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//========================================================================
//
// 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);
}
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