mirror of
https://github.com/morpheus65535/bazarr
synced 2024-12-28 10:38:26 +00:00
249 lines
7.9 KiB
Python
249 lines
7.9 KiB
Python
# -*- coding: utf-8 -*-
|
|
"""
|
|
werkzeug.security
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
Security related helpers such as secure password hashing tools.
|
|
|
|
:copyright: 2007 Pallets
|
|
:license: BSD-3-Clause
|
|
"""
|
|
import codecs
|
|
import hashlib
|
|
import hmac
|
|
import os
|
|
import posixpath
|
|
from random import SystemRandom
|
|
from struct import Struct
|
|
|
|
from ._compat import izip
|
|
from ._compat import PY2
|
|
from ._compat import range_type
|
|
from ._compat import text_type
|
|
from ._compat import to_bytes
|
|
from ._compat import to_native
|
|
|
|
SALT_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
|
|
DEFAULT_PBKDF2_ITERATIONS = 150000
|
|
|
|
_pack_int = Struct(">I").pack
|
|
_builtin_safe_str_cmp = getattr(hmac, "compare_digest", None)
|
|
_sys_rng = SystemRandom()
|
|
_os_alt_seps = list(
|
|
sep for sep in [os.path.sep, os.path.altsep] if sep not in (None, "/")
|
|
)
|
|
|
|
|
|
def pbkdf2_hex(
|
|
data, salt, iterations=DEFAULT_PBKDF2_ITERATIONS, keylen=None, hashfunc=None
|
|
):
|
|
"""Like :func:`pbkdf2_bin`, but returns a hex-encoded string.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param data: the data to derive.
|
|
:param salt: the salt for the derivation.
|
|
:param iterations: the number of iterations.
|
|
:param keylen: the length of the resulting key. If not provided,
|
|
the digest size will be used.
|
|
:param hashfunc: the hash function to use. This can either be the
|
|
string name of a known hash function, or a function
|
|
from the hashlib module. Defaults to sha256.
|
|
"""
|
|
rv = pbkdf2_bin(data, salt, iterations, keylen, hashfunc)
|
|
return to_native(codecs.encode(rv, "hex_codec"))
|
|
|
|
|
|
def pbkdf2_bin(
|
|
data, salt, iterations=DEFAULT_PBKDF2_ITERATIONS, keylen=None, hashfunc=None
|
|
):
|
|
"""Returns a binary digest for the PBKDF2 hash algorithm of `data`
|
|
with the given `salt`. It iterates `iterations` times and produces a
|
|
key of `keylen` bytes. By default, SHA-256 is used as hash function;
|
|
a different hashlib `hashfunc` can be provided.
|
|
|
|
.. versionadded:: 0.9
|
|
|
|
:param data: the data to derive.
|
|
:param salt: the salt for the derivation.
|
|
:param iterations: the number of iterations.
|
|
:param keylen: the length of the resulting key. If not provided
|
|
the digest size will be used.
|
|
:param hashfunc: the hash function to use. This can either be the
|
|
string name of a known hash function or a function
|
|
from the hashlib module. Defaults to sha256.
|
|
"""
|
|
if not hashfunc:
|
|
hashfunc = "sha256"
|
|
|
|
data = to_bytes(data)
|
|
salt = to_bytes(salt)
|
|
|
|
if callable(hashfunc):
|
|
_test_hash = hashfunc()
|
|
hash_name = getattr(_test_hash, "name", None)
|
|
else:
|
|
hash_name = hashfunc
|
|
return hashlib.pbkdf2_hmac(hash_name, data, salt, iterations, keylen)
|
|
|
|
|
|
def safe_str_cmp(a, b):
|
|
"""This function compares strings in somewhat constant time. This
|
|
requires that the length of at least one string is known in advance.
|
|
|
|
Returns `True` if the two strings are equal, or `False` if they are not.
|
|
|
|
.. versionadded:: 0.7
|
|
"""
|
|
if isinstance(a, text_type):
|
|
a = a.encode("utf-8")
|
|
if isinstance(b, text_type):
|
|
b = b.encode("utf-8")
|
|
|
|
if _builtin_safe_str_cmp is not None:
|
|
return _builtin_safe_str_cmp(a, b)
|
|
|
|
if len(a) != len(b):
|
|
return False
|
|
|
|
rv = 0
|
|
if PY2:
|
|
for x, y in izip(a, b):
|
|
rv |= ord(x) ^ ord(y)
|
|
else:
|
|
for x, y in izip(a, b):
|
|
rv |= x ^ y
|
|
|
|
return rv == 0
|
|
|
|
|
|
def gen_salt(length):
|
|
"""Generate a random string of SALT_CHARS with specified ``length``."""
|
|
if length <= 0:
|
|
raise ValueError("Salt length must be positive")
|
|
return "".join(_sys_rng.choice(SALT_CHARS) for _ in range_type(length))
|
|
|
|
|
|
def _hash_internal(method, salt, password):
|
|
"""Internal password hash helper. Supports plaintext without salt,
|
|
unsalted and salted passwords. In case salted passwords are used
|
|
hmac is used.
|
|
"""
|
|
if method == "plain":
|
|
return password, method
|
|
|
|
if isinstance(password, text_type):
|
|
password = password.encode("utf-8")
|
|
|
|
if method.startswith("pbkdf2:"):
|
|
args = method[7:].split(":")
|
|
if len(args) not in (1, 2):
|
|
raise ValueError("Invalid number of arguments for PBKDF2")
|
|
method = args.pop(0)
|
|
iterations = args and int(args[0] or 0) or DEFAULT_PBKDF2_ITERATIONS
|
|
is_pbkdf2 = True
|
|
actual_method = "pbkdf2:%s:%d" % (method, iterations)
|
|
else:
|
|
is_pbkdf2 = False
|
|
actual_method = method
|
|
|
|
if is_pbkdf2:
|
|
if not salt:
|
|
raise ValueError("Salt is required for PBKDF2")
|
|
rv = pbkdf2_hex(password, salt, iterations, hashfunc=method)
|
|
elif salt:
|
|
if isinstance(salt, text_type):
|
|
salt = salt.encode("utf-8")
|
|
mac = _create_mac(salt, password, method)
|
|
rv = mac.hexdigest()
|
|
else:
|
|
rv = hashlib.new(method, password).hexdigest()
|
|
return rv, actual_method
|
|
|
|
|
|
def _create_mac(key, msg, method):
|
|
if callable(method):
|
|
return hmac.HMAC(key, msg, method)
|
|
|
|
def hashfunc(d=b""):
|
|
return hashlib.new(method, d)
|
|
|
|
# Python 2.7 used ``hasattr(digestmod, '__call__')``
|
|
# to detect if hashfunc is callable
|
|
hashfunc.__call__ = hashfunc
|
|
return hmac.HMAC(key, msg, hashfunc)
|
|
|
|
|
|
def generate_password_hash(password, method="pbkdf2:sha256", salt_length=8):
|
|
"""Hash a password with the given method and salt with a string of
|
|
the given length. The format of the string returned includes the method
|
|
that was used so that :func:`check_password_hash` can check the hash.
|
|
|
|
The format for the hashed string looks like this::
|
|
|
|
method$salt$hash
|
|
|
|
This method can **not** generate unsalted passwords but it is possible
|
|
to set param method='plain' in order to enforce plaintext passwords.
|
|
If a salt is used, hmac is used internally to salt the password.
|
|
|
|
If PBKDF2 is wanted it can be enabled by setting the method to
|
|
``pbkdf2:method:iterations`` where iterations is optional::
|
|
|
|
pbkdf2:sha256:80000$salt$hash
|
|
pbkdf2:sha256$salt$hash
|
|
|
|
:param password: the password to hash.
|
|
:param method: the hash method to use (one that hashlib supports). Can
|
|
optionally be in the format ``pbkdf2:<method>[:iterations]``
|
|
to enable PBKDF2.
|
|
:param salt_length: the length of the salt in letters.
|
|
"""
|
|
salt = gen_salt(salt_length) if method != "plain" else ""
|
|
h, actual_method = _hash_internal(method, salt, password)
|
|
return "%s$%s$%s" % (actual_method, salt, h)
|
|
|
|
|
|
def check_password_hash(pwhash, password):
|
|
"""check a password against a given salted and hashed password value.
|
|
In order to support unsalted legacy passwords this method supports
|
|
plain text passwords, md5 and sha1 hashes (both salted and unsalted).
|
|
|
|
Returns `True` if the password matched, `False` otherwise.
|
|
|
|
:param pwhash: a hashed string like returned by
|
|
:func:`generate_password_hash`.
|
|
:param password: the plaintext password to compare against the hash.
|
|
"""
|
|
if pwhash.count("$") < 2:
|
|
return False
|
|
method, salt, hashval = pwhash.split("$", 2)
|
|
return safe_str_cmp(_hash_internal(method, salt, password)[0], hashval)
|
|
|
|
|
|
def safe_join(directory, *pathnames):
|
|
"""Safely join zero or more untrusted path components to a base
|
|
directory to avoid escaping the base directory.
|
|
|
|
:param directory: The trusted base directory.
|
|
:param pathnames: The untrusted path components relative to the
|
|
base directory.
|
|
:return: A safe path, otherwise ``None``.
|
|
"""
|
|
parts = [directory]
|
|
|
|
for filename in pathnames:
|
|
if filename != "":
|
|
filename = posixpath.normpath(filename)
|
|
|
|
if (
|
|
any(sep in filename for sep in _os_alt_seps)
|
|
or os.path.isabs(filename)
|
|
or filename == ".."
|
|
or filename.startswith("../")
|
|
):
|
|
return None
|
|
|
|
parts.append(filename)
|
|
|
|
return posixpath.join(*parts)
|