【作者】 李彬；

【导师】 刘桂雄； 卢国华；

【作者基本信息】 华南理工大学 ， 机械工程， 2013， 硕士

【摘要】 随着网络、通讯技术髙速发展，工业控制系统安全性受到密切关注，最需要关心的是验证现场设备安全运作，比如直接控制和监控现场设备的可编程控制器（PLC)，因此PLC的安全可靠性是控制系统可信发展的研究热点。论文以“基于MD5算法的PLC固件完整性增强方法研究”为题，研究PLC控制系统中固件在传输时基线截获并对其进行完整性验证技术，以增强PLC固件完整性。此方法不仅适用于PLC，而且可将其推广到任何有固件的嵌入式系统中，所以论文研究对于促进嵌入式系统的机械装备可靠性具有重要意义。论文分析了固件完整性增强技术、加密hash算法的国内外研究进展，研究了可信计算在完整性方面的机理和方法，建立了基于MD5算法的PLC固件完整性增强方法架构，提出了基于固件传输特征分析的固件基线获取、基于MD5算法的PLC固件完整性校验方法，研制了完整性验证软件及平台，设计了完整性验证实验、对比实验。论文主要工作包括：(一)研究可信计算理论与技术，分析可信计算与完整性保障的关系，将其运用到PLC固件完整性验证当中，提出了基于MD5算法的PLC固件完整性增强方法架构；(二)设定固件非结构化二进制代码和传输协议特征为研究对象，深入探讨固件数据提取和固件基线建立的方法；(三)利用截获数据搭建虚拟PLC平台，用电脑和电脑进行PLC固件数据传输，将建立的基线作为标准来校验PLC固件完整性，创新性地提出模拟PLC进行固件数据截取，并且在校验过程中为了避免发生不正确判断，增加验证过程可信性，将目前被视为非常优秀的中间技术^MD5哈希算法应用到验证过程中；(四）设计搭建了基于MD5的PLC固件完整性测试平台。在个人计算机上设计验证软件，通过Microsotf Visual Studio2008集成开发工具，用C#语言来编程创建应用程序，实现平台软件功能。设置4个对比试验，分别是固件数据的增加、固件数据的减少、固件数据的替换和完整固件数据的试验来进行对比说明。测试结果证明，本文设计的基于MD5算法的PLC固件完整性增强方法具有独创性，能准确的测试出固件完整性，不仅有效的验证终端控制PLC安全，保证整个系统的安全，而且为其他嵌入式控制系统提供了一种可行的思路。更多还原

【Abstract】 The security of industrial control system have been followed closely along with the rapiddevelopment of the network communication technique，the biggest concern is field devicessafely run，such as the programmable controller(PLC) is direct control and monitor fieldapparatus, so the safety and reliability of the PLC is a hot area for research control system.With the title of "Integrity of the PLC Firmware Enhancement Method Based on MD5，，，thethesis is studies the integrity verification technology of PLC use in control system, while thefirmware baseline intercepted during transmission，to enhance integrity of the PLC firmware.This method not only to apply the PLC, and it can be spread to any firmware embeddedsystems, so the thesis research has great significance to promote the embedded systemreliability of machinery and equipment.This paper analyses the enhancement technique of the firmware integrity and thedomestic and foreign research progress of hash algorithm, researches the mechanism andmethods of Trusted Computing’ s completeness, build a architecture, what is integrity of PLCfirmware based on the MD5algorithm, proposes a new way of the ifrmware baselineintercepted based on analyst firmware transmission characteristic, and integrity of PLCfirmware checking method based on the MD5algorithm, integrities verification sotfware andplatform was developed, integrities verification experiment and contrast experiment isdesigned.The main contributions of this paper are listed as follows:(1)This thesis makes a research on the design theory and technology of the trustedcomputing，the relationships between trusted computing and integrity assurance are analysis,applied it to the PLC firmware integrity verification, propose a architecture of PLC firmwareintegrity method based on the MD5algorithm;(2)This thesis set the unstructured binary code of the firmware and characteristics oftransfer protocol as a research object，data extraction and establish baseline of the firmwarewas discussed; (3)A virtual platform of PLC was constructed by intercept the data，transmit data of PLCfirmware between the computer and the computer, check integrity of the PLC firmware asstandard baseline, this article creatively points out we can intercept the data by simulating thePLC, MD5algorithm was applied to the validation process, which was regarded as very goodintermediate technology, in order to avoid wrong judgment，and increase creditability process;(4)The integrity of PLC firmware test platform is designed based on the MD5algorithm，it can achieve platform sotfware functions, through the Microsoft Visual Studio2008integrated development tools, and create applications by C#programming language. Testresult was found by four contrast test, include complete test，or the data increase or reduce，replace data of the firmware.Test shows that，integrity of the PLC firmware enhancement method based on MD5wasdesigned in this paper, which was original and can test the integrity of firmware accurately, themethod not only to validate terminal control of PLC eiffciently，but it also provided a usefulway for other embedded control system.更多还原