/cc @agl

OCSP nonces are unused in practice in the WebPKI, as far as I know. They require online signing of OCSP responses so I don't see that changing.

Even if that were not the case, why not add elements to the Request structure rather than change the function signature?

I had only implemented it since openssl was complaining by default and it sticks to the RFC. Openssl stopped complaining when I implemented them even though I don't sign responses.
My proposed addition (different than the example code) would modify the request structure, but also add another function for those that wanted to get extensions back from a function call for further processing.
Modifying the Request structure doesn't make sense because these extensions are in the tbsRequest.
I see your point about nonces not being necessary, though. I don't know where this protocol will be going in the future so it may be helpful to have access to those extensions at some point.

An update to this issue, I have submitted a review for it: https://go-review.googlesource.com/c/crypto/+/101915
The code has been modified to not break existing implementations but to add a function that will return request extensions with the parsed request and also enable a developer to add response extensions to their response via template.

/cc @FiloSottile

Change https://go.dev/cl/540735 mentions this issue: ocsp: support for request and response extensions

I've submitted a PR that adds the support without creating new functions:
https://go-review.googlesource.com/c/crypto/+/540735

CL 540735 adds the following new fields to Request and Response.

// Request represents an OCSP request. See RFC 6960.
type Request struct {
	// ...
	Extensions     []pkix.Extension
}

// Response represents an OCSP response containing a single SingleResponse. See
// RFC 6960.
type Response struct {
	// ...

	// ResponseExtensions contains raw X.509 extensions from the
	// responseExtensions field of the OCSP response. When marshaling OCSP
	// responses, the ResponseExtensions field is ignored, see
	// ResponseExtraExtensions.
	ResponseExtensions []pkix.Extension

	// ResponseExtraExtensions contains extensions to be copied, raw, into any
	// marshaled OCSP response (in the responseExtensions field). Values
	// override any extensions that would otherwise be produced based on the
	// other fields. The ResponseExtraExtensions field is not populated when
	// parsing certificates, see ResponseExtensions.
	ResponseExtraExtensions []pkix.Extension
}

/cc @golang/proposal-review @golang/security