p2pool/bitcoin/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4
   5 from p2pool.util import bases, math, pack
   6
   7 class ChecksummedType(pack.Type):
   8     def __init__(self, inner):
   9         self.inner = inner
  10
  11     def read(self, file):
  12         obj, file = self.inner.read(file)
  13         data = self.inner.pack(obj)
  14
  15         checksum, file = pack.read(file, 4)
  16         if checksum != hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]:
  17             raise ValueError('invalid checksum')
  18
  19         return obj, file
  20
  21     def write(self, file, item):
  22         data = self.inner.pack(item)
  23         return (file, data), hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]
  24
  25 class FloatingInteger(object):
  26     __slots__ = ['bits', '_target']
  27
  28     @classmethod
  29     def from_target_upper_bound(cls, target):
  30         n = bases.natural_to_string(target)
  31         if n and ord(n[0]) >= 128:
  32             n = '\x00' + n
  33         bits2 = (chr(len(n)) + (n + 3*chr(0))[:3])[::-1]
  34         bits = pack.IntType(32).unpack(bits2)
  35         return cls(bits)
  36
  37     def __init__(self, bits, target=None):
  38         self.bits = bits
  39         self._target = None
  40         if target is not None and self.target != target:
  41             raise ValueError('target does not match')
  42
  43     @property
  44     def target(self):
  45         res = self._target
  46         if res is None:
  47             res = self._target = math.shift_left(self.bits & 0x00ffffff, 8 * ((self.bits >> 24) - 3))
  48         return res
  49
  50     def __hash__(self):
  51         return hash(self.bits)
  52
  53     def __eq__(self, other):
  54         return self.bits == other.bits
  55
  56     def __ne__(self, other):
  57         return not (self == other)
  58
  59     def __cmp__(self, other):
  60         assert False
  61
  62     def __repr__(self):
  63         return 'FloatingInteger(bits=%s, target=%s)' % (hex(self.bits), hex(self.target))
  64
  65 class FloatingIntegerType(pack.Type):
  66     _inner = pack.IntType(32)
  67
  68     def read(self, file):
  69         bits, file = self._inner.read(file)
  70         return FloatingInteger(bits), file
  71
  72     def write(self, file, item):
  73         return self._inner.write(file, item.bits)
  74
  75 address_type = pack.ComposedType([
  76     ('services', pack.IntType(64)),
  77     ('address', pack.IPV6AddressType()),
  78     ('port', pack.IntType(16, 'big')),
  79 ])
  80
  81 tx_type = pack.ComposedType([
  82     ('version', pack.IntType(32)),
  83     ('tx_ins', pack.ListType(pack.ComposedType([
  84         ('previous_output', pack.PossiblyNoneType(dict(hash=0, index=2**32 - 1), pack.ComposedType([
  85             ('hash', pack.IntType(256)),
  86             ('index', pack.IntType(32)),
  87         ]))),
  88         ('script', pack.VarStrType()),
  89         ('sequence', pack.PossiblyNoneType(2**32 - 1, pack.IntType(32))),
  90     ]))),
  91     ('tx_outs', pack.ListType(pack.ComposedType([
  92         ('value', pack.IntType(64)),
  93         ('script', pack.VarStrType()),
  94     ]))),
  95     ('lock_time', pack.IntType(32)),
  96 ])
  97
  98 merkle_branch_type = pack.ListType(pack.IntType(256))
  99
 100 merkle_tx_type = pack.ComposedType([
 101     ('tx', tx_type),
 102     ('block_hash', pack.IntType(256)),
 103     ('merkle_branch', merkle_branch_type),
 104     ('index', pack.IntType(32)),
 105 ])
 106
 107 block_header_type = pack.ComposedType([
 108     ('version', pack.IntType(32)),
 109     ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 110     ('merkle_root', pack.IntType(256)),
 111     ('timestamp', pack.IntType(32)),
 112     ('bits', FloatingIntegerType()),
 113     ('nonce', pack.IntType(32)),
 114 ])
 115
 116 block_type = pack.ComposedType([
 117     ('header', block_header_type),
 118     ('txs', pack.ListType(tx_type)),
 119 ])
 120
 121 aux_pow_type = pack.ComposedType([
 122     ('merkle_tx', merkle_tx_type),
 123     ('merkle_branch', merkle_branch_type),
 124     ('index', pack.IntType(32)),
 125     ('parent_block_header', block_header_type),
 126 ])
 127
 128
 129 merkle_record_type = pack.ComposedType([
 130     ('left', pack.IntType(256)),
 131     ('right', pack.IntType(256)),
 132 ])
 133
 134 def merkle_hash(hashes):
 135     if not hashes:
 136         return 0
 137     hash_list = list(hashes)
 138     while len(hash_list) > 1:
 139         hash_list = [merkle_record_type.hash256(dict(left=left, right=left if right is None else right))
 140             for left, right in zip(hash_list[::2], hash_list[1::2] + [None])]
 141     return hash_list[0]
 142
 143 def calculate_merkle_branch(hashes, index):
 144     # XXX optimize this
 145
 146     hash_list = [(h, i == index, []) for i, h in enumerate(hashes)]
 147
 148     while len(hash_list) > 1:
 149         hash_list = [
 150             (
 151                 merkle_record_type.hash256(dict(left=left, right=right)),
 152                 left_f or right_f,
 153                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
 154             )
 155             for (left, left_f, left_l), (right, right_f, right_l) in
 156                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
 157         ]
 158
 159     res = [x['hash'] for x in hash_list[0][2]]
 160
 161     assert hash_list[0][1]
 162     assert check_merkle_branch(hashes[index], index, res) == hash_list[0][0]
 163     assert index == sum(k*2**i for i, k in enumerate([1-x['side'] for x in hash_list[0][2]]))
 164
 165     return res
 166
 167 def check_merkle_branch(tip_hash, index, merkle_branch):
 168     return reduce(lambda c, (i, h): merkle_record_type.hash256(
 169         dict(left=h, right=c) if 2**i & index else
 170         dict(left=c, right=h)
 171     ), enumerate(merkle_branch), tip_hash)
 172
 173 def target_to_average_attempts(target):
 174     return 2**256//(target + 1)
 175
 176 def target_to_difficulty(target):
 177     return (0xffff0000 * 2**(256-64) + 1)/(target + 1)
 178
 179 # tx
 180
 181 def tx_get_sigop_count(tx):
 182     return sum(script.get_sigop_count(txin['script']) for txin in tx['tx_ins']) + sum(script.get_sigop_count(txout['script']) for txout in tx['tx_outs'])
 183
 184 # human addresses
 185
 186 human_address_type = ChecksummedType(pack.ComposedType([
 187     ('version', pack.IntType(8)),
 188     ('pubkey_hash', pack.IntType(160)),
 189 ]))
 190
 191 pubkey_type = pack.PassthruType()
 192
 193 def pubkey_hash_to_address(pubkey_hash, net):
 194     return human_address_type.pack_base58(dict(version=net.ADDRESS_VERSION, pubkey_hash=pubkey_hash))
 195
 196 def pubkey_to_address(pubkey, net):
 197     return pubkey_hash_to_address(pubkey_type.hash160(pubkey), net)
 198
 199 def address_to_pubkey_hash(address, net):
 200     x = human_address_type.unpack_base58(address)
 201     if x['version'] != net.ADDRESS_VERSION:
 202         raise ValueError('address not for this net!')
 203     return x['pubkey_hash']
 204
 205 # transactions
 206
 207 def pubkey_to_script2(pubkey):
 208     return ('\x41' + pubkey_type.pack(pubkey)) + '\xac'
 209
 210 def pubkey_hash_to_script2(pubkey_hash):
 211     return '\x76\xa9' + ('\x14' + pack.IntType(160).pack(pubkey_hash)) + '\x88\xac'
 212
 213 def script2_to_address(script2, net):
 214     try:
 215         pubkey = script2[1:-1]
 216         script2_test = pubkey_to_script2(pubkey)
 217     except:
 218         pass
 219     else:
 220         if script2_test == script2:
 221             return pubkey_to_address(pubkey, net)
 222
 223     try:
 224         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 225         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 226     except:
 227         pass
 228     else:
 229         if script2_test2 == script2:
 230             return pubkey_hash_to_address(pubkey_hash, net)
 231
 232 def script2_to_human(script2, net):
 233     try:
 234         pubkey = script2[1:-1]
 235         script2_test = pubkey_to_script2(pubkey)
 236     except:
 237         pass
 238     else:
 239         if script2_test == script2:
 240             return 'Pubkey. Address: %s' % (pubkey_to_address(pubkey, net),)
 241
 242     try:
 243         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 244         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 245     except:
 246         pass
 247     else:
 248         if script2_test2 == script2:
 249             return 'Address. Address: %s' % (pubkey_hash_to_address(pubkey_hash, net),)
 250
 251     return 'Unknown. Script: %s'  % (script2.encode('hex'),)