///<inheritdoc/>
public override string Run(string input, bool forward)
{
var output = new StringBuilder();
int indexer = 0;
foreach (var c in input)
{
if (indexer == Key.Length)
{
indexer = 0;
}
var steps = Alphabet.IndexOf(Key[indexer]) * (forward ? 1 : -1);
output.Append(Alphabet.WrapChar(c, steps));
indexer++;
}
return(output.ToString());
}
/// <summary>
/// A special run for the Enigma. Simulates a key press and returns a result.
/// </summary>
/// <param name="input">The character that has been depressed</param>
/// <returns>The output, i.e the character that will be lit in the lamp</returns>
public virtual char Run(char input)
{
//Rotate the FastRotor
Rotors[0].Rotate();
//Get the index of the letter in the alphabet:
int index = Alphabet.IndexOf(input);
//Pass the current to the Stator:
index = Stator.GetPath(index, true);
//Pass the current through successive rotors:
for (int i = 0; i < Rotors.Count; i++)
{
index = Rotors[i].GetPath(index, true);
}
//Pass the current the Reflector
index = Reflector.GetPath(index, true);
//Pass through the rotors in reverse:
for (int i = Rotors.Count - 1; i > -1; i--)
{
var rotor = Rotors[i];
index = rotor.GetPath(index, false);
}
//Pass the current through the Stator:
index = Stator.GetPath(index, false);
var result = Alphabet[index];
//perform plugboard simulation:
if (Plugboard != null)
{
result = Plugboard.Simulate(result);
}
return(result);
}
public static EnigmaMachine Load(Stream stream)
{
using var reader = new BinaryReader(stream);
//HEADER
var buffer = reader.ReadString();
if (buffer != "EGMC")
{
throw new FormatException("Not a valid Enigma Machine File");
}
//ALPHABET
buffer = reader.ReadString();
if (buffer != "alph")
{
throw new FormatException("Not a valid Enigma Machine File");
}
var len = reader.ReadInt32();
buffer = reader.ReadString();
var alphabet = new Alphabet(buffer);
//AUTORESET
var autroreset = reader.ReadBoolean();
//STATOR AND REFLECTOR
var list = new string[] { "ETW ", "UKW " };
var wheels = new List <EnigmaWheel>(2);
foreach (var item in list)
{
buffer = reader.ReadString();
if (buffer != item)
{
throw new FormatException("Not a valid Enigma Machine File");
}
buffer = reader.ReadString();
if (buffer != "indx")
{
throw new FormatException("Not a valid Enigma Machine File");
}
len = reader.ReadInt32();
buffer = reader.ReadString();
var indexing = new Alphabet(buffer);
buffer = reader.ReadString();
if (buffer != "wire")
{
throw new FormatException("Invalid/Corrupted Enigma File");
}
len = reader.ReadInt32();
buffer = reader.ReadString();
var wiring = new Alphabet(buffer);
var wheel = new EnigmaWheel(indexing, wiring);
wheels.Add(wheel);
}
//ROTORS
buffer = reader.ReadString();
if (buffer != "ROTS")
{
throw new FormatException("Invalid/Corrupted Enigma File");
}
len = reader.ReadInt32();
var builder = new StringBuilder();
var rotors = new List <Rotor>();
while (true)
{
builder.Clear();
buffer = reader.ReadString();
if (buffer != "indx")
{
throw new FormatException("Invalid/Corrupted Enigma File");
}
len = reader.ReadInt32();
buffer = reader.ReadString();
var indexing = new Alphabet(buffer);
buffer = reader.ReadString();
if (buffer != "wire")
{
throw new FormatException("Invalid/Corrupted Enigma File");
}
len = reader.ReadInt32();
buffer = reader.ReadString();
var wiring = new Alphabet(buffer);
var wheel = new EnigmaWheel(indexing, wiring);
buffer = reader.ReadString();
if (buffer != "ntch")
{
throw new FormatException("Invalid/Corrupted Enigma File");
}
len = reader.ReadInt32();
for (int t = 0; t < len; t++)
{
builder.Append(reader.ReadChar());
}
var rotor = new Rotor(indexing, wiring, builder.ToString());
rotors.Add(rotor);
if (reader.PeekChar() == -1)
{
break;
}
}
//BUILDER
return(new EnigmaMachineBuilder()
.WithAlphabet(alphabet)
.WithRotors(rotors)
.WithStator(wheels[0])
.WithReflector(wheels[1])
.Build());
}
public void Save(Stream stream)
{
//header
using var writer = new BinaryWriter(stream);
//Header
writer.Write("EGMC");
//Alphabet
writer.Write("alph");
writer.Write(Alphabet.Count);
writer.Write(Alphabet.ToString());
//Whether we autoreset
writer.Write(AutoReset);
//Stator Indexing:
writer.Write("ETW ");
writer.Write("indx");
writer.Write(Stator.Indexing.Count);
writer.Write(Stator.Indexing.ToString());
//Stator Wiring
writer.Write("wire");
writer.Write(Stator.Wiring.Count);
writer.Write(Stator.Wiring.ToString());
//Reflector Indexing
writer.Write("UKW ");
writer.Write("indx");
writer.Write(Reflector.Indexing.Count);
writer.Write(Reflector.Indexing.ToString());
//Reflector Wiring
writer.Write("wire");
writer.Write(Reflector.Wiring.Count);
writer.Write(Reflector.Wiring.ToString());
//Rotors
writer.Write("ROTS");
writer.Write(Rotors.Count);
foreach (var rotor in Rotors)
{
//Indexing
writer.Write("indx");
writer.Write(rotor.Indexing.Count);
writer.Write(rotor.Indexing.ToString());
//Wiring
writer.Write("wire");
writer.Write(rotor.Wiring.Count);
writer.Write(rotor.Wiring.ToString());
//Turnover Notch
writer.Write("ntch");
writer.Write(rotor.TurnOver.Count);
foreach (var notch in rotor.TurnOver)
{
writer.Write(notch);
}
}
}
/// <summary>
/// Creates a rotor from the specified configuration
/// </summary>
/// <param name="indexing">The index etching/></param>
/// <param name="wiring">The wiring etching</param>
/// <param name="turnOvers">A string, each <see cref="char"/> representing a turnover point</param>
public Rotor(Alphabet indexing, Alphabet wiring, string turnOvers) : base(indexing, wiring)
{
TurnOver = new List <char>(turnOvers);
}
///<inheritdoc/>
public override string Run(string input, bool forward)
{
var keytable = new Alphabet(Alphabet.ToString())
{
Dimensions = Alphabet.Dimensions
};
var distinct = Key.Distinct().ToList();
for (int i = 0; i < distinct.Count; i++)
{
keytable.Move(distinct[i], i);
}
if (input.Length % 2 != 0)
{
input += Alphabet[Alphabet.Count - 1];
}
var multiplier = forward ? 1 : -1;
var output = new StringBuilder();
//Let the ciphering begin:
for (int i = 0; i < input.Length; i += 2)
{
var a = keytable.DimensionsOf(input[i]);
var b = keytable.DimensionsOf(input[i + 1]);
var newA = new Dimensions(b.X, a.Y);
var newB = new Dimensions(a.X, b.Y);
if (a.X == b.X || a.Y == b.Y)
{
newA = a;
newB = b;
//SamePoint
if (a == b)
{
newA.X = PrefferredOrientation == PrefferredOrientation.Horizontal ?
newA.X += multiplier : newA.X;
newA.Y = PrefferredOrientation == PrefferredOrientation.Vertical ?
newA.Y += multiplier : newA.Y;
newB = new Dimensions(newA.X, newA.Y);
}
//SameCol
else if (a.X == b.X)
{
newA.Y += multiplier;
newB.Y += multiplier;
}
//SameRow
else
{
newA.X += multiplier;
newB.X += multiplier;
}
newA.Limit(keytable.Dimensions);
newB.Limit(keytable.Dimensions);
}
output.Append(keytable[newA]);
output.Append(keytable[newB]);
}
return(output.ToString());
}
///<inheritdoc/>
public Rotor(Alphabet indexing, Alphabet wiring) : base(indexing, wiring)
{
}
/// <summary>
/// The alphabet to be used, in the machine and by the builder when creating the rotors and stators.
/// When not provided, the default <see cref="Alphabets.ASCII"/> is used.
/// </summary>
/// <param name="alphabet"></param>
/// <returns></returns>
public EnigmaMachineBuilder WithAlphabet(Alphabet alphabet)
{
_alphabet = alphabet;
return(this);
}
/// <summary>
/// Builds an <see cref="EnigmaMachine"/> with the provided parameters.
/// </summary>
/// <returns></returns>
public EnigmaMachine Build()
{
var shuffle = new Alphabet(_alphabet.ToString());
//the stator:
var stator = _stator;
if (stator == null)
{
stator = new EnigmaWheel(_alphabet.ToString(), _alphabet.ToString());
}
//the reflector
var reflector = _reflector;
if (reflector == null)
{
shuffle.Shuffle();
reflector = new EnigmaWheel(_alphabet.ToString(), shuffle.ToString());
reflector.Reflect();
}
//the rotors
List <Rotor> rotors;
if (_rotors == null)
{
rotors = new List <Rotor>();
for (int i = 0; i < _rotorCount; i++)
{
string notches = "";
for (int n = 0; n < _notchCount; n++)
{
char c;
do
{
int rnd = Horus.Random(0, _alphabet.Count);
c = _alphabet[rnd];
} while (notches.Contains(c));
notches += c;
}
shuffle.Shuffle();
var rotor = new Rotor(_alphabet.ToString(), shuffle.ToString(), notches);
rotors.Add(rotor);
}
}
else
{
rotors = new List <Rotor>(_rotors);
}
//the actual construction
return(new EnigmaMachine(rotors)
{
Alphabet = _alphabet,
AutoReset = _autoReset,
Stator = stator,
Reflector = reflector,
});
}
/// <summary>
/// Creates a wheel from the specified indexing and wiring
/// </summary>
/// <param name="indexing">The index etchings</param>
/// <param name="wiring">The scrambled of the indexing</param>
public EnigmaWheel(string indexing, string wiring)
{
Indexing = new Alphabet(indexing);
Wiring = new Alphabet(wiring);
}
/// <summary>
/// Creates a wheel from the specified indexing and wiring
/// </summary>
/// <param name="indexing">The index etchings</param>
/// <param name="wiring">The scrambled of the indexing</param>
public EnigmaWheel(Alphabet indexing, Alphabet wiring)
{
Indexing = indexing;
Wiring = wiring;
}
