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enigma.py
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enigma.py
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class EnigmaKey:
def __init__(self,
rotors,
indicators,
rings,
plugboardConnections
):
if rotors == None:
self.rotors ["I", "II", "III"]
else:
self.rotors = rotors
if indicators == None:
self.indicators = [0,0,0]
else:
self.indicators = indicators
if rings == None:
self.rings = [0,0,0]
else:
self.rings = rings
if plugboardConnections ==None:
self.plugboard = ""
else:
self.plugboard = plugboardConnections
class Reflector:
def __init__(self, encoding):
self.forwardWiring = Reflector.decodeWiring(encoding)
@staticmethod
def Create(name):
if name == "B":
return Reflector("YRUHQSLDPXNGOKMIEBFZCWVJAT")
elif name == "C":
return Reflector("FVPJIAOYEDRZXWGCTKUQSBNMHL")
else:
return Reflector("ZYXWVUTSRQPONMLKJIHGFEDCBA")
@staticmethod
def decodeWiring(encoding):
charWiring = encoding
wiring = []
for i in range(len(charWiring)):
wiring.append(ord(charWiring[i]) - 65)
return wiring
def forward(self, c):
return self.forwardWiring[c]
class Plugboard:
def __init__(self, connections):
self.wiring = self.decodePlugboard(connections)
@staticmethod
def nonAlphaSplit(text):
res = []
text = "#"+text
for i in range(len(text)):
ch = text[i]
if ch.isalpha():
prevCh = text[i-1]
if prevCh.isalpha():
res[-1] += ch
else:
res.append(ch)
return res
def forward(self, c):
return self.wiring[c]
@staticmethod
def identityPlugboard():
mapping = []
for i in range(26):
mapping.append(i)
return mapping
@staticmethod
def getUnpluggedCharacters(plugboard):
unpluggedCharacters = set()
for i in range(26):
unpluggedCharacters.add(i)
if plugboard== "":
return unpluggedCharacters
pairings = Plugboard.nonAlphaSplit(plugboard)
# Validate and create mapping
for pair in pairings:
c1 = ord(pair[0]) - 65
c2 = ord(pair[1]) - 65
unpluggedCharacters.remove(c1)
unpluggedCharacters.remove(c2)
return unpluggedCharacters
@staticmethod
def decodePlugboard(plugboard):
if (plugboard == None or plugboard== ""):
return Plugboard.identityPlugboard()
pairings = Plugboard.nonAlphaSplit(plugboard)
pluggedCharacters = set()
mapping = Plugboard.identityPlugboard()
# Validate and create mapping
for pair in pairings:
if (len(pair) != 2):
return Plugboard.identityPlugboard()
c1 = ord(pair[0]) - 65
c2 = ord(pair[1]) - 65
if (c1 in pluggedCharacters or c2 in pluggedCharacters):
return Plugboard.identityPlugboard()
pluggedCharacters.add(c1)
pluggedCharacters.add(c2)
mapping[c1] = c2
mapping[c2] = c1
return mapping
class Rotor:
def __init__(self,
name,
encoding,
rotorPosition,
notchPosition,
ringSetting,
overrideIsAtNotch = False
):
self.name = name
self.forwardWiring = self.decodeWiring(encoding)
self.backwardWiring = self.inverseWiring(self.forwardWiring)
self.rotorPosition = rotorPosition
self.notchPosition = notchPosition
self.ringSetting = ringSetting
self.overrideIsAtNotch = overrideIsAtNotch
@staticmethod
def Create(name, rotorPosition, ringSetting):
if name == "I":
return Rotor("I","EKMFLGDQVZNTOWYHXUSPAIBRCJ", rotorPosition, 16, ringSetting)
elif name == "II":
return Rotor("II","AJDKSIRUXBLHWTMCQGZNPYFVOE", rotorPosition, 4, ringSetting)
elif name == "III":
return Rotor("III","BDFHJLCPRTXVZNYEIWGAKMUSQO", rotorPosition, 21, ringSetting)
elif name == "IV":
return Rotor("IV","ESOVPZJAYQUIRHXLNFTGKDCMWB", rotorPosition, 9, ringSetting)
elif name == "V":
return Rotor("V","VZBRGITYUPSDNHLXAWMJQOFECK", rotorPosition, 25, ringSetting)
elif name == "VI":
return Rotor("VI","JPGVOUMFYQBENHZRDKASXLICTW", rotorPosition, 0, ringSetting, True)
elif name == "VII":
return Rotor("VII","NZJHGRCXMYSWBOUFAIVLPEKQDT", rotorPosition, 0, ringSetting, True)
elif name == "VIII":
return Rotor("VIII","FKQHTLXOCBJSPDZRAMEWNIUYGV", rotorPosition, 0, ringSetting, True)
else:
return Rotor("Identity","ABCDEFGHIJKLMNOPQRSTUVWXYZ", rotorPosition, 0, ringSetting)
def getName(self):
return self.name
def getPosition(self):
return self.rotorPosition
@staticmethod
def decodeWiring(encoding):
charWiring = encoding
wiring = []
for i in range(len(charWiring)):
wiring.append(ord(charWiring[i]) - 65)
return wiring
@staticmethod
def inverseWiring(wiring):
inverse = list(range(len(wiring)))
for i in range(len(wiring)):
forward = wiring[i]
inverse[forward] = i
return inverse
@staticmethod # protected static int
def encipher(k, pos, ring, mapping):
shift = pos - ring
return (mapping[(k + shift + 26) % 26] - shift + 26) % 26
def forward(self, c):
return Rotor.encipher(c, self.rotorPosition, self.ringSetting, self.forwardWiring)
def backward(self, c):
return Rotor.encipher(c, self.rotorPosition, self.ringSetting, self.backwardWiring)
def isAtNotch(self):
if self.overrideIsAtNotch:
self.rotorPosition == 12 or self.rotorPosition == 25
else:
return self.notchPosition == self.rotorPosition
def turnover(self):
self.rotorPosition = (self.rotorPosition + 1) % 26
class Enigma:
def __init__(self,
rotors,
reflector,
rotorPositions,
ringSettings,
plugboardConnections
):
# 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
self.leftRotor = Rotor.Create(rotors[0], rotorPositions[0], ringSettings[0])
self.middleRotor = Rotor.Create(rotors[1], rotorPositions[1], ringSettings[1])
self.rightRotor = Rotor.Create(rotors[2], rotorPositions[2], ringSettings[2])
self.reflector = Reflector.Create(reflector)
self.plugboard = Plugboard(plugboardConnections)
@staticmethod
def init_by_key(key):
return Enigma(key.rotors, "B", key.indicators, key.rings, key.plugboard)
def rotate(self):
# If middle rotor notch - double-stepping
if (self.middleRotor.isAtNotch()):
self.middleRotor.turnover()
self.leftRotor.turnover()
# If left-rotor notch
elif (self.rightRotor.isAtNotch()):
self.middleRotor.turnover()
# Increment right-most rotor
self.rightRotor.turnover()
def encrypt(self, c):
self.rotate()
# Plugboard in
c = self.plugboard.forward(c)
# Right to left
c1 = self.rightRotor.forward(c)
c2 = self.middleRotor.forward(c1)
c3 = self.leftRotor.forward(c2)
# Reflector
c4 = self.reflector.forward(c3)
# Left to right
c5 = self.leftRotor.backward(c4)
c6 = self.middleRotor.backward(c5)
c7 = self.rightRotor.backward(c6)
# Plugboard out
c7 = self.plugboard.forward(c7)
return c7
def encrypt_ch(self, c):
return chr(self.encrypt(ord(c) - 65) + 65)
def encrypt_text(self, text):
output = []
for i in range(len(text)):
output.append(self.encrypt_ch(text[i]))
return output
if __name__ == "__main__":
print(
"""This is an Enigma machine, written by Eric 2021
This code based on Mike Pound's github repository:
https://github.com/mikepound/enigma
It is rewritten in pure Python code
Let's set the key for enigma machine as followings:
e = Engima(
["VII", "V", "IV"], "B",
[10,5,12], [1,2,3],
"AD FT WH JO PN"
)
Please input your text to process: """)
e = Enigma(
["VII", "V", "IV"],
"B",
[10,5,12],
[1,2,3],
"AD FT WH JO PN"
)
#text = "HELLO WORLD"
text = input().upper()
print("\nFollowing is the output from Enigma Machine:")
texts = text.split(" ")
for t in texts:
print(t, "".join(e.encrypt_text(t)))