Files
stacks-puppet-node/blockstack/lib/operations/transfer.py
2016-02-23 15:56:09 -05:00

281 lines
8.8 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Blockstack
~~~~~
copyright: (c) 2014-2015 by Halfmoon Labs, Inc.
copyright: (c) 2016 by Blockstack.org
This file is part of Blockstack
Blockstack 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 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. If not, see <http://www.gnu.org/licenses/>.
"""
from pybitcoin import embed_data_in_blockchain, serialize_transaction, \
analyze_private_key, serialize_sign_and_broadcast, make_op_return_script, \
make_pay_to_address_script, BitcoinPrivateKey, BitcoinPublicKey, get_unspents, script_hex_to_address
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 *
from ..hashing import hash256_trunc128
from ..nameset import NAMEREC_FIELDS
# consensus hash fields (ORDER MATTERS!)
FIELDS = NAMEREC_FIELDS + [
'name_hash', # hash(name)
'consensus_hash', # consensus hash when this operation was sent
'keep_data' # whether or not to keep the profile data associated with the name when transferred
]
def get_transfer_recipient_from_outputs( outputs ):
"""
Given the outputs from a name transfer operation,
find the recipient's script hex.
By construction, it will be the first non-OP_RETURN
output (i.e. the second output).
This also applies to a NAME_IMPORT.
"""
ret = None
for output in outputs:
output_script = output['scriptPubKey']
output_asm = output_script.get('asm')
output_hex = output_script.get('hex')
output_addresses = output_script.get('addresses')
if output_asm[0:9] != 'OP_RETURN' and output_hex:
ret = output_hex
break
if ret is None:
raise Exception("No recipients found")
return ret
def transfer_sanity_check( name, consensus_hash ):
"""
Verify that data for a transfer is valid.
Return True on success
Raise Exception on error
"""
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)
# without the scheme, name must be 37 bytes
if name is not None and (len(name) > LENGTHS['blockchain_id_name']):
raise Exception("Name '%s' is too long; expected %s bytes" % (name, LENGTHS['blockchain_id_name']))
return True
def build(name, keepdata, consensus_hash, testset=False):
"""
Takes in a name to transfer. Name must include the namespace ID, but not the scheme.
Record format:
0 2 3 4 20 36
|-----|--|----|-------------------|---------------|
magic op keep hash128(name.ns_id) consensus hash
data?
"""
rc = transfer_sanity_check( name, consensus_hash )
if not rc:
raise Exception("Invalid transfer data")
data_disposition = None
if keepdata:
data_disposition = TRANSFER_KEEP_DATA
else:
data_disposition = TRANSFER_REMOVE_DATA
name_hash = hash256_trunc128( name )
disposition_hex = hexlify(data_disposition)
readable_script = 'NAME_TRANSFER 0x%s 0x%s 0x%s' % (disposition_hex, name_hash, consensus_hash)
hex_script = blockstack_script_to_hex(readable_script)
packaged_script = add_magic_bytes(hex_script, testset=testset)
return packaged_script
def make_outputs( data, inputs, new_name_owner_address, change_address, pay_fee=True, format='bin' ):
"""
Builds the outputs for a name transfer operation.
"""
dust_fee = None
op_fee = None
dust_value = DEFAULT_DUST_FEE
if pay_fee:
dust_fee = (len(inputs) + 2) * DEFAULT_DUST_FEE + DEFAULT_OP_RETURN_FEE
op_fee = DEFAULT_DUST_FEE
else:
dust_fee = 0
op_fee = 0
return [
# main output
{"script_hex": make_op_return_script(data, format=format),
"value": 0},
# new name owner output
{"script_hex": make_pay_to_address_script(new_name_owner_address),
"value": dust_value},
# change output
{"script_hex": make_pay_to_address_script(change_address),
"value": calculate_change_amount(inputs, op_fee, dust_fee)}
]
def broadcast(name, destination_address, keepdata, consensus_hash, private_key, blockchain_client, blockchain_broadcaster=None, tx_only=False, user_public_key=None, testset=False):
# sanity check
pay_fee = True
if user_public_key is not None:
pay_fee = False
tx_only = True
if user_public_key is None and private_key is None:
raise Exception("Missing both public and private key")
if not tx_only and private_key is None:
raise Exception("Need private key for broadcasting")
if blockchain_broadcaster is None:
blockchain_broadcaster = blockchain_client
from_address = None
inputs = None
private_key_obj = None
if user_public_key is not None:
# subsidizing
pubk = BitcoinPublicKey( user_public_key )
from_address = pubk.address()
inputs = get_unspents( from_address, blockchain_client )
elif private_key is not None:
# ordering directly
pubk = BitcoinPrivateKey( private_key ).public_key()
public_key = pubk.to_hex()
# get inputs and from address using private key
private_key_obj, from_address, inputs = analyze_private_key(private_key, blockchain_client)
nulldata = build(name, keepdata, consensus_hash, testset=testset)
outputs = make_outputs(nulldata, inputs, destination_address, from_address, pay_fee=pay_fee, format='hex')
if tx_only:
unsigned_tx = serialize_transaction( inputs, outputs )
return {"unsigned_tx": unsigned_tx}
else:
# serialize, sign, and broadcast the tx
response = serialize_sign_and_broadcast(inputs, outputs, private_key_obj, blockchain_broadcaster)
response.update({'data': nulldata})
return response
def parse(bin_payload, recipient):
"""
# NOTE: first three bytes were stripped
"""
if len(bin_payload) != 1 + LENGTHS['name_hash'] + LENGTHS['consensus_hash']:
log.error("Invalid transfer payload length %s" % len(bin_payload))
return None
disposition_char = bin_payload[0:1]
name_hash = bin_payload[1:1+LENGTHS['name_hash']]
consensus_hash = bin_payload[1+LENGTHS['name_hash']:]
if disposition_char not in [TRANSFER_REMOVE_DATA, TRANSFER_KEEP_DATA]:
log.error("Invalid disposition character")
return None
# keep data by default
disposition = True
if disposition_char == TRANSFER_REMOVE_DATA:
disposition = False
try:
rc = transfer_sanity_check( None, consensus_hash )
if not rc:
raise Exception("Invalid transfer data")
except Exception, e:
log.error("Invalid transfer data")
return None
return {
'opcode': 'NAME_TRANSFER',
'name_hash': hexlify( name_hash ),
'consensus_hash': hexlify( consensus_hash ),
'recipient': recipient,
'keep_data': disposition
}
def get_fees( inputs, outputs ):
"""
Given a transaction's outputs, look up its fees:
* the first output should be an OP_RETURN with the transfer info
* the second output should be the new owner's address, with a DEFAULT_DUST_FEE
* the third output should be the change address
Return (dust fees, operation fees) on success
Return (None, None) on invalid output listing
"""
if len(outputs) != 3:
return (None, None)
# 0: op_return
if not tx_output_is_op_return( outputs[0] ):
return (None, None)
if outputs[0]["value"] != 0:
return (None, None)
# 1: transfer address
if script_hex_to_address( outputs[1]["script_hex"] ) is None:
return (None, None)
# 2: change address
if script_hex_to_address( outputs[2]["script_hex"] ) is None:
return (None, None)
dust_fee = (len(inputs) + 2) * DEFAULT_DUST_FEE + DEFAULT_OP_RETURN_FEE
op_fee = DEFAULT_DUST_FEE
return (dust_fee, op_fee)