DES对称加密

    using System.IO; 
    using System.Security.Cryptography; 
    using System.Text; 
     
   
     
    //默认密钥向量 
    private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; 
    /// <summary> 
    /// DES加密字符串 
    /// </summary> 
    /// <param name="encryptString">待加密的字符串</param> 
    /// <param name="encryptKey">加密密钥,要求为8位</param> 
    /// <returns>加密成功返回加密后的字符串,失败返回源串</returns> 
    public static string EncryptDES(string encryptString, string encryptKey) 
    { 
        try
        { 
            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()); 
        } 
        catch
        { 
            return encryptString; 
        } 
    } 
     
    /// <summary> 
    /// DES解密字符串 
    /// </summary> 
    /// <param name="decryptString">待解密的字符串</param> 
    /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param> 
    /// <returns>解密成功返回解密后的字符串,失败返源串</returns> 
    public static string DecryptDES(string decryptString, string decryptKey) 
    { 
        try
        { 
            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 decryptString; 
        } 
    }