smtplib starttls gmail example

[Jean-Paul Calderone]

On Tue, 23 Jan 2007 23:48:59 GMT, py <py at th.on> wrote:
>Hi, Jean Paul.
>
>I read your code with interest. I wonder, does twisted also raise the socket error or does it know
>about this apparently well-known and often ignored incompatibility between the standard and
>the implementations?

Twisted delivers disconnection notification by passing an exception to a
method on a protocol instance.  So, whether it dealt with this SSL behavior
or not, you wouldn't see an exception being raised from the program I posted.
However, if one implements connectionLost (the method which Twisted calls on disconnect), if SSL shutdown isn't done cleanly, you will see an SSL exception
object instead of an exception which indicates clean shutdown.  However, since
the example I posted didn't actually directly interact with any protocol
object at all, all of this is hidden.  The program will appear to succeed
completely with no error, because the success condition it defines is for
the message to have been accepted by the remote host, not for the socket to
have been closed cleanly.

>
>Something else has occurred to me. After starting tls, all the xmitted commands and data are encrypted before they leave the client machine.
>so obviously they have to be decrypted by the server's socket lib before the smtp daemon can do what it's supposed to do.
>but i wonder if the encryption of the trailing \n.\n has something to do with the socket error, given that
>the error msg says something about premature EOF.

As to this, I'm not sure.  A cursory glance at smtplib.py suggests it is at
least trying to handling the \r\n.\r\n sequence which terminates a DATA
command correctly.  I'm not sure why you needed to add your own . when you
used it.  I think the SSL error is most likely unrelated, though.  I have
seen it from gmail's servers before as well.

Jean-Paul