1 files changed, 44 insertions, 0 deletions
diff --git a/src/main/java/de/bwlehrpool/bwlp_guac/WeakCrypto.java b/src/main/java/de/bwlehrpool/bwlp_guac/WeakCrypto.java
new file mode 100644
index 0000000..b7d8a11
--- /dev/null
+++ b/src/main/java/de/bwlehrpool/bwlp_guac/WeakCrypto.java
@@ -0,0 +1,44 @@
+package de.bwlehrpool.bwlp_guac;
+
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.SecretKeySpec;
+
+public class WeakCrypto {
+
+	private static 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 static byte reverseBits(byte input) {
+		byte result = 0x00;
+		for (int i = 0; i < 8; i++) {
+			result |= ((byte) ((input & (0x01 << i)) >>> i) << 7 - i);
+		}
+		return result;
+	}
+
+	public static byte[] vncEncrypt(byte[] pw_bytes, byte[] challenge) {
+		Cipher des;
+		try {
+			des = Cipher.getInstance("DES/ECB/NoPadding");
+			des.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(reverseBits(pw_bytes), 0, pw_bytes.length, "DES"));
+			return des.doFinal(challenge);
+		} catch (InvalidKeyException | NoSuchAlgorithmException | NoSuchPaddingException | IllegalBlockSizeException
+				| BadPaddingException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		return new byte[16];
+	}
+
+}