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trezor-firmware/python/trezorlib/tools.py
2019-04-15 19:15:12 +02:00

272 lines
6.9 KiB
Python

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2018 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 functools
import hashlib
import re
import struct
import unicodedata
from typing import List, NewType
from .coins import slip44
from .exceptions import TrezorFailure
CallException = TrezorFailure
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 btc_hash(data):
"""
Double-SHA256 hash as used in BTC
"""
return hashlib.sha256(hashlib.sha256(data).digest()).digest()
def hash_160(public_key):
md = hashlib.new("ripemd160")
md.update(hashlib.sha256(public_key).digest())
return md.digest()
def hash_160_to_bc_address(h160, address_type):
vh160 = struct.pack("<B", address_type) + h160
h = btc_hash(vh160)
addr = vh160 + h[0:4]
return b58encode(addr)
def compress_pubkey(public_key):
if public_key[0] == 4:
return bytes((public_key[64] & 1) + 2) + public_key[1:33]
raise ValueError("Pubkey is already compressed")
def public_key_to_bc_address(public_key, address_type, compress=True):
if public_key[0] == "\x04" and compress:
public_key = compress_pubkey(public_key)
h160 = hash_160(public_key)
return hash_160_to_bc_address(h160, address_type)
__b58chars = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
__b58base = len(__b58chars)
def b58encode(v):
""" encode v, which is a string of bytes, to base58."""
long_value = 0
for c in v:
long_value = long_value * 256 + c
result = ""
while long_value >= __b58base:
div, mod = divmod(long_value, __b58base)
result = __b58chars[mod] + result
long_value = div
result = __b58chars[long_value] + result
# Bitcoin does a little leading-zero-compression:
# leading 0-bytes in the input become leading-1s
nPad = 0
for c in v:
if c == 0:
nPad += 1
else:
break
return (__b58chars[0] * nPad) + result
def b58decode(v, length=None):
""" decode v into a string of len bytes."""
if isinstance(v, bytes):
v = v.decode()
for c in v:
if c not in __b58chars:
raise ValueError("invalid Base58 string")
long_value = 0
for (i, c) in enumerate(v[::-1]):
long_value += __b58chars.find(c) * (__b58base ** i)
result = b""
while long_value >= 256:
div, mod = divmod(long_value, 256)
result = struct.pack("B", mod) + result
long_value = div
result = struct.pack("B", long_value) + result
nPad = 0
for c in v:
if c == __b58chars[0]:
nPad += 1
else:
break
result = b"\x00" * nPad + result
if length is not None and len(result) != length:
return None
return result
def b58check_encode(v):
checksum = btc_hash(v)[:4]
return b58encode(v + checksum)
def b58check_decode(v, length=None):
dec = b58decode(v, length)
data, checksum = dec[:-4], dec[-4:]
if btc_hash(data)[:4] != checksum:
raise ValueError("invalid checksum")
return data
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 [str_to_harden(x) for x in n]
except Exception:
raise ValueError("Invalid BIP32 path", nstr)
def normalize_nfc(txt):
"""
Normalize message to NFC and return bytes suitable for protobuf.
This seems to be bitcoin-qt standard of doing things.
"""
if isinstance(txt, bytes):
txt = txt.decode()
return unicodedata.normalize("NFC", txt).encode()
class expect:
# Decorator checks if the method
# returned one of expected protobuf messages
# or raises an exception
def __init__(self, expected, field=None):
self.expected = expected
self.field = field
def __call__(self, f):
@functools.wraps(f)
def wrapped_f(*args, **kwargs):
__tracebackhide__ = True # for pytest # pylint: disable=W0612
ret = f(*args, **kwargs)
if not isinstance(ret, self.expected):
raise RuntimeError(
"Got %s, expected %s" % (ret.__class__, self.expected)
)
if self.field is not None:
return getattr(ret, self.field)
else:
return ret
return wrapped_f
def session(f):
# Decorator wraps a BaseClient method
# with session activation / deactivation
@functools.wraps(f)
def wrapped_f(client, *args, **kwargs):
__tracebackhide__ = True # for pytest # pylint: disable=W0612
client.open()
try:
return f(client, *args, **kwargs)
finally:
client.close()
return wrapped_f
# de-camelcasifier
# https://stackoverflow.com/a/1176023/222189
FIRST_CAP_RE = re.compile("(.)([A-Z][a-z]+)")
ALL_CAP_RE = re.compile("([a-z0-9])([A-Z])")
def from_camelcase(s):
s = FIRST_CAP_RE.sub(r"\1_\2", s)
return ALL_CAP_RE.sub(r"\1_\2", s).lower()
def dict_from_camelcase(d, renames=None):
if not isinstance(d, dict):
return d
if renames is None:
renames = {}
res = {}
for key, value in d.items():
newkey = from_camelcase(key)
renamed_key = renames.get(newkey) or renames.get(key)
if renamed_key:
newkey = renamed_key
if isinstance(value, list):
res[newkey] = [dict_from_camelcase(v, renames) for v in value]
else:
res[newkey] = dict_from_camelcase(value, renames)
return res