The Return URL or Callback URL serves as a listener, Setting a return/callback URL (also known as a redirect URI) is a crucial security and functional aspect of the OAuth 2.0 authorization process. It redirects users back to your application after they have successfully authenticated on a third-party service.
Note: It’s important to be aware that some OAuth Providers might not utilize the ‘Redirect URL’ field in your API App configuration. If you can’t find this option, it’s likely not applicable for your specific OAuth Provider.
Here are some reasons why you need to set a callback URL when using OAuth:
The callback URL helps prevent certain types of attacks, such as authorization code interception. When the user grants permission to your application, the authorization code is sent to the specified callback URL.This ensures that the sensitive information doesn’t get exposed in the browser’s address bar or in other less secure ways.
Authorization Flow Completion:
After the user grants permission on the provider’s site (e.g., OneDrive), the user is redirected back to your application. The callback URL is where your application receives the authorization code, allowing it to complete the OAuth flow by exchanging the code for an access token.
Verification of Authorization Response:
The callback URL allows your application to verify that the authorization response received from the authorization server (e.g., OneDrive) matches the expected response. This helps ensure the integrity of the communication and that the user’s authorization is genuine.
Access Token Retrieval:
The callback URL is the endpoint where your application can securely exchange the authorization code for an access token. This access token is then used to make authorized API requests on behalf of the user.
After the user grants permission, being redirected back to your application is a standard and user-friendly way to complete the authentication process. It provides a seamless experience for the user.
Configuring Redirect URIs in OAuth Application:
OAuth providers, like OneDrive, often require you to register and configure the allowed redirect URIs for your application. This adds an extra layer of security by ensuring that authorization codes are only sent to predefined callback URLs associated with your application.
Remember that the callback URL you specify during the OAuth setup needs to match the one configured on the OAuth provider’s side. This ensures a secure and successful authentication flow between your application and the OAuth provider. It does not store any tokens in our system.
When you use ZappySys provided Redirect URL, it will pass temporary code to this UI automatically and finish the flow without manual steps. it will not store any token in our System. If you don’t want to use ZappySys Return URL then your Token generation may not finish automatically and some manual steps will be needed after the login / grant permission step (in the browser).
Redirect URL (or some times referred as Return URL or Callback URL) is a very important setting in the OAuth authorization process. We highly recommend you to use secure OAuth friendly URL https://zappysys.com/oauth/ or https://zappysys.com/oauth2/. You have to register the same URL as is in the App portal where you registered the OAuth app (to obtain ClientID /Secret). Usually there is a setting to enter Redirect URL on the App Page. If you are not sure check with your API Provider or Admin who setup the OAuth App to get ClientID /Secret. This URL receives a very short lived code after you login / approve OAuth app in the browser (code usually expires in 60 seconds). Once code is received its captured by this UI to obtains the final Access Token / Refresh Token.
If you use other than ZappySys URL then your Token generation may not finish automatically and some manual steps will be needed after the login / grant permission step (in the browser). When you use ZappySys provided Redirect URL, it will pass temporary code to this UI automatically and finish the flow without manual steps.
If you do not use ZappySys supplied Redirect URL -OR- for some reason Automatic Token extraction is not finished after Redirect happens then perform the following steps following steps.
- Copy the code from web browser (it may be visible in the body or URL somewhere in address bar - such as code=xxxxxx you just need to copy xxxxx part)
- After you copy the code come back to this UI
- If <> button is still in the timer mode with Cancel caption then and click Cancel else you might see some prompt to paste the code
- When Code input box appears paste the code you copied in the previous step
- Click OK to finish the process
- You might see Access Token and Refresh Token populated on this UI if everything went OK
Guide: Authenticating API Using OAuth 2.0 - A Step-by-Step Tutorial