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

/*==LICENSE==*

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*==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_t fKey[4];

    uint32_t fActualFileSize;

    bool fBufferedStream;

    hsStream* fRAMStream;

    plFileName fWriteFileName;

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

    void IBufferFile();

    uint32_t IRead(uint32_t bytes, void* buffer);

    void IEncipher(uint32_t* const v);
    void IDecipher(uint32_t* const v);

    bool IWriteEncypted(hsStream* sourceStream, const plFileName& outputFile);

    static bool ICheckMagicString(FILE* fp);

public:
    // If you don't pass in a key (4 uint32_t's), the default one will be used
    plEncryptedStream(uint32_t* key=nil);
    ~plEncryptedStream();

    virtual bool    Open(const plFileName& name, const char* mode = "rb");
    virtual bool    Close();

    virtual uint32_t  Read(uint32_t byteCount, void* buffer);
    virtual uint32_t  Write(uint32_t byteCount, const void* buffer);
    virtual bool    AtEnd();
    virtual void    Skip(uint32_t deltaByteCount);
    virtual void    Rewind();
    virtual void    FastFwd();
    virtual uint32_t  GetEOF();

    uint32_t GetActualFileSize() const { return fActualFileSize;}

    static bool FileEncrypt(const plFileName& fileName);
    static bool FileDecrypt(const plFileName& fileName);

    static bool IsEncryptedFile(const plFileName& 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 plFileName& fileName, uint32_t* cryptKey = nil);
    static hsStream* OpenEncryptedFileWrite(const plFileName& fileName, uint32_t* cryptKey = nil);
};

#endif // plEncryptedStream_h_inc