332 lines
11 KiB
Python
332 lines
11 KiB
Python
#!/usr/bin/env python
|
|
#
|
|
# Electrum - lightweight Bitcoin client
|
|
# Copyright (C) 2012 thomasv@ecdsa.org
|
|
#
|
|
# This program 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.
|
|
#
|
|
# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
|
|
import threading, time, Queue, os, sys
|
|
from util import user_dir
|
|
from bitcoin import *
|
|
|
|
|
|
|
|
|
|
class WalletVerifier(threading.Thread):
|
|
|
|
def __init__(self, interface, config, get_transactions):
|
|
threading.Thread.__init__(self)
|
|
self.daemon = True
|
|
self.config = config
|
|
self.interface = interface
|
|
self.get_transactions = get_transactions
|
|
self.interface.register_channel('verifier')
|
|
self.verified_tx = config.get('verified_tx',[])
|
|
self.merkle_roots = config.get('merkle_roots',{}) # hashed by me
|
|
self.targets = config.get('targets',{}) # compute targets
|
|
self.lock = threading.Lock()
|
|
self.pending_headers = [] # headers that have not been verified
|
|
self.height = 0
|
|
self.local_height = 0
|
|
self.set_local_numblocks()
|
|
|
|
|
|
|
|
|
|
def run(self):
|
|
requested_merkle = []
|
|
requested_chunks = []
|
|
requested_headers = []
|
|
pending_headers_changed = False
|
|
|
|
# subscribe to block headers
|
|
self.interface.send([ ('blockchain.headers.subscribe',[])], 'verifier')
|
|
|
|
while True:
|
|
# request missing chunks
|
|
max_index = (self.height+1)/2016
|
|
if not requested_chunks:
|
|
for i in range(0, max_index + 1):
|
|
# test if we can read the first header of the chunk
|
|
if self.read_header(i*2016): continue
|
|
print "requesting chunk", i
|
|
self.interface.send([ ('blockchain.block.get_chunk',[i])], 'verifier')
|
|
requested_chunks.append(i)
|
|
break
|
|
|
|
# request missing headers
|
|
if not requested_chunks and self.local_height:
|
|
for i in range(self.local_height + 1, self.height + 1):
|
|
if i not in requested_headers:
|
|
print "requesting header", i
|
|
self.interface.send([ ('blockchain.block.get_header',[i])], 'verifier')
|
|
requested_headers.append(i)
|
|
|
|
# request missing tx merkle
|
|
txlist = self.get_transactions()
|
|
for tx in txlist:
|
|
if tx not in self.verified_tx:
|
|
if tx not in requested_merkle:
|
|
requested_merkle.append(tx)
|
|
self.request_merkle(tx)
|
|
#break
|
|
|
|
try:
|
|
r = self.interface.get_response('verifier',timeout=1)
|
|
except Queue.Empty:
|
|
time.sleep(1)
|
|
continue
|
|
|
|
# 3. handle response
|
|
method = r['method']
|
|
params = r['params']
|
|
result = r['result']
|
|
|
|
if method == 'blockchain.transaction.get_merkle':
|
|
tx_hash = params[0]
|
|
self.verify_merkle(tx_hash, result)
|
|
requested_merkle.remove(tx_hash)
|
|
|
|
elif method == 'blockchain.block.get_chunk':
|
|
index = params[0]
|
|
self.verify_chunk(index, result)
|
|
requested_chunks.remove(index)
|
|
|
|
elif method == 'blockchain.headers.subscribe':
|
|
self.height = result.get('block_height')
|
|
self.pending_headers.append(result)
|
|
pending_headers_changed = True
|
|
|
|
elif method == 'blockchain.block.get_header':
|
|
height = result.get('block_height')
|
|
requested_headers.remove(height)
|
|
self.pending_headers.append(result)
|
|
pending_headers_changed = True
|
|
|
|
# process pending headers
|
|
if pending_headers_changed:
|
|
self.pending_headers.sort(key=lambda x: x.get('block_height'))
|
|
print "pending headers", map(lambda x: x.get('block_height'), self.pending_headers)
|
|
for header in self.pending_headers:
|
|
if self.verify_header(header):
|
|
self.pending_headers.remove(header)
|
|
else:
|
|
break
|
|
pending_headers_changed = False
|
|
|
|
|
|
|
|
def request_merkle(self, tx_hash):
|
|
self.interface.send([ ('blockchain.transaction.get_merkle',[tx_hash]) ], 'verifier')
|
|
|
|
|
|
def verify_merkle(self, tx_hash, result):
|
|
tx_height = result.get('block_height')
|
|
self.merkle_roots[tx_hash] = self.hash_merkle_root(result['merkle'], tx_hash)
|
|
header = self.read_header(tx_height)
|
|
if header:
|
|
assert header.get('merkle_root') == self.merkle_roots[tx_hash]
|
|
self.verified_tx.append(tx_hash)
|
|
print "verified", tx_hash
|
|
self.config.set_key('verified_tx', self.verified_tx, True)
|
|
|
|
|
|
def verify_chunk(self, index, hexdata):
|
|
data = hexdata.decode('hex')
|
|
height = index*2016
|
|
num = len(data)/80
|
|
print "validate_chunk", index, num
|
|
|
|
if index == 0:
|
|
previous_hash = ("0"*64)
|
|
else:
|
|
prev_header = self.read_header(index*2016-1)
|
|
if prev_header is None: raise
|
|
previous_hash = self.hash_header(prev_header)
|
|
|
|
bits, target = self.get_target(index)
|
|
|
|
for i in range(num):
|
|
height = index*2016 + i
|
|
raw_header = data[i*80:(i+1)*80]
|
|
header = self.header_from_string(raw_header)
|
|
_hash = self.hash_header(header)
|
|
assert previous_hash == header.get('prev_block_hash')
|
|
assert bits == header.get('bits')
|
|
assert eval('0x'+_hash) < target
|
|
|
|
previous_header = header
|
|
previous_hash = _hash
|
|
|
|
self.save_chunk(index, data)
|
|
|
|
|
|
def verify_header(self, header):
|
|
# add header to the blockchain file
|
|
# if there is a reorg, push it in a stack
|
|
|
|
height = header.get('block_height')
|
|
|
|
prev_header = self.read_header(height -1)
|
|
if not prev_header:
|
|
print "no previous header", height
|
|
return
|
|
|
|
#prev_hash = prev_header.get('block_height')
|
|
prev_hash = self.hash_header(prev_header)
|
|
bits, target = self.get_target(height/2016)
|
|
_hash = self.hash_header(header)
|
|
try:
|
|
assert prev_hash == header.get('prev_block_hash')
|
|
assert bits == header.get('bits')
|
|
assert eval('0x'+_hash) < target
|
|
ok = True
|
|
except:
|
|
print "verify header failed", header
|
|
raise
|
|
# this could be caused by a reorg. request the previous header
|
|
ok = False
|
|
#request previous one
|
|
|
|
if ok:
|
|
self.save_header(header)
|
|
print "verify header: ok", height
|
|
return True
|
|
|
|
|
|
|
|
|
|
def header_to_string(self, res):
|
|
s = int_to_hex(res.get('version'),4) \
|
|
+ rev_hex(res.get('prev_block_hash')) \
|
|
+ rev_hex(res.get('merkle_root')) \
|
|
+ int_to_hex(int(res.get('timestamp')),4) \
|
|
+ int_to_hex(int(res.get('bits')),4) \
|
|
+ int_to_hex(int(res.get('nonce')),4)
|
|
return s
|
|
|
|
|
|
def header_from_string(self, s):
|
|
hex_to_int = lambda s: eval('0x' + s[::-1].encode('hex'))
|
|
h = {}
|
|
h['version'] = hex_to_int(s[0:4])
|
|
h['prev_block_hash'] = hash_encode(s[4:36])
|
|
h['merkle_root'] = hash_encode(s[36:68])
|
|
h['timestamp'] = hex_to_int(s[68:72])
|
|
h['bits'] = hex_to_int(s[72:76])
|
|
h['nonce'] = hex_to_int(s[76:80])
|
|
return h
|
|
|
|
|
|
def hash_header(self, header):
|
|
return rev_hex(Hash(self.header_to_string(header).decode('hex')).encode('hex'))
|
|
|
|
|
|
def hash_merkle_root(self, merkle_s, target_hash):
|
|
h = hash_decode(target_hash)
|
|
for item in merkle_s:
|
|
is_left = item[0] == 'L'
|
|
h = Hash( h + hash_decode(item[1:]) ) if is_left else Hash( hash_decode(item[1:]) + h )
|
|
return hash_encode(h)
|
|
|
|
def path(self):
|
|
wdir = user_dir()
|
|
if not os.path.exists( wdir ):
|
|
wdir = os.path.dirname(self.config.path)
|
|
return os.path.join( wdir, 'blockchain_headers')
|
|
|
|
def save_chunk(self, index, chunk):
|
|
filename = self.path()
|
|
if os.path.exists(filename):
|
|
f = open(filename,'rw+')
|
|
else:
|
|
print "creating file", filename
|
|
f = open(filename,'w+')
|
|
f.seek(index*2016*80)
|
|
h = f.write(chunk)
|
|
f.close()
|
|
self.set_local_numblocks()
|
|
|
|
def save_header(self, header):
|
|
data = self.header_to_string(header).decode('hex')
|
|
assert len(data) == 80
|
|
height = header.get('block_height')
|
|
filename = self.path()
|
|
f = open(filename,'rw+')
|
|
f.seek(height*80)
|
|
h = f.write(data)
|
|
f.close()
|
|
self.set_local_numblocks()
|
|
|
|
def set_local_numblocks(self):
|
|
name = self.path()
|
|
if os.path.exists(name):
|
|
self.local_height = os.path.getsize(name)/80 - 1
|
|
# print "local height", self.local_height, os.path.getsize(name)/80.
|
|
|
|
|
|
def read_header(self, block_height):
|
|
name = self.path()
|
|
if os.path.exists(name):
|
|
f = open(name,'rb')
|
|
f.seek(block_height*80)
|
|
h = f.read(80)
|
|
f.close()
|
|
if len(h) == 80:
|
|
h = self.header_from_string(h)
|
|
return h
|
|
|
|
|
|
def get_target(self, index):
|
|
|
|
max_target = 0x00000000FFFF0000000000000000000000000000000000000000000000000000
|
|
if index == 0: return 0x1d00ffff, max_target
|
|
|
|
first = self.read_header((index-1)*2016)
|
|
last = self.read_header(index*2016-1)
|
|
|
|
nActualTimespan = last.get('timestamp') - first.get('timestamp')
|
|
nTargetTimespan = 14*24*60*60
|
|
nActualTimespan = max(nActualTimespan, nTargetTimespan/4)
|
|
nActualTimespan = min(nActualTimespan, nTargetTimespan*4)
|
|
|
|
bits = last.get('bits')
|
|
# convert to bignum
|
|
MM = 256*256*256
|
|
a = bits%MM
|
|
if a < 0x8000:
|
|
a *= 256
|
|
target = (a) * pow(2, 8 * (bits/MM - 3))
|
|
|
|
# new target
|
|
new_target = min( max_target, (target * nActualTimespan)/nTargetTimespan )
|
|
|
|
# convert it to bits
|
|
c = ("%064X"%new_target)[2:]
|
|
i = 31
|
|
while c[0:2]=="00":
|
|
c = c[2:]
|
|
i -= 1
|
|
|
|
c = eval('0x'+c[0:6])
|
|
if c > 0x800000:
|
|
c /= 256
|
|
i += 1
|
|
|
|
new_bits = c + MM * i
|
|
# print "%3d"%index, "%8x"%bits, "%64X"%new_target, hex(c)[2:].upper(), hex(new_bits)
|
|
return new_bits, new_target
|
|
|