bip32: fix hardened char "h" vs "'" compatibility for some hw wallets

in particular, ledger: fix sign_message for some wallets

```
156.02 | E | plugins.ledger.ledger |
Traceback (most recent call last):
  File "...\electrum\electrum\plugins\ledger\ledger.py", line 1265, in sign_message
    result = base64.b64decode(self.client.sign_message(message, address_path))
  File "...\Python310\site-packages\ledger_bitcoin\client.py", line 230, in sign_message
    sw, response = self._make_request(self.builder.sign_message(message_bytes, bip32_path), client_intepreter)
  File "...\Python310\site-packages\ledger_bitcoin\command_builder.py", line 176, in sign_message
    bip32_path: List[bytes] = bip32_path_from_string(bip32_path)
  File "...\Python310\site-packages\ledger_bitcoin\common.py", line 68, in bip32_path_from_string
    return [int(p).to_bytes(4, byteorder="big") if "'" not in p
  File "...\Python310\site-packages\ledger_bitcoin\common.py", line 68, in <listcomp>
    return [int(p).to_bytes(4, byteorder="big") if "'" not in p
ValueError: invalid literal for int() with base 10: '84h'
```

Regression from df2bd61, where the
default hardened char was changed from "'" to "h". Note that there was
no corresponding wallet db upgrade, so some files use one char and
others use the other.

electrum/bip32.py

@@ -352,7 +352,9 @@ def convert_bip32_strpath_to_intpath(n: str) -> List[int]:
     return path
 
 
-def convert_bip32_intpath_to_strpath(path: Sequence[int]) -> str:
+def convert_bip32_intpath_to_strpath(path: Sequence[int], *, hardened_char=BIP32_HARDENED_CHAR) -> str:
+    assert isinstance(hardened_char, str), hardened_char
+    assert len(hardened_char) == 1, hardened_char
     s = "m/"
     for child_index in path:
         if not isinstance(child_index, int):
@@ -361,7 +363,7 @@ def convert_bip32_intpath_to_strpath(path: Sequence[int]) -> str:
             raise ValueError(f"bip32 path child index out of range: {child_index}")
         prime = ""
         if child_index & BIP32_PRIME:
-            prime = BIP32_HARDENED_CHAR
+            prime = hardened_char
             child_index = child_index ^ BIP32_PRIME
         s += str(child_index) + prime + '/'
     # cut trailing "/"
@@ -380,13 +382,13 @@ def is_bip32_derivation(s: str) -> bool:
         return True
 
 
-def normalize_bip32_derivation(s: Optional[str]) -> Optional[str]:
+def normalize_bip32_derivation(s: Optional[str], *, hardened_char=BIP32_HARDENED_CHAR) -> Optional[str]:
     if s is None:
         return None
     if not is_bip32_derivation(s):
         raise ValueError(f"invalid bip32 derivation: {s}")
     ints = convert_bip32_strpath_to_intpath(s)
-    return convert_bip32_intpath_to_strpath(ints)
+    return convert_bip32_intpath_to_strpath(ints, hardened_char=hardened_char)
 
 
 def is_all_public_derivation(path: Union[str, Iterable[int]]) -> bool:

electrum/keystore.py

@@ -508,7 +508,9 @@ def get_bip32_node_for_xpub(self) -> Optional[BIP32Node]:
         return self._xpub_bip32_node
 
     def get_derivation_prefix(self) -> Optional[str]:
-        return self._derivation_prefix
+        if self._derivation_prefix is None:
+            return None
+        return normalize_bip32_derivation(self._derivation_prefix)
 
     def get_root_fingerprint(self) -> Optional[str]:
         return self._root_fingerprint

electrum/plugins/digitalbitbox/digitalbitbox.py

@@ -19,6 +19,7 @@
 from electrum.crypto import sha256d, EncodeAES_bytes, DecodeAES_bytes, hmac_oneshot
 from electrum.bitcoin import public_key_to_p2pkh
 from electrum.bip32 import BIP32Node, convert_bip32_intpath_to_strpath, is_all_public_derivation
+from electrum.bip32 import normalize_bip32_derivation
 from electrum import descriptor
 from electrum import ecc
 from electrum.ecc import msg_magic
@@ -104,7 +105,8 @@ def has_usable_connection_with_device(self):
             return False
         return True
 
-    def _get_xpub(self, bip32_path):
+    def _get_xpub(self, bip32_path: str):
+        bip32_path = normalize_bip32_derivation(bip32_path, hardened_char="'")
         if self.check_device_dialog():
             return self.hid_send_encrypt(('{"xpub": "%s"}' % bip32_path).encode('utf8'))
 
@@ -458,6 +460,7 @@ def sign_message(self, sequence, message, password, *, script_type=None):
         try:
             message = message.encode('utf8')
             inputPath = self.get_derivation_prefix() + "/%d/%d" % sequence
+            inputPath = normalize_bip32_derivation(inputPath, hardened_char="'")
             msg_hash = sha256d(msg_magic(message))
             inputHash = to_hexstr(msg_hash)
             hasharray = []

electrum/plugins/ledger/ledger.py

@@ -10,7 +10,7 @@
 from electrum import bip32, constants, ecc
 from electrum import descriptor
 from electrum.base_wizard import ScriptTypeNotSupported
-from electrum.bip32 import BIP32Node, convert_bip32_intpath_to_strpath
+from electrum.bip32 import BIP32Node, convert_bip32_intpath_to_strpath, normalize_bip32_derivation
 from electrum.bitcoin import EncodeBase58Check, int_to_hex, is_b58_address, is_segwit_script_type, var_int
 from electrum.crypto import hash_160
 from electrum.i18n import _
@@ -430,7 +430,7 @@ def get_xpub(self, bip32_path, xtype):
             raise UserFacingException(MSG_NEEDS_FW_UPDATE_SEGWIT)
         if xtype in ['p2wpkh-p2sh', 'p2wsh-p2sh'] and not self.supports_segwit():
             raise UserFacingException(MSG_NEEDS_FW_UPDATE_SEGWIT)
-        bip32_path = bip32.normalize_bip32_derivation(bip32_path)
+        bip32_path = bip32.normalize_bip32_derivation(bip32_path, hardened_char="'")
         bip32_intpath = bip32.convert_bip32_strpath_to_intpath(bip32_path)
         bip32_path = bip32_path[2:]  # cut off "m/"
         if len(bip32_intpath) >= 1:
@@ -931,10 +931,10 @@ def has_usable_connection_with_device(self):
 
     @runs_in_hwd_thread
     @test_pin_unlocked
-    def get_xpub(self, bip32_path, xtype):
+    def get_xpub(self, bip32_path: str, xtype):
         # try silently first; if not a standard path, repeat with on-screen display
 
-        bip32_path = bip32_path.replace('h', '\'')
+        bip32_path = normalize_bip32_derivation(bip32_path, hardened_char="'")
 
         # cache known path/xpubs combinations in order to avoid requesting them many times
         if bip32_path in self._known_xpubs:
@@ -1300,14 +1300,18 @@ def decrypt_message(self, pubkey, message, password):
         raise UserFacingException(_('Encryption and decryption are currently not supported for {}').format(self.device))
 
     def sign_message(self, sequence, *args, **kwargs):
-        address_path = self.get_derivation_prefix()[2:] + "/%d/%d" % sequence
+        address_path = self.get_derivation_prefix() + "/%d/%d" % sequence
+        address_path = normalize_bip32_derivation(address_path, hardened_char="'")
+        address_path = address_path[2:]  # cut m/
         return self.get_client_dongle_object().sign_message(address_path, *args, **kwargs)
 
     def sign_transaction(self, *args, **kwargs):
         return self.get_client_dongle_object().sign_transaction(self, *args, **kwargs)
 
     def show_address(self, sequence, *args, **kwargs):
-        address_path = self.get_derivation_prefix()[2:] + "/%d/%d" % sequence
+        address_path = self.get_derivation_prefix() + "/%d/%d" % sequence
+        address_path = normalize_bip32_derivation(address_path, hardened_char="'")
+        address_path = address_path[2:]  # cut m/
         return self.get_client_dongle_object().show_address(address_path, *args, **kwargs)
 
 

electrum/tests/test_bitcoin.py

@@ -862,6 +862,10 @@ def test_convert_bip32_intpath_to_strpath(self):
         self.assertEqual("m", convert_bip32_intpath_to_strpath([]))
         self.assertEqual("m/44h/5241h/221", convert_bip32_intpath_to_strpath([2147483692, 2147488889, 221]))
 
+        self.assertEqual("m/0/1'/1'", convert_bip32_intpath_to_strpath([0, 0x80000001, 0x80000001], hardened_char="'"))
+        self.assertEqual("m", convert_bip32_intpath_to_strpath([], hardened_char="'"))
+        self.assertEqual("m/44'/5241'/221", convert_bip32_intpath_to_strpath([2147483692, 2147488889, 221], hardened_char="'"))
+
     def test_normalize_bip32_derivation(self):
         self.assertEqual("m/0/1h/1h", normalize_bip32_derivation("m/0/1h/1'"))
         self.assertEqual("m", normalize_bip32_derivation("m////"))