Re: [Tcpcrypt] v3 of the charter

[Joe Touch <[e-mail]>]

On 5/1/2014 8:04 AM, David Mazieres wrote:
> marcelo bagnulo braun <[e-mail]> writes:
>
>>> FWIW, mine too - IMO, the issue of anti-fingerprinting can be
>>> specified without reference to role, in which case whether
>>> simultaneous open is supported or not can be determined in a candidate
>>> solution.
>>>
>>
>> could you propose text?
>
> How about eliminating the paragraph about anti-fingerprinting, and
> instead changing this text:
>
>> - An extended API describing how applications can obtain further
>>    benefits of the proposed extensions. In particular, the hooks for
>>    supporting external authentication will be defined in this
>>    document. This will be an informational document.
>
> To the following:
>
>          ... In particular, the hooks for supporting external
>          authentication will be defined in this document.  In addition,
>          the document shall specify functions that allow control over any
>          session parameters such as accepted ciphers or re-use of
>          cryptographic material from prior sessions (if the protocol
>          supports such re-use) and that help prevent multiple TCP
>          Inc. connections from being linked to the same endpoint.

But that's not quite all of what fingerprinting implies.

I would suggest changing the current fingerprinting requirement:

- must allow client to avoid fingerprinting: some clients may want to 
avoid appearing as the same client when connecting to a remote peer on 
subsequent occasions.  This should either be the default (clients cannot 
be "fingerprinted" by the server based on shared state) or some 
mechanism should be available for clients to drop or ignore shared state 
to avoid being fingerprintable any more than would be present for a 
cleartext session.

to:

- must not increase information available for fingerprinting: endpoints 
should be identified by their IP address and port and no additional 
information should be provided that indicates the persistence of an 
endpoint or identity other than the IP address and port.

Joe