lbry-sdk/lbrynet/wallet/transaction.py

263 lines
11 KiB
Python

import struct
import hashlib
from binascii import hexlify, unhexlify
from typing import List, Iterable, Optional
import ecdsa
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.serialization import load_der_public_key
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives.asymmetric.utils import Prehashed
from ecdsa.util import sigencode_der
from torba.client.basetransaction import BaseTransaction, BaseInput, BaseOutput
from torba.client.hash import hash160, sha256, Base58
from lbrynet.schema.claim import Claim
from lbrynet.wallet.account import Account
from lbrynet.wallet.script import InputScript, OutputScript
class Input(BaseInput):
script: InputScript
script_class = InputScript
class Output(BaseOutput):
script: OutputScript
script_class = OutputScript
__slots__ = 'channel', 'private_key'
def __init__(self, *args, channel: Optional['Output'] = None,
private_key: Optional[str] = None, **kwargs) -> None:
super().__init__(*args, **kwargs)
self.channel = channel
self.private_key = private_key
def update_annotations(self, annotated):
super().update_annotations(annotated)
self.channel = annotated.channel if annotated else None
self.private_key = annotated.private_key if annotated else None
def get_fee(self, ledger):
name_fee = 0
if self.script.is_claim_name:
name_fee = len(self.script.values['claim_name']) * ledger.fee_per_name_char
return max(name_fee, super().get_fee(ledger))
@property
def is_claim(self) -> bool:
return self.script.is_claim_name or self.script.is_update_claim
@property
def claim_hash(self) -> bytes:
if self.script.is_claim_name:
return hash160(self.tx_ref.hash + struct.pack('>I', self.position))
elif self.script.is_update_claim or self.script.is_support_claim:
return self.script.values['claim_id']
else:
raise ValueError('No claim_id associated.')
@property
def claim_id(self) -> str:
return hexlify(self.claim_hash[::-1]).decode()
@property
def claim_name(self) -> str:
if self.script.is_claim_involved:
return self.script.values['claim_name'].decode()
raise ValueError('No claim_name associated.')
@property
def claim(self) -> Claim:
if self.is_claim:
if not isinstance(self.script.values['claim'], Claim):
self.script.values['claim'] = Claim.from_bytes(self.script.values['claim'])
return self.script.values['claim']
raise ValueError('Only claim name and claim update have the claim payload.')
@property
def permanent_url(self) -> str:
if self.script.is_claim_involved:
if self.channel is not None:
return "{}#{}/{}".format(
self.channel.claim_name,
self.channel.claim_id,
self.claim_name
)
return f"{self.claim_name}#{self.claim_id}"
raise ValueError('No claim associated.')
@property
def has_private_key(self):
return self.private_key is not None
def is_signed_by(self, channel: 'Output', ledger=None):
if self.claim.unsigned_payload:
pieces = [
Base58.decode(self.get_address(ledger)),
self.claim.unsigned_payload,
self.claim.signing_channel_hash
]
else:
pieces = [
self.tx_ref.tx.inputs[0].txo_ref.id.encode(),
self.claim.signing_channel_hash,
self.claim.to_message_bytes()
]
digest = sha256(b''.join(pieces))
public_key = load_der_public_key(channel.claim.channel.public_key_bytes, default_backend())
hash = hashes.SHA256()
signature = hexlify(self.claim.signature)
r = int(signature[:int(len(signature)/2)], 16)
s = int(signature[int(len(signature)/2):], 16)
encoded_sig = sigencode_der(r, s, len(signature)*4)
public_key.verify(encoded_sig, digest, ec.ECDSA(Prehashed(hash)))
return True
def sign(self, channel: 'Output', first_input_id=None):
self.claim.signing_channel_hash = channel.claim_hash
digest = sha256(b''.join([
first_input_id or self.tx_ref.tx.inputs[0].txo_ref.id.encode(),
self.claim.signing_channel_hash,
self.claim.to_message_bytes()
]))
private_key = ecdsa.SigningKey.from_pem(channel.private_key, hashfunc=hashlib.sha256)
self.claim.signature = private_key.sign_digest_deterministic(digest, hashfunc=hashlib.sha256)
self.script.generate()
def generate_channel_private_key(self):
private_key = ecdsa.SigningKey.generate(curve=ecdsa.SECP256k1, hashfunc=hashlib.sha256)
self.private_key = private_key.to_pem()
self.claim.channel.public_key_bytes = private_key.get_verifying_key().to_der()
return self.private_key
def is_channel_private_key(self, private_key_pem):
private_key = ecdsa.SigningKey.from_pem(private_key_pem, hashfunc=hashlib.sha256)
return self.claim.channel.public_key_bytes == private_key.get_verifying_key().to_der()
@classmethod
def pay_claim_name_pubkey_hash(
cls, amount: int, claim_name: str, claim: Claim, pubkey_hash: bytes) -> 'Output':
script = cls.script_class.pay_claim_name_pubkey_hash(
claim_name.encode(), claim, pubkey_hash)
txo = cls(amount, script)
return txo
@classmethod
def pay_update_claim_pubkey_hash(
cls, amount: int, claim_name: str, claim_id: str, claim: Claim, pubkey_hash: bytes) -> 'Output':
script = cls.script_class.pay_update_claim_pubkey_hash(
claim_name.encode(), unhexlify(claim_id)[::-1], claim, pubkey_hash)
txo = cls(amount, script)
return txo
@classmethod
def pay_support_pubkey_hash(cls, amount: int, claim_name: str, claim_id: str, pubkey_hash: bytes) -> 'Output':
script = cls.script_class.pay_support_pubkey_hash(claim_name.encode(), unhexlify(claim_id)[::-1], pubkey_hash)
return cls(amount, script)
@classmethod
def purchase_claim_pubkey_hash(cls, amount: int, claim_id: str, pubkey_hash: bytes) -> 'Output':
script = cls.script_class.purchase_claim_pubkey_hash(unhexlify(claim_id)[::-1], pubkey_hash)
return cls(amount, script)
class Transaction(BaseTransaction):
input_class = Input
output_class = Output
@classmethod
def pay(cls, amount: int, address: bytes, funding_accounts: List[Account], change_account: Account):
ledger = cls.ensure_all_have_same_ledger(funding_accounts, change_account)
output = Output.pay_pubkey_hash(amount, ledger.address_to_hash160(address))
return cls.create([], [output], funding_accounts, change_account)
@classmethod
def claim(cls, name: str, claim: Claim, amount: int, holding_address: bytes,
funding_accounts: List[Account], change_account: Account):
ledger = cls.ensure_all_have_same_ledger(funding_accounts, change_account)
claim_output = Output.pay_claim_name_pubkey_hash(
amount, name, claim, ledger.address_to_hash160(holding_address)
)
return cls.create([], [claim_output], funding_accounts, change_account)
@classmethod
def purchase(cls, claim: Output, amount: int, merchant_address: bytes,
funding_accounts: List[Account], change_account: Account):
ledger = cls.ensure_all_have_same_ledger(funding_accounts, change_account)
claim_output = Output.purchase_claim_pubkey_hash(
amount, claim.claim_id, ledger.address_to_hash160(merchant_address)
)
return cls.create([], [claim_output], funding_accounts, change_account)
@classmethod
def update(cls, previous_claim: Output, claim: Claim, amount: int, holding_address: bytes,
funding_accounts: List[Account], change_account: Account):
ledger = cls.ensure_all_have_same_ledger(funding_accounts, change_account)
updated_claim = Output.pay_update_claim_pubkey_hash(
amount, previous_claim.claim_name, previous_claim.claim_id,
claim, ledger.address_to_hash160(holding_address)
)
return cls.create([Input.spend(previous_claim)], [updated_claim], funding_accounts, change_account)
@classmethod
def support(cls, claim_name: str, claim_id: str, amount: int, holding_address: bytes,
funding_accounts: List[Account], change_account: Account):
ledger = cls.ensure_all_have_same_ledger(funding_accounts, change_account)
output = Output.pay_support_pubkey_hash(
amount, claim_name, claim_id, ledger.address_to_hash160(holding_address)
)
return cls.create([], [output], funding_accounts, change_account)
@classmethod
def abandon(cls, claims: Iterable[Output], funding_accounts: Iterable[Account], change_account: Account):
return cls.create([Input.spend(txo) for txo in claims], [], funding_accounts, change_account)
@property
def my_inputs(self):
for txi in self.inputs:
if txi.txo_ref.txo is not None and txi.txo_ref.txo.is_my_account:
yield txi
def _filter_my_outputs(self, f):
for txo in self.outputs:
if txo.is_my_account and f(txo.script):
yield txo
def _filter_other_outputs(self, f):
for txo in self.outputs:
if not txo.is_my_account and f(txo.script):
yield txo
@property
def my_claim_outputs(self):
return self._filter_my_outputs(lambda s: s.is_claim_name)
@property
def my_update_outputs(self):
return self._filter_my_outputs(lambda s: s.is_update_claim)
@property
def my_support_outputs(self):
return self._filter_my_outputs(lambda s: s.is_support_claim)
@property
def other_support_outputs(self):
return self._filter_other_outputs(lambda s: s.is_support_claim)
@property
def my_abandon_outputs(self):
for txi in self.inputs:
abandon = txi.txo_ref.txo
if abandon is not None and abandon.is_my_account and abandon.script.is_claim_involved:
is_update = False
if abandon.script.is_claim_name or abandon.script.is_update_claim:
for update in self.my_update_outputs:
if abandon.claim_id == update.claim_id:
is_update = True
break
if not is_update:
yield abandon