RFC 9412

The ORIGIN Extension in HTTP/3

📅 published June 2023, from ietf

The ORIGIN Extension in HTTP/3 🦋

Okay bestie, this is RFC 9412 from the IETF, titled The ORIGIN Extension in HTTP/3 🎀. It was written by Mike Bishop of Akamai, it's a Standards Track doc, and it was published in June 2023 (ISSN 2070-1721) ✨. The header has no "Obsoletes" or "Updates" line, so it doesn't replace or change anything listed there 💅.

Abstract

okay so the ORIGIN frame from HTTP/2 works just as well in HTTP/3 🫶 but it still needs its own registration, kind of like signing up separately for the same club 💅. This doc describes the ORIGIN frame for HTTP/3 ✨.

Status of This Memo

This is an Internet Standards Track document 🔥.

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). Further information on Internet Standards is available in 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 https://www.rfc-editor.org/info/rfc9412 🦋.

Copyright Notice

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 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License 📜.

Table of Contents 🧚

1.  Introduction
  1.1.  Notational Conventions
2.  The ORIGIN HTTP/3 Frame
  2.1.  Frame Layout
3.  Security Considerations
4.  IANA Considerations
5.  References
  5.1.  Normative References
  5.2.  Informative References
Author's Address

1. Introduction ✨

Okay so existing RFCs define extensions to HTTP/2 [HTTP/2] that are still super useful in HTTP/3 💜. Appendix A.2 of [HTTP/3] walks through the required updates for HTTP/2 frames to be used with HTTP/3 🍓.

[ORIGIN] defines the HTTP/2 ORIGIN frame, which tells you what origins are available on a given connection 👑. It defines a single HTTP/2 frame type, so it's a small but mighty one 💅.

1.1. Notational Conventions

Here's the key word situation 🎀. 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 🫶.

The frame diagram in this document uses the format defined in Section 1.3 of [QUIC-TRANSPORT] to show the order and size of fields 🧚.

2. The ORIGIN HTTP/3 Frame 🦋

The ORIGIN HTTP/3 frame lets a server say which origin or origins [RFC6454] it would like the client to treat as one or more members of the Origin Set (Section 2.3 of [ORIGIN]) for the connection it happens on 💖.

The semantics of the frame payload are identical to those of the HTTP/2 frame defined in [ORIGIN]. Where HTTP/2 reserves stream 0 for frames about the state of the connection, HTTP/3 defines a pair of unidirectional streams called "control streams" for that job 🌸.

Where [ORIGIN] says the ORIGIN frame is sent on stream 0, this should be interpreted to mean the HTTP/3 control stream. So basically, the ORIGIN frame goes from servers to clients on the server's control stream ✨.

HTTP/3 doesn't define a Flags field in the generic frame layout 🙈. Since no flags have been defined for the ORIGIN frame, this specification doesn't define a way to communicate flags in HTTP/3 💀.

2.1. Frame Layout

The ORIGIN frame's layout is nearly identical to the one used in HTTP/2, but we restate it here for clarity 🌈. The ORIGIN frame type is 0x0c (decimal 12), same as in HTTP/2 ⭐. The payload contains zero or more instances of the Origin-Entry field 💜.

HTTP/3 Origin-Entry {
  Origin-Len (16),
  ASCII-Origin (..),
}

HTTP/3 ORIGIN Frame {
  Type (i) = 0x0c,
  Length (i),
  Origin-Entry (..) ...,
}

                   Figure 1: ORIGIN Frame Layout

An Origin-Entry is a length-delimited string, and it has two fields 🫶:

Origin-Len: An unsigned, 16-bit integer indicating the length, in octets, of the ASCII-Origin field.
ASCII-Origin: An OPTIONAL sequence of characters containing the ASCII serialization of an origin ([RFC6454], Section 6.2) that the sender asserts this connection is or could be authoritative for 👑.

3. Security Considerations 🔥

🚨 Serious security moment, bestie: this document introduces no new security considerations beyond those discussed in [ORIGIN] and [HTTP/3]. Go check those two for the full picture 🙏.

4. IANA Considerations 🍓

This document registers a frame type in the "HTTP/3 Frame Types" registry defined by [HTTP/3], located at https://www.iana.org/assignments/http3-parameters/ ✨. The entry looks like this 💅:

Value:  0x0c
Frame Type:  ORIGIN
Status:  permanent
Reference:  Section 2
Date:  2023-03-14
Change Controller:  IETF
Contact:  HTTP WG <ietf-http-wg@w3.org>

5. References 📚

5.1. Normative References

[HTTP/2]   Thomson, M., Ed. and C. Benfield, Ed., "HTTP/2", RFC 9113,
           DOI 10.17487/RFC9113, June 2022,
           <https://www.rfc-editor.org/info/rfc9113>.

[HTTP/3]   Bishop, M., Ed., "HTTP/3", RFC 9114, DOI 10.17487/RFC9114,
           June 2022, <https://www.rfc-editor.org/info/rfc9114>.

[ORIGIN]   Nottingham, M. and E. Nygren, "The ORIGIN HTTP/2 Frame",
           RFC 8336, DOI 10.17487/RFC8336, March 2018,
           <https://www.rfc-editor.org/info/rfc8336>.

[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>.

5.2. Informative References

[QUIC-TRANSPORT]
           Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
           Multiplexed and Secure Transport", RFC 9000,
           DOI 10.17487/RFC9000, May 2021,
           <https://www.rfc-editor.org/info/rfc9000>.

[RFC6454]  Barth, A., "The Web Origin Concept", RFC 6454,
           DOI 10.17487/RFC6454, December 2011,
           <https://www.rfc-editor.org/info/rfc6454>.

Author's Address 💌

Mike Bishop
Akamai
Email: mbishop@evequefou.be

That's the whole RFC, bestie! 🌈💖 Go be a networking main character 👑✨

📦 where this page comes from

ietf: rfc9412 2023-06
💖 girlified by claude-haiku-5-5 on 2026-10-19: a language model's rewrite of the original, under its terms