c_des.cpp

RSA和DES的一些类~~可以对初学者有些帮助

        }; 
  //放大换位表 
  int e[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 
        }; 
  BYTE m_bit1[8] = {0}; 
  BYTE m_byte[64] = {0}; 
  BYTE m_byte1[64] = {0}; 
  BYTE key_n[16][8] = {0}; 
  BYTE l_bit[17][8] = {0}; 
  BYTE r_bit[17][8] = {0}; 
  BYTE e_byte[64] = {0}; 
  BYTE e_byte1[64] = {0}; 
  BYTE r_byte[64] = {0}; 
  BYTE r_byte1[64] = {0}; 
  int i, j; 
 
  //根据密钥生成16个子密钥 
  GenSubKey(k_bit, key_n); 
  //将待加密字串变换成01串 
  ASCII2Bin(m_bit, m_byte); 
  //按照ip表对待加密字串进行位变换 
  for(i = 0; i < 64; i++) 
    m_byte1[i] = m_byte[ip[i] - 1]; 
  //位变换后的待加密字串 
  Bin2ASCII(m_byte1, m_bit1); 
  //将位变换后的待加密字串分成两组，分别为前4字节L和后4字节R，作为迭代的基础（第0次迭代） 
  for(i = 0; i < 4; i++) 
    l_bit[0][i] = m_bit1[i], r_bit[0][i] = m_bit1[i + 4]; 
 
  //16次迭代运算 
  for(i = 1; i <= 16; i++) 
  { 
    //R的上一次的迭代结果作为L的当前次迭代结果 
    for(j = 0; j < 4; j++) 
        l_bit[i][j] = r_bit[i-1][j]; 
 
    ASCII2Bin(r_bit[i-1], r_byte); 
    //将R的上一次迭代结果按E表进行位扩展得到48位中间结果 
    for(j = 0; j < 48; j++) 
        r_byte1[j] = r_byte[e[j] - 1]; 
    Bin2ASCII(r_byte1, r_bit[i-1]); 
 
    //与第I-1个子密钥进行异或运算 
    for(j = 0; j < 6; j++) 
        r_bit[i-1][j] = r_bit[i-1][j] ^ key_n[i-1][j]; 
 
    //进行S选择，得到32位中间结果 
    SReplace(r_bit[i - 1]); 
     
    //结果与L的上次迭代结果异或得到R的此次迭代结果 
    for(j = 0; j < 4; j++) 
    { 
        r_bit[i][j] = l_bit[i-1][j] ^ r_bit[i-1][j]; 
    } 
  } 
  //组合最终迭代结果 
  for(i = 0; i < 4; i++) 
    e_bit[i] = r_bit[16][i], e_bit[i + 4] = l_bit[16][i]; 
   
  ASCII2Bin(e_bit, e_byte); 
  //按照表IP-1进行位变换 
  for(i = 0; i < 64; i++) 
    e_byte1[i] = e_byte[ip_1[i] - 1]; 
  //得到最后的加密结果 
  Bin2ASCII(e_byte1, e_bit); 
} 
 
/* 
*   undes 函数说明： 
*     DES解密，与加密步骤完全相同，只是迭代顺序是从16到1 
*   返回： 
*     无 
*   参数： 
*     const BYTE m_bit[8] 输入的密文 
*     const BYTE k_bit[8] 输入的密钥 
*     BYTE e_bit[8] 输出解密后的原文 
*/ 
void C_Des::undes(const BYTE m_bit[8], const BYTE k_bit[8], BYTE e_bit[8]) 
{ 
  //换位表IP 
  int ip[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 
        }; 
  //换位表IP_1 
  int ip_1[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 
        }; 
  //放大换位表 
  int e[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 
        }; 
  BYTE m_bit1[8] = {0}; 
  BYTE m_byte[64] = {0}; 
  BYTE m_byte1[64] = {0}; 
  BYTE key_n[16][8] = {0}; 
  BYTE l_bit[17][8] = {0}; 
  BYTE r_bit[17][8] = {0}; 
  BYTE e_byte[64] = {0}; 
  BYTE e_byte1[64] = {0}; 
  BYTE l_byte[64] = {0}; 
  BYTE l_byte1[64] = {0}; 
  int i = 0, j = 0; 
 
  //根据密钥生成16个子密钥 
  GenSubKey(k_bit, key_n); 
  //将待加密字串变换成01串 
  ASCII2Bin(m_bit, m_byte); 
  //按照ip表对待加密字串进行位变换 
  for(i = 0; i < 64; i++) 
    m_byte1[i] = m_byte[ip[i] - 1]; 
  //位变换后的待加密字串 
  Bin2ASCII(m_byte1, m_bit1); 
  //将位变换后的待加密字串分成两组，分别为前4字节R和后4字节L，作为迭代的基础（第16次迭代） 
  for(i = 0; i < 4; i++) 
    r_bit[16][i] = m_bit1[i], l_bit[16][i] = m_bit1[i + 4]; 
 
  //16次迭代运算 
  for(i = 16; i > 0; i--) 
  { 
    //L的上一次的迭代结果作为R的当前次迭代结果 
    for(j = 0; j < 4; j++) 
        r_bit[i-1][j] = l_bit[i][j]; 
 
    ASCII2Bin(l_bit[i], l_byte); 
    //将L的上一次迭代结果按E表进行位扩展得到48位中间结果 
    for(j = 0; j < 48; j++) 
        l_byte1[j] = l_byte[e[j] - 1]; 
    Bin2ASCII(l_byte1, l_bit[i]); 
 
    //与第I-1个子密钥进行异或运算 
    for(j = 0; j < 6; j++) 
        l_bit[i][j] = l_bit[i][j] ^ key_n[i-1][j]; 
 
    //进行S选择，得到32位中间结果 
    SReplace(l_bit[i]); 
     
    //结果与R的上次迭代结果异或得到L的此次迭代结果 
    for(j = 0; j < 4; j++) 
    { 
        l_bit[i-1][j] = r_bit[i][j] ^ l_bit[i][j]; 
    } 
  } 
  //组合最终迭代结果 
  for(i = 0; i < 4; i++) 
    e_bit[i] = l_bit[0][i], e_bit[i + 4] = r_bit[0][i]; 
   
  ASCII2Bin(e_bit, e_byte); 
  //按照表IP-1进行位变换 
  for(i = 0; i < 64; i++) 
    e_byte1[i] = e_byte[ip_1[i] - 1]; 
  //得到最后的结果 
  Bin2ASCII(e_byte1, e_bit); 
} 
 
/* 
*   SReplace 函数说明： 
*     S选择 
*   返回： 
*     无 
*   参数： 
*     BYTE s_bit[8] 输入暨选择后的输出 
*/ 
void C_Des::SReplace(BYTE s_bit[8]) 
{ 
  int p[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 
        }; 
  BYTE s[][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 
                } 
            }; 
  BYTE s_byte[64] = {0}; 
  BYTE s_byte1[64] = {0}; 
  BYTE row = 0, col = 0; 
  BYTE s_out_bit[8] = {0}; 
 
  //转成二进制字符串处理 
  ASCII2Bin(s_bit, s_byte); 
  for(int i = 0; i < 8; i++) 
  { 
    //0、5位为row，1、2、3、4位为col，在S表中选择一个八位的数 
    row = s_byte[i * 6] * 2 + s_byte[i * 6 + 5]; 
    col = s_byte[i * 6 + 1] * 8 + s_byte[i * 6 + 2] * 4 + s_byte[i * 6 + 3] * 2 + s_byte[i * 6 + 4]; 
    s_out_bit[i] = s[i][row][col]; 
  } 
  //将八个选择的八位数据压缩表示 
  s_out_bit[0] = (s_out_bit[0] << 4) + s_out_bit[1]; 
  s_out_bit[1] = (s_out_bit[2] << 4) + s_out_bit[3]; 
  s_out_bit[2] = (s_out_bit[4] << 4) + s_out_bit[5]; 
  s_out_bit[3] = (s_out_bit[6] << 4) + s_out_bit[7]; 
  //转成二进制字符串处理 
  ASCII2Bin(s_out_bit, s_byte); 
  //换位 
  for(i = 0; i < 32; i++) 
    s_byte1[i] = s_byte[p[i] - 1]; 
  //生成最后结果 
  Bin2ASCII(s_byte1, s_bit); 
} 
 

};