/// <summary>
/// Serializes a processor to a string. The string is encrypted and validated.
/// Thanks to Dean Brettle for help with this http://www.brettle.com.
/// </summary>
/// <param name="processor">Processor to serialize.</param>
/// <returns>The serialized processor.</returns>
internal string SerializeProcessor(IFileProcessor processor)
{
SettingsStorageObject so = new SettingsStorageObject();
MemoryStream ms = new MemoryStream();
MemoryStream outStream = new MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(ms, processor);
// Encrypt the serialized object
MemoryStream cipherTextStream = new MemoryStream();
SymmetricAlgorithm cipher = SymmetricAlgorithm.Create();
cipher.Mode = CipherMode.CBC;
cipher.Padding = PaddingMode.PKCS7;
cipher.Key = DefaultEncryptionKey;
CryptoStream cryptoStream = new CryptoStream(cipherTextStream, cipher.CreateEncryptor(), CryptoStreamMode.Write);
byte[] cryptoBytes = ms.ToArray();
cryptoStream.Write(cryptoBytes, 0, cryptoBytes.Length);
cryptoStream.Close();
so.CipherText = cipherTextStream.ToArray();
so.CipherIV = cipher.IV;
// Generate a hash for the encrypted data
KeyedHashAlgorithm kh = KeyedHashAlgorithm.Create();
kh.Key = DefaultValidationKey;
so.Hash = kh.ComputeHash(so.CipherText);
bf.Serialize(outStream, so);
return(Convert.ToBase64String(outStream.ToArray()));
}
/// <summary>
/// Deserializes a processor from an encrypted string. The string is encrypted and validated.
/// Thanks to Dean Brettle for help with this http://www.brettle.com.
/// </summary>
/// <param name="input">The encrypted and signed input string.</param>
/// <returns>The deserialized processor.</returns>
internal IFileProcessor DeserializeProcessor(string input)
{
MemoryStream ms;
BinaryFormatter bf = new BinaryFormatter();
byte[] bytes = Convert.FromBase64String(input);
ms = new MemoryStream(bytes);
SettingsStorageObject so = (SettingsStorageObject)bf.Deserialize(ms);
// Compute and check the hash
KeyedHashAlgorithm macAlgorithm = KeyedHashAlgorithm.Create();
MemoryStream hashStream = new MemoryStream(so.CipherText);
macAlgorithm.Key = DefaultValidationKey;
byte[] expectedHash = macAlgorithm.ComputeHash(hashStream);
bool valid = true;
if (expectedHash.Length != so.Hash.Length)
{
valid = false;
}
else
{
for (int i = 0; i < expectedHash.Length; i++)
{
if (expectedHash[i] != so.Hash[i])
{
valid = false;
break;
}
}
}
if (!valid)
{
throw new System.Security.SecurityException("Processor settings invalid");
}
// Decrypt the settings
MemoryStream cipherTextStream = new MemoryStream(so.CipherText);
SymmetricAlgorithm cipher = SymmetricAlgorithm.Create();
cipher.Mode = CipherMode.CBC;
cipher.Padding = PaddingMode.PKCS7;
cipher.Key = DefaultEncryptionKey;
cipher.IV = so.CipherIV;
CryptoStream cryptoStream = new CryptoStream(cipherTextStream, cipher.CreateDecryptor(), CryptoStreamMode.Read);
return((IFileProcessor)bf.Deserialize(cryptoStream));
}
/// <summary>
/// Serializes a processor to a string. The string is encrypted and validated.
/// Thanks to Dean Brettle for help with this http://www.brettle.com.
/// </summary>
/// <param name="processor">Processor to serialize.</param>
/// <returns>The serialized processor.</returns>
internal string SerializeProcessor(IFileProcessor processor)
{
SettingsStorageObject so = new SettingsStorageObject();
MemoryStream ms = new MemoryStream();
MemoryStream outStream = new MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(ms, processor);
// Encrypt the serialized object
MemoryStream cipherTextStream = new MemoryStream();
SymmetricAlgorithm cipher = SymmetricAlgorithm.Create();
cipher.Mode = CipherMode.CBC;
cipher.Padding = PaddingMode.PKCS7;
cipher.Key = DefaultEncryptionKey;
CryptoStream cryptoStream = new CryptoStream(cipherTextStream, cipher.CreateEncryptor(), CryptoStreamMode.Write);
byte[] cryptoBytes = ms.ToArray();
cryptoStream.Write(cryptoBytes, 0, cryptoBytes.Length);
cryptoStream.Close();
so.CipherText = cipherTextStream.ToArray();
so.CipherIV = cipher.IV;
// Generate a hash for the encrypted data
KeyedHashAlgorithm kh = KeyedHashAlgorithm.Create();
kh.Key = DefaultValidationKey;
so.Hash = kh.ComputeHash(so.CipherText);
bf.Serialize(outStream, so);
return Convert.ToBase64String(outStream.ToArray());
}
