/************************************************************************* * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * Copyright 2008 by Sun Microsystems, Inc. * * OpenOffice.org - a multi-platform office productivity suite * * $RCSfile: mscodec.hxx,v $ * $Revision: 1.5 $ * * This file is part of OpenOffice.org. * * OpenOffice.org is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 3 * only, as published by the Free Software Foundation. * * OpenOffice.org is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License version 3 for more details * (a copy is included in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU Lesser General Public License * version 3 along with OpenOffice.org. If not, see * * for a copy of the LGPLv3 License. * ************************************************************************/ #ifndef SVX_MSCODEC_HXX #define SVX_MSCODEC_HXX #include "rtl/cipher.h" #include "rtl/digest.h" #include "svx/svxdllapi.h" namespace svx { // ============================================================================ /** Encodes and decodes data from protected MSO 95- documents. */ class SVX_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 ] ); /** 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 ); // static ----------------------------------------------------------------- /** Calculates the 16-bit hash value for the given password. The password data may be longer than 16 bytes. The array does not need to be terminated with a NULL byte (but it can without invalidating the result). */ static sal_uInt16 GetHash( const sal_uInt8* pnPassData, sal_Size nSize ); protected: sal_uInt8 mpnKey[ 16 ]; /// Encryption key. sal_Size mnOffset; /// Key offset. private: SVX_DLLPRIVATE MSCodec_Xor95( const MSCodec_Xor95& ); SVX_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 SVX_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 SVX_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 SVX_DLLPUBLIC MSCodec_Std97 { public: explicit MSCodec_Std97(); ~MSCodec_Std97(); /** 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 pUnique Unique document identifier read from or written to the file. */ void InitKey( const sal_uInt16 pPassData[ 16 ], const sal_uInt8 pUnique[ 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 ); /** 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 occured). */ 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 ); private: SVX_DLLPRIVATE MSCodec_Std97( const MSCodec_Std97& ); SVX_DLLPRIVATE MSCodec_Std97& operator=( const MSCodec_Std97& ); rtlCipher m_hCipher; rtlDigest m_hDigest; sal_uInt8 m_pDigestValue[ RTL_DIGEST_LENGTH_MD5 ]; }; // ============================================================================ } // namespace svx #endif