115 lines
4.9 KiB
Python
115 lines
4.9 KiB
Python
# Electrum - Lightweight bitcoinprivate Client
|
|
# Copyright (c) 2012 Thomas Voegtlin
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person
|
|
# obtaining a copy of this software and associated documentation files
|
|
# (the "Software"), to deal in the Software without restriction,
|
|
# including without limitation the rights to use, copy, modify, merge,
|
|
# publish, distribute, sublicense, and/or sell copies of the Software,
|
|
# and to permit persons to whom the Software is furnished to do so,
|
|
# subject to the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be
|
|
# included in all copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
|
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
|
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
# SOFTWARE.
|
|
from .util import ThreadJob
|
|
from .bitcoin import *
|
|
from .blockchain import CHUNK_LEN
|
|
|
|
|
|
class SPV(ThreadJob):
|
|
""" Simple Payment Verification """
|
|
|
|
def __init__(self, network, wallet):
|
|
self.wallet = wallet
|
|
self.network = network
|
|
self.blockchain = network.blockchain()
|
|
# Keyed by tx hash. Value is None if the merkle branch was
|
|
# requested, and the merkle root once it has been verified
|
|
self.merkle_roots = {}
|
|
|
|
def run(self):
|
|
interface = self.network.interface
|
|
if not interface:
|
|
return
|
|
blockchain = interface.blockchain
|
|
if not blockchain:
|
|
return
|
|
lh = self.network.get_local_height()
|
|
unverified = self.wallet.get_unverified_txs()
|
|
for tx_hash, tx_height in unverified.items():
|
|
# do not request merkle branch before headers are available
|
|
if (tx_height > 0) and (tx_height <= lh):
|
|
header = blockchain.read_header(tx_height)
|
|
if header is None:
|
|
index = tx_height // CHUNK_LEN
|
|
if index < len(blockchain.checkpoints):
|
|
self.network.request_chunk(interface, index)
|
|
else:
|
|
if tx_hash not in self.merkle_roots:
|
|
request = ('blockchain.transaction.get_merkle',
|
|
[tx_hash, tx_height])
|
|
self.network.send([request], self.verify_merkle)
|
|
self.print_error('requested merkle', tx_hash)
|
|
self.merkle_roots[tx_hash] = None
|
|
|
|
if self.network.blockchain() != self.blockchain:
|
|
self.blockchain = self.network.blockchain()
|
|
self.undo_verifications()
|
|
|
|
def verify_merkle(self, r):
|
|
if self.wallet.verifier is None:
|
|
return # we have been killed, this was just an orphan callback
|
|
if r.get('error'):
|
|
self.print_error('received an error:', r)
|
|
return
|
|
params = r['params']
|
|
merkle = r['result']
|
|
# Verify the hash of the server-provided merkle branch to a
|
|
# transaction matches the merkle root of its block
|
|
tx_hash = params[0]
|
|
tx_height = merkle.get('block_height')
|
|
pos = merkle.get('pos')
|
|
merkle_root = self.hash_merkle_root(merkle['merkle'], tx_hash, pos)
|
|
header = self.network.blockchain().read_header(tx_height)
|
|
# FIXME: if verification fails below,
|
|
# we should make a fresh connection to a server to
|
|
# recover from this, as this TX will now never verify
|
|
if not header:
|
|
self.print_error(
|
|
"merkle verification failed for {} (missing header {})"
|
|
.format(tx_hash, tx_height))
|
|
return
|
|
if header.get('merkle_root') != merkle_root:
|
|
self.print_error(
|
|
"merkle verification failed for {} (merkle root mismatch {} != {})"
|
|
.format(tx_hash, header.get('merkle_root'), merkle_root))
|
|
return
|
|
# we passed all the tests
|
|
self.merkle_roots[tx_hash] = merkle_root
|
|
self.print_error("verified %s" % tx_hash)
|
|
self.wallet.add_verified_tx(tx_hash, (tx_height, header.get('timestamp'), pos))
|
|
|
|
@classmethod
|
|
def hash_merkle_root(cls, merkle_s, target_hash, pos):
|
|
h = hash_decode(target_hash)
|
|
for i in range(len(merkle_s)):
|
|
item = merkle_s[i]
|
|
h = Hash(hash_decode(item) + h) if ((pos >> i) & 1) else Hash(h + hash_decode(item))
|
|
return hash_encode(h)
|
|
|
|
def undo_verifications(self):
|
|
height = self.blockchain.get_checkpoint()
|
|
tx_hashes = self.wallet.undo_verifications(self.blockchain, height)
|
|
for tx_hash in tx_hashes:
|
|
self.print_error("redoing", tx_hash)
|
|
self.merkle_roots.pop(tx_hash, None)
|