Re: [secdir] secdir review of draft-ietf-tcpm-accurate-ecn-14

[Bob Briscoe <[e-mail]>]

Michael, see [BB2]

On 10/05/2021 14:28, Scharf, Michael wrote:
>>> I'm not a TCP or ECN expert, so please take my comments with a proverbial
>> grain of salt. Thinking about this strictly as a security geek, I see three places
>> where this scheme could be tampered with: the sender, the receiver, and
>> the network in between them.
>>> The security considerations section starts off by pointing out that there will
>> be consequences to tampering by a middlebox (the network in between),
>> and it describes the impact as limited.
>>> A malicious sender is not described, and I'm not sure that any such thing
>> reasonably exists, but I did wonder about this.
>>
>> [BB] A malicious sender is not described because the scope of AccECN is
>> purely about changes to TCP's feedback protocol between Data Receiver
>> and Data Sender. Malicious senders can ignore TCP feedback. So it
>> doesn't matter what we say when we update a feedback spec if malicious
>> senders can ignore the feedback anyway.
> Just a quick note on terminology: For data transfers from a "data sender" to a "data receiver", the malicious "sender" of the TCP option would be the "data receiver".
>
> So, a better phrasing might be:
>
>    "... malicious *data* senders can ignore the feedback anyway."
>
> When looking at the TCP option, a bit of care may be needed who is sending what (and for what purpose).

[BB2] Thx.
Also, in the Sec Consids section, we were careful to specify "Data 
rx/tx" except in one case, which I've fixed as well.


Bob

>
> Michael
>

-- 
________________________________________________________________
Bob Briscoe                               http://bobbriscoe.net/