Re: [OAUTH-WG] Proof-of-Possession Key Semantics for JWTs spec addressing final shepherd comment

John Bradley <ve7jtb@ve7jtb.com> Thu, 05 November 2015 04:51 UTC

Return-Path: <ve7jtb@ve7jtb.com>
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 D53101A911A for <oauth@ietfa.amsl.com>; Wed, 4 Nov 2015 20:51:47 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, 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 BCHtQ1PrQv67 for <oauth@ietfa.amsl.com>; Wed, 4 Nov 2015 20:51:44 -0800 (PST)
Received: from mail-pa0-x233.google.com (mail-pa0-x233.google.com [IPv6:2607:f8b0:400e:c03::233]) (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 AEDD41A1A4B for <oauth@ietf.org>; Wed, 4 Nov 2015 20:51:44 -0800 (PST)
Received: by padhx2 with SMTP id hx2so67048468pad.1 for <oauth@ietf.org>; Wed, 04 Nov 2015 20:51:44 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ve7jtb_com.20150623.gappssmtp.com; s=20150623; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=0BiZ6g7D5IgDQ8j9UzhcX6YaG+TBz4KCnIKiYbpFmXc=; b=yvZawJMlGPqQZKFZocqTOBF0nzKzE67wzt7rMcb90MA6O6AnORfuGCcv4Yj3s9Z1sD zpKyi/FxC423vNlkszxycqGoGHfYjTGNMI3vRe8I6+6W3A5llNs/rfGIZfEQHr94eO8B DQMdkKXZFaUEZTOAu++wfgTu+AnL2DwIg9d+vpYJ2vtM0ZhzGTm+/t3R7jdD1voDaQkP RZBE3dWnooE5/pgfmdVUKAxYZ0VJapPvrpYsc9Dh8Eh103jyNpkBiIolXhTJVutFpDKI HLSJlNOaVizUHth7H+ObjhMwSJ1hqegCbOAI/losWZMbOBO1xxJVZJqdRKDqKMweAL2V jAHw==
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:content-transfer-encoding:message-id:references :to; bh=0BiZ6g7D5IgDQ8j9UzhcX6YaG+TBz4KCnIKiYbpFmXc=; b=C4M/OH4sGEfxO7A2BvfiiB6JnhkxVR67nVEsUuJrlOmUwYfOFxU8jMOFFN3u8mffOP 39rFfQv/ScELujo342JR3lEukeKx3Omps6mp2bznx1yE9kYqOv91X8ZXclyfYYm0VO/X N3N+x1QHizjlMEtiiWLtPfZgBwQw1reCcVTNVE1boXq4MCGlKQi3v8RilaBGqoeRNP+0 LMHm92PJ7e2p0T+mhDQCmbnlb5OQbnA2FwPdl4hGGQfpvgPNq1rnRDe/VsjdGUl4tGgq 3LJ29eZGSlNT0m/6KIbwkSqrZjBwrlUkGu9ICGcohrTcrcK7McrzziHIR8ii/8/vEFUP LY3g==
X-Gm-Message-State: ALoCoQkSZfbCAY58wxzVHZLvdDZ47Df2OAbH+rxHjwbgE5itMYtNHCA1e7pUNKKzIa3bS12TSr3Y
X-Received: by 10.68.132.71 with SMTP id os7mr6862645pbb.125.1446699104267; Wed, 04 Nov 2015 20:51:44 -0800 (PST)
Received: from t20010c40000030089044b9d401462547.v6.meeting.ietf94.jp (t20010c40000030089044b9d401462547.v6.meeting.ietf94.jp. [2001:c40:0:3008:9044:b9d4:146:2547]) by smtp.gmail.com with ESMTPSA id bs3sm5024053pbd.89.2015.11.04.20.51.42 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 04 Nov 2015 20:51:43 -0800 (PST)
Content-Type: text/plain; charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\))
From: John Bradley <ve7jtb@ve7jtb.com>
In-Reply-To: <BN3PR0301MB12343B9AA4D6842E09D6A5BFA6290@BN3PR0301MB1234.namprd03.prod.outlook.com>
Date: Thu, 5 Nov 2015 13:51:43 +0900
Content-Transfer-Encoding: quoted-printable
Message-Id: <9E23AF3A-F758-4CB4-B920-4E1E2F61BCF4@ve7jtb.com>
References: <BY2PR03MB442F6667C49F8CF260D504DF52A0@BY2PR03MB442.namprd03.prod.outlook.com> <D2605993.2210B%kepeng.lkp@alibaba-inc.com> <BY2PR03MB4423CADD0E9897848961B99F52A0@BY2PR03MB442.namprd03.prod.outlook.com> <CA+k3eCRW=ggajMeL1z2cvLDkou9XsLMupicH-5HyDkadj0_o_g@mail.gmail.com> <BY2PR03MB44262EA4616E08287A91DB1F52A0@BY2PR03MB442.namprd03.prod.outlook.com> <563AA216.5010109@gmx.net> <A926F104-1624-4F32-9246-662594E66F5E@ve7jtb.com> <89A6E4DE-263B-4DB4-8882-54FA7103C721@mit.edu> <82079E8A-2AC8-4A42-9AF7-77FF2A3CAFC2@ve7jtb.com> <BN3PR0301MB12343B9AA4D6842E09D6A5BFA6290@BN3PR0301MB1234.namprd03.prod.outlook.com>
To: Anthony Nadalin <tonynad@microsoft.com>
X-Mailer: Apple Mail (2.2104)
Archived-At: <http://mailarchive.ietf.org/arch/msg/oauth/DRkFpAiQqvyVZYURfK47CpbJOWM>
Cc: "<oauth@ietf.org>" <oauth@ietf.org>
Subject: Re: [OAUTH-WG] Proof-of-Possession Key Semantics for JWTs spec addressing final shepherd comment
X-BeenThere: oauth@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: OAUTH WG <oauth.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/oauth>, <mailto:oauth-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/oauth/>
List-Post: <mailto:oauth@ietf.org>
List-Help: <mailto:oauth-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/oauth>, <mailto:oauth-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 05 Nov 2015 04:51:48 -0000

OK, no good reason unless the client is using a HSM that can do HMAC and can export a symmetric key wrapped in a asymmetric key provided by the AS.

We don’t currently cover that use case of sending a wrapped symmetric key to the AS in POP key distribution.   
I don’t know how common that is going to be, but it is worth thinking about defining.

John B.

> On Nov 5, 2015, at 1:45 PM, Anthony Nadalin <tonynad@microsoft.com> wrote:
> 
> Not sure why you think its weaker as it would be a wrapped key that the hardware produces 
> 
> -----Original Message-----
> From: OAuth [mailto:oauth-bounces@ietf.org] On Behalf Of John Bradley
> Sent: Wednesday, November 4, 2015 8:43 PM
> To: Justin Richer <jricher@mit.edu>
> Cc: <oauth@ietf.org> <oauth@ietf.org>
> Subject: Re: [OAUTH-WG] Proof-of-Possession Key Semantics for JWTs spec addressing final shepherd comment
> 
> In the asymmetric case the use of a HSM or secure element is the argument for the client selecting the public key.   In those cases the client is doing the key gen in hardware so one hopes it is OK.   In the symetric case the client generating the key is weaker (as in I can’t think of any really good reason).
> 
> 
>> On Nov 5, 2015, at 1:35 PM, Justin Richer <jricher@mit.edu> wrote:
>> 
>> I’d argue that it’s best practice, and in line with other parts of OAuth, if we assume the server generates it in the normal case (issuer -> presenter). Client generated token keys should be an exception, especially in the asymmetric case.
>> 
>> — Justin
>> 
>>> On Nov 5, 2015, at 1:32 PM, John Bradley <ve7jtb@ve7jtb.com> wrote:
>>> 
>>> Agreed the only real difference is the quality of the key.  If the server generates it, then it knows that the client is not using the fixed hex value of DEADBEEF for everything.
>>> 
>>> John B.
>>>> On Nov 5, 2015, at 9:25 AM, Hannes Tschofenig <hannes.tschofenig@gmx.net> wrote:
>>>> 
>>>> I agree that the effect is the same. From a security point of view 
>>>> there is only an impact if one of the two parties is in a better 
>>>> position to generate random numbers, which is the basis for 
>>>> generating a high entropy symmetric key.
>>>> 
>>>> On 11/04/2015 11:51 PM, Mike Jones wrote:
>>>>> Thanks for the detailed read, Brian.  You’re right that in the 
>>>>> symmetric case, either the issuer or the presenter can create the 
>>>>> symmetric PoP key and share it with the other party, since the effect is equivalent.
>>>>> I suspect that both the key distribution draft and this draft 
>>>>> should be updated with a sentence or two saying that either 
>>>>> approach can be taken.  Do others concur?
>>>>> 
>>>>> 
>>>>> 
>>>>>                                                         -- Mike
>>>>> 
>>>>> 
>>>>> 
>>>>> *From:*Brian Campbell [mailto:bcampbell@pingidentity.com]
>>>>> *Sent:* Thursday, November 05, 2015 7:48 AM
>>>>> *To:* Mike Jones
>>>>> *Cc:* Kepeng Li; oauth@ietf.org
>>>>> *Subject:* Re: [OAUTH-WG] Proof-of-Possession Key Semantics for 
>>>>> JWTs spec addressing final shepherd comment
>>>>> 
>>>>> 
>>>>> 
>>>>> +1 for the diagrams making the document more understandable.
>>>>> 
>>>>> One little nit/question, step 1 in both Symmetric and Asymmetric 
>>>>> keys shows the Presenter sending the key to the Issuer. It's 
>>>>> possible, however, for the key to be sent the other way. Presenter 
>>>>> sending it to the Issuer is probably preferred for asymmetric, 
>>>>> especially if the client can secure the private keys in hardware. 
>>>>> But I don't know if one way or the other is clearly better for 
>>>>> symmetric case and PoP key distribution currently has it the other 
>>>>> way <https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2ftools.ietf.org%2fhtml%2fdraft-ietf-oauth-pop-key-distribution-02%23section-4.2&data=01%7c01%7ctonynad%40microsoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=UgZEoqQiaUk9VdYpSQRvUeVVOQgIUg3UmAr18oQ7GtI%3d>.
>>>>> Should the intro text somehow mention the possibility that the 
>>>>> Issuer could create the key and send it to the Presenter?
>>>>> 
>>>>> I know it's only the introduction but it was just something that 
>>>>> jumped out at me.
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> On Wed, Nov 4, 2015 at 9:04 AM, Mike Jones 
>>>>> <Michael.Jones@microsoft.com <mailto:Michael.Jones@microsoft.com>> wrote:
>>>>> 
>>>>> Thanks for suggesting the diagrams, Kepeng. They make the document 
>>>>> more understandable.
>>>>> 
>>>>> -- Mike
>>>>> 
>>>>> -------------------------------------------------------------------
>>>>> -----
>>>>> 
>>>>> *From: *Kepeng Li <mailto:kepeng.lkp@alibaba-inc.com>
>>>>> *Sent: *‎11/‎5/‎2015 12:57 AM
>>>>> *To: *Mike Jones <mailto:Michael.Jones@microsoft.com>; 
>>>>> oauth@ietf.org <mailto:oauth@ietf.org>
>>>>> *Subject: *Re: Proof-of-Possession Key Semantics for JWTs spec 
>>>>> addressing final shepherd comment
>>>>> 
>>>>> Thank you Mike.
>>>>> 
>>>>> 
>>>>> 
>>>>> The diagrams look good to me.
>>>>> 
>>>>> 
>>>>> 
>>>>> Kind Regards
>>>>> 
>>>>> Kepeng
>>>>> 
>>>>> 
>>>>> 
>>>>> *发件人**: *Mike Jones <Michael.Jones@microsoft.com 
>>>>> <mailto:Michael.Jones@microsoft.com>>
>>>>> *日期**: *Thursday, 5 November, 2015 12:32 am
>>>>> *至**: *"oauth@ietf.org <mailto:oauth@ietf.org>" <oauth@ietf.org 
>>>>> <mailto:oauth@ietf.org>>
>>>>> *抄送**: *Li Kepeng <kepeng.lkp@alibaba-inc.com 
>>>>> <mailto:kepeng.lkp@alibaba-inc.com>>
>>>>> *主题**: *Proof-of-Possession Key Semantics for JWTs spec addressing 
>>>>> final shepherd comment
>>>>> 
>>>>> 
>>>>> 
>>>>> Proof-of-Possession Key Semantics for JWTs draft -06 addresses the 
>>>>> remaining document shepherd comment – adding use case diagrams to 
>>>>> the introduction.
>>>>> 
>>>>> 
>>>>> 
>>>>> The updated specification is available at:
>>>>> 
>>>>> ·        https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2ftools.ietf.org%2fhtml%2fdraft-ietf-oauth-proof-of-possession-06&data=01%7c01%7ctonynad%40microsoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=6hE6dOO0I1%2ffF005rVknyOFHuB18gdpZg9dftExLtCw%3d
>>>>> 
>>>>> 
>>>>> 
>>>>> An HTML formatted version is also available at:
>>>>> 
>>>>> ·       
>>>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fse
>>>>> lf-issued.info%2fdocs%2fdraft-ietf-oauth-proof-of-possession-06.htm
>>>>> l&data=01%7c01%7ctonynad%40microsoft.com%7c9456670075d04a51f85508d2
>>>>> e59ba294%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=EQd4rUcuyqdSP
>>>>> gmibtcfjMpJm6RWWwCZC85%2bCboEs54%3d
>>>>> 
>>>>> 
>>>>> 
>>>>>                                                         -- Mike
>>>>> 
>>>>> 
>>>>> 
>>>>> P.S.  This note was also posted at 
>>>>> https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fself-issued.info%2f%3fp%3d1471&data=01%7c01%7ctonynad%40microsoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=TMfX1tG5qucl%2be2KVpyMBuj72ZQ%2f%2bEKGoTyJyf%2bfJi4%3d and as @selfissued <https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2ftwitter.com%2fselfissued&data=01%7c01%7ctonynad%40microsoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=LfFAjchzCTh0x%2fY9hr0W%2fSohPGgb0JVjL%2f2Az%2f12BCg%3d>.
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> OAuth mailing list
>>>>> OAuth@ietf.org <mailto:OAuth@ietf.org> 
>>>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fww
>>>>> w.ietf.org%2fmailman%2flistinfo%2foauth&data=01%7c01%7ctonynad%40mi
>>>>> crosoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91
>>>>> ab2d7cd011db47%7c1&sdata=ND3ydaXOsPMsoRhE0Uyq0uznGy6MdYOLZQJHLhEQKJ
>>>>> s%3d
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> OAuth mailing list
>>>>> OAuth@ietf.org
>>>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fww
>>>>> w.ietf.org%2fmailman%2flistinfo%2foauth&data=01%7c01%7ctonynad%40mi
>>>>> crosoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91
>>>>> ab2d7cd011db47%7c1&sdata=ND3ydaXOsPMsoRhE0Uyq0uznGy6MdYOLZQJHLhEQKJ
>>>>> s%3d
>>>>> 
>>>> 
>>>> _______________________________________________
>>>> OAuth mailing list
>>>> OAuth@ietf.org
>>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fwww
>>>> .ietf.org%2fmailman%2flistinfo%2foauth&data=01%7c01%7ctonynad%40micr
>>>> osoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2
>>>> d7cd011db47%7c1&sdata=ND3ydaXOsPMsoRhE0Uyq0uznGy6MdYOLZQJHLhEQKJs%3d
>>> 
>>> _______________________________________________
>>> OAuth mailing list
>>> OAuth@ietf.org
>>> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fwww.
>>> ietf.org%2fmailman%2flistinfo%2foauth&data=01%7c01%7ctonynad%40micros
>>> oft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2d7c
>>> d011db47%7c1&sdata=ND3ydaXOsPMsoRhE0Uyq0uznGy6MdYOLZQJHLhEQKJs%3d
>> 
> 
> _______________________________________________
> OAuth mailing list
> OAuth@ietf.org
> https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fwww.ietf.org%2fmailman%2flistinfo%2foauth%0a&data=01%7c01%7ctonynad%40microsoft.com%7c9456670075d04a51f85508d2e59ba294%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=BLqSuDjWLY72fGm0UrpLwxQVnamMelggJeOpYJESVFs%3d