--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/com/glavsoft/rfb/protocol/auth/VncAuthentication.java	Thu Sep 11 07:30:03 2014 +0900
@@ -0,0 +1,100 @@
+// Copyright (C) 2010, 2011, 2012, 2013 GlavSoft LLC.
+// All rights reserved.
+//
+//-------------------------------------------------------------------------
+// This file is part of the TightVNC software.  Please visit our Web site:
+//
+//                       http://www.tightvnc.com/
+//
+// 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.
+//-------------------------------------------------------------------------
+//
+
+package com.glavsoft.rfb.protocol.auth;
+
+import com.glavsoft.exceptions.CryptoException;
+import com.glavsoft.exceptions.FatalException;
+import com.glavsoft.exceptions.TransportException;
+import com.glavsoft.rfb.CapabilityContainer;
+import com.glavsoft.rfb.IPasswordRetriever;
+import com.glavsoft.transport.Reader;
+import com.glavsoft.transport.Writer;
+
+import javax.crypto.*;
+import javax.crypto.spec.DESKeySpec;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.InvalidKeySpecException;
+
+public class VncAuthentication extends AuthHandler {
+	@Override
+	public SecurityType getType() {
+		return SecurityType.VNC_AUTHENTICATION;
+	}
+
+	@Override
+	public boolean authenticate(Reader reader,
+			Writer writer, CapabilityContainer authCaps, IPasswordRetriever passwordRetriever)
+	throws TransportException, FatalException {
+		byte [] challenge = reader.readBytes(16);
+		String password = passwordRetriever.getPassword();
+        if (null == password) return false;
+		byte [] key = new byte[8];
+        System.arraycopy(password.getBytes(), 0, key, 0, Math.min(key.length, password.getBytes().length));
+	    writer.write(encrypt(challenge, key));
+	    return false;
+	}
+
+  /**
+	 * Encript challenge by key using DES
+	 * @return encripted bytes
+	 * @throws CryptoException on problem with DES algorithm support or smth about
+	 */
+	public byte[] encrypt(byte[] challenge, byte[] key) throws CryptoException {
+		try {
+		    DESKeySpec desKeySpec = new DESKeySpec(mirrorBits(key));
+		    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
+		    SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
+		    Cipher desCipher = Cipher.getInstance("DES/ECB/NoPadding");
+		    desCipher.init(Cipher.ENCRYPT_MODE, secretKey);
+            return desCipher.doFinal(challenge);
+		} catch (NoSuchAlgorithmException e) {
+			throw new CryptoException("Cannot encrypt challenge", e);
+		} catch (NoSuchPaddingException e) {
+			throw new CryptoException("Cannot encrypt challenge", e);
+		} catch (IllegalBlockSizeException e) {
+			throw new CryptoException("Cannot encrypt challenge", e);
+		} catch (BadPaddingException e) {
+			throw new CryptoException("Cannot encrypt challenge", e);
+		} catch (InvalidKeyException e) {
+			throw new CryptoException("Cannot encrypt challenge", e);
+		} catch (InvalidKeySpecException e) {
+			throw new CryptoException("Cannot encrypt challenge", e);
+		}
+	}
+
+	private byte[] mirrorBits(byte[] k) {
+		byte[] key = new byte[8];
+		for (int i = 0; i < 8; i++) {
+			byte s = k[i];
+			s = (byte) (((s >> 1) & 0x55) | ((s << 1) & 0xaa));
+	        s = (byte) (((s >> 2) & 0x33) | ((s << 2) & 0xcc));
+	        s = (byte) (((s >> 4) & 0x0f) | ((s << 4) & 0xf0));
+	        key[i] = s;
+		}
+		return key;
+	}
+
+}