# Path: jose/backends/base.py
# class Key:
#     """
#     A simple interface for implementing JWK keys.
#     """
# 
#     def __init__(self, key, algorithm):
#         pass
# 
#     def sign(self, msg):
#         raise NotImplementedError()
# 
#     def verify(self, msg, sig):
#         raise NotImplementedError()
# 
#     def public_key(self):
#         raise NotImplementedError()
# 
#     def to_pem(self):
#         raise NotImplementedError()
# 
#     def to_dict(self):
#         raise NotImplementedError()
# 
#     def encrypt(self, plain_text, aad=None):
#         """
#         Encrypt the plain text and generate an auth tag if appropriate
# 
#         Args:
#             plain_text (bytes): Data to encrypt
#             aad (bytes, optional): Authenticated Additional Data if key's algorithm supports auth mode
# 
#         Returns:
#             (bytes, bytes, bytes): IV, cipher text, and auth tag
#         """
#         raise NotImplementedError()
# 
#     def decrypt(self, cipher_text, iv=None, aad=None, tag=None):
#         """
#         Decrypt the cipher text and validate the auth tag if present
#         Args:
#             cipher_text (bytes): Cipher text to decrypt
#             iv (bytes): IV if block mode
#             aad (bytes): Additional Authenticated Data to verify if auth mode
#             tag (bytes): Authentication tag if auth mode
# 
#         Returns:
#             bytes: Decrypted value
#         """
#         raise NotImplementedError()
# 
#     def wrap_key(self, key_data):
#         """
#         Wrap the the plain text key data
# 
#         Args:
#             key_data (bytes): Key data to wrap
# 
#         Returns:
#             bytes: Wrapped key
#         """
#         raise NotImplementedError()
# 
#     def unwrap_key(self, wrapped_key):
#         """
#         Unwrap the the wrapped key data
# 
#         Args:
#             wrapped_key (bytes): Wrapped key data to unwrap
# 
#         Returns:
#             bytes: Unwrapped key
#         """
#         raise NotImplementedError()
# 
# Path: jose/constants.py
# ALGORITHMS = Algorithms()
# 
# Path: jose/exceptions.py
# class JWKError(JOSEError):
#     pass
# 
# Path: jose/utils.py
# def base64url_decode(input):
#     """Helper method to base64url_decode a string.
# 
#     Args:
#         input (str): A base64url_encoded string to decode.
# 
#     """
#     rem = len(input) % 4
# 
#     if rem > 0:
#         input += b"=" * (4 - rem)
# 
#     return base64.urlsafe_b64decode(input)
# 
# def base64url_encode(input):
#     """Helper method to base64url_encode a string.
# 
#     Args:
#         input (str): A base64url_encoded string to encode.
# 
#     """
#     return base64.urlsafe_b64encode(input).replace(b"=", b"")


import hashlib
import hmac
import os
from jose.backends.base import Key
from jose.constants import ALGORITHMS
from jose.exceptions import JWKError
from jose.utils import base64url_decode, base64url_encode
    Performs signing and verification operations using HMAC
    and the specified hash function.
    """

    HASHES = {ALGORITHMS.HS256: hashlib.sha256, ALGORITHMS.HS384: hashlib.sha384, ALGORITHMS.HS512: hashlib.sha512}

    def __init__(self, key, algorithm):
        if algorithm not in ALGORITHMS.HMAC:
            raise JWKError("hash_alg: %s is not a valid hash algorithm" % algorithm)
        self._algorithm = algorithm
        self._hash_alg = self.HASHES.get(algorithm)

        if isinstance(key, dict):
            self.prepared_key = self._process_jwk(key)
            return

        if not isinstance(key, str) and not isinstance(key, bytes):
            raise JWKError("Expecting a string- or bytes-formatted key.")

        if isinstance(key, str):
            key = key.encode("utf-8")

        invalid_strings = [
            b"-----BEGIN PUBLIC KEY-----",
            b"-----BEGIN RSA PUBLIC KEY-----",
            b"-----BEGIN CERTIFICATE-----",
            b"ssh-rsa",
        ]

        if any(string_value in key for string_value in invalid_strings):

# Path: jose/backends/base.py
# class Key:
#     """
#     A simple interface for implementing JWK keys.
#     """
# 
#     def __init__(self, key, algorithm):
#         pass
# 
#     def sign(self, msg):
#         raise NotImplementedError()
# 
#     def verify(self, msg, sig):
#         raise NotImplementedError()
# 
#     def public_key(self):
#         raise NotImplementedError()
# 
#     def to_pem(self):
#         raise NotImplementedError()
# 
#     def to_dict(self):
#         raise NotImplementedError()
# 
#     def encrypt(self, plain_text, aad=None):
#         """
#         Encrypt the plain text and generate an auth tag if appropriate
# 
#         Args:
#             plain_text (bytes): Data to encrypt
#             aad (bytes, optional): Authenticated Additional Data if key's algorithm supports auth mode
# 
#         Returns:
#             (bytes, bytes, bytes): IV, cipher text, and auth tag
#         """
#         raise NotImplementedError()
# 
#     def decrypt(self, cipher_text, iv=None, aad=None, tag=None):
#         """
#         Decrypt the cipher text and validate the auth tag if present
#         Args:
#             cipher_text (bytes): Cipher text to decrypt
#             iv (bytes): IV if block mode
#             aad (bytes): Additional Authenticated Data to verify if auth mode
#             tag (bytes): Authentication tag if auth mode
# 
#         Returns:
#             bytes: Decrypted value
#         """
#         raise NotImplementedError()
# 
#     def wrap_key(self, key_data):
#         """
#         Wrap the the plain text key data
# 
#         Args:
#             key_data (bytes): Key data to wrap
# 
#         Returns:
#             bytes: Wrapped key
#         """
#         raise NotImplementedError()
# 
#     def unwrap_key(self, wrapped_key):
#         """
#         Unwrap the the wrapped key data
# 
#         Args:
#             wrapped_key (bytes): Wrapped key data to unwrap
# 
#         Returns:
#             bytes: Unwrapped key
#         """
#         raise NotImplementedError()
# 
# Path: jose/constants.py
# ALGORITHMS = Algorithms()
# 
# Path: jose/exceptions.py
# class JWKError(JOSEError):
#     pass
# 
# Path: jose/utils.py
# def base64url_decode(input):
#     """Helper method to base64url_decode a string.
# 
#     Args:
#         input (str): A base64url_encoded string to decode.
# 
#     """
#     rem = len(input) % 4
# 
#     if rem > 0:
#         input += b"=" * (4 - rem)
# 
#     return base64.urlsafe_b64decode(input)
# 
# def base64url_encode(input):
#     """Helper method to base64url_encode a string.
# 
#     Args:
#         input (str): A base64url_encoded string to encode.
# 
#     """
#     return base64.urlsafe_b64encode(input).replace(b"=", b"")


# Path: jose/backends/native.py
import hashlib
import hmac
import os
from jose.backends.base import Key
from jose.constants import ALGORITHMS
from jose.exceptions import JWKError
from jose.utils import base64url_decode, base64url_encode

    Performs signing and verification operations using HMAC
    and the specified hash function.
    """

    HASHES = {ALGORITHMS.HS256: hashlib.sha256, ALGORITHMS.HS384: hashlib.sha384, ALGORITHMS.HS512: hashlib.sha512}

    def __init__(self, key, algorithm):
        if algorithm not in ALGORITHMS.HMAC:
            raise JWKError("hash_alg: %s is not a valid hash algorithm" % algorithm)
        self._algorithm = algorithm
        self._hash_alg = self.HASHES.get(algorithm)

        if isinstance(key, dict):
            self.prepared_key = self._process_jwk(key)
            return

        if not isinstance(key, str) and not isinstance(key, bytes):
            raise JWKError("Expecting a string- or bytes-formatted key.")

        if isinstance(key, str):
            key = key.encode("utf-8")

        invalid_strings = [
            b"-----BEGIN PUBLIC KEY-----",
            b"-----BEGIN RSA PUBLIC KEY-----",
            b"-----BEGIN CERTIFICATE-----",
            b"ssh-rsa",
        ]

        if any(string_value in key for string_value in invalid_strings):

            raise JWKError(