1 from __future__ import division
9 from p2pool.util import bases, expiring_dict, math
11 class EarlyEnd(Exception):
14 class LateEnd(Exception):
18 # the same data can have only one unpacked representation, but multiple packed binary representations
21 # return hash(tuple(self.__dict__.items()))
23 #def __eq__(self, other):
24 # if not isinstance(other, Type):
25 # raise NotImplementedError()
26 # return self.__dict__ == other.__dict__
28 def _unpack(self, data):
29 f = StringIO.StringIO(data)
33 if f.tell() != len(data):
34 raise LateEnd('underread ' + repr((self, data)))
38 def unpack(self, data):
39 obj = self._unpack(data)
41 data2 = self._pack(obj)
43 assert self._unpack(data2) == obj
48 f = StringIO.StringIO()
57 data = self._pack(obj)
58 assert self._unpack(data) == obj
63 def pack_base58(self, obj):
64 return base58.base58_encode(self.pack(obj))
66 def unpack_base58(self, base58_data):
67 return self.unpack(base58.base58_decode(base58_data))
70 def hash160(self, obj):
71 return ShortHashType().unpack(hashlib.new('ripemd160', hashlib.sha256(self.pack(obj)).digest()).digest())
73 def hash256(self, obj):
74 return HashType().unpack(hashlib.sha256(hashlib.sha256(self.pack(obj)).digest()).digest())
76 class VarIntType(Type):
81 first, = struct.unpack('<B', data)
82 if first == 0xff: desc = '<Q'
83 elif first == 0xfe: desc = '<I'
84 elif first == 0xfd: desc = '<H'
86 length = struct.calcsize(desc)
87 data = file.read(length)
88 if len(data) != length:
90 return struct.unpack(desc, data)[0]
92 def write(self, file, item):
94 file.write(struct.pack('<B', item))
96 file.write(struct.pack('<BH', 0xfd, item))
97 elif item <= 0xffffffff:
98 file.write(struct.pack('<BI', 0xfe, item))
99 elif item <= 0xffffffffffffffff:
100 file.write(struct.pack('<BQ', 0xff, item))
102 raise ValueError('int too large for varint')
104 class VarStrType(Type):
105 def read(self, file):
106 length = VarIntType().read(file)
107 res = file.read(length)
108 if len(res) != length:
109 raise EarlyEnd('var str not long enough %r' % ((length, len(res), res),))
112 def write(self, file, item):
113 VarIntType().write(file, len(item))
116 class FixedStrType(Type):
117 def __init__(self, length):
120 def read(self, file):
121 res = file.read(self.length)
122 if len(res) != self.length:
123 raise EarlyEnd('early EOF!')
126 def write(self, file, item):
127 if len(item) != self.length:
128 raise ValueError('incorrect length!')
131 class EnumType(Type):
132 def __init__(self, inner, values):
137 for k, v in values.iteritems():
139 raise ValueError('duplicate value in values')
142 def read(self, file):
143 return self.keys[self.inner.read(file)]
145 def write(self, file, item):
146 self.inner.write(file, self.values[item])
148 class HashType(Type):
149 def read(self, file):
150 data = file.read(256//8)
151 if len(data) != 256//8:
152 raise EarlyEnd('incorrect length!')
153 return int(data[::-1].encode('hex'), 16)
155 def write(self, file, item):
157 raise ValueError("invalid hash value")
158 if item != 0 and item < 2**160:
159 warnings.warn("very low hash value - maybe you meant to use ShortHashType?")
160 file.write(('%064x' % (item,)).decode('hex')[::-1])
162 class ShortHashType(Type):
163 def read(self, file):
164 data = file.read(160//8)
165 if len(data) != 160//8:
166 raise EarlyEnd('incorrect length!')
167 return int(data[::-1].encode('hex'), 16)
169 def write(self, file, item):
171 raise ValueError("invalid hash value")
172 file.write(('%040x' % (item,)).decode('hex')[::-1])
174 class ListType(Type):
175 def __init__(self, type):
178 def read(self, file):
179 length = VarIntType().read(file)
180 return [self.type.read(file) for i in xrange(length)]
182 def write(self, file, item):
183 VarIntType().write(file, len(item))
185 self.type.write(file, subitem)
187 class StructType(Type):
188 def __init__(self, desc):
190 self.length = struct.calcsize(self.desc)
192 def read(self, file):
193 data = file.read(self.length)
194 if len(data) != self.length:
196 res, = struct.unpack(self.desc, data)
199 def write(self, file, item):
200 data = struct.pack(self.desc, item)
201 if struct.unpack(self.desc, data)[0] != item:
202 # special test because struct doesn't error on some overflows
203 raise ValueError("item didn't survive pack cycle (%r)" % (item,))
206 class IPV6AddressType(Type):
207 def read(self, file):
211 if data[:12] != '00000000000000000000ffff'.decode('hex'):
212 raise ValueError("ipv6 addresses not supported yet")
213 return '.'.join(str(ord(x)) for x in data[12:])
215 def write(self, file, item):
216 bits = map(int, item.split('.'))
218 raise ValueError("invalid address: %r" % (bits,))
219 data = '00000000000000000000ffff'.decode('hex') + ''.join(chr(x) for x in bits)
220 assert len(data) == 16, len(data)
223 class ComposedType(Type):
224 def __init__(self, fields):
227 def read(self, file):
229 for key, type_ in self.fields:
230 item[key] = type_.read(file)
233 def write(self, file, item):
234 for key, type_ in self.fields:
235 type_.write(file, item[key])
237 class ChecksummedType(Type):
238 def __init__(self, inner):
241 def read(self, file):
242 obj = self.inner.read(file)
243 data = self.inner.pack(obj)
245 if file.read(4) != hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4]:
246 raise ValueError("invalid checksum")
250 def write(self, file, item):
251 data = self.inner.pack(item)
253 file.write(hashlib.sha256(hashlib.sha256(data).digest()).digest()[:4])
255 class FloatingIntegerType(Type):
256 def read(self, file):
257 data = FixedStrType(4).read(file)
258 target = self._bits_to_target(data)
259 if self._target_to_bits(target) != data:
260 raise ValueError("bits in non-canonical form")
263 def write(self, file, item):
264 FixedStrType(4).write(file, self._target_to_bits(item))
266 def truncate_to(self, x):
267 return self._bits_to_target(self._target_to_bits(x, _check=False))
269 def _bits_to_target(self, bits, _check=True):
270 assert len(bits) == 4, repr(bits)
271 target1 = self._bits_to_target1(bits)
272 target2 = self._bits_to_target2(bits)
273 if target1 != target2:
276 if self._target_to_bits(target1, _check=False) != bits:
280 def _bits_to_target1(self, bits):
282 length = ord(bits[0])
283 return bases.string_to_natural((bits[1:] + "\0"*length)[:length])
285 def _bits_to_target2(self, bits):
286 bits = struct.unpack("<I", bits)[0]
287 return math.shift_left(bits & 0x00ffffff, 8 * ((bits >> 24) - 3))
289 def _target_to_bits(self, target, _check=True):
290 n = bases.natural_to_string(target)
291 if n and ord(n[0]) >= 128:
293 bits = (chr(len(n)) + (n + 3*chr(0))[:3])[::-1]
295 if self._bits_to_target(bits, _check=False) != target:
296 raise ValueError(repr((target, self._bits_to_target(bits, _check=False))))
299 class PossiblyNone(Type):
300 def __init__(self, none_value, inner):
301 self.none_value = none_value
304 def read(self, file):
305 value = self.inner.read(file)
306 return None if value == self.none_value else value
308 def write(self, file, item):
309 if item == self.none_value:
310 raise ValueError("none_value used")
311 self.inner.write(file, self.none_value if item is None else item)
313 address_type = ComposedType([
314 ('services', StructType('<Q')),
315 ('address', IPV6AddressType()),
316 ('port', StructType('>H')),
319 tx_type = ComposedType([
320 ('version', StructType('<I')),
321 ('tx_ins', ListType(ComposedType([
322 ('previous_output', PossiblyNone(dict(hash=0, index=2**32 - 1), ComposedType([
323 ('hash', HashType()),
324 ('index', StructType('<I')),
326 ('script', VarStrType()),
327 ('sequence', PossiblyNone(2**32 - 1, StructType('<I'))),
329 ('tx_outs', ListType(ComposedType([
330 ('value', StructType('<Q')),
331 ('script', VarStrType()),
333 ('lock_time', StructType('<I')),
336 block_header_type = ComposedType([
337 ('version', StructType('<I')),
338 ('previous_block', PossiblyNone(0, HashType())),
339 ('merkle_root', HashType()),
340 ('timestamp', StructType('<I')),
341 ('target', FloatingIntegerType()),
342 ('nonce', StructType('<I')),
345 block_type = ComposedType([
346 ('header', block_header_type),
347 ('txs', ListType(tx_type)),
351 merkle_record_type = ComposedType([
352 ('left', HashType()),
353 ('right', HashType()),
356 def merkle_hash(tx_list):
359 hash_list = map(tx_type.hash256, tx_list)
360 while len(hash_list) > 1:
361 hash_list = [merkle_record_type.hash256(dict(left=left, right=left if right is None else right))
362 for left, right in zip(hash_list[::2], hash_list[1::2] + [None])]
365 def target_to_average_attempts(target):
366 return 2**256//(target + 1)
368 human_address_type = ChecksummedType(ComposedType([
369 ('version', StructType("<B")),
370 ('pubkey_hash', ShortHashType()),
373 pubkey_type = FixedStrType(65)
375 def pubkey_hash_to_address(pubkey_hash, net):
376 return human_address_type.pack_base58(dict(version=net.BITCOIN_ADDRESS_VERSION, pubkey_hash=pubkey_hash))
378 def pubkey_to_address(pubkey, net):
379 return pubkey_hash_to_address(pubkey_type.hash160(pubkey), net)
381 def address_to_pubkey_hash(address, net):
382 x = human_address_type.unpack_base58(address)
383 if x['version'] != net.BITCOIN_ADDRESS_VERSION:
384 raise ValueError('address not for this net!')
385 return x['pubkey_hash']
387 class Mainnet(object):
388 BITCOIN_P2P_PREFIX = 'f9beb4d9'.decode('hex')
389 BITCOIN_P2P_PORT = 8333
390 BITCOIN_ADDRESS_VERSION = 0
392 class Testnet(object):
393 BITCOIN_P2P_PREFIX = 'fabfb5da'.decode('hex')
394 BITCOIN_P2P_PORT = 18333
395 BITCOIN_ADDRESS_VERSION = 111