CURLOPT_SSLENGINE (3) - Linux Manuals
CURLOPT_SSLENGINE: set SSL engine identifier
NAME
CURLOPT_SSLENGINE - set SSL engine identifierSYNOPSIS
#include <curl/curl.h>CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSLENGINE, char *id);
DESCRIPTION
Pass a pointer to a zero terminated string as parameter. It will be used as the identifier for the crypto engine you want to use for your private key.If the crypto device cannot be loaded, CURLE_SSL_ENGINE_NOTFOUND is returned.