des.c

ansiX9.8 算法的C语言实现,同时包含DES算法的C语言实现

/*
	DES加密, 解密程序
	作者: 卢旭潮
	时间: 1997.8.31
*/

#include <stdio.h>
#include <stdlib.h>

static void conv_8to64(const unsigned char *src, unsigned char *dst)
{
  int i, j;
  unsigned char *ptr = dst;
  for (i = 0; i < 8; i++)
	 for (j = 0; j < 8; j++)
		*ptr++ = (src[i] >> (7 - j)) & 0x01;
}

static void IP(const unsigned char *src, unsigned char *dst)
{
  int i;
  unsigned char IP_table[] = {
	 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,
	 56, 48, 40, 32, 24, 16,  8,  0,
	 58, 50, 42, 34, 26, 18, 10,  2,
	 60, 52, 44, 36, 28, 20, 12,  4,
	 62, 54, 46, 38, 30, 22, 14,  6
  };
  for (i = 0; i < 64; i++)
	 dst[i] = src[IP_table[i]];
}

static void PC_1(const unsigned char *src, unsigned char *dst)
{
  int i;
  unsigned char PC_table[] = {
    56, 48, 40, 32, 24, 16,  8,
     0, 57, 49, 41, 33, 25, 17,
     9,  1, 58, 50, 42, 34, 26,
	 18, 10,  2, 59, 51, 43, 35,
	 62, 54, 46, 38, 30, 22, 14,
	  6, 61, 53, 45, 37, 29, 21,
	 13,  5, 60, 52, 44, 36, 28,
	 20, 12,  4, 27, 19, 11,  3
  };
  for (i = 0; i < 56; i++)
	 dst[i] = src[PC_table[i]];
}

static void LS(unsigned char *data, unsigned char num)
{
  unsigned char i, temp, j;
  unsigned char temp1;
  if (num == 1) {
	 temp = data[0];
	 for (i = 0; i < 27; i++)
		data[i] = data[i+1];
	 data[27] = temp;
  }
  else {
	 temp = data[0];
	 temp1 = data[1];
	 for (i = 0; i < 26; i++)
		data[i] = data[i+2];
	 data[26] = temp;
	 data[27] = temp1;
  }
/*  for (j = 0; j < num; j++) {
	 temp = data[0];
	 for (i = 0; i < 27; i++)
		data[i] = data[i+1];
	 data[27] = temp;
  }
*/
}

static void PC_2(unsigned char *src, unsigned char *dst)
{
  int i;
  unsigned char PC2_table[] = {
	 13, 16, 10, 23,  0,  4,
	  2, 27, 14,  5, 20,  9,
	 22, 18, 11,  3, 25,  7,
	 15,  6, 26, 19, 12,  1,
	 40, 51, 30, 36, 46, 54,
	 29, 39, 50, 44, 32, 47,
    43, 48, 38, 55, 33, 52,
    45, 41, 49, 35, 28, 31
  };
  for (i = 0; i < 48; i++)
    dst[i] = src[PC2_table[i]];
}

static void get_key(const unsigned char *src, unsigned char dst[16][48])
{
  unsigned char buf[64], buf1[56];
  int i;
  unsigned char num;
  conv_8to64(src, buf);
  /* 排列选择1 */
  PC_1(buf, buf1);

  for (i = 0; i < 16; i++) {
    if (i == 0 || i == 1 || i == 8 || i == 15)
      num = 1;
    else
      num = 2;
    /* 循环左移 */
    LS(buf1,  num);
    LS(buf1+28,  num);
    /* 排列选择2 */
    PC_2(buf1, dst[i]);
  }
}

static void expand(unsigned char *src, unsigned char *dst)
{
  int i;
  unsigned char E_table[] = {
    31,  0,  1,  2,  3,  4,
     3,  4,  5,  6,  7,  8,
     7,  8,  9, 10, 11, 12,
    11, 12, 13, 14, 15, 16,
    15, 16, 17, 18, 19, 20,
    19, 20, 21, 22, 23, 24,
    23, 24, 25, 26, 27, 28,
    27, 28, 29, 30, 31,  0
  };
  for (i = 0; i < 48; i++)
    dst[i] = src[E_table[i]];
}

static void do_xor(unsigned char *src1, unsigned char *src2, int num)
{
  int i;
  for (i = 0; i < num; i++)
	 src1[i] ^= src2[i];
}

static void compress(unsigned char *data)
{
  int i, j, k;
  unsigned char buf[48], ch;
  unsigned char S_box[8][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}
    }
  };
  memcpy(buf, data, 48);
  for (i = 0; i < 8; i++) {
	 j = (buf[6*i] << 1) | buf[6*i+5];
	 k = (buf[6*i+1] << 3) | (buf[6*i+2] << 2) | (buf[6*i+3] << 1) | buf[6*i+4];
	 ch = S_box[i][j][k];
	 data[4*i] = (ch >> 3) & 0x01;
    data[4*i+1] = (ch >> 2) & 0x01;
    data[4*i+2] = (ch >> 1) & 0x01;
    data[4*i+3] = ch & 0x01;
  }
}

static void P_sort(unsigned char *data)
{
  unsigned char buf[32];
  int i;
  unsigned char P_table[] = {
    15,  6, 19, 20,
    28, 11, 27, 16,
     0, 14, 22, 25,
     4, 17, 30,  9,
     1,  7, 23, 13,
    31, 26,  2,  8,
    18, 12, 29,  5,
    21, 10,  3, 24
  };

  memcpy(buf, data, 32);
  for (i = 0; i < 32; i++)
    data[i] = buf[P_table[i]];
}

static void IP_1(unsigned char *src, unsigned char *dst)
{
  int i;
  unsigned char RIP_table[] = {
    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,
    32,  0, 40,  8, 48, 16, 56, 24
  };
  for (i = 0; i < 64; i++)
    dst[i] = src[RIP_table[i]];
}

static void conv_64to8(unsigned char *src, unsigned char *dst)
{
  int i, j;

  memset(dst, 0, 8);
  for (i = 0; i < 8; i++) {
    for (j = 0; j < 8; j++) {
		dst[i] |= src[8*i+j] << (7-j);
    }
  }
}

//************************************************************************
// 函数名： DES
// 功能  ： 标准DES算法
// 参数  ： src: 原码， dst: 目标码, key: 加密的密钥
//          flag:  'D'或'd': 解密, 'E' 或 'e': 加密
// 时间：   1998.3.24
//------------------------------------------------------------------------
void DES(const unsigned char *src, unsigned char *dst, const unsigned char *key, unsigned char flag)
{
  unsigned char buf[64], buf1[64];
  unsigned char kbuf[16][48];
  int           i;
  /* 得到16个密钥 */
  get_key(key, kbuf);

  conv_8to64(src, buf);
  /* 第一步: 初始排序IP(Initial Permutation), 目的是将明文的顺序打乱 */
  IP(buf, buf1);
  /* 第二步: 乘积变换, 为DES算法的核心 */
  for (i = 0; i < 16; i++) {
    /* 扩展置换, 把32位扩展为48位 */
    expand(buf1+32, buf);
	 /* 与子密钥进行异或 */
    if (flag == 'e' || flag == 'E')
      do_xor(buf, kbuf[i], 48);
    else
      do_xor(buf, kbuf[15-i], 48);
    /* 压缩代换, 48位变换为32位 */
    compress(buf);
    /* P排列 */
    P_sort(buf);
	 do_xor(buf, buf1, 32);
    memcpy(buf1, buf1+32, 32);
    memcpy(buf1+32, buf, 32);
  }
  /* 第三步: 最终排列 */
  memcpy(buf, buf1+32, 32);
  memcpy(buf+32, buf1, 32);
  IP_1(buf, buf1);
  conv_64to8(buf1, dst);
}

//************************************************************************
// 函数名： DoMac 
// 功能  ： X9.9 MAC算法
// 参数  ： strMacBuf: 参与MAC的数据 
//          nLen:  MACBUF 的长度 
//          strMac: MAC值 (8 bytes) 
//          strKey: KEY值 (8 bytes) 
// 时间：   2000.3.30 
//------------------------------------------------------------------------
int DoMac(strMacBuf, nLen, strMac, strKey)
unsigned char *strMacBuf, *strMac, *strKey;
int    nLen;
{
    int i;
    unsigned char tmp[8];

    memset(strMac, 0, 8);
    for(i = 0; i < nLen / 8; i++ ) {
      do_xor(strMac, strMacBuf+i*8, 8);
      DES(strMac, tmp, strKey, 'E'); 
      memcpy(strMac, tmp, 8);
    }
    if (nLen-i*8 > 0) { 
      do_xor(strMac, strMacBuf+i*8, nLen-i*8);
      DES(strMac, tmp, strKey, 'E'); 
      memcpy(strMac, tmp, 8);
    }

    return(0);
}

//************************************************************************
// 函数名： DoMacSimple 
// 功能  ： 先以八字节为单位进行异或，最后做DES。 
// 参数  ： strMacBuf: 参与MAC的数据 
//          nLen:  MACBUF 的长度 
//          strMac: MAC值 (8 bytes) 
//          strKey: KEY值 (8 bytes) 
// 时间：   2000.8.12 
//------------------------------------------------------------------------
int DoMacSimple(strMacBuf, nLen, strMac, strKey)
unsigned char *strMacBuf, *strMac, *strKey;
int    nLen;
{
    int i;
    unsigned char tmp[8];

    memset(strMac, 0, 8);
    for(i = 0; i < nLen / 8; i++ ) {
      do_xor(strMac, strMacBuf+i*8, 8);
    }
    if (nLen-i*8 > 0) { 
      do_xor(strMac, strMacBuf+i*8, nLen-i*8);
    }
/*
  fprintf(stderr, "Before Mac: ");
for (i = 0; i < 8; i++)
  fprintf(stderr, "%02x.", strMac[i]);
fprintf(stderr, "\n");
*/
    DES(strMac, tmp, strKey, 'E'); 
    memcpy(strMac, tmp, 8);
/*
  fprintf(stderr, "After Mac: ");
for (i = 0; i < 8; i++)
  fprintf(stderr, "%02x.", strMac[i]);
fprintf(stderr, "\n");
*/
    return(0);
}

void  HostDes(card_no, work_key, pin, encrypt_pin, flag)
unsigned char *card_no, *work_key, *pin, *encrypt_pin, flag;
{
   unsigned char  card_buf[16], pin_buf[17], enpin_buf[8];
   unsigned char  key_buf[8];
   int   i, ii;

   DspToHex(work_key, key_buf, 8);

/*
   memset(card_buf, 'F', sizeof(card_buf));
   memcpy(card_buf, card_no+1, 15);
   DspToHex(card_buf, card_buf, 8);
   card_buf[0] = 0;
*/
   memset(card_buf, 0, sizeof(card_buf)); 
   memcpy(card_buf+1, card_no+strlen(card_no)-13, 12);
   DspToHex(card_buf+1, card_buf+1, 6);
   card_buf[0] = 0;

   if(flag == 'e' || flag == 'E')
   {
       enpin_buf[0] = strlen(pin);
       memcpy(pin_buf, pin, strlen(pin));
       ii = strlen(pin);
       for(i = ii; i<17; i++)
       {
	  pin_buf[i] = 'F';
       }
       DspToHex(pin_buf, pin_buf, 8);

       do_xor(card_buf, pin_buf, 7);

       memcpy(enpin_buf+1, card_buf, 7);
for (i = 0; i < 8; i++)
  fprintf(stderr, "%02x.", enpin_buf[i]);
fprintf(stderr, "\n");

       DES(enpin_buf, encrypt_pin, key_buf, 'E');

       return;
   }

   if(flag == 'd' || flag == 'D' )
   {
       DES(encrypt_pin, pin_buf, key_buf, 'D');

       do_xor(pin_buf+1, card_buf, 7);

       HexToDsp(pin_buf+1, pin, 7);

       pin[pin_buf[0]&0x0f] = 0;

       return;
   }
}