des.java

关于DES加密解密的程序

//版权所有--董清潭
package des;

public class Des {
  /* Table - s1 */
  protected static byte[][] 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 }};

  /* Table - s2 */
  protected static byte[][] 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 }};

  /* Table - s3 */
  protected static byte[][] 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 }};

  /* Table - s4 */
  protected static byte[][] 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 }};

  /* Table - s5 */
  protected static byte[][] 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 }};

  /* Table - s6 */
  protected static byte[][] 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 }};

  /* Table - s7 */
  protected static byte[][] 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}};

  /* Table - s8 */
  protected static byte[][] 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}};
  //用于 S盒查找以确定对应的4位二进制数据＃
  protected static byte[] binary={
	0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 
	0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 
	1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 
	1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1 };
  
  //存储将要加密的明文或将要解密的密文  
  protected byte[] workData=new byte[64];
  protected String dataSrc;
  protected String dataDest;
  /*实验性数据
  protected static byte[] workData={
  0,0,0,0,0,0,0,1, 0,0,1,0,0,0,1,1, 0,1,0,0,0,1,0,1, 0,1,1,0,0,1,1,1,
  1,0,0,0,1,0,0,1, 1,0,1,0,1,0,1,1, 1,1,0,0,1,1,0,1, 1,1,1,0,1,1,1,1
  };
  */
  //用于数据变换中转
  protected byte[] bufout=new byte[64];
  //最终生成的密文或解密所得的明文
  protected byte[] output=new byte[64];
  protected byte[] Ln=new byte[32];
  protected byte[] Rn=new byte[32];
  protected byte[] LR=new byte[32];
  protected byte[] ER=new byte[48];
  protected byte[] temp=new byte[32];
  protected byte[] result=new byte[8];
  protected byte[] ki;
  protected String key;
  protected int readLen;
  protected boolean encFlag;   //1为加密，0为解密
  protected SubKey subKey;
  

  protected void convert4CharTo64bit(String data){
  	for (int i = 0; i<64; i++) {
  		workData[i]=0;
	}
	/* Convert from 4-char(coded in unicode) data into 64-bit data */ 

	for (int i = 0; i < readLen; i++) { 
		int j=data.charAt(i);
		workData[16*i+0]=(byte)((j/32768)%2);
	  	workData[16*i+1]=(byte)((j/16384)%2);
	  	workData[16*i+2]=(byte)((j/8192)%2);
	  	workData[16*i+3]=(byte)((j/4096)%2);
	  	workData[16*i+4]=(byte)((j/2048)%2);
	  	workData[16*i+5]=(byte)((j/1024)%2);
	  	workData[16*i+6]=(byte)((j/512)%2);
	  	workData[16*i+7]=(byte)((j/256)%2);
	  	workData[16*i+8]=(byte)((j/128)%2);
	  	workData[16*i+9]=(byte)((j/64)%2);
	  	workData[16*i+10]=(byte)((j/32)%2);
	  	workData[16*i+11]=(byte)((j/16)%2);
	  	workData[16*i+12]=(byte)((j/8)%2);
	  	workData[16*i+13]=(byte)((j/4)%2);
	  	workData[16*i+14]=(byte)((j/2)%2);
	  	workData[16*i+15]=(byte)(j%2);
	 } 
  }

  protected void convert64bitTo4Char(){		
	int j;
	char ch;
	StringBuffer strbuf=new StringBuffer();
	for (int i = 0; i<4; i++) {
		j=0;
		j=32768*output[16*i+0]+16384*output[16*i+1]+8192*output[16*i+2]+4096*output[16*i+3]+
		2048*output[16*i+4]+1024*output[16*i+5]+512*output[16*i+6]+256*output[16*i+7]+
		128*output[16*i+8]+64*output[16*i+9]+32*output[16*i+10]+16*output[16*i+11]+
		8*output[16*i+12]+4*output[16*i+13]+2*output[16*i+14]+output[16*i+15];
		ch=(char)j;	
		strbuf.append(ch);			 
	}
	dataDest=strbuf.toString();
}

  protected void IP(){
  	/* Initial Permutation of Data */ 
	bufout[ 0] = workData[57]; 
	bufout[ 1] = workData[49]; 
	bufout[ 2] = workData[41]; 
	bufout[ 3] = workData[33]; 
	bufout[ 4] = workData[25]; 
	bufout[ 5] = workData[17]; 
	bufout[ 6] = workData[ 9]; 
	bufout[ 7] = workData[ 1]; 
	bufout[ 8] = workData[59]; 
	bufout[ 9] = workData[51]; 
	bufout[10] = workData[43]; 
	bufout[11] = workData[35]; 
	bufout[12] = workData[27]; 
	bufout[13] = workData[19]; 
	bufout[14] = workData[11]; 
	bufout[15] = workData[ 3]; 
	bufout[16] = workData[61]; 
	bufout[17] = workData[53]; 
	bufout[18] = workData[45]; 
	bufout[19] = workData[37]; 
	bufout[20] = workData[29]; 
	bufout[21] = workData[21]; 
	bufout[22] = workData[13]; 
	bufout[23] = workData[ 5]; 
	bufout[24] = workData[63]; 
	bufout[25] = workData[55]; 
	bufout[26] = workData[47]; 
	bufout[27] = workData[39]; 
	bufout[28] = workData[31]; 
	bufout[29] = workData[23]; 
	bufout[30] = workData[15]; 
	bufout[31] = workData[ 7]; 
	bufout[32] = workData[56]; 
	bufout[33] = workData[48]; 
	bufout[34] = workData[40]; 
	bufout[35] = workData[32]; 
	bufout[36] = workData[24]; 
	bufout[37] = workData[16]; 
	bufout[38] = workData[ 8]; 
	bufout[39] = workData[ 0]; 
	bufout[40] = workData[58]; 
	bufout[41] = workData[50]; 
	bufout[42] = workData[42]; 
	bufout[43] = workData[34]; 
	bufout[44] = workData[26]; 
	bufout[45] = workData[18]; 
	bufout[46] = workData[10]; 
	bufout[47] = workData[ 2]; 
	bufout[48] = workData[60]; 
	bufout[49] = workData[52]; 
	bufout[50] = workData[44]; 
	bufout[51] = workData[36]; 
	bufout[52] = workData[28]; 
	bufout[53] = workData[20]; 
	bufout[54] = workData[12]; 
	bufout[55] = workData[ 4]; 
	bufout[56] = workData[62]; 
	bufout[57] = workData[54]; 
	bufout[58] = workData[46]; 
	bufout[59] = workData[38]; 
	bufout[60] = workData[30]; 
	bufout[61] = workData[22]; 
	bufout[62] = workData[14]; 
	bufout[63] = workData[ 6]; 
	
  }
  
  protected void XOR(byte[] op1,byte[] op2){
  	int len=op1.length;
  	for (int i = 0; i<len; i++) {
  		op1[i]=(byte)(op1[i] ^ op2[i]);
	}
  }
  
  protected void expand32To48bit(byte[] op){
  	/* Permute - E */ 
	ER[ 0] = op[31]; 
	ER[ 1] = op[ 0]; 
	ER[ 2] = op[ 1]; 
	ER[ 3] = op[ 2]; 
	ER[ 4] = op[ 3]; 
	ER[ 5] = op[ 4]; 
	ER[ 6] = op[ 3]; 
	ER[ 7] = op[ 4]; 
	ER[ 8] = op[ 5]; 
	ER[ 9] = op[ 6]; 
	ER[10] = op[ 7]; 
	ER[11] = op[ 8]; 
	ER[12] = op[ 7]; 
	ER[13] = op[ 8]; 
	ER[14] = op[ 9]; 
	ER[15] = op[10]; 
	ER[16] = op[11]; 
	ER[17] = op[12]; 
	ER[18] = op[11]; 
	ER[19] = op[12]; 
	ER[20] = op[13]; 
	ER[21] = op[14]; 
	ER[22] = op[15]; 
	ER[23] = op[16]; 
	ER[24] = op[15]; 
	ER[25] = op[16]; 
	ER[26] = op[17]; 
	ER[27] = op[18]; 
	ER[28] = op[19]; 
	ER[29] = op[20]; 
	ER[30] = op[19]; 
	ER[31] = op[20]; 
	ER[32] = op[21]; 
	ER[33] = op[22]; 
	ER[34] = op[23]; 
	ER[35] = op[24]; 
	ER[36] = op[23]; 
	ER[37] = op[24]; 
	ER[38] = op[25]; 
	ER[39] = op[26]; 
	ER[40] = op[27]; 
	ER[41] = op[28]; 
	ER[42] = op[27]; 
	ER[43] = op[28]; 
	ER[44] = op[29]; 
	ER[45] = op[30]; 
	ER[46] = op[31]; 
	ER[47] = op[ 0]; 
  }
  protected void sBox(){
  	/* 8 s-functions */
  	int valindex; 
	valindex = s1[2*ER[ 0]+ER[ 5]][2*(2*(2*ER[ 1]+ER[ 2])+ ER[ 3])+ER[ 4]]; 
	valindex = valindex * 4; 
	temp[ 0] = (byte)binary[0+valindex]; 
	temp[ 1] = (byte)binary[1+valindex]; 
	temp[ 2] = (byte)binary[2+valindex]; 
	temp[ 3] = (byte)binary[3+valindex]; 
	valindex = s2[2*ER[ 6]+ER[11]][2*(2*(2*ER[ 7]+ER[ 8])+ ER[ 9])+ER[10]]; 
	valindex = valindex = valindex * 4;  
	temp[ 4] = (byte)binary[0+valindex]; 
	temp[ 5] = (byte)binary[1+valindex]; 
	temp[ 6] = (byte)binary[2+valindex]; 
	temp[ 7] = (byte)binary[3+valindex]; 
	valindex = s3[2*ER[12]+ER[17]][2*(2*(2*ER[13]+ER[14])+ ER[15])+ER[16]]; 
	valindex = valindex = valindex * 4; 
	temp[ 8] = (byte)binary[0+valindex]; 
	temp[ 9] = (byte)binary[1+valindex]; 
	temp[10] = (byte)binary[2+valindex]; 
	temp[11] = (byte)binary[3+valindex]; 
	valindex = s4[2*ER[18]+ER[23]][2*(2*(2*ER[19]+ER[20])+ER[21])+ER[22]]; 
	valindex = valindex = valindex * 4; 
	temp[12] = (byte)binary[0+valindex]; 
	temp[13] = (byte)binary[1+valindex]; 
	temp[14] = (byte)binary[2+valindex]; 
	temp[15] = (byte)binary[3+valindex]; 
	valindex = s5[2*ER[24]+ER[29]][2*(2*(2*ER[25]+ER[26])+ER[27])+ER[28]]; 
	valindex = valindex = valindex * 4; 
	temp[16] = (byte)binary[0+valindex]; 
	temp[17] = (byte)binary[1+valindex]; 
	temp[18] = (byte)binary[2+valindex]; 
	temp[19] = (byte)binary[3+valindex]; 
	valindex = s6[2*ER[30]+ER[35]][2*(2*(2*ER[31]+ER[32])+ ER[33])+ER[34]]; 
	valindex = valindex = valindex * 4; 
	temp[20] = (byte)binary[0+valindex]; 
	temp[21] = (byte)binary[1+valindex]; 
	temp[22] = (byte)binary[2+valindex]; 
	temp[23] = (byte)binary[3+valindex]; 
	valindex = s7[2*ER[36]+ER[41]][2*(2*(2*ER[37]+ER[38])+ ER[39])+ER[40]]; 
	valindex = valindex = valindex * 4; 
	temp[24] = (byte)binary[0+valindex]; 
	temp[25] = (byte)binary[1+valindex]; 
	temp[26] = (byte)binary[2+valindex]; 
	temp[27] = (byte)binary[3+valindex]; 
	valindex = s8[2*ER[42]+ER[47]][2*(2*(2*ER[43]+ER[44])+ ER[45])+ER[46]]; 
	valindex = valindex = valindex * 4; 
	temp[28] = (byte)binary[0+valindex]; 
	temp[29] = (byte)binary[1+valindex]; 
	temp[30] = (byte)binary[2+valindex]; 
	temp[31] = (byte)binary[3+valindex]; 
  }
  protected void p(){
  	/* Permute - P */ 
	Rn[ 0] = temp[15]; 
	Rn[ 1] = temp[ 6]; 
	Rn[ 2] = temp[19]; 
	Rn[ 3] = temp[20]; 
	Rn[ 4] = temp[28]; 
	Rn[ 5] = temp[11]; 
	Rn[ 6] = temp[27]; 
	Rn[ 7] = temp[16]; 
	Rn[ 8] = temp[ 0]; 
	Rn[ 9] = temp[14]; 
	Rn[10] = temp[22]; 
	Rn[11] = temp[25]; 
	Rn[12] = temp[ 4]; 
	Rn[13] = temp[17]; 
	Rn[14] = temp[30]; 
	Rn[15] = temp[ 9]; 
	Rn[16] = temp[ 1]; 
	Rn[17] = temp[ 7]; 
	Rn[18] = temp[23]; 
	Rn[19] = temp[13]; 
	Rn[20] = temp[31]; 
	Rn[21] = temp[26]; 
	Rn[22] = temp[ 2]; 
	Rn[23] = temp[ 8]; 
	Rn[24] = temp[18]; 
	Rn[25] = temp[12]; 
	Rn[26] = temp[29]; 
	Rn[27] = temp[ 5]; 
	Rn[28] = temp[21]; 
	Rn[29] = temp[10]; 
	Rn[30] = temp[ 3]; 
	Rn[31] = temp[24];

  }
  protected void IIP(){
	/* Inverse Initial Permutation */ 
	output[ 0] = bufout[39]; 
	output[ 1] = bufout[ 7]; 
	output[ 2] = bufout[47]; 
	output[ 3] = bufout[15]; 
	output[ 4] = bufout[55]; 
	output[ 5] = bufout[23]; 
	output[ 6] = bufout[63]; 
	output[ 7] = bufout[31]; 
	output[ 8] = bufout[38]; 
	output[ 9] = bufout[ 6]; 
	output[10] = bufout[46]; 
	output[11] = bufout[14]; 
	output[12] = bufout[54]; 
	output[13] = bufout[22]; 
	output[14] = bufout[62]; 
	output[15] = bufout[30]; 
	output[16] = bufout[37]; 
	output[17] = bufout[ 5]; 
	output[18] = bufout[45]; 
	output[19] = bufout[13]; 
	output[20] = bufout[53]; 
	output[21] = bufout[21]; 
	output[22] = bufout[61]; 
	output[23] = bufout[29]; 
	output[24] = bufout[36]; 
	output[25] = bufout[ 4]; 
	output[26] = bufout[44]; 
	output[27] = bufout[12]; 
	output[28] = bufout[52]; 
	output[29] = bufout[20]; 
	output[30] = bufout[60]; 
	output[31] = bufout[28]; 
	output[32] = bufout[35]; 
	output[33] = bufout[ 3]; 
	output[34] = bufout[43]; 
	output[35] = bufout[11]; 
	output[36] = bufout[51]; 
	output[37] = bufout[19]; 
	output[38] = bufout[59]; 
	output[39] = bufout[27]; 
	output[40] = bufout[34]; 
	output[41] = bufout[ 2]; 
	output[42] = bufout[42]; 
	output[43] = bufout[10]; 
	output[44] = bufout[50]; 
	output[45] = bufout[18]; 
	output[46] = bufout[58]; 
	output[47] = bufout[26]; 
	output[48] = bufout[33]; 
	output[49] = bufout[ 1]; 
	output[50] = bufout[41]; 
	output[51] = bufout[ 9]; 
	output[52] = bufout[49]; 
	output[53] = bufout[17]; 
	output[54] = bufout[57]; 
	output[55] = bufout[25]; 
	output[56] = bufout[32]; 
	output[57] = bufout[ 0]; 
	output[58] = bufout[40]; 
	output[59] = bufout[ 8]; 
	output[60] = bufout[48]; 
	output[61] = bufout[16]; 
	output[62] = bufout[56]; 
	output[63] = bufout[24];
  }
  
  public Des(String key){
  	this.key=key;
  	subKey=new SubKey(key);
  }
  
  //解密	
  public String enc(String dataSrc,int readLen) {
  	this.dataSrc=dataSrc;
  	this.readLen=readLen;
  	convert4CharTo64bit(dataSrc);
  	IP();
  	for (int i = 0; i<32; i++) {
  			Ln[i]=bufout[i];     // L0
  			Rn[i]=bufout[32+i];  //R0
	}  	
  	for (int iter = 1; iter<17; iter++) {
  		for (int i = 0; i<32; i++) {
  			LR[i]=Ln[i];     
  			Ln[i]=Rn[i];
	    }  	
		expand32To48bit(Rn);  //Rn-1 expand to 48 bit save to ER[]
	  	switch(iter)
		{
			case 1:
				ki=subKey.k1; break;
			case 2:
				ki=subKey.k2; break;
			case 3:
				ki=subKey.k3; break;
			case 4:
				ki=subKey.k4; break;
			case 5:
				ki=subKey.k5; break;
			case 6:
				ki=subKey.k6; break;
			case 7:
				ki=subKey.k7; break;
			case 8:
				ki=subKey.k8; break;
			case 9:
				ki=subKey.k9; break;
			case 10:
				ki=subKey.k10; break;
			case 11:
				ki=subKey.k11; break;
			case 12:
				ki=subKey.k12; break;
			case 13:
				ki=subKey.k13; break;
			case 14:
				ki=subKey.k14; break;
			case 15:
				ki=subKey.k15; break;
			case 16:
				ki=subKey.k16; break;
					
		}
		
		XOR(ER,ki);
  		sBox();
  		p();
  		XOR(Rn,LR);
	}
	
	for (int i = 0; i<32; i++) {
		bufout[i]=Rn[i];
		bufout[32+i]=Ln[i];
    }
    IIP();
    convert64bitTo4Char();
    return dataDest;
   }
  //加密
  public String dec(String dataSrc,int readLen){
  	this.dataSrc=dataSrc;
  	this.readLen=readLen;
  	convert4CharTo64bit(dataSrc);
  	IP();
  	for (int i = 0; i<32; i++) {
  			Ln[i]=bufout[i];     // L0
  			Rn[i]=bufout[32+i];  //R0
	}  	
  	for (int iter = 1; iter<17; iter++) {
  		for (int i = 0; i<32; i++) {
  			LR[i]=Ln[i];     
  			Ln[i]=Rn[i];
	    }  	
		expand32To48bit(Rn);  //Rn-1 expand to 48 bit save to ER[]
		switch(iter)
		{
			case 1:
				ki=subKey.k16; break;
			case 2:
				ki=subKey.k15; break;
			case 3:
				ki=subKey.k14; break;
			case 4:
				ki=subKey.k13; break;
			case 5:
				ki=subKey.k12; break;
			case 6:
				ki=subKey.k11; break;
			case 7:
				ki=subKey.k10; break;
			case 8:
				ki=subKey.k9; break;
			case 9:
				ki=subKey.k8; break;
			case 10:
				ki=subKey.k7; break;
			case 11:
				ki=subKey.k6; break;
			case 12:
				ki=subKey.k5; break;
			case 13:
				ki=subKey.k4; break;
			case 14:
				ki=subKey.k3; break;
			case 15:
				ki=subKey.k2; break;
			case 16:
				ki=subKey.k1; break;
					
		}
		XOR(ER,ki);
  		sBox();
  		p();
  		XOR(Rn,LR);
  		
	}
	
	for (int i = 0; i<32; i++) {
		bufout[i]=Rn[i];
		bufout[32+i]=Ln[i];
    }
    IIP();
    convert64bitTo4Char();
    return dataDest;
  }

}