Need help decrypting

From: Steve Long (Steve_Noneya_at_NoSpam.com)
Date: 02/22/05 

Date: Tue, 22 Feb 2005 08:18:52 -0800

Hello,
I'm wondering if somebody can help me figure out how to decrypt data. I seem
to be able to encrypt data but have not been able to decrypt the very data
that I've encrypted. I know it's because I'm just not understanding the
whole process but I'm obviously just not getting it. Here's the encryption
function I'm using:

Private Sub Encryptpwd()
      Dim cdk As PasswordDeriveBytes = New PasswordDeriveBytes("passwd",
Nothing)
      Dim iv() As Byte = {0, 0, 0, 0, 0, 0, 0, 0}
      Dim key() As Byte = cdk.CryptDeriveKey("RC2", "SHA1", 128, iv)

      Console.WriteLine(key.Length * 8)
      ' Set up an RC2 object to encrypt with the derived key
      Dim rc2 As RC2CryptoServiceProvider = New RC2CryptoServiceProvider
      rc2.Key = key
      Dim b() As Byte = {21, 22, 23, 24, 25, 26, 27, 28}
      rc2.IV = b
      Dim plaintext() As Byte = Encoding.UTF8.GetBytes("iiMap")
      Dim ms As New MemoryStream
      Dim cs As CryptoStream = New CryptoStream(ms, rc2.CreateEncryptor(), _
                                                CryptoStreamMode.Write)
      cs.Write(plaintext, 0, plaintext.Length)
      cs.Close()
      Dim result() As Byte = ms.ToArray()
      Dim asc As New ASCIIEncoding
      txtResult.Text = asc.GetString(result)
      ms.Close()
   End Sub

When I try to decrypt the text that's in txtResult.Text, my result is always
and empty string:

Private Sub Decryptpwd()
      Dim cdk As PasswordDeriveBytes = New
PasswordDeriveBytes("pa[]ss!!wo//dd", Nothing)
      Dim iv() As Byte = {0, 0, 0, 0, 0, 0, 0, 0}
      Dim key() As Byte = cdk.CryptDeriveKey("RC2", "SHA1", 128, iv)

      Console.WriteLine(key.Length * 8)
      ' Set up an RC2 object to encrypt with the derived key
      Dim rc2 As RC2CryptoServiceProvider = New RC2CryptoServiceProvider
      rc2.Key = key
      Dim b() As Byte = {21, 22, 23, 24, 25, 26, 27, 28}
      rc2.IV = b
      Dim plaintext() As Byte = Encoding.UTF8.GetBytes(txtResult.Text)

      Dim ms As New MemoryStream
      Dim cs As CryptoStream = New CryptoStream(ms, rc2.CreateDecryptor(), _
                                                CryptoStreamMode.Write)
      cs.Write(plaintext, 0, plaintext.Length)
      Dim result(plaintext.Length - 1) As Byte
      ms.Read(result, 0, result.Length - 1)
      Dim asc As New ASCIIEncoding
      txtDecrypt.Text = asc.GetString(result)
      cs.Close()
      ms.Close()
   End Sub

I would very much appreciate someone setting me straight on this issue.
Thanks in advance
Steve

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