摘要近年来，个人隐私数据泄露的新闻层出不穷，通信安全成为人们越来越重视的话题。隐蔽信道是一种泄露隐蔽信息的通道。本文以传递隐蔽信息为目的，设计了一个 基于 HTTP 的网络存储隐蔽信道。79041

本文先研究了隐蔽信道、网络协议与 NDIS 中间层驱动的基本概念，并深入了解 了各类隐蔽信道的工作原理、优缺点与 HTTP 协议头的特性。然后针对 HTTP 协议 的特性设计算法对包进行拦截与修改，并使用内核编程完成对中间层驱动的编写。再 编写用户态程序 Server/Client 对中间层驱动进行调用，完成对 HTTP 包头拦截与修 改来实现隐蔽信息的传输。最后进行对隐蔽信道的测试与分析。主要步骤如下：

（1）了解隐蔽信道的基本概念，分析各类隐蔽信道的特点，对网络存储隐蔽信 道深入研究，从而进行隐蔽信道的初步设计。

（2）了解网络协议和内核编程的基本概念，对 HTTP 协议的结构进行分析。分 析其特性，根据 HTTP 协议头部的特性设计算法将隐蔽信息嵌入 HTTP 协议头部， 并通过内核编程编写中间层驱动完成对包的拦截修改。

（3）设计用户态程序 Server/Client 对中间层驱动功能调用，实现客户机与服务 机的隐蔽信息传输。

（4）利用虚拟机搭建实验环境，在服务端与客户端上安装驱动，并分别安上

Server 与 Client 进行隐蔽信道的测试与分析，从而验证隐蔽信道的有效和可行性。

毕业论文关键词 HTTP 隐蔽信道 NDIS 中间层驱动

毕 业 设 计 说 明 书 外 文 摘 要

Title  The design and implementation of network storage overt channel based on HTTP             

Abstract In recent years, the news of personal privacy data leaked emerge in endlessly, people pay more and more attention to the topic of communications security。 Covert channel can leak the hidden information。 This paper  aim at sending hidden message, designed a network storage covert channel based on HTTP。 

This paper first studied the covert channel, the network protocol, and the basic concept of the NDIS Intermediate Drivers, and understand the working principle, advantages and disadvantages of all kinds of covert channel and the characteristics of the head of the HTTP protocol。 Then according to the characteristics of the HTTP protocol to design algorithm to intercept and modify the pack, and use the kernel programming to complete the writing of the intermediate driver。 Then, writing user mode application Server/Client to call the intermediate drive, to intercept and modify the HTTP header to realize the hidden information transmission。 Finally, test and analysis of the covert channel。 The main steps are as follows: 

(1)Understand the basic concept of covert channel, analyzes the characteristics of various types of covert channel, deep researching in network storage covert channel, completing the preliminary design of the covert channel。 

（2）Understand the basic concept of network protocols and the kernel programming, to analyze the structure of the HTTP protocol。 Analyzing its characteristics, and according to the characteristics of the HTTP protocol 

header to design a algorithm to embed the hidden information in HTTP protocol header, and through the kernel programming to write an intermediate drivers to  modify and interception the packet。 

(3) Design user mode application Server/Client to use the intermediate drive, realize the hidden information transmission on Client and service machine。 

(4) Using virtual machine to build the experimental environment, install the driver on the host and the Client, and respectively install the Server and the Client for testing and analysis of covert channel, so as to verify the covert channel is effective and feasible。