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.
Attribute-based access control (ABAC) @cite_12 broadened the conception of roles into attributes compared to role-based access control (RBAC) @cite_0 . Extensible Access Control Markup Language (XACML), proposed in @cite_13 by OASIS, is primarily based on the ABAC model by defining structural elements such as Rule , Policy and Policy Set . Combining algorithms like deny-overrides and permit-overrides are also provided to resolve conflicts between rules or policies. XACML has specified the whole architecture about the supporting entities like PEP, PDP, PIP and the exchanging structures between those entities.
@cite_0 @cite_13 @cite_12
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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. 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. A widely adopted security mechanism is the specification of access control policies by means of the XACML language. In this paper, we propose a framework, called X-CREATE, for the systematic generation of test inputs (XACML requests). Differently from existing tools, XCREATE exploits the XACML Context Schema. In particular, the tool applies a XML-based methodology (XPT) to systematically produce a set of intermediate instances, covering the XACML Context Schema. Moreover, for request generation, X-CREATE applies a procedure for parsing the policy under test and assigning values to the generated intermediate instances. The aim of the proposed framework is twofold: testing of policy evaluation engines and testing of access control policies. The experimental results show that the fault detection effectiveness of X-CREATE is similar or higher than that of existing approaches. Access control policies in distributed systems, particularly implemented in the XACML standard language, are increasingly complex. Faults may exist in complex policies for various reasons such as misunderstanding of the access control requirements, omissions, and coding errors. These faults, if not removed before deployment, may lead to unauthorized accesses or denial of service. Manual localization of these faults, however, can be a challenging task. Inspired by spectrum-based fault localization for software debugging, this paper presents an approach for automatically localizing the fault(s) in a given XACML policy by exploring test coverage information of the policy elements. We investigate two test coverage criteria (i.e., reachability and firing) of policy elements and 14 scoring methods for ranking policy elements to determine the fault location(s). To evaluate the fault localization methods, we have used real-world policy files with different levels of complexity and a large number of policy mutants with one or two seeded faults. The experiment results show that the firing-based Naish2 and CBI-Inc methods are effective in fault localization of XACML policies.