Publications

2012
J. Mickens and M. Finifter, “Jigsaw: Efficient, Low-effort Mashup Isolation,” in USENIX WebApps, Boston, MA, 2012. PaperAbstract

A web application often includes content from a variety of origins. Securing such a mashup application is challenging because origins often distrust each other and wish to expose narrow interfaces to their private code and data. Jigsaw is a new framework for isolating these mashup components. Jigsaw is an extension of the JavaScript language that can be run inside standard browsers using a Jigsaw-to-JavaScript compiler. Unlike prior isolation schemes that require developers to specify complex, error-prone policies, Jigsaw leverages the well-understood public/private keywords from traditional object-oriented languages, making it easy for a domain to tag internal data as externally visible. Jigsaw provides strong iframe-like isolation, but unlike previous approaches that use actual iframes as isolation containers, Jigsaw allows mutually distrusting code to run inside the same frame; this allows scripts to share state using synchronous method calls instead of asynchronous message passing. Jigsaw also introduces a novel encapsulation mechanism called surrogates. Surrogates allow domains to safely exchange objects by reference instead of by value. This improves sharing efficiency by eliminating cross-origin marshaling overhead.

J. Mickens, “Rivet: Browser-agnostic Remote Debugging for Web Applications,” in USENIX ATC, Boston, MA, 2012. PaperAbstract

Rivet is the first fully-featured, browser-agnostic remote debugger for web applications. Using Rivet, developers can inspect and modify the state of live web pages that are running inside unmodified end-user web browsers. This allows developers to explore real application bugs in the context of the actual machines on which those bugs occur. To make an application Rivet-aware, developers simply add the Rivet JavaScript library to the client-side portion of the application. Later, when a user detects a problem with the application, the user informs Rivet; in turn, Rivet pauses the application and notifies a remote debug server that a debuggable session is available. The server can launch an interactive debugger front-end for a human developer, or use Rivet’s live patching mechanism to automatically install a fix on the client or run diagnostics for offline analysis. Experiments show that Rivet imposes negligible overhead during normal application operation. At debug time, Rivet’s network footprint is small, and Rivet is computationally fast enough to support non-trivial diagnostics and live patches.

2011
J. Mickens and M. Dhawan, “Atlantis: Robust, Extensible Execution Environments for Web Applications,” in SOSP, Cascais, Portugal, 2011. PaperAbstract

Today’s web applications run inside a complex browser environment that is buggy, ill-specified, and implemented in different ways by different browsers. Thus, web applications that desire robustness must use a variety of conditional code paths and ugly hacks to deal with the vagaries of their runtime. Our new exokernel browser, called Atlantis, solves this problem by providing pages with an extensible execution environment. Atlantis defines a narrow API for basic services like collecting user input, exchanging network data, and rendering images. By composing these primitives, web pages can define custom, high-level execution environments. Thus, an application which does not want a dependence on Atlantis’ predefined web stack can selectively redefine components of that stack, or define markup formats and scripting languages that look nothing like the current browser runtime. Unlike prior microkernel browsers like OP, and unlike compile-to-JavaScript frameworks like GWT, Atlantis is the first browsing system to truly minimize a web page’s dependence on black box browser code. This makes it much easier to develop robust, secure web applications.

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