def deserialize(xpubstr):
xpub_bytes = b58check_decode(xpubstr)
data = XpubStruct.parse(xpub_bytes)
node = HDNodeType(
depth=data.depth,
fingerprint=data.fingerprint,
child_num=data.child_num,
chain_code=data.chain_code,
)
if data.key[0] == 0:
node.private_key = data.key[1:]
else:
node.public_key = data.key
return data.version, node
def get_subnode(node, i):
# Public Child key derivation (CKD) algorithm of BIP32
i_as_bytes = struct.pack(">L", i)
if i & HARDENED_FLAG:
raise ValueError("Prime derivation not supported")
# Public derivation
data = node.public_key + i_as_bytes
I64 = hmac.HMAC(key=node.chain_code, msg=data,
digestmod=hashlib.sha512).digest()
I_left_as_exponent = int.from_bytes(I64[:32], "big")
# BIP32 magic converts old public key to new public point
point = SEC1Encoder.decode_public_key(node.public_key, secp256k1)
result = I_left_as_exponent * secp256k1.G + point
if point == Point.IDENTITY_ELEMENT:
raise ValueError("Point cannot be INFINITY")
# Convert public point to compressed public key
public_key = SEC1Encoder.encode_public_key(result)
return HDNodeType(
depth=node.depth + 1,
child_num=i,
chain_code=I64[32:],
fingerprint=hash_160(node.public_key)[:4],
public_key=public_key,
)
def _make_node_path(self, xpub, address_n):
bip32node = BIP32Node.from_xkey(xpub)
node = HDNodeType(
depth=bip32node.depth,
fingerprint=int.from_bytes(bip32node.fingerprint, 'big'),
child_num=int.from_bytes(bip32node.child_number, 'big'),
chain_code=bip32node.chaincode,
public_key=bip32node.eckey.get_public_key_bytes(compressed=True),
)
return HDNodePathType(node=node, address_n=address_n)
def _make_node_path(self, xpub, address_n):
_, depth, fingerprint, child_num, chain_code, key = deserialize_xpub(xpub)
node = HDNodeType(
depth=depth,
fingerprint=int.from_bytes(fingerprint, 'big'),
child_num=int.from_bytes(child_num, 'big'),
chain_code=chain_code,
public_key=key,
)
return HDNodePathType(node=node, address_n=address_n)
def _make_node_path(self, xpub, address_n):
pubkey = bip32_key_from_string(xpub)
derivation = pubkey.derivation()
node = HDNodeType(
depth=derivation.depth,
fingerprint=be_bytes_to_int(pubkey.fingerprint()),
child_num=derivation.n,
chain_code=derivation.chain_code,
public_key=pubkey.to_bytes(),
)
return HDNodePathType(node=node, address_n=address_n)