Files
python-teos/pisa/inspector.py
2019-10-10 09:59:11 +07:00

231 lines
8.0 KiB
Python

import re
from pisa import errors
import pisa.conf as conf
from pisa import bitcoin_cli, Logger
from pisa.appointment import Appointment
from pisa.block_processor import BlockProcessor
logger = Logger("Inspector")
# FIXME: The inspector logs the wrong messages sent form the users. A possible attack surface would be to send a really
# long field that, even if not accepted by PISA, would be stored in the logs. This is a possible DoS surface
# since pisa would store any kind of message (no matter the length). Solution: truncate the length of the fields
# stored + blacklist if multiple wrong requests are received.
class Inspector:
def inspect(self, data):
locator = data.get('locator')
start_time = data.get('start_time')
end_time = data.get('end_time')
dispute_delta = data.get('dispute_delta')
encrypted_blob = data.get('encrypted_blob')
cipher = data.get('cipher')
hash_function = data.get('hash_function')
block_height = BlockProcessor.get_block_count()
if block_height is not None:
rcode, message = self.check_locator(locator)
if rcode == 0:
rcode, message = self.check_start_time(start_time, block_height)
if rcode == 0:
rcode, message = self.check_end_time(end_time, start_time, block_height)
if rcode == 0:
rcode, message = self.check_delta(dispute_delta)
if rcode == 0:
rcode, message = self.check_blob(encrypted_blob)
if rcode == 0:
rcode, message = self.check_cipher(cipher)
if rcode == 0:
rcode, message = self.check_hash_function(hash_function)
if rcode == 0:
r = Appointment(locator, start_time, end_time, dispute_delta, encrypted_blob, cipher, hash_function)
else:
r = (rcode, message)
else:
# In case of an unknown exception, assign a special rcode and reason.
r = (errors.UNKNOWN_JSON_RPC_EXCEPTION, "Unexpected error occurred")
return r
@staticmethod
def check_locator(locator):
message = None
rcode = 0
if locator is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty locator received"
elif type(locator) != str:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong locator data type ({})".format(type(locator))
elif len(locator) != 64:
rcode = errors.APPOINTMENT_WRONG_FIELD_SIZE
message = "wrong locator size ({})".format(len(locator))
# TODO: #12-check-txid-regexp
elif re.search(r'^[0-9A-Fa-f]+$', locator) is None:
rcode = errors.APPOINTMENT_WRONG_FIELD_FORMAT
message = "wrong locator format ({})".format(locator)
if message is not None:
logger.error(message)
return rcode, message
@staticmethod
def check_start_time(start_time, block_height):
message = None
rcode = 0
# TODO: What's too close to the current height is not properly defined. Right now any appointment that is in the
# future will be accepted (even if it's only one block away).
t = type(start_time)
if start_time is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty start_time received"
elif t != int:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong start_time data type ({})".format(t)
elif start_time <= block_height:
rcode = errors.APPOINTMENT_FIELD_TOO_SMALL
if start_time < block_height:
message = "start_time is in the past"
else:
message = "start_time is too close to current height"
if message is not None:
logger.error(message)
return rcode, message
@staticmethod
def check_end_time(end_time, start_time, block_height):
message = None
rcode = 0
# TODO: What's too close to the current height is not properly defined. Right now any appointment that ends in
# the future will be accepted (even if it's only one block away).
t = type(end_time)
if end_time is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty end_time received"
elif t != int:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong end_time data type ({})".format(t)
elif start_time >= end_time:
rcode = errors.APPOINTMENT_FIELD_TOO_SMALL
if start_time > end_time:
message = "end_time is smaller than start_time"
else:
message = "end_time is equal to start_time"
elif block_height >= end_time:
rcode = errors.APPOINTMENT_FIELD_TOO_SMALL
if block_height > end_time:
message = 'end_time is in the past'
else:
message = 'end_time is too close to current height'
if message is not None:
logger.error(message)
return rcode, message
@staticmethod
def check_delta(dispute_delta):
message = None
rcode = 0
t = type(dispute_delta)
if dispute_delta is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty dispute_delta received"
elif t != int:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong dispute_delta data type ({})".format(t)
elif dispute_delta < conf.MIN_DISPUTE_DELTA:
rcode = errors.APPOINTMENT_FIELD_TOO_SMALL
message = "dispute delta too small. The dispute delta should be at least {} (current: {})".format(
conf.MIN_DISPUTE_DELTA, dispute_delta)
if message is not None:
logger.error(message)
return rcode, message
# ToDo: #6-define-checks-encrypted-blob
@staticmethod
def check_blob(encrypted_blob):
message = None
rcode = 0
t = type(encrypted_blob)
if encrypted_blob is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty encrypted_blob received"
elif t != str:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong encrypted_blob data type ({})".format(t)
elif re.search(r'^[0-9A-Fa-f]+$', encrypted_blob) is None:
rcode = errors.APPOINTMENT_WRONG_FIELD_FORMAT
message = "wrong encrypted_blob format ({})".format(encrypted_blob)
if message is not None:
logger.error(message)
return rcode, message
@staticmethod
def check_cipher(cipher):
message = None
rcode = 0
t = type(cipher)
if cipher is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty cipher received"
elif t != str:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong cipher data type ({})".format(t)
elif cipher.upper() not in conf.SUPPORTED_CIPHERS:
rcode = errors.APPOINTMENT_CIPHER_NOT_SUPPORTED
message = "cipher not supported: {}".format(cipher)
if message is not None:
logger.error(message)
return rcode, message
@staticmethod
def check_hash_function(hash_function):
message = None
rcode = 0
t = type(hash_function)
if hash_function is None:
rcode = errors.APPOINTMENT_EMPTY_FIELD
message = "empty hash_function received"
elif t != str:
rcode = errors.APPOINTMENT_WRONG_FIELD_TYPE
message = "wrong hash_function data type ({})".format(t)
elif hash_function.upper() not in conf.SUPPORTED_HASH_FUNCTIONS:
rcode = errors.APPOINTMENT_HASH_FUNCTION_NOT_SUPPORTED
message = "hash_function not supported {}".format(hash_function)
if message is not None:
logger.error(message)
return rcode, message