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).

       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

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)