h4cker/SCOR/802_1x.md

Understanding 802.1X and TrustSec Software-defined Segmentation

In the ever-evolving landscape of network security, understanding and implementing robust security protocols is paramount.

Among these, 802.1X and Cisco TrustSec, which involves software-defined segmentation, play a crucial role in securing network access and data transmission.

User Device (Supplicant) <----> Authenticator (Access Switch/Point) <----> Authentication Server (RADIUS)

1. [Supplicant]         ---- EAPOL-Start ---->        [Authenticator]
2. [Authenticator]      ---- EAP-Request/Identity --> [Supplicant]
3. [Supplicant]         ---- EAP-Response/Identity -> [Authenticator]
4. [Authenticator]      ---- EAP-Response/Identity -> [Authentication Server]
5. [Authentication Server] ---- EAP-Request (Challenge) ----> [Authenticator]
6. [Authenticator]      ---- EAP-Request (Challenge) ----> [Supplicant]
7. [Supplicant]         ---- EAP-Response (Challenge-Response) ----> [Authenticator]
8. [Authenticator]      ---- EAP-Response (Challenge-Response) ----> [Authentication Server]
9. [Authentication Server] <Decision (Success/Fail)> [Authenticator]
10. [Authenticator]     <Controls Port Access Based on Decision> [Supplicant]

What is 802.1X?

802.1X is an IEEE Standard for port-based Network Access Control (PNAC). It is a protocol that enhances security in networks, both wired and wireless, by providing an authentication mechanism for devices trying to connect to a LAN or WLAN.

Key Features of 802.1X:

• Authentication: It uses the Extensible Authentication Protocol (EAP) over LAN (EAPOL) to authenticate devices.
• RADIUS Server: Typically, 802.1X authentication involves three parties: a supplicant (client device), an authenticator (network switch or wireless access point), and an authentication server (usually a RADIUS server).
• Dynamic VLAN Assignment: Post-authentication, it can assign devices to specific VLANs based on policies.

802.1X is a network access control protocol that is part of the IEEE 802.1 group of networking protocols. It provides an authentication framework for wireless LANs (WLANs) and wired Ethernet networks, offering a means to control and secure network access at the point of entry. Let's dive into its technical aspects and the standards it encompasses.

Technical Overview of 802.1X

1. Components:

   • Supplicant: The client device seeking access to the network.
   • Authenticator: Typically a network switch or wireless access point that acts as an intermediary between the supplicant and the authentication server.
   • Authentication Server: Usually a RADIUS (Remote Authentication Dial-In User Service) server that verifies the credentials of the supplicant.

2. Process:

   • When a device attempts to connect to a network, the authenticator blocks all traffic except 802.1X authentication traffic.
   • The supplicant sends credentials (like a username and password) or a digital certificate to the authenticator.
   • The authenticator forwards these credentials to the authentication server.
   • The authentication server validates the credentials and informs the authenticator.
   • If authentication is successful, the authenticator grants network access to the supplicant; otherwise, access is denied.

3. EAP (Extensible Authentication Protocol):

   • 802.1X uses EAP to transport the authentication data between the supplicant and the authentication server.
   • EAP is flexible and supports multiple authentication methods, such as EAP-TLS (with certificates), PEAP (Protected EAP), and EAP-MD5.

802.1X Standards

• IEEE 802.1X-2001: The original standard, introduced the basic framework for port-based Network Access Control.
• IEEE 802.1X-2004: This revision improved the original standard, including clarifications and enhancements for EAP usage.
• IEEE 802.1X-2010: Integrated with the IEEE 802.1AE (MAC Security) to enhance the security of LANs. It also added support for more sophisticated key management techniques (such as MKA - MACsec Key Agreement).
• EAP Types: Various EAP methods are standardized in different RFCs (Request for Comments). For example, EAP-TLS is defined in RFC 5216, PEAP in RFC 2284, and EAP-TTLS in RFC 5281.

Advanced Considerations

• Dynamic VLAN Assignment: Post-authentication, the RADIUS server can assign the client to a specific VLAN based on its credentials.
• MACsec Integration: With IEEE 802.1X-2010, there's support for MACsec (802.1AE), providing encryption at the MAC layer for enhanced security.
• NAC (Network Access Control)/TrustSec: Often part of broader NAC solutions, 802.1X can be integrated with other systems for comprehensive access control policies.

Cisco TrustSec and Software-defined Segmentation

Cisco TrustSec is an innovative solution for segmenting network traffic and enforcing security policies. It's based on software-defined segmentation, which simplifies the process of segregating network traffic without the need to redesign the network.

Components of TrustSec:

• Security Group Tags (SGTs): TrustSec uses SGTs to tag packets with specific security levels. These tags dictate how traffic is treated across the network.
• Policy Enforcement: Policies are enforced based on SGTs, regardless of the network's topology.
• Scalability and Flexibility: It allows for dynamic changes in policy enforcement without the need to reconfigure network devices.

How 802.1X and TrustSec Work Together

The combination of 802.1X and Cisco TrustSec provides a comprehensive security framework for networks.

1. Device Authentication with 802.1X: When a device connects to the network, 802.1X authenticates it and determines its role in the network.
2. SGT Assignment: Post-authentication, TrustSec assigns an SGT to the device, defining its access level and permissions.
3. End-to-End Security: As the device communicates across the network, its traffic is segmented and secured based on its SGT, ensuring that data is only accessible to authorized devices.

Benefits of Integrating 802.1X with TrustSec

• Enhanced Security: Provides robust authentication and dynamic access control.
• Reduced Complexity: Simplifies network segmentation and reduces the need for complex ACLs (Access Control Lists).
• Improved Compliance: Helps in meeting regulatory compliance requirements by controlling who has access to what data.
• Flexibility: Adapts to changing security needs without extensive network reconfiguration.

Real-World Applications

• Corporate Networks: Protecting sensitive data by ensuring that only authenticated and authorized devices have access to specific network segments.
• Healthcare: Secure patient data by dynamically controlling access based on user roles and device types.
• Education: Manage network access for a diverse range of users and devices, providing secure connectivity for students, faculty, and staff.

Conclusion

Understanding and implementing 802.1X and Cisco TrustSec is crucial for organizations seeking to bolster their network security. By combining robust authentication with dynamic access control and segmentation, these technologies offer a formidable defense against various network threats. As networks continue to grow in complexity and scale, adopting these technologies will be integral to maintaining a secure and compliant network environment.