CURLOPT_HSTSWRITEFUNCTION (original) (raw)

CURLOPT_HSTSWRITEFUNCTION explained

Name

CURLOPT_HSTSWRITEFUNCTION - write callback for HSTS hosts

Synopsis

#include <curl/curl.h> struct curl_hstsentry { char name; size_t namelen; unsigned int includeSubDomains:1; char expire[18]; / YYYYMMDD HH:MM:SS [null-terminated] / }; struct curl_index { size_t index; / the provided entry's "index" or count / size_t total; / total number of entries to save */ }; CURLSTScode hstswrite(CURL *easy, struct curl_hstsentry *sts, struct curl_index *count, void *clientp); CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSWRITEFUNCTION, hstswrite);

Description

Pass a pointer to your callback function, as the prototype shows above.

This callback function gets called by libcurl repeatedly to allow the application to store the in-memory HSTS cache when libcurl is about to discard it.

Set the clientp argument with the CURLOPT_HSTSWRITEDATA option or it is NULL. When the callback is invoked, the sts pointer points to a populated struct: Read the hostname to 'name' (it is namelen bytes long and null terminated. The includeSubDomains field is non-zero if the entry matches subdomains. The expire string is a date stamp null-terminated string using the syntax YYYYMMDD HH:MM:SS.

The callback should return CURLSTS_OK if it succeeded and is prepared to be called again (for another host) or CURLSTS_DONE if there is nothing more to do. It can also return CURLSTS_FAIL to signal error.

This option does not enable HSTS, you need to use CURLOPT_HSTS_CTRL to do that.

Default

NULL - no callback.

Protocols

This functionality affects http only

Example

struct priv { void *custom; }; static CURLSTScode hswr_cb(CURL *easy, struct curl_hstsentry *sts, struct curl_index *count, void clientp) { / save the passed in HSTS data somewhere */ return CURLSTS_OK; } int main(void) { CURL curl = curl_easy_init(); if(curl) { struct priv my_stuff; CURLcode res; / set HSTS read callback / curl_easy_setopt(curl, CURLOPT_HSTSWRITEFUNCTION, hswr_cb); / pass in suitable argument to the callback */ curl_easy_setopt(curl, CURLOPT_HSTSWRITEDATA, &my_stuff); res = curl_easy_perform(curl); } }

Availability

Added in curl 7.74.0

Return value

This returns CURLE_OK.