Re: [Ntp] Antw: Re: Antw: Re: New rev of the NTP port randomization I-D (Fwd: New Version Notification for draft-gont-ntp-port-randomization-01.txt)

Harlan Stenn <stenn@nwtime.org> Wed, 29 May 2019 10:29 UTC

Return-Path: <stenn@nwtime.org>
X-Original-To: ntp@ietfa.amsl.com
Delivered-To: ntp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8451112009E for <ntp@ietfa.amsl.com>; Wed, 29 May 2019 03:29:34 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9fSKfAbqNhyu for <ntp@ietfa.amsl.com>; Wed, 29 May 2019 03:29:32 -0700 (PDT)
Received: from chessie.everett.org (chessie.everett.org [66.220.13.234]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id C8AE412003E for <ntp@ietf.org>; Wed, 29 May 2019 03:29:32 -0700 (PDT)
Received: from [10.208.75.157] (75-139-194-196.dhcp.knwc.wa.charter.com [75.139.194.196]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by chessie.everett.org (Postfix) with ESMTPSA id 45DRlw4NRBzL7T; Wed, 29 May 2019 10:29:32 +0000 (UTC)
To: ntp@ietf.org
References: <20190529102325.5241540605C@ip-64-139-1-69.sjc.megapath.net>
From: Harlan Stenn <stenn@nwtime.org>
Openpgp: preference=signencrypt
Autocrypt: addr=stenn@nwtime.org; prefer-encrypt=mutual; keydata= mQGNBFI2xmQBDACrPayw18eU4pIwCvKh7k0iMkAV9cvzs49kBppM+xoH+KKj4QWmkKELD39H ngQnT3RkKsTLlwxyLqPdUmeQNAY2M5fsOK+OF6EvwLPK9hbmE3Wx2moX+sbEUxJ2VzFhKSKb OPZALXwk1XxL0qBedz0xHYcDwaSAZZkEFXURv2pDIdrmnoUnq2gdC8GpoFJiXoUaCLSYzzaY ac4Njw7Mue8IqfzRQb70aMjXl/qmsmfmEVAyGXywDdc/ler4XSgiuYOV7Kf69bj9PFZZSMdJ MWgEyZH6lJ0TU5ccR2zp5ZRmWzQQkxJMyH2th7q0Nmz3aX4A0K4yE0Ba9/5Dr7ctpF15BrMF aEo4s5lwI6tUnkgMWo265mMzCz4mAPV/ac0w0OXQg7r9E2r0+dRapnzUlG43D0JLDqDr9uRR L6IrRQqoCWUC75lfmPYQYSlaTJaK68r3lXd0z1cXJUgVtEL5H3/Z71R2B20twcQVAnw2iIH6 L5vdrsIjHrMmkqRVbs9nNyEAEQEAAbQ5SGFybGFuIFN0ZW5uIChOZXR3b3JrIFRpbWUgRm91 bmRhdGlvbikgPHN0ZW5uQG53dGltZS5vcmc+iQG5BBMBAgAjBQJSNsblAhsvBwsJCAcDAgEG FQgCCQoLBBYCAwECHgECF4AACgkQyIwAt1pH+kBlzgv/QOg70vdj8wU/z97UPdlbxtN4THAB gfSX4N0VPKT5fjX1tFhuXZQAOv7wedR3Trh7TGteyg33TBAFf9A42mXZKi1IxAiQG118Hd8I 51rXwnugURIYQaIyQI+vbchRbwVyz+mVLTI/h6FdbsVzT4UFmir+ZMkb/XeZPu0HItk4OZHE 6hk+TuTiCnlqlCPLq371fXV54VOb91WZYD8EQFtK02QHGHsQqWvapdphiDVpYehmsPyiTESq NMKLVtjtyPkQ6S7QF3slSg+2q3j8lyxEA78Yl0MSFNU8B/BtKgzWP2itBOfi+rtUKg+jOY1V /s2uVk2kq2QmHJ/s5k5ldy3qVvoTpxvwBe0+EoBocTHYt+xxp0mTM6YY1xLiQpLznzluqg9z qtejX1gZOF4mgLiBIrhXzed3zsAazhTp5rNb1kn0brZFh6JC5Wk941eilnA4LqX8AWo0lmwo eb+mpwZK/5lNdage/anpVqft9wJ/8EcvST9TLUO4fPrmT3d/0LpWuQGNBFI2xmQBDADXLsBk I7CSa5UXlrNVFJQHER1VxRBKqjWWCh/8Qv9v3p3NrIc2UnhoZ1uWQ2voBGty5Xfy9k4afV5k WwDyRDUIb7PX+Tj4HjVVr7qvnOVe/0KzZpNq0Azd0ggFbsM+8mydktHIwJykW0NUsGwPRYuD OA0Lro0ohb5IiCt3sSQi1X1hYjo7O1Vmn8Gy/XYOnhnMux+5zDPO2yTkCNX5PocYi9IJJy6p Mq1yQV4Y2Dl8KtQzvtq55vCUxx6n0MMzFViGwNW6F4ge9ItO4tDScsgowDrHa208ehwOpv/i wjf93lCClQ6vaKmOBX872K/tdY/hwhxPPjgl1bcrOwMRYVemOPPehwnXH5bwclk1hvDQdkJQ 5pJOkE4VCryTF/iDAt4g2QnHocUwt3b6/ChUUWmj2GZ22OR12rbnCtLedwp0DpViKPUCQHBO vpgXdzE/L9zWar9fqM0EREMgfWbsJc9028qluCcFLIN1gYsq4cC+YGAcOu7HOI5orBBV4m9j XfsAEQEAAYkDPgQYAQIACQUCUjbGZAIbLgGpCRDIjAC3Wkf6QMDdIAQZAQIABgUCUjbGZAAK CRDfCQ/G52/8P/uWDACe7OEM+VETDRqjQgAwzX+RjCVPvtgrqc1SExS0fV7i1mUUxr/B8io3 Y1cRHFoFKmedxf8prHZq316Md5u4egjFdTT6ZqEqkK0hvv+i0pRpCa5EX9VIStcJStomZp8F cY34grA+EOWITaLQ4qNZUP7rf2e7gq1ubQTj7uLr6HZZvMZ5em+IvrOWEuWDI6yOiI6px04w RDfkoR2h6kgdw4V0PT4NjK9WYYKrVCf1bjLlVImNBEcXfvlUTrIYO8y6ptvoUsBQky5pQRvP 99Pn42WfyLy50aII6+vyudD4T0yLjXAz4KteUttxtIte64m/F9/7GEIZAxTUcLyOq/7bP4le h39jBckwc62iYzeK/VkU/bMMh2D68Z3QylMnhhcW27BcgQHPKsHhmFa2SNytYcuQiSdf9+pj 4i32ETz1nJAvYAAqgTF/0PL+8ZNQoEpe/n9woMKrlZrqD4EgFmhQ3bNVhlaXz1nuTZDrwPt1 yMxBuUNbCF4jFnaruwrSiGTRoIfUZQwAjQglahrV4/mcjfnvbNoseHX0PKd9q+wjg7MIjWqr f2CI8Fa6MdanqwYphz43I2yXANKFZuMWsWqyQYlvGuPUlUUcAL3stp24RkzDB1Q+JS0IZJST T2JSu0aTfUdWVNqr2UI19eX+zxbOTckSi3Ng14ezG8ZX194ZH10b8JzntQOwmA20pd5JDhug zQfASER+CZDiPPcQ4mvC4y7rMrfV6XGQbDynC3ekDxo8SC5SvjaczXMwXg6SZ8iFtEWmEwW9 r7zPjjIPDrX8w5LXBgxArM5o/HbERpc2EdAvMh1D7LC0SvmoE7fBKxsicVBe4h6vXjEZ+LLr /wuZiBld9OnxAUIpwptbBspO6WKTQYvgFH2OeDG27hiE5P4Xs4WSp5j9ez8OVB1iZnA2nCQ+ tNTjO8c+C/P92vPLx5+bpGRXTXMNaLh34PS3ZsYoUDkKZNhczRZUWJ7nynSbeeyF+QW7SLwA qY7O7dyk9LFTsfJqRQJ7tWnIAjJPCwmSgQ8Kl0UJ
Message-ID: <60a94bc9-4355-46d9-f6bd-2b54c5ef39b1@nwtime.org>
Date: Wed, 29 May 2019 03:29:31 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0
MIME-Version: 1.0
In-Reply-To: <20190529102325.5241540605C@ip-64-139-1-69.sjc.megapath.net>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ntp/A5Exzrvk-KSw6QtR3P_1cvmkxYw>
Subject: Re: [Ntp] Antw: Re: Antw: Re: New rev of the NTP port randomization I-D (Fwd: New Version Notification for draft-gont-ntp-port-randomization-01.txt)
X-BeenThere: ntp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <ntp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ntp>, <mailto:ntp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ntp/>
List-Post: <mailto:ntp@ietf.org>
List-Help: <mailto:ntp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ntp>, <mailto:ntp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 29 May 2019 10:29:35 -0000


On 5/29/2019 3:23 AM, Hal Murray wrote:
> 
> Ulrich.Windl@rz.uni-regensburg.de said:
>> I agree, but please don't treat it as 64-bit random value that is to be
>> guessed. 
> 
> It looks like 64 bits to me.  You don't need to put an actual time in that 
> slot.  Save the time, get a random number.  Put it in the packet and save it 
> too.  When a reply arrives, compare the "time stamp" in the packet with the 
> saved random number.  If they match, process using the saved time.
> 
> There was a draft describing that a year or so ago.

It's certainly a choice.

One that would prevent a friendly server from knowing how far off the
client's time really is.

-- 
Harlan Stenn, Network Time Foundation
http://nwtime.org - be a Member!