rsaencrypt.java

RSA加密算法的java实现源代码

package encryption;

import java.security.*;
import java.math.*;
import java.io.*;

public class RSAEncrypt {
    public static void main(String[] args) {
        if (args.length != 1) {
            System.out.println("Usage: java RSAEncrypt Number");
            System.exit(1);
        }
        RSAEncrypt obj = new RSAEncrypt();
        try {
            args[0] = "12345678901234567890";
            obj.encrypt(args[0],args[1],args[2]);
        } catch (ClassNotFoundException ex) {
            System.out.println("ClassNotFoundException");
        } catch (FileNotFoundException ex) {
            System.out.println("FileNotFoundException");
        } catch (IOException ex) {
            System.out.println("IOException");
        }
    }

    public String encrypt(String num, String etext, String ntext) throws
            ClassNotFoundException, FileNotFoundException, IOException {
        BigInteger plainText = new BigInteger(num);
        System.out.println("****p"+plainText.toString());
        BigInteger e=new BigInteger(etext);
        BigInteger n=new BigInteger(ntext);
        BigInteger cipherText = plainText.modPow(e, n);
        System.out.println("****c"+cipherText.toString());
        return cipherText.toString();
    }

    public static String getCode(String text){
        try{
            byte[] array = text.getBytes();
            BigInteger big = new BigInteger(array);
            return big.toString();
        }catch(Exception ex){
            return "error！";
        }
    }

    public static String getText(String num){
        try{
            BigInteger big = new BigInteger(num);
            String text=new String(big.toByteArray());
            return text;
        }catch(Exception ex){
            return "error！";
        }
    }

}