On 10/29/2015 1:53 PM, David Mazieres wrote:
> Joe Touch <[email protected]> writes:
> 
>> This appears to presume that tcp-eno is used only to negotiate tcptls.
>>
>> Given tcp-eno cannot be used for TCP-AO, what's the point of having a
>> protocol to negotiate only one of three security mechanisms?
> 
> What are the three?  I think Mirja's proposal is that TCP-ENO could
> negotiate between tcpcrypt and user-level TLS.  

It didn't appear that way from the post; it said to use tcpcrypt
opporunistically and use ENO only to negotiate the parameters for TLS (I
had thought that referred to Eric's TCP-TLS.

> AO is an authentication option rather than an encryption spec.
> AO-encrypt in ENC-BTNS mode probably doesn't meet the security
> requirements of ENO (the 16-byte ECDH limit could be problematic at a
> time when even 32-byte curves are starting to be deprecated, at least
> for top secret data).
> 
> That said, if you actually wanted AO-encrypt to work work with ENO, we
> could make it happen.

That could never protect the SYN itself, which is something TCP-AO-ENC
was intended to do. The AO variants protect the TCP header, which TCPINC
decided not to do. That's still (IMO) going to be important.

I.e., I see ENO as severely limited in this regard, and that needs to be
noted in the ENO doc.

Joe

_______________________________________________
Tcpinc mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/tcpinc

Reply via email to