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Yes, pinning the cert, (i.e. TOFU - Trust On First Use) is exactly the right way to treat self signed certificates and under that model they offer real security

Yes, pinning the cert, (i.e. TOFU - Trust On First Use) is exactly the right way to treat self signed certificates and under that model they offer real security. The idea that you can't do anything with self signed certs and nothing makes them okay is a much more troublesome untruth, IMO. Rejecting self-signed certs and only allowing users to use the broken CA PKI model is the wrong choice. Browsers didn't get it right. The CA model is broken, is actually being used to decrypt people's traffic and though your browser might pin a couple big sites, won't protect the rest very well by default. It's a bad hack and we should fix the underlying issue with the PKI. I believe moxie was right, a combination of perspectives + TOFU is the way to do this. Things that also work like this that we all rely on and generally seems more secure than most other things we use: SSH.

jlebar 12y ago
I'm not defending the CA model; there are lots of known problems. But using a CA-signed cert before pinning it is way better than blindly trusting whatever cert you get on your first connection, which is the OP's suggestion wrt SSCs. > Things that also work like this that we all rely on and generally seems more secure than most other things we use: SSH. When was the last time you verified a certificate's fingerprint out of band when connecting to a server for the first time? Maybe you're the kind of person who scrupulously does this, but in my experience even paranoid computer types don't, to say nothing of regular people. > I believe moxie was right, a combination of perspectives + TOFU is the way to do this. +1, it's hard to go wrong listening to Moxie.
drzaiusapelord 12y ago
>TOFU - Trust On First Use The scenarios where this works are pretty limited. Pretty much only a server you set up. Jane User has no idea if the first use of ecommercesite.com is actually safe. You generally do because you have other band access to that server to see the key or key fingerprint. Even that can be thwarted by a clever MITM attack. >Things that also work like this that we all rely on and generally seems more secure than most other things we use: SSH. Yeah, that's generally for system administrative access not general public access for the web. For that kind of access, you need higher safeguards, thus the CA system we have today.

jlebar 12y ago

I'm not defending the CA model; there are lots of known problems. But using a CA-signed cert before pinning it is way better than blindly trusting whatever cert you get on your first connection, which is the OP's suggestion wrt SSCs. > Things that also work like this that we all rely on and generally seems more secure than most other things we use: SSH. When was the last time you verified a certificate's fingerprint out of band when connecting to a server for the first time? Maybe you're the kind of person who scrupulously does this, but in my experience even paranoid computer types don't, to say nothing of regular people. > I believe moxie was right, a combination of perspectives + TOFU is the way to do this. +1, it's hard to go wrong listening to Moxie.

drzaiusapelord 12y ago

>TOFU - Trust On First Use The scenarios where this works are pretty limited. Pretty much only a server you set up. Jane User has no idea if the first use of ecommercesite.com is actually safe. You generally do because you have other band access to that server to see the key or key fingerprint. Even that can be thwarted by a clever MITM attack. >Things that also work like this that we all rely on and generally seems more secure than most other things we use: SSH. Yeah, that's generally for system administrative access not general public access for the web. For that kind of access, you need higher safeguards, thus the CA system we have today.