Content-Type restriction on http-01 is not enforced

[jsha]

Per spec, the Content-Type for http-01 challenges must be either empty or text/plain. However, we do not currently enforce this in Boulder.

[hlandau]

I do wonder if it's a good idea to enforce this, at least until ACME WG properly deliberates on the issues. See ietf-wg-acme/acme#9

[My1]

I think we should not care at all. there should be done 2 checks at best for this: size (to prevent download of loverly large "misplaced" files and most obviously content, that are things that are static and cannot change without affecting the actual validation.

[SkateScout]

Maybe it would also be an good idea if the client send an Accept header with its request.

[raboof]

It seems the restriction on Content-Type has been removed from the spec (ietf-wg-acme/acme#40), however it seems the private beta server does require it... should we close this issue and create a new one for lifting the restriction?

[My1]

I think yes we should.

[jsha]

Fixed.