Diffie-Hellman密钥交换算法综合实验报告

（网络安全方案设计基础）实验报告时间： 地点：软件实验室姓名班级学号指导教师实验成绩实验名称Diffie-Hellman密钥交换算法实验目的1、了解和掌握Diffie-Hellman算法原理及过程；2、通过密钥交换算法实现对称加解密密钥的保密传输；3、能够编写代码实现Diffie-Hellman算法，并实现数据保密传输。实验内容1、编写Diffie-Hellman程序，协商出用于收、发双方的加、解密密钥K；2、模拟发送端A，用协商出的密钥K，通过对称加密算法（具体算法不限）将文本文件加密；模拟接收端B，用协商出的密钥K，对接收到的密文解密。实验过程A端的代码#include<stdio.h>#include<math.h>intXa=3,Xb=5,Ya,Yb;/**********A端通过Yb计算Ka*************/intusera(alpha,q){intk1=pow(Yb,Xa);k1=k1%q;returnk1;}/**********B端通过Ya计算Kb*************/intuserb(alpha,q){intk2=pow(Ya,Xb);k2=k2%q;returnk2;/*函数声明*/voidInitSbox(unsignedcharsbox[]);voidKeyExpansion(unsignedcharkey[],char*k,intlen);voidUpsetSbox(unsignedcharsbox[],unsignedcharkey[]);voidDataProcess(unsignedcharsbox[],FILE*fp1,FILE*fp2);voidDataEncrypt(char*k,unsignedchar*key,unsignedchar*sbox,FILE*fp1,FILE*fp2);voidDataDecrypt(char*k1,unsignedchar*key,unsignedchar*sbox,FILE*fp1,FILE*fp2);intwrite_file(charname[],chardata[],intsize);intread_file(charname[],chardata[],intsize);/*初始化S盒*/voidInitSbox(unsignedcharsbox[]){inti;for(i=0;i<256;i++)sbox[i]=i;}/*密钥填充256数组刃voidKeyExpansion(unsignedcharkey[],char*k,intlen){inti;if(len<=256){for(i=0;i<256;i++)key[i]=k[i%len];}if(len>256){for(i=0;i<256;i++)key[i]=k[i];}}/*打乱S盒*/

intread_file(unsignedcharname[],chardata[],intsize){FILE*file=fopen(name,"rb+");if(file==NULL)return0;rewind(file);//移动指针到开头fread(data,sizeof(char),size,file);//读出一个数组fclose(file);return1;}intmain(intargc,constchar*argv[]){intq=11,alpha=2;intKa;unsignedcharkey1[25]={0x00},key2[25]={0x00};unsignedcharkey[256]={0x00};unsignedcharsbox[256]={0x00};FILE*fp1,*fp2;intflag=1,i;printf("A用户端\n");printf("q=11,a=2\n");//CalculatingYaYa=pow(alpha,Xa);Ya=Ya%q;printf("计算得到Ya=%d\n",Ya);printf("请输入B端的公钥Yb:");scanfC'%d",&Yb);Ka=usera(alpha,q);printf("计算得到最终公钥K=%d",Ka);key1[0]=Ka;/**********加密***********/fp1=fopen("mingwen.txt","r");if(fp1==NULL){printf（"打开源文件失败!\n"）;getchar();exit(0);fp2=fopen("miwen.txt","w");if(fp2==NULL){printf（"打开加密后文件失败!\n"）;getchar();exit(0);DataEncrypt(key1,key,sbox,fp1,fp2);return0;/********************************B端代码************************************/#include<stdio.h>#include<math.h>intXb=5,Ya,Yb;/*函数声明*/voidInitSbox(unsignedcharsbox[]);voidKeyExpansion(unsignedcharkey[],char*k,intlen);voidUpsetSbox(unsignedcharsbox[],unsignedcharkey[]);voidDataProcess(unsignedcharsbox[],FILE*fp1,FILE*fp2);voidDataEncrypt(char*k,unsignedchar*key,unsignedchar*sbox,FILE*fp1,FILE*fp2);voidDataDecrypt(char*k1,unsignedchar*key,unsignedchar*sbox,FILE*fp1,FILE*fp2);intwrite_file(charname[],chardata[],intsize);intread_file(charname[],chardata[],intsize);

/*加解密数据刃voidDataProcess(unsignedcharsbox[],FILE*fp1,FILE*fp2){//0加密，1解密inti=0,j=0,size=0;inttemp2,temp1,t;chark,cipherchar,data_Stream[100]={0x00};unsignedchartemp;charch=fgetc(fp1);while(ch!=EOF){i=(i+1)%256;temp2=j+(int)sbox[i];j=temp2%256;temp=sbox[i];sbox[i]=sbox[j];sbox[j]=temp;temp1=(int)sbox[i]+(int)sbox[j];t=temp1%256;data_Stream[size++]=k=sbox[t];cipherchar=chAk;fputc(cipherchar,fp2);ch=fgetc(fpl);printf("%c",ch);}write_file("Stream.txt",data_Stream,size);}/*解密总函数刃voidDataDecrypt(unsignedchar*k1,unsignedchar*key,unsignedchar*sbox,FILE*fp1,FILE*fp2){intlen=strlen(kl);KeyExpansion(key,k1,len);InitSbox(sbox);

UpsetSbox(sbox,key);printf("\n密文为：")；DataProcess(sbox,fp1,fp2);fclose(fpl);fclose(fp2);printf("\n解密成功，内容存于“jiemi.txt”中!\n\n");}/*******文件的写操作**********/intwrite_file(charname[],chardata[],intsize){FILE*file=fopen(name,"ab+");if(file==NULL)return0;fwrite(data,sizeof(char),size,file);//写入一个数组rewind(file);//移动指针到开头fclose(file);return1;}/******文件的操作*******/intread_file(unsignedcharname[],chardata[],intsize){FILE*file=fopen(name,"rb+");if(file==NULL)return0;rewind(file);//移动指针到开头fread(data,sizeof(char),size,file);//读出一个数组fclose(file);return1;}/**********B端通过Ya计算Kb*************/intuserb(alpha,q)intk2=pow(Ya,Xb);k2=k2%q;returnk2;intmain(intargc,constchar*argv[]){intq=11,alpha=2;intKb;unsignedcharkey1[25]={0x00},key2[25]={0x00};unsignedcharkey[256]={0x00};unsignedcharsbox[256]={0x00};FILE*fp1,*fp2;intflag=1,i;printf("B用户端\n");printf("q=11,a=2\n");//CalculatingYbYb=pow(alpha,Xb);Yb=Yb%q;printf("计算得到Yb=%d\n",Yb);printf("请输入A端的公钥Ya:");scanf("%d",&Ya);Kb=userb(alpha,q);printf("计算得到最终秘钥K=%d\n",Kb);key2[0]=Kb;/*********解密**********/fp1=fopen("miwen.txt","r");if(fp1==NULL){printf（"打开加密后文件失败!\n"）;getchar();exit(0);fp2=fopen("jiemi.txt","w");if(fp2==NULL){printf（"打开解密后文件失败!\n"）;getchar();exit(0);实图1R用户端q=1La=2计算得到Yb=10齿输入A端的公胡Ya:A用户端q=ll,a=2计算得到Ya.=8请输入B端的公钥Yb：A用户端q=llJa=2计算得到Y»=8请输入E端的公钥Yb：10计算得到最终公钥K=10明文为engChunHui加密成功,加密内容在;KmiwerLtxt"中PressanykeytocontinueB用户端q二11,a二2计算得到Yb=10诘输Xa端的公钥Ya:8十算廿到最河秘窃K=l。密文为：荏龙??u浚。鄙：0?解密成功，内容荐于"jiemi.txt”中!Pressanykeytocontinue1(图2)

存储明文的文件（图3）：mingwen.ttt-记事本文件出相露回格式。查窗切努助（W|180345301B7DengChunHui图3存储密文的文件（图4）：miwen.txt-记事本文件旧编辑㈤梏式⑼筐看M帮助（HJ榛臬€??U浚3\鄢！0?图4解密后的文件（图5）：jiemi.tx