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

PROTOCOLS

       All

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 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)