248 lines
9.2 KiB
Python
248 lines
9.2 KiB
Python
|
# ===================================================================
|
||
|
|
#
|
||
|
|
# Copyright (c) 2014, Legrandin <helderijs@gmail.com>
|
||
|
|
# All rights reserved.
|
||
|
|
#
|
||
|
|
# Redistribution and use in source and binary forms, with or without
|
||
|
|
# modification, are permitted provided that the following conditions
|
||
|
|
# are met:
|
||
|
|
#
|
||
|
|
# 1. Redistributions of source code must retain the above copyright
|
||
|
|
# notice, this list of conditions and the following disclaimer.
|
||
|
|
# 2. Redistributions in binary form must reproduce the above copyright
|
||
|
|
# notice, this list of conditions and the following disclaimer in
|
||
|
|
# the documentation and/or other materials provided with the
|
||
|
|
# distribution.
|
||
|
|
#
|
||
|
|
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||
|
|
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||
|
|
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||
|
|
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||
|
|
# COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||
|
|
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||
|
|
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||
|
|
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||
|
|
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
|
|
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||
|
|
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||
|
|
# POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
# ===================================================================
|
||
|
|
|
||
|
|
from binascii import unhexlify
|
||
|
|
|
||
|
|
from Cryptodome.Util.py3compat import bord, tobytes
|
||
|
|
|
||
|
|
from Cryptodome.Random import get_random_bytes
|
||
|
|
from Cryptodome.Util._raw_api import (load_pycryptodome_raw_lib,
|
||
|
|
VoidPointer, SmartPointer,
|
||
|
|
create_string_buffer,
|
||
|
|
get_raw_buffer, c_size_t,
|
||
|
|
c_uint8_ptr)
|
||
|
|
|
||
|
|
_raw_blake2b_lib = load_pycryptodome_raw_lib("Cryptodome.Hash._BLAKE2b",
|
||
|
|
"""
|
||
|
|
int blake2b_init(void **state,
|
||
|
|
const uint8_t *key,
|
||
|
|
size_t key_size,
|
||
|
|
size_t digest_size);
|
||
|
|
int blake2b_destroy(void *state);
|
||
|
|
int blake2b_update(void *state,
|
||
|
|
const uint8_t *buf,
|
||
|
|
size_t len);
|
||
|
|
int blake2b_digest(const void *state,
|
||
|
|
uint8_t digest[64]);
|
||
|
|
int blake2b_copy(const void *src, void *dst);
|
||
|
|
""")
|
||
|
|
|
||
|
|
|
||
|
|
class BLAKE2b_Hash(object):
|
||
|
|
"""A BLAKE2b hash object.
|
||
|
|
Do not instantiate directly. Use the :func:`new` function.
|
||
|
|
|
||
|
|
:ivar oid: ASN.1 Object ID
|
||
|
|
:vartype oid: string
|
||
|
|
|
||
|
|
:ivar block_size: the size in bytes of the internal message block,
|
||
|
|
input to the compression function
|
||
|
|
:vartype block_size: integer
|
||
|
|
|
||
|
|
:ivar digest_size: the size in bytes of the resulting hash
|
||
|
|
:vartype digest_size: integer
|
||
|
|
"""
|
||
|
|
|
||
|
|
# The internal block size of the hash algorithm in bytes.
|
||
|
|
block_size = 64
|
||
|
|
|
||
|
|
def __init__(self, data, key, digest_bytes, update_after_digest):
|
||
|
|
|
||
|
|
# The size of the resulting hash in bytes.
|
||
|
|
self.digest_size = digest_bytes
|
||
|
|
|
||
|
|
self._update_after_digest = update_after_digest
|
||
|
|
self._digest_done = False
|
||
|
|
|
||
|
|
# See https://tools.ietf.org/html/rfc7693
|
||
|
|
if digest_bytes in (20, 32, 48, 64) and not key:
|
||
|
|
self.oid = "1.3.6.1.4.1.1722.12.2.1." + str(digest_bytes)
|
||
|
|
|
||
|
|
state = VoidPointer()
|
||
|
|
result = _raw_blake2b_lib.blake2b_init(state.address_of(),
|
||
|
|
c_uint8_ptr(key),
|
||
|
|
c_size_t(len(key)),
|
||
|
|
c_size_t(digest_bytes)
|
||
|
|
)
|
||
|
|
if result:
|
||
|
|
raise ValueError("Error %d while instantiating BLAKE2b" % result)
|
||
|
|
self._state = SmartPointer(state.get(),
|
||
|
|
_raw_blake2b_lib.blake2b_destroy)
|
||
|
|
if data:
|
||
|
|
self.update(data)
|
||
|
|
|
||
|
|
|
||
|
|
def update(self, data):
|
||
|
|
"""Continue hashing of a message by consuming the next chunk of data.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
data (bytes/bytearray/memoryview): The next chunk of the message being hashed.
|
||
|
|
"""
|
||
|
|
|
||
|
|
if self._digest_done and not self._update_after_digest:
|
||
|
|
raise TypeError("You can only call 'digest' or 'hexdigest' on this object")
|
||
|
|
|
||
|
|
result = _raw_blake2b_lib.blake2b_update(self._state.get(),
|
||
|
|
c_uint8_ptr(data),
|
||
|
|
c_size_t(len(data)))
|
||
|
|
if result:
|
||
|
|
raise ValueError("Error %d while hashing BLAKE2b data" % result)
|
||
|
|
return self
|
||
|
|
|
||
|
|
|
||
|
|
def digest(self):
|
||
|
|
"""Return the **binary** (non-printable) digest of the message that has been hashed so far.
|
||
|
|
|
||
|
|
:return: The hash digest, computed over the data processed so far.
|
||
|
|
Binary form.
|
||
|
|
:rtype: byte string
|
||
|
|
"""
|
||
|
|
|
||
|
|
bfr = create_string_buffer(64)
|
||
|
|
result = _raw_blake2b_lib.blake2b_digest(self._state.get(),
|
||
|
|
bfr)
|
||
|
|
if result:
|
||
|
|
raise ValueError("Error %d while creating BLAKE2b digest" % result)
|
||
|
|
|
||
|
|
self._digest_done = True
|
||
|
|
|
||
|
|
return get_raw_buffer(bfr)[:self.digest_size]
|
||
|
|
|
||
|
|
|
||
|
|
def hexdigest(self):
|
||
|
|
"""Return the **printable** digest of the message that has been hashed so far.
|
||
|
|
|
||
|
|
:return: The hash digest, computed over the data processed so far.
|
||
|
|
Hexadecimal encoded.
|
||
|
|
:rtype: string
|
||
|
|
"""
|
||
|
|
|
||
|
|
return "".join(["%02x" % bord(x) for x in tuple(self.digest())])
|
||
|
|
|
||
|
|
|
||
|
|
def verify(self, mac_tag):
|
||
|
|
"""Verify that a given **binary** MAC (computed by another party)
|
||
|
|
is valid.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
mac_tag (bytes/bytearray/memoryview): the expected MAC of the message.
|
||
|
|
|
||
|
|
Raises:
|
||
|
|
ValueError: if the MAC does not match. It means that the message
|
||
|
|
has been tampered with or that the MAC key is incorrect.
|
||
|
|
"""
|
||
|
|
|
||
|
|
secret = get_random_bytes(16)
|
||
|
|
|
||
|
|
mac1 = new(digest_bits=160, key=secret, data=mac_tag)
|
||
|
|
mac2 = new(digest_bits=160, key=secret, data=self.digest())
|
||
|
|
|
||
|
|
if mac1.digest() != mac2.digest():
|
||
|
|
raise ValueError("MAC check failed")
|
||
|
|
|
||
|
|
|
||
|
|
def hexverify(self, hex_mac_tag):
|
||
|
|
"""Verify that a given **printable** MAC (computed by another party)
|
||
|
|
is valid.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
hex_mac_tag (string): the expected MAC of the message, as a hexadecimal string.
|
||
|
|
|
||
|
|
Raises:
|
||
|
|
ValueError: if the MAC does not match. It means that the message
|
||
|
|
has been tampered with or that the MAC key is incorrect.
|
||
|
|
"""
|
||
|
|
|
||
|
|
self.verify(unhexlify(tobytes(hex_mac_tag)))
|
||
|
|
|
||
|
|
|
||
|
|
def new(self, **kwargs):
|
||
|
|
"""Return a new instance of a BLAKE2b hash object.
|
||
|
|
See :func:`new`.
|
||
|
|
"""
|
||
|
|
|
||
|
|
if "digest_bytes" not in kwargs and "digest_bits" not in kwargs:
|
||
|
|
kwargs["digest_bytes"] = self.digest_size
|
||
|
|
|
||
|
|
return new(**kwargs)
|
||
|
|
|
||
|
|
|
||
|
|
def new(**kwargs):
|
||
|
|
"""Create a new hash object.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
data (bytes/bytearray/memoryview):
|
||
|
|
Optional. The very first chunk of the message to hash.
|
||
|
|
It is equivalent to an early call to :meth:`BLAKE2b_Hash.update`.
|
||
|
|
digest_bytes (integer):
|
||
|
|
Optional. The size of the digest, in bytes (1 to 64). Default is 64.
|
||
|
|
digest_bits (integer):
|
||
|
|
Optional and alternative to ``digest_bytes``.
|
||
|
|
The size of the digest, in bits (8 to 512, in steps of 8).
|
||
|
|
Default is 512.
|
||
|
|
key (bytes/bytearray/memoryview):
|
||
|
|
Optional. The key to use to compute the MAC (1 to 64 bytes).
|
||
|
|
If not specified, no key will be used.
|
||
|
|
update_after_digest (boolean):
|
||
|
|
Optional. By default, a hash object cannot be updated anymore after
|
||
|
|
the digest is computed. When this flag is ``True``, such check
|
||
|
|
is no longer enforced.
|
||
|
|
|
||
|
|
Returns:
|
||
|
|
A :class:`BLAKE2b_Hash` hash object
|
||
|
|
"""
|
||
|
|
|
||
|
|
data = kwargs.pop("data", None)
|
||
|
|
update_after_digest = kwargs.pop("update_after_digest", False)
|
||
|
|
|
||
|
|
digest_bytes = kwargs.pop("digest_bytes", None)
|
||
|
|
digest_bits = kwargs.pop("digest_bits", None)
|
||
|
|
if None not in (digest_bytes, digest_bits):
|
||
|
|
raise TypeError("Only one digest parameter must be provided")
|
||
|
|
if (None, None) == (digest_bytes, digest_bits):
|
||
|
|
digest_bytes = 64
|
||
|
|
if digest_bytes is not None:
|
||
|
|
if not (1 <= digest_bytes <= 64):
|
||
|
|
raise ValueError("'digest_bytes' not in range 1..64")
|
||
|
|
else:
|
||
|
|
if not (8 <= digest_bits <= 512) or (digest_bits % 8):
|
||
|
|
raise ValueError("'digest_bits' not in range 8..512, "
|
||
|
|
"with steps of 8")
|
||
|
|
digest_bytes = digest_bits // 8
|
||
|
|
|
||
|
|
key = kwargs.pop("key", b"")
|
||
|
|
if len(key) > 64:
|
||
|
|
raise ValueError("BLAKE2b key cannot exceed 64 bytes")
|
||
|
|
|
||
|
|
if kwargs:
|
||
|
|
raise TypeError("Unknown parameters: " + str(kwargs))
|
||
|
|
|
||
|
|
return BLAKE2b_Hash(data, key, digest_bytes, update_after_digest)
|