OAuth2 Authentication Flow

OAuth2 is a protocol for authorization that allows applications to gain limited access to user resources without revealing passwords. It’s widely used for integrating with third-party services and ensuring secure authentication.

This guide covers various OAuth2 flow types and their implementation.

Client Credentials Flow

Machine-to-Machine Authorization

Token Refresh

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State Parameter: Use state to protect against CSRF attacks

PKCE: Utilize PKCE for public clients (mobile applications)

Token Storage: Securely store tokens (httpOnly cookies, secure storage)

Frequently asked questions

What is Scope Validation?

Scope validation involves verifying the permissions requested by an application before granting access to resources. This ensures that the application only receives the necessary privileges.

What are Frequently Asked Questions (FAQ)?

Frequently Asked Questions (FAQ) – this section provides answers to common questions about OAuth2 authentication.

What is OAuth2 - a protocol for authorization (who has access to resources), then OpenID Connect (OIDC) - a protocol for authentication (who is the user), built on top of OAuth2. OIDC adds an ID token containing user information and standardizes the authentication process.

OAuth2 – a protocol for authorizing applications to access user resources, while OpenID Connect (OIDC) – a protocol for authenticating users, built upon OAuth2. OIDC incorporates an ID token that contains user details and standardizes the authentication procedure.

When is Authorization Code Flow used?

Authorization Code Flow is utilized when a user initiates the authorization process (e.g., web applications, mobile apps). Client Credentials Flow is employed for machine-to-machine communication without involving a human user (e.g., API to API, background jobs).

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