//RSA 基本实现版
import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.math.BigInteger;import java.util.Random;import java.util.Scanner;import org.omg.CORBA.PUBLIC_MEMBER;public class RSAFrame{    private RSA rsa = new RSA();    private BigInteger p, q, e, n, d, ran;    private Random rnd = new Random();  //全局变量    private int numBit = 10;        public static void main(String[] args)    {         RSAFrame myrsa=new RSAFrame();         myrsa.beforeMessage();  //计算p,q,n,ran,e,d的值         BigInteger[] encodingM =myrsa.Encryption(); //对输入的信息m进行加密         myrsa.Decryption(encodingM); //对密文进行解密         myrsa.showValue();    //输出p,q,n,ran,e,d的值    }        public void beforeMessage()   //在发生信息之前，把这些算出来    {        p = rsa.getPrimes(rnd);   //得到素数p        q = rsa.getPrimes(rnd);   //得到素数q        n = rsa.getN(p, q);       //得到p*q        ran = rsa.getRan(p, q);   //得到（p-1）*（q-1）,ran        e = rsa.getE(ran);        //根据生成的大随机数与ran公约数是否为1，得到了公钥e        d = rsa.getKey(e,ran);    //根据公钥e，和ran，生成了密钥d                        System.out.println("请输入随机数的位数(大于9):");        Scanner input=new Scanner(System.in);        numBit=input.nextInt();                if(numBit<9)        {            System.out.println("随机数的位数应该大于9");        }    }        public BigInteger[] Encryption()    {        String Message = "";        System.out.println("请输入要发送的消息M(please in English):");        InputStream mym= System.in;        BufferedReader rd = new BufferedReader(new InputStreamReader(mym));        try         {            Message= rd.readLine();            System.out.println("输入的消息为： "+Message);        }        catch(IOException e)         {            System.out.println(e.getMessage());        }                char[]c = Message.toCharArray();        BigInteger[] deal_message=new BigInteger[c.length];          for (int i = 0;i < c.length;i ++)        {    //       System.out.println(c[i]);  //分解成每一位：           int a=(int)c[i];           BigInteger bigInteger = BigInteger.valueOf(a);           deal_message[i]=bigInteger;  //成功赋值        }        deal_message=RSA.encodeRSA(deal_message,e,n);   //直接在原来基础上修改                return deal_message;    }        public void Decryption(BigInteger[] encodingM )    {        encodingM=RSA.dencodeRSA(encodingM, d, n);  //解码后，得到的信息，二维        char[] c=new char[encodingM.length];        for (int i = 0;i < encodingM.length;i ++)        {    //       System.out.println(encodingM[i]);  //分解成每一位：           int d = encodingM[i].intValue();           c[i]=(char)d;        }        String message = String.valueOf(c);        System.out.println("解密后的信息为： "+message);    }        private void showValue()    {        System.out.println(" ");        System.out.println("素数p： "+p);        System.out.println("素数q： "+q);        System.out.println("计算p*q: "+n);        System.out.println("计算(p-1)*(q-1): "+ran);        System.out.println(" ");        System.out.println("公钥e为： "+e);        System.out.println("密钥d为： "+d);    }}

import java.math.BigInteger;import java.util.Random;public class RSA {    private BigInteger primes = BigInteger.ZERO;    private BigInteger n, ran, d = BigInteger.ZERO;    private BigInteger e = BigInteger.ZERO;    private String m;    Random rnd = new Random();    private int numBit = 10;        public int getNumBit(int n)     {        numBit = n;        return numBit;    }        public BigInteger getPrimes(Random rnd)     {        return primes = BigInteger.probablePrime(numBit, rnd);    }    public BigInteger getN(BigInteger p, BigInteger q)     {        return n = p.multiply(q);    }    public BigInteger getRan(BigInteger p, BigInteger q)     {        /*long r = (p.intValue() - 1)*(q.intValue() - 1);        String tr = String.valueOf(r);*/        ran = (p.subtract(BigInteger.ONE)).multiply(q.subtract(BigInteger.ONE));                return ran;    }    public BigInteger getE(BigInteger ran)    {                BigInteger temp = null; //中间变量        e = BigInteger.ZERO;        do        {            temp = BigInteger.probablePrime(numBit, rnd);            // 随机生成一个素数，看他是否与ran的公约数为1，如果为1，e=temp退出循环            if((temp.gcd(ran)).equals(BigInteger.ONE))            {                e = temp;            }        }         while(!((temp.gcd(ran)).equals(BigInteger.ONE)));                return e;    }    public BigInteger getKey(BigInteger e, BigInteger ran)    {         d = e.modInverse(ran);         return d;    }        public static BigInteger[] encodeRSA(BigInteger[] encodeM , BigInteger e, BigInteger n)     {        //直接用encodeM表示：        for(int i=0; i < encodeM.length; i++)        {            encodeM[i] = encodeM[i].modPow(e, n);        }        return encodeM;    }        public  static BigInteger[] dencodeRSA(BigInteger[] encodeM, BigInteger d, BigInteger n)    {        if (encodeM == null) return null;         for (int i = 0; i <encodeM.length; i++)         {            encodeM[i] = encodeM[i].modPow(d,n);        }        return encodeM;    //直接返回    }}