CryptoStream calls Write when it shouldn't

[Daniel Weber]

Hi!

In my code I create a CryptoStream around another stream of my own, with
CryptoStreamMode.Read. So I just can read from the CryptoStream. When I
close that CryptoStream, however, the underlying stream's Write() method is
called, with an empty buffer (offset and count-parameters are also 0). My
streams' CanWrite property returns false, so the CryptoStream should not
call Write(). It shouldn't call Write() at all, because I created it with
CryptoStreamMode.Read.
The problem with it is, the Write() method of my stream throws a
NotSupportedException, and that's ok because it doesn't support writing. But
the CryptoStream doesn't seem to catch the exception, so it is directly
raised and executions stops. I cannot work with that but I still have to
throw the exception. It makes no sense not having my Write() method throw
that Exception.
What's going wrong ?

Thanks
Daniel