On 05/10/2018 19:01, Bruce Momjian wrote:
> On Fri, Oct 5, 2018 at 04:53:34PM +0200, Peter Eisentraut wrote:
>> On 23/05/2018 08:46, Heikki Linnakangas wrote:
>>> "tls-unique" and "tls-server-end-point" are overly technical to users.
>>> They don't care which one is used, there's no difference in security.
>>
>> A question was raised about this in a recent user group meeting.
>>
>> When someone steals the server certificate from the real database server
>> and sets up a MITM with that certificate, this would pass
>> tls-server-end-point channel binding, because both the MITM and the real
>> server have the same certificate. But with tls-unique they would have
>> different channel binding data, so the channel binding would detect this.
>>
>> Is that not correct?
>
> Not correct. First, they need to steal the server certificate and
> _private_ key that goes with the certificate to impersonate the owner of
> the certificate.
Right, I meant to imply that.
> If that happens, with tls-server-end-point, a MITM
> could replay what the real server sends to the MITM. You are right that
> tls-unique makes it harder for a MITM to reproduce the TLS shared key
> which is mixed with the password hash to prove the server knows the
> password hash.
So you appear to be saying the above *is* correct?
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
