- From: Mark Nottingham <mnot@mnot.net>
- Date: Wed, 8 Jul 2020 16:46:20 +1000
- To: "Julian F. Reschke" <julian.reschke@gmx.de>
- Cc: HTTP Working Group <ietf-http-wg@w3.org>
> On 30 Jun 2020, at 7:22 pm, Julian Reschke <julian.reschke@gmx.de> wrote:
>
> Hi there,
>
> I just noticed that RFC 4918 (WebDAV) and RFC 6920 (Naming Things with
> Hashes) give us the machinery to make request conditional on hashes.
>
> Example (based on
> <https://greenbytes.de/tech/webdav/draft-ietf-httpbis-digest-headers-02.html#server-returns-full-representation-data>)
>
> PUT /x HTTP/1.1
> Host: foo
> If: <ni:///sha-256;X48E9qOokqqrvdts8nOJRJN3OWDUoyWxBf7kbu9DBPE=>
> Content-Type: application/json
>
> {"hello": "world2"}
>
> All that would be needed is s statement that servers that support both
> the Digest field and the If header field SHOULD consider the ni: URIs
> built from the hashes as "state tokens" as defined in RFC 4918, Section 3.
As I read it, that means you'll get a 412 when the hash matches. The opposite would be more useful (i.e., an analogy to If-None-Match with hashes) would be more useful for many cases...
Having said that, I think a more specific header field would be more likely to get traction -- e.g., If-Not-Hash: ... That might enable several interesting use cases.
Cheers,
--
Mark Nottingham https://www.mnot.net/
Received on Wednesday, 8 July 2020 06:46:41 UTC