/// <summary>
/// Utility method to help write AES round-trip tests
/// </summary>
private static bool RoundTripHelper(byte[] input,
Type encryptionAlgorithm,
Type decryptionAlgorithm,
Action <SymmetricAlgorithm> encryptionSetup)
{
// Encryption parameters
byte[] key = null;
byte[] iv = null;
CipherMode cipherMode = CipherMode.CBC;
PaddingMode paddingMode = PaddingMode.PKCS7;
// Round tripping data
byte[] cipherText = null;
SymmetricAlgorithm encryptionObject = null;
try
{
// Setup the encryption algorithm
encryptionObject = (SymmetricAlgorithm)Activator.CreateInstance(encryptionAlgorithm);
encryptionSetup(encryptionObject);
// Encrypt the data
using (MemoryStream ms = new MemoryStream())
using (CryptoStream cs = new CryptoStream(ms, encryptionObject.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(input, 0, input.Length);
cs.FlushFinalBlock();
cipherText = ms.ToArray();
}
// Save the encryption parameters
key = encryptionObject.Key;
iv = encryptionObject.IV;
cipherMode = encryptionObject.Mode;
paddingMode = encryptionObject.Padding;
}
finally
{
if (encryptionObject != null)
{
(encryptionObject as IDisposable).Dispose();
}
}
byte[] roundTrip = null;
// Now verify the data
SymmetricAlgorithm decryptionObject = null;
try
{
decryptionObject = (SymmetricAlgorithm)Activator.CreateInstance(decryptionAlgorithm);
decryptionObject.Key = key;
decryptionObject.IV = iv;
decryptionObject.Mode = cipherMode;
decryptionObject.Padding = paddingMode;
using (MemoryStream ms = new MemoryStream())
using (CryptoStream cs = new CryptoStream(ms, decryptionObject.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cipherText, 0, cipherText.Length);
cs.FlushFinalBlock();
roundTrip = ms.ToArray();
}
}
finally
{
if (decryptionObject != null)
{
(decryptionObject as IDisposable).Dispose();
}
}
return(Util.CompareBytes(input, roundTrip));
}
