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)