Flexible Control of Downloaded Executable Content

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We present a security architecture that enables system and application access control requirements to be enforced on applications composed from downloaded executable content. Downloaded executable content consists of messages downloaded from remote hosts that contain executables that run, upon receipt, on the downloading principal's machine. Unless restricted, this content can perform malicious actions, including accessing its downloading principal's private data and sending messages on this principal's behalf. Current security architectures for controlling downloaded executable content (e.g., JDK 1.2) enable specification of access control requirements for content-based on its provider and identity. Since these access control requirements must cover every legal use of the class, they may include rights that are not necessary for a particular application of content. Therefore, using these systems, an application composed from downloaded executable content cannot enforce its access control requirements without the addition of application-specific security mechanisms. In this paper, we define an access control model with the following properties: (1) system administrators can define system access control requirements on applications and (2) application developers can use the same model to enforce application access control requirements without the need for ad hoc security mechanisms. This access control model uses features of role-based access control models to enable (1) specification of a single role that applies to multiple application instances; (2) selection of a content's access rights based on the content's application and role in the application; (3) consistency maintained between application state and content access rights; and (4) control of role administration. We detail a system architecture that uses this access control model to implement secure collaborative applications. Lastly, we describe an implementation of this architecture, called the Lava security architecture. © 1999, ACM. All rights reserved.