diff options
Diffstat (limited to 'kpdf/xpdf/xpdf/Parser.cpp')
| -rw-r--r-- | kpdf/xpdf/xpdf/Parser.cpp | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/kpdf/xpdf/xpdf/Parser.cpp b/kpdf/xpdf/xpdf/Parser.cpp new file mode 100644 index 00000000..95475b85 --- /dev/null +++ b/kpdf/xpdf/xpdf/Parser.cpp @@ -0,0 +1,227 @@ +//======================================================================== +// +// Parser.cpp +// +// 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 "Decrypt.h" +#include "Parser.h" +#include "XRef.h" +#include "Error.h" + +Parser::Parser(XRef *xrefA, Lexer *lexerA, GBool allowStreamsA) { + xref = xrefA; + lexer = lexerA; + inlineImg = 0; + allowStreams = allowStreamsA; + lexer->getObj(&buf1); + lexer->getObj(&buf2); +} + +Parser::~Parser() { + buf1.free(); + buf2.free(); + delete lexer; +} + +Object *Parser::getObj(Object *obj, Guchar *fileKey, + CryptAlgorithm encAlgorithm, int keyLength, + int objNum, int objGen) { + char *key; + Stream *str; + Object obj2; + int num; + DecryptStream *decrypt; + GString *s, *s2; + int c; + + // 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()) + obj->arrayAdd(getObj(&obj2, fileKey, encAlgorithm, keyLength, + objNum, objGen)); + if (buf1.isEOF()) + error(getPos(), "End of file inside array"); + shift(); + + // dictionary or stream + } else if (buf1.isCmd("<<")) { + shift(objNum); + 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; + } + obj->dictAdd(key, getObj(&obj2, fileKey, encAlgorithm, keyLength, + objNum, objGen)); + } + } + if (buf1.isEOF()) + error(getPos(), "End of file inside dictionary"); + // stream objects are not allowed inside content streams or + // object streams + if (allowStreams && buf2.isCmd("stream")) { + if ((str = makeStream(obj, fileKey, encAlgorithm, keyLength, + objNum, objGen))) { + obj->initStream(str); + } 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); + } + + // string + } else if (buf1.isString() && fileKey) { + s = buf1.getString(); + s2 = new GString(); + obj2.initNull(); + decrypt = new DecryptStream(new MemStream(s->getCString(), 0, + s->getLength(), &obj2), + fileKey, encAlgorithm, keyLength, + objNum, objGen); + decrypt->reset(); + while ((c = decrypt->getChar()) != EOF) { + s2->append((char)c); + } + delete decrypt; + obj->initString(s2); + shift(); + + // simple object + } else { + buf1.copy(obj); + shift(); + } + + return obj; +} + +Stream *Parser::makeStream(Object *dict, Guchar *fileKey, + CryptAlgorithm encAlgorithm, int keyLength, + int objNum, int objGen) { + Object obj; + BaseStream *baseStr; + 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; + } + baseStr = lexer->getStream()->getBaseStream(); + + // 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'"); + // kludge for broken PDF files: just add 5k to the length, and + // hope its enough + length += 5000; + } + + // make base stream + str = baseStr->makeSubStream(pos, gTrue, length, dict); + + // handle decryption + if (fileKey) { + str = new DecryptStream(str, fileKey, encAlgorithm, keyLength, + objNum, objGen); + } + + // get filters + str = str->addFilters(dict); + + return str; +} + +void Parser::shift(int objNum) { + 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, objNum); +} |