Re: [saag] [websec] Pinning

[Paul Hoffman <[e-mail]>]

On Jun 5, 2012, at 2:46 PM, Yoav Nir wrote:

>> The similarity of pinning and DANE has been discussed before. DANE relies on DNSSEC being deployed, which key-pinning does not.

Correct. Further, key-pinning in HTTP only applies to HTTP and relies on the client being able to establish a TLS session using non-key-pinning semantics. Key-pinning in TLS relies works with any lower-layer protocol and relies on the client being able to establish a TLS session using non-key-pinning semantics.

>> Come to think of it, the draft needs a section comparing with DANE, but that's for another thread.
>> 
>> draft-perrin-tls-tack seems to tackle the same problem as key-pinning. Instead of the pins getting attested to in HTTP headers, you have a special public/private key pair, that you use to sign the SPKI from the server certificate within the a TLS extension. Like key-pinning there's a TOFU element here, because the client only learns about the special key when it encounters it in a TLS handshake.
>> 
>> The obvious question is why would we need both key-pinning and tack.

It would be clearer if you said "both key-pinning in HTTP and key-pinning in TLS (tack)".

--Paul Hoffman