package com.cn.test.rsa;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.util.Random;

public class GenerServerDigest {

    //生成32位随机数

    public static String generatorRandom(){

        String _RndData;

        int b = 0;

        int a = 0;

        _RndData = "";

        Random r = new Random();

        for (int i = 0; i < 32; i++) {

            a = r.nextInt(26);

            b = (char) (a + 65);

            _RndData += new Character((char) b).toString();

        }

        return _RndData;

    }

    public static void main(String[] args) {

        String ServerDigest = null;

        try{

            //进行SHA1运算

            char[] HEXCHAR = { '0', '1', '2', '3', '4', '5', '6', '7',

                    '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

            String MsgtoDigest = GenerServerDigest.generatorRandom();

            MessageDigest md = null;

            md = MessageDigest.getInstance("SHA1");

            byte[] digest = md.digest(MsgtoDigest.getBytes()); 

            StringBuilder sb = new StringBuilder(digest.length * 2);

            for (int i = 0; i < digest.length; i++) {

                sb.append(HEXCHAR[(digest[i] & 0xf0) >>> 4]);

                sb.append(HEXCHAR[digest[i] & 0x0f]);

            }

            ServerDigest = sb.toString();

        } catch (NoSuchAlgorithmException e){

            e.printStackTrace();

        }

        System.out.println(ServerDigest);

    }

}