[Python-Dev] ssl module, non-blocking sockets and asyncore integration

Bill Janssen janssen at parc.com
Wed Sep 17 19:07:03 CEST 2008

Giampaolo Rodola' <gnewsg at gmail.com> wrote:

> In the meanwhile I noticed something in the ssl.py code which seems to
> be wrong:
>     def recv (self, buflen=1024, flags=0):
>         if self._sslobj:
>             if flags != 0:
>                 raise ValueError(
>                     "non-zero flags not allowed in calls to sendall()
> on %s" %
>                     self.__class__)
>             while True:
>                 try:
>                     return self.read(buflen)
>                 except SSLError, x:
>                     if x.args[0] == SSL_ERROR_WANT_READ:
>                         continue
>                     else:
>                         raise x
>         else:
>             return socket.recv(self, buflen, flags)
> I don't know the low levels but that while statement which continues
> in case of SSL_ERROR_WANT_READ seems to be wrong (blocking), at least
> when dealing with non-blocking sockets. I think the proper way of
> doing recv() here is letting SSL_ERROR_WANT_READ propagate and let the
> upper application (e.g. asyncore) deal with it.

It's an interesting point.  I'm not sure the underlying code will ever
raise this exception.  Please file a bug report to help us track this.



More information about the Python-Dev mailing list