def get_transaction(tx_hash):
blockchain = Blockchain()
transaction = blockchain.get_transaction_by_hash(tx_hash)
if transaction:
return json.dumps(transaction.to_dict())
response.status = 404
return json.dumps({'success': False, 'reason': 'Transaction Not Found'})
def get_block_header_by_hash(block_hash):
blockchain = Blockchain()
block_header = blockchain.get_block_header_by_hash(block_hash)
if block_header is None:
response.status = 404
return json.dumps({'success': False, 'reason': 'Block Not Found'})
return json.dumps(block_header.to_dict())
def get_transactions_index(block_hash):
blockchain = Blockchain()
transaction_inv = blockchain.get_transaction_hashes_by_block_hash(
block_hash)
if transaction_inv:
return json.dumps({'tx_hashes': transaction_inv})
response.status = 404
return json.dumps({'success': False, 'reason': 'Transactions Not Found'})
def get_block_header_by_height(height):
blockchain = Blockchain()
if height == "latest":
block_header = blockchain.get_tallest_block_header()
else:
block_header = blockchain.get_block_headers_by_height(height)
if block_header is None:
response.status = 404
return json.dumps({'success': False, 'reason': 'Block Not Found'})
return json.dumps(block_header.to_dict())
def get_blocks_inv(start_block_height, end_block_height):
blockchain = Blockchain()
blocks_range = end_block_height - start_block_height
if blocks_range < 1 or blocks_range > 500:
response.status = 400
return json.dumps({'success': False, 'reason': 'Bad request'})
blocks_inv = blockchain.get_hashes_range(start_block_height,
end_block_height)
if blocks_inv:
return json.dumps({'blocks_inv': blocks_inv})
response.status = 404
return json.dumps({'success': False, 'reason': 'Blocks not found'})
def full():
helptext = '''
Available commands:
===================
balance <public key (optional)>
history <public key (optional)>
getnodes
getblock <index (optional)>
getblocks <start index (optional)> <stop index (optional)>
mempoolcount
getmempool
getunconfirmedtx <tx hash>
mine <start | stop>
quit or exit
'''
peers = Peers()
api_client = ApiClient(peers)
blockchain = Blockchain()
mempool = Mempool()
validator = Validator()
ip = config['user']['ip']
public_key = config['user']['public_key']
if ip is None or public_key is None:
print("\n\npublic key and IP must be provided.\n\n")
sys.exit(1)
else:
print("\n\nfull node starting...\n\n")
full_node = FullNode(peers, api_client, blockchain, mempool, validator)
full_node.start()
miner = Miner(blockchain, mempool)
mining = False
while True:
cmd = input("{} ({}) full node > ".format(
config['network']['name'], config['network']['ticker_symbol']))
cmd_split = cmd.split()
try:
if cmd_split[0] == "balance":
if len(cmd_split) == 2:
url = full_node.BALANCE_URL.format(
"localhost", full_node.FULL_NODE_PORT, cmd_split[1])
else:
url = full_node.BALANCE_URL.format(
"localhost", full_node.FULL_NODE_PORT, public_key)
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "history":
if len(cmd_split) == 2:
url = full_node.TRANSACTION_HISTORY_URL.format(
"localhost", full_node.FULL_NODE_PORT, cmd_split[1])
response = requests.get(url)
else:
url = full_node.TRANSACTION_HISTORY_URL.format(
"localhost", full_node.FULL_NODE_PORT, public_key)
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "getnodes":
url = full_node.NODES_URL.format("localhost",
full_node.FULL_NODE_PORT)
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "getblock":
if len(cmd_split) == 2:
url = full_node.BLOCKS_URL.format("localhost",
full_node.FULL_NODE_PORT,
cmd_split[1])
else:
url = full_node.BLOCKS_URL.format("localhost",
full_node.FULL_NODE_PORT,
"latest")
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "getblocks":
if len(cmd_split) == 3:
url = full_node.BLOCKS_INV_URL.format(
"localhost", full_node.FULL_NODE_PORT, cmd_split[1],
cmd_split[2])
else:
url = full_node.BLOCKS_URL.format("localhost",
full_node.FULL_NODE_PORT,
"")
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "mempoolcount":
url = full_node.UNCONFIRMED_TRANSACTIONS_URL.format(
"localhost", full_node.FULL_NODE_PORT, "count")
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "getmempool":
url = full_node.UNCONFIRMED_TRANSACTIONS_URL.format(
"localhost", full_node.FULL_NODE_PORT, "")
response = requests.get(url)
print(response.json())
elif cmd_split[0] == "getunconfirmedtx":
if len(cmd_split) == 2:
url = full_node.UNCONFIRMED_TRANSACTIONS_URL.format(
"localhost", full_node.FULL_NODE_PORT, cmd_split[1])
response = requests.get(url)
print(response.json())
else:
print("\nRequires tx hash\n")
elif cmd_split[0] == "mine":
if len(cmd_split) == 2:
if cmd_split[1] == "start":
if mining is False:
print("\n\nminer starting...\n\n")
mining = True
miner.start()
elif cmd_split[1] == "stop":
if mining is True:
print("\n\nminer shutting down...\n\n")
mining = False
miner.shutdown()
else:
print("\nRequires: start | stop")
else:
print("\nRequires: start | stop")
elif cmd_split[0] in ("quit", "exit"):
if mining is True:
print("\n\nminer shutting down...\n\n")
miner.shutdown()
time.sleep(2)
full_node.shutdown()
time.sleep(2)
sys.exit(0)
else: # help
print(helptext)
except IndexError:
pass
def get_transaction_history(address):
blockchain = Blockchain()
transaction_history = blockchain.get_transaction_history(address)
return json.dumps(
[transaction.to_json() for transaction in transaction_history])
def get_balance(address):
blockchain = Blockchain()
return json.dumps(blockchain.get_balance(address))
def get_height():
blockchain = Blockchain()
return json.dumps({"height": blockchain.get_height()})
class Validator(object):
def __init__(self):
self.blockchain = Blockchain()
self.mempool = Mempool()
def check_hash_and_hash_pattern(self, block):
hash_difficulty = self.blockchain.calculate_hash_difficulty(
block.height)
if block.block_header.hash[:hash_difficulty].count(
'0') != hash_difficulty:
raise InvalidHash(
block.height,
"Incompatible Block Hash: {}".format(block.block_header.hash))
return
def check_height_and_previous_hash(self, block):
previous_block = self.blockchain.get_block_header_by_hash(
block.block_header.previous_hash)
if previous_block is None:
raise ChainContinuityError(
block.height,
"Incompatible block hash: {} and hash: {}".format(
block.height - 1, block.block_header.previous_hash))
previous_block_header, previous_block_branch, previous_block_height = previous_block
if previous_block_height != block.height - 1:
raise ChainContinuityError(
block.height,
"Incompatible block height: {}".format(block.height - 1))
return
def check_block_reward(self, block):
reward_amount = self.blockchain.get_reward(block.height)
for transaction in block.transactions[1:]:
if TransactionType(
transaction.tx_type) == TransactionType.COINBASE:
logger.warning("Block not valid. Multiple coinbases detected")
return False
reward_amount += transaction.fee
# first transaction is coinbase
reward_transaction = block.transactions[0]
if TransactionType(
reward_transaction.tx_type) != TransactionType.COINBASE:
logger.warning("Block not valid. Missing coinbase")
return False
if reward_transaction.amount != reward_amount:
logger.warning("Invalid block reward {} should be {}".format(
reward_transaction.amount, reward_amount))
return False
if reward_transaction.source != "0":
logger.warning("Invalid Coinbase source")
return False
return True
def validate_block_header(self, block_header, transactions_inv):
if self.blockchain.get_block_header_by_hash(block_header.hash):
logger.warning('Block Header already exists')
return False
if block_header.version != config['network']['version']:
logger.warning('Incompatible version')
return False
if block_header.merkle_root != self.calculate_merkle_root(
transactions_inv):
logger.warning('Invalid merkle root')
return False
previous_block = self.blockchain.get_block_header_by_hash(
block_header.previous_hash)
if previous_block is None:
return None
previous_block_header, previous_block_branch, previous_block_height = previous_block
if self.blockchain.calculate_hash_difficulty(
previous_block_height + 1) > block_header.hash_difficulty:
logger.warning('Invalid hash difficulty')
return False
return previous_block_height + 1
def validate_block(self, block, merkle_root):
if block.block_header.merkle_root != merkle_root:
logger.warning("invalid merkle root")
return False
if not self.check_block_reward(block):
logger.warning("Invalid block reward")
return False
return True
def validate_block_transactions_inv(self, transactions_inv):
"""
Checks a list of transaction hashes, checks for double-spends and/or entries in the mempool
Returns a list of unknown transaction hashes
:param transactions_inv:
:return: block_transactions, missing_transactions_inv
:rtype: tuple(list, list)
"""
missing_transactions_inv = []
block_transactions = []
for tx_hash in transactions_inv:
if self.blockchain.find_duplicate_transactions(tx_hash):
logger.warning(
'Transaction not valid. Double-spend prevented: {}'.
format(tx_hash))
return False
transaction = self.mempool.get_unconfirmed_transaction(tx_hash)
if transaction is None:
missing_transactions_inv.append(tx_hash)
else:
block_transactions.append(transaction)
return block_transactions, missing_transactions_inv
def validate_transaction(self, transaction):
"""
Validate a single transaction. Check for double-spend, invalid signature, and insufficient funds
:param transaction:
:return: boolean
:rtype: boolean
"""
if self.blockchain.find_duplicate_transactions(transaction.tx_hash):
logger.warning(
'Transaction not valid. Double-spend prevented: {}'.format(
transaction.tx_hash))
return False
if not transaction.verify():
logger.warning(
'Transaction not valid. Invalid transaction signature: {}'.
format(transaction.tx_hash))
return False
balance = self.blockchain.get_balance(transaction.source)
if transaction.amount + transaction.fee > balance:
logger.warning(
'Transaction not valid. Insufficient funds: {} {}<{}'.format(
transaction.tx_hash, balance,
transaction.amount + transaction.fee))
return False
return True
@staticmethod
def calculate_merkle_root(tx_hashes):
coinbase_hash = tx_hashes[0]
merkle_base = sorted(tx_hashes[1:])
merkle_base.insert(0, coinbase_hash)
while len(merkle_base) > 1:
temp_merkle_base = []
for i in range(0, len(merkle_base), 2):
if i == len(merkle_base) - 1:
temp_merkle_base.append(
hashlib.sha256(merkle_base[i]).hexdigest())
else:
temp_merkle_base.append(
hashlib.sha256(merkle_base[i] +
merkle_base[i + 1]).hexdigest())
merkle_base = temp_merkle_base
return merkle_base[0]
def __init__(self):
self.blockchain = Blockchain()
self.mempool = Mempool()
