# along with this program. If not, see <http://www.gnu.org/licenses/>.
-import threading, time, Queue, os, sys
-from util import user_dir
+import threading, time, Queue, os, sys, shutil
+from util import user_dir, appdata_dir, print_error
from bitcoin import *
-class WalletVerifier(threading.Thread):
- """ Simple Verification Protocol """
+class TxVerifier(threading.Thread):
+ """ Simple Payment Verification """
- def __init__(self, interface, config):
+ def __init__(self, network, storage):
threading.Thread.__init__(self)
self.daemon = True
- self.config = config
- self.interface = interface
- self.transactions = [] # monitored 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.storage = storage
+ self.network = network
+ self.transactions = {} # requested verifications (with height sent by the requestor)
+ self.verified_tx = storage.get('verified_tx3',{}) # height, timestamp of verified transactions
+ self.merkle_roots = storage.get('merkle_roots',{}) # hashed by me
self.lock = threading.Lock()
- self.pending_headers = [] # headers that have not been verified
- self.height = 0
- self.local_height = 0
- self.set_local_height()
+ self.running = False
+ self.queue = Queue.Queue()
+
def get_confirmations(self, tx):
""" return the number of confirmations of a monitored transaction. """
with self.lock:
- assert tx in self.transactions
- return (self.local_height - self.verified_tx[tx] + 1) if tx in self.verified_tx else 0
+ if tx in self.verified_tx:
+ height, timestamp, pos = self.verified_tx[tx]
+ conf = (self.network.get_local_height() - height + 1)
+ if conf <= 0: timestamp = None
+
+ elif tx in self.transactions:
+ conf = -1
+ timestamp = None
+
+ else:
+ conf = 0
+ timestamp = None
+
+ return conf, timestamp
+
+
+ def get_txpos(self, tx_hash):
+ "return position, even if the tx is unverified"
+ with self.lock:
+ x = self.verified_tx.get(tx_hash)
+ y = self.transactions.get(tx_hash)
+ if x:
+ height, timestamp, pos = x
+ return height, pos
+ elif y:
+ return y, 0
+ else:
+ return 1e12, 0
+
+
+ def get_height(self, tx_hash):
+ with self.lock:
+ v = self.verified_tx.get(tx_hash)
+ height = v[0] if v else None
+ return height
+
- def add(self, tx):
+ def add(self, tx_hash, tx_height):
""" add a transaction to the list of monitored transactions. """
+ assert tx_height > 0
with self.lock:
- if tx not in self.transactions:
- self.transactions.append(tx)
+ if tx_hash not in self.transactions.keys():
+ self.transactions[tx_hash] = tx_height
+
+ def stop(self):
+ with self.lock: self.running = False
+
+ def is_running(self):
+ with self.lock: return self.running
def run(self):
+ with self.lock:
+ self.running = True
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
- for tx in self.transactions:
- if tx not in self.verified_tx:
- if tx not in requested_merkle:
- requested_merkle.append(tx)
- self.request_merkle(tx)
- #break
+
+ while self.is_running():
+ # request missing tx
+ for tx_hash, tx_height in self.transactions.items():
+ if tx_hash not in self.verified_tx:
+ if self.merkle_roots.get(tx_hash) is None and tx_hash not in requested_merkle:
+ if self.network.send([ ('blockchain.transaction.get_merkle',[tx_hash, tx_height]) ], lambda i,r: self.queue.put(r)):
+ print_error('requesting merkle', tx_hash)
+ requested_merkle.append(tx_hash)
try:
- r = self.interface.get_response('verifier',timeout=1)
+ r = self.queue.get(timeout=1)
except Queue.Empty:
- time.sleep(1)
+ continue
+
+ if not r: continue
+
+ if r.get('error'):
+ print_error('Verifier received an error:', r)
continue
# 3. handle response
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
-
- self.interface.trigger_callback('updated')
-
-
- 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[tx_hash] = tx_height
- 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):
+ pos = result.get('pos')
+ self.merkle_roots[tx_hash] = self.hash_merkle_root(result['merkle'], tx_hash, pos)
+ header = self.network.get_header(tx_height)
+ if not header: return
+ assert header.get('merkle_root') == self.merkle_roots[tx_hash]
+ # we passed all the tests
+ timestamp = header.get('timestamp')
+ with self.lock:
+ self.verified_tx[tx_hash] = (tx_height, timestamp, pos)
+ print_error("verified %s"%tx_hash)
+ self.storage.put('verified_tx3', self.verified_tx, True)
+ self.network.trigger_callback('updated')
+
+
+ def hash_merkle_root(self, merkle_s, target_hash, pos):
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 )
+ 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 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_height()
-
- 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_height()
-
-
- def set_local_height(self):
- name = self.path()
- if os.path.exists(name):
- h = os.path.getsize(name)/80 - 1
- if self.local_height != h:
- self.local_height = h
-
-
- 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
+ def undo_verifications(self, height):
+ with self.lock:
+ items = self.verified_tx.items()[:]
+ for tx_hash, item in items:
+ tx_height, timestamp, pos = item
+ if tx_height >= height:
+ print_error("redoing", tx_hash)
+ with self.lock:
+ self.verified_tx.pop(tx_hash)
+ if tx_hash in self.merkle_roots:
+ self.merkle_roots.pop(tx_hash)