def has_corresponding_commit_transaction(self, transaction):
epoch_hashes = self.epoch.get_epoch_hashes()
commit_hash = transaction.commit_hash
for top, _epoch_hash in epoch_hashes.items():
commits = self.epoch.get_commits_for_epoch(top)
if commit_hash in commits:
commit = commits[commit_hash]
# check if commited random can be encrypted by reveal private key
try:
Private.decrypt(commit.rand, transaction.key)
except IntegrityError as e:
raise AcceptionException(
"Private key in reveal random transaction is not valid for corresponding commit transaction!"
)
else:
raise AcceptionException(
"Reveal transaction has no corresponding commit transaction in the chain!"
)
def reveal_commited_random(self, block_hash):
if block_hash == self.dag.genesis_block().get_hash():
return 0
seed = 0
commits = self.get_commits_for_epoch(block_hash)
reveals = self.get_reveals_for_epoch(block_hash)
randoms_list = []
for reveal in reveals:
if reveal.commit_hash in commits:
commit = commits[reveal.commit_hash]
key = Keys.from_bytes(reveal.key)
revealed_data = Private.decrypt(commit.rand, key)
randoms_list.append(
int.from_bytes(revealed_data, byteorder='big'))
seed = sum_random(randoms_list)
return seed
def test_commit_reveal(self):
dag = Dag(0)
epoch = Epoch(dag)
private = Private.generate()
prev_hash = ChainGenerator.fill_with_dummies(
dag,
dag.genesis_block().get_hash(),
Epoch.get_round_range(1, Round.PUBLIC))
randoms_list = []
for i in Epoch.get_round_range(1, Round.COMMIT):
random_value = int.from_bytes(os.urandom(32), byteorder='big')
randoms_list.append(random_value)
expected_seed = sum_random(randoms_list)
reveals = []
epoch_hash = dag.genesis_block().get_hash()
for i in Epoch.get_round_range(1, Round.COMMIT):
rand = randoms_list.pop()
random_bytes = rand.to_bytes(32, byteorder='big')
commit, reveal = TestEpoch.create_dummy_commit_reveal(
random_bytes, epoch_hash)
commit_block = BlockFactory.create_block_with_timestamp(
[prev_hash], i * BLOCK_TIME)
commit_block.system_txs = [commit]
signed_block = BlockFactory.sign_block(commit_block, private)
dag.add_signed_block(i, signed_block)
prev_hash = commit_block.get_hash()
reveals.append(reveal)
revealing_key = Keys.from_bytes(reveal.key)
encrypted_bytes = Public.encrypt(random_bytes,
Private.publickey(revealing_key))
decrypted_bytes = Private.decrypt(encrypted_bytes, revealing_key)
# TODO check if encryption decryption can work million times in a row
self.assertEqual(decrypted_bytes, random_bytes)
revealed_value = Private.decrypt(commit.rand, revealing_key)
self.assertEqual(revealed_value, random_bytes)
# self.assertEqual(len(reveals), ROUND_DURATION)
prev_hash = ChainGenerator.fill_with_dummies(
dag, prev_hash, Epoch.get_round_range(1, Round.SECRETSHARE))
for i in Epoch.get_round_range(1, Round.REVEAL):
reveal_block = BlockFactory.create_block_with_timestamp(
[prev_hash], i * BLOCK_TIME)
reveal_block.system_txs = [reveals.pop()]
signed_block = BlockFactory.sign_block(reveal_block, private)
dag.add_signed_block(i, signed_block)
prev_hash = reveal_block.get_hash()
prev_hash = ChainGenerator.fill_with_dummies(
dag, prev_hash, Epoch.get_round_range(1, Round.PRIVATE))
prev_hash = ChainGenerator.fill_with_dummies(
dag, prev_hash, Epoch.get_round_range(1, Round.FINAL))
seed = epoch.reveal_commited_random(prev_hash)
self.assertEqual(expected_seed, seed)
def dec_part_secret(privatekey, enc_data, number):
split = Private.decrypt(enc_data, privatekey)
if split:
return (number + 1, int.from_bytes(split, byteorder="big"))
return None