private byte[] EncryptStringToBytes_Aes(string plainText, byte[] Key, byte[] IV)
{
// Check arguments.
if (plainText == null || plainText.Length <= 0)
{
throw new ArgumentNullException("plainText");
}
if (Key == null || Key.Length <= 0)
{
throw new ArgumentNullException("Key");
}
if (IV == null || IV.Length <= 0)
{
throw new ArgumentNullException("IV");
}
byte[] encrypted;
string ivString;
// Create an AesManaged object
// with the specified key and IV.
using (AesManaged aesAlg = new AesManaged())
{
aesAlg.Key = Key;
aesAlg.IV = IV;
ivString = EncodingTools.Base64EncodeByteArrayToString(aesAlg.IV);
// Create an encryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
try
{
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
encrypted = msEncrypt.ToArray();
}
}
}
catch (Exception e)
{
encrypted = new byte[0];
_logger.AddLogEntry($"Failed to encrypt settings: {e.Message}");
}
}
// Return the encrypted bytes from the memory stream.
return(encrypted);
}
private Tuple <byte[], byte[]> FindIv(string input)
{
var splitInput = input.Split('|');
if (splitInput.Length != 2)
{
_logger.AddLogEntry("Failed to get IV from string provided.");
return(null);
}
// position 0 is IV
return(Tuple.Create(EncodingTools.Base64DecodeStringToByteArray(splitInput[0]), EncodingTools.Base64DecodeStringToByteArray(splitInput[1])));
}
public string AesEncrypt(string input, string pass, byte[] iv = null)
{
byte[] encrypted;
string ivString;
using (AesManaged aes = new AesManaged())
{
// Encrypt the string to an array of bytes.
aes.Key = Hashing.ComputeSha256(pass);
encrypted = EncryptStringToBytes_Aes(input, aes.Key, aes.IV);
ivString = EncodingTools.Base64EncodeByteArrayToString(aes.IV);
}
return(ivString + '|' + EncodingTools.Base64EncodeByteArrayToString(encrypted));
}
public string AesDecrypt(string input, string pass, byte[] iv = null)
{
string decrpyted;
byte[] encryptedMessage = EncodingTools.StringToByteArray(input);
if (iv == null)
{
var inputIvTuple = FindIv(input);
iv = inputIvTuple.Item1;
encryptedMessage = inputIvTuple.Item2;
// if still null :(
if (iv == null || encryptedMessage == null)
{
_logger.AddLogEntry($"Failed to gather required information. iv: {iv}, encryptedMessage: {encryptedMessage}");
return(string.Empty);
}
}
try
{
using (AesManaged aes = new AesManaged())
{
aes.Key = Hashing.ComputeSha256(pass);
aes.IV = iv;
// Encrypt the string to an array of bytes.
decrpyted = DecryptStringFromBytes_Aes(encryptedMessage, aes.Key, aes.IV);
}
}
catch (Exception e)
{
_logger.AddLogEntry($"Failed to decrypt message: {e}");
return(string.Empty);
}
return(decrpyted);
}
