/// <summary>
/// Decrypt received file
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void DownloadButton_Click(object sender, RoutedEventArgs e)
{
// TODO: select a place to save
SaveFileDialog saveFileDialog = new SaveFileDialog
{
Title = "Save as"
};
if (saveFileDialog.ShowDialog() == true)
{
FileStream outputStream = null;
MemoryStream memoryStream = null;
try
{
outputStream = new FileStream(saveFileDialog.FileName, FileMode.CreateNew, FileAccess.Write);
if (sender is Button button)
{
if (button.DataContext is Message message)
{
// convert packet to memoryStream
memoryStream = new MemoryStream(message.Packet.EncryptedData.Length + 2_000);
memoryStream.Write(new byte[] { (byte)message.Packet.DataType }, 0, 1);
memoryStream.Write(BitConverter.GetBytes((ushort)message.Packet.EncryptedSessionKey.Length), 0, 2);
memoryStream.Write(message.Packet.EncryptedSessionKey, 0, message.Packet.EncryptedSessionKey.Length);
memoryStream.Write(message.Packet.Iv, 0, message.Packet.Iv.Length);
memoryStream.Write(message.Packet.Hmac, 0, message.Packet.Hmac.Length);
memoryStream.Write(message.Packet.Signature, 0, message.Packet.Signature.Length);
await memoryStream.WriteAsync(message.Packet.EncryptedData, 0, message.Packet.EncryptedData.Length).ConfigureAwait(false);
try
{
await HybridEncryption.DecryptFile(memoryStream, outputStream, AsymmetricEncryption.PublicKeyFromXml(message.Sender.PublicKey)).ConfigureAwait(false);
await outputStream.FlushAsync().ConfigureAwait(false);
}
catch (CryptoException exception)
{
ErrorText = exception.Message;
MessageBox.Show(exception.Message);
}
}
}
}
catch (IOException exception)
{
MessageBox.Show(exception.Message);
}
finally
{
outputStream?.Close();
memoryStream?.Close();
}
}
}
public async Task Can_Decrypt_Large_Stream_Of_Data()
{
byte[] fileBytes = Random.GetNumbers(128_000_000);
MemoryStream rawStream = new MemoryStream(fileBytes);
MemoryStream encryptedBytes = new MemoryStream();
await HybridEncryption.EncryptFile(rawStream, encryptedBytes, asymmetricPublicKey);
encryptedBytes.Position = 0;
MemoryStream decryptedStream = new MemoryStream();
bool hashOk = await HybridEncryption.DecryptFile(encryptedBytes, decryptedStream, asymmetricPublicKey);
decryptedStream.Position = 0;
byte[] decryptedBytes = decryptedStream.ToArray();
Assert.True(hashOk);
CollectionAssert.IsNotEmpty(decryptedBytes);
CollectionAssert.AreEqual(fileBytes, decryptedBytes);
}
private async void DecryptButton_Click(object sender, RoutedEventArgs e)
{
ErrorTextBlock.Visibility = Visibility.Hidden;
StatusImage.Visibility = Visibility.Hidden;
if (UserInputRSADetails())
{
return;
}
// ask user for file to decrypt
string originalFile = null;
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Title = "Choose a file to decrypt";
openFileDialog.Filter = "Decrypted file (*.crypto)|*.crypto|All files (*.*)|*.*";
if (openFileDialog.ShowDialog() == true)
{
originalFile = openFileDialog.FileName;
}
// ask user for location to save decrypted file
string decryptedFile = null;
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Title = "Save as";
if (saveFileDialog.ShowDialog() == true)
{
decryptedFile = saveFileDialog.FileName;
}
// only open filestreams if files were selected by user
if (originalFile != null && decryptedFile != null)
{
// open streams
FileStream inputStream = null;
FileStream outputStream = null;
try
{
inputStream = File.OpenRead(originalFile);
outputStream = File.OpenWrite(decryptedFile);
bool succeeded = await HybridEncryption.DecryptFile(inputStream, outputStream, AsymmetricEncryption.PublicKeyFromXml(PublicRSAKeyReceiver.Text));
if (succeeded)
{
StatusImage.Visibility = Visibility.Visible;
StatusImage.Source = new BitmapImage(new Uri(@"/Images/checkmark.png", UriKind.Relative));
}
else
{
StatusImage.Visibility = Visibility.Visible;
StatusImage.Source = new BitmapImage(new Uri(@"/Images/redx.png", UriKind.Relative));
}
}
catch (IOException exception)
{
ErrorTextBlock.Visibility = Visibility.Visible;
ErrorTextBlock.Text = exception.Message;
}
finally
{
inputStream?.Close();
outputStream?.Close();
}
}
}
private async void DecryptFileStenographyButton_Click(object sender, RoutedEventArgs e)
{
FileStream stegFile = null;
MemoryStream encryptedData = null;
MemoryStream messageData = null;
try
{
// open file
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Title = "Choose a file to put decrypted message";
if (openFileDialog.ShowDialog() == true)
{
stegFile = new FileStream(openFileDialog.FileName, FileMode.Open, FileAccess.Read);
}
else
{
return;
}
// get length
byte[] stegBuffer = new byte[64];
stegFile.Read(stegBuffer, 0, 64);
byte[] lengthBuffer = new byte[8];
for (int i = 0; i < 8; i++)
{
lengthBuffer[i] = GlueByteTogether(stegBuffer.Skip(i * 8).Take(8).ToArray());
}
long length = BitConverter.ToInt64(lengthBuffer, 0);
encryptedData = new MemoryStream();
// read rest of bytes
long current = 0;
stegBuffer = new byte[8];
while (current < length)
{
current++;
// read from input
await stegFile.ReadAsync(stegBuffer, 0, 8);
// convert to single byte
byte gluedByte = GlueByteTogether(stegBuffer);
// write byte to memorystream
await encryptedData.WriteAsync(new byte[] { gluedByte }, 0, 1);
}
// decrypt data
messageData = new MemoryStream();
await HybridEncryption.DecryptFile(encryptedData, messageData, AsymmetricEncryption.PublicKeyFromXml(PublicRSAKeyReceiver.Text));
// show message to user
string message = Encoding.UTF8.GetString(messageData.ToArray());
MessageBox.Show(message);
}
catch (IOException exception)
{
ErrorTextBlock.Text = exception.Message;
ErrorTextBlock.Visibility = Visibility.Visible;
}
catch (CryptoException exception)
{
ErrorTextBlock.Text = exception.Message;
ErrorTextBlock.Visibility = Visibility.Visible;
}
finally
{
stegFile?.Close();
encryptedData?.Close();
messageData?.Close();
}
}
private async void DecryptMessageButton_Click(object sender, RoutedEventArgs e)
{
//bericht is leeg
ErrorTextBlock.Visibility = Visibility.Hidden;
StatusImage.Visibility = Visibility.Hidden;
if (UserInputRSADetails())
{
return;
}
// ask user for file to decrypt
string originalFile = null;
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Title = "Choose a file to put decrypted message";
openFileDialog.Filter = "Decrypted message (*.crypto)|*.crypto|All files (*.*)|*.*";
if (openFileDialog.ShowDialog() == true)
{
originalFile = openFileDialog.FileName;
}
// only open filestreams if files were selected by user
FileStream inputStream = null;
MemoryStream outputStream = null;
if (originalFile != null)
{
try
{
inputStream = File.OpenRead(originalFile);
outputStream = new MemoryStream();
bool succeeded = await HybridEncryption.DecryptFile(inputStream, outputStream, AsymmetricEncryption.PublicKeyFromXml(PublicRSAKeyReceiver.Text));
if (succeeded)
{
StatusImage.Visibility = Visibility.Visible;
StatusImage.Source = new BitmapImage(new Uri(@"/Images/checkmark.png", UriKind.Relative));
outputStream.Position = 0;
byte[] messageBuffer = new byte[outputStream.Length];
outputStream.Read(messageBuffer, 0, messageBuffer.Length);
string message = Encoding.UTF8.GetString(messageBuffer);
MessageBox.Show(message);
}
else
{
StatusImage.Visibility = Visibility.Visible;
StatusImage.Source = new BitmapImage(new Uri(@"/Images/redx.png", UriKind.Relative));
}
}
catch (IOException exception)
{
ErrorTextBlock.Visibility = Visibility.Visible;
ErrorTextBlock.Text = exception.Message;
}
finally
{
inputStream?.Close();
outputStream?.Close();
}
}
}