Is using the HTTP Content-Range header appropriate when sending a file in chunks using the POST method?

Question

I am working on an existing Silverlight file uploader that breaks files into multiple chunks and transmits the file using multiple HTTP requests.

Currently, it sends

Answer 1

Probably not, at least as of 2014 (the original answer is from 2011).

The updated HTTP 1.1 specification, rfc7231 (4.3.3), says the following about valid POST responses:

An origin server indicates response semantics by choosing an appropriate status code depending on the result of processing the POST request; almost all of the status codes defined by this specification might be received in a response to POST (the exceptions being 206 (Partial Content), 304 (Not Modified), and 416 (Range Not Satisfiable)).

Given that this language was explicitly added to the updated spec, I doubt the authors intended that the Content-Range header be used with the POST method.

Answer 2

Yes.

RFC 2616 (HTTP 1.1), Section 14 begins by stating:

For entity-header fields, both sender and recipient refer to either the client or the server, depending on who sends and who receives the entity.

Other than that, Section 14.16, which defines the Content-Range header, does not appear to contain any language limiting its use to either the request or response.