Andre Oppermann <[EMAIL PROTECTED]> writes:

> You have to differenciate two ways of invoking TLS:
>
>  1. You do it on the entire connection from the beginning. [...]
>  This is what happens on port 993 (IMAPSSL).  [...] The TLS
>  functionality can be implemented outsite of the imap daemon. Like
>  in this case with SSL/TLS tcpserver.

OK, and that's working fine with the TLS-patched tcpserver on 993.

>  2. TLS is a optional function on an existing port/protocol and has
>     to be started while already being in the protocol. By definition
>     IMAP on port 143 is unencrypted and has to be this way in the
>     beginning. If you now want to enable TLS for this connection you
>     have to do so within the IMAP session by requesting a STARTTLS
>     command. In this case the TLS functionality has to be implemented
>     inside the imap daemon and client. This way of doing things allows
>     for unencrypted and encrypted sessions on the same port.

OK, understood.  I'll disable tcpserver TLS for IMAP/143 and RTFM to
find how to do it in the courier-imap daemon itself.


> I for myself prefer running ssl/tls stuff the first way. That is
> much nicer and doesn't bloat the daemons with tls stuff. tcpserver
> is exactly the right place to put ssl/tls.

Agreed, it's very clean.  I need to find if my customers will be happy
with this or whether they want STARTTLS on 143.  Since they've already
said they want to prevent clear-text IMAP, I think IMAPS on 993 with
the TLS-tcpserver should be fine.

Thanks for your clear explanation.

Reply via email to