mirror of
https://github.com/aljazceru/python-teos.git
synced 2025-12-17 14:14:22 +01:00
83b3913cb5
+ Users need to be registered in order to send appointments (free registration for now) + The tower gives them a number of appointments to work with + Non-registered users and users with no enough appoitnemnts slots return the same error (to avoid proving) - Authentication does not cover get_* requests yet - No tests - No docs
98 lines
3.2 KiB
Python
98 lines
3.2 KiB
Python
import re
|
|
|
|
import teos.errors as errors
|
|
|
|
from common.appointment import Appointment
|
|
from common.cryptographer import Cryptographer
|
|
|
|
SUBSCRIPTION_SLOTS = 1
|
|
|
|
# TODO: UNITTEST, DOCS
|
|
class Gatekeeper:
|
|
def __init__(self):
|
|
self.registered_users = {}
|
|
|
|
@staticmethod
|
|
def check_user_pk(user_pk):
|
|
"""
|
|
Checks if a given value is a 33-byte hex encoded string.
|
|
|
|
Args:
|
|
user_pk(:mod:`str`): the value to be checked.
|
|
|
|
Returns:
|
|
:obj:`bool`: Whether or not the value matches the format.
|
|
"""
|
|
return isinstance(user_pk, str) and re.match(r"^[0-9A-Fa-f]{66}$", user_pk) is not None
|
|
|
|
def add_update_user(self, user_pk):
|
|
if not self.check_user_pk(user_pk):
|
|
raise ValueError("provided public key does not match expected format (33-byte hex string)")
|
|
|
|
if user_pk not in self.registered_users:
|
|
self.registered_users[user_pk] = SUBSCRIPTION_SLOTS
|
|
else:
|
|
self.registered_users[user_pk] += SUBSCRIPTION_SLOTS
|
|
|
|
return self.registered_users[user_pk]
|
|
|
|
def fill_subscription_slots(self, user_pk, n):
|
|
slots = self.registered_users.get(user_pk)
|
|
|
|
# FIXME: This looks pretty dangerous. I'm guessing race conditions can happen here.
|
|
if slots == n:
|
|
self.registered_users.pop(user_pk)
|
|
else:
|
|
self.registered_users[user_pk] -= n
|
|
|
|
def identify_user(self, appointment_data, signature):
|
|
"""
|
|
Checks if the provided user signature is comes from a registered user with available appointment slots.
|
|
|
|
Args:
|
|
appointment_data (:obj:`dict`): the appointment that was signed by the user.
|
|
signature (:obj:`str`): the user's signature (hex encoded).
|
|
|
|
Returns:
|
|
:obj:`tuple`: A tuple (return code, message) as follows:
|
|
|
|
- ``(0, None)`` if the user can be identified (recovered pk belongs to a registered user) and the user has
|
|
available slots.
|
|
- ``!= (0, None)`` otherwise.
|
|
|
|
The possible return errors are: ``APPOINTMENT_EMPTY_FIELD`` and ``APPOINTMENT_INVALID_SIGNATURE``.
|
|
"""
|
|
|
|
if signature is None:
|
|
rcode = errors.APPOINTMENT_EMPTY_FIELD
|
|
message = "empty signature received"
|
|
|
|
else:
|
|
appointment = Appointment.from_dict(appointment_data)
|
|
rpk = Cryptographer.recover_pk(appointment.serialize(), signature)
|
|
compressed_user_pk = Cryptographer.get_compressed_pk(rpk)
|
|
|
|
if compressed_user_pk and compressed_user_pk in self.registered_users:
|
|
rcode = 0
|
|
message = compressed_user_pk
|
|
|
|
else:
|
|
rcode = errors.APPOINTMENT_INVALID_SIGNATURE_OR_INSUFFICIENT_SLOTS
|
|
message = "invalid signature or the user does not have enough slots available"
|
|
|
|
return rcode, message
|
|
|
|
def get_slots(self, user_pk):
|
|
"""
|
|
Returns the number os available slots for a given user.
|
|
|
|
Args:
|
|
user_pk(:mod:`str`): the public key that identifies the user (33-bytes hex str)
|
|
|
|
Returns:
|
|
:obj:`int`: the number of available slots.
|
|
|
|
"""
|
|
slots = self.registered_users.get(user_pk)
|
|
return slots if slots is not None else 0
|