NAME

       CURLOPT_DOH_URL - provide the DNS-over-HTTPS URL

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_URL, char *URL);

DESCRIPTION

       Pass  in  a  pointer  to a URL for the DoH server to use for name resolving. The parameter
       should be a char pointer to a null-terminated string which must be  a  valid  and  correct
       HTTPS URL.

       libcurl  does  not  validate the syntax or use this variable until the transfer is issued.
       Even if you set a crazy value here, curl_easy_setopt(3) still returns CURLE_OK.

       curl sends POST requests to the given DNS-over-HTTPS URL.

       To find the DoH server itself, which might be specified using a  name,  libcurl  uses  the
       default  name lookup function. You can bootstrap that by providing the address for the DoH
       server with CURLOPT_RESOLVE(3).

       The application does not have to keep the string around after setting this option.

       Using this option multiple times makes the last set string override the previous ones. Set
       it to NULL to disable its use again.

INHERIT OPTIONS

       DoH  lookups  use  SSL  and  some  SSL  settings  from  your  transfer are inherited, like
       CURLOPT_SSL_CTX_FUNCTION(3).

       The hostname and peer certificate verification settings  are  not  inherited  but  can  be
       controlled separately via CURLOPT_DOH_SSL_VERIFYHOST(3) and CURLOPT_DOH_SSL_VERIFYPEER(3).

       A set CURLOPT_OPENSOCKETFUNCTION(3) callback is not inherited.

KNOWN BUGS

       Even  when DoH is set to be used with this option, there are still some name resolves that
       are performed without it, using the default name resolver mechanism.  This  includes  name
       resolves   done   for  CURLOPT_INTERFACE(3),  CURLOPT_FTPPORT(3),  a  proxy  type  set  to
       CURLPROXY_SOCKS4 or CURLPROXY_SOCKS5 and probably some more.

DEFAULT

       NULL

PROTOCOLS

       This functionality affects all supported protocols

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
           curl_easy_setopt(curl, CURLOPT_DOH_URL, "https://dns.example.com");
           curl_easy_perform(curl);
         }
       }

AVAILABILITY

       Added in curl 7.62.0

RETURN VALUE

       Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient heap space.

       Note that curl_easy_setopt(3) does immediately parse the given string so when given a  bad
       DoH  URL, libcurl might not detect the problem until it later tries to resolve a name with
       it.

SEE ALSO

       CURLOPT_DNS_CACHE_TIMEOUT(3), CURLOPT_RESOLVE(3), CURLOPT_VERBOSE(3)