From owner-freebsd-security@freebsd.org Thu Jul 2 14:22:48 2015 Return-Path: Delivered-To: freebsd-security@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5A4CA993C21 for ; Thu, 2 Jul 2015 14:22:48 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-wi0-x236.google.com (mail-wi0-x236.google.com [IPv6:2a00:1450:400c:c05::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E48301B60 for ; Thu, 2 Jul 2015 14:22:47 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: by wicgi11 with SMTP id gi11so75383487wic.0 for ; Thu, 02 Jul 2015 07:22:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=date:from:to:subject:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; bh=F4GtV2dRXGCbOZFEtRRcuVLY+PZJdJdtcOLrFu89cnk=; b=XSewZ31fnkCI3qgKml6ArUNxtQAnPynNqQIAzhLIqW/49eL0KHPiczq/CJdE31mD7h 3bny1+pmPM9q3RcneqAvX/9jfn3VnVOD5Xiblf/C5hhizQ49dHctURg3ITeOnP6TUR7x K+UqaBHBQuT1c0ekWVB8wB8p3uzm6yhmYz+QkyUMttOmK5IgtrH642s2qGX8QRr3P9CV te/egMlimyU1RJ/PqKMJjfl/AzKMzlIEFnN3fYkxMJ5u2LWH9Zoj98q/RpS4TW7JA3hc GL+pqjPOCog/c5R+uZ718EnwJqqCXo7LCkmE2k98RDay++lB9eHdg7icB1BhhrD1an1I uhsw== X-Received: by 10.194.59.212 with SMTP id b20mr55555185wjr.31.1435846966343; Thu, 02 Jul 2015 07:22:46 -0700 (PDT) Received: from gumby.homeunix.com (4e5670d0.skybroadband.com. [78.86.112.208]) by mx.google.com with ESMTPSA id i6sm8419307wjf.29.2015.07.02.07.22.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 Jul 2015 07:22:44 -0700 (PDT) Date: Thu, 2 Jul 2015 15:22:37 +0100 From: RW To: freebsd-security@freebsd.org Subject: Re: Leap Second Message-ID: <20150702152237.42ba56cf@gumby.homeunix.com> In-Reply-To: <21908.39278.416719.875140@hergotha.csail.mit.edu> References: <1435154274.964221.306546033.052903CD@webmail.messagingengine.com> <86bnfwxa4m.fsf@nine.des.no> <1435758941.105242.312562265.3103CECB@webmail.messagingengine.com> <20150701202728.GA9532@server.rulingia.com> <21908.39278.416719.875140@hergotha.csail.mit.edu> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.27; amd64-portbld-freebsd10.0) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Jul 2015 14:22:48 -0000 On Wed, 1 Jul 2015 21:52:46 -0400 Garrett Wollman wrote: > < said: > > > ntpd(8) has provision for specifying a leapsecond file which > > presumably makes it leap-second aware. I haven't looked into the > > details. > > The current NTP protocol, as implemented by ntpd, distributes > leap-second information if provided. This information may be provided > by higher-stratum (upstream) NTP servers, or by using the "leapfile" > configuration statement in ntp.conf to specify a local copy of the > leapseconds file in NIST/USNO format. No such file is provided by > default. We could easily do so, but shouldn't, because that file > would take precedence over the leap indicator learned from > higher-stratum servers, and that's not desirable for clients. I thought this sounded unlikely because the files have an explicit expiry date, so I looked it up. Apparently before 4.2.8 ntpd doesn't ignore expired leap-second files, so they continue to take precedence over fresh information from other servers.