C++

Google OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to get a Google OAuth2 access token from a desktop application or script. C++

#include <CkOAuth2.h>
#include <CkStringBuilder.h>

void ChilkatSample(void)
    {
    bool success = false;

    // To further clarify, see OAuth 2.0 Authorization Flow

    CkOAuth2 oauth2;

    // For Google OAuth2, set the listen port equal to the port used
    // in the Authorized Redirect URL for the Client ID.
    // For example, in this case the Authorized Redirect URL would be http://localhost:55568/
    // Your app should choose a port not likely not used by another application.
    oauth2.put_ListenPort(55568);

    oauth2.put_AuthorizationEndpoint("https://accounts.google.com/o/oauth2/v2/auth");
    oauth2.put_TokenEndpoint("https://www.googleapis.com/oauth2/v4/token");

    // Replace this with your actual client ID.
    oauth2.put_ClientId("GOOGLE-CLIENT-ID");

    // This is the scope for Google Drive.
    // See https://developers.google.com/identity/protocols/googlescopes
    // Add the scopes that you need.
    oauth2.put_Scope("https://www.googleapis.com/auth/drive");

    // Begin the OAuth2 authorization code flow.  This returns a URL that should be loaded in a browser.
    const char *url = oauth2.startAuth();
    if (oauth2.get_LastMethodSuccess() != true) {
        std::cout << oauth2.lastErrorText() << "\r\n";
        return;
    }

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    success = oauth2.LaunchBrowser(url);
    if (success == false) {
        std::cout << oauth2.lastErrorText() << "\r\n";
        return;
    }

    // Wait for the interactive user to grant permission in the interactive browser session.
    // We'll wait for a max of 90 seconds.
    int numMsWaited = 0;
    while ((numMsWaited < 90000) && (oauth2.get_AuthFlowState() < 3)) {
        oauth2.SleepMs(100);
        numMsWaited = numMsWaited + 100;
    }

    // If there was no response from the browser within 90 seconds, then 
    // the AuthFlowState will be equal to 1 or 2.
    // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    // In that case, cancel the background task started in the call to StartAuth.
    if (oauth2.get_AuthFlowState() < 3) {
        oauth2.Cancel();
        std::cout << "No response from the browser!" << "\r\n";
        return;
    }

    // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    // The possible AuthFlowState values are:
    // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (oauth2.get_AuthFlowState() == 5) {
        std::cout << "OAuth2 failed to complete." << "\r\n";
        std::cout << oauth2.failureInfo() << "\r\n";
        return;
    }

    if (oauth2.get_AuthFlowState() == 4) {
        std::cout << "OAuth2 authorization was denied." << "\r\n";
        std::cout << oauth2.accessTokenResponse() << "\r\n";
        return;
    }

    if (oauth2.get_AuthFlowState() != 3) {
        std::cout << "Unexpected AuthFlowState:" << oauth2.get_AuthFlowState() << "\r\n";
        return;
    }

    // Save the full JSON access token response to a file.
    CkStringBuilder sbJson;
    sbJson.Append(oauth2.accessTokenResponse());
    sbJson.WriteFile("qa_data/tokens/_googleDrive.json","utf-8",false);

    // The saved JSON response looks like this:

    // 	{
    // 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
    // 	 "token_type": "Bearer",
    // 	 "expires_in": 3600,
    // 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
    // 	}
    // 
    std::cout << "OAuth2 authorization granted!" << "\r\n";
    std::cout << "Access Token = " << oauth2.accessToken() << "\r\n";

    // Here is an example showing how to define your OAuth 2.0 Credential in the Google Cloud Console
    // Note: Even though your application is technically not a web app, you should still select "Web Application"
    // because the Redirect URI is going to http://localhost:55568/ where Chilkat will receive it in a background thread.

    // 
    }