def validate_hostname(hostname):
if hostname[-1] == ".":
# strip exactly one dot from the right, if present
hostname = hostname[:-1]
if len(hostname) > 253:
raise NamesError(
'The hostname "{}..." is longer than 253 characters.'.format(
hostname[:10]))
labels = hostname.split(".")
tld = labels[-1]
if re.match(r"[0-9]+$", tld):
raise NamesError(
'The TLD "{}" of the hostname "{}" must be not all-numeric.'.
format(tld, hostname))
allowed = re.compile(r"(?!-)[a-z0-9-]{1,63}(?<!-)$", re.IGNORECASE)
for label in labels:
if not allowed.match(label):
raise NamesError(
'The label "{}" of the hostname "{}" is invalid.'.format(
label, hostname))
return str(dns.name.from_text(hostname))
def validate_tsig_key(tsig_key):
if not tsig_key:
raise NamesError('Invalid tsig key: "{}".'.format(tsig_key))
try:
dns.tsigkeyring.from_text({'tmp.org.': tsig_key})
return tsig_key
except binascii.Error:
raise NamesError('Invalid tsig key: "{}".'.format(tsig_key))
def split_fqdn(self, fqdn):
"""Split hostname into record_name and zone_name
for example: www.example.com -> www. example.com.
"""
fqdn = validate_hostname(fqdn)
record_name = fqdn.replace(self.zone_name, '')
if record_name and len(record_name) < len(fqdn):
return (record_name, self.zone_name)
raise NamesError('FQDN "{}" is not splitable by zone "{}".')
def __init__(self, zones, fqdn=None, zone_name=None, record_name=None):
self.fqdn = None
"""The Fully Qualified Domain Name (e. g. ``www.example.com.``)"""
self.zone_name = None
"""The zone name (e. g. ``example.com.``)"""
self.record_name = None
"""The name resource record (e. g. ``www.``)"""
if fqdn and zone_name and record_name:
raise NamesError('Specify "fqdn" or "zone_name" and '
'"record_name".')
self._zones = zones
if fqdn:
self.fqdn = validate_hostname(fqdn)
split = self._zones.split_fqdn(fqdn)
if split:
self.record_name = split[0]
self.zone_name = split[1]
if not fqdn and zone_name and record_name:
self.record_name = validate_hostname(record_name)
self.zone_name = validate_hostname(zone_name)
zone = self._zones.get_zone_by_name(self.zone_name)
self.fqdn = zone.build_fqdn(self.record_name)
if not self.record_name:
raise NamesError('Value "record_name" is required.')
if not self.zone_name:
raise NamesError('Value "zone_name" is required.')
self._zone = self._zones.get_zone_by_name(self.zone_name)
self.tsig_key = self._zone.tsig_key
"""The twig key (e. g. ``tPyvZA==``)"""
def get_zone_by_name(self, zone_name):
zone_name = validate_hostname(zone_name)
if zone_name in self.zones:
return self.zones[validate_hostname(zone_name)]
raise NamesError('Unkown zone "{}".'.format(zone_name))