Re: [TLS] Constraining ECH to HKDF-based HPKE ciphersuites
Christopher Patton <cpatton@cloudflare.com> Mon, 17 August 2020 23:04 UTC
Return-Path: <cpatton@cloudflare.com>
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 417FF3A141B for <tls@ietfa.amsl.com>; Mon, 17 Aug 2020 16:04:23 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.099
X-Spam-Level:
X-Spam-Status: No, score=-2.099 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cloudflare.com
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 DtrvJbfhSLS0 for <tls@ietfa.amsl.com>; Mon, 17 Aug 2020 16:04:22 -0700 (PDT)
Received: from mail-qt1-x835.google.com (mail-qt1-x835.google.com [IPv6:2607:f8b0:4864:20::835]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 466DA3A1417 for <tls@ietf.org>; Mon, 17 Aug 2020 16:04:22 -0700 (PDT)
Received: by mail-qt1-x835.google.com with SMTP id s23so13768987qtq.12 for <tls@ietf.org>; Mon, 17 Aug 2020 16:04:22 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6LOBHrkfHbDVPaSnG4N3E+yFNG2tvjsALIOS1b0VUIY=; b=i0qYtswS19BTzr3ok8d+9OWUMAlZCzWx7koHSpxE6wyH8+CyIiCq0QxU6sf1Pp4rzm qNAIou+d/iieoVjOpCNcR13Qo5+8Q/y0LFB/DIwEhBB49ynzXKKu3ZSFyK7UYV7f2nAa aDAi8DbuATRc5MOsiK1vxKVNJRNIjBdEVgJ+Q=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6LOBHrkfHbDVPaSnG4N3E+yFNG2tvjsALIOS1b0VUIY=; b=P/HWY0YqQwaB8xDxAn5ygxvIMEH3eL9MRtY0plNWrHKb/XjYaXHqkHkhC/K3V+mQoV auWj9JStR8q7yl6mwQmeD4KobFXioYG25lPsbF/mRJ3mF57T7lfeXQld9XdCnCGQWDgk 7grt+LJxvU1KMimr4KdXYXCGXj2CfIZ1uFz/Hq1Opr2sH6lSEf/9nupBbAEqiOv3ljdr PjW5uUvNoP0SMi8ekkWCeo4wY7+I6SjGTvC2kf+yTwfEZiXnvdhX6jpsFnVxyF3aix/f mXj2beG/xCUvMuri0ulzvLX+/8zO+B5M3x9y3sxxNXoZ2Vcu8Mq8yEXhO1TXafqx68/Q 074w==
X-Gm-Message-State: AOAM530X/SKQ1SgQNJOtXyRyeuHPewrrKqJpGJZC7BRuR5rTHGKi6AJS d4YpTly1CgUI2PNiY2ZEPitCsYJP54LsLscKIIMM85qdrF3qGg==
X-Google-Smtp-Source: ABdhPJyp4kWMkwPjOxmVV/WIo6VJJ5HlG0mlo47ZMpfXIClIabu4WMXieDKEgw2ofbF0766O59w1wZipQTw5COH0SUg=
X-Received: by 2002:ac8:714d:: with SMTP id h13mr15643891qtp.388.1597705461189; Mon, 17 Aug 2020 16:04:21 -0700 (PDT)
MIME-Version: 1.0
References: <ee8c4bb1-554a-4f45-a1d5-17e49b320562@www.fastmail.com> <170e077f-2ad1-4794-9227-b7e9fcf74b0c@www.fastmail.com> <CAG2Zi22BdP_EYGrCiDMqKrkQN4ZwE-igBjQypMbUJrSiaXER=A@mail.gmail.com> <dae86080-2818-4ea8-8c2d-ae8cf55ab149@www.fastmail.com>
In-Reply-To: <dae86080-2818-4ea8-8c2d-ae8cf55ab149@www.fastmail.com>
From: Christopher Patton <cpatton@cloudflare.com>
Date: Mon, 17 Aug 2020 16:04:10 -0700
Message-ID: <CAG2Zi203YumwAiLPUVw8G731Lp+ByrYK+uFf_5Z2wvPb4QvC0A@mail.gmail.com>
To: Martin Thomson <mt@lowentropy.net>
Cc: "<tls@ietf.org>" <tls@ietf.org>
Content-Type: multipart/alternative; boundary="0000000000007873d405ad1aca4c"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/bW_VakB5zZ7wKqD2091b91yESAU>
Subject: Re: [TLS] Constraining ECH to HKDF-based HPKE ciphersuites
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: Mon, 17 Aug 2020 23:04:23 -0000
Just to be clear, you're proposing something like this? Referring to the
KDF API called for in draft-irtf-cfrg-hpke-05:
config_digest = Expand(PRK=Extract("some_salt", "some_label", IKM=config),
"some_info", 16)
It's maybe more hashing than necessary, but I'd be good with this.
Chris P.
- [TLS] Constraining ECH to HKDF-based HPKE ciphers… Christopher Wood
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Martin Thomson
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Christopher Patton
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Martin Thomson
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Christopher Patton
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Christopher Wood
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Martin Thomson
- Re: [TLS] Constraining ECH to HKDF-based HPKE cip… Christopher Patton