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

namespace WebService
{

    public class Encryption64
    {
        //private byte[] key = {};
        //private byte[] IV = {10, 20, 30, 40, 50, 60, 70, 80}; // it can be any byte value

        public static string Decrypt(string stringToDecrypt,
        string sEncryptionKey)
        {

            byte[] key = { };
            byte[] IV = { 10, 20, 30, 40, 50, 60, 70, 80 };
            byte[] inputByteArray = new byte[stringToDecrypt.Length];

            try
            {
                key = Encoding.UTF8.GetBytes(sEncryptionKey.Substring(0, 8));
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                inputByteArray = Convert.FromBase64String(stringToDecrypt);

                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(key, IV), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();

                Encoding encoding = Encoding.UTF8;
                return encoding.GetString(ms.ToArray());
            }
            catch (System.Exception ex)
            {
                return string.Empty;
            }
        }

        public static string Encrypt(string stringToEncrypt,
        string sEncryptionKey)
        {

            byte[] key = { };
            byte[] IV = { 10, 20, 30, 40, 50, 60, 70, 80 };
            byte[] inputByteArray; //Convert.ToByte(stringToEncrypt.Length)

            try
            {
                key = Encoding.UTF8.GetBytes(sEncryptionKey.Substring(0, 8));
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                inputByteArray = Encoding.UTF8.GetBytes(stringToEncrypt);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(key, IV), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();

                return Convert.ToBase64String(ms.ToArray());
            }
            catch (System.Exception ex)
            {
                return string.Empty;
            }
        }
    }




    /// <summary>
    /// Encrypt 的摘要说明。
    /// LiTianPing
    /// </summary>
    public class DEncrypt
    {
        /// <summary>
        /// 构造方法
        /// </summary>
        public DEncrypt()
        {
        }

        #region 使用 缺省密钥字符串 加密/解密string

        /// <summary>
        /// 使用缺省密钥字符串加密string
        /// </summary>
        /// <param name="original">明文</param>
        /// <returns>密文</returns>
        public static string Encrypt(string original)
        {
            return Encrypt(original, "%FSxh#s&A!Csd");
        }
        /// <summary>
        /// 使用缺省密钥字符串解密string
        /// </summary>
        /// <param name="original">密文</param>
        /// <returns>明文</returns>
        public static string Decrypt(string original)
        {
            return Decrypt(original, "%FSxh#s&A!Csd", System.Text.Encoding.Default);
        }

        #endregion

        #region 使用 给定密钥字符串 加密/解密string
        /// <summary>
        /// 使用给定密钥字符串加密string
        /// </summary>
        /// <param name="original">原始文字</param>
        /// <param name="key">密钥</param>
        /// <param name="encoding">字符编码方案</param>
        /// <returns>密文</returns>
        public static string Encrypt(string original, string key)
        {
            byte[] buff = System.Text.Encoding.Default.GetBytes(original);
            byte[] kb = System.Text.Encoding.Default.GetBytes(key);
            return Convert.ToBase64String(Encrypt(buff, kb));
        }
        /// <summary>
        /// 使用给定密钥字符串解密string
        /// </summary>
        /// <param name="original">密文</param>
        /// <param name="key">密钥</param>
        /// <returns>明文</returns>
        public static string Decrypt(string original, string key)
        {
            return Decrypt(original, key, System.Text.Encoding.Default);
        }

        /// <summary>
        /// 使用给定密钥字符串解密string,返回指定编码方式明文
        /// </summary>
        /// <param name="encrypted">密文</param>
        /// <param name="key">密钥</param>
        /// <param name="encoding">字符编码方案</param>
        /// <returns>明文</returns>
        public static string Decrypt(string encrypted, string key, Encoding encoding)
        {
            byte[] buff = Convert.FromBase64String(encrypted);
            byte[] kb = System.Text.Encoding.Default.GetBytes(key);
            return encoding.GetString(Decrypt(buff, kb));
        }
        #endregion

        #region 使用 缺省密钥字符串 加密/解密/byte[]
        /// <summary>
        /// 使用缺省密钥字符串解密byte[]
        /// </summary>
        /// <param name="encrypted">密文</param>
        /// <param name="key">密钥</param>
        /// <returns>明文</returns>
        public static byte[] Decrypt(byte[] encrypted)
        {
            byte[] key = System.Text.Encoding.Default.GetBytes("%FSxh#s&A!Csd");
            return Decrypt(encrypted, key);
        }
        /// <summary>
        /// 使用缺省密钥字符串加密
        /// </summary>
        /// <param name="original">原始数据</param>
        /// <param name="key">密钥</param>
        /// <returns>密文</returns>
        public static byte[] Encrypt(byte[] original)
        {
            byte[] key = System.Text.Encoding.Default.GetBytes("%FSxh#s&A!Csd");
            return Encrypt(original, key);
        }
        #endregion

        #region  使用 给定密钥 加密/解密/byte[]

        /// <summary>
        /// 生成MD5摘要
        /// </summary>
        /// <param name="original">数据源</param>
        /// <returns>摘要</returns>
        public static byte[] MakeMD5(byte[] original)
        {
            MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
            byte[] keyhash = hashmd5.ComputeHash(original);
            hashmd5 = null;
            return keyhash;
        }


        /// <summary>
        /// 使用给定密钥加密
        /// </summary>
        /// <param name="original">明文</param>
        /// <param name="key">密钥</param>
        /// <returns>密文</returns>
        public static byte[] Encrypt(byte[] original, byte[] key)
        {
            TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
            des.Key = MakeMD5(key);
            des.Mode = CipherMode.ECB;

            return des.CreateEncryptor().TransformFinalBlock(original, 0, original.Length);
        }

        /// <summary>
        /// 使用给定密钥解密数据
        /// </summary>
        /// <param name="encrypted">密文</param>
        /// <param name="key">密钥</param>
        /// <returns>明文</returns>
        public static byte[] Decrypt(byte[] encrypted, byte[] key)
        {
            TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
            des.Key = MakeMD5(key);
            des.Mode = CipherMode.ECB;

            return des.CreateDecryptor().TransformFinalBlock(encrypted, 0, encrypted.Length);
        }

        #endregion




    }
}