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These terms revolve around managing user identity when accessing systems. The process involves:
– Identification (declaring who you are)
– Authentication (verifying your identity)
– Authorization (granting appropriate permissions)
Key Authentication Methods
1. WWW-Authenticate
- A basic HTTP authentication protocol.
- Rarely used today due to limited control over login lifecycle and user experience.
2. Session-Cookie Authentication
- Common in web applications.
- Servers store session state (memory/database), browsers store session IDs in cookies.
- Example Command (Linux):
Check active sessions in a Linux system who last
3. Tokens
- Encoded data structures for validation (avoid repeated credential sending).
- Ensure data integrity via cryptography (not always encrypted).
4. JWT (JSON Web Tokens)
- Standardized token format: Header, Payload, Signature.
- Self-contained, enabling claims verification without server-side storage.
- Example JWT Decode Command (Linux):
echo "YOUR_JWT_TOKEN" | jq -R 'split(".") | .[bash] | @base64d | fromjson'
5. SSO (Single Sign-On)
- Unified authentication across multiple apps.
- Uses SAML or OIDC, relies on a central Identity Provider (IdP).
- Example SSO Check (Linux):
Check active SSO sessions (if using Keycloak, Okta, etc.) curl -v https://sso-provider.com/auth/realms/REALM/protocol/openid-connect/userinfo -H "Authorization: Bearer ACCESS_TOKEN"
6. OAuth 2.0
- Authorization framework for third-party access without exposing credentials.
- Grant Types: Authorization Code, Implicit, Client Credentials, Device Code.
- Example OAuth Token Request (cURL):
curl -X POST https://oauth-provider.com/token \ -d "client_id=CLIENT_ID" \ -d "client_secret=CLIENT_SECRET" \ -d "grant_type=authorization_code" \ -d "code=AUTH_CODE" \ -d "redirect_uri=REDIRECT_URI"
You Should Know:
- JWT Security Risks:
- If not signed/encrypted, JWTs can be tampered with.
- Verify JWT Signatures:
openssl dgst -sha256 -verify public_key.pem -signature jwt_signature jwt_payload
- Session Hijacking Prevention:
- Use HttpOnly and Secure flags for cookies.
- Example (Apache Config):
Header edit Set-Cookie ^(.)$ "$1; HttpOnly; Secure"
- OAuth Best Practices:
- Always use PKCE (Proof Key for Code Exchange) for public clients.
- Revoke Tokens After Use:
curl -X POST https://oauth-provider.com/revoke -d "token=TOKEN"
What Undercode Say:
Understanding authentication mechanisms is critical for secure system design. Session-based auth is simple but stateful, while JWT/OAuth enable stateless scalability. SSO reduces password fatigue but depends on IdP security. Always enforce HTTPS, token expiration, and rate limiting to mitigate attacks.
Expected Output:
Session, JWT, SSO, and OAuth 2.0 in One Diagram [Detailed technical breakdown with commands and best practices]
Relevant URL:
Free System Design PDF (158 pages)
References:
Reported By: Sahnlam Session – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
