Access control is an important component for web services such as a cloud. Current clouds tend to design the access control mechanism together with the policy language on their own. It leads to two issues: (i) a cloud user has to learn different policy languages to use multiple clouds, and (ii) a cloud service provider has to customize an authorization mechanism based on its business requirement, which brings high development cost. In this work, a new access control policy language called PERM modeling language (PML) is proposed to express various access control models such as access control list (ACL), role-based access control (RBAC) and attribute-based access control (ABAC), etc. PML's enforcement mechanism is designed in an interpreter-on-interpreter manner, which not only secures the authorization code with sandboxing, but also extends PML to all programming languages that support Lua. PML is already adopted by real-world projects such as Intel's RMD, VMware's Dispatch, Orange's Gobis and so on, which proves PML's usability. The performance evaluation on OpenStack, CloudStack and Amazon Web Services (AWS) shows PML's enforcement overhead per request is under 5.9us.
The work proposed in @cite_16 by , has defined a formal ABAC specification suitable for infrastructure as a service (IaaS) and implemented it in OpenStack. It includes two models: the operational model @math and the administrative model @math , which provide fine-grained access control for tenants. However, this work does not support external functions or decision combination, which limits its flexibility to express a customized model.
@cite_16
1992204376 2749040653 202035697 2412660217
Cloud Infrastructure as a Service (IaaS), where traditional IT infrastructure resources such as compute, storage and networking are owned by a cloud service provider (CSP) and offered as on-demand virtual resources to customers (tenants), is the fastest maturing service model in cloud computing. The transformation of physical resources into virtual offers great flexibility to CSP customers including network based remote collaborative administration. This flexibility can be fully availed only if complemented by commensurately flexible access control to the customers remote IT resources by the customer's IT users. Since customer policies in this regard can vary greatly, the CSP needs a flexible model to accommodate diverse policy requirements. In this paper, we investigate attribute-based access control (ABAC) in cloud IaaS. In ABAC, access requests are evaluated based on the attributes of cloud tenant users and those of objects such as virtual machines, storage volumes, networks, etc. We investigate the access control models supported by commercial IaaS providers such as Amazon AWS and opensource OpenStack, as well as other models in the literature, which mostly use role-based access control (RBAC). We demonstrate their limitations and motivate the need for ABAC support to realize the true potential of IaaS. Building on prior published ABAC models we define a formal ABAC model suitable for IaaS. As proof-of-concept we implement this model in OpenStack, a widely-used open source cloud IaaS software platform. We discuss enforcement alternatives in this context and partially evaluate their performance. This document provides Federal agencies with a definition of attribute based access control (ABAC). ABAC is a logical access control methodology where authorization to perform a set of operations is determined by evaluating attributes associated with the subject, object, requested operations, and, in some cases, environment conditions against policy, rules, or relationships that describe the allowable operations for a given set of attributes. This document also provides considerations for using ABAC to improve information sharing within organizations and between organizations while maintaining control of that information. The ubiquity of the Internet has led to increased resource sharing between large numbers of users in widely-disparate administrative domains. Unfortunately, traditional identity-based solutions to the authorization problem do not allow for the dynamic establishment of trust, and thus cannot be used to facilitate interactions between previously-unacquainted parties. Furthermore, the management of identity-based systems becomes burdensome as the number of users in the system increases. To address this gap between the needs of open computing systems and existing authorization infrastructures, researchers have begun to investigate novel attribute-based access control (ABAC) systems based on techniques such as trust negotiation and other forms of distributed proving. To date, research in these areas has been largely theoretical and has produced many important foundational results. However, if these techniques are to be safely deployed in practice, the systems-level barriers hindering their adoption must be overcome. In this thesis, we show that safely and securely adopting decentralized ABAC approaches to authorization is not simply a matter of implementation and deployment, but requires careful consideration of both formal properties and practical issues. To this end, we investigate a progression of important questions regarding the safety analysis, deployment, implementation, and optimization of these types of systems. We first show that existing ABAC theory does not properly account for the asynchronous nature of open systems, which allows attackers to subvert these systems by forcing decisions to be made using inconsistent system states. To address this, we develop provably-secure and lightweight consistency enforcement mechanisms suitable for use in trust negotiation and distributed proof systems. We next focus on deployment issues, and investigate how user interactions can be audited in the absence of concrete user identities. We develop the technique of virtual fingerprinting, which can be used to accomplish this task without adversely affecting the scalability of audit systems. Lastly, we present TrustBuilder2, which is the first fully-configurable framework for trust negotiation. Within this framework, we examine availability problems associated with the trust negotiation process and develop a novel approach to policy compliance checking that leverages an efficient pattern-matching approach to outperform existing techniques by orders of magnitude. Attribute-based access control (ABAC) has attracted considerable interest in recent years, resulting in an extensive literature on the subject, including the standardized XML-based language XACML. ABAC policies written in languages like XACML have a tree-like structure in which leaf nodes are associated with authorization decisions and non-leaf nodes are associated with decision-combining algorithms. In this paper, we consider the expressive power of the rule- and policy-combining algorithms defined by the XACML standard. In particular, we identify unexpected dependencies between the combining algorithms and demonstrate that there exist useful combining algorithms that cannot be expressed by any combination of XACML combining algorithms. We briefly discuss the decision operators defined in the PTaCL language, an abstract language for defining ABAC policies, and the advantages of replacing the XACML combining algorithms with the PTaCL operators. Following this, we review results in the literature on multi-valued logic and introduce the notion of canonically complete policy languages. We discuss important practical advantages of canonically complete policy languages, primarily in simplifying policy specification and providing efficiently enforceable policies. Finally, we propose a new policy authorization language PTaCL which is canonically complete and show it is capable of expressing any arbitrary policy in a normal form and discuss the advantages of using PTaCL over existing policy languages such as XACML and PTaCL.