AES对称加密解密类

2016-02-01 17:03:36 访问(2156) 赞(0) 踩(0)

using System;
using System.Text;
using System.Security.Cryptography; 

namespace eKing.AodbLib.Utils
{
    /// <summary>
    /// AES对称加密解密类
    /// </summary>
    public class AESHelper_Base64
    {
        #region 成员变量
        /// <summary>
        /// 密钥(32位,不足在后面补0)
        /// </summary>
        private const string _passwd = "ihlih*0037JOHT*)(PIJY*(()JI^)IO%";
        /// <summary>
        /// 运算模式
        /// </summary>
        private static CipherMode _cipherMode = CipherMode.ECB;
        /// <summary>
        /// 填充模式
        /// </summary>
        private static PaddingMode _paddingMode = PaddingMode.PKCS7;
        /// <summary>
        ///// 字符串采用的编码
        /// </summary>
        private static Encoding _encoding = Encoding.UTF8;
        #endregion

        #region 辅助方法
        /// <summary>
        /// 获取32byte密钥数据
        /// </summary>
        /// <param name="password">密码</param>
        /// <returns></returns>
        private static byte[] GetKeyArray(string password)
        {
            if (password == null)
            {
                password = string.Empty;
            }

            if (password.Length < 32)
            {
                password = password.PadRight(32, '0');
            }
            else if (password.Length > 32)
            {
                password = password.Substring(0, 32);
            }

            return _encoding.GetBytes(password);
        }

        /// <summary>
        /// 将字符数组转换成Base64字符串
        /// </summary>
        /// <param name="inputData"></param>
        /// <returns></returns>
        private static string ConvertByteToString(byte[] inputData)
        {
            string strRT = Convert.ToBase64String(inputData);
            return strRT;
        }

        /// <summary>
        /// 将Base64字符串转换成字符数组
        /// </summary>
        /// <param name="inputString"></param>
        /// <returns></returns>
        private static byte[] ConvertStringToByte(string inputString)
        {
            if (inputString == null || inputString.Length < 2)
            {
                throw new ArgumentException();
            }

            Byte[] toEncryptArray = Convert.FromBase64String(inputString);

            return toEncryptArray;
        }
        #endregion

        #region 加密
        /// <summary>
        /// 加密字节数据
        /// </summary>
        /// <param name="inputData">要加密的字节数据</param>
        /// <param name="password">密码</param>
        /// <returns></returns>
        public static byte[] Encrypt(byte[] inputData, string password)
        {
            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();

            try
            {
                aes.Key = GetKeyArray(password);
                aes.Mode = _cipherMode;
                aes.Padding = _paddingMode;
                ICryptoTransform transform = aes.CreateEncryptor();
                byte[] data = transform.TransformFinalBlock(inputData, 0, inputData.Length);
                
                if (aes != null)
                {
                    aes.Clear();
                    aes = null;
                }

                return data;
            }
            catch (Exception err)
            {
                throw err;
            }
            finally
            {
                if (aes != null)
                {
                    aes.Clear();
                    aes = null;
                }
            }
        }

        /// <summary>
        /// 加密字符串(加密为Base64进制字符串)
        /// </summary>
        /// <param name="inputString">要加密的字符串</param>
        /// <param name="password">密码</param>
        /// <returns></returns>
        public static string Encrypt(string inputString, string password)
        {
            try
            {
                byte[] toEncryptArray = _encoding.GetBytes(inputString);
                byte[] result = Encrypt(toEncryptArray, password);

                return ConvertByteToString(result);
            }
            catch (Exception err)
            {
                throw err;
            }

        }

        /// <summary>
        /// 字符串加密(加密为Base64进制字符串)
        /// </summary>
        /// <param name="inputString">需要加密的字符串</param>
        /// <returns>加密后的字符串</returns>
        public static string EncryptString(string inputString)
        {
            return Encrypt(inputString, _passwd);
        }
        #endregion

        #region 解密
        /// <summary>
        /// 解密字节数组
        /// </summary>
        /// <param name="inputData">要解密的字节数据</param>
        /// <param name="password">密码</param>
        /// <returns></returns>
        public static byte[] Decrypt(byte[] inputData, string password)
        {
            AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
            aes.Key = GetKeyArray(password);
            aes.Mode = _cipherMode;
            aes.Padding = _paddingMode;
            ICryptoTransform transform = aes.CreateDecryptor();
            byte[] data = null;
            try
            {
                data = transform.TransformFinalBlock(inputData, 0, inputData.Length);

                if (aes != null)
                {
                    aes.Clear();
                    aes = null;
                }

                return data;
            }
            catch (Exception err)
            {
                throw err;
            }
            finally
            {
                if (aes != null)
                {
                    aes.Clear();
                    aes = null;
                }
            }

            

        }

        /// <summary>
        /// 解密Base64进制的字符串为字符串
        /// </summary>
        /// <param name="inputString">要解密的字符串</param>
        /// <param name="password">密码</param>
        /// <returns>字符串</returns>
        public static string Decrypt(string inputString, string password)
        {
            try
            {
                if (string.IsNullOrEmpty(inputString)) return inputString;

                byte[] toDecryptArray = ConvertStringToByte(inputString);

                string decryptString = _encoding.GetString(Decrypt(toDecryptArray, password));

                return decryptString;
            }
            catch (Exception err)
            {
                throw err;
            }

        }

        /// <summary>
        /// 解密Base64进制的字符串为字符串
        /// </summary>
        /// <param name="inputString">需要解密的字符串</param>
        /// <returns>解密后的字符串</returns>
        public static string DecryptString(string inputString)
        {
            return Decrypt(inputString, _passwd);
        }
        #endregion
    }//end class
}