tkeystore: handle unusual derivation paths in PSBT - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
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DIR Submodules
---
DIR commit ac223073ba7998901bd9a10d32594ebf0583021f
DIR parent 0c3f36038599401c226addb05249c964247579da
HTML Author: SomberNight <somber.night@protonmail.com>
Date: Wed, 9 Dec 2020 09:38:40 +0100
keystore: handle unusual derivation paths in PSBT
If a tx contained a derivation path for a pubkey,
with a length=2 der suffix,
with the first element of the suffix not in (0, 1),
with a fingerprint that matches either our root or intermediate fp,
tthen processing that tx would raise and result in a crash reporter.
Traceback (most recent call last):
File ".../electrum/electrum/gui/qt/main_window.py", line 2718, in do_process_from_text
self.show_transaction(tx)
File ".../electrum/electrum/gui/qt/main_window.py", line 1041, in show_transaction
show_transaction(tx, parent=self, desc=tx_desc)
File ".../electrum/electrum/gui/qt/transaction_dialog.py", line 84, in show_transaction
d = TxDialog(tx, parent=parent, desc=desc, prompt_if_unsaved=prompt_if_unsaved)
File ".../electrum/electrum/gui/qt/transaction_dialog.py", line 680, in __init__
self.set_tx(tx)
File ".../electrum/electrum/gui/qt/transaction_dialog.py", line 218, in set_tx
tx.add_info_from_wallet(self.wallet)
File ".../electrum/electrum/transaction.py", line 1944, in add_info_from_wallet
wallet.add_input_info(txin, only_der_suffix=only_der_suffix)
File ".../electrum/electrum/wallet.py", line 1573, in add_input_info
is_mine = self._learn_derivation_path_for_address_from_txinout(txin, address)
File ".../electrum/electrum/wallet.py", line 2609, in _learn_derivation_path_for_address_from_txinout
pubkey, der_suffix = ks.find_my_pubkey_in_txinout(txinout, only_der_suffix=True)
File ".../electrum/electrum/keystore.py", line 155, in find_my_pubkey_in_txinout
path = self.get_pubkey_derivation(pubkey, txinout, only_der_suffix=only_der_suffix)
File ".../electrum/electrum/keystore.py", line 391, in get_pubkey_derivation
if not test_der_suffix_against_pubkey(der_suffix, pubkey):
File ".../electrum/electrum/keystore.py", line 368, in test_der_suffix_against_pubkey
if pubkey != self.derive_pubkey(*der_suffix):
File ".../electrum/electrum/keystore.py", line 491, in derive_pubkey
assert for_change in (0, 1)
AssertionError
Diffstat:
M electrum/keystore.py | 28 +++++++++++++++++++++-------
M electrum/wallet.py | 8 ++++++--
2 files changed, 27 insertions(+), 9 deletions(-)
---
DIR diff --git a/electrum/keystore.py b/electrum/keystore.py
t@@ -52,6 +52,9 @@ if TYPE_CHECKING:
from .wallet_db import WalletDB
+class CannotDerivePubkey(Exception): pass
+
+
class KeyStore(Logger, ABC):
type: str
t@@ -356,16 +359,25 @@ class MasterPublicKeyMixin(ABC):
@abstractmethod
def derive_pubkey(self, for_change: int, n: int) -> bytes:
+ """Returns pubkey at given path.
+ May raise CannotDerivePubkey.
+ """
pass
- def get_pubkey_derivation(self, pubkey: bytes,
- txinout: Union['PartialTxInput', 'PartialTxOutput'],
- *, only_der_suffix=True) \
- -> Union[Sequence[int], str, None]:
+ def get_pubkey_derivation(
+ self,
+ pubkey: bytes,
+ txinout: Union['PartialTxInput', 'PartialTxOutput'],
+ *,
+ only_der_suffix=True,
+ ) -> Union[Sequence[int], str, None]:
def test_der_suffix_against_pubkey(der_suffix: Sequence[int], pubkey: bytes) -> bool:
if len(der_suffix) != 2:
return False
- if pubkey != self.derive_pubkey(*der_suffix):
+ try:
+ if pubkey != self.derive_pubkey(*der_suffix):
+ return False
+ except CannotDerivePubkey:
return False
return True
t@@ -488,7 +500,8 @@ class Xpub(MasterPublicKeyMixin):
@lru_cache(maxsize=None)
def derive_pubkey(self, for_change: int, n: int) -> bytes:
for_change = int(for_change)
- assert for_change in (0, 1)
+ if for_change not in (0, 1):
+ raise CannotDerivePubkey("forbidden path")
xpub = self.xpub_change if for_change else self.xpub_receive
if xpub is None:
rootnode = self.get_bip32_node_for_xpub()
t@@ -658,7 +671,8 @@ class Old_KeyStore(MasterPublicKeyMixin, Deterministic_KeyStore):
@lru_cache(maxsize=None)
def derive_pubkey(self, for_change, n) -> bytes:
for_change = int(for_change)
- assert for_change in (0, 1)
+ if for_change not in (0, 1):
+ raise CannotDerivePubkey("forbidden path")
return self.get_pubkey_from_mpk(self.mpk, for_change, n)
def _get_private_key_from_stretched_exponent(self, for_change, n, secexp):
DIR diff --git a/electrum/wallet.py b/electrum/wallet.py
t@@ -61,7 +61,8 @@ from .bitcoin import COIN, TYPE_ADDRESS
from .bitcoin import is_address, address_to_script, is_minikey, relayfee, dust_threshold
from .crypto import sha256d
from . import keystore
-from .keystore import load_keystore, Hardware_KeyStore, KeyStore, KeyStoreWithMPK, AddressIndexGeneric
+from .keystore import (load_keystore, Hardware_KeyStore, KeyStore, KeyStoreWithMPK,
+ AddressIndexGeneric, CannotDerivePubkey)
from .util import multisig_type
from .storage import StorageEncryptionVersion, WalletStorage
from .wallet_db import WalletDB
t@@ -2611,7 +2612,10 @@ class Deterministic_Wallet(Abstract_Wallet):
# note: we already know the pubkey belongs to the keystore,
# but the script template might be different
if len(der_suffix) != 2: continue
- my_address = self.derive_address(*der_suffix)
+ try:
+ my_address = self.derive_address(*der_suffix)
+ except CannotDerivePubkey:
+ my_address = None
if my_address == address:
self._ephemeral_addr_to_addr_index[address] = list(der_suffix)
return True