Re: [lisp] Restarting last call on LISP threats

[Dino Farinacci <[e-mail]>]

>> Could you describe precisely the attack you have in mind?  The only
>> think I can see is relying on the birthday paradox but that is a
>> completely different story.
> 
> If an attacker is on-path it could see the nonce's (assuming that the LISP header is not encrypted, regardless of whether the data packet is encrypted). This could be an issue if the attacker is physically on-path. 

The source EID is encrypted so it can only see a cleartext source RLOC and can't associated it with anything.

When we merge lisp-cryto logic with echo-noncing, one has to determine if an xTR should participate in echo-noncing if the payload is not decrypted properly. That is, if I get a echoed nonce back from an attacker for a nonce I know I have sent and set the E-bit, and I cannot decrypt the payload that comes from the attacker, then I don't believe any NEW reachability information about the RLOC.

> This could also be an issue for attackers which are physically off-path if gleaning is used, since an attacker could use a gleaning attack to temporarily insert itself on-path, which in turn would allow it to see the nonce. 

So by now we know there are many issues with gleaning. So we should document them and say they shouldn't be used for the general global Internet use-case.

Dino

> 
> Ross
> 
> -----Original Message-----
> From: lisp [mailto:[e-mail]] On Behalf Of Damien Saucez
> Sent: Thursday, June 12, 2014 8:08 AM
> To: Ronald Bonica
> Cc: LISP mailing list list
> Subject: Re: [lisp] Restarting last call on LISP threats
> 
> Hello,
> 
> I am not sure I understand exactly what you are proposing.  How can a
> LISP router decide that a RLOC is done by simply receiving an ICMP
> packet from an attacker (except with LSB that is discussed in Sec
> 4.3.2.1.  )?  All the other techniques are triggered by the LISP
> router and are protected by the nonce.
> 
> Could you describe precisely the attack you have in mind?  The only
> think I can see is relying on the birthday paradox but that is a
> completely different story.
> 
> Damien Saucez 
> 
> On 10 Jun 2014, at 21:37, Ronald Bonica <[e-mail]> wrote:
> 
>> Dino,
>> 
>> Exactly! So, assume the following:
>> 
>> - LISP is deployed on the global Internet
>> - An RLOC is mapped to some number of EID prefixes
>> - For a subset of those EID prefixes, the above mentioned RLOC is preferred
>> - An ITR receives a hint indicating that the RLOC is down (either through a LISP data packet or an ICMP message)
>> 
>> The ITR will verify RLOC reachability (possibly by polling the RLOC). But until the ITR has receives a response to its poll, how should it behave? Should it continue sending traffic though the above mentioned RLOC? Or should it begin to send traffic through another RLOC, if one exists? I don't see a normative recommendation. 
>> 
>> However, both behaviors have their drawbacks and could be vectors for attack.
>> 
>>                                                                                                          Ron
>> 
>> 
>>> -----Original Message-----
>>> From: Dino Farinacci [mailto:[e-mail]]
>>> Sent: Tuesday, June 10, 2014 1:23 PM
>>> To: Ronald Bonica
>>> Cc: LISP mailing list list
>>> Subject: Re: [lisp] Restarting last call on LISP threats
>>> 
>>> As I keep saying Ron, you need to verify anything you intend to glean. The
>>> spec says the gleaning is "a hint" and not gospel.
>>> 
>>> Dino
>>> 
>>> On Jun 10, 2014, at 10:06 AM, Ronald Bonica <[e-mail]> wrote:
>>> 
>>>> Hi Dino,
>>>> 
>>>> Given that the LISP data packet or ICMP packet may be from an attacker, is
>>> it even safe to glean that? I think not.
>>>> 
>>>> 
>>>> Ron
>>>> 
>>>> 
>>>>> -----Original Message-----
>>>>> From: Dino Farinacci [mailto:[e-mail]]
>>>>> Sent: Tuesday, June 10, 2014 1:04 PM
>>>>> To: Ronald Bonica
>>>>> Cc: LISP mailing list list
>>>>> Subject: Re: [lisp] Restarting last call on LISP threats
>>>>> 
>>>>> 
>>>>> On Jun 10, 2014, at 9:57 AM, Ronald Bonica <[e-mail]> wrote:
>>>>> 
>>>>>> Earlier in this thread, we agreed that when LISP is deployed on the
>>>>>> global
>>>>> Internet, mapping information cannot be gleaned safely from incoming
>>>>> LISP data packets. Following that train of thought, when LISP is
>>>>> deployed on the global Internet, is it safe to glean routing locator
>>>>> reachability information from incoming LISP data packets as described
>>>>> in RFC 6830, Section 6.3, bullet 1. If not, I think that we need to mention
>>> this in the threats document.
>>>>> 
>>>>> What you can glean is that the source RLOC is up, but you cannot
>>>>> glean your path to it is reachable.
>>>>> 
>>>>>> Given that ICMP packets are easily spoofed, when LISP is deployed on
>>>>>> the
>>>>> global Internet, is it safe to glean routing locator reachability
>>>>> information from incoming ICMP packets as described in RFC 6830,
>>>>> Section 6.3, bullet 2 and bullet 4. If not, I think that we need to
>>>>> mention this in the threats document.
>>>>> 
>>>>> What you can glean is that the source RLOC is up, but you cannot
>>>>> glean your path to it is reachable.
>>>>> 
>>>>> Dino
>>>>> 
>>>> 
>> 
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