public static string DecryptStringWith3DES(string data, string key, string iv)
{
UnicodeEncoding unicode = new UnicodeEncoding();
Byte[] Bytes = Convert.FromBase64String(data);
MemoryStream mem = new MemoryStream(100);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
Byte[] KeyBytes = unicode.GetBytes(key);
Byte[] tmpBytes = new Byte[16];
Array.Copy(KeyBytes, tmpBytes, KeyBytes.Length < 16 ? KeyBytes.Length : 16);
KeyBytes = tmpBytes;
if(tdes.ValidKeySize(KeyBytes.Length*8))
System.Diagnostics.Debug.WriteLine("Key size valid");
if(TripleDESCryptoServiceProvider.IsWeakKey(KeyBytes))
System.Diagnostics.Debug.WriteLine("Key weak");
CryptoStream CrStream = new CryptoStream(mem, tdes.CreateDecryptor(KeyBytes, unicode.GetBytes(iv)), CryptoStreamMode.Write);
for(int i = 0; i < Bytes.Length; i++)
CrStream.WriteByte(Bytes[i]);
CrStream.FlushFinalBlock();
string result = unicode.GetString(mem.GetBuffer(), 0, (int)mem.Length);
CrStream.Dispose();
return result;
}
/// <summary>
/// Encrypt or decrypt a byte array using the TripleDESCryptoServiceProvider crypto provider and Rfc2898DeriveBytes to build the key and initialization vector.
/// </summary>
/// <param name="password">The password String to use in encrypting or decrypting.</param>
/// <param name="inBytes">The array of bytes to encrypt.</param>
/// <param name="encrypt">True to encrypt, False to decrypt.</param>
/// <returns></returns>
/// <remarks></remarks>
public static byte[] CryptBytes(String password, byte[] inBytes, bool encrypt)
{
// Make a triple DES service provider.
var desProvider = new TripleDESCryptoServiceProvider();
// Find a valid key size for this provider.
var keySize = 0;
for (var i = 1024; i >= 1; i--)
if (desProvider.ValidKeySize(i))
{
keySize = i;
break;
}
// Get the block size for this provider.
var blockSize = desProvider.BlockSize;
// Generate the key and initialization vector.
byte[] key = null;
byte[] iv = null;
byte[] salt = { 0x10, 0x20, 0x12, 0x23, 0x37, 0xA4, 0xC5, 0xA6, 0xF1, 0xF0, 0xEE, 0x21, 0x22, 0x45 };
MakeKeyAndIv(password, salt, keySize, blockSize, ref key, ref iv);
// Make the encryptor or decryptor.
var cryptoTransform = encrypt
? desProvider.CreateEncryptor(key, iv)
: desProvider.CreateDecryptor(key, iv);
byte[] result;
// Create the output stream.
using (var streamOut = new MemoryStream())
{
// Attach a crypto stream to the output stream.
var streamCrypto = new CryptoStream(streamOut, cryptoTransform, CryptoStreamMode.Write);
// Write the bytes into the CryptoStream.
streamCrypto.Write(inBytes, 0, inBytes.Length);
try
{
streamCrypto.FlushFinalBlock();
}
catch (CryptographicException)
{
// Ignore this one. The password is bad.
}
// Save the result.
result = streamOut.ToArray();
// Close the stream.
try
{
streamCrypto.Close();
}
catch (CryptographicException)
{
// Ignore this one. The password is bad.
}
streamOut.Close();
}
return result;
}
public static bool ValidateKeySize( EncryptionAlgorithm algID, int Lenght)
{
switch (algID)
{
case EncryptionAlgorithm.DES:
DES des = new DESCryptoServiceProvider();
return des.ValidKeySize(Lenght);
case EncryptionAlgorithm.Rc2:
RC2 rc = new RC2CryptoServiceProvider();
return rc.ValidKeySize(Lenght);
case EncryptionAlgorithm.Rijndael:
Rijndael rj = new RijndaelManaged();
return rj.ValidKeySize(Lenght);
case EncryptionAlgorithm.TripleDes:
TripleDES tDes = new TripleDESCryptoServiceProvider();
return tDes.ValidKeySize(Lenght);
default:
throw new CryptographicException("Algorithm " + algID + " Not Supported!");
}
}
