ras_encrypt_decrypt.java

一个对字串进行RAS方式加密的代码。 用于加密用户密码等敏感资料。 可以通过JSP页面进行调用

package eise.tools;

//------------------------------------------------------------------------------
/**
 * <p>Title: EISE加密程序</p>
 * <p>Description: 采用RSA算法加密一个字串</p>
 * <p>Copyright: Copyright (c) 2005-2006 By EISE Development Team</p>
 * <p>Company: EISE Development Team</p>
 * @author Zhan Hongfei
 * @version 1.0
 */
//------------------------------------------------------------------------------
import java.math.*;
import javax.swing.*;
//------------------------------------------------------------------------------
public class RAS_Encrypt_Decrypt extends JFrame {
  private static String P="229";//一定要是素数，由用户指定
  private static String Q="197";//一定要是素数，由用户指定
  private String PQ="-1";//由PQ计算得到
  private String EDM="-1";//由PQ计算得到
  private String M="-1";//由PQ计算得到
//-----上面参数只是计算用的，下面的参数是加密与解决要用的--------------------------------
  private String E="-1";//由PQ计算得到
  private String D="-1";//由PQ计算得到
  private String N="-1";//由PQ计算得到
//------------------------------------------------------------------------------
  public RAS_Encrypt_Decrypt(){
  this(P,Q);
 }
//------------------------------------------------------------------------------
  public RAS_Encrypt_Decrypt(String p,String q){
     P=p;Q=q;
     java.math.BigInteger biginteger = new BigInteger("1");
     java.math.BigInteger biginteger1 = new BigInteger(p);
     java.math.BigInteger biginteger3 = new BigInteger(q);
     java.math.BigInteger n_biginteger = biginteger1.multiply(biginteger3);
     java.math.BigInteger biginteger5 = biginteger1.subtract(biginteger);
     java.math.BigInteger biginteger7 = biginteger3.subtract(biginteger);
     java.math.BigInteger pq_biginteger = biginteger5.multiply(biginteger7);
     if(!biginteger1.isProbablePrime(10)){return;}
     if(!biginteger3.isProbablePrime(10)){return;}
     N=n_biginteger.toString();
     PQ=pq_biginteger.toString();
     java.math.BigInteger biginteger15 = biginteger.add(biginteger);
     java.math.BigInteger biginteger16 = biginteger.add(biginteger);
     for(java.math.BigInteger biginteger17=new BigInteger("0"); biginteger15.compareTo(n_biginteger)<0&&biginteger17.intValue()!=1;biginteger17=pq_biginteger.gcd(biginteger15)){biginteger15 = biginteger15.add(biginteger);}
     biginteger16 = biginteger15;
     E=biginteger16.toString();
     java.math.BigInteger biginteger19 = biginteger16.modInverse(pq_biginteger);
     D=biginteger19.toString();
     java.math.BigInteger biginteger21 = biginteger16.multiply(biginteger19);
     biginteger21 = biginteger21.subtract(biginteger);
     EDM=biginteger21.toString();
  }
//------------------------------------------------------------------------------
 public String encryptString(String text){
     String characternumbers="";//被加密的文字的整形表示码,每个字符的编码之间用空格分隔
     String characterbinary="";//被加密的文字的字节码,每个字符的编码之间用空格分隔
     String codeblocks="";
     String s8="";////被加密的文字的字节码,每个字符的编码之间无空格
     String encryptednumbers="";//被加密后的字节码,每个字符的编码之间用空格分隔
     String encryptedmessage="";//被加密后的文字
     String binaryblocks="";
     java.math.BigInteger e_biginteger = new BigInteger(E);
     java.math.BigInteger n_biginteger = new BigInteger(N);
     int k=0;
     byte byte0=2;
     for(int i=0;i<text.length();i++)
        {java.lang.String s6=text.substring(i,i+1);
         //-----拿到一个个的字符--------------------------------------------
         char c=text.charAt(i);
         //-----把字符转化为字节--------------------------------------------
         java.lang.String s=java.lang.Integer.toBinaryString(c);
          //-----不够8位的补到8位-------------------------------------------
         for(int l=s.length();l<8;l++){s="0"+s;}
         java.lang.String s5 = (new Integer(c)).toString();
         characternumbers=characternumbers+s5+"  ";
         characterbinary=characterbinary+s+"  ";
         s8=s8+s;
         k++;
         if(k==byte0)
           {java.math.BigInteger biginteger10=new BigInteger(s8,2);
            codeblocks=codeblocks+biginteger10.toString()+"  ";
            java.math.BigInteger biginteger13=biginteger10.modPow(e_biginteger, n_biginteger);
            java.lang.String s2=biginteger13.toString();
            encryptednumbers=encryptednumbers+s2+" ";
            for(int i1=0;i1<s2.length();i1+=2)
               {byte byte1;
                if(s2.length()-i1 > 1){byte1 = 2;}
                else{byte1 = 1;}
                java.lang.Integer integer = new Integer(s2.substring(i1, i1 + byte1));
                char c1 = (char)integer.intValue();
                encryptedmessage=encryptedmessage+c1;
               }
            k = 0;
            s8 = "";
           }
         }
     if(k>0&&k<byte0)
       {for(int j1 = k; j1 < byte0; j1++)
        s8 = "00000000" + s8;
        binaryblocks=binaryblocks+s8+"  ";
        java.math.BigInteger biginteger11 = new BigInteger(s8, 2);
        codeblocks=codeblocks+biginteger11+"  ";
        java.math.BigInteger biginteger14 = biginteger11.modPow(e_biginteger, n_biginteger);
        java.lang.String s3 = biginteger14.toString();
        encryptednumbers=encryptednumbers+s3+" ";
        for(int k1 = 0; k1 < s3.length(); k1 += 2)
           {byte byte2;
            if(s3.length()-k1>1){byte2 = 2;}
            else{byte2 = 1;}
            java.lang.Integer integer1 = new Integer(s3.substring(k1, k1 + byte2));
            char c2 = (char)integer1.intValue();
            encryptedmessage=encryptedmessage+c2;
           }
        }
     return encryptednumbers;
  }
//------------------------------------------------------------------------------
  public String decryptString(String text){
    String numberstodecrypt="";
    String decryptednumbers="";
    String decryptedmessage="";
    java.math.BigInteger biginteger2 = new BigInteger(D);
    java.math.BigInteger biginteger4 = new BigInteger(N);
    java.lang.String s11=text;
    int i2;
    for(int j=0;j<s11.length();j=i2+1)
       {int l1 = j;
        i2 = s11.indexOf(' ', j);
        java.lang.String s9 = s11.substring(l1, i2);
        java.math.BigInteger biginteger18 = new BigInteger(s9, 10);
        numberstodecrypt=numberstodecrypt+biginteger18.toString()+" ";
        java.math.BigInteger biginteger20 = biginteger18.modPow(biginteger2, biginteger4);
        java.lang.String s4 = biginteger20.toString();
        decryptednumbers=decryptednumbers+s4+" ";
        java.lang.String s1 = java.lang.Integer.toBinaryString(biginteger20.intValue());
        for(int j2=s1.length();j2<16;j2++){s1="0"+s1;}
        decryptednumbers=decryptednumbers+"'"+s1+"' ";
        for(int k2=1;k2<=2;k2++)
           {java.lang.String s10 = s1.substring((k2 - 1) * 8, k2 * 8);
            if(!s10.equals("00000000"))
              {java.math.BigInteger biginteger22 = new BigInteger(s10, 2);
               int l2 = biginteger22.intValue();
               char c3 = (char)l2;
               decryptedmessage=decryptedmessage+c3;
              }
           }
       }
    return decryptedmessage;
  }
//------------------------------------------------------------------------------
  public static void main(String[] args){
   RAS_Encrypt_Decrypt machine=new RAS_Encrypt_Decrypt("229","197");
   String text="the Hong kong Polytechnic University and Zhejiang University.";
   String encrypted_text=machine.encryptString(text);
   String decrypt_text=machine.decryptString(encrypted_text);
   System.out.println("original_text="+text);
   System.out.println("encrypted__text="+encrypted_text);
   System.out.println("decrypt__text="+decrypt_text);
  }
//------------------------------------------------------------------------------
}//end of class
//------------------------------------------------------------------------------