docTime Synchronization Security using IPsec and MACsec
download 
Plainte Transcription
Time Synchronization Security using IPsec and MACsec
Time Synchronization Security using IPsec and MACsec Appeared in ISPCS 2011 Tal Mizrahi Israel Networking Seminar May 2012 Time Synchronization Security • Time synchronization is used for various applications. • Securing the time protocol is a must for securing the applications that use it. • IEEE 1588 standard: Precision Time Protocol (PTP). • IEEE 1588 is challenging to secure: – A large number of nodes involved in the protocol. – Hop-by-hop data modification. • IEEE 1588 - Annex K: experimental security appendix. Time Synchronization Security using IPsec and MACsec 2 Agenda • Brief overview of IPsec, MACsec, and Annex K. • The IPsec and MACsec scenarios. • Attacker types. • Effectiveness of each attacker in the IPsec and MACsec scenarios, Annex K. • Summary and comparison. • Conclusion. Time Synchronization Security using IPsec and MACsec 3 IPsec • A suite of security protocols defined by the IETF (RFC 4301 – architecture). • Two main functions: – Integrity protection using Authentication Header (AH). – Confidentiality using Encapsulating Security Payload (ESP). • Both functions support: – Integrity protection using Integrity Check Value (ICV). – Replay protection using Sequence Number. • Both functions support: – Tunnel mode. – Transport mode. Partly Protected by ICV Ethernet Header IPv4 Header Next Header Payload Len Reserved 1B 1B 2B Security Parameters Index (SPI) 4B Sequence Number Field 4B Integrity Check Value – ICV (variable length) • IPsec AH encapsulation. Protected by ICV IP Header (tunnel mode) IP Payload Ethernet FCS 4B Time Synchronization Security using IPsec and MACsec 4 MACsec • IEEE 802.1AE – MAC security protocol. • IEEE 802.1X – authentication, key exchange. • Supports both encrypted and non-encrypted mode. • Integrity protection using Integrity Check Value (ICV). – L2 header protected by ICV. MAC DA MAC SA MACsec Ethertype 2B MACsec Header Encrypted • MACsec encrypted packet. Protected by ICV • Replay protection using Sequence Number. 6B / 14B Ethertype 2B Ethernet Payload Integrity Check Value – ICV 16B Ethernet FCS 4B Time Synchronization Security using IPsec and MACsec 5 IEEE 1588 Annex K • Experimental annex in IEEE 1588-2008 (v2). • Provides data integrity using symmetric key scheme. • Authentication TLV includes: – Integrity Check Value (ICV). – Replay protection using replayCounter. Ethernet Header IPv4/IPv6 + UDP Headers (optional) • Annex K authenticated packet. Protected by ICV PTP Header PTP Payload Authentication TLV Ethernet FCS 4B Time Synchronization Security using IPsec and MACsec 6 PTP Security – the IPsec Scenario • Can be used when PTP is transported over an IP network. • Network-to-network configuration. • IPsec can be used in encrypted (ESP) or authenticated (AH) mode. • Either dedicated tunnel for time sync, or single tunnel for all traffic. • Typical example: Femtocells in 3GPP. Security GW Slave Customer Network Security GW IPsec Tunnel Master Clock Operator Network Public Network Time Synchronization Security using IPsec and MACsec 7 PTP Security – the MACsec Scenario • Can be used in L2 networks. • Either with/without encryption. • All data is secured on a hop-by-hop basis. • Typical example: Audio and Video Bridging (AVB). L2 Network Slave MACsec Tunnel MACsec Tunnel Master Clock L2 Bridge Time Synchronization Security using IPsec and MACsec 8 Typical Attackers • Mary – internal man-in-the-middle (MITM). • Jeanie – internal injector. • Emma – external MITM. • Enya – external injector. Slave 2 Security GW Tu Security u re c GW Se Slave 1 n Jeanie (2) l ne Security GW Secure Tunnel Emma Master Security Clock GW Secure Tunnel Mary (1) Mary (2) Enya Trusted Network Jeanie (1) Trusted Network Time Synchronization Security using IPsec and MACsec 9 Enya – WHAT can Enya do? Slave 2 Security GW Secure Tunnel Emma GW Mary (1) Secure Tunnel Mary (2) Jeanie (1) MACsec Enya Trusted Network 1588 Annex K Slave 1 Security GW Master Security Clock IPsec Security r cu GW Se un eT Jeanie (2) l ne • • • • Trusted Network • Cryptographic Performance Attack. • L2/L3 DoS attacks. Time Synchronization Security using IPsec and MACsec • 10 Emma – WHAT can Emma do? Slave 2 Security GW Security GW Secure Tunnel Mary (2) Enya Trusted Network • • • • Mary (1) Secure Tunnel Packet Interception and Removal. Packet Delay Manipulation. Cryptographic Performance Attack. L2/L3 DoS attacks. Time Synchronization Security using IPsec and MACsec • • • Jeanie (1) 1588 Annex K Emma GW IPsec Slave 1 n Master Security Clock MACsec Tu Security u re c GW Se Jeanie (2) l ne • • • • • • • • Trusted Network 11 Jeanie – WHAT can Jeanie do? Slave 2 Security GW Tu Security u re c GW Se Slave 1 n Jeanie (2) l ne Security GW Secure Tunnel Emma Master Security Clock Secure Tunnel GW Mary (1) Mary (2) Enya Trusted Network Spoofing. • • Replay. Replay Attack. • Rogue Master Attack. • L2/L3 DoS attacks. Time Synchronization Security using IPsec and MACsec Jeanie (1) Trusted Network 12 Jeanie (1) – WHERE can Jeanie be found? Slave 2 Security GW IPsec scenario. Security GW c Se Jeanie (2) Master Security Clock GW IPsec Tunnel Slave 1 • Jeanie 1 is relevant specifically in the IPsec scenario. • Network-to-network scheme. ur un eT l ne Mary (1) Jeanie (1) Trusted Network Trusted Network Slave 2 el Se MACsec scenario / Annex K Slave 1 r cu n un T e Jeanie (2) Secure Tunnel Time Synchronization Security using IPsec and MACsec Secure Tunnel Master Clock 13 Mary – WHAT can Mary do? Slave 2 Security GW Security GW Slave 1 c Se u re n Tu Jeanie (2) l ne Security GW Secure Tunnel Emma Secure Tunnel GW Mary (1) Mary (2) Enya • • • • • • • Master Security Clock Trusted Interception Network and Manipulation. Packet Packet Delay Manipulation. Packet Interception and Removal. Spoofing. Replay. Rogue Master Attack. L2/L3 DoS attacks. Time Synchronization Security using IPsec and MACsec Jeanie (1) Trusted Network 14 Mary – WHERE can Mary be found? Security GW IPsec scenario. • Mary 1 is relevant specifically in the IPsec scenario. • Network-to-network scheme. Slave 2 Security GW cu Se re Tu nn el Jeanie (2) Master Security Clock GW IPsec Tunnel Slave 1 Trusted Network Mary (1) Jeanie (1) Trusted Network • Mary 2 is relevant specifically in the MACsec scenario. • Hop-by-hop scheme. Slave 2 l cu Se Slave 1 re Tu e nn Secure Tunnel MACsec scenario / Annex K Time Synchronization Security using IPsec and MACsec Secure Tunnel Mary (2) Master Clock 15 Analysis Summary IEEE 1588 Annex K Hop-by-hop IPsec Scenario L3 typically public network Network-to-network + (TCs/BCs) ~ (no TCs/BCs) + (TCs/BCs) L2/L3 DoS Attack Prevention + - - Internal attackers “trusted network” (Jeanie 1, Mary 1) + - + - + - Threats Characteristics MACsec Scenario L2 typically LAN Network Security approach Accuracy in Any Hop-by-hop the Internal MITM attacks in intermediate nodes (Mary 2) Security GW Security GW Slave 1 c Se ur u eT e nn l Secure Tunnel Emma Jeanie (2) Security GW Security GW Secure Tunnel Master Clock Mary (1) Mary (2) Enya Security using IPsec and MACsec Time Synchronization Jeanie (1) 16 Conclusion • IPsec and MACsec are used in different topologies and scenarios. • Two complementary building blocks for securing time synchronization. • Intermediate solutions in the absence of a standard security solution for PTP. • Hybrid solutions can be used in certain topologies. Master Clock Cs MA Security GW Public Network ne l L2 Network IPsec Tunnel Slave e un cT Hybrid Security GW Time Synchronization Security using IPsec and MACsec 17 Thanks!