ntorfsm

Details

An NTorFSM steps through each state of a circuit handshake. At each step an NTorFSM expects to receive a certain kind of cell. Either this cell is received, processed, and a response cell is returned or an exception is raised (and the circuit is destroyed).

NTorFSM’s also derive key material and add RelayCrypto objects to the associated circuit’s crypt_path.

class circuit.handshake.ntorfsm.NTorFSM(circuit_id, path, crypt_path)

Bases: object

Finite state machine to step through an ntor handshake with relays on a circuit’s path.

recvCell(cell)

Call a handler function to process cell based on this ntor fsm’s current state.

Parameters:cell (cell) – cell received from this ntor fsm’s circuit Returns:cell, None may return either the next cell to send to step through handshakes with relays on this path or None if no response is required

getInitiatingCell()

Build and return the initiating cell for this ntor fsm - a Create2Cell.

Advance this ntor fsm’s state.

Returns:oppy.cell.fixedlen.Create2Cell

isDone()

Return True iff this ntor fsm’s state is State.DONE

Returns:bool True if state is State.DONE