[jose] Clean interop with "oth"

Richard Barnes <rlb@ipv.sx> Tue, 11 November 2014 05:01 UTC

Return-Path: <rlb@ipv.sx>
X-Original-To: jose@ietfa.amsl.com
Delivered-To: jose@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 07C891AD554 for <jose@ietfa.amsl.com>; Mon, 10 Nov 2014 21:01:37 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.977
X-Spam-Level:
X-Spam-Status: No, score=-1.977 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7] 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 x3L-C7QCgVLK for <jose@ietfa.amsl.com>; Mon, 10 Nov 2014 21:01:36 -0800 (PST)
Received: from mail-yk0-f173.google.com (mail-yk0-f173.google.com [209.85.160.173]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E90F21AD54C for <jose@ietf.org>; Mon, 10 Nov 2014 21:01:35 -0800 (PST)
Received: by mail-yk0-f173.google.com with SMTP id 20so5026853yks.18 for <jose@ietf.org>; Mon, 10 Nov 2014 21:01:35 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:date:message-id:subject:from:to :content-type; bh=4cvH3jBayb6oGDlPv7QfeJQdmW0hx5Av+mdcyI/6Xdg=; b=NBlK1Q/YQb7MdxHtZFD+sQyQBY2ZLFP69H85PfwX3IJw5KpYfgFcAwqZUB3XsO2FKE jDP/8I+jEytzjN4rHwq+Fl9/BPLah2cV/5WMmv5FX1wF7pr79ze7LTQ6QMi8ntYtKvJP 4ojRHlI/FigPnGsVKDyxZDSQtK2Pz/6g1Sep7vxvtLSuCozpBxfrtQVhp+HZTheWxa10 CcOyteOMviaoj5A3nDOFj3xw1zm8971BYS40DDmDhj6r48+K33yFOcd2pwwfCjekP5i/ E1wJ7dUKqPgBkH2bKFZbDfY5WcZwCWy/8rwpv4ZdO7tDd5lyIqr4UrkLXnjs/BrduZg/ tkMA==
X-Gm-Message-State: ALoCoQmlBv4L4ISZifDU8zdUtYrxDRkesc+VUK1d6RuFD9BlKw5J6/kXJ8KQupRHkzV+sH4MexKc
MIME-Version: 1.0
X-Received: by 10.220.213.197 with SMTP id gx5mr253171vcb.51.1415682095224; Mon, 10 Nov 2014 21:01:35 -0800 (PST)
Received: by 10.31.149.1 with HTTP; Mon, 10 Nov 2014 21:01:35 -0800 (PST)
Date: Mon, 10 Nov 2014 19:01:35 -1000
Message-ID: <CAL02cgToqHMvpeXdvnRTf7PEpvsbZf+kP7zM5i=r5rzJP86wCA@mail.gmail.com>
From: Richard Barnes <rlb@ipv.sx>
To: "jose@ietf.org" <jose@ietf.org>
Content-Type: multipart/alternative; boundary="089e0118306866b1cc05078e2c55"
Archived-At: http://mailarchive.ietf.org/arch/msg/jose/5ZYwOwzXtaCE8Mv4E8_3UtePefw
Subject: [jose] Clean interop with "oth"
X-BeenThere: jose@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Javascript Object Signing and Encryption <jose.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/jose>, <mailto:jose-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/jose/>
List-Post: <mailto:jose@ietf.org>
List-Help: <mailto:jose-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/jose>, <mailto:jose-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 11 Nov 2014 05:01:37 -0000

It seems clear that there are no implementations today that support the
"oth" element, i.e., that support RSA with a modulus with multiple
factors.  At least some of them simply ignore the "oth" element, which
unfortunately leads to incorrect operation.  I would propose something of
the following form in JWA:

"""
If the consumer of a JWK does not support multi-prime RSA moduli and it
encounters a private key that includes the "oth" parameter, then it MUST
reject the key.
"""