class Election:
"""Election class."""
def __init__(self, events_queue=None):
self.bigchain = Bigchain()
self.events_queue = events_queue
def check_for_quorum(self, next_vote):
"""
Checks if block has enough invalid votes to make a decision
Args:
next_vote: The next vote.
"""
try:
block_id = next_vote['vote']['voting_for_block']
node = next_vote['node_pubkey']
except KeyError:
return
next_block = self.bigchain.get_block(block_id)
result = self.bigchain.block_election(next_block)
self.handle_block_events(result, block_id)
if result['status'] == self.bigchain.BLOCK_INVALID:
return Block.from_dict(next_block)
# Log the result
if result['status'] != self.bigchain.BLOCK_UNDECIDED:
msg = 'node:%s block:%s status:%s' % \
(node, block_id, result['status'])
# Extra data can be accessed via the log formatter.
# See logging.dictConfig.
logger_results.debug(msg,
extra={
'current_vote': next_vote,
'election_result': result,
})
def requeue_transactions(self, invalid_block):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
logger.info('Rewriting %s transactions from invalid block %s',
len(invalid_block.transactions), invalid_block.id)
for tx in invalid_block.transactions:
self.bigchain.write_transaction(tx)
return invalid_block
def handle_block_events(self, result, block_id):
if self.events_queue:
if result['status'] == self.bigchain.BLOCK_UNDECIDED:
return
elif result['status'] == self.bigchain.BLOCK_INVALID:
event_type = EventTypes.BLOCK_INVALID
elif result['status'] == self.bigchain.BLOCK_VALID:
event_type = EventTypes.BLOCK_VALID
event = Event(event_type, self.bigchain.get_block(block_id))
self.events_queue.put(event)
class Election:
def __init__(self):
self.bigchain = Bigchain()
def check_for_quorum(self, next_vote):
"""
Checks if block has enough invalid votes to make a decision
"""
next_block = r.table('bigchain')\
.get(next_vote['vote']['voting_for_block'])\
.run(self.bigchain.conn)
if self.bigchain.block_election_status(next_block) == self.bigchain.BLOCK_INVALID:
return next_block
def requeue_transactions(self, invalid_block):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
logger.info('Rewriting %s transactions from invalid block %s',
len(invalid_block['block']['transactions']),
invalid_block['id'])
for tx in invalid_block['block']['transactions']:
self.bigchain.write_transaction(tx)
return invalid_block
def create_duplicate_tx():
##################################################### 1.CREATE
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
# Digital Asset Definition (e.g. bicycle)
asset = Asset(data={"bicycle": {"manufacturer": "bkfab", "serial_number": "abcd1234"}})
# Metadata Definition
metadata = {'planet': 'earth1'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
tx = Transaction.create([alice.public_key], [([alice.public_key], 1)], metadata=metadata, asset=asset)
print(" ")
print("1.tx_create asset id : alice-----bicycle(", tx.to_dict()['transaction']['asset']['id'], ")----->alice")
print("1.tx_create tx id : ", tx.to_dict()['id'])
# sign with alice's private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
print("1.tx_create db response : ", b.write_transaction(tx))
# wait 2 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("1.tx_create query : ", tx)
print(" ")
#####################################################
print("2.write dulpicate tx: ", b.write_transaction(tx))
class Election:
def __init__(self):
self.bigchain = Bigchain()
def check_for_quorum(self, next_vote):
"""
Checks if block has enough invalid votes to make a decision
"""
next_block = r.table('bigchain')\
.get(next_vote['vote']['voting_for_block'])\
.run(self.bigchain.conn)
if self.bigchain.block_election_status(
next_block) == self.bigchain.BLOCK_INVALID:
return next_block
def requeue_transactions(self, invalid_block):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
logger.info('Rewriting %s transactions from invalid block %s',
len(invalid_block['block']['transactions']),
invalid_block['id'])
for tx in invalid_block['block']['transactions']:
self.bigchain.write_transaction(tx)
return invalid_block
class Election:
"""Election class."""
def __init__(self):
self.bigchain = Bigchain()
def check_for_quorum(self, next_vote):
"""
Checks if block has enough invalid votes to make a decision
Args:
next_vote: The next vote.
"""
next_block = self.bigchain.get_block(
next_vote['vote']['voting_for_block'])
block_status = self.bigchain.block_election_status(next_block['id'],
next_block['block']['voters'])
if block_status == self.bigchain.BLOCK_INVALID:
return Block.from_dict(next_block)
def requeue_transactions(self, invalid_block):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
logger.info('Rewriting %s transactions from invalid block %s',
len(invalid_block.transactions),
invalid_block.id)
for tx in invalid_block.transactions:
self.bigchain.write_transaction(tx)
return invalid_block
class Election:
"""Election class."""
def __init__(self):
self.bigchain = Bigchain()
def check_for_quorum(self, next_vote):
"""
Checks if block has enough invalid votes to make a decision
Args:
next_vote: The next vote.
"""
next_block = self.bigchain.get_block(
next_vote['vote']['voting_for_block'])
block_status = self.bigchain.block_election_status(
next_block['id'], next_block['block']['voters'])
if block_status == self.bigchain.BLOCK_INVALID:
return Block.from_dict(next_block)
def requeue_transactions(self, invalid_block):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
logger.info('Rewriting %s transactions from invalid block %s',
len(invalid_block.transactions), invalid_block.id)
for tx in invalid_block.transactions:
self.bigchain.write_transaction(tx)
return invalid_block
def create():
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
# Digital Asset Definition (e.g. bicycle)
asset = Asset(data={
"bicycle": {
"manufacturer": "bkfab",
"serial_number": "abcd1234"
}
})
# Metadata Definition
metadata = {'planet': 'earth'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
tx = Transaction.create([alice.public_key], [([alice.public_key], 1)],
metadata=metadata,
asset=asset)
# sign with private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
b.write_transaction(tx)
# wait 2 sec
sleep(2)
# get tx by id
tx = b.get_transaction(tx_id)
return tx.to_dict()
class Election:
"""Election class."""
def __init__(self, events_queue=None):
self.bigchain = Bigchain()
self.events_queue = events_queue
def check_for_quorum(self, next_vote):
"""Checks if block has enough invalid votes to make a decision
Args:
next_vote: The next vote.
"""
try:
block_id = next_vote['vote']['voting_for_block']
node = next_vote['node_pubkey']
except KeyError:
return
next_block = self.bigchain.get_block(block_id)
result = self.bigchain.block_election(next_block)
self.handle_block_events(result, block_id)
if result['status'] == self.bigchain.BLOCK_INVALID:
return Block.from_dict(next_block)
# Log the result
if result['status'] != self.bigchain.BLOCK_UNDECIDED:
msg = 'node:%s block:%s status:%s' % \
(node, block_id, result['status'])
# Extra data can be accessed via the log formatter.
# See logging.dictConfig.
logger_results.debug(msg, extra={
'current_vote': next_vote,
'election_result': result,
})
def requeue_transactions(self, invalid_block):
"""Liquidates transactions from invalid blocks so they can be processed again
"""
logger.info('Rewriting %s transactions from invalid block %s',
len(invalid_block.transactions),
invalid_block.id)
for tx in invalid_block.transactions:
self.bigchain.write_transaction(tx)
return invalid_block
def handle_block_events(self, result, block_id):
if self.events_queue:
if result['status'] == self.bigchain.BLOCK_UNDECIDED:
return
elif result['status'] == self.bigchain.BLOCK_INVALID:
event_type = EventTypes.BLOCK_INVALID
elif result['status'] == self.bigchain.BLOCK_VALID:
event_type = EventTypes.BLOCK_VALID
event = Event(event_type, self.bigchain.get_block(block_id))
self.events_queue.put(event)
def merge_utxo(alicepub, alicepriv, include_spent):
asset = Asset(data={
"bicycle": {
"manufacturer": "bkfab",
"serial_number": "abcd1234"
}
},
data_id="334cd061-846b-4213-bd25-588e951def5f")
metadata = {'planet': 'earth'}
b = Bigchain()
utxo = b.get_outputs_filtered_not_include_freeze(alicepub, include_spent)
for u in utxo:
# print(u)
u.pop('details')
print('userA unspent asset:')
print(json.dumps(utxo, indent=4))
inputs = []
balance = 0
utxo = b.get_outputs_filtered_not_include_freeze(alicepub, include_spent)
for i in utxo:
f = Fulfillment.from_dict({
'fulfillment': i['details'],
'input': {
'cid': i['cid'],
'txid': i['txid'],
},
'owners_before': [alicepub],
})
inputs.append(f)
balance += i['amount']
length = len(utxo)
if balance <= 0:
print('No need to merge, because of lack of balance')
elif length <= 1:
print('No need to merge, because utxo len = 1')
else:
tx = Transaction.transfer(inputs, [([alicepub], balance)],
metadata=metadata,
asset=asset)
tx = tx.sign([alicepriv])
tx_id = tx.to_dict()['id']
# write to backlog
b.write_transaction(tx)
# wait 2 sec
print("========userA merge multi-asset========")
print("========wait for block and vote...========")
sleep(5)
# get tx by id
tx = b.get_transaction(tx_id)
print("merge txid:" + tx.to_dict()['id'])
utxo = b.get_outputs_filtered_not_include_freeze(alicepub, include_spent)
for u in utxo:
# print(u)
u.pop('details')
print('userA unspent asset:')
print(json.dumps(utxo, indent=4))
def create_write_transaction(tx_left):
b = Bigchain()
while tx_left > 0:
# use uuid to prevent duplicate transactions (transactions with the same hash)
tx = b.create_transaction(b.me, b.me, None, 'CREATE',
payload={'msg': str(uuid.uuid4())})
tx_signed = b.sign_transaction(tx, b.me_private)
b.write_transaction(tx_signed)
tx_left -= 1
def test_full_pipeline(monkeypatch, user_pk):
from bigchaindb.backend import query
from bigchaindb.models import Transaction
CONFIG = {
'keyring': ['aaa', 'bbb'],
'backlog_reassign_delay': 0.01
}
config_utils.update_config(CONFIG)
b = Bigchain()
original_txs = {}
original_txc = []
monkeypatch.setattr('time.time', lambda: 1)
for i in range(100):
tx = Transaction.create([b.me], [([user_pk], 1)],
metadata={'msg': random.random()})
tx = tx.sign([b.me_private])
original_txc.append(tx.to_dict())
b.write_transaction(tx)
original_txs = list(query.get_stale_transactions(b.connection, 0))
original_txs = {tx['id']: tx for tx in original_txs}
assert len(original_txs) == 100
monkeypatch.undo()
inpipe = Pipe()
# Each time the StaleTransactionMonitor pipeline runs, it reassigns
# all eligible transactions. Passing this inpipe prevents that from
# taking place more than once.
inpipe.put(())
outpipe = Pipe()
pipeline = stale.create_pipeline(backlog_reassign_delay=1,
timeout=1)
pipeline.setup(indata=inpipe, outdata=outpipe)
pipeline.start()
# to terminate
for _ in range(100):
outpipe.get()
pipeline.terminate()
assert len(list(query.get_stale_transactions(b.connection, 0))) == 100
reassigned_txs = list(query.get_stale_transactions(b.connection, 0))
# check that every assignment timestamp has increased, and every tx has a new assignee
for reassigned_tx in reassigned_txs:
assert reassigned_tx['assignment_timestamp'] > original_txs[reassigned_tx['id']]['assignment_timestamp']
assert reassigned_tx['assignee'] != original_txs[reassigned_tx['id']]['assignee']
def mint_coin(user_pk):
b = Bigchain()
coin_id = uuid.uuid4()
for i in range(10):
payload = {
'coin_id': str(coin_id),
'coin_share': str(i)
}
tx = b.create_transaction(b.me, user_pk, None, 'CREATE', payload=payload)
tx_signed = b.sign_transaction(tx, b.me_private)
b.write_transaction(tx_signed)
print('MINT {} {} {}'.format(tx['id'], coin_id, i))
def transfer_coin(user_vk, user_sk, coin_id):
b = Bigchain()
coins = get_owned_coins(user_vk)
if coin_id in coins.keys():
for tx in coins[coin_id]:
tx_input = {'txid': tx['id'], 'cid': 0}
tx_transfer = b.create_transaction(user_vk, b.me, tx_input, 'TRANSFER',
payload=tx['transaction']['data']['payload'])
tx_transfer_signed = b.sign_transaction(tx_transfer, user_sk)
b.write_transaction(tx_transfer_signed)
print('TRANSFER {} {} {}'.format(tx_transfer_signed['id'],
coin_id, tx['transaction']['data']['payload']['coin_share']))
def mint_coin(user_pk):
b = Bigchain()
coin_id = uuid.uuid4()
for i in range(10):
payload = {'coin_id': str(coin_id), 'coin_share': str(i)}
tx = b.create_transaction(b.me,
user_pk,
None,
'CREATE',
payload=payload)
tx_signed = b.sign_transaction(tx, b.me_private)
b.write_transaction(tx_signed)
print('MINT {} {} {}'.format(tx['id'], coin_id, i))
def requeue_transactions(self):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
while True:
invalid_block = self.q_invalid_blocks.get()
# poison pill
if invalid_block == 'stop':
logger.info('clean exit')
return
b = Bigchain()
for tx in invalid_block['block']['transactions']:
b.write_transaction(tx)
def requeue_transactions(self):
"""
Liquidates transactions from invalid blocks so they can be processed again
"""
while True:
invalid_block = self.q_invalid_blocks.get()
# poison pill
if invalid_block == 'stop':
logger.info('clean exit')
return
b = Bigchain()
for tx in invalid_block['block']['transactions']:
b.write_transaction(tx)
def pay_royalties(label_vk, artist_vk, tx, label_share=7, artist_share=3):
b = Bigchain()
payload = tx['transaction']['data']['payload']
tx_input = {'txid': tx['id'], 'cid': 0}
if int(payload['coin_share']) < artist_share:
new_owner = artist_vk
else:
new_owner = label_vk
tx_royalties = b.create_transaction(b.me, new_owner, tx_input, 'TRANSFER', payload=payload)
tx_royalties_signed = b.sign_transaction(tx_royalties, b.me_private)
b.write_transaction(tx_royalties_signed)
print('ROYALTIES {} {} {} {}'.format(tx_royalties['id'], payload['coin_id'],
payload['coin_share'], new_owner))
def transfer_coin(user_vk, user_sk, coin_id):
b = Bigchain()
coins = get_owned_coins(user_vk)
if coin_id in coins.keys():
for tx in coins[coin_id]:
tx_input = {'txid': tx['id'], 'cid': 0}
tx_transfer = b.create_transaction(
user_vk,
b.me,
tx_input,
'TRANSFER',
payload=tx['transaction']['data']['payload'])
tx_transfer_signed = b.sign_transaction(tx_transfer, user_sk)
b.write_transaction(tx_transfer_signed)
print('TRANSFER {} {} {}'.format(
tx_transfer_signed['id'], coin_id,
tx['transaction']['data']['payload']['coin_share']))
def pay_royalties(label_vk, artist_vk, tx, label_share=7, artist_share=3):
b = Bigchain()
payload = tx['transaction']['data']['payload']
tx_input = {'txid': tx['id'], 'cid': 0}
if int(payload['coin_share']) < artist_share:
new_owner = artist_vk
else:
new_owner = label_vk
tx_royalties = b.create_transaction(b.me,
new_owner,
tx_input,
'TRANSFER',
payload=payload)
tx_royalties_signed = b.sign_transaction(tx_royalties, b.me_private)
b.write_transaction(tx_royalties_signed)
print('ROYALTIES {} {} {} {}'.format(tx_royalties['id'],
payload['coin_id'],
payload['coin_share'], new_owner))
prdct_pubkey = base58.b58encode(prdct_pubkey)
# Define a private and public key representing the producer
prdusr_privkey, prdusr_pubkey = crypto.generate_key_pair()
# Define a private and public key representing a future product owner
ownr_privkey, ownr_pubkey = crypto.generate_key_pair()
# Create a multisig transaction including the three pre-produced public keys signed with
# master key of the BigchainDB instance holder
tx_msig = b.create_transaction(b.me, [prdct_pubkey, prdusr_pubkey, ownr_pubkey], None, 'CREATE')
# Sign the multisig
tx_msig_signed = b.sign_transaction(tx_msig, b.me_private)
# Write the signed multig transaction to the federated BigchainDB
# Results in {'deleted': 0, 'unchanged': 0, 'errors': 0, 'skipped': 0, 'inserted': 1, 'replaced': 0}
b.write_transaction(tx_msig_signed)
# Check the uploaded multisig transaction
tx_msig_retrieved = b.get_transaction(tx_msig_signed['id'])
"""
Has to result in JSON string like :
{'transaction': {'timestamp': '1481491650', 'operation': 'CREATE', 'data': {'uuid': 'f75d216a-1966-4cef-8de4-71ce57563aae', 'payload': None}, 'conditions': [{'cid': 0, 'condition': {'details': {'type_id': 2, 'subfulfillments': [{'signature': None, 'weight': 1, 'public_key': '5GjT173hXbwm9R5x2Sk4y6NgeqCCA2JrwdyZdzKPvC6a', 'type_id': 4, 'type': 'fulfillment', 'bitmask': 32}, {'signature': None, 'weight': 1, 'public_key': '3NdRQzR9x1vuPJmHcKFJzFZnErjs3NS9LVCzU5UWDrQt', 'type_id': 4, 'type': 'fulfillment', 'bitmask': 32}, {'signature': None, 'weight': 1, 'public_key': 'BSoNeHng8wc1CJXF4gwTKZYQDuL6AXKuNuisQ57VZDuo', 'type_id': 4, 'type': 'fulfillment', 'bitmask': 32}], 'type': 'fulfillment', 'threshold': 3, 'bitmask': 41}, 'uri': 'cc:2:29:Qy_H1gssES5-IxGKOJv-pNtUDEz17TmGAlJn6rDkriE:306'}, 'new_owners': ['5GjT173hXbwm9R5x2Sk4y6NgeqCCA2JrwdyZdzKPvC6a', '3NdRQzR9x1vuPJmHcKFJzFZnErjs3NS9LVCzU5UWDrQt', 'BSoNeHng8wc1CJXF4gwTKZYQDuL6AXKuNuisQ57VZDuo']}], 'fulfillments': [{'current_owners': ['5sShezEyMTWsSM7D4mHVLBMksEr3AxNdP7RB9XjgEm59'], 'input': None, 'fid': 0, 'fulfillment': 'cf:4:SFrZKwost0FPXd7KN210xFM47KHIweSunvI5Ue6LkljQADZJ9AidR9JdR_B8rN-PX_qbz5meeGTJdf8oJPxa4rR3K-_eTh6yLNYnTeBjA_i4N9cE3rukkAzZGpGV1FwK'}]}, 'id': 'bd36ee938e6b5b1cf1b54eed2537c38445eaad672d3c882288cfc01f22b56a14', 'version': 1}
"""
# create a test user
testuser1_priv, testuser1_pub = crypto.generate_key_pair()
# define a digital asset data payload
digital_asset_payload = {'msg': 'Hello BigchainDB!'}
# a create transaction uses the operation `CREATE` and has no inputs
tx = b.create_transaction(b.me, testuser1_pub, None, 'CREATE', payload=digital_asset_payload)
# all transactions need to be signed by the user creating the transaction
tx_signed = b.sign_transaction(tx, b.me_private)
# write the transaction to the bigchain
# the transaction will be stored in a backlog where it will be validated,
# included in a block, and written to the bigchain
b.write_transaction(tx_signed)
sleep(8)
"""
Read the Creation Transaction from the DB
"""
tx_retrieved = b.get_transaction(tx_signed['id'])
print(json.dumps(tx_retrieved, sort_keys=True, indent=4, separators=(',', ':')))
print(testuser1_pub)
print(b.me)
print(tx_retrieved['id'])
def create_transfer():
##################################################### 1.CREATE
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
# Digital Asset Definition (e.g. bicycle)
asset = Asset(data={"bicycle": {"manufacturer": "bkfab", "serial_number": "abcd1234"}})
# Metadata Definition
metadata = {'planet': 'earth'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
tx = Transaction.create([alice.public_key], [([alice.public_key], 1)], metadata=metadata, asset=asset)
print(" ")
print("1.tx_create asset id : alice-----bicycle(", tx.to_dict()['transaction']['asset']['id'], ")----->alice")
print("1.tx_create tx id : ", tx.to_dict()['id'])
# sign with alice's private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
print("1.tx_create db response : ", b.write_transaction(tx))
# wait 2 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("1.tx_create query : ", tx)
# print("tx1_id:"+tx.to_dict()['id'])
print(" ")
##################################################### 2.TRANSFER
# inputs and asset [fake]
cid = 0
condition = tx.to_dict()['transaction']['conditions'][cid]
inputs = Fulfillment.from_dict({
'fulfillment': condition['condition']['details'],
'input': {
'cid': cid,
'txid': tx.to_dict()['id'],
},
'owners_before': [bob.public_key],
})
asset = Asset.from_dict(tx.to_dict()['transaction']['asset'])
# transfer
tx = Transaction.transfer([inputs], [([bob.public_key], 1)], asset)
print("2.tx_fake asset id : bob-----bicycle(", tx.to_dict()['transaction']['asset']['id'], ")----->bob")
print("2.tx_fake tx id : ", tx.to_dict()['id'])
# sign with bob's private key [fake]
tx = tx.sign([bob.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
print("2.tx_fake db response : ", b.write_transaction(tx))
# wait 2 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("2.tx_fake query : ", tx)
# print("tx2_id:"+tx.to_dict()['id'])
print(" ")
payload_A = {
"msg" : "node send -50 to A,is -50",
"issue" : "cost",
"category" : "currency",
"amount" : 50,
"asset":"",
# final owner 's account
"account":300,
"previous":testuser1_last['txid'],
"trader":testuser2_pub
}
tx_create= b.create_transaction(b.me, testuser1_pub, None, 'CREATE', payload=payload_A)
tx_create_signed = b.sign_transaction(tx_create, b.me_private)
if b.is_valid_transaction(tx_create_signed):
b.write_transaction(tx_create_signed)
# node create transaction for b,
testuser2_last=b.get_owned_ids(testuser2_pub).pop()
payload_B = {
"msg" : "node send +50 to B,is +50",
"issue" : "earn",
"category" : "currency",
"amount" : 50,
"asset":"",
# final owner 's account
"account":400,
"previous":testuser2_last['txid'],
"trader":testuser1_pub
}
# "PRICE": "50" ,
# "QUANTITY": "50000" ,
# "SIDE": "S" ,
# "TYPE": "EQ"
# },
# ...]
data = []
with open('data.csv', 'r') as fid:
reader = csv.DictReader(fid)
for row in reader:
data.append(row)
# generate distinct users from the CPTY1 column and assign keys
users = []
for user_name in set([d['CPTY1'] for d in data]):
sk, vk = b.generate_keys()
user = users.append(
{
'name': user_name,
'signing_key': sk,
'verifying_key': vk
}
)
# create assets on the blockchain with the payload and assign to the user
for asset in data:
user = [u for u in users if u['name'] == asset['CPTY1']][0]
tx = b.create_transaction(b.me, user['verifying_key'], None, 'CREATE', payload=asset)
tx_signed = b.sign_transaction(tx, b.me_private)
b.write_transaction(tx_signed)
def create_transfer():
##################################################### 1.CREATE
# Cryptographic Identities Generation
alice, bob, tom = generate_keypair(), generate_keypair(), generate_keypair(
)
asset = Asset(data={'money': 'RMB'},
data_id='20170628150000',
divisible=True)
metadata = {'planet': 'earth'}
tx = Transaction.create([alice.public_key], [([alice.public_key], 1000)],
metadata=metadata,
asset=asset)
print(" ")
print("1.tx_create asset id : alice-----money 1000(",
tx.to_dict()['transaction']['asset']['id'], ")----->alice")
print("1.tx_create tx id : ", tx.to_dict()['id'])
# sign with alice's private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
print("1.tx_create db response : ", b.write_transaction(tx))
# wait 4 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("1.tx_create query : ", tx)
# print("tx1_id:"+tx.to_dict()['id'])
print(" ")
##################################################### 2.TRANSFER
# inputs and asset
cid = 0
condition = tx.to_dict()['transaction']['conditions'][cid]
inputs = Fulfillment.from_dict({
'fulfillment':
condition['condition']['details'],
'input': {
'cid': cid,
'txid': tx.to_dict()['id'],
},
'owners_before':
condition['owners_after'],
})
asset = Asset.from_dict(tx.to_dict()['transaction']['asset'])
# transfer
tx = Transaction.transfer([inputs], [([bob.public_key], 300),
([alice.public_key], 700)], asset)
print("2.tx_transfer asset id : alice-----money 300(",
tx.to_dict()['transaction']['asset']['id'], ")----->bob")
print("2.tx_transfer tx id : ", tx.to_dict()['id'])
print("2.tx_transfer tx : ", tx.to_dict())
print(" ")
# sign with alice's private key
tx = tx.sign([alice.private_key])
# man in the middle attack, then write to backlog
tx.conditions[0].amount = 600
tx.conditions[1].amount = 400
print("3.tx_attack asset id : alice-----money 600(",
tx.to_dict()['transaction']['asset']['id'], ")----->tom")
print("3.tx_attack tx id : ", tx.to_dict()['id'])
print("3.tx_attack tx : ", tx.to_dict())
tx_id = tx.to_dict()['id']
b = Bigchain()
print("3.tx_attack db response : ", b.write_transaction(tx))
# wait 4 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("3.tx_attack query : ", tx)
print(" ")
class ChainQuery(object):
def __init__(self, host=None, port=None, dbname=None,pub_key=None,priv_key=None,keyring=[],
consensus_plugin=None):
self.host = host
self.port = port
self.dbname = dbname
self.conn =r.connect(host=host,port=port,db=dbname)
self.bigchain=Bigchain(host=host,port=port,dbname=dbname,public_key=pub_key,private_key=priv_key,keyring=keyring,consensus_plugin=consensus_plugin)
#test
def test(self):
tables=r.db('bigchain').table_list().run(self.conn)
#print(tables)
return tables
# create key_pair for user
def generate_key_pair(self):
return crypto.generate_key_pair()
# create asset
def create_asset(self,public_key, digital_asset_payload):
tx = self.bigchain.create_transaction(self.bigchain.me, public_key, None, 'CREATE', payload=digital_asset_payload)
tx_signed = self.bigchain.sign_transaction(tx, self.bigchain.me_private)
return self.bigchain.write_transaction(tx_signed)
# get transaction by payload_uuid
def getTxid_by_payload_uuid(self,payload_uuid):
cursor = r.table('bigchain') \
.get_all(payload_uuid, index='payload_uuid') \
.pluck({'block':{'transactions':'id'}}) \
.run(self.conn)
transactions = list(cursor)
return transactions
# get transaction by payload
def getTxid_by_payload(self,payload):
pass
# get currentowner of a payload(assert)
def getOwnerofAssert(self,payload):
return
# get one's assert
def get_owned_asserts(self,pub_key):
return
# if tx contains someone
def tx_contains_one(self,tx,one_pub):
for condition in tx['conditions']:
if one_pub in condition['new_owners']:
return True
for fullfillment in tx['fulfillments']:
if one_pub in fullfillment['current_owners']:
return True
# transfer assert to another, old_owner create this transaction,so need old_owner's pub/priv key.
def transfer_assert(self,old_owner_pub,old_owner_priv,new_owner_pub,tx_id):
tx_transfer=self.bigchain.create_transaction(old_owner_pub,new_owner_pub,tx_id,'TRANSFER')
tx_transfer_signed=self.bigchain.sign_transaction(tx_transfer,old_owner_priv)
#check if the transaction is valid
check=self.bigchain.is_valid_transaction(tx_transfer_signed)
if check:
self.bigchain.write_transaction(tx_transfer_signed)
else:
logger.info('this transaction is invalid.')
from bigchaindb import Bigchain
import writeout
import random
b = Bigchain()
random.seed(3)
for x in range(1,8):
# define a digital asset data payload
digital_asset_payload = {'choice': random.randint(0,100)}
# a create transaction uses the operation `CREATE` and has no inputs
priv, pub = writeout.importData("user"+str(x))
tx = b.create_transaction(b.me, pub, None, 'CREATE', payload=digital_asset_payload)
#tx = b.create_transaction(b.me, pub, None, 'CREATE')
# all transactions need to be signed by the user creating the transaction
tx_signed = b.sign_transaction(tx, b.me_private)
writeout.exportData(tx_signed, "user"+str(x)+"vote")
# write the transaction to the bigchain
# the transaction will be stored in a backlog where it will be validated,
# included in a block, and written to the bigchain
print(b.write_transaction(tx_signed))
def create_double():
##################################################### 1.CREATE
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
# Digital Asset Definition (e.g. money)
asset = Asset(data={'money': 'RMB'},
data_id='20170628150000',
divisible=True)
# Metadata Definition
metadata = {'planet': 'earth'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
tx = Transaction.create([alice.public_key], [([alice.public_key], 100),
([alice.public_key], 100)],
metadata=metadata,
asset=asset)
print(" ")
print("1.tx_create asset id : alice-----money(",
tx.to_dict()['transaction']['asset']['id'], ")----->alice")
print("1.tx_create tx id : ", tx.to_dict()['id'])
# sign with alice's private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
print("1.tx_create db response : ", b.write_transaction(tx))
# wait 2 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
unspent = b.get_outputs_filtered_not_include_freeze(
alice.public_key, False)
print("1.tx_create query : ", tx)
print("1.tx_create unspent : ", unspent)
print(" ")
##################################################### 2.TRANSFER
# inputs and asset
cid = 0
condition = tx.to_dict()['transaction']['conditions'][cid]
inputs = Fulfillment.from_dict({
'fulfillment':
condition['condition']['details'],
'input': {
'cid': cid,
'txid': tx.to_dict()['id'],
},
'owners_before': [alice.public_key],
})
asset = Asset.from_dict(tx.to_dict()['transaction']['asset'])
# transfer
tx1 = Transaction.transfer([inputs], [([bob.public_key], 100)], asset)
print("2.tx_transfer asset id : alice-----money(",
tx1.to_dict()['transaction']['asset']['id'], ")----->bob")
print("2.tx_transfer tx id : ", tx1.to_dict()['id'])
# sign with alice's private key
tx1 = tx1.sign([alice.private_key])
tx1_id = tx1.to_dict()['id']
# write to backlog
b = Bigchain()
print("2.tx_transfer db response : ", b.write_transaction(tx1))
# wait 2 sec
sleep(delay)
# get tx by id
tx1 = b.get_transaction(tx1_id)
block = list(b.get_blocks_status_containing_tx(tx1_id).keys())[0]
votes = list(b.backend.get_votes_by_block_id(block))
votes_cast = [vote['vote']['is_block_valid'] for vote in votes]
election = b.get_blocks_status_containing_tx(tx1_id)
print("2.tx_transfer query : ", tx1)
print("2.tx_transfer block : ", block)
print("2. votes : ", votes)
print("2. votes_cast : ", votes_cast)
print("2. election : ", election)
print(" ")
##################################################### 3.INTERVAL
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
# Digital Asset Definition (e.g. money)
asset = Asset(data={'money': 'RMB'},
data_id='20170628150000',
divisible=True)
# Metadata Definition
metadata = {'planet': 'earth'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
txi = Transaction.create([alice.public_key], [([alice.public_key], 100),
([alice.public_key], 100)],
metadata=metadata,
asset=asset)
print(" ")
print("1.tx_create asset id : alice-----money(",
tx.to_dict()['transaction']['asset']['id'], ")----->alice")
print("1.tx_create tx id : ", txi.to_dict()['id'])
# sign with alice's private key
txi = txi.sign([alice.private_key])
tx_id = txi.to_dict()['id']
# write to backlog
b = Bigchain()
print("1.tx_create db response : ", b.write_transaction(tx))
# wait 2 sec
sleep(delay)
##################################################### 3.TRANSFER
# inputs and asset [double spend]
cid = 1
condition = tx.to_dict()['transaction']['conditions'][cid]
inputs = Fulfillment.from_dict({
'fulfillment':
condition['condition']['details'],
'input': {
'cid': cid,
'txid': tx.to_dict()['id'],
},
'owners_before': [alice.public_key],
})
asset = Asset.from_dict(tx.to_dict()['transaction']['asset'])
# transfer
tx1 = Transaction.transfer([inputs], [([bob.public_key], 100)], asset)
print("3.tx_double asset id : alice-----money(",
tx1.to_dict()['transaction']['asset']['id'], ")----->bob")
print("3.tx_double tx id : ", tx1.to_dict()['id'])
# sign with alice's private key
tx1 = tx1.sign([alice.private_key])
tx1_id = tx1.to_dict()['id']
# write to backlog
b = Bigchain()
print("3.tx_double db response : ", b.write_transaction(tx1))
# wait 2 sec
sleep(delay)
# get tx by id
tx1 = b.get_transaction(tx1_id)
block = list(b.get_blocks_status_containing_tx(tx1_id).keys())[0]
votes = list(b.backend.get_votes_by_block_id(block))
votes_cast = [vote['vote']['is_block_valid'] for vote in votes]
election = b.get_blocks_status_containing_tx(tx1_id)
print("3.tx_transfer query : ", tx1)
print("3.tx_transfer block : ", block)
print("3. votes : ", votes)
print("3. votes_cast : ", votes_cast)
print("3. election : ", election)
print(" ")
b = Bigchain()
govt_priv, govt_pub = writeout.importData("govt")
for x in range(1,8):
priv, pub = writeout.importData("user"+str(x))
tx_signed = writeout.importData("user"+str(x)+"vote")
tx_retrieved = b.get_transaction(tx_signed['id'])
print(tx_retrieved)
# create a transfer transaction
tx_transfer = b.create_transaction(pub, govt_pub, tx_retrieved['id'], 'TRANSFER')
print(tx_transfer)
# sign the transaction
tx_transfer_signed = b.sign_transaction(tx_transfer, priv)
print(tx_transfer_signed)
# write the transaction
b.write_transaction(tx_transfer_signed)
# check if the transaction is already in the bigchain
tx_transfer_retrieved = b.get_transaction(tx_transfer_signed['id'])
print(tx_transfer_retrieved)
data = b.validate_transaction(tx_transfer_signed)
print(data)
def transactions(request, format=None):
'''
URL:
transactions/
Use for:
get or create bill transaction
Para:
GET:
field - filter every json dict
operation - CREATE or TRANSFER
limit - limit list length, less than 100
sortby - sort by specified field, for timestamp
order - the order for sort, asc or des, default asc
receive_pubk - public key to get all transactions`id by receive,
do not support some paras like limit
origin_pubk - public key to get all transactions`id by origin
POST:
origin_pubk - transaction origin public key, if no this value, will
create one CREATE transaction
origin_prik - transaction origin private key, if no this value, will
create one CREATE transaction
pre_txid - previous transaction id
receive_pubk - transaction receive public key
data - data json string
'''
if request.method == 'GET':
# get paras
fields = request.GET.getlist('field')
limit = request.GET.get('limit', None)
sortby = request.GET.get('sortby', None)
order = request.GET.get('order', None)
receive_pubk = request.GET.get('receive_pubk', None)
origin_pubk = request.GET.get('origin_pubk', None)
operation = request.GET.get('operation', None)
# make sort function for rethinkdb driver
sort_func = None
if sortby != None:
sort_func = lambda ts: ts['transaction'][sortby]
# make filter
filtes_funcs = []
if receive_pubk != None:
filtes_funcs.append(lambda x: x['transaction'].contains(lambda x: \
x['conditions'].contains(lambda x: x['new_owners'].\
contains(receive_pubk))))
elif origin_pubk != None:
filtes_funcs.append(lambda x: x['transaction'].contains(lambda x: \
x['fulfillments'].contains(lambda x: x['current_owners'].\
contains(origin_pubk))))
if operation != None:
filtes_funcs.append(lambda t: t.contains(\
lambda x: x['transaction']['operation'] == operation))
# get datas
datas = rdb_select(sortby=sort_func,
order=order,
filtes=filtes_funcs,
keys=['block', 'transactions'],
limit=limit)
# can`t pluck, limit this data by rethinkdb driver, handle with hand
# limit
try:
limit = int(limit)
except TypeError:
limit = 100
limit = min(100, limit) # limit less than 100
# return datas by max operation
if limit == 1 and sortby != None:
return Response(field_filter(datas[0], fields))
# return normal datas, it`s format willbe [[d1, ...], [d2, ..], ...]
# change format to [d1, d2, d3...]
ans = []
for alist in datas:
for data in alist:
if len(ans) >= limit:
return Response(ans)
ans.append(field_filter(data, fields)) # filter data
return Response(ans)
elif request.method == 'POST':
# get paras
origin_pubk = request.POST.get('origin_pubk', None)
origin_prik = request.POST.get('origin_prik', None)
pre_txid = request.POST.get('pre_txid', None)
receive_pubk = request.POST.get('receive_pubk', None)
data = request.POST.get('data', '{}')
# make sure paras
receive_prik = ''
bdb_input = None
bdb_type = 'CREATE'
bdb = Bigchain()
try:
data = json.loads(data) # json string to json data
except JSONDecodeError:
return error(400, 'Wrong json string format')
# bill data format checker
left_money = 0
pre_data = None
billm = 'Bill_amount_money'
bill = 'bill'
if billm not in data.keys():
return error(400, 'Wrong data format')
# make sure paras
if receive_pubk == None: # create a pair
receive_prik, receive_pubk = crypto.generate_key_pair()
if origin_pubk == None: # create transaction
origin_pubk = bdb.me
origin_prik = bdb.me_private
else: # transfer transaction
bdb_type = 'TRANSFER'
if origin_prik == None:
return error(400, 'need private key')
if pre_txid == None:
return error(400, 'need pre_txid when transfer')
# get previous bill, and check it
pre_tx = bdb.get_transaction(pre_txid)
if pre_tx == None:
return error(400, 'This pre_txid does not exist')
# make input, in our case, the key 'cid' will always be 0
bdb_input = {'cid': 0, 'txid': pre_txid}
# check bdb_input belong origin
if bdb_input not in bdb.get_owned_ids(origin_pubk):
return error(400, 'This pre_txid does not belong the origin')
# money check
pre_data = pre_tx['transaction']['data']['payload']
pre_money = pre_data[bill][billm]
now_money = data[billm]
if now_money > pre_money:
return error(400, 'money to less')
left_money = pre_money - now_money
# start transaction
tx = bdb.create_transaction(origin_pubk,
receive_pubk,
bdb_input,
bdb_type,
payload={
'pre_txid': pre_txid,
'bill': data
})
bdb.write_transaction(bdb.sign_transaction(tx, origin_prik))
# create new bill with left money
if pre_data != None:
# change data
pre_data[bill][billm] = left_money
pre_data['pre_txid'] = pre_txid
ltx = bdb.create_transaction(bdb.me,
origin_pubk,
None,
'CREATE',
payload=pre_data)
bdb.write_transaction(bdb.sign_transaction(ltx, bdb.me_private))
return Response({
'txid': tx['id'],
'receive_pubk': receive_pubk,
'receive_prik': receive_prik
})
print("testuser1_priv:" + testuser1_priv)
print("testuser1_pub:" + testuser1_pub)
payload = {
"msg": "first charge for user A",
"issue": "charge",
"category": "currency",
"amount": 300,
"asset": "",
"account": 0,
"previous": "genesis",
"trader": ""
}
tx = b.create_transaction(b.me, testuser1_pub, None, 'CREATE', payload=payload)
tx_signed = b.sign_transaction(tx, b.me_private)
if b.is_valid_transaction(tx_signed):
b.write_transaction(tx_signed)
print(tx_signed)
# user B
testuser2_priv, testuser2_pub = crypto.generate_key_pair()
print("testuser2_priv:" + testuser2_priv)
print("testuser2_pub:" + testuser2_pub)
payload2 = {
"msg": "first charge for user B",
"issue": "charge",
"category": "currency",
"amount": 400,
"asset": "",
"account": 0,
"previous": "genesis",
"trader": ""
from bigchaindb import Bigchain
import writeout
import random
b = Bigchain()
random.seed(3)
for x in range(1, 8):
# define a digital asset data payload
digital_asset_payload = {'choice': random.randint(0, 100)}
# a create transaction uses the operation `CREATE` and has no inputs
priv, pub = writeout.importData("user" + str(x))
tx = b.create_transaction(b.me,
pub,
None,
'CREATE',
payload=digital_asset_payload)
#tx = b.create_transaction(b.me, pub, None, 'CREATE')
# all transactions need to be signed by the user creating the transaction
tx_signed = b.sign_transaction(tx, b.me_private)
writeout.exportData(tx_signed, "user" + str(x) + "vote")
# write the transaction to the bigchain
# the transaction will be stored in a backlog where it will be validated,
# included in a block, and written to the bigchain
print(b.write_transaction(tx_signed))
def create_transfer(alicepub, alicepriv, include_spent):
##################################################### 1.CREATE
# Cryptographic Identities Generation
# alice, bob = generate_keypair(), generate_keypair()
# Digital Asset Definition (e.g. bicycle)
asset = Asset(data={
"bicycle": {
"manufacturer": "bkfab",
"serial_number": "abcd1234"
}
},
data_id="334cd061-846b-4213-bd25-588e951def5f")
# Metadata Definition
metadata = {'planet': 'earth'}
# create trnsaction TODO : owners_before might be node_pubkey in v0.8.0
tx = Transaction.create([alicepub], [([alicepub], 100)],
metadata=metadata,
asset=asset)
# sign with alice's private key
tx = tx.sign([alicepriv])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
b.write_transaction(tx)
print("========create 100 asset for userA========")
print("========wait for block and vote...========")
# wait 2 sec
sleep(5)
# get tx by id
tx = b.get_transaction(tx_id)
print("create 100 asset tx1_id:" + tx.to_dict()['id'])
##################################################### 3.UTXO
# inputs and asset
utxo = b.get_outputs_filtered_not_include_freeze(alicepub, include_spent)
for u in utxo:
# print(u)
u.pop('details')
print('userA unspent asset:')
print(json.dumps(utxo, indent=4))
# print(json.load(utxo))
##################################################### 2.Freeze
# inputs and asset
cid = 0
condition = tx.to_dict()['transaction']['conditions'][cid]
inputs = Fulfillment.from_dict({
'fulfillment':
condition['condition']['details'],
'input': {
'cid': cid,
'txid': tx.to_dict()['id'],
},
'owners_before':
condition['owners_after'],
})
asset = Asset.from_dict(tx.to_dict()['transaction']['asset'])
# transfer
tx = Transaction.freeze_asset([inputs], [([alicepub], 90, True),
([alicepub], 10, False)], asset)
# sign with alice's private key
tx = tx.sign([alicepriv])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
b.write_transaction(tx)
print("========freeze 90 asset for userA ========")
print("========wait for block and vote...========")
# wait 2 sec
sleep(5)
# get tx by id
tx = b.get_transaction(tx_id)
print("freeze 90 asset tx2_id:" + tx.to_dict()['id'])
##################################################### 3.UTXO
# inputs and asset
utxo = b.get_outputs_filtered_not_include_freeze(alicepub, include_spent)
for u in utxo:
# print(u)
u.pop('details')
print('userA unspent asset:')
print(json.dumps(utxo, indent=4))
def create_transfer(public_key, private_key, include_spent):
asset = Asset(data={
"bicycle": {
"manufacturer": "bkfab",
"serial_number": "abcd1234"
}
},
data_id="334cd061-846b-4213-bd25-588e951def5f")
##################################################### 1.getfreeze
b = Bigchain()
utxo_freeze = b.get_freeze_outputs_only(public_key)
# for u in utxo_freeze:
# # print(u)
# u.pop('details')
print('userA frozen asset:')
print(json.dumps(utxo_freeze, indent=4))
# print(json.load(utxo))
#
# ##################################################### 2.Unfreeze
inputs = []
balance = 0
for i in utxo_freeze:
f = Fulfillment.from_dict({
'fulfillment': i['details'],
'input': {
'cid': i['cid'],
'txid': i['txid'],
},
'owners_before': [public_key],
})
inputs.append(f)
balance += i['amount']
# create trnsaction
tx = Transaction.freeze_asset(inputs, [([public_key], balance, False)],
asset)
# # inputs and asset
# sign with alice's private key
tx = tx.sign([private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
b.write_transaction(tx)
print("unfreeze asset for userA")
print("========wait for block and vote...========")
# wait 2 sec
sleep(5)
# get tx by id
tx = b.get_transaction(tx_id)
print("unfreeze asset tx1_id:" + tx.to_dict()['id'])
##################################################### 3.UTXO
# inputs and asset
utxo = b.get_outputs_filtered_not_include_freeze(public_key, include_spent)
for u in utxo:
# print(u)
u.pop('details')
print('userA unspent asset:')
print(json.dumps(utxo, indent=4))
class ChainQuery(object):
def __init__(
self, host=None, port=None, dbname=None, pub_key=None, priv_key=None, keyring=[], consensus_plugin=None
):
self.host = host
self.port = port
self.dbname = dbname
self.conn = r.connect(host=host, port=port, db=dbname)
self.bigchain = Bigchain(
host=host,
port=port,
dbname=dbname,
public_key=pub_key,
private_key=priv_key,
keyring=keyring,
consensus_plugin=consensus_plugin,
)
# test
def test(self):
tables = r.db("bigchain").table_list().run(self.conn)
# print(tables)
return tables
# create key_pair for user
def generate_key_pair(self):
return crypto.generate_key_pair()
# create asset
def create_asset(self, public_key, digital_asset_payload):
tx = self.bigchain.create_transaction(
self.bigchain.me, public_key, None, "CREATE", payload=digital_asset_payload
)
tx_signed = self.bigchain.sign_transaction(tx, self.bigchain.me_private)
return self.bigchain.write_transaction(tx_signed)
# get transaction by payload_uuid
def getTxid_by_payload_uuid(self, payload_uuid):
cursor = (
r.table("bigchain")
.get_all(payload_uuid, index="payload_uuid")
.pluck({"block": {"transactions": "id"}})
.run(self.conn)
)
transactions = list(cursor)
return transactions
# get transaction by payload
def getTxid_by_payload(self, payload):
pass
# get currentowner of a payload(assert)
def getOwnerofAssert(self, payload):
return
# get one's assert
def get_owned_asserts(self, pub_key):
return
# if tx contains someone
def tx_contains_one(self, tx, one_pub):
for condition in tx["conditions"]:
if one_pub in condition["new_owners"]:
return True
for fullfillment in tx["fulfillments"]:
if one_pub in fullfillment["current_owners"]:
return True
# transfer assert to another, old_owner create this transaction,so need old_owner's pub/priv key.
def transfer_assert(self, old_owner_pub, old_owner_priv, new_owner_pub, tx_id):
tx_transfer = self.bigchain.create_transaction(old_owner_pub, new_owner_pub, tx_id, "TRANSFER")
tx_transfer_signed = self.bigchain.sign_transaction(tx_transfer, old_owner_priv)
# check if the transaction is valid
check = self.bigchain.is_valid_transaction(tx_transfer_signed)
if check:
self.bigchain.write_transaction(tx_transfer_signed)
else:
logger.info("this transaction is invalid.")
def create_transfer():
##################################################### 1.CREATE
# Cryptographic Identities Generation
alice, bob, tom = generate_keypair(), generate_keypair(), generate_keypair()
asset = Asset(data={"bicycle": {"manufacturer": "bkfab", "serial_number": "abcd1234"}})
metadata = {'planet': 'earth'}
tx = Transaction.create([alice.public_key], [([alice.public_key], 1)], metadata=metadata, asset=asset)
print(" ")
print("1.tx_create asset id : alice-----bicycle(", tx.to_dict()['transaction']['asset']['id'], ")----->alice")
print("1.tx_create tx id : ", tx.to_dict()['id'])
# sign with alice's private key
tx = tx.sign([alice.private_key])
tx_id = tx.to_dict()['id']
# write to backlog
b = Bigchain()
print("1.tx_create db response : ", b.write_transaction(tx))
# wait 4 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("1.tx_create query : ", tx)
# print("tx1_id:"+tx.to_dict()['id'])
print(" ")
##################################################### 2.TRANSFER
# inputs and asset
cid = 0
condition = tx.to_dict()['transaction']['conditions'][cid]
inputs = Fulfillment.from_dict({
'fulfillment': condition['condition']['details'],
'input': {
'cid': cid,
'txid': tx.to_dict()['id'],
},
'owners_before': condition['owners_after'],
})
asset = Asset.from_dict(tx.to_dict()['transaction']['asset'])
# transfer
tx = Transaction.transfer([inputs], [([bob.public_key], 1)], asset)
print("2.tx_transfer asset id : alice-----bicycle(", tx.to_dict()['transaction']['asset']['id'], ")----->bob")
print("2.tx_transfer tx id : ", tx.to_dict()['id'])
print("2.tx_transfer tx : ", tx.to_dict())
print(" ")
# sign with alice's private key
tx = tx.sign([alice.private_key])
# man in the middle attack, then write to backlog
tx.conditions[0].owners_after = [tom.public_key]
print("3.tx_attack asset id : alice-----bicycle(", tx.to_dict()['transaction']['asset']['id'], ")----->tom")
print("3.tx_attack tx id : ", tx.to_dict()['id'])
print("3.tx_attack tx : ", tx.to_dict())
tx_id = tx.to_dict()['id']
b = Bigchain()
print("3.tx_attack db response : ", b.write_transaction(tx))
# wait 4 sec
sleep(delay)
# get tx by id
tx = b.get_transaction(tx_id)
print("3.tx_attack query : ", tx)
print(" ")