#include "stdafx.h"
#include <stdio.h>
#include <memory.h>
#include <string.h>
#include "yDES.h"

// 初始置换表
const static BYTE 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
};

// 逆初始置换表
const static BYTE 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
};

// 扩展置换表
static const BYTE Extension_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
};

// P盒置换表
const static BYTE 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
};

// 密钥置换表 
const static BYTE PCK_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
};

// 压缩置换表 
const static BYTE PCC_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
};

// 每轮移动的位数 
const static BYTE LOOP_Table[16] = {
	1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
};

// S盒设计
const static BYTE S_Box[8][4][16] = {
	// S盒1 
	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,
	// S盒2 
    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,
	// S盒3 
    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,
	// S盒4 
     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,
	// S盒5 
     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,
	// S盒6 
    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,
	// S盒7 
     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,
	// S盒8 
    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
};

// 字节转换函数
void yDES::ByteToBit(bool *Out, const BYTE *In, int bits)
{
    for(int i=0; i<bits; ++i)
        Out[i] = ( In[i>>3] >> (i&7) ) & 1;
}

// 比特转换函数
void yDES::BitToByte(BYTE *Out, const bool *In, int bits)
{
    memset(Out, 0, bits>>3);
    for(int i=0; i<bits; ++i)
        Out[i>>3] |= In[i]<<(i&7);
}


// 变换函数
void yDES::Transform(bool *Out, bool *In, const BYTE *Table, int len)
{
    for(int i=0; i<len; ++i)
        Tmp[i] = In[ Table[i]-1 ];
    memcpy(Out, Tmp, len);
}

// 异或函数的实现
void yDES::Xor(bool *InA, const bool *InB, int len)
{
    for(int i=0; i<len; ++i)
        InA[i] ^= InB[i];
}

// 轮转函数
void yDES::RotateL(bool *In, int len, int loop)
{
    memcpy(Tmp, In, loop);
    memcpy(In, In+loop, len-loop);
    memcpy(In+len-loop, Tmp, loop);
}

// S函数的实现
void yDES::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);
    }
}

// F函数的实现
void yDES::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);
}



// 设置子密钥
void yDES::SetSubKey(PSubKey pSubKey, const BYTE Key[8])
{
    static bool K[64], *KL=&K[0], *KR=&K[28];
    ByteToBit(K, Key, 64); //转换格式
    Transform(K, K, PCK_Table, 56); 
	// 由56位密钥产生48位子密钥
    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); 
    }
}


// 设置密钥
void yDES::SetKey(const BYTE* 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;
}

// DES加解密函数
void yDES::DES(BYTE Out[8],const BYTE *In, 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]); // 调用F函数
            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);
}

// DES加解密函数（可以对长明文分段加密）
bool yDES::DES_Act(BYTE *Out,const BYTE *In, size_t datalen, const BYTE *Key, int keylen, bool Type)
{
    if( !( Out && In && Key && (datalen=(datalen+7)&0xfffffff8) ) ) 
		return false;
	SetKey(Key, keylen);
	if( !Is3DES ) {   // 1次DES
		for(long i = 0,j = datalen>>3; i < j; ++i, Out += 8,In += 8)
			DES(Out, In, &SubKey[0], Type);
	} else{   // 3次DES 加密:加(key0)-解(key1)-加(key0) 解密::解(key0)-加(key1)-解(key0)
		for(long i=0,j=datalen>>3; i<j; ++i,Out+=8,In+=8) {
			DES(Out, In,  &SubKey[0], Type);
			DES(Out, Out, &SubKey[1], !Type);
			DES(Out, Out, &SubKey[0], Type);
		}
	}

	return true;
}