//For SBoxes Transformation
private string DoPermutation(string text, int[,] order)
{
int rowIndex = ToInt32(text[0].ToString() + text[text.Length - 1].ToString(), 2);
int colIndex = ToInt32(text.Substring(1, 4), 2);
return(Converts.FromDecimalToBinary(order[rowIndex, colIndex]));
}
private string MainAlgorithm(bool isEncode, string text, string key, bool IsTextBinary)
{
var hexKey = Converts.FromTextToHex(key);
var binaryKey = Converts.FromHexToBinary(hexKey);
var keyPlus = DoPermutation(binaryKey, Rearranging.KeyPosition);
var C0 = TextHelper.SetLeftHalvesKey(keyPlus);
var D0 = TextHelper.SetRightHalvesKey(keyPlus);
var keys = SetAllKeys(C0, D0);
var binaryText = !IsTextBinary?Converts.FromTextToBinary(text) : text;
binaryText = TextHelper.setTextMutipleOf64Bits(binaryText);
var cipherTextBuilder = new StringBuilder(binaryText.Length);
for (int i = 0; i < (binaryText.Length / LENGTH_OF_DES_BLOCKS); i++)
{
var permutatedText = DoPermutation(
binaryText.Substring(i * LENGTH_OF_DES_BLOCKS, LENGTH_OF_DES_BLOCKS),
Rearranging.FirstChangingIP);
var L0 = TextHelper.SetLeftHalvesKey(permutatedText);
var R0 = TextHelper.SetRightHalvesKey(permutatedText);
var finalText = FinalEncription(L0, R0, keys, !isEncode);
if (!isEncode && LENGTH_OF_DES_BLOCKS * (i + 1) == binaryText.Length)
{
var lastText = new StringBuilder(finalText.TrimEnd('0'));
var count = finalText.Length - lastText.Length;
if ((count % 8) != 0)
{
count = 8 - (count % 8);
}
var appendText = string.Empty;
for (int k = 0; k < count; k++)
{
appendText += "0";
}
cipherTextBuilder.Append(lastText.ToString() + appendText);
}
else
{
cipherTextBuilder.Append(finalText);
}
}
return(Converts.FromBinaryToText(cipherTextBuilder.ToString()));
}