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  will  then  automatically
       redirect  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. HSTS is disabled by default.

PROTOCOLS

       HTTPS and HTTP

EXAMPLE

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

AVAILABILITY

       Added in 7.74.0

RETURN VALUE

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

SEE ALSO

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