package com.frank.common.utils;

import com.alibaba.fastjson.JSON;
import com.frank.common.entity.TokenHeader;
import com.frank.common.entity.TokenPlayload;
import com.frank.common.entity.User;

import java.rmi.server.UID;
import java.util.UUID;

/**
* Description:Token生成工具
* 第一部分我們稱它為頭部（header),第二部分我們稱其為載荷（payload, 類似于飛機上承載的物品)，第三部分是簽證（signature).
* Auth: Frank
* Date: 2017-11-02
* Time: 下午 5:05
*/
public class TokenUtil {
public static final String TOKEN_AES_KEY = "xiangli8Token";
public static final String REFREH_TOKEN_AES_KEY = "xiangli8RefreshToken";
public static final String JWT_TYP = "JWT";
public static final String JWT_ALG = "AES";
public static final String JWT_EXP = "30";
public static final String JWT_ISS = "xiangli8";

/**
* 獲得token
* @param data 自定義數(shù)據(jù)
* @param <T> 自定義數(shù)據(jù)
* @return
* @throws Exception
*/
public static <T> String getToken(T data) throws Exception {
TokenPlayload<T> userTokenPlayload = new TokenPlayload<>();
userTokenPlayload.setExpData(data);
String jwt = createJWT(userTokenPlayload);
return jwt;
}

/**
* 生成jwt的header部分內(nèi)容
* @return
* @throws Exception
*/
private static String tokenHeaderBase64() throws Exception {
TokenHeader tokenHeader = new TokenHeader();
tokenHeader.setTyp(JWT_TYP);
tokenHeader.setAlg(JWT_ALG);

String headerJson = JSON.toJSONString(tokenHeader);

String headerBase64 = Base64Util.encryptBASE64(headerJson.getBytes());

return headerBase64;
}

/**
* 生成jwt的payload部分內(nèi)容
* @param tokenPlayload
* @param <T>自定義的數(shù)據(jù)塊
* @return
* @throws Exception
*/
private static <T> String tokenPayloadBase64(TokenPlayload<T> tokenPlayload) throws Exception {
tokenPlayload.setIss(JWT_ISS);
tokenPlayload.setExp(JWT_EXP);

tokenPlayload.setIat(String.valueOf(System.currentTimeMillis()));

String headerJson =JSON.toJSONString(tokenPlayload);

String headerBase64 = Base64Util.encryptBASE64(headerJson.getBytes());

return headerBase64;
}

/**
* 生成JWT
* @return
*/
public static <T> String createJWT(TokenPlayload<T> tokenPlayload) throws Exception {
StringBuilder jwtSb = new StringBuilder();
StringBuilder headerPlayloadSb = new StringBuilder();

String tokenHeaderBase64 = tokenHeaderBase64();
String tokenPayloadBase64 = tokenPayloadBase64(tokenPlayload);

jwtSb.append(tokenHeaderBase64);
jwtSb.append(".");
jwtSb.append(tokenPayloadBase64);
jwtSb.append(".");

headerPlayloadSb.append(tokenHeaderBase64);
headerPlayloadSb.append(tokenPayloadBase64);

String headerPlayloadSalt = SaltUtil.addSalt(headerPlayloadSb.toString());

String key = AesUtil.initKey(TOKEN_AES_KEY+tokenPlayload.getIat());

String signature = Base64Util.encryptBASE64(AesUtil.encrypt(headerPlayloadSalt.getBytes(),key));

jwtSb.append(signature);

return Base64Util.encryptBASE64(jwtSb.toString().getBytes());
}

/**
* 校驗token是否是服務器生成的，以防token被修改
* @param jwtBase64
* @return
* @throws Exception
*/
public static <T> boolean verifyJWT(String jwtBase64) throws Exception {
String jwt = new String (Base64Util.decryptBASE64(jwtBase64));

if(!jwt.contains(".")){
return false;
}

String[] jwts = jwt.split("\\.");
if(jwts.length<3){
return false;
}

TokenPlayload tTokenPlayload = JSON.parseObject(new String(Base64Util.decryptBASE64(jwts[1])),TokenPlayload.class);
String key = AesUtil.initKey(TOKEN_AES_KEY+tTokenPlayload.getIat());

//解析出header跟playload
StringBuilder headerPlayloadSb = new StringBuilder();
headerPlayloadSb.append(jwts[0]);
headerPlayloadSb.append(jwts[1]);

//解析signature
String headerPlayloadSalt = new String (AesUtil.decrypt(Base64Util.decryptBASE64(jwts[2]),key));

return SaltUtil.verifyPwd(headerPlayloadSb.toString(),headerPlayloadSalt);
}

 

public static void main(String[] args) throws Exception {
String jwt = getToken(new User(1L,"你是逗逼"));
System.out.println("jwt:"+jwt);
System.out.println("verifyJWT:"+verifyJWT(jwt));
}
}