public void Run(IBackgroundTaskInstance taskInstance)
{
Debug.WriteLine("Background task activated!");
_deferral = taskInstance.GetDeferral();
_exitEvent = new ManualResetEvent(false);
UDPListener.StartListening();
SecondaryAuthenticationFactorAuthentication.AuthenticationStageChanged += OnStageChanged;
_exitEvent.WaitOne();
UDPListener.StopListening();
findAuth = false;
_deferral.Complete();
}
private async Task DiscoverDevice()
{
var authStageInfo = await SecondaryAuthenticationFactorAuthentication.GetAuthenticationStageInfoAsync();
if (authStageInfo.Stage != SecondaryAuthenticationFactorAuthenticationStage.CollectingCredential)
{
return; // Bad status!
}
findAuth = true;
var deviceList = await SecondaryAuthenticationFactorRegistration.FindAllRegisteredDeviceInfoAsync(SecondaryAuthenticationFactorDeviceFindScope.User);
var db = new DatabaseContext();
var devicesInDb = db.Devices.ToList();
db.Dispose();
IPDiscover.DiscoverIP();
foreach (var device in deviceList)
{
var deviceInDb = devicesInDb.Find(d => d.DeviceId.ToString() == device.DeviceId);
if (deviceInDb == null)
{
continue;
}
var session = new DeviceAuthSession
{
LastIP = deviceInDb.LastConnectedHost,
MACAddress = deviceInDb.DeviceMacAddress,
DeviceID = device.DeviceId,
DeviceInDb = deviceInDb
};
deviceSessions.Add(session);
}
while (findAuth)
{
foreach (var session in deviceSessions)
{
switch (session.Status)
{
case DeviceStatus.NotConnected:
var payload = Convert.ToBase64String(Encoding.UTF8.GetBytes(session.DeviceID));
var data = Encoding.UTF8.GetBytes(DeviceDiscoverPrefix + payload);
if (!string.IsNullOrWhiteSpace(session.LastIP))
{
try
{
UDPListener.Send(session.LastIP, data);
}
catch (Exception)
{
// ignored
}
}
var ips = session.FindIPs()?.ToList();
if ((ips == null || !ips.Any()) && string.IsNullOrWhiteSpace(session.MACAddress) && IPDiscover.IsDiscoveryCompleted)
{
session.Status = DeviceStatus.Unreachable;
continue;
}
if (ips != null)
{
foreach (var ip in ips)
{
try
{
UDPListener.Send(ip, data);
}
catch (Exception)
{
// ignored
}
}
}
await UDPListener.Send(UDPListener.DeviceMulticastGroupAddress, data);
break;
case DeviceStatus.Unreachable:
deviceSessions.Remove(session);
break;
case DeviceStatus.Established:
findAuth = false;
break;
}
}
Thread.Sleep(1000);
}
Auth(deviceSessions.FirstOrDefault(s => s.Status == DeviceStatus.Established));
CurrentSession = null;
}
private async void Auth(DeviceAuthSession session)
{
if (session == null)
{
await SecondaryAuthenticationFactorAuthentication.ShowNotificationMessageAsync("",
SecondaryAuthenticationFactorAuthenticationMessage.Invalid);
return;
}
var deviceInDb = session.DeviceInDb;
await SecondaryAuthenticationFactorAuthentication.ShowNotificationMessageAsync(deviceInDb.DeviceFriendlyName,
SecondaryAuthenticationFactorAuthenticationMessage.ReadyToSignIn);
IBuffer svcAuthNonce = CryptographicBuffer.GenerateRandom(256 / 8);
SecondaryAuthenticationFactorAuthenticationResult authResult = await
SecondaryAuthenticationFactorAuthentication.StartAuthenticationAsync(
session.DeviceID,
svcAuthNonce);
if (authResult.Status != SecondaryAuthenticationFactorAuthenticationStatus.Started)
{
var message = SecondaryAuthenticationFactorAuthenticationMessage.Invalid;
switch (authResult.Status)
{
case SecondaryAuthenticationFactorAuthenticationStatus.DisabledByPolicy:
message = SecondaryAuthenticationFactorAuthenticationMessage.DisabledByPolicy;
break;
case SecondaryAuthenticationFactorAuthenticationStatus.InvalidAuthenticationStage:
break;
default:
return;
}
await SecondaryAuthenticationFactorAuthentication.ShowNotificationMessageAsync(null, message);
return;
}
var auth = authResult.Authentication;
CurrentSession = session;
for (int retries = 0; retries < 3; retries++)
{
var svcAuthHmac = auth.ServiceAuthenticationHmac;
var deviceNonce = auth.DeviceNonce;
var sessionNonce = auth.SessionNonce;
var arr = new byte[3 + svcAuthHmac.Length + deviceNonce.Length + sessionNonce.Length];
arr[0] = (byte)svcAuthHmac.Length;
arr[1] = (byte)deviceNonce.Length;
arr[2] = (byte)sessionNonce.Length;
Array.Copy(svcAuthHmac.ToArray(), 0, arr, 3, svcAuthHmac.Length);
Array.Copy(deviceNonce.ToArray(), 0, arr, 3 + svcAuthHmac.Length, deviceNonce.Length);
Array.Copy(sessionNonce.ToArray(), 0, arr, 3 + svcAuthHmac.Length + deviceNonce.Length, sessionNonce.Length);
var payload = Convert.ToBase64String(arr);
UDPListener.Send(session.LastIP, Encoding.UTF8.GetBytes(DeviceDiscoverPrefix + payload));
AuthResultReceivedEvent = new ManualResetEvent(false);
try
{
AuthResultReceivedEvent.WaitOne(20000);
}
catch (Exception)
{
// ignored
}
var result = session.ResultBytes;
if (result == null || result.Length <= 2 || result.Length != 2 + result[0] + result[1])
{
return;
/*await SecondaryAuthenticationFactorAuthentication.ShowNotificationMessageAsync("",
* SecondaryAuthenticationFactorAuthenticationMessage.TryAgain);
* await auth.AbortAuthenticationAsync("No data got.");
* continue;*/
}
var deviceHmac = new Buffer(result[0]);
var sessionHmac = new Buffer(result[1]);
result.CopyTo(2, deviceHmac, 0, result[0]);
result.CopyTo(2 + result[0], sessionHmac, 0, result[1]);
var status = await auth.FinishAuthenticationAsync(deviceHmac, sessionHmac);
switch (status)
{
case SecondaryAuthenticationFactorFinishAuthenticationStatus.Completed:
// The credential data is collected and ready for unlock
CurrentSession = null;
return;
default:
await SecondaryAuthenticationFactorAuthentication.ShowNotificationMessageAsync("",
SecondaryAuthenticationFactorAuthenticationMessage.TryAgain);
break;
}
}
await SecondaryAuthenticationFactorAuthentication.ShowNotificationMessageAsync(deviceInDb.DeviceFriendlyName,
SecondaryAuthenticationFactorAuthenticationMessage.UnauthorizedUser);
CurrentSession = null;
}