4 from electrum import Interface
5 from electrum.bitcoin import Hash, rev_hex, int_to_hex
7 """validate a transaction (SPV)"""
10 i = Interface({'server':'ecdsa.org:50002:s'})
14 def merkle_root(merkle):
16 merkle = map (lambda tx_hash: tx_hash.decode('hex')[::-1], merkle)
17 while len(merkle) != 1:
18 if len(merkle)%2: merkle.append( merkle[-1] )
21 n.append( Hash( merkle[0] + merkle[1] ) )
26 return merkle[0][::-1].encode('hex')
30 header = int_to_hex(res.get('version'),4) \
31 + rev_hex(res.get('prev_block_hash')) \
32 + rev_hex(res.get('merkle_root')) \
33 + int_to_hex(int(res.get('timestamp')),4) \
34 + int_to_hex(int(res.get('bits')),4) \
35 + int_to_hex(int(res.get('nonce')),4)
36 return rev_hex(Hash(header.decode('hex')).encode('hex'))
39 def verify_tx(tx_hash):
41 res = i.synchronous_get([ ('blockchain.transaction.get_merkle',[tx_hash]) ])[0]
42 assert tx_hash in res.get('merkle')
43 assert res.get('merkle_root') == merkle_root(res['merkle'])
44 block_height = res.get('block_height')
48 for height in range(block_height-10,block_height+10):
49 headers_requests.append( ('blockchain.block.get_header',[height]) )
50 res = i.synchronous_get(headers_requests)
54 if _hash: assert _hash == header.get('prev_block_hash')
55 _hash = hash_header(header)
57 if height==block_height:
58 assert header.get('merkle_root') == res.get('merkle_root')
65 tx = '587430e52af2cec98b3fd543083469ffa7a5f5dd2bd569898a7897a64e2eb031'