1
0
mirror of https://github.com/trezor/trezor-firmware.git synced 2024-11-30 03:18:20 +00:00
trezor-firmware/trezorlib/tools.py
matejcik 85b85c67b3 trezorlib: reentrant session handling
This fixes the breakage introduced by transport reshuffles.
It's still not great and I'd love to see context manager based sessions.
But it's good enough for now.
2018-11-12 12:22:32 +01:00

268 lines
6.8 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 TrezorException
CallException = TrezorException
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()
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