| Server IP : 172.67.216.182 / Your IP : 162.158.108.89 Web Server : Apache System : Linux krdc-ubuntu-s-2vcpu-4gb-amd-blr1-01.localdomain 5.15.0-142-generic #152-Ubuntu SMP Mon May 19 10:54:31 UTC 2025 x86_64 User : www ( 1000) PHP Version : 7.4.33 Disable Function : passthru,exec,system,putenv,chroot,chgrp,chown,shell_exec,popen,proc_open,pcntl_exec,ini_alter,ini_restore,dl,openlog,syslog,readlink,symlink,popepassthru,pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,imap_open,apache_setenv MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : OFF | Sudo : ON | Pkexec : ON Directory : /usr/lib/python3/dist-packages/cryptography/hazmat/backends/openssl/ |
Upload File : |
# 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 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: bytes) -> None:
res = self._backend._lib.CMAC_Update(self._ctx, data, len(data))
self._backend.openssl_assert(res == 1)
def finalize(self) -> bytes:
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) -> "_CMACContext":
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: bytes) -> None:
digest = self.finalize()
if not constant_time.bytes_eq(digest, signature):
raise InvalidSignature("Signature did not match digest.")