Improved File System Security Through Restrictive Access
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Improving Route Scalability: Nexthops As Separate Objects
Improving Route Scalability: Nexthops as Separate Objects September 2019 David Ahern | Cumulus Networks !1 Agenda Executive Summary ▪ If you remember nothing else about this talk … Driving use case Review legacy route API Dive into Nexthop API Benefits of the new API Cumulus Networks !2 Performance with the Legacy Route API route route route prefix/lenroute prefix/lendev prefix/lendev gatewayprefix/len gatewaydev gatewaydev gateway Cumulus Networks !3 Splitting Next Hops from Routes Routes with separate Nexthop objects Legacy Route API route route prefix/len nexthop route nexthop id dev route gateway prefix/lenroute prefix/lendev prefix/lendev gatewayprefix/len gatewaydev gatewaydev gateway route prefix/len nexthop nexthop nexthop id group nexthopdev nexthop[N] gatewaydev gateway Cumulus Networks !4 Dramatically Improves Route Scalability … Cumulus Networks !5 … with the Potential for Constant Insert Times Cumulus Networks !6 Networking Operating System Using Linux APIs Routing daemon or utility manages switchd ip FRR entries in kernel FIBs via rtnetlink APIs SDK userspace ▪ Enables other control plane software to use Linux networking APIs rtnetlink Data path connections, stats, troubleshooting, … FIB notifications FIB Management of hardware offload is separate kernel upper devices tunnels ▪ Keeps hardware in sync with kernel ... eth0 swp1 swp2 swpN Userspace driver with SDK leveraging driver driver driver kernel notifications NIC switch ASIC H / W Cumulus Networks !7 NOS with switchdev Driver In-kernel switchdev driver ip FRR Leverages -
Stackable File Systems As a Security Tool
Stackable File Systems as a Security Tool Erez Zadok Computer Science Department, Columbia University [email protected] CUCS-036-99 Abstract Programmers often prefer to use existing system security services, such as file system security, rather than im- plement their own in an application. Traditional Unix security is generally considered inadequate and few operating systems offer enhanced security features such as ACLs[24] or immutable files[12]. Additional file system security features are always sought, but implementing them is a difficult task because modifying and porting existing file systems is costly or not possible. We advocate adding new security features using stackable file systems. As a starting point, we propose a portable, stackable template called the wrapper file system or Wrapfs, a minimal file system from which a wide range of file systems can be prototyped. A developer can modify a copy of the template and add only that which is necessary to achieve the desired functionality. The Wrapfs template takes care of kernel internals, freeing the developer from the details of operating system internals. Wrapfs imposes an overhead of only 5–7%. This paper describes the design, implementation, and porting of Wrapfs. We discuss several prototype file sys- tems written using Wrapfs that illustrate the ease with which security features can be implemented. The examples demonstrate security features such as encryption, access control, intrusion detection, intrusion avoidance, and analy- sis. 1 Introduction Security has become and integral part of computing in recent years. To provide the strongest possible security to users, security solutions sometimes consume a large amount of resources, and may inconvenience their users too much. -
Taxonomy of Linux Kernel Vulnerability Solutions
Taxonomy of Linux Kernel Vulnerability Solutions Serguei A. Mokhov Marc-Andre´ Laverdiere` Djamel Benredjem Computer Security Laboratory Computer Security Laboratory Computer Security Laboratory Concordia Institute for Concordia Institute for Concordia Institute for Information Systems Engineering Information Systems Engineering Information Systems Engineering Concordia University, Concordia University, Concordia University, Montreal, Quebec, Canada Montreal, Quebec, Canada Montreal, Quebec, Canada Email: [email protected] Email: ma [email protected] Email: d [email protected] Abstract—This paper presents the results of a case study on C programs in general, as well as statistics on their relative software vulnerability solutions in the Linux kernel. Our major importance. We also introduce a new methodology to track contribution is the introduction of a classification of methods used the patch solving a security issue based only on the contents to solve vulnerabilities. Our research shows that precondition validation, error handling, and redesign are the most used of the security advisory. methods in solving vulnerabilities in the Linux kernel. This The paper is organized as follows: we examine previous contribution is accompanied with statistics on the occurrence work that was done regarding Linux and C security in of the different types of vulnerabilities and their solutions that Section II, followed by a description of the methodology we observed during our case study, combined with example used in order to obtain the solutions to the vulnerabilities in source code patches. We also combine our findings with existing programming guidelines to create the first security-oriented Section III. Afterwards, in Section IV, we show our results, coding guidelines for the Linux kernel. -
Mesalock Linux: Towards a Memory-Safe Linux Distribution
MesaLock Linux Towards a memory-safe Linux distribution Mingshen Sun MesaLock Linux Maintainer | Baidu X-Lab, USA Shanghai Jiao Tong University, 2018 whoami • Senior Security Research in Baidu X-Lab, Baidu USA • PhD, The Chinese University of Hong Kong • System security, mobile security, IoT security, and car hacking • MesaLock Linux, TaintART, Pass for iOS, etc. • mssun @ GitHub | https://mssun.me !2 MesaLock Linux • Why • What • How !3 Why • Memory corruption occurs in a computer program when the contents of a memory location are unintentionally modified; this is termed violating memory safety. • Memory safety is the state of being protected from various software bugs and security vulnerabilities when dealing with memory access, such as buffer overflows and dangling pointers. !4 Stack Buffer Overflow • https://youtu.be/T03idxny9jE !5 Types of memory errors • Access errors • Buffer overflow • Race condition • Use after free • Uninitialized variables • Memory leak • Double free !6 Memory-safety in user space • CVE-2017-13089 wget: Stack-based buffer overflow in HTTP protocol handling • A stack-based buffer overflow when processing chunked, encoded HTTP responses was found in wget. By tricking an unsuspecting user into connecting to a malicious HTTP server, an attacker could exploit this flaw to potentially execute arbitrary code. • https://bugzilla.redhat.com/show_bug.cgi?id=1505444 • POC: https://github.com/r1b/CVE-2017-13089 !7 What • Linux distribution • Memory-safe user space !8 Linux Distribution • A Linux distribution (often abbreviated as distro) is an operating system made from a software collection, which is based upon the Linux kernel and, often, a package management system. !9 Linux Distros • Server: CentOS, Federa, RedHat, Debian • Desktop: Ubuntu • Mobile: Android • Embedded: OpenWRT, Yocto • Hard-core: Arch Linux, Gentoo • Misc: ChromeOS, Alpine Linux !10 Security and Safety? • Gentoo Hardened: enables several risk-mitigating options in the toolchain, supports PaX, grSecurity, SELinux, TPE and more. -
A Steganographic File System for the Linux Kernel
A Steganographic File System for the Linux Kernel by Ashley Morgan Anderson The University of Exeter COM3401 Individual Project 11th August 2007 Abstract Encryption is all around us these days, yet the security of private data on home computers is overlooked by many. The presence of cipher-text — in some instances — can make things worse, therefore the only way to overcome this is to hide the data. The Ancient Greeks knew about this risk and as such fabricated some of the most ingenious methods of steganography ever used. However, steganography has come along way in the last 3000 years, and is more important today than ever before (due to tightening restrictions governing encryption). This paper looks at how different mediums have been used to ensure messages and data remain private, as well as proposing a new file system which takes care of hiding files for the user. Whilst not the first, it does include many unique features which are intended to provide a more natural interface. I certify that all material in this project which is not my own work has been identified. ...................................... A.M. Anderson Contents 1 Introduction 1 2 Background 2 2.1 Steganography . 2 2.2 File Systems . 4 2.3 Steganographic File Systems . 6 3 Design 11 3.1 Implemented Design . 11 3.2 Potential Driver Types . 13 3.3 Initial File System . 15 3.4 Encryption . 15 3.5 A Discarded Design . 16 4 Development 17 4.1 The Tools . 17 4.2 The Process . 18 5 Testing 19 5.1 Progressive . 19 5.2 Forensic Analysis . -
Adecuándose a La Norma ISO/IEC 1799 Mediante Software Libre
Adecu´andose a la norma ISO/IEC 1799 mediante software libre * Jose Fernando Carvajal Vi´on Grupo de Inter´esen Seguridad de ATI (ATI-GISI) <[email protected]> Javier Fern´andez-Sanguino Pe˜na Grupo de Inter´esen Seguridad de ATI (ATI-GISI) <[email protected]> 28 de octubre de 2002 Resumen Este art´ıculo muestra la forma de adecuar a la norma ISO/IEC 17999 un sistema de informaci´onimplementado en un servidor cuyo software de sistema operativo se basa en alguna alternativa de software Libre y c´odigo abierto. La utilizaci´onde una distribuci´onDebian GNU/Linux sirve como base a la que a˜nadir las utilidades y paquetes necesarios para conseguir el objetivo. ´Indice 1. Introducci´on 1 2. Objetivo y Asunciones 2 3. Cumplimiento de la Norma ISO/IEC 17799 en GNU/Linux 4 4. Conclusiones 4 5. Referencias 5 6. Referencias de herramientas 7 7. Referencias Generales 11 *Copyright (c) 2002 Jose Fernando Carvajal y Javier Fern´andez-Sanguino. Se otorga permiso para copiar, distribuir y/o modificar este documento bajo los t´erminos de la Licencia de Documen- taci´onLibre GNU, Versi´on1.1 o cualquier otra versi´onposterior publicada por la Free Software Foundation. Puede consultar una copia de la licencia en: http://www.gnu.org/copyleft/fdl.html 1 1. Introducci´on De forma general para mantener la seguridad de los activos de informaci´on se deben preservar las caracter´ısticas siguientes [1]. 1. Confidencialidad: s´oloel personal o equipos autorizados pueden acceder a la informaci´on. 2. Integridad: la informaci´on y sus m´etodos de proceso son exactos y completos. -
Cryptographic File Systems
Cryptographic Filesystems Background and Implementations for Linux and OpenBSD Background ● Loop device primer ● Keys, cipher modes, salting, key hashing ● Journaling file systems and encrypted swap ● Offset, sizelimit, hard/soft block size paramters explained ● Issues with software suspend Loopback Primer /dev/hda1 losetup /dev/loop0 myloop.dat /dev/loop0 /dev/hda2 losetup /dev/loop1 \ /dev/hda2 Filesystem with various /dev/loop1 files and directories Loopback Primer G76g(*gF *^tF0OB( 6g)%)f5( /dev/loop0 *&(*6bP( Dear Bob, this is the message ● The loopback device supports cryptographic transforms ● Knowing the key reveals a filesystem within a normal file (or block device) Keys ● Encryption with user supplied key ● Encryption with hashed key – rmd160, sha256, sha384, sha512, ... ● Using multiple keys (typically 64) – every sector (512b) uses different key Basic block cipher modes ● Currently only ECB (Electronic Code Book) and CBC (Cipher Block Chaining) widely supported ● ECB directly encipher plaintext – Same plaintext block always encrypts to same ciphertext. Is considered weak. ● CBC uses the previous block as IV – Basically solves ECB's dictionary problem – Only provides very limited integrity Key iterations and salt ● Key can be hashed 1000 times – significantly slows down brute force attack on password ● Salt is a string appended to the password – slows down brute force attack on password – poor man's two factor authentication Journaling ● Fine on device backed loop device ● Avoid on file backed loop devices – The VM can write -
Cryptographic File Systems Performance: What You Don't Know Can Hurt You Charles P
Cryptographic File Systems Performance: What You Don't Know Can Hurt You Charles P. Wright, Jay Dave, and Erez Zadok Stony Brook University Appears in the proceedings of the 2003 IEEE Security In Storage Workshop (SISW 2003) Abstract interact with disks, caches, and a variety of other com- plex system components — all having a dramatic effect Securing data is more important than ever, yet cryp- on performance. tographic file systems still have not received wide use. In this paper we perform a real world performance One barrier to the adoption of cryptographic file systems comparison between several systems that are used is that the performance impact is assumed to be too high, to secure file systems on laptops, workstations, and but in fact is largely unknown. In this paper we first moderately-sized file servers. We also emphasize multi- survey available cryptographic file systems. Second, programming workloads, which are not often inves- we perform a performance comparison of a representa- tigated. Multi-programmed workloads are becoming tive set of the systems, emphasizing multiprogrammed more important even for single user machines, in which workloads. Third, we discuss interesting and counterin- Windowing systems are often used to run multiple appli- tuitive results. We show the overhead of cryptographic cations concurrently. We expect cryptographic file sys- file systems can be minimal for many real-world work- tems to become a commodity component of future oper- loads, and suggest potential improvements to existing ating systems. systems. We have observed not only general trends with We present results from a variety of benchmarks, an- each of the cryptographic file systems we compared but alyzing the behavior of file systems for metadata op- also anomalies based on complex interactions with the erations, raw I/O operations, and combined with CPU operating system, disks, CPUs, and ciphers. -
Linux Networking 101
The Gorilla ® Guide to… Linux Networking 101 Inside this Guide: • Discover how Linux continues its march toward world domination • Learn basic Linux administration tips • See how easy it can be to build your entire network on a Linux foundation • Find out how Cumulus Linux is your ticket to networking freedom David M. Davis ActualTech Media Helping You Navigate The Technology Jungle! In Partnership With www.actualtechmedia.com The Gorilla Guide To… Linux Networking 101 Author David M. Davis, ActualTech Media Editors Hilary Kirchner, Dream Write Creative, LLC Christina Guthrie, Guthrie Writing & Editorial, LLC Madison Emery, Cumulus Networks Layout and Design Scott D. Lowe, ActualTech Media Copyright © 2017 by ActualTech Media. All rights reserved. No portion of this book may be reproduced or used in any manner without the express written permission of the publisher except for the use of brief quotations. The information provided within this eBook is for general informational purposes only. While we try to keep the information up- to-date and correct, there are no representations or warranties, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the information, products, services, or related graphics contained in this book for any purpose. Any use of this information is at your own risk. ActualTech Media Okatie Village Ste 103-157 Bluffton, SC 29909 www.actualtechmedia.com Entering the Jungle Introduction: Six Reasons You Need to Learn Linux ....................................................... 7 1. Linux is the future ........................................................................ 9 2. Linux is on everything .................................................................. 9 3. Linux is adaptable ....................................................................... 10 4. Linux has a strong community and ecosystem ........................... 10 5. -
Hello Marte OS Using an Emulator Daniel Sangorrin [email protected]
Hello MaRTE OS using an emulator Daniel Sangorrin [email protected] 2009-3-4 Revision History Revision 1.3 2009-3-4 Revised by: dsl Add mtools for mounting the images. Update installation instructions referencing INSTALL file. Revision 1.2 2007-6-15 Revised by: dsl Added the process to create a FAT16 image file for QEMU Revision 1.1 2007-6-9 Revised by: dsl Updated to MaRTE OS v1.6 snapshot This document tries to introduce people to MaRTE OS in a very simple way. Table of Contents 1. Preface........................................................................................................................................................................2 1.1. Feedback.........................................................................................................................................................2 2. Let’s see MaRTE OS running!.................................................................................................................................2 2.1. Install the emulator QEMU............................................................................................................................2 2.2. ...and run these MaRTE OS Demos! ..............................................................................................................2 3. Hello MaRTE! ...........................................................................................................................................................3 3.1. The compiler GNAT-GPL ..............................................................................................................................3 -
Linux Based Live CD on Optical Disks
Pobrane z czasopisma Annales AI- Informatica http://ai.annales.umcs.pl Data: 26/09/2021 15:23:08 Annales UMCS Annales UMCS Informatica AI 5 (2006) 29-36 Informatica Lublin-Polonia Sectio AI http://www.annales.umcs.lublin.pl/ Linux based Live CD on optical disks 1 2* Michał Chromiak , Andrzej Góźdź 1Institute of Mathematics, Maria Curie-Skłodowska University, Pl. M.Curie-Skłodowskiej 1, 20-031 Lublin, Poland 2Institute of Physics, Maria Curie-Skłodowska University, Pl. M.Curie-Skłodowskiej 1, 20-031 Lublin, Poland Abstract We present an introduction to LiveCD system remastering based on a prospective UnionFS filesystem. 1. Introduction Regarding increasing popularity of the LiveCD distributions1 of a Linux system we compile the essential knowledge of how the LiveCD works (based on many rather scattered documents [1-8]) to facilitate preparation of the specialized distributions of systems based on this idea. We describe one of the most efficient ways of system architecture managing using UnionFS. All steps of the procedure were tested using laptops which have often more exotic hardware than desktopUMCS computers. The possibility of booting a PC from a CD/DVD ROM has raised several possibilities, including the most important one, namely, the possibility of running the required system or programs independently of the actual operational system, configuration, and resources of the PC. The self-configuring CD/DVD ROMs can be also useful for administrative purposes and as the rescue disks. The LiveCD distributions allow for cheap and effective use of the PCs as the special servers, routers and other active elements over the network. This idea of the LiveCD systems is based on the possibility opened by the El Torito extension to the standard ISO 9660 system and the Linux kernel capabilities. -
Practical Practical
PRACTICAL PRACTICAL GPLCOMPLIANCE GPLCOMPLIANCE A GUIDE FOR STARTUPS, SMALL ABUSINESSES GUIDE FOR STARTUPS, AND ENGINEERS SMALL BUSINESSES AND ENGINEERS ARMIJN HEMEL, MSC AND SHANE COUGHLAN ARMIJN HEMEL, MSC AND SHANE COUGHLAN Copyright © 2017 Linux Foundation All rights reserved. This book or any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of the publisher except for the use of brief quotations in a book review and certain other noncommercial uses permitted by copyright law. Printed in the United States of America First Edition, 2017 ISBN: 978-0-9989078-0-2 1 Letterman Drive Building D Suite D4700 San Francisco CA 94129 Phone/Fax: +1 415 723 9709 https://linuxfoundation.org About the Authors Shane Coughlan Shane Coughlan is an expert in communi- cation, security, and business development. His professional accomplishments include spearheading the licensing team that elevated Open Invention Network into the largest patent non-aggression community in history, establishing the leading professional network of open source legal experts, and aligning stakeholders to launch both the first law journal and the first law book dedicated to open source. He currently leads the OpenChain community as Program Manager. Shane has extensive knowledge of open source governance, internal process development, supply chain management, and community building. His experience includes engagement with the enterprise, embedded, mobile, and automotive industries. Armijn Hemel Armijn Hemel is the owner of Tjaldur Software Governance Solutions. He is an active re- searcher of and internationally recognized expert in open source license compliance and supply chain management. He studied computer science at Utrecht University in The Netherlands, where he pioneered reproducible builds with NixOS.