关于DEC加密解密显示的问题...

[coo_key]

///
/// DEC 加密过程
///
///
///
///
public static string Encode(string data)
{
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
int i = cryptoProvider.KeySize;
MemoryStream ms = new MemoryStream();
CryptoStream cst = new CryptoStream(ms,cryptoProvider.CreateEncryptor(byKey,byIV),CryptoStreamMode.Write);

StreamWriter sw = new StreamWriter(cst);
sw.Write(data);
sw.Flush();
cst.FlushFinalBlock();
sw.Flush();
return Convert.ToBase64String(ms.GetBuffer(),0,(int)ms.Length);
}


///
/// DEC 解密过程
///
///
///
///
public static string Decode(string data)
{
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

byte[] byEnc;
try
{
byEnc = Convert.FromBase64String(data);
}
catch
{
return null;
}

DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
MemoryStream ms = new MemoryStream(byEnc);
CryptoStream cst = new CryptoStream(ms,cryptoProvider.CreateDecryptor(byKey,byIV),CryptoStreamMode.Read);
StreamReader sr = new StreamReader(cst);
return sr.ReadToEnd();
}

加密解密的函数如上

我现在把这个编译成一个类之后放到VB.net的winform中调用
写入数据库的代码是：

SqlCommand_Update.CommandText = "Update Users set Password = @Password where UserName = '" & user & "'"
SqlCommand_Update.Parameters.Add("@Password", System.Data.SqlDbType.Binary)

Dim pass As String = ZCB.Framework.Security.Encode(Txt_Password.Text)

Dim passByte As Byte()
passByte = Convert.FromBase64String(pass)

SqlCommand_Update.Parameters(0).Value = passByte
Try
SqlCommand_Update.ExecuteNonQuery()

可以正确写入....

读出的代码是：
strSQL = "SELECT Password FROM Users WHERE Password is not Null and UserName = '" + UserName + "'"
If PublicSub.Search(strSQL, True) = True Then

Dim passByte As Byte() = CType(PublicVar.Pub_DataRow.Item(0), Byte())

Dim pass As String = Convert.ToBase64String(passByte)

Txt_Password.Text = ZCB.Framework.Security.Decode(pass)

会在return sr.ReadToEnd();的时候报错误的数据这个错误
我数据库中的格式是Binary 16

[coo_key]

如果我密码是6位就会报错〉。。
我跟踪了一下，从数据库读出来之后Ctype成byte()之后便成16位的，写入的时候是8位的，所以出错..但是我从数据库读出来后把后面的0截断掉，传一个8位的解密还是有问题，晕

[coo_key]

没有人知道阿？