OAuth 2.0 is an authorization framework that enables applications to obtain limited access to user accounts on an HTTP service. It allows third-party clients to access user resources without exposing user credentials.

Key Concepts

  • Client: The application that requests access to protected resources.
  • Resource Owner: The end-user who authorizes the client to access their resources.
  • Resource Server: The server that hosts the protected resources.
  • Authorization Server: The server that authenticates the resource owner and issues authorization grants.

Authorization Grant Types

  1. Authorization Code: The client requests authorization from the resource owner and receives an authorization code. The client then exchanges the authorization code for an access token.
  2. Implicit Grant: The client requests an access token directly from the authorization server. This grant type is less secure than the authorization code grant.
  3. Resource Owner Password Credentials: The client requests an access token by presenting the resource owner's credentials.
  4. Client Credentials: The client requests an access token using its client credentials.

Flow Diagram

graph LR
A[Client] --> B{Request Authorization}
B -->|Yes| C[Authorization Server]
B -->|No| D[Error]
C --> E{Grant Access?}
E -->|Yes| F[Issue Access Token]
E -->|No| G[Deny Access]
F --> H[Client]
H --> I{Access Protected Resources}
I -->|Success| J[Resource Data]
I -->|Failure| K[Error]

Best Practices

  • Use HTTPS to protect sensitive data during the authorization process.
  • Implement proper error handling and logging.
  • Store access tokens securely.
  • Regularly rotate client credentials.

OAuth 2.0 Flow Diagram

For more information, please refer to our OAuth 2.0 Tutorial.