Troubleshooting

As we've discovered throughout the book, the OAuth 2.0 protocol is simply a series of structured HTTP requests and responses to facilitate the transfer of data. Because of the straightforward nature of the protocol, we are able to troubleshoot issues with basic tools. In fact, we can simulate the majority of our implemented OAuth 2.0 flows with these tools alone, separate from our application. Here is the approach we will take:

• If it's a POST request, we can simulate it with a cURL command
• If it's a GET request, we can simulate it directly within our browser, or with a cURL command

With this approach in mind, we can now look at the various flows that we've examined in the book, this time, simulating them with our tools instead of within our application. Let's begin!

The implicit grant flow

The purpose of the implicit grant flow is to gain authorization from the user in the form of an access token from the service provider. It begins with the authorization...