Internet Engineering Task Force (IETF) E. Wilde
Request for Comments: 8091 CA Technologies
Category: Informational February 2017
ISSN: 2070-1721
A Media Type Structured Syntax Suffix for JSON Text Sequences
Abstract
Structured syntax suffixes for media types allow other media types to
build on them and make it explicit that they are built on an existing
media type as their foundation. This specification defines and
registers "+json-seq" as a structured syntax suffix for JSON text
sequences.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8091.
Copyright Notice
Copyright (c) 2017 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
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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
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. The "+json-seq" Structured Syntax Suffix . . . . . . . . . . 2
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
6.1. Normative References . . . . . . . . . . . . . . . . . . 4
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
Media type structured syntax suffixes [RFC6838] were introduced as a
way for a media type to signal that it is based on another media type
as its foundation. Some structured syntax suffixes were registered
initially [RFC6839], including "+json", for the widely popular JSON
format [RFC7159].
JSON text sequences [RFC7464] is a recent specification in the JSON
space that defines how a sequence of multiple JSON texts can be
represented in one representation. This document defines and
registers the "+json-seq" structured syntax suffix in the "Structured
Syntax Suffix Registry".
2. Terminology
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].
3. The "+json-seq" Structured Syntax Suffix
The use case for the "+json-seq" structured syntax suffix is the same
as for "+json": It SHOULD be used by media types when parsing the
JSON text sequence of a media type leads to a meaningful result, by
simply using the generic JSON text sequence processing.
Applications encountering such a media type can then either simply
use generic processing if all they need is a generic view of the JSON
text sequence, or they can use generic JSON text sequence tools for
initial parsing and then implement their own specific processing on
top of that generic parsing tool.
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4. IANA Considerations
Structured Syntax Suffixes are registered within the "Structured
Syntax Suffix Registry" maintained at
<https://www.iana.org/assignments/media-type-structured-suffix>.
IANA has registered the "+json-seq" structured syntax suffix in
accordance with [RFC6838].
Name: JSON Text Sequence
+suffix: +json-seq
References: [RFC7464], RFC 8091
Encoding considerations: See [RFC7464] Section 2.2
Fragment identifier considerations: The syntax and semantics of
fragment identifiers specified for +json-seq SHOULD be as
specified for "application/json-seq". (At publication of this
document, there is no fragment identification syntax defined for
"application/json-seq".)
The syntax and semantics for fragment identifiers for a
specific "xxx/yyy+json-seq" SHOULD be processed as follows:
For cases defined in +json-seq, where the fragment
identifier resolves per the +json-seq rules, then process as
specified in +json-seq.
For cases defined in +json-seq, where the fragment
identifier does not resolve per the +json-seq rules, then
process as specified in "xxx/yyy+json-seq".
For cases not defined in +json-seq, then process as
specified in "xxx/yyy+json-seq".
Interoperability considerations: n/a
Security considerations: See [RFC7464] Section 3
Contact: Applications and Real-Time Area Discussion
(art@ietf.org), or any IESG-designated successor.
Author/Change controller: The Applications and Real-Time Area
Working Group. IESG has change control over this registration.
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5. Security Considerations
All the security considerations of JSON text sequences [RFC7464]
apply. They are as follows:
All the security considerations of JSON [RFC7159] apply. This format
provides no cryptographic integrity protection of any kind.
As usual, parsers must operate on input that is assumed to be
untrusted. This means that parsers must fail gracefully in the face
of malicious inputs.
Note that incremental JSON text parsers can produce partial results
and later indicate failure to parse the remainder of a text. A
sequence parser that uses an incremental JSON text parser might treat
a sequence like '<RS>"foo"<LF>456<LF><RS>' as a sequence of one
element ("foo"), while a sequence parser that uses a non-incremental
JSON text parser might treat the same sequence as being empty. This
effect, and texts that fail to parse and are ignored, can be used to
smuggle data past sequence parsers that don't warn about JSON text
failures.
Repeated parsing and re-encoding of a JSON text sequence can result
in the addition (or stripping) of trailing LF bytes from (to)
individual sequence element JSON texts. This can break signature
validation. JSON has no canonical form for JSON texts, therefore
neither does the JSON text sequence format.
6. References
6.1. 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,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13,
RFC 6838, DOI 10.17487/RFC6838, January 2013,
<http://www.rfc-editor.org/info/rfc6838>.
[RFC7464] Williams, N., "JavaScript Object Notation (JSON) Text
Sequences", RFC 7464, DOI 10.17487/RFC7464, February 2015,
<http://www.rfc-editor.org/info/rfc7464>.
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6.2. Informative References
[RFC6839] Hansen, T. and A. Melnikov, "Additional Media Type
Structured Syntax Suffixes", RFC 6839,
DOI 10.17487/RFC6839, January 2013,
<http://www.rfc-editor.org/info/rfc6839>.
[RFC7159] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
2014, <http://www.rfc-editor.org/info/rfc7159>.
Acknowledgements
Thanks for comments and suggestions provided by Ben Campbell, Allan
Doyle, Warren Kumari, Sean Leonard, Alexey Melnikov, Brian Raymor,
and Peter Yee.
Author's Address
Erik Wilde
CA Technologies
Email: erik.wilde@dret.net
URI: http://dret.net/netdret/
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