How To Authenticate Users With Office 365 WebForm Application

This is a new feature that most corporate applications are using to authenticate users with office365 before redirecting them to the application.

Last week, I had a requirement to authenticate users. I did search Google but all the solutions support Owin and related libs, MVC etc.There is no solution for Web form application with .NET 4.0.

 

For this, you have to follow these steps -

 

Create application using Microsoft account at this URL.

 

 

• Mention Redirect URL where you want to hit after authentication.
• Copy AppId that will help us later.
• In Login.aspx, create a button, and onclick of this button, write the following code.

<input type="button" ID="BtnSignInMicrosoft" Class="bofficesignin" runat="server" value="Sign in with Office 365" onclick="RedirectToOffice(); return false;" /> and javascript code function RedirectToOffice() { var OfficeRedirectUrl = "
<%=ConfigurationManager.AppSettings("YourRediectURL mention on application creation")%>"; var Office365ClientId = "
    <%=ConfigurationManager.AppSettings("Office365ClientId")%>"; var OfficeUrl = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize?response_type=id_token+token&client_id="+ Office365ClientId +"&redirect_uri=" + OfficeRedirectUrl + "&scope=openid+https%3A%2F%2Foutlook.office.com%2Fmail.read&nonce=13c9217a-d565-fb9e-d66d-d5ad18fa6f0b&response_mode=form_post"; window.open(OfficeUrl,"_self"); }

Write the following code on your redirect page.

If Request.Form.Item("id_token") Is Nothing = False Then
Dim objWebClient As New System.Net.WebClient
Dim HeaderData As New WebHeaderCollection
Dim jSerializer As New JavaScriptSerializer
Dim ResponseString As String = String.Empty
Dim ResponseData As Dictionary(Of String, String)
Dim Email As String = String.Empty
Dim TokenID As String = Request.Form.Item("id_token")
Dim AccessToken As String = Request.Form.Item("access_token")
TokenID = TokenID.Substring(0, TokenID.IndexOf("."))
HeaderData("Authorization") = "Bearer " + AccessToken
' Dim objOutlookSetting As OutLookSetting = Serializar.Deserialize(Of OutLookSetting)(BLL.SettingManager.GetValueByKey("EAAdminOutlookSetting"))
HeaderData("client-request-id") = ConfigurationManager.AppSettings("Office365ClientId")
HeaderData("return-client-request-id") = "true"
objWebClient.Headers = HeaderData
ResponseString = objWebClient.DownloadString("https://outlook.office.com/api/v2.0/Me")
ResponseData = jSerializer.Deserialize(Of Dictionary(Of String, String))(ResponseString)
Email = ResponseData("EmailAddress")

And, the rest of the flow will remain the same in your application.