Re: [TLS] Constant-time Algorithms

Martin Thomson <mt@lowentropy.net> Tue, 18 May 2021 22:56 UTC

Return-Path: <mt@lowentropy.net>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 86D303A12FA for <tls@ietfa.amsl.com>; Tue, 18 May 2021 15:56:36 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.097
X-Spam-Level:
X-Spam-Status: No, score=-2.097 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_BLOCKED=0.001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=lowentropy.net header.b=l+oS5gn2; dkim=pass (2048-bit key) header.d=messagingengine.com header.b=j/muwv1D
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 95JZe5YBPxJY for <tls@ietfa.amsl.com>; Tue, 18 May 2021 15:56:31 -0700 (PDT)
Received: from wout5-smtp.messagingengine.com (wout5-smtp.messagingengine.com [64.147.123.21]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id ABEFE3A12F2 for <tls@ietf.org>; Tue, 18 May 2021 15:56:31 -0700 (PDT)
Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailout.west.internal (Postfix) with ESMTP id 1F23A16CF for <tls@ietf.org>; Tue, 18 May 2021 18:56:30 -0400 (EDT)
Received: from imap10 ([10.202.2.60]) by compute2.internal (MEProxy); Tue, 18 May 2021 18:56:30 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lowentropy.net; h=mime-version:message-id:in-reply-to:references:date:from:to :subject:content-type; s=fm2; bh=UDqpcE046FiwR2yX/zO88Z7Pty2J3hT /KKBNKDGKRPw=; b=l+oS5gn2+ST1O2ihF1nTDkIpWvgDVzbFuBKrgoRzV7u1vXN qpfy2q6v1tBzS08cMzB6ero9JevXaquQNCtlDv6liUTQ8KNWCZ3rWbo1SWmbzdl6 9xiKz8IoKt/aIqoAmMsLzugG43U1B3wdLIqhkJZp9Kl5FDSFpcomyLlEWoIUUEYL P97jKddMGLXFw2z8NE1PYNj/W0UUrxO18B42pep/ZD1YL+ruhRPszQd73z7LVQtQ W18vkQNwcko5E9d7ccCY+Z+kjJhetzEEUp+mK8pDrOvCyQy3MTVuNbIFZ1+e9ann VQHb+k27NFGaq80A9B+CErCkLPjkrw+9oLVHiaw==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=UDqpcE 046FiwR2yX/zO88Z7Pty2J3hT/KKBNKDGKRPw=; b=j/muwv1DochjdXSLiUdByX CErkM1KoY0UKwoQaEc4klLjLb+5/0mgg2I07twWSPHM8Jtkxkhh3fjwCf9MCSPtG 4vXE/AbVl8x6h9CT3e+f+OFDU+thDwg/iQBbyxppXf1GEp1OVZJvoT6uxFad2TCy fL0d+9hWpX0GRHSEPzdbn4NWTYb0vwCdHqCECA6qTe3chnUi80vn6ULHCPvYTSvd 5GNt/oB9a8BU2dDQMd9Ymgz9RuLnG8IHnGj8m5sLbdg82iXAqkVXMv7+defsDBr1 EO5NYpjggp165PQLycBu1gr2JWS6ImzqmRgImFUSHO/lzvaIM9clRSQenmtysL8Q ==
X-ME-Sender: <xms:HUakYAEdDixC2abqiP17SRH5FT6Ear0Xcb7hTMhb_bdT6laxOPMsYA> <xme:HUakYJVb81IuNpeEi4RsOboXa7lNd_UHAZozqtzHaLiwBZU5ozitJ4dxa-br0glm8 ZptrwMds0RfxMEc6ho>
X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrvdeikedgudefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefofgggkfgjfhffhffvufgtsehttd ertderredtnecuhfhrohhmpedfofgrrhhtihhnucfvhhhomhhsohhnfdcuoehmtheslhho figvnhhtrhhophihrdhnvghtqeenucggtffrrghtthgvrhhnpeekteeuieektdekleefke evhfekffevvdevgfekgfeluefgvdejjeegffeigedtjeenucevlhhushhtvghrufhiiigv pedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehmtheslhhofigvnhhtrhhophihrdhnvg ht
X-ME-Proxy: <xmx:HUakYKI0opChft2BRPo19HpsUppMKy7UWgjNBkZQ0WFHsMtxw7_tZQ> <xmx:HUakYCFhlZa4Y6kn9wrnKdQwHxorgaq4BV3u9Sv61fZwwFuLn7QUpg> <xmx:HUakYGXFjbc_pPQ0NoQrB_RePY0yvSW20g7VfXHa2hJM5TgqhTpzig> <xmx:HUakYOjGSs7rJJSXZI-XwcBjss8ZeN6Nckf4sjYJt-wC1yvqMLSyQg>
Received: by mailuser.nyi.internal (Postfix, from userid 501) id 59EAC4E0129; Tue, 18 May 2021 18:56:29 -0400 (EDT)
X-Mailer: MessagingEngine.com Webmail Interface
User-Agent: Cyrus-JMAP/3.5.0-alpha0-448-gae190416c7-fm-20210505.004-gae190416
Mime-Version: 1.0
Message-Id: <7852e921-53a4-419f-848c-726b50647532@www.fastmail.com>
In-Reply-To: <CAF8qwaBGv4+wPKWd6No3uqPrm4JPomQ1fAu3pJPF+QewtGzTRg@mail.gmail.com>
References: <b76514a1-82a7-8364-06e8-095c26ef6974@pobox.com> <c2549fed-a6cb-cc1a-f0ff-a473bc83dea5@pobox.com> <CAF8qwaBGv4+wPKWd6No3uqPrm4JPomQ1fAu3pJPF+QewtGzTRg@mail.gmail.com>
Date: Wed, 19 May 2021 08:56:09 +1000
From: "Martin Thomson" <mt@lowentropy.net>
To: tls@ietf.org
Content-Type: text/plain
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/IiAdawVX0aljjm2Xvl55a7FvsMw>
Subject: Re: [TLS] Constant-time Algorithms
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.29
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: Tue, 18 May 2021 22:56:37 -0000

On Wed, May 19, 2021, at 01:58, David Benjamin wrote:
> constant-time should be a default baseline requirement for implementing any cryptographic primitive.

Or put more generally, ...

Avoiding side channels through value-independence should be a default baseline requirement for handling any secret.