package com.segerp.tygl.weixin.common;

import java.io.UnsupportedEncodingException;

import java.security.GeneralSecurityException;

import java.security.SecureRandom;

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

/**

 * 字符串加密解密类

 * */

public class AesStrUtils {

    //private static final String SECRETKEY = "F0D7432CFDB62E21F8DF70CF47F06948";

    private static final String SECRETKEY = "BB6D93B3BD1FB173DDADB78748E0C6D3";

    public static void main(String[] args) throws Exception {

        // 加密

        String encryptResultStr = encryptStr("123", SECRETKEY);

        System.out.println("加密后：" + encryptResultStr);

        // 解密

        String decryptResultStr = decryptStr(encryptResultStr, SECRETKEY);

        System.out.println("解密后：" + decryptResultStr);

    }

    /**

     * 字符串加密

     *

     * @param srcStr

     *            加密字符串

     * @param password

     *            加密密钥

     * */

    public static String encryptStr(String srcStr, String password) {

        byte[] encryptResult = encryptData_AES(srcStr, password);

        String encryptResultStr = parseByte2HexStr(encryptResult);

        return encryptResultStr;

    }

    /**

     * 字符串解密

     *

     * @param srcStr

     *            解密字符串

     * @param password

     *            加密密钥

     * */

    public static String decryptStr(String srcStr, String password) {

        String returnValue = "";

        try {

            byte[] decryptFrom = parseHexStr2Byte(srcStr);

            byte[] decryptResult = decryptData_AES(decryptFrom, password);

            returnValue = new String(decryptResult, "utf-8");

        } catch (UnsupportedEncodingException e) {

            e.printStackTrace();

        }

        return returnValue;

    }

    /**

     * 将二进制转换成16进制

     *

     * @param buf

     * @return

     */

    private static String parseByte2HexStr(byte buf[]) {

        StringBuffer sb = new StringBuffer();

        for (int i = 0; i < buf.length; i++) {

            String hex = Integer.toHexString(buf[i] & 0xFF);

            if (hex.length() == 1) {

                hex = '0' + hex;

            }

            sb.append(hex.toUpperCase());

        }

        return sb.toString();

    }

    /**

     * 加密

     *

     * @param content

     *            需要加密的内容

     * @param password

     *            加密密码

     * @return

     */

    private static byte[] encryptData_AES(String content, String password) {

        try {

            //SecretKey secretKey = getKey(password);

            //byte[] enCodeFormat = secretKey.getEncoded();

            byte[] enCodeFormat = parseHexStr2Byte(password);

            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");

            Cipher cipher = Cipher.getInstance("AES");// 创建密码器

            byte[] byteContent = content.getBytes("utf-8");

            cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化

            byte[] result = cipher.doFinal(byteContent);

            return result; // 加密

        } catch (Exception e) {

            e.printStackTrace();

        }

        return null;

    }

    /**

     * 将16进制转换为二进制

     *

     * @param hexStr

     * @return

     */

    private static byte[] parseHexStr2Byte(String hexStr) {

        if (hexStr.length() < 1)

            return null;

        byte[] result = new byte[hexStr.length() / 2];

        for (int i = 0; i < hexStr.length() / 2; i++) {

            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);

            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),

                    16);

            result[i] = (byte) (high * 16 + low);

        }

        return result;

    }

    /**

     * 生成指定字符串的密钥

     *

     * @param secret  要生成密钥的字符

     * @return secretKey 生成后的密钥

     * @throws GeneralSecurityException

     */

    private static SecretKey getKey(String secret) throws GeneralSecurityException {

        try {

              KeyGenerator _generator = KeyGenerator.getInstance("AES");

              SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");

              secureRandom.setSeed(secret.getBytes());

              _generator.init(128,secureRandom);

              return _generator.generateKey();

          }  catch (Exception e) {

               throw new RuntimeException("初始化密钥出现异常");

          }

    }

    /**

     * 解密

     *

     * @param content

     *            待解密内容

     * @param password

     *            解密密钥

     * @return

     */

    private static byte[] decryptData_AES(byte[] content, String password) {

        try {

            //SecretKey secretKey = getKey(password);

            //byte[] enCodeFormat = secretKey.getEncoded();

            byte[] enCodeFormat = parseHexStr2Byte(password);

            SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");

            Cipher cipher = Cipher.getInstance("AES");// 创建密码器

            cipher.init(Cipher.DECRYPT_MODE, key);// 初始化

            byte[] result = cipher.doFinal(content);

            return result; // 加密

        } catch (Exception e) {

            e.printStackTrace();

        }

        return null;

    }

}