NAME

       CURLOPT_HSTS_CTRL - control HSTS behavior

SYNOPSIS

       #include <curl/curl.h>

       #define CURLHSTS_ENABLE       (1<<0)
       #define CURLHSTS_READONLYFILE (1<<1)

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTS_CTRL, long bitmask);

DESCRIPTION

       HSTS  (HTTP  Strict Transport Security) means that an HTTPS server can instruct the client
       to not contact it again over clear-text HTTP for a certain period into the future. libcurl
       then  automatically  redirects  HTTP  attempts to such hosts to instead use HTTPS. This is
       done by libcurl retaining this knowledge in an in-memory cache.

       Populate the long bitmask with the correct set of features  to  instruct  libcurl  how  to
       handle HSTS for the transfers using this handle.

BITS

       CURLHSTS_ENABLE
              Enable the in-memory HSTS cache for this handle.

       CURLHSTS_READONLYFILE
              Make  the  HSTS file (if specified) read-only - makes libcurl not save the cache to
              the file when closing the handle.

DEFAULT

       0

PROTOCOLS

       This functionality affects http only

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           curl_easy_setopt(curl, CURLOPT_HSTS_CTRL, (long)CURLHSTS_ENABLE);
           curl_easy_perform(curl);
         }
       }

AVAILABILITY

       Added in curl 7.74.0

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_ALTSVC(3), CURLOPT_CONNECT_TO(3), CURLOPT_HSTS(3), CURLOPT_RESOLVE(3)