Re: [Teep] Call for adoption of draft-thaler-teep-otrp-over-http

Mingliang Pei <Mingliang_Pei@symantec.com> Wed, 12 June 2019 21:59 UTC

Return-Path: <Mingliang_Pei@symantec.com>
X-Original-To: teep@ietfa.amsl.com
Delivered-To: teep@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 97F601201C9 for <teep@ietfa.amsl.com>; Wed, 12 Jun 2019 14:59:23 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.31
X-Spam-Level:
X-Spam-Status: No, score=-4.31 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_DKIMWL_WL_HIGH=-0.01] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=symantec.com header.b=Pjpr1dD4; dkim=pass (1024-bit key) header.d=symantec.com header.b=ccQLp21f
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 0iXqTdFv7bzh for <teep@ietfa.amsl.com>; Wed, 12 Jun 2019 14:59:20 -0700 (PDT)
Received: from asbsmtoutape02.symantec.com (asbsmtoutape02.symantec.com [155.64.138.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 24473120192 for <teep@ietf.org>; Wed, 12 Jun 2019 14:59:19 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; d=Symantec.com; s=2; c=relaxed/simple; q=dns/txt; i=@Symantec.com; t=1560376759; x=2424290359; h=From:Sender:Reply-To:Subject:Date:Message-ID:To:Cc:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=O+GvxklLebjwySYaEbUO7UyLJWxEdbMYwcNLN/XzktQ=; b=Pjpr1dD4znrDhI5JE/zDLBhF2fVzhraXVuPDwwX1M5mLbaqlEM++8x7J3Nw7sg+M xlwercYUW0y826FEm/8k1MOSRZQ+wiN3tNfsQlprrKBqhua4FSOhAahLRocOUYMi WhgJLP2uUyeuPMYXlS224HmXABDbbyABmp864hJqp7k=;
Received: from asbsmtmtaapi01.symc.symantec.com (asb1-f5-symc-ext-prd-snat7.net.symantec.com [10.90.75.7]) by asbsmtoutape02.symantec.com (Symantec Messaging Gateway) with SMTP id 85.45.49042.6B5710D5; Wed, 12 Jun 2019 21:59:19 +0000 (GMT)
X-AuditID: 0a5af81a-08dff7000000bf92-ee-5d0175b6fbb3
Received: from tus3xchcaspin01.SYMC.SYMANTEC.COM (asb1-f5-symc-ext-prd-snat5.net.symantec.com [10.90.75.5]) by asbsmtmtaapi01.symc.symantec.com (Symantec Messaging Gateway) with SMTP id FE.92.52441.6B5710D5; Wed, 12 Jun 2019 21:59:18 +0000 (GMT)
Received: from TUSXCHMBXWPI01.SYMC.SYMANTEC.COM (10.44.91.33) by tus3xchcaspin01.SYMC.SYMANTEC.COM (10.44.91.13) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 12 Jun 2019 14:59:18 -0700
Received: from NAM01-BN3-obe.outbound.protection.outlook.com (10.44.128.5) by TUSXCHMBXWPI01.SYMC.SYMANTEC.COM (10.44.91.33) with Microsoft SMTP Server (TLS) id 15.0.1395.4 via Frontend Transport; Wed, 12 Jun 2019 14:59:18 -0700
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=symantec.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=O+GvxklLebjwySYaEbUO7UyLJWxEdbMYwcNLN/XzktQ=; b=ccQLp21fvVrXnYmiX/ZuNJlC3CCH/yIREY84z3YAwYSQQhzsrp2zz9Zs3zf5dcQmIE8vqJy8FCb0odCUzypQiwGCrnDehle/uKviWj4jfVLGHlKyL+JFBQuZIm0AHmPeT6BRu3Pfz+qQmn6SiG8YMMEVpD2Q4lPvjM5oVCqDBow=
Received: from CH2PR16MB3574.namprd16.prod.outlook.com (52.132.247.213) by CH2PR16MB3558.namprd16.prod.outlook.com (52.132.247.209) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1987.11; Wed, 12 Jun 2019 21:59:16 +0000
Received: from CH2PR16MB3574.namprd16.prod.outlook.com ([fe80::95db:48ae:5b72:c17b]) by CH2PR16MB3574.namprd16.prod.outlook.com ([fe80::95db:48ae:5b72:c17b%6]) with mapi id 15.20.1965.017; Wed, 12 Jun 2019 21:59:16 +0000
From: Mingliang Pei <Mingliang_Pei@symantec.com>
To: Dave Thaler <dthaler=40microsoft.com@dmarc.ietf.org>, Anders Rundgren <anders.rundgren.net@gmail.com>, "Wheeler, David M" <david.m.wheeler@intel.com>, Hannes Tschofenig <Hannes.Tschofenig@arm.com>, "Nancy Cam-Winget (ncamwing)" <ncamwing@cisco.com>, "teep@ietf.org" <teep@ietf.org>
Thread-Topic: [Teep] Call for adoption of draft-thaler-teep-otrp-over-http
Thread-Index: AQHVFOGEwUKGBoO0w0ufhIS/wg0a4KaABlcAgADZDICAAUgp4IAACFwAgABCB4CAFZmwAIAAe+/Q//+tfIA=
Date: Wed, 12 Jun 2019 21:59:16 +0000
Message-ID: <C0D44D2C-D513-48B6-A194-B79F746BC0DB@symantec.com>
References: <B57377C9-72EC-45C4-B5C2-9A6443B8C073@cisco.com> <246ce79a-75a6-4e4d-d76a-2b54eb71cf75@gmail.com> <BN6PR21MB0497781C059E34E015875C55A31E0@BN6PR21MB0497.namprd21.prod.outlook.com> <VI1PR08MB5360C0AFED2E8DDA94734016FA1F0@VI1PR08MB5360.eurprd08.prod.outlook.com> <0627F5240443D2498FAA65332EE46C843B74679C@CRSMSX102.amr.corp.intel.com> <ce9c0b4c-8d18-1f29-9b53-b3e4220683b6@gmail.com> <AA45ADF2-3326-4017-8A83-A55B2DC40391@symantec.com> <BN6PR21MB0497B4071A5701DD04871B44A3EC0@BN6PR21MB0497.namprd21.prod.outlook.com>
In-Reply-To: <BN6PR21MB0497B4071A5701DD04871B44A3EC0@BN6PR21MB0497.namprd21.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
user-agent: Microsoft-MacOutlook/10.d.1.180523
authentication-results: spf=none (sender IP is ) smtp.mailfrom=Mingliang_Pei@symantec.com;
x-originating-ip: [155.64.23.38]
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: 2370833c-4c2c-418e-36f8-08d6ef813687
x-microsoft-antispam: BCL:0; PCL:0; RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(2017052603328)(7193020); SRVR:CH2PR16MB3558;
x-ms-traffictypediagnostic: CH2PR16MB3558:
x-ms-exchange-purlcount: 2
x-microsoft-antispam-prvs: <CH2PR16MB3558B549263B045BA9223594ECEC0@CH2PR16MB3558.namprd16.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:9508;
x-forefront-prvs: 0066D63CE6
x-forefront-antispam-report: SFV:NSPM; SFS:(10009020)(346002)(39860400002)(376002)(136003)(396003)(366004)(13464003)(40434004)(51444003)(199004)(189003)(305945005)(71190400001)(71200400001)(33656002)(7736002)(66066001)(14454004)(26005)(25786009)(8936002)(186003)(6506007)(6306002)(76176011)(36756003)(5024004)(14444005)(102836004)(256004)(58126008)(45080400002)(478600001)(6512007)(316002)(110136005)(53546011)(10290500003)(966005)(5660300002)(80792005)(486006)(53936002)(6486002)(2906002)(81156014)(81166006)(6116002)(3846002)(229853002)(446003)(86362001)(8676002)(2616005)(73956011)(6436002)(66946007)(66556008)(64756008)(99286004)(76116006)(66446008)(6246003)(66476007)(91956017)(68736007)(72206003)(2501003)(476003)(11346002); DIR:OUT; SFP:1101; SCL:1; SRVR:CH2PR16MB3558; H:CH2PR16MB3574.namprd16.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; A:1; MX:1;
received-spf: None (protection.outlook.com: symantec.com does not designate permitted sender hosts)
x-ms-exchange-senderadcheck: 1
x-microsoft-antispam-message-info: CS69Bf8sd0gSQyLrE2/zwZ9qPk4FuWuf7ijYk1lY9eAxJ7E0tlv4vEIjcHz4w+5+kP/EsCCTmkTj3R7NCjrienXOZMP20l9VZ4PKmgq1AYwpvQ01FJdDSL1R9Rx1RnrPfG97JkaM37inorN0zxTE9SjmONMJ5cls0WWbAiMVgpflXPAHGNgufMptt5yo/iXefseaYBnR/K4aMViLobPQpi+7EWy089yAiq3OHBum9sRkQ+FUGlZZGGA4vL5aq5/tHTtCbiHW6Uc+JzWI7pQHqrmd9vILyGX7hYyLsJdwlOvlNze5jiWsBdEPAlWImddZJZwQPD6rc/xc2NZoeQpGQSGnQEC+GvUP1tR+Mt/FUUh3iiAc0VG9cbNZTPFw4AGMcr6jkYZDQJ0214et2xT8gT3Mtc1lgJsa6MIXSLkBF18=
Content-Type: text/plain; charset="utf-8"
Content-ID: <B5650CE7D7E77C479EBAACBB84A3E0FB@namprd16.prod.outlook.com>
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 2370833c-4c2c-418e-36f8-08d6ef813687
X-MS-Exchange-CrossTenant-originalarrivaltime: 12 Jun 2019 21:59:16.2145 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 3b217a9b-6c58-428b-b022-5ad741ce2016
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: Mingliang_Pei@symantec.com
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR16MB3558
X-OriginatorOrg: symantec.com
X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrEKsWRmVeSWpSXmKPExsXCFeXNrru9lDHWYIqbxcNXS1gtmi6eYrO4 N/8rk8XNGaeYLCZNmcxksfTPN2YHNo8189Ywekz5vZHV48SyK6weO2fdZfdYsuQnk8fiPS+Z AtiiuGxSUnMyy1KL9O0SuDK+N/xmLXjlVtFxeStzA2ODaxcjJ4eEgInE0gOfWLsYuTiEBD4y Shzb95api5EDLPFkljBE/DujxO6zbxghnKOMEht+nGSGcF4wStzrPswO4rAITGCW2L2rGSoz lUni5eVZUM4jRok5z9rABrMJGEhcuJMHEhcRWMoksWbVPXaQS4QFPCXmzZ4NZosIeEk0r2pi hbCTJGY0NLOB2CwCqhLzzv1lBrF5Bewlzm3shjpqNovE/+ZGRpAFnAKxEutWpIPUMAqISXw/ tYYJxGYWEJe49WQ+E8TXAhJL9pxnhrBFJV4+/ge2S1RAT6Jn51U2iN5YiZ8tDxghahQkNn5+ zwJhy0pcmt8NFfeVuH+rB+x9CYGbjBI7tn1lgYSelsTspgKIGimJ748/skPY2RKPP1yDukFN 4sabDuYJjCazkJw3C6ibWUBTYv0ufYiwh8SKzilMELaixJTuh+yzwL4XlDg58wnLAkbWVYwK icVJxbkl+aUliQWpBkZ6xZW5ySAiEZiukvWS83M3MYJT1g+pHYxP7vgcYhTgYFTi4c0rYowV Yk0sA6o8xCjBwawkwmuUzRArxJuSWFmVWpQfX1Sak1p8iFGag0VJnJedH6haID2xJDU7NbUg tQgmy8TBKdXAaPf++KZl6ueXRL+fIHXum49FTl//XstFSrMfHdogv7b6oVXEUxXZ81vDYo9I S4VG3578YlJyyKTVYV+Yj1UoHJ7T5HVVyX5/UsC+J1HrMoN23uNWnqCueF+ctzsyOeXbXDeF cpl6Y8NMLyXpsx857v/kjc4/tDK8gIHTzP5+3MMs3Wlq+2YvV2Ipzkg01GIuKk4EANy6qtxV AwAA
X-Brightmail-Tracker: H4sIAAAAAAAAA02SW0hUURSG3ec2xyFhO94WlqFGRkY6QsYQXR+qsZRSywfL7KgHFW/TjIpC xOREeHvQMrKZ1CgVk8FLoXgls6w0tNIKR3TyRjimZKWZqJlnzjz0svnW2v9a69+bxZKyGtqd TUxN59WpXLI3I6Wkkafpvc0ZKEo+P75fMTFbSStyPvQxCnPFEqEwlfYRilsltwlF1dpv8iij NJYbkbJktZFWvqn+SCtb9WMSZWXlCqF81GEhzjKR0oNxfHJiJq/2P3xZmrCsXaVVsyeycoea SC3SHs9HLAt4H0zrnfKRlJXhZQTt/XNIDHoQNPzpJcVgBoG54IVECChcREJ7m852c4cAy5De FkwiuP/1JiE0ZrAc3o+mCnlnXEWAsda8WW7POuEgKDcYrOyMT4GuNocWOQZKtTpGYArvhPKB dVJgB3wEBhoLbKYMFGzoriNhgD2OgrqaeEGDsCss9xkJgUnsBiPTFVYGjKGy4x0psgtYpv5a Z7lgPyhs/cSItVGwcmMciRpPaPz1nRLZAwYrCmz5EPgyUmh9PmATgpbmJUr8PV8w5KhEjTss T/2QiJwEUwufbR58YHgu1+ZhGzT155FiHzMDgxvFqAjJ9f/51m+2JfFuqG/zF9NKqMkrIUT2 gpKCCYne+i2O0HtvmnqA6FrkyWliNCnpKekcp0qUB/hpslNihYPbXKxYv9i0lCfIulqrri2o ay24G2EWeW9xaJGgKBnNZW4qu9FWlvJ2c3h6cfGCDMdz6XwSz6t4dbQ6I5nXdCOCtXfXosCI iOrAwEmL83zw84xRp8W6+kvsmiV8YuGh3XT8IZ6QepWumg9kGydnZl4Wn8sOvbajzDf6SlzY rqt3I+Q1w2lyO93J9dA81ezYW0O8ZPsOn7apotem8Mz+rM6QV47HTHvOxPU8a/IwLZz/Jivr knSGpZFpIYyd5+OGoKWfqf2J3pQmgQvwJdUa7h87KLO+OwMAAA==
X-CFilter-Loop: ASB01
Archived-At: <https://mailarchive.ietf.org/arch/msg/teep/dvN_tZTfzSbBx97yxJ-rUQtf3oQ>
Subject: Re: [Teep] Call for adoption of draft-thaler-teep-otrp-over-http
X-BeenThere: teep@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: A Protocol for Dynamic Trusted Execution Environment Enablement <teep.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/teep>, <mailto:teep-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/teep/>
List-Post: <mailto:teep@ietf.org>
List-Help: <mailto:teep-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/teep>, <mailto:teep-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 12 Jun 2019 21:59:24 -0000

Agreed, Dave, thanks, Ming

On 6/12/19, 2:42 PM, "Dave Thaler" <dthaler=40microsoft.com@dmarc.ietf.org> wrote:

    JSON vs CBOR (or anything else) should not affect the transport draft as currently specified.  The transport just carries a generic payload and feeds it into the Agent as an opaque buffer.
    The broker has no visibility into the encoding, it just transports raw payloads.  Only the OTrP implementation knows whether it's JSON or CBOR or whatever, so in my view that's a discussion
    on the OTrP spec not the otrp-over-http spec.
    
    Dave
    
    -----Original Message-----
    From: Mingliang Pei <Mingliang_Pei=40symantec.com@dmarc.ietf.org> 
    Sent: Wednesday, June 12, 2019 12:31 PM
    To: Anders Rundgren <anders.rundgren.net@gmail.com>; Wheeler, David M <david.m.wheeler@intel.com>; Hannes Tschofenig <Hannes.Tschofenig@arm.com>; Dave Thaler <dthaler@microsoft.com>; Nancy Cam-Winget (ncamwing) <ncamwing@cisco.com>; teep@ietf.org
    Subject: Re: [Teep] Call for adoption of draft-thaler-teep-otrp-over-http
    
    Sorry for late catch up on email thread. I think we need to support CBOR too, and favor to add it as a subsequent separate draft. I also endorse the adoption of the transport draft.
    
    Thanks,
    
    Ming
    
    On 5/29/19, 11:40 AM, "TEEP on behalf of Anders Rundgren" <teep-bounces@ietf.org on behalf of anders.rundgren.net@gmail.com> wrote:
    
        Hi David,
        Since you mention the unfinished architecture document, have you seen https://clicktime.symantec.com/3SuxTt9iJ9KUAHy9YKwWpAq7Vc?u=https%3A%2F%2Fnam06.safelinks.protection.outlook.com%2F%3Furl%3Dhttps%253A%252F%252Fgithub.com%252Fietf-teep%252Farchitecture%252Fissues%252F52%2523issuecomment-493652265%26data%3D02%257C01%257Cdthaler%2540microsoft.com%257C6e15170aecc640e93c7508d6ef6c85b8%257C72f988bf86f141af91ab2d7cd011db47%257C1%257C0%257C636959646713484101%26sdata%3DmRuPRP7F%252Fv8s6F2eSbsA8V%252F4NycbmK4U3Xn7rIedpKE%253D%26reserved%3D0 ?
        
        This is about creating a *unified* (JSON/CBOR independent) TEE management API.
        
        Ten years ago I had something similar to OTrP but felt it was becoming "clunky" and limiting, so I threw it out and haven't regretted it a second.
        The switch wasn't that difficult after getting the core mechanics in place.
        Much later when I was forced switching protocol format from XML to JSON, *not a single bit* changed in the API.
        
        Regards,
        Anders
        
        
        On 2019-05-29 16:43, Wheeler, David M wrote:
        > I am more in favor of a CBOR/CWT binding than JSON, although I agree that JSON and JWT is more commonly deployed at the moment.
        > 
        > The direction I think we should push this is toward CBOR. However, I think that it is fine to build JSON into the OTrP protocol spec and then have an alternative specification that provides CBOR bindings – I would be willing to work with Anders on a such a specification (after the arch document is complete 😉 ).
        > 
        > Thanks,
        > 
        > Dave Wheeler
        > 
        > *From:* TEEP <teep-bounces@ietf.org> *On Behalf Of *Hannes Tschofenig
        > *Sent:* Wednesday, May 29, 2019 7:35 AM
        > *To:* Dave Thaler <dthaler=40microsoft.com@dmarc.ietf.org>; Anders Rundgren <anders.rundgren.net@gmail.com>; Nancy Cam-Winget (ncamwing) <ncamwing@cisco.com>; teep@ietf.org
        > *Subject:* Re: [Teep] Call for adoption of draft-thaler-teep-otrp-over-http
        > 
        >   * The IoT market has adopted CBOR rather than JSON.
        > 
        >   * That’s a bit overstated, “IoT” is very broad and hence there are _/many/_ IoT “markets”, and many of them have not adopted CBOR. For example, if you look in industrial IoT, the dominant protocol is OPC UA, which uses neither CBOR nor JSON. In consumer IoT like in devices on shelves now, I think you will find that JSON is far more deployed than CBOR is (e.g., Hue light bulbs and many other IoT devices use JSON-over-HTTP). It is true that /some/ of the IoT market has adopted CBOR.  For example, OCF adopted CBOR, but OCF has very little actual deployment today.
        > 
        > I agree with Dave here. I think it is fair to say that the JWT has been implement and deployed by the Web community. Particularly in the OAuth context it is widely deployed.
        > 
        > CBOR has been suggested for IoT-related specifications but CBOR, COSE and CWT is definitely not widely implement and even less widely used.
        > 
        > The question I wonder is whether the current deployment status matters in our case and I don’t think it has any relationship to the call for adoption of draft-thaler-teep-otrp-over-http.
        > 
        > When the initial version of OTrP was written there was the assumption that the encoding of the protocol in JSON would be more convenient for Web developers given that the main deployment use case was for mobile phones and tablets.
        > 
        > Now, there is of course the question whether Web developers should be exposed to the details and the encoding of the OTrP protocol itself. I think that’s an important question. Afterall, we are trying to make the life of developers simpler with this work.
        > 
        > Since the formation of the TEEP group we have also added other use cases extending our original goals for OTrP. This makes me believe that it is worthwhile to look into a CBOR-based encoding as well. I also would like to take advance of ongoing working work in SUIT & RATS.
        > 
        > Ciao
        > Hannes
        > 
        > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
        > 
        
        _______________________________________________
        TEEP mailing list
        TEEP@ietf.org
        https://clicktime.symantec.com/39GgxxuNwUX4UT6LXHifmoH7Vc?u=https%3A%2F%2Fnam06.safelinks.protection.outlook.com%2F%3Furl%3Dhttps%253A%252F%252Fwww.ietf.org%252Fmailman%252Flistinfo%252Fteep%26data%3D02%257C01%257Cdthaler%2540microsoft.com%257C6e15170aecc640e93c7508d6ef6c85b8%257C72f988bf86f141af91ab2d7cd011db47%257C1%257C0%257C636959646713494087%26sdata%3DTiFDthL%252BxRuHOHfHH9hbed6mmLfKG8I5E6sdo4Tuu5M%253D%26reserved%3D0