Re: [TLS] Removing the "hint" from the Session Ticket Lifetime hint

"Salz, Rich" <rsalz@akamai.com> Mon, 29 February 2016 17:15 UTC

Return-Path: <rsalz@akamai.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8F5D91B37F3 for <tls@ietfa.amsl.com>; Mon, 29 Feb 2016 09:15:24 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.707
X-Spam-Level:
X-Spam-Status: No, score=-2.707 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RP_MATCHES_RCVD=-0.006, SPF_PASS=-0.001] autolearn=ham
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 6M1OBi5t-DrU for <tls@ietfa.amsl.com>; Mon, 29 Feb 2016 09:15:22 -0800 (PST)
Received: from prod-mail-xrelay06.akamai.com (prod-mail-xrelay06.akamai.com [96.6.114.98]) by ietfa.amsl.com (Postfix) with ESMTP id 5306F1B37FB for <tls@ietf.org>; Mon, 29 Feb 2016 09:15:20 -0800 (PST)
Received: from prod-mail-xrelay06.akamai.com (localhost.localdomain [127.0.0.1]) by postfix.imss70 (Postfix) with ESMTP id 5791116BE3F; Mon, 29 Feb 2016 17:15:19 +0000 (GMT)
Received: from prod-mail-relay08.akamai.com (prod-mail-relay08.akamai.com [172.27.22.71]) by prod-mail-xrelay06.akamai.com (Postfix) with ESMTP id 41E0616BDF7; Mon, 29 Feb 2016 17:15:19 +0000 (GMT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=akamai.com; s=a1; t=1456766119; bh=cAZ2CZuuyW2o1f/9oQQfh8hv1g92+LKa6J44Eqr7jhU=; l=334; h=From:To:CC:Date:References:In-Reply-To:From; b=qx8EfgPYfPoRiKAOVhHQJgr9bQS+S4RJiFtGZTRIcbhN04Szrvd7AelZAe+9R0JF9 LgZzqcwYFvwsbPYgOXtfUSRCxgn1ioU6424P6ojg3l1QCkYzYmAc3ij+QB9aK/g14F fJ7PpwSSVWYkOw2uXotu+uBVcW5vhDBkmgdXZlGU=
Received: from email.msg.corp.akamai.com (usma1ex-cas2.msg.corp.akamai.com [172.27.123.31]) by prod-mail-relay08.akamai.com (Postfix) with ESMTP id 2616C98082; Mon, 29 Feb 2016 17:15:19 +0000 (GMT)
Received: from USMA1EX-DAG1MB1.msg.corp.akamai.com (172.27.123.101) by usma1ex-dag1mb4.msg.corp.akamai.com (172.27.123.104) with Microsoft SMTP Server (TLS) id 15.0.1130.7; Mon, 29 Feb 2016 12:15:18 -0500
Received: from USMA1EX-DAG1MB1.msg.corp.akamai.com ([172.27.123.101]) by usma1ex-dag1mb1.msg.corp.akamai.com ([172.27.123.101]) with mapi id 15.00.1130.005; Mon, 29 Feb 2016 12:15:18 -0500
From: "Salz, Rich" <rsalz@akamai.com>
To: "mrex@sap.com" <mrex@sap.com>
Thread-Topic: [TLS] Removing the "hint" from the Session Ticket Lifetime hint
Thread-Index: AQHRcxQvwcrtO6b+8Em/JRVX41Ode59DQxwQ
Date: Mon, 29 Feb 2016 17:15:18 +0000
Message-ID: <b2702702d18e4b1f8e4e167534c31ade@usma1ex-dag1mb1.msg.corp.akamai.com>
References: <a593a46739ba463ea9d5f5577a093a12@ustx2ex-dag1mb1.msg.corp.akamai.com> <20160229171102.1EB5C1A453@ld9781.wdf.sap.corp>
In-Reply-To: <20160229171102.1EB5C1A453@ld9781.wdf.sap.corp>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [172.19.117.146]
Content-Type: text/plain; charset="Windows-1252"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/cJOWUNZM1sCeoRa4dZjBKvSkmfY>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Removing the "hint" from the Session Ticket Lifetime hint
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tls/>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 29 Feb 2016 17:15:24 -0000

> What should be memorized/stored is absolute time-of-creation.

If the structure itself includes absolute times, then the memorization is (trivially) simpler.

> How long to consider it valid, is a local issue and not necessarily a constant
> validity period over time. 

True.  Treat it as a hint from the server.