OAuth Flow Implementation Workflow
Implement an OAuth 2.0 authorization code flow with PKCE for secure third-party authentication.
Objective
Add secure third-party authentication using OAuth 2.0 with PKCE.
Environment
- An OAuth provider with authorization code and PKCE support
- A web application backend to handle callbacks
- HTTPS for secure token exchange
Steps
1. Configure provider
Register the application with the OAuth provider and obtain client credentials.
Expected state: Client ID and secret are obtained from the provider.
2. Implement auth request
Create the authorization request with PKCE challenge and redirect to the provider.
Expected state: Users are redirected to the provider for authorization.
3. Handle callback
Implement the callback handler to exchange the auth code for tokens using the PKCE verifier.
Expected state: Authorization codes are exchanged for access tokens.
4. Store tokens securely
Store access and refresh tokens using secure, http-only cookies or server-side sessions.
Expected state: Tokens are stored securely and cannot be stolen via XSS.
5. Test the flow
Complete the full OAuth flow and verify the user is authenticated.
Expected state: The OAuth flow works end-to-end and the user is logged in.
Decision points
Use PKCE for server-side apps?
- Yes, always
- No, only for SPAs
Use PKCE for all client types; it adds security with minimal complexity.
Expected outcome
The application supports secure third-party authentication via OAuth 2.0 with PKCE.
Verification
Complete the OAuth flow in a browser and confirm the user is authenticated; verify tokens are stored securely.
Cleanup
Remove test OAuth credentials after verification.
PKCE prevents code interception
PKCE adds a proof of key exchange that prevents an intercepted authorization code from being used by an attacker.
Implementation Notes
This workflow provides a structured approach to ensure consistent results across team members and environments.
Common Pitfalls
Skipping verification steps or rushing through the process can lead to incomplete results. Always follow each step in order and verify before proceeding.
Quick Reference
# Execute the workflow steps as documented above
echo "Workflow completed successfully"