#pragma execution_character_set("utf-8")
// DES.cpp: implementation of the DES class.
//
//////////////////////////////////////////////////////////////////////
#include <string>
#include <memory.h>
#include "des.h"


	
////////////////////////////////////////////////////////////////////////
// initial permutation IP
const char 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 
const char 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
const char 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 
const char 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) 
const char 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) 
const char 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 
const char LOOP_Table[16] = {
    1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
};
// The (in)famous S-boxes 
const char 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
};


//DES::DES()
//{
//    m_mode = DM_CBC;
//    m_pad_type = PT_ISO_1;
//}

DES::DES(DES_MODE mode, PAD_TYPE pad_type)
{
    m_mode = mode;
    m_pad_type = pad_type;
}

DES::~DES()
{
}

/*******************************************************************/
/*
  函 数 名 称:    ByteToBit
  功 能 描 述：    把BYTE转化为Bit流
  参 数 说 明：    Out:    输出的Bit流[in][out]
                In:        输入的BYTE流[in]
                bits:    Bit流的长度[in]

  返回值 说明：    void
/*******************************************************************/
void ByteToBit(bool *Out, const char *In, int bits)
{
    for(int i=0; i<bits; ++i)
        Out[i] = (In[i>>3]>>(7 - i&7)) & 1;
}

/*******************************************************************/
/*
  函 数 名 称:    BitToByte
  功 能 描 述：    把Bit转化为Byte流
  参 数 说 明：    Out:    输出的BYTE流[in][out]
                In:        输入的Bit流[in]
                bits:    Bit流的长度[in]

  返回值 说明：    void
/*******************************************************************/
void BitToByte(char *Out, const bool *In, int bits)
{
    memset(Out, 0, bits>>3);
    for(int i=0; i<bits; ++i)
        Out[i>>3] |= In[i]<<(7 - i&7);
}



/*******************************************************************/
/*
  函 数 名 称:    RotateL
  功 能 描 述：    把BIT流按位向左迭代
  参 数 说 明：    In:        输入的Bit流[in]
                len:    Bit流的长度[in]
                loop:    向左迭代的长度

  返回值 说明：    void
/*******************************************************************/
void RotateL(bool *In, int len, int loop)
{
    bool Tmp[256];

    memcpy(Tmp, In, loop);
    memcpy(In, In+loop, len-loop);
    memcpy(In+len-loop, Tmp, loop);
}



/*******************************************************************/
/*
  函 数 名 称:    Xor
  功 能 描 述：    把两个Bit流进行异或
  参 数 说 明：    InA:    输入的Bit流[in][out]
                InB:    输入的Bit流[in]
                loop:    Bit流的长度

  返回值 说明：    void
/*******************************************************************/
void Xor(bool *InA, const bool *InB, int len)
{
    for(int i=0; i<len; ++i)
        InA[i] ^= InB[i];
}


/*******************************************************************/
/*
  函 数 名 称:    Transform
  功 能 描 述：    把两个Bit流按表进行位转化
  参 数 说 明：    Out:    输出的Bit流[out]
                In:        输入的Bit流[in]
                Table:    转化需要的表指针
                len:    转化表的长度

  返回值 说明：    void
/*******************************************************************/
void Transform(bool *Out, bool *In, const char *Table, int len)
{
    bool Tmp[256];

    for(int i=0; i<len; ++i)
        Tmp[i] = In[ Table[i]-1 ];
    memcpy(Out, Tmp, len);
}



/*******************************************************************/
/*
  函 数 名 称:    S_func
  功 能 描 述：    实现数据加密S BOX模块
  参 数 说 明：    Out:    输出的32Bit[out]
                In:        输入的48Bit[in]

  返回值 说明：    void
/*******************************************************************/
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];    //组织SID下标
        
        for(int l=0; l<4; ++l)                                //把相应4bit赋值
            Out[l] = (S_Box[i][j][k]>>(3 - l)) & 1;
    }
}


/*******************************************************************/
/*
  函 数 名 称:    F_func
  功 能 描 述：    实现数据加密到输出P
  参 数 说 明：    Out:    输出的32Bit[out]
                In:        输入的48Bit[in]

  返回值 说明：    void
/*******************************************************************/
void F_func(bool In[32], const bool Ki[48])
{
    bool MR[48];
    Transform(MR, In, E_Table, 48);
    Xor(MR, Ki, 48);
    S_func(In, MR);
    Transform(In, In, P_Table, 32);
}



bool DES::Encrypt(char *in, unsigned int inLen, const char *key, unsigned char keyLen, char *out)
{
    std::string s(in, inLen);
    
    RunPad(s);
    
    //return RunDes(DT_ENCRYPT, in, inLen, key, keyLen, out);
    return RunDes(DT_ENCRYPT, s.c_str(), s.length(), key, keyLen, out);
}

bool DES::Decrypt(char *in, unsigned int inLen, const char *key, unsigned char keyLen, char *out)
{
    std::string s(in, inLen);
    
    RunPad(s);
    
    //return RunDes(DT_DECRYPT, in, inLen, key, keyLen, out);
    return RunDes(DT_DECRYPT, s.c_str(), s.length(), key, keyLen, out);
}

/*******************************************************************/
/*
  函 数 名 称:    RunDes
  功 能 描 述：    执行DES算法对文本加解密
  参 数 说 明：    desType    :类型：加密ENCRYPT，解密DECRYPT
                in        :待加密串指针
                inLen    :待加密串的长度，同时Out的缓冲区大小应大于或者等于datalen
                key        :密钥(可为8位,16位,24位)支持3密钥
                keyLen    :密钥长度，多出24位部分将被自动裁减
                out        :待输出串指针

  返回值 说明：    bool    :是否加密成功
/*******************************************************************/
//bool DES::RunDes(DES_TYPE desType,char* In,char* Out,unsigned datalen,const char* Key,const unsigned char keylen)
bool DES::RunDes(DES_TYPE desType, const char* in,unsigned int inLen, const char* key,const unsigned char keyLen, char* out)
{
    //判断输入合法性
    if(!(in && out && key && inLen && keyLen>=8))
    {
        return false;
    }
    
    //只处理8的整数倍，不足长度自己填充
    if(inLen & 0x00000007)
        return false;
    
    bool m_SubKey[3][16][48];    //秘钥
    //构造并生成SubKeys
    unsigned char nKey    =    (keyLen>>3)>3 ? 3: (keyLen>>3);
    for(int i=0; i < nKey; i++)
    {
        SetSubKey(&m_SubKey[i], &key[i<<3]);
    }

    if(m_mode == DM_ECB)    //ECB模式
    {
        if(nKey    ==    1)    //单Key
        {
            for(int i = 0, j = inLen >> 3; i<j; ++i, out += 8, in += 8)
            {
                Des(out, in, &m_SubKey[0], desType);
            }
        }
        else if(nKey == 2)    //3DES 2Key
        {
            for(int i = 0, j = inLen >> 3; i<j; ++i, out += 8, in += 8)
            {
                Des(out, in, &m_SubKey[0], desType);
                Des(out, out, &m_SubKey[1], ((desType == DT_ENCRYPT) ? (DT_DECRYPT) : (DT_ENCRYPT)));
                Des(out, out, &m_SubKey[0], desType);
            }
        }
        else            //3DES 3Key
        {
            for(int i = 0, j = inLen >> 3; i<j; ++i, out += 8, in += 8)
            {
                Des(out, in, &m_SubKey[desType ? 2 : 0], desType);
                Des(out, out, &m_SubKey[1], ((desType == DT_ENCRYPT) ? (DT_DECRYPT) : (DT_ENCRYPT)));
                Des(out, out, &m_SubKey[desType ? 0 : 2], desType);    
            }
        }
    }    
    else    //CBC模式
    {
        char cvec[8] = "";    //扭转向量
        char cvin[8] = "";    //中间变量

        if(nKey == 1)    //单Key
        {
            for(int i = 0, j = inLen >> 3; i<j; ++i, out += 8, in += 8)
            {
                if(desType == DT_ENCRYPT)
                {
                    for(int j = 0; j < 8; ++j)    //将输入与扭转变量异或
                    {
                        cvin[j] = in[j] ^ cvec[j];
                    }
                }
                else
                {
                    memcpy(cvin, in, 8);
                }

                Des(out, cvin, &m_SubKey[0], desType);

                if(desType    ==    DT_ENCRYPT)
                {
                    memcpy(cvec, out, 8);    //将输出设定为扭转变量
                }
                else
                {
                    for(int j = 0; j < 8; ++j)    //将输出与扭转变量异或
                    {
                        out[j] = out[j] ^ cvec[j];
                    }
                    memcpy(cvec, cvin, 8);    //将输入设定为扭转变量
                }
            }
        }
        else if(nKey == 2)    //3DES CBC 2Key
        {
            for(int i = 0, j = inLen >> 3; i < j; ++i, out += 8, in += 8)
            {
                if(desType == DT_ENCRYPT)
                {
                    for(int j = 0; j < 8; ++j)        //将输入与扭转变量异或
                    {
                        cvin[j] = in[j] ^ cvec[j];
                    }
                }
                else
                {
                    memcpy(cvin, in, 8);
                }
                
                Des(out, cvin, &m_SubKey[0], desType);
                Des(out, out, &m_SubKey[1], ((desType==DT_ENCRYPT)?(DT_DECRYPT):(DT_ENCRYPT)));
                Des(out, out, &m_SubKey[0], desType);
                
                if(desType == DT_ENCRYPT)
                {
                    memcpy(cvec, out, 8);    //将输出设定为扭转变量
                }
                else
                {
                    for(int j = 0; j < 8; ++j)    //将输出与扭转变量异或
                    {
                        out[j] = out[j] ^ cvec[j];
                    }
                    memcpy(cvec, cvin, 8);            //将输入设定为扭转变量
                }
            }
        }
        else            //3DES CBC 3Key
        {
            for(int i = 0, j = inLen >> 3; i < j; ++i, out += 8, in += 8)
            {
                if(desType == DT_ENCRYPT)
                {
                    for(int j = 0; j < 8; ++j)        //将输入与扭转变量异或
                    {
                        cvin[j] = in[j] ^ cvec[j];
                    }
                }
                else
                {
                    memcpy(cvin, in, 8);
                }
                
                Des(out, cvin, &m_SubKey[desType ? 2 : 0], desType);
                Des(out, out, &m_SubKey[1], ((desType==DT_ENCRYPT)?(DT_DECRYPT):(DT_ENCRYPT)));
                Des(out, out, &m_SubKey[desType ? 0 : 2], desType);
                
                if(desType == DT_ENCRYPT)
                {
                    memcpy(cvec, out, 8);    //将输出设定为扭转变量
                }
                else
                {
                    for(int j = 0; j < 8; ++j)        //将输出与扭转变量异或
                    {
                        out[j] = out[j] ^ cvec[j];
                    }
                    memcpy(cvec,cvin,8);            //将输入设定为扭转变量
                }
            }
        }
    }
    
    return true;
}




/*******************************************************************/
/*
  函 数 名 称:    RunPad
  功 能 描 述：    根据协议对加密前的数据进行填充
  参 数 说 明：    nPadType    :类型：PAD类型
                In        :数据串指针
                Out        :填充输出串指针
                datalen    :数据的长度
                padlen    :(in,out)输出buffer的长度，填充后的长度

  返回值 说明：    bool    :是否填充成功
/*******************************************************************/
bool DES::RunPad(const char* in,unsigned int inLen,char* out,unsigned int &padlen)
{
    int res = (inLen & 0x00000007);
    
    if(res == 0)
    {
        return true;
    }
    
    
    //if(padlen < (inLen + 8 - res))
    //{
    //    return false;
    //}
    //else
    //{
        padlen = (inLen + 8 - res);
        memcpy(out, in, inLen);
    //}
    
    
    if(m_pad_type == PT_ISO_1)
    {
        memset(out + inLen, 0x00, 8 - res);
    }
    else if(m_pad_type == PT_ISO_2)
    {
        memset(out + inLen, 0x80, 1);
        memset(out + inLen, 0x00, 7 - res);
    }
    else if(m_pad_type == PT_PKCS_7)
    {
        memset(out + inLen, 8 - res, 8 - res);
    }
    else
    {
        return false;
    }

    return true;
}

bool DES::RunPad(std::string &in)
{
    int res = (in.length() & 0x00000007);
    
    if(res == 0)
    {
        return true;
    }
    
    if(m_pad_type == PT_ISO_1)
    {
        in.append(8-res, 0x00);
    }
    else if(m_pad_type == PT_ISO_2)
    {
        in.append(1, 0x80);
        if(7 - res > 0)
        {
            in.append(7 - res, 0x00);
        }
    }
    else if(m_pad_type == PT_PKCS_7)
    {
        in.append(8-res, 8-res);
    }
    else
    {
        return false;
    }
    
    return true;
}




//计算并填充子密钥到SubKey数据中
void DES::SetSubKey(PSubKey pSubKey, const char Key[8])
{
    bool K[64], *KL=&K[0], *KR=&K[28];
    ByteToBit(K, Key, 64);
    Transform(K, K, PC1_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, PC2_Table, 48);
    }
}



//DES单元运算
void DES::Des(char Out[8], const char In[8], const PSubKey pSubKey, DES_TYPE desType)
{
    bool M[64], tmp[32], *Li=&M[0], *Ri=&M[32];
    ByteToBit(M, In, 64);
    Transform(M, M, IP_Table, 64);
    if( desType == DT_ENCRYPT )
    {
        for(int i=0; i<16; ++i)
        {
            memcpy(tmp, Ri, 32);        //Ri[i-1] 保存
            F_func(Ri, (*pSubKey)[i]);    //Ri[i-1]经过转化和SBox输出为P
            Xor(Ri, Li, 32);            //Ri[i] = P XOR Li[i-1]
            memcpy(Li, tmp, 32);        //Li[i] = Ri[i-1]
        }
    }
    else
    {
        for(int i=15; i>=0; --i) 
        {
            memcpy(tmp, Ri, 32);        //Ri[i-1] 保存
            F_func(Ri, (*pSubKey)[i]);    //Ri[i-1]经过转化和SBox输出为P
            Xor(Ri, Li, 32);            //Ri[i] = P XOR Li[i-1]
            memcpy(Li, tmp, 32);        //Li[i] = Ri[i-1]
        }
    }
    RotateL(M,64,32);                    //Ri与Li换位重组M
    Transform(M, M, IPR_Table, 64);        //最后结果进行转化
    BitToByte(Out, M, 64);                //组织成字符
}


/*
std::string des_encrypt(std::string in, std::string key)
{

}

std::string des_decrypt(std::string in, std::string key)
{

}
*/