Help with "Length of the data to decrypt is invalid" message error

[SM]

Hi,
I need your help, the following code is not working, ret = sr.ReadToEnd()
throws the message error : Length of the data to decrypt is invalid.
Any idea ?
thank you

public string Decrypting(stri ng Source, string Key)
{
string ret = "";
try
{
// convert from Base64 to binary
byte[] bytIn =
System.Convert. FromBase64Strin g(Source);

// create a MemoryStream with the input
System.IO.Memor yStream ms = new
System.IO.Memor yStream(bytIn, 0, bytIn.Length);

byte[] bytKey = GetLegalKey(Key );

// set the private key
mobjCryptoServi ce.Key = bytKey;
mobjCryptoServi ce.IV = bytKey;

// create a Decryptor from the Provider Service
instance
ICryptoTransfor m encrypto =
mobjCryptoServi ce.CreateDecryp tor();

// create Crypto Stream that transforms a stream
using the decryption
CryptoStream cs = new CryptoStream(ms , encrypto,
CryptoStreamMod e.Read);

// read out the result from the Crypto Stream
System.IO.Strea mReader sr = new
System.IO.Strea mReader(cs);

ret = sr.ReadToEnd();
}
catch (Exception Ex)
{
MessageBox.Show (Ex.Message.ToS tring());
}
return ret;
}

[Peter Duniho]

On Thu, 08 May 2008 06:41:24 -0700, SM <sa*******@hotm ail.comwrote:

I need your help, the following code is not working, ret = sr.ReadToEnd()
throws the message error : Length of the data to decrypt is invalid.
Any idea ?

Unfortunately, the most obvious idea is that the length of the data to
decrypt is in fact invalid.

If you can post a concise-but-complete code example that reliably
demonstrates the problem from start to finish, then perhaps some advice
can be offered. Such a sample would start with some given data, would
encode the text to bytes, encrypt it, convert to Base64, and then pass
that result to something like you've posted here to be converted back from
Base64 and then decrypted and read as text.

Without such an example, it's hard to say. You've only posted half of the
implementation, and the error could be somewhere in the encryption stage,
or some asymmetry between a valid encryption and your decryption code.

Pete