147 lines
4.1 KiB
Python
147 lines
4.1 KiB
Python
import sys
|
|
import warnings
|
|
|
|
from six import PY3, binary_type, text_type
|
|
|
|
from cryptography.hazmat.bindings.openssl.binding import Binding
|
|
|
|
|
|
binding = Binding()
|
|
binding.init_static_locks()
|
|
ffi = binding.ffi
|
|
lib = binding.lib
|
|
|
|
|
|
# This is a special CFFI allocator that does not bother to zero its memory
|
|
# after allocation. This has vastly better performance on large allocations and
|
|
# so should be used whenever we don't need the memory zeroed out.
|
|
no_zero_allocator = ffi.new_allocator(should_clear_after_alloc=False)
|
|
|
|
|
|
def text(charp):
|
|
"""
|
|
Get a native string type representing of the given CFFI ``char*`` object.
|
|
|
|
:param charp: A C-style string represented using CFFI.
|
|
|
|
:return: :class:`str`
|
|
"""
|
|
if not charp:
|
|
return ""
|
|
return native(ffi.string(charp))
|
|
|
|
|
|
def exception_from_error_queue(exception_type):
|
|
"""
|
|
Convert an OpenSSL library failure into a Python exception.
|
|
|
|
When a call to the native OpenSSL library fails, this is usually signalled
|
|
by the return value, and an error code is stored in an error queue
|
|
associated with the current thread. The err library provides functions to
|
|
obtain these error codes and textual error messages.
|
|
"""
|
|
errors = []
|
|
|
|
while True:
|
|
error = lib.ERR_get_error()
|
|
if error == 0:
|
|
break
|
|
errors.append((
|
|
text(lib.ERR_lib_error_string(error)),
|
|
text(lib.ERR_func_error_string(error)),
|
|
text(lib.ERR_reason_error_string(error))))
|
|
|
|
raise exception_type(errors)
|
|
|
|
|
|
def make_assert(error):
|
|
"""
|
|
Create an assert function that uses :func:`exception_from_error_queue` to
|
|
raise an exception wrapped by *error*.
|
|
"""
|
|
def openssl_assert(ok):
|
|
"""
|
|
If *ok* is not True, retrieve the error from OpenSSL and raise it.
|
|
"""
|
|
if ok is not True:
|
|
exception_from_error_queue(error)
|
|
|
|
return openssl_assert
|
|
|
|
|
|
def native(s):
|
|
"""
|
|
Convert :py:class:`bytes` or :py:class:`unicode` to the native
|
|
:py:class:`str` type, using UTF-8 encoding if conversion is necessary.
|
|
|
|
:raise UnicodeError: The input string is not UTF-8 decodeable.
|
|
|
|
:raise TypeError: The input is neither :py:class:`bytes` nor
|
|
:py:class:`unicode`.
|
|
"""
|
|
if not isinstance(s, (binary_type, text_type)):
|
|
raise TypeError("%r is neither bytes nor unicode" % s)
|
|
if PY3:
|
|
if isinstance(s, binary_type):
|
|
return s.decode("utf-8")
|
|
else:
|
|
if isinstance(s, text_type):
|
|
return s.encode("utf-8")
|
|
return s
|
|
|
|
|
|
def path_string(s):
|
|
"""
|
|
Convert a Python string to a :py:class:`bytes` string identifying the same
|
|
path and which can be passed into an OpenSSL API accepting a filename.
|
|
|
|
:param s: An instance of :py:class:`bytes` or :py:class:`unicode`.
|
|
|
|
:return: An instance of :py:class:`bytes`.
|
|
"""
|
|
if isinstance(s, binary_type):
|
|
return s
|
|
elif isinstance(s, text_type):
|
|
return s.encode(sys.getfilesystemencoding())
|
|
else:
|
|
raise TypeError("Path must be represented as bytes or unicode string")
|
|
|
|
|
|
if PY3:
|
|
def byte_string(s):
|
|
return s.encode("charmap")
|
|
else:
|
|
def byte_string(s):
|
|
return s
|
|
|
|
|
|
# A marker object to observe whether some optional arguments are passed any
|
|
# value or not.
|
|
UNSPECIFIED = object()
|
|
|
|
_TEXT_WARNING = (
|
|
text_type.__name__ + " for {0} is no longer accepted, use bytes"
|
|
)
|
|
|
|
|
|
def text_to_bytes_and_warn(label, obj):
|
|
"""
|
|
If ``obj`` is text, emit a warning that it should be bytes instead and try
|
|
to convert it to bytes automatically.
|
|
|
|
:param str label: The name of the parameter from which ``obj`` was taken
|
|
(so a developer can easily find the source of the problem and correct
|
|
it).
|
|
|
|
:return: If ``obj`` is the text string type, a ``bytes`` object giving the
|
|
UTF-8 encoding of that text is returned. Otherwise, ``obj`` itself is
|
|
returned.
|
|
"""
|
|
if isinstance(obj, text_type):
|
|
warnings.warn(
|
|
_TEXT_WARNING.format(label),
|
|
category=DeprecationWarning,
|
|
stacklevel=3
|
|
)
|
|
return obj.encode('utf-8')
|
|
return obj
|