package cn.com.goldenwater.dcproj.utils;

import org.springframework.util.Base64Utils;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.util.HashMap;
import java.util.Map;

/**
 * @author rf
 * @version 1.0
 * @date 2021-1-15 15:16
 */
public class DecryptUtil {

    private final static String KEY = "}a?7_sa@KXE>NV%@";


    public static Map<String, String> decrypt(String accessId) throws Exception {
        final KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
        SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
        random.setSeed(KEY.getBytes());
        keyGenerator.init(128, random);
        final SecretKey secretKey = keyGenerator.generateKey();
        final Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        final String decode = new String(cipher.doFinal(Base64Utils.decodeFromString(URLDecoder.decode(accessId, "UTF-8"))), StandardCharsets.UTF_8);
        final String[] infos = decode.split("\\|");
        String userLoginName = infos[0];
        String userGuid = infos[1];
        String userMobile = infos[2];
        String timestamp = infos[3];
        if (Long.parseLong(timestamp) - System.currentTimeMillis() > 30 * 1000)
            throw new Exception("已过期");
        HashMap<String, String> res = new HashMap<>();
        res.put("userLoginName", userLoginName);
        res.put("userGuid", userGuid);
        res.put("userMobile", userMobile);
        return res;
    }

}