package com.whyc.util;

import org.apache.commons.codec.digest.DigestUtils;

public class MD5Util {

    /**加密*/
    public static String encryptMD5(String data){
        String result=null;
        if(data!=null && data.length()>0){
            result= DigestUtils.md5Hex(data);
        }
        return result;
    }

    /**
     * 使用timestamp+盐方式,进行签名验证
     * 当前时间戳为13位数
     */
    public static boolean checkSignMD5(String time,String randomStr,String sign){
        String usefulNum = randomStr;
        //加盐方式,根据末尾的值进行不同的加密规则
        char lastChar = time.charAt(12);
        int lastNum = Integer.parseInt(String.valueOf(lastChar));
        switch (lastNum){
            //在第一位加字符串 rd@c3doed
            case 0: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3dozero");break;
            case 1: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doenoe");break;
            case 2: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doktwo");break;
            case 3: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3dolthree");break;
            case 4: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doexfour");break;
            case 5: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doedefive");break;
            case 6: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doedhsix");break;
            case 7: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doedtseven");break;
            case 8: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doedbeight");break;
            case 9: usefulNum += time.replace(String.valueOf(lastChar),"rd@c3doedrnine");break;
        }
        //MD5加密后
        String signNow = encryptMD5(usefulNum);
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10; i++) {
            sb.append(signNow.charAt(i * 2));
        }
        String signResult = sb.append(signNow).toString();
        return sign.equals(signResult);
    }
}