When a user enters a URL into their browser’s address window or clicks on a link, the browser makes a Hypertext Transfer Protocol (HTTP) request to the web server for the specified content, be it an ASP.NET page, an image, a JavaScript file, or any other type of content. The web server is tasked with returning the requested content. In doing so, it must determine a number of things about the request, including who made the request and whether the identity is authorized to retrieve the requested content.
By default, browsers send HTTP requests that lack any sort of identification information. But if the browser does include authentication information then the web server starts the authentication workflow, which attempts to identify the client making the request. The steps of the authentication workflow depend on the type of authentication being used by the web application. ASP.NET supports three types of authentication: Windows, Passport, and forms. This tutorial series focuses on forms authentication, but let’s take a minute to compare and contrast Windows authentication user stores and workflow.
Authentication via Windows Authentication
The Windows authentication workflow uses one of the following authentication techniques:
- Basic authentication
- Digest authentication
- Windows Integrated Authentication
All three techniques work in roughly the same way: when an unauthorized, anonymous request arrives, the web server sends back an HTTP response that indicates that authorization is required to continue. The browser then displays a modal dialog box that prompts the user for their username and password (see Figure 1). This information is then sent back to the web server via an HTTP header.

Figure 1: A Modal Dialog Box Prompts the User for His Credentials
The supplied credentials are validated against the web server’s Windows User Store. This means that each authenticated user in your web application must have a Windows account in your organization. This is commonplace in intranet scenarios. In fact, when using Windows Integrated Authentication in an intranet setting, the browser automatically provides the web server with the credentials used to log on to the network, thereby suppressing the dialog box shown in Figure 1. While Windows authentication is great for intranet applications, it is usually unfeasible for Internet applications since you do not want to create Windows accounts for each and every user who signs up at your site.
All these information is based on the Article bublished by Mr Scott Mitchell in asp.netyou can visit it http://www.asp.net/learn/security/tutorial-01-cs.aspx and download source code.
href="http://linkpartners.dotnetforum.lk/default.aspx"> src="http://linkpartners.dotnetforum.lk/images/banners/120x90.jpg"
style="border:0px; height: 90px; width: 120px" />
