Re: [TLS] PQC key exchange sizes

2022-07-27 Thread Sofía Celi
Dear, all, I wrote some of the open challenges of putting post-quantum cryptography into protocols over here: https://sofiaceli.com/thoughts/Taxonomy.pdf The document is very open ended atm but the idea is to develop into a list of concrete problems. As I mentioned on our talk at the TLS WG

Re: [TLS] Representing IP addresses in SNI -- proposed draft

2022-07-27 Thread Erik Nygren
Both of these are very good concerns about the compatibility risk. I think David's alternative of having a new extension (eg, server_name_ip) might address a bunch of the issues and be cleaner than any of the other hacks. It would have a higher implementation overhead, but also might be more likely

Re: [TLS] PQC key exchange sizes

2022-07-27 Thread Rob Sayre
Hi, There's also data from the old Chrome/Cloudflare experiment, in the discussion section: https://blog.cloudflare.com/the-tls-post-quantum-experiment/ I /think/ the discussion says that sending handshake messages somewhat above the MTU didn't matter much, except on the slowest connections. They

Re: [TLS] Representing IP addresses in SNI -- proposed draft

2022-07-27 Thread David Benjamin
I agree this is quite a compatibility risk. In addition to messing with SNI lookup, there are servers that try to correlate TLS SNI and HTTP Host. Indeed, when we accidentally sent IP literals in SNI, we broke a server that tried to do that but got very confused by the colons in an IPv6 literal. Th

Re: [TLS] Representing IP addresses in SNI -- proposed draft

2022-07-27 Thread Martin Thomson
Hi Erik, As far as it goes, this might work. However, I'm not sure about the effect of this on compatibility. I'm concerned that maybe this would end up causing some servers to choke. Servers that receive SNI can sometimes use that SNI value to lookup the correct certificate. Your design co

Re: [TLS] PQC key exchange sizes

2022-07-27 Thread Bas Westerbaan
On the QUIC side, there is the "*Q*uantum Ready" interop test: https://docs.google.com/spreadsheets/d/1D0tW89vOoaScs3IY9RGC0UesWGAwE6xyLk0l4JtvTVg/edit#gid=438405370 On Wed, Jul 27, 2022 at 8:57 PM Kampanakis, Panos wrote: > Gotcha. This is a reasonable explanation for a potential problem, b

Re: [TLS] PQC key exchange sizes

2022-07-27 Thread Kampanakis, Panos
Gotcha. This is a reasonable explanation for a potential problem, but I would also like to see experimental proof that DTLS implementation X, Y, Z have the problem. TLS implementations don't deal with big ClientHellos today so we could assume they would have a problem, but when tested they do OK

[TLS] Representing IP addresses in SNI -- proposed draft

2022-07-27 Thread Erik Nygren
Following discussions in ADD around the DDR draft (as well as in UTA around Martin Thomson's PR to add IP address SANs to 6125-bis), I wrote up a draft on how IP addresses might be represented in SNI: https://datatracker.ietf.org/doc/draft-nygren-tls-ip-in-sni/ There are at least three diff

Re: [TLS] PQC key exchange sizes

2022-07-27 Thread Ilari Liusvaara
On Wed, Jul 27, 2022 at 02:27:12AM +, Kampanakis, Panos wrote: > Hi Ilari, > > > - DTLS-level fragmentation. There are buggy implementations that > > break if one tries this. > > DTLS servers have been fragmenting and sending cert chains that don’t > fit in the MTU for a long time. Is this

Re: [TLS] PQC key exchange sizes

2022-07-27 Thread Martin Thomson
On Tue, Jul 26, 2022, at 22:21, Kampanakis, Panos wrote: > Why are 2-3 packet CHs unworkable? Loss probability is a contributing factor for sure, but the thing that really hurts is the extra round trip that many servers will induce when they cannot process the TLS ClientHello in one go. ___