Python and SSL

[billiejoex]

Hi,
I developed an ftp-server library and now I would like to add support
for SSL/TLS as described in RFC 2228: http://tools.ietf.org/html/rfc2228
Currenlty I'm searching for documentation about this subject and I
would like to start to ask some questions:

- I noticed that socket module provides an SSL class (socket.ssl) but
even if documentation reports that it does not do any certificate
verification a lot of stdlib modules (imaplib, poplib, smtplib,
httplib and urllib2) provides SSL extension classes wherein socket.ssl
is used. What does it mean?

- On top of that why such extension classes [examples: 1, 2, 3]
accepts key-files and cert-files as optional argouments if no
certificate verification occurs?
[1] poplib.POP3_SSL( host[, port[, keyfile[, certfile]]])
[2] imaplib.IMAP4_SSL( [host[, port[, keyfile[, certfile]]]])
[3] smtplib.starttls( [keyfile[, certfile]])

- By searching through the web I found some daemons supporting SSL
such as this one:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/442473
By looking at the code I notice that pyopenssl package is used and
that a certificate file is required. Why do I need to use pyopenssl
and how do I generate the cert file?

Could someone point me in the right direction?

Thanks in advance.