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Using Frankencerts for Automated Adversarial Testing of Certificate
Using Frankencerts for Automated Adversarial Testing of Certificate Validation in SSL/TLS Implementations Chad Brubaker ∗ y Suman Janay Baishakhi Rayz Sarfraz Khurshidy Vitaly Shmatikovy ∗Google yThe University of Texas at Austin zUniversity of California, Davis Abstract—Modern network security rests on the Secure Sock- many open-source implementations of SSL/TLS are available ets Layer (SSL) and Transport Layer Security (TLS) protocols. for developers who need to incorporate SSL/TLS into their Distributed systems, mobile and desktop applications, embedded software: OpenSSL, NSS, GnuTLS, CyaSSL, PolarSSL, Ma- devices, and all of secure Web rely on SSL/TLS for protection trixSSL, cryptlib, and several others. Several Web browsers against network attacks. This protection critically depends on include their own, proprietary implementations. whether SSL/TLS clients correctly validate X.509 certificates presented by servers during the SSL/TLS handshake protocol. In this paper, we focus on server authentication, which We design, implement, and apply the first methodology for is the only protection against man-in-the-middle and other large-scale testing of certificate validation logic in SSL/TLS server impersonation attacks, and thus essential for HTTPS implementations. Our first ingredient is “frankencerts,” synthetic and virtually any other application of SSL/TLS. Server authen- certificates that are randomly mutated from parts of real cer- tication in SSL/TLS depends entirely on a single step in the tificates and thus include unusual combinations of extensions handshake protocol. As part of its “Server Hello” message, and constraints. Our second ingredient is differential testing: if the server presents an X.509 certificate with its public key. -
Libressl Presentatie2
Birth of LibreSSL and its current status Frank Timmers Consutant, Snow B.V. Background What is LibreSSL • A fork of OpenSSL 1.0.1g • Being worked on extensively by a number of OpenBSD developers What is OpenSSL • OpenSSL is an open source SSL/TLS crypto library • Currently the de facto standard for many servers and clients • Used for securing http, smtp, imap and many others Alternatives • Netscape Security Services (NSS) • BoringSSL • GnuTLS What is Heartbleed • Heartbleed was a bug leaking of private data (keys) from both client and server • At this moment known as “the worst bug ever” • Heartbeat code for DTLS over UDP • So why was this also included in the TCP code? • Not the reason to create a fork Why did this happen • Nobody looked • Or at least didn’t admit they looked Why did nobody look • The code is horrible • Those who did look, quickly looked away and hoped upstream could deal with it Why was the code so horrible • Buggy re-implementations of standard libc functions like random() and malloc() • Forces all platforms to use these buggy implementations • Nested #ifdef, #ifndefs (up to 17 layers deep) through out the code • Written in “OpenSSL C”, basically their own dialect • Everything on by default Why was it so horrible? crypto_malloc • Never frees memory (Tools like Valgrind, Coverity can’t spot bugs) • Used LIFO recycling (Use after free?) • Included debug malloc by default, logging private data • Included the ability to replace malloc/free at runtime #ifdef trees • #ifdef, #elif, #else trees up to 17 layers deep • Throughout the complete source • Some of which could never be reached • Hard to see what is or not compiled in 1. -
BSD – Alternativen Zu Linux
∗BSD { Alternativen zu Linux Karl Lockhoff March 19, 2015 Inhaltsverzeichnis I Woher kommt BSD? I Was ist BSD? I Was ist sind die Unterschiede zwischen FreeBSD, NetBSD und OpenBSD? I Warum soll ich *BSD statt Linux einsetzen? I Chuck Haley und Bill Joy entwickeln den vi in Berkeley I Bill Joy erstellt eine Sammlung von Tools, 1BSD I Unix Version 7 erscheint I 2BSD erscheint (Basis f¨urdie Weiterentwicklung PDP-11) I 3BSD erscheint (erstmalig mit einen eigenen Kernel) I 4BSD erscheint (enth¨altdas fast file system (ffs)) I Bill Joy wechselt zu Sun Microsystems I Kirk McKusick ¨ubernimmt die Entwicklung von BSD I 1978 I 1979 I 1980 I 1981 Woher kommt BSD? I 1976 I Unix Version 6 erscheint I 2BSD erscheint (Basis f¨urdie Weiterentwicklung PDP-11) I 3BSD erscheint (erstmalig mit einen eigenen Kernel) I 4BSD erscheint (enth¨altdas fast file system (ffs)) I Bill Joy wechselt zu Sun Microsystems I Kirk McKusick ¨ubernimmt die Entwicklung von BSD I Bill Joy erstellt eine Sammlung von Tools, 1BSD I Unix Version 7 erscheint I 1979 I 1980 I 1981 Woher kommt BSD? I 1976 I Unix Version 6 erscheint I 1978 I Chuck Haley und Bill Joy entwickeln den vi in Berkeley I 2BSD erscheint (Basis f¨urdie Weiterentwicklung PDP-11) I 3BSD erscheint (erstmalig mit einen eigenen Kernel) I 4BSD erscheint (enth¨altdas fast file system (ffs)) I Bill Joy wechselt zu Sun Microsystems I Kirk McKusick ¨ubernimmt die Entwicklung von BSD I Unix Version 7 erscheint I 1979 I 1980 I 1981 Woher kommt BSD? I 1976 I Unix Version 6 erscheint I 1978 I Chuck Haley und Bill Joy entwickeln den -
Arxiv:1911.09312V2 [Cs.CR] 12 Dec 2019
Revisiting and Evaluating Software Side-channel Vulnerabilities and Countermeasures in Cryptographic Applications Tianwei Zhang Jun Jiang Yinqian Zhang Nanyang Technological University Two Sigma Investments, LP The Ohio State University [email protected] [email protected] [email protected] Abstract—We systematize software side-channel attacks with three questions: (1) What are the common and distinct a focus on vulnerabilities and countermeasures in the cryp- features of various vulnerabilities? (2) What are common tographic implementations. Particularly, we survey past re- mitigation strategies? (3) What is the status quo of cryp- search literature to categorize vulnerable implementations, tographic applications regarding side-channel vulnerabili- and identify common strategies to eliminate them. We then ties? Past work only surveyed attack techniques and media evaluate popular libraries and applications, quantitatively [20–31], without offering unified summaries for software measuring and comparing the vulnerability severity, re- vulnerabilities and countermeasures that are more useful. sponse time and coverage. Based on these characterizations This paper provides a comprehensive characterization and evaluations, we offer some insights for side-channel of side-channel vulnerabilities and countermeasures, as researchers, cryptographic software developers and users. well as evaluations of cryptographic applications related We hope our study can inspire the side-channel research to side-channel attacks. We present this study in three di- community to discover new vulnerabilities, and more im- rections. (1) Systematization of literature: we characterize portantly, to fortify applications against them. the vulnerabilities from past work with regard to the im- plementations; for each vulnerability, we describe the root cause and the technique required to launch a successful 1. -
Crypto Projects That Might Not Suck
Crypto Projects that Might not Suck Steve Weis PrivateCore ! http://bit.ly/CryptoMightNotSuck #CryptoMightNotSuck Today’s Talk ! • Goal was to learn about new projects and who is working on them. ! • Projects marked with ☢ are experimental or are relatively new. ! • Tried to cite project owners or main contributors; sorry for omissions. ! Methodology • Unscientific survey of projects from Twitter and mailing lists ! • Excluded closed source projects & crypto currencies ! • Stats: • 1300 pageviews on submission form • 110 total nominations • 89 unique nominations • 32 mentioned today The People’s Choice • Open Whisper Systems: https://whispersystems.org/ • Moxie Marlinspike (@moxie) & open source community • Acquired by Twitter 2011 ! • TextSecure: Encrypt your texts and chat messages for Android • OTP-like forward security & Axolotl key racheting by @trevp__ • https://github.com/whispersystems/textsecure/ • RedPhone: Secure calling app for Android • ZRTP for key agreement, SRTP for call encryption • https://github.com/whispersystems/redphone/ Honorable Mention • ☢ Networking and Crypto Library (NaCl): http://nacl.cr.yp.to/ • Easy to use, high speed XSalsa20, Poly1305, Curve25519, etc • No dynamic memory allocation or data-dependent branches • DJ Bernstein (@hashbreaker), Tanja Lange (@hyperelliptic), Peter Schwabe (@cryptojedi) ! • ☢ libsodium: https://github.com/jedisct1/libsodium • Portable, cross-compatible NaCL • OpenDNS & Frank Denis (@jedisct1) The Old Standbys • Gnu Privacy Guard (GPG): https://www.gnupg.org/ • OpenSSH: http://www.openssh.com/ -
Post-Quantum Authentication in Openssl with Hash-Based Signatures
Recalling Hash-Based Signatures Motivations for Cryptographic Library Integration Cryptographic Libraries OpenSSL & open-quantum-safe XMSS Certificate Signing in OpenSSL / open-quantum-safe Conclusions Post-Quantum Authentication in OpenSSL with Hash-Based Signatures Denis Butin, Julian Wälde, and Johannes Buchmann TU Darmstadt, Germany 1 / 26 I Quantum computers are not available yet, but deployment of new crypto takes time, so transition must start now I Well established post-quantum signature schemes: hash-based cryptography (XMSS and variants) I Our goal: make post-quantum signatures available in a popular security software library: OpenSSL Recalling Hash-Based Signatures Motivations for Cryptographic Library Integration Cryptographic Libraries OpenSSL & open-quantum-safe XMSS Certificate Signing in OpenSSL / open-quantum-safe Conclusions Overall Motivation I Networking requires authentication; authentication is realized by cryptographic signature schemes I Shor’s algorithm (1994): most public-key cryptography (RSA, DSA, ECDSA) breaks once large quantum computers exist I Post-quantum cryptography: public-key algorithms thought to be secure against quantum computer attacks 2 / 26 Recalling Hash-Based Signatures Motivations for Cryptographic Library Integration Cryptographic Libraries OpenSSL & open-quantum-safe XMSS Certificate Signing in OpenSSL / open-quantum-safe Conclusions Overall Motivation I Networking requires authentication; authentication is realized by cryptographic signature schemes I Shor’s algorithm (1994): most public-key -
Mandoc: Becoming the Main BSD Manual Toolbox
mandoc: becoming the main BSD manual toolbox BSDCan 2015, June 13, Ottawa Ingo Schwarze <[email protected]> Cynthia Livingston’sOTTB “Bedifferent” (c) 2013 C. Livingston (with permission) > Ingo Schwarze: mandoc page 2: INTROI BSDCan 2015, June 13, Ottawa Brief history of UNIX documentation • The key point: All documentation in one place and one format. Easy to find, uniform and easy to read and write. Be correct, complete, concise. • 1964: RUNOFF/roffmarkup syntax by Jerome H. Saltzer,MIT. Unobtrusive,diff(1)-friendly,easy to hand-edit, simple tools, high quality output. • 1971: Basic manual structure by Ken Thompson and Dennis Ritchie for the AT&T Version 1 UNIX manuals, Bell Labs. • 1979: man(7) physical markup language for AT&T Version 7 UNIX. • 1989: mdoc(7) semantic markup by Cynthia Livingston for 4.3BSD-Reno. Powerful, self-contained, portable. • 1989: GNU troffbyJames Clarke. • 2001: mdoc(7) rewrite by Werner Lemberg and Ruslan Ermilovfor groff-1.17. • 2008: mandoc(1) started by Kristaps Dzonsons. • 2010: mandoc(1) is the only documentation formatter in the OpenBSD base system. • 2014: mandoc(1) used by default in OpenBSD, FreeBSD, NetBSD, illumos. 16:19:30 What is the mandoc toolbox? → < > Ingo Schwarze: mandoc page 3: INTROIIBSDCan 2015, June 13, Ottawa What is the mandoc toolbox? User perspective:man(1), the manual viewer One comprehensive tool! Normal operation always proceeds in three steps: 1. Find one or more manuals in the file system or using a database by manual name — man(1) — or by search query — apropos(1) =man -k The result of this step can be printed out with man -w. -
Black-Box Security Analysis of State Machine Implementations Joeri De Ruiter
Black-box security analysis of state machine implementations Joeri de Ruiter 18-03-2019 Agenda 1. Why are state machines interesting? 2. How do we know that the state machine is implemented correctly? 3. What can go wrong if the implementation is incorrect? What are state machines? • Almost every protocol includes some kind of state • State machine is a model of the different states and the transitions between them • When receiving a messages, given the current state: • Decide what action to perform • Which message to respond with • Which state to go the next Why are state machines interesting? • State machines play a very important role in security protocols • For example: • Is the user authenticated? • Did we agree on keys? And if so, which keys? • Are we encrypting our traffic? • Every implementation of a protocol has to include the corresponding state machine • Mistakes can lead to serious security issues! State machine example Confirm transaction Verify PIN 0000 Failed Init Failed Verify PIN 1234 OK Verified Confirm transaction OK State machines in specifications • Often specifications do not explicitly contain a state machine • Mainly explained in lots of prose • Focus usually on happy flow • What to do if protocol flow deviates from this? Client Server ClientHello --------> ServerHello Certificate* ServerKeyExchange* CertificateRequest* <-------- ServerHelloDone Certificate* ClientKeyExchange CertificateVerify* [ChangeCipherSpec] Finished --------> [ChangeCipherSpec] <-------- Finished Application Data <-------> Application Data -
Openbsd 6.4 / Openbgpd 6.4
OpenBSD 6.4 / OpenBGPD 6.4 Peter Hessler [email protected] OpenBSD 18 October, 2018 openbsd 23 year anniversary on October 18th 6.4 released today 6.4 major improvements to our arm64 and armv7 platforms many improvements and drivers for modern amd64 based laptops many improvements for guest OSes in our virtualization hypervisor defenses against ROP attacks and misbehaving applications we are upstream for openssh tmux libressl mandoc opensmtpd network wifi join lacp administrative knobs microtik EoIP further work in an SMP-safe network stack more unlocked syscalls (sendmsg, sendto, recvfrom, and recvmsg) networks(5) support has been removed network daemons ospf6d routing domains (VRFs) slaacd fully pledged slaacd better behaved on networks (DAD, network roaming, etc) rad replaces rtadvd OpenBGPD and the RIPE Community Projects Fund money was raised Thank you to RIPE Community Projects Fund DE-CIX, Netnod, AMS-IX, BCIX, LONAP, Asteroid, Namex, University of Oslo apologies if I missed anyone OpenBGPD and the RIPE Community Projects Fund money was spent Claudio Jeker is now working full time on OpenBGPD 1 year of funding is secured 5 months of effort so far OpenBGPD 6.4 RFC8212 compliance (default deny policy) remove announce self, move to filter rules instead RPKI ROA support (static table, no RTR support) sets for prefixes, ASNum, and origins (prefix + source-as) ... replaces many filter rules with a single fast lookup background soft-reconfig on config reload ... on reload, withdraws and updates are still processed 154 commits since 6.3 OpenBGPD 6.4 YYCIX is using this in production already 46 members 6.3 370,000 filter rules 6.4 less than 6,000 filter rules OpenBGPD 6.5 - the future better community filtering .. -
You Really Shouldn't Roll Your Own Crypto: an Empirical Study of Vulnerabilities in Cryptographic Libraries
You Really Shouldn’t Roll Your Own Crypto: An Empirical Study of Vulnerabilities in Cryptographic Libraries Jenny Blessing Michael A. Specter Daniel J. Weitzner MIT MIT MIT Abstract A common aphorism in applied cryptography is that cryp- The security of the Internet rests on a small number of open- tographic code is inherently difficult to secure due to its com- source cryptographic libraries: a vulnerability in any one of plexity; that one should not “roll your own crypto.” In par- them threatens to compromise a significant percentage of web ticular, the maxim that complexity is the enemy of security traffic. Despite this potential for security impact, the character- is a common refrain within the security community. Since istics and causes of vulnerabilities in cryptographic software the phrase was first popularized in 1999 [52], it has been in- are not well understood. In this work, we conduct the first voked in general discussions about software security [32] and comprehensive analysis of cryptographic libraries and the vul- cited repeatedly as part of the encryption debate [26]. Conven- nerabilities affecting them. We collect data from the National tional wisdom holds that the greater the number of features Vulnerability Database, individual project repositories and in a system, the greater the risk that these features and their mailing lists, and other relevant sources for eight widely used interactions with other components contain vulnerabilities. cryptographic libraries. Unfortunately, the security community lacks empirical ev- Among our most interesting findings is that only 27.2% of idence supporting the “complexity is the enemy of security” vulnerabilities in cryptographic libraries are cryptographic argument with respect to cryptographic software. -
Mandoc
mandoc from scratch to the standard BSD documentation toolkit in 6 years EuroBSDCon, Stockholm, October 4, 2015 Ingo Schwarze <[email protected]> using some material from: Training a foal to replace Enhancing the modern Let’smake mandoc: becoming avenerable workhorse: toolbox for the classic manuals the main BSD mandoc in OpenBSD documentation formats: more useful! manual toolbox BSDCan 2011 newtrends in mandoc EuroBSD- BSDCan 2015 BSDCan 2014 Con 2014 Csikó — Foal © 2010 Keajuvenile © 2007 Sofi ©2014 “Bedifferent” © 2013 Adam Tomkó @flickr (CC) Brent Barrett @flickr (CC) Alica Dimitrova Cynthia Livingston > Ingo Schwarze: 6 years of mandoc page 2: INTROI Stockholm, October 4, 2015 Contents 1. Intro: Documentation — whyand how(EuroBSDCon/BSDCan 2014) 2. Using mandoc: Searching — unified interface — web display (BSDCan 2014/15) News: equations — unicode (BSDCan 2015) Maintaining documentation: warnings — help — portable software (all) 3. The groff → mandoc replacement project (BSDCan 2011) 4. Software isn’tperfect. Bugs, security issues, performance (BSDCan 2015/14) 5. Conclusion —status — future — thanks (BSDCan 2015) http://mdocml.bsd.lv/press.html has all the slides of these talks Black Lakenear King Mountain, Gatineau Park, Quebec, Canada © 2012 Lezumbalaberenjena@flickr (CC) 14:04:30 NYC*BUG 2015 Whydocument software? → < > Ingo Schwarze: 6 years of mandoc page 3: INTROIIStockholm, October 4, 2015 Let’smakemanuals more useful! Requirements for good documentation • correct • complete • concise • easy to find and access, all in one local place • not just plain text: function of words must be marked up for display and search Rotonda Sveti Georgi, Sofi ©2006 Preslav @wikimedia (PD) • easy to read: in particular,uniform display markup and style • easy to write: in particular,one simple, standard input language The formatted documentation must seem simple to end users. -
Security Issues in the Diffie-Hellman Key Agreement Protocol
Security Issues in the Diffie-Hellman Key Agreement Protocol Jean-Franc¸ois Raymond and Anton Stiglic Zero-Knowledge Systems Inc. jfr, anton ¡ @zeroknowledge.com Abstract Diffie-Hellman key agreement protocol [20] implementations have been plagued by serious security flaws. The attacks can be very subtle and, more often than not, have not been taken into account by protocol designers. In this summary we discuss both theoretical attacks against the Diffie-Hellman key agreement pro- tocol and attacks based on implementation details . It is hoped that computer se- curity practitioners will obtain enough information to build and design secure and efficient versions of this classic key agreement protocol. 1 Introduction In their landmark 1976 paper “New Directions in Cryptography”[20], Diffie and Hell- man present a secure key agreement protocol that can be carried out over public com- munication channels. Their protocol is still widely used to this day. Even though the protocol seems quite simple, it can be vulnerable to certain attacks. As with many cryptographic protocols, the Diffie-Hellman key agreement protocol (DH protocol) has subtle problems that cryptographers have taken many years to discover. This vulnerability is compounded by the fact that programmers often do not have a proper understanding of the security issues. In fact, bad implementations of crypto- graphic protocols are, unfortunately, common [2]. In this work, we attempt to give a comprehensive listing of attacks on the DH proto- col. This listing will, in turn, allow us to motivate protocol design decisions. Note that throughout this presentation emphasis is placed on practice. After reading this paper, one might not have an extremely detailed understanding of previous work and theoret- ical problems, but should have a very good idea about how to securely implement the DH protocol in different settings.