CURLOPT_HSTS_CTRL - control HSTS behavior

NAME  SYNOPSIS  DESCRIPTION  BITS  DEFAULT  PROTOCOLS  EXAMPLE  AVAILABILITY  RETURN VALUE  SEE ALSO 

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NAME

CURLOPT_HSTS_CTRL − control HSTS behavior

SYNOPSIS

#include <curl/curl.h>

#define CURLHSTS_ENABLE (1L << 0)
#define CURLHSTS_READONLYFILE (1L << 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, CURLHSTS_ENABLE);
curl_easy_perform(curl);
}
}

AVAILABILITY

Added in curl 7.74.0

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non−zero means an error occurred, see libcurl−errors(3).

SEE ALSO

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

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