[Technical Errata Reported] RFC7230 (4667)

[RFC Errata System <[e-mail]>]

The following errata report has been submitted for RFC7230,
"Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing".

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You may review the report below and at:
http://www.rfc-editor.org/errata_search.php?rfc=7230&eid=4667

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Type: Technical
Reported by: Alex Rousskov <[e-mail]>

Section: 4.1.1

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


Corrected Text
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chunk-ext      = *( ";" OWS chunk-ext-name [ "=" chunk-ext-val ] )

Notes
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The infamous "implicit *LWS" syntax rule in RFC 2616 allowed whitespace between ";" and chunk-ext-name in chunk-ext. Some HTTP agents generate that whitespace. In my experience, HTTP agents that can parse chunk extensions usually can handle that whitespace. Moreover, ICAP, which generally relies on HTTP/1 for its message syntax, uses that whitespace when defining the "ieof" chunk extension in RFC 3507 Section 4.5:

      \r\n
      0; ieof\r\n\r\n

IMHO, RFC 7230 should either allow OWS before chunk-ext-name or at the very least explicitly document the HTTP/1 syntax change and its effect on parsers used for both ICAP and HTTP/1 messages (a very common case for ICAP-supporting HTTP intermediaries and ICAP services).

I also recommend adding BWS around "=", for consistency and RFC 2616 backward compatibility reasons. HTTPbis RFCs already do that for transfer-parameter and auth-param that have similar syntax.

Please also consider adding OWS _before_ ";" for consistency and RFC 2616 backward compatibility reasons. HTTPbis RFCs already do that for transfer-extension, accept-ext,  t-ranking, and other constructs with similar syntax.

If all of the above suggestions are applied, the final syntax becomes:

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

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RFC7230 (draft-ietf-httpbis-p1-messaging-26)
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Title               : Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
Publication Date    : June 2014
Author(s)           : R. Fielding, Ed., J. Reschke, Ed.
Category            : PROPOSED STANDARD
Source              : Hypertext Transfer Protocol Bis APP
Area                : Applications
Stream              : IETF
Verifying Party     : IESG