HTTP/2 Extended SETTINGS Extension
draft-bishop-httpbis-extended-settings-01

Document Type Active Internet-Draft (individual)
Last updated 2016-11-15
Stream (None)
Intended RFC status (None)
Formats plain text xml pdf html bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
HTTPbis                                                        M. Bishop
Internet-Draft                                                 Microsoft
Intended status: Informational                         November 15, 2016
Expires: May 19, 2017

                   HTTP/2 Extended SETTINGS Extension
               draft-bishop-httpbis-extended-settings-01

Abstract

   HTTP/2 defines the SETTINGS frame to contain a single 32-bit value
   per setting.  While this is sufficient to convey everything used in
   the core HTTP/2 specification, some protocols will require more
   complex values, such as arrays of code-points or strings.

   For such protocols, this extension defines a parallel to the SETTINGS
   frame, EXTENDED_SETTINGS, where the value of a setting is not a
   32-bit value, but a variable-length opaque data blob whose
   interpretation is subject entirely to the definition of the protocol
   using it.

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 19, 2017.

Copyright Notice

   Copyright (c) 2016 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

Bishop                    Expires May 19, 2017                  [Page 1]
Internet-Draft              EXTENDED_SETTINGS              November 2016

   carefully, as they describe your rights and restrictions with respect
   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Detection of Support  . . . . . . . . . . . . . . . . . . . .   3
   3.  Extension Frame Types . . . . . . . . . . . . . . . . . . . .   3
     3.1.  EXTENDED_SETTINGS Frame . . . . . . . . . . . . . . . . .   3
       3.1.1.  EXTENDED_SETTINGS Format  . . . . . . . . . . . . . .   4
     3.2.  EXTENDED_SETTINGS_ACK Frame . . . . . . . . . . . . . . .   5
   4.  Settings Synchronization  . . . . . . . . . . . . . . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
     6.1.  Signature Methods . . . . . . . . . . . . . . . . . . . .   6
     6.2.  HTTP/2 SETTINGS_HTTP_CERT_AUTH Setting  . . . . . . . . .   6
     6.3.  New HTTP/2 Frames . . . . . . . . . . . . . . . . . . . .   7
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   In [I-D.bishop-httpbis-http2-additional-certs], values for which IANA
   registries already exist must be communicated between two HTTP/2
   implementations.  Since the SETTINGS frame constrains setting values
   to a 32-bit value, the existing version of that draft divides the
   32-bit value into halves and dedicates bits to each currently-known
   value.  This requires the creation of two duplicative IANA
   registries, and enormously constrains future extensibility since each
   future supported value will consume one of only sixteen bits.  It
   also causes divergence from other places in the protocol where a
   bitmask is not required and a more sensible value can be used.

   [MS-HTTP2E], likewise, defines a very limited bitmap in the 32-bit
   value - two bits are defined, all others are reserved (and not
   useful).  The setting fits easily in a single byte, and need not
   consume a four-byte value every time it is transferred.

   Alternately, a number of recent and in-progress HTTP/2 extensions
   describe properties of the connection that are informative to the
   peer ([RFC7838], [I-D.ietf-httpbis-origin-frame]).  These are
Show full document text