Web storage

Abstract: Users regularly enter sensitive data, such as passwords, credit card numbers, or tax information, into the browser window. While modern browsers provide powerful client-side privacy measures to protect this data, none of these defenses prevent a browser compromised by malware from stealing it. In this work, we present Fidelius, a new architecture that uses trusted hardware enclaves integrated into the browser to enable protection of user secrets during web browsing sessions, even if the entire underlying browser and OS are fully controlled by a malicious attacker. Fidelius solves many challenges involved in providing protection for browsers in a fully malicious environment, offering support for integrity and privacy for form data, JavaScript execution, XMLHttpRequests, and protected web storage, while minimizing the TCB. Moreover, interactions between the enclave and the browser, the keyboard, and the display all require new protocols, each with their own security considerations. Finally, Fidelius takes into account UI considerations to ensure a consistent and simple interface for both developers and users. As part of this project, we develop the first open source system that provides a trusted path from input and output peripherals to a hardware enclave with no reliance on additional hypervisor security assumptions. These components may be of independent interest and useful to future projects. We implement and evaluate Fidelius to measure its performance overhead, finding that Fidelius imposes acceptable overhead on page load and user interaction for secured pages and has no impact on pages and page components that do not use its enhanced security features.

Abstract: Users regularly enter sensitive data, such as passwords, credit card numbers, or tax information, into the browser window. While modern browsers provide powerful client-side privacy measures to protect this data, none of these defenses prevent a browser compromised by malware from stealing it. In this work, we present Fidelius, a new architecture that uses trusted hardware enclaves integrated into the browser to enable protection of user secrets during web browsing sessions, even if the entire underlying browser and OS are fully controlled by a malicious attacker. Fidelius solves many challenges involved in providing protection for browsers in a fully malicious environment, offering support for integrity and privacy for form data, JavaScript execution, XMLHttpRequests, and protected web storage, while minimizing the TCB. Moreover, interactions between the enclave and the browser, the keyboard, and the display all require new protocols, each with their own security considerations. Finally, Fidelius takes into account UI considerations to ensure a consistent and simple interface for both developers and users. As part of this project, we develop the first open source system that provides a trusted path from input and output peripherals to a hardware enclave with no reliance on additional hypervisor security assumptions. These components may be of independent interest and useful to future projects. We implement and evaluate Fidelius to measure its performance overhead, finding that Fidelius imposes acceptable overhead on page load and user interaction for secured pages and has no impact on pages and page components that do not use its enhanced security features.

Abstract: BrowserID is a complex, real-world Single Sign-On SSO System for web applications recently developed by Mozilla. It employs new HTML5 features such as web messaging and web storage and cryptographic assertions to provide decentralized login, with the intent to respect users' privacy. It can operate in a primary and a secondary identity provider mode. While in the primary mode BrowserID runs with arbitrary identity providers, in the secondary mode there is one identity provider only, namely Mozilla's default identity provider. We recently proposed an expressive general model for the web infrastructure and, based on this web model, analyzed the security of the secondary identity provider mode of BrowserID. The analysis revealed several severe vulnerabilities, which have been fixed by Mozilla. In this paper, we complement our prior work by analyzing the even more complex primary identity provider mode of BrowserID. We do not only study authentication properties as before, but also privacy properties. During our analysis we discovered new and practical attacks that do not apply to the secondary mode: an identity injection attack, which violates a central authentication property of SSO systems, and attacks that break the privacy promise of BrowserID and which do not seem to be fixable without a major redesign of the system. Interestingly, some of our attacks on privacy make use of a browser side channel that, to the best of our knowledge, has not gained a lot of attention so far. For the authentication bug, we propose a fix and formally prove in a slight extension of our general web model that the fixed system satisfies all the authentication requirements we consider. This constitutes the most complex formal analysis of a web application based on an expressive model of the web infrastructure so far. As another contribution, we identify and prove important security properties of generic web features in the extended web model to facilitate future analysis efforts of web standards and web applications.

Abstract: Currently, WWW, large enterprises, and desktop users suffer from an inability to efficiently access and manage differently structured data. The same data objects (e.g. Product) stored by different databases, repositories, distributed web storage systems, etc are named, referenced, and combined internally into schemas or data structures differently. This leads to structural mismatch of data that often consists of the same semantic objects (e.g. EBay and Yahoo! online auction offers).