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Diffstat (limited to 'oox/inc/oox/core/binarycodec.hxx')
| -rw-r--r-- | oox/inc/oox/core/binarycodec.hxx | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/oox/inc/oox/core/binarycodec.hxx b/oox/inc/oox/core/binarycodec.hxx new file mode 100644 index 000000000000..ced63250f3e1 --- /dev/null +++ b/oox/inc/oox/core/binarycodec.hxx @@ -0,0 +1,321 @@ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * 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 + * <http://www.openoffice.org/license.html> + * for a copy of the LGPLv3 License. + * + ************************************************************************/ + +#ifndef OOX_CORE_BINARYCODEC_HXX +#define OOX_CORE_BINARYCODEC_HXX + +#include <com/sun/star/uno/Sequence.hxx> +#include <com/sun/star/beans/NamedValue.hpp> + +#include <rtl/cipher.h> +#include <rtl/digest.h> + +namespace oox { class AttributeList; } + +namespace oox { +namespace core { + +// ============================================================================ + +class CodecHelper +{ +public: + /** Returns the password hash if it is in the required 16-bit limit. */ + static sal_uInt16 getPasswordHash( const AttributeList& rAttribs, sal_Int32 nElement ); + +private: + CodecHelper(); + ~CodecHelper(); +}; + +// ============================================================================ + +/** Encodes and decodes data from/to protected MS Office documents. + + Implements a simple XOR encoding/decoding algorithm used in MS Office + versions up to MSO 95. + */ +class BinaryCodec_XOR +{ +public: + /** Enumerates codec types supported by this XOR codec implementation. */ + enum CodecType + { + CODEC_WORD, /// MS Word XOR codec. + CODEC_EXCEL /// MS Excel XOR codec. + }; + +public: + /** Default constructor. + + Two-step construction in conjunction with the initKey() and verifyKey() + functions allows to try to initialize with different passwords (e.g. + built-in default password used for Excel workbook protection). + */ + explicit BinaryCodec_XOR( CodecType eCodecType ); + + ~BinaryCodec_XOR(); + + /** Initializes the algorithm with the specified password. + + @param pnPassData + 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. + */ + 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 the initKey() function 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 the initKey() function before + this function can be used. + */ + void startBlock(); + + /** Decodes a block of memory. + + @precond + The codec must be initialized with the initKey() function before + this function can be used. + + @param pnDestData + Destination buffer. Will contain the decrypted data afterwards. + @param pnSrcData + Encrypted data block. + @param nBytes + Size of the passed data blocks. pnDestData and pnSrcData must be of + this size. + + @return + True = decoding was successful (no error occured). + */ + bool decode( + sal_uInt8* pnDestData, + const sal_uInt8* pnSrcData, + sal_Int32 nBytes ); + + /** 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 the initKey() function before + this function can be used. + + @param nBytes + Number of bytes to be skipped (cipher "seeks" forward). + + @return + True = skip was successful (no error occured). + */ + bool skip( sal_Int32 nBytes ); + +private: + CodecType meCodecType; /// Codec type. + sal_uInt8 mpnKey[ 16 ]; /// Encryption key. + sal_Int32 mnOffset; /// Key offset. + sal_uInt16 mnBaseKey; /// Base key from password. + sal_uInt16 mnHash; /// Hash value from password. +}; + +// ============================================================================ + +/** 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 BinaryCodec_RCF +{ +public: + /** Default constructor. + + Two-step construction in conjunction with the initKey() and verifyKey() + functions allows to try to initialize with different passwords (e.g. + built-in default password used for Excel workbook protection). + */ + explicit BinaryCodec_RCF(); + + ~BinaryCodec_RCF(); + + /** Initializes the algorithm with the encryption data. + + @param aData + The sequence contains the necessary data to initialize + the codec. + */ + 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 pnPassData + Unicode character array containing the password. Must be zero + terminated, which results in a maximum length of 15 characters. + @param pnSalt + Random salt data block read from or written to the file. + */ + void initKey( + const sal_uInt16 pnPassData[ 16 ], + const sal_uInt8 pnSalt[ 16 ] ); + + /** Verifies the validity of the password using the passed salt data. + + @precond + The codec must be initialized with the initKey() function before + this function can be used. + + @param pnVerifier + Verifier block read from the file. + @param pnVerifierHash + Verifier hash read from the file. + + @return + True = test was successful. + */ + bool verifyKey( + const sal_uInt8 pnVerifier[ 16 ], + const sal_uInt8 pnVerifierHash[ 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 MS Word files and 1024 + bytes for MS Excel files. + + @precond + The codec must be initialized with the initKey() function before + this function can be used. + + @param nCounter + Block counter used to rekey the cipher. + */ + bool startBlock( sal_Int32 nCounter ); + + /** Decodes a block of memory. + + @see rtl_cipher_decode() + + @precond + The codec must be initialized with the initKey() function before + this function can be used. + + @param pnDestData + Destination buffer. Will contain the decrypted data afterwards. + @param pnSrcData + Encrypted data block. + @param nBytes + Size of the passed data blocks. pnDestData and pnSrcData must be of + this size. + + @return + True = decoding was successful (no error occured). + */ + bool decode( + sal_uInt8* pnDestData, + const sal_uInt8* pnSrcData, + sal_Int32 nBytes ); + + /** 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 the initKey() function before + this function can be used. + + @param nBytes + Number of bytes to be skipped (cipher "seeks" forward). + + @return + True = skip was successful (no error occured). + */ + bool skip( sal_Int32 nBytes ); + +private: + void InitKeyImpl( + const sal_uInt8 pKeyData[64], + const sal_uInt8 pUnique[16] ); + + rtlCipher mhCipher; + rtlDigest mhDigest; + sal_uInt8 mpnDigestValue[ RTL_DIGEST_LENGTH_MD5 ]; + sal_uInt8 mpnUnique[16]; +}; + +// ============================================================================ + +} // namespace core +} // namespace oox + +#endif |