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# Copyright 2019, Battelle Memorial Institute.
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from http.cookies import SimpleCookie
import logging

from volttron.platform import get_platform_config

try:
    import jwt
except ImportError:
    logging.getLogger().warning("Missing library jwt within web package.")

from . discovery import DiscoveryInfo, DiscoveryError

# Used outside so we make it available through this file.
from . master_web_service import MasterWebService

_log = logging.getLogger(__name__)


class NotAuthorized(Exception):
    pass


def get_bearer(env):

    # Test if HTTP_AUTHORIZATION header is passed
    http_auth = env.get('HTTP_AUTHORIZATION')
    if http_auth:
        auth_type, bearer = http_auth.split(' ')
        if auth_type.upper() != 'BEARER':
            raise NotAuthorized("Invalid HTTP_AUTHORIZATION header passed, must be Bearer")
    else:
        cookiestr = env.get('HTTP_COOKIE')
        if not cookiestr:
            raise NotAuthorized()
        cookie = SimpleCookie(cookiestr)
        if 'Bearer' in cookie:
            bearer = cookie.get('Bearer').value
            return bearer
        else:
            return None


def get_user_claims(env, ssl_public_key):
    algorithm, encode_key = __get_key_and_algorithm__(env, ssl_public_key)
    bearer = get_bearer(env)
    return jwt.decode(bearer, encode_key, algorithm=algorithm)



def __get_key_and_algorithm__(env, ssl_public_key):
    config = get_platform_config()
    publickey = env.get("WEB_PUBLIC_KEY")
    if publickey is not None or ssl_public_key is not None:
        algorithm = 'RS256'
    else:
        algorithm = 'HS256'

    if algorithm == 'HS256':
        if config.get('web-secret-key') is None:
            raise ValueError("invalid configuration detected web_secret_key must be set!")

    if algorithm == 'RS256' and ssl_public_key is None:
        encode_key = publickey
    elif algorithm == 'RS256' and ssl_public_key:
        encode_key = ssl_public_key
    else:
        encode_key = config.get('web-secret-key')

    return algorithm, encode_key


def get_user_claim_from_bearer(bearer, web_secret_key=None, tls_public_key=None):
    if web_secret_key is None and tls_public_key is None:
        raise ValueError("web_secret_key or tls_public_key must be set")
    if web_secret_key is None and tls_public_key is None:
        raise ValueError("web_secret_key or tls_public_key must be set not both")

    if web_secret_key is not None:
        algorithm = 'HS256'
        pubkey = web_secret_key
    else:
        algorithm = 'RS256'
        pubkey = tls_public_key
        # if isinstance(tls_public_key, str):
        #     pubkey = CertWrapper.load_cert(tls_public_key)
    return jwt.decode(bearer, pubkey, algorithms=algorithm)



