3 ms·

SNI works because it is not encrypted, that's the point why it was introduced in the first place. What key are you going to use to encrypt it?

• dullgiulio 9y ago
  In theory you don't need a key if you do a DH exchange, but I suppose that's too many round trips and makes things generally much more complicated in the protocol later (unless you discard the first DH-exchange, wasting even more round-trips).
  • Ajedi32 9y ago
    DH exchange on its own isn't secure against active MITM attackers.
    • aaomidi 9y ago
      You can use a public key in the dns record and also activate dnssec. But dnssec isn't really that secure so...
      • gruez 9y ago
        >You can use a public key in the dns record and also activate dnssec. then you dont even need certificates, just use DANE.
      • topranks 9y ago
        DNSSEC is secure. The root is well protected. It's not trying to solve the problem of privacy, only authentication.
• hannob 9y ago
  See lengthy discussions on the tls-wg list. What definitely works is opportunistic encryption of the SNI name. You could also build something where that is later authenticated with the server's key and you could raise an alarm if it isn't. Or you could re-use a previously used session key for at least all resumed sessions. Yeah, not perfect, but better than nothing.