Java DES 算法加密

最新推荐文章于 2024-04-23 15:13:36 发布

duglyjp

最新推荐文章于 2024-04-23 15:13:36 发布

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CC 4.0 BY-SA版权

文章标签： java byte buffer string output 加密

本文链接：https://blog.youkuaiyun.com/duglyjp/article/details/6166256

本文提供了一个使用Java实现的DES加密与解密算法示例，详细展示了如何通过一系列复杂的数据变换过程完成加密和解密操作。代码中包含了密钥处理、数据块处理等关键步骤。

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对应于之前的iphone C语言DES加密。这次贴个Java的。

package desencrypter;

import java.io.UnsupportedEncodingException;

/************************************************
DES 加密算法
*************************************************/

public class DESEncrypter {
private static String strDefaultKey = "12345678";
public String digestHexStr;
//28
static final int pc_1_cp[]={
  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};
//28
static final int pc_1_dp[]={
  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};
//48
static final int pc_2p[]={
  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};
//16
static final int ls_countp[]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
//64
static final int iip_tab_p[]={
  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};
//64
static final int _iip_tab_p[]={
  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};
//48
static final int e_r_p[]={
  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
static final int local_PP[]={
  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};
//[8][4][16]
static final int ccom_SSS_p[][][]={
  {{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}}, /* err on */

  {{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}, /* err on */
  {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[][] C=new byte[17][28];
byte[][] D=new byte[17][28];
byte[][] K=new byte[17][48];
public DESEncrypter() {
  return;
}
/*iu2b把int转换成byte
*
*/
private static byte iu2b ( int input) {
  byte output1;
  output1 = (byte)(input & 0xff);
  return output1;
}

private static int b2iu(byte b) {
return b < 0 ? b & 0x7F + 128 : b;
}

/*把一个byte类型的数转换成十六进制的ASCII表示
*
*/
public static String byteHEX(byte ib) {
  char[] Digit = { '0','1','2','3','4','5','6','7','8','9', 'A','B','C','D','E','F' };
  char[] ob = new char[2];
  ob[0] = Digit[(ib >>> 4) & 0X0F];
  ob[1] = Digit[ib & 0X0F];
  String s = new String(ob);
  return s;
}
/*byte数组的块拷贝函数
*
*/
private void desMemcpy (byte[] output, byte[] input, int outpos, int inpos, int len) {
  int i;
  for (i = 0; i < len; i++)
   output[outpos + i] = input[inpos + i];
}
private void Fexpand0(byte[] in,byte[] out) {
  int divide;
  int i,j;
  byte temp1;

  for (i=0;i<8;i++)
  {
   divide=7;
   for (j=0;j<8;j++)
   {
    temp1=in[i];
    out[8*i+j]=iu2b((b2iu(temp1)>>>divide)&1);
    divide--;
   }
  }
}
private void FLS(byte[] bits,byte[] buffer,int count) {
  int i,j;
  for (i=0;i<28;i++)
  {
   buffer[i]=bits[(i+count)%28];
  }
}
private void Fson(byte[] cc,byte[] dd,byte[] kk) {
  int i,j;
  byte[] buffer=new byte[56];
  for (i=0;i<28;i++)
   buffer[i]=cc[i];

for (i=28;i<56;i++)
buffer[i]=dd[i-28];

  for (i=0;i<48;i++)
   kk[i]=buffer[pc_2p[i]-1];
}
private void Fsetkeystar(byte[] bits) {
  int i,j;

  for (i=0;i<28;i++)
   C[0][i]=bits[pc_1_cp[i]-1];
  for (i=0;i<28;i++)
   D[0][i]=bits[pc_1_dp[i]-1];
  for (j=0;j<16;j++)
  {
   FLS(C[j],C[j+1],ls_countp[j]);
   FLS(D[j],D[j+1],ls_countp[j]);
   Fson(C[j+1],D[j+1],K[j+1]);
  }
}
private void Fiip(byte[] text,byte[] ll,byte[] rr) {
  int i,j;
  byte[] buffer=new byte[64];
  byte[] tmp=new byte[64];
  Fexpand0(text,buffer);

for (i=0;i<32;i++)
ll[i]=buffer[iip_tab_p[i]-1];

  for (i=0;i<32;i++)
   rr[i]=buffer[iip_tab_p[i+32]-1];
}
private void Fs_box(byte[] aa,byte[] bb) {
  int i,j,k,m;
  int y,z;
  byte[] ss=new byte[8];
  m=0;
  for (i=0;i<8;i++)
  {
   j=6*i;
   y=b2iu(aa[j])*2+b2iu(aa[j+5]);
   z=b2iu(aa[j+1])*8+b2iu(aa[j+2])*4+b2iu(aa[j+3])*2+b2iu(aa[j+4]);
   ss[i]=iu2b(ccom_SSS_p[i][y][z]);
   y=3;
   for (k=0;k<4;k++)
   {
    bb[m++]=iu2b((b2iu(ss[i])>>>y)&1);
    y--;
   }

  }
}
private void FF(int n,byte[] ll,byte[] rr,byte[] LL,byte[] RR) {
  int i,j;
  byte[] buffer=new byte[64],tmp=new byte[64];
  for (i=0;i<48;i++)
   buffer[i]=rr[e_r_p[i]-1];
  for (i=0;i<48;i++)
   buffer[i]=iu2b((b2iu(buffer[i])+b2iu(K[n][i]))&1);

Fs_box(buffer,tmp);

for (i=0;i<32;i++)
buffer[i]=tmp[local_PP[i]-1];

for (i=0;i<32;i++)
RR[i]=iu2b((b2iu(buffer[i])+b2iu(ll[i]))&1);

  for (i=0;i<32;i++)
   LL[i]=rr[i];
}
private void _Fiip(byte[] text,byte[] ll,byte[] rr) {
  int i,j;
  byte[] tmp=new byte[64];
  for (i=0;i<32;i++)
   tmp[i]=ll[i];
  for (i=32;i<64;i++)
   tmp[i]=rr[i-32];
  for (i=0;i<64;i++)
   text[i]=tmp[_iip_tab_p[i]-1];
}
private void Fcompress016(byte[] out,byte[] in) {
  int times;
  int i,j;

  for (i=0;i<16;i++)
  {
   times=3;
   in[i]='0';
   for (j=0;j<4;j++)
   {
    in[i]=iu2b(b2iu(in[i])+(b2iu(out[i*16+j])<<times));
    times--;
   }
  }
}
void Fcompress0(byte[] out,byte[] in) {
  int times;
  int i,j;

  for (i=0;i<8;i++)
  {
   times=7;
   in[i]=0;
   for (j=0;j<8;j++)
   {
    in[i]=iu2b(b2iu(in[i])+(b2iu(out[i*8+j])<<times));
    times--;
   }
  }
}
private void Fencrypt0(byte[] text,byte[] mtext) {
  byte[] ll=new byte[64],rr=new byte[64],LL=new byte[64],RR=new byte[64];
  byte[] tmp=new byte[64];
  int i,j;
  Fiip(text,ll,rr);

  for (i=1;i<17;i++)
  {
   FF(i,ll,rr,LL,RR);
   for (j=0;j<32;j++)
   {
    ll[j]=LL[j];
    rr[j]=RR[j];
   }
  }

_Fiip(tmp,rr,ll);

  Fcompress0(tmp,mtext);
}
private void FDES(byte[] key,byte[] text,byte[] mtext) {
  byte[] tmp=new byte[64];
  Fexpand0(key,tmp);
  Fsetkeystar(tmp);
  Fencrypt0(text,mtext);
}

/*加密*/
public int ENCRYPT(byte[] key, byte[] s,byte[] d,int len ) {
  int i,j;
  byte[] cData=new byte[8];
  byte[] cEncryptData=new byte[8];
  for (i=0;i<len;i+=8) {
   if ((i+8)>len) {
    desMemcpy(cData,s,0,i,len-i);
    for (j = len-i; j < 8; j++)
     cData[j] = 0;
   } else
    desMemcpy(cData,s,0,i,8);
   FDES(key,cData,cEncryptData);
   desMemcpy(d,cEncryptData,i,0,8);

  }
  return i;
}
private void Fdiscrypt0(byte[] mtext,byte[] text) {
  byte[] ll=new byte[64],rr=new byte[64],LL=new byte[64],RR=new byte[64];
  byte[] tmp=new byte[64];
  int i,j;
  Fiip(mtext,ll,rr);

  for (i=16;i>0;i--)
  {
   FF(i,ll,rr,LL,RR);
   for (j=0;j<32;j++)
   {
    ll[j]=LL[j];
    rr[j]=RR[j];
   }
  }

_Fiip(tmp,rr,ll);

  Fcompress0(tmp,text);
}
/*****************************************************************************
* function: DES
* parameter:u_char * key; key for encrypt
* u_char* mtext; encipher data
* u_char* text; plain data
* return:none
*****************************************************************************/
private void _FDES(byte[] key,byte[] mtext,byte[] text) {
  byte[] tmp=new byte[64];
  Fexpand0(key,tmp);
  Fsetkeystar(tmp);
  Fdiscrypt0(mtext,text);
}
/*解密*/
public int DECRYPT(byte[] key, byte[] s,byte[] d,int len ) {
  int i;
  byte[] cData=new byte[8];
  byte[] cEncryptData=new byte[8];
  for(i=0;i<len;i+=8) {
   desMemcpy(cEncryptData,d,0,i,8);
   _FDES(key,cEncryptData,cData);
   desMemcpy(s,cData,i,0,8);
  }
  return i;
}

public static byte[] hexStr2ByteArr(String strIn) {
  byte[] arrB = strIn.getBytes();
  int iLen = arrB.length;

  byte[] arrOut = new byte[iLen / 2];
  for (int i = 0; i < iLen; i = i + 2) {
   String strTmp = new String(arrB, i, 2);
   arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
  }
  return arrOut;
}

/*
* 加密密钥获取
*/
public byte[] getEncryptKey(){
  DESEncrypter m = new DESEncrypter();
  return m.strDefaultKey.getBytes();
}
/*
* 加密
*/
public byte[] getEncryptData(String inputStr) throws UnsupportedEncodingException {
  int encryptDataLen;
  DESEncrypter _Des = new DESEncrypter();
  byte[] byte2=new byte[3000];
  byte[] byte1=inputStr.getBytes("UTF-8");
  byte[] byteMiW=new byte[3000];
  encryptDataLen=_Des.ENCRYPT(_Des.getEncryptKey(),byte1,byte2,byte1.length);
  digestHexStr = "";
  for (int i = 0; i < encryptDataLen; i++) {
   digestHexStr += byteHEX(byte2[i]);
  }
  System.out.println("密文:["+digestHexStr+"]");
  byteMiW=_Des.hexStr2ByteArr(digestHexStr);
  return byteMiW;
}

/*
* 解密
*/
public String getDecryptData(byte[] byteMiW) throws UnsupportedEncodingException {
  DESEncrypter _Des = new DESEncrypter();
  byte[] byteMingW=new byte[3000]; //明文
  _Des.DECRYPT(_Des.getEncryptKey(),byteMingW,byteMiW,byteMiW.length);
  return new String(new String(byteMingW,"UTF-8"));
}
public static void main(String args[]) throws UnsupportedEncodingException{
  DESEncrypter _Des = new DESEncrypter();
  byte[] MiW=new byte[3000];
  MiW = _Des.getEncryptData("你好，全世界的猴子");
  System.out.println("明文:["+ _Des.getDecryptData(MiW)+"]");
}
}