Load key files manually before making SSH connections

Change-Id: I63828b940d9bedcfff854f6732a78c09828666af
This commit is contained in:
Federico Ressi 2021-06-30 13:18:29 +02:00
parent 592eccd0ef
commit f526f4eae7

View File

@ -18,8 +18,8 @@ from __future__ import absolute_import
import collections
import contextlib
import getpass
import io
import os
import socket
import subprocess
import time
import threading
@ -579,6 +579,21 @@ def ssh_client(host, port=None, username=None, proxy_jump=None,
**connect_parameters)
def load_private_keys(key_filenames: typing.List[str]):
pkeys = []
for filename in key_filenames:
if os.path.exists(filename):
try:
with io.open(filename, 'rt') as fd:
pkey = paramiko.RSAKey.from_private_key(fd)
except Exception:
LOG.error('Unable to get RSAKey private key from file: '
f'{filename}', exc_info=1)
else:
pkeys.append(pkey)
return pkeys
def ssh_connect(hostname, username=None, port=None, connection_interval=None,
connection_attempts=None, connection_timeout=None,
proxy_command=None, proxy_client=None, key_filename=None,
@ -587,13 +602,9 @@ def ssh_connect(hostname, username=None, port=None, connection_interval=None,
client.set_missing_host_key_policy(paramiko.WarningPolicy())
login = _command.ssh_login(hostname=hostname, username=username, port=port)
if key_filename:
# Ensures we try enough times to try all keys
tobiko.check_valid_type(key_filename, list)
connection_attempts = max(connection_attempts or 1,
len(key_filename),
1)
assert isinstance(key_filename, list)
pkeys = load_private_keys(key_filename)
auth_failed: typing.Optional[Exception] = None
for attempt in tobiko.retry(count=connection_attempts,
timeout=connection_timeout,
interval=connection_interval,
@ -603,8 +614,8 @@ def ssh_connect(hostname, username=None, port=None, connection_interval=None,
LOG.debug(f"Logging in to '{login}'...\n"
f" - parameters: {parameters}\n"
f" - attempt: {attempt.details}\n")
try:
for pkey in pkeys + [None]:
succeeded = False
proxy_sock = ssh_proxy_sock(
hostname=hostname,
port=port,
@ -613,29 +624,35 @@ def ssh_connect(hostname, username=None, port=None, connection_interval=None,
timeout=connection_timeout,
connection_attempts=1,
connection_interval=connection_interval)
try:
client.connect(hostname=hostname,
username=username,
port=port,
sock=proxy_sock,
key_filename=key_filename,
pkey=pkey,
**parameters)
except ValueError as ex:
attempt.check_limits()
if (str(ex) == 'q must be exactly 160, 224, or 256 bits long' and
len(key_filename) > 1):
# Must try without the first key
LOG.debug(f"Retry connecting with the next key: {ex}")
key_filename = key_filename[1:]
except paramiko.ssh_exception.AuthenticationException as ex:
if auth_failed is not None:
ex.__cause__ = auth_failed
auth_failed = ex
continue
else:
raise
except (EOFError, socket.error, socket.timeout,
paramiko.SSHException) as ex:
except Exception as ex:
LOG.debug(f"Error logging in to '{login}': {ex}", exc_info=1)
attempt.check_limits()
LOG.debug(f"Error logging in to '{login}': {ex}")
break
else:
LOG.debug(f"Successfully logged in to '{login}'")
succeeded = True
return client, proxy_sock
finally:
if not succeeded:
try:
proxy_sock.close()
except Exception:
pass
else:
if isinstance(auth_failed, Exception):
raise auth_failed
def ssh_proxy_sock(hostname=None, port=None, command=None, client=None,