}
void Parser::shift() {
if (inlineImg > 0) {
if (inlineImg < 2) {
++inlineImg;
} else {
// in a damaged content stream, if 'ID' shows up in the middle
// of a dictionary, we need to reset
inlineImg = 0;
}
} else if (buf2.isCmd("ID")) {
lexer->skipChar(); // skip char after 'ID' command
inlineImg = 1;
}
buf1.free();
buf1 = buf2;
if (inlineImg > 0) // don't buffer inline image data
buf2.initNull();
else
lexer->getObj(&buf2);
}
|
