1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_HSTS_CTRL 5Section: 3 6Source: libcurl 7Protocol: 8 - HTTP 9See-also: 10 - CURLOPT_ALTSVC (3) 11 - CURLOPT_CONNECT_TO (3) 12 - CURLOPT_HSTS (3) 13 - CURLOPT_RESOLVE (3) 14Added-in: 7.74.0 15--- 16 17# NAME 18 19CURLOPT_HSTS_CTRL - control HSTS behavior 20 21# SYNOPSIS 22 23~~~c 24#include <curl/curl.h> 25 26#define CURLHSTS_ENABLE (1<<0) 27#define CURLHSTS_READONLYFILE (1<<1) 28 29CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTS_CTRL, long bitmask); 30~~~ 31 32# DESCRIPTION 33 34HSTS (HTTP Strict Transport Security) means that an HTTPS server can instruct 35the client to not contact it again over clear-text HTTP for a certain period 36into the future. libcurl then automatically redirects HTTP attempts to such 37hosts to instead use HTTPS. This is done by libcurl retaining this knowledge 38in an in-memory cache. 39 40Populate the long *bitmask* with the correct set of features to instruct 41libcurl how to handle HSTS for the transfers using this handle. 42 43# BITS 44 45## CURLHSTS_ENABLE 46 47Enable the in-memory HSTS cache for this handle. 48 49## CURLHSTS_READONLYFILE 50 51Make the HSTS file (if specified) read-only - makes libcurl not save the cache 52to the file when closing the handle. 53 54# DEFAULT 55 560 57 58# %PROTOCOLS% 59 60# EXAMPLE 61 62~~~c 63int main(void) 64{ 65 CURL *curl = curl_easy_init(); 66 if(curl) { 67 curl_easy_setopt(curl, CURLOPT_HSTS_CTRL, (long)CURLHSTS_ENABLE); 68 curl_easy_perform(curl); 69 } 70} 71~~~ 72 73# %AVAILABILITY% 74 75# RETURN VALUE 76 77Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. 78
