search

SanKumar2015 / EST-coaps

EST over CoAPs IETF draft
1 stars 1 forks source link

ct="62 280 284 281 TBD287" (Klaus WGLC review 2/12/2019) #127

Closed csosto-pk closed 5 years ago

csosto-pk commented 5 years ago

Klaus asked

The return of the content types allows the client to choose the most appropriate one." -- Does the example actually match what a server returns? E.g., does ct="62 280 284 281 TBD287" mean that a server actually returns a TBD287 representation or would it always be a 62 (multipart) representation that happens to contain a TBD287 representation?

csosto-pk commented 5 years ago

I am not sure we need to return only 62.

RFC5272 says

The Content-Format code "ct" attribute provides a hint about the Content-Formats this resource returns. Note that this is only a hint, and it does not override the Content-Format Option of a CoAP response obtained by actually requesting the representation of the resource. [...] The Content-Format code attribute MAY include a space-separated sequence of Content-Format codes, indicating that multiple content-formats are available.

So ct="62 280 284 281 TBD287" could hint to the client that all the following formats are supported for the multipart server-side keygen.

csosto-pk commented 5 years ago

Peter removed them in commit 6d12b50.

I think we still can keep them there. RFC5272 says

The Content-Format code "ct" attribute provides a hint about the Content-Formats this resource returns. Note that this is only a hint, and it does not override the Content-Format Option of a CoAP response obtained by actually requesting the representation of the resource. [...] The Content-Format code attribute MAY include a space-separated sequence of Content-Format codes, indicating that multiple content-formats are available.

So ct="62 280 284 281 TBD287" could hint to the client that all the following formats are supported for the multipart server-side keygen.

We need to clarify that with Klaus et al.

mcr commented 5 years ago

If we resolved the CT issue by allocating 4 CT for the 2x2 combinations, then we would list those for CT here instead of 62 + contents.

csosto-pk commented 5 years ago

62 is compulsory. The others are put in as hints if they are supported. If we end up defining four new multipart content-format combinations then these will go in the ct="...".

Sent an email to ask Klaus if he agrees.

csosto-pk commented 5 years ago

According to mailing list discussions, this value can only be 62... Need to fix.

csosto-pk commented 5 years ago

Fixed. Only kept "ct=62" in the resource discovery response.