draft-ietf-httpbis-p3-payload-07.txt | draft-ietf-httpbis-p3-payload-08.txt | |||
---|---|---|---|---|
HTTPbis Working Group R. Fielding, Ed. | HTTPbis Working Group R. Fielding, Ed. | |||
Internet-Draft Day Software | Internet-Draft Day Software | |||
Obsoletes: 2616 (if approved) J. Gettys | Obsoletes: 2616 (if approved) J. Gettys | |||
Intended status: Standards Track One Laptop per Child | Intended status: Standards Track One Laptop per Child | |||
Expires: January 14, 2010 J. Mogul | Expires: April 29, 2010 J. Mogul | |||
HP | HP | |||
H. Frystyk | H. Frystyk | |||
Microsoft | Microsoft | |||
L. Masinter | L. Masinter | |||
Adobe Systems | Adobe Systems | |||
P. Leach | P. Leach | |||
Microsoft | Microsoft | |||
T. Berners-Lee | T. Berners-Lee | |||
W3C/MIT | W3C/MIT | |||
Y. Lafon, Ed. | Y. Lafon, Ed. | |||
W3C | W3C | |||
J. Reschke, Ed. | J. Reschke, Ed. | |||
greenbytes | greenbytes | |||
July 13, 2009 | October 26, 2009 | |||
HTTP/1.1, part 3: Message Payload and Content Negotiation | HTTP/1.1, part 3: Message Payload and Content Negotiation | |||
draft-ietf-httpbis-p3-payload-07 | draft-ietf-httpbis-p3-payload-08 | |||
Status of this Memo | Status of this Memo | |||
This Internet-Draft is submitted to IETF in full conformance with the | This Internet-Draft is submitted to IETF in full conformance with the | |||
provisions of BCP 78 and BCP 79. This document may contain material | provisions of BCP 78 and BCP 79. This document may contain material | |||
from IETF Documents or IETF Contributions published or made publicly | from IETF Documents or IETF Contributions published or made publicly | |||
available before November 10, 2008. The person(s) controlling the | available before November 10, 2008. The person(s) controlling the | |||
copyright in some of this material may not have granted the IETF | copyright in some of this material may not have granted the IETF | |||
Trust the right to allow modifications of such material outside the | Trust the right to allow modifications of such material outside the | |||
IETF Standards Process. Without obtaining an adequate license from | IETF Standards Process. Without obtaining an adequate license from | |||
skipping to change at page 2, line 10 | skipping to change at page 2, line 10 | |||
Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
The list of current Internet-Drafts can be accessed at | The list of current Internet-Drafts can be accessed at | |||
http://www.ietf.org/ietf/1id-abstracts.txt. | http://www.ietf.org/ietf/1id-abstracts.txt. | |||
The list of Internet-Draft Shadow Directories can be accessed at | The list of Internet-Draft Shadow Directories can be accessed at | |||
http://www.ietf.org/shadow.html. | http://www.ietf.org/shadow.html. | |||
This Internet-Draft will expire on January 14, 2010. | This Internet-Draft will expire on April 29, 2010. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2009 IETF Trust and the persons identified as the | Copyright (c) 2009 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 in effect on the date of | Provisions Relating to IETF Documents in effect on the date of | |||
publication of this document (http://trustee.ietf.org/license-info). | publication of this document (http://trustee.ietf.org/license-info). | |||
Please review these documents carefully, as they describe your rights | Please review these documents carefully, as they describe your rights | |||
skipping to change at page 2, line 41 | skipping to change at page 2, line 41 | |||
HTTP message content, metadata, and content negotiation. | HTTP message content, metadata, and content negotiation. | |||
Editorial Note (To be removed by RFC Editor) | Editorial Note (To be removed by RFC Editor) | |||
Discussion of this draft should take place on the HTTPBIS working | Discussion of this draft should take place on the HTTPBIS working | |||
group mailing list (ietf-http-wg@w3.org). The current issues list is | group mailing list (ietf-http-wg@w3.org). The current issues list is | |||
at <http://tools.ietf.org/wg/httpbis/trac/report/11> and related | at <http://tools.ietf.org/wg/httpbis/trac/report/11> and related | |||
documents (including fancy diffs) can be found at | documents (including fancy diffs) can be found at | |||
<http://tools.ietf.org/wg/httpbis/>. | <http://tools.ietf.org/wg/httpbis/>. | |||
The changes in this draft are summarized in Appendix E.8. | The changes in this draft are summarized in Appendix E.9. | |||
Table of Contents | Table of Contents | |||
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 5 | 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 5 | 1.2. Requirements . . . . . . . . . . . . . . . . . . . . . . . 6 | |||
1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 6 | 1.3. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 6 | |||
1.2.2. ABNF Rules defined in other Parts of the | 1.3.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 6 | |||
1.3.2. ABNF Rules defined in other Parts of the | ||||
Specification . . . . . . . . . . . . . . . . . . . . 6 | Specification . . . . . . . . . . . . . . . . . . . . 6 | |||
2. Protocol Parameters . . . . . . . . . . . . . . . . . . . . . 6 | 2. Protocol Parameters . . . . . . . . . . . . . . . . . . . . . 7 | |||
2.1. Character Sets . . . . . . . . . . . . . . . . . . . . . . 6 | 2.1. Character Sets . . . . . . . . . . . . . . . . . . . . . . 7 | |||
2.1.1. Missing Charset . . . . . . . . . . . . . . . . . . . 7 | 2.1.1. Missing Charset . . . . . . . . . . . . . . . . . . . 8 | |||
2.2. Content Codings . . . . . . . . . . . . . . . . . . . . . 7 | 2.2. Content Codings . . . . . . . . . . . . . . . . . . . . . 8 | |||
2.2.1. Content Coding Registry . . . . . . . . . . . . . . . 9 | ||||
2.3. Media Types . . . . . . . . . . . . . . . . . . . . . . . 9 | 2.3. Media Types . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
2.3.1. Canonicalization and Text Defaults . . . . . . . . . . 9 | 2.3.1. Canonicalization and Text Defaults . . . . . . . . . . 10 | |||
2.3.2. Multipart Types . . . . . . . . . . . . . . . . . . . 10 | 2.3.2. Multipart Types . . . . . . . . . . . . . . . . . . . 11 | |||
2.4. Language Tags . . . . . . . . . . . . . . . . . . . . . . 11 | 2.4. Language Tags . . . . . . . . . . . . . . . . . . . . . . 11 | |||
3. Entity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 | 3. Entity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 | |||
3.1. Entity Header Fields . . . . . . . . . . . . . . . . . . . 12 | 3.1. Entity Header Fields . . . . . . . . . . . . . . . . . . . 12 | |||
3.2. Entity Body . . . . . . . . . . . . . . . . . . . . . . . 12 | 3.2. Entity Body . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
3.2.1. Type . . . . . . . . . . . . . . . . . . . . . . . . . 12 | 3.2.1. Type . . . . . . . . . . . . . . . . . . . . . . . . . 13 | |||
3.2.2. Entity Length . . . . . . . . . . . . . . . . . . . . 13 | 3.2.2. Entity Length . . . . . . . . . . . . . . . . . . . . 13 | |||
4. Content Negotiation . . . . . . . . . . . . . . . . . . . . . 13 | 4. Content Negotiation . . . . . . . . . . . . . . . . . . . . . 14 | |||
4.1. Server-driven Negotiation . . . . . . . . . . . . . . . . 14 | 4.1. Server-driven Negotiation . . . . . . . . . . . . . . . . 14 | |||
4.2. Agent-driven Negotiation . . . . . . . . . . . . . . . . . 15 | 4.2. Agent-driven Negotiation . . . . . . . . . . . . . . . . . 15 | |||
4.3. Transparent Negotiation . . . . . . . . . . . . . . . . . 15 | 4.3. Transparent Negotiation . . . . . . . . . . . . . . . . . 16 | |||
5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 16 | 5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 16 | |||
5.1. Accept . . . . . . . . . . . . . . . . . . . . . . . . . . 16 | 5.1. Accept . . . . . . . . . . . . . . . . . . . . . . . . . . 17 | |||
5.2. Accept-Charset . . . . . . . . . . . . . . . . . . . . . . 18 | 5.2. Accept-Charset . . . . . . . . . . . . . . . . . . . . . . 19 | |||
5.3. Accept-Encoding . . . . . . . . . . . . . . . . . . . . . 19 | 5.3. Accept-Encoding . . . . . . . . . . . . . . . . . . . . . 20 | |||
5.4. Accept-Language . . . . . . . . . . . . . . . . . . . . . 20 | 5.4. Accept-Language . . . . . . . . . . . . . . . . . . . . . 21 | |||
5.5. Content-Encoding . . . . . . . . . . . . . . . . . . . . . 22 | 5.5. Content-Encoding . . . . . . . . . . . . . . . . . . . . . 23 | |||
5.6. Content-Language . . . . . . . . . . . . . . . . . . . . . 23 | 5.6. Content-Language . . . . . . . . . . . . . . . . . . . . . 23 | |||
5.7. Content-Location . . . . . . . . . . . . . . . . . . . . . 24 | 5.7. Content-Location . . . . . . . . . . . . . . . . . . . . . 24 | |||
5.8. Content-MD5 . . . . . . . . . . . . . . . . . . . . . . . 24 | 5.8. Content-MD5 . . . . . . . . . . . . . . . . . . . . . . . 25 | |||
5.9. Content-Type . . . . . . . . . . . . . . . . . . . . . . . 26 | 5.9. Content-Type . . . . . . . . . . . . . . . . . . . . . . . 26 | |||
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 | 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27 | |||
6.1. Message Header Registration . . . . . . . . . . . . . . . 26 | 6.1. Message Header Registration . . . . . . . . . . . . . . . 27 | |||
7. Security Considerations . . . . . . . . . . . . . . . . . . . 27 | 6.2. Content Coding Registry . . . . . . . . . . . . . . . . . 27 | |||
7.1. Privacy Issues Connected to Accept Headers . . . . . . . . 27 | 7. Security Considerations . . . . . . . . . . . . . . . . . . . 28 | |||
7.2. Content-Disposition Issues . . . . . . . . . . . . . . . . 28 | 7.1. Privacy Issues Connected to Accept Headers . . . . . . . . 28 | |||
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28 | 7.2. Content-Disposition Issues . . . . . . . . . . . . . . . . 29 | |||
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28 | 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 29 | |||
9.1. Normative References . . . . . . . . . . . . . . . . . . . 28 | 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 29 | |||
9.2. Informative References . . . . . . . . . . . . . . . . . . 30 | 9.1. Normative References . . . . . . . . . . . . . . . . . . . 29 | |||
9.2. Informative References . . . . . . . . . . . . . . . . . . 31 | ||||
Appendix A. Differences Between HTTP Entities and RFC 2045 | Appendix A. Differences Between HTTP Entities and RFC 2045 | |||
Entities . . . . . . . . . . . . . . . . . . . . . . 31 | Entities . . . . . . . . . . . . . . . . . . . . . . 32 | |||
A.1. MIME-Version . . . . . . . . . . . . . . . . . . . . . . . 31 | A.1. MIME-Version . . . . . . . . . . . . . . . . . . . . . . . 32 | |||
A.2. Conversion to Canonical Form . . . . . . . . . . . . . . . 32 | A.2. Conversion to Canonical Form . . . . . . . . . . . . . . . 33 | |||
A.3. Conversion of Date Formats . . . . . . . . . . . . . . . . 32 | A.3. Conversion of Date Formats . . . . . . . . . . . . . . . . 33 | |||
A.4. Introduction of Content-Encoding . . . . . . . . . . . . . 32 | A.4. Introduction of Content-Encoding . . . . . . . . . . . . . 33 | |||
A.5. No Content-Transfer-Encoding . . . . . . . . . . . . . . . 33 | A.5. No Content-Transfer-Encoding . . . . . . . . . . . . . . . 34 | |||
A.6. Introduction of Transfer-Encoding . . . . . . . . . . . . 33 | A.6. Introduction of Transfer-Encoding . . . . . . . . . . . . 34 | |||
A.7. MHTML and Line Length Limitations . . . . . . . . . . . . 33 | A.7. MHTML and Line Length Limitations . . . . . . . . . . . . 34 | |||
Appendix B. Additional Features . . . . . . . . . . . . . . . . . 33 | Appendix B. Additional Features . . . . . . . . . . . . . . . . . 34 | |||
B.1. Content-Disposition . . . . . . . . . . . . . . . . . . . 34 | B.1. Content-Disposition . . . . . . . . . . . . . . . . . . . 35 | |||
Appendix C. Compatibility with Previous Versions . . . . . . . . 34 | Appendix C. Compatibility with Previous Versions . . . . . . . . 35 | |||
C.1. Changes from RFC 2068 . . . . . . . . . . . . . . . . . . 34 | C.1. Changes from RFC 2068 . . . . . . . . . . . . . . . . . . 35 | |||
C.2. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 35 | C.2. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 36 | |||
Appendix D. Collected ABNF . . . . . . . . . . . . . . . . . . . 35 | Appendix D. Collected ABNF . . . . . . . . . . . . . . . . . . . 36 | |||
Appendix E. Change Log (to be removed by RFC Editor before | Appendix E. Change Log (to be removed by RFC Editor before | |||
publication) . . . . . . . . . . . . . . . . . . . . 37 | publication) . . . . . . . . . . . . . . . . . . . . 38 | |||
E.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 37 | E.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 38 | |||
E.2. Since draft-ietf-httpbis-p3-payload-00 . . . . . . . . . . 37 | E.2. Since draft-ietf-httpbis-p3-payload-00 . . . . . . . . . . 38 | |||
E.3. Since draft-ietf-httpbis-p3-payload-01 . . . . . . . . . . 38 | E.3. Since draft-ietf-httpbis-p3-payload-01 . . . . . . . . . . 39 | |||
E.4. Since draft-ietf-httpbis-p3-payload-02 . . . . . . . . . . 38 | E.4. Since draft-ietf-httpbis-p3-payload-02 . . . . . . . . . . 39 | |||
E.5. Since draft-ietf-httpbis-p3-payload-03 . . . . . . . . . . 39 | E.5. Since draft-ietf-httpbis-p3-payload-03 . . . . . . . . . . 40 | |||
E.6. Since draft-ietf-httpbis-p3-payload-04 . . . . . . . . . . 39 | E.6. Since draft-ietf-httpbis-p3-payload-04 . . . . . . . . . . 40 | |||
E.7. Since draft-ietf-httpbis-p3-payload-05 . . . . . . . . . . 39 | E.7. Since draft-ietf-httpbis-p3-payload-05 . . . . . . . . . . 40 | |||
E.8. Since draft-ietf-httpbis-p3-payload-06 . . . . . . . . . . 40 | E.8. Since draft-ietf-httpbis-p3-payload-06 . . . . . . . . . . 41 | |||
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 | E.9. Since draft-ietf-httpbis-p3-payload-07 . . . . . . . . . . 41 | |||
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 42 | Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 | |||
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 44 | ||||
1. Introduction | 1. Introduction | |||
This document defines HTTP/1.1 message payloads (a.k.a., content), | This document defines HTTP/1.1 message payloads (a.k.a., content), | |||
the associated metadata header fields that define how the payload is | the associated metadata header fields that define how the payload is | |||
intended to be interpreted by a recipient, the request header fields | intended to be interpreted by a recipient, the request header fields | |||
that may influence content selection, and the various selection | that may influence content selection, and the various selection | |||
algorithms that are collectively referred to as HTTP content | algorithms that are collectively referred to as HTTP content | |||
negotiation. | negotiation. | |||
This document is currently disorganized in order to minimize the | This document is currently disorganized in order to minimize the | |||
changes between drafts and enable reviewers to see the smaller errata | changes between drafts and enable reviewers to see the smaller errata | |||
changes. The next draft will reorganize the sections to better | changes. The next draft will reorganize the sections to better | |||
reflect the content. In particular, the sections on entities will be | reflect the content. In particular, the sections on entities will be | |||
renamed payload and moved to the first half of the document, while | renamed payload and moved to the first half of the document, while | |||
the sections on content negotiation and associated request header | the sections on content negotiation and associated request header | |||
fields will be moved to the second half. The current mess reflects | fields will be moved to the second half. The current mess reflects | |||
how widely dispersed these topics and associated requirements had | how widely dispersed these topics and associated requirements had | |||
become in [RFC2616]. | become in [RFC2616]. | |||
1.1. Requirements | 1.1. Terminology | |||
This specification uses a number of terms to refer to the roles | ||||
played by participants in, and objects of, the HTTP communication. | ||||
content negotiation | ||||
The mechanism for selecting the appropriate representation when | ||||
servicing a request. The representation of entities in any | ||||
response can be negotiated (including error responses). | ||||
entity | ||||
The information transferred as the payload of a request or | ||||
response. An entity consists of metadata in the form of entity- | ||||
header fields and content in the form of an entity-body. | ||||
representation | ||||
An entity included with a response that is subject to content | ||||
negotiation. There may exist multiple representations associated | ||||
with a particular response status. | ||||
variant | ||||
A resource may have one, or more than one, representation(s) | ||||
associated with it at any given instant. Each of these | ||||
representations is termed a `variant'. Use of the term `variant' | ||||
does not necessarily imply that the resource is subject to content | ||||
negotiation. | ||||
1.2. Requirements | ||||
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | |||
document are to be interpreted as described in [RFC2119]. | document are to be interpreted as described in [RFC2119]. | |||
An implementation is not compliant if it fails to satisfy one or more | An implementation is not compliant if it fails to satisfy one or more | |||
of the MUST or REQUIRED level requirements for the protocols it | of the MUST or REQUIRED level requirements for the protocols it | |||
implements. An implementation that satisfies all the MUST or | implements. An implementation that satisfies all the MUST or | |||
REQUIRED level and all the SHOULD level requirements for its | REQUIRED level and all the SHOULD level requirements for its | |||
protocols is said to be "unconditionally compliant"; one that | protocols is said to be "unconditionally compliant"; one that | |||
satisfies all the MUST level requirements but not all the SHOULD | satisfies all the MUST level requirements but not all the SHOULD | |||
level requirements for its protocols is said to be "conditionally | level requirements for its protocols is said to be "conditionally | |||
compliant." | compliant." | |||
1.2. Syntax Notation | 1.3. Syntax Notation | |||
This specification uses the ABNF syntax defined in Section 1.2 of | This specification uses the ABNF syntax defined in Section 1.2 of | |||
[Part1] (which extends the syntax defined in [RFC5234] with a list | [Part1] (which extends the syntax defined in [RFC5234] with a list | |||
rule). Appendix D shows the collected ABNF, with the list rule | rule). Appendix D shows the collected ABNF, with the list rule | |||
expanded. | expanded. | |||
The following core rules are included by reference, as defined in | The following core rules are included by reference, as defined in | |||
[RFC5234], Appendix B.1: ALPHA (letters), CR (carriage return), CRLF | [RFC5234], Appendix B.1: ALPHA (letters), CR (carriage return), CRLF | |||
(CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double quote), | (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double quote), | |||
HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any 8-bit | HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any 8-bit | |||
sequence of data), SP (space), VCHAR (any visible USASCII character), | sequence of data), SP (space), VCHAR (any visible USASCII character), | |||
and WSP (whitespace). | and WSP (whitespace). | |||
1.2.1. Core Rules | 1.3.1. Core Rules | |||
The core rules below are defined in Section 1.2.2 of [Part1]: | The core rules below are defined in Section 1.2.2 of [Part1]: | |||
quoted-string = <quoted-string, defined in [Part1], Section 1.2.2> | quoted-string = <quoted-string, defined in [Part1], Section 1.2.2> | |||
token = <token, defined in [Part1], Section 1.2.2> | token = <token, defined in [Part1], Section 1.2.2> | |||
OWS = <OWS, defined in [Part1], Section 1.2.2> | OWS = <OWS, defined in [Part1], Section 1.2.2> | |||
1.2.2. ABNF Rules defined in other Parts of the Specification | 1.3.2. ABNF Rules defined in other Parts of the Specification | |||
The ABNF rules below are defined in other parts: | The ABNF rules below are defined in other parts: | |||
absolute-URI = <absolute-URI, defined in [Part1], Section 2.1> | absolute-URI = <absolute-URI, defined in [Part1], Section 2.6> | |||
Content-Length = <Content-Length, defined in [Part1], Section 8.2> | Content-Length = <Content-Length, defined in [Part1], Section 9.2> | |||
message-header = <message-header, defined in [Part1], Section 4.2> | header-field = <header-field, defined in [Part1], Section 3.2> | |||
partial-URI = <partial-URI, defined in [Part1], Section 2.1> | partial-URI = <partial-URI, defined in [Part1], Section 2.6> | |||
qvalue = <qvalue, defined in [Part1], Section 3.5> | qvalue = <qvalue, defined in [Part1], Section 6.4> | |||
Last-Modified = <Last-Modified, defined in [Part4], Section 6.6> | Last-Modified = <Last-Modified, defined in [Part4], Section 6.6> | |||
Content-Range = <Content-Range, defined in [Part5], Section 5.2> | Content-Range = <Content-Range, defined in [Part5], Section 5.2> | |||
Expires = <Expires, defined in [Part6], Section 3.3> | Expires = <Expires, defined in [Part6], Section 3.3> | |||
2. Protocol Parameters | 2. Protocol Parameters | |||
2.1. Character Sets | 2.1. Character Sets | |||
skipping to change at page 8, line 16 | skipping to change at page 8, line 46 | |||
content-coding = token | content-coding = token | |||
All content-coding values are case-insensitive. HTTP/1.1 uses | All content-coding values are case-insensitive. HTTP/1.1 uses | |||
content-coding values in the Accept-Encoding (Section 5.3) and | content-coding values in the Accept-Encoding (Section 5.3) and | |||
Content-Encoding (Section 5.5) header fields. Although the value | Content-Encoding (Section 5.5) header fields. Although the value | |||
describes the content-coding, what is more important is that it | describes the content-coding, what is more important is that it | |||
indicates what decoding mechanism will be required to remove the | indicates what decoding mechanism will be required to remove the | |||
encoding. | encoding. | |||
The Internet Assigned Numbers Authority (IANA) acts as a registry for | ||||
content-coding value tokens. Initially, the registry contains the | ||||
following tokens: | ||||
gzip | ||||
An encoding format produced by the file compression program "gzip" | ||||
(GNU zip) as described in [RFC1952]. This format is a Lempel-Ziv | ||||
coding (LZ77) with a 32 bit CRC. | ||||
compress | compress | |||
The encoding format produced by the common UNIX file compression | See Section 6.2.2.1 of [Part1]. | |||
program "compress". This format is an adaptive Lempel-Ziv-Welch | ||||
coding (LZW). | ||||
Use of program names for the identification of encoding formats is | ||||
not desirable and is discouraged for future encodings. Their use | ||||
here is representative of historical practice, not good design. | ||||
For compatibility with previous implementations of HTTP, | ||||
applications SHOULD consider "x-gzip" and "x-compress" to be | ||||
equivalent to "gzip" and "compress" respectively. | ||||
deflate | deflate | |||
See Section 6.2.2.2 of [Part1]. | ||||
The "zlib" format defined in [RFC1950] in combination with the | gzip | |||
"deflate" compression mechanism described in [RFC1951]. | ||||
See Section 6.2.2.3 of [Part1]. | ||||
identity | identity | |||
The default (identity) encoding; the use of no transformation | The default (identity) encoding; the use of no transformation | |||
whatsoever. This content-coding is used only in the Accept- | whatsoever. This content-coding is used only in the Accept- | |||
Encoding header, and SHOULD NOT be used in the Content-Encoding | Encoding header, and SHOULD NOT be used in the Content-Encoding | |||
header. | header. | |||
New content-coding value tokens SHOULD be registered; to allow | 2.2.1. Content Coding Registry | |||
interoperability between clients and servers, specifications of the | ||||
content coding algorithms needed to implement a new value SHOULD be | The HTTP Content Coding Registry defines the name space for the | |||
publicly available and adequate for independent implementation, and | content coding names. | |||
conform to the purpose of content coding defined in this section. | ||||
Registrations MUST include the following fields: | ||||
o Name | ||||
o Description | ||||
o Pointer to specification text | ||||
Values to be added to this name space require expert review and a | ||||
specification (see "Expert Review" and "Specification Required" in | ||||
Section 4.1 of [RFC5226]), and MUST conform to the purpose of content | ||||
coding defined in this section. | ||||
The registry itself is maintained at | ||||
<http://www.iana.org/assignments/http-parameters>. | ||||
2.3. Media Types | 2.3. Media Types | |||
HTTP uses Internet Media Types [RFC2046] in the Content-Type | HTTP uses Internet Media Types [RFC2046] in the Content-Type | |||
(Section 5.9) and Accept (Section 5.1) header fields in order to | (Section 5.9) and Accept (Section 5.1) header fields in order to | |||
provide open and extensible data typing and type negotiation. | provide open and extensible data typing and type negotiation. | |||
media-type = type "/" subtype *( OWS ";" OWS parameter ) | media-type = type "/" subtype *( OWS ";" OWS parameter ) | |||
type = token | type = token | |||
subtype = token | subtype = token | |||
skipping to change at page 11, line 17 | skipping to change at page 11, line 48 | |||
behavior as a MIME user agent would upon receipt of a multipart type. | behavior as a MIME user agent would upon receipt of a multipart type. | |||
If an application receives an unrecognized multipart subtype, the | If an application receives an unrecognized multipart subtype, the | |||
application MUST treat it as being equivalent to "multipart/mixed". | application MUST treat it as being equivalent to "multipart/mixed". | |||
Note: The "multipart/form-data" type has been specifically defined | Note: The "multipart/form-data" type has been specifically defined | |||
for carrying form data suitable for processing via the POST | for carrying form data suitable for processing via the POST | |||
request method, as described in [RFC2388]. | request method, as described in [RFC2388]. | |||
2.4. Language Tags | 2.4. Language Tags | |||
A language tag identifies a natural language spoken, written, or | A language tag, as defined in [RFC5646], identifies a natural | |||
otherwise conveyed by human beings for communication of information | language spoken, written, or otherwise conveyed by human beings for | |||
to other human beings. Computer languages are explicitly excluded. | communication of information to other human beings. Computer | |||
HTTP uses language tags within the Accept-Language and Content- | languages are explicitly excluded. HTTP uses language tags within | |||
Language fields. | the Accept-Language and Content-Language fields. | |||
The syntax and registry of HTTP language tags is the same as that | In summary, a language tag is composed of one or more parts: A | |||
defined by [RFC1766]. In summary, a language tag is composed of 1 or | primary language subtag followed by a possibly empty series of | |||
more parts: A primary language tag and a possibly empty series of | ||||
subtags: | subtags: | |||
language-tag = primary-tag *( "-" subtag ) | language-tag = <Language-Tag, defined in [RFC5646], Section 2.1> | |||
primary-tag = 1*8ALPHA | ||||
subtag = 1*8ALPHA | ||||
White space is not allowed within the tag and all tags are case- | White space is not allowed within the tag and all tags are case- | |||
insensitive. The name space of language tags is administered by the | insensitive. The name space of language subtags is administered by | |||
IANA. Example tags include: | the IANA (see | |||
<http://www.iana.org/assignments/language-subtag-registry>). | ||||
en, en-US, en-cockney, i-cherokee, x-pig-latin | Example tags include: | |||
where any two-letter primary-tag is an ISO-639 language abbreviation | en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN | |||
and any two-letter initial subtag is an ISO-3166 country code. (The | ||||
last three tags above are not registered tags; all but the last are | See [RFC5646] for further information. | |||
examples of tags which could be registered in future.) | ||||
3. Entity | 3. Entity | |||
Request and Response messages MAY transfer an entity if not otherwise | Request and Response messages MAY transfer an entity if not otherwise | |||
restricted by the request method or response status code. An entity | restricted by the request method or response status code. An entity | |||
consists of entity-header fields and an entity-body, although some | consists of entity-header fields and an entity-body, although some | |||
responses will only include the entity-headers. | responses will only include the entity-headers. | |||
In this section, both sender and recipient refer to either the client | In this section, both sender and recipient refer to either the client | |||
or the server, depending on who sends and who receives the entity. | or the server, depending on who sends and who receives the entity. | |||
3.1. Entity Header Fields | 3.1. Entity Header Fields | |||
Entity-header fields define metainformation about the entity-body or, | Entity-header fields define metainformation about the entity-body or, | |||
if no body is present, about the resource identified by the request. | if no body is present, about the resource identified by the request. | |||
entity-header = Content-Encoding ; Section 5.5 | entity-header = Content-Encoding ; Section 5.5 | |||
/ Content-Language ; Section 5.6 | / Content-Language ; Section 5.6 | |||
/ Content-Length ; [Part1], Section 8.2 | / Content-Length ; [Part1], Section 9.2 | |||
/ Content-Location ; Section 5.7 | / Content-Location ; Section 5.7 | |||
/ Content-MD5 ; Section 5.8 | / Content-MD5 ; Section 5.8 | |||
/ Content-Range ; [Part5], Section 5.2 | / Content-Range ; [Part5], Section 5.2 | |||
/ Content-Type ; Section 5.9 | / Content-Type ; Section 5.9 | |||
/ Expires ; [Part6], Section 3.3 | / Expires ; [Part6], Section 3.3 | |||
/ Last-Modified ; [Part4], Section 6.6 | / Last-Modified ; [Part4], Section 6.6 | |||
/ extension-header | / extension-header | |||
extension-header = message-header | extension-header = header-field | |||
The extension-header mechanism allows additional entity-header fields | The extension-header mechanism allows additional entity-header fields | |||
to be defined without changing the protocol, but these fields cannot | to be defined without changing the protocol, but these fields cannot | |||
be assumed to be recognizable by the recipient. Unrecognized header | be assumed to be recognizable by the recipient. Unrecognized header | |||
fields SHOULD be ignored by the recipient and MUST be forwarded by | fields SHOULD be ignored by the recipient and MUST be forwarded by | |||
transparent proxies. | transparent proxies. | |||
3.2. Entity Body | 3.2. Entity Body | |||
The entity-body (if any) sent with an HTTP request or response is in | The entity-body (if any) sent with an HTTP request or response is in | |||
a format and encoding defined by the entity-header fields. | a format and encoding defined by the entity-header fields. | |||
entity-body = *OCTET | entity-body = *OCTET | |||
An entity-body is only present in a message when a message-body is | An entity-body is only present in a message when a message-body is | |||
present, as described in Section 4.3 of [Part1]. The entity-body is | present, as described in Section 3.3 of [Part1]. The entity-body is | |||
obtained from the message-body by decoding any Transfer-Encoding that | obtained from the message-body by decoding any Transfer-Encoding that | |||
might have been applied to ensure safe and proper transfer of the | might have been applied to ensure safe and proper transfer of the | |||
message. | message. | |||
3.2.1. Type | 3.2.1. Type | |||
When an entity-body is included with a message, the data type of that | When an entity-body is included with a message, the data type of that | |||
body is determined via the header fields Content-Type and Content- | body is determined via the header fields Content-Type and Content- | |||
Encoding. These define a two-layer, ordered encoding model: | Encoding. These define a two-layer, ordered encoding model: | |||
skipping to change at page 13, line 17 | skipping to change at page 13, line 43 | |||
present, it indicates that the sender does not know the media type of | present, it indicates that the sender does not know the media type of | |||
the data; recipients MAY either assume that it is "application/ | the data; recipients MAY either assume that it is "application/ | |||
octet-stream" ([RFC2046], Section 4.5.1) or examine the content to | octet-stream" ([RFC2046], Section 4.5.1) or examine the content to | |||
determine its type. | determine its type. | |||
Content-Encoding may be used to indicate any additional content | Content-Encoding may be used to indicate any additional content | |||
codings applied to the data, usually for the purpose of data | codings applied to the data, usually for the purpose of data | |||
compression, that are a property of the requested resource. There is | compression, that are a property of the requested resource. There is | |||
no default encoding. | no default encoding. | |||
Note that neither the interpretation of the data type of a message | ||||
nor the behaviors caused by it are defined by HTTP; this potentially | ||||
includes examination of the content to override any indicated type | ||||
("sniffing"). | ||||
3.2.2. Entity Length | 3.2.2. Entity Length | |||
The entity-length of a message is the length of the message-body | The entity-length of a message is the length of the message-body | |||
before any transfer-codings have been applied. Section 4.4 of | before any transfer-codings have been applied. Section 3.4 of | |||
[Part1] defines how the transfer-length of a message-body is | [Part1] defines how the transfer-length of a message-body is | |||
determined. | determined. | |||
4. Content Negotiation | 4. Content Negotiation | |||
Most HTTP responses include an entity which contains information for | Most HTTP responses include an entity which contains information for | |||
interpretation by a human user. Naturally, it is desirable to supply | interpretation by a human user. Naturally, it is desirable to supply | |||
the user with the "best available" entity corresponding to the | the user with the "best available" entity corresponding to the | |||
request. Unfortunately for servers and caches, not all users have | request. Unfortunately for servers and caches, not all users have | |||
the same preferences for what is "best," and not all user agents are | the same preferences for what is "best," and not all user agents are | |||
skipping to change at page 16, line 29 | skipping to change at page 17, line 7 | |||
This section defines the syntax and semantics of HTTP/1.1 header | This section defines the syntax and semantics of HTTP/1.1 header | |||
fields related to the payload of messages. | fields related to the payload of messages. | |||
For entity-header fields, both sender and recipient refer to either | For entity-header fields, both sender and recipient refer to either | |||
the client or the server, depending on who sends and who receives the | the client or the server, depending on who sends and who receives the | |||
entity. | entity. | |||
5.1. Accept | 5.1. Accept | |||
The request-header field "Accept" can be used to specify certain | The "Accept" request-header field can be used by user agents to | |||
media types which are acceptable for the response. Accept headers | specify response media types that are acceptable. Accept headers can | |||
can be used to indicate that the request is specifically limited to a | be used to indicate that the request is specifically limited to a | |||
small set of desired types, as in the case of a request for an in- | small set of desired types, as in the case of a request for an in- | |||
line image. | line image. | |||
Accept = "Accept" ":" OWS Accept-v | Accept = "Accept" ":" OWS Accept-v | |||
Accept-v = #( media-range [ accept-params ] ) | Accept-v = #( media-range [ accept-params ] ) | |||
media-range = ( "*/*" | media-range = ( "*/*" | |||
/ ( type "/" "*" ) | / ( type "/" "*" ) | |||
/ ( type "/" subtype ) | / ( type "/" subtype ) | |||
) *( OWS ";" OWS parameter ) | ) *( OWS ";" OWS parameter ) | |||
skipping to change at page 17, line 10 | skipping to change at page 17, line 34 | |||
The asterisk "*" character is used to group media types into ranges, | The asterisk "*" character is used to group media types into ranges, | |||
with "*/*" indicating all media types and "type/*" indicating all | with "*/*" indicating all media types and "type/*" indicating all | |||
subtypes of that type. The media-range MAY include media type | subtypes of that type. The media-range MAY include media type | |||
parameters that are applicable to that range. | parameters that are applicable to that range. | |||
Each media-range MAY be followed by one or more accept-params, | Each media-range MAY be followed by one or more accept-params, | |||
beginning with the "q" parameter for indicating a relative quality | beginning with the "q" parameter for indicating a relative quality | |||
factor. The first "q" parameter (if any) separates the media-range | factor. The first "q" parameter (if any) separates the media-range | |||
parameter(s) from the accept-params. Quality factors allow the user | parameter(s) from the accept-params. Quality factors allow the user | |||
or user agent to indicate the relative degree of preference for that | or user agent to indicate the relative degree of preference for that | |||
media-range, using the qvalue scale from 0 to 1 (Section 3.5 of | media-range, using the qvalue scale from 0 to 1 (Section 6.4 of | |||
[Part1]). The default value is q=1. | [Part1]). The default value is q=1. | |||
Note: Use of the "q" parameter name to separate media type | Note: Use of the "q" parameter name to separate media type | |||
parameters from Accept extension parameters is due to historical | parameters from Accept extension parameters is due to historical | |||
practice. Although this prevents any media type parameter named | practice. Although this prevents any media type parameter named | |||
"q" from being used with a media range, such an event is believed | "q" from being used with a media range, such an event is believed | |||
to be unlikely given the lack of any "q" parameters in the IANA | to be unlikely given the lack of any "q" parameters in the IANA | |||
media type registry and the rare usage of any media type | media type registry and the rare usage of any media type | |||
parameters in Accept. Future media types are discouraged from | parameters in Accept. Future media types are discouraged from | |||
registering any parameter named "q". | registering any parameter named "q". | |||
skipping to change at page 18, line 40 | skipping to change at page 19, line 23 | |||
| text/html;level=3 | 0.7 | | | text/html;level=3 | 0.7 | | |||
+-------------------+---------------+ | +-------------------+---------------+ | |||
Note: A user agent might be provided with a default set of quality | Note: A user agent might be provided with a default set of quality | |||
values for certain media ranges. However, unless the user agent is a | values for certain media ranges. However, unless the user agent is a | |||
closed system which cannot interact with other rendering agents, this | closed system which cannot interact with other rendering agents, this | |||
default set ought to be configurable by the user. | default set ought to be configurable by the user. | |||
5.2. Accept-Charset | 5.2. Accept-Charset | |||
The request-header field "Accept-Charset" can be used to indicate | The "Accept-Charset" request-header field can be used by user agents | |||
what character sets are acceptable for the response. This field | to indicate what response character sets are acceptable. This field | |||
allows clients capable of understanding more comprehensive or | allows clients capable of understanding more comprehensive or | |||
special-purpose character sets to signal that capability to a server | special-purpose character sets to signal that capability to a server | |||
which is capable of representing documents in those character sets. | which is capable of representing documents in those character sets. | |||
Accept-Charset = "Accept-Charset" ":" OWS | Accept-Charset = "Accept-Charset" ":" OWS | |||
Accept-Charset-v | Accept-Charset-v | |||
Accept-Charset-v = 1#( ( charset / "*" ) | Accept-Charset-v = 1#( ( charset / "*" ) | |||
[ OWS ";" OWS "q=" qvalue ] ) | [ OWS ";" OWS "q=" qvalue ] ) | |||
Character set values are described in Section 2.1. Each charset MAY | Character set values are described in Section 2.1. Each charset MAY | |||
skipping to change at page 19, line 25 | skipping to change at page 20, line 8 | |||
If no Accept-Charset header is present, the default is that any | If no Accept-Charset header is present, the default is that any | |||
character set is acceptable. If an Accept-Charset header is present, | character set is acceptable. If an Accept-Charset header is present, | |||
and if the server cannot send a response which is acceptable | and if the server cannot send a response which is acceptable | |||
according to the Accept-Charset header, then the server SHOULD send | according to the Accept-Charset header, then the server SHOULD send | |||
an error response with the 406 (Not Acceptable) status code, though | an error response with the 406 (Not Acceptable) status code, though | |||
the sending of an unacceptable response is also allowed. | the sending of an unacceptable response is also allowed. | |||
5.3. Accept-Encoding | 5.3. Accept-Encoding | |||
The request-header field "Accept-Encoding" is similar to Accept, but | The "Accept-Encoding" request-header field can be used by user agents | |||
restricts the content-codings (Section 2.2) that are acceptable in | to indicate what response content-codings (Section 2.2) are | |||
the response. | acceptable in the response. | |||
Accept-Encoding = "Accept-Encoding" ":" OWS | Accept-Encoding = "Accept-Encoding" ":" OWS | |||
Accept-Encoding-v | Accept-Encoding-v | |||
Accept-Encoding-v = | Accept-Encoding-v = | |||
#( codings [ OWS ";" OWS "q=" qvalue ] ) | #( codings [ OWS ";" OWS "q=" qvalue ] ) | |||
codings = ( content-coding / "*" ) | codings = ( content-coding / "*" ) | |||
Each codings value MAY be given an associated quality value which | Each codings value MAY be given an associated quality value which | |||
represents the preference for that encoding. The default value is | represents the preference for that encoding. The default value is | |||
q=1. | q=1. | |||
skipping to change at page 20, line 4 | skipping to change at page 20, line 35 | |||
Accept-Encoding: | Accept-Encoding: | |||
Accept-Encoding: * | Accept-Encoding: * | |||
Accept-Encoding: compress;q=0.5, gzip;q=1.0 | Accept-Encoding: compress;q=0.5, gzip;q=1.0 | |||
Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0 | Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0 | |||
A server tests whether a content-coding is acceptable, according to | A server tests whether a content-coding is acceptable, according to | |||
an Accept-Encoding field, using these rules: | an Accept-Encoding field, using these rules: | |||
1. If the content-coding is one of the content-codings listed in the | 1. If the content-coding is one of the content-codings listed in the | |||
Accept-Encoding field, then it is acceptable, unless it is | Accept-Encoding field, then it is acceptable, unless it is | |||
accompanied by a qvalue of 0. (As defined in Section 3.5 of | accompanied by a qvalue of 0. (As defined in Section 6.4 of | |||
[Part1], a qvalue of 0 means "not acceptable.") | [Part1], a qvalue of 0 means "not acceptable.") | |||
2. The special "*" symbol in an Accept-Encoding field matches any | 2. The special "*" symbol in an Accept-Encoding field matches any | |||
available content-coding not explicitly listed in the header | available content-coding not explicitly listed in the header | |||
field. | field. | |||
3. If multiple content-codings are acceptable, then the acceptable | 3. If multiple content-codings are acceptable, then the acceptable | |||
content-coding with the highest non-zero qvalue is preferred. | content-coding with the highest non-zero qvalue is preferred. | |||
4. The "identity" content-coding is always acceptable, unless | 4. The "identity" content-coding is always acceptable, unless | |||
skipping to change at page 20, line 47 | skipping to change at page 21, line 31 | |||
messages sent with other content-codings. The server might also | messages sent with other content-codings. The server might also | |||
make this decision based on information about the particular user- | make this decision based on information about the particular user- | |||
agent or client. | agent or client. | |||
Note: Most HTTP/1.0 applications do not recognize or obey qvalues | Note: Most HTTP/1.0 applications do not recognize or obey qvalues | |||
associated with content-codings. This means that qvalues will not | associated with content-codings. This means that qvalues will not | |||
work and are not permitted with x-gzip or x-compress. | work and are not permitted with x-gzip or x-compress. | |||
5.4. Accept-Language | 5.4. Accept-Language | |||
The request-header field "Accept-Language" is similar to Accept, but | The "Accept-Language" request-header field can be used by user agents | |||
restricts the set of natural languages that are preferred as a | to indicate the set of natural languages that are preferred in the | |||
response to the request. Language tags are defined in Section 2.4. | response. Language tags are defined in Section 2.4. | |||
Accept-Language = "Accept-Language" ":" OWS | Accept-Language = "Accept-Language" ":" OWS | |||
Accept-Language-v | Accept-Language-v | |||
Accept-Language-v = | Accept-Language-v = | |||
1#( language-range [ OWS ";" OWS "q=" qvalue ] ) | 1#( language-range [ OWS ";" OWS "q=" qvalue ] ) | |||
language-range = | language-range = | |||
<language-range, defined in [RFC4647], Section 2.1> | <language-range, defined in [RFC4647], Section 2.1> | |||
Each language-range can be given an associated quality value which | Each language-range can be given an associated quality value which | |||
represents an estimate of the user's preference for the languages | represents an estimate of the user's preference for the languages | |||
skipping to change at page 22, line 23 | skipping to change at page 23, line 7 | |||
the user, we remind implementors of the fact that users are not | the user, we remind implementors of the fact that users are not | |||
familiar with the details of language matching as described above, | familiar with the details of language matching as described above, | |||
and should provide appropriate guidance. As an example, users | and should provide appropriate guidance. As an example, users | |||
might assume that on selecting "en-gb", they will be served any | might assume that on selecting "en-gb", they will be served any | |||
kind of English document if British English is not available. A | kind of English document if British English is not available. A | |||
user agent might suggest in such a case to add "en" to get the | user agent might suggest in such a case to add "en" to get the | |||
best matching behavior. | best matching behavior. | |||
5.5. Content-Encoding | 5.5. Content-Encoding | |||
The entity-header field "Content-Encoding" is used as a modifier to | The "Content-Encoding" entity-header field indicates what content- | |||
the media-type. When present, its value indicates what additional | codings have been applied to the entity-body, and thus what decoding | |||
content codings have been applied to the entity-body, and thus what | mechanisms must be applied in order to obtain the media-type | |||
decoding mechanisms must be applied in order to obtain the media-type | ||||
referenced by the Content-Type header field. Content-Encoding is | referenced by the Content-Type header field. Content-Encoding is | |||
primarily used to allow a document to be compressed without losing | primarily used to allow a document to be compressed without losing | |||
the identity of its underlying media type. | the identity of its underlying media type. | |||
Content-Encoding = "Content-Encoding" ":" OWS Content-Encoding-v | Content-Encoding = "Content-Encoding" ":" OWS Content-Encoding-v | |||
Content-Encoding-v = 1#content-coding | Content-Encoding-v = 1#content-coding | |||
Content codings are defined in Section 2.2. An example of its use is | Content codings are defined in Section 2.2. An example of its use is | |||
Content-Encoding: gzip | Content-Encoding: gzip | |||
skipping to change at page 23, line 12 | skipping to change at page 23, line 43 | |||
acceptable to the origin server, the server SHOULD respond with a | acceptable to the origin server, the server SHOULD respond with a | |||
status code of 415 (Unsupported Media Type). | status code of 415 (Unsupported Media Type). | |||
If multiple encodings have been applied to an entity, the content | If multiple encodings have been applied to an entity, the content | |||
codings MUST be listed in the order in which they were applied. | codings MUST be listed in the order in which they were applied. | |||
Additional information about the encoding parameters MAY be provided | Additional information about the encoding parameters MAY be provided | |||
by other entity-header fields not defined by this specification. | by other entity-header fields not defined by this specification. | |||
5.6. Content-Language | 5.6. Content-Language | |||
The entity-header field "Content-Language" describes the natural | The "Content-Language" entity-header field describes the natural | |||
language(s) of the intended audience for the enclosed entity. Note | language(s) of the intended audience for the entity. Note that this | |||
that this might not be equivalent to all the languages used within | might not be equivalent to all the languages used within the entity- | |||
the entity-body. | body. | |||
Content-Language = "Content-Language" ":" OWS Content-Language-v | Content-Language = "Content-Language" ":" OWS Content-Language-v | |||
Content-Language-v = 1#language-tag | Content-Language-v = 1#language-tag | |||
Language tags are defined in Section 2.4. The primary purpose of | Language tags are defined in Section 2.4. The primary purpose of | |||
Content-Language is to allow a user to identify and differentiate | Content-Language is to allow a user to identify and differentiate | |||
entities according to the user's own preferred language. Thus, if | entities according to the user's own preferred language. Thus, if | |||
the body content is intended only for a Danish-literate audience, the | the body content is intended only for a Danish-literate audience, the | |||
appropriate field is | appropriate field is | |||
skipping to change at page 24, line 7 | skipping to change at page 24, line 34 | |||
An example would be a beginner's language primer, such as "A First | An example would be a beginner's language primer, such as "A First | |||
Lesson in Latin," which is clearly intended to be used by an English- | Lesson in Latin," which is clearly intended to be used by an English- | |||
literate audience. In this case, the Content-Language would properly | literate audience. In this case, the Content-Language would properly | |||
only include "en". | only include "en". | |||
Content-Language MAY be applied to any media type -- it is not | Content-Language MAY be applied to any media type -- it is not | |||
limited to textual documents. | limited to textual documents. | |||
5.7. Content-Location | 5.7. Content-Location | |||
The entity-header field "Content-Location" MAY be used to supply the | The "Content-Location" entity-header field is used to supply a URI | |||
resource location for the entity enclosed in the message when that | for the entity in the message when it is accessible from a location | |||
entity is accessible from a location separate from the requested | separate from the requested resource's URI. | |||
resource's URI. A server SHOULD provide a Content-Location for the | ||||
variant corresponding to the response entity; especially in the case | A server SHOULD provide a Content-Location for the variant | |||
where a resource has multiple entities associated with it, and those | corresponding to the response entity, especially in the case where a | |||
entities actually have separate locations by which they might be | resource has multiple entities associated with it, and those entities | |||
individually accessed, the server SHOULD provide a Content-Location | actually have separate locations by which they might be individually | |||
for the particular variant which is returned. | accessed, the server SHOULD provide a Content-Location for the | |||
particular variant which is returned. | ||||
Content-Location = "Content-Location" ":" OWS | Content-Location = "Content-Location" ":" OWS | |||
Content-Location-v | Content-Location-v | |||
Content-Location-v = | Content-Location-v = | |||
absolute-URI / partial-URI | absolute-URI / partial-URI | |||
The value of Content-Location also defines the base URI for the | ||||
entity. | ||||
The Content-Location value is not a replacement for the original | The Content-Location value is not a replacement for the original | |||
requested URI; it is only a statement of the location of the resource | requested URI; it is only a statement of the location of the resource | |||
corresponding to this particular entity at the time of the request. | corresponding to this particular entity at the time of the request. | |||
Future requests MAY specify the Content-Location URI as the request- | Future requests MAY specify the Content-Location URI as the request- | |||
target if the desire is to identify the source of that particular | target if the desire is to identify the source of that particular | |||
entity. | entity. | |||
Section 6.1 of [Part2] describes how clients may process the Content- | ||||
Location header field. | ||||
A cache cannot assume that an entity with a Content-Location | A cache cannot assume that an entity with a Content-Location | |||
different from the URI used to retrieve it can be used to respond to | different from the URI used to retrieve it can be used to respond to | |||
later requests on that Content-Location URI. However, the Content- | later requests on that Content-Location URI. However, the Content- | |||
Location can be used to differentiate between multiple entities | Location can be used to differentiate between multiple entities | |||
retrieved from a single requested resource, as described in Section | retrieved from a single requested resource, as described in Section | |||
2.6 of [Part6]. | 2.6 of [Part6]. | |||
If the Content-Location is a relative URI, the relative URI is | If the Content-Location is a relative URI, the relative URI is | |||
interpreted relative to the request-target. | interpreted relative to the request-target. | |||
The meaning of the Content-Location header in requests is undefined; | The meaning of the Content-Location header in requests is undefined; | |||
servers are free to ignore it in those cases. | servers are free to ignore it in those cases. | |||
5.8. Content-MD5 | 5.8. Content-MD5 | |||
The entity-header field "Content-MD5", as defined in [RFC1864], is an | The "Content-MD5" entity-header field, as defined in [RFC1864], is an | |||
MD5 digest of the entity-body for the purpose of providing an end-to- | MD5 digest of the entity-body that provides an end-to-end message | |||
end message integrity check (MIC) of the entity-body. (Note: a MIC | integrity check (MIC) of the entity-body. Note that a MIC is good | |||
is good for detecting accidental modification of the entity-body in | for detecting accidental modification of the entity-body in transit, | |||
transit, but is not proof against malicious attacks.) | but is not proof against malicious attacks. | |||
Content-MD5 = "Content-MD5" ":" OWS Content-MD5-v | Content-MD5 = "Content-MD5" ":" OWS Content-MD5-v | |||
Content-MD5-v = <base64 of 128 bit MD5 digest as per [RFC1864]> | Content-MD5-v = <base64 of 128 bit MD5 digest as per [RFC1864]> | |||
The Content-MD5 header field MAY be generated by an origin server or | The Content-MD5 header field MAY be generated by an origin server or | |||
client to function as an integrity check of the entity-body. Only | client to function as an integrity check of the entity-body. Only | |||
origin servers or clients MAY generate the Content-MD5 header field; | origin servers or clients MAY generate the Content-MD5 header field; | |||
proxies and gateways MUST NOT generate it, as this would defeat its | proxies and gateways MUST NOT generate it, as this would defeat its | |||
value as an end-to-end integrity check. Any recipient of the entity- | value as an end-to-end integrity check. Any recipient of the entity- | |||
body, including gateways and proxies, MAY check that the digest value | body, including gateways and proxies, MAY check that the digest value | |||
in this header field matches that of the entity-body as received. | in this header field matches that of the entity-body as received. | |||
skipping to change at page 26, line 11 | skipping to change at page 26, line 40 | |||
HTTP, unlike MIME, does not use Content-Transfer-Encoding, and | HTTP, unlike MIME, does not use Content-Transfer-Encoding, and | |||
does use Transfer-Encoding and Content-Encoding. Another is that | does use Transfer-Encoding and Content-Encoding. Another is that | |||
HTTP more frequently uses binary content types than MIME, so it is | HTTP more frequently uses binary content types than MIME, so it is | |||
worth noting that, in such cases, the byte order used to compute | worth noting that, in such cases, the byte order used to compute | |||
the digest is the transmission byte order defined for the type. | the digest is the transmission byte order defined for the type. | |||
Lastly, HTTP allows transmission of text types with any of several | Lastly, HTTP allows transmission of text types with any of several | |||
line break conventions and not just the canonical form using CRLF. | line break conventions and not just the canonical form using CRLF. | |||
5.9. Content-Type | 5.9. Content-Type | |||
The entity-header field "Content-Type" indicates the media type of | The "Content-Type" entity-header field indicates the media type of | |||
the entity-body sent to the recipient or, in the case of the HEAD | the entity-body. In the case of responses to the HEAD method, the | |||
method, the media type that would have been sent had the request been | media type is that which would have been sent had the request been a | |||
a GET. | GET. | |||
Content-Type = "Content-Type" ":" OWS Content-Type-v | Content-Type = "Content-Type" ":" OWS Content-Type-v | |||
Content-Type-v = media-type | Content-Type-v = media-type | |||
Media types are defined in Section 2.3. An example of the field is | Media types are defined in Section 2.3. An example of the field is | |||
Content-Type: text/html; charset=ISO-8859-4 | Content-Type: text/html; charset=ISO-8859-4 | |||
Further discussion of methods for identifying the media type of an | Further discussion of methods for identifying the media type of an | |||
entity is provided in Section 3.2.1. | entity is provided in Section 3.2.1. | |||
6. IANA Considerations | 6. IANA Considerations | |||
6.1. Message Header Registration | 6.1. Message Header Registration | |||
The Message Header Registry located at <http://www.iana.org/ | The Message Header Registry located at <http://www.iana.org/ | |||
assignments/message-headers/message-header-index.html> should be | assignments/message-headers/message-header-index.html> should be | |||
updated with the permanent registrations below (see [RFC3864]): | updated with the permanent registrations below (see [RFC3864]): | |||
skipping to change at page 27, line 6 | skipping to change at page 27, line 34 | |||
| Content-Language | http | standard | Section 5.6 | | | Content-Language | http | standard | Section 5.6 | | |||
| Content-Location | http | standard | Section 5.7 | | | Content-Location | http | standard | Section 5.7 | | |||
| Content-MD5 | http | standard | Section 5.8 | | | Content-MD5 | http | standard | Section 5.8 | | |||
| Content-Type | http | standard | Section 5.9 | | | Content-Type | http | standard | Section 5.9 | | |||
| MIME-Version | http | | Appendix A.1 | | | MIME-Version | http | | Appendix A.1 | | |||
+---------------------+----------+----------+--------------+ | +---------------------+----------+----------+--------------+ | |||
The change controller is: "IETF (iesg@ietf.org) - Internet | The change controller is: "IETF (iesg@ietf.org) - Internet | |||
Engineering Task Force". | Engineering Task Force". | |||
6.2. Content Coding Registry | ||||
The registration procedure for HTTP Content Codings is now defined by | ||||
Section 2.2.1 of this document. | ||||
The HTTP Content Codings Registry located at | ||||
<http://www.iana.org/assignments/http-parameters> should be updated | ||||
with the registration below: | ||||
+----------+-----------------------------------+--------------------+ | ||||
| Name | Description | Reference | | ||||
+----------+-----------------------------------+--------------------+ | ||||
| compress | UNIX "compress" program method | Section 6.2.2.1 of | | ||||
| | | [Part1] | | ||||
| deflate | "zlib" format [RFC1950] with | Section 6.2.2.2 of | | ||||
| | "deflate" compression | [Part1] | | ||||
| gzip | Same as GNU zip [RFC1952] | Section 6.2.2.3 of | | ||||
| | | [Part1] | | ||||
| identity | No transformation | Section 2.2 | | ||||
+----------+-----------------------------------+--------------------+ | ||||
7. Security Considerations | 7. Security Considerations | |||
This section is meant to inform application developers, information | This section is meant to inform application developers, information | |||
providers, and users of the security limitations in HTTP/1.1 as | providers, and users of the security limitations in HTTP/1.1 as | |||
described by this document. The discussion does not include | described by this document. The discussion does not include | |||
definitive solutions to the problems revealed, though it does make | definitive solutions to the problems revealed, though it does make | |||
some suggestions for reducing security risks. | some suggestions for reducing security risks. | |||
7.1. Privacy Issues Connected to Accept Headers | 7.1. Privacy Issues Connected to Accept Headers | |||
skipping to change at page 28, line 29 | skipping to change at page 29, line 36 | |||
[ISO-8859-1] | [ISO-8859-1] | |||
International Organization for Standardization, | International Organization for Standardization, | |||
"Information technology -- 8-bit single-byte coded graphic | "Information technology -- 8-bit single-byte coded graphic | |||
character sets -- Part 1: Latin alphabet No. 1", ISO/ | character sets -- Part 1: Latin alphabet No. 1", ISO/ | |||
IEC 8859-1:1998, 1998. | IEC 8859-1:1998, 1998. | |||
[Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, | and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, | |||
and Message Parsing", draft-ietf-httpbis-p1-messaging-07 | and Message Parsing", draft-ietf-httpbis-p1-messaging-08 | |||
(work in progress), July 2009. | (work in progress), October 2009. | |||
[Part2] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part2] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
and J. Reschke, Ed., "HTTP/1.1, part 2: Message | and J. Reschke, Ed., "HTTP/1.1, part 2: Message | |||
Semantics", draft-ietf-httpbis-p2-semantics-07 (work in | Semantics", draft-ietf-httpbis-p2-semantics-08 (work in | |||
progress), July 2009. | progress), October 2009. | |||
[Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional | and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional | |||
Requests", draft-ietf-httpbis-p4-conditional-07 (work in | Requests", draft-ietf-httpbis-p4-conditional-08 (work in | |||
progress), July 2009. | progress), October 2009. | |||
[Part5] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part5] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
and J. Reschke, Ed., "HTTP/1.1, part 5: Range Requests and | and J. Reschke, Ed., "HTTP/1.1, part 5: Range Requests and | |||
Partial Responses", draft-ietf-httpbis-p5-range-07 (work | Partial Responses", draft-ietf-httpbis-p5-range-08 (work | |||
in progress), July 2009. | in progress), October 2009. | |||
[Part6] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | [Part6] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., | |||
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., | |||
Nottingham, M., Ed., and J. Reschke, Ed., "HTTP/1.1, part | Nottingham, M., Ed., and J. Reschke, Ed., "HTTP/1.1, part | |||
6: Caching", draft-ietf-httpbis-p6-cache-07 (work in | 6: Caching", draft-ietf-httpbis-p6-cache-08 (work in | |||
progress), July 2009. | progress), October 2009. | |||
[RFC1766] Alvestrand, H., "Tags for the Identification of | ||||
Languages", RFC 1766, March 1995. | ||||
[RFC1864] Myers, J. and M. Rose, "The Content-MD5 Header Field", | [RFC1864] Myers, J. and M. Rose, "The Content-MD5 Header Field", | |||
RFC 1864, October 1995. | RFC 1864, October 1995. | |||
[RFC1950] Deutsch, L. and J-L. Gailly, "ZLIB Compressed Data Format | [RFC1950] Deutsch, L. and J-L. Gailly, "ZLIB Compressed Data Format | |||
Specification version 3.3", RFC 1950, May 1996. | Specification version 3.3", RFC 1950, May 1996. | |||
RFC 1950 is an Informational RFC, thus it may be less | RFC 1950 is an Informational RFC, thus it may be less | |||
stable than this specification. On the other hand, this | stable than this specification. On the other hand, this | |||
downward reference was present since the publication of | downward reference was present since the publication of | |||
RFC 2068 in 1997 ([RFC2068]), therefore it is unlikely to | RFC 2068 in 1997 ([RFC2068]), therefore it is unlikely to | |||
cause problems in practice. See also [BCP97]. | cause problems in practice. See also [BCP97]. | |||
[RFC1951] Deutsch, P., "DEFLATE Compressed Data Format Specification | ||||
version 1.3", RFC 1951, May 1996. | ||||
RFC 1951 is an Informational RFC, thus it may be less | ||||
stable than this specification. On the other hand, this | ||||
downward reference was present since the publication of | ||||
RFC 2068 in 1997 ([RFC2068]), therefore it is unlikely to | ||||
cause problems in practice. See also [BCP97]. | ||||
[RFC1952] Deutsch, P., Gailly, J-L., Adler, M., Deutsch, L., and G. | [RFC1952] Deutsch, P., Gailly, J-L., Adler, M., Deutsch, L., and G. | |||
Randers-Pehrson, "GZIP file format specification version | Randers-Pehrson, "GZIP file format specification version | |||
4.3", RFC 1952, May 1996. | 4.3", RFC 1952, May 1996. | |||
RFC 1952 is an Informational RFC, thus it may be less | RFC 1952 is an Informational RFC, thus it may be less | |||
stable than this specification. On the other hand, this | stable than this specification. On the other hand, this | |||
downward reference was present since the publication of | downward reference was present since the publication of | |||
RFC 2068 in 1997 ([RFC2068]), therefore it is unlikely to | RFC 2068 in 1997 ([RFC2068]), therefore it is unlikely to | |||
cause problems in practice. See also [BCP97]. | cause problems in practice. See also [BCP97]. | |||
skipping to change at page 30, line 12 | skipping to change at page 31, line 8 | |||
[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, March 1997. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
[RFC4647] Phillips, A., Ed. and M. Davis, Ed., "Matching of Language | [RFC4647] Phillips, A., Ed. and M. Davis, Ed., "Matching of Language | |||
Tags", BCP 47, RFC 4647, September 2006. | Tags", BCP 47, RFC 4647, September 2006. | |||
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax | [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax | |||
Specifications: ABNF", STD 68, RFC 5234, January 2008. | Specifications: ABNF", STD 68, RFC 5234, January 2008. | |||
[RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying | ||||
Languages", BCP 47, RFC 5646, September 2009. | ||||
9.2. Informative References | 9.2. Informative References | |||
[BCP97] Klensin, J. and S. Hartman, "Handling Normative References | [BCP97] Klensin, J. and S. Hartman, "Handling Normative References | |||
to Standards-Track Documents", BCP 97, RFC 4897, | to Standards-Track Documents", BCP 97, RFC 4897, | |||
June 2007. | June 2007. | |||
[RFC1945] Berners-Lee, T., Fielding, R., and H. Nielsen, "Hypertext | [RFC1945] Berners-Lee, T., Fielding, R., and H. Nielsen, "Hypertext | |||
Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996. | Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996. | |||
[RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail | [RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail | |||
skipping to change at page 31, line 12 | skipping to change at page 32, line 10 | |||
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO | [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO | |||
10646", RFC 3629, STD 63, November 2003. | 10646", RFC 3629, STD 63, November 2003. | |||
[RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration | [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration | |||
Procedures for Message Header Fields", BCP 90, RFC 3864, | Procedures for Message Header Fields", BCP 90, RFC 3864, | |||
September 2004. | September 2004. | |||
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and | [RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and | |||
Registration Procedures", BCP 13, RFC 4288, December 2005. | Registration Procedures", BCP 13, RFC 4288, December 2005. | |||
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an | ||||
IANA Considerations Section in RFCs", BCP 26, RFC 5226, | ||||
May 2008. | ||||
[RFC5322] Resnick, P., "Internet Message Format", RFC 5322, | [RFC5322] Resnick, P., "Internet Message Format", RFC 5322, | |||
October 2008. | October 2008. | |||
Appendix A. Differences Between HTTP Entities and RFC 2045 Entities | Appendix A. Differences Between HTTP Entities and RFC 2045 Entities | |||
HTTP/1.1 uses many of the constructs defined for Internet Mail | HTTP/1.1 uses many of the constructs defined for Internet Mail | |||
([RFC5322]) and the Multipurpose Internet Mail Extensions (MIME | ([RFC5322]) and the Multipurpose Internet Mail Extensions (MIME | |||
[RFC2045]) to allow entities to be transmitted in an open variety of | [RFC2045]) to allow entities to be transmitted in an open variety of | |||
representations and with extensible mechanisms. However, RFC 2045 | representations and with extensible mechanisms. However, RFC 2045 | |||
discusses mail, and HTTP has a few features that are different from | discusses mail, and HTTP has a few features that are different from | |||
skipping to change at page 32, line 33 | skipping to change at page 33, line 35 | |||
octets 13 and 10 to represent CR and LF, as is the case for some | octets 13 and 10 to represent CR and LF, as is the case for some | |||
multi-byte character sets. | multi-byte character sets. | |||
Implementors should note that conversion will break any cryptographic | Implementors should note that conversion will break any cryptographic | |||
checksums applied to the original content unless the original content | checksums applied to the original content unless the original content | |||
is already in canonical form. Therefore, the canonical form is | is already in canonical form. Therefore, the canonical form is | |||
recommended for any content that uses such checksums in HTTP. | recommended for any content that uses such checksums in HTTP. | |||
A.3. Conversion of Date Formats | A.3. Conversion of Date Formats | |||
HTTP/1.1 uses a restricted set of date formats (Section 3.2 of | HTTP/1.1 uses a restricted set of date formats (Section 6.1 of | |||
[Part1]) to simplify the process of date comparison. Proxies and | [Part1]) to simplify the process of date comparison. Proxies and | |||
gateways from other protocols SHOULD ensure that any Date header | gateways from other protocols SHOULD ensure that any Date header | |||
field present in a message conforms to one of the HTTP/1.1 formats | field present in a message conforms to one of the HTTP/1.1 formats | |||
and rewrite the date if necessary. | and rewrite the date if necessary. | |||
A.4. Introduction of Content-Encoding | A.4. Introduction of Content-Encoding | |||
RFC 2045 does not include any concept equivalent to HTTP/1.1's | RFC 2045 does not include any concept equivalent to HTTP/1.1's | |||
Content-Encoding header field. Since this acts as a modifier on the | Content-Encoding header field. Since this acts as a modifier on the | |||
media type, proxies and gateways from HTTP to MIME-compliant | media type, proxies and gateways from HTTP to MIME-compliant | |||
skipping to change at page 33, line 22 | skipping to change at page 34, line 22 | |||
Proxies and gateways from HTTP to MIME-compliant protocols are | Proxies and gateways from HTTP to MIME-compliant protocols are | |||
responsible for ensuring that the message is in the correct format | responsible for ensuring that the message is in the correct format | |||
and encoding for safe transport on that protocol, where "safe | and encoding for safe transport on that protocol, where "safe | |||
transport" is defined by the limitations of the protocol being used. | transport" is defined by the limitations of the protocol being used. | |||
Such a proxy or gateway SHOULD label the data with an appropriate | Such a proxy or gateway SHOULD label the data with an appropriate | |||
Content-Transfer-Encoding if doing so will improve the likelihood of | Content-Transfer-Encoding if doing so will improve the likelihood of | |||
safe transport over the destination protocol. | safe transport over the destination protocol. | |||
A.6. Introduction of Transfer-Encoding | A.6. Introduction of Transfer-Encoding | |||
HTTP/1.1 introduces the Transfer-Encoding header field (Section 8.7 | HTTP/1.1 introduces the Transfer-Encoding header field (Section 9.7 | |||
of [Part1]). Proxies/gateways MUST remove any transfer-coding prior | of [Part1]). Proxies/gateways MUST remove any transfer-coding prior | |||
to forwarding a message via a MIME-compliant protocol. | to forwarding a message via a MIME-compliant protocol. | |||
A.7. MHTML and Line Length Limitations | A.7. MHTML and Line Length Limitations | |||
HTTP implementations which share code with MHTML [RFC2557] | HTTP implementations which share code with MHTML [RFC2557] | |||
implementations need to be aware of MIME line length limitations. | implementations need to be aware of MIME line length limitations. | |||
Since HTTP does not have this limitation, HTTP does not fold long | Since HTTP does not have this limitation, HTTP does not fold long | |||
lines. MHTML messages being transported by HTTP follow all | lines. MHTML messages being transported by HTTP follow all | |||
conventions of MHTML, including line length limitations and folding, | conventions of MHTML, including line length limitations and folding, | |||
skipping to change at page 34, line 7 | skipping to change at page 35, line 7 | |||
interoperability with, other HTTP/1.1 applications. Some of these | interoperability with, other HTTP/1.1 applications. Some of these | |||
describe proposed experimental features, and some describe features | describe proposed experimental features, and some describe features | |||
that experimental deployment found lacking that are now addressed in | that experimental deployment found lacking that are now addressed in | |||
the base HTTP/1.1 specification. | the base HTTP/1.1 specification. | |||
A number of other headers, such as Content-Disposition and Title, | A number of other headers, such as Content-Disposition and Title, | |||
from SMTP and MIME are also often implemented (see [RFC2076]). | from SMTP and MIME are also often implemented (see [RFC2076]). | |||
B.1. Content-Disposition | B.1. Content-Disposition | |||
The Content-Disposition response-header field has been proposed as a | The "Content-Disposition" response-header field has been proposed as | |||
means for the origin server to suggest a default filename if the user | a means for the origin server to suggest a default filename if the | |||
requests that the content is saved to a file. This usage is derived | user requests that the content is saved to a file. This usage is | |||
from the definition of Content-Disposition in [RFC2183]. | derived from the definition of Content-Disposition in [RFC2183]. | |||
content-disposition = "Content-Disposition" ":" OWS | content-disposition = "Content-Disposition" ":" OWS | |||
content-disposition-v | content-disposition-v | |||
content-disposition-v = disposition-type | content-disposition-v = disposition-type | |||
*( OWS ";" OWS disposition-parm ) | *( OWS ";" OWS disposition-parm ) | |||
disposition-type = "attachment" / disp-extension-token | disposition-type = "attachment" / disp-extension-token | |||
disposition-parm = filename-parm / disp-extension-parm | disposition-parm = filename-parm / disp-extension-parm | |||
filename-parm = "filename" "=" quoted-string | filename-parm = "filename" "=" quoted-string | |||
disp-extension-token = token | disp-extension-token = token | |||
disp-extension-parm = token "=" ( token / quoted-string ) | disp-extension-parm = token "=" ( token / quoted-string ) | |||
skipping to change at page 35, line 20 | skipping to change at page 36, line 20 | |||
The Alternates, Content-Version, Derived-From, Link, URI, Public and | The Alternates, Content-Version, Derived-From, Link, URI, Public and | |||
Content-Base header fields were defined in previous versions of this | Content-Base header fields were defined in previous versions of this | |||
specification, but not commonly implemented. See Section 19.6.2 of | specification, but not commonly implemented. See Section 19.6.2 of | |||
[RFC2068]. | [RFC2068]. | |||
C.2. Changes from RFC 2616 | C.2. Changes from RFC 2616 | |||
Clarify contexts that charset is used in. (Section 2.1) | Clarify contexts that charset is used in. (Section 2.1) | |||
Remove base URI setting semantics for Content-Location due to poor | ||||
implementation support, which was caused by too many broken servers | ||||
emitting bogus Content-Location headers, and also the potentially | ||||
undesirable effect of potentially breaking relative links in content- | ||||
negotiated resources. (Section 5.7) | ||||
Remove reference to non-existant identity transfer-coding value | Remove reference to non-existant identity transfer-coding value | |||
tokens. (Appendix A.5) | tokens. (Appendix A.5) | |||
Appendix D. Collected ABNF | Appendix D. Collected ABNF | |||
Accept = "Accept:" OWS Accept-v | Accept = "Accept:" OWS Accept-v | |||
Accept-Charset = "Accept-Charset:" OWS Accept-Charset-v | Accept-Charset = "Accept-Charset:" OWS Accept-Charset-v | |||
Accept-Charset-v = *( "," OWS ) ( charset / "*" ) [ OWS ";" OWS "q=" | Accept-Charset-v = *( "," OWS ) ( charset / "*" ) [ OWS ";" OWS "q=" | |||
qvalue ] *( OWS "," [ OWS ( charset / "*" ) [ OWS ";" OWS "q=" | qvalue ] *( OWS "," [ OWS ( charset / "*" ) [ OWS ";" OWS "q=" | |||
qvalue ] ] ) | qvalue ] ] ) | |||
skipping to change at page 35, line 46 | skipping to change at page 37, line 6 | |||
] ) | ] ) | |||
Accept-v = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [ | Accept-v = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [ | |||
OWS media-range [ accept-params ] ] ) ] | OWS media-range [ accept-params ] ] ) ] | |||
Content-Encoding = "Content-Encoding:" OWS Content-Encoding-v | Content-Encoding = "Content-Encoding:" OWS Content-Encoding-v | |||
Content-Encoding-v = *( "," OWS ) content-coding *( OWS "," [ OWS | Content-Encoding-v = *( "," OWS ) content-coding *( OWS "," [ OWS | |||
content-coding ] ) | content-coding ] ) | |||
Content-Language = "Content-Language:" OWS Content-Language-v | Content-Language = "Content-Language:" OWS Content-Language-v | |||
Content-Language-v = *( "," OWS ) language-tag *( OWS "," [ OWS | Content-Language-v = *( "," OWS ) language-tag *( OWS "," [ OWS | |||
language-tag ] ) | language-tag ] ) | |||
Content-Length = <Content-Length, defined in [Part1], Section 8.2> | Content-Length = <Content-Length, defined in [Part1], Section 9.2> | |||
Content-Location = "Content-Location:" OWS Content-Location-v | Content-Location = "Content-Location:" OWS Content-Location-v | |||
Content-Location-v = absolute-URI / partial-URI | Content-Location-v = absolute-URI / partial-URI | |||
Content-MD5 = "Content-MD5:" OWS Content-MD5-v | Content-MD5 = "Content-MD5:" OWS Content-MD5-v | |||
Content-MD5-v = <base64 of 128 bit MD5 digest as per [RFC1864]> | Content-MD5-v = <base64 of 128 bit MD5 digest as per [RFC1864]> | |||
Content-Range = <Content-Range, defined in [Part5], Section 5.2> | Content-Range = <Content-Range, defined in [Part5], Section 5.2> | |||
Content-Type = "Content-Type:" OWS Content-Type-v | Content-Type = "Content-Type:" OWS Content-Type-v | |||
Content-Type-v = media-type | Content-Type-v = media-type | |||
Expires = <Expires, defined in [Part6], Section 3.3> | Expires = <Expires, defined in [Part6], Section 3.3> | |||
Last-Modified = <Last-Modified, defined in [Part4], Section 6.6> | Last-Modified = <Last-Modified, defined in [Part4], Section 6.6> | |||
MIME-Version = "MIME-Version:" OWS MIME-Version-v | MIME-Version = "MIME-Version:" OWS MIME-Version-v | |||
MIME-Version-v = 1*DIGIT "." 1*DIGIT | MIME-Version-v = 1*DIGIT "." 1*DIGIT | |||
OWS = <OWS, defined in [Part1], Section 1.2.2> | OWS = <OWS, defined in [Part1], Section 1.2.2> | |||
absolute-URI = <absolute-URI, defined in [Part1], Section 2.1> | absolute-URI = <absolute-URI, defined in [Part1], Section 2.6> | |||
accept-ext = OWS ";" OWS token [ "=" ( token / quoted-string ) ] | accept-ext = OWS ";" OWS token [ "=" ( token / quoted-string ) ] | |||
accept-params = OWS ";" OWS "q=" qvalue *accept-ext | accept-params = OWS ";" OWS "q=" qvalue *accept-ext | |||
attribute = token | attribute = token | |||
charset = token | charset = token | |||
codings = ( content-coding / "*" ) | codings = ( content-coding / "*" ) | |||
content-coding = token | content-coding = token | |||
content-disposition = "Content-Disposition:" OWS | content-disposition = "Content-Disposition:" OWS | |||
content-disposition-v | content-disposition-v | |||
content-disposition-v = disposition-type *( OWS ";" OWS | content-disposition-v = disposition-type *( OWS ";" OWS | |||
skipping to change at page 36, line 39 | skipping to change at page 37, line 46 | |||
disp-extension-parm = token "=" ( token / quoted-string ) | disp-extension-parm = token "=" ( token / quoted-string ) | |||
disp-extension-token = token | disp-extension-token = token | |||
disposition-parm = filename-parm / disp-extension-parm | disposition-parm = filename-parm / disp-extension-parm | |||
disposition-type = "attachment" / disp-extension-token | disposition-type = "attachment" / disp-extension-token | |||
entity-body = *OCTET | entity-body = *OCTET | |||
entity-header = Content-Encoding / Content-Language / Content-Length | entity-header = Content-Encoding / Content-Language / Content-Length | |||
/ Content-Location / Content-MD5 / Content-Range / Content-Type / | / Content-Location / Content-MD5 / Content-Range / Content-Type / | |||
Expires / Last-Modified / extension-header | Expires / Last-Modified / extension-header | |||
extension-header = message-header | extension-header = header-field | |||
filename-parm = "filename=" quoted-string | filename-parm = "filename=" quoted-string | |||
header-field = <header-field, defined in [Part1], Section 3.2> | ||||
language-range = <language-range, defined in [RFC4647], Section 2.1> | language-range = <language-range, defined in [RFC4647], Section 2.1> | |||
language-tag = primary-tag *( "-" subtag ) | language-tag = <Language-Tag, defined in [RFC5646], Section 2.1> | |||
media-range = ( "*/*" / ( type "/*" ) / ( type "/" subtype ) ) *( OWS | media-range = ( "*/*" / ( type "/*" ) / ( type "/" subtype ) ) *( OWS | |||
";" OWS parameter ) | ";" OWS parameter ) | |||
media-type = type "/" subtype *( OWS ";" OWS parameter ) | media-type = type "/" subtype *( OWS ";" OWS parameter ) | |||
message-header = <message-header, defined in [Part1], Section 4.2> | ||||
parameter = attribute "=" value | parameter = attribute "=" value | |||
partial-URI = <partial-URI, defined in [Part1], Section 2.1> | partial-URI = <partial-URI, defined in [Part1], Section 2.6> | |||
primary-tag = 1*8ALPHA | ||||
quoted-string = <quoted-string, defined in [Part1], Section 1.2.2> | quoted-string = <quoted-string, defined in [Part1], Section 1.2.2> | |||
qvalue = <qvalue, defined in [Part1], Section 3.5> | qvalue = <qvalue, defined in [Part1], Section 6.4> | |||
subtag = 1*8ALPHA | ||||
subtype = token | subtype = token | |||
token = <token, defined in [Part1], Section 1.2.2> | token = <token, defined in [Part1], Section 1.2.2> | |||
type = token | type = token | |||
value = token / quoted-string | value = token / quoted-string | |||
ABNF diagnostics: | ABNF diagnostics: | |||
; Accept defined but not used | ; Accept defined but not used | |||
skipping to change at page 40, line 23 | skipping to change at page 41, line 28 | |||
E.8. Since draft-ietf-httpbis-p3-payload-06 | E.8. Since draft-ietf-httpbis-p3-payload-06 | |||
Closed issues: | Closed issues: | |||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/80>: "Content- | o <http://tools.ietf.org/wg/httpbis/trac/ticket/80>: "Content- | |||
Location isn't special" | Location isn't special" | |||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/155>: "Content | o <http://tools.ietf.org/wg/httpbis/trac/ticket/155>: "Content | |||
Sniffing" | Sniffing" | |||
E.9. Since draft-ietf-httpbis-p3-payload-07 | ||||
Closed issues: | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/13>: "Updated | ||||
reference for language tags" | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/110>: "Clarify rules | ||||
for determining what entities a response carries" | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/154>: "Content- | ||||
Location base-setting problems" | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/155>: "Content | ||||
Sniffing" | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/188>: "pick IANA | ||||
policy (RFC5226) for Transfer Coding / Content Coding" | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/189>: "move | ||||
definitions of gzip/deflate/compress to part 1" | ||||
Partly resolved issues: | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/148>: "update IANA | ||||
requirements wrt Transfer-Coding values" (add the IANA | ||||
Considerations subsection) | ||||
o <http://tools.ietf.org/wg/httpbis/trac/ticket/149>: "update IANA | ||||
requirements wrt Content-Coding values" (add the IANA | ||||
Considerations subsection) | ||||
Index | Index | |||
A | A | |||
Accept header 16 | Accept header 17 | |||
Accept-Charset header 18 | Accept-Charset header 19 | |||
Accept-Encoding header 19 | Accept-Encoding header 20 | |||
Accept-Language header 20 | Accept-Language header 21 | |||
Alternates header 35 | Alternates header 36 | |||
C | C | |||
Coding Format | ||||
compress 8 | compress 8 | |||
Content Type Sniffing 13 | deflate 8 | |||
Content-Base header 35 | gzip 9 | |||
Content-Disposition header 34 | identity 9 | |||
Content-Encoding header 22 | compress (Coding Format) 8 | |||
content negotiation 5 | ||||
Content-Base header 36 | ||||
Content-Disposition header 35 | ||||
Content-Encoding header 23 | ||||
Content-Language header 23 | Content-Language header 23 | |||
Content-Location header 24 | Content-Location header 24 | |||
Content-MD5 header 24 | Content-MD5 header 25 | |||
Content-Type header 26 | Content-Type header 26 | |||
Content-Version header 35 | Content-Version header 36 | |||
D | D | |||
deflate 8 | deflate (Coding Format) 8 | |||
Derived-From header 35 | Derived-From header 36 | |||
E | ||||
entity 5 | ||||
G | G | |||
Grammar | Grammar | |||
Accept 16 | Accept 17 | |||
Accept-Charset 18 | Accept-Charset 19 | |||
Accept-Charset-v 18 | Accept-Charset-v 19 | |||
Accept-Encoding 19 | Accept-Encoding 20 | |||
Accept-Encoding-v 19 | Accept-Encoding-v 20 | |||
accept-ext 16 | accept-ext 17 | |||
Accept-Language 21 | Accept-Language 21 | |||
Accept-Language-v 21 | Accept-Language-v 21 | |||
accept-params 16 | accept-params 17 | |||
Accept-v 16 | Accept-v 17 | |||
attribute 9 | attribute 10 | |||
charset 7 | charset 7 | |||
codings 19 | codings 20 | |||
content-coding 8 | content-coding 8 | |||
content-disposition 34 | content-disposition 35 | |||
content-disposition-v 34 | content-disposition-v 35 | |||
Content-Encoding 22 | Content-Encoding 23 | |||
Content-Encoding-v 22 | Content-Encoding-v 23 | |||
Content-Language 23 | Content-Language 23 | |||
Content-Language-v 23 | Content-Language-v 23 | |||
Content-Location 24 | Content-Location 24 | |||
Content-Location-v 24 | Content-Location-v 24 | |||
Content-MD5 25 | Content-MD5 25 | |||
Content-MD5-v 25 | Content-MD5-v 25 | |||
Content-Type 26 | Content-Type 26 | |||
Content-Type-v 26 | Content-Type-v 26 | |||
disp-extension-parm 34 | disp-extension-parm 35 | |||
disp-extension-token 34 | disp-extension-token 35 | |||
disposition-parm 34 | disposition-parm 35 | |||
disposition-type 34 | disposition-type 35 | |||
entity-body 12 | entity-body 13 | |||
entity-header 12 | entity-header 12 | |||
extension-header 12 | extension-header 12 | |||
filename-parm 34 | filename-parm 35 | |||
language-range 21 | language-range 21 | |||
language-tag 11 | language-tag 12 | |||
media-range 16 | media-range 17 | |||
media-type 9 | media-type 9 | |||
MIME-Version 31 | MIME-Version 32 | |||
MIME-Version-v 31 | MIME-Version-v 32 | |||
parameter 9 | parameter 10 | |||
primary-tag 11 | ||||
subtag 11 | ||||
subtype 9 | subtype 9 | |||
type 9 | type 9 | |||
value 9 | value 10 | |||
gzip 8 | gzip (Coding Format) 9 | |||
H | H | |||
Headers | Headers | |||
Accept 16 | Accept 17 | |||
Accept-Charset 18 | Accept-Charset 19 | |||
Accept-Encoding 19 | Accept-Encoding 20 | |||
Accept-Language 20 | Accept-Language 21 | |||
Alternate 35 | Alternate 36 | |||
Content-Base 35 | Content-Base 36 | |||
Content-Disposition 34 | Content-Disposition 35 | |||
Content-Encoding 22 | Content-Encoding 23 | |||
Content-Language 23 | Content-Language 23 | |||
Content-Location 24 | Content-Location 24 | |||
Content-MD5 24 | Content-MD5 25 | |||
Content-Type 26 | Content-Type 26 | |||
Content-Version 35 | Content-Version 36 | |||
Derived-From 35 | Derived-From 36 | |||
Link 35 | Link 36 | |||
MIME-Version 31 | MIME-Version 32 | |||
Public 35 | Public 36 | |||
URI 35 | URI 36 | |||
I | I | |||
identity 8 | identity (Coding Format) 9 | |||
L | L | |||
Link header 35 | Link header 36 | |||
M | M | |||
MIME-Version header 31 | MIME-Version header 32 | |||
P | P | |||
Public header 35 | Public header 36 | |||
R | ||||
representation 5 | ||||
U | U | |||
URI header 35 | URI header 36 | |||
V | ||||
variant 5 | ||||
Authors' Addresses | Authors' Addresses | |||
Roy T. Fielding (editor) | Roy T. Fielding (editor) | |||
Day Software | Day Software | |||
23 Corporate Plaza DR, Suite 280 | 23 Corporate Plaza DR, Suite 280 | |||
Newport Beach, CA 92660 | Newport Beach, CA 92660 | |||
USA | USA | |||
Phone: +1-949-706-5300 | Phone: +1-949-706-5300 | |||
End of changes. 98 change blocks. | ||||
266 lines changed or deleted | 354 lines changed or added | |||
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