DES加密算法
#include
#include
#include
#include
using namespace std;
const static char IP_Table[64] =//初始置换
{
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7
};
const static char IPR_Table[64] = //初始逆置换表
{
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
};
static const char Extension_Table[48]= //扩展置换表
{
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,
24,25,26,27,28,29,28,29,30,31,32,1
};
const static char P_Table[32]= //P盒置换表
{
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
};
const static char PCK_Table[56] =//密钥置换（原64位去掉奇偶校验位后）
{
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4
};
const static char LOOP_Table[16] =//左移
{
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
const static char PCC_Table[48] =//压缩置换表
{
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
};
const static char S_Box[8][4][16] =//8个S盒
{
{
// S1
{ 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 }
},
{
// S2
{ 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 }
},
{
// S3
{ 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 }
},
{
// S4
{ 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 }
},
{
// S5
{ 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 }
},
{
// S6
{ 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 }
},
{
// S7
{ 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 }
},
{
// S8
{ 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 }
}
};
typedef bool (*PSubKey)[16][48];
enum{ENCRYPT,DECRYPT};
static bool SubKey[2][16][48];
static bool Is3DES;
static char Tmp[256],deskey[16];
static void SetKey(const char *Key,int len);
static void SetSubKey(PSubKey pSubKey,const char Key[8]);
static void F_func(bool In[32],const bool Ki[48]);
static void S_func(bool Out[32],const bool In[48]);
static void Transform(bool *Out[32],const bool In[48],int len);
static void Xor(bool *InA,const bool *InB,int len);
static void RotateL(bool *In,int len,int loop);
static void ByteToBit(bool *Out,const char *In,int bits);
static void BitToByte(char *Out,const bool *In,int bits);
static void myDES(char Out[8],char In[8],const PSubKey pSubKey,bool Type);
bool DES_Act(char *Out,char *In,long datalen,const char *Key,int keylen,bool Type);
void main()
{
char key[]={0,2,1,0,9,4,5,1,7,8,5,0,7,2,8};
char plain_text[]=" Welcome to DES world! It is wonderful!";
char encrypt_text[255];
char decrypt_text[255];
memset(encrypt_text,0,sizeof(encrypt_text));
memset(decrypt_text,0,sizeof(decrypt_text));
printf("\nDES加密前的明文:\n");
printf("%s\n\n",plain_text);
DES_Act(encrypt_text,plain_text,sizeof(plain_text),key,sizeof(key),ENCRYPT);
printf("\nDES加密后的密文:\n");
printf("%s\n\n",encrypt_text);
DES_Act(decrypt_text,encrypt_text,sizeof(plain_text),key,sizeof(key),DECRYPT);
printf("\n解密后的输出：\n");
printf("%s\n",decrypt_text);
}
void ByteToBit(bool *Out,const char *In,int bits)
{
for(int i=0;i
Out[i]=(In[i>>3]>>(i&7))&1;
}
void BitToByte(char *Out,const bool *In,int bits)
{
memset(Out,0,bits>>3);
for(int i=0;i
Out[i>>3] |=In[i]<<(i&7);
}
void Transform(bool *Out,bool *In,const char *Table,int len)
{
for(int i=0;i
Tmp[i]=In[Table[i]-1];
memcpy(Out,Tmp,len);
}
void Xor(bool *InA,const bool *InB,int len)
{
for(int i=0;i
InA[i]^=InB[i];
}
void RotateL(bool *In,int len,int loop)
{
memcpy(Tmp,In,loop);
memcpy(In,In+loop,len-loop);
memcpy(In+len-loop,Tmp,loop);
}
void S_func(bool Out[32],const bool In[48])
{
for(char i=0,j,k;i<8;++i,In+=6,Out+=4)
{
j = (In[0]<<1)+In[5];
k = (In[1]<<3)+(In[2]<<2)+(In[3]<<1)+In[4];
ByteToBit(Out,&S_Box[i][j][k],4);
}
}
void F_func(bool In[32],const bool Ki[48])
{
static bool MR[48];
Transform(MR,In,Extension_Table,48);
Xor(MR,Ki,48);
S_func(In,MR);
Transform(In,In,P_Table,32);
}
void SetSubKey(PSubKey pSubKey,const char Key[8])
{
static bool K[64],*KL=&K[0],*KR=&K[28];
ByteToBit(K,Key,64);
Transform(K,K,PCK_Table,56);
for(int i=0;i<16;i++)
{
RotateL(KL,28,LOOP_Table[i]);
RotateL(KR,28,LOOP_Table[i]);
Transform((*pSubKey)[i],K,PCC_Table,48);
}
}
void SetKey(const char *Key,int len)
{
memset(deskey,0,16);
memcpy(deskey,Key,len>16?16:len);
SetSubKey(&SubKey[0],&deskey[0]);
Is3DES=len>8?(SetSubKey(&SubKey[1],&deskey[8]),true):false;
}
void DES(char Out[8],char In[8],const PSubKey pSubKey,bool Type)
{
static bool M[64],tmp[32],*Li=&M[0],*Ri=&M[32];
ByteToBit(M,In,64);
Transform(M,M,IP_Table,64);
if(Type==ENCRYPT)
{
for(int i=0;i<16;i++)
{
memcpy(tmp,Ri,32);
F_func(Ri,(*pSubKey)[i]);
Xor(Ri,Li,32);
memcpy(Li,tmp,32);
}
}
else
{
for(int i=15;i>=0;i--)
{
memcpy(tmp,Li,32);
F_func(Li,(*pSubKey)[i]);
Xor(Li,Ri,32);
memcpy(Ri,tmp,32);
}
}
Transform(M,M,IPR_Table,64);
BitToByte(Out,M,64);
}
bool DES_Act(char *Out,char *In,long datalen,const char *Key,int keylen,bool Type)
{
if(!(Out&&In&&Key && (datalen=datalen+7)&0xfffffff8))
return false;
SetKey(Key,keylen);
if(!Is3DES)
{
for(long i=0,j=datalen>>3;i
DES(Out,In,&SubKey[0],Type);
}
else
{
for(long i=0,j=datalen>>3;i
{
DES(Out,In,&SubKey[0],Type);
DES(Out,Out,&SubKey[1],!Type);
DES(Out,Out,&SubKey[0],Type);
}
}
return true;
}