Add latest bip32 test vector

.github/workflows/python-package.yml

@@ -8,7 +8,6 @@ on:
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -23,12 +22,23 @@ jobs:
     - name: Installation (deps and package)
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest
+        pip install pytest
         pip install -r requirements.txt -r tests/requirements.txt
         python setup.py install
-    - name: Linter (flake8)
-      run: |
-        flake8 ./bip32/ --count --show-source --statistics --max-line-length=90
     - name: Test with pytest
       run: |
         pytest -vvv
+
+  linter:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.9
+    - name: Run `black` on the source code
+      run: |
+        python -m pip install --upgrade pip
+        pip install black
+        python -m black --check bip32 tests

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Next
+
+- Added test vector #4 for private keys with leading zeros (see https://github.com/bitcoin/bips/pull/1030)
+
 ## 0.1
 
 - Started to use a changelog

bip32/bip32.py

@@ -3,17 +3,23 @@
 import hmac
 
 from .utils import (
-    HARDENED_INDEX, _derive_hardened_private_child,
-    _derive_unhardened_private_child, _derive_public_child,
-    _serialize_extended_key, _unserialize_extended_key,
-    _hardened_index_in_path, _privkey_to_pubkey, _deriv_path_str_to_list
+    HARDENED_INDEX,
+    _derive_hardened_private_child,
+    _derive_unhardened_private_child,
+    _derive_public_child,
+    _serialize_extended_key,
+    _unserialize_extended_key,
+    _hardened_index_in_path,
+    _privkey_to_pubkey,
+    _deriv_path_str_to_list,
 )
 
 
 class PrivateDerivationError(ValueError):
     """
     Tried to use a derivation requiring private keys, without private keys.
     """
+
     pass
 
 
@@ -23,8 +29,16 @@ def __init__(self, message):
 
 
 class BIP32:
-    def __init__(self, chaincode, privkey=None, pubkey=None, fingerprint=None,
-                 depth=0, index=0, network="main"):
+    def __init__(
+        self,
+        chaincode,
+        privkey=None,
+        pubkey=None,
+        fingerprint=None,
+        depth=0,
+        index=0,
+        network="main",
+    ):
         """
         :param chaincode: The master chaincode, used to derive keys. As bytes.
         :param privkey: The master private key for this index (default 0).
@@ -81,11 +95,13 @@ def get_extended_privkey_from_path(self, path):
         chaincode, privkey = self.master_chaincode, self.master_privkey
         for index in path:
             if index & HARDENED_INDEX:
-                privkey, chaincode = \
-                    _derive_hardened_private_child(privkey, chaincode, index)
+                privkey, chaincode = _derive_hardened_private_child(
+                    privkey, chaincode, index
+                )
             else:
-                privkey, chaincode = \
-                    _derive_unhardened_private_child(privkey, chaincode, index)
+                privkey, chaincode = _derive_unhardened_private_child(
+                    privkey, chaincode, index
+                )
 
         return chaincode, privkey
 
@@ -121,18 +137,19 @@ def get_extended_pubkey_from_path(self, path):
         if _hardened_index_in_path(path):
             for index in path:
                 if index & HARDENED_INDEX:
-                    key, chaincode = \
-                        _derive_hardened_private_child(key, chaincode, index)
+                    key, chaincode = _derive_hardened_private_child(
+                        key, chaincode, index
+                    )
                 else:
-                    key, chaincode = \
-                        _derive_unhardened_private_child(key, chaincode, index)
+                    key, chaincode = _derive_unhardened_private_child(
+                        key, chaincode, index
+                    )
                 pubkey = _privkey_to_pubkey(key)
         # We won't need private keys for the whole path, so let's only use
         # public key derivation.
         else:
             for index in path:
-                pubkey, chaincode = \
-                    _derive_public_child(pubkey, chaincode, index)
+                pubkey, chaincode = _derive_public_child(pubkey, chaincode, index)
 
         return chaincode, pubkey
 
@@ -165,10 +182,14 @@ def get_xpriv_from_path(self, path):
         else:
             parent_pubkey = self.get_pubkey_from_path(path[:-1])
         chaincode, privkey = self.get_extended_privkey_from_path(path)
-        extended_key = _serialize_extended_key(privkey, self.depth + len(path),
-                                               parent_pubkey,
-                                               path[-1], chaincode,
-                                               self.network)
+        extended_key = _serialize_extended_key(
+            privkey,
+            self.depth + len(path),
+            parent_pubkey,
+            path[-1],
+            chaincode,
+            self.network,
+        )
 
         return base58.b58encode_check(extended_key).decode()
 
@@ -192,31 +213,41 @@ def get_xpub_from_path(self, path):
         else:
             parent_pubkey = self.get_pubkey_from_path(path[:-1])
         chaincode, pubkey = self.get_extended_pubkey_from_path(path)
-        extended_key = _serialize_extended_key(pubkey, self.depth + len(path),
-                                               parent_pubkey,
-                                               path[-1], chaincode,
-                                               self.network)
+        extended_key = _serialize_extended_key(
+            pubkey,
+            self.depth + len(path),
+            parent_pubkey,
+            path[-1],
+            chaincode,
+            self.network,
+        )
 
         return base58.b58encode_check(extended_key).decode()
 
     def get_master_xpriv(self):
         """Get the encoded extended private key of the master private key"""
         if self.master_privkey is None:
             raise PrivateDerivationError
-        extended_key = _serialize_extended_key(self.master_privkey, self.depth,
-                                               self.parent_fingerprint,
-                                               self.index,
-                                               self.master_chaincode,
-                                               self.network)
+        extended_key = _serialize_extended_key(
+            self.master_privkey,
+            self.depth,
+            self.parent_fingerprint,
+            self.index,
+            self.master_chaincode,
+            self.network,
+        )
         return base58.b58encode_check(extended_key).decode()
 
     def get_master_xpub(self):
         """Get the encoded extended public key of the master public key"""
-        extended_key = _serialize_extended_key(self.master_pubkey, self.depth,
-                                               self.parent_fingerprint,
-                                               self.index,
-                                               self.master_chaincode,
-                                               self.network)
+        extended_key = _serialize_extended_key(
+            self.master_pubkey,
+            self.depth,
+            self.parent_fingerprint,
+            self.index,
+            self.master_chaincode,
+            self.network,
+        )
         return base58.b58encode_check(extended_key).decode()
 
     @classmethod
@@ -229,11 +260,16 @@ def from_xpriv(cls, xpriv):
             raise InvalidInputError("'xpriv' must be a string")
 
         extended_key = base58.b58decode_check(xpriv)
-        (network, depth, fingerprint,
-         index, chaincode, key) = _unserialize_extended_key(extended_key)
+        (
+            network,
+            depth,
+            fingerprint,
+            index,
+            chaincode,
+            key,
+        ) = _unserialize_extended_key(extended_key)
         # We need to remove the trailing `0` before the actual private key !!
-        return BIP32(chaincode, key[1:], None, fingerprint, depth, index,
-                     network)
+        return BIP32(chaincode, key[1:], None, fingerprint, depth, index, network)
 
     @classmethod
     def from_xpub(cls, xpub):
@@ -245,8 +281,14 @@ def from_xpub(cls, xpub):
             raise InvalidInputError("'xpub' must be a string")
 
         extended_key = base58.b58decode_check(xpub)
-        (network, depth, fingerprint,
-         index, chaincode, key) = _unserialize_extended_key(extended_key)
+        (
+            network,
+            depth,
+            fingerprint,
+            index,
+            chaincode,
+            key,
+        ) = _unserialize_extended_key(extended_key)
         return BIP32(chaincode, None, key, fingerprint, depth, index, network)
 
     @classmethod
@@ -255,6 +297,5 @@ def from_seed(cls, seed, network="main"):
 
         :param seed: The seed as bytes.
         """
-        secret = hmac.new("Bitcoin seed".encode(), seed,
-                          hashlib.sha512).digest()
+        secret = hmac.new("Bitcoin seed".encode(), seed, hashlib.sha512).digest()
         return BIP32(secret[32:], secret[:32], network=network)

bip32/utils.py

@@ -40,13 +40,15 @@ def _derive_unhardened_private_child(privkey, chaincode, index):
     assert not index & HARDENED_INDEX
     pubkey = _privkey_to_pubkey(privkey)
     # payload is the I from the BIP. Index is 32 bits unsigned int, BE.
-    payload = hmac.new(chaincode, pubkey + index.to_bytes(4, "big"),
-                       hashlib.sha512).digest()
+    payload = hmac.new(
+        chaincode, pubkey + index.to_bytes(4, "big"), hashlib.sha512
+    ).digest()
     try:
         child_private = coincurve.PrivateKey(payload[:32]).add(privkey)
     except ValueError:
-        raise BIP32DerivationError("Invalid private key at index {}, try the "
-                                   "next one!".format(index))
+        raise BIP32DerivationError(
+            "Invalid private key at index {}, try the " "next one!".format(index)
+        )
     return child_private.secret, payload[32:]
 
 
@@ -62,13 +64,15 @@ def _derive_hardened_private_child(privkey, chaincode, index):
     assert isinstance(privkey, bytes) and isinstance(chaincode, bytes)
     assert index & HARDENED_INDEX
     # payload is the I from the BIP. Index is 32 bits unsigned int, BE.
-    payload = hmac.new(chaincode, b'\x00' + privkey + index.to_bytes(4, "big"),
-                       hashlib.sha512).digest()
+    payload = hmac.new(
+        chaincode, b"\x00" + privkey + index.to_bytes(4, "big"), hashlib.sha512
+    ).digest()
     try:
         child_private = coincurve.PrivateKey(payload[:32]).add(privkey)
     except ValueError:
-        raise BIP32DerivationError("Invalid private key at index {}, try the "
-                                   "next one!".format(index))
+        raise BIP32DerivationError(
+            "Invalid private key at index {}, try the " "next one!".format(index)
+        )
     return child_private.secret, payload[32:]
 
 
@@ -84,19 +88,22 @@ def _derive_public_child(pubkey, chaincode, index):
     assert isinstance(pubkey, bytes) and isinstance(chaincode, bytes)
     assert not index & HARDENED_INDEX
     # payload is the I from the BIP. Index is 32 bits unsigned int, BE.
-    payload = hmac.new(chaincode, pubkey + index.to_bytes(4, "big"),
-                       hashlib.sha512).digest()
+    payload = hmac.new(
+        chaincode, pubkey + index.to_bytes(4, "big"), hashlib.sha512
+    ).digest()
     try:
         tmp_pub = coincurve.PublicKey.from_secret(payload[:32])
     except ValueError:
-        raise BIP32DerivationError("Invalid private key at index {}, try the "
-                                   "next one!".format(index))
+        raise BIP32DerivationError(
+            "Invalid private key at index {}, try the " "next one!".format(index)
+        )
     parent_pub = coincurve.PublicKey(pubkey)
     try:
         child_pub = coincurve.PublicKey.combine_keys([tmp_pub, parent_pub])
     except ValueError:
-        raise BIP32DerivationError("Invalid public key at index {}, try the "
-                                   "next one!".format(index))
+        raise BIP32DerivationError(
+            "Invalid public key at index {}, try the " "next one!".format(index)
+        )
     return child_pub.format(), payload[32:]
 
 
@@ -106,8 +113,7 @@ def _pubkey_to_fingerprint(pubkey):
     return rip.digest()[:4]
 
 
-def _serialize_extended_key(key, depth, parent, index, chaincode,
-                            network="main"):
+def _serialize_extended_key(key, depth, parent, index, chaincode, network="main"):
     """Serialize an extended private *OR* public key, as spec by bip-0032.
 
     :param key: The public or private key to serialize. Note that if this is
@@ -131,8 +137,7 @@ def _serialize_extended_key(key, depth, parent, index, chaincode,
         elif len(parent) == 4:
             fingerprint = parent
         else:
-            raise ValueError("Bad parent, a fingerprint or a pubkey is"
-                             " required")
+            raise ValueError("Bad parent, a fingerprint or a pubkey is" " required")
     else:
         fingerprint = bytes(4)  # master
     # A privkey or a compressed pubkey
@@ -147,7 +152,7 @@ def _serialize_extended_key(key, depth, parent, index, chaincode,
     extended += index.to_bytes(4, "big")
     extended += chaincode
     if is_privkey:
-        extended += b'\x00'
+        extended += b"\x00"
     extended += key
     return extended
 
@@ -188,7 +193,7 @@ def _deriv_path_str_to_list(strpath):
     """
     if not REGEX_DERIVATION_PATH.match(strpath):
         raise ValueError("invalid format")
-    indexes = strpath.split('/')[1:]
+    indexes = strpath.split("/")[1:]
     list_path = []
     for i in indexes:
         # if HARDENED