CWE-ou-minkata/Sources/Plasma/PubUtilLib/plFile/plEncryptedStream.h

/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#ifndef plEncryptedStream_h_inc
#define plEncryptedStream_h_inc

#include "hsStream.h"

//
// Encrypt a large file by running FileEncrypt on it.  Small files can be done
// in the usual way, but they will be in memory until Close is called.  Files
// will be decrypted on the fly during read.operations
//
class plEncryptedStream : public hsStream
{
protected:
    FILE* fRef;
    UInt32 fKey[4];

    UInt32 fActualFileSize;

    bool fBufferedStream;

    hsStream* fRAMStream;

    wchar* fWriteFileName;

    enum OpenMode { kOpenRead, kOpenWrite, kOpenFail };
    OpenMode fOpenMode;

    void IBufferFile();

    UInt32 IRead(UInt32 bytes, void* buffer);

    void IEncipher(UInt32* const v);
    void IDecipher(UInt32* const v);

    bool IWriteEncypted(hsStream* sourceStream, const wchar* outputFile);

    static bool ICheckMagicString(FILE* fp);

public:
    // If you don't pass in a key (4 UInt32's), the default one will be used
    plEncryptedStream(UInt32* key=nil);
    ~plEncryptedStream();

    virtual hsBool  Open(const char* name, const char* mode = "rb");
    virtual hsBool  Open(const wchar* name, const wchar* mode = L"rb");
    virtual hsBool  Close();

    virtual UInt32  Read(UInt32 byteCount, void* buffer);
    virtual UInt32  Write(UInt32 byteCount, const void* buffer);
    virtual hsBool  AtEnd();
    virtual void    Skip(UInt32 deltaByteCount);
    virtual void    Rewind();
    virtual void    FastFwd();
    virtual UInt32  GetEOF();

    UInt32 GetActualFileSize() const { return fActualFileSize;}

    static bool FileEncrypt(const char* fileName);
    static bool FileEncrypt(const wchar* fileName);
    static bool FileDecrypt(const char* fileName);
    static bool FileDecrypt(const wchar* fileName);

    static bool IsEncryptedFile(const char* fileName);
    static bool IsEncryptedFile(const wchar* fileName);

    // Attempts to create a read-binary stream for the requested file.  If it's
    // encrypted, you'll get a plEncryptedStream, otherwise just a standard
    // hsUNIXStream.  Remember to delete the stream when you're done with it.
    static hsStream* OpenEncryptedFile(const char* fileName, bool requireEncrypted = true, UInt32* cryptKey = nil);
    static hsStream* OpenEncryptedFile(const wchar* fileName, bool requireEncrypted = true, UInt32* cryptKey = nil);
    static hsStream* OpenEncryptedFileWrite(const char* fileName, UInt32* cryptKey = nil);
    static hsStream* OpenEncryptedFileWrite(const wchar* fileName, UInt32* cryptKey = nil);
};

#endif // plEncryptedStream_h_inc