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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/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#ifndef INCLUDED_FILTER_MSFILTER_MSCODEC_HXX
#define INCLUDED_FILTER_MSFILTER_MSCODEC_HXX
#include <com/sun/star/uno/Sequence.hxx>
#include <com/sun/star/beans/NamedValue.hpp>
#include <rtl/cipher.h>
#include <rtl/digest.h>
#include <filter/msfilter/msfilterdllapi.h>
namespace msfilter {
/** Encodes and decodes data from protected MSO 95- documents.
*/
class MSFILTER_DLLPUBLIC MSCodec_Xor95
{
public:
explicit MSCodec_Xor95(int nRotateDistance);
virtual ~MSCodec_Xor95();
/** Initializes the algorithm with the specified password.
@param pPassData
Character array containing the password. Must be zero terminated,
which results in a maximum length of 15 characters.
*/
void InitKey( const sal_uInt8 pnPassData[ 16 ] );
/** Initializes the algorithm with the encryption data.
@param aData
The sequence contains the necessary data to initialize
the codec.
*/
sal_Bool InitCodec( const ::com::sun::star::uno::Sequence< ::com::sun::star::beans::NamedValue >& aData );
/** Retrieves the encryption data
@return
The sequence contains the necessary data to initialize
the codec.
*/
::com::sun::star::uno::Sequence< ::com::sun::star::beans::NamedValue > GetEncryptionData();
/** Verifies the validity of the password using the passed key and hash.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param nKey
Password key value read from the file.
@param nHash
Password hash value read from the file.
@return
true = Test was successful.
*/
bool VerifyKey( sal_uInt16 nKey, sal_uInt16 nHash ) const;
/** Reinitializes the codec to start a new memory block.
Resets the internal key offset to 0.
@precond
The codec must be initialized with InitKey() before this function
can be used.
*/
void InitCipher();
/** Decodes a block of memory inplace.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param pnData
Encrypted data block. Will contain the decrypted data afterwards.
@param nBytes
Size of the passed data block.
*/
virtual void Decode( sal_uInt8* pnData, sal_Size nBytes )=0;
/** Lets the cipher skip a specific amount of bytes.
This function sets the cipher to the same state as if the specified
amount of data has been decoded with one or more calls of Decode().
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param nBytes
Number of bytes to be skipped (cipher "seeks" forward).
*/
void Skip( sal_Size nBytes );
protected:
sal_uInt8 mpnKey[ 16 ]; /// Encryption key.
sal_Size mnOffset; /// Key offset.
private:
MSFILTER_DLLPRIVATE MSCodec_Xor95( const MSCodec_Xor95& );
MSFILTER_DLLPRIVATE MSCodec_Xor95& operator=( const MSCodec_Xor95& );
sal_uInt16 mnKey; /// Base key from password.
sal_uInt16 mnHash; /// Hash value from password.
int mnRotateDistance;
};
/** Encodes and decodes data from protected MSO XLS 95- documents.
*/
class MSFILTER_DLLPUBLIC MSCodec_XorXLS95 : public MSCodec_Xor95
{
public:
explicit MSCodec_XorXLS95() : MSCodec_Xor95(2) {}
/** Decodes a block of memory inplace.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param pnData
Encrypted data block. Will contain the decrypted data afterwards.
@param nBytes
Size of the passed data block.
*/
virtual void Decode( sal_uInt8* pnData, sal_Size nBytes );
};
/** Encodes and decodes data from protected MSO Word 95- documents.
*/
class MSFILTER_DLLPUBLIC MSCodec_XorWord95 : public MSCodec_Xor95
{
public:
explicit MSCodec_XorWord95() : MSCodec_Xor95(7) {}
/** Decodes a block of memory inplace.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param pnData
Encrypted data block. Will contain the decrypted data afterwards.
@param nBytes
Size of the passed data block.
*/
virtual void Decode( sal_uInt8* pnData, sal_Size nBytes );
};
/** Encodes and decodes data from protected MSO 97+ documents.
This is a wrapper class around low level cryptographic functions from RTL.
Implementation is based on the wvDecrypt package by Caolan McNamara:
http://www.csn.ul.ie/~caolan/docs/wvDecrypt.html
*/
class MSFILTER_DLLPUBLIC MSCodec_Std97
{
public:
explicit MSCodec_Std97();
~MSCodec_Std97();
/** Initializes the algorithm with the encryption data.
@param aData
The sequence contains the necessary data to initialize
the codec.
*/
sal_Bool InitCodec( const ::com::sun::star::uno::Sequence< ::com::sun::star::beans::NamedValue >& aData );
/** Retrieves the encryption data
@return
The sequence contains the necessary data to initialize
the codec.
*/
::com::sun::star::uno::Sequence< ::com::sun::star::beans::NamedValue > GetEncryptionData();
/** Initializes the algorithm with the specified password and document ID.
@param pPassData
Wide character array containing the password. Must be zero
terminated, which results in a maximum length of 15 characters.
@param pDocId
Unique document identifier read from or written to the file.
*/
void InitKey(
const sal_uInt16 pPassData[ 16 ],
const sal_uInt8 pDocId[ 16 ] );
/** Verifies the validity of the password using the passed salt data.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param pSaltData
Salt data block read from the file.
@param pSaltDigest
Salt digest read from the file.
@return
true = Test was successful.
*/
bool VerifyKey(
const sal_uInt8 pSaltData[ 16 ],
const sal_uInt8 pSaltDigest[ 16 ] );
/** Rekeys the codec using the specified counter.
After reading a specific amount of data the cipher algorithm needs to
be rekeyed using a counter that counts the data blocks.
The block size is for example 512 Bytes for Word files and 1024 Bytes
for Excel files.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param nCounter
Block counter used to rekey the cipher.
*/
bool InitCipher( sal_uInt32 nCounter );
/** Creates an MD5 digest of salt digest. */
bool CreateSaltDigest(
const sal_uInt8 nSaltData[16], sal_uInt8 nSaltDigest[16] );
/** Encodes a block of memory.
@see rtl_cipher_encode()
@precond
The codec must be initialized with InitKey() before this function
can be used. The destination buffer must be able to take all
unencoded data from the source buffer (usually this means it must be
as long as or longer than the source buffer).
@param pData
Unencrypted source data block.
@param nDatLen
Size of the passed source data block.
@param pBuffer
Destination buffer for the encrypted data.
@param nBufLen
Size of the destination buffer.
@return
true = Encoding was successful (no error occurred).
*/
bool Encode(
const void* pData, sal_Size nDatLen,
sal_uInt8* pBuffer, sal_Size nBufLen );
/** Decodes a block of memory.
@see rtl_cipher_decode()
@precond
The codec must be initialized with InitKey() before this function
can be used. The destination buffer must be able to take all
encoded data from the source buffer (usually this means it must be
as long as or longer than the source buffer).
@param pData
Encrypted source data block.
@param nDatLen
Size of the passed source data block.
@param pBuffer
Destination buffer for the decrypted data.
@param nBufLen
Size of the destination buffer.
@return
true = Decoding was successful (no error occurred).
*/
bool Decode(
const void* pData, sal_Size nDatLen,
sal_uInt8* pBuffer, sal_Size nBufLen );
/** Lets the cipher skip a specific amount of bytes.
This function sets the cipher to the same state as if the specified
amount of data has been decoded with one or more calls of Decode().
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param nDatLen
Number of bytes to be skipped (cipher "seeks" forward).
*/
bool Skip( sal_Size nDatLen );
/** Gets salt data and salt digest.
@precond
The codec must be initialized with InitKey() before this function
can be used.
@param pSalt
Salt, a random number.
@param pSaltData
Salt data block generated from the salt.
@param pSaltDigest
Salt digest generated from the salt.
*/
void GetEncryptKey (
const sal_uInt8 pSalt[16],
sal_uInt8 pSaltData[16],
sal_uInt8 pSaltDigest[16]);
/* allows to get the unique document id from the codec
*/
void GetDocId( sal_uInt8 pDocId[16] );
void GetDigestFromSalt( const sal_uInt8 pSaltData[16], sal_uInt8 pDigest[16] );
private:
void InitKeyImpl(
const sal_uInt8 pKeyData[64],
const sal_uInt8 pDocId[16] );
private:
MSFILTER_DLLPRIVATE MSCodec_Std97( const MSCodec_Std97& );
MSFILTER_DLLPRIVATE MSCodec_Std97& operator=( const MSCodec_Std97& );
rtlCipher m_hCipher;
rtlDigest m_hDigest;
sal_uInt8 m_pDigestValue[ RTL_DIGEST_LENGTH_MD5 ];
sal_uInt8 m_pDocId[16];
};
} // namespace msfilter
#endif
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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