private async void EncryptMessageButton_Click(object sender, RoutedEventArgs e)
{
StatusImage.Visibility = Visibility.Hidden;
ErrorTextBlock.Visibility = Visibility.Hidden;
if (UserInputRSADetails())
{
return;
}
// ask user for location to save encrypted message
string encryptedFile = null;
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Title = "Save as";
saveFileDialog.Filter = "Encrypted message (*.crypto)|*.crypto";
if (saveFileDialog.ShowDialog() == true)
{
encryptedFile = saveFileDialog.FileName;
}
// only open filestreams if files were selected by user
if (encryptedFile != null)
{
// open streams
MemoryStream inputStream = new MemoryStream();
byte[] messageBytes = Encoding.UTF8.GetBytes(InputMessageBox.Text);
inputStream.Write(messageBytes, 0, messageBytes.Length);
// message requires a minimum length, pad it with 32 0x00 bytes
if (inputStream.Length < 32)
{
inputStream.Write(new byte[32], 0, 32);
}
inputStream.Position = inputStream.Seek(0, SeekOrigin.Begin);
FileStream outputStream = null;
try
{
outputStream = File.OpenWrite(encryptedFile);
await HybridEncryption.EncryptFile(inputStream, outputStream, AsymmetricEncryption.PublicKeyFromXml(PublicRSAKeyReceiver.Text));
MessageBox.Show("Done");
}
catch (IOException exception)
{
ErrorTextBlock.Visibility = Visibility.Visible;
ErrorTextBlock.Text = exception.Message;
}
finally
{
inputStream?.Close();
outputStream?.Close();
}
}
}
public void Can_Encrypt_Stream_Of_Data()
{
byte[] fileBytes = Random.GetNumbers(2048);
MemoryStream inputStream = new MemoryStream(fileBytes);
EncryptedPacket encryptedPacket = HybridEncryption.EncryptFile(inputStream, asymmetricPublicKey);
Assert.NotNull(encryptedPacket);
CollectionAssert.AreNotEqual(fileBytes, encryptedPacket.EncryptedData);
}
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 EncryptFileStenographyButton_Click(object sender, RoutedEventArgs e)
{
ErrorTextBlock.Visibility = Visibility.Hidden;
FileStream baseFile = null;
FileStream saveFile = null;
MemoryStream messageData = null;
MemoryStream encryptedData = null;
try
{
// put original message into a memory stream
byte[] messageBytes = Encoding.UTF8.GetBytes(InputMessageBox.Text);
messageData = new MemoryStream();
messageData.Write(messageBytes, 0, messageBytes.Length);
if (messageData.Length < 32) // make sure it's longer than the minimum length
{
messageData.Write(new byte[32], 0, 32);
}
messageData.Position = 0;
// select file to use as base
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Title = "Choose a file to put encrypted message";
if (openFileDialog.ShowDialog() == true)
{
baseFile = new FileStream(openFileDialog.FileName, FileMode.Open, FileAccess.Read);
}
else
{
return;
}
// select file to save
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Title = "Save as";
saveFileDialog.DefaultExt = openFileDialog.SafeFileName.Split('.').Last();
saveFileDialog.AddExtension = true;
if (saveFileDialog.ShowDialog() == true)
{
saveFile = new FileStream(saveFileDialog.FileName, FileMode.Create, FileAccess.Write);
}
else
{
return;
}
// encrypt message into memory stream
encryptedData = new MemoryStream();
await HybridEncryption.EncryptFile(messageData, encryptedData, AsymmetricEncryption.PublicKeyFromXml(PublicRSAKeyReceiver.Text)).ConfigureAwait(false);
encryptedData.Position = 0;
// write length to output
byte[] baseFileBuffer = new byte[8];
byte[] length = BitConverter.GetBytes(encryptedData.Length);
for (int i = 0; i < 8; i++)
{
await baseFile.ReadAsync(baseFileBuffer, 0, 8); // read 8 bytes of input
HideInBytes(baseFileBuffer, length[i]);
await saveFile.WriteAsync(baseFileBuffer, 0, 8); // write 8 bytes to output
}
// hide message in output
byte[] encryptedDataBuffer = new byte[1];
for (int i = 0; i < encryptedData.Length; i++)
{
await encryptedData.ReadAsync(encryptedDataBuffer, 0, 1);
await baseFile.ReadAsync(baseFileBuffer, 0, 8); // read 8 bytes of input
HideInBytes(baseFileBuffer, encryptedDataBuffer[0]);
await saveFile.WriteAsync(baseFileBuffer, 0, 8); // write 8 bytes to output
}
// write rest of file to output
byte[] fileBuffer = new byte[1024];
while (await baseFile.ReadAsync(fileBuffer, 0, 1024) > 0)
{
await saveFile.WriteAsync(fileBuffer, 0, 1024);
}
await saveFile.FlushAsync().ConfigureAwait(false);
}
catch (IOException exception)
{
ErrorTextBlock.Text = exception.Message;
ErrorTextBlock.Visibility = Visibility.Visible;
}
catch (CryptoException exception)
{
ErrorTextBlock.Text = exception.Message;
ErrorTextBlock.Visibility = Visibility.Visible;
}
finally
{
baseFile?.Close();
saveFile?.Close();
messageData?.Close();
encryptedData?.Close();
}
}
private async void EncryptButton_Click(object sender, RoutedEventArgs e)
{
ErrorTextBlock.Visibility = Visibility.Hidden;
StatusImage.Visibility = Visibility.Hidden;
if (UserInputRSADetails())
{
return;
}
// ask user for file to encrypt
string originalFile = null;
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Title = "Choose a file to encrypt";
if (openFileDialog.ShowDialog() == true)
{
originalFile = openFileDialog.FileName;
}
// ask user for location to save encrypted file
string encryptedFile = null;
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Title = "Save as";
saveFileDialog.Filter = "Encrypted file (*.crypto)|*.crypto"; // TODO: verzin betere file extensie
if (saveFileDialog.ShowDialog() == true)
{
encryptedFile = saveFileDialog.FileName;
}
// only open filestreams if files were selected by user
if (originalFile != null && encryptedFile != null)
{
// open streams
FileStream inputStream = null;
FileStream outputStream = null;
try
{
inputStream = File.OpenRead(originalFile);
outputStream = File.OpenWrite(encryptedFile);
await HybridEncryption.EncryptFile(inputStream, outputStream, AsymmetricEncryption.PublicKeyFromXml(PublicRSAKeyReceiver.Text));
MessageBox.Show("Done"); // TODO: tell user their encryption is done
}
catch (IOException exception)
{
ErrorTextBlock.Visibility = Visibility.Visible;
ErrorTextBlock.Text = exception.Message;
}
finally
{
inputStream?.Close();
outputStream?.Close();
}
}
}
/// <summary>
/// Send a file to currently selected user
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void SendAttachmentButton_Click(object sender, RoutedEventArgs e)
{
// get currently selected contact, do nothing if none is selected
ContactPerson contact = (ContactPerson)ContactListListView.SelectedItem;
if (contact == null)
{
return;
}
// ask user to select file
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Title = "Choose a file to encrypt";
openFileDialog.Multiselect = false;
if (openFileDialog.ShowDialog() == true)
{
FileStream fileStream;
FileInfo fileInfo;
try
{
fileInfo = new FileInfo(openFileDialog.FileName);
if (fileInfo.Length > 10_000_000) // only upload files smaller than 10MB
{
ErrorText = "Due to server limitations, files bigger than 10MB (10 000 000 bytes) are not supported.";
return;
}
fileStream = new FileStream(openFileDialog.FileName, FileMode.Open, FileAccess.Read);
// encrypt file for receiver
EncryptedPacket packetForReceiver = null;
await Task.Run(() =>
{
try
{
packetForReceiver = HybridEncryption.EncryptFile(fileStream, AsymmetricEncryption.PublicKeyFromXml(contact.PublicKey));
}
catch (CryptoException exception)
{
// show to user
ErrorText = exception.Message;
}
});
// send to receiver
await Client.SendNewMessage(packetForReceiver, contact.Id);
}
catch (IOException exception)
{
// show to user
ErrorText = exception.Message;
}
catch (ClientException exception)
{
// show to user
ErrorText = exception.Message;
}
}
}