The role of concurrency in an evolutionary view of programming abstractions

In this paper we examine how concurrency has been embodied in mainstream programming languages. In particular, we rely on the evolutionary talking borrowed from biology to discuss major historical landmarks and crucial concepts that shaped the development of programming languages. We examine the general development process, occasionally deepening into some language, trying to uncover evolutionary lineages related to specific programming traits. We mainly focus on concurrency, discussing the different abstraction levels involved in present-day concurrent programming and emphasizing the fact that they correspond to different levels of explanation. We then comment on the role of theoretical research on the quest for suitable programming abstractions, recalling the importance of changing the working framework and the way of looking every so often. This paper is not meant to be a survey of modern mainstream programming languages: it would be very incomplete in that sense. It aims instead at pointing out a number of remarks and connect them under an evolutionary perspective, in order to grasp a unifying, but not simplistic, view of the programming languages development process

ESCUDO: A Fine-grained Protection Model for Web Browsers

Web applications are no longer simple hyperlinked documents. They have progressively evolved to become highly complex---web pages combine content from several sources (with varying levels of trustworthiness), and incorporate significant portions of client-side code. However, the prevailing web protection model, the same-origin policy, has not adequately evolved to manage the security consequences of this additional complexity. As a result, web applications have become attractive targets of exploitation. We argue that this disconnection between the protection needs of modern web applications and the protection models used by web browsers that manage those applications amounts to a failure of access control. In this paper, we present Escudo, a new web browser protection model designed based on established principles of mandatory access control. We describe our implementation of a prototype of Escudo in the Lobo web browser, and illustrate how web applications can use Escudo for securing their resources. Our evaluation results indicate that Escudo incurs low overhead. To support backwards compatibility, Escudo defaults to the same-origin policy for legacy applications

The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux

The increasing availability of cloud computing and scientific super computers brings great potential for making R accessible through public or shared resources. This allows us to efficiently run code requiring lots of cycles and memory, or embed R functionality into, e.g., systems and web services. However some important security concerns need to be addressed before this can be put in production. The prime use case in the design of R has always been a single statistician running R on the local machine through the interactive console. Therefore the execution environment of R is entirely unrestricted, which could result in malicious behavior or excessive use of hardware resources in a shared environment. Properly securing an R process turns out to be a complex problem. We describe various approaches and illustrate potential issues using some of our personal experiences in hosting public web services. Finally we introduce the RAppArmor package: a Linux based reference implementation for dynamic sandboxing in R on the level of the operating system

The bigwig Project

We present the results of the <bigwig> project, which aims to design and implement a high-level domain-specific language for programming interactive Web services. A fundamental aspect of the development of the World Wide Web during the last decade is the gradual change from static to dynamic generation of Web pages. Generating Web pages dynamically in dialogue with the client has the advantage of providing up-to-date and tailor-made information. The development of systems for constructing such dynamic Web services has emerged as a whole new research area. The <bigwig> language is designed by analyzing its application domain and identifying fundamental aspects of Web services inspired by problems and solutions in existing Web service development languages. The core of the design consists of a session-centered service model together with a flexible template-based mechanism for dynamic Web page construction. Using specialized program analyses, certain Web specific properties are verified at compile-time, for instance that only valid HTML 4.01 is ever shown to the clients. In addition, the design provides high-level solutions to form field validation, caching of dynamic pages, and temporal-logic based concurrency control, and it proposes syntax macros for making highly domain-specific languages. The language is implemented via widely available Web technologies, such as Apache on the server-side and JavaScript and Java Applets on the client-side. We conclude with experience and evaluation of the project

Improving application security with data flow assertions

Resin is a new language runtime that helps prevent security vulnerabilities, by allowing programmers to specify application-level data flow assertions. Resin provides policy objects, which programmers use to specify assertion code and metadata; data tracking, which allows programmers to associate assertions with application data, and to keep track of assertions as the data flow through the application; and filter objects, which programmers use to define data flow boundaries at which assertions are checked. Resin's runtime checks data flow assertions by propagating policy objects along with data, as that data moves through the application, and then invoking filter objects when data crosses a data flow boundary, such as when writing data to the network or a file. Using Resin, Web application programmers can prevent a range of problems, from SQL injection and cross-site scripting, to inadvertent password disclosure and missing access control checks. Adding a Resin assertion to an application requires few changes to the existing application code, and an assertion can reuse existing code and data structures. For instance, 23 lines of code detect and prevent three previously-unknown missing access control vulnerabilities in phpBB, a popular Web forum application. Other assertions comprising tens of lines of code prevent a range of vulnerabilities in Python and PHP applications. A prototype of Resin incurs a 33% CPU overhead running the HotCRP conference management application.Nokia Researc