Additional Media Type Structured Syntax Suffixes
draft-ietf-appsawg-media-type-suffix-regs-08
The information below is for an old version of the document that is already published as an RFC.
Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 6839.
|
|
---|---|---|---|
Authors | Tony Hansen , Alexey Melnikov | ||
Last updated | 2020-07-29 (Latest revision 2012-11-05) | ||
Replaces | draft-hansen-media-type-suffix-regs | ||
RFC stream | Internet Engineering Task Force (IETF) | ||
Intended RFC status | Informational | ||
Formats | |||
Reviews |
GENART Last Call review
by Martin Thomson
Ready w/nits
|
||
Additional resources | Mailing list discussion | ||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Murray Kucherawy | ||
Shepherd write-up | Show Last changed 2012-10-23 | ||
IESG | IESG state | Became RFC 6839 (Informational) | |
Action Holders |
(None)
|
||
Consensus boilerplate | Unknown | ||
Telechat date | (None) | ||
Responsible AD | Barry Leiba | ||
IESG note | |||
Send notices to | (None) |
draft-ietf-appsawg-media-type-suffix-regs-08
Network Working Group T. Hansen Internet-Draft AT&T Laboratories Updates: 3023 (if approved) A. Melnikov Intended status: Informational Isode Ltd Expires: May 9, 2013 November 5, 2012 Additional Media Type Structured Syntax Suffixes draft-ietf-appsawg-media-type-suffix-regs-08 Abstract A content media type name sometimes includes partitioned meta- information distinguish by a Structured Syntax, to permit noting an attribute of the media as a suffix to the name. This document defines several Structured Syntax Suffixes for use with media type registrations. In particular, it defines and registers the "+json", "+ber", "+der", "+fastinfoset", "+wbxml" and "+zip" Structured Syntax Suffixes, and provides a Message Type Structured Syntax Suffix registration form for the "+xml" Structured Syntax Suffix. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on May 9, 2013. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect Hansen & Melnikov Expires May 9, 2013 [Page 1] Internet-Draft Additional Media Type Suffixes November 2012 to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. When to Use these Structured Syntax Suffixes . . . . . . . . . 3 3. Initial Structured Syntax Suffix Definitions . . . . . . . . . 4 3.1. The +json Structured Syntax Suffix . . . . . . . . . . . . 4 3.2. The +ber Structured Syntax Suffixes . . . . . . . . . . . 5 3.3. The +der Structured Syntax Suffixes . . . . . . . . . . . 6 3.4. The +fastinfoset Structured Syntax Suffix . . . . . . . . 8 3.5. The +wbxml Structured Syntax Suffix . . . . . . . . . . . 9 3.6. The +zip Structured Syntax Suffix . . . . . . . . . . . . 10 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6.1. Normative References . . . . . . . . . . . . . . . . . . . 13 6.2. Informative References . . . . . . . . . . . . . . . . . . 14 Appendix A. Change History . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 Hansen & Melnikov Expires May 9, 2013 [Page 2] Internet-Draft Additional Media Type Suffixes November 2012 1. Introduction [RFC3023] created the +xml suffix convention that can be used when defining names for media types whose representation uses XML underneath. That is, they could have been successfully parsed as if the media type had been application/xml in addition to their being parsed as their media type that is using the +xml suffix. [I-D.ietf-appsawg-media-type-regs] defines the Message Type Structured Syntax Suffixes registry to be used for such Structured Syntax Suffixes. A variety of Structured Syntax Suffixes have already been used in some media type registrations, in particular "+json", "+der", "+fastinfoset" and "+wbxml". This document defines and registers these Structured Syntax Suffixes in the Structured Syntax Suffix registry, along with "+ber" and "+zip". In addition, this document updates [RFC3023] to formally register the "+xml" Structured Syntax Suffix according to procedure defined in [I-D.ietf-appsawg-media-type-regs]. Discussion of this document should occur in the Apps Area Working Group (apps-discuss@ietf.org). [RFC Editor note: remove this paragraph.] The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. When to Use these Structured Syntax Suffixes Each of the Structured Syntax Suffixes defined in this document is appropriate for use when the media type identifies the semantics of the protocol payload. That is, knowing the semantics of the specific media type provides for more specific processing of the content than that afforded by generic processing of the underlying representation. At the same time, using the suffix allows receivers of the media types to do generic processing of the underlying representation in cases where they do not need to perform special handling of the particular semantics of the exact media type, and, there is no special knowledge needed by such a generic processor in order to parse that underlying representation other than what would be needed to parse any example of that underlying representation. Hansen & Melnikov Expires May 9, 2013 [Page 3] Internet-Draft Additional Media Type Suffixes November 2012 3. Initial Structured Syntax Suffix Definitions 3.1. The +json Structured Syntax Suffix [RFC4627] defines the "application/json" media type. The suffix "+json" MAY be used with any media type whose representation follows that established for "application/json". The Message Type Structured Syntax Suffix registration form follows. See [I-D.ietf-appsawg-media-type-regs] for definitions of each of the registration form headings. Name: JavaScript Object Notation (JSON) +suffix: +json References: [RFC4627] Encoding considerations: Per [RFC4627], JSON is allowed to be represented using UTF-8, UTF-16, or UTF-32. When JSON is written in UTF-8, JSON is 8bit compatible ([RFC2045]). When JSON is written in UTF-16 or UTF-32, JSON is binary ([RFC2045]). Fragment identifier considerations: The syntax and semantics of fragment identifiers specified for +json SHOULD be as specified for "application/json". (At publication of this document, there is no fragment identification syntax defined for "application/json".) The syntax and semantics for fragment identifiers for a specific "xxx/yyy+json" SHOULD be processed as follows: For cases defined in +json, where the fragment identifier resolves per the +json rules, then as specified in +json. For cases defined in +json, where the fragment identifier does not resolve per the +json rules, then as specified in "xxx/ yyy+json". Hansen & Melnikov Expires May 9, 2013 [Page 4] Internet-Draft Additional Media Type Suffixes November 2012 For cases not defined in +json, then as specified in "xxx/yyy+json". Interoperability considerations: n/a Security considerations: See [RFC4627] Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 3.2. The +ber Structured Syntax Suffixes The ITU defined the Basic Encoding Rules (BER) message transfer syntax in [ITU.X690.2008]. The suffix "+ber" MAY be used with any media type whose representation follows the BER message transfer syntax. (The expert reviewer for Message Type Structured Syntax Suffix registrations ought to be aware of the relationship between BER and DER to aid in selecting the proper suffix.) The Message Type Structured Syntax Suffix registration form for +ber follows: Name: Basic Encoding Rules (BER) message transfer syntax +suffix: +ber References: [ITU.X690.2008] Encoding considerations: BER is a binary encoding. Fragment identifier considerations: At publication of this document, there is no fragment identification syntax defined for +ber. The syntax and semantics for fragment identifiers for a specific "xxx/yyy+ber" SHOULD be processed as follows: For cases defined in +ber, where the fragment identifier resolves per the +ber rules, then as specified in +ber. Hansen & Melnikov Expires May 9, 2013 [Page 5] Internet-Draft Additional Media Type Suffixes November 2012 For cases defined in +ber, where the fragment identifier does not resolve per the +ber rules, then as specified in "xxx/ yyy+ber". For cases not defined in +ber, then as specified in "xxx/yyy+ber". Interoperability considerations: n/a Security considerations: Each individual media type registered with a +ber suffix can have additional security considerations. BER has a type-length-value structure, and it is easy to construct malicious content with invalid length fields that can cause buffer overrun conditions. BER allows for arbitrary levels of nesting, which may make it possible to construct malicious content that will cause a stack overflow. Interpreters of the BER structures should be aware of these issues and should take appropriate measures to guard against buffer overflows and stack overruns in particular and malicious content in general. Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 3.3. The +der Structured Syntax Suffixes The ITU defined the Distinguished Encoding Rules (DER) message transfer syntax in [ITU.X690.2008]. The suffix "+der" MAY be used with any media type whose representation follows the DER message transfer syntax. (The expert reviewer for Message Type Structured Syntax Suffix registrations ought to be aware of the relationship between BER and DER to aid in selecting the proper suffix.) The Message Type Structured Syntax Suffix registration form for +der follows: Hansen & Melnikov Expires May 9, 2013 [Page 6] Internet-Draft Additional Media Type Suffixes November 2012 Name: Distinguished Encoding Rules (DER) message transfer syntax +suffix: +der References: [ITU.X690.2008] Encoding considerations: DER is a binary encoding. Fragment identifier considerations: At publication of this document, there is no fragment identification syntax defined for +der. The syntax and semantics for fragment identifiers for a specific "xxx/yyy+der" SHOULD be processed as follows: For cases defined in +der, where the fragment identifier resolves per the +der rules, then as specified in +der. For cases defined in +der, where the fragment identifier does not resolve per the +der rules, then as specified in "xxx/ yyy+der". For cases not defined in +der, then as specified in "xxx/yyy+der". Interoperability considerations: n/a Security considerations: Each individual media type registered with a +der suffix can have additional security considerations. DER has a type-length-value structure, and it is easy to construct malicious content with invalid length fields that can cause buffer overrun conditions. DER allows for arbitrary levels of nesting, which may make it possible to construct malicious content that will cause a stack overflow. Hansen & Melnikov Expires May 9, 2013 [Page 7] Internet-Draft Additional Media Type Suffixes November 2012 Interpreters of the DER structures should be aware of these issues and should take appropriate measures to guard against buffer overflows and stack overruns in particular and malicious content in general. Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 3.4. The +fastinfoset Structured Syntax Suffix The ITU defined the Fast Infoset document format as a binary representation of the XML Information Set in [ITU.X891.2005]. These documents further define the "application/fastinfoset" media type. The suffix "+fastinfoset" MAY be used with any media type whose representation follows that established for "application/ fastinfoset". The Message Type Structured Syntax Suffix registration form follows: Name: Fast Infoset document format +suffix: +fastinfoset References: [ITU.X891.2005] Encoding considerations: Fast Infoset is a binary encoding. The binary, quoted-printable and base64 content- transfer-encodings are suitable for use with Fast Infoset. Fragment identifier considerations: The syntax and semantics of fragment identifiers specified for +fastinfoset SHOULD be as specified for "application/fastinfoset". (At publication of this document, there is no fragment identification syntax defined for "application/fastinfoset".) The syntax and semantics for fragment identifiers for a specific "xxx/ yyy+fastinfoset" SHOULD be processed as follows: Hansen & Melnikov Expires May 9, 2013 [Page 8] Internet-Draft Additional Media Type Suffixes November 2012 For cases defined in +fastinfoset, where the fragment identifier resolves per the +fastinfoset rules, then as specified in +fastinfoset. For cases defined in +fastinfoset, where the fragment identifier does not resolve per the +fastinfoset rules, then as specified in "xxx/yyy+fastinfoset". For cases not defined in +fastinfoset, then as specified in "xxx/yyy+fastinfoset". Interoperability considerations: n/a Security considerations: There are no security considerations inherent in Fast Infoset. Each individual media type registered with a +fastinfoset suffix can have additional security considerations. Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 3.5. The +wbxml Structured Syntax Suffix The WAP Forum has defined the WAP Binary XML (WBXML) document format as a binary representation of XML in [WBXML]. This document further defines the "application/vnd.wap.wbxml" media type. The suffix "+wbxml" MAY be used with any media type whose representation follows that established for "application/vnd.wap.wbxml". The Message Type Structured Syntax Suffix registration form follows: Name: WAP Binary XML (WBXML) document format +suffix: +wbxml References: [WBXML] Encoding considerations: WBXML is a binary encoding. Fragment identifier considerations: The syntax and semantics of fragment identifiers specified for +wbxml SHOULD be as specified for "application/vnd.wap.wbxml". (At publication of this document, there is no Hansen & Melnikov Expires May 9, 2013 [Page 9] Internet-Draft Additional Media Type Suffixes November 2012 fragment identification syntax defined for "application/vnd.wap.wbxml".) The syntax and semantics for fragment identifiers for a specific "xxx/yyy+wbxml" SHOULD be processed as follows: For cases defined in +wbxml, where the fragment identifier resolves per the +wbxml rules, then as specified in +wbxml. For cases defined in +wbxml, where the fragment identifier does not resolve per the +wbxml rules, then as specified in "xxx/yyy+wbxml". For cases not defined in +wbxml, then as specified in "xxx/yyy+wbxml". Interoperability considerations: n/a Security considerations: There are no security considerations inherent in WBXML. Each individual media type registered with a +wbxml suffix can have additional security considerations. Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 3.6. The +zip Structured Syntax Suffix The ZIP format is a public domain, cross-platform, interoperable file storage and transfer format, originally defined by PKWARE, Inc.; it supports compression and encryption and is used as the underlying representation by a variety of file formats. The media type "application/zip" has been registered for such files. The suffix "+zip" MAY be used with any media type whose representation follows that established for "application/zip". The Message Type Structured Syntax Suffix registration form follows: Name: ZIP file storage and transfer format +suffix: +zip Hansen & Melnikov Expires May 9, 2013 [Page 10] Internet-Draft Additional Media Type Suffixes November 2012 References: [ZIP] Encoding considerations: ZIP is a binary encoding. Fragment identifier considerations: The syntax and semantics of fragment identifiers specified for +zip SHOULD be as specified for "application/zip". (At publication of this document, there is no fragment identification syntax defined for "application/zip".) The syntax and semantics for fragment identifiers for a specific "xxx/yyy+zip" SHOULD be processed as follows: For cases defined in +zip, where the fragment identifier resolves per the +zip rules, then as specified in +zip. For cases defined in +zip, where the fragment identifier does not resolve per the +zip rules, then as specified in "xxx/ yyy+zip". For cases not defined in +zip, then as specified in "xxx/yyy+zip". Interoperability considerations: n/a Security considerations: ZIP files support two forms of encryption: Strong Encryption and AES 128-bit, 192-bit and 256-bit encryption; see the specification for further details. Each individual media type registered with a +zip suffix can have additional security considerations. Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 4. IANA Considerations See the Message Type Structured Syntax Suffix registration forms in Section 3.1 - Section 3.6. Hansen & Melnikov Expires May 9, 2013 [Page 11] Internet-Draft Additional Media Type Suffixes November 2012 The following Structured Syntax Suffix registration for "+xml" shall be used to reflect the information found in [RFC3023], with the addition of fragment identifier considerations: Name: Extensible Markup Language (XML) +suffix: +xml References: [RFC3023] Encoding considerations: Per [RFC3023], XML is allowed to be represented using both 7-bit and 8-bit encodings. When XML is written in UTF-8, XML is 8bit compatible ([RFC2045]). When XML is written in UTF-16 or UTF-32, XML is binary ([RFC2045]). Fragment identifier considerations: The syntax and semantics of fragment identifiers specified for +xml SHOULD be as specified for "application/xml". (At publication of this document, the fragment identification syntax considerations for "application/xml" are defined in [RFC3023], sections 5 and 7.) The syntax and semantics for fragment identifiers for a specific "xxx/yyy+xml" SHOULD be processed as follows: For cases defined in +xml, where the fragment identifier resolves per the +xml rules, then as specified in +xml. For cases defined in +xml, where the fragment identifier does not resolve per the +xml rules, then as specified in "xxx/ yyy+xml". For cases not defined in +xml, then as specified in "xxx/yyy+xml". Interoperability considerations: See [RFC3023]. Security considerations: See [RFC3023] Hansen & Melnikov Expires May 9, 2013 [Page 12] Internet-Draft Additional Media Type Suffixes November 2012 Contact: Apps Area Working Group (apps-discuss@ietf.org) Author/Change controller: The Apps Area Working Group. IESG has change control over this registration. 5. Security Considerations See the Security considerations sections found in the Message Type Structured Syntax Suffix registration forms from Section 3.1 - Section 3.5. When updating a +<suffix> registration, care should be taken to review all previously-registered xxx/yyy+<suffix> media types as to whether they might be affected by the updated +<suffix> registration. Because the generic fragment identifier processing rules take precedence over media-type-specific rules, introducing new or changing existing definitions may break the existing registrations of specific media types, as well as particular implementations of applications that process affected media types. Such changes can introduce interoperability and security issues. When updating the fragment identifier processing rules for a specific xxx/yyy+<suffix> media type, care should be taken to review the generic fragment identifier processing rules for the +<suffix> registration and not introduce any conflicts. Because the generic fragment identifier processing rules take precedence over media-type- specific rules, such conflicting processing requirements should be ignored by an implementation, but such conflicts can introduce interoperability and security issues. Note that [FRAGID-BP] provides additional advice to designers of fragment identifier rules for media type suffixes and specific media types. 6. References 6.1. Normative References [RFC4627] Crockford, D., "The application/json Media Type for JavaScript Object Notation (JSON)", RFC 4627, July 2006. [ITU.X690.2008] International Telecommunications Union, "Recommendation ITU-T X.690 | ISO/IEC 8825-1 (2008), ASN.1 encoding rules: Specification of basic encoding Rules (BER), Canonical encoding rules (CER) and Distinguished encoding rules Hansen & Melnikov Expires May 9, 2013 [Page 13] Internet-Draft Additional Media Type Suffixes November 2012 (DER)", ITU-T Recommendation X.690, November 2008. [ITU.X891.2005] International Telecommunications Union, "Recommendation ITU-T X.891 | ISO/IEC 24824-1 (2007), Generic applications of ASN.1: Fast infoset", ITU-T Recommendation X.891, May 2005. [WBXML] Open Mobile Alliance, "Binary XML Content Format Specification", OMA Wireless Access Protocol WAP-192- WBXML-20010725-a, July 2001. [ZIP] PKWARE, Inc., "APPNOTE.TXT - .ZIP File Format Specification", PKWARE .ZIP File Format Specification - Version 6.3.2, September 2007. [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types", RFC 3023, January 2001. 6.2. Informative References [I-D.ietf-appsawg-media-type-regs] Freed, N., Klensin, J., and T. Hansen, "Media Type Specifications and Registration Procedures", draft-ietf-appsawg-media-type-regs-14 (work in progress), June 2012. [FRAGID-BP] Tennison, J., "Best Practices for Fragment Identifiers and Media Type Definitions", July 2012, <http://www.w3.org/TR/fragid-best-practices/>. Appendix A. Change History This section is to be removed before publication. draft-ietf-appsawg-media-type-suffix-regs-07 Added information based on IANA and GEN-ART reviews. Hansen & Melnikov Expires May 9, 2013 [Page 14] Internet-Draft Additional Media Type Suffixes November 2012 draft-ietf-appsawg-media-type-suffix-regs-06 Clarified why this document updates RFC 3023. draft-ietf-appsawg-media-type-suffix-regs-05 Added an Informative reference to http://www.w3.org/TR/fragid-best-practices/. Minor editorial changes. draft-ietf-appsawg-media-type-suffix-regs-03 Added generic fragment idenfier rules to +ber/+der to make them consistant with other registrations. Added some warning about how adding/changing fragment identifier rules for a +suffix can affect fragment identifier processing rules for previously registered xxx/yyy+suffix media types. draft-ietf-appsawg-media-type-suffix-regs-02 Added BER/DER security considerations. Reworked fragment identifier wording some more. draft-ietf-appsawg-media-type-suffix-regs-01 Reordered the sections. Cleaned up some MUSTard. Fixed some references. Added encoding considerations. Reworked fragment identifier wording. draft-ietf-appsawg-media-type-suffix-regs-00 Added the fragment identifier consideration sections. Added a note about +xml fragment identifier considerations. draft-hansen-media-type-suffix-regs-02 Added +zip. Fixed up the ISO document references. Minor changes. draft-hansen-media-type-suffix-regs-01 Added +ber. Minor changes. Hansen & Melnikov Expires May 9, 2013 [Page 15] Internet-Draft Additional Media Type Suffixes November 2012 Authors' Addresses Tony Hansen AT&T Laboratories 200 Laurel Ave. South Middletown, NJ 07748 USA Email: tony+sss@maillennium.att.com Alexey Melnikov Isode Ltd 5 Castle Business Village 36 Station Road Hampton, Middlesex TW12 2BX UK Email: Alexey.Melnikov@isode.com Hansen & Melnikov Expires May 9, 2013 [Page 16]