Initial commit

src/de/uni_hamburg/informatik/svs/bazidecrypt/Main.java

@@ -0,0 +1,32 @@
+package de.uni_hamburg.informatik.svs.bazidecrypt;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Arrays;
+
+public class Main {
+
+    public static void main(String[] args) {
+        try {
+            byte[] content = Files.readAllBytes(Paths.get(args[0]));
+            System.out.println(decodeBazi(content, getMessageKey(content)));
+        } catch (IOException | IndexOutOfBoundsException e) {
+            System.err.println("Datei konnte nicht gelesen werden: " + e.getMessage());
+        }
+    }
+
+    private static byte[] getMessageKey(byte[] message) {
+        return Arrays.copyOfRange(message, message.length - 10, message.length);
+    }
+
+    private static String decodeBazi(byte[] message, byte[] key) {
+        byte[] result = new byte[message.length];
+
+        for (int i = 0; i < message.length; ++i) {
+            result[i] = (byte) (message[i] ^ key[i % 10]);
+        }
+
+        return new String(result);
+    }
+}