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nucypher
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Method for obtaining a task specification

pull/863/head
David Núñez 2019-03-21 12:22:09 +01:00
parent bd44c7d65f
commit 04f3908343
1 changed files with 15 additions and 17 deletions
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32
nucypher/policy/models.py
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@ -541,6 +541,13 @@ class WorkOrder:
self.cfrag = cfrag # TODO: we need to store them in case of Ursula misbehavior
self.reencryption_signature = reencryption_signature
def get_specification(self, ursula_pubkey, alice_address, blockhash):
task_specification = (bytes(self.capsule),
bytes(ursula_pubkey),
alice_address,
blockhash)
return b''.join(task_specification)
def __bytes__(self):
data = bytes(self.capsule) + bytes(self.signature)
if self.cfrag and self.reencryption_signature:
@ -601,24 +608,19 @@ class WorkOrder:
# TODO: Bob's input to prove freshness for this work order
blockhash = b'\x00' * 32
tasks = []
tasks, tasks_bytes = [], []
for capsule in capsules:
if alice_verifying_key != capsule.get_correctness_keys()["verifying"]:
raise ValueError("Capsules in this work order are inconsistent.")
task_specification = (bytes(capsule),
bytes(ursula.stamp),
alice_address,
blockhash)
signature = bob.stamp(b''.join(task_specification))
task = cls.Task(capsule, signature)
task = cls.Task(capsule, signature=None)
specification = task.get_specification(ursula.stamp, alice_address, blockhash)
task.signature = bob.stamp(specification)
tasks.append(task)
tasks_bytes.append(bytes(task))
# TODO: What's the goal of the receipt? Should it include only the capsules?
receipt_bytes = b"wo:" + bytes(ursula.stamp) + \
msgpack.dumps([bytes(task) for task in tasks])
receipt_bytes = b"wo:" + bytes(ursula.stamp) + msgpack.dumps(tasks_bytes)
receipt_signature = bob.stamp(receipt_bytes)
return cls(bob=bob, arrangement_id=arrangement_id, tasks=tasks,
@ -647,12 +649,8 @@ class WorkOrder:
tasks.append(task)
# Each task signature has to match the original specification
task_specification = (bytes(task.capsule),
ursula_pubkey_bytes,
alice_address,
blockhash)
task_specification = b''.join(task_specification)
if not task.signature.verify(task_specification, bob_pubkey_sig):
specification = task.get_specification(ursula_pubkey_bytes, alice_address, blockhash)
if not task.signature.verify(specification, bob_pubkey_sig):
raise InvalidSignature()
bob = Bob.from_public_keys({SigningPower: bob_pubkey_sig})