diff options
Diffstat (limited to 'include/filter/msfilter/mscodec.hxx')
| -rw-r--r-- | include/filter/msfilter/mscodec.hxx | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/include/filter/msfilter/mscodec.hxx b/include/filter/msfilter/mscodec.hxx new file mode 100644 index 000000000000..f321441e2941 --- /dev/null +++ b/include/filter/msfilter/mscodec.hxx @@ -0,0 +1,370 @@ +/* -*- 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 SVX_MSCODEC_HXX +#define SVX_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: */ |