1 files changed, 141 insertions, 0 deletions
diff --git a/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java b/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java
new file mode 100644
index 0000000..8bd4bd0
--- /dev/null
+++ b/src/main/java/de/bwlehrpool/bwlp_guac/VncConnection.java
@@ -0,0 +1,141 @@
+package de.bwlehrpool.bwlp_guac;
+
+import java.io.Closeable;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.SecretKeySpec;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class VncConnection implements Closeable {
+
+	private static final Logger LOGGER = LoggerFactory.getLogger(VncConnection.class);
+
+	private final Socket sock;
+	private final DataOutputStream out;
+	private final DataInputStream in;
+
+	public VncConnection(String host, int port) throws IOException {
+		sock = new Socket();
+		sock.connect(new InetSocketAddress(host, port), 1200);
+		sock.setSoTimeout(1000);
+		out = new DataOutputStream(sock.getOutputStream());
+		in = new DataInputStream(sock.getInputStream());
+	}
+
+	public String handshake() throws IOException {
+		byte[] buffer = new byte[12];
+		in.readFully(buffer);
+		out.write("RFB 003.008\n".getBytes());
+		out.flush();
+		return new String(buffer).substring(4, 11);
+	}
+
+	public boolean tryLogin(String passwd) throws IOException {
+		if (passwd == null)
+			return false; // Paswordless not supported yet (although simpler..)
+		int numTypes = in.read();
+		if (numTypes == 0) {
+			LOGGER.info("VNC Server @ " + sock.getRemoteSocketAddress() + " does not support any auth methods");
+			printError();
+			return false;
+		}
+		boolean ok = false;
+		for (int i = 0; i < numTypes; ++i) {
+			if (in.read() == 2) {
+				ok = true;
+				break; // Found "VNC Authentication"
+			}
+		}
+		if (!ok) {
+			LOGGER.info("VNC Server @ " + sock.getRemoteSocketAddress() + " does not support VNC Authentication");
+			return false;
+		}
+		out.write(2); // Pick passwd auth
+		// Get challenge data
+		byte[] challenge = new byte[16];
+		int ret = in.read(challenge);
+		if (ret != 16) {
+			LOGGER.info("Didn't receive challenge from VNC server @ " + sock.getRemoteSocketAddress());
+			return false;
+		}
+		// pad pw to 8 bytes
+		byte[] pw_bytes = passwd.getBytes();
+		pw_bytes = Arrays.copyOf(pw_bytes, 8);
+		// Encrypt
+		Cipher des;
+		try {
+			des = Cipher.getInstance("DES/ECB/NoPadding");
+			des.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(reverseBits(pw_bytes), 0, pw_bytes.length, "DES"));
+			out.write(des.doFinal(challenge));
+		} catch (InvalidKeyException | NoSuchAlgorithmException | NoSuchPaddingException | IllegalBlockSizeException
+				| BadPaddingException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		// check reply
+		int securityReply = in.readInt();
+		if (securityReply != 0) {
+			LOGGER.info("Security reply = " + securityReply + " for VNC server @ " + sock.getRemoteSocketAddress());
+			return false;
+		}
+		return true;
+	}
+
+	private void printError() throws IOException {
+		int len = in.readInt();
+		byte[] msg = new byte[len];
+		in.readFully(msg);
+		LOGGER.info(new String(msg, StandardCharsets.ISO_8859_1));
+	}
+
+	@Override
+	public void close() throws IOException {
+		try {
+			in.close();
+		} catch (Exception e) {
+		}
+		try {
+			out.close();
+		} catch (Exception e) {
+		}
+		try {
+			sock.close();
+		} catch (Exception e) {
+		}
+	}
+
+	/*
+	 * 
+	 */
+
+	private byte[] reverseBits(byte[] b) {
+		byte[] result = new byte[b.length];
+		for (int i = 0; i < b.length; i++) {
+			result[i] = reverseBits(b[i]);
+		}
+		return result;
+	}
+
+	private byte reverseBits(byte input) {
+		byte result = 0x00;
+		for (int i = 0; i < 8; i++) {
+			result |= ((byte) ((input & (0x01 << i)) >>> i) << 7 - i);
+		}
+		return result;
+	}
+	
+}