public void TestSwap()
{
CStreamWriter writer = new CStreamWriter();
// fill buffer with Length-1 bytes
writer.Write(LongData);
Assert.AreEqual(LongData.Length, writer.Position);
Assert.IsFalse(writer.IsSwapped);
// fill last byte
writer.WriteByte(5);
Assert.AreEqual(LongData.Length + 1, writer.Position);
Assert.IsFalse(writer.IsSwapped);
// write one byte more, assert swap
writer.WriteByte(10);
Assert.AreEqual(LongData.Length + 2, writer.Position);
Assert.IsTrue(writer.IsSwapped);
}
public void Execute()
{
try
{
// this is for localization
ResourceManager resourceManager = new ResourceManager("Cryptool.RC4.Properties.Resources", GetType().Assembly);
// make sure we have a valid data input
if (inputData == null)
{
GuiLogMessage(resourceManager.GetString("ErrorInputDataNotProvided"), NotificationLevel.Error);
return;
}
// make sure we have a valid key input
if (inputKey == null)
{
GuiLogMessage(resourceManager.GetString("ErrorInputKeyNotProvided"), NotificationLevel.Error);
return;
}
byte[] key = ToByteArray(inputKey);
// make sure the input key is within the desired range
if ((key.Length < 5 || key.Length > 256))
{
GuiLogMessage(resourceManager.GetString("ErrorInputKeyInvalidLength"), NotificationLevel.Error);
return;
}
// now execute the actual encryption
using (CStreamReader reader = inputData.CreateReader())
{
// create the output stream
outputStreamWriter = new CStreamWriter();
// some variables
int i = 0;
int j = 0;
// create the sbox
byte[] sbox = new byte[256];
// initialize the sbox sequentially
for (i = 0; i < 256; i++)
{
sbox[i] = (byte)(i);
}
// re-align the sbox (and incorporate the key)
j = 0;
for (i = 0; i < 256; i++)
{
j = (j + sbox[i] + key[i % key.Length]) % 256;
byte sboxOld = sbox[i];
sbox[i] = sbox[j];
sbox[j] = sboxOld;
}
// process the input data using the modified sbox
int position = 0;
DateTime startTime = DateTime.Now;
// some inits
i = 0;
j = 0;
long bytesRead = 0;
const long blockSize = 256;
byte[] buffer = new byte[blockSize];
while ((bytesRead = reader.Read(buffer, 0, buffer.Length)) > 0 && !stop)
{
for (long n = 0; n < bytesRead; n++)
{
i = (i + 1) % 256;
j = (j + sbox[i]) % 256;
byte sboxOld = sbox[i];
sbox[i] = sbox[j];
sbox[j] = sboxOld;
byte sboxRandom = sbox[(sbox[i] + sbox[j]) % 256];
byte cipherByte = (byte)(sboxRandom ^ buffer[n]);
outputStreamWriter.WriteByte(cipherByte);
}
if ((int)(reader.Position * 100 / reader.Length) > position)
{
position = (int)(reader.Position * 100 / reader.Length);
ProgressChanged(reader.Position, reader.Length);
}
}
outputStreamWriter.Close();
// dump status information
DateTime stopTime = DateTime.Now;
TimeSpan duration = stopTime - startTime;
if (!stop)
{
GuiLogMessage("Encryption complete! (in: " + reader.Length.ToString() + " bytes, out: " + outputStreamWriter.Length.ToString() + " bytes)", NotificationLevel.Info);
GuiLogMessage("Time used: " + duration.ToString(), NotificationLevel.Debug);
OnPropertyChanged("OutputStream");
}
if (stop)
{
GuiLogMessage("Aborted!", NotificationLevel.Info);
}
}
}
catch (CryptographicException cryptographicException)
{
GuiLogMessage(cryptographicException.Message, NotificationLevel.Error);
}
catch (Exception exception)
{
GuiLogMessage(exception.Message, NotificationLevel.Error);
}
finally
{
ProgressChanged(1, 1);
}
}
private void Encrypt()
{
int length = settings.BlockKeyLen, bytesRead = 0;
int roundMax = (int)(inputStreamReader.Length / length) + 1;
List <byte> xor = new List <byte>();
List <byte> index = new List <byte>();
List <byte> ciphertext = new List <byte>();
byte[] plaintext = new byte[length];
matrixKey = new byte[passwordBytes.Length];
Buffer.BlockCopy(passwordBytes, 0, matrixKey, 0, passwordBytes.Length);
int round = 1;
while ((bytesRead = inputStreamReader.ReadFully(plaintext)) > 0)
{
if (bytesRead < length)
{
// in der letzten Runde Padding durch hinzufügen von Leerzeichen bis der Puffer voll ist
for (int i = bytesRead; i < plaintext.Length; i++)
{
plaintext[i] = 0x20;
}
}
// Schlüssel generieren
Generator(round);
// Verschlüsseln
// 1. Klartext XOR Blockschlüssel
for (int i = 0; i < length; i++)
{
xor.Add((byte)(plaintext[i] ^ blockKey[i]));
}
// bit conversation
int puffer = 0;
int bitCount = 0;
for (int i = 0; i < length; i++)
{
puffer <<= 8; // mache für die nächsten 8 Bits Platz
puffer |= xor[i]; // schreibe die nächsten 8 Bits in den Puffer
bitCount += 8; // bitCount als Zähler für die Bits im Puffer, erhöhe um 8
index.Add((byte)(puffer >> (bitCount - 7) & 0x7F)); // lies die obersten 7 Bits aus
bitCount -= 7; // verringere um 7, da 7 Bits ausgelesen wurden
// aus Performancegründen werden die gelesenen Bits nicht gelöscht
if (bitCount == 7)
{
index.Add((byte)(puffer & 0x7F)); // haben sich 7 Bits angesammelt, so ließ sie aus
bitCount = 0; // 7 Bits gelesen, 7 - 7 = 0
}
}
switch (bitCount)
{
case 1: index.Add((byte)(puffer & 0x01)); break;
case 2: index.Add((byte)(puffer & 0x03)); break;
case 3: index.Add((byte)(puffer & 0x07)); break;
case 4: index.Add((byte)(puffer & 0x0F)); break;
case 5: index.Add((byte)(puffer & 0x1F)); break;
case 6: index.Add((byte)(puffer & 0x3F)); break;
default: break;
}
// Abbildung auf Chiffre-Alphabet
for (int i = 0; i < index.Count; i++)
{
outputStreamWriter.WriteByte(cipherChars[index[i]]);
}
// Debugdaten schreiben
if (settings.Debug)
{
WriteDebug("\r\n\r\nplaintext (hex): \r\n ");
foreach (byte b in plaintext)
{
WriteDebug(String.Format(" {0:X2}", b));
}
WriteDebug("\r\n\r\nplaintext xor block key (hex): \r\n ");
xor.ForEach(delegate(byte b)
{
WriteDebug(String.Format(" {0:X2}", b));
});
WriteDebug("\r\n\r\nindex: \r\n ");
index.ForEach(delegate(byte b)
{
WriteDebug(String.Format(" {0}", b));
});
WriteDebug("\r\n\r\nciphertext (hex): \r\n ");
CStreamReader reader = outputStreamWriter.CreateReader();
int start = settings.BlockKeyLen * (round - 1);
reader.Seek(start, SeekOrigin.Begin);
for (int i = 0; i < index.Count; i++)
{
WriteDebug(String.Format(" {0:X2}", (byte)reader.ReadByte()));
}
WriteDebug("\r\n\r\n>>>>>>>>>> END OF ROUND <<<<<<<<<<\r\n\r\n\r\n");
}
// Vorbereitungen für die nächste Runde
cipherChars.Clear();
blockKey.Clear();
xor.Clear();
index.Clear();
if (stop)
{
break;
}
roundMax = (int)(inputStreamReader.Length / length) + 1;
ProgressChanged(round, roundMax);
round++;
}
}
