OXIESEC PANEL

Name	Size	Modified	Perms
📁 ..	-	04/29/2025 04:07:53 PM	rwxr-xr-x
📄 __init__.py	336 bytes	10/17/2019 01:00:23 PM	rw-r--r--
📁 __pycache__	-	04/29/2025 04:07:53 PM	rwxr-xr-x
📄 aead.py	5.62 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 backend.py	94.95 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 ciphers.py	9.12 KB	02/29/2024 10:30:05 AM	rw-r--r--
📄 cmac.py	2.79 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 decode_asn1.py	32.52 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 dh.py	10.56 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 dsa.py	9.99 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 ec.py	12.29 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 ed25519.py	5.94 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 ed448.py	5.9 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 encode_asn1.py	23.04 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 hashes.py	3.12 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 hmac.py	2.93 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 ocsp.py	13.33 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 poly1305.py	2.3 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 rsa.py	17 KB	02/29/2024 10:30:05 AM	rw-r--r--
📄 utils.py	2.28 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 x25519.py	5.45 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 x448.py	4.42 KB	10/17/2019 01:00:23 PM	rw-r--r--
📄 x509.py	19.63 KB	10/17/2019 01:00:23 PM	rw-r--r--

Editing: cmac.py

# 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

from cryptography import utils
from cryptography.exceptions import (
    InvalidSignature, UnsupportedAlgorithm, _Reasons
)
from cryptography.hazmat.primitives import constant_time
from cryptography.hazmat.primitives.ciphers.modes import CBC

class _CMACContext(object):
    def __init__(self, backend, algorithm, ctx=None):
        if not backend.cmac_algorithm_supported(algorithm):
            raise UnsupportedAlgorithm("This backend does not support CMAC.",
                                       _Reasons.UNSUPPORTED_CIPHER)

self._backend = backend
        self._key = algorithm.key
        self._algorithm = algorithm
        self._output_length = algorithm.block_size // 8

if ctx is None:
            registry = self._backend._cipher_registry
            adapter = registry[type(algorithm), CBC]

evp_cipher = adapter(self._backend, algorithm, CBC)

ctx = self._backend._lib.CMAC_CTX_new()

self._backend.openssl_assert(ctx != self._backend._ffi.NULL)
            ctx = self._backend._ffi.gc(ctx, self._backend._lib.CMAC_CTX_free)

key_ptr = self._backend._ffi.from_buffer(self._key)
            res = self._backend._lib.CMAC_Init(
                ctx, key_ptr, len(self._key),
                evp_cipher, self._backend._ffi.NULL
            )
            self._backend.openssl_assert(res == 1)

self._ctx = ctx

algorithm = utils.read_only_property("_algorithm")

def update(self, data):
        res = self._backend._lib.CMAC_Update(self._ctx, data, len(data))
        self._backend.openssl_assert(res == 1)

def finalize(self):
        buf = self._backend._ffi.new("unsigned char[]", self._output_length)
        length = self._backend._ffi.new("size_t *", self._output_length)
        res = self._backend._lib.CMAC_Final(
            self._ctx, buf, length
        )
        self._backend.openssl_assert(res == 1)

self._ctx = None

return self._backend._ffi.buffer(buf)[:]

def copy(self):
        copied_ctx = self._backend._lib.CMAC_CTX_new()
        copied_ctx = self._backend._ffi.gc(
            copied_ctx, self._backend._lib.CMAC_CTX_free
        )
        res = self._backend._lib.CMAC_CTX_copy(
            copied_ctx, self._ctx
        )
        self._backend.openssl_assert(res == 1)
        return _CMACContext(
            self._backend, self._algorithm, ctx=copied_ctx
        )

def verify(self, signature):
        digest = self.finalize()
        if not constant_time.bytes_eq(digest, signature):
            raise InvalidSignature("Signature did not match digest.")