Apparently I've been doing it "wrong" all these years. I've always created my own CA and signed my certificates with it, and I thought that's what the term "self-signed" meant.
On Mon, Feb 1, 2016 at 5:50 PM, Edward Ned Harvey (blu) <b...@nedharvey.com> wrote: > > From: Discuss [mailto:discuss-bounces+blu=nedharvey....@blu.org] On > > Behalf Of Tom Metro > > > > > Ever-so-slightly better than no encryption. > > > > Huh? We're talking about using a self-signed cert for IMAP access, right? > > > > Self-signed certs have all the same cryptographic benefits as a CA > > signed cert, including having your client validate the cert, if you > > install your own root cert on your clients. > > > > The only down-side to self-signed certs is the inconvenience of having > > to install the root certs on your clients. This is why they aren't used > > for public web sites. > > Creating a self-signed cert isn't the same thing as creating your own CA > and installing the CA root as a trusted root on your clients. If you create > your own CA and distribute your own CA root to all your clients - as you > said - you'll get pretty good security (unless you screw something up). A > self-signed cert is one which certifies itself. The client cannot follow > any chain to a trusted root, so the client needs to either reject the cert, > or prompt for user interaction (in which case, users almost invariably > click "accept," and thus are easy to attack via MITM). If the user accepts > the cert, some clients (such as firefox) have the option to do certificate > pinning, so it won't prompt again when it sees the same self-signed cert, > similar to the way ssh behaves when connecting to a new unrecognized server. > > But if you have a client that prompts you to accept a self-signed cert, > and you accept it, and the client pins it, and at a later time the cert > changes (MITM attack)... Does the client prompt you again? Openssh refuses > to talk to a server with a pubkey different from the pinned key, as it > should. But every SSL client I've ever seen (firefox, chrome, ie, etc) will > prompt you again to accept the unrecognized cert, so even highly technical > and reasonably alert people are still vulnerable to the MITM attack on a > self-signed cert. ... As David in particularly would be, because he > mentioned a checkbox for "ssl accept any certificate," and asked "is that a > good option?" > _______________________________________________ > Discuss mailing list > Discuss@blu.org > http://lists.blu.org/mailman/listinfo/discuss > -- John Abreau / Executive Director, Boston Linux & Unix Email j...@blu.org / WWW http://www.abreau.net / PGP-Key-ID 0x920063C6 PGP-Key-Fingerprint A5AD 6BE1 FEFE 8E4F 5C23 C2D0 E885 E17C 9200 63C6 _______________________________________________ Discuss mailing list Discuss@blu.org http://lists.blu.org/mailman/listinfo/discuss