/// <summary>
/// 類說明：Assistant
/// 編 碼 人：蘇飛
/// 聯繫方式：361983679  
/// 更新網站：http://www.sufeinet.com/thread-655-1-1.html
/// </summary>
using System;
using System.Text;
using System.Security.Cryptography;
using System.IO;
using System.Text.RegularExpressions;
using System.Collections;

namespace DotNet.Utilities
{
    /// <summary>
    /// MySecurity(安全類) 的摘要說明。
    /// </summary>
    public class MySecurity
    {
        /// <summary>
        /// 初始化安全類
        /// </summary>
        public MySecurity()
        {
            ///默認密碼
            key = "0123456789";
        }
        private string key; //默認密鑰

        private byte[] sKey;
        private byte[] sIV;

        #region 加密字符串
        /// <summary>
        /// 加密字符串
        /// </summary>
        /// <param name="inputStr">輸入字符串</param>
        /// <param name="keyStr">密碼，可以為「」</param>
        /// <returns>輸出加密後字符串</returns>
        static public string SEncryptString(string inputStr, string keyStr)
        {
            MySecurity ws = new MySecurity();
            return ws.EncryptString(inputStr, keyStr);
        }
        /// <summary>
        /// 加密字符串
        /// </summary>
        /// <param name="inputStr">輸入字符串</param>
        /// <param name="keyStr">密碼，可以為「」</param>
        /// <returns>輸出加密後字符串</returns>
        public string EncryptString(string inputStr, string keyStr)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            if (keyStr == "")
                keyStr = key;
            byte[] inputByteArray = Encoding.Default.GetBytes(inputStr);
            byte[] keyByteArray = Encoding.Default.GetBytes(keyStr);
            SHA1 ha = new SHA1Managed();
            byte[] hb = ha.ComputeHash(keyByteArray);
            sKey = new byte[8];
            sIV = new byte[8];
            for (int i = 0; i < 8; i++)
                sKey[i] = hb[i];
            for (int i = 8; i < 16; i++)
                sIV[i - 8] = hb[i];
            des.Key = sKey;
            des.IV = sIV;
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            cs.Close();
            ms.Close();
            return ret.ToString();
        }
        #endregion

        #region 加密字符串 密鑰為系統默認 0123456789
        /// <summary>
        /// 加密字符串 密鑰為系統默認
        /// </summary>
        /// <param name="inputStr">輸入字符串</param>
        /// <returns>輸出加密後字符串</returns>
        static public string SEncryptString(string inputStr)
        {
            MySecurity ws = new MySecurity();
            return ws.EncryptString(inputStr, "");
        }
        #endregion


        #region 加密文件
        /// <summary>
        /// 加密文件
        /// </summary>
        /// <param name="filePath">輸入文件路徑</param>
        /// <param name="savePath">加密後輸出文件路徑</param>
        /// <param name="keyStr">密碼，可以為「」</param>
        /// <returns></returns>  
        public bool EncryptFile(string filePath, string savePath, string keyStr)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            if (keyStr == "")
                keyStr = key;
            FileStream fs = File.OpenRead(filePath);
            byte[] inputByteArray = new byte[fs.Length];
            fs.Read(inputByteArray, 0, (int)fs.Length);
            fs.Close();
            byte[] keyByteArray = Encoding.Default.GetBytes(keyStr);
            SHA1 ha = new SHA1Managed();
            byte[] hb = ha.ComputeHash(keyByteArray);
            sKey = new byte[8];
            sIV = new byte[8];
            for (int i = 0; i < 8; i++)
                sKey[i] = hb[i];
            for (int i = 8; i < 16; i++)
                sIV[i - 8] = hb[i];
            des.Key = sKey;
            des.IV = sIV;
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            fs = File.OpenWrite(savePath);
            foreach (byte b in ms.ToArray())
            {
                fs.WriteByte(b);
            }
            fs.Close();
            cs.Close();
            ms.Close();
            return true;
        }
        #endregion

        #region 解密字符串
        /// <summary>
        /// 解密字符串
        /// </summary>
        /// <param name="inputStr">要解密的字符串</param>
        /// <param name="keyStr">密鑰</param>
        /// <returns>解密後的結果</returns>
        static public string SDecryptString(string inputStr, string keyStr)
        {
            MySecurity ws = new MySecurity();
            return ws.DecryptString(inputStr, keyStr);
        }
        /// <summary>
        ///  解密字符串 密鑰為系統默認
        /// </summary>
        /// <param name="inputStr">要解密的字符串</param>
        /// <returns>解密後的結果</returns>
        static public string SDecryptString(string inputStr)
        {
            MySecurity ws = new MySecurity();
            return ws.DecryptString(inputStr, "");
        }
        /// <summary>
        /// 解密字符串
        /// </summary>
        /// <param name="inputStr">要解密的字符串</param>
        /// <param name="keyStr">密鑰</param>
        /// <returns>解密後的結果</returns>
        public string DecryptString(string inputStr, string keyStr)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            if (keyStr == "")
                keyStr = key;
            byte[] inputByteArray = new byte[inputStr.Length / 2];
            for (int x = 0; x < inputStr.Length / 2; x++)
            {
                int i = (Convert.ToInt32(inputStr.Substring(x * 2, 2), 16));
                inputByteArray[x] = (byte)i;
            }
            byte[] keyByteArray = Encoding.Default.GetBytes(keyStr);
            SHA1 ha = new SHA1Managed();
            byte[] hb = ha.ComputeHash(keyByteArray);
            sKey = new byte[8];
            sIV = new byte[8];
            for (int i = 0; i < 8; i++)
                sKey[i] = hb[i];
            for (int i = 8; i < 16; i++)
                sIV[i - 8] = hb[i];
            des.Key = sKey;
            des.IV = sIV;
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            return System.Text.Encoding.Default.GetString(ms.ToArray());
        }
        #endregion

        #region 解密文件
        /// <summary>
        /// 解密文件
        /// </summary>
        /// <param name="filePath">輸入文件路徑</param>
        /// <param name="savePath">解密後輸出文件路徑</param>
        /// <param name="keyStr">密碼，可以為「」</param>
        /// <returns></returns>    
        public bool DecryptFile(string filePath, string savePath, string keyStr)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            if (keyStr == "")
                keyStr = key;
            FileStream fs = File.OpenRead(filePath);
            byte[] inputByteArray = new byte[fs.Length];
            fs.Read(inputByteArray, 0, (int)fs.Length);
            fs.Close();
            byte[] keyByteArray = Encoding.Default.GetBytes(keyStr);
            SHA1 ha = new SHA1Managed();
            byte[] hb = ha.ComputeHash(keyByteArray);
            sKey = new byte[8];
            sIV = new byte[8];
            for (int i = 0; i < 8; i++)
                sKey[i] = hb[i];
            for (int i = 8; i < 16; i++)
                sIV[i - 8] = hb[i];
            des.Key = sKey;
            des.IV = sIV;
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            fs = File.OpenWrite(savePath);
            foreach (byte b in ms.ToArray())
            {
                fs.WriteByte(b);
            }
            fs.Close();
            cs.Close();
            ms.Close();
            return true;
        }
        #endregion


        #region MD5加密
        /// <summary>
        /// 128位MD5算法加密字符串
        /// </summary>
        /// <param name="text">要加密的字符串</param>    
        public static string MD5(string text)
        {

            //如果字符串為空，則返回
            if (Tools.IsNullOrEmpty<string>(text))
            {
                return "";
            }
            //返回MD5值的字符串表示
            return MD5(text);
        }

        /// <summary>
        /// 128位MD5算法加密Byte數組
        /// </summary>
        /// <param name="data">要加密的Byte數組</param>    
        public static string MD5(byte[] data)
        {
            //如果Byte數組為空，則返回
            if (Tools.IsNullOrEmpty<byte[]>(data))
            {
                return "";
            }

            try
            {
                //創建MD5密碼服務提供程序
                MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();

                //計算傳入的字節數組的哈希值
                byte[] result = md5.ComputeHash(data);

                //釋放資源
                md5.Clear();

                //返回MD5值的字符串表示
                return Convert.ToBase64String(result);
            }
            catch
            {

                //LogHelper.WriteTraceLog(TraceLogLevel.Error, ex.Message);
                return "";
            }
        }
        #endregion

        #region Base64加密
        /// <summary>
        /// Base64加密
        /// </summary>
        /// <param name="text">要加密的字符串</param>
        /// <returns></returns>
        public static string EncodeBase64(string text)
        {
            //如果字符串為空，則返回
            if (Tools.IsNullOrEmpty<string>(text))
            {
                return "";
            }

            try
            {
                char[] Base64Code = new char[]{'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T',
											'U','V','W','X','Y','Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n',
											'o','p','q','r','s','t','u','v','w','x','y','z','0','1','2','3','4','5','6','7',
											'8','9','+','/','='};
                byte empty = (byte)0;
                ArrayList byteMessage = new ArrayList(Encoding.Default.GetBytes(text));
                StringBuilder outmessage;
                int messageLen = byteMessage.Count;
                int page = messageLen / 3;
                int use = 0;
                if ((use = messageLen % 3) > 0)
                {
                    for (int i = 0; i < 3 - use; i++)
                        byteMessage.Add(empty);
                    page++;
                }
                outmessage = new System.Text.StringBuilder(page * 4);
                for (int i = 0; i < page; i++)
                {
                    byte[] instr = new byte[3];
                    instr[0] = (byte)byteMessage[i * 3];
                    instr[1] = (byte)byteMessage[i * 3 + 1];
                    instr[2] = (byte)byteMessage[i * 3 + 2];
                    int[] outstr = new int[4];
                    outstr[0] = instr[0] >> 2;
                    outstr[1] = ((instr[0] & 0x03) << 4) ^ (instr[1] >> 4);
                    if (!instr[1].Equals(empty))
                        outstr[2] = ((instr[1] & 0x0f) << 2) ^ (instr[2] >> 6);
                    else
                        outstr[2] = 64;
                    if (!instr[2].Equals(empty))
                        outstr[3] = (instr[2] & 0x3f);
                    else
                        outstr[3] = 64;
                    outmessage.Append(Base64Code[outstr[0]]);
                    outmessage.Append(Base64Code[outstr[1]]);
                    outmessage.Append(Base64Code[outstr[2]]);
                    outmessage.Append(Base64Code[outstr[3]]);
                }
                return outmessage.ToString();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        #endregion

        #region Base64解密
        /// <summary>
        /// Base64解密
        /// </summary>
        /// <param name="text">要解密的字符串</param>
        public static string DecodeBase64(string text)
        {
            //如果字符串為空，則返回
            if (Tools.IsNullOrEmpty<string>(text))
            {
                return "";
            }

            //將空格替換為加號
            text = text.Replace(" ", "+");

            try
            {
                if ((text.Length % 4) != 0)
                {
                    return "包含不正確的BASE64編碼";
                }
                if (!Regex.IsMatch(text, "^[A-Z0-9/+=]*$", RegexOptions.IgnoreCase))
                {
                    return "包含不正確的BASE64編碼";
                }
                string Base64Code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
                int page = text.Length / 4;
                ArrayList outMessage = new ArrayList(page * 3);
                char[] message = text.ToCharArray();
                for (int i = 0; i < page; i++)
                {
                    byte[] instr = new byte[4];
                    instr[0] = (byte)Base64Code.IndexOf(message[i * 4]);
                    instr[1] = (byte)Base64Code.IndexOf(message[i * 4 + 1]);
                    instr[2] = (byte)Base64Code.IndexOf(message[i * 4 + 2]);
                    instr[3] = (byte)Base64Code.IndexOf(message[i * 4 + 3]);
                    byte[] outstr = new byte[3];
                    outstr[0] = (byte)((instr[0] << 2) ^ ((instr[1] & 0x30) >> 4));
                    if (instr[2] != 64)
                    {
                        outstr[1] = (byte)((instr[1] << 4) ^ ((instr[2] & 0x3c) >> 2));
                    }
                    else
                    {
                        outstr[2] = 0;
                    }
                    if (instr[3] != 64)
                    {
                        outstr[2] = (byte)((instr[2] << 6) ^ instr[3]);
                    }
                    else
                    {
                        outstr[2] = 0;
                    }
                    outMessage.Add(outstr[0]);
                    if (outstr[1] != 0)
                        outMessage.Add(outstr[1]);
                    if (outstr[2] != 0)
                        outMessage.Add(outstr[2]);
                }
                byte[] outbyte = (byte[])outMessage.ToArray(Type.GetType("System.Byte"));
                return Encoding.Default.GetString(outbyte);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        #endregion
    }
}
