Internet DRAFT - draft-bedford-app-importmap-media-reg
draft-bedford-app-importmap-media-reg
Network Working Group G. Bedford, Ed.
Internet-Draft Verve Interactive Pty Ltd
Intended status: Informational November 17, 2019
Expires: May 20, 2020
application/importmap+json MIME Type Registration
draft-bedford-app-importmap-media-reg-00
Abstract
Media type registration for JSON import map definitions that control
the behavior of JavaScript imports.
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
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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 20, 2020.
Copyright Notice
Copyright (c) 2019 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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
2. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Security Considerations . . . . . . . . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
4.1. The application/importmap+json Media Type . . . . . . . . 3
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
6. Normative References . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
This memo defines a media type Section 4.1 for application/
importmap+json.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Example
An example application.importmap, following the import maps
specification (https://wicg.github.io/import-maps/) can be written:
{
"imports": {
"pkg": "/lib/pkg/main.js"
}
}
This would support the following workflow in browsers:
<script type="importmap" src="/application.importmap"></script>
<script type="module">
// loads /lib/pkg/main.js
import pkg from 'pkg';
</script>
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3. Security Considerations
The following security considerations apply when using application/
importmap+json: Control of the import map should be considered to be
a form of execution-level application control. This is because
import maps have the ability to direct which module resolutions are
to be provided for all module import specifiers in a given JavaScript
environment, including for example the ability to map arbitrary
import specifiers into data: URLs. Integration with existing policy
systems, such as CORS and CSP, can be used to mitigate and restrict
unwanted target URLs from being executed. The import maps
specification states that only those import maps served to browsers
with the `application/importmap+json` MIME type will be executed
allowing for server-level control of import map deployment to
mitigate unintended usage in browsers.
4. IANA Considerations
This document defines a single action for IANA:
4.1. The application/importmap+json Media Type
The application/importmap+json Media Type is defined as follows:
Type name: application
Subtype name: importmap+json
Required parameters: none
Optional parameters: none
Encoding considerations: 8bit (always UTF-8)
Security considerations: discussed in Section 3 of [RFCXXXX].
Interoperability considerations: none
Published specification: https://wicg.github.io/import-maps/
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Applications that use this media type: This is primarily a browser-
specific media type but may also be adopted in
other JavaScript environments.
Fragment identifier considerations: N/A
Additional information:
Deprecated alias names for this type: N/A
Magic number(s): none
File extension(s): .importmap
Macintosh file type code(s): Same as for
application/json
Person & email address to contact for further information: WICG
Mailing List <public-wicg@w3.org> or at import
maps GitHub repository https://github.com/WICG/
import-maps
Intended usage: COMMON
Restrictions on usage: No restrictions apply.
Author: See the Authors' Addresses section of [RFCXXXX]
Change controller: WHATWG
Provisional registration? yes
5. Acknowledgements
Thanks to Domenic Denicola for their work in specifying import maps
and the browser integration of JavaScript modules.
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6. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", STD 90, RFC 8259,
DOI 10.17487/RFC8259, December 2017,
<https://www.rfc-editor.org/info/rfc8259>.
[W3C.WD-CSP3]
Kesteren, A., "Content Security Policy Level 3", World
Wide Web Consortium CR WD-CSP3, February 2019,
<https://w3c.github.io/webappsec-csp/>.
[WHATWG-fetch]
Kesteren, A., "Fetch Standard - CORS Protocol", WHATWG
Living Standard WHATWG-fetch, October 2019,
<https://fetch.spec.whatwg.org/#cors-protocol>.
Author's Address
Guy Bedford (editor)
Verve Interactive Pty Ltd
19 Garfield Road
Cape Town, Western Cape 7708
South Africa
Email: guybedford@gmail.com
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