Hi Ravi,

Seems like this was stuck in your outbox and sent a duplicate email to the one 
from August 10?

Tommy

> On Aug 10, 2022, at 1:40 AM, Ravi sankar MANTHA 
> <[email protected]> wrote:
> 
> Hi,
>  
> In Section 6.2 of RFC 9230, its mentioned that SetupBaseS takes only 2 
> parameters  (pkR, "odoh query")
> 
> However, reference implementations are indeed using a randomiser from client 
> side.
> 
> enc, ctxI, err := hpke.SetupBaseS(suite, rand.Reader, pkR, 
> []byte(ODOH_LABEL_QUERY))
> (https://github.com/cloudflare/odoh-go/blob/7c6d9ff448c53e0e546f2afe915ad9608e11f7bd/odoh.go#L471)
> 
> This has an implication on target implementations,
> 
> If Targets assume the randomizer is not present in shared secret derivation, 
> then Context is unique for Target Public Key and they may choose not to 
> store/derive it per message per Public Key. 
> 
> If random seed is present, then contexts are unique only per message (DSN 
> Query).
> 
> So, this has an interoperability impact as Encrypt/Decrypt fails for Query 
> Responses if wrong shared key/Context is used on Target side.
> 
>  IMHO, we might need to clarify this in RFC either by updating pseudocode for 
> SetupBaseS or add a note that Target should derive shared secret/Context with 
> every oblivious DNS query. Or its implicit somewhere in the RFC ?
> 
> Regards,
> 
> Ravi Mantha
> 
>  
> 
>  
> _______________________________________________
> dns-privacy mailing list
> [email protected] <mailto:[email protected]>
> https://www.ietf.org/mailman/listinfo/dns-privacy

_______________________________________________
dns-privacy mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/dns-privacy

Reply via email to