Files
stacks-puppet-node/blockstack_client/operations/update.py
2017-02-20 21:04:47 -05:00

191 lines
6.0 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Blockstack-client
~~~~~
copyright: (c) 2014-2015 by Halfmoon Labs, Inc.
copyright: (c) 2016 by Blockstack.org
This file is part of Blockstack-client.
Blockstack-client is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Blockstack-client is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Blockstack-client. If not, see <http://www.gnu.org/licenses/>.
"""
import pybitcoin
from pybitcoin import embed_data_in_blockchain, make_op_return_tx, BlockchainInfoClient, \
hex_hash160, broadcast_transaction, serialize_transaction, \
make_op_return_outputs, make_op_return_script, make_pay_to_address_script
from pybitcoin.transactions.outputs import calculate_change_amount
from utilitybelt import is_hex
from binascii import hexlify, unhexlify
from ..b40 import b40_to_hex, bin_to_b40, is_b40
from ..config import *
from ..scripts import *
import virtualchain
log = virtualchain.get_logger("blockstack-server")
def update_sanity_test( name, consensus_hash, data_hash ):
"""
Verify the validity of an update's data
Return True if valid
Raise exception if not
"""
if name is not None and (not is_b40( name ) or "+" in name or name.count(".") > 1):
raise Exception("Name '%s' has non-base-38 characters" % name)
if data_hash is not None and not is_hex( data_hash ):
raise Exception("Invalid hex string '%s': not hex" % (data_hash))
if len(data_hash) != 2 * LENGTH_VALUE_HASH:
raise Exception("Invalid hex string '%s': bad length" % (data_hash))
return True
def build(name, consensus_hash, data_hash=None):
"""
Takes in the name to update the data for and the data update itself.
Name must include the namespace ID, but not the scheme.
Record format:
0 2 3 19 39
|-----|--|-----------------------------------|-----------------------|
magic op hash128(name.ns_id,consensus hash) hash160(data)
"""
rc = update_sanity_test( name, consensus_hash, data_hash )
if not rc:
raise Exception("Invalid update data")
hex_name = hash256_trunc128( name + consensus_hash )
readable_script = 'NAME_UPDATE 0x%s 0x%s' % (hex_name, data_hash)
hex_script = blockstack_script_to_hex(readable_script)
packaged_script = add_magic_bytes(hex_script)
return packaged_script
def make_outputs( data, inputs, change_address, tx_fee, pay_fee=True ):
"""
Make outputs for an update.
Raise ValueError if there are not enough inputs to make the transaction
"""
dust_fee = None
op_fee = None
dust_value = None
if pay_fee:
dust_fee = (len(inputs) + 1) * DEFAULT_DUST_FEE + DEFAULT_OP_RETURN_FEE + tx_fee
op_fee = DEFAULT_DUST_FEE
dust_value = DEFAULT_DUST_FEE
else:
# will be subsidized
dust_fee = 0
op_fee = 0
dust_value = 0
return [
# main output
{"script_hex": make_op_return_script(str(data), format='hex'),
"value": 0},
# change output
{"script_hex": virtualchain.make_payment_script(change_address),
"value": calculate_change_amount(inputs, op_fee, dust_fee)}
]
def make_transaction(name, data_hash, consensus_hash, owner_addr, blockchain_client, tx_fee=0, subsidize=False, safety=True):
"""
Write a name update into the blockchain.
Returns a JSON object with 'data' set to the nulldata and 'transaction_hash' set to the transaction hash on success.
"""
name = str(name)
data_hash = str(data_hash)
consensus_hash = str(consensus_hash)
owner_addr = str(owner_addr)
tx_fee = int(tx_fee)
assert len(consensus_hash) == LENGTH_CONSENSUS_HASH * 2
assert is_name_valid(name)
# sanity check
pay_fee = True
if subsidize:
pay_fee = False
inputs = tx_get_unspents( owner_addr, blockchain_client )
if safety:
assert len(inputs) > 0, "No UTXOs for {}".format(owner_addr)
nulldata = build(name, consensus_hash, data_hash=data_hash)
outputs = make_outputs( nulldata, inputs, owner_addr, tx_fee, pay_fee=pay_fee )
return (inputs, outputs)
def get_fees( inputs, outputs ):
"""
Given a transaction's outputs, look up its fees:
* there should be two outputs: the OP_RETURN and change address
Return (dust fees, operation fees) on success
Return (None, None) on invalid output listing
"""
if len(outputs) != 2:
log.debug("Got %s outputs, not 2" % len(outputs))
return (None, None)
# 0: op_return
if not tx_output_is_op_return( outputs[0] ):
log.debug("Not an OP_RETURN output: %s" % outputs[0])
return (None, None)
if outputs[0]["value"] != 0:
log.debug("Outputs[0] has non-zero value")
return (None, None)
# 1: change address
if virtualchain.script_hex_to_address( outputs[1]["script_hex"] ) is None:
return (None, None)
dust_fee = (len(inputs) + 1) * DEFAULT_DUST_FEE + DEFAULT_OP_RETURN_FEE
op_fee = 0
return (dust_fee, op_fee)
def snv_consensus_extras( name_rec, block_id, blockchain_name_data ):
"""
Given a name record most recently affected by an instance of this operation,
find the dict of consensus-affecting fields from the operation that are not
already present in the name record.
"""
ret_op = {}
# reconstruct name_hash
ret_op['name_consensus_hash'] = hash256_trunc128( str(name_rec['name']) + str(name_rec['consensus_hash']) )
return ret_op