自由手記

using System;

using System.Text;

using System.Security.Cryptography;

using System.IO;

//預設金鑰向量

private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

/// <summary>

/// DES加密字串

/// </summary>

/// <param name="encryptString">待加密的字串</param>

/// <param name="encryptKey">加密金鑰,要求為8位</param>

/// <returns>加密成功返回加密後的字串，失敗返回源串</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解密字串

/// </summary>

/// <param name="decryptString">待解密的字串</param>

/// <param name="decryptKey">解密金鑰,要求為8位,和加密金鑰相同</param>

/// <returns>解密成功返回解密後的字串，失敗返源串</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;

}

}