DES加密解密原理与实现-优快云博客

程序演示:

加密:

void CDESDlg::OnEncrypt()

{

UpdateData(true);

GetDlgItem(IDC_BUTTON2)->EnableWindow(true);

static int IPRTable[64]={40,8,48,16,56,24,64,32,

39,7,47,15,55,23,63,31,

38,6,46,14,54,22,62,30,

37,5,45,13,53,21,61,29,

36,4,44,12,52,20,60,28,

35,3,43,11,51,19,59,27,

34,2,42,10,50,18,58,26,

33,1,41,9,49,17,57,25};

// TODO: Add your control notification handler code here

isDecryption = false;

memset(L,0,64*32);

memset(R,0,64*32);

memset(C,0,64*28);

memset(D,0,64*28);

memset(frk_all,0,64*32);

//明文转成二进制

if(NEVER_PLAINTEXT_TO_BINARY)

{

memset(MyPlainText,0,2048);

StringToBinary(m_PlainText,MyPlainText,2048);

NEVER_PLAINTEXT_TO_BINARY=false;

}

//密文转成二进制

if(NEVER_KEY_TO_BINARY)

{

memset(Key,0,64);

StringToBinary(m_Key,Key,64);

NEVER_KEY_TO_BINARY=false;

}

int tmp[8];

memset(tmp,0,8);

int miwen[64];

int mitmp[64];

m_CipherText="";

int round=ceil((double)m_PlainText.GetLength()/8);

for(i=0;i<round;i++)

{

memset(PlainText,0,64);

for(register j=0;j<64;j++)

{

PlainText[j]=MyPlainText[i*64+j];

}

InitData();

Iterate();

//////////////////////////////////////////////////////////////////////////

// 最后一次生成的L16与R16调换位置装入密文字符串里

memset(miwen, 0, 64);

// 逆初始置换

memset(mitmp, 0, 64);

for(register x=0; x<32; x++)

{

mitmp[x]=R0[x];

mitmp[32+x]=L0[x];

//交换L0,R0的值

L0[x]=mitmp[x];

R0[x]=mitmp[x+32];

}

for (j=0;j<32;j++)

{

L[i][j]=L0[j];

R[i][j]=R0[j];

frk_all[i][j]=frk[j];

}

for (j=0;j<28;j++)

{

C[i][j]=C0[j];

D[i][j]=D0[j];

}

for(x=0; x<64; x++)

{

miwen[x]=mitmp[IPRTable[x]-1];

}

for(x=0;x<64;x++)

{

m_CipherText=m_CipherText+(char)(48+miwen[x]);

if((x+1)%8==0)

m_CipherText=m_CipherText+" ";

}

UpdateData(false);

GetDlgItem(IDC_BUTTON1)->EnableWindow(false);

}

解密:

void CDESDlg::OnDecrypt()

{

// TODO: Add your control notification handler code here

UpdateData(true);

static int IPRTable[64]={40,8,48,16,56,24,64,32,

39,7,47,15,55,23,63,31,

38,6,46,14,54,22,62,30,

37,5,45,13,53,21,61,29,

36,4,44,12,52,20,60,28,

35,3,43,11,51,19,59,27,

34,2,42,10,50,18,58,26,

33,1,41,9,49,17,57,25};

int minwen[64];

int mintmp[64];

CString str="";

m_OriginalText="";

isDecryption = true;

int round=ceil((double)m_PlainText.GetLength()/8);

for (i=0;i<round;i++)

{

for (j=0;j<32;j++)

{

L0[j]=L[i][j];

R0[j]=R[i][j];

frk[j]=frk_all[i][j];

}

for (j=0;j<28;j++)

{

C0[j]=C[i][j];

D0[j]=D[i][j];

}

//////////////////////////////////////////////////////////////////////////

/// 重新开始16次迭代算法

Iterate();

//////////////////////////////////////////////////////////////////////////

// 最后一次生成的L16<->R16调换位置

memset(minwen, 0, 64);

// 逆初始置换

memset(mintmp, 0, 64);

for(register i=0; i<32; i++)

{

mintmp[i]=R0[i];

mintmp[32+i]=L0[i];

}

for(i=0; i<64; i++)

{

minwen[i]=mintmp[IPRTable[i]-1];

}

//////////////////////////////////////////////////////////////////////////

// 将密文ASCII码放入编辑框里面去

for(i=0; i<8; i++)

{

int tmp=0;

tmp+=minwen[8*i];

for(int j=1; j<8; j++)

{

tmp*=2;

tmp+=minwen[i*8+j];

}

str.Format("%c", tmp);

m_OriginalText+=str;

str="";

}

// MessageBox(m_OriginalText,NULL);

}

UpdateData(false);

// 让解密按钮无效;

GetDlgItem(IDC_BUTTON2)->EnableWindow(false);

}

子密钥

void CDESDlg::ProduceSubKey( int SubKeyLen, /*子密钥序号*/ int NumOfSubKey)

{

// //置换选择表2

static int ReplaceTable_2[48]={14,17,11,24,1,5,

3,28,15,6,21,10,

23,19,12,4,26,8,

16,7,27,20,13,2,

41,52,31,37,47,55,

30,40,51,45,33,48,

44,49,39,56,34,53,

46,42,50,36,29,32};

//第一次进行置换1

if (FIRST_REPLACE_ONE)

{

RepalceOne(C0,D0,28,SubKeyLen);

FIRST_REPLACE_ONE=false;

}

int j=2; // 移位次数

if( NumOfSubKey==1||NumOfSubKey==2||

NumOfSubKey==9||NumOfSubKey==16)

{

j=1;

}

//////////////////////////////////////////////////////////////////////////

//如果为解密，迭代移位的次序变换相反方向

if (isDecryption)

{

if(NumOfSubKey==16)

{

j=0;

}

else if(NumOfSubKey==15||NumOfSubKey==8||NumOfSubKey==1)

{

j=-1;

}

else

{

j=-2;

}

//临时密钥左右部

int CTmp[28],DTmp[28];

//临时56位子密钥

int TmpKey[56];

memset(CTmp, 0, 28);

memset(DTmp, 0, 28);

for(i=0; i<28; i++)

{

CTmp[i]=C0[(i+j+28)%28];

DTmp[i]=D0[(i+j+28)%28];

}

//////////////////////////////////////////////////////////////////////////

// 将CTMP， DTMP的数据存入C0，D0中去

for(i=0; i<28; i++)

{

C0[i]=CTmp[i];

D0[i]=DTmp[i];

}

memset(TmpKey,0,56);

for(i=0;i<28;i++)

{

TmpKey[i]=C0[i];

TmpKey[i+28]=D0[i];

}

//生成子密钥SubKey

for(i=0;i<SubKeyLen;i++)

SubKey[i]=TmpKey[ReplaceTable_2[i]-1];

}

16轮迭代:

// 进行16轮迭代

void CDESDlg::Iterate()

{

//8个S盒

static int SBox[8][4][16] = {

{

14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7,

0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8,

4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0,

15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13

{

15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10,

3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5,

0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15,

13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9

{

10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,

13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,

13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,

1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12

{

7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,

13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,

10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,

3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14

{

2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,

14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6,

4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14,

11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3

{

12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11,

10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8,

9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6,

4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13

{

4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,

13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6,

1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,

6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12

{

13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7,

1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2,

7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8,

2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11

}

};

//E扩展变换表

static int ExtendTable[48]={32,1,2,3,4,5,

4,5,6,7,8,9,

8,9,10,11,12,13,

12,13,14,15,16,17,

16,17,18,19,20,21,

20,21,22,23,24,25,

24,25,26,27,28,29,

28,29,30,31,32,31};

//P变换表

static int PChangeTable[32]={16,7,20,21,

29,12,28,17,

1,15,23,26,

5,18,31,10,

2,8,24,14,

32,27,3,9,

19,13,30,6,

22,11,4,25};

//加密模式

if (!isDecryption)

{

for (int num=1;num<=16;num++)

//解密模式

{

int ExtendR0[48];

for(int i=0;i<48;i++)//经过E变换扩充，由32位变为48位

ExtendR0[i]=R0[ExtendTable[i]-1];

ProduceSubKey(48,num);

for(i=0;i<48;i++)//与K1按位作不进位加法运算

ExtendR0[i]=ExtendR0[i]+SubKey[i];

for(i=0;i<48;i++)

{

if(ExtendR0[i]==2)

ExtendR0[i]=0;

}

int SGroup[8][6];

memset(SGroup,0,48);

for(i=0;i<8;i++)//48位分成8组

{

for (int j=0;j<6;j++)

{

SGroup[i][j]=ExtendR0[i*6+j];

}

int SEight[8];

memset(SEight,0,8);

//下面经过S盒，得到8个数

for(i=0; i<8; i++)

{

SEight[i]=SBox[i][SGroup[i][5]+SGroup[i][0]*2][SGroup[i][1]*8+SGroup[i][2]*4+SGroup[i][3]*2+SGroup[i][4]];

}

//////////////////////////////////////////////////////////////////////////

// 将8个数分别转换成2进制，再存入到frk[32]

int f[32];

memset(f, 0, 32);

for(i=0; i<8; i++)

{

int tmp[4];

memset(tmp, 0, 4);

for(int j=0; j<4; j++)

{

tmp[j]=SEight[i]%2;

SEight[i]/=2;

}

for(j=0; j<4; j++)

{

f[4*i+j]=tmp[3-j];

}

// 经过P变换存入frk[32]

for(i=0; i<32; i++)

{

frk[i]=f[PChangeTable[i]-1];

}

int Ltmp[32], Rtmp[32];

memset(Ltmp, 0, 32);

memset(Rtmp, 0, 32);

for(i=0; i<32; i++)

{

Ltmp[i]=R0[i];

Rtmp[i]=(L0[i]+frk[i])%2;

}

// 最后将数据存入L0，RO里面去

for(i=0; i<32; i++)

{

L0[i]=Ltmp[i];

R0[i]=Rtmp[i];

}

else{

for (int num=16;num>=1;num--)

//解密模式

{

int ExtendR0[48];

for(int i=0;i<48;i++)//经过E变换扩充，由32位变为48位

ExtendR0[i]=R0[ExtendTable[i]-1];

ProduceSubKey(48,num);

for(i=0;i<48;i++)//与K1按位作不进位加法运算

ExtendR0[i]=ExtendR0[i]+SubKey[i];

for(i=0;i<48;i++)

{

if(ExtendR0[i]==2)

ExtendR0[i]=0;

}

int SGroup[8][6];

memset(SGroup,0,48);

for(i=0;i<8;i++)//48位分成8组

{

for (int j=0;j<6;j++)

{

SGroup[i][j]=ExtendR0[i*6+j];

}

/*s21[i]=RE1[i+6];*/

}

int SEight[8];

memset(SEight,0,8);

//下面经过S盒，得到8个数

for(i=0; i<8; i++)

{

SEight[i]=SBox[i][SGroup[i][5]+SGroup[i][0]*2][SGroup[i][1]*8+SGroup[i][2]*4+SGroup[i][3]*2+SGroup[i][4]];

}

//////////////////////////////////////////////////////////////////////////

// 将8个数分别转换成2进制，再存入到frk[32]

int f[32];

memset(f, 0, 32);

for(i=0; i<8; i++)

{

int tmp[4];

memset(tmp, 0, 4);

for(int j=0; j<4; j++)

{

tmp[j]=SEight[i]%2;

SEight[i]/=2;

}

for(j=0; j<4; j++)

{

f[4*i+j]=tmp[3-j];

}

// 经过P变换存入frk[32]

for(i=0; i<32; i++)

{

frk[i]=f[PChangeTable[i]-1];

}

int Ltmp[32], Rtmp[32];

memset(Ltmp, 0, 32);

memset(Rtmp, 0, 32);

for(i=0; i<32; i++)

{

Ltmp[i]=R0[i];

Rtmp[i]=(L0[i]+frk[i])%2;

}

// 最后将数据存入L0，RO里面去

for(i=0; i<32; i++)

{

L0[i]=Ltmp[i];

R0[i]=Rtmp[i];

}

程序源代码下载

欢迎大家评论！

对称加密算法DES实现