CURLOPT_HSTS_CTRL(3)       curl_easy_setopt options       CURLOPT_HSTS_CTRL(3)

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);

EXPERIMENTAL
       Warning: this feature is early code and is marked as experimental. It
       can only be enabled by explicitly telling configure with --enable-hsts.
       You are advised to not ship this in production before the experimental
       label is removed.

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),

libcurl 7.77.0                 November 4, 2020           CURLOPT_HSTS_CTRL(3)