WebAuthenticationBroker

0.1

Helper.Windows.cs

                                using System;

using System.Collections;

using System.Reflection;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Navigation;

namespace PSWebAuthBroker_ab8baa5cebae4693a6fc517d7b0f69c3

{

    public class BrokerWindow : IDisposable

    {

        Window window;

        WebBrowser browser;

        /// <summary>

        /// Initializes a new BrokerWindow object.

        /// </summary>

        public BrokerWindow()

        {

            window = new Window();

            browser = new WebBrowser();

            browser.Tag = this;

            browser.Navigating += browserNavigating;

            browser.Navigated += browserNavigated;

            window.Tag = this;

            window.Title = "Authnetication Broker";

            window.MinWidth = 440;

            window.MinHeight = 330;

            window.Width = 550;

            window.Height = 450;

            window.Content = browser;

            window.Closing += windowClosing;

        }

        /// <summary>

        /// Displays the broker and authenticates the user. This method must not be called twice.

        /// </summary>

        public bool AuthenticateUser()

        {

            browser.Navigate(InitialUri);

            return window.ShowDialog() == true;

        }

        /// <summary>

        /// Gets/sets the title for the window.

        /// </summary>

        public string Title { get { return window.Title; } set { window.Title = value; } }

        /// <summary>

        /// Gets/sets the initial URI to navigate to.

        /// </summary>

        public string InitialUri { get; set; }

        /// <summary>

        /// Gets/sets whether the broker should use current URI as the title.

        /// </summary>

        public bool TitleIsUri { get; set; }

        /// <summary>

        /// Gets the extracted information object.

        /// </summary>

        public object Extracted { get; private set; }

        /// <summary>

        /// Gets/sets an extractor delegate that extracts authentication information from the URI.

        /// This delegate is called each time the broker has navigated.

        /// Returning null from this delegate continues the authentication procedure.

        /// Returning non-null from this delegate terminates the authentication procedure.

        /// </summary>

        public Func<string, object> CompletionExtractor { get; set; }

        /// <summary>

        /// Gets/sets a predicate whether a URI should be allowed to display within this broker.

        /// This delegate is called each time before the broker navigates.

        /// Returning true from this delegate allows navigation.

        /// Returning false from this delegate disallows navigation.

        /// An example usage is to only allow HTTPS pages.

        /// </summary>

        public Func<string, bool> UriPredicate { get; set; }

        private static void browserNavigating(object sender, NavigatingCancelEventArgs e)

        {

            var that = (BrokerWindow)((WebBrowser)sender).Tag;

            var uriUri = e.Uri;

            var uri = (uriUri != null ? uriUri.AbsoluteUri : null);

            var pred = that.UriPredicate ?? (_ => true);

            if (!pred(uri))

            {

                MessageBox.Show(that.window,

                    "The URI is disallowed in this authentication broker.\r\nThe URI is " + uri,

                    "Navigation cancelled",

                    MessageBoxButton.OK,

                    MessageBoxImage.Warning);

                e.Cancel = true;

            }

        }

        const BindingFlags InstancePublicMethod = BindingFlags.Instance | BindingFlags.Public | BindingFlags.InvokeMethod;

        const BindingFlags InstancePublicSetProp = BindingFlags.Instance | BindingFlags.Public | BindingFlags.SetProperty;

        static readonly object[] CreateScriptElementParams = new object[] { "SCRIPT" };

        static readonly object[] SetTypeJSParams = new object[] { "application/javascript" };

        static readonly object[] SetInnerHtmlJSParams = new object[] { "window.onerror = function () { return true; };" };

        static readonly object[] GetHeadParams = new object[] { "head" };

        private static void SuppressJavaScriptErrors(WebBrowser browser)

        {

            try

            {

                var doc = browser.Document;

                var scriptElement = doc.GetType().InvokeMember("createElement", InstancePublicMethod,

                    null, doc, CreateScriptElementParams);

                scriptElement.GetType().InvokeMember("type", InstancePublicSetProp,

                    null, scriptElement, SetTypeJSParams);

                scriptElement.GetType().InvokeMember("innerHTML", InstancePublicSetProp,

                    null, scriptElement, SetInnerHtmlJSParams);

                var heads = doc.GetType().InvokeMember("getElementsByTagName", InstancePublicMethod,

                    null, doc, GetHeadParams);

                foreach (var head in (IEnumerable)heads)

                {

                    head.GetType().InvokeMember("appendChild", InstancePublicMethod,

                        null, head, new object[] { scriptElement });

                    break;

                }

            }

            catch { }

        }

        private static void browserNavigated(object sender, NavigationEventArgs e)

        {

            var that = (BrokerWindow)((WebBrowser)sender).Tag;

            SuppressJavaScriptErrors(that.browser);

            var srcUri = that.browser.Source;

            var newSource = (srcUri != null ? srcUri.AbsoluteUri : null);

            if (that.TitleIsUri)

            {

                that.window.Title = newSource ?? "Authentication Broker";

            }

            var extractor = that.CompletionExtractor ?? (_ => null);

            var extracted = extractor(newSource ?? "");

            if (!ReferenceEquals(extracted, null))

            {

                that.Extracted = extracted;

                that.window.DialogResult = true;

                that.window.Close();

            }

        }

        private static void windowClosing(object sender, System.ComponentModel.CancelEventArgs e)

        {

            var that = (BrokerWindow)((Window)sender).Tag;

            that.Dispose();

        }

        /// <summary>

        /// Disposes the object.

        /// This method is automatically called when the UI is dismissed.

        /// </summary>

        public void Dispose()

        {

            window.Content = null;

            browser.Dispose();

        }

    }

}