Securing Commercial Operating Systems
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NSA Security-Enhanced Linux (Selinux)
Integrating Flexible Support for Security Policies into the Linux Operating System http://www.nsa.gov/selinux Stephen D. Smalley [email protected] Information Assurance Research Group National Security Agency ■ Information Assurance Research Group ■ 1 Outline · Motivation and Background · What SELinux Provides · SELinux Status and Adoption · Ongoing and Future Development ■ Information Assurance Research Group ■ 2 Why Secure the Operating System? · Information attacks don't require a corrupt user. · Applications can be circumvented. · Must process in the clear. · Network is too far. · Hardware is too close. · End system security requires a secure OS. · Secure end-to-end transactions requires secure end systems. ■ Information Assurance Research Group ■ 3 Mandatory Access Control · A ªmissing linkº of security in current operating systems. · Defined by three major properties: ± Administratively-defined security policy. ± Control over all subjects (processes) and objects. ± Decisions based on all security-relevant information. ■ Information Assurance Research Group ■ 4 Discretionary Access Control · Existing access control mechanism of current OSes. · Limited to user identity / ownership. · Vulnerable to malicious or flawed software. · Subject to every user©s discretion (or whim). · Only distinguishes admin vs. non-admin for users. · Only supports coarse-grained privileges for programs. · Unbounded privilege escalation. ■ Information Assurance Research Group ■ 5 What can MAC offer? · Strong separation of security domains · System, application, and data integrity · Ability to limit program privileges · Processing pipeline guarantees · Authorization limits for legitimate users ■ Information Assurance Research Group ■ 6 MAC Implementation Issues · Must overcome limitations of traditional MAC ± More than just Multi-Level Security / BLP · Policy flexibility required ± One size does not fit all! · Maximize security transparency ± Compatibility for applications and existing usage. -
Spf Based Selinux Operating System for Multimedia Applications
International Journal of Reviews in Computing st 31 December 2011. Vol. 8 IJRIC © 2009 - 2011 IJRIC & LLS. All rights reserved. ISSN: 2076-3328 www.ijric.org E-ISSN: 2076-3336 SPF BASED SELINUX OPERATING SYSTEM FOR MULTIMEDIA APPLICATIONS 1NITISH PATHAK, 2NEELAM SHARMA 1BVICAM, GGSIPU, Delhi, India 2Department of Information Technology, Maharaja Agrasen Institute of Technology, Delhi, India E-mail: [email protected], [email protected] ABSTRACT Trusted Operating Systems, offer a number of security mechanisms that can help protect information, make a system difficult to break into, and confine attacks far better than traditional operating systems. However, this security will come at a cost, since it can degrade the performance of an operating system. This performance loss is one of the reasons why Trusted Operating Systems have not become popular. While Trusted Operating Systems offer an incredible amount of security, observations about computing workloads suggest that only some parts of the operating system security are actually necessary. Web servers are the best example. For many web servers, the majority of the information on the server is publicly readable and available on the Internet. Therefore, if a Trusted Operating System is used on a web server, any security used to secure the confidentiality of the server’s information is not necessary. Any security used to protect the confidentiality of web server data can be considered a waste of computational resources. The security needed in web servers is the security to protect the integrity of data, not the confidentiality of data. Other workloads such as multimedia or database workloads may also only need parts of the operating system security. -
Inspecting Data from the Safety of Your Trusted Execution Environment
Inspecting data from the safety of your trusted execution environment John Williams johnwwil [at] u.washington.edu June, 2015 Abstract: This paper presents a proof of concept that uses ARM TrustZone to perform introspection of a Linux kernel running in the normal world from within a secure-world system. Techniques from existing volatile-memory analysis applications are repurposed for application in real-time through asynchronous introspection of the normal world. The solution presented here leverages open-source software that is actively being developed to support additional architectures. 1 INTRODUCTION As technology becomes more prevalent in our day-to-day lives, we increasingly rely on mobile devices for both business and personal purposes. Emerging security threats, such as rootkits that can scan memory for protected PCI information, have been responsible for large-scale breaches. It has been predicted that targeted exploit kits and attack services will soon exist for mobile platforms, which could enable the exploitation of mobile devices on an unprecedented scale [1]. Techniques for mitigating such threats to mobile devices have largely evolved in parallel with industry demand for them. While some companies have indeed made progress through continued addition of product features that increase the security of devices, other companies have simply pivoted their marketing efforts to emphasize or recast certain aspects of their existing capabilities. In order to select the right products and features for protecting sensitive data and activities, effective segmentation is key. While segmentation within devices has traditionally been implemented at the operating system level, in recent years architectural modification at the chip level has emerged as a way to provide hard segmentation between execution environments. -
Leveraging ARM Trustzone and Verifiable Computing to Provide Auditable Mobile Functions Nuno O
Leveraging ARM TrustZone and Verifiable Computing to Provide Auditable Mobile Functions Nuno O. Duarte Sileshi Demesie Yalew INESC-ID / IST, University of Lisbon KTH Royal Institute of Technology [email protected] [email protected] Nuno Santos Miguel Correia INESC-ID / IST, University of Lisbon INESC-ID / IST, University of Lisbon [email protected] [email protected] ABSTRACT 1 INTRODUCTION The increase of personal data on mobile devices has been fol- For over 30 years [5], an important problem that has fasci- lowed by legislation that forces service providers to process nated the research community is about trusting the result of and maintain users’ data under strict data protection policies. computations performed on untrusted platforms. Since the In this paper, we propose a new primitive for mobile applica- advent of cloud computing, this interest has further grown tions called auditable mobile function (AMF) to help service in obtaining proofs of code execution on untrusted clouds. providers enforcing such policies by enabling them to process An approach to address this problem that has garnered sensitive data within users’ devices and collecting proofs of particular attention is verifiable computing. At a high-level, function execution integrity. We present SafeChecker, a com- verifiable computing consists of studying how a prover can putation verification system that provides mobile application convince a verifier of a mathematical assertion. The main support for AMFs, and evaluate the practicality of different obstacle faced by this field has been practicality, as the costs usage scenario AMFs on TrustZone-enabled hardware. of computing and verifying proofs over general computa- tions tend to be very high [21]. -
Looking Back: Addendum
Looking Back: Addendum David Elliott Bell Abstract business environment produced by Steve Walker’s Com- puter Security Initiative.3 The picture of computer and network security painted in What we needed then and what we need now are “self- my 2005 ACSAC paper was bleak. I learned at the con- less acts of security” that lead to strong, secure commercial ference that the situation is even bleaker than it seemed. products.4 Market-driven self-interest does not result in al- We connect our most sensitive networks to less-secure net- truistic product decisions. Commercial and government ac- works using low-security products, creating high-value tar- quisitions with tight deadlines are the wrong place to ex- gets that are extremely vulnerable to sophisticated attack or pect broad-reaching initiatives for the common good. Gov- subversion. Only systems of the highest security are suffi- ernment must champion selfless acts of security separately cient to thwart such attacks and subversions. The environ- from acquisitions. ment for commercial security products can be made healthy again. 3 NSA Has the Mission In 1981, the Computer Security Evaluation Center was 1 Introduction established at the National Security Agency (NSA). It was charged with publishing technical standards for evaluating In the preparation of a recent ACSAC paper [1], I con- trusted computer systems, with evaluating commercial and firmed my opinion that computer and network security is in GOTS products, and with maintaining an Evaluated Prod- sad shape. I also made the editorial decision to soft-pedal ucts List (EPL) of products successfully evaluated. NSA criticism of my alma mater, the National Security Agency. -
Trusted Computing Serving an Anonymity Service
Trusted Computing Serving an Anonymity Service Alexander Böttcher Bernhard Kauer Hermann Härtig Technische Universität Dresden Department of Computer Science Operating Systems Group {boettcher, kauer, haertig}@os.inf.tu-dresden.de Abstract [15] in the authors’ group, will show. An unknown crim- inal to be investigated was supposed to use an anonymity We leveraged trusted computing technology to service. The police and later on the German Federal Bu- counteract certain insider attacks. Furthermore, we reau of Criminal Investigation (FBCI) required to investi- show with one of the rare server based scenarios that gate a criminal that uses a known URL. In order to enable an anonymity service can profit from trusted comput- criminal prosecution by a given warrant the software was ing. We based our design on the Nizza Architecture extended to log connection data [6, 5]. This function of [14] with its small kernel and minimal multi-server the anonymity software [3] was used only with a warrant OS. We even avoided Nizza’s legacy container and but without directly notifying the users. After the warrant got a much smaller, robust and hopefully more secure was reversed the FBCI showed up with a delivery warrant system, since we believe that minimizing the trusted for a log record (which were later on reversed illegal [4]), computing base is an essential requirement for trust first at the institute and later on at the institute’s directors into software. private home. This incident shows a whole class of attacks on the 1 Introduction anonymity and more general every computing service. Vendor and providers under constraint can reveal the ser- Anonymity while using the Internet is widely considered vice because of insider knowledge and physical access a legitimate and - for many use cases - essential require- to those services. -
The Nizza Secure-System Architecture
Appears in the proceedings of CollaborateCom 2005, San Jose, CA, USA The Nizza Secure-System Architecture Hermann Härtig Michael Hohmuth Norman Feske Christian Helmuth Adam Lackorzynski Frank Mehnert Michael Peter Technische Universität Dresden Institute for System Architecture D-01062 Dresden, Germany [email protected] Abstract rely on a standard OS (including the kernel) to assure their security properties. The trusted computing bases (TCBs) of applications run- To address the conflicting requirements of complete ning on today’s commodity operating systems have become functionality and the protection of security-sensitive data, extremely large. This paper presents an architecture that researchers have devised system architectures that reduce allows to build applications with a much smaller TCB. It the system’s TCB by running kernels in untrusted mode is based on a kernelized architecture and on the reuse of in a secure compartment on top of a small security kernel; legacy software using trusted wrappers. We discuss the de- security-sensitive services run alongside the OS in isolated sign principles, the architecture and some components, and compartments of their own. This architecture is widely re- a number of usage examples. ferred to as kernelized standard OS or kernelized system. In this paper, we describe Nizza, a new kernelized- system architecture. In the design of Nizza, we set out to answer the question of how small the TCB can be made. 1 Introduction We have argued in previous work that the (hardware and software) technologies needed to build small secure-system Desktop and hand-held computers are used for many platforms have become much more mature since earlier at- functions, often in parallel, some of which are security tempts [8]. -
Reducing TCB Size by Using Untrusted Components — Small Kernels Versus Virtual-Machine Monitors
To be published in Proceedings of the 11th ACM SIGOPS European Workshop, Leuven, Belgium, 2004 Reducing TCB size by using untrusted components — small kernels versus virtual-machine monitors Michael Hohmuth Michael Peter Hermann Hartig¨ Jonathan S. Shapiro Technische Universitat¨ Dresden Johns Hopkins University Department of Computer Science Department of Computer Science Operating Systems Group Systems Research Laboratory hohmuth,peter,haertig ¡ @os.inf.tu-dresden.de [email protected] Abstract tems, such as message passing and memory sharing, the overall size of the TCB (which includes all components an Secure systems are best built on top of a small trusted oper- application relies on) can actually be reduced for a large class ating system: The smaller the operating system, the easier it of applications. can be assured or verified for correctness. Another assumption we address in this paper is that all In this paper, we oppose the view that virtual-machine components on which an application has operational depen- monitors (VMMs) are the smallest systems that provide se- dencies must be in this application’s TCB. This presumption cure isolation because they have been specifically designed leads to the unnecessary inclusion of many (protocol and de- to provide little more than this property. The problem with vice) drivers into the TCB. this assertion is that VMMs typically do not support inter- The basic idea for reducing TCB size is to extract sys- process communication, complicating the use of untrusted tem components from the TCB and consider them as un- components inside a secure systems. trusted without violating the security requirements of user We propose extending traditional VMMs with features for applications. -
Trusted Computer System Evaluation Criteria
DoD 5200.28-STD Supersedes CSC-STD-00l-83, dtd l5 Aug 83 Library No. S225,7ll DEPARTMENT OF DEFENSE STANDARD DEPARTMENT OF DEFENSE TRUSTED COMPUTER SYSTEM EVALUATION CRITERIA DECEMBER l985 December 26, l985 Page 1 FOREWORD This publication, DoD 5200.28-STD, "Department of Defense Trusted Computer System Evaluation Criteria," is issued under the authority of an in accordance with DoD Directive 5200.28, "Security Requirements for Automatic Data Processing (ADP) Systems," and in furtherance of responsibilities assigned by DoD Directive 52l5.l, "Computer Security Evaluation Center." Its purpose is to provide technical hardware/firmware/software security criteria and associated technical evaluation methodologies in support of the overall ADP system security policy, evaluation and approval/accreditation responsibilities promulgated by DoD Directive 5200.28. The provisions of this document apply to the Office of the Secretary of Defense (ASD), the Military Departments, the Organization of the Joint Chiefs of Staff, the Unified and Specified Commands, the Defense Agencies and activities administratively supported by OSD (hereafter called "DoD Components"). This publication is effective immediately and is mandatory for use by all DoD Components in carrying out ADP system technical security evaluation activities applicable to the processing and storage of classified and other sensitive DoD information and applications as set forth herein. Recommendations for revisions to this publication are encouraged and will be reviewed biannually by the National Computer Security Center through a formal review process. Address all proposals for revision through appropriate channels to: National Computer Security Center, Attention: Chief, Computer Security Standards. DoD Components may obtain copies of this publication through their own publications channels. -
Secure Bootstrap Is Not Enough: Shoring up the Trusted Computing Base James Hendricks Leendert Van Doorn Carnegie Mellon University IBM T.J
Proceedings of the Eleventh SIGOPS European Workshop, ACM SIGOPS, Leuven, Belgium, September 2004. Secure Bootstrap is Not Enough: Shoring up the Trusted Computing Base James Hendricks Leendert van Doorn Carnegie Mellon University IBM T.J. Watson Research Center 5000 Forbes Ave 19 Skyline Drive Pittsburgh, PA Hawthorne, NY [email protected] [email protected] Abstract for each bootstrap step before it is executed. For exam- We propose augmenting secure boot with a mechanism ple, the BIOS could verify a public-key signature of the to protect against compromises to field-upgradeable de- disk’s boot sector to ensure its authenticity; the boot sector vices. In particular, secure boot standards should verify could then verify the public-key signature of the OS boot- the firmware of all devices in the computer, not just de- strap code, which could likewise verify the privileged OS vices that are accessible by the host CPU. Modern comput- processes and drivers. Though such an approach would ob- ers contain many autonomous processing elements, such viously not guarantee the security of the OS code, it would as disk controllers, disks, network adapters, and coproces- at least guarantee the authenticity. sors, that all have field-upgradeable firmware and are an A weakness to this approach is that the BIOS in most essential component of the computer system’s trust model. personal computers is writable. One solution is to store Ignoring these devices opens the system to attacks similar the BIOS on a ROM. However, a ROM-based approach to those secure boot was engineered to defeat. -
Trusted Computing Base
Microkernels and L4 Introduction COMP9242 2006/S2 Week 1 cse/UNSW/NICTA WHY MICROKERNELS? MONOLITHIC KERNEL WHY MICROKERNELS? MONOLITHIC KERNEL: • Kernel has access to everything § all optimisations possible § all techniques/mechanisms/concepts implementable WHY MICROKERNELS? MONOLITHIC KERNEL: • Kernel has access to everything § all optimisations possible § all techniques/mechanisms/concepts implementable • Can be extended by simply adding code WHY MICROKERNELS? MONOLITHIC KERNEL: • Kernel has access to everything § all optimisations possible § all techniques/mechanisms/concepts implementable • Can be extended by simply adding code • Cost: Complexity § growing size § limited maintainability cse/UNSW/NICTA COMP9242 2006/S2 W1 P1 MICROKERNEL:IDEA • Small kernel providing core functionality § only code running in privileged mode • Most OS services provided by user-level servers • Applications communicate with servers via message-passing IPC Application syscall user mode VFS IPC, file system Application UNIX Device File Server Driver Server Scheduler, virtual memory kernel IPC mode Device drivers, Dispatcher, ... IPC, virtual memory Hardware Hardware cse/UNSW/NICTA COMP9242 2006/S2 W1 P2 TRUSTED COMPUTING BASE The part of the system which must be trusted to operate correctly TRUSTED COMPUTING BASE The part of the system which must be trusted to operate correctly Application Service Hardware System: traditional embedded TRUSTED COMPUTING BASE The part of the system which must be trusted to operate correctly Application Service Hardware System: -
TC) and Next Generation Secured Computing Base (NGSCB
Trusted Computing (TC) and Next Generation Secured Computing Base (NGSCB) “For years, Bill Gate has dreamed of finding a way to make the Chinese pay for software: TC looks like being the answer to his prayer.” – Ross Anderson [Reference 7] The Trusted Computing (TC) and Next Generation Secured Computing Base (NGSCB) Version 1.0 Spring 2005 Computer Networking Management By: Jianji (Joseph) Yu Jeffrey Khuu Joseph Yu and Jeffrey Khuu Computer Network Management Page 1 of 10 Trusted Computing (TC) and Next Generation Secured Computing Base (NGSCB) Table of Contents 1. Introduction ……………………………………………………………3 Overview 1.1 The Trusted Computing: Trusted Computing Base (TCB) And Trusted Computing Group (TCG) …………………………3 1.2 Next Generation Secured Computing Base (NGSCB) ......…4 2. NGSCB ……………………………………………………………....….5 2.1 Features 2.1.1 Two operating environments ….............………………….…..5 2.1.2 Four features of NGSCB …..……………......………....…...5 2.2 Architecture 2.2.1 Two primary system components in Trusted operating environment ………………...….6 2.2.2 Nexus …………...……………………………………………..7 2.2.3 NCA …………………………..……......…………………………. 7 2.3 NGSCB Summary …………...………….......…………………….8 3. Analysis of NGSCB ……………………………………………9 3.1 The current problematic computing ……………………………9 3.2 Applications ………………………………………………….……….9 3.3 Will NGSCB be the solution? …………………………….………9 4.References …………………………………………………………....10 Joseph Yu and Jeffrey Khuu Computer Network Management Page 2 of 10 Trusted Computing (TC) and Next Generation Secured Computing Base (NGSCB) 1. Introduction Overview 1.1 The Trusted Computing ² Trusted Computing (TC) The term Trusted Computing (TC) means the computer security integrated with hardware and software security components. As Ross Anderson suggested, the original motivation of TC was intended for digital rights management (DRM); that limits the abuse of file sharing over the network and making illegal copies without the authorization from the vendors, perhaps, restrict user's computing actions.