lbry-sdk/torba/baseaccount.py
2018-06-13 23:00:53 -05:00

184 lines
6.6 KiB
Python

from typing import Dict
from binascii import unhexlify
from twisted.internet import defer
from torba.mnemonic import Mnemonic
from torba.bip32 import PrivateKey, PubKey, from_extended_key_string
from torba.hash import double_sha256, aes_encrypt, aes_decrypt
class KeyChain:
def __init__(self, account, parent_key, chain_number, minimum_usable_addresses):
self.account = account
self.db = account.ledger.db
self.main_key = parent_key.child(chain_number) # type: PubKey
self.chain_number = chain_number
self.minimum_usable_addresses = minimum_usable_addresses
def get_keys(self):
return self.db.get_keys(self.account, self.chain_number)
def get_addresses(self):
return self.db.get_addresses(self.account, self.chain_number)
@defer.inlineCallbacks
def ensure_enough_useable_addresses(self):
usable_address_count = yield self.db.get_usable_address_count(
self.account, self.chain_number
)
if usable_address_count >= self.minimum_usable_addresses:
defer.returnValue([])
new_addresses_needed = self.minimum_usable_addresses - usable_address_count
start = yield self.db.get_last_address_index(
self.account, self.chain_number
)
end = start + new_addresses_needed
new_keys = []
for index in range(start+1, end+1):
new_keys.append((index, self.main_key.child(index)))
yield self.db.add_keys(
self.account, self.chain_number, new_keys
)
defer.returnValue([
key[1].address for key in new_keys
])
@defer.inlineCallbacks
def has_gap(self):
if len(self.addresses) < self.minimum_gap:
defer.returnValue(False)
for address in self.addresses[-self.minimum_gap:]:
if (yield self.ledger.is_address_old(address)):
defer.returnValue(False)
defer.returnValue(True)
class BaseAccount:
mnemonic_class = Mnemonic
private_key_class = PrivateKey
public_key_class = PubKey
def __init__(self, ledger, seed, encrypted, private_key,
public_key, receiving_gap=20, change_gap=6):
self.ledger = ledger # type: baseledger.BaseLedger
self.seed = seed # type: str
self.encrypted = encrypted # type: bool
self.private_key = private_key # type: PrivateKey
self.public_key = public_key # type: PubKey
self.receiving, self.change = self.keychains = (
KeyChain(self, public_key, 0, receiving_gap),
KeyChain(self, public_key, 1, change_gap)
)
ledger.account_created(self)
@classmethod
def generate(cls, ledger, password): # type: (baseledger.BaseLedger, str) -> BaseAccount
seed = cls.mnemonic_class().make_seed()
return cls.from_seed(ledger, seed, password)
@classmethod
def from_seed(cls, ledger, seed, password):
# type: (baseledger.BaseLedger, str, str) -> BaseAccount
private_key = cls.get_private_key_from_seed(ledger, seed, password)
return cls(
ledger=ledger, seed=seed, encrypted=False,
private_key=private_key,
public_key=private_key.public_key
)
@classmethod
def get_private_key_from_seed(cls, ledger, seed, password):
# type: (baseledger.BaseLedger, str, str) -> PrivateKey
return cls.private_key_class.from_seed(
ledger, cls.mnemonic_class.mnemonic_to_seed(seed, password)
)
@classmethod
def from_dict(cls, ledger, d): # type: (baseledger.BaseLedger, Dict) -> BaseAccount
if not d['encrypted']:
private_key = from_extended_key_string(ledger, d['private_key'])
public_key = private_key.public_key
else:
private_key = d['private_key']
public_key = from_extended_key_string(ledger, d['public_key'])
return cls(
ledger=ledger,
seed=d['seed'],
encrypted=d['encrypted'],
private_key=private_key,
public_key=public_key,
receiving_gap=d['receiving_gap'],
change_gap=d['change_gap']
)
def to_dict(self):
return {
'ledger': self.ledger.get_id(),
'seed': self.seed,
'encrypted': self.encrypted,
'private_key': self.private_key if self.encrypted else
self.private_key.extended_key_string(),
'public_key': self.public_key.extended_key_string(),
'receiving_gap': self.receiving.minimum_usable_addresses,
'change_gap': self.change.minimum_usable_addresses,
}
def decrypt(self, password):
assert self.encrypted, "Key is not encrypted."
secret = double_sha256(password)
self.seed = aes_decrypt(secret, self.seed)
self.private_key = from_extended_key_string(self.ledger, aes_decrypt(secret, self.private_key))
self.encrypted = False
def encrypt(self, password):
assert not self.encrypted, "Key is already encrypted."
secret = double_sha256(password)
self.seed = aes_encrypt(secret, self.seed)
self.private_key = aes_encrypt(secret, self.private_key.extended_key_string())
self.encrypted = True
@defer.inlineCallbacks
def ensure_enough_useable_addresses(self):
addresses = []
for keychain in self.keychains:
new_addresses = yield keychain.ensure_enough_useable_addresses()
addresses.extend(new_addresses)
defer.returnValue(addresses)
def get_private_key(self, chain, index):
assert not self.encrypted, "Cannot get private key on encrypted wallet account."
return self.private_key.child(chain).child(index)
def get_least_used_receiving_address(self, max_transactions=1000):
return self._get_least_used_address(
self.receiving_keys,
max_transactions
)
def get_least_used_change_address(self, max_transactions=100):
return self._get_least_used_address(
self.change_keys,
max_transactions
)
def _get_least_used_address(self, keychain, max_transactions):
ledger = self.ledger
address = ledger.get_least_used_address(self, keychain, max_transactions)
if address:
return address
address = keychain.generate_next_address()
ledger.subscribe_history(address)
return address
@defer.inlineCallbacks
def get_balance(self):
utxos = yield self.ledger.get_unspent_outputs(self)
defer.returnValue(sum(utxo.amount for utxo in utxos))