You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

151 lines
4.2 KiB

# -*- coding: utf-8 -*-
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2018 The Electrum developers
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import base64
import os
import hashlib
import hmac
import pyaes
from .util import assert_bytes, InvalidPassword, to_bytes, to_string
try:
from Cryptodome.Cipher import AES
except:
AES = None
class InvalidPadding(Exception):
pass
def append_PKCS7_padding(data):
assert_bytes(data)
padlen = 16 - (len(data) % 16)
return data + bytes([padlen]) * padlen
def strip_PKCS7_padding(data):
assert_bytes(data)
if len(data) % 16 != 0 or len(data) == 0:
raise InvalidPadding("invalid length")
padlen = data[-1]
if padlen > 16:
raise InvalidPadding("invalid padding byte (large)")
for i in data[-padlen:]:
if i != padlen:
raise InvalidPadding("invalid padding byte (inconsistent)")
return data[0:-padlen]
def aes_encrypt_with_iv(key, iv, data):
assert_bytes(key, iv, data)
data = append_PKCS7_padding(data)
if AES:
e = AES.new(key, AES.MODE_CBC, iv).encrypt(data)
else:
aes_cbc = pyaes.AESModeOfOperationCBC(key, iv=iv)
aes = pyaes.Encrypter(aes_cbc, padding=pyaes.PADDING_NONE)
e = aes.feed(data) + aes.feed() # empty aes.feed() flushes buffer
return e
def aes_decrypt_with_iv(key, iv, data):
assert_bytes(key, iv, data)
if AES:
cipher = AES.new(key, AES.MODE_CBC, iv)
data = cipher.decrypt(data)
else:
aes_cbc = pyaes.AESModeOfOperationCBC(key, iv=iv)
aes = pyaes.Decrypter(aes_cbc, padding=pyaes.PADDING_NONE)
data = aes.feed(data) + aes.feed() # empty aes.feed() flushes buffer
try:
return strip_PKCS7_padding(data)
except InvalidPadding:
raise InvalidPassword()
def EncodeAES(secret, s):
assert_bytes(s)
iv = bytes(os.urandom(16))
ct = aes_encrypt_with_iv(secret, iv, s)
e = iv + ct
return base64.b64encode(e)
def DecodeAES(secret, e):
e = bytes(base64.b64decode(e))
iv, e = e[:16], e[16:]
s = aes_decrypt_with_iv(secret, iv, e)
return s
def pw_encode(s, password):
if password:
secret = Hash(password)
return EncodeAES(secret, to_bytes(s, "utf8")).decode('utf8')
else:
return s
def pw_decode(s, password):
if password is not None:
secret = Hash(password)
try:
d = to_string(DecodeAES(secret, s), "utf8")
except Exception:
raise InvalidPassword()
return d
else:
return s
def sha256(x: bytes) -> bytes:
x = to_bytes(x, 'utf8')
return bytes(hashlib.sha256(x).digest())
def Hash(x: bytes) -> bytes:
x = to_bytes(x, 'utf8')
out = bytes(sha256(sha256(x)))
return out
def hash_160(x: bytes) -> bytes:
try:
md = hashlib.new('ripemd160')
md.update(sha256(x))
return md.digest()
except BaseException:
from . import ripemd
md = ripemd.new(sha256(x))
return md.digest()
def hmac_oneshot(key: bytes, msg: bytes, digest) -> bytes:
if hasattr(hmac, 'digest'):
# requires python 3.7+; faster
return hmac.digest(key, msg, digest)
else:
return hmac.new(key, msg, digest).digest()