📄 des.java
字号:
//密钥的Kn的生成
//package TestJava;
import java.io.*;
import java.lang.Long;
import java.lang.Integer;
public class DES
{
public static StringBuffer cndn(StringBuffer c,int j)
{
String c1front=c.substring(j,28);
String c1back=c.substring(0,j);
StringBuffer c1=new StringBuffer(28);
c1.append(c1front);
c1.append(c1back);
return c1;
}
//-----异或运算-----------------------
public static StringBuffer xorfunction(StringBuffer A,StringBuffer B)
{
StringBuffer C=new StringBuffer(32);
String Astring=A.substring(0); //把StringBuffer变为String
String Bstring=B.substring(0);
Long ALong=Long.valueOf(Astring,2);
Long BLong=Long.valueOf(Bstring,2);
long Along=ALong.longValue();
long Blong=BLong.longValue();
long c=Along^Blong;
String cString=Long.toBinaryString(c); //把异或得到的结果转换为二进制串
StringBuffer c32=new StringBuffer(32);
c32.append(cString);
if(cString.length()<32)
for(int i=0;i<(32-cString.length());i++)
c32.insert(0,0);
C.append(c32);
return C;
}
//----函数f-------------------------------------------
public static StringBuffer Ffunction(StringBuffer R,StringBuffer K)
{
//s替换表
int s[][][]={{{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}}};
//置换
int displaceans1[]={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};
//-----------------
StringBuffer ans=new StringBuffer(32);
StringBuffer Rnew=new StringBuffer(48);
Rnew.append(R);
//Rnew=R;
Rnew.insert(0,R.charAt(31));
for(int i=5;i<47;i=i+5) //把32位的R插值变换成48位
{
Rnew.insert(i,Rnew.charAt(i));
i=i+1;
if(i>46) break;
Rnew.insert(i,Rnew.charAt(i-2));
}
Rnew.insert(47,R.charAt(0));
String Rnewstring=Rnew.substring(0); //把StringBuffer变为String
String Kstring=K.substring(0);
Long RLong=Long.valueOf(Rnewstring,2);
Long KLong=Long.valueOf(Kstring,2);
long Rlong=RLong.longValue();
long Klong=KLong.longValue();
long xor=Rlong^Klong;
String ans48string=Long.toBinaryString(xor); //把异或得到的结果转换为二进制串,可能不是48位
StringBuffer ans48=new StringBuffer(48);
ans48.append(ans48string);
if(ans48.length()<48)
for(int i=0;i<(48-ans48string.length());i++) //把异或得到的二进制串补齐48位
ans48.insert(0,0);
String R4=null,R6=null,R6side=null,R6center=null;
StringBuffer R6side_Buffer=new StringBuffer(2);
Long xLong,yLong;
int j=0,sanswer,x,y;
StringBuffer ans1=new StringBuffer(32);
StringBuffer R4_4=new StringBuffer(4);
for(int i=0;i<8;i++)
{
R6=ans48.substring(j,j+6);
R6center=R6.substring(1,5);
R6side_Buffer=new StringBuffer(2);
R6side_Buffer.append(R6.charAt(0));
R6side_Buffer.append(R6.charAt(5));
R6side=R6side_Buffer.substring(0); //把StringBuffer变为String
xLong=Long.valueOf(R6side,2); //计算在s数组中的位置
yLong=Long.valueOf(R6center,2);
x=(int)xLong.longValue();
y=(int)yLong.longValue();
sanswer=s[i][x][y];
R4=null;
R4=Integer.toBinaryString(sanswer); //六位变四位
R4_4=null;
R4_4=new StringBuffer(4);
R4_4.append(R4);
if(R4.length()<4)
for(int m=0;m<(4-R4.length());m++)
R4_4.insert(0,0);
ans1.append(R4_4); //得到32位字符串
j=j+6;
}
//-----------------------
//置换
for(int i=0;i<32;i++)
{
ans.insert(i,ans1.charAt(displaceans1[i]-1));
}
return ans;
}
//-----------加密----------------------------
//-------------------------------------------
public static void encodefunction()throws IOException
{
BufferedReader keyinCipher=new BufferedReader(new InputStreamReader(System.in));
System.out.println("对明文进行加密");
System.out.print("请输入密钥：");
String Cipher;
Cipher=keyinCipher.readLine(); //读入密钥
System.out.println();
int Cipherlength=Cipher.length();
if(Cipherlength!=16)
System.out.println("密钥位数不对");
BufferedReader keyinplain=new BufferedReader(new InputStreamReader(System.in));
System.out.print("请输入明文:");
String plaintext;
plaintext=keyinplain.readLine(); //读入明文
System.out.println();
int plaintextlength=plaintext.length();
if(plaintextlength!=16)
System.out.println("明文位数不对");
//String Cipher=new String("123abc1111111111");
//System.out.print("密钥为:");
//System.out.println(Cipher); //输出密钥
StringBuffer Cipher_code=new StringBuffer(64);
StringBuffer binarystr=new StringBuffer(4);
int Cipher_length,w;
Cipher_length=Cipher.length();
for(int i=0;i<Cipher_length;i++)
{
String chartostr=null,binarychar=null;
binarystr=null;
binarystr=new StringBuffer(4);
chartostr=String.valueOf(Cipher.charAt(i));
w=Integer.parseInt(chartostr,16); //把每一个字母转换为int
binarychar=Integer.toBinaryString(w);
binarystr.append(binarychar);
if(binarychar.length()<5)
{
for(int j=0;j<4-binarychar.length();j++)
{
binarystr.insert(0,0);
}
} //把密钥中的每一位变为四位
//的二进制字符串
Cipher_code.append(binarystr);
}
//System.out.println(Cipher_code); //输出密钥所对应的二进制码
//-----------------------------------------------
//转换为56位编码Cipher_code56
/*
StringBuffer Cipher_code56=new StringBuffer(56);
int j=0;
for(int i=0;i<64;i++)
{
if((i+1)%8==0)
continue;
else
{
Cipher_code56.insert(j,Cipher_code.charAt(i));
j++;
}
}
System.out.println(Cipher_code56);
*/
//-----------------------------------------
//初始置换得到cn，dn
int displacec0[]={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};
int displaced0[]={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};
int move[]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
StringBuffer c0=new StringBuffer(28);
StringBuffer d0=new StringBuffer(28);
for(int i=0;i<28;i++)
{
c0.insert(i,Cipher_code.charAt(displacec0[i]-1));
d0.insert(i,Cipher_code.charAt(displaced0[i]-1));
}
StringBuffer c[]=new StringBuffer[16];
StringBuffer d[]=new StringBuffer[16];
c[0]=new StringBuffer(28);
d[0]=new StringBuffer(28);
c[0]=cndn(c0,move[0]);
d[0]=cndn(d0,move[0]);
for(int i=1;i<16;i++)
{
c[i]=new StringBuffer(28);
d[i]=new StringBuffer(28);
c[i]=cndn(c[i-1],move[i]);
d[i]=cndn(d[i-1],move[i]);
//System.out.println("c"+i+":"+c[i]);
//System.out.println("d"+i+":"+d[i]);
}
/*
for(int i=0;i<16;i++)
{
System.out.println(c[i]);
System.out.println(d[i]);
}
*/
//---------------------------------
//置换2：由cn，dn得到kn即k[]
int conbinition[]={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};
StringBuffer k[]=new StringBuffer[16];
for(int i=0;i<16;i++)
{
k[i]=new StringBuffer(48);
for(int j=0;j<48;j++)
{
if(conbinition[j]>28)
k[i].insert(j,d[i].charAt((conbinition[j]-1)%28));
else
k[i].insert(j,c[i].charAt(conbinition[j]-1));
}
//System.out.println("k"+i+k[i]);
}
//-----------------------------------
//明文的处理
//---------------------------
//把读入的明文变为64位编码
StringBuffer plaintext_code=new StringBuffer(64);
StringBuffer binarystr_plaintext=new StringBuffer(4);
int plaintext_length,w_plaintext;
plaintext_length=plaintext.length();
for(int i=0;i<plaintext_length;i++)
{
String chartostr_plaintext=null,binarychar_plaintext=null;
binarystr_plaintext=null;
binarystr_plaintext=new StringBuffer(4);
chartostr_plaintext=String.valueOf(plaintext.charAt(i));
w_plaintext=Integer.parseInt(chartostr_plaintext,16); //把每一个字母转换为int
binarychar_plaintext=Integer.toBinaryString(w_plaintext);
binarystr_plaintext.append(binarychar_plaintext);
if(binarychar_plaintext.length()<5)
{
for(int j=0;j<4-binarychar_plaintext.length();j++)
{
binarystr_plaintext.insert(0,0);
}
} //把密文中的每一位变为四位
//的二进制字符串
plaintext_code.append(binarystr_plaintext);
}
//System.out.println(plaintext_code);
//--------------------------------------
//对明文进行初始置换得到L0和R0
int replaceL0[]={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};
int replaceR0[]={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};
StringBuffer L[]=new StringBuffer[17];
StringBuffer R[]=new StringBuffer[17];
L[0]=new StringBuffer(32);
R[0]=new StringBuffer(32);
for(int i=0;i<32;i++)
{
L[0].insert(i,plaintext_code.charAt(replaceL0[i]-1));
R[0].insert(i,plaintext_code.charAt(replaceR0[i]-1));
}
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