532 research outputs found

    A Generic Checkpoint-Restart Mechanism for Virtual Machines

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    It is common today to deploy complex software inside a virtual machine (VM). Snapshots provide rapid deployment, migration between hosts, dependability (fault tolerance), and security (insulating a guest VM from the host). Yet, for each virtual machine, the code for snapshots is laboriously developed on a per-VM basis. This work demonstrates a generic checkpoint-restart mechanism for virtual machines. The mechanism is based on a plugin on top of an unmodified user-space checkpoint-restart package, DMTCP. Checkpoint-restart is demonstrated for three virtual machines: Lguest, user-space QEMU, and KVM/QEMU. The plugins for Lguest and KVM/QEMU require just 200 lines of code. The Lguest kernel driver API is augmented by 40 lines of code. DMTCP checkpoints user-space QEMU without any new code. KVM/QEMU, user-space QEMU, and DMTCP need no modification. The design benefits from other DMTCP features and plugins. Experiments demonstrate checkpoint and restart in 0.2 seconds using forked checkpointing, mmap-based fast-restart, and incremental Btrfs-based snapshots

    KVM Based Virtualization and Remote Management

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    In the recent past, cloud computing is the most significant shifts and Kernel Virtual Machine (KVM) is the most commonly deployed hypervisor which are used in the IaaS layer of the cloud computing systems. The Hypervisor is the one which provides the complete virtualization environment which will intend to virtualize as much as hardware and systems which will include the CPUs, Memory, network interfaces and so on. Because of the virtualization technologies such as the KVM and others such as ESXi, there has been a significant decrease in the usage if the resources and decrease in the costs involved. Firstly, in this Paper I will be discussing about the different hypervisors that are used for the virtualization of the systems, then I discuss about how the virtualization using the Kernel Virtual Machine (KVM) is made easy, and then discuss about the Host security, the access and the security of the KVM virtual machines by the remote management using the Secure Sell (SSH) tunnels, Simple Authentication and Secure Layer (SASL) authentication and Transport Layer Security (TLS)

    HyBIS: Windows Guest Protection through Advanced Memory Introspection

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    Effectively protecting the Windows OS is a challenging task, since most implementation details are not publicly known. Windows has always been the main target of malwares that have exploited numerous bugs and vulnerabilities. Recent trusted boot and additional integrity checks have rendered the Windows OS less vulnerable to kernel-level rootkits. Nevertheless, guest Windows Virtual Machines are becoming an increasingly interesting attack target. In this work we introduce and analyze a novel Hypervisor-Based Introspection System (HyBIS) we developed for protecting Windows OSes from malware and rootkits. The HyBIS architecture is motivated and detailed, while targeted experimental results show its effectiveness. Comparison with related work highlights main HyBIS advantages such as: effective semantic introspection, support for 64-bit architectures and for latest Windows (8.x and 10), advanced malware disabling capabilities. We believe the research effort reported here will pave the way to further advances in the security of Windows OSes

    Security challenges with virtualization

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    Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2009Virtualização é uma palavra em voga no mundo das tecnologias de informação. Com a promessa de reduzir o constante crescimento das infra-estruturas informáticas dentro de um centro de processamento de dados, aliado a outros aspectos importantes como disponibilidade e escalabilidade, as tecnologias de virtualização têm vindo a ganhar popularidade, não só entre os profissionais de tecnologias de informação mas também administradores e directores. No entanto, o aumento da adopção do uso desta tecnologia expõe o sistema a novas preocupações de segurança que normalmente são negligenciadas. Esta tese apresenta o estado da arte das soluções actualmente mais usadas de virtualização de servidores e também um estudo literário dos vários problemas de segurança das tecnologias de virtualização. Estes problemas não são específicos em termos de produto, e são abordados no âmbito de tecnologias de virtualização. No entanto, nesta tese é feita uma análise de vulnerabilidades de duas das mais conhecidas soluções de virtualização: Vmware EXS e Xen. No final, são descritas algumas soluções para melhorar a segurança de acesso a banco online e de comercio electrónico, usando virtualização.Virtualization is a hype word in the IT world. With the promise to reduce the ever-growing infrastructure inside data centers allied to other important concerns such as availability and scalability, virtualization technology has been gaining popularity not only with IT professionals but also among administrators and directors as well. The increasingly rising rate of the adoption of this technology has exposed these systems to new security concerns which in recent history have been ignored or simply overlooked. This thesis presents an in depth state of art look at the currently most used server virtualization solutions, as well as a literature study on various security issues found within this virtualization technology. These issues can be applied to all the current virtualization technologies available without focusing on a specific solution. However, we do a vulnerability analysis of two of the most known virtualization solutions: VMware ESX and Xen. Finally, we describe some solutions on how to improve the security of online banking and e-commerce, using virtualization

    Holistic debugging - enabling instruction set simulation for software quality assurance

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    We present holistic debugging, a novel method for observing execution of complex and distributed software. It builds on an instruction set simulator, which provides reproducible experiments and non-intrusive probing of state in a distributed system. Instruction set simulators, however, only provide low-level information, so a holistic debugger contains a translation framework that maps this information to higher abstraction level observation tools, such as source code debuggers. We have created Nornir, a proof-of-concept holistic debugger, built on the simulator Simics. For each observed process in the simulated system, Nornir creates an abstraction translation stack, with virtual machine translators that map machine-level storage contents (e.g. physical memory, registers) provided by Simics, to application-level data (e.g. virtual memory contents) by parsing the data structures of operating systems and virtual machines. Nornir includes a modified version of the GNU debugger (GDB), which supports non-intrusive symbolic debugging of distributed applications. Nornir's main interface is a debugger shepherd, a programmable interface that controls multiple debuggers, and allows users to coherently inspect the entire state of heterogeneous, distributed applications. It provides a robust observation platform for construction of new observation tools

    Privacy in cloud computing

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    Tese de mestrado em Segurança Informática, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2010O paradigma cloud computing está progressivamente a integrar-se nas tecnologias de informação e é também visto por muitos como a próxima grande viragem na indústria da computação. A sua integração significa grandes alterações no modo como olhamos para a segurança dos dados de empresas que decidem confiar informação confidencial aos fornecedores de serviços cloud. Esta alteração implica um nível muito elevado de confiança no fornecedor do serviço. Ao mudar para a cloud, uma empresa relega para o fornecedor do serviço controlo sobre os seus dados, porque estes vão executar em hardware que é propriedade do fornecedor e sobre o qual a empresa não tem qualquer controlo. Este facto irá pesar muito na decisão, de mudar para a cloud, de empresas que tratam informação delicada (p.ex., informação médica ou financeira). Neste trabalho propomos demonstrar de que forma um administrador malicioso, com acesso ao hardware do fornecedor, consegue violar a privacidade dos dados que o utilizador da cloud confiou ao prestador desses serviços. Definimos como objectivo uma análise detalhada de estratégias de ataque que poderão ajudar um administrador malicioso a quebrar a privacidade de clientes da cloud, bem como a eficácia demonstrada contra esses mesmos ataques por mecanismos de protecção já propostos para a cloud. Pretendemos que este trabalho seja capaz de alertar a comunidade científica para a gravidade dos problemas de segurança que actualmente existem na cloud e, que ao mesmo tempo, sirva como motivação para uma acção célere desta, de forma a encontrar soluções para esses problemas.The paradigm of cloud computing is progressively integrating itself in the Information Technology industry and it is also seen by many experts as the next big shift in this industry. This integration implies considerable alterations in the security schemes used to ensure that the privacy of confidential information, companies entrust to the cloud provider, is kept. It also means that the level of trust in the cloud provider must be considerably high. When moving to the cloud, a company relinquishes control over its data to the cloud provider. This happens because, when operating in the cloud, the data is going to execute on top of the hardware owned by the cloud provider and, in this scenario, the client has no control over that hardware. Companies that deal with sensitive data (e.g., medical or financial records) have to weigh the importance of this problem when considering moving their data to the cloud. In this work, we provide a demonstration of how a malicious administrator, with access to the hardware of the cloud provider, is capable of violating the privacy of the data entrusted to the cloud provider by his clients. Our objective is to offer a detailed analysis of attack strategies that can be used by a malicious administrator to break the privacy of cloud clients, as well as the level of efficacy demonstrated by some protection mechanism that have already been proposed for the cloud. We also hope that this work is capable of capturing the attention of the research community to the security problems existent in the cloud and, that at the same time, it works as a motivation factor for a prompt action in order to find solutions for these problems

    Checkpointing as a Service in Heterogeneous Cloud Environments

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    A non-invasive, cloud-agnostic approach is demonstrated for extending existing cloud platforms to include checkpoint-restart capability. Most cloud platforms currently rely on each application to provide its own fault tolerance. A uniform mechanism within the cloud itself serves two purposes: (a) direct support for long-running jobs, which would otherwise require a custom fault-tolerant mechanism for each application; and (b) the administrative capability to manage an over-subscribed cloud by temporarily swapping out jobs when higher priority jobs arrive. An advantage of this uniform approach is that it also supports parallel and distributed computations, over both TCP and InfiniBand, thus allowing traditional HPC applications to take advantage of an existing cloud infrastructure. Additionally, an integrated health-monitoring mechanism detects when long-running jobs either fail or incur exceptionally low performance, perhaps due to resource starvation, and proactively suspends the job. The cloud-agnostic feature is demonstrated by applying the implementation to two very different cloud platforms: Snooze and OpenStack. The use of a cloud-agnostic architecture also enables, for the first time, migration of applications from one cloud platform to another.Comment: 20 pages, 11 figures, appears in CCGrid, 201
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