p2pool/bitcoin/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4
   5 from p2pool.util import bases, math, pack
   6 from . import base58
   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):
  16         self.inner = inner
  17
  18     def read(self, file):
  19         obj, file = self.inner.read(file)
  20         data = self.inner.pack(obj)
  21
  22         checksum, file = pack.read(file, 4)
  23         if checksum != hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]:
  24             raise ValueError('invalid checksum')
  25
  26         return obj, file
  27
  28     def write(self, file, item):
  29         data = self.inner.pack(item)
  30         return (file, data), hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]
  31
  32 class FloatingInteger(object):
  33     __slots__ = ['bits', '_target']
  34
  35     @classmethod
  36     def from_target_upper_bound(cls, target):
  37         n = bases.natural_to_string(target)
  38         if n and ord(n[0]) >= 128:
  39             n = '\x00' + n
  40         bits2 = (chr(len(n)) + (n + 3*chr(0))[:3])[::-1]
  41         bits = pack.IntType(32).unpack(bits2)
  42         return cls(bits)
  43
  44     def __init__(self, bits, target=None):
  45         self.bits = bits
  46         self._target = None
  47         if target is not None and self.target != target:
  48             raise ValueError('target does not match')
  49
  50     @property
  51     def target(self):
  52         res = self._target
  53         if res is None:
  54             res = self._target = math.shift_left(self.bits & 0x00ffffff, 8 * ((self.bits >> 24) - 3))
  55         return res
  56
  57     def __hash__(self):
  58         return hash(self.bits)
  59
  60     def __eq__(self, other):
  61         return self.bits == other.bits
  62
  63     def __ne__(self, other):
  64         return not (self == other)
  65
  66     def __cmp__(self, other):
  67         assert False
  68
  69     def __repr__(self):
  70         return 'FloatingInteger(bits=%s, target=%s)' % (hex(self.bits), hex(self.target))
  71
  72 class FloatingIntegerType(pack.Type):
  73     _inner = pack.IntType(32)
  74
  75     def read(self, file):
  76         bits, file = self._inner.read(file)
  77         return FloatingInteger(bits), file
  78
  79     def write(self, file, item):
  80         return self._inner.write(file, item.bits)
  81
  82 address_type = pack.ComposedType([
  83     ('services', pack.IntType(64)),
  84     ('address', pack.IPV6AddressType()),
  85     ('port', pack.IntType(16, 'big')),
  86 ])
  87
  88 tx_type = pack.ComposedType([
  89     ('version', pack.IntType(32)),
  90     ('tx_ins', pack.ListType(pack.ComposedType([
  91         ('previous_output', pack.PossiblyNoneType(dict(hash=0, index=2**32 - 1), pack.ComposedType([
  92             ('hash', pack.IntType(256)),
  93             ('index', pack.IntType(32)),
  94         ]))),
  95         ('script', pack.VarStrType()),
  96         ('sequence', pack.PossiblyNoneType(2**32 - 1, pack.IntType(32))),
  97     ]))),
  98     ('tx_outs', pack.ListType(pack.ComposedType([
  99         ('value', pack.IntType(64)),
 100         ('script', pack.VarStrType()),
 101     ]))),
 102     ('lock_time', pack.IntType(32)),
 103 ])
 104
 105 merkle_branch_type = pack.ListType(pack.IntType(256))
 106
 107 merkle_tx_type = pack.ComposedType([
 108     ('tx', tx_type),
 109     ('block_hash', pack.IntType(256)),
 110     ('merkle_branch', merkle_branch_type),
 111     ('index', pack.IntType(32)),
 112 ])
 113
 114 block_header_type = pack.ComposedType([
 115     ('version', pack.IntType(32)),
 116     ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 117     ('merkle_root', pack.IntType(256)),
 118     ('timestamp', pack.IntType(32)),
 119     ('bits', FloatingIntegerType()),
 120     ('nonce', pack.IntType(32)),
 121 ])
 122
 123 block_type = pack.ComposedType([
 124     ('header', block_header_type),
 125     ('txs', pack.ListType(tx_type)),
 126 ])
 127
 128 aux_pow_type = pack.ComposedType([
 129     ('merkle_tx', merkle_tx_type),
 130     ('merkle_branch', merkle_branch_type),
 131     ('index', pack.IntType(32)),
 132     ('parent_block_header', block_header_type),
 133 ])
 134
 135
 136 merkle_record_type = pack.ComposedType([
 137     ('left', pack.IntType(256)),
 138     ('right', pack.IntType(256)),
 139 ])
 140
 141 def merkle_hash(hashes):
 142     if not hashes:
 143         return 0
 144     hash_list = list(hashes)
 145     while len(hash_list) > 1:
 146         hash_list = [hash256(merkle_record_type.pack(dict(left=left, right=left if right is None else right)))
 147             for left, right in zip(hash_list[::2], hash_list[1::2] + [None])]
 148     return hash_list[0]
 149
 150 def calculate_merkle_branch(hashes, index):
 151     # XXX optimize this
 152
 153     hash_list = [(h, i == index, []) for i, h in enumerate(hashes)]
 154
 155     while len(hash_list) > 1:
 156         hash_list = [
 157             (
 158                 hash256(merkle_record_type.pack(dict(left=left, right=right))),
 159                 left_f or right_f,
 160                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
 161             )
 162             for (left, left_f, left_l), (right, right_f, right_l) in
 163                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
 164         ]
 165
 166     res = [x['hash'] for x in hash_list[0][2]]
 167
 168     assert hash_list[0][1]
 169     assert check_merkle_branch(hashes[index], index, res) == hash_list[0][0]
 170     assert index == sum(k*2**i for i, k in enumerate([1-x['side'] for x in hash_list[0][2]]))
 171
 172     return res
 173
 174 def check_merkle_branch(tip_hash, index, merkle_branch):
 175     return reduce(lambda c, (i, h): hash256(merkle_record_type.pack(
 176         dict(left=h, right=c) if 2**i & index else
 177         dict(left=c, right=h)
 178     )), enumerate(merkle_branch), tip_hash)
 179
 180 def target_to_average_attempts(target):
 181     return 2**256//(target + 1)
 182
 183 def target_to_difficulty(target):
 184     return (0xffff0000 * 2**(256-64) + 1)/(target + 1)
 185
 186 # tx
 187
 188 def tx_get_sigop_count(tx):
 189     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'])
 190
 191 # human addresses
 192
 193 human_address_type = ChecksummedType(pack.ComposedType([
 194     ('version', pack.IntType(8)),
 195     ('pubkey_hash', pack.IntType(160)),
 196 ]))
 197
 198 def pubkey_hash_to_address(pubkey_hash, net):
 199     return base58.encode(human_address_type.pack(dict(version=net.ADDRESS_VERSION, pubkey_hash=pubkey_hash)))
 200
 201 def pubkey_to_address(pubkey, net):
 202     return pubkey_hash_to_address(hash160(pubkey), net)
 203
 204 def address_to_pubkey_hash(address, net):
 205     x = human_address_type.unpack(base58.decode(address))
 206     if x['version'] != net.ADDRESS_VERSION:
 207         raise ValueError('address not for this net!')
 208     return x['pubkey_hash']
 209
 210 # transactions
 211
 212 def pubkey_to_script2(pubkey):
 213     return ('\x41' + pubkey) + '\xac'
 214
 215 def pubkey_hash_to_script2(pubkey_hash):
 216     return '\x76\xa9' + ('\x14' + pack.IntType(160).pack(pubkey_hash)) + '\x88\xac'
 217
 218 def script2_to_address(script2, net):
 219     try:
 220         pubkey = script2[1:-1]
 221         script2_test = pubkey_to_script2(pubkey)
 222     except:
 223         pass
 224     else:
 225         if script2_test == script2:
 226             return pubkey_to_address(pubkey, net)
 227
 228     try:
 229         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 230         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 231     except:
 232         pass
 233     else:
 234         if script2_test2 == script2:
 235             return pubkey_hash_to_address(pubkey_hash, net)
 236
 237 def script2_to_human(script2, net):
 238     try:
 239         pubkey = script2[1:-1]
 240         script2_test = pubkey_to_script2(pubkey)
 241     except:
 242         pass
 243     else:
 244         if script2_test == script2:
 245             return 'Pubkey. Address: %s' % (pubkey_to_address(pubkey, net),)
 246
 247     try:
 248         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 249         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 250     except:
 251         pass
 252     else:
 253         if script2_test2 == script2:
 254             return 'Address. Address: %s' % (pubkey_hash_to_address(pubkey_hash, net),)
 255
 256     return 'Unknown. Script: %s'  % (script2.encode('hex'),)