trezorlib: deprecate client.expand_path and move the staticmethod

to an ordinary function tools.parse_path

Also remove PRIME_DERIVATION_FLAG and move it to tools.HARDENED_FLAG

trezorctl

@@ -23,18 +23,17 @@
 import base64
 import binascii
 import click
-import functools
 import json
 import os
 import sys
 
 from trezorlib.client import TrezorClient, TrezorClientVerbose, CallException, format_protobuf
-from trezorlib.transport import get_transport, enumerate_devices, TransportException
+from trezorlib.transport import get_transport, enumerate_devices
 from trezorlib import coins
 from trezorlib import messages as proto
 from trezorlib import protobuf
-from trezorlib.ckd_public import PRIME_DERIVATION_FLAG
 from trezorlib import stellar
+from trezorlib import tools
 
 
 class ChoiceType(click.Choice):
@@ -449,7 +448,7 @@ def self_test(connect):
 @click.pass_obj
 def get_address(connect, coin, address, script_type, show_display):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     return client.get_address(coin, address_n, show_display, script_type=script_type)
 
 
@@ -461,7 +460,7 @@ def get_address(connect, coin, address, script_type, show_display):
 @click.pass_obj
 def get_public_node(connect, coin, address, curve, show_display):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     result = client.get_public_node(address_n, ecdsa_curve_name=curve, show_display=show_display, coin_name=coin)
     return {
         'node': {
@@ -502,7 +501,7 @@ def sign_tx(connect, coin):
 
         if address_n is None:
             pass
-        elif address_n[0] == (49 | PRIME_DERIVATION_FLAG):
+        elif address_n[0] == tools.H_(49):
             script_type = 'p2shsegwit'
 
         return script_type
@@ -518,7 +517,7 @@ def sign_tx(connect, coin):
         if not prev:
             break
         prev_hash, prev_index = prev
-        address_n = click.prompt('BIP-32 path to derive the key', type=client.expand_path)
+        address_n = click.prompt('BIP-32 path to derive the key', type=tools.parse_path)
         amount = click.prompt('Input amount (satoshis)', type=int, default=0)
         sequence = click.prompt('Sequence Number to use (RBF opt-in enabled by default)', type=int, default=0xfffffffd)
         script_type = click.prompt('Input type', type=CHOICE_INPUT_SCRIPT_TYPE, default=default_script_type(address_n))
@@ -540,7 +539,7 @@ def sign_tx(connect, coin):
             address_n = None
         else:
             address = None
-            address_n = click.prompt('BIP-32 path (for change output)', type=client.expand_path, default='')
+            address_n = click.prompt('BIP-32 path (for change output)', type=tools.parse_path, default='')
             if not address_n:
                 break
         amount = click.prompt('Amount to spend (satoshis)', type=int)
@@ -581,7 +580,7 @@ def sign_tx(connect, coin):
 @click.pass_obj
 def sign_message(connect, coin, address, message, script_type):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     typemap = {
         'address': proto.InputScriptType.SPENDADDRESS,
         'segwit': proto.InputScriptType.SPENDWITNESS,
@@ -613,7 +612,7 @@ def verify_message(connect, coin, address, signature, message):
 @click.pass_obj
 def ethereum_sign_message(connect, address, message):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     ret = client.ethereum_sign_message(address_n, message)
     output = {
         'message': message,
@@ -648,7 +647,7 @@ def ethereum_verify_message(connect, address, signature, message):
 @click.pass_obj
 def encrypt_keyvalue(connect, address, key, value):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     res = client.encrypt_keyvalue(address_n, key, value.encode())
     return binascii.hexlify(res)
 
@@ -660,7 +659,7 @@ def encrypt_keyvalue(connect, address, key, value):
 @click.pass_obj
 def decrypt_keyvalue(connect, address, key, value):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     return client.decrypt_keyvalue(address_n, key, binascii.unhexlify(value))
 
 
@@ -674,7 +673,7 @@ def decrypt_keyvalue(connect, address, key, value):
 def encrypt_message(connect, coin, display_only, address, pubkey, message):
     client = connect()
     pubkey = binascii.unhexlify(pubkey)
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     res = client.encrypt_message(pubkey, message, display_only, coin, address_n)
     return {
         'nonce': binascii.hexlify(res.nonce),
@@ -690,7 +689,7 @@ def encrypt_message(connect, coin, display_only, address, pubkey, message):
 @click.pass_obj
 def decrypt_message(connect, address, payload):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     payload = base64.b64decode(payload)
     nonce, message, msg_hmac = payload[:33], payload[33:-8], payload[-8:]
     return client.decrypt_message(address_n, nonce, message, msg_hmac)
@@ -707,7 +706,7 @@ def decrypt_message(connect, address, payload):
 @click.pass_obj
 def ethereum_get_address(connect, address, show_display):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     address = client.ethereum_get_address(address_n, show_display)
     return '0x%s' % binascii.hexlify(address).decode()
 
@@ -774,7 +773,7 @@ def ethereum_sign_tx(connect, host, chain_id, address, value, gas_limit, gas_pri
     to_address = ethereum_decode_hex(to)
 
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     address = '0x%s' % (binascii.hexlify(client.ethereum_get_address(address_n)).decode())
 
     if gas_price is None or gas_limit is None or nonce is None or publish:
@@ -836,7 +835,7 @@ def ethereum_sign_tx(connect, host, chain_id, address, value, gas_limit, gas_pri
 @click.pass_obj
 def nem_get_address(connect, address, network, show_display):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     return client.nem_get_address(address_n, network, show_display)
 
 
@@ -847,7 +846,7 @@ def nem_get_address(connect, address, network, show_display):
 @click.pass_obj
 def nem_sign_tx(connect, address, file, broadcast):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     transaction = client.nem_sign_tx(address_n, json.load(file))
 
     payload = {
@@ -873,7 +872,7 @@ def nem_sign_tx(connect, address, file, broadcast):
 @click.pass_obj
 def lisk_get_address(connect, address, show_display):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     return client.lisk_get_address(address_n, show_display)
 
 
@@ -883,7 +882,7 @@ def lisk_get_address(connect, address, show_display):
 @click.pass_obj
 def lisk_get_public_key(connect, address, show_display):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     res = client.lisk_get_public_key(address_n, show_display)
     output = {
         "public_key": binascii.hexlify(res.public_key).decode()
@@ -897,7 +896,7 @@ def lisk_get_public_key(connect, address, show_display):
 @click.pass_obj
 def lisk_sign_message(connect, address, message):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     res = client.lisk_sign_message(address_n, message)
     output = {
         'message': message,
@@ -925,7 +924,7 @@ def lisk_verify_message(connect, pubkey, signature, message):
 @click.pass_obj
 def lisk_sign_tx(connect, address, file):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     transaction = client.lisk_sign_tx(address_n, json.load(file))
 
     payload = {
@@ -946,7 +945,7 @@ def lisk_sign_tx(connect, address, file):
 @click.pass_obj
 def cosi_commit(connect, address, data):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     return client.cosi_commit(address_n, binascii.unhexlify(data))
 
 
@@ -958,7 +957,7 @@ def cosi_commit(connect, address, data):
 @click.pass_obj
 def cosi_sign(connect, address, data, global_commitment, global_pubkey):
     client = connect()
-    address_n = client.expand_path(address)
+    address_n = tools.parse_path(address)
     return client.cosi_sign(address_n, binascii.unhexlify(data), binascii.unhexlify(global_commitment), binascii.unhexlify(global_pubkey))
 
 

trezorlib/client.py

@@ -34,7 +34,6 @@ from . import messages as proto
 from . import tools
 from . import mapping
 from . import nem
-from .coins import slip44
 from . import stellar
 from .debuglink import DebugLink
 from .protobuf import MessageType
@@ -490,7 +489,6 @@ class DebugLinkMixin(object):
 
 
 class ProtocolMixin(object):
-    PRIME_DERIVATION_FLAG = 0x80000000
     VENDORS = ('bitcointrezor.com', 'trezor.io')
 
     def __init__(self, state=None, *args, **kwargs):
@@ -513,44 +511,15 @@ class ProtocolMixin(object):
     def _get_local_entropy(self):
         return os.urandom(32)
 
-    def _convert_prime(self, n):
+    @staticmethod
+    def _convert_prime(n: tools.Address) -> tools.Address:
         # Convert minus signs to uint32 with flag
-        return [int(abs(x) | self.PRIME_DERIVATION_FLAG) if x < 0 else x for x in n]
+        return [tools.H_(int(abs(x))) if x < 0 else x for x in n]
 
     @staticmethod
     def expand_path(n):
-        # Convert string of bip32 path to list of uint32 integers with prime flags
-        # 0/-1/1' -> [0, 0x80000001, 0x80000001]
-        if not n:
-            return []
-
-        n = n.split('/')
-
-        # m/a/b/c => a/b/c
-        if n[0] == 'm':
-            n = n[1:]
-
-        # coin_name/a/b/c => 44'/SLIP44_constant'/a/b/c
-        if n[0] in slip44:
-            n = ["44'", "%d'" % slip44[n[0]]] + n[1:]
-
-        path = []
-        for x in n:
-            prime = False
-            if x.endswith("'"):
-                x = x.replace('\'', '')
-                prime = True
-            if x.startswith('-'):
-                prime = True
-
-            x = abs(int(x))
-
-            if prime:
-                x |= ProtocolMixin.PRIME_DERIVATION_FLAG
-
-            path.append(x)
-
-        return path
+        warnings.warn('expand_path is deprecated, use tools.parse_path', DeprecationWarning)
+        return tools.parse_path(n)
 
     @expect(proto.PublicKey)
     def get_public_node(self, n, ecdsa_curve_name=None, show_display=False, coin_name=None):

trezorlib/tests/support/ckd_public.py

@@ -30,8 +30,6 @@ from ecdsa.ellipticcurve import Point, INFINITY
 from trezorlib import tools
 from trezorlib import messages
 
-PRIME_DERIVATION_FLAG = 0x80000000
-
 
 def point_to_pubkey(point):
     order = SECP256k1.order
@@ -61,7 +59,7 @@ def sec_to_public_pair(pubkey):
 
 
 def is_prime(n):
-    return (bool)(n & PRIME_DERIVATION_FLAG)
+    return bool(n & tools.HARDENED_FLAG)
 
 
 def fingerprint(pubkey):

trezorlib/tools.py

@@ -18,9 +18,21 @@
 # along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 import hashlib
-import binascii
 import struct
-import sys
+from typing import NewType, List
+
+from .coins import slip44
+
+HARDENED_FLAG = 1 << 31
+
+Address = NewType('Address', List[int])
+
+
+def H_(x: int) -> int:
+    """
+    Shortcut function that "hardens" a number in a BIP44 path.
+    """
+    return x | HARDENED_FLAG
 
 
 def Hash(data):
@@ -109,3 +121,41 @@ def b58decode(v, length):
         return None
 
     return result
+
+
+def parse_path(nstr: str) -> Address:
+    """
+    Convert BIP32 path string to list of uint32 integers with hardened flags.
+    Several conventions are supported to set the hardened flag: -1, 1', 1h
+
+    e.g.: "0/1h/1" -> [0, 0x80000001, 1]
+
+    :param nstr: path string
+    :return: list of integers
+    """
+    if not nstr:
+        return []
+
+    n = nstr.split('/')
+
+    # m/a/b/c => a/b/c
+    if n[0] == 'm':
+        n = n[1:]
+
+    # coin_name/a/b/c => 44'/SLIP44_constant'/a/b/c
+    if n[0] in slip44:
+        coin_id = slip44[n[0]]
+        n[0:1] = ['44h', '{}h'.format(coin_id)]
+
+    def str_to_harden(x: str) -> int:
+        if x.startswith('-'):
+            return H_(abs(int(x)))
+        elif x.endswith(('h', "'")):
+            return H_(int(x[:-1]))
+        else:
+            return int(x)
+
+    try:
+        return list(str_to_harden(x) for x in n)
+    except Exception:
+        raise ValueError('Invalid BIP32 path', nstr)