HTTP Servlet support for s/mime Content-Type

[lgtti]

Hi,

to support the IoT RFC EST (7030, https://www.rfc-editor.org/rfc/rfc7030.html) I need to configure the response mime and s/mime type.
In this RFC, the enroll certificate response requires a specific Content-Type with a smime-type extension.

Content-Type: application/pkcs7-mime; smime-type=certs-only

but checking the source code of the HttpServletResponse.setContentType method (and the more generic addHeader)
the evidence is that only " ;chartset=xxx" is allowed.

How can i return the requested Content-Type header?