/*
 * ********************************************************************************************************************
 *
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 *      :JMRMMD  ..    ,  1MMRM1;         ;MBMBBR:   MBM  ;MB:  BMB:   MBM. RMBr   sBMH   BM0         UMB,  BMB.  KMBv
 *     ;.   XOW  B1; :uM: 1RE,   i           .2BMBs  rMB. MBO   MBO    JMB; MBB     MBM   BBS    7MBMBOBM:  MBW   :BMc
 *     OBRJ.SEE  MRDOWOR, 3DE:7OBM       .     ;BMB   RMR7BM    BMB    MBB. BMB    ,BMR  .BBZ   MMB   rMB,  BMM   rMB7
 *     :FBRO0D0  RKXSXPR. JOKOOMPi       BMBSSWBMB;    BMBB:    MBMB0ZMBMS  .BMBOXRBMB    MBMDE RBM2;SMBM;  MBB   xBM2
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 *           .UB  OOGDM. MK,                                          Copyright (c) 2015-2019.  斯伯坦机器人
 *              ,  XMW  ..
 *                  r                                                                     All rights reserved.
 *
 * ********************************************************************************************************************
 */

package com.sybotan.service.utils.crypt

import javax.crypto.Cipher
import javax.crypto.KeyGenerator
import javax.crypto.spec.SecretKeySpec
import java.io.IOException
import java.security.Key
import java.security.NoSuchAlgorithmException
import java.security.SecureRandom
import java.util.*

/**
 * AES安全编码组件
 *
 * @author Andy
 */
abstract class SAESCoderUtil : SCoderUtil() {
    companion object {
        const val ALGORITHM = "AES"

        /**
         * 转换密钥
         *
         * @param key
         * @return
         * @throws Exception
         */
        @Throws(Exception::class)
        private fun toKey(key: ByteArray): Key {
            return SecretKeySpec(key, ALGORITHM)
        }

        /**
         * 解密
         *
         * @param data
         * @param key
         * @return
         * @throws Exception
         */
        @Throws(Exception::class)
        fun decrypt(data: ByteArray, key: String): ByteArray {
            val k = toKey(Base64.getDecoder().decode(key))

            val cipher = Cipher.getInstance(ALGORITHM)
            cipher.init(Cipher.DECRYPT_MODE, k)

            return cipher.doFinal(data)
        } // Fun decrypt()

        /**
         * 加密
         *
         * @param data
         * @param key
         * @return
         * @throws Exception
         */
        @Throws(Exception::class)
        fun encrypt(data: ByteArray, key: String): ByteArray {
            val k = toKey(Base64.getDecoder().decode(key))
            val cipher = Cipher.getInstance(ALGORITHM)
            cipher.init(Cipher.ENCRYPT_MODE, k)

            return cipher.doFinal(data)
        } // Fun encrypt()

        /**
         * 生成密钥
         *
         * @param seed
         * @return
         * @throws IOException
         * @throws NoSuchAlgorithmException
         */
        @Throws(IOException::class, NoSuchAlgorithmException::class)
        @JvmOverloads
        fun initKey(seed: String? = null): String? {
            val secureRandom = if (seed != null) {
                SecureRandom(Base64.getDecoder().decode(seed))
            } else {
                SecureRandom()
            }

            val kg = KeyGenerator.getInstance(ALGORITHM)
            kg.init(secureRandom)

            val secretKey = kg.generateKey()

            return Base64.getEncoder().encodeToString(secretKey.encoded)
        } // Fun initKey()
    } // companion object
} // Class SAESCoderUtil