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!"); } }