package com.fr.plugin.xx.saml;

import com.fr.third.org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.Key;

/**
 * @author xx
 * @date 2020/11/11
 */
public class DesECBUtil {
    /**
     * 加密数据
     *
     * @param encryptString
     * @param encryptKey
     * @return
     * @throws Exception
     */
    public static String encryptDES(String encryptString, String encryptKey) throws Exception {
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(getKey(encryptKey), "DES"));
        byte[] encryptedData = cipher.doFinal(encryptString.getBytes("UTF-8"));
        return Base64.encodeBase64String(encryptedData);
    }

    /**
     * key 不足8位补位
     *
     * @param
     */
    public static byte[] getKey(String keyRule) {
        Key key = null;
        byte[] keyByte = keyRule.getBytes();
        // 创建一个空的八位数组,默认情况下为0 
        byte[] byteTemp = new byte[8];
        // 将用户指定的规则转换成八位数组 
        for (int i = 0; i < byteTemp.length && i < keyByte.length; i++) {
            byteTemp[i] = keyByte[i];
        }
        key = new SecretKeySpec(byteTemp, "DES");
        return key.getEncoded();
    }

    /***
     * 解密数据
     * @param decryptString
     * @param decryptKey
     * @return
     * @throws Exception
     */

    public static String decryptDES(String decryptString, String decryptKey) throws Exception {
        byte[] sourceBytes = Base64.decodeBase64(decryptString);
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(getKey(decryptKey), "DES"));
        byte[] decoded = cipher.doFinal(sourceBytes);
        return new String(decoded, "UTF-8");

    }

}