计算机信息安全对称密钥加密DES源代码（C++版）

#include <stdio.h> #include <string.h> #include <windows.h> #include <conio.h> #include "Schedle.h"//该头文件中包含了DES算法中所使用的全部变换表 class CShift{ public: DWORDLONG mask[16]; int step[16]; CShift(){ for(int i=0;i<16;i++){ step[i]=2;//其余轮的迭代中，循环左移的位数是2位 mask[i]=0xc000000; } step[0]=step[1]=step[8]=step[15]=1;//第1、2、9、16轮迭代中，循环左移的位数是1位 mask[0]=mask[1]=mask[8]=mask[15]=0x8000000; } }; class CDES{ public: CDES(){ m_dwlKey=0; m_dwlData=0; ConvertTableToMask(dwlKey_PC_1,64); ConvertTableToMask(dwlKey_PC_2,56); ConvertTableToMask(dwlData_IP,64); ConvertTableToMask(dwlData_Expansion,32); ConvertTableToMask(dwlData_FP,64); ConvertTableToMask(dwlData_P,32); Generate_S(); } void EncryptKey(char *); unsigned char* EncryptData(unsigned char *); unsigned char* DescryptData(unsigned char*); private: void ConvertTableToMask(DWORDLONG *,int); void Generate_S(void); DWORDLONG ProcessByte(unsigned char*,BOOL); DWORDLONG PermuteTable(DWORDLONG,DWORDLONG*,int); void Generate_K(void); void EncryptKernel(void); DWORDLONG Generate_B(DWORDLONG,DWORDLONG*); DWORDLONG dwlData_S[9][4][16]; CShift m_shift; DWORDLONG m_dwlKey; DWORDLONG m_dwlData; DWORDLONG m_dwl_K[17]; }; void CDES::EncryptKey(char *key){//输入种子密钥 printf("\n请输入种子密钥: %s\n",key); m_dwlKey=ProcessByte((unsigned char*)key,TRUE); m_dwlKey=PermuteTable(m_dwlKey,dwlKey_PC_1,56); Generate_K();//16轮的子密钥生成函数 } void CDES::Generate_K(void){ DWORDLONG C[17],D[17],tmp; C[0]=m_dwlKey>>28; D[0]=m_dwlKey&0xfffffff; for(int i=1;i<=16;i++){ tmp=(C[i-1]&m_shift.mask[i-1])>>(28-m_shift.step[i-1]); C[i]=((C[i-1]<<m_shift.step[i-1])|tmp)&0x0fffffff; tmp=(D[i-1]&m_shift.mask[i-1])>>(28-m_shift.step[i-1]); D[i]=((D[i-1]<<m_shift.step[i-1])|tmp)&0x0fffffff; m_dwl_K[i]=(C[i]<<28)|D[i]; m_dwl_K[i]=PermuteTable(m_dwl_K[i],dwlKey_PC_2,48); } } DWORDLONG CDES::ProcessByte(unsigned char *key,BOOL shift){//将每1个字符形式的数据转换成8位二进制数据形式 unsigned char tmp; DWORDLONG byte=0; int i=0; while(i<8){ while(*key){ if(byte!=0) byte<<=8; tmp=*key; if(shift) tmp<<=1; byte|=tmp; i++; key++; } if(i<8) byte<<=8; i++; } return byte; } DWORDLONG CDES::PermuteTable(DWORDLONG dwlPara,DWORDLONG* dwlTable,int nDestLen){//置换表函数 int i=0; DWORDLONG tmp=0,moveBit; while(i<nDestLen){ moveBit=1; if(dwlTable[i]&dwlPara){ moveBit<<=nDestLen-i-1; tmp|=moveBit; } i++; } return tmp; } void CDES::ConvertTableToMask(DWORDLONG *mask,int max){ int i=0; DWORDLONG nBit=1; while(mask[i]!=0){ nBit=1; nBit<<=max-mask[i]; mask[i++]=nBit; } } void CDES::Generate_S(void){//S盒变换 int i; int j,m,n; m=n=0; j=1; for(i=0;i<512;i++){ dwlData_S[j][m][n]=S_box[i]; n=(n+1)%16; if(!n){ m=(m+1)%4; if(!m) j++; } } } unsigned char* CDES::EncryptData(unsigned char *block){//加密函数 unsigned char *EncrytedData=new unsigned char(15); printf("\n输入的明文分组为: %s\n",block); m_dwlData=ProcessByte(block,0); m_dwlData=PermuteTable(m_dwlData,dwlData_IP,64); EncryptKernel();//调用轮函数 DWORDLONG bit6=m_dwlData; for(int i=0;i<11;i++){ EncrytedData[7-i]=(unsigned char)(bit6&0x3f)+46; bit6>>=6; } EncrytedData[8]='\0'; printf("\n加密后的密文为: %s",EncrytedData); for(i=0;i<8;i++){ EncrytedData[7-i]=(unsigned char)(m_dwlData&0xff); m_dwlData>>=8; } EncrytedData[8]='\0'; return EncrytedData; } void CDES::EncryptKernel(void){ //轮函数 int i=1; DWORDLONG L[17],R[17],B[9],EK,PSB; L[0]=m_dwlData>>32; R[0]=m_dwlData&0xffffffff; //16轮迭代 for(i=1;i<=16;i++){ L[i]=R[i-1]; R[i-1]=PermuteTable(R[i-1],dwlData_Expansion,48); EK=R[i-1]^m_dwl_K[i]; PSB=Generate_B(EK,B);//在函数Generate_B(EK,B)中进行了P置换，故PSB=轮函数 R[i]=L[i-1]^PSB; } R[16]<<=32; m_dwlData=R[16]|L[16]; m_dwlData=PermuteTable(m_dwlData,dwlData_FP,64); } unsigned char* CDES::DescryptData(unsigned char *desData){//解密算法 int i=1; unsigned char *DescryptedData=new unsigned char(15); DWORDLONG L[17],R[17],B[9],EK,PSB; DWORDLONG dataPara; dataPara=ProcessByte(desData,0); dataPara=PermuteTable(dataPara,dwlData_IP,64); R[16]=dataPara>>32; L[16]=dataPara&0xffffffff; for(i=16;i>=1;i--){ R[i-1]=L[i]; L[i]=PermuteTable(L[i],dwlData_Expansion,48); EK=L[i]^m_dwl_K[i]; PSB=Generate_B(EK,B); L[i-1]=R[i]^PSB; } L[0]<<=32; dataPara=L[0]|R[0]; dataPara=PermuteTable(dataPara,dwlData_FP,64); for(i=0;i<8;i++){ DescryptedData[7-i]=(unsigned char)(dataPara&0xff); dataPara>>=8; } DescryptedData[8]='\0'; printf("\n\n解密后的明文为: %s\n",DescryptedData); return DescryptedData; } DWORDLONG CDES::Generate_B(DWORDLONG EKPara,DWORDLONG *block){ int i,m,n; DWORDLONG tmp=0; for(i=8;i>0;i--){ block[i]=EKPara&0x3f; m=(int)(block[i]&0x20)>>4; m|=block[i]&0x01; n=(int)(block[i]<<1)>>2; block[i]=dwlData_S[i][m][n]; EKPara>>=6; } for(i=1;i<=8;i++){ tmp|=block[i]; tmp<<=4; } tmp>>=4; tmp=PermuteTable(tmp,dwlData_P,32);//经过P置换得到32位的输出数据 return tmp; } void main(void){ CDES des; des.EncryptKey("12345678");//调用“输入种子密钥”函数，得到初始种子密钥12345678 unsigned char *result=des.EncryptData((unsigned char*)"cipherte");//输入的明文分组为cipherte，调用加密函数EncryptData对其进行加密 des.DescryptData(result);//调用解密函数DescryptData对密文进行解密 }