Implicit Flow

  • Should not use it in favor of Authorization Code with PKCE

Benefits

  • The application never sees the user’s credentials
  • Mobile or Browser app uses the underlying session storage so single-sign on scenarios work as expected

Drawbacks

  • The access token is exposed to the end user and therefore at risk
  • Doesn’t support refresh tokens
  • Most people use the implicit flow as the front Single sign on interface to a backend application which is actually using authorization code flow or similar behind the scenes. SSO with Google, Facebook etc these days have been implemented with this flow
  • Making it secure is hard

Uses

  • use it very rarely at best
  • it should be Plan B or maybe OAuth provider doesn’t support Auth code with PKCE

Security

  • Use SSL/TLS
  • Always Validate your token
  • Use CORS