def test_top_blocks_in_range(self):
dag = Dag(0)
prev_hash = dag.genesis_block().get_hash()
ChainGenerator.fill_with_dummies_and_skips(dag, prev_hash, range(1, 8),
[3, 5])
ChainGenerator.fill_with_dummies_and_skips(dag, prev_hash, range(1, 8),
[4])
ChainGenerator.fill_with_dummies_and_skips(dag, prev_hash, range(1, 7),
[4, 5])
tops = dag.get_branches_for_timeslot_range(3, 6)
self.assertEqual(len(tops), 3)
self.assertIn(dag.blocks_by_number[4][0].get_hash(), tops)
self.assertIn(dag.blocks_by_number[5][0].get_hash(), tops)
self.assertIn(dag.blocks_by_number[3][1].get_hash(), tops)
tops = dag.get_branches_for_timeslot_range(4, 5)
self.assertEqual(len(tops), 1)
self.assertIn(dag.blocks_by_number[4][0].get_hash(), tops)
tops = dag.get_branches_for_timeslot_range(3, 5)
self.assertEqual(len(tops), 3)
self.assertIn(dag.blocks_by_number[4][0].get_hash(), tops)
self.assertIn(dag.blocks_by_number[3][0].get_hash(), tops)
self.assertIn(dag.blocks_by_number[3][1].get_hash(), tops)
class Node:
def __init__(self,
genesis_creation_time,
node_id,
network,
block_signer=BlockSigner(Private.generate()),
validators=Validators(),
behaviour=Behaviour(),
logger=DummyLogger()):
self.logger = logger
self.dag = Dag(genesis_creation_time)
self.epoch = Epoch(self.dag)
self.epoch.set_logger(self.logger)
self.permissions = Permissions(self.epoch, validators)
self.mempool = Mempool()
self.utxo = Utxo(self.logger)
self.conflict_watcher = ConflictWatcher(self.dag)
self.behaviour = behaviour
self.block_signer = block_signer
self.node_pubkey = Private.publickey(block_signer.private_key)
self.logger.info("Public key is %s",
Keys.to_visual_string(self.node_pubkey))
self.network = network
self.node_id = node_id
self.epoch_private_keys = [] # TODO make this single element
# self.epoch_private_keys where first element is era number, and second is key to reveal commited random
self.reveals_to_send = {}
self.sent_shares_epochs = [] # epoch hashes of secret shares
self.last_expected_timeslot = 0
self.last_signed_block_number = 0
self.tried_to_sign_current_block = False
self.owned_utxos = []
self.terminated = False
self.blocks_buffer = [
] # uses while receive block and do not have its ancestor in local dag (before verify)
def start(self):
pass
def handle_timeslot_changed(self, previous_timeslot_number,
current_timeslot_number):
self.last_expected_timeslot = current_timeslot_number
self.try_to_broadcast_maliciously_delayed_block()
return self.try_to_send_negative_gossip(previous_timeslot_number)
def try_to_broadcast_maliciously_delayed_block(self):
if self.behaviour.block_to_delay_broadcasting:
if self.behaviour.malicious_block_broadcast_delay > 0:
self.behaviour.malicious_block_broadcast_delay -= 1
else:
self.network.broadcast_block(
self.node_id,
self.behaviour.block_to_delay_broadcasting.pack())
self.behaviour.block_to_delay_broadcasting = None
def try_to_send_negative_gossip(self, previous_timeslot_number):
if previous_timeslot_number not in self.dag.blocks_by_number:
epoch_block_number = Epoch.convert_to_epoch_block_number(
previous_timeslot_number)
allowed_to_send_negative_gossip = False
epoch_hashes = self.epoch.get_epoch_hashes()
for _, epoch_hash in epoch_hashes.items():
permissions = self.permissions.get_gossip_permission(
epoch_hash, epoch_block_number)
for permission in permissions:
if permission.public_key == self.node_pubkey:
allowed_to_send_negative_gossip = True
break
if allowed_to_send_negative_gossip:
self.broadcast_gossip_negative(previous_timeslot_number)
return True
return False
def step(self):
current_block_number = self.epoch.get_current_timeframe_block_number()
if self.epoch.is_new_epoch_upcoming(current_block_number):
self.epoch.accept_tops_as_epoch_hashes()
# service method for update node behavior (if behavior is temporary)
self.behaviour.update(Epoch.get_epoch_number(current_block_number))
# service method for update transport behavior (if behavior is temporary)
self.behaviour.update_transport(current_block_number)
current_round = self.epoch.get_round_by_block_number(
current_block_number)
if current_round == Round.PUBLIC:
self.try_to_publish_public_key(current_block_number)
elif current_round == Round.SECRETSHARE:
self.try_to_share_random()
# elif current_round == Round.PRIVATE:
# do nothing as private key should be included to block by block signer
elif current_round == Round.COMMIT:
self.try_to_commit_random()
elif current_round == Round.REVEAL:
self.try_to_reveal_random()
elif current_round == Round.FINAL:
# at this point we may remove everything systemic from mempool,
# so it does not interfere with pubkeys for next epoch
self.mempool.remove_all_systemic_transactions()
if self.behaviour.wants_to_hold_stake:
self.broadcast_stakehold_transaction()
self.behaviour.wants_to_hold_stake = False
if self.behaviour.wants_to_release_stake:
self.broadcast_stakerelease_transaction()
self.behaviour.wants_to_release_stake = False
if self.behaviour.malicious_send_negative_gossip_count > 0:
self.broadcast_gossip_negative(self.last_expected_timeslot)
self.behaviour.malicious_send_negative_gossip_count -= 1
if self.behaviour.malicious_send_positive_gossip_count > 0:
zero_block = self.dag.blocks_by_number[0][
0].block # send genesis block malicious
self.broadcast_gossip_positive(zero_block.get_hash())
self.behaviour.malicious_send_positive_gossip_count -= 1
if self.owned_utxos:
self.broadcast_payments()
if current_block_number != self.last_expected_timeslot:
self.tried_to_sign_current_block = False
should_wait = self.handle_timeslot_changed(
previous_timeslot_number=self.last_expected_timeslot,
current_timeslot_number=current_block_number)
if should_wait:
return
if not self.tried_to_sign_current_block:
self.try_to_sign_block(current_block_number)
self.tried_to_sign_current_block = True # will reset in next timeslot
async def run(self):
while True:
self.step()
await asyncio.sleep(1)
def try_to_sign_block(self, current_block_number):
epoch_block_number = Epoch.convert_to_epoch_block_number(
current_block_number)
allowed_to_sign = False
epoch_hashes = self.epoch.get_epoch_hashes()
for top, epoch_hash in epoch_hashes.items():
permission = self.permissions.get_sign_permission(
epoch_hash, epoch_block_number)
if permission.public_key == self.node_pubkey:
allowed_to_sign = True
break
if allowed_to_sign:
should_skip_maliciously = self.behaviour.is_malicious_skip_block()
# first_epoch_ever = self.epoch.get_epoch_number(current_block_number) == 1
if should_skip_maliciously: # and not first_epoch_ever: # skip first epoch check
self.epoch_private_keys.clear()
self.logger.info("Maliciously skiped block")
else:
if self.last_signed_block_number < current_block_number:
self.last_signed_block_number = current_block_number
self.sign_block(current_block_number)
else:
# skip once more block broadcast in same timeslot
pass
def sign_block(self, current_block_number):
current_round_type = self.epoch.get_round_by_block_number(
current_block_number)
epoch_number = Epoch.get_epoch_number(current_block_number)
system_txs = self.get_system_transactions_for_signing(
current_round_type)
payment_txs = self.get_payment_transactions_for_signing(
current_block_number)
tops = self.dag.get_top_blocks_hashes()
chosen_top = self.dag.get_longest_chain_top(tops)
conflicting_tops = [top for top in tops if top != chosen_top]
current_top_blocks = [
chosen_top
] + conflicting_tops # first link in dag is not considered conflict, the rest is.
if self.behaviour.off_malicious_links_to_wrong_blocks:
current_top_blocks = []
all_hashes = list(self.dag.blocks_by_hash.keys())
for _ in range(random.randint(1, 3)):
block_hash = random.choice(all_hashes)
current_top_blocks.append(block_hash)
self.logger.info(
"Maliciously connecting block at slot %s to random hashes",
current_block_number)
block = BlockFactory.create_block_dummy(current_top_blocks)
block.system_txs = system_txs
block.payment_txs = payment_txs
signed_block = BlockFactory.sign_block(block,
self.block_signer.private_key)
if self.behaviour.malicious_block_broadcast_delay > 0:
self.behaviour.block_to_delay_broadcasting = signed_block
return # don't do broadcasting, wait a few timeslots1
self.dag.add_signed_block(current_block_number, signed_block)
self.utxo.apply_payments(payment_txs)
self.conflict_watcher.on_new_block_by_validator(
block.get_hash(), epoch_number, self.node_pubkey)
if not self.behaviour.transport_cancel_block_broadcast: # behaviour flag for cancel block broadcast
self.logger.debug("Broadcasting signed block number %s",
current_block_number)
self.network.broadcast_block(self.node_id, signed_block.pack())
else:
self.logger.info(
"Created but maliciously skipped broadcasted block")
if self.behaviour.malicious_excessive_block_count > 0:
additional_block_timestamp = block.timestamp + 1
additional_block = BlockFactory.create_block_with_timestamp(
current_top_blocks, additional_block_timestamp)
additional_block.system_txs = block.system_txs
additional_block.payment_txs = block.payment_txs
signed_add_block = BlockFactory.sign_block(
additional_block, self.block_signer.private_key)
self.dag.add_signed_block(current_block_number, signed_add_block)
self.conflict_watcher.on_new_block_by_validator(
signed_add_block.get_hash(), epoch_number,
self.node_pubkey) #mark our own conflict for consistency
self.logger.info("Sending additional block")
self.network.broadcast_block(self.node_id, signed_add_block.pack())
self.behaviour.malicious_excessive_block_count -= 1
def get_system_transactions_for_signing(self, round):
system_txs = self.mempool.pop_round_system_transactions(round)
# skip non valid system_txs
verifier = InBlockTransactionsAcceptor(self.epoch, self.permissions,
self.logger)
system_txs = [t for t in system_txs if verifier.check_if_valid(t)]
# get gossip conflicts hashes (validate_gossip() ---> [gossip_negative_hash, gossip_positive_hash])
conflicts_gossip = self.validate_gossip(self.dag, self.mempool)
gossip_mempool_txs = self.mempool.pop_current_gossips(
) # POP gossips to block
system_txs += gossip_mempool_txs
if round == Round.PRIVATE:
if self.epoch_private_keys:
key_reveal_tx = self.form_private_key_reveal_transaction()
system_txs.append(key_reveal_tx)
if conflicts_gossip:
for conflict in conflicts_gossip:
self.logger.info(
"Adding penalty to block with conflicting gossips %s",
conflicts_gossip)
penalty_gossip_tx = \
TransactionFactory.create_penalty_gossip_transaction(conflict=conflict,
node_private=self.block_signer.private_key)
system_txs.append(penalty_gossip_tx)
return system_txs
def get_payment_transactions_for_signing(self, block_number):
node_public = Private.publickey(self.block_signer.private_key)
pseudo_address = sha256(node_public).digest()
block_reward = TransactionFactory.create_block_reward(
pseudo_address, block_number)
block_reward_hash = block_reward.get_hash()
self.owned_utxos.append(block_reward_hash)
payment_txs = [block_reward] + self.mempool.pop_payment_transactions()
return payment_txs
def try_to_publish_public_key(self, current_block_number):
if self.epoch_private_keys:
return
epoch_hashes = self.epoch.get_epoch_hashes()
for _, epoch_hash in epoch_hashes.items():
allowed_round_validators = self.permissions.get_ordered_randomizers_pubkeys_for_round(
epoch_hash, Round.PUBLIC)
pubkey_publishers_pubkeys = [
validator.public_key for validator in allowed_round_validators
]
if self.node_pubkey in pubkey_publishers_pubkeys:
node_private = self.block_signer.private_key
pubkey_index = self.permissions.get_signer_index_from_public_key(
self.node_pubkey, epoch_hash)
generated_private = Private.generate()
tx = TransactionFactory.create_public_key_transaction(
generated_private=generated_private,
epoch_hash=epoch_hash,
validator_index=pubkey_index,
node_private=node_private)
if self.behaviour.malicious_wrong_signature:
tx.signature = b'0' + tx.signature[1:]
self.epoch_private_keys.append(generated_private)
self.logger.debug("Broadcasted public key")
self.logger.debug(Keys.to_visual_string(tx.generated_pubkey))
self.mempool.add_transaction(tx)
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(tx))
def try_to_share_random(self):
epoch_hashes = self.epoch.get_epoch_hashes()
for top, epoch_hash in epoch_hashes.items():
if epoch_hash in self.sent_shares_epochs: continue
allowed_to_share_random = self.permissions.get_secret_sharers_pubkeys(
epoch_hash)
if not self.node_pubkey in allowed_to_share_random: continue
split_random = self.form_split_random_transaction(top, epoch_hash)
self.sent_shares_epochs.append(epoch_hash)
self.mempool.add_transaction(split_random)
self.network.broadcast_transaction(
self.node_id, TransactionParser.pack(split_random))
def try_to_commit_random(self):
epoch_hashes = self.epoch.get_epoch_hashes().values()
for epoch_hash in epoch_hashes:
if epoch_hash not in self.reveals_to_send:
allowed_to_commit_list = self.permissions.get_commiters_pubkeys(
epoch_hash)
if self.node_pubkey not in allowed_to_commit_list:
continue
pubkey_index = self.permissions.get_committer_index_from_public_key(
self.node_pubkey, epoch_hash)
commit, reveal = TransactionFactory.create_commit_reveal_pair(
self.block_signer.private_key, os.urandom(32),
pubkey_index, epoch_hash)
self.reveals_to_send[epoch_hash] = reveal
self.logger.info("Broadcasting commit")
self.mempool.add_transaction(commit)
self.network.broadcast_transaction(
self.node_id, TransactionParser.pack(commit))
def try_to_reveal_random(self):
for epoch_hash in list(self.reveals_to_send.keys()):
reveal = self.reveals_to_send[epoch_hash]
self.logger.info("Broadcasting reveal")
self.mempool.add_transaction(reveal)
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(reveal))
del self.reveals_to_send[epoch_hash]
def form_private_key_reveal_transaction(self):
tx = TransactionFactory.create_private_key_transaction(
self.epoch_private_keys.pop(0))
return tx
def form_split_random_transaction(self, top_hash, epoch_hash):
ordered_senders = self.permissions.get_ordered_randomizers_pubkeys_for_round(
epoch_hash, Round.PUBLIC)
published_pubkeys = self.epoch.get_public_keys_for_epoch(top_hash)
self.logger.info("Ordered pubkeys for secret sharing:")
sorted_published_pubkeys = []
for sender in ordered_senders:
raw_pubkey = Keys.to_bytes(sender.public_key)
raw_pubkey_index = self.permissions.get_signer_index_from_public_key(
raw_pubkey, epoch_hash)
if raw_pubkey_index in published_pubkeys:
generated_pubkey = published_pubkeys[raw_pubkey_index]
sorted_published_pubkeys.append(
Keys.from_bytes(generated_pubkey))
self.logger.info(Keys.to_visual_string(generated_pubkey))
else:
sorted_published_pubkeys.append(None)
self.logger.info("None")
tx = self.form_secret_sharing_transaction(sorted_published_pubkeys,
epoch_hash)
return tx
def form_secret_sharing_transaction(self, sorted_public_keys, epoch_hash):
random_bytes = os.urandom(32)
splits = split_secret(random_bytes, MINIMAL_SECRET_SHARERS,
TOTAL_SECRET_SHARERS)
encoded_splits = encode_splits(splits, sorted_public_keys)
self.logger.info("Formed split random")
node_private = self.block_signer.private_key
pubkey_index = self.permissions.get_secret_sharer_from_public_key(
self.node_pubkey, epoch_hash)
tx = TransactionFactory.create_split_random_transaction(
encoded_splits, pubkey_index, epoch_hash, node_private)
return tx
def get_allowed_signers_for_next_block(self, block):
current_block_number = self.epoch.get_current_timeframe_block_number()
epoch_block_number = Epoch.convert_to_epoch_block_number(
current_block_number)
if self.epoch.is_new_epoch_upcoming(current_block_number):
self.epoch.accept_tops_as_epoch_hashes()
epoch_hashes = self.epoch.get_epoch_hashes()
allowed_signers = []
for prev_hash in block.prev_hashes:
epoch_hash = None
if prev_hash in epoch_hashes:
epoch_hash = epoch_hashes[prev_hash]
else:
epoch_hash = self.epoch.find_epoch_hash_for_block(prev_hash)
if epoch_hash:
# self.logger.info("Calculating permissions from epoch_hash %s", epoch_hash.hex())
allowed_pubkey = self.permissions.get_sign_permission(
epoch_hash, epoch_block_number)
allowed_signers.append(allowed_pubkey)
assert len(
allowed_signers) > 0, "No signers allowed to sign next block"
return allowed_signers
# -------------------------------------------------------------------------------
# Handlers
# -------------------------------------------------------------------------------
def handle_block_message(self, node_id, raw_signed_block):
signed_block = SignedBlock()
signed_block.parse(raw_signed_block)
block_number = self.epoch.get_block_number_from_timestamp(
signed_block.block.timestamp)
self.logger.info(
"Received block with number %s at timeslot %s with hash %s",
block_number, self.epoch.get_current_timeframe_block_number(),
signed_block.block.get_hash().hex())
# CHECK_ANCESTOR
blocks_by_hash = self.dag.blocks_by_hash
is_orphan_block = False
for prev_hash in signed_block.block.prev_hashes: # by every previous hash
if prev_hash not in blocks_by_hash: # verify local ancestor for incoming block
is_orphan_block = True
# CHECK_ORPHAN_DISTANCE
block_out_of_epoch = False
epoch_end_block = self.epoch.get_epoch_end_block_number(
self.epoch.current_epoch)
if block_number >= epoch_end_block:
# income block from future epoch, cant validate signer
block_out_of_epoch = True
# CHECK ALLOWED SIGNER
if not block_out_of_epoch: # if incoming block not out of current epoch
allowed_signers = self.get_allowed_signers_for_block_number(
block_number)
allowed_pubkey = None
for allowed_signer in allowed_signers:
if signed_block.verify_signature(allowed_signer):
allowed_pubkey = allowed_signer
break
else:
allowed_pubkey = 'block_out_of_epoch' # process block as orphan
if allowed_pubkey: # IF SIGNER ALLOWED
if not is_orphan_block: # PROCESS NORMAL BLOCK (same epoch)
if self.epoch.is_new_epoch_upcoming(
block_number): # CHECK IS NEW EPOCH
self.epoch.accept_tops_as_epoch_hashes()
block_verifier = BlockAcceptor(
self.epoch, self.logger) # VERIFY BLOCK AS NORMAL
if block_verifier.check_if_valid(signed_block.block):
self.insert_verified_block(signed_block, allowed_pubkey)
return
else: # PROCESS ORPHAN BLOCK (same epoch)
orphan_block_verifier = OrphanBlockAcceptor(
self.epoch, self.blocks_buffer, self.logger)
if orphan_block_verifier.check_if_valid(signed_block.block):
self.blocks_buffer.append(signed_block)
self.logger.info("Orphan block added to buffer")
# for every parent for received block
for prev_hash in signed_block.block.prev_hashes: # check received block ancestor
if prev_hash not in self.dag.blocks_by_hash: # check parent in local dag
# if parent not exist in local DAG ask for parent
self.network.direct_request_block_by_hash(
self.node_id, node_id, prev_hash)
if len(self.blocks_buffer) > 0:
self.process_block_buffer()
self.logger.info("Orphan block buffer process success")
else:
self.logger.error(
"Received block from %d, but its signature is wrong", node_id)
def handle_transaction_message(self, node_id, raw_transaction):
transaction = TransactionParser.parse(raw_transaction)
verifier = MempoolTransactionsAcceptor(self.epoch, self.permissions,
self.logger)
if verifier.check_if_valid(transaction):
self.mempool.add_transaction(transaction)
# PROCESS NEGATIVE GOSSIP
if isinstance(transaction, NegativeGossipTransaction):
self.logger.info(
"Received negative gossip about block %s at timeslot %s",
transaction.number_of_block,
self.epoch.get_current_timeframe_block_number())
current_gossips = self.mempool.get_negative_gossips_by_block(
transaction.number_of_block)
for gossip in current_gossips:
# negative gossip already send by node, skip positive gossip searching and broadcasting
if gossip.pubkey == self.node_pubkey:
return
if self.dag.has_block_number(transaction.number_of_block):
signed_block_by_number = self.dag.blocks_by_number[
transaction.number_of_block]
self.broadcast_gossip_positive(
signed_block_by_number[0].get_hash())
# PROCESS POSITIVE GOSSIP
if isinstance(transaction, PositiveGossipTransaction):
# ----> ! make request ONLY if block in timeslot
self.logger.info(
"Received positive gossip about block %s at timeslot %s",
transaction.block_hash.hex(),
self.epoch.get_current_timeframe_block_number())
if transaction.block_hash not in self.dag.blocks_by_hash:
self.network.get_block_by_hash(
sender_node_id=self.node_id,
receiver_node_id=
node_id, # request TO ----> receiver_node_id
block_hash=transaction.block_hash)
else:
self.logger.error("Received tx is invalid")
# -------------------------------------------------------------------------------
# Broadcast
# -------------------------------------------------------------------------------
def broadcast_stakehold_transaction(self):
node_private = self.block_signer.private_key
tx = TransactionFactory.create_stake_hold_transaction(
1000, node_private)
self.logger.info("Broadcasted StakeHold transaction")
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(tx))
def broadcast_stakerelease_transaction(self):
node_private = self.block_signer.private_key
tx = TransactionFactory.create_stake_release_transaction(node_private)
self.logger.info("Broadcasted release stake transaction")
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(tx))
def broadcast_gossip_negative(self, block_number):
node_private = self.block_signer.private_key
tx = TransactionFactory.create_negative_gossip_transaction(
block_number, node_private)
self.mempool.append_gossip_tx(
tx) # ADD ! TO LOCAL MEMPOOL BEFORE BROADCAST
self.logger.info("Broadcasted negative gossip transaction")
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(tx))
def broadcast_gossip_positive(self, signed_block_hash):
node_private = self.block_signer.private_key
tx = TransactionFactory.create_positive_gossip_transaction(
signed_block_hash, node_private)
self.mempool.append_gossip_tx(
tx) # ADD ! TO LOCAL MEMPOOL BEFORE BROADCAST
# self.logger.info("Broadcasted positive gossip transaction")
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(tx))
def broadcast_payments(self):
for utxo in self.owned_utxos:
tx = TransactionFactory.create_payment(
utxo, 0, [os.urandom(32), os.urandom(32)], [10, 5])
self.mempool.add_transaction(tx)
self.network.broadcast_transaction(self.node_id,
TransactionParser.pack(tx))
# self.logger.info("Broadcasted payment with hash %s", tx.get_hash())
self.owned_utxos.clear()
# -------------------------------------------------------------------------------
# Targeted request
# -------------------------------------------------------------------------------
def request_block_by_hash(self, block_hash):
# no need validate/ public info ?
signed_block = self.dag.blocks_by_hash[block_hash]
self.network.broadcast_block(self.node_id, signed_block.pack())
# method returns block directly to sender without broadcast
def direct_request_block_by_hash(self, sender_node, block_hash):
signed_block = self.dag.blocks_by_hash[block_hash]
self.network.direct_response_block_by_hash(self.node_id, sender_node,
signed_block.pack())
# -------------------------------------------------------------------------------
# Internal
# -------------------------------------------------------------------------------
def insert_verified_block(self, signed_block, allowed_pubkey):
block = signed_block.block
block_number = self.epoch.get_block_number_from_timestamp(
block.timestamp)
epoch_number = Epoch.get_epoch_number(block_number)
self.dag.add_signed_block(block_number, signed_block)
self.mempool.remove_transactions(block.system_txs)
self.mempool.remove_transactions(block.payment_txs)
self.utxo.apply_payments(block.payment_txs)
self.conflict_watcher.on_new_block_by_validator(
block.get_hash(), epoch_number, allowed_pubkey)
def process_block_buffer(self):
while len(self.blocks_buffer) > 0:
block_from_buffer = self.blocks_buffer.pop()
block_number = self.epoch.get_block_number_from_timestamp(
block_from_buffer.block.timestamp)
if self.epoch.is_new_epoch_upcoming(
block_number): # CHECK IS NEW EPOCH
self.epoch.accept_tops_as_epoch_hashes()
# validate block from buffer by signature
allowed_signers = self.get_allowed_signers_for_block_number(
block_number)
allowed_pubkey = None
for allowed_signer in allowed_signers:
if block_from_buffer.verify_signature(allowed_signer):
allowed_pubkey = allowed_signer
break
if allowed_pubkey:
block_verifier = BlockAcceptor(self.epoch, self.logger)
if block_verifier.check_if_valid(
block_from_buffer.block): # VERIFY BLOCK AS NORMAL
self.insert_verified_block(block_from_buffer,
allowed_pubkey)
else:
self.logger.info("Block from buffer verification failed")
else:
self.logger.info("Block from buffer wrong signature")
def get_allowed_signers_for_block_number(self, block_number):
# TODO take cached epoch hashes if block is of lastest epoch
prev_epoch_number = self.epoch.get_epoch_number(block_number) - 1
prev_epoch_start = self.epoch.get_epoch_start_block_number(
prev_epoch_number)
prev_epoch_end = self.epoch.get_epoch_end_block_number(
prev_epoch_number)
# this will extract every unconnected block in epoch, which is practically epoch hash
# TODO maybe consider blocks to be epoch hashes if they are in final round and consider everything else is orphan
epoch_hashes = self.dag.get_branches_for_timeslot_range(
prev_epoch_start, prev_epoch_end + 1)
if prev_epoch_number == 0:
epoch_hashes = [self.dag.genesis_block().get_hash()]
allowed_signers = []
for epoch_hash in epoch_hashes:
epoch_block_number = Epoch.convert_to_epoch_block_number(
block_number)
allowed_pubkey = self.permissions.get_sign_permission(
epoch_hash, epoch_block_number).public_key
allowed_signers.append(allowed_pubkey)
assert len(allowed_signers) > 0, "No signers allowed to sign block"
return allowed_signers
@staticmethod
def validate_gossip(dag, mempool):
result = []
# -------------- mempool validation
mem_negative_gossips = mempool.get_all_negative_gossips()
# for every negative in mempool get authors and positives
for negative in mem_negative_gossips: # we can have many negatives by not existing block
negative_author = negative.pubkey
# get block by negative number
# skip another validations (if current validator have no block)
if dag.has_block_number(negative.number_of_block):
# get block hash
blocks_by_negative = dag.blocks_by_number[
negative.number_of_block]
for block in blocks_by_negative: # we can have more than one block by number
positives_for_negative = \
mempool.get_positive_gossips_by_block_hash(block.get_hash())
# if have no positives for negative - do nothing
for positive in positives_for_negative:
if positive.pubkey == negative_author:
# add to conflict result positive and negative gossips hash with same author
result.append(
[positive.get_hash(),
negative.get_hash()])
# -------------- dag validation
# provide penalty for standalone positive gossip (without negative) ?
# what else we can validate by tx_by_hash ?
# dag_negative_gossips = dag.get_negative_gossips()
# dag_positive_gossips = dag.get_positive_gossips()
# dag_penalty_gossips = dag.get_penalty_gossips()
return result
