file reorganization with top-level module

2018-07-11 17:38:47 +02:00
parent 30a7952cbb
commit 097ac144d9
317 changed files with 438 additions and 470 deletions
--- a/electrum/crypto.py
+++ b/electrum/crypto.py
@@ -0,0 +1,151 @@
+# -*- 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()