Return-Path: X-Original-To: oauth@ietfa.amsl.com Delivered-To: oauth@ietfa.amsl.com Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id BF0791A07EA for ; Mon, 31 Mar 2014 05:34:07 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -0.145 X-Spam-Level: X-Spam-Status: No, score=-0.145 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FRT_ADOBE2=2.455, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=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 x4wMs09V1v9C for ; Mon, 31 Mar 2014 05:34:05 -0700 (PDT) Received: from mail-ob0-f173.google.com (mail-ob0-f173.google.com [209.85.214.173]) by ietfa.amsl.com (Postfix) with ESMTP id CA2D91A082F for ; Mon, 31 Mar 2014 05:34:05 -0700 (PDT) Received: by mail-ob0-f173.google.com with SMTP id gq1so9121024obb.32 for ; Mon, 31 Mar 2014 05:34:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:cc:message-id:references:to; bh=xsSXLqgo1EwFJOgcTP+M8T9XQTlNtks+XT4sC80vNfU=; b=fZD0D05IGA6KjQPA63B6ka3vfZ1vBUrJkw1IKczkuB8buZjHW/zMG1IPrlXtnbIc5A scBdKtNYaEvfWoQIgpV42JCVxpKUfpvngTZRC+9SXsbbCsA/NTxrWCiaGUV6c9OXxTUf VfEMK9cAi0x11Rf8Daj8bVSGAwW8bXvGmGj9XSJBcpyDuU5yKpF/jm8hFPd7gF0dyBiB QGOGc+ChrJn6TdRRtuVsrEq3pKVzgnP+49oQu0Gtj1zAlej8QdGIuV9plM7kwSBUnmCH 04sfXd7uSLX3QGeB1nikUXO6c6tBWoLAjI4NmfUPfy9EEppfM3QfkJOhplM8s/6+SgmB XCSA== X-Gm-Message-State: ALoCoQkTYBMo3WFCDKcRLksCSfYLLEQkkcxDuOM+guhqp67yNzbdh5LZgTna3mjrrphsJ9j2UA/T X-Received: by 10.60.37.199 with SMTP id a7mr2804580oek.41.1396269242514; Mon, 31 Mar 2014 05:34:02 -0700 (PDT) Received: from [192.168.10.212] (ip-64-134-11-246.public.wayport.net. [64.134.11.246]) by mx.google.com with ESMTPSA id c7sm60972107oek.12.2014.03.31.05.34.00 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 31 Mar 2014 05:34:00 -0700 (PDT) Content-Type: multipart/alternative; boundary="Apple-Mail=_99EBCEE7-2AB0-4A6F-A234-1F1F723CCD5E" Mime-Version: 1.0 (Mac OS X Mail 7.2 \(1874\)) From: John Bradley In-Reply-To: <9B0FC530-C3D7-4BA8-85FC-7457B7BEA194@adobe.com> Date: Mon, 31 Mar 2014 09:34:00 -0300 Message-Id: <8480C7F7-E43B-4094-BBE3-95E13E8AE33A@ve7jtb.com> References: <9B0FC530-C3D7-4BA8-85FC-7457B7BEA194@adobe.com> To: Antonio Sanso X-Mailer: Apple Mail (2.1874) Archived-At: http://mailarchive.ietf.org/arch/msg/oauth/LgfRcJ5rPCoE-MLX7IhAkrLhhdk Cc: "oauth@ietf.org" , "jose@ietf.org" Subject: Re: [OAUTH-WG] JWE with A128CBC-HS256 X-BeenThere: oauth@ietf.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: OAUTH WG List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 31 Mar 2014 12:34:08 -0000 --Apple-Mail=_99EBCEE7-2AB0-4A6F-A234-1F1F723CCD5E Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Thanks, I will have a look. On Mar 31, 2014, at 3:43 AM, Antonio Sanso wrote: > thanks a lot John, >=20 > On Mar 28, 2014, at 5:09 PM, John Bradley wrote: >=20 >> This reference may be useful to you. = http://tools.ietf.org/html/draft-mcgrew-aead-aes-cbc-hmac-sha2 >>=20 >> The part of the spec you need is = http://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-24#page-23 >>=20 >> We originally used a KDF as you mention. In order to simplify the = alg and align with draft-mcgrew-aead-aes-cbc-hmac-sha2. >>=20 >> K is the concatenation of the AES key and teh HMAC Key. >=20 > question, are the examples in the spec already updated to use the new = mechanism?=20 > There are some obsolete references in the JWE spec. E.g. in [2] says: >=20 > as described where this algorithm is > defined in Sections 4.8 and 4.8.3 of JWA, >=20 > These sections seems to point to on old version of the spec (Section = 4.8.3 doesn=92t even exist anymore in JWA) >=20 > regards >=20 > antonio >=20 > [2] = http://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-24#appendix= -B >=20 >>=20 >> John B. >>=20 >>=20 >> On Mar 28, 2014, at 11:19 AM, Antonio Sanso wrote: >>=20 >>> hi *, >>>=20 >>> in the JWT specification [0] there is an example of a JWE that use = A128CBC-HS256 for content encrpyption. >>> Now I am not a cryptographer my self but IIUC the same CEK is used = for encrypting with AES and authentication HMAC. >>>=20 >>> AFAIK is better to use two different keys for those 2 different = primitives (this will not obviously apply to AES_GCM). >>>=20 >>> Unless I am missing something... :) >>>=20 >>> regards >>>=20 >>> antonio >>>=20 >>> [0] = http://tools.ietf.org/html/draft-ietf-oauth-json-web-token-19#appendix-A.1= >>> [1] = http://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-24#appendix= -A.2 >>> _______________________________________________ >>> OAuth mailing list >>> OAuth@ietf.org >>> https://www.ietf.org/mailman/listinfo/oauth >>=20 >=20 --Apple-Mail=_99EBCEE7-2AB0-4A6F-A234-1F1F723CCD5E Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 Thanks,  I will have a = look.

On Mar 31, 2014, at 3:43 AM, Antonio Sanso = <asanso@adobe.com> = wrote:

thanks a lot John,

On Mar 28, 2014, at 5:09 PM, John Bradley <ve7jtb@ve7jtb.com> wrote:

This reference may be useful to you. http://tools.ietf.org/html/draft-mcgrew-aead-aes-cbc-hmac-sha2

The part of the spec you need is  http://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-24= #page-23

We originally used a KDF as you mention.  In order to simplify the = alg and align with draft-mcgrew-aead-aes-cbc-hmac-sha2.

K is the concatenation of the AES key and teh HMAC Key.

question,  are the examples in the spec already updated to use = the new mechanism? 
There are some obsolete references in the JWE spec. E.g. in [2] = says:

as described where this =
algorithm is
   defined in Sections 4.8 and 4.8.3 of JWA,

These sections seems to point to on old version of the spec = (Section 4.8.3 doesn=92t even exist anymore in JWA)

regards

antonio



John B.


On Mar 28, 2014, at 11:19 AM, Antonio Sanso <asanso@adobe.com> wrote:

hi *,

in the JWT specification [0] there is an example of a JWE that use = A128CBC-HS256 for content encrpyption.
Now I am not a cryptographer my self but IIUC the same CEK is used for = encrypting with AES and authentication HMAC.

AFAIK is better to use two different keys for those 2 different = primitives (this will not obviously apply to AES_GCM).

Unless I am missing something... :)

regards

antonio

[0] = http://tools.ietf.org/html/draft-ietf-oauth-json-web-token-19#appendix-A.1=
[1] = http://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-24#appendix= -A.2
_______________________________________________
OAuth mailing list
OAuth@ietf.org
https://www.ietf.org/= mailman/listinfo/oauth



= --Apple-Mail=_99EBCEE7-2AB0-4A6F-A234-1F1F723CCD5E--