193 lines
7.4 KiB
Java
193 lines
7.4 KiB
Java
package de.vanitasvitae.enigmandroid.enigma;
|
|
|
|
import java.security.SecureRandom;
|
|
import java.util.Random;
|
|
|
|
import de.vanitasvitae.enigmandroid.enigma.rotors.Reflector;
|
|
import de.vanitasvitae.enigmandroid.enigma.rotors.Rotor;
|
|
|
|
/**
|
|
* Concrete Implementation of the Enigma Machine type M4 of the german Kriegsmarine
|
|
* Copyright (C) 2015 Paul Schaub
|
|
|
|
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.
|
|
* @author vanitasvitae
|
|
*/
|
|
public class Enigma_M4 extends Enigma
|
|
{
|
|
private Rotor rotor1;
|
|
private Rotor rotor2;
|
|
private Rotor rotor3;
|
|
private Rotor rotor4;
|
|
|
|
private Reflector reflector;
|
|
|
|
private Plugboard plugboard;
|
|
|
|
public Enigma_M4()
|
|
{
|
|
super();
|
|
machineType = "M4";
|
|
}
|
|
|
|
@Override
|
|
public void initialize()
|
|
{
|
|
this.plugboard = new Plugboard();
|
|
this.rotor1 = Rotor.createRotor(30, 0, 0);
|
|
this.rotor2 = Rotor.createRotor(31, 0, 0);
|
|
this.rotor3 = Rotor.createRotor(32, 0, 0);
|
|
this.rotor4 = Rotor.createRotor(38, 0, 0);
|
|
this.reflector = Reflector.createReflector(30);
|
|
this.prefAnomaly = true;
|
|
}
|
|
|
|
@Override
|
|
/**
|
|
* Set the enigma into the next mechanical state.
|
|
* This rotates the first rotor and eventually also the second/third.
|
|
* Also this method handles the anomaly in case it should happen.
|
|
*/
|
|
public void nextState()
|
|
{
|
|
//Rotate rotors
|
|
rotor1.rotate();
|
|
//Eventually turn next rotor (usual turnOver or anomaly)
|
|
if (rotor1.isAtTurnoverPosition() || (this.doAnomaly && prefAnomaly))
|
|
{
|
|
rotor2.rotate();
|
|
//Set doAnomaly for next call of encryptChar
|
|
this.doAnomaly = rotor2.doubleTurnAnomaly();
|
|
//Eventually rotate next rotor
|
|
if (rotor2.isAtTurnoverPosition())
|
|
{
|
|
rotor3.rotate();
|
|
}
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public void randomState()
|
|
{
|
|
Random rand = new SecureRandom();
|
|
|
|
int rotor1, rotor2=-1, rotor3=-1;
|
|
int rotor4;
|
|
int ref;
|
|
rotor1 = rand.nextInt(8);
|
|
while(rotor2 == -1 || rotor2 == rotor1) rotor2 = rand.nextInt(8);
|
|
while(rotor3 == -1 || rotor3 == rotor2 || rotor3 == rotor1) rotor3 = rand.nextInt(8);
|
|
rotor4 = rand.nextInt(2);
|
|
ref = rand.nextInt(2);
|
|
|
|
int rot1 = rand.nextInt(26);
|
|
int rot2 = rand.nextInt(26);
|
|
int rot3 = rand.nextInt(26);
|
|
int rot4 = rand.nextInt(26);
|
|
int rotRef = rand.nextInt(26);
|
|
int ring1 = rand.nextInt(26);
|
|
int ring2 = rand.nextInt(26);
|
|
int ring3 = rand.nextInt(26);
|
|
int ring4 = rand.nextInt(26);
|
|
int ringRef = rand.nextInt(26);
|
|
|
|
this.rotor1 = Rotor.createRotor(30 + rotor1, rot1, ring1);
|
|
this.rotor2 = Rotor.createRotor(30 + rotor2, rot2, ring2);
|
|
this.rotor3 = Rotor.createRotor(30 + rotor3, rot3, ring3);
|
|
this.rotor4 = Rotor.createRotor(38 + rotor4, rot4, ring4);
|
|
this.reflector = Reflector.createReflector(30 + ref);
|
|
reflector.setRotation(rotRef);
|
|
reflector.setRingSetting(ringRef);
|
|
}
|
|
|
|
@Override
|
|
/**
|
|
* Substitute char k by sending the signal through the enigma.
|
|
* The signal passes the plugboard, the rotors and returns back after going through the
|
|
* reflector wheel.
|
|
*
|
|
* @param k input char
|
|
* @return substituted output char
|
|
*/
|
|
public char encryptChar(char k)
|
|
{
|
|
nextState(); //Rotate rotors
|
|
int x = ((int) k)-65; //Cast to int and remove Unicode Offset (A=65 in Unicode.)
|
|
//Encryption
|
|
//forward direction
|
|
x = plugboard.encrypt(x);
|
|
x = rotor1.normalize(x + rotor1.getRotation() - rotor1.getRingSetting());
|
|
x = rotor1.encryptForward(x);
|
|
x = rotor1.normalize(x - rotor1.getRotation() + rotor1.getRingSetting() + rotor2.getRotation() - rotor2.getRingSetting());
|
|
x = rotor2.encryptForward(x);
|
|
x = rotor1.normalize(x - rotor2.getRotation() + rotor2.getRingSetting() + rotor3.getRotation() - rotor3.getRingSetting());
|
|
x = rotor3.encryptForward(x);
|
|
x = rotor1.normalize(x - rotor3.getRotation() + rotor3.getRingSetting() + rotor4.getRotation() - rotor4.getRingSetting());
|
|
x = rotor4.encryptForward(x);
|
|
x = rotor1.normalize(x - rotor4.getRotation() + rotor4.getRingSetting());
|
|
//backward direction
|
|
x = reflector.encrypt(x);
|
|
x = rotor1.normalize(x + rotor4.getRotation() - rotor4.getRingSetting());
|
|
x = rotor4.encryptBackward(x);
|
|
x = rotor1.normalize(x + rotor3.getRotation() - rotor3.getRingSetting() - rotor4.getRotation() + rotor4.getRingSetting());
|
|
x = rotor3.encryptBackward(x);
|
|
x = rotor1.normalize(x + rotor2.getRotation() - rotor2.getRingSetting() - rotor3.getRotation() + rotor3.getRingSetting());
|
|
x = rotor2.encryptBackward(x);
|
|
x = rotor1.normalize(x + rotor1.getRotation() - rotor1.getRingSetting() - rotor2.getRotation() + rotor2.getRingSetting());
|
|
x = rotor1.encryptBackward(x);
|
|
x = rotor1.normalize(x - rotor1.getRotation() + rotor1.getRingSetting());
|
|
x = plugboard.encrypt(x);
|
|
return (char) (x + 65); //Add Offset again and cast back to char
|
|
}
|
|
|
|
@Override
|
|
public void setState(EnigmaStateBundle state)
|
|
{
|
|
rotor1 = Rotor.createRotor(state.getTypeRotor1(), state.getRotationRotor1(), state.getRingSettingRotor1());
|
|
rotor2 = Rotor.createRotor(state.getTypeRotor2(), state.getRotationRotor2(), state.getRingSettingRotor2());
|
|
rotor3 = Rotor.createRotor(state.getTypeRotor3(), state.getRotationRotor3(), state.getRingSettingRotor3());
|
|
rotor4 = Rotor.createRotor(state.getTypeRotor4(), state.getRotationRotor4(), state.getRingSettingRotor4());
|
|
reflector = Reflector.createReflector(state.getTypeReflector());
|
|
plugboard.setConfiguration(state.getConfigurationPlugboard());
|
|
|
|
}
|
|
|
|
@Override
|
|
public EnigmaStateBundle getState()
|
|
{
|
|
EnigmaStateBundle state = new EnigmaStateBundle();
|
|
state.setTypeRotor1(rotor1.getNumber());
|
|
state.setTypeRotor2(rotor2.getNumber());
|
|
state.setTypeRotor3(rotor3.getNumber());
|
|
state.setTypeRotor4(rotor4.getNumber());
|
|
|
|
state.setRotationRotor1(rotor1.getRotation());
|
|
state.setRotationRotor2(rotor2.getRotation());
|
|
state.setRotationRotor3(rotor3.getRotation());
|
|
state.setRotationRotor4(rotor4.getRotation());
|
|
|
|
state.setRingSettingRotor1(rotor1.getRingSetting());
|
|
state.setRingSettingRotor2(rotor2.getRingSetting());
|
|
state.setRingSettingRotor3(rotor3.getRingSetting());
|
|
state.setRingSettingRotor4(rotor4.getRingSetting());
|
|
|
|
state.setTypeReflector(reflector.getNumber());
|
|
|
|
state.setConfigurationPlugboard(plugboard.getConfiguration());
|
|
|
|
return state;
|
|
}
|
|
}
|