OCSP stapling with nginx

For OCSP requests used for OCSP stapling nginx uses GET requests, as described in RFC 2560.

On the other hand, OpenSSL as of last released OpenSSL 1.0.2d only supports POST requests in the OCSP responder daemon available via openssl ocsp. It doesn't recognize GET requests and prints Invalid request for such requests.

To make this work, you may try OpenSSL from master branch - it seems to contain an attempt to improve OCSP responder code and should handle GET requests properly now. I've never tried though, and may be there are other problems. Please also keep in mind it's unreleased code.

You may also consider using another OCSP responder.