As the landscape of secure authentication evolves, understanding and implementing Authorization Code Flow with Proof Key for Code Exchange (PKCE) becomes crucial for developers. In this post, we'll delve into the practical aspects of using Postman to seamlessly obtain an access token using the Authorization Code Flow with PKCE. Now, let's navigate the practical landscape of OAuth PKCE with Postman and discover the seamless process of obtaining an access token.

Process

1. Open a New Request Tab in Postman : To kickstart the process, fire up Postman and create a new request. Name it Authorization Code Flow with PKCE.

2. Configure OAuth 2.0 : Navigate to the Authorization tab within your request and choose OAuth 2.0 as the authorization type.

3. Configure New Token:

   • Grant Type: Choose the Authorization Code flow (with PKCE) as the grant type.

   • Callback URL: Set the callback URL to handle the redirection after a successful authentication.

   • Auth URL: Specify the authorization URL, pointing to the location where authentication requests are initiated.

   • Access Token URL: Define the URL responsible for issuing access tokens upon successful authentication.

   • Client ID: Identify your application by providing the assigned client ID.

   • Client Secret: A client secret is a secret known only to the OAuth application and the authorization server. It is generated by the authorization server during the process of application registration 'leave it as blank' for now.

   • Code Challenge Method: Specify the code challenge method as S256.

   • Code Verifier: Provide the code verifier generated for this specific authentication request.

   • Scope: In my case it is read

   • State: Include a random string as a state parameter for added security and to mitigate cross-site request forgery (CSRF) attacks.

   • Client Authentication: choose Send as Basic Auth header

4. Get New Access Token: With the configuration in place, click on the "Get New Access Token" button within Postman, triggering the authentication process. Now you need to provide login credentials to authenticate and authorize the requested access.

5. Token Details: Upon successful authentication, Postman will display the response containing essential token details, marking the completion of the Authorization Code Flow with PKCE.

Conclusion

By following this step-by-step guide, you'll gain a deeper understanding of the configuration nuances, ensuring a robust and secure authentication experience for your applications. For a comprehensive understanding of OAuth PKCE itself, consider exploring additional resources at the following links:

• oauth

• auth0

• okta