asp.net 加密解密類

這裡給大家一個現成的C#加密解密類，由 admin10000.com 提供，包含MD5、SHA1、DES加密和解密，Base64編碼解碼。

首先匯入命名空間

      using System.Web.Security;     using System.Security.Cryptography;     using System.Text;     using System.IO;

/// <summary>
/// EncryptHelper 來自 www.Admin10000.com
/// </summary>

public class EncryptHelper{        // 提供8個字元作為DES密鑰（程式自動截取前8個字元）         private static string key = "admin10000.com";        /// <summary>        /// DES對稱式加密解密的密鑰        /// </summary>         public static string Key        {                get                {                        return key;                }                set                {                        key = value;                }        }        /// <summary>        /// MD5 加密（無法復原加密）        /// </summary>        /// <param name="pass">要加密的原始字串</param>        /// <returns></returns>         public static string MD5Encrypt(string pass)        {                    System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();                byte[] bytResult = md5.ComputeHash(System.Text.Encoding.UTF8.GetBytes(pass));                md5.Clear();                string strResult = BitConverter.ToString(bytResult);                strResult = strResult.Replace("-", "");                return strResult;                        /* 另一種方法                pass = FormsAuthentication.HashPasswordForStoringInConfigFile(pass, "MD5");                return pass;                */            }        /// <summary>        /// SHA1 加密（無法復原加密）        /// </summary>        /// <param name="pass">要加密的原始字串</param>        /// <returns></returns>         public static string SHA1Encrypt(string pass)        {                System.Security.Cryptography.SHA1 sha1 = new System.Security.Cryptography.SHA1CryptoServiceProvider();                byte[] bytResult = sha1.ComputeHash(System.Text.Encoding.UTF8.GetBytes(pass));                sha1.Clear();                string strResult = BitConverter.ToString(bytResult);                strResult = strResult.Replace("-", "");                return strResult;                /* 另一種方法                pass = FormsAuthentication.HashPasswordForStoringInConfigFile(pass, "SHA1");                return pass;                */        }        /// <summary>        /// DES加密字串        /// </summary>        /// <param name="encryptString">待加密的字串</param>        /// <returns>加密成功返回加密後的字串，失敗返回源串</returns>         public static string DESEncrypt(string encryptString)        {                try                {                        byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));                        byte[] rgbIV = rgbKey;                        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();                        cStream.Close();                        return Convert.ToBase64String(mStream.ToArray());                }                catch                {                        return encryptString;                }        }        /// <summary>        /// DES解密字串        /// </summary>        /// <param name="decryptString">待解密的字串</param>        /// <returns>解密成功返回解密後的字串，失敗返源串</returns>         public static string DESDecrypt(string decryptString)        {                try                {                        byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));                        byte[] rgbIV = rgbKey;                        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();                        cStream.Close();                        return Encoding.UTF8.GetString(mStream.ToArray());                }                catch                {                        return decryptString;                }        }        /// <summary>        /// 將一般字元串編碼為BASE64字串        /// </summary>        /// <param name="str">源字串</param>        /// <returns></returns>         public static string Base64Encode(string str)        {                return Convert.ToBase64String(Encoding.UTF8.GetBytes(str));        }        /// <summary>        /// 解碼BASE64字串        /// </summary>        /// <param name="str">Base64字串</param>        /// <returns></returns>         public static string Base64Decode(string base64Str)        {                return Encoding.UTF8.GetString(Convert.FromBase64String(base64Str));        }}

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