Re:Hijack of Amazon’s domain service used to reroute web tra...
by tialaramex on Tuesday April 24, 2018 @07:29PM
(#16917560)
DNSSEC plus CAA today would let you tell Let's Encrypt "No thanks, automation is too dangerous for my high-value names". If the hijacker fakes the answer, DNSSEC fails, Let's Encrypt says "DNSSEC failed, no issuance". If the hijacker allows the real answer, Let's Encrypt says "CAA says forbidden, no issuance".
I posted in response to pfg's comment above a mechanism that high value targets could choose, which is modelled on how Facebook behave today but (since we're proving a point here) more extreme. Make a deal with a CA, forbid all other CAs from issuing.
The other thing about Let's Encrypt is that they wouldn't be a good target for such an attacker because they are seeing the world from more than one place. You specify particularly a global BGP hijack, but those are hard, which is why this wasn't global. Tricking just, say, the original San Francisco office of Let's Encrypt doesn't get the job done.
I posted in response to pfg's comment above a mechanism that high value targets could choose, which is modelled on how Facebook behave today but (since we're proving a point here) more extreme. Make a deal with a CA, forbid all other CAs from issuing.
The other thing about Let's Encrypt is that they wouldn't be a good target for such an attacker because they are seeing the world from more than one place. You specify particularly a global BGP hijack, but those are hard, which is why this wasn't global. Tricking just, say, the original San Francisco office of Let's Encrypt doesn't get the job done.