C〓〓〓の3 DS暗号解読アルゴリズムの実例コード

using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.IO;
namespace ConsoleApplication1
{
    /// <summary>
    ///     
    /// </summary>
    public class EncryptHelper
    {
        
        //        
        private SymmetricAlgorithm mCSP = new TripleDESCryptoServiceProvider();
        #region       
        /// <summary>
        ///       
        /// </summary>
        /// <param name="Value">       </param>
        /// <param name="sKey">  ，  32 </param>
        /// <param name="sIV">  ，   12   </param>
        /// <returns>       </returns>
        public string EncryptString(string Value, string sKey,string sIV)
        {
            try
            {
                ICryptoTransform ct;
                MemoryStream ms;
                CryptoStream cs;
                byte[] byt;
                mCSP.Key = Convert.FromBase64String(sKey);
                mCSP.IV = Convert.FromBase64String(sIV);
                //         
                mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
                //              
                mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
                ct = mCSP.CreateEncryptor(mCSP.Key, mCSP.IV);//      
                byt = Encoding.UTF8.GetBytes(Value);
                ms = new MemoryStream();
                cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
                cs.Write(byt, 0, byt.Length);
                cs.FlushFinalBlock();
                cs.Close();
                return Convert.ToBase64String(ms.ToArray());
            }
            catch (Exception ex)
            {
                //MessageBox.Show(ex.Message, "    ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return ("Error in Encrypting " + ex.Message);
            }
        }
        /// <summary>
        ///      
        /// </summary>
        /// <param name="Value">       </param>
        /// <param name="sKey">  ，  32 </param>
        /// <param name="sIV">  ，   12   </param>
        /// <returns>       </returns>
        public string DecryptString(string Value, string sKey, string sIV)
        {
            try
            {
                ICryptoTransform ct;//      
                MemoryStream ms;//   
                CryptoStream cs;//              
                byte[] byt;
                // 3DES      byte
                mCSP.Key = Convert.FromBase64String(sKey);
                // 3DES      byte
                mCSP.IV = Convert.FromBase64String(sIV);
                mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
                mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
                ct = mCSP.CreateDecryptor(mCSP.Key, mCSP.IV);//        
                byt = Convert.FromBase64String(Value);
                ms = new MemoryStream();
                cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
                cs.Write(byt, 0, byt.Length);
                cs.FlushFinalBlock();
                cs.Close();
                return Encoding.UTF8.GetString(ms.ToArray());
            }
            catch (Exception ex)
            {
                //MessageBox.Show(ex.Message, "    ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return ("Error in Decrypting " + ex.Message);
            }
        }
        #endregion
    }
}