init

2022-12-04 01:25:28 +01:00
commit 3db4f94e6a
31 changed files with 2762 additions and 0 deletions
--- a/Enigma/Rotor.java
+++ b/Enigma/Rotor.java
@@ -0,0 +1,109 @@
+/**
+ * Class for the rotors of the Enigma.
+ *
+ */
+public class Rotor implements EnigmaComponent {
+    /**
+     * Position where rotor "ticks" next rotor.
+     */
+    private int tickPos;
+
+    /**
+     * Current position of the rotor.
+     */
+    private int initialPos;
+
+    /**
+     * If Rotor has succesor.
+     */
+    private Rotor next;
+
+    /**
+     * Permutation of the rotor.
+     */
+    private int[] permu;
+
+    /**
+     * Inverse permutation of the rotor.
+     */
+    private int[] invPermu;
+
+    /**
+     * @param tickPos Position where rotor "ticks" next rotor
+     * @param initialPos Current position of the rotor
+     * @param permu Permutation of the rotor
+     */
+    Rotor(final int tickPos, final int initialPos, final int[] permu) {
+        this.tickPos = tickPos;
+        this.initialPos = initialPos;
+        this.permu = permu;
+        this.invPermu = calcInvPermu(permu);
+        this.next = null;
+    }
+
+    /**
+     * Setter for the next-rotor-pointer.
+     * @param next Next rotor
+     */
+    public final void setNext(final Rotor next) {
+        this.next = next;
+    }
+
+    /**
+     * Calculates the inverese permutation.
+     * @param permu permutation
+     * @return <code>inverse permutation</code>
+     */
+    private int[] calcInvPermu(final int[] permu) {
+        int[] array = new int[permu.length];
+        for (int i = 0; i < permu.length; i++) {
+            for (int k = 0; k < permu.length; k++) {
+               if (i == permu[k]) {
+                    array[i] = k;
+                }
+            }
+        }
+        return array;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public final int encode(final int i) {
+        if (((permu[((initialPos + i) % permu.length)] - initialPos
+                + permu.length) % permu.length) < 0) {
+            return (((permu[((initialPos + i) % permu.length)]
+                           - initialPos + permu.length)
+                           % permu.length) + permu.length);
+        }
+        return (permu[((initialPos + i) % permu.length)]
+                      - initialPos + permu.length) % permu.length;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public final int decode(final int i) {
+        if (((invPermu[((initialPos + i) % permu.length)]
+                       - initialPos + permu.length) % permu.length) < 0) {
+            return (((invPermu[((initialPos + i) % permu.length)]
+                              - initialPos + permu.length)
+                              % permu.length) + permu.length);
+        }
+        return (invPermu[((initialPos + i) % permu.length)]
+                         - initialPos + permu.length) % permu.length;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public final void tick() {
+        if (initialPos == permu.length) {
+            initialPos = 0;
+        }
+        initialPos++;
+        if (initialPos == (tickPos + 1) && next != null) {
+            next.tick();
+        }
+    }
+}