Here is a self-contained, non-third-party WPF sample that runs Google auth (it can also be easily converted to winforms).
If you run it, you will not log in and the application will show you a button. If you click this button, the built-in web browser control will be launched using Google authorization. After authentication, the application simply displays your name returned by Google.
Note that it is based on the official Google example here: https://github.com/googlesamples/oauth-apps-for-windows , but it uses a built-in browser instead of spawning an external one (and several other differences).
XAML Code:
<Window x:Class="GoogleAuth.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="750" Width="525"> <Window.Resources> <BooleanToVisibilityConverter x:Key="btv" /> </Window.Resources> <Grid> <DockPanel Visibility="{Binding State.IsSigned, Converter={StaticResource btv}}"> <Label>You are signed as:</Label> <Label Content="{Binding State.Token.Name}" /> </DockPanel> <Grid Visibility="{Binding State.IsNotSigned, Converter={StaticResource btv}}"> <Grid.RowDefinitions> <RowDefinition Height="23" /> <RowDefinition Height="*" /> </Grid.RowDefinitions> <Button Click="Button_Click">Click to Sign In</Button> <WebBrowser Grid.Row="1" x:Name="Wb" Height="Auto" /> </Grid> </Grid> </Window>
C # code:
using System; using System.ComponentModel; using System.IO; using System.Net; using System.Net.Sockets; using System.Runtime.Serialization; using System.Runtime.Serialization.Json; using System.Security.Cryptography; using System.Text; using System.Threading; using System.Windows; using System.Windows.Threading; namespace GoogleAuth { public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); State = new OAuthState(); DataContext = this; } public OAuthState State { get; } private void Button_Click(object sender, RoutedEventArgs e) { var thread = new Thread(HandleRedirect); thread.Start(); } private async void HandleRedirect() { State.Token = null; // for example, let pretend I want also want to have access to WebAlbums var scopes = new string[] { "https://picasaweb.google.com/data/" }; var request = OAuthRequest.BuildLoopbackRequest(scopes); var listener = new HttpListener(); listener.Prefixes.Add(request.RedirectUri); listener.Start(); // note: add a reference to System.Windows.Presentation and a 'using System.Windows.Threading' for this to compile await Dispatcher.BeginInvoke(() => { Wb.Navigate(request.AuthorizationRequestUri); }); // here, we'll wait for redirection from our hosted webbrowser var context = await listener.GetContextAsync(); // browser has navigated to our small http servern answer anything here string html = string.Format("<html><body></body></html>"); var buffer = Encoding.UTF8.GetBytes(html); context.Response.ContentLength64 = buffer.Length; var stream = context.Response.OutputStream; var responseTask = stream.WriteAsync(buffer, 0, buffer.Length).ContinueWith((task) => { stream.Close(); listener.Stop(); }); string error = context.Request.QueryString["error"]; if (error != null) return; string state = context.Request.QueryString["state"]; if (state != request.State) return; string code = context.Request.QueryString["code"]; State.Token = request.ExchangeCodeForAccessToken(code); } } // state model public class OAuthState : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; private OAuthToken _token; public OAuthToken Token { get => _token; set { if (_token == value) return; _token = value; PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Token))); PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsSigned))); PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsNotSigned))); } } public bool IsSigned => Token != null && Token.ExpirationDate > DateTime.Now; public bool IsNotSigned => !IsSigned; } // This is a sample. Fille information (email, etc.) can depend on scopes [DataContract] public class OAuthToken { [DataMember(Name = "access_token")] public string AccessToken { get; set; } [DataMember(Name = "token_type")] public string TokenType { get; set; } [DataMember(Name = "expires_in")] public int ExpiresIn { get; set; } [DataMember(Name = "refresh_token")] public string RefreshToken { get; set; } [DataMember] public string Name { get; set; } [DataMember] public string Email { get; set; } [DataMember] public string Picture { get; set; } [DataMember] public string Locale { get; set; } [DataMember] public string FamilyName { get; set; } [DataMember] public string GivenName { get; set; } [DataMember] public string Id { get; set; } [DataMember] public string Profile { get; set; } [DataMember] public string[] Scopes { get; set; } // not from google response, but we store this public DateTime ExpirationDate { get; set; } } // largely inspired from // https://github.com/googlesamples/oauth-apps-for-windows public sealed class OAuthRequest { // TODO: this is a sample, please change these two, use your own! private const string ClientId = "581786658708-elflankerquo1a6vsckabbhn25hclla0.apps.googleusercontent.com"; private const string ClientSecret = "3f6NggMbPtrmIBpgx-MK2xXK"; private const string AuthorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth"; private const string TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"; private const string UserInfoEndpoint = "https://www.googleapis.com/oauth2/v3/userinfo"; private OAuthRequest() { } public string AuthorizationRequestUri { get; private set; } public string State { get; private set; } public string RedirectUri { get; private set; } public string CodeVerifier { get; private set; } public string[] Scopes { get; private set; } // https://developers.google.com/identity/protocols/OAuth2InstalledApp public static OAuthRequest BuildLoopbackRequest(params string[] scopes) { var request = new OAuthRequest { CodeVerifier = RandomDataBase64Url(32), Scopes = scopes }; string codeChallenge = Base64UrlEncodeNoPadding(Sha256(request.CodeVerifier)); const string codeChallengeMethod = "S256"; string scope = BuildScopes(scopes); request.RedirectUri = string.Format("http://{0}:{1}/", IPAddress.Loopback, GetRandomUnusedPort()); request.State = RandomDataBase64Url(32); request.AuthorizationRequestUri = string.Format("{0}?response_type=code&scope=openid%20profile{6}&redirect_uri={1}&client_id={2}&state={3}&code_challenge={4}&code_challenge_method={5}", AuthorizationEndpoint, Uri.EscapeDataString(request.RedirectUri), ClientId, request.State, codeChallenge, codeChallengeMethod, scope); return request; } // https://developers.google.com/identity/protocols/OAuth2InstalledApp Step 5: Exchange authorization code for refresh and access tokens public OAuthToken ExchangeCodeForAccessToken(string code) { if (code == null) throw new ArgumentNullException(nameof(code)); string tokenRequestBody = string.Format("code={0}&redirect_uri={1}&client_id={2}&code_verifier={3}&client_secret={4}&scope=&grant_type=authorization_code", code, Uri.EscapeDataString(RedirectUri), ClientId, CodeVerifier, ClientSecret ); return TokenRequest(tokenRequestBody, Scopes); } // this is not used in this sample, but can be used to refresh a token from an old one // https://developers.google.com/identity/protocols/OAuth2InstalledApp Refreshing an access token public OAuthToken Refresh(OAuthToken oldToken) { if (oldToken == null) throw new ArgumentNullException(nameof(oldToken)); string tokenRequestBody = string.Format("refresh_token={0}&client_id={1}&client_secret={2}&grant_type=refresh_token", oldToken.RefreshToken, ClientId, ClientSecret ); return TokenRequest(tokenRequestBody, oldToken.Scopes); } private static T Deserialize<T>(string json) { if (string.IsNullOrWhiteSpace(json)) return default(T); return Deserialize<T>(Encoding.UTF8.GetBytes(json)); } private static T Deserialize<T>(byte[] json) { if (json == null || json.Length == 0) return default(T); using (var ms = new MemoryStream(json)) { return Deserialize<T>(ms); } } private static T Deserialize<T>(Stream json) { if (json == null) return default(T); var ser = CreateSerializer(typeof(T)); return (T)ser.ReadObject(json); } private static DataContractJsonSerializer CreateSerializer(Type type) { if (type == null) throw new ArgumentNullException(nameof(type)); var settings = new DataContractJsonSerializerSettings { DateTimeFormat = new DateTimeFormat("yyyy-MM-dd'T'HH:mm:ss.fffK") }; return new DataContractJsonSerializer(type, settings); } // https://stackoverflow.com/questions/223063/how-can-i-create-an-httplistener-class-on-a-random-port-in-c/ private static int GetRandomUnusedPort() { var listener = new TcpListener(IPAddress.Loopback, 0); listener.Start(); var port = ((IPEndPoint)listener.LocalEndpoint).Port; listener.Stop(); return port; } private static string RandomDataBase64Url(int length) { using (var rng = new RNGCryptoServiceProvider()) { var bytes = new byte[length]; rng.GetBytes(bytes); return Base64UrlEncodeNoPadding(bytes); } } private static byte[] Sha256(string text) { using (var sha256 = new SHA256Managed()) { return sha256.ComputeHash(Encoding.ASCII.GetBytes(text)); } } private static string Base64UrlEncodeNoPadding(byte[] buffer) { string b64 = Convert.ToBase64String(buffer); // converts base64 to base64url. b64 = b64.Replace('+', '-'); b64 = b64.Replace('/', '_'); // strips padding. b64 = b64.Replace("=", ""); return b64; } private static OAuthToken TokenRequest(string tokenRequestBody, string[] scopes) { var request = (HttpWebRequest)WebRequest.Create(TokenEndpoint); request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; byte[] bytes = Encoding.ASCII.GetBytes(tokenRequestBody); using (var requestStream = request.GetRequestStream()) { requestStream.Write(bytes, 0, bytes.Length); } var response = request.GetResponse(); using (var responseStream = response.GetResponseStream()) { var token = Deserialize<OAuthToken>(responseStream); token.ExpirationDate = DateTime.Now + new TimeSpan(0, 0, token.ExpiresIn); var user = GetUserInfo(token.AccessToken); token.Name = user.Name; token.Picture = user.Picture; token.Email = user.Email; token.Locale = user.Locale; token.FamilyName = user.FamilyName; token.GivenName = user.GivenName; token.Id = user.Id; token.Profile = user.Profile; token.Scopes = scopes; return token; } } private static UserInfo GetUserInfo(string accessToken) { var request = (HttpWebRequest)WebRequest.Create(UserInfoEndpoint); request.Method = "GET"; request.Headers.Add(string.Format("Authorization: Bearer {0}", accessToken)); var response = request.GetResponse(); using (var stream = response.GetResponseStream()) { return Deserialize<UserInfo>(stream); } } private static string BuildScopes(string[] scopes) { string scope = null; if (scopes != null) { foreach (var sc in scopes) { scope += "%20" + Uri.EscapeDataString(sc); } } return scope; } // https://developers.google.com/+/web/api/rest/openidconnect/getOpenIdConnect [DataContract] private class UserInfo { [DataMember(Name = "name")] public string Name { get; set; } [DataMember(Name = "kind")] public string Kind { get; set; } [DataMember(Name = "email")] public string Email { get; set; } [DataMember(Name = "picture")] public string Picture { get; set; } [DataMember(Name = "locale")] public string Locale { get; set; } [DataMember(Name = "family_name")] public string FamilyName { get; set; } [DataMember(Name = "given_name")] public string GivenName { get; set; } [DataMember(Name = "sub")] public string Id { get; set; } [DataMember(Name = "profile")] public string Profile { get; set; } [DataMember(Name = "gender")] public string Gender { get; set; } } } }
Please note that the display of the web browser is completely dependent on Google, and it can vary significantly depending on the environment, such as cookies, language, etc.
