// URLs to help understand this topic: // https://developers.google.com/identity/protocols/OAuth2InstalledApp // private bool oauth2_google(string scope) { // Generates state and PKCE values. string state = m_prng.GenRandom(32, base64Url); string code_verifier = m_prng.GenRandom(32, base64Url); Chilkat.Crypt2 crypt = new Chilkat.Crypt2(); crypt.EncodingMode = base64Url; crypt.HashAlgorithm = "SHA256"; string code_challenge = crypt.HashStringENC(code_verifier); const string code_challenge_method = "S256"; //Create a Chilkat socket for listening. Begin listening asynchronously. Chilkat.Socket listenSocket = new Chilkat.Socket(); int backlog = 5; int listenPort = 0; // Passing a listenPort = 0 causes BindAndListen to find a random unused port. // The chosen port will be available via the ListenPort property. if (!listenSocket.BindAndListen(listenPort, backlog)) { fgAppendToErrorLog(listenSocket.LastErrorText); popupError("Failed to BindAndListen"); return(false); } // Get the chosen listen port // This ListenPort property is available starting in Chilkat v9.5.0.59 listenPort = listenSocket.ListenPort; // Creates a redirect URI using an available port on the loopback address. string redirect_uri = "http://127.0.0.1:" + listenPort.ToString() + "/"; //Wait a max of 5 minutes. The OnTaskCompleted event is called when an incoming connection //arrives, or when the listen failed. listenSocket.OnTaskCompleted += listenSocket_OnTaskCompleted; Chilkat.Task task = listenSocket.AcceptNextConnectionAsync(5 * 60000); if (task == null) { MessageBox.Show("Failed to start socket accept..."); return(false); } // Add some information that will be needed by the TaskCompleted event.. Chilkat.JsonObject taskData = new Chilkat.JsonObject(); taskData.AppendString("code_verifier", code_verifier); taskData.AppendString("redirect_uri", redirect_uri); task.UserData = taskData.Emit(); // Start the task. task.Run(); // Creates the OAuth 2.0 authorization request. Chilkat.StringBuilder sbAuthRequest = new Chilkat.StringBuilder(); sbAuthRequest.Append(authorizationEndpoint); sbAuthRequest.Append("?response_type=code&scope="); sbAuthRequest.Append(m_encoder.EncodeString(scope, "utf-8", "url")); sbAuthRequest.Append("&redirect_uri="); sbAuthRequest.Append(m_encoder.EncodeString(redirect_uri, "utf-8", "url")); sbAuthRequest.Append("&client_id="); sbAuthRequest.Append(googleAppClientId); sbAuthRequest.Append("&state="); sbAuthRequest.Append(state); sbAuthRequest.Append("&code_challenge="); sbAuthRequest.Append(code_challenge); sbAuthRequest.Append("&code_challenge_method="); sbAuthRequest.Append(code_challenge_method); // Here is a shorter way of building the URL in C# //string authorizationRequest = string.Format("{0}?response_type=code&scope={6}&redirect_uri={1}&client_id={2}&state={3}&code_challenge={4}&code_challenge_method={5}", // authorizationEndpoint, // 0 // System.Uri.EscapeDataString(redirect_uri), // 1 // googleAppClientId, // 2 // state, // 3 // code_challenge, // 4 // code_challenge_method, // 5 // System.Uri.EscapeDataString(scope)); // 6 // Get authorization from Google account owner... webBrowser1.Navigate(sbAuthRequest.GetAsString()); return(true); }