move TrezorClient.expand_path to bitcoin.py

and allow its input to end with a '/' slash

electrum/base_wizard.py

@@ -346,6 +346,7 @@ class BaseWizard(object):
         except ScriptTypeNotSupported:
             raise  # this is handled in derivation_dialog
         except BaseException as e:
+            traceback.print_exc(file=sys.stderr)
             self.show_error(e)
             return
         d = {

electrum/bitcoin.py

@@ -24,7 +24,7 @@
 # SOFTWARE.
 
 import hashlib
-import hmac
+from typing import List
 
 from .util import bfh, bh2u, BitcoinException, print_error, assert_bytes, to_bytes, inv_dict
 from . import version
@@ -708,6 +708,24 @@ def bip32_derivation(s):
         i = int(n[:-1]) + BIP32_PRIME if n[-1] == "'" else int(n)
         yield i
 
+def convert_bip32_path_to_list_of_uint32(n: str) -> List[int]:
+    """Convert bip32 path to list of uint32 integers with prime flags
+    m/0/-1/1' -> [0, 0x80000001, 0x80000001]
+
+    based on code in trezorlib
+    """
+    path = []
+    for x in n.split('/')[1:]:
+        if x == '': continue
+        prime = 0
+        if x.endswith("'"):
+            x = x.replace('\'', '')
+            prime = BIP32_PRIME
+        if x.startswith('-'):
+            prime = BIP32_PRIME
+        path.append(abs(int(x)) | prime)
+    return path
+
 def is_bip32_derivation(x):
     try:
         [ i for i in bip32_derivation(x)]

electrum/plugins/keepkey/clientbase.py

@@ -4,7 +4,7 @@ from struct import pack
 from electrum.i18n import _
 from electrum.util import PrintError, UserCancelled
 from electrum.keystore import bip39_normalize_passphrase
-from electrum.bitcoin import serialize_xpub
+from electrum.bitcoin import serialize_xpub, convert_bip32_path_to_list_of_uint32
 
 
 class GuiMixin(object):
@@ -141,21 +141,7 @@ class KeepKeyClientBase(GuiMixin, PrintError):
 
     @staticmethod
     def expand_path(n):
-        '''Convert bip32 path to list of uint32 integers with prime flags
-        0/-1/1' -> [0, 0x80000001, 0x80000001]'''
-        # This code is similar to code in trezorlib where it unfortunately
-        # is not declared as a staticmethod.  Our n has an extra element.
-        PRIME_DERIVATION_FLAG = 0x80000000
-        path = []
-        for x in n.split('/')[1:]:
-            prime = 0
-            if x.endswith("'"):
-                x = x.replace('\'', '')
-                prime = PRIME_DERIVATION_FLAG
-            if x.startswith('-'):
-                prime = PRIME_DERIVATION_FLAG
-            path.append(abs(int(x)) | prime)
-        return path
+        return convert_bip32_path_to_list_of_uint32(n)
 
     def cancel(self):
         '''Provided here as in keepkeylib but not trezorlib.'''

electrum/plugins/safe_t/clientbase.py

@@ -4,7 +4,7 @@ from struct import pack
 from electrum.i18n import _
 from electrum.util import PrintError, UserCancelled
 from electrum.keystore import bip39_normalize_passphrase
-from electrum.bitcoin import serialize_xpub
+from electrum.bitcoin import serialize_xpub, convert_bip32_path_to_list_of_uint32
 
 
 class GuiMixin(object):
@@ -143,21 +143,7 @@ class SafeTClientBase(GuiMixin, PrintError):
 
     @staticmethod
     def expand_path(n):
-        '''Convert bip32 path to list of uint32 integers with prime flags
-        0/-1/1' -> [0, 0x80000001, 0x80000001]'''
-        # This code is similar to code in safetlib where it unfortunately
-        # is not declared as a staticmethod.  Our n has an extra element.
-        PRIME_DERIVATION_FLAG = 0x80000000
-        path = []
-        for x in n.split('/')[1:]:
-            prime = 0
-            if x.endswith("'"):
-                x = x.replace('\'', '')
-                prime = PRIME_DERIVATION_FLAG
-            if x.startswith('-'):
-                prime = PRIME_DERIVATION_FLAG
-            path.append(abs(int(x)) | prime)
-        return path
+        return convert_bip32_path_to_list_of_uint32(n)
 
     def cancel(self):
         '''Provided here as in keepkeylib but not safetlib.'''

electrum/plugins/trezor/clientbase.py

@@ -4,7 +4,7 @@ from struct import pack
 from electrum.i18n import _
 from electrum.util import PrintError, UserCancelled
 from electrum.keystore import bip39_normalize_passphrase
-from electrum.bitcoin import serialize_xpub
+from electrum.bitcoin import serialize_xpub, convert_bip32_path_to_list_of_uint32
 
 
 class GuiMixin(object):
@@ -152,21 +152,7 @@ class TrezorClientBase(GuiMixin, PrintError):
 
     @staticmethod
     def expand_path(n):
-        '''Convert bip32 path to list of uint32 integers with prime flags
-        0/-1/1' -> [0, 0x80000001, 0x80000001]'''
-        # This code is similar to code in trezorlib where it unfortunately
-        # is not declared as a staticmethod.  Our n has an extra element.
-        PRIME_DERIVATION_FLAG = 0x80000000
-        path = []
-        for x in n.split('/')[1:]:
-            prime = 0
-            if x.endswith("'"):
-                x = x.replace('\'', '')
-                prime = PRIME_DERIVATION_FLAG
-            if x.startswith('-'):
-                prime = PRIME_DERIVATION_FLAG
-            path.append(abs(int(x)) | prime)
-        return path
+        return convert_bip32_path_to_list_of_uint32(n)
 
     def cancel(self):
         '''Provided here as in keepkeylib but not trezorlib.'''

electrum/tests/test_bitcoin.py

@@ -11,7 +11,7 @@ from electrum.bitcoin import (
     deserialize_privkey, serialize_privkey, is_segwit_address,
     is_b58_address, address_to_scripthash, is_minikey, is_compressed, is_xpub,
     xpub_type, is_xprv, is_bip32_derivation, seed_type, EncodeBase58Check,
-    script_num_to_hex, push_script, add_number_to_script, int_to_hex)
+    script_num_to_hex, push_script, add_number_to_script, int_to_hex, convert_bip32_path_to_list_of_uint32)
 from electrum import ecc, crypto, constants
 from electrum.ecc import number_to_string, string_to_number
 from electrum.transaction import opcodes
@@ -470,6 +470,11 @@ class Test_xprv_xpub(SequentialTestCase):
         self.assertFalse(is_bip32_derivation(""))
         self.assertFalse(is_bip32_derivation("m/q8462"))
 
+    def test_convert_bip32_path_to_list_of_uint32(self):
+        self.assertEqual([0, 0x80000001, 0x80000001], convert_bip32_path_to_list_of_uint32("m/0/-1/1'"))
+        self.assertEqual([], convert_bip32_path_to_list_of_uint32("m/"))
+        self.assertEqual([2147483692, 2147488889, 221], convert_bip32_path_to_list_of_uint32("m/44'/5241'/221"))
+
     def test_xtype_from_derivation(self):
         self.assertEqual('standard', xtype_from_derivation("m/44'"))
         self.assertEqual('standard', xtype_from_derivation("m/44'/"))