def create_wrong_blockchain_100():
DNI = 19
RSA = rsa_key()
num_blocks = 100
now = time()
transactions = map(
lambda i: transaction(
int(hashlib.sha256(f"Transaction #{i}".encode()).hexdigest(), 16),
RSA), range(100))
blockChain = block_chain(next(transactions))
for _ in range(1, DNI):
blockChain.add_block(next(transactions))
print(f'New block from transaction #{_ + 1} added!')
print(f"Pre-verification: {blockChain.verify()}")
for _ in range(DNI, num_blocks):
print(f'Wrong block from transaction #{_ + 1} added!')
blockChain.add_wrong_block(next(transactions))
with open(f'100_blocks_{DNI}_wrong.pickle', 'wb') as f:
pickle.dump(blockChain, f)
print(f"Verification: {blockChain.verify()}\nTime elapsed: {time() - now}")
def fitxer_100_blocs_valids_fins_XX_DNI():
"""
Un fitxer amb una cadena de 100 blocs que només sigui vàlida fins al bloc XX on XX són les dues darreres
xifres del vostre DNI.
"""
XX_DNI = 81 # ara mateix NO INCLÒS EN ELS VÀLIDS
rsa_0 = blockchain.rsa_key()
size_message = 256
m_0 = random.randint(2**(size_message // 2 - 1),
2**(size_message // 2) - 1)
t_0 = blockchain.transaction(m_0, rsa_0)
cadena_de_blocs = blockchain.block_chain(t_0)
for i in range(1, XX_DNI):
print(i)
rsa = blockchain.rsa_key()
m = random.randint(2**(size_message // 2 - 1),
2**(size_message // 2) - 1)
t = blockchain.transaction(m, rsa)
cadena_de_blocs.add_block(t)
print(cadena_de_blocs.verify())
for i in range(XX_DNI, 100):
print(i)
rsa = blockchain.rsa_key()
m = random.randint(2**(size_message // 2 - 1),
2**(size_message // 2) - 1)
t = blockchain.transaction(m, rsa)
t.signature = random.randint(
0, sys.maxsize
) # fem que sigui invàlida la transacció, també podríem alterar el hash etc
# Nota: en tindríem prou amb alterar-ne un de sol (el 81) perquè els següents també fossin invàlids, es trenca la cadena
cadena_de_blocs.add_block(t)
print(cadena_de_blocs.verify())
fitxer_de_sortida = '81_blocks_valids.block'
with open(fitxer_de_sortida, 'wb') as file:
pickle.dump(cadena_de_blocs, file)
def fitxer_100_blocs_valids(): """Un fitxer amb una cadena vàlida de 100 blocs""" rsa_0 = blockchain.rsa_key() m_0 = random.randint(0,sys.maxsize) t_0 = blockchain.transaction(m_0,rsa_0) cadena_de_blocs = blockchain.block_chain(t_0) for i in range (1,100): print(i) rsa = blockchain.rsa_key() m = random.randint(0,sys.maxsize) t = blockchain.transaction(m,rsa) cadena_de_blocs.add_block(t) print(cadena_de_blocs.verify()) fitxer_de_sortida = '100_blocks_valids.block' with open(fitxer_de_sortida, 'wb') as file: pickle.dump(cadena_de_blocs, file)
def main(mode, data, height):
"""
client implementation of block chain
Argument : [AddBlock, PrintBlock, PrintChain]
AddBlock : Mine a new block to the longest chain
PrintBlock: Print the block of specify height
PrintChain: Print the whole block chain
"""
bc = block_chain()
if mode == 'AddBlock':
if data == None:
sys.exit("Data not specify! --data/-d to specify data")
bc.addBlock(data)
elif mode == 'PrintChain':
bc.printChain()
elif mode == 'PrintBlock':
if height == None:
sys.exit("height not specify! --heihgt/-h to specify height")
bc.printBlock(height)
from flask import Flask, jsonify, request
from blockchain import block_chain
# Instantiate the Node
app = Flask(__name__)
# Generate a globally unique address for this node
node_identifier = str(uuid4()).replace('-', '')
# Instantiate the Blockchain
blockchain = block_chain()
@app.route('/mine', methods=['GET'])
def mine():
# We run the proof of work algorithm to get the next proof...
last_block = blockchain.last_block
proof = blockchain.proof_of_work(last_block)
# We must receive a reward for finding the proof.
# The sender is "0" to signify that this node has mined a new coin.
blockchain.new_transaction(
sender="0",
recipient=node_identifier,
amount=1,
)
# Forge the new Block by adding it to the chain
previous_hash = blockchain.hash(last_block)
block = blockchain.new_block(proof, previous_hash)