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h2-websockets: apply AUTH48 changes #694

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122 changes: 68 additions & 54 deletions draft-ietf-httpbis-h2-websockets.md
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Expand Up @@ -32,36 +32,36 @@ over a single stream of an HTTP/2 connection.
# Introduction

The Hypertext Transfer Protocol (HTTP) {{!RFC7230}} provides compatible resource-level semantics
across different versions but it does not offer compatibility at the connection management
level. Other protocols, such as WebSockets, that rely on connection management details of HTTP must
across different versions, but it does not offer compatibility at the connection-management
level. Other protocols that rely on connection-management details of HTTP, such as WebSockets, must
be updated for new versions of HTTP.

The WebSocket Protocol {{!RFC6455}} uses the HTTP/1.1
Upgrade mechanism (Section 6.7 of {{!RFC7230}}) to transition a TCP connection from HTTP into a
WebSocket connection. A different approach must be taken with HTTP/2
{{!RFC7540}}. HTTP/2 does not allow connection-wide header fields and status
codes such as the Upgrade and Connection request header fields or the 101
(Switching Protocols) response code due to its multiplexing nature. These are all required
{{!RFC7540}}. Due to its multiplexing nature, HTTP/2 does not allow connection-wide header fields or status
codes, such as the Upgrade and Connection request-header fields or the 101
(Switching Protocols) response code. These are all required
by the {{!RFC6455}} opening handshake.

Being able to bootstrap WebSockets from HTTP/2 allows one TCP
connection to be shared by both protocols and extends HTTP/2's
more efficient use of the network to WebSockets.

This document extends the HTTP CONNECT method (as specified for HTTP/2 in Section 8.3 of
{{RFC7540}}). The extension allows the substitution of a new protocol name to connect to rather than
This document extends the HTTP CONNECT method, as specified for HTTP/2 in Section 8.3 of
{{RFC7540}}. The extension allows the substitution of a new protocol name to connect to rather than
the external host normally used by CONNECT. The result is a tunnel on a single HTTP/2 stream that
can carry data for WebSockets (or any other protocol). The other streams on the connection may carry
more extended CONNECT tunnels, traditional HTTP/2 data, or a mixture of both.

This tunneled stream will be multiplexed with other regular streams on
the connection and enjoys the normal priority, cancellation, and flow
control features of HTTP/2.
the connection and enjoys the normal priority, cancellation, and flow-control
features of HTTP/2.

Streams that successfully establish a WebSocket connection using a
tunneled stream and the modifications to the opening handshake defined
in this document then use the traditional WebSocket Protocol, treating
the stream as if were the TCP connection in that specification.
the stream as if it were the TCP connection in that specification.

# Terminology

Expand All @@ -73,24 +73,24 @@ appear in all capitals, as shown here.

# The SETTINGS_ENABLE_CONNECT_PROTOCOL SETTINGS Parameter

This document adds a new SETTINGS Parameter to those defined by
This document adds a new SETTINGS parameter to those defined by
{{!RFC7540}}, Section 6.5.2.

The new parameter name is SETTINGS_ENABLE_CONNECT_PROTOCOL. The value
of the parameter MUST be 0 or 1.

Upon receipt of SETTINGS_ENABLE_CONNECT_PROTOCOL with a value of 1, a client
MAY use the Extended CONNECT definition of this document when creating new
MAY use the Extended CONNECT as defined in this document when creating new
streams. Receipt of this parameter by a server does not have any
impact.

A sender MUST NOT send a SETTINGS_ENABLE_CONNECT_PROTOCOL parameter with the
value of 0 after previously sending a value of 1.

The use of a SETTINGS Parameter to opt-in to an otherwise incompatible
Using a SETTINGS parameter to opt into an otherwise incompatible
protocol change is a use of "Extending HTTP/2" defined by Section 5.5
of {{!RFC7540}}. Specifically, the addition a new pseudo-header field ":protocol" and the change in meaning
of the ":authority" pseudo-header field in {{method}} require opt-in negotiation. If a client were to use the provisions of the extended
of {{!RFC7540}}. Specifically, the addition a new pseudo-header field, ":protocol", and the change in meaning
of the :authority pseudo-header field in {{method}} require opt-in negotiation. If a client were to use the provisions of the extended
CONNECT method defined in this document without first receiving a
SETTINGS_ENABLE_CONNECT_PROTOCOL parameter, a non-supporting peer would
detect a malformed request and generate a stream error (Section
Expand All @@ -103,69 +103,69 @@ Usage of the CONNECT method in HTTP/2 is defined by Section 8.3 of

* A new pseudo-header field :protocol MAY be included on request HEADERS indicating the desired protocol
to be spoken on the tunnel created by CONNECT. The pseudo-header field is single valued and contains a
value from the HTTP Upgrade Token Registry located at
https://www.iana.org/assignments/http-upgrade-tokens/http-upgrade-tokens.xhtml
value from the "Hypertext Transfer Protocol (HTTP) Upgrade Token Registry" located at
\<https://www.iana.org/assignments/http-upgrade-tokens/\>

* On requests that contain the :protocol pseudo-header field, the :scheme and
:path pseudo-header fields of the target URI (See {{usingExtended}}) MUST also be included.
:path pseudo-header fields of the target URI (see {{usingExtended}}) MUST also be included.

* On requests bearing the :protocol pseudo-header field, the :authority
pseudo-header field is interpreted according to Section 8.1.2.3
of {{!RFC7540}} instead of Section 8.3 of {{!RFC7540}}. In particular, the server
of {{!RFC7540}} instead of Section 8.3 of that document. In particular, the server
MUST NOT create a tunnel to the host indicated by the :authority as it
would with a CONNECT method request that was not modified by this extension.

Upon receiving a CONNECT request bearing the :protocol pseudo-header field
Upon receiving a CONNECT request bearing the :protocol pseudo-header field,
the server establishes a tunnel to another service of the protocol
type indicated by the pseudo-header field. This service may or may not be
co-located with the server.

# Using Extended CONNECT To Bootstrap the WebSocket Protocol {#usingExtended}
# Using Extended CONNECT to Bootstrap the WebSocket Protocol {#usingExtended}

The :protocol pseudo-header field MUST be included in the CONNECT request
The :protocol pseudo-header field MUST be included in the CONNECT request,
and it MUST have a value of `websocket` to initiate a WebSocket
connection on an HTTP/2 stream. Other HTTP request and response
header fields, such as those for manipulating cookies, may be included in
connection on an HTTP/2 stream. Other HTTP request and response-header
fields, such as those for manipulating cookies, may be included in
the HEADERS with the CONNECT method as usual. This request replaces
the GET-based request in {{!RFC6455}} and is used to process the
WebSockets opening handshake.

The scheme of the target URI (Section 5.1 of {{!RFC7230}}) MUST be `https` for `wss` schemed
WebSockets and `http` for `ws` schemed WebSockets. The remainder of the Target URI is the same as
the websocket URI. The websocket URI is still used for proxy autoconfiguration. The security
The scheme of the target URI (Section 5.1 of {{!RFC7230}}) MUST be "https" for "wss"-schemed
WebSockets and "http" for "ws"-schemed WebSockets. The remainder of the target URI is the same as
the WebSocket URI. The WebSocket URI is still used for proxy autoconfiguration. The security
requirements for the HTTP/2 connection used by this specification are established by {{!RFC7540}}
for https requests and {{!RFC8164}} for http requests.

{{!RFC6455}} requires the use of Connection and Upgrade header fields that
are not part of HTTP/2. They MUST NOT be included in the CONNECT
request defined here.

{{!RFC6455}} requires the use of a Host header field which is also not part of
{{!RFC6455}} requires the use of a Host header field that is also not part of
HTTP/2. The Host information is conveyed as part of the :authority
pseudo-header field which is required on every HTTP/2 transaction.
pseudo-header field, which is required on every HTTP/2 transaction.

Implementations using this extended CONNECT to bootstrap WebSockets do
not do the processing of the {{!RFC6455}} Sec-WebSocket-Key and
Sec-WebSocket-Accept header fields as that functionality has been superseded
not do the processing of the Sec-WebSocket-Key and
Sec-WebSocket-Accept header fields of {{!RFC6455}} as that functionality has been superseded
by the :protocol pseudo-header field.

The Origin {{!RFC6454}}, Sec-WebSocket-Version, Sec-WebSocket-Protocol,
and Sec-WebSocket-Extensions header fields are used in the CONNECT request
and response header fields in the same way as defined in {{!RFC6455}}. Note
that HTTP/1 header field names were case-insensitive and HTTP/2 requires
they be encoded as lower case.
and response-header fields as defined in {{!RFC6455}}. Note
that HTTP/1 header field names were case insensitive, whereas HTTP/2 requires
they be encoded as lowercase.

After successfully processing the opening handshake, the peers should
proceed with the WebSocket Protocol {{!RFC6455}} using the HTTP/2
stream from the CONNECT transaction as if it were the TCP connection
referred to in {{!RFC6455}}. The state of the WebSocket connection at
this point is OPEN as defined by {{!RFC6455}}, Section 4.1.
this point is OPEN, as defined by {{!RFC6455}}, Section 4.1.

The HTTP/2 stream closure is also analogous to the TCP connection closure of
{{!RFC6455}}. Orderly TCP level closures are represented as END_STREAM
({{!RFC7540}}, Section 6.1) flags and RST exceptions are represented
with the RST_STREAM ({{!RFC7540}}, Section 6.4) frame with the CANCEL
({{!RFC7540}}, Section 7) error code.
{{!RFC6455}}. Orderly TCP-level closures are represented as END_STREAM
flags ({{!RFC7540}}, Section 6.1). RST exceptions are represented
with the RST_STREAM frame ({{!RFC7540}}, Section 6.4) with the CANCEL
error code ({{!RFC7540}}, Section 7).

## Example
~~~ example
Expand Down Expand Up @@ -210,8 +210,8 @@ HTTP/2 and WebSockets concurrently.

This document does not change how WebSockets interacts with HTTP forward
proxies. If a client wishing to speak WebSockets connects via HTTP/2
to an HTTP proxy it should continue to use a traditional (i.e. not with
a :protocol pseudo-header field) CONNECT to tunnel through that proxy to the
to an HTTP proxy, it should continue to use a traditional CONNECT (i.e., not with
a :protocol pseudo-header field) to tunnel through that proxy to the
WebSocket server via HTTP.

The resulting version of HTTP on that tunnel determines whether
Expand All @@ -221,34 +221,48 @@ described in this document.
# Security Considerations

{{!RFC6455}} ensures that non-WebSockets clients, especially
XMLHttpRequest based clients, cannot make a WebSocket connection. Its
primary mechanism for doing that is the use of Sec- prefixed request
header fields that cannot be created by XMLHttpRequest-based clients. This
XMLHttpRequest-based clients, cannot make a WebSocket connection. Its
primary mechanism for doing that is the use of Sec-prefixed request-header
fields that cannot be created by XMLHttpRequest-based clients. This
specification addresses that concern in two ways:

* XMLHttpRequest also prohibits use of the CONNECT method in addition to Sec- prefixed request
header fields.
* XMLHttpRequest also prohibits use of the CONNECT method in addition to Sec-prefixed request-header fields.

* The use of a pseudo-header field is something that is connection specific
and HTTP/2 does not ever allow to be created outside of the protocol stack.
* The use of a pseudo-header field is something that is connection specific,
and HTTP/2 never allows a pseudo-header to be created outside of the protocol stack.

The security considerations of {{!RFC6455}} section 10 continue to apply to the use of the WebSocket
Protocol when using this specification with the exception of 10.8. That section is not relevant
because it is specific to the boostrapping handshake that is changed in this document.
The security considerations of {{!RFC6455}}, Section 10 continue to apply to the use of the WebSocket
Protocol when using this specification, with the exception of 10.8. That section is not relevant,
because it is specific to the bootstrapping handshake that is changed in this document.

# IANA Considerations

This document establishes an entry for the HTTP/2 Settings Registry
that was established by Section 11.3 of {{!RFC7540}}.
## A New HTTP/2 Setting

Name: SETTINGS_ENABLE_CONNECT_PROTOCOL
This document registers an entry in the "HTTP/2 Settings" registry
that was established by Section 11.3 of {{!RFC7540}}.

Code: 0x8

Name: SETTINGS_ENABLE_CONNECT_PROTOCOL

Initial Value: 0

Specification: This document

## A New HTTP Upgrade Token

This document registers an entry in the "HTTP Upgrade Tokens" registry
that was established by {{!RFC7230}}.

Value: websocket

Description: The Web Socket Protocol

Expected Version Tokens:

References: {{RFC6455}} \[RFC8441\]

--- back

# Acknowledgments
Expand Down