Architectures for Inlining Security Monitors in Web Applications

Abstract

Abstract. Securing JavaScript in the browser is an open and challenging problem. Code from pervasive third-party JavaScript libraries exacerbates the problem because it is executed with the same privileges as the code that uses the libraries. An additional complication is that the different stakeholders have different interests in the security policies to be enforced in web applications. This paper focuses on securing JavaScript code by inlining security checks in the code before it is executed. We achieve great flexibility in the deployment options by considering security monitors implemented as security-enhanced JavaScript interpreters. We propose architectures for inlining security monitors for JavaScript: via browser extension, via web proxy, via suffix proxy (web service), and via integrator. Being parametric in the monitor itself, the architectures provide freedom in the choice of where the monitor is injected, allowing to serve the interests of the different stake holders: the users, code developers, code integrators, as well as the system and network administrators. We report on experiments that demonstrate successful deployment of a JavaScript information-flow monitor with the different architectures.

Monitoring of Client-Cloud Interaction

“…For example, a suffix proxy for domain suffix.org could offer the services of google.com transparently over domain google.com.suffix.org. A suffix proxy can observe and modify complete web requests and responses for monitoring purposes, and a use case is JavaScript code instrumentation for adding security controls [115]. Furthermore, a suffix proxy can access encrypted HTTPS communication when SSL/TLS client authentication is not performed.…”

“…Today's SaaS delivery models often rely on web technology, and web mashups are a popular approach to achieve composition and JavaScript code reuse [57,174]. An example for an integration-driven monitoring in mashups is to instrument untrusted third-party JavaScript code [115].…”

“…Suffix proxy. For web-based applications, a suffix proxy [115] is similar to a forward proxy: it acts as a middle man between client and service by forwarding client requests and gathering service responses. Contrary to traditional web proxies, a suffix proxy exploits the hierarchical naming scheme in the Domain Name System (DNS) to transparently and dynamically re-host existing services under a different DNS host name.…”

“…A web proxy is a networked software component that acts as a middle man. It forwards web requests and responses between a client and a service and eventually takes corrective actions by filtering or modifying content [98,115]. Proxy architectures are popular for the Hypertext Transfer Protocol (HTTP) used in today's web applications and services.…”

Correct Software in Web Applications and Web Services

“…Our research is focused on providing a client-centric identity meta-system which allows a client to maintain a private identity directory while offering individual users automatic authentication to cloud-based services via a single sign-on, privacyenhanced service. In the paper [115], we have introduced the concept of an identity management machine (IdMM), an ASM-based, client-centric, single sign-on tool for small and medium enterprises that want to adopt or migrate to cloud-based services. This concept has been further refined in the paper [116] where we described the architecture of the IdMM.…”