On 2014-09-30, Giancarlo Razzolini <[email protected]> wrote: > On 30-09-2014 16:03, Ted Unangst wrote: >> In theory, we could sign the ssh fingerprint page, but I don't think >> that's a good idea at the current time. There are some issues with >> expiring old data. > This would be a significant improvement. If you are 99,99% certain you > got the release right, them you could quickly verify every other peace > of the OpenBSD infrastructure. And it would render other solutions > irrelevant (DNSSEC+SSHFP for example). Could you elaborate on the > expiring issue?
There is no "expiry time" on a signify signature. If an anoncvs server were to be compromised such that you could no longer trust its key, there is no way we could "revoke" that signed web page. If an attacker was able to cause you to keep seeing an old version of the page, you'd have no way to know that this server's key was no longer to be trusted. This is actually something that dnssec can handle to some extent (you can set expiry times when signing a zone). But even then, signing a page with the host fingerprints...well, all it lets you do is verify that the server you're connecting to has a matching ssh host key and maybe that nobody has noticed and reported any problems with the code it's handing out within a certain window. It gives no guarantees that the program code handed out by that server is correct. In fact, verifying the host like this could be seen as giving a bit of a false sense of security.
