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import codecs
class Immutable(type):
def __init__(cls, name, bases, dct):
type.__setattr__(cls,"attr",set(dct.keys()))
type.__init__(cls, name, bases, dct)
def __setattr__(cls, name, value):
# Mock Py_TPFLAGS_IMMUTABLETYPE
qualname = '.'.join([cls.__module__, cls.__name__])
raise TypeError(f"cannot set '{name}' attribute of immutable type '{qualname}'")
def make_blake_hash(class_name, cffi_mod):
_ffi = cffi_mod.ffi
_lib = cffi_mod.lib
class _blake(metaclass=Immutable):
SALT_SIZE = _lib.BLAKE_SALTBYTES
PERSON_SIZE = _lib.BLAKE_PERSONALBYTES
MAX_KEY_SIZE = _lib.BLAKE_KEYBYTES
MAX_DIGEST_SIZE = _lib.BLAKE_OUTBYTES
def __new__(cls, _string=None, *, digest_size=MAX_DIGEST_SIZE,
key=None, salt=None, person=None, fanout=1, depth=1,
leaf_size=None, node_offset=None, node_depth=0,
inner_size=0, last_node=False, usedforsecurity=True):
self = super().__new__(cls)
self._param = _ffi.new("blake_param*")
self._state = _ffi.new("blake_state*")
# Set digest size.
if not 1 <= digest_size <= self.MAX_DIGEST_SIZE:
raise ValueError(
"digest_size must be between 1 and %s bytes" %
self.MAX_DIGEST_SIZE)
self._param.digest_length = digest_size
# Set salt parameter.
if salt is not None:
if len(salt) > self.SALT_SIZE:
raise ValueError(
"maximum salt length is %d bytes" %
self.SALT_SIZE)
_ffi.memmove(self._param.salt, salt, len(salt))
# Set personalization parameter.
if person:
if len(person) > _lib.BLAKE_PERSONALBYTES:
raise ValueError("maximum person length is %d bytes" %
_lib.BLAKE_PERSONALBYTES)
_ffi.memmove(self._param.personal, person, len(person))
# Set tree parameters.
if not 0 <= fanout <= 255:
raise ValueError("fanout must be between 0 and 255")
self._param.fanout = fanout
if not 1 <= depth <= 255:
raise ValueError("depth must be between 1 and 255")
self._param.depth = depth
if leaf_size is not None:
if leaf_size > 0xFFFFFFFF:
raise OverflowError("leaf_size is too large")
if leaf_size < 0:
raise ValueError("value must be positive")
# NB: Simple assignment here would be incorrect on big
# endian platforms.
_lib.store32(_ffi.addressof(self._param, 'leaf_length'),
leaf_size)
if node_offset is not None:
if node_offset < 0:
raise ValueError("value must be positive")
if class_name == 'blake2s':
if node_offset > 0xFFFFFFFFFFFF:
# maximum 2**48 - 1
raise OverflowError("node_offset is too large")
_lib.store48(_lib.addressof_node_offset(self._param),
node_offset)
else:
# NB: Simple assignment here would be incorrect on big
# endian platforms.
_lib.store64(_lib.addressof_node_offset(self._param),
node_offset)
if not 0 <= node_depth <= 255:
raise ValueError("node_depth must be between 0 and 255")
self._param.node_depth = node_depth
if not 0 <= inner_size <= _lib.BLAKE_OUTBYTES:
raise ValueError("inner_size must be between 0 and is %d" %
_lib.BLAKE_OUTBYTES)
self._param.inner_length = inner_size
# Set key length.
if key:
if len(key) > _lib.BLAKE_KEYBYTES:
raise ValueError("maximum key length is %d bytes" %
_lib.BLAKE_KEYBYTES)
self._param.key_length = len(key)
# Initialize hash state.
if _lib.blake_init_param(self._state, self._param) < 0:
raise RuntimeError("error initializing hash state")
# Set last node flag (must come after initialization).
self._state.last_node = last_node
# Process key block if any.
if key:
block = _ffi.new("uint8_t[]", _lib.BLAKE_BLOCKBYTES)
_ffi.memmove(block, key, len(key))
_lib.blake_update(self._state, block, len(block))
# secure_zero_memory(block, sizeof(block)
if _string is not None:
self.update(_string)
return self
@property
def name(self):
return class_name
@property
def block_size(self):
return _lib.BLAKE_BLOCKBYTES
@property
def digest_size(self):
return self._param.digest_length
def update(self, data):
if isinstance(data, memoryview):
buf = data.tobytes()
else:
buf = _ffi.from_buffer(data)
_lib.blake_update(self._state, buf, len(buf))
def digest(self):
digest = _ffi.new("char[]", _lib.BLAKE_OUTBYTES)
state_copy = _ffi.new("blake_state*")
_ffi.memmove(state_copy, self._state, _ffi.sizeof("blake_state"))
_lib.blake_final(state_copy, digest, self._param.digest_length)
return _ffi.unpack(digest, self._param.digest_length)
def hexdigest(self):
return codecs.encode(self.digest(), 'hex').decode()
def copy(self):
copy = super().__new__(type(self))
copy._state = _ffi.new("blake_state*")
_ffi.memmove(copy._state, self._state, _ffi.sizeof("blake_state"))
copy._param = _ffi.new("blake_param*")
_ffi.memmove(copy._param, self._param, _ffi.sizeof("blake_param"))
return copy
type.__setattr__(_blake, '__name__' ,class_name)
type.__setattr__(_blake, '__qualname__' ,class_name)
return _blake
from . import _blake2b_cffi
blake2b = make_blake_hash('blake2b', _blake2b_cffi)
from . import _blake2s_cffi
blake2s = make_blake_hash('blake2s', _blake2s_cffi)
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