EAP Overview (Extensible Authentication Protocol) Team Golmaal: Vaibhav Sharma Vineet Banga Manender Verma Lovejit Sandhu Abizar Attar

Contents: Introduction Architecture Features Implementations – Cisco LEAP – EAP-TLS – EAP-MD5 – PEAP – Other Subtypes Comparison Chart 2CmpE 209 Team Golmaal

Introduction What is EAP? – Defined by RFC 2284 and 3748 – Universal Authentication Framework – Mainly used in Wireless Networks and Point to point connections – A flexible protocol used to carry arbitrary authentication information. – Typically rides on top of another protocol such as 802.1x or RADIUS 3CmpE 209 Team Golmaal

EAP Architecture 4CmpE 209 Team Golmaal

EAP Features Provides some common functions and a negotiation of the desired authentication mechanism called methods. Currently there are about 40 different methods Methods defined in IETF RFCs include – EAP-MD5 – EAP-OTP – EAP-GTC – EAP-TLS – EAP-IKEv2 and in addition a number of vendor specific methods and new proposals exist Commonly used modern methods capable of operating in wireless networks include EAP-TLS, EAP-SIM, EAP-AKA, PEAP, LEAP and EAP-TTLS 5CmpE 209 Team Golmaal

Cisco LEAP Lightweight Extensible Authentication Protocol also known as Cisco-Wireless EAP Proprietary wireless LAN authentication method developed by Cisco Systems. Provides username/password-based authentication between a wireless client and a RADIUS server like Cisco ACS or Interlink AAA Among a few protocols used with the IEEE 802.1X standard for LAN port access control. 6CmpE 209 Team Golmaal

Architecture of LEAP Access Point Client ACS Server 7CmpE 209 Team Golmaal

LEAP Process 8CmpE 209 Team Golmaal

Limitations of LEAP Uses a modified authentication protocol version of MS-CHAP in which user credentials are not strongly protected. Can be susceptible to eavesdropping. For more robust implementations use of cryptography is necessary for securing user credentials 9CmpE 209 Team Golmaal

ASLEAP 10CmpE 209 Team Golmaal

Cisco’s Response to Limitation of LEAP Suggests that network administrators to have either of the two reactive techniques: – Force users to have stronger, more complicated passwords – Switch to alternative protocol developed by Cisco (EAP-FAST) for more security. 11CmpE 209 Team Golmaal

EAP TLS An Internet Engineering Task Force (IETF) standard (RFC 2716) that is based on the TLS protocol (RFC 2246) Considered extension to SSL Uses digital certificates for both user and server authentication It uses PKI to secure communication to the RADIUS authentication server EAP-TLS is the original standard wireless LAN EAP authentication protocol Supported my all operating systems and network appliances. 12CmpE 209 Team Golmaal

EAP Authentication Process in wireless network

EAP-TTLS (Extension of EAP-TLS) Extends EAP-TLS Securely tunnels Client authentication within TLS records TTLS requires only server-side certificates but in EAP TLS more certificates are used These certificates are used for one-way TLS authentication (network to user), and once you have a nice, safe, encrypted and integrity-checked channel, you can use EAP inside of the TLS tunnel for any other authentication 14CmpE 209 Team Golmaal

PEAP PEAP is an IETF draft RFC authored by Cisco Systems, Microsoft, and RSA Security A method to securely transmit authentication information, including passwords, over wired or wireless networks Uses a digital certificate only for server authentication Very similar to TTLS! A TLS tunnel is established, and another EAP session takes place inside For user authentication, PEAP supports various EAP-encapsulated methods within a protected TLS tunnel PEAP sub-types - PEAPv0/EAP-MSCHAPv2 - PEAPv1/EAP-GTC 15CmpE 209 Team Golmaal

PEAP authentication process 16CmpE 209 Team Golmaal

EAP MD5 One of the most simple EAP types that can be used. Uses MD5 hashing. EAP-MD5 offers no key management or dynamic key generation, requiring the use of static WEP keys Okay for wired LANs, offers minimal security in wireless Vulnerable to dictionary attacks, and does not support mutual authentication or key generation Unsuitable with dynamic WEP, or WPA/WPA2 enterprise 17CmpE 209 Team Golmaal

Other EAP Subtypes EAP-PSK: pure symmetric-key EAP EAP-IKEv2: EAP authentication method based on the Internet Key Exchange Protocol version 2 (IKEv2) EAP-FAST: Flexible Authentication via Secure Tunneling (it is a proposal by Cisco Systems to fix the weaknesses of LEAP) EAP-SIM: Used for authentication and session key distribution using the Global System for Mobile Communications (GSM) Subscriber Identity Module (SIM) EAP-AKA: It is for UMTS Authentication and Key Agreement is used for authentication and session key distribution using the Universal Mobile Telecommunications System (UMTS) 18CmpE 209 Team Golmaal

EAP-MD5LEAPEAP-TLSEAP-TTLSPEAP Server Authentication NonePassword HashPublic Key (Certificat e) Supplicant Authentication Password Hash Public Key (Certificate or Smart Card) CHAP, PAP, MS- CHAP(v2), EAP Any EAP, like EAP-MS- CHAPv2 or Public Key Dynamic Key Delivery NoYes Security Risks Identity exposed, Dictionary attack, Man-in- the-Middle (MitM) attack, Session hijacking Identity exposed, Dictionary attack Identity exposed MitM attackMitM attack; Identity hidden in Phase 2 but potential exposure in Phase 1 Comparison Chart 19CmpE 209 Team Golmaal

References tworking_solutions_white_paper09186a008009c8b3.shtml sid7_gci843996,00.html 20CmpE 209 Team Golmaal