John

Looks good.

My thinking on 'MAY', coloured by comments I have seen previously from
ADs, is that 'MAY' means much the same as 'MAY NOT' and so adds little
to a specification!  I would be inclined, although not too strongly, to
be more assertive, something like

'Where the security considerations outlined above are a concern, users
of this protocol SHOULD .....'

I think it right to mention IPsec and TCP-AO here.  I wonder at the
absence of SSH, which is probably the only security protocol I have used
to access a router.  I wonder too, if the advent of the work of SIDR
will lead to X.509 certificates being the norm for routers, which would
facilitate other forms of security but suspect that that is too far off
to consider now.

Tom Petch

----- Original Message -----
From: "John G.Scudder" <[email protected]>
To: "t.petch" <[email protected]>
Cc: "Christopher Morrow" <[email protected]>;
<[email protected]>; <[email protected]>; <[email protected]>;
<[email protected]>
Sent: Friday, July 24, 2015 9:18 AM

Thanks for your comments, Tom.

> On Jul 21, 2015, at 10:26 AM, t.petch <[email protected]> wrote:
>
> Looking at the Security Considerations, I would like to see more.
>
> An SNMP MIB module calls out which objects might be sensitive to a GET
> (or SET) while this just has a blanket warning. The Internet only
exists
> because this kind of information is propagated to all and sundry so if
> this introduces a threat, then I think more detail is needed,

I take your point. On the other hand, I'm not prepared to write a
thorough exploration of any conceivable misuse of the information that's
exposed, since the information is (at least!) "everything that's in BGP,
now and in the future". I've expanded the text a little to try to
address the question, but if you (or others in the WG) think a more
thorough treatment is needed, please send text (or a reference to an
existing document).

> especially
> as the I-D goes on to say 'MAY use some type of secure transport'
which
> is somewhat open!

I'm not quite sure how this relates to your previous point since the
transport part is specific to authentication, data integrity and
transport protection. Possibly you were expecting confidentiality from
the transport as well, or possibly you are thinking of what we were when
that text was written, namely that authentication prevents an imposter
from directly receiving the information. I've tried to address that too.

> If, for example, this is more sensitive because it is
> exposing Adj-RIB-in pre the application of policy, then I think that
> that needs saying; or whatever.
>
> I think that the last paragaph makes a good point, identifying a
threat,
> but weakens it by calling for mutual authentication, which can be a
pig
> to
> achieve.  If the threat is masquerade of a monitored router, then only
> the router needs authentication which is much easier, and so more
likely
> to happen.

I added some text to indicate why I think mutual is desirable.

> /IPSec/IPsec/

Fixed.

Proposed section below. No new draft issued, since I anticipate we may
iterate on this. Please take a look and ideally either suggest
modifications or ack and I'll publish it as -13.

--John

11.  Security Considerations

   This document defines a mechanism to obtain a full dump or provide
   continuous monitoring of a BGP speaker's local BGP table, including
   received BGP messages.  This capability could allow an outside party
   to obtain information not otherwise obtainable.  For example,
   although it's hard to consider the content of BGP routes in the
   public Internet to be confidential, BGP is used in private contexts
   as well, for example for L3VPN [RFC4364].  As another example, a
   clever attacker might be able to infer the content of the monitored
   router's import policy by comparing the pre-policy routes exposed by
   BMP, to post-policy routes exported in BGP.

   Implementations of this protocol MUST require manual configuration of
   the monitored and monitoring devices.

   Users of this protocol MAY use some type of transport providing
   mutual authentication, data integrity and transport protection, such
   as IPsec [RFC4303] or TCP-AO [RFC5925].  If confidentiality is
   considered a concern, a transport providing that as well could be
   selected.

   Unless a transport that provides mutual authentication is used, an
   attacker could masquerade as the monitored router and trick a
   monitoring station into accepting false information, or could
   masquerade as a monitoring station and gain unauthorized access to
   BMP data.  Unless a transport that provides confidentiality is used,
   a passive attacker could gain access to BMP data in flight.  However,
   BGP is not commonly deployed over a transport providing
   confidentiality, so it's debatable whether it's crucial to provide
   confidentiality once the data is propagated into BMP.



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