CURLOPT_DOH_URL − provide the DNS-over-HTTPS URL
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_URL, char *URL);
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 a HTTPS URL.
libcurl doesn’t 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.
NULL - there is no default DOH URL. If this option isn’t set, libcurl will use the default name resolver.
CURL *curl =
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_setopt(curl, CURLOPT_DOH_URL, "https://dns.example.com");
Added in 7.62.0
Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
Note that curl_easy_setopt(3) won’t actually parse the given string so given a bad DOH URL, curl will not detect a problem until it tries to resolve a name with it.