package de.vanitasvitae.enigmandroid.enigma; import java.security.SecureRandom; import java.util.Random; import de.vanitasvitae.enigmandroid.MainActivity; 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; protected static int machineTypeOffset = 30; public Enigma_M4() { super(); machineType = "M4"; } @Override public void initialize() { this.plugboard = new Plugboard(); this.rotor1 = Rotor.createRotor(machineTypeOffset, 0, 0); this.rotor2 = Rotor.createRotor(machineTypeOffset+1, 0, 0); this.rotor3 = Rotor.createRotor(machineTypeOffset+2, 0, 0); this.rotor4 = Rotor.createRotor(machineTypeOffset + 8, 0, 0); this.reflector = Reflector.createReflector(machineTypeOffset); this.prefAnomaly = ((MainActivity) MainActivity.ActivitySingleton.getInstance() .getActivity()).getPrefAnomaly(); } @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 protected void generateState() { int r1, r2=-1, r3=-1; int r4; int ref; r1 = rand.nextInt(8); while(r2 == -1 || r2 == r1) r2 = rand.nextInt(8); while(r3 == -1 || r3 == r2 || r3 == r1) r3 = rand.nextInt(8); r4 = 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(machineTypeOffset + r1, rot1, ring1); this.rotor2 = Rotor.createRotor(machineTypeOffset + r2, rot2, ring2); this.rotor3 = Rotor.createRotor(machineTypeOffset + r3, rot3, ring3); this.rotor4 = Rotor.createRotor(machineTypeOffset + 8 + r4, rot4, ring4); this.reflector = Reflector.createReflector(machineTypeOffset + ref); this.reflector.setRotation(rotRef); this.reflector.setRingSetting(ringRef); this.plugboard = new Plugboard(); this.plugboard.setConfiguration(Plugboard.seedToPlugboardConfiguration(rand)); } @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; } @Override public void restoreState(String mem) { String plugboardConf = mem.substring(mem.lastIndexOf(":p") + 2); long s = Long.valueOf(mem.substring(0, mem.indexOf(":p"))); s = removeDigit(s, 20); //Remove machine type int r1 = getValue(s, 10); s = removeDigit(s, 10); int r2 = getValue(s, 10); s = removeDigit(s,10); int r3 = getValue(s, 10); s = removeDigit(s,10); int r4 = getValue(s, 10); s = removeDigit(s,10); int ref = getValue(s, 10); s = removeDigit(s,10); int rot1 = getValue(s, 26); s = removeDigit(s,26); int ring1 = getValue(s, 26); s = removeDigit(s,26); int rot2 = getValue(s, 26); s = removeDigit(s,26); int ring2 = getValue(s, 26); s = removeDigit(s,26); int rot3 = getValue(s, 26); s = removeDigit(s,26); int ring3 = getValue(s, 26); s = removeDigit(s,26); int rot4 = getValue(s, 26); s = removeDigit(s,26); int ring4 = getValue(s, 26); s = removeDigit(s,26); int rotRef = getValue(s, 26); s = removeDigit(s,26); int ringRef = getValue(s, 26); this.rotor1 = Rotor.createRotor(machineTypeOffset + r1, rot1, ring1); this.rotor2 = Rotor.createRotor(machineTypeOffset + r2, rot2, ring2); this.rotor3 = Rotor.createRotor(machineTypeOffset + r3, rot3, ring3); this.rotor4 = Rotor.createRotor(machineTypeOffset + r4, rot4, ring4); this.reflector = Reflector.createReflector(machineTypeOffset + ref); this.reflector.setRotation(rotRef); this.reflector.setRingSetting(ringRef); this.plugboard = new Plugboard(); plugboard.setConfiguration(Plugboard.stringToConfiguration(plugboardConf)); } @Override public String stateToString() { String save = MainActivity.APP_ID+"/"; long s = reflector.getRingSetting(); s = addDigit(s, reflector.getRotation(), 26); s = addDigit(s, rotor4.getRingSetting(), 26); s = addDigit(s, rotor4.getRotation(), 26); s = addDigit(s, rotor3.getRingSetting(), 26); s = addDigit(s, rotor3.getRotation(), 26); s = addDigit(s, rotor2.getRingSetting(), 26); s = addDigit(s, rotor2.getRotation(), 26); s = addDigit(s, rotor1.getRingSetting(), 26); s = addDigit(s, rotor1.getRotation(), 26); s = addDigit(s, reflector.getNumber(), 10); s = addDigit(s, rotor4.getNumber(), 10); s = addDigit(s, rotor3.getNumber(), 10); s = addDigit(s, rotor2.getNumber(), 10); s = addDigit(s, rotor1.getNumber(), 10); s = addDigit(s, 2, 20); save = save+s; save = save + ":p" + Plugboard.configurationToString(getState().getConfigurationPlugboard()); return save; } }