bitcoin: disallow importing/sweeping segwit scripts with uncompressed pubkey

fixes #4638

electrum/bitcoin.py

@@ -527,6 +527,9 @@ WIF_SCRIPT_TYPES = {
 WIF_SCRIPT_TYPES_INV = inv_dict(WIF_SCRIPT_TYPES)
 
 
+def is_segwit_script_type(txin_type: str) -> bool:
+    return txin_type in ('p2wpkh', 'p2wpkh-p2sh', 'p2wsh', 'p2wsh-p2sh')
+
 
 def serialize_privkey(secret: bytes, compressed: bool, txin_type: str,
                       internal_use: bool=False) -> str:
@@ -576,6 +579,10 @@ def deserialize_privkey(key: str) -> Tuple[str, bytes, bool]:
     if len(vch) not in [33, 34]:
         raise BitcoinException('invalid vch len for WIF key: {}'.format(len(vch)))
     compressed = len(vch) == 34
+
+    if is_segwit_script_type(txin_type) and not compressed:
+        raise BitcoinException('only compressed public keys can be used in segwit scripts')
+
     secret_bytes = vch[1:33]
     # we accept secrets outside curve range; cast into range here:
     secret_bytes = ecc.ECPrivkey.normalize_secret_bytes(secret_bytes)

electrum/plugins/ledger/ledger.py

@@ -4,7 +4,7 @@ import sys
 import traceback
 
 from electrum import ecc
-from electrum.bitcoin import TYPE_ADDRESS, int_to_hex, var_int
+from electrum.bitcoin import TYPE_ADDRESS, int_to_hex, var_int, is_segwit_script_type
 from electrum.bip32 import BIP32Node
 from electrum.i18n import _
 from electrum.keystore import Hardware_KeyStore
@@ -518,7 +518,7 @@ class Ledger_KeyStore(Hardware_KeyStore):
         client = self.get_client()
         address_path = self.get_derivation()[2:] + "/%d/%d"%sequence
         self.handler.show_message(_("Showing address ..."))
-        segwit = Transaction.is_segwit_inputtype(txin_type)
+        segwit = is_segwit_script_type(txin_type)
         segwitNative = txin_type == 'p2wpkh'
         try:
             client.getWalletPublicKey(address_path, showOnScreen=True, segwit=segwit, segwitNative=segwitNative)

electrum/tests/test_bitcoin.py

@@ -8,7 +8,7 @@ from electrum.bitcoin import (public_key_to_p2pkh, address_from_private_key,
                               is_b58_address, address_to_scripthash, is_minikey,
                               is_compressed_privkey, EncodeBase58Check, DecodeBase58Check,
                               script_num_to_hex, push_script, add_number_to_script, int_to_hex,
-                              opcodes, base_encode, base_decode)
+                              opcodes, base_encode, base_decode, BitcoinException)
 from electrum.bip32 import (BIP32Node, convert_bip32_intpath_to_strpath,
                             xpub_from_xprv, xpub_type, is_xprv, is_bip32_derivation,
                             is_xpub, convert_bip32_path_to_list_of_uint32,
@@ -736,6 +736,12 @@ class Test_keyImport(SequentialTestCase):
             self.assertEqual(priv_details['compressed'],
                              is_compressed_privkey(priv_details['priv']))
 
+    @needs_test_with_all_ecc_implementations
+    def test_segwit_uncompressed_pubkey(self):
+        with self.assertRaises(BitcoinException):
+            is_private_key("p2wpkh-p2sh:5JKXxT3wAZHcybJ9YNkuHur9vou6uuAnorBV9A8vVxGNFH5wvTW",
+                           raise_on_error=True)
+
 
 class TestBaseEncode(SequentialTestCase):
 

electrum/transaction.py

@@ -39,7 +39,7 @@ from .bitcoin import (TYPE_ADDRESS, TYPE_PUBKEY, TYPE_SCRIPT, hash_160,
                       hash160_to_p2sh, hash160_to_p2pkh, hash_to_segwit_addr,
                       hash_encode, var_int, TOTAL_COIN_SUPPLY_LIMIT_IN_BTC, COIN,
                       push_script, int_to_hex, push_script, b58_address_to_hash160,
-                      opcodes, add_number_to_script, base_decode)
+                      opcodes, add_number_to_script, base_decode, is_segwit_script_type)
 from .crypto import sha256d
 from .keystore import xpubkey_to_address, xpubkey_to_pubkey
 
@@ -815,11 +815,7 @@ class Transaction:
         if _type == 'address' and guess_for_address:
             _type = cls.guess_txintype_from_address(txin['address'])
         has_nonzero_witness = txin.get('witness', '00') not in ('00', None)
-        return cls.is_segwit_inputtype(_type) or has_nonzero_witness
-
-    @classmethod
-    def is_segwit_inputtype(cls, txin_type):
-        return txin_type in ('p2wpkh', 'p2wpkh-p2sh', 'p2wsh', 'p2wsh-p2sh')
+        return is_segwit_script_type(_type) or has_nonzero_witness
 
     @classmethod
     def guess_txintype_from_address(cls, addr):