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: poly1305.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.exceptions import InvalidSignature
from cryptography.hazmat.primitives import constant_time

_POLY1305_TAG_SIZE = 16
_POLY1305_KEY_SIZE = 32

class _Poly1305Context(object):
    def __init__(self, backend, key):
        self._backend = backend

key_ptr = self._backend._ffi.from_buffer(key)
        # This function copies the key into OpenSSL-owned memory so we don't
        # need to retain it ourselves
        evp_pkey = self._backend._lib.EVP_PKEY_new_raw_private_key(
            self._backend._lib.NID_poly1305,
            self._backend._ffi.NULL, key_ptr, len(key)
        )
        self._backend.openssl_assert(evp_pkey != self._backend._ffi.NULL)
        self._evp_pkey = self._backend._ffi.gc(
            evp_pkey, self._backend._lib.EVP_PKEY_free
        )
        ctx = self._backend._lib.Cryptography_EVP_MD_CTX_new()
        self._backend.openssl_assert(ctx != self._backend._ffi.NULL)
        self._ctx = self._backend._ffi.gc(
            ctx, self._backend._lib.Cryptography_EVP_MD_CTX_free
        )
        res = self._backend._lib.EVP_DigestSignInit(
            self._ctx, self._backend._ffi.NULL, self._backend._ffi.NULL,
            self._backend._ffi.NULL, self._evp_pkey
        )
        self._backend.openssl_assert(res == 1)

def update(self, data):
        data_ptr = self._backend._ffi.from_buffer(data)
        res = self._backend._lib.EVP_DigestSignUpdate(
            self._ctx, data_ptr, len(data)
        )
        self._backend.openssl_assert(res != 0)

def finalize(self):
        buf = self._backend._ffi.new("unsigned char[]", _POLY1305_TAG_SIZE)
        outlen = self._backend._ffi.new("size_t *")
        res = self._backend._lib.EVP_DigestSignFinal(self._ctx, buf, outlen)
        self._backend.openssl_assert(res != 0)
        self._backend.openssl_assert(outlen[0] == _POLY1305_TAG_SIZE)
        return self._backend._ffi.buffer(buf)[:outlen[0]]

def verify(self, tag):
        mac = self.finalize()
        if not constant_time.bytes_eq(mac, tag):
            raise InvalidSignature("Value did not match computed tag.")