using System;
using System.Collections.Generic;
using System.Text;
namespace SimpleCryptographer.DES
{
class ProcessDES : CommonProcess
{
public ProcessDES(Form1.ProgressEventHandler IncrementProgress, Form1.ProgressInitHandler InitProgress)
{
this.IncrementProgress = IncrementProgress;
this.InitProgress = InitProgress;
}
#region Event for progress bar
public event Form1.ProgressInitHandler InitProgress;
public event Form1.ProgressEventHandler IncrementProgress;
protected virtual void OnIncrementProgress(ProgressEventArgs e)
{
if (IncrementProgress != null)
IncrementProgress(this, e);
}
protected virtual void OnInitProgress(ProgressInitArgs e)
{
if (InitProgress != null)
InitProgress(this, e);
}
#endregion
#region Encryption Process
public override/*static*/ string EncryptionStart(string text, string key, bool IsTextBinary)
{
#region Get 16 sub-keys using key
string hex_key = this.FromTextToHex(key);
string binary_key = this.FromHexToBinary(hex_key);
string key_plus = this.DoPermutation(binary_key, DESData.pc_1);
string C0 = "", D0 = "";
C0 = this.SetLeftHalvesKey(key_plus);
D0 = this.SetRightHalvesKey(key_plus);
Keys keys = this.SetAllKeys(C0, D0);
#endregion
#region Encrypt process
//string hex_text = this.FromTextToHex(text);
string binaryText = "";
if (IsTextBinary == false)
{
binaryText = this.FromTextToBinary(text);
}
else
{
binaryText = text;
}
binaryText = this.setTextMutipleOf64Bits(binaryText);
#region Initialize Progress Bar
OnInitProgress(new ProgressInitArgs(binaryText.Length));
#endregion
StringBuilder EncryptedTextBuilder = new StringBuilder(binaryText.Length);
for (int i = 0; i < (binaryText.Length / 64); i++)
{
string PermutatedText = this.DoPermutation(binaryText.Substring(i * 64, 64), DESData.ip);
string L0 = "", R0 = "";
L0 = this.SetLeftHalvesKey(PermutatedText);
R0 = this.SetRightHalvesKey(PermutatedText);
string FinalText = this.FinalEncription(L0, R0, keys, false);
EncryptedTextBuilder.Append(FinalText);
#region Increase Progress Bar
OnIncrementProgress(new ProgressEventArgs(FinalText.Length));
#endregion
}
return EncryptedTextBuilder.ToString();
#endregion
}
#endregion
#region Decryption Process
public override/*static*/ string DecryptionStart(string text, string key, bool IsTextBinary)
{
#region Get 16 sub-keys using key
string hex_key = this.FromTextToHex(key);
string binary_key = this.FromHexToBinary(hex_key);
string key_plus = this.DoPermutation(binary_key, DESData.pc_1);
string C0 = "", D0 = "";
C0 = this.SetLeftHalvesKey(key_plus);
D0 = this.SetRightHalvesKey(key_plus);
Keys keys = this.SetAllKeys(C0, D0);
#endregion
#region Decrypt process
string binaryText = "";
if (IsTextBinary == false)
{
binaryText = this.FromTextToBinary(text);
}
else
{
binaryText = text;
}
binaryText = this.setTextMutipleOf64Bits(binaryText);
#region Initialize Progress Bar
OnInitProgress(new ProgressInitArgs(binaryText.Length));
#endregion
StringBuilder DecryptedTextBuilder = new StringBuilder(binaryText.Length);
for (int i = 0; i < (binaryText.Length / 64); i++)
{
string PermutatedText = this.DoPermutation(binaryText.Substring(i * 64, 64), DESData.ip);
string L0 = "", R0 = "";
L0 = this.SetLeftHalvesKey(PermutatedText);
R0 = this.SetRightHalvesKey(PermutatedText);
string FinalText = this.FinalEncription(L0, R0, keys, true);
#region It's for correct subtracted '0' that have added for set text multiple of 64bit
if ((i * 64 + 64) == binaryText.Length)
{
StringBuilder last_text = new StringBuilder(FinalText.TrimEnd('0'));
int count = FinalText.Length - last_text.Length;
if ((count % 8) != 0)
{
count = 8 - (count % 8);
}
string append_text = "";
for (int k = 0; k < count; k++)
{
append_text += "0";
}
DecryptedTextBuilder.Append(last_text.ToString() + append_text);
}
#endregion
else
{
DecryptedTextBuilder.Append(FinalText);
}
//DecryptedTextBuilder.Append(FinalText);
#region Increase Progress Bar
OnIncrementProgress(new ProgressEventArgs(FinalText.Length));
#endregion
}
return DecryptedTextBuilder.ToString();//.TrimEnd('0');
#endregion
}
#endregion
#region Check a string whether Korean or not. - not used in this program.
public /*static*/ bool IsKorean(char word)
{
if (word >= '\xAC00' && word <= '\xD7AF')
{
return true;
}
if (word >= '\x3130' && word <= '\x318F')
{
return true;
}
return false;
}
#endregion
#region Transform a text to a hex
public string FromTextToHex(string text)
{
string hexstring = "";
foreach (char word in text)
{
hexstring += String.Format("{0:X}", Convert.ToInt32(word));
}
return hexstring;
}
#endregion
#region Transform a hex or a binary number to text
public string FromHexToText(string hexstring)
{
StringBuilder text = new StringBuilder(hexstring.Length / 2);
for (int i = 0; i < (hexstring.Length / 2); i++)
{
string word = hexstring.Substring(i * 2, 2);
text.Append((char)Convert.ToInt32(word, 16));
}
return text.ToString();
}
public /*static*/ string FromBinaryToText(string binarystring)
{
StringBuilder text = new StringBuilder(binarystring.Length / 8);
for (int i = 0; i < (binarystring.Length / 8); i++)
{
string word = binarystring.Substring(i * 8, 8);
text.Append((char)Convert.ToInt32(word, 2));
//text += (char)Convert.ToInt32(word, 16);
}
return text.ToString();
}
#endregion
#region Set a length of text to multiple of 64 bits
public string setTextMutipleOf64Bits(string text)
{
if ((text.Length % 64) != 0)
{
int maxLength = 0;
maxLength = ((text.Length / 64) + 1) * 64;
text = text.PadRight(maxLength, '0');
}
return text;
}
#endregion
#region Transform an integer to binary number
public string FromTextToBinary(string text)
{
StringBuilder binarystring = new StringBuilder(text.Length * 8);
foreach (char word in text)
{
int binary = (int)word;
int factor = 128;
for (int i = 0; i < 8; i++)
{
if (binary >= factor)
{
binary -= factor;
binarystring.Append("1");
}
else
{
binarystring.Append("0");
}
factor /= 2;
}
}
return binarystring.ToString();
}
public static string FromDeciamlToBinary(int binary)
{
if (binary < 0)
{
Console.WriteLine("It requires a integer greater than 0.");
return null;
}
string binarystring = "";
int factor = 128;
for (int i = 0; i < 8; i++)
{
if (binary >= factor)
{
binary -= factor;
binarystring += "1";
}
else
{
binarystring += "0";
}
factor /= 2;
}
return binarystring;
}
public static byte FromBinaryToByte(string binary)
{
byte value = 0;
int factor = 128;
for (int i = 0; i < 8; i++)
{
if (binary[i] == '1')
{
value += (byte)factor;
}
factor /= 2;
}
return value;
}
#endregion
#region Transform a hex integer to a binary number
public string FromHexToBinary(string hexstring)
{
string binarystring = "";
try
{
for (int i = 0; i < hexstring.Length; i++)
{
int hex = Convert.ToInt32(hexstring[i].ToString(), 16);
int factor = 8;
for(int j=0; j<4; j++)
{
if (hex >= factor)
{
hex -= factor;
binarystring += "1";
}
else
{
binarystring += "0";
}
factor /= 2;
}
}
}
catch (Exception e)
{
Console.WriteLine(e.Message + " - wrong hexa integer format.");
}
return binarystring;
}
#endregion
#region Permutation
public string DoPermutation(string text, int[] order)
{
StringBuilder PermutatedText = new StringBuilder(order.Length);
for (int i = 0; i < order.Length; i++)
{
PermutatedText.Append(text[order[i] - 1]);
}
return PermutatedText.ToString();
}
//For SBoxes Transformation
public string DoPermutation(string text, int[,] order)
{
string PermutatedText = "";
int rowIndex = Convert.ToInt32(text[0].ToString() + text[text.Length - 1].ToString(), 2);
int colIndex = Convert.ToInt32(text.Substring(1, 4), 2);
PermutatedText = ProcessDES.FromDeciamlToBinary(order[rowIndex, colIndex]);
return PermutatedText;
}
#endregion
#region Divide a text to left and right halves
public string SetLeftHalvesKey(string text)
{
return this.SetHalvesKey(true, text);
}
public string SetRightHalvesKey(string text)
{
return this.SetHalvesKey(false, text);
}
public string SetHalvesKey(bool IsLeft, string text)
{
if ((text.Length % 8) != 0)
{
Console.WriteLine("The key is not multiple of 8bit.");
return null;
}
int midindex = (text.Length / 2) - 1;
string result = "";
if (IsLeft)
{
result = text.Substring(0, midindex + 1);
}
else
{
result = text.Substring(midindex + 1);
}
return result;
}
#endregion
#region Do Leftshift
public string LeftShift(string text)
{
return this.LeftShift(text, 1);
}
public string LeftShift(string text, int count)
{
if (count < 1)
{
Console.WriteLine("The count of leftshift is must more than 1 time.");
return null;
}
string temp = text.Substring(0, count);
StringBuilder shifted = new StringBuilder(text.Length);
shifted.Append(text.Substring(count) + temp);
return shifted.ToString();
}
#endregion
#region Key���� ���ϴ� ���� - Get all of keys
public Keys SetAllKeys(string C0, string D0)
{
Keys keys = new Keys();
keys.Cn[0] = C0;
keys.Dn[0] = D0;
for (int i = 1; i < keys.Cn.Length; i++)
{
keys.Cn[i] = this.LeftShift(keys.Cn[i - 1], DESData.nrOfShifts[i]);
keys.Dn[i] = this.LeftShift(keys.Dn[i - 1], DESData.nrOfShifts[i]);
keys.Kn[i - 1] = this.DoPermutation(keys.Cn[i] + keys.Dn[i], DESData.pc_2);
}
return keys;
}
#endregion
#region Do Encryption
public string FinalEncription(string L0, string R0, Keys keys, bool IsReverse)
{
string Ln = "", Rn = "", Ln_1 = L0, Rn_1 = R0;
int i = 0;
if (IsReverse == true)
{
i = 15;
}
while (this.IsEnough(i, IsReverse))
{
Ln = Rn_1;
Rn = this.XOR(Ln_1, this.f(Rn_1, keys.Kn[i]));
//Next Step of L1, R1 is L2 = R1, R2 = L1 + f(R1, K2), hence, value of Step1's Ln, Rn is Rn_1, Ln_1 in Step2.
Ln_1 = Ln;
Rn_1 = Rn;
if (IsReverse == false)
{
i += 1;
}
else
{
i -= 1;
}
}
string R16L16 = Rn + Ln;
string Encripted_Text = this.DoPermutation(R16L16, DESData.ip_1);
return Encripted_Text;
}
public /*static*/ bool IsEnough(int i, bool IsReverse)
{
return (IsReverse == false) ? i < 16 : i >= 0;
}
#endregion
#region The function f
public string f(string Rn_1, string Kn)
{
string E_Rn_1 = this.E_Selection(Rn_1);
string XOR_Rn_1_Kn = this.XOR(E_Rn_1, Kn);
string sBoxedText = this.sBox_Transform(XOR_Rn_1_Kn);
string P_sBoxedText = this.P(sBoxedText);
return P_sBoxedText;
}
#endregion
#region The function P
public string P(string text)
{
string PermutatedText = "";
PermutatedText = this.DoPermutation(text, DESData.pc_p);
return PermutatedText;
}
#endregion
#region SBoxes transformation
public string sBox_Transform(string text)
{
StringBuilder TransformedText = new StringBuilder(32);
for (int i = 0; i < 8; i++)
{
string temp = text.Substring(i * 6, 6);
TransformedText.Append(this.DoPermutation(temp, DESData.sBoxes[i]));
}
return TransformedText.ToString();
}
#endregion
#region E Selection
public string E_Selection(string Rn_1)
{
string ExpandedText = this.DoPermutation(Rn_1, DESData.pc_e);
return ExpandedText;
}
#endregion
#region XOR operation
public string XOR(string text1, string text2)
{
if (text1.Length != text2.Length)
{
Console.WriteLine("Two data blocks for XOR are must get same size.");
return null;
}
StringBuilder XORed_Text = new StringBuilder(text1.Length);
for (int i = 0; i < text1.Length; i++)
{
if (text1[i] != text2[i])
{
XORed_Text.Append("1");
}
else
{
XORed_Text.Append("0");
}
}
return XORed_Text.ToString();
}
#endregion
}
}
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