SSL: include <openssl/hmac.h>. This header carries the definition of HMAC_Init_ex(). In OpenSSL this header is included by <openssl/ssl.h>, but it's not so in BoringSSL. It's probably a good idea to explicitly include this header anyway, regardless of whether it's included by other headers or not.

if exists("b:did_indent")
    finish
endif
let b:did_indent = 1

setlocal indentexpr=

" cindent actually works for nginx' simple file structure
setlocal cindent
" Just make sure that the comments are not reset as defs would be.
setlocal cinkeys-=0#