def open(self) -> None:
self._pre_open_closing_log(closing=False)
if not self.socket:
self.socket = Socket(
host=self._base_transport_args.host,
port=self._base_transport_args.port,
timeout=self._base_transport_args.timeout_socket,
)
if not self.socket.isalive():
self.socket.open()
self.session = Session()
self._set_timeout(value=self._base_transport_args.timeout_transport)
try:
self.session.handshake(self.socket.sock)
except Exception as exc:
self.logger.critical("failed to complete handshake with host")
raise ScrapliConnectionNotOpened from exc
if self.plugin_transport_args.auth_strict_key:
self.logger.debug(
f"attempting to validate {self._base_transport_args.host} public key"
)
self._verify_key()
self._authenticate()
if not self.session.userauth_authenticated():
msg = "all authentication methods failed"
self.logger.critical(msg)
raise ScrapliAuthenticationFailed(msg)
self._open_channel()
self._post_open_closing_log(closing=False)
class ParamikoTransport(Transport):
def __init__(self, base_transport_args: BaseTransportArgs,
plugin_transport_args: PluginTransportArgs) -> None:
super().__init__(base_transport_args=base_transport_args)
self.plugin_transport_args = plugin_transport_args
self.socket: Optional[Socket] = None
self.session: Optional[_ParamikoTransport] = None
self.session_channel: Optional[Channel] = None
def open(self) -> None:
self._pre_open_closing_log(closing=False)
if not self.socket:
self.socket = Socket(
host=self._base_transport_args.host,
port=self._base_transport_args.port,
timeout=self._base_transport_args.timeout_socket,
)
if not self.socket.isalive():
self.socket.open()
try:
self.session = _ParamikoTransport(self.socket.sock) # type: ignore
self.session.start_client()
except Exception as exc:
self.logger.critical("failed to complete handshake with host")
raise ScrapliConnectionNotOpened from exc
if self.plugin_transport_args.auth_strict_key:
self.logger.debug(
f"attempting to validate {self._base_transport_args.host} public key"
)
self._verify_key()
self._authenticate()
if not self.session.is_authenticated():
msg = "all authentication methods failed"
self.logger.critical(msg)
raise ScrapliAuthenticationFailed(msg)
self._open_channel()
self._post_open_closing_log(closing=False)
def _verify_key(self) -> None:
"""
Verify target host public key, raise exception if invalid/unknown
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
ScrapliAuthenticationFailed: if host is not in known hosts
ScrapliAuthenticationFailed: if host is in known hosts but public key does not match
"""
if not self.session:
raise ScrapliConnectionNotOpened
known_hosts = SSHKnownHosts(
self.plugin_transport_args.ssh_known_hosts_file)
if self._base_transport_args.host not in known_hosts.hosts.keys():
raise ScrapliAuthenticationFailed(
f"{self._base_transport_args.host} not in known_hosts!")
remote_server_key = self.session.get_remote_server_key()
remote_public_key = remote_server_key.get_base64()
if known_hosts.hosts[self._base_transport_args.
host]["public_key"] != remote_public_key:
raise ScrapliAuthenticationFailed(
f"{self._base_transport_args.host} in known_hosts but public key does not match!"
)
def _authenticate(self) -> None:
"""
Parent method to try all means of authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
ScrapliAuthenticationFailed: if auth fails
"""
if not self.session:
raise ScrapliConnectionNotOpened
if self.plugin_transport_args.auth_private_key:
self._authenticate_public_key()
if self.session.is_authenticated():
return
if (not self.plugin_transport_args.auth_password
or not self.plugin_transport_args.auth_username):
msg = (
f"Failed to authenticate to host {self._base_transport_args.host} with private "
f"key `{self.plugin_transport_args.auth_private_key}`. Unable to continue "
"authentication, missing username, password, or both.")
raise ScrapliAuthenticationFailed(msg)
self._authenticate_password()
def _authenticate_public_key(self) -> None:
"""
Attempt to authenticate with public key authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
try:
paramiko_key = RSAKey(
filename=self.plugin_transport_args.auth_private_key)
self.session.auth_publickey(
username=self.plugin_transport_args.auth_username,
key=paramiko_key)
except AuthenticationException:
pass
except Exception: # pylint: disable=W0703
pass
def _authenticate_password(self) -> None:
"""
Attempt to authenticate with password authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
try:
self.session.auth_password(
username=self.plugin_transport_args.auth_username,
password=self.plugin_transport_args.auth_password,
)
return
except AuthenticationException:
pass
def _open_channel(self) -> None:
"""
Open channel, acquire pty, request interactive shell
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
self.session_channel = self.session.open_session()
self._set_timeout(self._base_transport_args.timeout_transport)
self.session_channel.get_pty()
self.session_channel.invoke_shell()
def close(self) -> None:
self._pre_open_closing_log(closing=True)
if self.session_channel:
self.session_channel.close()
if self.socket:
self.socket.close()
self.session = None
self.session_channel = None
self._post_open_closing_log(closing=True)
def isalive(self) -> bool:
if not self.session:
return False
_isalive: bool = self.session.is_alive()
return _isalive
def read(self) -> bytes:
if not self.session_channel:
raise ScrapliConnectionNotOpened
try:
buf: bytes = self.session_channel.recv(65535)
except Exception as exc:
msg = (
"encountered EOF reading from transport; typically means the device closed the "
"connection")
self.logger.critical(msg)
raise ScrapliConnectionError(msg) from exc
return buf
def write(self, channel_input: bytes) -> None:
if not self.session_channel:
raise ScrapliConnectionNotOpened
self.session_channel.send(channel_input)
def _set_timeout(self, value: float) -> None:
"""
Set session object timeout value
Args:
value: timeout in seconds
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session_channel:
raise ScrapliConnectionNotOpened
self.session_channel.settimeout(value)
class ParamikoTransport(Transport):
def __init__(self, base_transport_args: BaseTransportArgs,
plugin_transport_args: PluginTransportArgs) -> None:
"""
Paramiko transport plugin.
This transport supports some additional `transport_options` to control behavior --
`enable_rsa2` is bool defaulting to `False`. Please see the paramiko changelog entry for
version 2.9.0 here: https://www.paramiko.org/changelog.html. Basically, even though
scrapli *tries* to default to safe/sane/secure things where possible, it is also focused
on *network* devices which maybe sometimes are less up-to-date/safe/secure than we'd
all hope. In this case paramiko 2.9.0 defaults to supporting only RSA2based servers,
which, causes issues for the devices in the test suite, and likely for many other
network devices out there. So, by default, we'll *disable* this. If you wish to enable
this you can simply pass `True` to this transport option!
Args:
base_transport_args: scrapli base transport plugin arguments
plugin_transport_args: paramiko ssh specific transport plugin arguments
Returns:
N/A
Raises:
N/A
"""
super().__init__(base_transport_args=base_transport_args)
self.plugin_transport_args = plugin_transport_args
self.socket: Optional[Socket] = None
self.session: Optional[_ParamikoTransport] = None
self.session_channel: Optional[Channel] = None
def open(self) -> None:
self._pre_open_closing_log(closing=False)
if not self.socket:
self.socket = Socket(
host=self._base_transport_args.host,
port=self._base_transport_args.port,
timeout=self._base_transport_args.timeout_socket,
)
if not self.socket.isalive():
self.socket.open()
try:
self.session = _ParamikoTransport(self.socket.sock) # type: ignore
self.session.start_client()
except Exception as exc:
self.logger.critical("failed to complete handshake with host")
raise ScrapliConnectionNotOpened from exc
if self.plugin_transport_args.auth_strict_key:
self.logger.debug(
f"attempting to validate {self._base_transport_args.host} public key"
)
self._verify_key()
self._authenticate()
if not self.session.is_authenticated():
msg = "all authentication methods failed"
self.logger.critical(msg)
raise ScrapliAuthenticationFailed(msg)
self._open_channel()
self._post_open_closing_log(closing=False)
def _verify_key(self) -> None:
"""
Verify target host public key, raise exception if invalid/unknown
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
ScrapliAuthenticationFailed: if host is not in known hosts
ScrapliAuthenticationFailed: if host is in known hosts but public key does not match
"""
if not self.session:
raise ScrapliConnectionNotOpened
known_hosts = SSHKnownHosts(
self.plugin_transport_args.ssh_known_hosts_file)
known_host_public_key = known_hosts.lookup(
self._base_transport_args.host)
if not known_host_public_key:
raise ScrapliAuthenticationFailed(
f"{self._base_transport_args.host} not in known_hosts!")
remote_server_key = self.session.get_remote_server_key()
remote_public_key = remote_server_key.get_base64()
if known_host_public_key["public_key"] != remote_public_key:
raise ScrapliAuthenticationFailed(
f"{self._base_transport_args.host} in known_hosts but public key does not match!"
)
def _authenticate(self) -> None:
"""
Parent method to try all means of authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
ScrapliAuthenticationFailed: if auth fails
"""
if not self.session:
raise ScrapliConnectionNotOpened
if self.plugin_transport_args.auth_private_key:
self._authenticate_public_key()
if self.session.is_authenticated():
return
if (not self.plugin_transport_args.auth_password
or not self.plugin_transport_args.auth_username):
msg = (
f"Failed to authenticate to host {self._base_transport_args.host} with private "
f"key `{self.plugin_transport_args.auth_private_key}`. Unable to continue "
"authentication, missing username, password, or both.")
raise ScrapliAuthenticationFailed(msg)
self._authenticate_password()
def _authenticate_public_key(self) -> None:
"""
Attempt to authenticate with public key authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
if self._base_transport_args.transport_options.get(
"enable_rsa2", False) is False:
self.session.disabled_algorithms = {
"keys": ["rsa-sha2-256", "rsa-sha2-512"]
}
try:
paramiko_key = RSAKey(
filename=self.plugin_transport_args.auth_private_key)
self.session.auth_publickey(
username=self.plugin_transport_args.auth_username,
key=paramiko_key)
except AuthenticationException:
pass
except Exception: # pylint: disable=W0703
pass
def _authenticate_password(self) -> None:
"""
Attempt to authenticate with password authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
try:
self.session.auth_password(
username=self.plugin_transport_args.auth_username,
password=self.plugin_transport_args.auth_password,
)
return
except AuthenticationException:
pass
def _open_channel(self) -> None:
"""
Open channel, acquire pty, request interactive shell
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
self.session_channel = self.session.open_session()
self._set_timeout(self._base_transport_args.timeout_transport)
self.session_channel.get_pty()
self.session_channel.invoke_shell()
def close(self) -> None:
self._pre_open_closing_log(closing=True)
if self.session_channel:
self.session_channel.close()
if self.socket:
self.socket.close()
self.session = None
self.session_channel = None
self._post_open_closing_log(closing=True)
def isalive(self) -> bool:
if not self.session:
return False
_isalive: bool = self.session.is_alive()
return _isalive
def read(self) -> bytes:
if not self.session_channel:
raise ScrapliConnectionNotOpened
try:
buf: bytes = self.session_channel.recv(65535)
except Exception as exc:
msg = (
"encountered EOF reading from transport; typically means the device closed the "
"connection")
self.logger.critical(msg)
raise ScrapliConnectionError(msg) from exc
return buf
def write(self, channel_input: bytes) -> None:
if not self.session_channel:
raise ScrapliConnectionNotOpened
self.session_channel.send(channel_input)
def _set_timeout(self, value: float) -> None:
"""
Set session object timeout value
Args:
value: timeout in seconds
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session_channel:
raise ScrapliConnectionNotOpened
self.session_channel.settimeout(value)
def socket_transport():
"""Fixture to provide Socket instance"""
return Socket(host="localhost", port=22, timeout=10.0)
class Ssh2Transport(Transport):
def __init__(self, base_transport_args: BaseTransportArgs,
plugin_transport_args: PluginTransportArgs) -> None:
super().__init__(base_transport_args=base_transport_args)
self.plugin_transport_args = plugin_transport_args
self.socket: Optional[Socket] = None
self.session: Optional[Session] = None
self.session_channel: Optional[Channel] = None
def open(self) -> None:
self._pre_open_closing_log(closing=False)
if not self.socket:
self.socket = Socket(
host=self._base_transport_args.host,
port=self._base_transport_args.port,
timeout=self._base_transport_args.timeout_socket,
)
if not self.socket.isalive():
self.socket.open()
self.session = Session()
self._set_timeout(value=self._base_transport_args.timeout_transport)
try:
self.session.handshake(self.socket.sock)
except Exception as exc:
self.logger.critical("failed to complete handshake with host")
raise ScrapliConnectionNotOpened from exc
if self.plugin_transport_args.auth_strict_key:
self.logger.debug(
f"attempting to validate {self._base_transport_args.host} public key"
)
self._verify_key()
self._authenticate()
if not self.session.userauth_authenticated():
msg = "all authentication methods failed"
self.logger.critical(msg)
raise ScrapliAuthenticationFailed(msg)
self._open_channel()
self._post_open_closing_log(closing=False)
def _verify_key(self) -> None:
"""
Verify target host public key, raise exception if invalid/unknown
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
ScrapliAuthenticationFailed: if public key verification fails
"""
if not self.session:
raise ScrapliConnectionNotOpened
known_hosts = SSHKnownHosts(
self.plugin_transport_args.ssh_known_hosts_file)
known_host_public_key = known_hosts.lookup(
self._base_transport_args.host)
if not known_host_public_key:
raise ScrapliAuthenticationFailed(
f"{self._base_transport_args.host} not in known_hosts!")
remote_server_key_info = self.session.hostkey()
encoded_remote_server_key = remote_server_key_info[0]
raw_remote_public_key = base64.encodebytes(encoded_remote_server_key)
remote_public_key = raw_remote_public_key.replace(b"\n", b"").decode()
if known_host_public_key["public_key"] != remote_public_key:
raise ScrapliAuthenticationFailed(
f"{self._base_transport_args.host} in known_hosts but public key does not match!"
)
def _authenticate(self) -> None:
"""
Parent method to try all means of authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
ScrapliAuthenticationFailed: if auth fails
"""
if not self.session:
raise ScrapliConnectionNotOpened
if self.plugin_transport_args.auth_private_key:
self._authenticate_public_key()
if self.session.userauth_authenticated():
return
if (not self.plugin_transport_args.auth_password
or not self.plugin_transport_args.auth_username):
msg = (
f"Failed to authenticate to host {self._base_transport_args.host} with private "
f"key `{self.plugin_transport_args.auth_private_key}`. Unable to continue "
"authentication, missing username, password, or both.")
raise ScrapliAuthenticationFailed(msg)
self._authenticate_password()
def _authenticate_public_key(self) -> None:
"""
Attempt to authenticate with public key authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
try:
self.session.userauth_publickey_fromfile(
self.plugin_transport_args.auth_username,
self.plugin_transport_args.auth_private_key.encode(),
self.plugin_transport_args.auth_private_key_passphrase,
)
except (AuthenticationError, SSH2Error):
pass
def _authenticate_password(self) -> None:
"""
Attempt to authenticate with password authentication
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
try:
self.session.userauth_password(
username=self.plugin_transport_args.auth_username,
password=self.plugin_transport_args.auth_password,
)
return
except AuthenticationError:
pass
try:
self.session.userauth_keyboardinteractive(
self.plugin_transport_args.auth_username,
self.plugin_transport_args.auth_password)
except AttributeError:
msg = (
"Keyboard interactive authentication may not be supported in your "
"ssh2-python version.")
self.logger.warning(msg)
except AuthenticationError:
pass
def _open_channel(self) -> None:
"""
Open channel, acquire pty, request interactive shell
Args:
N/A
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
self.session_channel = self.session.open_session()
self.session_channel.pty()
self.session_channel.shell()
def close(self) -> None:
self._pre_open_closing_log(closing=True)
if self.session_channel:
self.session_channel.close()
if self.socket:
self.socket.close()
self.session = None
self.session_channel = None
self._post_open_closing_log(closing=True)
def isalive(self) -> bool:
if not self.session_channel:
return False
return not self.session_channel.eof()
def read(self) -> bytes:
if not self.session_channel:
raise ScrapliConnectionNotOpened
try:
buf: bytes
_, buf = self.session_channel.read(65535)
except Exception as exc:
msg = (
"encountered EOF reading from transport; typically means the device closed the "
"connection")
self.logger.critical(msg)
raise ScrapliConnectionError(msg) from exc
return buf
def write(self, channel_input: bytes) -> None:
if not self.session_channel:
raise ScrapliConnectionNotOpened
self.session_channel.write(channel_input)
def _set_timeout(self, value: float) -> None:
"""
Set session object timeout value
Args:
value: timeout in seconds
Returns:
None
Raises:
ScrapliConnectionNotOpened: if session is unopened/None
"""
if not self.session:
raise ScrapliConnectionNotOpened
# ssh2-python expects timeout in milliseconds
self.session.set_timeout(value * 1000)