hc-cert-dns/updater/acmedns.py

165 lines
5.5 KiB
Python

#!/usr/bin/env python
import json
import os
import requests
import sys
### EDIT THESE: Configuration values ###
# URL to acme-dns instance
ACMEDNS_URL = "https://auth.acme-dns.io"
# Path for acme-dns credential storage
STORAGE_PATH = "/etc/letsencrypt/acmedns.json"
# Whitelist for address ranges to allow the updates from
# Example: ALLOW_FROM = ["192.168.10.0/24", "::1/128"]
ALLOW_FROM = []
# Force re-registration. Overwrites the already existing acme-dns accounts.
FORCE_REGISTER = False
### DO NOT EDIT BELOW THIS POINT ###
### HERE BE DRAGONS ###
DOMAIN = os.environ["CERTBOT_DOMAIN"]
if DOMAIN.startswith("*."):
DOMAIN = DOMAIN[2:]
VALIDATION_DOMAIN = "_acme-challenge." + DOMAIN
VALIDATION_TOKEN = os.environ["CERTBOT_VALIDATION"]
class AcmeDnsClient(object):
"""
Handles the communication with ACME-DNS API
"""
def __init__(self, acmedns_url):
self.acmedns_url = acmedns_url
def register_account(self, allowfrom):
"""Registers a new ACME-DNS account"""
if allowfrom:
# Include whitelisted networks to the registration call
reg_data = {"allowfrom": allowfrom}
res = requests.post(
self.acmedns_url + "/register", data=json.dumps(reg_data)
)
else:
res = requests.post(self.acmedns_url + "/register")
if res.status_code == 201:
# The request was successful
return res.json()
else:
# Encountered an error
msg = (
"Encountered an error while trying to register a new acme-dns "
"account. HTTP status {}, Response body: {}"
)
print(msg.format(res.status_code, res.text))
sys.exit(1)
def update_txt_record(self, account, txt):
"""Updates the TXT challenge record to ACME-DNS subdomain."""
update = {"subdomain": account["subdomain"], "txt": txt}
headers = {
"X-Api-User": account["username"],
"X-Api-Key": account["password"],
"Content-Type": "application/json",
}
res = requests.post(
self.acmedns_url + "/update", headers=headers, data=json.dumps(update)
)
if res.status_code == 200:
# Successful update
return
else:
msg = (
"Encountered an error while trying to update TXT record in "
"acme-dns. \n"
"------- Request headers:\n{}\n"
"------- Request body:\n{}\n"
"------- Response HTTP status: {}\n"
"------- Response body: {}"
)
s_headers = json.dumps(headers, indent=2, sort_keys=True)
s_update = json.dumps(update, indent=2, sort_keys=True)
s_body = json.dumps(res.json(), indent=2, sort_keys=True)
print(msg.format(s_headers, s_update, res.status_code, s_body))
sys.exit(1)
class Storage(object):
def __init__(self, storagepath):
self.storagepath = storagepath
self._data = self.load()
def load(self):
"""Reads the storage content from the disk to a dict structure"""
data = dict()
filedata = ""
try:
with open(self.storagepath, "r") as fh:
filedata = fh.read()
except IOError as e:
if os.path.isfile(self.storagepath):
# Only error out if file exists, but cannot be read
print("ERROR: Storage file exists but cannot be read")
sys.exit(1)
try:
data = json.loads(filedata)
except ValueError:
if len(filedata) > 0:
# Storage file is corrupted
print("ERROR: Storage JSON is corrupted")
sys.exit(1)
return data
def save(self):
"""Saves the storage content to disk"""
serialized = json.dumps(self._data)
try:
with os.fdopen(
os.open(self.storagepath, os.O_WRONLY | os.O_CREAT, 0o600), "w"
) as fh:
fh.truncate()
fh.write(serialized)
except IOError as e:
print("ERROR: Could not write storage file.")
sys.exit(1)
def put(self, key, value):
"""Puts the configuration value to storage and sanitize it"""
# If wildcard domain, remove the wildcard part as this will use the
# same validation record name as the base domain
if key.startswith("*."):
key = key[2:]
self._data[key] = value
def fetch(self, key):
"""Gets configuration value from storage"""
try:
return self._data[key]
except KeyError:
return None
if __name__ == "__main__":
# Init
client = AcmeDnsClient(ACMEDNS_URL)
storage = Storage(STORAGE_PATH)
# Check if an account already exists in storage
account = storage.fetch(DOMAIN)
if FORCE_REGISTER or not account:
# Create and save the new account
account = client.register_account(ALLOW_FROM)
storage.put(DOMAIN, account)
storage.save()
# Display the notification for the user to update the main zone
msg = "Please add the following CNAME record to your main DNS zone:\n{}"
cname = "{} CNAME {}.".format(VALIDATION_DOMAIN, account["fulldomain"])
print(msg.format(cname))
# Update the TXT record in acme-dns instance
client.update_txt_record(account, VALIDATION_TOKEN)