.NET Framework

Integrating Windows Live Authentication in your application

Gaurav Khanna — Mon, 17 Dec 2007 07:42:11 GMT

For one of my pet projects I am writing, I was contemplating how to integrate Windows Live Authentication with my standalone application, similar to Windows Live Messenger. Turns out, it is really easy! Below are the three steps that were needed for the integration:

Download the Windows Live Client SDK from here and install it.
Create a new project and add reference to Microsoft.WindowsLive.Id.Client assembly
Write code similar to the one below:

using System;
using Microsoft.WindowsLive.Id.Client;

namespace WLAuthenticate
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            // Attempt user authentication
            Console.WriteLine("Enter your passport email address: ");
            string strPassportEmail = Console.ReadLine();
            if (String.IsNullOrEmpty(strPassportEmail))
            {
                Console.WriteLine("Enter valid address!");
                return;
            }

            // Got the details - attempt to authenticate
            IdentityManager idMgr = null;
            Identity curID = null;

            // Create the identity manager
            idMgr = IdentityManager.CreateInstance("OrganizationName;name@company.com;ClientAuthSample",
                "Windows Live Client Authentication Sample App");

            // and now create the user's identity from it..
            curID = idMgr.CreateIdentity(strPassportEmail);
            bool fAuthenticated = false;

            if (curID != null)
            {
                if (curID.SavedCredentials == CredentialType.UserNameAndPassword)
                {
                    // the credentials are persisted in local store and we can authenticate
                    fAuthenticated = curID.Authenticate(AuthenticationType.Silent);
                }
                else
                {
                    // Credentials not available locally, so show the signin dialog...
                    curID = idMgr.CreateIdentity();

                    // This will prompt for credentials to authenticate...
                    fAuthenticated = curID.Authenticate();
                }

                if (fAuthenticated)
                {
                    Console.WriteLine("Authenticated with Windows Live!");
                    Console.WriteLine("Your username is {0}", curID.UserName);
                    
                    // Close the authentication
                    curID.CloseIdentityHandle();
                }
            }
            
        }
    }
}

Easy, isn't it :) ?

The only thing to be kept in mind is that if the passport authentication details are not persisted on the machine where authentication is attempted, then you will need to invoke Identity.Authenticate method without any arguments. This overload uses COM subsystem to display the Windows Live signin dialog to attempt authentication and requires the calling thread to be in STA mode and thus, tagged with STAThread attribute. Hence, I have set this attribute to the Main method above. Not setting this attribute will result in a ThreadStateException being raised.

[Article] AppDomains and Unhandled Exception Notifications

Gaurav Khanna — Sun, 16 Dec 2007 05:46:30 GMT

One always strives to write exception safe application but there are times when an exception can go unhandled.

In the .NET Framework, the AppDomain class exposes the UnhandledException event that can be used by by the managed application to know when an exception has gone unhandled. In the writeup, AppDomains and Unhandled Exception Notifications, I discuss the specifics of when and how this notification is made, what is the relationship between the thread that had unhandled exception and the AppDomain(s) for which this notification will be done and what should be done during the notification callback.

The source code for the article can be downloaded from here.

Enumerating AppDomains - I

Gaurav Khanna — Sun, 10 Jun 2007 03:45:46 GMT

Surprisingly, enumerating AppDomains is not that straightforward. The System.AppDomain type does not expose functionality to enumerate them at all. The way to enumerate them will be to use the V1 Hosting interface, ICorRuntimeHost and then invoke the EnumDomains and NextDomain methods against it to get the list. If you are using CLR 2.0, you needn't worry as CLR 2.0 does implement the V1 interfaces as well.

Below is the snippet that exemplifies the concept (note: AppDomains will only be enumerated in the current process - I will discuss AppDomain enumeration in remote processes later). You can download the source code (VS Solution) from http://www.wintoolzone.com/ListDotNET.aspx?Listtype=5

// EnumAppDomains.cpp : Defines the entry point for the console application.
// 
#include "stdafx.h"
#include <windows.h>
#include "mscoree.h"

#import "C:\\Windows\\Microsoft.NET\\Framework\\v2.0.50727\\mscorlib.tlb" raw_interfaces_only

using namespace mscorlib; 

#define EXITONERROR(hr, mesg) \
if (FAILED(hr)) \
{ \
    printf("%s\n", mesg); \
    ExitProcess(1); \
} 

#define SUCCESSFUL(hr) (SUCCEEDED(hr) && hr != S_FALSE) 
int _tmain(int argc, _TCHAR* argv[])
{
    ICorRuntimeHost * pV1HostPtr = NULL;
    HRESULT hr = CorBindToRuntimeEx(NULL,
                NULL, 0, 
                CLSID_CorRuntimeHost,
                IID_ICorRuntimeHost,
                (LPVOID *)&pV1HostPtr);

    EXITONERROR(hr, "Unable to get ICorRuntimeHost*"); 
    
    // Start the runtime
    hr = pV1HostPtr->Start();
    EXITONERROR(hr, "Unable to start the runtime"); 
    
    // Enumerate the AppDomains
    HDOMAINENUM adEnum;
    hr = pV1HostPtr->EnumDomains(&adEnum);
    EXITONERROR(hr, "Unable to enumerate AppDomains");
    
    // Loop thru the domains
    IUnknown * pDomainUnk = NULL;
    hr = pV1HostPtr->NextDomain(adEnum, &pDomainUnk);
    while(SUCCESSFUL(hr))
    {
        // Got the IUnknown* to the AppDomain - convert it to AppDomain pointer
        _AppDomain * pCurDomain = NULL;
        hr = pDomainUnk->QueryInterface(__uuidof(_AppDomain), (VOID**)&pCurDomain);
        if (SUCCESSFUL(hr))
        {
            // Display the name of the AppDomain
            BSTR str;
            if (SUCCESSFUL(pCurDomain->get_FriendlyName(&str)))
            {
            wprintf(L"AppDomain: %s\n",str);
            }
            else
            {
                printf("AppDomain: unable to get the name!\n");
            }
        } 
    
        // Loop onto the next Domain
        hr = pV1HostPtr->NextDomain(adEnum, &pDomainUnk);
    } 

    // Stop the runtime
    if (pV1HostPtr)
    {
        pV1HostPtr->Stop();
    }

    return 0;
}

Technorati tags: CLR Hosting, CorBindToRuntimeEx, Hosting, AppDomains, Enumeration, EnumDomains

WinToolZone.Bluetooth - Support for authentication

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 21:42:00 GMT

[Originally posted on 10th July 2006]

WinToolZone.Bluetooth now has authentication support. You can use a BluetoothDevice object (which is used represent a Bluetooth device that has been detected) and use the SendPassKey method to send a pass key for authentication:

   1:  bth.Devices[ i ].SendPassKey("123", null);

Also, I have added OnIncomingAuthenticationRequest event handler against a BluetoothDevice object that can be used to setup an event handler, which will be invoked when the Bluetooth device sends an authentication request to the machine running WinToolZone.Bluetooth:

   1:  bth.Devices[ i ].OnIncomingAuthenticationRequest += new

   2:  BluetoothDevice.IncomingAuthenticationRequestHandler(

   3:  Program_OnIncomingAuthenticationRequest);

The event handler is implemented as shown below:

   1:   static void Program_OnIncomingAuthenticationRequest(

   2:                 BluetoothDevice refDeviceRequestingAuthentication)

   3:   {

   4:    Console.WriteLine("{0} is requesting me to send pass key.",

   5:      refDeviceRequestingAuthentication.Name);

6:

   7:    bool bSentResponse =

   8:    refDeviceRequestingAuthentication.SendAuthenticationResponse("123", null);

   9:    Console.WriteLine("Sent response: {0}",bSentResponse.ToString());

  10:   }

The handler gets as an argument the BluetoothDevice instance representing the device that sent the authentication request. To send the pass key back as part of completing the incoming authentication process, SendAuthenticationResponse method of BluetoothDevice is used.

For a partnership/bonding that has been established with a Bluetooth device, DeleteDeviceAuthentication method has been introduced that should be invoked against the BluetoothDevice instance representing the partnered device to break the partnership.

WinToolZone.Bluetooth - Added device enumeration support

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 21:39:00 GMT

[Originally posted on 6th July 2006]

WinToolZone.Bluetooth, the managed Bluetooth API for the desktop that I am working on, now has the support for enumerating devices as well. The snippet below exemplifies it:

   1:  Bluetooth bth = new Bluetooth();

2:

   3:      // EnumRadios(bth);

4:

   5:      if (bth.RefreshDevices(false, true, true, true, true, null) == false)

   6:      {

   7:           Console.WriteLine("Unable to enum devices");

   8:           return;

   9:      }

10:

  11:      foreach (BluetoothDevice device in bth.Devices)

  12:      {

  13:           Console.WriteLine("Devicename: {0}", device.Name);

  14:           Console.WriteLine("LastSeen: {0}", device.LastSeen.ToString());

  15:           Console.WriteLine("LastUsed: {0}", device.LastUsed.ToString());

  16:           Console.WriteLine("Connected: {0}", device.IsConnected.ToString());

  17:           Console.WriteLine("Remembered: {0}", device.IsRemembered.ToString());

  18:           Console.WriteLine("Authenticated: {0}", device.IsAuthenticated.ToString());

  19:           Console.WriteLine("DeviceClass: {0}", device.DeviceClassID);

  20:           Console.WriteLine("Address: {0}\n", device.Address.ToString());

21:

  22:      }

And below is an output screenshot:

WinToolZone.Bluetooth - Managed Bluetooth API for the desktop

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 21:28:00 GMT

[Originally posted on 5th July 2006]

One of the communication protocols not present in .NET Framework class libraries is Bluetooth. So today, I started to work on my implementation of a managed API for Bluetooth programming - WinToolZone.Bluetooth. I am authoring it using Managed C++ and leveraging the Microsoft Bluetooth stack APIs.

I just completed implementing the support for enumerating the Bluetooth radios on a machine. Below is a C# program that exemplifies how they can be enumerated:

   1:  using System;

   2:  using System.Collections.Generic;

   3:  using System.Text;

   4:  using WinToolZone;

5:

   6:  namespace BTHCSClient

   7:  {

   8:      class Program

   9:      {

  10:          static void Main(string[] args)

  11:          {

  12:              Bluetooth bth = new Bluetooth();

  13:              if (bth.RefreshRadios())

  14:              {

  15:                  foreach (BluetoothRadio radio in bth.Radios)

  16:                  {

  17:                      Console.WriteLine("RadioName: {0}", radio.Name);

  18:                      Console.WriteLine("Address: {0}", radio.Address.ToString());

  19:                      Console.WriteLine("ManuID: {0}", radio.ManufacturerID);

  20:                      Console.WriteLine("LMPSubversion: {0}", radio.LMPSubversion);

  21:                      Console.WriteLine("DeviceClass: {0}", radio.DeviceClass);

  22:                  }

  23:              }

  24:              else

  25:              {

  26:                  Console.WriteLine("Unable to enumerate BTH radios");

  27:              }

  28:          }

  29:      }

  30:  }

DesktopSMS - Send, Receive and Reply to SMS from the desktop

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 21:24:00 GMT

[Originally posted on 31st July 2006]

Ever wanted to compose SMS from the ease of desktop instead of the phone? Wanted to be notified on the desktop, while you are working, when a SMS is received and reply to it from there itself?

DesktopSMS, for Windows Mobile 5.0 based SmartPhone and PocketPC devices, will let you do just that! Based upon .NET Framework 2.0, .NET Compact Framework 2.0 and Windows Mobile 5.0, it allows you to compose, receive and reply to SMS while the phone is connected to your machine via ActiveSync. Below are some screenshots of the same:

Likewise, when a SMS is received, a popup comes on your screen that will allow you to reply as well:

You can even select recepients from Microsoft Outlook's Contact folder as message receipient, provided they have mobile phone number specified. It comes with complete documentation and installer.

Download DesktopSMS from http://www.wintoolzone.com/showpage.aspx?url=listdotnet.aspx?Listtype=1

[Download] TransNTFS v1.0.0.1 - support for folders, symbolic and hard links and more

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 21:19:00 GMT

I have updated TransNTFS, my managed implementation for the transactional NTFS APIs that have been introduced with Windows Vista. TransNTFS now also supports the following operations under a transaction:

Creation and deletion of folders
Deletion of files
Creation of symbolic links
Creation of hard links

It comes with complete documentation (as always) and can be downloaded from http://www.wintoolzone.com/ListDotNET.aspx?Listtype=3

[Download] TransNTFS - Managed implementation of Transactional NTFS (TxF) APIs

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 20:49:00 GMT

Sometime back, I had made a post regarding a native C++ class I had authored for using some of the Transactional NTFS (TxF)APIs introduced in Windows Vista.

Almost two weeks from that post, I just finished my managed implementation, TransNTFS, that enables you to use the TxF APIs from managed code. As always, Managed C++ enabled the implementation with excellent ease. It comes with complete documentation and can be downloaded from http://www.wintoolzone.com/ListDotNET.aspx?Listtype=3.

Below is an example usage of how to copy a file under a transaction:

   1:  using System;

   2:  using System.Collections.Generic;

   3:  using System.Text;

   4:  using WinToolZone;

5:

   6:  namespace ManagedTransactionCopyDemo

   7:  {

   8:  class Program

   9:  {

  10:  static void Main(string[] args)

  11:  {

  12:  TransNTFS refTC = new TransNTFS();

13:

  14:  // Init the transaction

  15:  bool fSuccess = refTC.BeginTransaction();

  16:  if (fSuccess)

  17:  {

  18:  fSuccess = refTC.CopyFile("d:\\transcopy.pdb", "d:\\t.pdb", false);

  19:  if (fSuccess)

  20:  {

  21:  fSuccess = refTC.Commit();

  22:  if (fSuccess)

  23:  {

  24:  Console.WriteLine("Copy successful!");

  25:  }

  26:  else

  27:  {

  28:  ShowErrorAndExit("Commit failed!", refTC.LastError);

  29:  }

  30:  }

  31:  else

  32:  {

  33:  ShowErrorAndExit("Copy failed!", refTC.LastError);

  34:  }

  35:  }

  36:  else

  37:  {

  38:  ShowErrorAndExit("Unable to start the transaction!", refTC.LastError);

  39:  }

  40:  }

41:

  42:  private static void ShowErrorAndExit(string p, int p_2)

  43:  {

  44:  Console.WriteLine("ERROR: {0}", p);

  45:  Console.WriteLine("CODE: {0}", p_2);

  46:  System.Environment.Exit(1);

  47:  }

  48:  }

  49:  }

Article: Customizing AppDomain Creation

Gaurav Khanna [gaurav@wintoolzone.com] — Thu, 29 Mar 2007 20:47:00 GMT

Did you have a scenario where you wished you could customize the creation of AppDomains? Or, you could control how many AppDomains any code that runs in your application context (e.g. if you are writing a plugin load framework) could create? Or, how about reusing AppDomains for various assemblies?

I have just finished an article on how any of the above scenarios can be accomplished using the System.AppDomainManager type, introduced in .NET Framework 2.0, by intercept AppDomain creation requests.

You can read the article at http://www.wintoolzone.com/articles/Customizing_AppDomain_Creation.aspx and download associated source code from http://www.wintoolzone.com/downloads/Customizing_AppDomain_Creation_src.zip