Upgrading to TLS Within HTTP/1.1
RFC 2817
| Document | Type |
RFC - Proposed Standard
(May 2000; Errata)
Updates RFC 2616
|
|
|---|---|---|---|
| Last updated | 2013-03-02 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 2817 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Network Working Group R. Khare
Request for Comments: 2817 4K Associates / UC Irvine
Updates: 2616 S. Lawrence
Category: Standards Track Agranat Systems, Inc.
May 2000
Upgrading to TLS Within HTTP/1.1
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2000). All Rights Reserved.
Abstract
This memo explains how to use the Upgrade mechanism in HTTP/1.1 to
initiate Transport Layer Security (TLS) over an existing TCP
connection. This allows unsecured and secured HTTP traffic to share
the same well known port (in this case, http: at 80 rather than
https: at 443). It also enables "virtual hosting", so a single HTTP +
TLS server can disambiguate traffic intended for several hostnames at
a single IP address.
Since HTTP/1.1 [1] defines Upgrade as a hop-by-hop mechanism, this
memo also documents the HTTP CONNECT method for establishing end-to-
end tunnels across HTTP proxies. Finally, this memo establishes new
IANA registries for public HTTP status codes, as well as public or
private Upgrade product tokens.
This memo does NOT affect the current definition of the 'https' URI
scheme, which already defines a separate namespace
(http://example.org/ and https://example.org/ are not equivalent).
Khare & Lawrence Standards Track [Page 1]
RFC 2817 HTTP Upgrade to TLS May 2000
Table of Contents
1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Requirements Terminology . . . . . . . . . . . . . . . . . . . 4
3. Client Requested Upgrade to HTTP over TLS . . . . . . . . . . 4
3.1 Optional Upgrade . . . . . . . . . . . . . . . . . . . . . . . 4
3.2 Mandatory Upgrade . . . . . . . . . . . . . . . . . . . . . . 4
3.3 Server Acceptance of Upgrade Request . . . . . . . . . . . . . 4
4. Server Requested Upgrade to HTTP over TLS . . . . . . . . . . 5
4.1 Optional Advertisement . . . . . . . . . . . . . . . . . . . . 5
4.2 Mandatory Advertisement . . . . . . . . . . . . . . . . . . . 5
5. Upgrade across Proxies . . . . . . . . . . . . . . . . . . . . 6
5.1 Implications of Hop By Hop Upgrade . . . . . . . . . . . . . . 6
5.2 Requesting a Tunnel with CONNECT . . . . . . . . . . . . . . . 6
5.3 Establishing a Tunnel with CONNECT . . . . . . . . . . . . . . 7
6. Rationale for the use of a 4xx (client error) Status Code . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
7.1 HTTP Status Code Registry . . . . . . . . . . . . . . . . . . 8
7.2 HTTP Upgrade Token Registry . . . . . . . . . . . . . . . . . 8
8. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8.1 Implications for the https: URI Scheme . . . . . . . . . . . . 10
8.2 Security Considerations for CONNECT . . . . . . . . . . . . . 10
References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 11
A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
Full Copyright Statement . . . . . . . . . . . . . . . . . . . 13
1. Motivation
The historical practice of deploying HTTP over SSL3 [3] has
distinguished the combination from HTTP alone by a unique URI scheme
and the TCP port number. The scheme 'http' meant the HTTP protocol
alone on port 80, while 'https' meant the HTTP protocol over SSL on
port 443. Parallel well-known port numbers have similarly been
requested -- and in some cases, granted -- to distinguish between
secured and unsecured use of other application protocols (e.g.
snews, ftps). This approach effectively halves the number of
available well known ports.
At the Washington DC IETF meeting in December 1997, the Applications
Area Directors and the IESG reaffirmed that the practice of issuing
parallel "secure" port numbers should be deprecated. The HTTP/1.1
Upgrade mechanism can apply Transport Layer Security [6] to an open
HTTP connection.
Khare & Lawrence Standards Track [Page 2]
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