TC:Medium:Collaborative Research:Techniques to Retrofit Legacy Code

这个奖项是根据2009年的《美国恢复和再投资法案》(Public Law 111-5)资助的。尽管也许不幸的是，作为一个实际问题，软件通常是以功能为主要目标构建的，而安全功能只是在以后才添加，通常是在发现漏洞之后。为了降低成本并增加安全更新过程中的安全性，目标是开发一种方法，包括自动化和半自动的工具和技术，以将授权策略执行功能添加到遗留软件系统中。主要的见解是，更新代码中涉及的大部分任务可以自动化或已经自动化，因此设计过程集中于实现进一步的自动化，并将这些任务聚合到一个单一的、连贯的方法中正在开发技术和工具来：(1)通过分析和插装带注释的应用程序源代码来识别和标记与安全相关的对象和I/O通道；(2)插入代码以协调对标记实体的访问；(3)将插入的检查抽象为策略相关的、安全敏感的操作，这些操作由应用的安全策略授权(或拒绝)；(4)在部署时将改进的遗留代码与站点的特定策略集成，以通过高级策略分析确保应用正确地实施该站点的策略，以及(5)验证由改进的应用正确地实施OS策略委派。正在开发的技术和工具不仅对改进有用，而且对于增强和验证已经配备了安全功能的现有代码也有用；因此，在创建更安全的软件方面提高了最先进的水平。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Though perhaps unfortunate, as a practical matter software is oftenbuilt with functionality as a primary goal, and security features areonly added later, often after vulnerabilities have been identified.To reduce the cost and increase assurance in the process of securityretrofitting, the aim to develop a methodology involving automated andsemi-automated tools and techniques to add authorization policyenforcement functionality to legacy software systems.The main insight is that major portions of the tasks involved inretrofitting code can be or already have been automated, so the designprocess focuses on enabling further automation and aggregating thesetasks into a single, coherent approach.More specifically, techniques and tools are being developed to: (1)identify and label security-relevant objects and I/O channels byanalyzing and instrumenting annotated application source code; (2)insert code to mediate access to labeled entities; (3) abstract theinserted checks into policy-relevant, security-sensitive operationsthat are authorized (or denied) by the application's security policy;(4) integrate the retrofitted legacy code with the site's specificpolicy at deployment time to ensure, through advanced policy analysis,that the application enforces that site's policy correctly, and (5)verify correct enforcement of OS policy delegation by the retrofittedapplication.The techniques and tools being developed are useful not onlyfor retrofitting, but also for augmenting and verifying existing codealready outfitted with security functionality; hence improving thestate-of-the-art in creating more secure software.