Internet Engineering Task Force (IETF)                  R. Fielding, Ed.
Request for Comments: 9112                                         Adobe
STD: 99                                               M. Nottingham, Ed.
Obsoletes: 7230                                                   Fastly
Category: Standards Track                                J. Reschke, Ed.
ISSN: 2070-1721                                               greenbytes
                                                               June 2022





The Hypertext Transfer Protocol (HTTP) is a stateless application-level protocol for distributed, collaborative, hypertext information systems. This document specifies the HTTP/1.1 message syntax, message parsing, connection management, and related security concerns.

HyperText Transfer Protocol(HTTP)は、分散、共同、ハイパーテキスト情報システムのためのステートレスアプリケーションレベルのプロトコルです。このドキュメントは、HTTP/1.1メッセージの構文、メッセージの解析、接続管理、および関連するセキュリティの懸念を指定します。

This document obsoletes portions of RFC 7230.

このドキュメントは、RFC 7230の一部を廃止します。

Status of This Memo


This is an Internet Standards Track document.


This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.

このドキュメントは、インターネットエンジニアリングタスクフォース(IETF)の製品です。IETFコミュニティのコンセンサスを表しています。公開レビューを受けており、インターネットエンジニアリングステアリンググループ(IESG)からの出版が承認されています。インターネット標準の詳細については、RFC 7841のセクション2で入手できます。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved.

著作権(c)2022 IETF Trustおよび文書著者として特定された人。全著作権所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.

このドキュメントは、BCP 78およびIETFドキュメント(に関連するIETF Trustの法的規定の対象となります。この文書に関するあなたの権利と制限を説明するので、これらの文書を注意深く確認してください。このドキュメントから抽出されたコードコンポーネントには、セクション4.Eで説明されている法的規定のセクション4.Eで説明されており、修正されたBSDライセンスで説明されているように保証なしで提供される修正されたBSDライセンステキストを含める必要があります。

This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.


Table of Contents


   1.  Introduction
     1.1.  Requirements Notation
     1.2.  Syntax Notation
   2.  Message
     2.1.  Message Format
     2.2.  Message Parsing
     2.3.  HTTP Version
   3.  Request Line
     3.1.  Method
     3.2.  Request Target
       3.2.1.  origin-form
       3.2.2.  absolute-form
       3.2.3.  authority-form
       3.2.4.  asterisk-form
     3.3.  Reconstructing the Target URI
   4.  Status Line
   5.  Field Syntax
     5.1.  Field Line Parsing
     5.2.  Obsolete Line Folding
   6.  Message Body
     6.1.  Transfer-Encoding
     6.2.  Content-Length
     6.3.  Message Body Length
   7.  Transfer Codings
     7.1.  Chunked Transfer Coding
       7.1.1.  Chunk Extensions
       7.1.2.  Chunked Trailer Section
       7.1.3.  Decoding Chunked
     7.2.  Transfer Codings for Compression
     7.3.  Transfer Coding Registry
     7.4.  Negotiating Transfer Codings
   8.  Handling Incomplete Messages
   9.  Connection Management
     9.1.  Establishment
     9.2.  Associating a Response to a Request
     9.3.  Persistence
       9.3.1.  Retrying Requests
       9.3.2.  Pipelining
     9.4.  Concurrency
     9.5.  Failures and Timeouts
     9.6.  Tear-down
     9.7.  TLS Connection Initiation
     9.8.  TLS Connection Closure
   10. Enclosing Messages as Data
     10.1.  Media Type message/http
     10.2.  Media Type application/http
   11. Security Considerations
     11.1.  Response Splitting
     11.2.  Request Smuggling
     11.3.  Message Integrity
     11.4.  Message Confidentiality
   12. IANA Considerations
     12.1.  Field Name Registration
     12.2.  Media Type Registration
     12.3.  Transfer Coding Registration
     12.4.  ALPN Protocol ID Registration
   13. References
     13.1.  Normative References
     13.2.  Informative References
   Appendix A.  Collected ABNF
   Appendix B.  Differences between HTTP and MIME
     B.1.  MIME-Version
     B.2.  Conversion to Canonical Form
     B.3.  Conversion of Date Formats
     B.4.  Conversion of Content-Encoding
     B.5.  Conversion of Content-Transfer-Encoding
     B.6.  MHTML and Line Length Limitations
   Appendix C.  Changes from Previous RFCs
     C.1.  Changes from HTTP/0.9
     C.2.  Changes from HTTP/1.0
       C.2.1.  Multihomed Web Servers
       C.2.2.  Keep-Alive Connections
       C.2.3.  Introduction of Transfer-Encoding
     C.3.  Changes from RFC 7230
   Authors' Addresses
1. Introduction
1. はじめに

The Hypertext Transfer Protocol (HTTP) is a stateless application-level request/response protocol that uses extensible semantics and self-descriptive messages for flexible interaction with network-based hypertext information systems. HTTP/1.1 is defined by:

HyperText Transfer Protocol(HTTP)は、ネットワークベースのハイパーテキスト情報システムとの柔軟な相互作用のために、拡張可能なセマンティクスと自己記述的なメッセージを使用するステートレスアプリケーションレベルのリクエスト/応答プロトコルです。HTTP/1.1は次のように定義されています。

* This document

* このドキュメント

* "HTTP Semantics" [HTTP]

* 「HTTPセマンティクス」[HTTP]

* "HTTP Caching" [CACHING]

* 「HTTPキャッシュ」[キャッシュ]

This document specifies how HTTP semantics are conveyed using the HTTP/1.1 message syntax, framing, and connection management mechanisms. Its goal is to define the complete set of requirements for HTTP/1.1 message parsers and message-forwarding intermediaries.


This document obsoletes the portions of RFC 7230 related to HTTP/1.1 messaging and connection management, with the changes being summarized in Appendix C.3. The other parts of RFC 7230 are obsoleted by "HTTP Semantics" [HTTP].

このドキュメントは、HTTP/1.1メッセージングと接続管理に関連するRFC 7230の部分を廃止し、変更は付録C.3に要約されています。RFC 7230の他の部分は、「HTTPセマンティクス」[HTTP]によって廃止されています。

1.1. Requirements Notation
1.1. 要件表記

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

この文書のキーワード "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", および "OPTIONAL" はBCP 14 [RFC2119] [RFC8174]で説明されているように、すべて大文字の場合にのみ解釈されます。

Conformance criteria and considerations regarding error handling are defined in Section 2 of [HTTP].


1.2. Syntax Notation
1.2. 構文表記

This specification uses the Augmented Backus-Naur Form (ABNF) notation of [RFC5234], extended with the notation for case-sensitivity in strings defined in [RFC7405].


It also uses a list extension, defined in Section 5.6.1 of [HTTP], that allows for compact definition of comma-separated lists using a "#" operator (similar to how the "*" operator indicates repetition). Appendix A shows the collected grammar with all list operators expanded to standard ABNF notation.


As a convention, ABNF rule names prefixed with "obs-" denote obsolete grammar rules that appear for historical reasons.


The following core rules are included by reference, as defined in [RFC5234], Appendix B.1: ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double quote), HEXDIG (hexadecimal 0-9/A-F/a-f), HTAB (horizontal tab), LF (line feed), OCTET (any 8-bit sequence of data), SP (space), and VCHAR (any visible [USASCII] character).

[RFC5234]、付録B.1:アルファ(文字)、CR(キャリッジリターン)、CRLF(CR LF)、CTL(コントロール)、数字(10-9)で定義されているように、次のコアルールが参照により含まれます。、dquote(二重引用)、hexdig(hexadecimal 0-9/a-f/a-f)、htab(水平タブ)、lf(ラインフィード)、オクテット(データの8ビットシーケンス)、sp(スペース)、およびvchar(目に見える[usascii]文字)。

The rules below are defined in [HTTP]:


     BWS           = <BWS, see [HTTP], Section 5.6.3>
     OWS           = <OWS, see [HTTP], Section 5.6.3>
     RWS           = <RWS, see [HTTP], Section 5.6.3>
     absolute-path = <absolute-path, see [HTTP], Section 4.1>
     field-name    = <field-name, see [HTTP], Section 5.1>
     field-value   = <field-value, see [HTTP], Section 5.5>
     obs-text      = <obs-text, see [HTTP], Section 5.6.4>
     quoted-string = <quoted-string, see [HTTP], Section 5.6.4>
     token         = <token, see [HTTP], Section 5.6.2>
     transfer-coding =
                     <transfer-coding, see [HTTP], Section 10.1.4>

The rules below are defined in [URI]:


     absolute-URI  = <absolute-URI, see [URI], Section 4.3>
     authority     = <authority, see [URI], Section 3.2>
     uri-host      = <host, see [URI], Section 3.2.2>
     port          = <port, see [URI], Section 3.2.3>
     query         = <query, see [URI], Section 3.4>
2. Message
2. メッセージ

HTTP/1.1 clients and servers communicate by sending messages. See Section 3 of [HTTP] for the general terminology and core concepts of HTTP.


2.1. Message Format
2.1. メッセージ形式

An HTTP/1.1 message consists of a start-line followed by a CRLF and a sequence of octets in a format similar to the Internet Message Format [RFC5322]: zero or more header field lines (collectively referred to as the "headers" or the "header section"), an empty line indicating the end of the header section, and an optional message body.


HTTP-message = start-line CRLF *( field-line CRLF ) CRLF [ message-body ]

http-message = start-line crlf *(field-line crlf)crlf [message-body]

A message can be either a request from client to server or a response from server to client. Syntactically, the two types of messages differ only in the start-line, which is either a request-line (for requests) or a status-line (for responses), and in the algorithm for determining the length of the message body (Section 6).


     start-line     = request-line / status-line

In theory, a client could receive requests and a server could receive responses, distinguishing them by their different start-line formats. In practice, servers are implemented to only expect a request (a response is interpreted as an unknown or invalid request method), and clients are implemented to only expect a response.


HTTP makes use of some protocol elements similar to the Multipurpose Internet Mail Extensions (MIME) [RFC2045]. See Appendix B for the differences between HTTP and MIME messages.


2.2. Message Parsing
2.2. メッセージの解析

The normal procedure for parsing an HTTP message is to read the start-line into a structure, read each header field line into a hash table by field name until the empty line, and then use the parsed data to determine if a message body is expected. If a message body has been indicated, then it is read as a stream until an amount of octets equal to the message body length is read or the connection is closed.


A recipient MUST parse an HTTP message as a sequence of octets in an encoding that is a superset of US-ASCII [USASCII]. Parsing an HTTP message as a stream of Unicode characters, without regard for the specific encoding, creates security vulnerabilities due to the varying ways that string processing libraries handle invalid multibyte character sequences that contain the octet LF (%x0A). String-based parsers can only be safely used within protocol elements after the element has been extracted from the message, such as within a header field line value after message parsing has delineated the individual field lines.

受信者は、US-ASCII [USASCII]のスーパーセットであるエンコードのオクテットのシーケンスとしてHTTPメッセージを解析する必要があります。特定のエンコードに関係なく、HTTPメッセージをユニコード文字のストリームとして解析すると、文字列処理ライブラリがオクテットLF(%x0a)を含む無効なマルチバイト文字シーケンスを処理する方法がさまざまな方法でセキュリティの脆弱性を作成します。文字列ベースのパーサーは、メッセージから個々のフィールドラインを描写した後のヘッダーフィールドライン値内など、メッセージから要素が抽出された後、プロトコル要素内でのみ安全に使用できます。

Although the line terminator for the start-line and fields is the sequence CRLF, a recipient MAY recognize a single LF as a line terminator and ignore any preceding CR.


A sender MUST NOT generate a bare CR (a CR character not immediately followed by LF) within any protocol elements other than the content. A recipient of such a bare CR MUST consider that element to be invalid or replace each bare CR with SP before processing the element or forwarding the message.


Older HTTP/1.0 user agent implementations might send an extra CRLF after a POST request as a workaround for some early server applications that failed to read message body content that was not terminated by a line-ending. An HTTP/1.1 user agent MUST NOT preface or follow a request with an extra CRLF. If terminating the request message body with a line-ending is desired, then the user agent MUST count the terminating CRLF octets as part of the message body length.


In the interest of robustness, a server that is expecting to receive and parse a request-line SHOULD ignore at least one empty line (CRLF) received prior to the request-line.


A sender MUST NOT send whitespace between the start-line and the first header field.


A recipient that receives whitespace between the start-line and the first header field MUST either reject the message as invalid or consume each whitespace-preceded line without further processing of it (i.e., ignore the entire line, along with any subsequent lines preceded by whitespace, until a properly formed header field is received or the header section is terminated). Rejection or removal of invalid whitespace-preceded lines is necessary to prevent their misinterpretation by downstream recipients that might be vulnerable to request smuggling (Section 11.2) or response splitting (Section 11.1) attacks.


When a server listening only for HTTP request messages, or processing what appears from the start-line to be an HTTP request message, receives a sequence of octets that does not match the HTTP-message grammar aside from the robustness exceptions listed above, the server SHOULD respond with a 400 (Bad Request) response and close the connection.


2.3. HTTP Version
2.3. HTTPバージョン

HTTP uses a "<major>.<minor>" numbering scheme to indicate versions of the protocol. This specification defines version "1.1". Section 2.5 of [HTTP] specifies the semantics of HTTP version numbers.


The version of an HTTP/1.x message is indicated by an HTTP-version field in the start-line. HTTP-version is case-sensitive.


     HTTP-version  = HTTP-name "/" DIGIT "." DIGIT
     HTTP-name     = %s"HTTP"

When an HTTP/1.1 message is sent to an HTTP/1.0 recipient [HTTP/1.0] or a recipient whose version is unknown, the HTTP/1.1 message is constructed such that it can be interpreted as a valid HTTP/1.0 message if all of the newer features are ignored. This specification places recipient-version requirements on some new features so that a conformant sender will only use compatible features until it has determined, through configuration or the receipt of a message, that the recipient supports HTTP/1.1.


Intermediaries that process HTTP messages (i.e., all intermediaries other than those acting as tunnels) MUST send their own HTTP-version in forwarded messages, unless it is purposefully downgraded as a workaround for an upstream issue. In other words, an intermediary is not allowed to blindly forward the start-line without ensuring that the protocol version in that message matches a version to which that intermediary is conformant for both the receiving and sending of messages. Forwarding an HTTP message without rewriting the HTTP-version might result in communication errors when downstream recipients use the message sender's version to determine what features are safe to use for later communication with that sender.


A server MAY send an HTTP/1.0 response to an HTTP/1.1 request if it is known or suspected that the client incorrectly implements the HTTP specification and is incapable of correctly processing later version responses, such as when a client fails to parse the version number correctly or when an intermediary is known to blindly forward the HTTP-version even when it doesn't conform to the given minor version of the protocol. Such protocol downgrades SHOULD NOT be performed unless triggered by specific client attributes, such as when one or more of the request header fields (e.g., User-Agent) uniquely match the values sent by a client known to be in error.


3. Request Line
3. リクエスト行

A request-line begins with a method token, followed by a single space (SP), the request-target, and another single space (SP), and ends with the protocol version.


     request-line   = method SP request-target SP HTTP-version

Although the request-line grammar rule requires that each of the component elements be separated by a single SP octet, recipients MAY instead parse on whitespace-delimited word boundaries and, aside from the CRLF terminator, treat any form of whitespace as the SP separator while ignoring preceding or trailing whitespace; such whitespace includes one or more of the following octets: SP, HTAB, VT (%x0B), FF (%x0C), or bare CR. However, lenient parsing can result in request smuggling security vulnerabilities if there are multiple recipients of the message and each has its own unique interpretation of robustness (see Section 11.2).


HTTP does not place a predefined limit on the length of a request-line, as described in Section 2.3 of [HTTP]. A server that receives a method longer than any that it implements SHOULD respond with a 501 (Not Implemented) status code. A server that receives a request-target longer than any URI it wishes to parse MUST respond with a 414 (URI Too Long) status code (see Section 15.5.15 of [HTTP]).


Various ad hoc limitations on request-line length are found in practice. It is RECOMMENDED that all HTTP senders and recipients support, at a minimum, request-line lengths of 8000 octets.


3.1. Method
3.1. 方法

The method token indicates the request method to be performed on the target resource. The request method is case-sensitive.


     method         = token

The request methods defined by this specification can be found in Section 9 of [HTTP], along with information regarding the HTTP method registry and considerations for defining new methods.


3.2. Request Target
3.2. ターゲットをリクエストします

The request-target identifies the target resource upon which to apply the request. The client derives a request-target from its desired target URI. There are four distinct formats for the request-target, depending on both the method being requested and whether the request is to a proxy.


     request-target = origin-form
                    / absolute-form
                    / authority-form
                    / asterisk-form

No whitespace is allowed in the request-target. Unfortunately, some user agents fail to properly encode or exclude whitespace found in hypertext references, resulting in those disallowed characters being sent as the request-target in a malformed request-line.


Recipients of an invalid request-line SHOULD respond with either a 400 (Bad Request) error or a 301 (Moved Permanently) redirect with the request-target properly encoded. A recipient SHOULD NOT attempt to autocorrect and then process the request without a redirect, since the invalid request-line might be deliberately crafted to bypass security filters along the request chain.


A client MUST send a Host header field (Section 7.2 of [HTTP]) in all HTTP/1.1 request messages. If the target URI includes an authority component, then a client MUST send a field value for Host that is identical to that authority component, excluding any userinfo subcomponent and its "@" delimiter (Section 4.2 of [HTTP]). If the authority component is missing or undefined for the target URI, then a client MUST send a Host header field with an empty field value.


A server MUST respond with a 400 (Bad Request) status code to any HTTP/1.1 request message that lacks a Host header field and to any request message that contains more than one Host header field line or a Host header field with an invalid field value.


3.2.1. origin-form
3.2.1. 原点形式

The most common form of request-target is the "origin-form".


origin-form = absolute-path [ "?" query ]

Origin-form = absolute-path ["?"クエリ]

When making a request directly to an origin server, other than a CONNECT or server-wide OPTIONS request (as detailed below), a client MUST send only the absolute path and query components of the target URI as the request-target. If the target URI's path component is empty, the client MUST send "/" as the path within the origin-form of request-target. A Host header field is also sent, as defined in Section 7.2 of [HTTP].


For example, a client wishing to retrieve a representation of the resource identified as


directly from the origin server would open (or reuse) a TCP connection to port 80 of the host "" and send the lines:

Origin Serverから直接、ホスト「」のポート80へのTCP接続を開きます(または再利用します)。

   GET /where?q=now HTTP/1.1

followed by the remainder of the request message.


3.2.2. absolute-form
3.2.2. 絶対形式

When making a request to a proxy, other than a CONNECT or server-wide OPTIONS request (as detailed below), a client MUST send the target URI in "absolute-form" as the request-target.


     absolute-form  = absolute-URI

The proxy is requested to either service that request from a valid cache, if possible, or make the same request on the client's behalf either to the next inbound proxy server or directly to the origin server indicated by the request-target. Requirements on such "forwarding" of messages are defined in Section 7.6 of [HTTP].


An example absolute-form of request-line would be:


   GET HTTP/1.1

A client MUST send a Host header field in an HTTP/1.1 request even if the request-target is in the absolute-form, since this allows the Host information to be forwarded through ancient HTTP/1.0 proxies that might not have implemented Host.


When a proxy receives a request with an absolute-form of request-target, the proxy MUST ignore the received Host header field (if any) and instead replace it with the host information of the request-target. A proxy that forwards such a request MUST generate a new Host field value based on the received request-target rather than forward the received Host field value.


When an origin server receives a request with an absolute-form of request-target, the origin server MUST ignore the received Host header field (if any) and instead use the host information of the request-target. Note that if the request-target does not have an authority component, an empty Host header field will be sent in this case.

Origin Serverがリクエストターゲットの絶対形式でリクエストを受信した場合、Origin Serverは受信したホストヘッダーフィールド(存在する場合)を無視し、代わりにリクエストターゲットのホスト情報を使用する必要があります。リクエストターゲットに権限コンポーネントがない場合、この場合は空のホストヘッダーフィールドが送信されることに注意してください。

A server MUST accept the absolute-form in requests even though most HTTP/1.1 clients will only send the absolute-form to a proxy.


3.2.3. authority-form
3.2.3. 権限形式

The "authority-form" of request-target is only used for CONNECT requests (Section 9.3.6 of [HTTP]). It consists of only the uri-host and port number of the tunnel destination, separated by a colon (":").

リクエストターゲットの「権限形式」は、接続要求にのみ使用されます([HTTP]のセクション9.3.6)。これは、コロン( ":")で区切られたトンネルの目的地のURIホストとポート番号のみで構成されています。

authority-form = uri-host ":" port

authority-form = uri-host ":"ポート

When making a CONNECT request to establish a tunnel through one or more proxies, a client MUST send only the host and port of the tunnel destination as the request-target. The client obtains the host and port from the target URI's authority component, except that it sends the scheme's default port if the target URI elides the port. For example, a CONNECT request to "" looks like the following:


CONNECT HTTP/1.1 Host: http/1.1ホスト:www.example.comを接続します

3.2.4. asterisk-form
3.2.4. アスタリスク形式

The "asterisk-form" of request-target is only used for a server-wide OPTIONS request (Section 9.3.7 of [HTTP]).


asterisk-form = "*"

Asterisk-form = "*"

When a client wishes to request OPTIONS for the server as a whole, as opposed to a specific named resource of that server, the client MUST send only "*" (%x2A) as the request-target. For example,



オプション * http/1.1

If a proxy receives an OPTIONS request with an absolute-form of request-target in which the URI has an empty path and no query component, then the last proxy on the request chain MUST send a request-target of "*" when it forwards the request to the indicated origin server.


For example, the request



would be forwarded by the final proxy as



after connecting to port 8001 of host "".


3.3. Reconstructing the Target URI
3.3. ターゲットURIの再構築

The target URI is the request-target when the request-target is in absolute-form. In that case, a server will parse the URI into its generic components for further evaluation.


Otherwise, the server reconstructs the target URI from the connection context and various parts of the request message in order to identify the target resource (Section 7.1 of [HTTP]):


* If the server's configuration provides for a fixed URI scheme, or a scheme is provided by a trusted outbound gateway, that scheme is used for the target URI. This is common in large-scale deployments because a gateway server will receive the client's connection context and replace that with their own connection to the inbound server. Otherwise, if the request is received over a secured connection, the target URI's scheme is "https"; if not, the scheme is "http".

* サーバーの構成が固定URIスキームを提供する場合、またはスキームが信頼できるアウトバウンドゲートウェイによって提供される場合、そのスキームはターゲットURIに使用されます。これは、ゲートウェイサーバーがクライアントの接続コンテキストを受信し、インバウンドサーバーへの独自の接続に置き換えるため、大規模な展開で一般的です。それ以外の場合、リクエストが担保付き接続で受信された場合、ターゲットURIのスキームは「HTTPS」です。そうでない場合、スキームは「HTTP」です。

* If the request-target is in authority-form, the target URI's authority component is the request-target. Otherwise, the target URI's authority component is the field value of the Host header field. If there is no Host header field or if its field value is empty or invalid, the target URI's authority component is empty.

* リクエストターゲットが権限形式にある場合、ターゲットURIの権限コンポーネントはリクエストターゲットです。それ以外の場合、ターゲットURIの権限コンポーネントは、ホストヘッダーフィールドのフィールド値です。ホストヘッダーフィールドがない場合、またはそのフィールド値が空または無効な場合、ターゲットURIの権限コンポーネントは空です。

* If the request-target is in authority-form or asterisk-form, the target URI's combined path and query component is empty. Otherwise, the target URI's combined path and query component is the request-target.

* リクエストターゲットが権威形式またはアスタリスク形式である場合、ターゲットURIの組み合わせパスとクエリコンポーネントが空です。それ以外の場合、ターゲットURIの組み合わせパスとクエリコンポーネントがリクエストターゲットです。

* The components of a reconstructed target URI, once determined as above, can be recombined into absolute-URI form by concatenating the scheme, "://", authority, and combined path and query component.

* 再構築されたターゲットURIのコンポーネントは、上記のように決定されると、スキームを合わせて「//」、権威、およびクエリコンポーネントを結合することにより、絶対尿型に再結合できます。

Example 1: The following message received over a secure connection


   GET /pub/WWW/TheProject.html HTTP/1.1

has a target URI of


Example 2: The following message received over an insecure connection



has a target URI of


If the target URI's authority component is empty and its URI scheme requires a non-empty authority (as is the case for "http" and "https"), the server can reject the request or determine whether a configured default applies that is consistent with the incoming connection's context. Context might include connection details like address and port, what security has been applied, and locally defined information specific to that server's configuration. An empty authority is replaced with the configured default before further processing of the request.


Supplying a default name for authority within the context of a secured connection is inherently unsafe if there is any chance that the user agent's intended authority might differ from the default. A server that can uniquely identify an authority from the request context MAY use that identity as a default without this risk. Alternatively, it might be better to redirect the request to a safe resource that explains how to obtain a new client.


Note that reconstructing the client's target URI is only half of the process for identifying a target resource. The other half is determining whether that target URI identifies a resource for which the server is willing and able to send a response, as defined in Section 7.4 of [HTTP].


4. Status Line
4. ステータス行

The first line of a response message is the status-line, consisting of the protocol version, a space (SP), the status code, and another space and ending with an OPTIONAL textual phrase describing the status code.


status-line = HTTP-version SP status-code SP [ reason-phrase ]

ステータスライン= http-version spステータスコードSP [Reason-Phrase]

Although the status-line grammar rule requires that each of the component elements be separated by a single SP octet, recipients MAY instead parse on whitespace-delimited word boundaries and, aside from the line terminator, treat any form of whitespace as the SP separator while ignoring preceding or trailing whitespace; such whitespace includes one or more of the following octets: SP, HTAB, VT (%x0B), FF (%x0C), or bare CR. However, lenient parsing can result in response splitting security vulnerabilities if there are multiple recipients of the message and each has its own unique interpretation of robustness (see Section 11.1).


The status-code element is a 3-digit integer code describing the result of the server's attempt to understand and satisfy the client's corresponding request. A recipient parses and interprets the remainder of the response message in light of the semantics defined for that status code, if the status code is recognized by that recipient, or in accordance with the class of that status code when the specific code is unrecognized.


     status-code    = 3DIGIT

HTTP's core status codes are defined in Section 15 of [HTTP], along with the classes of status codes, considerations for the definition of new status codes, and the IANA registry for collecting such definitions.


The reason-phrase element exists for the sole purpose of providing a textual description associated with the numeric status code, mostly out of deference to earlier Internet application protocols that were more frequently used with interactive text clients.

Interactive Textクライアントでより頻繁に使用される以前のインターネットアプリケーションプロトコルに主に敬意を払って、数値ステータスコードに関連付けられたテキスト説明を提供するという唯一の目的のために、Reason-Phrase要素が存在します。

     reason-phrase  = 1*( HTAB / SP / VCHAR / obs-text )

A client SHOULD ignore the reason-phrase content because it is not a reliable channel for information (it might be translated for a given locale, overwritten by intermediaries, or discarded when the message is forwarded via other versions of HTTP). A server MUST send the space that separates the status-code from the reason-phrase even when the reason-phrase is absent (i.e., the status-line would end with the space).


5. Field Syntax
5. フィールド構文

Each field line consists of a case-insensitive field name followed by a colon (":"), optional leading whitespace, the field line value, and optional trailing whitespace.

各フィールドラインは、ケースに依存しないフィールド名で構成されており、それに続くコロン( ":")、オプションの先頭の白文学、フィールドライン値、およびオプションの末尾の白文学が続きます。

field-line = field-name ":" OWS field-value OWS

field-line = field-name ":" ows field-value ows

Rules for parsing within field values are defined in Section 5.5 of [HTTP]. This section covers the generic syntax for header field inclusion within, and extraction from, HTTP/1.1 messages.


5.1. Field Line Parsing
5.1. フィールドライン解析

Messages are parsed using a generic algorithm, independent of the individual field names. The contents within a given field line value are not parsed until a later stage of message interpretation (usually after the message's entire field section has been processed).


No whitespace is allowed between the field name and colon. In the past, differences in the handling of such whitespace have led to security vulnerabilities in request routing and response handling. A server MUST reject, with a response status code of 400 (Bad Request), any received request message that contains whitespace between a header field name and colon. A proxy MUST remove any such whitespace from a response message before forwarding the message downstream.


A field line value might be preceded and/or followed by optional whitespace (OWS); a single SP preceding the field line value is preferred for consistent readability by humans. The field line value does not include that leading or trailing whitespace: OWS occurring before the first non-whitespace octet of the field line value, or after the last non-whitespace octet of the field line value, is excluded by parsers when extracting the field line value from a field line.


5.2. Obsolete Line Folding
5.2. 時代遅れの線の折りたたみ

Historically, HTTP/1.x field values could be extended over multiple lines by preceding each extra line with at least one space or horizontal tab (obs-fold). This specification deprecates such line folding except within the "message/http" media type (Section 10.1).


obs-fold = OWS CRLF RWS ; obsolete line folding

obsfold = ows crlf rws;時代遅れの線の折りたたみ

A sender MUST NOT generate a message that includes line folding (i.e., that has any field line value that contains a match to the obs-fold rule) unless the message is intended for packaging within the "message/http" media type.


A server that receives an obs-fold in a request message that is not within a "message/http" container MUST either reject the message by sending a 400 (Bad Request), preferably with a representation explaining that obsolete line folding is unacceptable, or replace each received obs-fold with one or more SP octets prior to interpreting the field value or forwarding the message downstream.


A proxy or gateway that receives an obs-fold in a response message that is not within a "message/http" container MUST either discard the message and replace it with a 502 (Bad Gateway) response, preferably with a representation explaining that unacceptable line folding was received, or replace each received obs-fold with one or more SP octets prior to interpreting the field value or forwarding the message downstream.


A user agent that receives an obs-fold in a response message that is not within a "message/http" container MUST replace each received obs-fold with one or more SP octets prior to interpreting the field value.


6. Message Body
6. メッセージ本文

The message body (if any) of an HTTP/1.1 message is used to carry content (Section 6.4 of [HTTP]) for the request or response. The message body is identical to the content unless a transfer coding has been applied, as described in Section 6.1.


     message-body = *OCTET

The rules for determining when a message body is present in an HTTP/1.1 message differ for requests and responses.


The presence of a message body in a request is signaled by a Content-Length or Transfer-Encoding header field. Request message framing is independent of method semantics.


The presence of a message body in a response, as detailed in Section 6.3, depends on both the request method to which it is responding and the response status code. This corresponds to when response content is allowed by HTTP semantics (Section 6.4.1 of [HTTP]).


6.1. Transfer-Encoding
6.1. 転送エンコード

The Transfer-Encoding header field lists the transfer coding names corresponding to the sequence of transfer codings that have been (or will be) applied to the content in order to form the message body. Transfer codings are defined in Section 7.


     Transfer-Encoding = #transfer-coding
                          ; defined in [HTTP], Section 10.1.4

Transfer-Encoding is analogous to the Content-Transfer-Encoding field of MIME, which was designed to enable safe transport of binary data over a 7-bit transport service ([RFC2045], Section 6). However, safe transport has a different focus for an 8bit-clean transfer protocol. In HTTP's case, Transfer-Encoding is primarily intended to accurately delimit dynamically generated content. It also serves to distinguish encodings that are only applied in transit from the encodings that are a characteristic of the selected representation.


A recipient MUST be able to parse the chunked transfer coding (Section 7.1) because it plays a crucial role in framing messages when the content size is not known in advance. A sender MUST NOT apply the chunked transfer coding more than once to a message body (i.e., chunking an already chunked message is not allowed). If any transfer coding other than chunked is applied to a request's content, the sender MUST apply chunked as the final transfer coding to ensure that the message is properly framed. If any transfer coding other than chunked is applied to a response's content, the sender MUST either apply chunked as the final transfer coding or terminate the message by closing the connection.


For example,


Transfer-Encoding: gzip, chunked


indicates that the content has been compressed using the gzip coding and then chunked using the chunked coding while forming the message body.


Unlike Content-Encoding (Section 8.4.1 of [HTTP]), Transfer-Encoding is a property of the message, not of the representation. Any recipient along the request/response chain MAY decode the received transfer coding(s) or apply additional transfer coding(s) to the message body, assuming that corresponding changes are made to the Transfer-Encoding field value. Additional information about the encoding parameters can be provided by other header fields not defined by this specification.


Transfer-Encoding MAY be sent in a response to a HEAD request or in a 304 (Not Modified) response (Section 15.4.5 of [HTTP]) to a GET request, neither of which includes a message body, to indicate that the origin server would have applied a transfer coding to the message body if the request had been an unconditional GET. This indication is not required, however, because any recipient on the response chain (including the origin server) can remove transfer codings when they are not needed.

転送エンコードは、ヘッドリクエストへの応答または304(変更されていない)応答([http]のセクション15.4.5)で送信される場合があります。リクエストが無条件のGETであった場合、サーバーはメッセージ本文に転送コーディングを適用していました。ただし、応答チェーンの受信者(Origin Serverを含む)の受信者は、不要な場合に転送コードを削除できるため、この表示は必要ありません。

A server MUST NOT send a Transfer-Encoding header field in any response with a status code of 1xx (Informational) or 204 (No Content). A server MUST NOT send a Transfer-Encoding header field in any 2xx (Successful) response to a CONNECT request (Section 9.3.6 of [HTTP]).


A server that receives a request message with a transfer coding it does not understand SHOULD respond with 501 (Not Implemented).


Transfer-Encoding was added in HTTP/1.1. It is generally assumed that implementations advertising only HTTP/1.0 support will not understand how to process transfer-encoded content, and that an HTTP/1.0 message received with a Transfer-Encoding is likely to have been forwarded without proper handling of the chunked transfer coding in transit.


A client MUST NOT send a request containing Transfer-Encoding unless it knows the server will handle HTTP/1.1 requests (or later minor revisions); such knowledge might be in the form of specific user configuration or by remembering the version of a prior received response. A server MUST NOT send a response containing Transfer-Encoding unless the corresponding request indicates HTTP/1.1 (or later minor revisions).


Early implementations of Transfer-Encoding would occasionally send both a chunked transfer coding for message framing and an estimated Content-Length header field for use by progress bars. This is why Transfer-Encoding is defined as overriding Content-Length, as opposed to them being mutually incompatible. Unfortunately, forwarding such a message can lead to vulnerabilities regarding request smuggling (Section 11.2) or response splitting (Section 11.1) attacks if any downstream recipient fails to parse the message according to this specification, particularly when a downstream recipient only implements HTTP/1.0.


A server MAY reject a request that contains both Content-Length and Transfer-Encoding or process such a request in accordance with the Transfer-Encoding alone. Regardless, the server MUST close the connection after responding to such a request to avoid the potential attacks.


A server or client that receives an HTTP/1.0 message containing a Transfer-Encoding header field MUST treat the message as if the framing is faulty, even if a Content-Length is present, and close the connection after processing the message. The message sender might have retained a portion of the message, in buffer, that could be misinterpreted by further use of the connection.


6.2. Content-Length
6.2. コンテンツレングス

When a message does not have a Transfer-Encoding header field, a Content-Length header field (Section 8.6 of [HTTP]) can provide the anticipated size, as a decimal number of octets, for potential content. For messages that do include content, the Content-Length field value provides the framing information necessary for determining where the data (and message) ends. For messages that do not include content, the Content-Length indicates the size of the selected representation (Section 8.6 of [HTTP]).


A sender MUST NOT send a Content-Length header field in any message that contains a Transfer-Encoding header field.


      |  *Note:* HTTP's use of Content-Length for message framing
      |  differs significantly from the same field's use in MIME, where
      |  it is an optional field used only within the "message/external-
      |  body" media-type.
6.3. Message Body Length
6.3. メッセージボディの長さ

The length of a message body is determined by one of the following (in order of precedence):


1. Any response to a HEAD request and any response with a 1xx (Informational), 204 (No Content), or 304 (Not Modified) status code is always terminated by the first empty line after the header fields, regardless of the header fields present in the message, and thus cannot contain a message body or trailer section.

1. ヘッドリクエストへの応答と1xx(情報)、204(コンテンツなし)、または304(変更されていない)ステータスコードを含む応答は、ヘッダーフィールドの後に最初の空の行によって常に終了します。メッセージ、したがってメッセージ本文またはトレーラーセクションを含めることはできません。

2. Any 2xx (Successful) response to a CONNECT request implies that the connection will become a tunnel immediately after the empty line that concludes the header fields. A client MUST ignore any Content-Length or Transfer-Encoding header fields received in such a message.

2. 接続要求に対する2xx(成功)応答は、ヘッダーフィールドを終了する空の行の直後に接続がトンネルになることを意味します。クライアントは、そのようなメッセージで受信したコンテンツレングスまたは転送エンコードヘッダーフィールドを無視する必要があります。

3. If a message is received with both a Transfer-Encoding and a Content-Length header field, the Transfer-Encoding overrides the Content-Length. Such a message might indicate an attempt to perform request smuggling (Section 11.2) or response splitting (Section 11.1) and ought to be handled as an error. An intermediary that chooses to forward the message MUST first remove the received Content-Length field and process the Transfer-Encoding (as described below) prior to forwarding the message downstream.

3. 転送エンコードとコンテンツ長ヘッダーフィールドの両方でメッセージが受信された場合、転送エンコードはコンテンツレングスをオーバーライドします。このようなメッセージは、要求の密輸(セクション11.2)または応答分割(セクション11.1)を実行する試みを示している可能性があり、エラーとして処理する必要があります。メッセージを転送することを選択した仲介者は、最初に受信したコンテンツレングスフィールドを削除し、メッセージを下流に転送する前に(以下で説明するように)転送エンコードを処理する必要があります。

4. If a Transfer-Encoding header field is present and the chunked transfer coding (Section 7.1) is the final encoding, the message body length is determined by reading and decoding the chunked data until the transfer coding indicates the data is complete.

4. 転送エンコードヘッダーフィールドが存在し、チャンクされた転送コーディング(セクション7.1)が最終エンコーディングである場合、メッセージボディの長さは、転送コーディングがデータが完了することを示すまで、チャンクデータを読み取り、デコードすることによって決定されます。

If a Transfer-Encoding header field is present in a response and the chunked transfer coding is not the final encoding, the message body length is determined by reading the connection until it is closed by the server.


If a Transfer-Encoding header field is present in a request and the chunked transfer coding is not the final encoding, the message body length cannot be determined reliably; the server MUST respond with the 400 (Bad Request) status code and then close the connection.


5. If a message is received without Transfer-Encoding and with an invalid Content-Length header field, then the message framing is invalid and the recipient MUST treat it as an unrecoverable error, unless the field value can be successfully parsed as a comma-separated list (Section 5.6.1 of [HTTP]), all values in the list are valid, and all values in the list are the same (in which case, the message is processed with that single value used as the Content-Length field value). If the unrecoverable error is in a request message, the server MUST respond with a 400 (Bad Request) status code and then close the connection. If it is in a response message received by a proxy, the proxy MUST close the connection to the server, discard the received response, and send a 502 (Bad Gateway) response to the client. If it is in a response message received by a user agent, the user agent MUST close the connection to the server and discard the received response.

5. 転送エンコードなしでメッセージが受信され、コンテンツレングスのヘッダーフィールドが無効になった場合、メッセージフレーミングは無効であり、フィールド値をコンマ分離リストとして正常に解析できる場合を除き、受信者はそれを回復不可能なエラーとして扱う必要があります。([http]のセクション5.6.1)、リスト内のすべての値は有効であり、リスト内のすべての値は同じです(この場合、メッセージはコンテンツレングスのフィールド値として使用される単一値で処理されます)。回復不可能なエラーがリクエストメッセージにある場合、サーバーは400(悪い要求)ステータスコードで応答し、接続を閉じる必要があります。プロキシによって受信された応答メッセージにある場合、プロキシはサーバーへの接続を閉じ、受信した応答を破棄し、クライアントに502(悪いゲートウェイ)応答を送信する必要があります。ユーザーエージェントが受信した応答メッセージに含まれている場合、ユーザーエージェントはサーバーへの接続を閉じて、受信した応答を破棄する必要があります。

6. If a valid Content-Length header field is present without Transfer-Encoding, its decimal value defines the expected message body length in octets. If the sender closes the connection or the recipient times out before the indicated number of octets are received, the recipient MUST consider the message to be incomplete and close the connection.

6. 有効なコンテンツレングスヘッダーフィールドが転送エンコードなしで存在する場合、その小数値はオクテットの予想されるメッセージボディの長さを定義します。指定されたオクテットの数を受信する前に送信者が接続を閉じるか、受信者がタイムアウトした場合、受信者はメッセージが不完全で接続を閉じることを検討する必要があります。

7. If this is a request message and none of the above are true, then the message body length is zero (no message body is present).

7. これがリクエストメッセージであり、上記のいずれも真でない場合、メッセージボディの長さはゼロです(メッセージ本文は存在しません)。

8. Otherwise, this is a response message without a declared message body length, so the message body length is determined by the number of octets received prior to the server closing the connection.

8. それ以外の場合、これはメッセージボディの長さが宣言されていない応答メッセージであるため、メッセージボディの長さは、サーバーが接続を閉じる前に受信したオクテットの数によって決定されます。

Since there is no way to distinguish a successfully completed, close-delimited response message from a partially received message interrupted by network failure, a server SHOULD generate encoding or length-delimited messages whenever possible. The close-delimiting feature exists primarily for backwards compatibility with HTTP/1.0.


      |  *Note:* Request messages are never close-delimited because they
      |  are always explicitly framed by length or transfer coding, with
      |  the absence of both implying the request ends immediately after
      |  the header section.

A server MAY reject a request that contains a message body but not a Content-Length by responding with 411 (Length Required).


Unless a transfer coding other than chunked has been applied, a client that sends a request containing a message body SHOULD use a valid Content-Length header field if the message body length is known in advance, rather than the chunked transfer coding, since some existing services respond to chunked with a 411 (Length Required) status code even though they understand the chunked transfer coding. This is typically because such services are implemented via a gateway that requires a content length in advance of being called, and the server is unable or unwilling to buffer the entire request before processing.


A user agent that sends a request that contains a message body MUST send either a valid Content-Length header field or use the chunked transfer coding. A client MUST NOT use the chunked transfer coding unless it knows the server will handle HTTP/1.1 (or later) requests; such knowledge can be in the form of specific user configuration or by remembering the version of a prior received response.


If the final response to the last request on a connection has been completely received and there remains additional data to read, a user agent MAY discard the remaining data or attempt to determine if that data belongs as part of the prior message body, which might be the case if the prior message's Content-Length value is incorrect. A client MUST NOT process, cache, or forward such extra data as a separate response, since such behavior would be vulnerable to cache poisoning.


7. Transfer Codings
7. コーディングを転送します

Transfer coding names are used to indicate an encoding transformation that has been, can be, or might need to be applied to a message's content in order to ensure "safe transport" through the network. This differs from a content coding in that the transfer coding is a property of the message rather than a property of the representation that is being transferred.


All transfer-coding names are case-insensitive and ought to be registered within the HTTP Transfer Coding registry, as defined in Section 7.3. They are used in the Transfer-Encoding (Section 6.1) and TE (Section 10.1.4 of [HTTP]) header fields (the latter also defining the "transfer-coding" grammar).


7.1. Chunked Transfer Coding
7.1. チャンク転送コーディング

The chunked transfer coding wraps content in order to transfer it as a series of chunks, each with its own size indicator, followed by an OPTIONAL trailer section containing trailer fields. Chunked enables content streams of unknown size to be transferred as a sequence of length-delimited buffers, which enables the sender to retain connection persistence and the recipient to know when it has received the entire message.


     chunked-body   = *chunk

chunk = chunk-size [ chunk-ext ] CRLF chunk-data CRLF chunk-size = 1*HEXDIG last-chunk = 1*("0") [ chunk-ext ] CRLF

chunk = chunk-size [chunk-ext] crlf chunk-data crlf chunk-size = 1*hexdig last-chunk = 1*( "0")[chunk-ext] crlf

     chunk-data     = 1*OCTET ; a sequence of chunk-size octets

The chunk-size field is a string of hex digits indicating the size of the chunk-data in octets. The chunked transfer coding is complete when a chunk with a chunk-size of zero is received, possibly followed by a trailer section, and finally terminated by an empty line.


A recipient MUST be able to parse and decode the chunked transfer coding.


HTTP/1.1 does not define any means to limit the size of a chunked response such that an intermediary can be assured of buffering the entire response. Additionally, very large chunk sizes may cause overflows or loss of precision if their values are not represented accurately in a receiving implementation. Therefore, recipients MUST anticipate potentially large hexadecimal numerals and prevent parsing errors due to integer conversion overflows or precision loss due to integer representation.


The chunked coding does not define any parameters. Their presence SHOULD be treated as an error.


7.1.1. Chunk Extensions
7.1.1. チャンクエクステンション

The chunked coding allows each chunk to include zero or more chunk extensions, immediately following the chunk-size, for the sake of supplying per-chunk metadata (such as a signature or hash), mid-message control information, or randomization of message body size.


     chunk-ext      = *( BWS ";" BWS chunk-ext-name
                         [ BWS "=" BWS chunk-ext-val ] )

chunk-ext-name = token chunk-ext-val = token / quoted-string

Chunk-ext-name = token chunk-ext-val = token / quoted-string

The chunked coding is specific to each connection and is likely to be removed or recoded by each recipient (including intermediaries) before any higher-level application would have a chance to inspect the extensions. Hence, the use of chunk extensions is generally limited to specialized HTTP services such as "long polling" (where client and server can have shared expectations regarding the use of chunk extensions) or for padding within an end-to-end secured connection.


A recipient MUST ignore unrecognized chunk extensions. A server ought to limit the total length of chunk extensions received in a request to an amount reasonable for the services provided, in the same way that it applies length limitations and timeouts for other parts of a message, and generate an appropriate 4xx (Client Error) response if that amount is exceeded.


7.1.2. Chunked Trailer Section
7.1.2. チャンクされたトレーラーセクション

A trailer section allows the sender to include additional fields at the end of a chunked message in order to supply metadata that might be dynamically generated while the content is sent, such as a message integrity check, digital signature, or post-processing status. The proper use and limitations of trailer fields are defined in Section 6.5 of [HTTP].


     trailer-section   = *( field-line CRLF )

A recipient that removes the chunked coding from a message MAY selectively retain or discard the received trailer fields. A recipient that retains a received trailer field MUST either store/ forward the trailer field separately from the received header fields or merge the received trailer field into the header section. A recipient MUST NOT merge a received trailer field into the header section unless its corresponding header field definition explicitly permits and instructs how the trailer field value can be safely merged.


7.1.3. Decoding Chunked
7.1.3. ダンクのデコード

A process for decoding the chunked transfer coding can be represented in pseudo-code as:


     length := 0
     read chunk-size, chunk-ext (if any), and CRLF
     while (chunk-size > 0) {
        read chunk-data and CRLF
        append chunk-data to content
        length := length + chunk-size
        read chunk-size, chunk-ext (if any), and CRLF
     read trailer field
     while (trailer field is not empty) {
        if (trailer fields are stored/forwarded separately) {
            append trailer field to existing trailer fields
        else if (trailer field is understood and defined as mergeable) {
            merge trailer field with existing header fields
        else {
            discard trailer field
        read trailer field
     Content-Length := length
     Remove "chunked" from Transfer-Encoding
7.2. Transfer Codings for Compression
7.2. 圧縮のためにコーディングを転送します

The following transfer coding names for compression are defined by the same algorithm as their corresponding content coding:


compress (and x-compress) See Section of [HTTP].


deflate See Section of [HTTP].


gzip (and x-gzip) See Section of [HTTP].


The compression codings do not define any parameters. The presence of parameters with any of these compression codings SHOULD be treated as an error.


7.3. Transfer Coding Registry
7.3. コーディングレジストリを転送します

The "HTTP Transfer Coding Registry" defines the namespace for transfer coding names. It is maintained at <>.


Registrations MUST include the following fields:


* Name

* 名前

* Description

* 説明

* Pointer to specification text

* 仕様テキストへのポインタ

Names of transfer codings MUST NOT overlap with names of content codings (Section 8.4.1 of [HTTP]) unless the encoding transformation is identical, as is the case for the compression codings defined in Section 7.2.


The TE header field (Section 10.1.4 of [HTTP]) uses a pseudo-parameter named "q" as the rank value when multiple transfer codings are acceptable. Future registrations of transfer codings SHOULD NOT define parameters called "q" (case-insensitively) in order to avoid ambiguities.


Values to be added to this namespace require IETF Review (see Section 4.8 of [RFC8126]) and MUST conform to the purpose of transfer coding defined in this specification.


Use of program names for the identification of encoding formats is not desirable and is discouraged for future encodings.


7.4. Negotiating Transfer Codings
7.4. 転送コードの交渉

The TE field (Section 10.1.4 of [HTTP]) is used in HTTP/1.1 to indicate what transfer codings, besides chunked, the client is willing to accept in the response and whether the client is willing to preserve trailer fields in a chunked transfer coding.


A client MUST NOT send the chunked transfer coding name in TE; chunked is always acceptable for HTTP/1.1 recipients.


Three examples of TE use are below.


   TE: deflate
   TE: trailers, deflate;q=0.5

When multiple transfer codings are acceptable, the client MAY rank the codings by preference using a case-insensitive "q" parameter (similar to the qvalues used in content negotiation fields; see Section 12.4.2 of [HTTP]). The rank value is a real number in the range 0 through 1, where 0.001 is the least preferred and 1 is the most preferred; a value of 0 means "not acceptable".


If the TE field value is empty or if no TE field is present, the only acceptable transfer coding is chunked. A message with no transfer coding is always acceptable.


The keyword "trailers" indicates that the sender will not discard trailer fields, as described in Section 6.5 of [HTTP].


Since the TE header field only applies to the immediate connection, a sender of TE MUST also send a "TE" connection option within the Connection header field (Section 7.6.1 of [HTTP]) in order to prevent the TE header field from being forwarded by intermediaries that do not support its semantics.


8. Handling Incomplete Messages
8. 不完全なメッセージの処理

A server that receives an incomplete request message, usually due to a canceled request or a triggered timeout exception, MAY send an error response prior to closing the connection.


A client that receives an incomplete response message, which can occur when a connection is closed prematurely or when decoding a supposedly chunked transfer coding fails, MUST record the message as incomplete. Cache requirements for incomplete responses are defined in Section 3.3 of [CACHING].


If a response terminates in the middle of the header section (before the empty line is received) and the status code might rely on header fields to convey the full meaning of the response, then the client cannot assume that meaning has been conveyed; the client might need to repeat the request in order to determine what action to take next.


A message body that uses the chunked transfer coding is incomplete if the zero-sized chunk that terminates the encoding has not been received. A message that uses a valid Content-Length is incomplete if the size of the message body received (in octets) is less than the value given by Content-Length. A response that has neither chunked transfer coding nor Content-Length is terminated by closure of the connection and, if the header section was received intact, is considered complete unless an error was indicated by the underlying connection (e.g., an "incomplete close" in TLS would leave the response incomplete, as described in Section 9.8).


9. Connection Management
9. 接続管理

HTTP messaging is independent of the underlying transport- or session-layer connection protocol(s). HTTP only presumes a reliable transport with in-order delivery of requests and the corresponding in-order delivery of responses. The mapping of HTTP request and response structures onto the data units of an underlying transport protocol is outside the scope of this specification.


As described in Section 7.3 of [HTTP], the specific connection protocols to be used for an HTTP interaction are determined by client configuration and the target URI. For example, the "http" URI scheme (Section 4.2.1 of [HTTP]) indicates a default connection of TCP over IP, with a default TCP port of 80, but the client might be configured to use a proxy via some other connection, port, or protocol.


HTTP implementations are expected to engage in connection management, which includes maintaining the state of current connections, establishing a new connection or reusing an existing connection, processing messages received on a connection, detecting connection failures, and closing each connection. Most clients maintain multiple connections in parallel, including more than one connection per server endpoint. Most servers are designed to maintain thousands of concurrent connections, while controlling request queues to enable fair use and detect denial-of-service attacks.


9.1. Establishment
9.1. 確率

It is beyond the scope of this specification to describe how connections are established via various transport- or session-layer protocols. Each HTTP connection maps to one underlying transport connection.


9.2. Associating a Response to a Request
9.2. リクエストへの応答を関連付けます

HTTP/1.1 does not include a request identifier for associating a given request message with its corresponding one or more response messages. Hence, it relies on the order of response arrival to correspond exactly to the order in which requests are made on the same connection. More than one response message per request only occurs when one or more informational responses (1xx; see Section 15.2 of [HTTP]) precede a final response to the same request.

HTTP/1.1には、特定の要求メッセージを対応する1つ以上の応答メッセージに関連付けるための要求識別子は含まれていません。したがって、同じ接続でリクエストが行われる順序に正確に対応するために、応答の到着の順序に依存しています。要求ごとに複数の応答メッセージは、1つ以上の情報応答(1xx; [http]のセクション15.2を参照)が同じリクエストに対する最終的な応答の前に発生した場合にのみ発生します。

A client that has more than one outstanding request on a connection MUST maintain a list of outstanding requests in the order sent and MUST associate each received response message on that connection to the first outstanding request that has not yet received a final (non-1xx) response.


If a client receives data on a connection that doesn't have outstanding requests, the client MUST NOT consider that data to be a valid response; the client SHOULD close the connection, since message delimitation is now ambiguous, unless the data consists only of one or more CRLF (which can be discarded per Section 2.2).


9.3. Persistence
9.3. 持続性

HTTP/1.1 defaults to the use of "persistent connections", allowing multiple requests and responses to be carried over a single connection. HTTP implementations SHOULD support persistent connections.


A recipient determines whether a connection is persistent or not based on the protocol version and Connection header field (Section 7.6.1 of [HTTP]) in the most recently received message, if any:


* If the "close" connection option is present (Section 9.6), the connection will not persist after the current response; else,

* 「閉じる」接続オプションが存在する場合(セクション9.6)、現在の応答の後に接続が続きません。そうしないと、

* If the received protocol is HTTP/1.1 (or later), the connection will persist after the current response; else,

* 受信したプロトコルがHTTP/1.1(またはそれ以降)の場合、現在の応答の後に接続が持続します。そうしないと、

* If the received protocol is HTTP/1.0, the "keep-alive" connection option is present, either the recipient is not a proxy or the message is a response, and the recipient wishes to honor the HTTP/1.0 "keep-alive" mechanism, the connection will persist after the current response; otherwise,

* 受信したプロトコルがHTTP/1.0の場合、「キープアライブ」接続オプションが存在する場合、受信者はプロキシではないか、メッセージが応答であり、受信者はHTTP/1.0 "Keep-Alive"メカニズムを尊重したいと考えています。、接続は現在の応答の後に続きます。それ以外は、

* The connection will close after the current response.

* 現在の応答の後、接続は閉じられます。

A client that does not support persistent connections MUST send the "close" connection option in every request message.


A server that does not support persistent connections MUST send the "close" connection option in every response message that does not have a 1xx (Informational) status code.


A client MAY send additional requests on a persistent connection until it sends or receives a "close" connection option or receives an HTTP/1.0 response without a "keep-alive" connection option.


In order to remain persistent, all messages on a connection need to have a self-defined message length (i.e., one not defined by closure of the connection), as described in Section 6. A server MUST read the entire request message body or close the connection after sending its response; otherwise, the remaining data on a persistent connection would be misinterpreted as the next request. Likewise, a client MUST read the entire response message body if it intends to reuse the same connection for a subsequent request.


A proxy server MUST NOT maintain a persistent connection with an HTTP/1.0 client (see Appendix C.2.2 for information and discussion of the problems with the Keep-Alive header field implemented by many HTTP/1.0 clients).


See Appendix C.2.2 for more information on backwards compatibility with HTTP/1.0 clients.


9.3.1. Retrying Requests
9.3.1. リクエストの再試行

Connections can be closed at any time, with or without intention. Implementations ought to anticipate the need to recover from asynchronous close events. The conditions under which a client can automatically retry a sequence of outstanding requests are defined in Section 9.2.2 of [HTTP].


9.3.2. Pipelining
9.3.2. パイプライン

A client that supports persistent connections MAY "pipeline" its requests (i.e., send multiple requests without waiting for each response). A server MAY process a sequence of pipelined requests in parallel if they all have safe methods (Section 9.2.1 of [HTTP]), but it MUST send the corresponding responses in the same order that the requests were received.


A client that pipelines requests SHOULD retry unanswered requests if the connection closes before it receives all of the corresponding responses. When retrying pipelined requests after a failed connection (a connection not explicitly closed by the server in its last complete response), a client MUST NOT pipeline immediately after connection establishment, since the first remaining request in the prior pipeline might have caused an error response that can be lost again if multiple requests are sent on a prematurely closed connection (see the TCP reset problem described in Section 9.6).


Idempotent methods (Section 9.2.2 of [HTTP]) are significant to pipelining because they can be automatically retried after a connection failure. A user agent SHOULD NOT pipeline requests after a non-idempotent method, until the final response status code for that method has been received, unless the user agent has a means to detect and recover from partial failure conditions involving the pipelined sequence.


An intermediary that receives pipelined requests MAY pipeline those requests when forwarding them inbound, since it can rely on the outbound user agent(s) to determine what requests can be safely pipelined. If the inbound connection fails before receiving a response, the pipelining intermediary MAY attempt to retry a sequence of requests that have yet to receive a response if the requests all have idempotent methods; otherwise, the pipelining intermediary SHOULD forward any received responses and then close the corresponding outbound connection(s) so that the outbound user agent(s) can recover accordingly.


9.4. Concurrency
9.4. 並行性

A client ought to limit the number of simultaneous open connections that it maintains to a given server.


Previous revisions of HTTP gave a specific number of connections as a ceiling, but this was found to be impractical for many applications. As a result, this specification does not mandate a particular maximum number of connections but, instead, encourages clients to be conservative when opening multiple connections.


Multiple connections are typically used to avoid the "head-of-line blocking" problem, wherein a request that takes significant server-side processing and/or transfers very large content would block subsequent requests on the same connection. However, each connection consumes server resources.


Furthermore, using multiple connections can cause undesirable side effects in congested networks. Using larger numbers of connections can also cause side effects in otherwise uncongested networks, because their aggregate and initially synchronized sending behavior can cause congestion that would not have been present if fewer parallel connections had been used.


Note that a server might reject traffic that it deems abusive or characteristic of a denial-of-service attack, such as an excessive number of open connections from a single client.


9.5. Failures and Timeouts
9.5. 障害とタイムアウト

Servers will usually have some timeout value beyond which they will no longer maintain an inactive connection. Proxy servers might make this a higher value since it is likely that the client will be making more connections through the same proxy server. The use of persistent connections places no requirements on the length (or existence) of this timeout for either the client or the server.


A client or server that wishes to time out SHOULD issue a graceful close on the connection. Implementations SHOULD constantly monitor open connections for a received closure signal and respond to it as appropriate, since prompt closure of both sides of a connection enables allocated system resources to be reclaimed.


A client, server, or proxy MAY close the transport connection at any time. For example, a client might have started to send a new request at the same time that the server has decided to close the "idle" connection. From the server's point of view, the connection is being closed while it was idle, but from the client's point of view, a request is in progress.


A server SHOULD sustain persistent connections, when possible, and allow the underlying transport's flow-control mechanisms to resolve temporary overloads rather than terminate connections with the expectation that clients will retry. The latter technique can exacerbate network congestion or server load.


A client sending a message body SHOULD monitor the network connection for an error response while it is transmitting the request. If the client sees a response that indicates the server does not wish to receive the message body and is closing the connection, the client SHOULD immediately cease transmitting the body and close its side of the connection.


9.6. Tear-down
9.6. 取り壊す

The "close" connection option is defined as a signal that the sender will close this connection after completion of the response. A sender SHOULD send a Connection header field (Section 7.6.1 of [HTTP]) containing the "close" connection option when it intends to close a connection. For example,


Connection: close


as a request header field indicates that this is the last request that the client will send on this connection, while in a response, the same field indicates that the server is going to close this connection after the response message is complete.


Note that the field name "Close" is reserved, since using that name as a header field might conflict with the "close" connection option.


A client that sends a "close" connection option MUST NOT send further requests on that connection (after the one containing the "close") and MUST close the connection after reading the final response message corresponding to this request.


A server that receives a "close" connection option MUST initiate closure of the connection (see below) after it sends the final response to the request that contained the "close" connection option. The server SHOULD send a "close" connection option in its final response on that connection. The server MUST NOT process any further requests received on that connection.


A server that sends a "close" connection option MUST initiate closure of the connection (see below) after it sends the response containing the "close" connection option. The server MUST NOT process any further requests received on that connection.


A client that receives a "close" connection option MUST cease sending requests on that connection and close the connection after reading the response message containing the "close" connection option; if additional pipelined requests had been sent on the connection, the client SHOULD NOT assume that they will be processed by the server.


If a server performs an immediate close of a TCP connection, there is a significant risk that the client will not be able to read the last HTTP response. If the server receives additional data from the client on a fully closed connection, such as another request sent by the client before receiving the server's response, the server's TCP stack will send a reset packet to the client; unfortunately, the reset packet might erase the client's unacknowledged input buffers before they can be read and interpreted by the client's HTTP parser.


To avoid the TCP reset problem, servers typically close a connection in stages. First, the server performs a half-close by closing only the write side of the read/write connection. The server then continues to read from the connection until it receives a corresponding close by the client, or until the server is reasonably certain that its own TCP stack has received the client's acknowledgement of the packet(s) containing the server's last response. Finally, the server fully closes the connection.


It is unknown whether the reset problem is exclusive to TCP or might also be found in other transport connection protocols.


Note that a TCP connection that is half-closed by the client does not delimit a request message, nor does it imply that the client is no longer interested in a response. In general, transport signals cannot be relied upon to signal edge cases, since HTTP/1.1 is independent of transport.


9.7. TLS Connection Initiation
9.7. TLS接続開始

Conceptually, HTTP/TLS is simply sending HTTP messages over a connection secured via TLS [TLS13].

概念的には、HTTP/TLSは、TLS [TLS13]を介して保護された接続を介してHTTPメッセージを送信しているだけです。

The HTTP client also acts as the TLS client. It initiates a connection to the server on the appropriate port and sends the TLS ClientHello to begin the TLS handshake. When the TLS handshake has finished, the client may then initiate the first HTTP request. All HTTP data MUST be sent as TLS "application data" but is otherwise treated like a normal connection for HTTP (including potential reuse as a persistent connection).

HTTPクライアントは、TLSクライアントとしても機能します。適切なポートのサーバーへの接続を開始し、TLS ClientHelloを送信してTLSハンドシェイクを開始します。TLSの握手が終了したら、クライアントは最初のHTTP要求を開始することがあります。すべてのHTTPデータは、TLS「アプリケーションデータ」として送信する必要がありますが、それ以外の場合はHTTPの通常の接続のように扱われます(潜在的な再利用を含む)。

9.8. TLS Connection Closure
9.8. TLS接続閉鎖

TLS uses an exchange of closure alerts prior to (non-error) connection closure to provide secure connection closure; see Section 6.1 of [TLS13]. When a valid closure alert is received, an implementation can be assured that no further data will be received on that connection.


When an implementation knows that it has sent or received all the message data that it cares about, typically by detecting HTTP message boundaries, it might generate an "incomplete close" by sending a closure alert and then closing the connection without waiting to receive the corresponding closure alert from its peer.


An incomplete close does not call into question the security of the data already received, but it could indicate that subsequent data might have been truncated. As TLS is not directly aware of HTTP message framing, it is necessary to examine the HTTP data itself to determine whether messages are complete. Handling of incomplete messages is defined in Section 8.


When encountering an incomplete close, a client SHOULD treat as completed all requests for which it has received either


1. as much data as specified in the Content-Length header field or

1. コンテンツレングスヘッダーフィールドで指定されているように多くのデータまたは

2. the terminal zero-length chunk (when Transfer-Encoding of chunked is used).

2. 端子ゼロ長塊(チャンクの転送エンコードが使用される場合)。

A response that has neither chunked transfer coding nor Content-Length is complete only if a valid closure alert has been received. Treating an incomplete message as complete could expose implementations to attack.


A client detecting an incomplete close SHOULD recover gracefully.


Clients MUST send a closure alert before closing the connection. Clients that do not expect to receive any more data MAY choose not to wait for the server's closure alert and simply close the connection, thus generating an incomplete close on the server side.


Servers SHOULD be prepared to receive an incomplete close from the client, since the client can often locate the end of server data.


Servers MUST attempt to initiate an exchange of closure alerts with the client before closing the connection. Servers MAY close the connection after sending the closure alert, thus generating an incomplete close on the client side.


10. Enclosing Messages as Data
10. メッセージをデータとして囲む
10.1. Media Type message/http
10.1. メディアタイプメッセージ/http

The "message/http" media type can be used to enclose a single HTTP request or response message, provided that it obeys the MIME restrictions for all "message" types regarding line length and encodings. Because of the line length limitations, field values within "message/http" are allowed to use line folding (obs-fold), as described in Section 5.2, to convey the field value over multiple lines. A recipient of "message/http" data MUST replace any obsolete line folding with one or more SP characters when the message is consumed.


Type name: message


Subtype name: http


Required parameters: N/A


Optional parameters: version, msgtype


version: The HTTP-version number of the enclosed message (e.g., "1.1"). If not present, the version can be determined from the first line of the body.

バージョン:囲まれたメッセージのHTTPバージョン数(例: "1.1")。存在しない場合、バージョンはボディの最初の行から決定できます。

msgtype: The message type -- "request" or "response". If not present, the type can be determined from the first line of the body.

msgtype:メッセージタイプ - 「リクエスト」または「応答」。存在しない場合、タイプは身体の最初の行から決定できます。

Encoding considerations: only "7bit", "8bit", or "binary" are permitted


Security considerations: see Section 11


Interoperability considerations: N/A


Published specification: RFC 9112 (see Section 10.1).

公開された仕様:RFC 9112(セクション10.1を参照)。

Applications that use this media type: N/A


Fragment identifier considerations: N/A


   Additional information:  Magic number(s):  N/A

Deprecated alias names for this type: N/A


                            File extension(s):  N/A
                            Macintosh file type code(s):  N/A

Person and email address to contact for further information: See Aut hors' Addresses section.

詳細については、個人とメールアドレスをお問い合わせください:Aut Horsのアドレスセクションを参照してください。

Intended usage: COMMON


Restrictions on usage: N/A


Author: See Authors' Addresses section.


Change controller: IESG

Change Controller:IESG

10.2. Media Type application/http
10.2. メディアタイプアプリケーション/http

The "application/http" media type can be used to enclose a pipeline of one or more HTTP request or response messages (not intermixed).


Type name: application


Subtype name: http


Required parameters: N/A


Optional parameters: version, msgtype


version: The HTTP-version number of the enclosed messages (e.g., "1.1"). If not present, the version can be determined from the first line of the body.

バージョン:囲まれたメッセージのHTTPバージョン数(例: "1.1")。存在しない場合、バージョンはボディの最初の行から決定できます。

msgtype: The message type -- "request" or "response". If not present, the type can be determined from the first line of the body.

msgtype:メッセージタイプ - 「リクエスト」または「応答」。存在しない場合、タイプは身体の最初の行から決定できます。

Encoding considerations: HTTP messages enclosed by this type are in "binary" format; use of an appropriate Content-Transfer-Encoding is required when transmitted via email.


Security considerations: see Section 11


Interoperability considerations: N/A


Published specification: RFC 9112 (see Section 10.2).

公開された仕様:RFC 9112(セクション10.2を参照)。

Applications that use this media type: N/A


Fragment identifier considerations: N/A


   Additional information:  Deprecated alias names for this type:  N/A
                            Magic number(s):  N/A
                            File extension(s):  N/A
                            Macintosh file type code(s):  N/A

Person and email address to contact for further information: See Aut hors' Addresses section.

詳細については、個人とメールアドレスをお問い合わせください:Aut Horsのアドレスセクションを参照してください。

Intended usage: COMMON


Restrictions on usage: N/A


Author: See Authors' Addresses section.


Change controller: IESG

Change Controller:IESG

11. Security Considerations
11. セキュリティ上の考慮事項

This section is meant to inform developers, information providers, and users about known security considerations relevant to HTTP message syntax and parsing. Security considerations about HTTP semantics, content, and routing are addressed in [HTTP].


11.1. Response Splitting
11.1. 応答分割

Response splitting (a.k.a. CRLF injection) is a common technique, used in various attacks on Web usage, that exploits the line-based nature of HTTP message framing and the ordered association of requests to responses on persistent connections [Klein]. This technique can be particularly damaging when the requests pass through a shared cache.


Response splitting exploits a vulnerability in servers (usually within an application server) where an attacker can send encoded data within some parameter of the request that is later decoded and echoed within any of the response header fields of the response. If the decoded data is crafted to look like the response has ended and a subsequent response has begun, the response has been split, and the content within the apparent second response is controlled by the attacker. The attacker can then make any other request on the same persistent connection and trick the recipients (including intermediaries) into believing that the second half of the split is an authoritative answer to the second request.


For example, a parameter within the request-target might be read by an application server and reused within a redirect, resulting in the same parameter being echoed in the Location header field of the response. If the parameter is decoded by the application and not properly encoded when placed in the response field, the attacker can send encoded CRLF octets and other content that will make the application's single response look like two or more responses.


A common defense against response splitting is to filter requests for data that looks like encoded CR and LF (e.g., "%0D" and "%0A"). However, that assumes the application server is only performing URI decoding rather than more obscure data transformations like charset transcoding, XML entity translation, base64 decoding, sprintf reformatting, etc. A more effective mitigation is to prevent anything other than the server's core protocol libraries from sending a CR or LF within the header section, which means restricting the output of header fields to APIs that filter for bad octets and not allowing application servers to write directly to the protocol stream.

応答分割に対する一般的な防御は、エンコードされたCRやLF(「%0D」および「%0A」などのように見えるデータのリクエストをフィルタリングすることです。ただし、Application Serverは、Charset Transcoding、XML Entity Translation、Base64 Decoding、Sprintf Reforattingなど、より曖昧なデータ変換ではなく、URIデコードのみを実行していると想定しています。より効果的な緩和は、サーバーのコアプロトコルライブラリ以外を防ぐことですヘッダーセクション内でCRまたはLFを送信します。これは、ヘッダーフィールドの出力をAPIに制限し、悪いオクテットをフィルタリングすることを意味し、アプリケーションサーバーがプロトコルストリームに直接書き込むことを許可しないことを意味します。

11.2. Request Smuggling
11.2. 密輸をリクエストします

Request smuggling ([Linhart]) is a technique that exploits differences in protocol parsing among various recipients to hide additional requests (which might otherwise be blocked or disabled by policy) within an apparently harmless request. Like response splitting, request smuggling can lead to a variety of attacks on HTTP usage.


This specification has introduced new requirements on request parsing, particularly with regard to message framing in Section 6.3, to reduce the effectiveness of request smuggling.


11.3. Message Integrity
11.3. メッセージの整合性

HTTP does not define a specific mechanism for ensuring message integrity, instead relying on the error-detection ability of underlying transport protocols and the use of length or chunk-delimited framing to detect completeness. Historically, the lack of a single integrity mechanism has been justified by the informal nature of most HTTP communication. However, the prevalence of HTTP as an information access mechanism has resulted in its increasing use within environments where verification of message integrity is crucial.


The mechanisms provided with the "https" scheme, such as authenticated encryption, provide protection against modification of messages. Care is needed, however, to ensure that connection closure cannot be used to truncate messages (see Section 9.8). User agents might refuse to accept incomplete messages or treat them specially. For example, a browser being used to view medical history or drug interaction information needs to indicate to the user when such information is detected by the protocol to be incomplete, expired, or corrupted during transfer. Such mechanisms might be selectively enabled via user agent extensions or the presence of message integrity metadata in a response.


The "http" scheme provides no protection against accidental or malicious modification of messages.


Extensions to the protocol might be used to mitigate the risk of unwanted modification of messages by intermediaries, even when the "https" scheme is used. Integrity might be assured by using message authentication codes or digital signatures that are selectively added to messages via extensible metadata fields.


11.4. Message Confidentiality
11.4. メッセージの機密性

HTTP relies on underlying transport protocols to provide message confidentiality when that is desired. HTTP has been specifically designed to be independent of the transport protocol, such that it can be used over many forms of encrypted connection, with the selection of such transports being identified by the choice of URI scheme or within user agent configuration.


The "https" scheme can be used to identify resources that require a confidential connection, as described in Section 4.2.2 of [HTTP].


12. IANA Considerations
12. IANAの考慮事項

The change controller for the following registrations is: "IETF ( - Internet Engineering Task Force".

次の登録の変更コントローラーは、「IETF( - インターネットエンジニアリングタスクフォース」です。

12.1. Field Name Registration
12.1. フィールド名登録

IANA has added the following field names to the "Hypertext Transfer Protocol (HTTP) Field Name Registry" at <>, as described in Section 18.4 of [HTTP].

IANAは、[http]のセクション18.4で説明されているように、「> <> <> <> <>」の「ハイパーテキスト転送プロトコル(http)フィールド名レジストリ」に追加したフィールド名を追加しました。

   | Field Name        | Status    | Section | Comments   |
   | Close             | permanent | 9.6     | (reserved) |
   | MIME-Version      | permanent | B.1     |            |
   | Transfer-Encoding | permanent | 6.1     |            |

Table 1


12.2. Media Type Registration
12.2. メディアタイプの登録

IANA has updated the "Media Types" registry at <> with the registration information in Sections 10.1 and 10.2 for the media types "message/ http" and "application/http", respectively.

IANAは、<> <>の「メディアタイプ」レジストリを更新しました。"、 それぞれ。

12.3. Transfer Coding Registration
12.3. コーディング登録を転送します

IANA has updated the "HTTP Transfer Coding Registry" at <> with the registration procedure of Section 7.3 and the content coding names summarized in the table below.

IANAは、セクション7.3の登録手順で「> <>」の「HTTP転送レジストリ」を更新し、以下の表にまとめたコンテンツコーディング名を更新しました。

   | Name       | Description                               | Section |
   | chunked    | Transfer in a series of chunks            | 7.1     |
   | compress   | UNIX "compress" data format [Welch]       | 7.2     |
   | deflate    | "deflate" compressed data ([RFC1951])     | 7.2     |
   |            | inside the "zlib" data format ([RFC1950]) |         |
   | gzip       | GZIP file format [RFC1952]                | 7.2     |
   | trailers   | (reserved)                                | 12.3    |
   | x-compress | Deprecated (alias for compress)           | 7.2     |
   | x-gzip     | Deprecated (alias for gzip)               | 7.2     |

Table 2


      |  *Note:* the coding name "trailers" is reserved because its use
      |  would conflict with the keyword "trailers" in the TE header
      |  field (Section 10.1.4 of [HTTP]).
12.4. ALPN Protocol ID Registration
12.4. ALPNプロトコルID登録

IANA has updated the "TLS Application-Layer Protocol Negotiation (ALPN) Protocol IDs" registry at < tls-extensiontype-values/> with the registration below:

IANAは、「TLSアプリケーションレイヤープロトコルネゴシエーション(ALPN)プロトコルIDS」レジストリを< tls-extensiontype-values/>に更新しました。

          | Protocol | Identification Sequence     | Reference |
          | HTTP/1.1 | 0x68 0x74 0x74 0x70 0x2f    | RFC 9112  |
          |          | 0x31 0x2e 0x31 ("http/1.1") |           |

Table 3


13. References
13. 参考文献
13.1. Normative References
13.1. 引用文献

[CACHING] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Caching", STD 98, RFC 9111, DOI 10.17487/RFC9111, June 2022, <>.

[キャッシュ]フィールディング、R。、編、ノッティンガム、M.、編、J。レスケ、編、「HTTPキャッシュ」、STD 98、RFC 9111、DOI 10.17487/RFC9111、2022年6月、<>。

[HTTP] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "HTTP Semantics", STD 97, RFC 9110, DOI 10.17487/RFC9110, June 2022, <>.

[HTTP] Fielding、R.、Ed。、Nottingham、M.、Ed。、およびJ. Reschke、ed。、 "HTTP Semantics"、Std 97、RFC 9110、DOI 10.17487/RFC9110、2022年6月、<>。

[RFC1950] Deutsch, P. and J-L. Gailly, "ZLIB Compressed Data Format Specification version 3.3", RFC 1950, DOI 10.17487/RFC1950, May 1996, <>.

[RFC1950] Deutsch、P。およびJ-L。Gailly、「Zlib圧縮データ形式の仕様バージョン3.3」、RFC 1950、DOI 10.17487/RFC1950、1996年5月、<>。

[RFC1951] Deutsch, P., "DEFLATE Compressed Data Format Specification version 1.3", RFC 1951, DOI 10.17487/RFC1951, May 1996, <>.

[RFC1951] Deutsch、P。、「圧縮データ形式の仕様バージョン1.3」、RFC 1951、DOI 10.17487/RFC1951、1996年5月、<>。

[RFC1952] Deutsch, P., "GZIP file format specification version 4.3", RFC 1952, DOI 10.17487/RFC1952, May 1996, <>.

[RFC1952] Deutsch、P。、「GZIPファイル形式の仕様バージョン4.3」、RFC 1952、DOI 10.17487/RFC1952、1996年5月、<>。

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <>.

[RFC2119] Bradner、S。、「要件レベルを示すためにRFCで使用するためのキーワード」、BCP 14、RFC 2119、DOI 10.17487/RFC2119、1997年3月、<>。

[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/RFC5234, January 2008, <>.

[RFC5234] Crocker、D.、ed。P. Overell、「構文仕様のためのBNFの増強:ABNF:STD 68、RFC 5234、DOI 10.17487/RFC5234、2008年1月、<>。

[RFC7405] Kyzivat, P., "Case-Sensitive String Support in ABNF", RFC 7405, DOI 10.17487/RFC7405, December 2014, <>.

[RFC7405] Kyzivat、P。、「ABNFでのケースセンシティブストリングサポート」、RFC 7405、DOI 10.17487/RFC7405、2014年12月、<>

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <>.

[RFC8174] Leiba、B。、「RFC 2119キーワードの大文字と小文字のあいまいさ」、BCP 14、RFC 8174、DOI 10.17487/RFC8174、2017年5月、<>。

[TLS13] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, <>.

[TLS13] Rescorla、E。、「輸送層セキュリティ(TLS)プロトコルバージョン1.3」、RFC 8446、DOI 10.17487/RFC8446、2018年8月、<>

[URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, <>.

[URI] Berners-Lee、T.、Fielding、R。、およびL. Masinter、「Uniform Resource Identifier(URI):Generic Syntax」、Std 66、RFC 3986、DOI 10.17487/RFC3986、2005年1月、<>。

[USASCII] American National Standards Institute, "Coded Character Set -- 7-bit American Standard Code for Information Interchange", ANSI X3.4, 1986.

[USASCII] American National Standards Institute、「コード化された文字セット - 情報交換のための7ビットアメリカ標準コード」、ANSI X3.4、1986。

[Welch] Welch, T., "A Technique for High-Performance Data Compression", IEEE Computer 17(6), DOI 10.1109/MC.1984.1659158, June 1984, <>.

[ウェルチ]ウェルチ、T。、「高性能データ圧縮の手法」、IEEEコンピューター17(6)、DOI 10.1109/MC.1984.1659158、1984年6月、<>。

13.2. Informative References
13.2. 参考引用

[HTTP/1.0] Berners-Lee, T., Fielding, R., and H. Frystyk, "Hypertext Transfer Protocol -- HTTP/1.0", RFC 1945, DOI 10.17487/RFC1945, May 1996, <>.

[HTTP/1.0] Berners-Lee、T.、Fielding、R。、およびH. Frystyk、「HyperText Transfer Protocol-HTTP/1.0」、RFC 1945、DOI 10.17487/RFC1945、1996年5月、<https://>。

[Klein] Klein, A., "Divide and Conquer - HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics", March 2004, < whitepaper_httpresponse.pdf>.

[クライン]クライン、A。、「分割と征服-HTTP応答分割、Webキャッシュ中毒攻撃、および関連トピック」、2004年3月< whitepaper_httpresponse.pdf>。

[Linhart] Linhart, C., Klein, A., Heled, R., and S. Orrin, "HTTP Request Smuggling", June 2005, <>.

[Linhart] Linhart、C.、Klein、A.、Heled、R。、およびS. Orrin、「HTTP Request Smuggling」、2005年6月、<>。

[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996, <>.

[RFC2045] Freed、N。およびN. Borenstein、「多目的インターネットメール拡張機能(MIME)パート1:インターネットメッセージボディの形式」、RFC 2045、DOI 10.17487/RFC2045、1996年11月、<>。

[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, DOI 10.17487/RFC2046, November 1996, <>.

[RFC2046] Freed、N。およびN. Borenstein、「多目的インターネットメール拡張機能(MIME)パート2:メディアタイプ」、RFC 2046、DOI 10.17487/RFC2046、1996年11月、<https://www.rfc-editor.orgg/info/rfc2046>。

[RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples", RFC 2049, DOI 10.17487/RFC2049, November 1996, <>.

[RFC2049] Freed、N。and N. Borenstein、「多目的インターネットメール拡張機能(MIME)パート5:適合基準と例」、RFC 2049、DOI 10.17487/RFC2049、1996年11月、<>。

[RFC2068] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2068, DOI 10.17487/RFC2068, January 1997, <>.

[RFC2068] Fielding、R.、Gettys、J.、Mogul、J.、Frystyk、H。、およびT. Berners-Lee、 "HyperText Transfer Protocol-HTTP/1.1"、RFC 2068、DOI 10.17487/RFC2068、1月1997、<>。

[RFC2557] Palme, J., Hopmann, A., and N. Shelness, "MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)", RFC 2557, DOI 10.17487/RFC2557, March 1999, <>.

[RFC2557] Palme、J.、Hopmann、A。、およびN. Shelness、「HTML(MHTML)などの集計文書のMIMEカプセル化」、RFC 2557、DOI 10.17487/RFC2557、1999年3月、<HTTPS://>。

[RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322, DOI 10.17487/RFC5322, October 2008, <>.

[RFC5322] Resnick、P.、ed。、「インターネットメッセージフォーマット」、RFC 5322、DOI 10.17487/RFC5322、2008年10月、<。

[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing", RFC 7230, DOI 10.17487/RFC7230, June 2014, <>.

[RFC7230] Fielding、R.、ed。and J. Reschke、ed。、「HyperText Transfer Protocol(HTTP/1.1):メッセージの構文とルーティング」、RFC 7230、DOI 10.17487/RFC7230、2014年6月、<>。

[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, <>.

[RFC8126] Cotton、M.、Leiba、B。、およびT. Narten、「RFCSでIANA考慮事項セクションを書くためのガイドライン」、BCP 26、RFC 8126、DOI 10.17487/RFC8126、2017年6月、<https://>。

Appendix A. Collected ABNF
付録A. ABNFを収集しました

In the collected ABNF below, list rules are expanded per Section 5.6.1 of [HTTP].


   BWS = <BWS, see [HTTP], Section 5.6.3>
   HTTP-message = start-line CRLF *( field-line CRLF ) CRLF [
    message-body ]
   HTTP-name = %x48.54.54.50 ; HTTP
   HTTP-version = HTTP-name "/" DIGIT "." DIGIT
   OWS = <OWS, see [HTTP], Section 5.6.3>
   RWS = <RWS, see [HTTP], Section 5.6.3>
   Transfer-Encoding = [ transfer-coding *( OWS "," OWS transfer-coding
    ) ]
   absolute-URI = <absolute-URI, see [URI], Section 4.3>
   absolute-form = absolute-URI
   absolute-path = <absolute-path, see [HTTP], Section 4.1>
   asterisk-form = "*"
   authority = <authority, see [URI], Section 3.2>
   authority-form = uri-host ":" port
   chunk = chunk-size [ chunk-ext ] CRLF chunk-data CRLF
   chunk-data = 1*OCTET
   chunk-ext = *( BWS ";" BWS chunk-ext-name [ BWS "=" BWS chunk-ext-val
    ] )
   chunk-ext-name = token
   chunk-ext-val = token / quoted-string
   chunk-size = 1*HEXDIG
   chunked-body = *chunk last-chunk trailer-section CRLF
   field-line = field-name ":" OWS field-value OWS
   field-name = <field-name, see [HTTP], Section 5.1>
   field-value = <field-value, see [HTTP], Section 5.5>
   last-chunk = 1*"0" [ chunk-ext ] CRLF
   message-body = *OCTET
   method = token
   obs-fold = OWS CRLF RWS
   obs-text = <obs-text, see [HTTP], Section 5.6.4>
   origin-form = absolute-path [ "?" query ]
   port = <port, see [URI], Section 3.2.3>
   query = <query, see [URI], Section 3.4>
   quoted-string = <quoted-string, see [HTTP], Section 5.6.4>
   reason-phrase = 1*( HTAB / SP / VCHAR / obs-text )
   request-line = method SP request-target SP HTTP-version
   request-target = origin-form / absolute-form / authority-form /

start-line = request-line / status-line status-code = 3DIGIT status-line = HTTP-version SP status-code SP [ reason-phrase ]

start-line = request-line / status-line status-code = 3digit status-line = http-version spステータスコードSP [Reason-Phrase]

   token = <token, see [HTTP], Section 5.6.2>
   trailer-section = *( field-line CRLF )
   transfer-coding = <transfer-coding, see [HTTP], Section 10.1.4>
   uri-host = <host, see [URI], Section 3.2.2>
Appendix B. Differences between HTTP and MIME

HTTP/1.1 uses many of the constructs defined for the Internet Message Format [RFC5322] and Multipurpose Internet Mail Extensions (MIME) [RFC2045] to allow a message body to be transmitted in an open variety of representations and with extensible fields. However, some of these constructs have been reinterpreted to better fit the needs of interactive communication, leading to some differences in how MIME constructs are used within HTTP. These differences were carefully chosen to optimize performance over binary connections, allow greater freedom in the use of new media types, ease date comparisons, and accommodate common implementations.


This appendix describes specific areas where HTTP differs from MIME. Proxies and gateways to and from strict MIME environments need to be aware of these differences and provide the appropriate conversions where necessary.


B.1. MIME-Version
B.1. mime-version

HTTP is not a MIME-compliant protocol. However, messages can include a single MIME-Version header field to indicate what version of the MIME protocol was used to construct the message. Use of the MIME-Version header field indicates that the message is in full conformance with the MIME protocol (as defined in [RFC2045]). Senders are responsible for ensuring full conformance (where possible) when exporting HTTP messages to strict MIME environments.


B.2. Conversion to Canonical Form
B.2. 標準形式への変換

MIME requires that an Internet mail body part be converted to canonical form prior to being transferred, as described in Section 4 of [RFC2049], and that content with a type of "text" represents line breaks as CRLF, forbidding the use of CR or LF outside of line break sequences [RFC2046]. In contrast, HTTP does not care whether CRLF, bare CR, or bare LF are used to indicate a line break within content.

MIMEでは、[RFC2049]のセクション4で説明されているように、転送される前にインターネットメールボディの部分を標準形式に変換する必要があり、「テキスト」の種類を持つコンテンツは、CRLFとしての線切断を表し、CRまたはCRの使用を禁止することを必要とします。ラインブレイクシーケンスの外側のLF [RFC2046]。対照的に、HTTPは、CRLF、Bare CR、またはBare LFがコンテンツ内のラインブレイクを示すために使用されるかどうかを気にしません。

A proxy or gateway from HTTP to a strict MIME environment ought to translate all line breaks within text media types to the RFC 2049 canonical form of CRLF. Note, however, this might be complicated by the presence of a Content-Encoding and by the fact that HTTP allows the use of some charsets that do not use octets 13 and 10 to represent CR and LF, respectively.

HTTPから厳格なMIME環境へのプロキシまたはゲートウェイは、テキストメディアタイプ内のすべてのラインブレークをRFC 2049 CRLF形式に変換する必要があります。ただし、これは、コンテンツエンコードの存在と、HTTPがそれぞれCRとLFを表すためにオクテット13と10を使用しない一部の充電器を使用できるという事実によって複雑になる可能性があります。

Conversion will break any cryptographic checksums applied to the original content unless the original content is already in canonical form. Therefore, the canonical form is recommended for any content that uses such checksums in HTTP.


B.3. Conversion of Date Formats
B.3. 日付形式の変換

HTTP/1.1 uses a restricted set of date formats (Section 5.6.7 of [HTTP]) to simplify the process of date comparison. Proxies and gateways from other protocols ought to ensure that any Date header field present in a message conforms to one of the HTTP/1.1 formats and rewrite the date if necessary.


B.4. Conversion of Content-Encoding
B.4. コンテンツエンコードの変換

MIME does not include any concept equivalent to HTTP's Content-Encoding header field. Since this acts as a modifier on the media type, proxies and gateways from HTTP to MIME-compliant protocols ought to either change the value of the Content-Type header field or decode the representation before forwarding the message. (Some experimental applications of Content-Type for Internet mail have used a media-type parameter of ";conversions=<content-coding>" to perform a function equivalent to Content-Encoding. However, this parameter is not part of the MIME standards.)

MIMEには、HTTPのコンテンツエンコードヘッダーフィールドに相当するコンセプトは含まれていません。これはメディアタイプの修飾子として機能するため、HTTPからMIMEに準拠したプロトコルへのプロキシとゲートウェイは、メッセージを転送する前にコンテンツタイプのヘッダーフィールドの値を変更するか、表現をデコードする必要があります。(インターネットメールのコンテンツタイプのいくつかの実験的アプリケーションでは、 "; conventions = <content-coding>"のメディアタイプのパラメーターを使用して、コンテンツエンコードに相当する関数を実行しました。ただし、このパラメーターはMIME標準の一部ではありません。。)

B.5. Conversion of Content-Transfer-Encoding
B.5. コンテンツ移動エンコードの変換

HTTP does not use the Content-Transfer-Encoding field of MIME. Proxies and gateways from MIME-compliant protocols to HTTP need to remove any Content-Transfer-Encoding prior to delivering the response message to an HTTP client.


Proxies and gateways from HTTP to MIME-compliant protocols are responsible for ensuring that the message is in the correct format and encoding for safe transport on that protocol, where "safe transport" is defined by the limitations of the protocol being used. Such a proxy or gateway ought to transform and label the data with an appropriate Content-Transfer-Encoding if doing so will improve the likelihood of safe transport over the destination protocol.


B.6. MHTML and Line Length Limitations
B.6. MHTMLおよびラインの長さの制限

HTTP implementations that share code with MHTML [RFC2557] implementations need to be aware of MIME line length limitations. Since HTTP does not have this limitation, HTTP does not fold long lines. MHTML messages being transported by HTTP follow all conventions of MHTML, including line length limitations and folding, canonicalization, etc., since HTTP transfers message-bodies without modification and, aside from the "multipart/byteranges" type (Section 14.6 of [HTTP]), does not interpret the content or any MIME header lines that might be contained therein.

MHTML [RFC2557]とコードを共有するHTTP実装は、MIMEラインの長さの制限を認識する必要があります。HTTPにはこの制限がないため、HTTPは長い行を折りません。HTTPは変更なしでメッセージボディを転送し、「MultiPart/Byteranges」タイプ([http]のセクション14.6」を除いて、MHTMLのすべての規則に従って、ラインの長さの制限と折り畳み、標準化などを含むMHTMLのすべての規則に従います。)、その中に含まれる可能性のあるコンテンツまたはMIMEヘッダーラインを解釈しません。

Appendix C. Changes from Previous RFCs
C.1. Changes from HTTP/0.9
C.1. HTTP/0.9からの変更

Since HTTP/0.9 did not support header fields in a request, there is no mechanism for it to support name-based virtual hosts (selection of resource by inspection of the Host header field). Any server that implements name-based virtual hosts ought to disable support for HTTP/0.9. Most requests that appear to be HTTP/0.9 are, in fact, badly constructed HTTP/1.x requests caused by a client failing to properly encode the request-target.


C.2. Changes from HTTP/1.0
C.2. HTTP/1.0からの変更
C.2.1. Multihomed Web Servers
C.2.1. マルチホームWebサーバー

The requirements that clients and servers support the Host header field (Section 7.2 of [HTTP]), report an error if it is missing from an HTTP/1.1 request, and accept absolute URIs (Section 3.2) are among the most important changes defined by HTTP/1.1.


Older HTTP/1.0 clients assumed a one-to-one relationship of IP addresses and servers; there was no established mechanism for distinguishing the intended server of a request other than the IP address to which that request was directed. The Host header field was introduced during the development of HTTP/1.1 and, though it was quickly implemented by most HTTP/1.0 browsers, additional requirements were placed on all HTTP/1.1 requests in order to ensure complete adoption. At the time of this writing, most HTTP-based services are dependent upon the Host header field for targeting requests.


C.2.2. Keep-Alive Connections
C.2.2. アリブな接続を維持します

In HTTP/1.0, each connection is established by the client prior to the request and closed by the server after sending the response. However, some implementations implement the explicitly negotiated ("Keep-Alive") version of persistent connections described in Section 19.7.1 of [RFC2068].


Some clients and servers might wish to be compatible with these previous approaches to persistent connections, by explicitly negotiating for them with a "Connection: keep-alive" request header field. However, some experimental implementations of HTTP/1.0 persistent connections are faulty; for example, if an HTTP/1.0 proxy server doesn't understand Connection, it will erroneously forward that header field to the next inbound server, which would result in a hung connection.


One attempted solution was the introduction of a Proxy-Connection header field, targeted specifically at proxies. In practice, this was also unworkable, because proxies are often deployed in multiple layers, bringing about the same problem discussed above.


As a result, clients are encouraged not to send the Proxy-Connection header field in any requests.


Clients are also encouraged to consider the use of "Connection: keep-alive" in requests carefully; while they can enable persistent connections with HTTP/1.0 servers, clients using them will need to monitor the connection for "hung" requests (which indicate that the client ought to stop sending the header field), and this mechanism ought not be used by clients at all when a proxy is being used.


C.2.3. Introduction of Transfer-Encoding
C.2.3. 転送エンコードの導入

HTTP/1.1 introduces the Transfer-Encoding header field (Section 6.1). Transfer codings need to be decoded prior to forwarding an HTTP message over a MIME-compliant protocol.


C.3. Changes from RFC 7230
C.3. RFC 7230からの変更

Most of the sections introducing HTTP's design goals, history, architecture, conformance criteria, protocol versioning, URIs, message routing, and header fields have been moved to [HTTP]. This document has been reduced to just the messaging syntax and connection management requirements specific to HTTP/1.1.


Bare CRs have been prohibited outside of content. (Section 2.2)


The ABNF definition of authority-form has changed from the more general authority component of a URI (in which port is optional) to the specific host:port format that is required by CONNECT. (Section 3.2.3)


Recipients are required to avoid smuggling/splitting attacks when processing an ambiguous message framing. (Section 6.1)


In the ABNF for chunked extensions, (bad) whitespace around ";" and "=" has been reintroduced. Whitespace was removed in [RFC7230], but that change was found to break existing implementations. (Section 7.1.1)

チャンクされたエクステンションのABNFで、(悪い)白い空間 ";"および「=」は再導入されています。Whitespaceは[RFC7230]で削除されましたが、その変更は既存の実装を破ることがわかった。(セクション7.1.1)

Trailer field semantics now transcend the specifics of chunked transfer coding. The decoding algorithm for chunked (Section 7.1.3) has been updated to encourage storage/forwarding of trailer fields separately from the header section, to only allow merging into the header section if the recipient knows the corresponding field definition permits and defines how to merge, and otherwise to discard the trailer fields instead of merging. The trailer part is now called the trailer section to be more consistent with the header section and more distinct from a body part. (Section 7.1.2)


Transfer coding parameters called "q" are disallowed in order to avoid conflicts with the use of ranks in the TE header field. (Section 7.3)




See Appendix "Acknowledgements" of [HTTP], which applies to this document as well.





a c d f g h m o r t x



absolute-form (of request-target) Section 3.2.2 application/http Media Type *_Section 10.2_* asterisk-form (of request-target) Section 3.2.4 authority-form (of request-target) Section 3.2.3

絶対形式(リクエストターゲットの)セクション3.2.2アプリケーション/HTTPメディアタイプ * _Section 10.2_ * ASTERISK-FORM(リクエストターゲットの)セクション3.2.4 Authority-Form(リクエストターゲットの)セクション3.2.3



         chunked (Coding Format)  Section 6.1; Section 6.3
         chunked (transfer coding)  *_Section 7.1_*
         close  Section 9.3; *_Section 9.6_*
         compress (transfer coding)  *_Section 7.2_*
         Connection header field  Section 9.6
         Content-Length header field  Section 6.2
         Content-Transfer-Encoding header field  Appendix B.5



deflate (transfer coding) *_Section 7.2_*

Deflate(転送コーディング) *_Section 7.2_ *



            Close  *_Section 9.6, Paragraph 4_*
            MIME-Version  *_Appendix B.1_*
            Transfer-Encoding  *_Section 6.1_*



            ALPHA  *_Section 1.2_*
            CR  *_Section 1.2_*
            CRLF  *_Section 1.2_*
            CTL  *_Section 1.2_*
            DIGIT  *_Section 1.2_*
            DQUOTE  *_Section 1.2_*
            HEXDIG  *_Section 1.2_*
            HTAB  *_Section 1.2_*
            HTTP-message  *_Section 2.1_*
            HTTP-name  *_Section 2.3_*
            HTTP-version  *_Section 2.3_*
            LF  *_Section 1.2_*
            OCTET  *_Section 1.2_*
            SP  *_Section 1.2_*
            Transfer-Encoding  *_Section 6.1_*
            VCHAR  *_Section 1.2_*
            absolute-form  Section 3.2; *_Section 3.2.2_*
            asterisk-form  Section 3.2; *_Section 3.2.4_*
            authority-form  Section 3.2; *_Section 3.2.3_*
            chunk  *_Section 7.1_*
            chunk-data  *_Section 7.1_*
            chunk-ext  Section 7.1; *_Section 7.1.1_*
            chunk-ext-name  *_Section 7.1.1_*
            chunk-ext-val  *_Section 7.1.1_*
            chunk-size  *_Section 7.1_*
            chunked-body  *_Section 7.1_*
            field-line  *_Section 5_*; Section 7.1.2
            field-name  Section 5
            field-value  Section 5
            last-chunk  *_Section 7.1_*
            message-body  *_Section 6_*
            method  *_Section 3.1_*
            obs-fold  *_Section 5.2_*
            origin-form  Section 3.2; *_Section 3.2.1_*
            reason-phrase  *_Section 4_*
            request-line  *_Section 3_*
            request-target  *_Section 3.2_*
            start-line  *_Section 2.1_*
            status-code  *_Section 4_*
            status-line  *_Section 4_*
            trailer-section  Section 7.1; *_Section 7.1.2_*
         gzip (transfer coding)  *_Section 7.2_*



Header Fields MIME-Version *_Appendix B.1_* Transfer-Encoding *_Section 6.1_* header line Section 2.1 header section Section 2.1 headers Section 2.1

ヘッダーフィールドMime-version * _Appendix B.1_ *転送エンコード * _Section 6.1_ *ヘッダーラインセクション2.1ヘッダーセクションセクション2.1ヘッダーセクション2.1



         Media Type
            application/http  *_Section 10.2_*
            message/http  *_Section 10.1_*
         message/http Media Type  *_Section 10.1_*
         method  *_Section 3.1_*
         MIME-Version header field  *_Appendix B.1_*



origin-form (of request-target) Section 3.2.1




request-target *_Section 3.2_*

リクエストターゲット *_セクション3.2_ *



Transfer-Encoding header field *_Section 6.1_*

転送エンコードヘッダーフィールド *_Section 6.1_ *



         x-compress (transfer coding)  *_Section 7.2_*
         x-gzip (transfer coding)  *_Section 7.2_*

Authors' Addresses


Roy T. Fielding (editor) Adobe 345 Park Ave San Jose, CA 95110 United States of America Email: URI:

Roy T. Fielding(編集者)Adobe 345 Park Ave San Jose、CA 95110アメリカ合衆国電子メール URI:

Mark Nottingham (editor) Fastly Prahran Australia Email: URI:

マーク・ノッティンガム(編集者)急速にPrahran Australiaメール uri:

   Julian Reschke (editor)
   greenbytes GmbH
   Hafenweg 16
   48155 Münster