I am decrypting using RSACyptoServiceProvider with a 1024 bit key and OAEP
padding set to false.  I load the RSA key in from an XML string (originally
from a machine key store container) that is pass to this method.  It works
fine on WinXP, but fails on Win98, with a CryptographicException containing
the following unhelpful message:

    Unknown failure; unable to generate error message.

On Win98 I am running IE v6.0.2800.1106 and I believe it has strong
cryptography built-in.  The Exception is raised in the call to rsa.Decrypt().
The stack trace shows it is actually raised within _DecryptKey(IntPtr hCSP,
IntPtr hPubKey, Byte[] rgbKey, Int32 dwFlags) which is called directly by
rsa.Decrypt().  

FromXmlString() works correctly on both platforms and I have used
ExportParameters() to confirm the keys are identical on both Win98 and WinXP.


Has anyone had this problem before?  I would appreciate your help.

Thanks,
Scott.

Here is the C# function:

private byte[] RSADecrypt(byte[] msg, string xmlKey)
{
 try
 {
   RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
   rsa.FromXmlString(xmlKey);
   return (rsa.Decrypt(msg, false));
 }
 catch (CryptographicException e)
 {
   .....
 }
}