How OAuth2.0 Works?

OAuth 2.0 has become the trusted standard for web authorization, offering users a secure and convenient way to grant access to their data across different platforms, such as LinkedIn, Facebook, and Google, without needing to share their passwords.

Looking Back at Authentication Methods

Before the advent of OAuth 2.0, authentication methods had their limitations:

• Basic Authentication: Although simple, it posed security risks by requiring users to repeatedly enter their usernames and passwords.
• Digest Authentication: This was similar to basic auth but with a more secure password hashing mechanism. However, it still wasn’t perfect.
• Session Cookies: While useful for website navigation, they weren’t suitable for authorization across various platforms.
• Single Sign-On (SSO): While enabling login to multiple applications with one set of credentials, it often required complex implementations like SAML.

Why OAuth 2.0 Reigns Supreme

OAuth 2.0 addresses the shortcomings of previous methods by offering:

• Enhanced Security: It eliminates the need for users to share their passwords with third-party applications.
• Fine-Grained Access Control: Users have the power to decide what data each application can access.
• Seamless Scalability: It seamlessly works across different platforms and applications.

The Three-Act Play of OAuth 2.0

In OAuth 2.0’s authorization flow, three main characters take the stage:

1. Client Application: This is the application requesting access to user data, such as a photo editing app.
2. Resource Server: This is the platform where the user’s data resides, like a social media platform.
3. User: The individual who grants or denies access to their data.

The Flow Unveiled

Here’s how the OAuth 2.0 authorization flow unfolds:

1. Client Requests Authorization: The client app seeks the user’s permission to access their data.
2. User Makes a Decision: The user is directed to the resource server’s login page, where they can grant or deny the request.
3. Authorization Granted (or Denied): If the user grants access, the resource server redirects them back to the client app with a special authorization code. If denied, they’re redirected without the code.
4. Client Exchanges Code for Access Token: The client app uses the authorization code to obtain an access token from the resource server, acting as a secure key to access the user’s data.
5. Data Access Granted: Finally, armed with the access token, the client app can retrieve the authorized user data from the resource server.

In summary, OAuth 2.0 is the hero of modern web authorization, offering users peace of mind and control over their data while enabling seamless interaction between applications.