p2pool/bitcoin/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4
   5 import p2pool
   6 from p2pool.util import math, pack
   7
   8 def hash256(data):
   9     return pack.IntType(256).unpack(hashlib.sha256(hashlib.sha256(data).digest()).digest())
  10
  11 def hash160(data):
  12     return pack.IntType(160).unpack(hashlib.new('ripemd160', hashlib.sha256(data).digest()).digest())
  13
  14 class ChecksummedType(pack.Type):
  15     def __init__(self, inner, checksum_func=lambda data: hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]):
  16         self.inner = inner
  17         self.checksum_func = checksum_func
  18
  19     def read(self, file):
  20         obj, file = self.inner.read(file)
  21         data = self.inner.pack(obj)
  22
  23         calculated_checksum = self.checksum_func(data)
  24         checksum, file = pack.read(file, len(calculated_checksum))
  25         if checksum != calculated_checksum:
  26             raise ValueError('invalid checksum')
  27
  28         return obj, file
  29
  30     def write(self, file, item):
  31         data = self.inner.pack(item)
  32         return (file, data), self.checksum_func(data)
  33
  34 class FloatingInteger(object):
  35     __slots__ = ['bits', '_target']
  36
  37     @classmethod
  38     def from_target_upper_bound(cls, target):
  39         n = math.natural_to_string(target)
  40         if n and ord(n[0]) >= 128:
  41             n = '\x00' + n
  42         bits2 = (chr(len(n)) + (n + 3*chr(0))[:3])[::-1]
  43         bits = pack.IntType(32).unpack(bits2)
  44         return cls(bits)
  45
  46     def __init__(self, bits, target=None):
  47         self.bits = bits
  48         self._target = None
  49         if target is not None and self.target != target:
  50             raise ValueError('target does not match')
  51
  52     @property
  53     def target(self):
  54         res = self._target
  55         if res is None:
  56             res = self._target = math.shift_left(self.bits & 0x00ffffff, 8 * ((self.bits >> 24) - 3))
  57         return res
  58
  59     def __hash__(self):
  60         return hash(self.bits)
  61
  62     def __eq__(self, other):
  63         return self.bits == other.bits
  64
  65     def __ne__(self, other):
  66         return not (self == other)
  67
  68     def __cmp__(self, other):
  69         assert False
  70
  71     def __repr__(self):
  72         return 'FloatingInteger(bits=%s, target=%s)' % (hex(self.bits), hex(self.target))
  73
  74 class FloatingIntegerType(pack.Type):
  75     _inner = pack.IntType(32)
  76
  77     def read(self, file):
  78         bits, file = self._inner.read(file)
  79         return FloatingInteger(bits), file
  80
  81     def write(self, file, item):
  82         return self._inner.write(file, item.bits)
  83
  84 address_type = pack.ComposedType([
  85     ('services', pack.IntType(64)),
  86     ('address', pack.IPV6AddressType()),
  87     ('port', pack.IntType(16, 'big')),
  88 ])
  89
  90 tx_type = pack.ComposedType([
  91     ('version', pack.IntType(32)),
  92     ('tx_ins', pack.ListType(pack.ComposedType([
  93         ('previous_output', pack.PossiblyNoneType(dict(hash=0, index=2**32 - 1), pack.ComposedType([
  94             ('hash', pack.IntType(256)),
  95             ('index', pack.IntType(32)),
  96         ]))),
  97         ('script', pack.VarStrType()),
  98         ('sequence', pack.PossiblyNoneType(2**32 - 1, pack.IntType(32))),
  99     ]))),
 100     ('tx_outs', pack.ListType(pack.ComposedType([
 101         ('value', pack.IntType(64)),
 102         ('script', pack.VarStrType()),
 103     ]))),
 104     ('lock_time', pack.IntType(32)),
 105 ])
 106
 107 merkle_link_type = pack.ComposedType([
 108     ('branch', pack.ListType(pack.IntType(256))),
 109     ('index', pack.IntType(32)),
 110 ])
 111
 112 merkle_tx_type = pack.ComposedType([
 113     ('tx', tx_type),
 114     ('block_hash', pack.IntType(256)),
 115     ('merkle_link', merkle_link_type),
 116 ])
 117
 118 block_header_type = pack.ComposedType([
 119     ('version', pack.IntType(32)),
 120     ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 121     ('merkle_root', pack.IntType(256)),
 122     ('timestamp', pack.IntType(32)),
 123     ('bits', FloatingIntegerType()),
 124     ('nonce', pack.IntType(32)),
 125 ])
 126
 127 block_type = pack.ComposedType([
 128     ('header', block_header_type),
 129     ('txs', pack.ListType(tx_type)),
 130 ])
 131
 132 # merged mining
 133
 134 aux_pow_type = pack.ComposedType([
 135     ('merkle_tx', merkle_tx_type),
 136     ('merkle_link', merkle_link_type),
 137     ('parent_block_header', block_header_type),
 138 ])
 139
 140 aux_pow_coinbase_type = pack.ComposedType([
 141     ('merkle_root', pack.IntType(256, 'big')),
 142     ('size', pack.IntType(32)),
 143     ('nonce', pack.IntType(32)),
 144 ])
 145
 146 def make_auxpow_tree(chain_ids):
 147     for size in (2**i for i in xrange(31)):
 148         if size < len(chain_ids):
 149             continue
 150         res = {}
 151         for chain_id in chain_ids:
 152             pos = (1103515245 * chain_id + 1103515245 * 12345 + 12345) % size
 153             if pos in res:
 154                 break
 155             res[pos] = chain_id
 156         else:
 157             return res, size
 158     raise AssertionError()
 159
 160 # merkle trees
 161
 162 merkle_record_type = pack.ComposedType([
 163     ('left', pack.IntType(256)),
 164     ('right', pack.IntType(256)),
 165 ])
 166
 167 def merkle_hash(hashes):
 168     if not hashes:
 169         return 0
 170     hash_list = list(hashes)
 171     while len(hash_list) > 1:
 172         hash_list = [hash256(merkle_record_type.pack(dict(left=left, right=right)))
 173             for left, right in zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])]
 174     return hash_list[0]
 175
 176 def calculate_merkle_link(hashes, index):
 177     # XXX optimize this
 178
 179     hash_list = [(h, i == index, []) for i, h in enumerate(hashes)]
 180
 181     while len(hash_list) > 1:
 182         hash_list = [
 183             (
 184                 hash256(merkle_record_type.pack(dict(left=left, right=right))),
 185                 left_f or right_f,
 186                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
 187             )
 188             for (left, left_f, left_l), (right, right_f, right_l) in
 189                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
 190         ]
 191
 192     res = [x['hash'] for x in hash_list[0][2]]
 193
 194     assert hash_list[0][1]
 195     if p2pool.DEBUG:
 196         assert check_merkle_branch(hashes[index], index, res) == hash_list[0][0]
 197     assert index == sum(k*2**i for i, k in enumerate([1-x['side'] for x in hash_list[0][2]]))
 198
 199     return dict(branch=res, index=index)
 200
 201 def check_merkle_link(tip_hash, link):
 202     if link['index'] >= 2**len(link['branch']):
 203         raise ValueError('index too large')
 204     return reduce(lambda c, (i, h): hash256(merkle_record_type.pack(
 205         dict(left=h, right=c) if (link['index'] >> i) & 1 else
 206         dict(left=c, right=h)
 207     )), enumerate(link['branch']), tip_hash)
 208
 209 # targets
 210
 211 def target_to_average_attempts(target):
 212     return 2**256//(target + 1)
 213
 214 def target_to_difficulty(target):
 215     return (0xffff0000 * 2**(256-64) + 1)/(target + 1)
 216
 217 def difficulty_to_target(difficulty):
 218     return (0xffff0000 * 2**(256-64) + 1)/difficulty - 1
 219
 220 # tx
 221
 222 def tx_get_sigop_count(tx):
 223     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'])
 224
 225 # human addresses
 226
 227 base58_alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 228
 229 def base58_encode(bindata):
 230     bindata2 = bindata.lstrip(chr(0))
 231     return base58_alphabet[0]*(len(bindata) - len(bindata2)) + math.natural_to_string(math.string_to_natural(bindata2), base58_alphabet)
 232
 233 def base58_decode(b58data):
 234     b58data2 = b58data.lstrip(base58_alphabet[0])
 235     return chr(0)*(len(b58data) - len(b58data2)) + math.natural_to_string(math.string_to_natural(b58data2, base58_alphabet))
 236
 237 human_address_type = ChecksummedType(pack.ComposedType([
 238     ('version', pack.IntType(8)),
 239     ('pubkey_hash', pack.IntType(160)),
 240 ]))
 241
 242 def pubkey_hash_to_address(pubkey_hash, net):
 243     return base58_encode(human_address_type.pack(dict(version=net.ADDRESS_VERSION, pubkey_hash=pubkey_hash)))
 244
 245 def pubkey_to_address(pubkey, net):
 246     return pubkey_hash_to_address(hash160(pubkey), net)
 247
 248 def address_to_pubkey_hash(address, net):
 249     x = human_address_type.unpack(base58_decode(address))
 250     if x['version'] != net.ADDRESS_VERSION:
 251         raise ValueError('address not for this net!')
 252     return x['pubkey_hash']
 253
 254 # transactions
 255
 256 def pubkey_to_script2(pubkey):
 257     assert len(pubkey) <= 75
 258     return (chr(len(pubkey)) + pubkey) + '\xac'
 259
 260 def pubkey_hash_to_script2(pubkey_hash):
 261     return '\x76\xa9' + ('\x14' + pack.IntType(160).pack(pubkey_hash)) + '\x88\xac'
 262
 263 def script2_to_address(script2, net):
 264     try:
 265         pubkey = script2[1:-1]
 266         script2_test = pubkey_to_script2(pubkey)
 267     except:
 268         pass
 269     else:
 270         if script2_test == script2:
 271             return pubkey_to_address(pubkey, net)
 272
 273     try:
 274         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 275         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 276     except:
 277         pass
 278     else:
 279         if script2_test2 == script2:
 280             return pubkey_hash_to_address(pubkey_hash, net)
 281
 282 def script2_to_human(script2, net):
 283     try:
 284         pubkey = script2[1:-1]
 285         script2_test = pubkey_to_script2(pubkey)
 286     except:
 287         pass
 288     else:
 289         if script2_test == script2:
 290             return 'Pubkey. Address: %s' % (pubkey_to_address(pubkey, net),)
 291
 292     try:
 293         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 294         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 295     except:
 296         pass
 297     else:
 298         if script2_test2 == script2:
 299             return 'Address. Address: %s' % (pubkey_hash_to_address(pubkey_hash, net),)
 300
 301     return 'Unknown. Script: %s'  % (script2.encode('hex'),)