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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
*/
#ifndef INCLUDED_XMLSECURITY_INC_PDFIO_PDFDOCUMENT_HXX
#define INCLUDED_XMLSECURITY_INC_PDFIO_PDFDOCUMENT_HXX
#include <map>
#include <vector>
#include <com/sun/star/security/XCertificate.hpp>
#include <tools/stream.hxx>
#include <xmlsecuritydllapi.h>
#include <sigstruct.hxx>
namespace xmlsecurity
{
namespace pdfio
{
class PDFTrailerElement;
class PDFObjectElement;
class PDFHexStringElement;
/// A byte range in a PDF file.
class PDFElement
{
public:
virtual bool Read(SvStream& rStream) = 0;
virtual ~PDFElement() { }
};
enum class TokenizeMode
{
/// Full file.
END_OF_STREAM,
/// Till the first %%EOF token.
EOF_TOKEN,
/// Till the end of the current object.
END_OF_OBJECT,
/// Same as END_OF_OBJECT, but for object streams (no endobj keyword).
STORED_OBJECT
};
/// The type column of an entry in a cross-reference stream.
enum class XRefEntryType
{
/// xref "n" or xref stream "1".
NOT_COMPRESSED,
/// xref stream "2.
COMPRESSED
};
/// An entry in a cross-reference stream.
struct XRefEntry
{
XRefEntryType m_eType;
/**
* Non-compressed: The byte offset of the object, starting from the
* beginning of the file.
* Compressed: The object number of the object stream in which this object is
* stored.
*/
sal_uInt64 m_nOffset;
/**
* Non-compressed: The generation number of the object.
* Compressed: The index of this object within the object stream.
*/
sal_uInt64 m_nGenerationNumber;
/// Are changed as part of an incremental update?.
bool m_bDirty;
XRefEntry();
};
/**
* In-memory representation of an on-disk PDF document.
*
* The PDF element list is not meant to be saved back to disk, but some
* elements remember their source offset / length, and based on that it's
* possible to modify the input file.
*/
class XMLSECURITY_DLLPUBLIC PDFDocument
{
/// This vector owns all elements.
std::vector< std::unique_ptr<PDFElement> > m_aElements;
/// Object ID <-> object offset map.
std::map<size_t, XRefEntry> m_aXRef;
/// Object offset <-> Object pointer map.
std::map<size_t, PDFObjectElement*> m_aOffsetObjects;
/// Object ID <-> Object pointer map.
std::map<size_t, PDFObjectElement*> m_aIDObjects;
/// List of xref offsets we know.
std::vector<size_t> m_aStartXRefs;
/// List of EOF offsets we know.
std::vector<size_t> m_aEOFs;
PDFTrailerElement* m_pTrailer;
/// When m_pTrailer is nullptr, this can still have a dictionary.
PDFObjectElement* m_pXRefStream;
/// All editing takes place in this buffer, if it happens.
SvMemoryStream m_aEditBuffer;
static int AsHex(char ch);
/// Decode a hex dump.
static std::vector<unsigned char> DecodeHexString(PDFHexStringElement* pElement);
public:
PDFDocument();
PDFDocument& operator=(const PDFDocument&) = delete;
PDFDocument(const PDFDocument&) = delete;
/// @name Low-level functions, to be used by PDFElement subclasses.
//@{
static OString ReadKeyword(SvStream& rStream);
static size_t FindStartXRef(SvStream& rStream);
void ReadXRef(SvStream& rStream);
void ReadXRefStream(SvStream& rStream);
static void SkipWhitespace(SvStream& rStream);
/// Instead of all whitespace, just skip CR and NL characters.
static void SkipLineBreaks(SvStream& rStream);
size_t GetObjectOffset(size_t nIndex) const;
const std::vector< std::unique_ptr<PDFElement> >& GetElements();
std::vector<PDFObjectElement*> GetPages();
/// Remember the end location of an EOF token.
void PushBackEOF(size_t nOffset);
/// Look up object based on object number, possibly by parsing object streams.
PDFObjectElement* LookupObject(size_t nObjectNumber);
/// Access to the input document, even after the input stream is gone.
SvMemoryStream& GetEditBuffer();
/// Tokenize elements from current offset.
bool Tokenize(SvStream& rStream, TokenizeMode eMode, std::vector< std::unique_ptr<PDFElement> >& rElements, PDFObjectElement* pObject);
/// Register an object (owned directly or indirectly by m_aElements) as a provider for a given ID.
void SetIDObject(size_t nID, PDFObjectElement* pObject);
//@}
/// @name High-level functions, to be used by others.
//@{
/// Read elements from the start of the stream till its end.
bool Read(SvStream& rStream);
/// Sign the read document with xCertificate in the edit buffer.
bool Sign(const css::uno::Reference<css::security::XCertificate>& xCertificate, const OUString& rDescription);
/// Serializes the contents of the edit buffer.
bool Write(SvStream& rStream);
/// Get a list of signatures embedded into this document.
std::vector<PDFObjectElement*> GetSignatureWidgets();
/**
* @param rInformation The actual result.
* @param bLast If this is the last signature in the file, so it covers the whole file physically.
* @return If we can determinate a result.
*/
static bool ValidateSignature(SvStream& rStream, PDFObjectElement* pSignature, SignatureInformation& rInformation, bool bLast);
/// Remove the nth signature from read document in the edit buffer.
bool RemoveSignature(size_t nPosition);
//@}
};
} // namespace pdfio
} // namespace xmlsecurity
#endif // INCLUDED_XMLSECURITY_INC_PDFIO_PDFDOCUMENT_HXX
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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