----- Original Message -----
From: "Eric H. Christensen" sparks@fedoraproject.org To: "Reindl Harald" h.reindl@thelounge.net Cc: security@lists.fedoraproject.org Sent: Friday, 8 August, 2014 3:44:40 PM Subject: Re: proposed text for crypto-policies in Packaging Guidelines
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512
On Fri, Aug 08, 2014 at 03:36:51PM +0200, Reindl Harald wrote:
Am 08.08.2014 um 15:21 schrieb Nikos Mavrogiannopoulos:
Postfix is a different kind of beast though. It does not typically use TLS, but uses some kind of opportunistic security that allows anonymous ciphersuites. So it's a bit hard to enforce anything there, as man-in-the-middle attacks are possible by design
and keep in mind in case of opportunistic TLS if you restrict ciphers and the SMTP client don't support what you offer it falls back to completly plaintext which defeats the intention
Falling back to an insecure cipher only provides a false sense of security which isn't any better than plaintext.
the alternative is no encryption at all, so it is more secure than plain text
and until most SMTP servers won't have properly configured TLS with certificates, it will have to remain like this