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trezor-firmware/python/src/trezorlib/ckd_public.py
matejcik 67b879ac07 python: restructure package
This deserves some explanation.

* tests were moved to separate python/tests subdir
* trezorlib was moved to python/src, so that it does not exist on
PYTHONPATH by default
(see https://blog.ionelmc.ro/2014/05/25/python-packaging/ for details)
* everything was updated to understand the new structure
* trezorctl was changed from a top-level executable script to a module
`trezorlib.cli.trezorctl` and is installed via the entry_points
mechanism.
This should make it work normally on Windows!

The package should be installable as normal through pip and pipenv, no
changes are needed on that side.

The source package from pypi will include unit tests. (Device tests were
completely moved out). Wheel will exclude them, because users don't need
them.
That shrinks the .whl from 520 kB to 270 - nice!

python: reorganize remaining unit tests
2019-08-12 12:57:25 +02:00

153 lines
4.3 KiB
Python

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2019 SatoshiLabs and contributors
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3
# as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the License along with this library.
# If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
import hashlib
import hmac
import struct
import warnings
import ecdsa
from ecdsa.curves import SECP256k1
from ecdsa.ellipticcurve import INFINITY, Point
from ecdsa.util import number_to_string, string_to_number
from trezorlib import messages, tools
warnings.warn("ckd_public module is deprecated and will be removed", DeprecationWarning)
def point_to_pubkey(point):
order = SECP256k1.order
x_str = number_to_string(point.x(), order)
y_str = number_to_string(point.y(), order)
vk = x_str + y_str
return struct.pack("B", (vk[63] & 1) + 2) + vk[0:32] # To compressed key
def sec_to_public_pair(pubkey):
"""Convert a public key in sec binary format to a public pair."""
x = string_to_number(pubkey[1:33])
sec0 = pubkey[:1]
if sec0 not in (b"\2", b"\3"):
raise ValueError("Compressed pubkey expected")
def public_pair_for_x(generator, x, is_even):
curve = generator.curve()
p = curve.p()
alpha = (pow(x, 3, p) + curve.a() * x + curve.b()) % p
beta = ecdsa.numbertheory.square_root_mod_prime(alpha, p)
if is_even == bool(beta & 1):
return (x, p - beta)
return (x, beta)
return public_pair_for_x(
ecdsa.ecdsa.generator_secp256k1, x, is_even=(sec0 == b"\2")
)
def is_prime(n):
return bool(n & tools.HARDENED_FLAG)
def fingerprint(pubkey):
return string_to_number(tools.hash_160(pubkey)[:4])
def get_address(public_node, address_type):
return tools.public_key_to_bc_address(public_node.public_key, address_type)
def public_ckd(public_node, n):
if not isinstance(n, list):
raise ValueError("Parameter must be a list")
node = messages.HDNodeType(**public_node)
for i in n:
node = get_subnode(node, i)
return node
def get_subnode(node, i):
# Public Child key derivation (CKD) algorithm of BIP32
i_as_bytes = struct.pack(">L", i)
if is_prime(i):
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 = string_to_number(I64[:32])
node_out = messages.HDNodeType()
node_out.depth = node.depth + 1
node_out.child_num = i
node_out.chain_code = I64[32:]
node_out.fingerprint = fingerprint(node.public_key)
# BIP32 magic converts old public key to new public point
x, y = sec_to_public_pair(node.public_key)
point = I_left_as_exponent * SECP256k1.generator + Point(
SECP256k1.curve, x, y, SECP256k1.order
)
if point == INFINITY:
raise ValueError("Point cannot be INFINITY")
# Convert public point to compressed public key
node_out.public_key = point_to_pubkey(point)
return node_out
def serialize(node, version=0x0488B21E):
s = b""
s += struct.pack(">I", version)
s += struct.pack(">B", node.depth)
s += struct.pack(">I", node.fingerprint)
s += struct.pack(">I", node.child_num)
s += node.chain_code
if node.private_key:
s += b"\x00" + node.private_key
else:
s += node.public_key
s += tools.btc_hash(s)[:4]
return tools.b58encode(s)
def deserialize(xpub):
data = tools.b58decode(xpub, None)
if tools.btc_hash(data[:-4])[:4] != data[-4:]:
raise ValueError("Checksum failed")
node = messages.HDNodeType()
node.depth = struct.unpack(">B", data[4:5])[0]
node.fingerprint = struct.unpack(">I", data[5:9])[0]
node.child_num = struct.unpack(">I", data[9:13])[0]
node.chain_code = data[13:45]
key = data[45:-4]
if key[0] == 0:
node.private_key = key[1:]
else:
node.public_key = key
return node