draft-ietf-httpbis-h2-websockets-05.txt   draft-ietf-httpbis-h2-websockets-06.txt 
HTTP P. McManus HTTP P. McManus
Internet-Draft Mozilla Internet-Draft Mozilla
Updates: 6455 (if approved) May 6, 2018 Updates: 6455 (if approved) May 31, 2018
Intended status: Standards Track Intended status: Standards Track
Expires: November 7, 2018 Expires: December 2, 2018
Bootstrapping WebSockets with HTTP/2 Bootstrapping WebSockets with HTTP/2
draft-ietf-httpbis-h2-websockets-05 draft-ietf-httpbis-h2-websockets-06
Abstract Abstract
This document defines a mechanism for running the WebSocket Protocol This document defines a mechanism for running the WebSocket Protocol
(RFC 6455) over a single stream of an HTTP/2 connection. (RFC 6455) over a single stream of an HTTP/2 connection.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on November 7, 2018. This Internet-Draft will expire on December 2, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. The SETTINGS_ENABLE_CONNECT_PROTOCOL SETTINGS Parameter . . . 3 3. The SETTINGS_ENABLE_CONNECT_PROTOCOL SETTINGS Parameter . . . 3
4. The Extended CONNECT Method . . . . . . . . . . . . . . . . . 3 4. The Extended CONNECT Method . . . . . . . . . . . . . . . . . 4
5. Using Extended CONNECT To Bootstrap The WebSocket Protocol . 4 5. Using Extended CONNECT To Bootstrap the WebSocket Protocol . 4
5.1. Example . . . . . . . . . . . . . . . . . . . . . . . . . 5 5.1. Example . . . . . . . . . . . . . . . . . . . . . . . . . 5
6. Design Considerations . . . . . . . . . . . . . . . . . . . . 5 6. Design Considerations . . . . . . . . . . . . . . . . . . . . 6
7. About Intermediaries . . . . . . . . . . . . . . . . . . . . 6 7. About Intermediaries . . . . . . . . . . . . . . . . . . . . 6
8. Security Considerations . . . . . . . . . . . . . . . . . . . 6 8. Security Considerations . . . . . . . . . . . . . . . . . . . 7
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
10. Normative References . . . . . . . . . . . . . . . . . . . . 6 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7 10.1. Normative References . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7 10.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
The Hypertext Transfer Protocol (HTTP) provides compatible resource- The Hypertext Transfer Protocol (HTTP) [RFC7230] provides compatible
level semantics across different versions but it does not offer resource-level semantics across different versions but it does not
compatibility at the connection management level. Other protocols, offer compatibility at the connection management level. Other
such as WebSockets, that rely on connection management details of protocols, such as WebSockets, that rely on connection management
HTTP must be updated for new versions of HTTP. details of HTTP must be updated for new versions of HTTP.
The WebSocket Protocol [RFC6455] uses the HTTP/1.1 [RFC7230] Upgrade The WebSocket Protocol [RFC6455] uses the HTTP/1.1 Upgrade mechanism
mechanism to transition a TCP connection from HTTP into a WebSocket (Section 6.7 of [RFC7230]) to transition a TCP connection from HTTP
connection. A different approach must be taken with HTTP/2 into a WebSocket connection. A different approach must be taken with
[RFC7540]. HTTP/2 does not allow connection-wide headers and status HTTP/2 [RFC7540]. HTTP/2 does not allow connection-wide headers and
codes such as the Upgrade and Connection request headers or the 101 status codes such as the Upgrade and Connection request headers or
response code due to its multiplexing nature. These are all required the 101 response code due to its multiplexing nature. These are all
by the [RFC6455] opening handshake. required by the [RFC6455] opening handshake.
Being able to bootstrap WebSockets from HTTP/2 allows one TCP Being able to bootstrap WebSockets from HTTP/2 allows one TCP
connection to be shared by both protocols and extends HTTP/2's more connection to be shared by both protocols and extends HTTP/2's more
efficient use of the network to WebSockets. efficient use of the network to WebSockets.
This document extends the HTTP/2 CONNECT method. The extension This document extends the HTTP CONNECT method (as specified for
allows the substitution of a new protocol name to connect to rather HTTP/2 in Section 8.3 of [RFC7540]). The extension allows the
than the external host normally used by CONNECT. The result is a substitution of a new protocol name to connect to rather than the
tunnel on a single HTTP/2 stream that can carry data for WebSockets external host normally used by CONNECT. The result is a tunnel on a
(or any other protocol). The other streams on the connection may single HTTP/2 stream that can carry data for WebSockets (or any other
carry more extended CONNECT tunnels, traditional HTTP/2 data, or a protocol). The other streams on the connection may carry more
mixture of both. extended CONNECT tunnels, traditional HTTP/2 data, or a mixture of
both.
This tunneled stream will be multiplexed with other regular streams This tunneled stream will be multiplexed with other regular streams
on the connection and enjoys the normal priority, cancellation, and on the connection and enjoys the normal priority, cancellation, and
flow control features of HTTP/2. flow control features of HTTP/2.
Streams that successfully establish a WebSocket connection using a Streams that successfully establish a WebSocket connection using a
tunneled stream and the modifications to the opening handshake tunneled stream and the modifications to the opening handshake
defined in this document then use the traditional WebSocket Protocol, defined in this document then use the traditional WebSocket Protocol,
treating the stream as if were the TCP connection in that treating the stream as if were the TCP connection in that
specification. specification.
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Upon receipt of SETTINGS_ENABLE_CONNECT_PROTOCOL with a value of 1, a Upon receipt of SETTINGS_ENABLE_CONNECT_PROTOCOL with a value of 1, a
client MAY use the Extended CONNECT definition of this document when client MAY use the Extended CONNECT definition of this document when
creating new streams. Receipt of this parameter by a server does not creating new streams. Receipt of this parameter by a server does not
have any impact. have any impact.
A sender MUST NOT send a SETTINGS_ENABLE_CONNECT_PROTOCOL parameter A sender MUST NOT send a SETTINGS_ENABLE_CONNECT_PROTOCOL parameter
with the value of 0 after previously sending a value of 1. with the value of 0 after previously sending a value of 1.
The use of a SETTINGS Parameter to opt-in to an otherwise The use of a SETTINGS Parameter to opt-in to an otherwise
incompatible protocol change is a use of "Extending HTTP/2" defined incompatible protocol change is a use of "Extending HTTP/2" defined
by Section 5.5 of [RFC7540]. If a client were to use the provisions by Section 5.5 of [RFC7540]. Specifically, the addition a new
of the extended CONNECT method defined in this document without first pseudo-header ":protocol" and the change in meaning of the
receiving a SETTINGS_ENABLE_CONNECT_PROTOCOL parameter, a non- ":authority" pseudo-header in Section 4 require opt-in negotiation.
supporting peer would detect a malformed request and generate a If a client were to use the provisions of the extended CONNECT method
stream error (Section 8.1.2.6 of [RFC7540]). 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 8.1.2.6 of [RFC7540]).
4. The Extended CONNECT Method 4. The Extended CONNECT Method
Usage of the CONNECT method in HTTP/2 is defined by Section 8.3 of Usage of the CONNECT method in HTTP/2 is defined by Section 8.3 of
[RFC7540]. This extension modifies the method in the following ways: [RFC7540]. This extension modifies the method in the following ways:
o A new pseudo-header :protocol MAY be included on request HEADERS o A new pseudo-header :protocol MAY be included on request HEADERS
indicating the desired protocol to be spoken on the tunnel created indicating the desired protocol to be spoken on the tunnel created
by CONNECT. The pseudo-header is single valued and contains a by CONNECT. The pseudo-header is single valued and contains a
value from the HTTP Upgrade Token Registry defined by [RFC7230]. value from the HTTP Upgrade Token Registry located at
https://www.iana.org/assignments/http-upgrade-tokens/http-upgrade-
tokens.xhtml [1].
o On requests bearing the :protocol pseudo-header, the :scheme and o On requests bearing the :protocol pseudo-header, the :scheme and
:path pseudo-header fields MUST be included. :path pseudo-header fields MUST be included.
o On requests bearing the :protocol pseudo-header, the :authority o On requests bearing the :protocol pseudo-header, the :authority
pseudo-header field is interpreted according to Section 8.1.2.3 of pseudo-header field is interpreted according to Section 8.1.2.3 of
[RFC7540] instead of Section 8.3 of [RFC7540]. In particular the [RFC7540] instead of Section 8.3 of [RFC7540]. In particular the
server MUST NOT make a new TCP connection to the host and port server MUST NOT make a new TCP connection to the host and port
indicated by the :authority. indicated by the :authority.
Upon receiving a CONNECT request bearing the :protocol pseudo-header Upon receiving a CONNECT request bearing the :protocol pseudo-header
the server establishes a tunnel to another service of the protocol the server establishes a tunnel to another service of the protocol
type indicated by the pseudo-header. This service may or may not be type indicated by the pseudo-header. This service may or may not be
co-located with the server. co-located with the server.
5. Using Extended CONNECT To Bootstrap The WebSocket Protocol 5. Using Extended CONNECT To Bootstrap the WebSocket Protocol
The pseudo-header :protocol MUST be included in the CONNECT request The pseudo-header :protocol MUST be included in the CONNECT request
and it MUST have a value of "websocket" to initiate a WebSocket and it MUST have a value of "websocket" to initiate a WebSocket
connection on an HTTP/2 stream. Other HTTP request and response connection on an HTTP/2 stream. Other HTTP request and response
headers, such as those for manipulating cookies, may be included in headers, such as those for manipulating cookies, may be included in
the HEADERS with the CONNECT method as usual. This request replaces the HEADERS with the CONNECT method as usual. This request replaces
the GET-based request in [RFC6455] and is used to process the the GET-based request in [RFC6455] and is used to process the
WebSockets opening handshake. WebSockets opening handshake.
The scheme of the Target URI [RFC7230] MUST be "https" for "wss" The scheme of the Target URI (Section 5.1 of [RFC7230]) MUST be
schemed WebSockets and "http" for "ws" schemed WebSockets. The "https" for "wss" schemed WebSockets and "http" for "ws" schemed
websocket URI is still used for proxy autoconfiguration. WebSockets. The websocket URI is still used for proxy
autoconfiguration.
[RFC6455] requires the use of Connection and Upgrade headers that are [RFC6455] requires the use of Connection and Upgrade headers that are
not part of HTTP/2. They MUST NOT be included in the CONNECT request not part of HTTP/2. They MUST NOT be included in the CONNECT request
defined here. defined here.
[RFC6455] requires the use of a Host header which is also not part of [RFC6455] requires the use of a Host header which is also not part of
HTTP/2. The Host information is conveyed as part of the :authority HTTP/2. The Host information is conveyed as part of the :authority
pseudo-header which is required on every HTTP/2 transaction. pseudo-header which is required on every HTTP/2 transaction.
Implementations using this extended CONNECT to bootstrap WebSockets Implementations using this extended CONNECT to bootstrap WebSockets
do not do the processing of the [RFC6455] Sec-WebSocket-Key and Sec- do not do the processing of the [RFC6455] Sec-WebSocket-Key and Sec-
WebSocket-Accept headers as that functionality has been superseded by WebSocket-Accept headers as that functionality has been superseded by
the :protocol pseudo-header. the :protocol pseudo-header.
The Sec-WebSocket-Version, Origin [RFC6454], Sec-WebSocket-Protocol, The Origin [RFC6454], Sec-WebSocket-Version, Sec-WebSocket-Protocol,
and Sec-WebSocket-Extensions headers are used on the CONNECT request and Sec-WebSocket-Extensions headers are used on the CONNECT request
and response headers in the same way as defined in [RFC6455]. Note and response headers in the same way as defined in [RFC6455]. Note
that HTTP/1 header names were case-insensitive and HTTP/2 requires that HTTP/1 header names were case-insensitive and HTTP/2 requires
they be encoded as lower case. they be encoded as lower case.
After successfully processing the opening handshake, the peers should After successfully processing the opening handshake, the peers should
proceed with The WebSocket Protocol [RFC6455] using the HTTP/2 stream proceed with the WebSocket Protocol [RFC6455] using the HTTP/2 stream
from the CONNECT transaction as if it were the TCP connection from the CONNECT transaction as if it were the TCP connection
referred to in [RFC6455]. The state of the WebSocket connection at 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 of The HTTP/2 stream closure is also analogous to the TCP connection of
[RFC6455]. Orderly TCP level closures are represented as END_STREAM [RFC6455]. Orderly TCP level closures are represented as END_STREAM
([RFC7540], Section 6.1) flags and RST exceptions are represented ([RFC7540], Section 6.1) flags and RST exceptions are represented
with the RST_STREAM ([RFC7540], Section 6.4) frame with the CANCEL with the RST_STREAM ([RFC7540], Section 6.4) frame with the CANCEL
([RFC7540], Section 7) error code. ([RFC7540], Section 7) error code.
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described in this document. described in this document.
8. Security Considerations 8. Security Considerations
[RFC6455] ensures that non-WebSockets clients, especially [RFC6455] ensures that non-WebSockets clients, especially
XMLHttpRequest based clients, cannot make a WebSocket connection. XMLHttpRequest based clients, cannot make a WebSocket connection.
Its primary mechanism for doing that is the use of Sec- prefixed Its primary mechanism for doing that is the use of Sec- prefixed
request headers that cannot be created by XMLHttpRequest-based request headers that cannot be created by XMLHttpRequest-based
clients. This specification addresses that concern in two ways: clients. This specification addresses that concern in two ways:
o The CONNECT method is prohibited from being used by XMLHttpRequest o XMLHttpRequest also prohibits use of the CONNECT method in
addition to Sec- prefixed request headers.
o The use of a pseudo-header is something that is connection o The use of a pseudo-header is something that is connection
specific and HTTP/2 does not ever allow to be created outside of specific and HTTP/2 does not ever allow to be created outside of
the protocol stack. the protocol stack.
9. IANA Considerations 9. IANA Considerations
This document establishes an entry for the HTTP/2 Settings Registry This document establishes an entry for the HTTP/2 Settings Registry
that was established by Section 11.3 of [RFC7540]. that was established by Section 11.3 of [RFC7540].
Name: SETTINGS_ENABLE_CONNECT_PROTOCOL Name: SETTINGS_ENABLE_CONNECT_PROTOCOL
Code: 0x8 Code: 0x8
Initial Value: 0 Initial Value: 0
Specification: This document Specification: This document
10. Normative References 10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC6454] Barth, A., "The Web Origin Concept", RFC 6454, [RFC6454] Barth, A., "The Web Origin Concept", RFC 6454,
DOI 10.17487/RFC6454, December 2011, DOI 10.17487/RFC6454, December 2011,
<https://www.rfc-editor.org/info/rfc6454>. <https://www.rfc-editor.org/info/rfc6454>.
skipping to change at page 7, line 27 skipping to change at page 8, line 19
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext [RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540, Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015, DOI 10.17487/RFC7540, May 2015,
<https://www.rfc-editor.org/info/rfc7540>. <https://www.rfc-editor.org/info/rfc7540>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
10.2. URIs
[1] https://www.iana.org/assignments/http-upgrade-tokens/http-
upgrade-tokens.xhtml
Acknowledgments Acknowledgments
The 2017 HTTP Workshop had a very productive discussion that helped The 2017 HTTP Workshop had a very productive discussion that helped
determine the key problem and acceptable level of solution determine the key problem and acceptable level of solution
complexity. complexity.
Author's Address Author's Address
Patrick McManus Patrick McManus
Mozilla Mozilla
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