import os
import socket
+import getpass
from binascii import hexlify
from cStringIO import StringIO
from select import select
from session import Session
import logging
-logger = logging.getLogger('ncclient.transport.ssh')
+logger = logging.getLogger("ncclient.transport.ssh")
BUF_SIZE = 4096
-MSG_DELIM = ']]>]]>'
+MSG_DELIM = "]]>]]>"
TICK = 0.1
-def default_unknown_host_cb(host, key):
- """An `unknown host callback` returns :const:`True` if it finds the key
- acceptable, and :const:`False` if not.
+def default_unknown_host_cb(host, fingerprint):
+ """An unknown host callback returns `True` if it finds the key acceptable, and `False` if not.
- This default callback always returns :const:`False`, which would lead to
- :meth:`connect` raising a :exc:`SSHUnknownHost` exception.
+ This default callback always returns `False`, which would lead to :meth:`connect` raising a :exc:`SSHUnknownHost` exception.
+
+ Supply another valid callback if you need to verify the host key programatically.
- Supply another valid callback if you need to verify the host key
- programatically.
+ *host* is the hostname that needs to be verified
- :arg host: the host for whom key needs to be verified
- :type host: string
-
- :arg key: a hex string representing the host key fingerprint
- :type key: string
+ *fingerprint* is a hex string representing the host key fingerprint, colon-delimited e.g. `"4b:69:6c:72:6f:79:20:77:61:73:20:68:65:72:65:21"`
"""
return False
+def _colonify(fp):
+ finga = fp[:2]
+ for idx in range(2, len(fp), 2):
+ finga += ":" + fp[idx:idx+2]
+ return finga
class SSHSession(Session):
# parsing-related, see _parse()
self._parsing_state = 0
self._parsing_pos = 0
-
+
def _parse(self):
- '''Messages ae delimited by MSG_DELIM. The buffer could have grown by a
- maximum of BUF_SIZE bytes everytime this method is called. Retains state
- across method calls and if a byte has been read it will not be
- considered again. '''
+ "Messages ae delimited by MSG_DELIM. The buffer could have grown by a maximum of BUF_SIZE bytes everytime this method is called. Retains state across method calls and if a byte has been read it will not be considered again."
delim = MSG_DELIM
n = len(delim) - 1
expect = self._parsing_state
elif x == delim[expect]: # what we expected
expect += 1 # expect the next delim char
else:
+ expect = 0
continue
# loop till last delim char expected, break if other char encountered
for i in range(expect, n):
self._parsing_pos = self._buffer.tell()
def load_known_hosts(self, filename=None):
- """Load host keys from a :file:`known_hosts`-style file. Can be called multiple
- times.
+ """Load host keys from an openssh :file:`known_hosts`-style file. Can be called multiple times.
- If *filename* is not specified, looks in the default locations i.e.
- :file:`~/.ssh/known_hosts` and :file:`~/ssh/known_hosts` for Windows.
+ If *filename* is not specified, looks in the default locations i.e. :file:`~/.ssh/known_hosts` and :file:`~/ssh/known_hosts` for Windows.
"""
if filename is None:
filename = os.path.expanduser('~/.ssh/known_hosts')
self._transport.close()
self._connected = False
- def connect(self, host, port=830, timeout=None,
- unknown_host_cb=default_unknown_host_cb,
- username=None, password=None,
- key_filename=None, allow_agent=True, look_for_keys=True):
- """Connect via SSH and initialize the NETCONF session. First attempts
- the publickey authentication method and then password authentication.
+ # REMEMBER to update transport.rst if sig. changes, since it is hardcoded there
+ def connect(self, host, port=830, timeout=None, unknown_host_cb=default_unknown_host_cb,
+ username=None, password=None, key_filename=None, allow_agent=True, look_for_keys=True):
+ """Connect via SSH and initialize the NETCONF session. First attempts the publickey authentication method and then password authentication.
- To disable attemting publickey authentication altogether, call with
- *allow_agent* and *look_for_keys* as :const:`False`. This may be needed
- for Cisco devices which immediately disconnect on an incorrect
- authentication attempt.
+ To disable attempting publickey authentication altogether, call with *allow_agent* and *look_for_keys* as `False`.
- :arg host: the hostname or IP address to connect to
- :type host: `string`
+ *host* is the hostname or IP address to connect to
- :arg port: by default 830, but some devices use the default SSH port of 22 so this may need to be specified
- :type port: `int`
+ *port* is by default 830, but some devices use the default SSH port of 22 so this may need to be specified
- :arg timeout: an optional timeout for the TCP handshake
- :type timeout: `int`
+ *timeout* is an optional timeout for socket connect
- :arg unknown_host_cb: called when a host key is not recognized
- :type unknown_host_cb: see :meth:`signature <ssh.default_unknown_host_cb>`
+ *unknown_host_cb* is called when the server host key is not recognized. It takes two arguments, the hostname and the fingerprint (see the signature of :func:`default_unknown_host_cb`)
- :arg username: the username to use for SSH authentication
- :type username: `string`
+ *username* is the username to use for SSH authentication
- :arg password: the password used if using password authentication, or the passphrase to use for unlocking keys that require it
- :type password: `string`
+ *password* is the password used if using password authentication, or the passphrase to use for unlocking keys that require it
- :arg key_filename: a filename where a the private key to be used can be found
- :type key_filename: `string`
+ *key_filename* is a filename where a the private key to be used can be found
- :arg allow_agent: enables querying SSH agent (if found) for keys
- :type allow_agent: `bool`
+ *allow_agent* enables querying SSH agent (if found) for keys
- :arg look_for_keys: enables looking in the usual locations for ssh keys (e.g. :file:`~/.ssh/id_*`)
- :type look_for_keys: `bool`
+ *look_for_keys* enables looking in the usual locations for ssh keys (e.g. :file:`~/.ssh/id_*`)
"""
-
if username is None:
- raise SSHError("No username specified")
-
+ username = getpass.getuser()
+
sock = None
for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM):
af, socktype, proto, canonname, sa = res
continue
break
else:
- raise SSHError("Could not open socket")
+ raise SSHError("Could not open socket to %s:%s" % (host, port))
t = self._transport = paramiko.Transport(sock)
t.set_log_channel(logger.name)
server_key = t.get_remote_server_key()
known_host = self._host_keys.check(host, server_key)
- fingerprint = hexlify(server_key.get_fingerprint())
+ fingerprint = _colonify(hexlify(server_key.get_fingerprint()))
if not known_host and not unknown_host_cb(host, fingerprint):
raise SSHUnknownHostError(host, fingerprint)
self._connected = True # there was no error authenticating
c = self._channel = self._transport.open_session()
- c.set_name('netconf')
- c.invoke_subsystem('netconf')
+ c.set_name("netconf")
+ c.invoke_subsystem("netconf")
self._post_connect()
-
+
# on the lines of paramiko.SSHClient._auth()
def _auth(self, username, password, key_filenames, allow_agent,
look_for_keys):
for cls in (paramiko.RSAKey, paramiko.DSSKey):
try:
key = cls.from_private_key_file(key_filename, password)
- logger.debug('Trying key %s from %s' %
+ logger.debug("Trying key %s from %s" %
(hexlify(key.get_fingerprint()), key_filename))
self._transport.auth_publickey(username, key)
return
if allow_agent:
for key in paramiko.Agent().get_keys():
try:
- logger.debug('Trying SSH agent key %s' %
+ logger.debug("Trying SSH agent key %s" %
hexlify(key.get_fingerprint()))
self._transport.auth_publickey(username, key)
return
keyfiles = []
if look_for_keys:
- rsa_key = os.path.expanduser('~/.ssh/id_rsa')
- dsa_key = os.path.expanduser('~/.ssh/id_dsa')
+ rsa_key = os.path.expanduser("~/.ssh/id_rsa")
+ dsa_key = os.path.expanduser("~/.ssh/id_dsa")
if os.path.isfile(rsa_key):
keyfiles.append((paramiko.RSAKey, rsa_key))
if os.path.isfile(dsa_key):
keyfiles.append((paramiko.DSSKey, dsa_key))
# look in ~/ssh/ for windows users:
- rsa_key = os.path.expanduser('~/ssh/id_rsa')
- dsa_key = os.path.expanduser('~/ssh/id_dsa')
+ rsa_key = os.path.expanduser("~/ssh/id_rsa")
+ dsa_key = os.path.expanduser("~/ssh/id_dsa")
if os.path.isfile(rsa_key):
keyfiles.append((paramiko.RSAKey, rsa_key))
if os.path.isfile(dsa_key):
for cls, filename in keyfiles:
try:
key = cls.from_private_key_file(filename, password)
- logger.debug('Trying discovered key %s in %s' %
+ logger.debug("Trying discovered key %s in %s" %
(hexlify(key.get_fingerprint()), filename))
self._transport.auth_publickey(username, key)
return
# need pep-3134 to do this right
raise AuthenticationError(repr(saved_exception))
- raise AuthenticationError('No authentication methods available')
+ raise AuthenticationError("No authentication methods available")
def run(self):
chan = self._channel
q = self._q
try:
while True:
- # select on a paramiko ssh channel object does not ever return
- # it in the writable list, so it channel's don't exactly emulate
- # the socket api
+ # select on a paramiko ssh channel object does not ever return it in the writable list, so channels don't exactly emulate the socket api
r, w, e = select([chan], [], [], TICK)
- # will wakeup evey TICK seconds to check if something
- # to send, more if something to read (due to select returning
- # chan in readable list)
+ # will wakeup evey TICK seconds to check if something to send, more if something to read (due to select returning chan in readable list)
if r:
data = chan.recv(BUF_SIZE)
if data:
else:
raise SessionCloseError(self._buffer.getvalue())
if not q.empty() and chan.send_ready():
- logger.debug('sending message')
+ logger.debug("Sending message")
data = q.get() + MSG_DELIM
while data:
n = chan.send(data)
raise SessionCloseError(self._buffer.getvalue(), data)
data = data[n:]
except Exception as e:
- logger.debug('broke out of main loop, error=%r', e)
+ logger.debug("Broke out of main loop, error=%r", e)
self.close()
self._dispatch_error(e)
@property
def transport(self):
- """Underlying `paramiko.Transport
- <http://www.lag.net/paramiko/docs/paramiko.Transport-class.html>`_
- object. This makes it possible to call methods like set_keepalive on it.
- """
+ "Underlying `paramiko.Transport <http://www.lag.net/paramiko/docs/paramiko.Transport-class.html>`_ object. This makes it possible to call methods like :meth:`~paramiko.Transport.set_keepalive` on it."
return self._transport
-
projects / ncclient / blobdiff