openmedialibrary_platform_w.../Lib/site-packages/cryptography/utils.py
2016-01-31 20:14:46 +05:30

129 lines
3.5 KiB
Python

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
from __future__ import absolute_import, division, print_function
import abc
import binascii
import inspect
import struct
import sys
import warnings
# the functions deprecated in 1.0 are on an arbitrarily extended deprecation
# cycle and should not be removed until we agree on when that cycle ends.
DeprecatedIn10 = DeprecationWarning
DeprecatedIn12 = PendingDeprecationWarning
def read_only_property(name):
return property(lambda self: getattr(self, name))
def register_interface(iface):
def register_decorator(klass):
verify_interface(iface, klass)
iface.register(klass)
return klass
return register_decorator
if hasattr(int, "from_bytes"):
int_from_bytes = int.from_bytes
else:
def int_from_bytes(data, byteorder, signed=False):
assert byteorder == 'big'
assert not signed
if len(data) % 4 != 0:
data = (b'\x00' * (4 - (len(data) % 4))) + data
result = 0
while len(data) > 0:
digit, = struct.unpack('>I', data[:4])
result = (result << 32) + digit
data = data[4:]
return result
def int_to_bytes(integer, length=None):
hex_string = '%x' % integer
if length is None:
n = len(hex_string)
else:
n = length * 2
return binascii.unhexlify(hex_string.zfill(n + (n & 1)))
class InterfaceNotImplemented(Exception):
pass
if hasattr(inspect, "signature"):
signature = inspect.signature
else:
signature = inspect.getargspec
def verify_interface(iface, klass):
for method in iface.__abstractmethods__:
if not hasattr(klass, method):
raise InterfaceNotImplemented(
"{0} is missing a {1!r} method".format(klass, method)
)
if isinstance(getattr(iface, method), abc.abstractproperty):
# Can't properly verify these yet.
continue
sig = signature(getattr(iface, method))
actual = signature(getattr(klass, method))
if sig != actual:
raise InterfaceNotImplemented(
"{0}.{1}'s signature differs from the expected. Expected: "
"{2!r}. Received: {3!r}".format(
klass, method, sig, actual
)
)
if sys.version_info >= (2, 7):
def bit_length(x):
return x.bit_length()
else:
def bit_length(x):
return len(bin(x)) - (2 + (x <= 0))
class _DeprecatedValue(object):
def __init__(self, value, message, warning_class):
self.value = value
self.message = message
self.warning_class = warning_class
class _ModuleWithDeprecations(object):
def __init__(self, module):
self.__dict__["_module"] = module
def __getattr__(self, attr):
obj = getattr(self._module, attr)
if isinstance(obj, _DeprecatedValue):
warnings.warn(obj.message, obj.warning_class, stacklevel=2)
obj = obj.value
return obj
def __setattr__(self, attr, value):
setattr(self._module, attr, value)
def __dir__(self):
return ["_module"] + dir(self._module)
def deprecated(value, module_name, message, warning_class):
module = sys.modules[module_name]
if not isinstance(module, _ModuleWithDeprecations):
sys.modules[module_name] = module = _ModuleWithDeprecations(module)
return _DeprecatedValue(value, message, warning_class)