DOCSLIB.ORG

Attacking and Securing Network Time Protocol

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Attacking and Securing Network Time Protocol Boston University OpenBU http://open.bu.edu Theses & Dissertations Boston University Theses & Dissertations 2019 Attacking and securing network time protocol https://hdl.handle.net/2144/39584 Boston University BOSTON UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES Dissertation ATTACKING AND SECURING NETWORK TIME PROTOCOL by AANCHAL MALHOTRA M.S., Boston University, 2015 Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2019 c 2019 by AANCHAL MALHOTRA All rights reserved Approved by First Reader Sharon Goldberg, PhD Associate Professor of Computer Science Second Reader Ran Canetti, PhD Professor of Computer Science Third Reader Leonid Reyzin, PhD Professor of Computer Science Acknowledgements First and foremost I want to thank my advisor Prof. Sharon Goldberg for being a tremendous mentor. Since the beginning of my graduate school, Sharon believed in me like nobody else and gave me unwavering support throughout. The joy and enthusiasm she brings to research is contagious and has been a great motivation, particularly during tough times in my Ph.D. pursuit. I am also grateful for the excellent example she has set as a strong woman, a successful professor and a wonderful mother. I'd like to give a big shout out to Prof. Leonid Reyzin and Mayank Varia for being my \second" mentors. I am grateful to Leo for providing indespensable advise in almost every aspect of my research and personal life. I thank Mayank who taught me how to think like an applied cyptographer and for introducing me to the technical tools needed to do my research. Mayank's ability to offer an extremely clear exposition of almost any topic simply amazes me. I especially thank Prof. Steve Homer for always looking out for me and helping me navigate the processes of Ph.D. program efficiently. I would not have achieved this milestone without my extremely competent and awesome co-authors. I have thoroughly enjoyed the process of coming up with hard questions and brainstorming solutions together, which incented me to widen my re- search from various perspectives. I am also grateful to my industry collaborators and IETF pals. I spent a fantastic summer as a security research intern at NLnet Labs, Amsterdam where my mentors Willem Toorop and Benno Overeinder went above and beyond to teach me the ins and outs of DNS protocol. I was also fortunate to have spent three months as cryptography engineer at Cloudflare, San Francisco. I am extremely thankful to my mentor Nick Sullivan there for making the seemingly hard task of taking an idea from inception to the running code in production, a smooth and enjoyable experience. I am also iv grateful to Nick for being a part of my Ph.D. committee and providing insightful comments on my thesis. I have benefited substantially also from my conversations with several experts at IETF including Allison Mankin, Daniel Franke, Harlan Stenn, Jared Mauch, Karen O'Donoghue, Miroslav Lichvar, Rich Salz, Suresh Krishnan, Tal Mizrahi and others on various aspects of Internet protocols and security and the complexities involved in standardization processes. My time at Boston University would not have been as much fun and worthy with- out my friends Ethan Heilman, Nabeel Akhtar, Oxana Poburinnaya, Sarah Scheffler, Tommy Unger, and William Koch, Yilei Chen. I cannot but express my deep gratitude to my partner Abhishek Sharma for always being my critic and for holding up with me during my lows. You are my biggest inspiration and the sole reason that I started my journey as a researcher in the first place. Last but not the least I'd like to thank my parents Poonam and Harish and my brother Parul for believing in me and supporting me throughout this long and eventful journey. I have thoroughly enjoyed my Ph.D. student life mainly because of all the amazing people around me. v ATTACKING AND SECURING NETWORK TIME PROTOCOL AANCHAL MALHOTRA Boston University, Graduate School of Arts and Sciences, 2019 Major Professor: Sharon Goldberg, Associate Professor of Computer Science ABSTRACT Network Time Protocol (NTP) is used to synchronize time between computer systems communicating over unreliable, variable-latency, and untrusted network paths. Time is critical for many applications; in particular it is heavily utilized by cryptographic protocols. Despite its importance, the community still lacks visibility into the robust- ness of the NTP ecosystem itself, the integrity of the timing information transmitted by NTP, and the impact that any error in NTP might have upon the security of other protocols that rely on timing information. In this thesis, we seek to accomplish the following broad goals: 1. Demonstrate that the current design presents a security risk, by showing that network attackers can exploit NTP and then use it to attack other core Internet protocols that rely on time. 2. Improve NTP to make it more robust, and rigorously analyze the security of the improved protocol. 3. Establish formal and precise security requirements that should be satisfied by a network time-synchronization protocol, and prove that these are sufficient for the security of other protocols that rely on time. vi We take the following approach to achieve our goals incrementally. 1. We begin by (a) scrutinizing NTP's core protocol (RFC 5905) and (b) stati- cally analyzing code of its reference implementation to identify vulnerabilities in protocol design, ambiguities in specifications, and flaws in reference imple- mentations. We then leverage these observations to show several off- and on- path denial-of-service and time-shifting attacks on NTP clients. We then show cache-flushing and cache-sticking attacks on DNSSEC that leverage NTP. We quantify the attack surface using Internet measurements, and suggest simple countermeasures that can improve the security of NTP and DNS(SEC). 2. Next we move beyond identifying attacks and leverage ideas from Universal Composability (UC) security framework to develop a cryptographic model for attacks on NTP's datagram protocol. We use this model to prove the security of a new backwards-compatible protocol that correctly synchronizes time in the face of both off- and on-path network attackers. 3. Next, we propose general security notions for network time-synchronization pro- tocols within the UC framework and formulate ideal functionalities that capture a number of prevalent forms of time measurement within existing systems. We show how they can be realized by real-world protocols (including but not limited to NTP), and how they can be used to assert security of time-reliant applica- tions | specifically, cryptographic certificates with revocation and expiration times. Our security framework allows for a clear and modular treatment of the use of time in security-sensitive systems. Our work makes the core NTP protocol and its implementations more robust and secure, thus improving the security of applications and protocols that rely on time. vii Contents 1 Introduction 1 1.1 Time Synchronization & Network Time Protocol (NTP) . .1 1.2 Motivation to Secure NTP . .2 1.3 Our Novel Research Approach Towards Network Protocol Security . .3 1.4 NTP Security: History & Current-State-of-Art . .5 1.5 Our Goals . .8 1.6 Our Contributions . .9 1.6.1 Attacking and fixing different modes of NTP (unauthenticated and authenticated) Chapters 2, 3, 5 . .9 1.6.2 Leveraging NTP to attack DNS (Chapter 4) . 14 1.6.3 New provably-secure NTP (Chapter 5) . 16 1.6.4 A Universally-Composable Treatment of Network Time (Chap- ter 6) . 18 2 Attacking the Network Time Protocol 21 2.1 Introduction . 21 2.2 Why time matters: Implications of attacks on NTP . 24 2.3 The NTP Ecosystem . 28 2.3.1 Background: The NTP Protocol. 29 2.3.2 Measuring the NTP ecosystem. 32 2.4 How to step time with NTP . 36 2.4.1 Time skimming . 36 viii 2.4.2 Exploiting reboot. 37 2.4.3 Recommendation: Careful with -g ............... 40 2.5 Kiss-o'-Death: Off-path Denial-of-Service Attacks . 41 2.5.1 Why are off-path attacks hard? . 41 2.5.2 Exploiting the Kiss-O'-Death Packet. 42 2.5.3 Low-rate off-path denial-of-service attack on NTP clients. 45 2.5.4 Pinning to a bad timekeeper. (Part 1: The attack) . 47 2.5.5 Detour: NTP's clock discipline algorithms. 48 2.5.6 Pinning to a bad timekeeper. (Part 2: Attack surface) . 50 2.5.7 Recommendation: Kiss-o'-Death considered harmful. 52 2.6 Off-Path NTP Fragmentation Attack . 54 2.6.1 Why are off-path attacks hard? . 54 2.6.2 IPv4 packet fragmentation. 55 2.6.3 Exploiting overlapping IPv4 fragments. 59 2.6.4 Planting spoofed fragments in the fragment buffer. 61 2.6.5 Conditions required for our attack. 64 2.6.6 Proof-of-concept implementation of our attack. 65 2.6.7 Measuring the attack surface: Servers. 68 2.6.8 Measuring the attack surface: Clients. 70 2.6.9 Recommendations: Fragmentation still considered harmful. 72 2.7 Related work . 73 2.8 Conclusion . 74 3 Attacking NTP's Authenticated Broadcast Mode 78 3.1 Introduction . 78 3.2 NTP's broadcast mode . 79 3.3 Timeshifting Attacks . 82 ix 3.4 Denial of Service Attacks . 84 3.5 Measurement Results . 86 3.6 Recommendations . 88 3.7 Conclusion . 89 4 The Impact of Time on DNS Security 91 4.1 Introduction . 91 4.2 Time and the DNS ecosystem . 94 4.2.1 Absolute time vs Relative time . 94 4.2.2 The Domain Name System (DNS) . 97 4.2.3 Time in DNS . 98 4.3 Using Time to Attack the DNS Cache . 100 4.3.1 Cache Expiration Attack . 101 4.3.2 Implications of the Cache Expiration Attack .
Load more

Recommended publications
  • Option 33: Dual Internal NTP Server Setup and Operation Guidelines
    -DISCONTINUED PRODUCT- Option 33: Dual Internal NTP Server Setup and Operation Guidelines Document No. PD0042100D – April 2009 Arbiter Systems, Inc. 1324 Vendels Circle, Suite 121 Paso Robles, CA 93446 U.S.A. (805) 237-3831, (800) 321-3831 http://www.arbiter.com mailto: [email protected] 1 Option 33: Dual Internal NTP Server 1.1 General Description Option 33, Dual Internal Network Time Protocol (NTP) Server, is used in the Arbiter Systems line of 19-inch, rack mount Satellite-Controlled Clocks. This option comes with a six-foot phone cable and RJ-11 to DB-9F adapter for connecting to the RS-232, or NTP Setup, port. 1.1.1 Option 33 Option 33 allows the clock to act as time server over an Ethernet network using the network time protocol operating in server mode - symmetric operation modes are not supported. Time is distributed over the network interface to computers, controllers and other equipment needing the correct time. Option 33 understands NTP Version 1, Version 2, and Version 3 frames, and optionally supports authentication via DES and MD5 cryptographic checksums. If authentication is not used, the controller can typically be used for hundreds of clients without overloading it. Authentication requires typically 40 ms for checking and generating the cryptograms, which is covered and averaged out by the protocol. Option 33 supports full SNTP and all NTP functions required for reliable server operation. Functions not required for server operation are not implemented. 1.1.2 Hardware Configuration. Option 33 consists of two building blocks; two OEM NTP modules and an interface to the GPS clock.
    [Show full text]
  • Netflix and Twitch Traffic Characterization
    University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2015-09-30 NetFlix and Twitch Traffic Characterization Laterman, Michel Laterman, M. (2015). NetFlix and Twitch Traffic Characterization (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/27074 http://hdl.handle.net/11023/2562 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY NetFlix and Twitch Traffic Characterization by Michel Laterman A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN COMPUTER SCIENCE CALGARY, ALBERTA SEPTEMBER, 2015 c Michel Laterman 2015 Abstract Streaming video content is the largest contributor to inbound network traffic at the University of Calgary. Over five months, from December 2014 { April 2015, over 2.7 petabytes of traffic on 49 billion connections was observed. This thesis presents traffic characterizations for two large video streaming services, namely NetFlix and Twitch. These two services contribute a significant portion of inbound bytes. NetFlix provides TV series and movies on demand. Twitch offers live streaming of video game play. These services share many characteristics, including asymmetric connections, content delivery mechanisms, and content popularity patterns.
    [Show full text]
  • Architect's Guide for Securing Network Equipment
    JANUARY 2018 ARCHITECT’S GUIDE FOR SECURING NETWORK EQUIPMENT Trusted Computing Group 3855 SW 153rd Drive Tel (503) 619-0562 Fax (503) 644-6708 [email protected] www.trustedcomputinggroup.org Architect’s Guide for Security Network Equipment Copyright© 2018 Trusted Computing Group | All Rights Reserved ARCHITECT’S GUIDE FOR SECURING NETWORK EQUIPMENT As part of the critical infrastructure of an enterprise, network equipment (Side Bar 1) is subject to the same types of attacks and threats as PCs, servers and the network itself. THESE THREATS INCLUDE: UNAUTHORIZED DEVICES UNAUTHORIZED CODE FIRMWARE IMPLANTS THAT 1 THAT CAN GAIN ACCESS 2 THAT CAN INTERFERE 3 CAN RENDER ATTACKS TO NETWORKED DATA WITH SAFE OPERATION INVISIBLE AND UNREMOVABLE Preserving the integrity and security of network equipment is essential to maintaining customer privacy and network reliability. Trusted Computing solutions can be used to provide these requirements. This Architect’s Guide makes the case for addressing network security and provides some initial guidance from ongoing efforts in this area. AWARENESS PRIOR TO ACTION Experts in providing trust to all aspects of an It is important to distinguish network security enterprise have found that many designers are not provided by items such as firewalls, VPNs, MPLS concerned about protecting the low-level, embedded domains, access lists, intrusion detection, network portions of their infrastructure. For example, those access controls, Radius, DMZs and a host of other people who are interested specifically in network functions that prevent inappropriate access to security are extremely concerned about almost all networked resources, from Secure Network aspects that involve anti-viruses and software but Equipment.
    [Show full text]
  • Network Time Protocol (NTP) General Overview
    Network Time Protocol (NTP) General Overview David L. Mills University of Delaware http://www.eecis.udel.edu/~mills mailto:[email protected] alautun, Maya glyph 2-Aug-04 1 Introduction z Network Time Protocol (NTP) synchronizes clocks of hosts and routers in the Internet. z NIST estimates 10-20 million NTP servers and clients deployed in the Internet and its tributaries all over the world. Every Windows/XP has an NTP client. z NTP provides nominal accuracies of low tens of milliseconds on WANs, submilliseconds on LANs, and submicroseconds using a precision time source such as a cesium oscillator or GPS receiver. z NTP software has been ported to almost every workstation and server platform available today - from PCs to Crays - Unix, Windows, VMS and embedded systems, even home routers. z The NTP architecture, protocol and algorithms have been evolved over the last two decades to the latest NTP Version 4 described in this and related briefings. 2-Aug-04 2 The Sun never sets on NTP z NTP is argueably the longest running, continuously operating, ubiquitously available protocol in the Internet – USNO and NIST, as well as equivalents in other countries, provide multiple NTP primary servers directly synchronized to national standard cesium clock ensembles and GPS – Over 230 Internet primary serversare in Australia, Canada, Chile, France, Germany, Isreal, Italy, Holland, Japan, Norway, Sweden, Switzerland, UK, and US. z Well over a million Internet servers and clients all over the world – National and regional service providers BBN, MCI, Sprint, Alternet, etc. – Agencies and organizations: US Weather Service, US Treasury Service, IRS, PBS, Merrill Lynch, Citicorp, GTE, Sun, DEC, HP, etc.
    [Show full text]
  • Which Time Server Option Is Best for Synchronizing Your Clocks
    WHICH TIME SERVER OPTION IS BEST FOR SYNCHRONIZING YOUR CLOCKS? Any electronic device that automatically displays REGARDING MASTER the current local time – your clocks, phone, tablet, TIME CONTROLLERS computer and even most TVs – has to pull that time from a time server. AND The time server acts as a messenger of sorts; IP NETWORK CLOCKS it reads the time from a reference clock and distributes that information via a computer network (ETHERNET OR WI-FI) to your device when the device requests it. The time server could be a local network time server or an internet time server. SNTP, or Simple Network Time Protocol, is an internet standard protocol that allows a clock or device to contact a server and get the current time. It’s a simplification of the more robustNTP (Network Time Protocol) and is used in most embedded devices and computers. Once the device receives the current Coordinated Universal Time (UTC), the device applies offsets such as time zone or daylight saving time considerations, as well as the time spent on the network retrieving the time, before displaying the accurate local time. January 2018 AMERICAN TIME WHITE PAPER BY: MAX BLOM When it comes to syncing time for your organization’s clocks, you have 3 options: Let’s take a look at how each of these options work, their pros and cons, and our recommendation. Port 123 is reserved specifically for External Server IP Address NTP/SNTP communication 1 The NIST – the U.S. Department of Commerce’s National Institute of Standards and Technology – is the primary source for synchronizing time systems in the U.S.
    [Show full text]
  • Endrun TECHNOLOGIES Præcis Cntp Network Time Server
    Smarter Timing Solutions EndRun TECHNOLOGIES Præcis Cntp Network Time Server User’s Manual Præcis Cntp Network Time Server User’s Manual EndRun Technologies 1360 North Dutton Avenue #200 Santa Rosa, California USA 95401 Phone 707-573-8633 • Fax 707-573-8619 Preface Thank you for purchasing the Præcis Cntp Network Time Server. Our goal in developing this product is to bring precise, Universal Coordinated Time (UTC) into your network quickly, easily and reliably. Your new Præcis Cntp is fabricated using the highest quality materials and manufacturing processes available today, and will give you years of troublefree service. About EndRun Technologies Founded in 1998 and headquartered in Santa Rosa, California, we are the leaders in the exciting new time and frequency distribution technology based on the Code Division Multiple Access (CDMA) mobile telecommunications infrastructure. Our innovative designs and painstaking attention to the details of efficient manufacturability have made us the first to bring this technology to the broad synchronization market at prices small businesses can afford. EndRun Technologies markets this technology in three major product lines: Network Time Sources/Servers – These units are configured for optimum performance in operation with network servers/networks running the Internet protocol known as the Network Time Protocol (NTP). Instrumentation Time and Frequency References – These products provide UTC traceable time and frequency signals for use in precision test and measurement instrumentation. OEM Time and Frequency Engines – These products provide the core time and frequency capabilities to our customers who require lower cost and tighter integration with their own products. About this manual This manual will guide you through simple installation and set up procedures.
    [Show full text]
  • Networkingsimple Network Time Protocol
    IBM i Version 7.2 Networking Simple Network Time Protocol IBM Note Before using this information and the product it supports, read the information in “Notices” on page 11. This document may contain references to Licensed Internal Code. Licensed Internal Code is Machine Code and is licensed to you under the terms of the IBM License Agreement for Machine Code. © Copyright International Business Machines Corporation 1998, 2013. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Simple Network Time Protocol...............................................................................1 PDF file for Simple Network Time Protocol.................................................................................................1 SNTP concepts............................................................................................................................................. 1 SNTP client............................................................................................................................................. 2 SNTP server............................................................................................................................................ 2 Scenario: Synchronizing clocks with IBM i..................................................................................................3 Configuring System A as an SNTP client and server..............................................................................5 Configuring
    [Show full text]
  • NBAR2 Standard Protocol Pack 1.0
    NBAR2 Standard Protocol Pack 1.0 Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 527-0883 © 2013 Cisco Systems, Inc. All rights reserved. CONTENTS CHAPTER 1 Release Notes for NBAR2 Standard Protocol Pack 1.0 1 CHAPTER 2 BGP 3 BITTORRENT 6 CITRIX 7 DHCP 8 DIRECTCONNECT 9 DNS 10 EDONKEY 11 EGP 12 EIGRP 13 EXCHANGE 14 FASTTRACK 15 FINGER 16 FTP 17 GNUTELLA 18 GOPHER 19 GRE 20 H323 21 HTTP 22 ICMP 23 IMAP 24 IPINIP 25 IPV6-ICMP 26 IRC 27 KAZAA2 28 KERBEROS 29 L2TP 30 NBAR2 Standard Protocol Pack 1.0 iii Contents LDAP 31 MGCP 32 NETBIOS 33 NETSHOW 34 NFS 35 NNTP 36 NOTES 37 NTP 38 OSPF 39 POP3 40 PPTP 41 PRINTER 42 RIP 43 RTCP 44 RTP 45 RTSP 46 SAP 47 SECURE-FTP 48 SECURE-HTTP 49 SECURE-IMAP 50 SECURE-IRC 51 SECURE-LDAP 52 SECURE-NNTP 53 SECURE-POP3 54 SECURE-TELNET 55 SIP 56 SKINNY 57 SKYPE 58 SMTP 59 SNMP 60 SOCKS 61 SQLNET 62 SQLSERVER 63 SSH 64 STREAMWORK 65 NBAR2 Standard Protocol Pack 1.0 iv Contents SUNRPC 66 SYSLOG 67 TELNET 68 TFTP 69 VDOLIVE 70 WINMX 71 NBAR2 Standard Protocol Pack 1.0 v Contents NBAR2 Standard Protocol Pack 1.0 vi CHAPTER 1 Release Notes for NBAR2 Standard Protocol Pack 1.0 NBAR2 Standard Protocol Pack Overview The Network Based Application Recognition (NBAR2) Standard Protocol Pack 1.0 is provided as the base protocol pack with an unlicensed Cisco image on a device.
    [Show full text]
  • New Milestone in Network Time Security As Internet Draft Approved
    New milestone in Network Time Security as Internet Draft approved Stockholm, Sweden - 27 March 2020- Netnod, a leading provider of interconnection and DNS services, is pleased to announce that the Internet Draft ‘Network Time Security for the Network Time Protocol’ has been approved as a Proposed Standard. The approval came from the Internet Engineering Steering Group (IESG) on 25 March during the virtual IETF meeting. Netnod staff have been instrumental in developing this protocol which adds a much needed layer of security to the Network Time Protocol (NTP) and follows from Netnod’s launch of one of the first NTS-enabled NTP services in October 2019. The new standard (https://tools.ietf.org/html/draft-ietf-ntp-using-nts-for-ntp-28) adds an important layer of security to NTP in a similar way that Transport Layer Security (TLS) adds security to the Hypertext Transfer Protocol (HTTP), which users can see in their web browsers as a closed padlock. As described in the Proposed Standard, NTS is: ”a mechanism for using Transport Layer Security (TLS) and Authenticated Encryption with Associated Data (AEAD) to provide cryptographic security for the client-server mode of the Network Time Protocol (NTP).” NTP, the most popular protocol in use for synchronizing time, is more than 30 years old and vulnerable to Man-in-the-Middle (MITM) attacks. With many of today’s most important security processes dependent on accurate time, the consequences of receiving time from a malicious source are serious. Everything from establishing encrypted TLS sessions and using DNSSEC to time-stamping financial transactions and preventing online fraud depends on accurate and secure time.
    [Show full text]
  • IBM Z Server Time Protocol Guide
    Front cover Draft Document for Review August 3, 2020 1:37 pm SG24-8480-00 IBM Z Server Time Protocol Guide Octavian Lascu Franco Pinto Gatto Gobehi Hans-Peter Eckam Jeremy Koch Martin Söllig Sebastian Zimmermann Steve Guendert Redbooks Draft Document for Review August 3, 2020 7:26 pm 8480edno.fm IBM Redbooks IBM Z Server Time Protocol Guide August 2020 SG24-8480-00 8480edno.fm Draft Document for Review August 3, 2020 7:26 pm Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (August 2020) This edition applies to IBM Server Time Protocol for IBM Z and covers IBM z15, IBM z14, and IBM z13 server generations. This document was created or updated on August 3, 2020. © Copyright International Business Machines Corporation 2020. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Draft Document for Review August 3, 2020 8:32 pm 8480TOC.fm Contents Notices . vii Trademarks . viii Preface . ix Authors. ix Comments welcome. .x Stay connected to IBM Redbooks . xi Chapter 1. Introduction to Server Time Protocol . 1 1.1 Introduction to time synchronization . 2 1.1.1 Insertion of leap seconds . 2 1.1.2 Time-of-Day (TOD) Clock . 3 1.1.3 Industry requirements . 4 1.1.4 Time synchronization in a Parallel Sysplex. 6 1.2 Overview of Server Time Protocol (STP) . 7 1.3 STP concepts and terminology . 9 1.3.1 STP facility . 9 1.3.2 TOD clock synchronization .
    [Show full text]
  • Encryption Is Futile: Delay Attacks on High-Precision Clock Synchronization 1
    R. ANNESSI, J. FABINI, F.IGLESIAS, AND T. ZSEBY: ENCRYPTION IS FUTILE: DELAY ATTACKS ON HIGH-PRECISION CLOCK SYNCHRONIZATION 1 Encryption is Futile: Delay Attacks on High-Precision Clock Synchronization Robert Annessi, Joachim Fabini, Felix Iglesias, and Tanja Zseby Institute of Telecommunications TU Wien, Austria Email: fi[email protected] Abstract—Clock synchronization has become essential to mod- endanger control decisions, and adversely affect the overall ern societies since many critical infrastructures depend on a functionality of a wide range of (critical) services that depend precise notion of time. This paper analyzes security aspects on accurate time. of high-precision clock synchronization protocols, particularly their alleged protection against delay attacks when clock syn- In recent years, security of clock synchronization received chronization traffic is encrypted using standard network security increased attention as various attacks on clock synchronization protocols such as IPsec, MACsec, or TLS. We use the Precision protocols (and countermeasures) were proposed. For this Time Protocol (PTP), the most widely used protocol for high- reason, clock synchronization protocols need to be secured precision clock synchronization, to demonstrate that statistical whenever used outside of fully trusted network environments. traffic analysis can identify properties that support selective message delay attacks even for encrypted traffic. We furthermore Clock synchronization protocols are specifically susceptible to identify a fundamental conflict in secure clock synchronization delay attacks since the times when messages are sent and between the need of deterministic traffic to improve precision and received have an actual effect on the receiver’s notion of the need to obfuscate traffic in order to mitigate delay attacks.
    [Show full text]
  • Ipv6-Security Monitoring
    Security Monitoring ITU/APNIC/MICT IPv6 Security Workshop 23rd – 27th May 2016 Bangkok Last updated 22 July 2014 1 Managing and Monitoring IPv6 Networks p SNMP Monitoring p IPv6-Capable SNMP Management Tools p NetFlow Analysis p Syslog p Keeping accurate time p Intrusion Detection p Managing the Security Configuration 2 Using SNMP for Managing IPv6 Networks 3 What is SNMP? p SNMP – Simple Network Management Protocol p Industry standard, hundreds of tools exist to exploit it p Present on any decent network equipment p Query/response based: GET / SET p Monitoring generally uses GET p Object Identifiers (OIDs) p Keys to identify each piece of data p Concept of MIB (Management Information Base) p Defines a collection of OIDs What is SNMP? p Typical queries n Bytes In/Out on an interface, errors n CPU load n Uptime n Temperature or other vendor specific OIDs p For hosts (servers or workstations) n Disk space n Installed software n Running processes n ... p Windows and UNIX have SNMP agents What is SNMP? p UDP protocol, port 161 p Different versions n v1 (1988) – RFC1155, RFC1156, RFC1157 p Original specification n v2 – RFC1901 ... RFC1908 + RFC2578 p Extends v1, new data types, better retrieval methods (GETBULK) p Used is version v2c (simple security model) n v3 – RFC3411 ... RFC3418 (w/security) p Typically we use SNMPv2 (v2c) SNMP roles p Terminology: n Manager (the monitoring station) n Agent (running on the equipment/server) How does it work? p Basic commands n GET (manager → agent) p Query for a value n GET-NEXT (manager → agent) p Get next value (e.g.
    [Show full text]