From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: matthias@urlichs.de Received: from krantz.zx2c4.com (localhost [127.0.0.1]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 6eeff9dd for ; Mon, 21 May 2018 15:34:26 +0000 (UTC) Received: from netz.smurf.noris.de (mail.vm.smurf.noris.de [IPv6:2001:780:107:8:83::]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 1364226e for ; Mon, 21 May 2018 15:34:25 +0000 (UTC) Subject: Re: WG: Need for HW-clock independent timestamps To: Bruno Wolff III References: <403fa228-40e5-cbe4-4135-15b71cf76553@cgws.de> <20180521112235.v2ksniasmd36kern@ghostArch.localdomain> <97874cad-ac60-5a88-a384-f036f9688668@cgws.de> <20180521123558.qemdunuwgr4u7gsj@ghostArch.localdomain> <8fc246f8-7662-2fd2-f6ee-93d6802a37f0@urlichs.de> <20180521145618.GA3199@wolff.to> From: Matthias Urlichs Message-ID: Date: Mon, 21 May 2018 17:34:42 +0200 MIME-Version: 1.0 In-Reply-To: <20180521145618.GA3199@wolff.to> Content-Type: text/plain; charset=utf-8 Cc: wireguard@lists.zx2c4.com List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 21.05.2018 16:56, Bruno Wolff III wrote: > If you want to go that route, you should just treat it as a two part > number. One for a boot count, that would get incremented every boot > and saved and a low order part that is reset to 0 at every boot. That'd work for me, though I prefer to use an opaque number / base64string-of-12-bytes that doesn't look like it means something. > Note that this scheme leaks information to the peer. Rebooting is likely to leak that information anyway, because the peer sees a period with no packets from you (also, it can't ping you) followed by a possibly-premature re-key (depending on how long your boot process takes). I might also wonder why you'd peer with somebody whom you don't trust not to collect and/or abuse the information that you just rebooted … -- -- Matthias Urlichs