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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);

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

Enable the in-memory HSTS cache for this handle.
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),

September 6, 2021 libcurl 7.79.1