Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing

en · official · sha256:48d3c2df23d66fff10dd5ac623a3a440749f20110a49e6ece036aa807c823cfc

1.1. Requirements Notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Conformance criteria and considerations regarding error handling are defined in Section 2.5.

Ссылаются нормы: assert-16

en · official · sha256:46c66855bda647d16ada634829e2a4c958bb496498b12e90da87a555c8ee6d80

3.3.3. Message Body Length 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. 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. 3. If a Transfer-Encoding header field is present and the chunked transfer coding (Section 4.1) 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. 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. 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 9.5) or response splitting (Section 9.4) and ought to be handled as an error. A sender MUST remove the received Content-Length field prior to forwarding such a message downstream. 4. If a message is received without Transfer-Encoding and with either multiple Content-Length header fields having differing field-values or a single Content-Length header field having an invalid value, then the message framing is invalid and the recipient MUST treat it as an unrecoverable error. If this is a request message, the server MUST respond with a 400 (Bad Request) status code and then close the connection. If this is 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 Fielding & Reschke Standards Track [Page 32]  RFC 7230 HTTP/1.1 Message Syntax and Routing June 2014 Gateway) response to the client. If this is a response message received by a user agent, the user agent MUST close the connection to the server and discard the received response. 5. 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. 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. 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. Since there is no way to distinguish a successfully completed, close-delimited 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. 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 containing a message body MUST send a valid Content-Length header field if it does not know 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 Fielding & Reschke Standards Track [Page 33]  RFC 7230 HTTP/1.1 Message Syntax and Routing June 2014 data belongs as part of the prior response 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.

Ссылаются нормы: ForwardingWithContentLengthDeviates7230, ForwardingWithoutContentLengthConforms7230, ProcessingConflictingContentLengthDeviates7230, RejectingConflictingContentLengthConforms7230, assert-10, assert-11, assert-12, assert-9