(Note: I removed "SSL_CTX_set_ecdh_auto(ctx, 1);" to make it compile)
It responds Chrome with ERR_RESPONSE_HEADERS_TRUNCATED, while changing the text sent to "Hello there" works and shows "Hello there" in Chrome. Same goes for Curl. I've tested self-signed certs and one "half-signed" (crap signer).
This is on Linux (Fedora 24) and I have OpenSSL 1.1.0 but I'm pretty sure Node.js 5.x uses OpenSSL 1.0.2g.