1 from __future__ import division
8 from p2pool.util import bases, expiring_dict, math
10 class EarlyEnd(Exception):
13 class LateEnd(Exception):
16 def read((data, pos), length):
17 data2 = data[pos:pos + length]
18 if len(data2) != length:
20 return data2, (data, pos + length)
23 # the same data can have only one unpacked representation, but multiple packed binary representations
26 # return hash(tuple(self.__dict__.items()))
28 #def __eq__(self, other):
29 # if not isinstance(other, Type):
30 # raise NotImplementedError()
31 # return self.__dict__ == other.__dict__
33 def _unpack(self, data):
34 obj, (data2, pos) = self.read((data, 0))
44 f = self.write(None, obj)
54 def unpack(self, data):
55 obj = self._unpack(data)
58 data2 = self._pack(obj)
60 assert self._unpack(data2) == obj
65 data = self._pack(obj)
67 assert self._unpack(data) == obj
72 def pack_base58(self, obj):
73 return base58.base58_encode(self.pack(obj))
75 def unpack_base58(self, base58_data):
76 return self.unpack(base58.base58_decode(base58_data))
79 def hash160(self, obj):
80 return ShortHashType().unpack(hashlib.new('ripemd160', hashlib.sha256(self.pack(obj)).digest()).digest())
82 def hash256(self, obj):
83 return HashType().unpack(hashlib.sha256(hashlib.sha256(self.pack(obj)).digest()).digest())
85 class VarIntType(Type):
86 # redundancy doesn't matter here because bitcoin and p2pool both reencode before hashing
88 data, file = read(file, 1)
93 desc, length = '<H', 2
95 desc, length = '<I', 4
97 desc, length = '<Q', 8
99 raise AssertionError()
100 data, file = read(file, length)
101 return struct.unpack(desc, data)[0], file
103 def write(self, file, item):
105 file = file, struct.pack('<B', item)
107 file = file, struct.pack('<BH', 0xfd, item)
108 elif item <= 0xffffffff:
109 file = file, struct.pack('<BI', 0xfe, item)
110 elif item <= 0xffffffffffffffff:
111 file = file, struct.pack('<BQ', 0xff, item)
113 raise ValueError('int too large for varint')
116 class VarStrType(Type):
117 _inner_size = VarIntType()
119 def read(self, file):
120 length, file = self._inner_size.read(file)
121 return read(file, length)
123 def write(self, file, item):
124 file = self._inner_size.write(file, len(item))
127 class FixedStrType(Type):
128 def __init__(self, length):
131 def read(self, file):
132 return read(file, self.length)
134 def write(self, file, item):
135 if len(item) != self.length:
136 raise ValueError('incorrect length!')
139 class EnumType(Type):
140 def __init__(self, inner, values):
145 for k, v in values.iteritems():
147 raise ValueError('duplicate value in values')
150 def read(self, file):
151 data, file = self.inner.read(file)
152 return self.keys[data], file
154 def write(self, file, item):
155 return self.inner.write(file, self.values[item])
157 class HashType(Type):
158 def read(self, file):
159 data, file = read(file, 256//8)
160 return int(data[::-1].encode('hex'), 16), file
162 def write(self, file, item):
163 if not 0 <= item < 2**256:
164 raise ValueError("invalid hash value")
165 if item != 0 and item < 2**160:
166 warnings.warn("very low hash value - maybe you meant to use ShortHashType? %x" % (item,))
167 return file, ('%064x' % (item,)).decode('hex')[::-1]
169 class ShortHashType(Type):
170 def read(self, file):
171 data, file = read(file, 160//8)
172 return int(data[::-1].encode('hex'), 16), file
174 def write(self, file, item):
176 raise ValueError("invalid hash value")
177 return file, ('%040x' % (item,)).decode('hex')[::-1]
179 class ListType(Type):
180 _inner_size = VarIntType()
182 def __init__(self, type):
185 def read(self, file):
186 length, file = self._inner_size.read(file)
188 for i in xrange(length):
189 item, file = self.type.read(file)
193 def write(self, file, item):
194 file = self._inner_size.write(file, len(item))
196 file = self.type.write(file, subitem)
199 class FastLittleEndianUnsignedInteger(Type):
200 def read(self, file):
201 data, file = read(file, 4)
202 data = map(ord, data)
203 return data[0] + (data[1] << 8) + (data[2] << 16) + (data[3] << 24), file
205 def write(self, file, item):
206 return StructType("<I").write(file, item)
208 class StructType(Type):
209 def __init__(self, desc):
211 self.length = struct.calcsize(self.desc)
213 def read(self, file):
214 data, file = read(file, self.length)
215 res, = struct.unpack(self.desc, data)
218 def write(self, file, item):
219 data = struct.pack(self.desc, item)
220 if struct.unpack(self.desc, data)[0] != item:
221 # special test because struct doesn't error on some overflows
222 raise ValueError("item didn't survive pack cycle (%r)" % (item,))
225 class IPV6AddressType(Type):
226 def read(self, file):
227 data, file = read(file, 16)
228 if data[:12] != '00000000000000000000ffff'.decode('hex'):
229 raise ValueError("ipv6 addresses not supported yet")
230 return '.'.join(str(ord(x)) for x in data[12:]), file
232 def write(self, file, item):
233 bits = map(int, item.split('.'))
235 raise ValueError("invalid address: %r" % (bits,))
236 data = '00000000000000000000ffff'.decode('hex') + ''.join(chr(x) for x in bits)
237 assert len(data) == 16, len(data)
240 class ComposedType(Type):
241 def __init__(self, fields):
244 def read(self, file):
246 for key, type_ in self.fields:
247 item[key], file = type_.read(file)
250 def write(self, file, item):
251 for key, type_ in self.fields:
252 file = type_.write(file, item[key])
255 class ChecksummedType(Type):
256 def __init__(self, inner):
259 def read(self, file):
260 obj, file = self.inner.read(file)
261 data = self.inner.pack(obj)
263 if file.read(4) != hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]:
264 raise ValueError("invalid checksum")
268 def write(self, file, item):
269 data = self.inner.pack(item)
271 return file, hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]
273 class FloatingIntegerType(Type):
274 # redundancy doesn't matter here because bitcoin checks binary bits against its own computed bits
275 # so it will always be encoded 'normally' in blocks (they way bitcoin does it)
276 _inner = StructType("<I")
277 _inner = FastLittleEndianUnsignedInteger()
279 def read(self, file):
280 bits, file = self._inner.read(file)
281 target = self._bits_to_target(bits)
283 if self._target_to_bits(target) != bits:
284 raise ValueError("bits in non-canonical form")
287 def write(self, file, item):
288 return self._inner.write(file, self._target_to_bits(item))
290 def truncate_to(self, x):
291 return self._bits_to_target(self._target_to_bits(x, _check=False))
293 def _bits_to_target(self, bits2):
294 target = math.shift_left(bits2 & 0x00ffffff, 8 * ((bits2 >> 24) - 3))
295 assert target == self._bits_to_target1(struct.pack("<I", bits2))
296 assert self._target_to_bits(target, _check=False) == bits2
299 def _bits_to_target1(self, bits):
301 length = ord(bits[0])
302 return bases.string_to_natural((bits[1:] + "\0"*length)[:length])
304 def _target_to_bits(self, target, _check=True):
305 n = bases.natural_to_string(target)
306 if n and ord(n[0]) >= 128:
308 bits2 = (chr(len(n)) + (n + 3*chr(0))[:3])[::-1]
309 bits = struct.unpack("<I", bits2)[0]
311 if self._bits_to_target(bits) != target:
312 raise ValueError(repr((target, self._bits_to_target(bits, _check=False))))
315 class PossiblyNone(Type):
316 def __init__(self, none_value, inner):
317 self.none_value = none_value
320 def read(self, file):
321 value, file = self.inner.read(file)
322 return None if value == self.none_value else value, file
324 def write(self, file, item):
325 if item == self.none_value:
326 raise ValueError("none_value used")
327 return self.inner.write(file, self.none_value if item is None else item)
329 address_type = ComposedType([
330 ('services', StructType('<Q')),
331 ('address', IPV6AddressType()),
332 ('port', StructType('>H')),
335 tx_type = ComposedType([
336 ('version', StructType('<I')),
337 ('tx_ins', ListType(ComposedType([
338 ('previous_output', PossiblyNone(dict(hash=0, index=2**32 - 1), ComposedType([
339 ('hash', HashType()),
340 ('index', StructType('<I')),
342 ('script', VarStrType()),
343 ('sequence', PossiblyNone(2**32 - 1, StructType('<I'))),
345 ('tx_outs', ListType(ComposedType([
346 ('value', StructType('<Q')),
347 ('script', VarStrType()),
349 ('lock_time', StructType('<I')),
352 block_header_type = ComposedType([
353 ('version', StructType('<I')),
354 ('previous_block', PossiblyNone(0, HashType())),
355 ('merkle_root', HashType()),
356 ('timestamp', StructType('<I')),
357 ('target', FloatingIntegerType()),
358 ('nonce', StructType('<I')),
361 block_type = ComposedType([
362 ('header', block_header_type),
363 ('txs', ListType(tx_type)),
367 merkle_record_type = ComposedType([
368 ('left', HashType()),
369 ('right', HashType()),
372 def merkle_hash(tx_list):
375 hash_list = map(tx_type.hash256, tx_list)
376 while len(hash_list) > 1:
377 hash_list = [merkle_record_type.hash256(dict(left=left, right=left if right is None else right))
378 for left, right in zip(hash_list[::2], hash_list[1::2] + [None])]
381 def target_to_average_attempts(target):
382 return 2**256//(target + 1)
386 human_address_type = ChecksummedType(ComposedType([
387 ('version', StructType("<B")),
388 ('pubkey_hash', ShortHashType()),
391 pubkey_type = FixedStrType(65)
393 def pubkey_hash_to_address(pubkey_hash, net):
394 return human_address_type.pack_base58(dict(version=net.BITCOIN_ADDRESS_VERSION, pubkey_hash=pubkey_hash))
396 def pubkey_to_address(pubkey, net):
397 return pubkey_hash_to_address(pubkey_type.hash160(pubkey), net)
399 def address_to_pubkey_hash(address, net):
400 x = human_address_type.unpack_base58(address)
401 if x['version'] != net.BITCOIN_ADDRESS_VERSION:
402 raise ValueError('address not for this net!')
403 return x['pubkey_hash']
405 # network definitions
407 class Mainnet(object):
408 BITCOIN_P2P_PREFIX = 'f9beb4d9'.decode('hex')
409 BITCOIN_P2P_PORT = 8333
410 BITCOIN_ADDRESS_VERSION = 0
412 class Testnet(object):
413 BITCOIN_P2P_PREFIX = 'fabfb5da'.decode('hex')
414 BITCOIN_P2P_PORT = 18333
415 BITCOIN_ADDRESS_VERSION = 111