/// <Summary> 
/// DES3 encryption and decryption 
/// </ Summary> 
public class Des3 
{ 
#region CBC mode ** 
 
/// <Summary> 
/// DES3 CBC mode encryption 
/// </ Summary> 
/// <Param name = "key"> key </ param> 
/// <Param name = "iv"> IV </ param> 
/// <Param name = "data"> byte array plaintext </ param> 
/// <Returns> byte array ciphertext </ returns> 
public static byte [] Des3EncodeCBC (byte [] key, byte [] iv, byte [] data) 
{ 
// Copy on MSDN 
 
try 
{ 
// Create a MemoryStream. 
MemoryStream mStream = new MemoryStream (); 
 
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider (); 
tdsp.Mode = CipherMode.CBC; // Default 
tdsp.Padding = PaddingMode.PKCS7; // Default 
 
// Create a CryptoStream using the MemoryStream 
// And the passed key and initialization vector (IV). 
CryptoStream cStream = new CryptoStream (mStream, 
tdsp.CreateEncryptor (key, iv), 
CryptoStreamMode.Write); 
 
// Write the byte array to the crypto stream and flush it. 
cStream.Write (data, 0, data.Length); 
cStream.FlushFinalBlock (); 
 
// Get an array of bytes from the 
// MemoryStream that holds the 
// Encrypted data. 
byte [] ret = mStream.ToArray (); 
 
// Close the streams. 
cStream.Close (); 
mStream.Close (); 
 
// Return the encrypted buffer. 
return ret; 
} 
catch (CryptographicException e) 
{ 
Console.WriteLine ("A Cryptographic error occurred: {0}", e.Message); 
return null; 
} 
} 
 
/// <Summary> 
/// DES3 CBC mode decryption 
/// </ Summary> 
/// <Param name = "key"> key </ param> 
/// <Param name = "iv"> IV </ param> 
/// <Param name = "data"> byte array ciphertext </ param> 
/// <Returns> byte array plaintext </ returns> 
public static byte [] Des3DecodeCBC (byte [] key, byte [] iv, byte [] data) 
{ 
try 
{ 
// Create a new MemoryStream using the passed 
// Array of encrypted data. 
MemoryStream msDecrypt = new MemoryStream (data); 
 
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider (); 
tdsp.Mode = CipherMode.CBC; 
tdsp.Padding = PaddingMode.PKCS7; 
 
// Create a CryptoStream using the MemoryStream 
// And the passed key and initialization vector (IV). 
CryptoStream csDecrypt = new CryptoStream (msDecrypt, 
tdsp.CreateDecryptor (key, iv), 
CryptoStreamMode.Read); 
 
// Create buffer to hold the decrypted data. 
byte [] fromEncrypt = new byte; 
 
// Read the decrypted data out of the crypto stream 
// And place it into the temporary buffer. 
csDecrypt.Read (fromEncrypt, 0, fromEncrypt.Length); 
 
// Convert the buffer into a string and return it. 
return fromEncrypt; 
} 
catch (CryptographicException e) 
{ 
Console.WriteLine ("A Cryptographic error occurred: {0}", e.Message); 
return null; 
} 
} 
 
#endregion 
 
#region ECB mode 
 
/// <Summary> 
/// DES3 ECB mode encryption 
/// </ Summary> 
/// <Param name = "key"> key </ param> 
/// <Param name = "iv"> IV (when the mode ECB, IV useless) </ param> 
/// <Param name = "str"> plaintext byte array </ param> 
/// <Returns> byte array ciphertext </ returns> 
public static byte [] Des3EncodeECB (byte [] key, byte [] iv, byte [] data) 
{ 
try 
{ 
// Create a MemoryStream. 
MemoryStream mStream = new MemoryStream (); 
 
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider (); 
tdsp.Mode = CipherMode.ECB; 
tdsp.Padding = PaddingMode.PKCS7; 
// Create a CryptoStream using the MemoryStream 
// And the passed key and initialization vector (IV). 
CryptoStream cStream = new CryptoStream (mStream, 
tdsp.CreateEncryptor (key, iv), 
CryptoStreamMode.Write); 
 
// Write the byte array to the crypto stream and flush it. 
cStream.Write (data, 0, data.Length); 
cStream.FlushFinalBlock (); 
 
// Get an array of bytes from the 
// MemoryStream that holds the 
// Encrypted data. 
byte [] ret = mStream.ToArray (); 
 
// Close the streams. 
cStream.Close (); 
mStream.Close (); 
 
// Return the encrypted buffer. 
return ret; 
} 
catch (CryptographicException e) 
{ 
Console.WriteLine ("A Cryptographic error occurred: {0}", e.Message); 
return null; 
} 
 
} 
 
/// <Summary> 
/// DES3 ECB decryption mode 
/// </ Summary> 
/// <Param name = "key"> key </ param> 
/// <Param name = "iv"> IV (when the mode ECB, IV useless) </ param> 
/// <Param name = "str"> byte array ciphertext </ param> 
/// <Returns> byte array plaintext </ returns> 
public static byte [] Des3DecodeECB (byte [] key, byte [] iv, byte [] data) 
{ 
try 
{ 
// Create a new MemoryStream using the passed 
// Array of encrypted data. 
MemoryStream msDecrypt = new MemoryStream (data); 
 
TripleDESCryptoServiceProvider tdsp = new TripleDESCryptoServiceProvider (); 
tdsp.Mode = CipherMode.ECB; 
tdsp.Padding = PaddingMode.PKCS7; 
 
// Create a CryptoStream using the MemoryStream 
// And the passed key and initialization vector (IV). 
CryptoStream csDecrypt = new CryptoStream (msDecrypt, 
tdsp.CreateDecryptor (key, iv), 
CryptoStreamMode.Read); 
 
// Create buffer to hold the decrypted data. 
byte [] fromEncrypt = new byte; 
 
// Read the decrypted data out of the crypto stream 
// And place it into the temporary buffer. 
csDecrypt.Read (fromEncrypt, 0, fromEncrypt.Length); 
 
// Convert the buffer into a string and return it. 
return fromEncrypt; 
} 
catch (CryptographicException e) 
{ 
Console.WriteLine ("A Cryptographic error occurred: {0}", e.Message); 
return null; 
} 
} 
 
#endregion 
 
/// <Summary> 
/// Class Testing 
/// </ Summary> 
public static void Test () 
{ 
System.Text.Encoding utf8 = System.Text.Encoding.UTF8; 
 
// Key is abcdefghijklmnopqrstuvwx of Base64 encoding 
byte [] key = Convert.FromBase64String ("YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4"); 
byte [] iv = new byte [] {1, 2, 3, 4, 5, 6, 7, 8}; // When the mode when the ECB, IV useless 
byte [] data = utf8.GetBytes ("China ABCabc123"); 
 
System.Console.WriteLine ("ECB mode:"); 
byte [] str1 = Des3.Des3EncodeECB (key, iv, data); 
byte [] str2 = Des3.Des3DecodeECB (key, iv, str1); 
System.Console.WriteLine (Convert.ToBase64String (str1)); 
System.Console.WriteLine (System.Text.Encoding.UTF8.GetString (str2)); 
 
System.Console.WriteLine (); 
 
System.Console.WriteLine ("CBC mode:"); 
byte [] str3 = Des3.Des3EncodeCBC (key, iv, data); 
byte [] str4 = Des3.Des3DecodeCBC (key, iv, str3); 
System.Console.WriteLine (Convert.ToBase64String (str3)); 
System.Console.WriteLine (utf8.GetString (str4)); 
 
System.Console.WriteLine (); 
 
} 
 
}