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_Convert_XML_String_To_Public_Key()
{
string xml = AsymmetricEncryption.PublicKeyAsXml();
RSAParameters rsaParameters = AsymmetricEncryption.PublicKeyFromXml(xml);
Assert.NotNull(rsaParameters);
CollectionAssert.AreEqual(publicKey.Exponent, rsaParameters.Exponent);
CollectionAssert.AreEqual(publicKey.Modulus, rsaParameters.Modulus);
}
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 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 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();
}
}
}
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>
/// Add received messages from list of packets
/// </summary>
/// <param name="received"></param>
/// <returns>Amount of packages which failed to be decrypted</returns>
private async Task <int> AddReceivedMessages(IList <StrippedDownEncryptedPacket> received)
{
// try to link messages to contacts
BoxedInt boxedInt = new BoxedInt();
List <Task> tasks = new List <Task>(received.Count);
foreach (StrippedDownEncryptedPacket packet in received)
{
// find sender in contact list
tasks.Add(Task.Run(() =>
{
ContactPerson sender = contactList.FirstOrDefault(c => c.Id == packet.Sender.Id);
if (sender != null)
{
// ignore duplicates
if (sender.Messages.All(m => m.SendTime != packet.SendDateTime))
{
if (packet.DataType == DataType.Message)
{
try
{
string message = Encoding.UTF8.GetString(HybridEncryption.Decrypt(packet.EncryptedPacket, AsymmetricEncryption.PublicKeyFromXml(sender.PublicKey)));
// add new message to chat
lock (sender.LockObject)
{
sender.Messages.Add(new Message
{
SenderName = sender.UserName,
SendTime = packet.SendDateTime,
MessageFromSender = message,
DataType = packet.DataType,
Packet = packet,
Sender = sender
});
}
}
catch (CryptoException)
{
lock (boxedInt)
{
boxedInt.Integer++;
}
}
}
else
{
lock (sender.LockObject)
{
sender.Messages.Add(new Message
{
SenderName = sender.UserName,
SendTime = packet.SendDateTime,
MessageFromSender = $"This is a {packet.DataType}",
DataType = packet.DataType,
Packet = packet,
Sender = sender
});
}
}
}
}
}));
}
await Task.WhenAll(tasks);
return(boxedInt.Integer);
}
/// <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;
}
}
}
/// <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();
}
}
}
/// <summary>
/// Send a new message
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void SendButton_Click(object sender, RoutedEventArgs e)
{
ContactPerson contact = (ContactPerson)ContactListListView.SelectedItem;
if (contact == null)
{
return;
}
EncryptedPacket packetForReceiver = null, packetForSender = null;
string text = MessageTextBox.Text;
await Task.Run(() =>
{
try
{
packetForReceiver = HybridEncryption.Encrypt(DataType.Message, Encoding.UTF8.GetBytes(text), AsymmetricEncryption.PublicKeyFromXml(contact.PublicKey));
packetForSender = HybridEncryption.Encrypt(DataType.Message, Encoding.UTF8.GetBytes(text), AsymmetricEncryption.PublicKey);
}
catch (CryptoException exception)
{
ErrorText = exception.Message;
}
});
// try to send message and clear input
if (packetForReceiver != null && packetForSender != null)
{
try
{
// send to server
await Client.SendNewMessage(packetForReceiver, contact.Id, true);
await Client.SendNewMessage(packetForSender, contact.Id, false);
// add to chat
contact.Messages.Add(new Message
{
SenderName = Client.UserName,
SendTime = DateTime.Now,
MessageFromSender = MessageTextBox.Text,
DataType = DataType.Message
});
MessageTextBox.Clear();
}
catch (ClientException exception)
{
// show message to user
ErrorText = exception.Message;
}
}
}