Removed the title monitoring, as it was dependent on to many factory (Edge cutting the title).

Greenshot/Forms/AboutForm.Designer.cs

@@ -21,6 +21,7 @@
 
 using System.Windows.Forms;
 using Greenshot.Helpers;
+using GreenshotPlugin.Core;
 
 namespace Greenshot.Forms {
 	partial class AboutForm {

GreenshotImgurPlugin/ImgurUtils.cs

@@ -169,11 +169,11 @@ namespace GreenshotImgurPlugin {
 				{
 					AuthUrlPattern = "https://api.imgur.com/oauth2/authorize?response_type=token&client_id={ClientId}&state={State}",
 					TokenUrl = "https://api.imgur.com/oauth2/token",
-					RedirectUrl = "https://getgreenshot.org/oauth/imgur",
+					RedirectUrl = "https://getgreenshot.org/authorize/imgur",
 					CloudServiceName = "Imgur",
 					ClientId = ImgurCredentials.CONSUMER_KEY,
 					ClientSecret = ImgurCredentials.CONSUMER_SECRET,
-					AuthorizeMode = OAuth2AuthorizeMode.MonitorTitle,
+					AuthorizeMode = OAuth2AuthorizeMode.JsonReceiver,
 					RefreshToken = Config.RefreshToken,
 					AccessToken = Config.AccessToken,
 					AccessTokenExpires = Config.AccessTokenExpires

GreenshotPlugin/Core/OAuth/LocalJsonReceiver.cs

@@ -0,0 +1,191 @@
+/*
+ * Greenshot - a free and open source screenshot tool
+ * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
+ *
+ * For more information see: http://getgreenshot.org/
+ * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using System.Threading;
+using log4net;
+using Newtonsoft.Json;
+
+namespace GreenshotPlugin.Core.OAuth
+{
+    /// <summary>
+    /// OAuth 2.0 verification code receiver that runs a local server on a free port
+    /// and waits for a call with the authorization verification code.
+    /// </summary>
+    public class LocalJsonReceiver
+    {
+        private static readonly ILog Log = LogManager.GetLogger(typeof(LocalJsonReceiver));
+        private readonly ManualResetEvent _ready = new ManualResetEvent(true);
+        private IDictionary<string, string> _returnValues;
+
+        /// <summary>
+        /// The url format for the website to post to. Expects one port parameter.
+        /// Default: http://localhost:{0}/authorize/
+        /// </summary>
+        public string ListeningUrlFormat { get; set; } = "http://localhost:{0}/authorize/";
+
+        private string _listeningUri;
+        /// <summary>
+        /// The URL where the server is listening
+        /// </summary>
+        public string ListeningUri {
+            get {
+                if (string.IsNullOrEmpty(_listeningUri))
+                {
+                    _listeningUri = string.Format(ListeningUrlFormat, GetRandomUnusedPort());
+                }
+                return _listeningUri;
+            }
+            set => _listeningUri = value;
+        }
+
+        /// <summary>
+        /// This action is called when the URI must be opened, default is just to run Process.Start
+        /// </summary>
+        public Action<string> OpenUriAction
+        {
+            set;
+            get;
+        } = authorizationUrl =>
+        {
+            Log.DebugFormat("Open a browser with: {0}", authorizationUrl);
+            using var process = Process.Start(authorizationUrl);
+        };
+
+        /// <summary>
+        /// Timeout for waiting for the website to respond
+        /// </summary>
+        public TimeSpan Timeout { get; set; } = TimeSpan.FromMinutes(4);
+
+        /// <summary>
+        /// The OAuth code receiver
+        /// </summary>
+        /// <param name="oauth2Settings">OAuth2Settings</param>
+        /// <returns>Dictionary with values</returns>
+        public IDictionary<string, string> ReceiveCode(OAuth2Settings oauth2Settings) {
+            using var listener = new HttpListener();
+            // Make sure the port is stored in the state, so the website can process this.
+            oauth2Settings.State = new Uri(ListeningUri).Port.ToString();
+            listener.Prefixes.Add(ListeningUri);
+            try {
+                listener.Start();
+                _ready.Reset();
+
+                listener.BeginGetContext(ListenerCallback, listener);
+                OpenUriAction(oauth2Settings.FormattedAuthUrl);
+                _ready.WaitOne(Timeout, true);
+            } catch (Exception) {
+                // Make sure we can clean up, also if the thead is aborted
+                _ready.Set();
+                throw;
+            } finally {
+                listener.Close();
+            }
+
+            return _returnValues;
+        }
+
+        /// <summary>
+        /// Handle a connection async, this allows us to break the waiting
+        /// </summary>
+        /// <param name="result">IAsyncResult</param>
+        private void ListenerCallback(IAsyncResult result) {
+            HttpListener listener = (HttpListener)result.AsyncState;
+
+            //If not listening return immediately as this method is called one last time after Close()
+            if (!listener.IsListening) {
+                return;
+            }
+
+            // Use EndGetContext to complete the asynchronous operation.
+            HttpListenerContext context = listener.EndGetContext(result);
+
+            // Handle request
+            HttpListenerRequest request = context.Request;
+
+            if (request.HasEntityBody)
+            {
+                // Process the body
+                using var body = request.InputStream;
+                using var reader = new StreamReader(body, request.ContentEncoding);
+                using var jsonTextReader = new JsonTextReader(reader);
+                var serializer = new JsonSerializer();
+                _returnValues = serializer.Deserialize<Dictionary<string, string>>(jsonTextReader);
+            }
+
+            // Create the response.
+            using (HttpListenerResponse response = context.Response)
+            {
+                if (request.HttpMethod == "OPTIONS")
+                {
+                    response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With");
+                    response.AddHeader("Access-Control-Allow-Methods", "POST");
+                    response.AddHeader("Access-Control-Max-Age", "1728000");
+                }
+
+                response.AppendHeader("Access-Control-Allow-Origin", "*");
+                if (request.HasEntityBody)
+                {
+                    response.ContentType = "application/json";
+                    // currently only return the version, more can be added later
+                    string jsonContent = "{\"version\": \"" + EnvironmentInfo.GetGreenshotVersion(true) + "\"}";
+
+                    // Write a "close" response.
+                    byte[] buffer = Encoding.UTF8.GetBytes(jsonContent);
+                    // Write to response stream.
+                    response.ContentLength64 = buffer.Length;
+                    using var stream = response.OutputStream;
+                    stream.Write(buffer, 0, buffer.Length);
+                }
+            }
+
+            if (_returnValues != null)
+            {
+                _ready.Set();
+            }
+            else
+            {
+                // Make sure the next request is processed
+                listener.BeginGetContext(ListenerCallback, listener);
+            }
+        }
+
+        /// <summary>
+        /// Returns a random, unused port.
+        /// </summary>
+        /// <returns>port to use</returns>
+        private static int GetRandomUnusedPort() {
+            var listener = new TcpListener(IPAddress.Loopback, 0);
+            try {
+                listener.Start();
+                return ((IPEndPoint)listener.LocalEndpoint).Port;
+            } finally {
+                listener.Stop();
+            }
+        }
+    }
+}

GreenshotPlugin/Core/OAuth/OAuth2AuthorizeMode.cs

@@ -27,8 +27,7 @@ namespace GreenshotPlugin.Core.OAuth
     public enum OAuth2AuthorizeMode {
         Unknown,		 // Will give an exception, caller needs to specify another value
         LocalServer,	 // Will specify a redirect URL to http://localhost:port/authorize, while having a HttpListener
-        MonitorTitle,	 // Will monitor for title changes, the title needs the status and query params
-        Pin,			 // Not implemented yet: Will ask the user to enter the shown PIN
+        JsonReceiver,	 // Will start a local HttpListener and wait for a Json post
         EmbeddedBrowser // Will open into an embedded _browser (OAuthLoginForm), and catch the redirect
     }
 }

GreenshotPlugin/Core/OAuth/OAuth2Helper.cs

@@ -21,12 +21,9 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Drawing;
 using System.Net;
-using System.Windows.Forms;
 using GreenshotPlugin.Controls;
-using GreenshotPlugin.Hooking;
 
 namespace GreenshotPlugin.Core.OAuth {
     /// <summary>
@@ -134,7 +131,7 @@ namespace GreenshotPlugin.Core.OAuth {
 
 		/// <summary>
 		/// Go out and retrieve a new access token via refresh-token with the TokenUrl in the settings
-		/// Will upate the access token, refresh token, expire date
+		/// Will update the access token, refresh token, expire date
 		/// </summary>
 		/// <param name="settings"></param>
 		public static void GenerateAccessToken(OAuth2Settings settings) {
@@ -159,22 +156,23 @@ namespace GreenshotPlugin.Core.OAuth {
 			//	"token_type":"Bearer",
 
 			IDictionary<string, object> accessTokenResult = JSONHelper.JsonDecode(accessTokenJsonResult);
-			if (accessTokenResult.ContainsKey("error")) {
-				if ("invalid_grant" == (string)accessTokenResult["error"]) {
+			if (accessTokenResult.ContainsKey("error"))
+            {
+                if ("invalid_grant" == (string)accessTokenResult["error"]) {
 					// Refresh token has also expired, we need a new one!
 					settings.RefreshToken = null;
 					settings.AccessToken = null;
 					settings.AccessTokenExpires = DateTimeOffset.MinValue;
 					settings.Code = null;
 					return;
-				} else {
-					if (accessTokenResult.ContainsKey("error_description")) {
-						throw new Exception($"{accessTokenResult["error"]} - {accessTokenResult["error_description"]}");
-					} else {
-						throw new Exception((string)accessTokenResult["error"]);
-					}
 				}
-			}
+
+                if (accessTokenResult.ContainsKey("error_description")) {
+                    throw new Exception($"{accessTokenResult["error"]} - {accessTokenResult["error_description"]}");
+                }
+
+                throw new Exception((string)accessTokenResult["error"]);
+            }
 
 			if (accessTokenResult.ContainsKey(AccessToken))
 			{
@@ -205,76 +203,62 @@ namespace GreenshotPlugin.Core.OAuth {
 			{
 				OAuth2AuthorizeMode.LocalServer => AuthenticateViaLocalServer(settings),
 				OAuth2AuthorizeMode.EmbeddedBrowser => AuthenticateViaEmbeddedBrowser(settings),
-                OAuth2AuthorizeMode.MonitorTitle => AuthenticateViaDefaultBrowser(settings),
+                OAuth2AuthorizeMode.JsonReceiver => AuthenticateViaDefaultBrowser(settings),
                 _ => throw new NotImplementedException($"Authorize mode '{settings.AuthorizeMode}' is not 'yet' implemented."),
 			};
 			return completed;
 		}
 
         /// <summary>
-        /// Authenticate via the default browser, using the browser title.
+        /// Authenticate via the default browser, via the Greenshot website.
+        /// It will wait for a Json post.
         /// If this works, return the code
         /// </summary>
         /// <param name="settings">OAuth2Settings with the Auth / Token url etc</param>
         /// <returns>true if completed, false if canceled</returns>
         private static bool AuthenticateViaDefaultBrowser(OAuth2Settings settings)
         {
-            var monitor = new WindowsTitleMonitor();
+			var codeReceiver = new LocalJsonReceiver();
+            IDictionary<string, string> result = codeReceiver.ReceiveCode(settings);
 
-            string error = null;
-			var fields = new HashSet<string>();
-            int nrOfFields = 100;
-
-			monitor.TitleChangeEvent += args =>
+            foreach (var key in result.Keys)
             {
-                if (!args.Title.Contains(settings.State))
+                switch (key)
                 {
-                    return;
+                    case AccessToken:
+                        settings.AccessToken = result[key];
+                        break;
+                    case ExpiresIn:
+                        if (int.TryParse(result[key], out var seconds))
+                        {
+                            settings.AccessTokenExpires = DateTimeOffset.Now.AddSeconds(seconds);
+                        }
+                        break;
+                    case RefreshToken:
+                        settings.RefreshToken = result[key];
+                        break;
                 }
+            }
 
-                var title = args.Title;
-                title = title.Substring(0,title.IndexOf(' '));
-
-                var parameters = NetworkHelper.ParseQueryString(title);
-
-                if (parameters.ContainsKey("nr"))
+            if (result.TryGetValue("error", out var error))
+            {
+                if (result.TryGetValue("error_description", out var errorDescription))
                 {
-                    nrOfFields = int.Parse(parameters["nr"]);
+                    throw new Exception(errorDescription);
                 }
+                if ("access_denied" == error)
+                {
+                    throw new UnauthorizedAccessException("Access denied");
+                }
+                throw new Exception(error);
+			}
+            if (result.TryGetValue(Code, out var code) && !string.IsNullOrEmpty(code))
+            {
+                settings.Code = code;
+                GenerateRefreshToken(settings);
+            }
 
-                foreach (var key in parameters.Keys)
-                {
-                    fields.Add(key);
-                    switch (key)
-                    {
-                        case AccessToken:
-                            settings.AccessToken = parameters[key];
-                            break;
-                        case ExpiresIn:
-                            if (int.TryParse(parameters[key], out var seconds))
-                            {
-                                settings.AccessTokenExpires = DateTimeOffset.Now.AddSeconds(seconds);
-                            }
-                            break;
-                        case RefreshToken:
-                            settings.RefreshToken = parameters[key];
-                            break;
-                        case Error:
-                            error = parameters[key];
-                            break;
-					}
-                }
-            };
-			using (var process = Process.Start(settings.FormattedAuthUrl))
-			{
-                while (nrOfFields > fields.Count)
-                {
-					// Have the thread process Forms events
-					Application.DoEvents();
-                }
-			};
-			monitor.Dispose();
-            return error == null;
+			return true;
         }
 
         /// <summary>