Transcript EAP (Extensible Authentication Protocol)

EAP Overview
(Extensible Authentication
Protocol)
Team Golmaal:
Vaibhav Sharma
Vineet Banga
Manender Verma
Lovejit Sandhu
Abizar Attar
Contents:
• Introduction
• Architecture
• Features
• Implementations
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Cisco LEAP
EAP-TLS
EAP-MD5
PEAP
Other Subtypes
• Comparison Chart
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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
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EAP Architecture
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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
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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
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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.
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Architecture of LEAP
Client
ACS Server
Access Point
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LEAP Process
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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
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ASLEAP
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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.
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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.
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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
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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
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PEAP authentication process
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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
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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)
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Comparison Chart
EAP-MD5
LEAP
EAP-TLS
EAP-TTLS
PEAP
Server
Authentication
None
Password Hash
Public Key
(Certificat
e)
Public Key
(Certificat
e)
Public Key
(Certificat
e)
Supplicant
Authentication
Password Hash
Password Hash
Public Key
(Certificate or
Smart
Card)
CHAP, PAP, MSCHAP(v2),
EAP
Any EAP, like
EAP-MSCHAPv2 or
Public Key
No
Yes
Yes
Yes
Yes
Dynamic Key
Delivery
Security Risks
Identity
exposed,
Dictionary
attack,
Man-inthe-Middle
(MitM)
attack,
Session
hijacking
Identity
exposed,
Dictionary
attack
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Identity
exposed
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MitM attack
MitM attack;
Identity
hidden in
Phase 2
but
potential
exposure
in Phase 1
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References
• http://en.wikipedia.org/wiki/Extensible_Authentication_Protocol
• http://www.wifiplanet.com/tutorials/article.php/3075481
• http://wireless.utk.edu/documentation/papers/802.1x-chris.pdf
• http://www.cisco.com/en/US/netsol/ns339/ns395/ns176/ns178/ne
tworking_solutions_white_paper09186a008009c8b3.shtml
• http://searchnetworking.techtarget.com/originalContent/0,289142,
sid7_gci843996,00.html
• http://asleap.sourceforge.net
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