NAME

       CURLOPT_HSTSREADFUNCTION - read 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] */
       };

       CURLSTScode hstsread(CURL *easy, struct curl_hstsentry *sts, void *userp);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSREADFUNCTION, hstsread);

DESCRIPTION

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

       This  callback  function gets called by libcurl repeatedly when it populates the in-memory
       HSTS cache.

       Set the userp argument with the CURLOPT_HSTSREADDATA(3) option or it will be NULL.

       When this callback is invoked, the sts pointer points to a populated struct: Copy the host
       name   to   'name'  (no  longer  than  'namelen'  bytes).  Make  it  null-terminated.  Set
       'includeSubDomains' to TRUE or FALSE. Set 'expire' to a date stamp or a zero length string
       for *forever* (wrong date stamp format might cause the name to not get accepted)

       The  callback  should  return CURLSTS_OK if it returns a name and is prepared to be called
       again (for another host) or CURLSTS_DONE if it has no entry to return. It can also  return
       CURLSTS_FAIL  to  signal  error.  Returning CURLSTS_FAIL will stop the transfer from being
       performed and make CURLE_ABORTED_BY_CALLBACK get returned.

       This option does not enable HSTS, you need to use CURLOPT_HSTS_CTRL(3) to do that.

DEFAULT

       NULL - no callback.

PROTOCOLS

       This feature is only used for HTTP(S) transfer.

EXAMPLE

       {
         /* set HSTS read callback */
         curl_easy_setopt(curl, CURLOPT_HSTSREADFUNCTION, hstsread);

         /* pass in suitable argument to the callback */
         curl_easy_setopt(curl, CURLOPT_HSTSREADDATA, &hstspreload[0]);

         result = curl_easy_perform(curl);
       }

AVAILABILITY

       Added in 7.74.0

RETURN VALUE

       This will return CURLE_OK.

SEE ALSO

       CURLOPT_HSTSREADDATA(3),          CURLOPT_HSTSWRITEFUNCTION(3),           CURLOPT_HSTS(3),
       CURLOPT_HSTS_CTRL(3),