Opened 10 years ago
Closed 9 years ago
#442 closed design (fixed)
BWS
Reported by: | mnot@… | Owned by: | draft-ietf-httpbis-p1-messaging@… |
---|---|---|---|
Priority: | normal | Milestone: | 23 |
Component: | p1-messaging | Severity: | In WG Last Call |
Keywords: | Cc: |
Description
p1 3.2.3 says:
BWS is used where the grammar allows optional whitespace, for historical reasons, but senders SHOULD NOT generate it in messages; recipients MUST accept such bad optional whitespace and remove it before interpreting the field value or forwarding the message downstream.
http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-22#section-3.2.3
Throughout our specs, BWS is used at the end of header fields:
header-field = field-name ":" OWS field-value BWS
and in transfer-codings:
transfer-parameter = attribute BWS "=" BWS value
and in Expect headers:
expectation = expect-name [ BWS "=" BWS expect-value]
*( OWS ";" [ OWS expect-param ] )
expect-param = expect-name [ BWS "=" BWS expect-value ]
and, finally, in auth-params on challenges and credentials:
auth-param = token BWS "=" BWS ( token / quoted-string )
Is this whitespace really "bad" enough to MUST-require that intermediaries (including load balancers and other hardware!) remove it before forwarding the message?
Attachments (1)
Change History (13)
Changed 10 years ago by julian.reschke@…
comment:1 Changed 10 years ago by mnot@…
- Milestone changed from unassigned to 23
Also in p2, add (regarding media type parameters):
Note that unlike some similar constructs in other headers, media type parameters do not allow whitespace (even "bad" whitespace) around the "=" character.
comment:2 Changed 10 years ago by julian.reschke@…
comment:3 Changed 10 years ago by julian.reschke@…
- Resolution set to incorporated
- Status changed from new to closed
comment:4 follow-up: ↓ 5 Changed 10 years ago by mnot@…
- Resolution incorporated deleted
- Status changed from closed to reopened
p2 as well, please...
comment:5 in reply to: ↑ 4 Changed 10 years ago by julian.reschke@…
comment:6 Changed 10 years ago by julian.reschke@…
- Resolution set to incorporated
- Status changed from reopened to closed
comment:7 Changed 10 years ago by fielding@…
- Resolution incorporated deleted
- Status changed from closed to reopened
Note that I changed this wording slightly in [2253].
Also, I am reopening this issue because the use of BWS for trailing whitespace is inconsistent with the other uses of BWS. Trailing whitespace isn't bad — it's just wasteful — and calling it bad is a problem with our other suggestion for replacing sequences of whitespace (obs-fold and HTAB) with sequences of SP for in-place message filtering. The existing SHOULD in OWS seems to be more appropriate. I can't remember why I made it BWS here.
comment:8 Changed 10 years ago by mnot@…
+1
comment:9 Changed 10 years ago by fielding@…
comment:10 Changed 10 years ago by fielding@…
- Resolution set to incorporated
- Status changed from reopened to closed
comment:11 Changed 9 years ago by mnot@…
- Resolution incorporated deleted
- Status changed from closed to reopened
comment:12 Changed 9 years ago by mnot@…
- Resolution set to fixed
- Status changed from reopened to closed
Proposed patch