DESCryptoServiceProvider加密解密

http://www.dotblogs.com.tw/phoenix7765/archive/2008/08/30/5254.aspx

using ...System; 
using System.IO; 
using System.Security.Cryptography; 
using System.Text;  
 
namespace Clib 
{ 
    /// <!--Security類別--> 
    /**//// <summary> 
    /// Security類別 - design By Phoenix 2008 - 
    /// </summary> 
    public class Security 
    { 
        private string _Key; 
        private string _IV; 
 
        /**//// <summary> 
        /// 加密金鑰(8個英文字) 
        /// </summary> 
        public string Key 
        { 
            set 
            { 
                _Key = value.Length == 8 ? value : "PhoenixK"; 
            } 
        } 
        /**//// <summary> 
        /// 初始化向量(8個英文字) 
        /// </summary> 
        public string IV 
        { 
            set 
            { 
                _IV = value.Length == 8 ? value : "PhoenixI"; 
            } 
        } 
 
        /**//// <summary> 
        /// 初始化 Clib.Security 類別的新執行個體 
        /// </summary> 
        public Security() 
        { 
            _Key = "PhoenixK"; 
            _IV = "PhoenixI"; 
        } 
 
        /**//// <summary> 
        /// 初始化 Clib.Security 類別的新執行個體 
        /// </summary> 
        /// <param name="newKey">加密金鑰</param> 
        /// <param name="newIV">初始化向量</param> 
        public Security(string newKey,string newIV) 
        { 
            this.Key = newKey; 
            this.IV = newIV; 
        } 
 
        /// <!--加密字串--> 
        /**//// <summary> 
        /// 加密字串 - design By Phoenix 2008 - 
        /// </summary> 
        /// <param name="value">加密的字串</param> 
        /// <returns>加密過後的字串</returns> 
        public string Encrypt(string value) 
        { 
            return Encrypt(value, _Key,_IV); 
        } 
 
        /// <!--解密字串--> 
        /**//// <summary> 
        /// 解密字串 - design By Phoenix 2008 - 
        /// </summary> 
        /// <param name="value">解密的字串</param> 
        /// <returns>解密過後的字串</returns> 
        public string Decrypt(string value) 
        { 
            return Decrypt(value, _Key,_IV); 
        } 
 
        /// <!--DEC 加密法 --> 
        /**//// <summary> 
        /// DEC 加密法 - design By Phoenix 2008 - 
        /// </summary> 
        /// <param name="pToEncrypt">加密的字串</param> 
        /// <param name="sKey">加密金鑰</param> 
        /// <param name="sIV">初始化向量</param> 
        /// <returns></returns> 
        private string Encrypt(string pToEncrypt, string sKey,string sIV) 
        { 
            StringBuilder ret = new StringBuilder(); 
            using (DESCryptoServiceProvider des = new DESCryptoServiceProvider()) 
            { 
                //將字元轉換為Byte 
                byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt); 
                //設定加密金鑰(轉為Byte) 
                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); 
                //設定初始化向量(轉為Byte) 
                des.IV = ASCIIEncoding.ASCII.GetBytes(sIV); 
 
                using (MemoryStream ms = new MemoryStream()) 
                { 
                    using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write)) 
                    { 
                        cs.Write(inputByteArray, 0, inputByteArray.Length); 
                        cs.FlushFinalBlock(); 
                    } 
                    //輸出資料 
                    foreach (byte b in ms.ToArray()) 
                        ret.AppendFormat("...{0:X2}", b); 
                } 
            } 
            //回傳 
            return ret.ToString(); 
        } 
 
        /// <!--DEC 解密法--> 
        /**//// <summary> 
        /// DEC 解密法 - design By Phoenix 2008 - 
        /// </summary> 
        /// <param name="pToDecrypt">解密的字串</param> 
        /// <param name="sKey">加密金鑰</param> 
        /// <param name="sIV">初始化向量</param> 
        /// <returns></returns> 
        private string Decrypt(string pToDecrypt, string sKey, string sIV) 
        { 
            using (DESCryptoServiceProvider des = new DESCryptoServiceProvider()) 
            { 
 
                byte[] inputByteArray = new byte[pToDecrypt.Length / 2]; 
                //反轉 
                for (int x = 0; x < pToDecrypt.Length / 2; x++) 
                { 
                    int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16)); 
                    inputByteArray[x] = (byte)i; 
                } 
                //設定加密金鑰(轉為Byte) 
                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); 
                //設定初始化向量(轉為Byte) 
                des.IV = ASCIIEncoding.ASCII.GetBytes(sIV); 
                using (MemoryStream ms = new MemoryStream()) 
                { 
                    using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write)) 
                    { 
                        //例外處理 
                        try 
                        { 
                            cs.Write(inputByteArray, 0, inputByteArray.Length); 
                            cs.FlushFinalBlock(); 
                            //輸出資料 
                            return System.Text.Encoding.Default.GetString(ms.ToArray()); 
                        } 
                        catch (CryptographicException) 
                        { 
                            //若金鑰或向量錯誤，傳回N/A 
                            return "N/A"; 
                        } 
                    } 
                } 
            } 
        } 
 
        /// <!--驗證加密字串--> 
        /**//// <summary> 
        /// 驗證加密字串 - design By Phoenix 2008 - 
        /// </summary> 
        /// <param name="EnString">加密後的字串</param> 
        /// <param name="FoString">加密前的字串</param> 
        /// <returns>是/否</returns> 
        public bool ValidateString(string EnString, string FoString) 
        { 
            //呼叫Decrypt解密 
            //判斷是否相符 
            //回傳結果 
            return Decrypt(EnString, _Key,_IV) == FoString.ToString() ? true : false; 
        } 
    } 
}