【作者】 王瑞昌；

【导师】 翟高寿；

【作者基本信息】 北京交通大学 ， 计算机软件与理论， 2007， 硕士

【摘要】 操作系统的安全性是保障整个信息系统安全性的根本所在,近年来关于安全操作系统的研究也正逐步升温,而隐蔽通道分析是构建安全操作系统的一个重要组成部分,同时也是构建高等级安全操作系统的一个瓶颈。其间,隐蔽通道的标识是隐蔽通道分析的基础和最为关键的一环。本论文首先研究了隐蔽通道的相关概念,分析了现有隐蔽通道标识方法中存在的一些问题,然后选用共享资源矩阵法作为突破口,对其进行改进,以试图克服操作系统隐蔽通道标识复杂繁琐且工作量巨大的问题,设计并实现了一个基于源代码的隐蔽通道标识工具。具体而言,首先对系统源代码进行扫描,分析出代码中的变量和函数;其次,根据语句信息流规则分析信息流,构造关于共享变量和函数的共享资源矩阵;再次,按照共享资源矩阵法标识出代码中的潜在的隐蔽通道。在此基础上,本论文还选用了Linux内核的部分源代码作为实例,尝试标识出其代码中的潜在隐蔽通道,验证了相关分析标识工具的有效性。最后,论文就研究过程中存在的问题及今后的努力方向进行了总结与展望。更多还原

【Abstract】 The security of operating systems is the fundamental point to protect the security of the whole information system. In recent years, research on secure operating systems is heated gradually as well. And the analysis of covert channels is an important component of establishing a secure operating system, and at the same time it is a bottleneck of the construction of the high-grade secure operating system. Meantime, the identification of covert channels is the foundation and the most critical link of covert channel analysis.In the paper, related concepts of covert channels are studied at first. And existing problems of methods of covert channel identification are further analyzed. Then the shared resource matrix method is chosen as the breakthrough of the research direction. The method is improved so that problems about identification complexity and heavy workload could be solved. The tool of covert channel identification based on source codes are designed and implemented. In detail, firstly system source codes are scaned to analyze variables and functions of the codes. Secondly information flows are analyzed according to the rules of statement information flow, to construct the shared resource matrix about shared variables and functions. Thirdly, potential covert channels in the system can be identified in accordance with the shared resource matrix method.Based on this, part of the Linux kernel source codes are chosen as an example to attempt to identify potential covert channels of the codes so that the effectiveness of the identification tools can be verified. Finally, existing problems of the research process are summed up and the directions of future efforts are forecasted.更多还原