lbry-sdk/lbry/lbry/wallet/server/coin.py
2020-01-01 15:57:56 -05:00

364 lines
12 KiB
Python

import struct
from hashlib import sha256
from torba.server.script import ScriptPubKey, OpCodes
from torba.server.util import cachedproperty
from torba.server.hash import hash_to_hex_str, HASHX_LEN
from torba.server.tx import DeserializerSegWit
from lbry.wallet.script import OutputScript
from .session import LBRYElectrumX, LBRYSessionManager
from .block_processor import LBRYBlockProcessor
from .daemon import LBCDaemon
from .db.writer import LBRYDB
from collections import namedtuple
import re
import struct
from decimal import Decimal
from hashlib import sha256
from functools import partial
import base64
from typing import Type, List
import torba.server.util as util
from torba.server.hash import Base58, hash160, double_sha256, hash_to_hex_str
from torba.server.hash import HASHX_LEN, hex_str_to_hash
from torba.server.script import ScriptPubKey, OpCodes
import torba.server.tx as lib_tx
import torba.server.block_processor as block_proc
from torba.server.db import DB
import torba.server.daemon as daemon
from torba.server.session import ElectrumX, DashElectrumX, SessionManager
Block = namedtuple("Block", "raw header transactions")
OP_RETURN = OpCodes.OP_RETURN
class CoinError(Exception):
"""Exception raised for coin-related errors."""
class Coin:
"""Base class of coin hierarchy."""
REORG_LIMIT = 200
# Not sure if these are coin-specific
RPC_URL_REGEX = re.compile('.+@(\\[[0-9a-fA-F:]+\\]|[^:]+)(:[0-9]+)?')
VALUE_PER_COIN = 100000000
CHUNK_SIZE = 2016
BASIC_HEADER_SIZE = 80
STATIC_BLOCK_HEADERS = True
SESSIONCLS = ElectrumX
DESERIALIZER = lib_tx.Deserializer
DAEMON = daemon.Daemon
BLOCK_PROCESSOR = block_proc.BlockProcessor
SESSION_MANAGER = SessionManager
DB = DB
HEADER_VALUES = [
'version', 'prev_block_hash', 'merkle_root', 'timestamp', 'bits', 'nonce'
]
HEADER_UNPACK = struct.Struct('< I 32s 32s I I I').unpack_from
MEMPOOL_HISTOGRAM_REFRESH_SECS = 500
XPUB_VERBYTES = bytes('????', 'utf-8')
XPRV_VERBYTES = bytes('????', 'utf-8')
ENCODE_CHECK = Base58.encode_check
DECODE_CHECK = Base58.decode_check
# Peer discovery
PEER_DEFAULT_PORTS = {'t': '50001', 's': '50002'}
PEERS: List[str] = []
@classmethod
def lookup_coin_class(cls, name, net):
"""Return a coin class given name and network.
Raise an exception if unrecognised."""
req_attrs = ['TX_COUNT', 'TX_COUNT_HEIGHT', 'TX_PER_BLOCK']
for coin in util.subclasses(Coin):
if (coin.NAME.lower() == name.lower() and
coin.NET.lower() == net.lower()):
coin_req_attrs = req_attrs.copy()
missing = [attr for attr in coin_req_attrs
if not hasattr(coin, attr)]
if missing:
raise CoinError(f'coin {name} missing {missing} attributes')
return coin
raise CoinError(f'unknown coin {name} and network {net} combination')
@classmethod
def sanitize_url(cls, url):
# Remove surrounding ws and trailing /s
url = url.strip().rstrip('/')
match = cls.RPC_URL_REGEX.match(url)
if not match:
raise CoinError(f'invalid daemon URL: "{url}"')
if match.groups()[1] is None:
url += f':{cls.RPC_PORT:d}'
if not url.startswith('http://') and not url.startswith('https://'):
url = 'http://' + url
return url + '/'
@classmethod
def genesis_block(cls, block):
"""Check the Genesis block is the right one for this coin.
Return the block less its unspendable coinbase.
"""
header = cls.block_header(block, 0)
header_hex_hash = hash_to_hex_str(cls.header_hash(header))
if header_hex_hash != cls.GENESIS_HASH:
raise CoinError(f'genesis block has hash {header_hex_hash} expected {cls.GENESIS_HASH}')
return header + bytes(1)
@classmethod
def hashX_from_script(cls, script):
"""Returns a hashX from a script, or None if the script is provably
unspendable so the output can be dropped.
"""
if script and script[0] == OP_RETURN:
return None
return sha256(script).digest()[:HASHX_LEN]
@staticmethod
def lookup_xverbytes(verbytes):
"""Return a (is_xpub, coin_class) pair given xpub/xprv verbytes."""
# Order means BTC testnet will override NMC testnet
for coin in util.subclasses(Coin):
if verbytes == coin.XPUB_VERBYTES:
return True, coin
if verbytes == coin.XPRV_VERBYTES:
return False, coin
raise CoinError('version bytes unrecognised')
@classmethod
def address_to_hashX(cls, address):
"""Return a hashX given a coin address."""
return cls.hashX_from_script(cls.pay_to_address_script(address))
@classmethod
def P2PKH_address_from_hash160(cls, hash160):
"""Return a P2PKH address given a public key."""
assert len(hash160) == 20
return cls.ENCODE_CHECK(cls.P2PKH_VERBYTE + hash160)
@classmethod
def P2PKH_address_from_pubkey(cls, pubkey):
"""Return a coin address given a public key."""
return cls.P2PKH_address_from_hash160(hash160(pubkey))
@classmethod
def P2SH_address_from_hash160(cls, hash160):
"""Return a coin address given a hash160."""
assert len(hash160) == 20
return cls.ENCODE_CHECK(cls.P2SH_VERBYTES[0] + hash160)
@classmethod
def hash160_to_P2PKH_script(cls, hash160):
return ScriptPubKey.P2PKH_script(hash160)
@classmethod
def hash160_to_P2PKH_hashX(cls, hash160):
return cls.hashX_from_script(cls.hash160_to_P2PKH_script(hash160))
@classmethod
def pay_to_address_script(cls, address):
"""Return a pubkey script that pays to a pubkey hash.
Pass the address (either P2PKH or P2SH) in base58 form.
"""
raw = cls.DECODE_CHECK(address)
# Require version byte(s) plus hash160.
verbyte = -1
verlen = len(raw) - 20
if verlen > 0:
verbyte, hash160 = raw[:verlen], raw[verlen:]
if verbyte == cls.P2PKH_VERBYTE:
return cls.hash160_to_P2PKH_script(hash160)
if verbyte in cls.P2SH_VERBYTES:
return ScriptPubKey.P2SH_script(hash160)
raise CoinError(f'invalid address: {address}')
@classmethod
def privkey_WIF(cls, privkey_bytes, compressed):
"""Return the private key encoded in Wallet Import Format."""
payload = bytearray(cls.WIF_BYTE) + privkey_bytes
if compressed:
payload.append(0x01)
return cls.ENCODE_CHECK(payload)
@classmethod
def header_hash(cls, header):
"""Given a header return hash"""
return double_sha256(header)
@classmethod
def header_prevhash(cls, header):
"""Given a header return previous hash"""
return header[4:36]
@classmethod
def static_header_offset(cls, height):
"""Given a header height return its offset in the headers file.
If header sizes change at some point, this is the only code
that needs updating."""
assert cls.STATIC_BLOCK_HEADERS
return height * cls.BASIC_HEADER_SIZE
@classmethod
def static_header_len(cls, height):
"""Given a header height return its length."""
return (cls.static_header_offset(height + 1)
- cls.static_header_offset(height))
@classmethod
def block_header(cls, block, height):
"""Returns the block header given a block and its height."""
return block[:cls.static_header_len(height)]
@classmethod
def block(cls, raw_block, height):
"""Return a Block namedtuple given a raw block and its height."""
header = cls.block_header(raw_block, height)
txs = cls.DESERIALIZER(raw_block, start=len(header)).read_tx_block()
return Block(raw_block, header, txs)
@classmethod
def decimal_value(cls, value):
"""Return the number of standard coin units as a Decimal given a
quantity of smallest units.
For example 1 BTC is returned for 100 million satoshis.
"""
return Decimal(value) / cls.VALUE_PER_COIN
@classmethod
def electrum_header(cls, header, height):
h = dict(zip(cls.HEADER_VALUES, cls.HEADER_UNPACK(header)))
# Add the height that is not present in the header itself
h['block_height'] = height
# Convert bytes to str
h['prev_block_hash'] = hash_to_hex_str(h['prev_block_hash'])
h['merkle_root'] = hash_to_hex_str(h['merkle_root'])
return h
class LBC(Coin):
DAEMON = LBCDaemon
SESSIONCLS = LBRYElectrumX
BLOCK_PROCESSOR = LBRYBlockProcessor
SESSION_MANAGER = LBRYSessionManager
DESERIALIZER = DeserializerSegWit
DB = LBRYDB
NAME = "LBRY"
SHORTNAME = "LBC"
NET = "mainnet"
BASIC_HEADER_SIZE = 112
CHUNK_SIZE = 96
XPUB_VERBYTES = bytes.fromhex("0488b21e")
XPRV_VERBYTES = bytes.fromhex("0488ade4")
P2PKH_VERBYTE = bytes.fromhex("55")
P2SH_VERBYTES = bytes.fromhex("7A")
WIF_BYTE = bytes.fromhex("1C")
GENESIS_HASH = ('9c89283ba0f3227f6c03b70216b9f665'
'f0118d5e0fa729cedf4fb34d6a34f463')
TX_COUNT = 2716936
TX_COUNT_HEIGHT = 329554
TX_PER_BLOCK = 1
RPC_PORT = 9245
REORG_LIMIT = 200
PEERS = [
]
@classmethod
def genesis_block(cls, block):
'''Check the Genesis block is the right one for this coin.
Return the block less its unspendable coinbase.
'''
header = cls.block_header(block, 0)
header_hex_hash = hash_to_hex_str(cls.header_hash(header))
if header_hex_hash != cls.GENESIS_HASH:
raise CoinError(f'genesis block has hash {header_hex_hash} expected {cls.GENESIS_HASH}')
return block
@classmethod
def electrum_header(cls, header, height):
version, = struct.unpack('<I', header[:4])
timestamp, bits, nonce = struct.unpack('<III', header[100:112])
return {
'version': version,
'prev_block_hash': hash_to_hex_str(header[4:36]),
'merkle_root': hash_to_hex_str(header[36:68]),
'claim_trie_root': hash_to_hex_str(header[68:100]),
'timestamp': timestamp,
'bits': bits,
'nonce': nonce,
'block_height': height,
}
@cachedproperty
def address_handlers(self):
return ScriptPubKey.PayToHandlers(
address=self.P2PKH_address_from_hash160,
script_hash=self.P2SH_address_from_hash160,
pubkey=self.P2PKH_address_from_pubkey,
unspendable=lambda: None,
strange=self.claim_address_handler,
)
@classmethod
def address_from_script(cls, script):
'''Given a pk_script, return the address it pays to, or None.'''
return ScriptPubKey.pay_to(cls.address_handlers, script)
@classmethod
def claim_address_handler(cls, script):
'''Parse a claim script, returns the address
'''
output = OutputScript(script)
if output.is_pay_pubkey_hash:
return cls.P2PKH_address_from_hash160(output.values['pubkey_hash'])
if output.is_pay_script_hash:
return cls.P2SH_address_from_hash160(output.values['script_hash'])
if output.is_pay_pubkey:
return cls.P2PKH_address_from_pubkey(output.values['pubkey'])
if output.is_return_data:
return None
return None
@classmethod
def hashX_from_script(cls, script):
'''
Overrides electrumx hashX from script by extracting addresses from claim scripts.
'''
if script and script[0] == OpCodes.OP_RETURN or not script:
return None
if script[0] in [
OutputScript.OP_CLAIM_NAME,
OutputScript.OP_UPDATE_CLAIM,
OutputScript.OP_SUPPORT_CLAIM,
]:
return cls.address_to_hashX(cls.claim_address_handler(script))
else:
return sha256(script).digest()[:HASHX_LEN]
class LBCRegTest(LBC):
NET = "regtest"
GENESIS_HASH = '6e3fcf1299d4ec5d79c3a4c91d624a4acf9e2e173d95a1a0504f677669687556'
XPUB_VERBYTES = bytes.fromhex('043587cf')
XPRV_VERBYTES = bytes.fromhex('04358394')
P2PKH_VERBYTE = bytes.fromhex("6f")
P2SH_VERBYTES = bytes.fromhex("c4")
class LBCTestNet(LBCRegTest):
NET = "testnet"
GENESIS_HASH = '9c89283ba0f3227f6c03b70216b9f665f0118d5e0fa729cedf4fb34d6a34f463'