add subdomains support

authenticator.py

@@ -37,6 +37,7 @@ import tempfile
 import time
 import urllib.request
 
+import tldextract
 import untangle
 
 from config import apikey, wait
@@ -52,14 +53,20 @@ def sleep(minutes):
 domain = os.environ['CERTBOT_DOMAIN']
 validation = os.environ['CERTBOT_VALIDATION']
 tmpdir = os.path.join(tempfile.gettempdir(), "CERTBOT_"+domain)
+rrhost = "_acme-challenge"
 
 if "NAMESILO_API" in os.environ:
     apikey = os.environ['NAMESILO_API']
 
 
+tld = tldextract.extract(domain)
+nsdomain = tld.domain+"."+tld.suffix
+if tld.subdomain:
+    rrhost += "."+tld.subdomain
+
 url = "https://www.namesilo.com/api/dnsAddRecord?\
-version=1&type=xml&key="+apikey+"&domain="+domain+"&rrtype=TXT\
-&rrhost=_acme-challenge&rrvalue="+validation+"&rrttl=3600"
+version=1&type=xml&key="+apikey+"&domain="+nsdomain+"&rrtype=TXT\
+&rrhost="+rrhost+"&rrvalue="+validation+"&rrttl=3600"
 
 req = urllib.request.Request(
     url,