Re: [secdir] Secdir review of draft-ietf-ippm-6man-pdm-option-05: Timing Attacks

Tero Kivinen <kivinen@iki.fi> Tue, 10 January 2017 12:05 UTC

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Date: Tue, 10 Jan 2017 14:05:15 +0200
From: Tero Kivinen <kivinen@iki.fi>
To: <nalini.elkins@insidethestack.com>
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Subject: Re: [secdir] Secdir review of draft-ietf-ippm-6man-pdm-option-05: Timing Attacks
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nalini.elkins@insidethestack.com writes:
> Tero,
> 
> I believe this is the last outstanding issue!  After we reach
> agreement, I will rewrite the draft to: 
...
> 8.4 Timing Attacks 
> 
> The fact that PDM can help in the separation of node processing time 
> from network latency brings value to performance monitoring.  Yet, 
> it is this very characteristic of PDM which may be misused to make 
> certain new type of timing attacks against protocols and 
> implementations possible. 
> 
> That is, in some cases, depending on the nature of the cryptographic 
> protocol used, it may be possible to leak the long term credentials 
> of the device.  For example, if and attacker is able to create an attack 
> which causes the enterprise to turn on PDM to diagnose the attack, 
> then the attacker might use PDM during that debugging time to launch 
> a timing attack against the long term keying material used by the 
> cryptographic protocol. 
> 
> An implementation may want to be sure that PDM is enabled only for 
> certain ip addresses, or only for some ports.  Additionally, we 
> recommend that the implementation SHOULD require an explicit 
> restart of monitoring after a certain timeperiod (for example for 1 hour), 
> to make sure that PDM is not accidently left on after 
> debugging has been done etc. 
> 
> Even so, if using PDM, we introduce the concept of user "Consent to 
> be Measured" as a pre-requisite for using PDM.  Consent is common in 
> enterprises and with some subscription services. So, if with PDM, we 
> recommend that the user SHOULD consent to its use. 

This new text looks good.
-- 
kivinen@iki.fi