p2pool/bitcoin/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4 import itertools
   5 import random
   6
   7 import p2pool
   8 from p2pool.util import math, pack
   9
  10 def hash256(data):
  11     return pack.IntType(256).unpack(hashlib.sha256(hashlib.sha256(data).digest()).digest())
  12
  13 def hash160(data):
  14     return pack.IntType(160).unpack(hashlib.new('ripemd160', hashlib.sha256(data).digest()).digest())
  15
  16 class ChecksummedType(pack.Type):
  17     def __init__(self, inner):
  18         self.inner = inner
  19
  20     def read(self, file):
  21         obj, file = self.inner.read(file)
  22         data = self.inner.pack(obj)
  23
  24         checksum, file = pack.read(file, 4)
  25         if checksum != hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]:
  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), hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]
  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_branch_type = pack.ListType(pack.IntType(256))
 108
 109 merkle_tx_type = pack.ComposedType([
 110     ('tx', tx_type),
 111     ('block_hash', pack.IntType(256)),
 112     ('merkle_branch', merkle_branch_type),
 113     ('index', pack.IntType(32)),
 114 ])
 115
 116 block_header_type = pack.ComposedType([
 117     ('version', pack.IntType(32)),
 118     ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 119     ('merkle_root', pack.IntType(256)),
 120     ('timestamp', pack.IntType(32)),
 121     ('bits', FloatingIntegerType()),
 122     ('nonce', pack.IntType(32)),
 123 ])
 124
 125 block_type = pack.ComposedType([
 126     ('header', block_header_type),
 127     ('txs', pack.ListType(tx_type)),
 128 ])
 129
 130 # merged mining
 131
 132 aux_pow_type = pack.ComposedType([
 133     ('merkle_tx', merkle_tx_type),
 134     ('merkle_branch', merkle_branch_type),
 135     ('index', pack.IntType(32)),
 136     ('parent_block_header', block_header_type),
 137 ])
 138
 139 aux_pow_coinbase_type = pack.ComposedType([
 140     ('merkle_root', pack.IntType(256, 'big')),
 141     ('size', pack.IntType(32)),
 142     ('nonce', pack.IntType(32)),
 143 ])
 144
 145 def make_auxpow_tree(chain_ids):
 146     for size in (2**i for i in xrange(31)):
 147         if size < len(chain_ids):
 148             continue
 149         res = {}
 150         for chain_id in chain_ids:
 151             pos = (1103515245 * chain_id + 1103515245 * 12345 + 12345) % size
 152             if pos in res:
 153                 break
 154             res[pos] = chain_id
 155         else:
 156             return res, size
 157     raise AssertionError()
 158
 159 # merkle trees
 160
 161 merkle_record_type = pack.ComposedType([
 162     ('left', pack.IntType(256)),
 163     ('right', pack.IntType(256)),
 164 ])
 165
 166 def merkle_hash(hashes):
 167     if not hashes:
 168         return 0
 169     hash_list = list(hashes)
 170     while len(hash_list) > 1:
 171         hash_list = [hash256(merkle_record_type.pack(dict(left=left, right=left if right is None else right)))
 172             for left, right in zip(hash_list[::2], hash_list[1::2] + [None])]
 173     return hash_list[0]
 174
 175 def calculate_merkle_branch(hashes, index):
 176     # XXX optimize this
 177
 178     hash_list = [(h, i == index, []) for i, h in enumerate(hashes)]
 179
 180     while len(hash_list) > 1:
 181         hash_list = [
 182             (
 183                 hash256(merkle_record_type.pack(dict(left=left, right=right))),
 184                 left_f or right_f,
 185                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
 186             )
 187             for (left, left_f, left_l), (right, right_f, right_l) in
 188                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
 189         ]
 190
 191     res = [x['hash'] for x in hash_list[0][2]]
 192
 193     assert hash_list[0][1]
 194     if p2pool.DEBUG:
 195         assert check_merkle_branch(hashes[index], index, res) == hash_list[0][0]
 196     assert index == sum(k*2**i for i, k in enumerate([1-x['side'] for x in hash_list[0][2]]))
 197
 198     return res
 199
 200 def check_merkle_branch(tip_hash, index, merkle_branch):
 201     return reduce(lambda c, (i, h): hash256(merkle_record_type.pack(
 202         dict(left=h, right=c) if 2**i & index else
 203         dict(left=c, right=h)
 204     )), enumerate(merkle_branch), tip_hash)
 205
 206 # targets
 207
 208 def target_to_average_attempts(target):
 209     return 2**256//(target + 1)
 210
 211 def target_to_difficulty(target):
 212     return (0xffff0000 * 2**(256-64) + 1)/(target + 1)
 213
 214 # tx
 215
 216 def tx_get_sigop_count(tx):
 217     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'])
 218
 219 # human addresses
 220
 221 base58_alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 222
 223 def base58_encode(bindata):
 224     bindata2 = bindata.lstrip(chr(0))
 225     return base58_alphabet[0]*(len(bindata) - len(bindata2)) + math.natural_to_string(math.string_to_natural(bindata2), base58_alphabet)
 226
 227 def base58_decode(b58data):
 228     b58data2 = b58data.lstrip(base58_alphabet[0])
 229     return chr(0)*(len(b58data) - len(b58data2)) + math.natural_to_string(math.string_to_natural(b58data2, base58_alphabet))
 230
 231 human_address_type = ChecksummedType(pack.ComposedType([
 232     ('version', pack.IntType(8)),
 233     ('pubkey_hash', pack.IntType(160)),
 234 ]))
 235
 236 def pubkey_hash_to_address(pubkey_hash, net):
 237     return base58_encode(human_address_type.pack(dict(version=net.ADDRESS_VERSION, pubkey_hash=pubkey_hash)))
 238
 239 def pubkey_to_address(pubkey, net):
 240     return pubkey_hash_to_address(hash160(pubkey), net)
 241
 242 def address_to_pubkey_hash(address, net):
 243     x = human_address_type.unpack(base58_decode(address))
 244     if x['version'] != net.ADDRESS_VERSION:
 245         raise ValueError('address not for this net!')
 246     return x['pubkey_hash']
 247
 248 # transactions
 249
 250 def pubkey_to_script2(pubkey):
 251     assert len(pubkey) <= 75
 252     return (chr(len(pubkey)) + pubkey) + '\xac'
 253
 254 def pubkey_hash_to_script2(pubkey_hash):
 255     return '\x76\xa9' + ('\x14' + pack.IntType(160).pack(pubkey_hash)) + '\x88\xac'
 256
 257 def script2_to_address(script2, net):
 258     try:
 259         pubkey = script2[1:-1]
 260         script2_test = pubkey_to_script2(pubkey)
 261     except:
 262         pass
 263     else:
 264         if script2_test == script2:
 265             return pubkey_to_address(pubkey, net)
 266
 267     try:
 268         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 269         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 270     except:
 271         pass
 272     else:
 273         if script2_test2 == script2:
 274             return pubkey_hash_to_address(pubkey_hash, net)
 275
 276 def script2_to_human(script2, net):
 277     try:
 278         pubkey = script2[1:-1]
 279         script2_test = pubkey_to_script2(pubkey)
 280     except:
 281         pass
 282     else:
 283         if script2_test == script2:
 284             return 'Pubkey. Address: %s' % (pubkey_to_address(pubkey, net),)
 285
 286     try:
 287         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 288         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 289     except:
 290         pass
 291     else:
 292         if script2_test2 == script2:
 293             return 'Address. Address: %s' % (pubkey_hash_to_address(pubkey_hash, net),)
 294
 295     return 'Unknown. Script: %s'  % (script2.encode('hex'),)