drf之auth认证

drf总流程链接

https://www.cnblogs.com/daviddd/p/11918405.html

drf之auth认证

'''
承上rest_framework总流程的5.2认证

认证：
1. 执行dispatch方法，中的initialize_request
封装新的request，然后执行get_authenticators，实例化认证类对象列表，并封装到request中


2. 执行initial中的perform_authrentication 方法，执行request.user 中的_authenticate
方法，循环认证类对象列表，并执行authenticate方法，返回none，或者一个元组,或者抛出异常

'''
class APIView(View):


    # 3.22authentication_classes 配置，全局配置在settings文件中或自定义在需要的类中
    authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES

    settings = api_settings

    schema = DefaultSchema()


    def initialize_request(self, request, *args, **kwargs):
        """
        Returns the initial request object.
        """
        parser_context = self.get_parser_context(request)

        return Request(
            request,
            parsers=self.get_parsers(),

            # 承接总流程的3.2过程
            authenticators=self.get_authenticators(),
        )


    # 3.21实例化认证函数并存放到一个列表中
    def get_authenticators(self):
        """
        Instantiates and returns the list of authenticators that this view can use.
        """
        return [auth() for auth in self.authentication_classes]


    # 封装请求头后执行initial函数，版本，认证。。。
    def initial(self, request, *args, **kwargs):

        # 5.2认证
        self.perform_authentication(request)


    # 5.21当后端执行request.user时，调用request的user()函数
    def perform_authentication(self, request):
        """
        Perform authentication on the incoming request.

        Note that if you override this and simply 'pass', then authentication
        will instead be performed lazily, the first time either
        `request.user` or `request.auth` is accessed.
        """
        request.user


    # 5.22封装request.user,request.auth
    @property
    def user(self):
        """
        Returns the user associated with the current request, as authenticated
        by the authentication classes provided to the request.
        """
        if not hasattr(self, '_user'):

            # 5.23
            with wrap_attributeerrors():

                # 5.24
                self._authenticate()
        return self._user




    def _authenticate(self):
        """
        Attempt to authenticate the request using each authentication instance
        in turn.
        """
        for authenticator in self.authenticators:
            try:

                # 5.25，调用认证类中的authenticate函数，自己定义则调用自己的
                user_auth_tuple = authenticator.authenticate(self)
            except exceptions.APIException:
                self._not_authenticated()
                raise


            # 5.27得到authenticate的返回值user_auth_tuple，封装user，auth
            if user_auth_tuple is not None:
                self._authenticator = authenticator
                self.user, self.auth = user_auth_tuple
                return


        # 5.28 user，auth 分类
        self._not_authenticated()


    # 5.26执行认证类中的authenticate函数，自己定义则执行自己的，返回返回值
    def authenticate(self, request):
        """
        Returns a `User` if a correct username and password have been supplied
        using HTTP Basic authentication.  Otherwise returns `None`.
        """

        # 5.261封装auth
        auth = get_authorization_header(request).split()

        if not auth or auth[0].lower() != b'basic':
            return None

        if len(auth) == 1:
            msg = _('Invalid basic header. No credentials provided.')
            raise exceptions.AuthenticationFailed(msg)
        elif len(auth) > 2:
            msg = _('Invalid basic header. Credentials string should not contain spaces.')
            raise exceptions.AuthenticationFailed(msg)

        try:
            auth_parts = base64.b64decode(auth[1]).decode(HTTP_HEADER_ENCODING).partition(':')
        except (TypeError, UnicodeDecodeError, binascii.Error):
            msg = _('Invalid basic header. Credentials not correctly base64 encoded.')
            raise exceptions.AuthenticationFailed(msg)

        userid, password = auth_parts[0], auth_parts[2]

        # 5.262封装user
        return self.authenticate_credentials(userid, password, request)


   # 5.29 执行_not_authenticated函数，UNAUTHENTICATED_USER，UNAUTHENTICATED_TOKEN可以自定义
   def _not_authenticated(self):
        """
        Set authenticator, user & authtoken representing an unauthenticated request.
        设置表示未经身份验证的请求的身份验证器、用户和身份验证器。默认值为"无"、"匿名用户"和"无
        Defaults are None, AnonymousUser & None.
        # Authentication
        'UNAUTHENTICATED_USER': 'django.contrib.auth.models.AnonymousUser',
        'UNAUTHENTICATED_TOKEN': None,
        """
        self._authenticator = None

        if api_settings.UNAUTHENTICATED_USER:
            self.user = api_settings.UNAUTHENTICATED_USER()
        else:
            self.user = None

        if api_settings.UNAUTHENTICATED_TOKEN:
            self.auth = api_settings.UNAUTHENTICATED_TOKEN()
        else:
            self.auth = None