URL parameter encryption and decryption process

Public static string Encode (string str, string key)
2 {
3 DESCryptoServiceProvider provider = new DESCryptoServiceProvider ();
4 provider. Key = Encoding. ASCII. GetBytes (key. Substring (0, 8 ));
5 provider. IV = Encoding. ASCII. GetBytes (key. Substring (0, 8 ));
6 byte [] bytes = Encoding. UTF8.GetBytes (str );
7 MemoryStream stream = new MemoryStream ();
8 CryptoStream stream2 = new CryptoStream (stream, provider. CreateEncryptor (), CryptoStreamMode. Write );
9 stream2.Write (bytes, 0, bytes. Length );
10 stream2.FlushFinalBlock ();
11 StringBuilder builder = new StringBuilder ();
12 foreach (byte num in stream. ToArray ())
13 {
14 builder. AppendFormat ("{0: X2}", num );
15}
16 stream. Close ();
17 return builder. ToString ();
18}

 

Decryption code

1 public static string Decode (string str, string key)
2 {
3 DESCryptoServiceProvider provider = new DESCryptoServiceProvider ();
4 provider. Key = Encoding. ASCII. GetBytes (key. Substring (0, 8 ));
5 provider. IV = Encoding. ASCII. GetBytes (key. Substring (0, 8 ));
6 byte [] buffer = new byte [str. Length/2];
7 for (int I = 0; I <(str. Length/2); I ++)
8 {
9 int num2 = Convert. ToInt32 (str. Substring (I * 2, 2), 0x10 );
10 buffer [I] = (byte) num2;
11}
12 MemoryStream stream = new MemoryStream ();
13 CryptoStream stream2 = new CryptoStream (stream, provider. CreateDecryptor (), CryptoStreamMode. Write );
14 stream2.Write (buffer, 0, buffer. Length );
15 stream2.FlushFinalBlock ();
16 stream. Close ();
17 return Encoding. GetEncoding ("GB2312"). GetString (stream. ToArray ());
18}

 

Front-end

<P>
<Asp: TextBox ID = "txtbox" runat = "server"> </asp: TextBox>
<Asp: Button ID = "btnok" runat = "server" onclick = "btnok_Click" Text = "encrypted"/>
<Asp: Button ID = "btncanel" runat = "server" Text = "decrypt" onclick = "btncanel_Click"/>
</P>

 

 

Background code

1 protected void btnok_Click (object sender, EventArgs e)
2 {
3
4 txtbox. Text = Helper. Encode (txtbox. Text. Trim (), "Rainight"). Trim ();
5
6
7
8
9}
10
11 protected void btncanel_Click (object sender, EventArgs e)
12 {
13 txtbox. Text = Helper. Decode (txtbox. Text. Trim (), "Rainight"). Trim ();
14 Response. Write (Helper. Decode (txtbox. Text. Trim (), "Rainight "));
15}