// The CipherResult contains all important settings (options) and the resulting CipherText (in Byte Array)
public static byte[] BasicAesDecryption(CipherResult cO, string passPhrase)
{
var myRijndael = new RijndaelManaged();
myRijndael.BlockSize = 128;
myRijndael.KeySize = cO.KeySizeInBytes * 8;
myRijndael.IV = cO.AesRijndaelIv;
myRijndael.Padding = PaddingMode.PKCS7;
myRijndael.Mode = CipherMode.CBC;
var salt = cO.Salt;
if (cO.DerivationType == "scrypt")
{
myRijndael.Key =
ScryptHandler.GetOnlyHashBytes(System.Text.Encoding.UTF8.GetBytes(passPhrase), cO);
}
else
{
Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(System.Text.Encoding.UTF8.GetBytes(passPhrase), salt,
cO.DerivationIterations);
myRijndael.Key = rfc2898.GetBytes(cO.KeySizeInBytes);
}
var encryptedBytes = cO.CipherOutput;
ICryptoTransform transform = myRijndael.CreateDecryptor();
byte[] cipherText = transform.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
return(cipherText);
}
public static byte[] GetOnlyHashBytes(byte[] password, CipherResultText sO)
{
var bytes = SCrypt.ComputeDerivedKey(password, ScryptHandler.StringToByteArray(sO.Salt), sO.Cost, sO.BlockSize, sO.Parallel, null, sO.KeySizeInBytes);
//return Convert.ToBase64String(bytes);
return(bytes);
}
// The resulting CipherResult contains all important settings (options) and the resulting CipherText (in Byte Array)
public static CipherResult BasicAesEncryption(byte[] bytesToEncrypt, string passPhrase, EncryptionOptions eO = null)
{
// Salt and IV is randomly generated each time, but is preprended to encrypted cipher text
// so that the same Salt and IV values can be used when decrypting.
var myRijndael = new RijndaelManaged();
myRijndael.BlockSize = 128;
if (eO == null)
{
eO = new EncryptionOptions();
myRijndael.IV = GenerateXBytesOfRandomEntropy(16); //IV must be 16 bytes / 128 bit
eO.RijndaelIv = myRijndael.IV;
}
else if (eO.RijndaelIv == null)
{
myRijndael.IV = GenerateXBytesOfRandomEntropy(16); //IV must be 16 bytes / 128 bit
eO.RijndaelIv = myRijndael.IV;
}
else
{
myRijndael.IV = eO.RijndaelIv;
}
myRijndael.Padding = PaddingMode.PKCS7;
myRijndael.Mode = CipherMode.CBC;
// Using Scrypt for Key Derivation
if (eO.DerivationType == null || eO.DerivationType == "scrypt")
{
eO.DerivationType = "scrypt";
myRijndael.Key =
ScryptHandler.GetOnlyHashBytes(System.Text.Encoding.UTF8.GetBytes(passPhrase), eO);
}
// Using RFC2898 for Key Derivation
else
{
if (eO.Salt == null)
{
eO.Salt = GenerateXBytesOfRandomEntropy(32);
}
myRijndael.KeySize = eO.KeySizeInBytes * 8;
Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(System.Text.Encoding.UTF8.GetBytes(passPhrase), eO.Salt,
eO.DerivationIterations);
myRijndael.Key = rfc2898.GetBytes(eO.KeySizeInBytes);
}
byte[] utf8Text = bytesToEncrypt;
ICryptoTransform transform = myRijndael.CreateEncryptor();
byte[] cipherText = transform.TransformFinalBlock(utf8Text, 0, utf8Text.Length);
var cipherWithSaltAndIvObject = new CipherResult(eO, cipherText);
return(cipherWithSaltAndIvObject);
}
