一个可以用来加密/解密的类

可以用来加/解密数据库用户、密码等
using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
namespace Common
{
///

/// SecurityService 的摘要说明。
///

public class SecurityService
{
static protected Byte[] byteKey = {125, 14, 45, 67, 112, 79, 77, 99, 37, 104, 13, 9, 118, 51, 87, 108};
static protected Byte[] byteIV = {86, 19, 79, 15, 72, 58, 117, 45};
static public string SymmetricEncrypt(String sPlainText)
{
Byte[] bytePlaintext;
MemoryStream EncryptedStream;
ICryptoTransform Encryptor;
CryptoStream TheCryptoStream;
if(sPlainText=="") return "";
bytePlaintext = Encoding.ASCII.GetBytes(sPlainText);
EncryptedStream = new MemoryStream(sPlainText.Length);
Encryptor = GetEncryptor();
TheCryptoStream = new CryptoStream(EncryptedStream, Encryptor, CryptoStreamMode.Write);
TheCryptoStream.Write(bytePlaintext, 0, bytePlaintext.Length);
TheCryptoStream.FlushFinalBlock();
TheCryptoStream.Close();
return Convert.ToBase64String(EncryptedStream.ToArray());
}//End Function
static public string SymmetricDecrypt(String sEncryptedText)
{
Byte[] byteEncrypted;
MemoryStream PlaintextStream;
ICryptoTransform Decryptor;
CryptoStream TheCryptoStream;
if (sEncryptedText == "") return "";
byteEncrypted = Convert.FromBase64String(sEncryptedText.Trim());