/*******************************************************

 *

 * 作者：朱皖苏

 * 创建日期：20180521

 * 说明：此文件只包含一个类，具体内容见类型注释。

 * 运行环境：.NET 4.0

 * 版本号：1.0.0

 *

 * 历史记录：

 * 创建文件 朱皖苏 20180521 20:08

 *

*******************************************************/

using System;

using System.IO;

using System.Security.Cryptography;

using System.Text;

namespace Dben.CommonLib.Cryptography

{

    /// <summary>

    /// Aes 加密

    /// </summary>

    public class AESEncryption

    {

        /// <summary>

        /// AES加密

        /// </summary>

        /// <param name="encryptString">待加密字符串</param>

        /// <param name="key">16位密钥</param>

        /// <returns></returns>

        public static string EncryptAes(string encryptString, string key)

        {

            try

            {

                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);

                SymmetricAlgorithm des = Aes.Create();

                des.Key = Encoding.ASCII.GetBytes(key.Substring(, ));

                des.IV = Encoding.ASCII.GetBytes(key.Substring());

                des.Mode = CipherMode.CBC;

                des.Padding = PaddingMode.Zeros;

                using (MemoryStream mStream = new MemoryStream())

                {

                    using (CryptoStream cStream = new CryptoStream(mStream, des.CreateEncryptor(), CryptoStreamMode.Write))

                    {

                        cStream.Write(inputByteArray, , inputByteArray.Length);

                        cStream.FlushFinalBlock();

                        byte[] desBytes = mStream.ToArray();

                        StringBuilder sb = new StringBuilder();

                        for (int i = ; i < desBytes.Length; i++)

                        {

                            sb.Append(desBytes[i].ToString("x2"));

                        }

                        return sb.ToString();

                    }

                }

            }

            catch (Exception)

            {

                return encryptString;

            }

        }

        /// <summary>

        /// AES解密

        /// </summary>

        /// <param name="decryptString">解密字符串</param>

        /// <param name="key">密钥</param>

        /// <returns></returns>

        public static string DecryptAes(string decryptString, string key)

        {

            try

            {

                byte[] inputByteArray = StrToToHexByte(decryptString);

                SymmetricAlgorithm des = Aes.Create();

                des.Key = Encoding.ASCII.GetBytes(key.Substring(, ));

                des.IV = Encoding.ASCII.GetBytes(key.Substring());

                des.Padding = PaddingMode.Zeros;

                des.Mode = CipherMode.CBC;

                MemoryStream mStream = new MemoryStream();

                CryptoStream cStream = new CryptoStream(mStream, des.CreateDecryptor(), CryptoStreamMode.Write);

                cStream.Write(inputByteArray, , inputByteArray.Length);

                cStream.FlushFinalBlock();

                byte[] desDecryBytes = mStream.ToArray();

                return Encoding.UTF8.GetString(desDecryBytes);

            }

            catch (Exception)

            {

                return decryptString;

            }

        }

        /// <summary>

        /// 转16进制字符串

        /// </summary>

        /// <param name="hexString">待转换字符串</param>

        /// <returns></returns>

        private static byte[] StrToToHexByte(string hexString)

        {

            try

            {

                hexString = hexString.Replace(" ", "");

                if ((hexString.Length % ) != )

                    hexString += " ";

                byte[] returnBytes = new byte[hexString.Length / ];

                for (int i = ; i < returnBytes.Length; i++)

                    returnBytes[i] = Convert.ToByte(hexString.Substring(i * , ), );

                return returnBytes;

            }

            catch (Exception)

            {

                return null;

            }

        }

    }

}