Windows.COPYDATASTRUCT GetEncryptedMasterKeyTransmission()
{
byte[] encryptedMessage;
byte[] iv;
using (SecureBytesWrapper sbwKey = new SecureBytesWrapper(App.Settings.PasswordMasterKey, true))
{
Encrypt(sbwKey.Bytes, out encryptedMessage, out iv);
}
Windows.COPYDATASTRUCT cds = new Windows.COPYDATASTRUCT();
cds.cbData = sizeof(int) + iv.Length + encryptedMessage.Length;
byte[] combinedMessage = new byte[cds.cbData];
byte[] lengthBytes = BitConverter.GetBytes(iv.Length);
Buffer.BlockCopy(lengthBytes, 0, combinedMessage, 0, lengthBytes.Length);
Buffer.BlockCopy(iv, 0, combinedMessage, lengthBytes.Length, iv.Length);
Buffer.BlockCopy(encryptedMessage, 0, combinedMessage, lengthBytes.Length + iv.Length, encryptedMessage.Length);
cds.lpData = Marshal.AllocHGlobal(cds.cbData);
Marshal.Copy(combinedMessage, 0, cds.lpData, combinedMessage.Length);
cds.dwData = new IntPtr(11);
// caller needs to Marshal.FreeHGlobal(cds.lpData);
return(cds);
}
public void ReceiveEncryptedMasterKeyTransmission(Windows.COPYDATASTRUCT cds)
{
byte[] combinedMessage = new byte[cds.cbData];
Marshal.Copy(cds.lpData, combinedMessage, 0, cds.cbData);
int ivLength = BitConverter.ToInt32(combinedMessage, 0);
// validate length...
if (ivLength > cds.cbData)
{
// throw exception .. ?
throw new ApplicationException("Master Key transmission failed: Initialization Vector received incorrectly");
}
byte[] iv = new byte[ivLength];
Buffer.BlockCopy(combinedMessage, sizeof(int), iv, 0, ivLength);
byte[] encryptedMessage = new byte[cds.cbData - (ivLength + sizeof(int))];
Buffer.BlockCopy(combinedMessage, sizeof(int) + ivLength, encryptedMessage, 0, encryptedMessage.Length);
using (SecureBytesWrapper sbw = new SecureBytesWrapper())
{
Decrypt(encryptedMessage, iv, sbw);
if (!App.Settings.TryPasswordMasterKey(sbw.Bytes))
{
throw new ApplicationException("Master Key transmission failed: Master Key received incorrectly");
}
}
}
public void ReceivePublicKeyTransmission(Windows.COPYDATASTRUCT cds)
{
byte[] remotePublicKey = new byte[cds.cbData];
Marshal.Copy(cds.lpData, remotePublicKey, 0, cds.cbData);
SetRemotePublicKey(remotePublicKey);
}
public void TransmitEncryptedMasterKey(Windows.MainWindow localWindow)
{
Windows.COPYDATASTRUCT cds = GetEncryptedMasterKeyTransmission();
HwndSource source = PresentationSource.FromVisual(localWindow) as HwndSource;
Windows.MainWindow.SendMessage(this.RemoteWindow, Windows.MainWindow.WM_COPYDATA, source.Handle, ref cds);
Marshal.FreeHGlobal(cds.lpData);
}
Windows.COPYDATASTRUCT GetPublicKeyTransmission(bool isRequest)
{
Windows.COPYDATASTRUCT cds = new Windows.COPYDATASTRUCT();
cds.cbData = LocalPublicKey.Bytes.Length;
cds.lpData = Marshal.AllocHGlobal(cds.cbData);
Marshal.Copy(LocalPublicKey.Bytes, 0, cds.lpData, LocalPublicKey.Bytes.Length);
if (isRequest)
{
cds.dwData = new IntPtr(10);
}
else
{
cds.dwData = new IntPtr(12);
}
// caller needs to Marshal.FreeHGlobal(cds.lpData);
return(cds);
}
public static bool ReceiveTransmission(Windows.MainWindow window, IntPtr remoteWindow, System.Diagnostics.Process remoteProcess, Windows.COPYDATASTRUCT cds)
{
Session session = Sessions.FirstOrDefault(q => q.RemoteWindow == remoteWindow && q.Process.Id == remoteProcess.Id);
if (session == null)
{
session = new Session(remoteWindow, remoteProcess);
Sessions.Add(session);
}
switch ((long)cds.dwData)
{
case 10:
if (!App.Settings.HasPasswordMasterKey)
{
return(false);
}
session.ReceivePublicKeyTransmission(cds);
session.TransmitPublicKey(window, false);
session.TransmitEncryptedMasterKey(window);
return(true);
case 11:
session.ReceiveEncryptedMasterKeyTransmission(cds);
return(true);
case 12:
session.ReceivePublicKeyTransmission(cds);
return(true);
}
return(false);
}
