Скачать или смотреть Resolving the Google OAuth2 Error for Desktop Applications

Struggling with the `invalid_request` error while using Google OAuth2 for your desktop app? Learn how to identify and fix this issue effectively in our detailed guide!
---
This video is based on the question https://stackoverflow.com/q/75783761/ asked by the user 'user3420815' ( https://stackoverflow.com/u/4126219/ ) and on the answer https://stackoverflow.com/a/75795104/ provided by the user 'user3420815' ( https://stackoverflow.com/u/4126219/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Google OAuth2 Error - Desktop App doesn't comply

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Resolving the Google OAuth2 Error for Desktop Applications: A Complete Guide

When developing a desktop application with Google OAuth 2.0 authentication, you may encounter a common error that halts your progress: the dreaded invalid_request error. This issue can be particularly frustrating, especially when your initial steps seem to be working correctly. In this guide, we will explore the root cause of this error and provide clear, step-by-step solutions to resolve it.

The Issue: Understanding the Error

Initially, the error you may receive when trying to authenticate your app looks like this:

[[See Video to Reveal this Text or Code Snippet]]

This error typically suggests that there is a problem with the way you are handling the OAuth 2.0 flow, particularly around your redirect URI and the parameters being sent to the token endpoint.

Your Current Setup

You might already have set up your Google Cloud Console for the project correctly, as illustrated below:

Publishing Status: Testing

Testers added via E-Mail: Yes

OAuth Client ID Type: Desktop app created

The Sequence of Events

Your application flow might look like this:

Directing users to the Google authentication page via a generated URL.

Logging in through the browser with the correct tester account.

Receiving an authorization code upon redirection.

So what could go wrong here, causing you to hit the invalid_request error when calling the https://oauth2.googleapis.com/token endpoint with your parameters? Let’s investigate.

The Solution: Fixing the Error

After thorough troubleshooting, it was determined that the primary issue lies with the redirect_uri parameter being incorrectly formatted. Here’s how you can fix it step-by-step.

Step 1: Inspect the Redirect URI

In your OAuth 2.0 flow, ensure that the redirect_uri you’re sending to the token endpoint matches exactly what you set in the Google Cloud Console. It should not be double-encoded.

For instance, if you are using the redirect URI http://localhost:8080, it should look as follows when sent to the token endpoint:

Correctly encoded: http%3A%2F%2Flocalhost%3A8080

Incorrectly double-encoded (This is a common mistake): http%253A%252F%252Flocalhost%253A8080

Step 2: Update Your Request Code

In the code you are using to submit the form to the token endpoint, make sure that the redirect_uri is not already encoded. The code should look like this, with encodedRedirectUri being the appropriately encoded value:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Test the Changes

After making the necessary adjustments, run your application again. You should see that your desktop app is now complying with Google’s OAuth 2.0 framework, and the authentication process should pass without the invalid_request error.

Additional Tips

Always ensure you’re using the most recent version of the libraries and dependencies you use in your project.

Carefully check for typos in your client ID, client secret, and any other credentials needed for authentication.

Conclusion

Dealing with OAuth 2.0 errors can be complex and confusing, especially when working with desktop applications. However, by understanding the error messages and taking a systematic approach to analyzing your code and configuration, you can effectively resolve issues like the invalid_request error. Follow the outlined steps to ensure your desktop app works smoothly with Google OAuth 2.0, bolstering your application's user experience and security.

If you have any additional questions or need further clarification, feel free to reach out in the comments below. Happy coding!