📄 des.c
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/*========================================================================
FileName : DES.CPP
Date : 2004-2-24
Auther : YangPengHui
Email : cpuyph@yahoo.com.cn
========================================================================*/
#include "string.h"
#include "des.h"
#define xdata
#define code
extern U8 gbDesKey[17];
extern U8 gbDesKeyLen;
U8 DemoMelody[500];
// initial permutation IP
code U8 IP_Table[64] =
{
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
};
// final permutation IP^-1
code U8 IPR_Table[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
};
// expansion operation matrix
code U8 E_Table[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, 1
};
// 32-bit permutation function P used on the output of the S-boxes
code U8 P_Table[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
};
// permuted choice table (key)
code U8 PC1_Table[56] =
{
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
};
// permuted choice key (table)
code U8 PC2_Table[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
};
// number left rotations of pc1
code U8 LOOP_Table[16] =
{
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
// The (in)famous S-boxes
code U8 S_Box[8][4][16] =
{
// 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 U8 (*PSubKey)[16][48];
xdata U8 SubKey[2][16][48];// 16圈子密钥
xdata U8 *Tmp;
//-----------------------------------------------------------------------
void ByteToBit(xdata U8 *Out, xdata U8 *In, U8 len)// 字节组转换成位组
{
U8 i, n;
if(len < 8)
n = len - 1;
else
n = 7;
for(i=0; i<len; i++)
Out[i] = (In[i>>3] >> (n - (i&n))) & 1;
}
//-----------------------------------------------------------------------
void BitToByte(xdata U8 *Out, xdata U8 *In, U8 len)// 位组转换成字节组
{
U8 i, n;
if(len < 8)
n = len - 1;
else
n = 7;
memset(Out, 0, len>>3);
for(i=0; i<len; ++i)
Out[i>>3] |= In[i] << (n-(i&n));
}
//-----------------------------------------------------------------------
void Transform(xdata U8 *Out, xdata U8 *In, xdata U8 *Table, U8 len)// 变换
{
U8 i;
for(i=0; i<len; i++)
Tmp[i] = In[ Table[i]-1 ];
memcpy(Out, Tmp, len);
}
//-----------------------------------------------------------------------
void Xor(xdata U8 *InA, xdata U8 *InB, U8 len)// 异或
{
U8 i;
for(i=0; i<len; i++)
InA[i] ^= InB[i];
}
//-----------------------------------------------------------------------
void RotateL(xdata U8 *In, U8 len, U8 loop)// 循环左移
{
memcpy(Tmp, In, loop);
memcpy(In, In+loop, len-loop);
memcpy(In+len-loop, Tmp, loop);
}
//-----------------------------------------------------------------------
void S_func(xdata U8 *Out, xdata U8 *In)
{
U8 i,row, col;
for(i=0; i<8; ++i,In+=6,Out+=4)
{
row = (In[0]<<1) + In[5];
col = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4];
ByteToBit(Out, (xdata U8*)&S_Box[i][row][col], 4);
}
}
//-----------------------------------------------------------------------
void F_func(xdata U8 *In, xdata U8 *Ki)
{
xdata U8 MR[48];
Transform(MR, In, (xdata U8*)E_Table, 48);
Xor(MR, Ki, 48);
S_func(In, MR);
Transform(In, In, (xdata U8*)P_Table, 32);
}
//-----------------------------------------------------------------------
void SetSubKey(xdata PSubKey pSubKey, xdata U8 *Key)// 设置子密钥 key[8]
{
xdata U8 K[64], *KL=&K[0], *KR=&K[28];
U8 i;
ByteToBit(K, Key, 64);
Transform(K, K, (xdata U8*)PC1_Table, 56);
for(i=0; i<16; ++i)//生成16个子密钥
{
RotateL(KL, 28, LOOP_Table[i]);
RotateL(KR, 28, LOOP_Table[i]);
Transform((xdata U8*)(*pSubKey)[i], K, (xdata U8*)PC2_Table, 48);
}
}
//-----------------------------------------------------------------------
U8 SetKey(void)
{
SetSubKey((xdata PSubKey )&SubKey[0], &gbDesKey[0]);
if(gbDesKeyLen > 8)
{
SetSubKey((xdata PSubKey )&SubKey[1], &gbDesKey[8]);
return TRUE;
}
else
return FALSE;
}
//-----------------------------------------------------------------------
void DES(xdata U8 *In, xdata PSubKey pSubKey, U8 Type)//标准DES加/解密
{
xdata U8 M[64], tmp[32], *Li=&M[0], *Ri=&M[32];
S8 i;
ByteToBit(M, In, 64);
Transform(M, M, (xdata U8*)IP_Table, 64);
if( Type == ENCRYPT )
{
for(i=0; i<16; i++)
{
memcpy(tmp, Ri, 32);
F_func(Ri, (xdata U8*)(*pSubKey)[i]);
Xor(Ri, Li, 32);
memcpy(Li, tmp, 32);
}
// Note ! We must reverse the order of the last (16) two blocks and apply
// the final permutation to: M = R16L16, not M=L16R16
memcpy(tmp, Li, 32);
memcpy(M, &M[32], 32);
memcpy(&M[32], tmp, 32);
}
else
{
memcpy(tmp, Li, 32);
memcpy(M, &M[32], 32);
memcpy(&M[32], tmp, 32);
for(i=15; i>=0; i--)
{
memcpy(tmp, Li, 32);
F_func(Li, (xdata U8*)(*pSubKey)[i]);
Xor(Li, Ri, 32);
memcpy(Ri, tmp, 32);
}
}
Transform(M, M, (xdata U8*)IPR_Table, 64);
BitToByte(In, M, 64);
}
//-----------------------------------------------------------------------
U8 DesGo(xdata U8 *In, U8 DataLen, U8 Type)
{
U8 i, j, Is3Des;// 3次DES标志
j = DataLen >> 3;
if((DataLen % 8) != 0)
j ++;
i = j << 3;
if(i > DataLen && Type == ENCRYPT)
memset(In+DataLen,0,i - DataLen);
Tmp = (xdata U8 *)&DemoMelody;
memset(Tmp, 0, 256);
Is3Des = SetKey();
if(Is3Des == 0)
{ // 1次DES
for(i=0; i<j; ++i,In+=8)
DES(In, (xdata PSubKey )&SubKey[0], Type);
}
else
{ // 3次DES 加密:加(key0)-解(key1)-加(key0) 解密::解(key0)-加(key1)-解(key0)
for(i=0; i<j; ++i,In+=8)
{
DES(In, (xdata PSubKey )&SubKey[0], Type);
DES(In, (xdata PSubKey )&SubKey[1], !Type);
DES(In, (xdata PSubKey )&SubKey[0], Type);
}
}
return (j<<3);
}
/*-----------------------------------------------------------------------
Desctiption : Message Authentication Check
Input : data string and data length
Output : MAC reselt
Return : TRUE or FALSE
-----------------------------------------------------------------------*/
void MacGo(xdata U8 *In, xdata U8 *Mac, U8 DataLen)
{
xdata U8 Vector[9], oldDesKey[17];//初始向量
xdata U8 *str; //信息
U8 i, j, flag, oldKeyLen;
str = In;
j = DataLen >> 3;
flag = (DataLen % 8);
memcpy(oldDesKey, gbDesKey, 16);
memset(&gbDesKey[8], 0, 8); //only use front 8 bytes
oldKeyLen = gbDesKeyLen;
gbDesKeyLen = 8;
memset(Vector, 0, sizeof(Vector));//初始向量置0
for(i=0; i<j; i++)
{
Xor(Vector, str, 8);
DesGo(Vector, 8, ENCRYPT);
str += 8;
DataLen -= 8;
}
if(flag > 0)
{
xdata U8 tempBuff[8];
memset(tempBuff, 0, 8);
memcpy(tempBuff, str, DataLen);
Xor(Vector, tempBuff, 64);
DesGo(Vector, 8, ENCRYPT);
}
memcpy(Mac, Vector, 8);
memcpy(gbDesKey, oldDesKey, 16);
gbDesKeyLen = oldKeyLen;
}
//-----------------------------------------------------------------------
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