加密解密

//加密解密
    public class GF_Encrypt
    {
        ///

        /// DES加密
        ///

        /// 加密字符串
        /// 密钥
        ///
        public static string string_Encrypt(string pToEncrypt, string sKey)
        {
            if (pToEncrypt == "") return "";
            if (sKey.Length < 8) sKey = sKey + "xuE29xWp";
            if (sKey.Length > 8) sKey = sKey.Substring(0, 8);
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            //把字符串放到byte数组中 
            //原来使用的UTF8编码，我改成Unicode编码了，不行 
            byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);
            //建立加密对象的密钥和偏移量 
            //原文使用ASCIIEncoding.ASCII方法的GetBytes方法 
            //使得输入密码必须输入英文文本 
            des.Key = ASCIIEncoding.Default.GetBytes(sKey);
            des.IV = ASCIIEncoding.Default.GetBytes(sKey);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            //Write  the  byte  array  into  the  crypto  stream 
            //(It  will  end  up  in  the  memory  stream) 
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            //Get  the  data  back  from  the  memory  stream,  and  into  a  string 
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                //Format  as  hex 
                ret.AppendFormat("{0:X2}", b);
            }
            ret.ToString();
            return ret.ToString();
        }
 
        ///

        /// DES解密
        ///

        /// 解密字符串
        /// 解密密钥
        /// 返回值
        ///
        public static bool string_Decrypt(string pToDecrypt, string sKey, out string outstr)
        {
            if (pToDecrypt == "")
            {
                outstr = "";
                return true;
            };
            if (sKey.Length < 8) sKey = sKey + "xuE29xWp";
            if (sKey.Length > 8) sKey = sKey.Substring(0, 8);
            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                //Put  the  input  string  into  the  byte  array 
                byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
                for (int x = 0; x < pToDecrypt.Length / 2; x++)
                {
                    int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                    inputByteArray[x] = (byte)i;
                }
                //建立加密对象的密钥和偏移量，此值重要，不能修改 
                des.Key = ASCIIEncoding.Default.GetBytes(sKey);
                des.IV = ASCIIEncoding.Default.GetBytes(sKey);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                //Flush  the  data  through  the  crypto  stream  into  the  memory  stream 
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                //Get  the  decrypted  data  back  from  the  memory  stream 
                //建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象 
                StringBuilder ret = new StringBuilder();
                outstr = System.Text.Encoding.Default.GetString(ms.ToArray());
                return true;
            }
            catch
            {
                outstr = "";
                return false;
            }
        }
 
        ///

        /// 加密
        ///

        public class AES
        {
            //默认密钥向量
            private static byte[] Keys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };
 
            public static string Encode(string encryptString, string encryptKey)
            {
                encryptKey = GF_GET.GetSubString(encryptKey, 32, "");
                encryptKey = encryptKey.PadRight(32, ' ');
 
                RijndaelManaged rijndaelProvider = new RijndaelManaged();
                rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32));
                rijndaelProvider.IV = Keys;
                ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();
 
                byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
                byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);
 
                return Convert.ToBase64String(encryptedData);
            }
 
            public static string Decode(string decryptString, string decryptKey)
            {
                try
                {
                    decryptKey = GF_GET.GetSubString(decryptKey, 32, "");
                    decryptKey = decryptKey.PadRight(32, ' ');
 
                    RijndaelManaged rijndaelProvider = new RijndaelManaged();
                    rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);
                    rijndaelProvider.IV = Keys;
                    ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();
 
                    byte[] inputData = Convert.FromBase64String(decryptString);
                    byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputData.Length);
 
                    return Encoding.UTF8.GetString(decryptedData);
                }
                catch
                {
                    return "";
                }
 
            }
 
        }
 
        ///

        /// 加密
        ///

        public class DES
        {
            //默认密钥向量
            private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
 
            ///

            /// DES加密字符串
            ///

            /// 待加密的字符串
            /// 加密密钥,要求为8位
            /// 加密成功返回加密后的字符串,失败返回源串
            public static string Encode(string encryptString, string encryptKey)
            {
                encryptKey = GF_GET.GetSubString(encryptKey, 8, "");
                encryptKey = encryptKey.PadRight(8, ' ');
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
 
            }
 
            ///

            /// DES解密字符串
            ///

            /// 待解密的字符串
            /// 解密密钥,要求为8位,和加密密钥相同
            /// 解密成功返回解密后的字符串,失败返源串
            public static string Decode(string decryptString, string decryptKey)
            {
                try
                {
                    decryptKey = GF_GET.GetSubString(decryptKey, 8, "");
                    decryptKey = decryptKey.PadRight(8, ' ');
                    byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
                    byte[] rgbIV = Keys;
                    byte[] inputByteArray = Convert.FromBase64String(decryptString);
                    DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
 
                    MemoryStream mStream = new MemoryStream();
                    CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                    cStream.Write(inputByteArray, 0, inputByteArray.Length);
                    cStream.FlushFinalBlock();
                    return Encoding.UTF8.GetString(mStream.ToArray());
                }
                catch
                {
                    return "";
                }
            }
        }
 
        ///

        /// MD5函数
        ///

        /// 原始字符串
        /// MD5结果
        public static string MD5(string str)
        {
            byte[] b = Encoding.UTF8.GetBytes(str);
            b = new MD5CryptoServiceProvider().ComputeHash(b);
            string ret = "";
            for (int i = 0; i < b.Length; i++)
                ret += b[i].ToString("x").PadLeft(2, '0');
 
            return ret;
        }
 
        ///

        /// SHA256函数
        ///

        /// /// 原始字符串
        /// SHA256结果
        public static string SHA256(string str)
        {
            byte[] SHA256Data = Encoding.UTF8.GetBytes(str);
            SHA256Managed Sha256 = new SHA256Managed();
            byte[] Result = Sha256.ComputeHash(SHA256Data);
            return Convert.ToBase64String(Result);  //返回长度为44字节的字符串
        }
    }