Akamai

mbishop@evequefou.be

art httpbis The ORIGIN frame for HTTP/2 is equally applicable to HTTP/3, but it needs to be separately registered. This document 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 .

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Table of Contents

• .  Introduction
  • .  Notational Conventions
• .  The ORIGIN HTTP/3 Frame
  • .  Frame Layout
• .  Security Considerations
• .  IANA Considerations
• .  References
  • .  Normative References
  • .  Informative References
• Author's Address

Introduction Existing RFCs define extensions to HTTP/2 that remain useful in HTTP/3. describes the required updates for HTTP/2 frames to be used with HTTP/3. defines the HTTP/2 ORIGIN frame, which indicates what origins are available on a given connection. It defines a single HTTP/2 frame type.

Notational Conventions 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 when, and only when, they appear in all capitals, as shown here. The frame diagram in this document uses the format defined in to illustrate the order and size of fields.

The ORIGIN HTTP/3 Frame The ORIGIN HTTP/3 frame allows a server to indicate what origin or origins the server would like the client to consider as one or more members of the Origin Set () for the connection within which it occurs. The semantics of the frame payload are identical to those of the HTTP/2 frame defined in . Where HTTP/2 reserves stream 0 for frames related to the state of the connection, HTTP/3 defines a pair of unidirectional streams called "control streams" for this purpose. Where indicates that the ORIGIN frame is sent on stream 0, this should be interpreted to mean the HTTP/3 control stream: that is, the ORIGIN frame is sent from servers to clients on the server's control stream. HTTP/3 does not define a Flags field in the generic frame layout. As no flags have been defined for the ORIGIN frame, this specification does not define a mechanism for communicating such flags in HTTP/3.

Frame Layout The ORIGIN frame has a layout that is nearly identical to the layout used in HTTP/2; the information is restated here for clarity. The ORIGIN frame type is 0x0c (decimal 12), as in HTTP/2. The payload contains zero or more instances of the Origin-Entry field.

ORIGIN Frame Layout HTTP/3 Origin-Entry { Origin-Len (16), ASCII-Origin (..), } HTTP/3 ORIGIN Frame { Type (i) = 0x0c, Length (i), Origin-Entry (..) ..., }

An Origin-Entry is a length-delimited string. Specifically, it contains 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 () that the sender asserts this connection is or could be authoritative for.

Security Considerations This document introduces no new security considerations beyond those discussed in and .

IANA Considerations This document registers a frame type in the "HTTP/3 Frame Types" registry defined by , located at .

Value:

0x0c

Frame Type:

ORIGIN

Status:

permanent

Reference:

Date:

2023-03-14

Change Controller:

IETF

Contact:

HTTP WG <ietf-http-wg@w3.org>

References Normative References This specification describes an optimized expression of the semantics of the Hypertext Transfer Protocol (HTTP), referred to as HTTP version 2 (HTTP/2). HTTP/2 enables a more efficient use of network resources and a reduced latency by introducing field compression and allowing multiple concurrent exchanges on the same connection. This document obsoletes RFCs 7540 and 8740. The QUIC transport protocol has several features that are desirable in a transport for HTTP, such as stream multiplexing, per-stream flow control, and low-latency connection establishment. This document describes a mapping of HTTP semantics over QUIC. This document also identifies HTTP/2 features that are subsumed by QUIC and describes how HTTP/2 extensions can be ported to HTTP/3. This document specifies the ORIGIN frame for HTTP/2, to indicate what origins are available on a given connection. In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. Informative References This document defines the core of the QUIC transport protocol. QUIC provides applications with flow-controlled streams for structured communication, low-latency connection establishment, and network path migration. QUIC includes security measures that ensure confidentiality, integrity, and availability in a range of deployment circumstances. Accompanying documents describe the integration of TLS for key negotiation, loss detection, and an exemplary congestion control algorithm. This document defines the concept of an "origin", which is often used as the scope of authority or privilege by user agents. Typically, user agents isolate content retrieved from different origins to prevent malicious web site operators from interfering with the operation of benign web sites. In addition to outlining the principles that underlie the concept of origin, this document details how to determine the origin of a URI and how to serialize an origin into a string. It also defines an HTTP header field, named "Origin", that indicates which origins are associated with an HTTP request. [STANDARDS-TRACK]

Author's Address Akamai

mbishop@evequefou.be