Security

1. Security Olga Torstensson Halmstad University

2. Key terms • WEP • TKIP • MIC • EAP • 802.1X • WPA • CCKM • RADIUS • SSH • Encryption • RSA RC4 (WEP) • DES, 3DES, AES • Cipher • BKR

3. Advanced Security Terms • WEP – Wired Equivalent Privacy • EAP – Extensible Authentication Protocol • TKIP – Temporal Key Integrity Protocol • CKIP – Cisco Key Integrity Protocol • CMIC – Cisco Message Integrity Check • Broadcast Key Rotation – Group Key Update • WPA – Wi-Fi Protected Access (WPA)

4. Security Fundamentals Balancing Security and Access

5. Vulnerabilities • Technology • TCP/IP • WEP and Broadcast SSID • Association Process • Wireless Interference • Configuration • Default passwords • Unneeded Services enabled • Few or no filters • Poor device maintenance • Policy • Weak Security Policy • No Security Policy • Poorly enforced Policy • Physical Access • Poor or no monitoring

6. Threats • Internal • External • Structured • Unstructured

7. The Security Attack—Recon and Access

8. The Security Attacks—DoS

9. WLAN Security Wheel Always have a good WLAN Security Policy in place. Secure the network based on the policy

10. WLAN Security Considerations • Authentication – only authorized users and devices should be allowed. • Encryption – traffic should be protected from unauthorized access. • Administration Security – only authorized users should be able to access and configure the AP configuration interfaces.

11. Common Protocols which use Encryption • When using a public network such as a WLAN, FTP, HTTP, POP3, and SMTP are insecure and should be avoided whenever possible. Utilize protocols with encryption. No Encryption Traffic Encryption Web Browsing HTTP HTTPS * File Transfer SCP TFTP or FTP Email POP3 or SMTP SPOP3 * Remote Mgmt Telnet SSH * SSL/TLS

12. WLAN Security Hierarchy Enhanced Security 802.1x, TKIP/WPA Encryption, Mutual Authentication, Scalable Key Mgmt., etc. Basic Security Open Access 40-bit or 128-bitStatic WEP Encryption No Encryption, Basic Authentication Home Use Business Public “Hotspots” VirtualPrivateNetwork (VPN) Business Traveler, Telecommuter Remote Access

13. Basic WLAN Security • Admin Authentication on AP • To prevent unauthorized access to the AP configuration interfaces: • Configure a secret password for the privileged mode access. (good) • Configure local usernames/passwords. (better) • Configure AP to utilize a security server for user access. (best)

14. User Manager

15. Admin Access CLI View

16. Console Password

17. SSID Manager

18. SSID Manager (cont)

19. Global SSID Properties

20. SSID CLI View

21. WEP • WEP is a key. • WEP scrambles communications between AP and client. • AP and client must use same WEP keys. • WEP keys encrypt unicast and multicast. • WEP is easily attacked

22. ? Supported Devices • What can be a client? • Client • Non-Root bridge • Repeater access point • Workgroup Bridge • Authenticator? • Root access point • Root bridge

23. Enabling LEAP on the Client

24. Configuring LEAP on the Client

25. WEP Encryption Keys

26. Enterprise WLAN AuthenticationAuthentication Types • Open Authentication to the Access Point • Shared Key Authentication to the Access Point • EAP Authentication to the Network • MAC Address Authentication to the Network • Combining MAC-Based, EAP, and Open Authentication • Using CCKM for Authenticated Clients • Using WPA Key Management

27. WLAN Security:802.1X Authentication Radius Server AP • Mutual Authentication • EAP-TLS • EAP-Transport Layer Security • Mutual Authentication implementation • Used in WPA interoperability testing • LEAP • “Lightweight” EAP • Nearly all major OS’s supported: • WinXP/2K/NT/ME/98/95/CE, Linux, Mac, DOS • PEAP • “Protected” EAP • Uses certificates or One Time Passwords (OTP) • Supported by Cisco, Microsoft, & RSA • GTC (Cisco) & MSCHAPv2 (Microsoft) versions Client

28. EAP • Extensible Authentication Protocol (802.1x authentication) • Provides dynamic WEP keys to user devices. • Dynamic is more secure, since it changes. • Harder for intruders to hack…by the time they have performed the calculation to learn the key, they key has changed!

29. Basic RADIUS Topology • RADIUS can be implemented: • Locally on an IOS AP • Up to 50 users • On a ACS Server

30. Local Radius Server

31. Local Radius Server Statistics

32. Radius Server User Groups

33. ACS Server Options Cisco Secure ACS Software Cisco ACS Solution Engine

34. Backup Security Server Manager

35. Global Server Properties

36. Enterprise Encryption WPA Interoperable, Enterprise-Class Security

37. Cipher “Suite” • Cipher suites are sets of encryption and integrity algorithms. • Suites provide protection of WEP and allow use of authenticated key management. • Suites with TKIP provide best security. • Must use a cipher suite to enable: • WPA – Wi-Fi Protected Access • CCKM – Cisco Centralized Key Management

38. Configuring the Suite • Create WEP keys • Enable Cipher “Suite” and WEP • Configure Broadcast Key Rotation • Follow the Rules

39. WEP Key Restrictions

40. Security Levels

41. Enterprise WLAN Security Evolution • TKIP/WPA • Successor to WEP • Cisco’s pre-standard TKIP has been shipping since Dec.’01 • Cisco introduced TKIP into 802.11i committee • 802.11i-standardized TKIP part of Wi-Fi Protected Access (WPA) • WPA software upgrade now available for AP1100 & AP1200 • AES • The “Gold Standard” of encryption • AES is part of 802.11i standard • - AES will be part of WPA2 standard (expected in 2004)

42. Encryption Modes

43. Encryption Global Properties

44. Matching Client to AP

45. Matching Client to AP

46. Matching Client to AP

47. Matching Client to AP

48. Matching Client to AP

49. Matching Client to AP

50. Advanced Security: MAC Authentication