def _parse_service_accept(self, m): service = m.get_string() if service == 'ssh-userauth': self.transport._log(DEBUG, 'userauth is OK') m = Message() m.add_byte(chr(MSG_USERAUTH_REQUEST)) m.add_string(self.username) m.add_string('ssh-connection') m.add_string(self.auth_method) if self.auth_method == 'password': m.add_boolean(False) password = self.password if isinstance(password, unicode): password = password.encode('UTF-8') m.add_string(password) elif self.auth_method == 'publickey': m.add_boolean(True) m.add_string(self.private_key.get_name()) m.add_string(str(self.private_key)) blob = self._get_session_blob(self.private_key, 'ssh-connection', self.username) sig = self.private_key.sign_ssh_data(self.transport.rng, blob) m.add_string(str(sig)) elif self.auth_method == 'keyboard-interactive': m.add_string('') m.add_string(self.submethods) elif self.auth_method == 'none': pass else: raise SSHException('Unknown auth method "%s"' % self.auth_method) self.transport._send_message(m) else: self.transport._log(DEBUG, 'Service request "%s" accepted (?)' % service)
def resize_pty(self, width=80, height=24): """ Resize the pseudo-terminal. This can be used to change the width and height of the terminal emulation created in a previous L{get_pty} call. @param width: new width (in characters) of the terminal screen @type width: int @param height: new height (in characters) of the terminal screen @type height: int @raise SSHException: if the request was rejected or the channel was closed """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('window-change') m.add_boolean(True) m.add_int(width) m.add_int(height) m.add_int(0).add_int(0) self._event_pending() self.transport._send_user_message(m) self._wait_for_event()
def invoke_shell(self): """ Request an interactive shell session on this channel. If the server allows it, the channel will then be directly connected to the stdin, stdout, and stderr of the shell. Normally you would call L{get_pty} before this, in which case the shell will operate through the pty, and the channel will be connected to the stdin and stdout of the pty. When the shell exits, the channel will be closed and can't be reused. You must open a new channel if you wish to open another shell. @raise SSHException: if the request was rejected or the channel was closed """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('shell') m.add_boolean(1) self._event_pending() self.transport._send_user_message(m) self._wait_for_event()
def _auth_message(self): m = Message() m.add_byte(chr(MSG_USERAUTH_REQUEST)) m.add_string(self.username) m.add_string('ssh-connection') m.add_string(self.auth_method) if self.auth_method == 'password': m.add_boolean(False) password = self.password if isinstance(password, unicode): password = password.encode('UTF-8') m.add_string(password) elif self.auth_method == 'publickey': m.add_boolean(True) m.add_string(self.private_key.get_name()) m.add_string(str(self.private_key)) blob = self._get_session_blob(self.private_key, 'ssh-connection', self.username) sig = self.private_key.sign_ssh_data(self.transport.rng, blob) m.add_string(str(sig)) elif self.auth_method == 'keyboard-interactive': m.add_string('') m.add_string(self.submethods) elif self.auth_method == 'none': pass else: raise SSHException('Unknown auth method "%s"' % self.auth_method) return m
def _parse_service_accept(self, m): service = m.get_string() if service == b'ssh-userauth': self.transport._log(DEBUG, 'userauth is OK') m = Message() m.add_byte(chr(MSG_USERAUTH_REQUEST)) m.add_string(self.username) m.add_string('ssh-connection') m.add_string(self.auth_method) if self.auth_method == 'password': m.add_boolean(False) password = self.password if isinstance(password, str): password = password.encode('UTF-8') m.add_string(password) elif self.auth_method == 'publickey': m.add_boolean(True) m.add_string(self.private_key.get_name()) m.add_string(bytes(self.private_key)) blob = self._get_session_blob(self.private_key, 'ssh-connection', self.username) sig = self.private_key.sign_ssh_data(self.transport.rng, blob) m.add_string(str(sig)) elif self.auth_method == 'keyboard-interactive': m.add_string(b'') m.add_string(self.submethods) elif self.auth_method == 'none': pass else: raise SSHException('Unknown auth method "%s"' % self.auth_method) self.transport._send_message(m) else: self.transport._log(DEBUG, 'Service request "%s" accepted (?)' % service)
def invoke_subsystem(self, subsystem): """ Request a subsystem on the server (for example, C{sftp}). If the server allows it, the channel will then be directly connected to the requested subsystem. When the subsystem finishes, the channel will be closed and can't be reused. @param subsystem: name of the subsystem being requested. @type subsystem: str @raise SSHException: if the request was rejected or the channel was closed """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('subsystem') m.add_boolean(True) m.add_string(subsystem) self._event_pending() self.transport._send_user_message(m) self._wait_for_event()
def exec_command(self, command): """ Execute a command on the server. If the server allows it, the channel will then be directly connected to the stdin, stdout, and stderr of the command being executed. When the command finishes executing, the channel will be closed and can't be reused. You must open a new channel if you wish to execute another command. @param command: a shell command to execute. @type command: str @raise SSHException: if the request was rejected or the channel was closed """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('exec') m.add_boolean(True) m.add_string(command) self._event_pending() self.transport._send_user_message(m) self._wait_for_event()
def get_pty(self, term='vt100', width=80, height=24): """ Request a pseudo-terminal from the server. This is usually used right after creating a client channel, to ask the server to provide some basic terminal semantics for a shell invoked with L{invoke_shell}. It isn't necessary (or desirable) to call this method if you're going to exectue a single command with L{exec_command}. @param term: the terminal type to emulate (for example, C{'vt100'}) @type term: str @param width: width (in characters) of the terminal screen @type width: int @param height: height (in characters) of the terminal screen @type height: int @raise SSHException: if the request was rejected or the channel was closed """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('pty-req') m.add_boolean(True) m.add_string(term) m.add_int(width) m.add_int(height) # pixel height, width (usually useless) m.add_int(0).add_int(0) m.add_string('') self._event_pending() self.transport._send_user_message(m) self._wait_for_event()
def _parse_userauth_request(self, m): if not self.transport.server_mode: # er, uh... what? m = Message() m.add_byte(chr(MSG_USERAUTH_FAILURE)) m.add_string('none') m.add_boolean(0) self.transport._send_message(m) return if self.authenticated: # ignore return username = m.get_string() service = m.get_string() method = m.get_string() self.transport._log(DEBUG, 'Auth request (type=%s) service=%s, username=%s' % (method, service, username)) if service != 'ssh-connection': self._disconnect_service_not_available() return if (self.auth_username is not None) and (self.auth_username != username): self.transport._log(WARNING, 'Auth rejected because the client attempted to change username in mid-flight') self._disconnect_no_more_auth() return self.auth_username = username if method == 'none': result = self.transport.server_object.check_auth_none(username) elif method == 'password': changereq = m.get_boolean() password = m.get_string() try: password = password.decode('UTF-8') except UnicodeError: # some clients/servers expect non-utf-8 passwords! # in this case, just return the raw byte string. pass if changereq: # always treated as failure, since we don't support changing passwords, but collect # the list of valid auth types from the callback anyway self.transport._log(DEBUG, 'Auth request to change passwords (rejected)') newpassword = m.get_string() try: newpassword = newpassword.decode('UTF-8', 'replace') except UnicodeError: pass result = AUTH_FAILED else: result = self.transport.server_object.check_auth_password(username, password) elif method == 'publickey': sig_attached = m.get_boolean() keytype = m.get_string() keyblob = m.get_string() try: key = self.transport._key_info[keytype](Message(keyblob)) except SSHException, e: self.transport._log(INFO, 'Auth rejected: public key: %s' % str(e)) key = None except:
def _get_session_blob(self, key, service, username): m = Message() m.add_string(self.transport.session_id) m.add_byte(chr(MSG_USERAUTH_REQUEST)) m.add_string(username) m.add_string(service) m.add_string(b'publickey') m.add_boolean(1) m.add_string(key.get_name()) m.add_string(bytes(key)) return bytes(m)
def _get_session_blob(self, key, service, username): m = Message() m.add_string(self.transport.session_id) m.add_byte(chr(MSG_USERAUTH_REQUEST)) m.add_string(username) m.add_string(service) m.add_string('publickey') m.add_boolean(1) m.add_string(key.get_name()) m.add_string(str(key)) return str(m)
def _interactive_query(self, q): # make interactive query instead of response m = Message() m.add_byte(chr(MSG_USERAUTH_INFO_REQUEST)) m.add_string(q.name) m.add_string(q.instructions) m.add_string('') m.add_int(len(q.prompts)) for p in q.prompts: m.add_string(p[0]) m.add_boolean(p[1]) self.transport._send_message(m)
def _send_auth_result(self, username, method, result): # okay, send result m = Message() if result == AUTH_SUCCESSFUL: self.transport._log(INFO, 'Auth granted (%s).' % method) m.add_byte(chr(MSG_USERAUTH_SUCCESS)) self.authenticated = True else: self.transport._log(INFO, 'Auth rejected (%s).' % method) m.add_byte(chr(MSG_USERAUTH_FAILURE)) m.add_string(self.transport.server_object.get_allowed_auths(username)) if result == AUTH_PARTIALLY_SUCCESSFUL: m.add_boolean(1) else: m.add_boolean(0) self.auth_fail_count += 1 self.transport._send_message(m) if self.auth_fail_count >= 10: self._disconnect_no_more_auth() if result == AUTH_SUCCESSFUL: self.transport._auth_trigger()
def send_exit_status(self, status): """ Send the exit status of an executed command to the client. (This really only makes sense in server mode.) Many clients expect to get some sort of status code back from an executed command after it completes. @param status: the exit code of the process @type status: int @since: 1.2 """ # in many cases, the channel will not still be open here. # that's fine. m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('exit-status') m.add_boolean(False) m.add_int(status) self.transport._send_user_message(m)
def _send_auth_result(self, username, method, result): # okay, send result m = Message() if result == AUTH_SUCCESSFUL: self.transport._log(INFO, 'Auth granted (%s).' % method) m.add_byte(chr(MSG_USERAUTH_SUCCESS)) self.authenticated = True else: self.transport._log(INFO, 'Auth rejected (%s).' % method) m.add_byte(chr(MSG_USERAUTH_FAILURE)) m.add_string( self.transport.server_object.get_allowed_auths(username)) if result == AUTH_PARTIALLY_SUCCESSFUL: m.add_boolean(1) else: m.add_boolean(0) self.auth_fail_count += 1 self.transport._send_message(m) if self.auth_fail_count >= 10: self._disconnect_no_more_auth() if result == AUTH_SUCCESSFUL: self.transport._auth_trigger()
def test_1_encode(self): msg = Message() msg.add_int(23) msg.add_int(123789456) msg.add_string('q') msg.add_string('hello') msg.add_string('x' * 1000) self.assertEquals(str(msg), self.__a) msg = Message() msg.add_boolean(True) msg.add_boolean(False) msg.add_byte('\xf3') msg.add_bytes('\x00\x3f') msg.add_list(['huey', 'dewey', 'louie']) self.assertEquals(str(msg), self.__b) msg = Message() msg.add_int64(5) msg.add_int64(0xf5e4d3c2b109L) msg.add_mpint(17) msg.add_mpint(0xf5e4d3c2b109L) msg.add_mpint(-0x65e4d3c2b109L) self.assertEquals(str(msg), self.__c)
def request_forward_agent(self, handler): """ Request for a forward SSH Agent on this channel. This is only valid for an ssh-agent from openssh !!! @param handler: a required handler to use for incoming SSH Agent connections @type handler: function @return: if we are ok or not (at that time we always return ok) @rtype: boolean @raise: SSHException in case of channel problem. """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('*****@*****.**') m.add_boolean(False) self.transport._send_user_message(m) self.transport._set_forward_agent_handler(handler) return True
def request_x11(self, screen_number=0, auth_protocol=None, auth_cookie=None, single_connection=False, handler=None): """ Request an x11 session on this channel. If the server allows it, further x11 requests can be made from the server to the client, when an x11 application is run in a shell session. From RFC4254:: It is RECOMMENDED that the 'x11 authentication cookie' that is sent be a fake, random cookie, and that the cookie be checked and replaced by the real cookie when a connection request is received. If you omit the auth_cookie, a new secure random 128-bit value will be generated, used, and returned. You will need to use this value to verify incoming x11 requests and replace them with the actual local x11 cookie (which requires some knoweldge of the x11 protocol). If a handler is passed in, the handler is called from another thread whenever a new x11 connection arrives. The default handler queues up incoming x11 connections, which may be retrieved using L{Transport.accept}. The handler's calling signature is:: handler(channel: Channel, (address: str, port: int)) @param screen_number: the x11 screen number (0, 10, etc) @type screen_number: int @param auth_protocol: the name of the X11 authentication method used; if none is given, C{"MIT-MAGIC-COOKIE-1"} is used @type auth_protocol: str @param auth_cookie: hexadecimal string containing the x11 auth cookie; if none is given, a secure random 128-bit value is generated @type auth_cookie: str @param single_connection: if True, only a single x11 connection will be forwarded (by default, any number of x11 connections can arrive over this session) @type single_connection: bool @param handler: an optional handler to use for incoming X11 connections @type handler: function @return: the auth_cookie used """ if self.closed or self.eof_received or self.eof_sent or not self.active: raise SSHException('Channel is not open') if auth_protocol is None: auth_protocol = 'MIT-MAGIC-COOKIE-1' if auth_cookie is None: auth_cookie = binascii.hexlify(self.transport.rng.read(16)) m = Message() m.add_byte(chr(MSG_CHANNEL_REQUEST)) m.add_int(self.remote_chanid) m.add_string('x11-req') m.add_boolean(True) m.add_boolean(single_connection) m.add_string(auth_protocol) m.add_string(auth_cookie) m.add_int(screen_number) self._event_pending() self.transport._send_user_message(m) self._wait_for_event() self.transport._set_x11_handler(handler) return auth_cookie
def _parse_userauth_request(self, m): if not self.transport.server_mode: # er, uh... what? m = Message() m.add_byte(chr(MSG_USERAUTH_FAILURE)) m.add_string('none') m.add_boolean(0) self.transport._send_message(m) return if self.authenticated: # ignore return username = m.get_string() service = m.get_string() method = m.get_string() self.transport._log( DEBUG, 'Auth request (type=%s) service=%s, username=%s' % (method, service, username)) if service != 'ssh-connection': self._disconnect_service_not_available() return if (self.auth_username is not None) and (self.auth_username != username): self.transport._log( WARNING, 'Auth rejected because the client attempted to change username in mid-flight' ) self._disconnect_no_more_auth() return self.auth_username = username if method == 'none': result = self.transport.server_object.check_auth_none(username) elif method == 'password': changereq = m.get_boolean() password = m.get_string() try: password = password.decode('UTF-8') except UnicodeError: # some clients/servers expect non-utf-8 passwords! # in this case, just return the raw byte string. pass if changereq: # always treated as failure, since we don't support changing passwords, but collect # the list of valid auth types from the callback anyway self.transport._log( DEBUG, 'Auth request to change passwords (rejected)') newpassword = m.get_string() try: newpassword = newpassword.decode('UTF-8', 'replace') except UnicodeError: pass result = AUTH_FAILED else: result = self.transport.server_object.check_auth_password( username, password) elif method == 'publickey': sig_attached = m.get_boolean() keytype = m.get_string() keyblob = m.get_string() try: key = self.transport._key_info[keytype](Message(keyblob)) except SSHException, e: self.transport._log(INFO, 'Auth rejected: public key: %s' % str(e)) key = None except:
def _parse_userauth_request(self, m): if not self.transport.server_mode: # er, uh... what? m = Message() m.add_byte(chr(MSG_USERAUTH_FAILURE)) m.add_string('none') m.add_boolean(0) self.transport._send_message(m) return if self.authenticated: # ignore return username = m.get_string() service = m.get_string() method = m.get_string() self.transport._log(DEBUG, 'Auth request (type=%s) service=%s, username=%s' % (method, service, username)) if service != 'ssh-connection': self._disconnect_service_not_available() return if (self.auth_username is not None) and (self.auth_username != username): self.transport._log(WARNING, 'Auth rejected because the client attempted to change username in mid-flight') self._disconnect_no_more_auth() return self.auth_username = username if method == 'none': result = self.transport.server_object.check_auth_none(username) elif method == 'password': changereq = m.get_boolean() password = m.get_string() try: password = password.decode('UTF-8') except UnicodeError: # some clients/servers expect non-utf-8 passwords! # in this case, just return the raw byte string. pass if changereq: # always treated as failure, since we don't support changing passwords, but collect # the list of valid auth types from the callback anyway self.transport._log(DEBUG, 'Auth request to change passwords (rejected)') newpassword = m.get_string() try: newpassword = newpassword.decode('UTF-8', 'replace') except UnicodeError: pass result = AUTH_FAILED else: result = self.transport.server_object.check_auth_password(username, password) elif method == 'publickey': sig_attached = m.get_boolean() keytype = m.get_string() keyblob = m.get_string() try: key = self.transport._key_info[keytype](Message(keyblob)) except SSHException as e: self.transport._log(INFO, 'Auth rejected: public key: %s' % str(e)) key = None except: self.transport._log(INFO, 'Auth rejected: unsupported or mangled public key') key = None if key is None: self._disconnect_no_more_auth() return # first check if this key is okay... if not, we can skip the verify result = self.transport.server_object.check_auth_publickey(username, key) if result != AUTH_FAILED: # key is okay, verify it if not sig_attached: # client wants to know if this key is acceptable, before it # signs anything... send special "ok" message m = Message() m.add_byte(chr(MSG_USERAUTH_PK_OK)) m.add_string(keytype) m.add_string(keyblob) self.transport._send_message(m) return sig = Message(m.get_string()) blob = self._get_session_blob(key, service, username) if not key.verify_ssh_sig(blob, sig): self.transport._log(INFO, 'Auth rejected: invalid signature') result = AUTH_FAILED elif method == 'keyboard-interactive': lang = m.get_string() submethods = m.get_string() result = self.transport.server_object.check_auth_interactive(username, submethods) if isinstance(result, InteractiveQuery): # make interactive query instead of response self._interactive_query(result) return else: result = self.transport.server_object.check_auth_none(username) # okay, send result self._send_auth_result(username, method, result)