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 * to a null-terminated string which must be URL-encoded in the  following
       format: "https://host:port/path". It MUST specify an 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) will still return 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 will use the
       default  name lookup function. You can bootstrap that by providing the address for the DoH
       server with CURLOPT_RESOLVE(3).

       Disable DoH use again by setting this option to NULL.

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  -  there  is  no  default  DoH  URL. If this option is not set, libcurl will use the
       default name resolver.

PROTOCOLS

       All

EXAMPLE

       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 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) will not 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_VERBOSE(3), CURLOPT_RESOLVE(3),