p2pool/bitcoin/data.py

   1 from __future__ import division
   2
   3 import hashlib
   4
   5 from p2pool.util import bases, math, pack
   6
   7 def hash256(data):
   8     return pack.IntType(256).unpack(hashlib.sha256(hashlib.sha256(data).digest()).digest())
   9
  10 def hash160(data):
  11     return pack.IntType(160).unpack(hashlib.new('ripemd160', hashlib.sha256(data).digest()).digest())
  12
  13 class ChecksummedType(pack.Type):
  14     def __init__(self, inner):
  15         self.inner = inner
  16
  17     def read(self, file):
  18         obj, file = self.inner.read(file)
  19         data = self.inner.pack(obj)
  20
  21         checksum, file = pack.read(file, 4)
  22         if checksum != hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]:
  23             raise ValueError('invalid checksum')
  24
  25         return obj, file
  26
  27     def write(self, file, item):
  28         data = self.inner.pack(item)
  29         return (file, data), hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]
  30
  31 class FloatingInteger(object):
  32     __slots__ = ['bits', '_target']
  33
  34     @classmethod
  35     def from_target_upper_bound(cls, target):
  36         n = bases.natural_to_string(target)
  37         if n and ord(n[0]) >= 128:
  38             n = '\x00' + n
  39         bits2 = (chr(len(n)) + (n + 3*chr(0))[:3])[::-1]
  40         bits = pack.IntType(32).unpack(bits2)
  41         return cls(bits)
  42
  43     def __init__(self, bits, target=None):
  44         self.bits = bits
  45         self._target = None
  46         if target is not None and self.target != target:
  47             raise ValueError('target does not match')
  48
  49     @property
  50     def target(self):
  51         res = self._target
  52         if res is None:
  53             res = self._target = math.shift_left(self.bits & 0x00ffffff, 8 * ((self.bits >> 24) - 3))
  54         return res
  55
  56     def __hash__(self):
  57         return hash(self.bits)
  58
  59     def __eq__(self, other):
  60         return self.bits == other.bits
  61
  62     def __ne__(self, other):
  63         return not (self == other)
  64
  65     def __cmp__(self, other):
  66         assert False
  67
  68     def __repr__(self):
  69         return 'FloatingInteger(bits=%s, target=%s)' % (hex(self.bits), hex(self.target))
  70
  71 class FloatingIntegerType(pack.Type):
  72     _inner = pack.IntType(32)
  73
  74     def read(self, file):
  75         bits, file = self._inner.read(file)
  76         return FloatingInteger(bits), file
  77
  78     def write(self, file, item):
  79         return self._inner.write(file, item.bits)
  80
  81 address_type = pack.ComposedType([
  82     ('services', pack.IntType(64)),
  83     ('address', pack.IPV6AddressType()),
  84     ('port', pack.IntType(16, 'big')),
  85 ])
  86
  87 tx_type = pack.ComposedType([
  88     ('version', pack.IntType(32)),
  89     ('tx_ins', pack.ListType(pack.ComposedType([
  90         ('previous_output', pack.PossiblyNoneType(dict(hash=0, index=2**32 - 1), pack.ComposedType([
  91             ('hash', pack.IntType(256)),
  92             ('index', pack.IntType(32)),
  93         ]))),
  94         ('script', pack.VarStrType()),
  95         ('sequence', pack.PossiblyNoneType(2**32 - 1, pack.IntType(32))),
  96     ]))),
  97     ('tx_outs', pack.ListType(pack.ComposedType([
  98         ('value', pack.IntType(64)),
  99         ('script', pack.VarStrType()),
 100     ]))),
 101     ('lock_time', pack.IntType(32)),
 102 ])
 103
 104 merkle_branch_type = pack.ListType(pack.IntType(256))
 105
 106 merkle_tx_type = pack.ComposedType([
 107     ('tx', tx_type),
 108     ('block_hash', pack.IntType(256)),
 109     ('merkle_branch', merkle_branch_type),
 110     ('index', pack.IntType(32)),
 111 ])
 112
 113 block_header_type = pack.ComposedType([
 114     ('version', pack.IntType(32)),
 115     ('previous_block', pack.PossiblyNoneType(0, pack.IntType(256))),
 116     ('merkle_root', pack.IntType(256)),
 117     ('timestamp', pack.IntType(32)),
 118     ('bits', FloatingIntegerType()),
 119     ('nonce', pack.IntType(32)),
 120 ])
 121
 122 block_type = pack.ComposedType([
 123     ('header', block_header_type),
 124     ('txs', pack.ListType(tx_type)),
 125 ])
 126
 127 aux_pow_type = pack.ComposedType([
 128     ('merkle_tx', merkle_tx_type),
 129     ('merkle_branch', merkle_branch_type),
 130     ('index', pack.IntType(32)),
 131     ('parent_block_header', block_header_type),
 132 ])
 133
 134
 135 merkle_record_type = pack.ComposedType([
 136     ('left', pack.IntType(256)),
 137     ('right', pack.IntType(256)),
 138 ])
 139
 140 def merkle_hash(hashes):
 141     if not hashes:
 142         return 0
 143     hash_list = list(hashes)
 144     while len(hash_list) > 1:
 145         hash_list = [hash256(merkle_record_type.pack(dict(left=left, right=left if right is None else right)))
 146             for left, right in zip(hash_list[::2], hash_list[1::2] + [None])]
 147     return hash_list[0]
 148
 149 def calculate_merkle_branch(hashes, index):
 150     # XXX optimize this
 151
 152     hash_list = [(h, i == index, []) for i, h in enumerate(hashes)]
 153
 154     while len(hash_list) > 1:
 155         hash_list = [
 156             (
 157                 hash256(merkle_record_type.pack(dict(left=left, right=right))),
 158                 left_f or right_f,
 159                 (left_l if left_f else right_l) + [dict(side=1, hash=right) if left_f else dict(side=0, hash=left)],
 160             )
 161             for (left, left_f, left_l), (right, right_f, right_l) in
 162                 zip(hash_list[::2], hash_list[1::2] + [hash_list[::2][-1]])
 163         ]
 164
 165     res = [x['hash'] for x in hash_list[0][2]]
 166
 167     assert hash_list[0][1]
 168     assert check_merkle_branch(hashes[index], index, res) == hash_list[0][0]
 169     assert index == sum(k*2**i for i, k in enumerate([1-x['side'] for x in hash_list[0][2]]))
 170
 171     return res
 172
 173 def check_merkle_branch(tip_hash, index, merkle_branch):
 174     return reduce(lambda c, (i, h): hash256(merkle_record_type.pack(
 175         dict(left=h, right=c) if 2**i & index else
 176         dict(left=c, right=h)
 177     )), enumerate(merkle_branch), tip_hash)
 178
 179 def target_to_average_attempts(target):
 180     return 2**256//(target + 1)
 181
 182 def target_to_difficulty(target):
 183     return (0xffff0000 * 2**(256-64) + 1)/(target + 1)
 184
 185 # tx
 186
 187 def tx_get_sigop_count(tx):
 188     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'])
 189
 190 # human addresses
 191
 192 base58_alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 193
 194 def base58_encode(bindata):
 195     bindata2 = bindata.lstrip(chr(0))
 196     return base58_alphabet[0]*(len(bindata) - len(bindata2)) + bases.natural_to_string(bases.string_to_natural(bindata2), base58_alphabet)
 197
 198 def base58_decode(b58data):
 199     b58data2 = b58data.lstrip(base58_alphabet[0])
 200     return chr(0)*(len(b58data) - len(b58data2)) + bases.natural_to_string(bases.string_to_natural(b58data2, base58_alphabet))
 201
 202 human_address_type = ChecksummedType(pack.ComposedType([
 203     ('version', pack.IntType(8)),
 204     ('pubkey_hash', pack.IntType(160)),
 205 ]))
 206
 207 def pubkey_hash_to_address(pubkey_hash, net):
 208     return base58_encode(human_address_type.pack(dict(version=net.ADDRESS_VERSION, pubkey_hash=pubkey_hash)))
 209
 210 def pubkey_to_address(pubkey, net):
 211     return pubkey_hash_to_address(hash160(pubkey), net)
 212
 213 def address_to_pubkey_hash(address, net):
 214     x = human_address_type.unpack(base58_decode(address))
 215     if x['version'] != net.ADDRESS_VERSION:
 216         raise ValueError('address not for this net!')
 217     return x['pubkey_hash']
 218
 219 # transactions
 220
 221 def pubkey_to_script2(pubkey):
 222     return ('\x41' + pubkey) + '\xac'
 223
 224 def pubkey_hash_to_script2(pubkey_hash):
 225     return '\x76\xa9' + ('\x14' + pack.IntType(160).pack(pubkey_hash)) + '\x88\xac'
 226
 227 def script2_to_address(script2, net):
 228     try:
 229         pubkey = script2[1:-1]
 230         script2_test = pubkey_to_script2(pubkey)
 231     except:
 232         pass
 233     else:
 234         if script2_test == script2:
 235             return pubkey_to_address(pubkey, net)
 236
 237     try:
 238         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 239         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 240     except:
 241         pass
 242     else:
 243         if script2_test2 == script2:
 244             return pubkey_hash_to_address(pubkey_hash, net)
 245
 246 def script2_to_human(script2, net):
 247     try:
 248         pubkey = script2[1:-1]
 249         script2_test = pubkey_to_script2(pubkey)
 250     except:
 251         pass
 252     else:
 253         if script2_test == script2:
 254             return 'Pubkey. Address: %s' % (pubkey_to_address(pubkey, net),)
 255
 256     try:
 257         pubkey_hash = pack.IntType(160).unpack(script2[3:-2])
 258         script2_test2 = pubkey_hash_to_script2(pubkey_hash)
 259     except:
 260         pass
 261     else:
 262         if script2_test2 == script2:
 263             return 'Address. Address: %s' % (pubkey_hash_to_address(pubkey_hash, net),)
 264
 265     return 'Unknown. Script: %s'  % (script2.encode('hex'),)