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))
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()
def get():
# Cryptographic Identities Generation
alice, bob = generate_keypair(), generate_keypair()
print(" ")
# 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],
metadata=metadata,
asset=asset)
# sign with private key
tx = tx.sign([alice.private_key])
# get tx by id
b = Bigchain()
block = b.create_block([tx])
block_voters = block.to_dict()['block']['voters']
print(block_voters)
tx_id = '2cb004cad29c0b79872646558f8c867a4c0aecbc4997f0917'
tx = b.get_transaction(tx_id)
print(
"block status : ",
b.block_election_status(
'2257384a0cee8cf98bd82c3142dd38eee5c268c124b5b357b773b8c6c1fa1221',
block_voters))
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))
class Block:
"""This class encapsulates the logic to create blocks.
Note:
Methods of this class will be executed in different processes.
"""
def __init__(self):
"""Initialize the Block creator"""
self.bigchain = Bigchain()
self.txs = []
def filter_tx(self, tx):
"""Filter a transaction.
Args:
tx (dict): the transaction to process.
Returns:
The transaction if assigned to the current node,
``None`` otherwise.
"""
if tx['assignee'] == self.bigchain.me:
tx.pop('assignee')
tx.pop('assignment_timestamp')
return tx
def validate_tx(self, tx):
"""Validate a transaction.
Also checks if the transaction already exists in the blockchain. If it
does, or it's invalid, it's deleted from the backlog immediately.
Args:
tx (dict): the transaction to validate.
Returns:
The transaction if valid, ``None`` otherwise.
"""
if self.bigchain.transaction_exists(tx['id']):
# if the transaction already exists, we must check whether
# it's in a valid or undecided block
tx, status = self.bigchain.get_transaction(tx['id'],
include_status=True)
if status == self.bigchain.TX_VALID \
or status == self.bigchain.TX_UNDECIDED:
# if the tx is already in a valid or undecided block,
# then it no longer should be in the backlog, or added
# to a new block. We can delete and drop it.
r.table('backlog').get(tx['id']) \
.delete(durability='hard') \
.run(self.bigchain.conn)
return None
tx_validated = self.bigchain.is_valid_transaction(tx)
if tx_validated:
return tx
else:
# if the transaction is not valid, remove it from the
# backlog
r.table('backlog').get(tx['id']) \
.delete(durability='hard') \
.run(self.bigchain.conn)
return None
def create(self, tx, timeout=False):
"""Create a block.
This method accumulates transactions to put in a block and outputs
a block when one of the following conditions is true:
- the size limit of the block has been reached, or
- a timeout happened.
Args:
tx (dict): the transaction to validate, might be None if
a timeout happens.
timeout (bool): ``True`` if a timeout happened
(Default: ``False``).
Returns:
The block, if a block is ready, or ``None``.
"""
if tx:
self.txs.append(tx)
if len(self.txs) == 1000 or (timeout and self.txs):
block = self.bigchain.create_block(self.txs)
self.txs = []
return block
def write(self, block):
"""Write the block to the Database.
Args:
block (dict): the block of transactions to write to the database.
Returns:
The block.
"""
logger.info('Write new block %s with %s transactions',
block['id'],
len(block['block']['transactions']))
self.bigchain.write_block(block)
return block
def delete_tx(self, block):
"""Delete transactions.
Args:
block (dict): the block containg the transactions to delete.
Returns:
The block.
"""
r.table('backlog')\
.get_all(*[tx['id'] for tx in block['block']['transactions']])\
.delete(durability='hard')\
.run(self.bigchain.conn)
return block
from bigchaindb import Bigchain
import writeout
b = Bigchain()
for x in range(1,8):
tx_signed = writeout.importData("user"+str(x)+"vote")
tx_retrieved = b.get_transaction(tx_signed['id'])
print(b.transaction_exists(tx_retrieved['id']))
import hashlib
# monkey patch hashlib with sha3 functions
import sha3
import json
from bigchaindb import Bigchain
import writeout
b = Bigchain()
user1priv, user1pub = writeout.importData("user1")
user2priv, user2pub = writeout.importData("user2")
user3priv, user3pub = writeout.importData("user3")
govt_priv, govt_pub = writeout.importData("govt")
gids = b.get_owned_ids(govt_pub)
for id in gids:
t = b.get_transaction(id)
print(t)
#data = {'vote': 30}
#tx_serialized = bytes(json.dumps(data, skipkeys=False, ensure_ascii=False, separators=(',', ':')).encode("utf-8"))
#tx_hash = hashlib.sha3_256(tx_serialized).hexdigest()
#txs = b.get_tx_by_payload_hash(tx_hash)
#for tx in txs:
# print(tx)
from bigchaindb import Bigchain
import writeout
b = Bigchain()
for x in range(1, 8):
tx_signed = writeout.importData("user" + str(x) + "vote")
tx_retrieved = b.get_transaction(tx_signed['id'])
print(b.transaction_exists(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(" ")
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(" ")
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))
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))
# 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'])
"""
Transfer the Digital Asset
"""
# create a second testuser
testuser2_priv, testuser2_pub = crypto.generate_key_pair()
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
})
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 Block:
"""This class encapsulates the logic to create blocks.
Note:
Methods of this class will be executed in different processes.
"""
def __init__(self):
"""Initialize the Block creator"""
self.bigchain = Bigchain()
self.txs = []
def filter_tx(self, tx):
"""Filter a transaction.
Args:
tx (dict): the transaction to process.
Returns:
The transaction if assigned to the current node,
``None`` otherwise.
"""
if tx['assignee'] == self.bigchain.me:
tx.pop('assignee')
tx.pop('assignment_timestamp')
return tx
def validate_tx(self, tx):
"""Validate a transaction.
Also checks if the transaction already exists in the blockchain. If it
does, or it's invalid, it's deleted from the backlog immediately.
Args:
tx (dict): the transaction to validate.
Returns:
The transaction if valid, ``None`` otherwise.
"""
if self.bigchain.transaction_exists(tx['id']):
# if the transaction already exists, we must check whether
# it's in a valid or undecided block
tx, status = self.bigchain.get_transaction(tx['id'],
include_status=True)
if status == self.bigchain.TX_VALID \
or status == self.bigchain.TX_UNDECIDED:
# if the tx is already in a valid or undecided block,
# then it no longer should be in the backlog, or added
# to a new block. We can delete and drop it.
r.table('backlog').get(tx['id']) \
.delete(durability='hard') \
.run(self.bigchain.conn)
return None
tx_validated = self.bigchain.is_valid_transaction(tx)
if tx_validated:
return tx
else:
# if the transaction is not valid, remove it from the
# backlog
r.table('backlog').get(tx['id']) \
.delete(durability='hard') \
.run(self.bigchain.conn)
return None
def create(self, tx, timeout=False):
"""Create a block.
This method accumulates transactions to put in a block and outputs
a block when one of the following conditions is true:
- the size limit of the block has been reached, or
- a timeout happened.
Args:
tx (dict): the transaction to validate, might be None if
a timeout happens.
timeout (bool): ``True`` if a timeout happened
(Default: ``False``).
Returns:
The block, if a block is ready, or ``None``.
"""
if tx:
self.txs.append(tx)
if len(self.txs) == 1000 or (timeout and self.txs):
block = self.bigchain.create_block(self.txs)
self.txs = []
return block
def write(self, block):
"""Write the block to the Database.
Args:
block (dict): the block of transactions to write to the database.
Returns:
The block.
"""
logger.info('Write new block %s with %s transactions',
block['id'],
len(block['block']['transactions']))
self.bigchain.write_block(block)
return block
def delete_tx(self, block):
"""Delete transactions.
Args:
block (dict): the block containg the transactions to delete.
Returns:
The block.
"""
r.table('backlog')\
.get_all(*[tx['id'] for tx in block['block']['transactions']])\
.delete(durability='hard')\
.run(self.bigchain.conn)
return block
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(" ")
