import logging
import os.path
import threading
import paramiko
def load_host_keys(path):
if os.path.exists(path) and os.path.isfile(path):
return paramiko.hostkeys.HostKeys(filename=path)
return paramiko.hostkeys.HostKeys()
def get_policy_dictionary():
dic = {
k.lower(): v for k, v in vars(paramiko.client).items() if type(v)
is type and issubclass(v, paramiko.client.MissingHostKeyPolicy)
and v is not paramiko.client.MissingHostKeyPolicy
}
return dic
def get_policy_class(policy):
origin_policy = policy
policy = policy.lower()
if not policy.endswith('policy'):
policy += 'policy'
dic = get_policy_dictionary()
logging.debug(dic)
try:
cls = dic[policy]
except KeyError:
raise ValueError('Unknown policy {!r}'.format(origin_policy))
return cls
def check_policy_setting(policy_class, host_keys_settings):
host_keys = host_keys_settings['host_keys']
host_keys_filename = host_keys_settings['host_keys_filename']
system_host_keys = host_keys_settings['system_host_keys']
if policy_class is paramiko.client.AutoAddPolicy:
host_keys.save(host_keys_filename) # for permission test
elif policy_class is paramiko.client.RejectPolicy:
if not host_keys and not system_host_keys:
raise ValueError(
'Reject policy could not be used without host keys.'
)
class AutoAddPolicy(paramiko.client.MissingHostKeyPolicy):
"""
thread-safe AutoAddPolicy
"""
lock = threading.Lock()
def is_missing_host_key(self, client, hostname, key):
k = client._system_host_keys.lookup(hostname) or \
client._host_keys.lookup(hostname)
if k is None:
return True
host_key = k.get(key.get_name(), None)
if host_key is None:
return True
if host_key != key:
raise paramiko.BadHostKeyException(hostname, key, host_key)
def missing_host_key(self, client, hostname, key):
with self.lock:
if self.is_missing_host_key(client, hostname, key):
keytype = key.get_name()
logging.info(
'Adding {} host key for {}'.format(keytype, hostname)
)
client._host_keys._entries.append(
paramiko.hostkeys.HostKeyEntry([hostname], key)
)
with open(client._host_keys_filename, 'a') as f:
f.write('{} {} {}\n'.format(
hostname, keytype, key.get_base64()
))
paramiko.client.AutoAddPolicy = AutoAddPolicy
