README.md

🔹 How Spring Security Validates the OTT?

Spring Security has a built-in filter and authentication provider to handle One-Time Token (OTT) validation.

🔗 Request to /login/ott?token=XYZ

1. The user clicks on the magic link or enters the token manually.
2. The request is sent to /login/ott with the token as a query parameter.

🛡️ Spring Security Intercepts the Request

• OneTimeTokenAuthenticationFilter (part of Spring Security) intercepts the request.
• It extracts the token value from the request (token=XYZ).

🔄 Delegates to Authentication Manager

• Spring Security delegates the token to OneTimeTokenAuthenticationProvider.

✅ Token Validation Process

✔ Checks if the token exists in the database or token storage.
✔ Validates token expiry (time-limited).
✔ Verifies token association with the correct user.

🔓 Authentication Success or Failure

✅ If valid → Spring Security authenticates the user and starts a session.
❌ If invalid/expired → Returns an authentication error (401 Unauthorized).

---

This structure makes it clear, professional, and easy to read for GitHub users. Let me know if you need any changes! 🚀