KviCryptEngine.h

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#ifndef _KVI_CRYPT_ENGINE_H_
#define _KVI_CRYPT_ENGINE_H_

//=============================================================================
//
//   File : KviCryptEngine.h
//   Creation date : Fri Nov 03 2000 01:45:21 CEST by Szymon Stefanek
//
//   This file is part of the KVIrc IRC client distribution
//   Copyright (C) 2000-2010 Szymon Stefanek (pragma at kvirc dot net)
//
//   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 2
//   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, write to the Free Software Foundation,
//   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
//=============================================================================

#include "kvi_settings.h"

//
// Base class for all IRC crypt engines
// These intend to encrypt plain text into something
// that can be sent through the IRC protocol...
// so it should not contain NULL, CR, LF and other
// similar stuff...
//

#include "KviHeapObject.h"

#include <QObject>

class KviCString;

#ifdef COMPILE_CRYPT_SUPPORT
class KviCryptEngine;

typedef KviCryptEngine * (*crypt_engine_allocator_func)();
typedef void (*crypt_engine_deallocator_func)(KviCryptEngine *);
#endif //COMPILE_CRYPT_SUPPORT

// we must include this declaration to make moc happy even
// if we're not compiling the crypt support

class KVILIB_API KviCryptEngine : public QObject, public KviHeapObject
{
        Q_OBJECT
        friend class KviCryptEngineManager;

public:
        enum EngineFlag
        {
                CanEncrypt = 1,
                CanDecrypt = 2,
                WantEncryptKey = 4,
                WantDecryptKey = 8
        };

        enum EncryptResult
        {
                Encrypted,
                Encoded,
                EncryptError
        };

        enum DecryptResult
        {
                DecryptOkWasEncrypted,
                DecryptOkWasEncoded,
                DecryptOkWasPlainText,
                DecryptError
        };

        KviCryptEngine();
        virtual ~KviCryptEngine();

#ifdef COMPILE_CRYPT_SUPPORT
private:
        crypt_engine_deallocator_func m_deallocFunc; // this is accessed by KviCryptEngineManager only
        QString m_szLastError;
        int m_iMaxEncryptLen;

public:
        void setMaxEncryptLen(int m) { m_iMaxEncryptLen = m; };
        int maxEncryptLen() { return m_iMaxEncryptLen; };
        virtual bool init(const char * encKey, int encKeyLen, const char * decKey, int decKeyLen);
        //
        // Encrypts utf8 plainText and returns the encrypted
        // data in outBuffer. The encrypted data must be
        // suitable for sending through an IRC (eventually DCC
        // that is less restrictive) connection and must be utf8 encoded: so
        // no NULL, CR and LF in the output.
        // 0x01 should be also avoided since
        // it is the CTCP delimiter.
        // Converting the result in a HEX string
        // is a good trick...also Base64 could be used.
        // Should return false in case of an error.
        // Theoretically we could allow NULLs in plainText
        // but this is not the case of KVIrc.
        //
        virtual EncryptResult encrypt(const char * plainText, KviCString & outBuffer);
        //
        // Decrypts the utf8 data in inBuffer and puts the decrypted utf8
        // stuff in plainText. inBuffer is the thingie
        // that we got from outBuffer of encrupt() so it
        // follows the same rules.
        // Should return false in case of error.
        //
        virtual DecryptResult decrypt(const char * inBuffer, KviCString & plainText);
        //
        // Returns the string containing the description
        // of the last error or an empty string if there
        // was no error after the last init() call.
        //
        const QString & lastError() { return m_szLastError; };
protected:
        //
        // The following two should have clear meaning
        //
        void clearLastError() { m_szLastError = ""; };
        void setLastError(const QString & err) { m_szLastError = err; };
#endif //COMPILE_CRYPT_SUPPORT
};

#endif // _KVI_CRYPT_ENGINE_H_