// 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);
}
