SAML2 federated authentication for ADFS.

Authentication workflow for the Active Directory Federated Services
(ADFS) by Microsoft is different from 'standard' ECP based one.
This plugin allows for authentication and fetching security token with SAML2
assertion inside, sending to the Service Provide and retrieving an
unscoped token.

Change-Id: I588de1967a7fb92c5928686d092895847553923a
Implements: blueprint add-saml2-cli-authentication

1 files changed, 490 insertions, 41 deletions

diff --git a/keystoneclient/contrib/auth/v3/saml2.py b/keystoneclient/contrib/auth/v3/saml2.py
index f2b458e..c9eedac 100644
--- a/keystoneclient/contrib/auth/v3/saml2.py
+++ b/keystoneclient/contrib/auth/v3/saml2.py
@@ -10,14 +10,72 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import datetime
+import uuid
+
 from lxml import etree
 from oslo.config import cfg
+from six.moves import urllib
 
 from keystoneclient import access
 from keystoneclient.auth.identity import v3
 from keystoneclient import exceptions
 
 
+class _BaseSAMLPlugin(v3.AuthConstructor):
+
+    HTTP_MOVED_TEMPORARILY = 302
+    PROTOCOL = 'saml2'
+
+    @staticmethod
+    def _first(_list):
+        if len(_list) != 1:
+            raise IndexError("Only single element list is acceptable")
+        return _list[0]
+
+    @staticmethod
+    def str_to_xml(content, msg=None, include_exc=True):
+        try:
+            return etree.XML(content)
+        except etree.XMLSyntaxError as e:
+            if not msg:
+                msg = str(e)
+            else:
+                msg = msg % e if include_exc else msg
+            raise exceptions.AuthorizationFailure(msg)
+
+    @staticmethod
+    def xml_to_str(content, **kwargs):
+        return etree.tostring(content, **kwargs)
+
+    @property
+    def token_url(self):
+        """Return full URL where authorization data is sent."""
+        values = {
+            'host': self.auth_url.rstrip('/'),
+            'identity_provider': self.identity_provider,
+            'protocol': self.PROTOCOL
+        }
+        url = ("%(host)s/OS-FEDERATION/identity_providers/"
+               "%(identity_provider)s/protocols/%(protocol)s/auth")
+        url = url % values
+
+        return url
+
+    @classmethod
+    def get_options(cls):
+        options = super(_BaseSAMLPlugin, cls).get_options()
+        options.extend([
+            cfg.StrOpt('identity-provider', help="Identity Provider's name"),
+            cfg.StrOpt('identity-provider-url',
+                       help="Identity Provider's URL"),
+            cfg.StrOpt('user-name', dest='username', help='Username',
+                       deprecated_name='username'),
+            cfg.StrOpt('password', help='Password')
+        ])
+        return options
+
+
 class Saml2UnscopedTokenAuthMethod(v3.AuthMethod):
     _method_parameters = []
 
@@ -26,7 +84,7 @@ class Saml2UnscopedTokenAuthMethod(v3.AuthMethod):
                                               'be called'))
 
 
-class Saml2UnscopedToken(v3.AuthConstructor):
+class Saml2UnscopedToken(_BaseSAMLPlugin):
     """Implement authentication plugin for SAML2 protocol.
 
     ECP stands for ``Enhanced Client or Proxy`` and is a SAML2 extension
@@ -47,8 +105,6 @@ class Saml2UnscopedToken(v3.AuthConstructor):
 
     _auth_method_class = Saml2UnscopedTokenAuthMethod
 
-    PROTOCOL = 'saml2'
-    HTTP_MOVED_TEMPORARILY = 302
     SAML2_HEADER_INDEX = 0
     ECP_SP_EMPTY_REQUEST_HEADERS = {
         'Accept': 'text/html; application/vnd.paos+xml',
@@ -118,19 +174,6 @@ class Saml2UnscopedToken(v3.AuthConstructor):
         self.identity_provider_url = identity_provider_url
         self.username, self.password = username, password
 
-    @classmethod
-    def get_options(cls):
-        options = super(Saml2UnscopedToken, cls).get_options()
-        options.extend([
-            cfg.StrOpt('identity-provider', help="Identity Provider's name"),
-            cfg.StrOpt('identity-provider-url',
-                       help="Identity Provider's URL"),
-            cfg.StrOpt('user-name', dest='username', help='Username',
-                       deprecated_name='username'),
-            cfg.StrOpt('password', help='Password')
-        ])
-        return options
-
     def _handle_http_302_ecp_redirect(self, session, response, method,
                                       **kwargs):
         if response.status_code != self.HTTP_MOVED_TEMPORARILY:
@@ -140,11 +183,6 @@ class Saml2UnscopedToken(v3.AuthConstructor):
         return session.request(location, method, authenticated=False,
                                **kwargs)
 
-    def _first(self, _list):
-        if len(_list) != 1:
-            raise IndexError("Only single element is acceptable")
-        return _list[0]
-
     def _prepare_idp_saml2_request(self, saml2_authn_request):
         header = saml2_authn_request[self.SAML2_HEADER_INDEX]
         saml2_authn_request.remove(header)
@@ -230,8 +268,7 @@ class Saml2UnscopedToken(v3.AuthConstructor):
         sp_response_consumer_url = self.saml2_authn_request.xpath(
             self.ECP_SERVICE_PROVIDER_CONSUMER_URL,
             namespaces=self.ECP_SAML2_NAMESPACES)
-        self.sp_response_consumer_url = self._first(
-            sp_response_consumer_url)
+        self.sp_response_consumer_url = self._first(sp_response_consumer_url)
         return False
 
     def _send_idp_saml2_authn_request(self, session):
@@ -259,8 +296,7 @@ class Saml2UnscopedToken(v3.AuthConstructor):
             self.ECP_IDP_CONSUMER_URL,
             namespaces=self.ECP_SAML2_NAMESPACES)
 
-        self.idp_response_consumer_url = self._first(
-            idp_response_consumer_url)
+        self.idp_response_consumer_url = self._first(idp_response_consumer_url)
 
         self._check_consumer_urls(session, self.idp_response_consumer_url,
                                   self.sp_response_consumer_url)
@@ -300,21 +336,7 @@ class Saml2UnscopedToken(v3.AuthConstructor):
 
         self.authenticated_response = response
 
-    @property
-    def token_url(self):
-        """Return full URL where authorization data is sent."""
-        values = {
-            'host': self.auth_url.rstrip('/'),
-            'identity_provider': self.identity_provider,
-            'protocol': self.PROTOCOL
-        }
-        url = ("%(host)s/OS-FEDERATION/identity_providers/"
-               "%(identity_provider)s/protocols/%(protocol)s/auth")
-        url = url % values
-
-        return url
-
-    def _get_unscoped_token(self, session, **kwargs):
+    def _get_unscoped_token(self, session):
         """Get unscoped OpenStack token after federated authentication.
 
         This is a multi-step process including multiple HTTP requests.
@@ -408,11 +430,438 @@ class Saml2UnscopedToken(v3.AuthConstructor):
                                      unscoped token json included.
 
         """
-        token, token_json = self._get_unscoped_token(session, **kwargs)
+        token, token_json = self._get_unscoped_token(session)
         return access.AccessInfoV3(token,
                                    **token_json)
 
 
+class ADFSUnscopedToken(_BaseSAMLPlugin):
+    """Authentication plugin for Microsoft ADFS2.0 IdPs."""
+
+    _auth_method_class = Saml2UnscopedTokenAuthMethod
+
+    DEFAULT_ADFS_TOKEN_EXPIRATION = 120
+
+    HEADER_SOAP = {"Content-Type": "application/soap+xml; charset=utf-8"}
+    HEADER_X_FORM = {"Content-Type": "application/x-www-form-urlencoded"}
+
+    NAMESPACES = {
+        's': 'http://www.w3.org/2003/05/soap-envelope',
+        'a': 'http://www.w3.org/2005/08/addressing',
+        'u': ('http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+              'wss-wssecurity-utility-1.0.xsd')
+    }
+
+    ADFS_TOKEN_NAMESPACES = {
+        's': 'http://www.w3.org/2003/05/soap-envelope',
+        't': 'http://docs.oasis-open.org/ws-sx/ws-trust/200512'
+    }
+    ADFS_ASSERTION_XPATH = ('/s:Envelope/s:Body'
+                            '/t:RequestSecurityTokenResponseCollection'
+                            '/t:RequestSecurityTokenResponse')
+
+    def __init__(self, auth_url, identity_provider, identity_provider_url,
+                 service_provider_endpoint, username, password, **kwargs):
+        """Constructor for ``ADFSUnscopedToken``.
+
+        :param auth_url: URL of the Identity Service
+        :type auth_url: string
+
+        :param identity_provider: name of the Identity Provider the client
+                                  will authenticate against. This parameter
+                                  will be used to build a dynamic URL used to
+                                  obtain unscoped OpenStack token.
+        :type identity_provider: string
+
+        :param identity_provider_url: An Identity Provider URL, where the SAML2
+                                      authentication request will be sent.
+        :type identity_provider_url: string
+
+        :param service_provider_endpoint: Endpoint where an assertion is being
+            sent, for instance: ``https://host.domain/Shibboleth.sso/ADFS``
+        :type service_provider_endpoint: string
+
+        :param username: User's login
+        :type username: string
+
+        :param password: User's password
+        :type password: string
+
+        """
+
+        super(ADFSUnscopedToken, self).__init__(auth_url=auth_url, **kwargs)
+        self.identity_provider = identity_provider
+        self.identity_provider_url = identity_provider_url
+        self.service_provider_endpoint = service_provider_endpoint
+        self.username, self.password = username, password
+
+    @classmethod
+    def get_options(cls):
+        options = super(ADFSUnscopedToken, cls).get_options()
+
+        options.extend([
+            cfg.StrOpt('service-provider-endpoint',
+                       help="Service Provider's Endpoint")
+        ])
+        return options
+
+    @property
+    def _uuid4(self):
+        return str(uuid.uuid4())
+
+    def _cookies(self, session):
+        """Check if cookie jar is not empty.
+
+        keystoneclient.session.Session object doesn't have a cookies attribute.
+        We should then try fetching cookies from the underlying
+        requests.Session object. If that fails too, there is something wrong
+        and let Python raise the AttributeError.
+
+        :param session
+        :return: True if cookie jar is nonempty, False otherwise
+        :raises: AttributeError in case cookies are not find anywhere
+
+        """
+        try:
+            return bool(session.cookies)
+        except AttributeError:
+            pass
+
+        return bool(session.session.cookies)
+
+    def _token_dates(self, fmt='%Y-%m-%dT%H:%M:%S.%fZ'):
+        """Calculate created and expires datetime objects.
+
+        The method is going to be used for building ADFS Request Security
+        Token message. Time interval between ``created`` and ``expires``
+        dates is now static and equals to 120 seconds. ADFS security tokens
+        should not be live too long, as currently ``keystoneclient``
+        doesn't have mechanisms for reusing such tokens (every time ADFS authn
+        method is called, keystoneclient will login with the ADFS instance).
+
+        :param fmt: Datetime format for specifying string format of a date.
+                    It should not be changed if the method is going to be used
+                    for building the ADFS security token request.
+        :type fmt: string
+
+        """
+
+        date_created = datetime.datetime.utcnow()
+        date_expires = date_created + datetime.timedelta(
+            seconds=self.DEFAULT_ADFS_TOKEN_EXPIRATION)
+        return [_time.strftime(fmt) for _time in (date_created, date_expires)]
+
+    def _prepare_adfs_request(self):
+        """Build the ADFS Request Security Token SOAP message.
+
+        Some values like username or password are inserted in the request.
+
+        """
+
+        WSS_SECURITY_NAMESPACE = {
+            'o': ('http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+                  'wss-wssecurity-secext-1.0.xsd')
+        }
+
+        TRUST_NAMESPACE = {
+            'trust': 'http://docs.oasis-open.org/ws-sx/ws-trust/200512'
+        }
+
+        WSP_NAMESPACE = {
+            'wsp': 'http://schemas.xmlsoap.org/ws/2004/09/policy'
+        }
+
+        WSA_NAMESPACE = {
+            'wsa': 'http://www.w3.org/2005/08/addressing'
+        }
+
+        root = etree.Element(
+            '{http://www.w3.org/2003/05/soap-envelope}Envelope',
+            nsmap=self.NAMESPACES)
+
+        header = etree.SubElement(
+            root, '{http://www.w3.org/2003/05/soap-envelope}Header')
+        action = etree.SubElement(
+            header, "{http://www.w3.org/2005/08/addressing}Action")
+        action.set(
+            "{http://www.w3.org/2003/05/soap-envelope}mustUnderstand", "1")
+        action.text = ('http://docs.oasis-open.org/ws-sx/ws-trust/200512'
+                       '/RST/Issue')
+
+        messageID = etree.SubElement(
+            header, '{http://www.w3.org/2005/08/addressing}MessageID')
+        messageID.text = 'urn:uuid:' + self._uuid4
+        replyID = etree.SubElement(
+            header, '{http://www.w3.org/2005/08/addressing}ReplyTo')
+        address = etree.SubElement(
+            replyID, '{http://www.w3.org/2005/08/addressing}Address')
+        address.text = 'http://www.w3.org/2005/08/addressing/anonymous'
+
+        to = etree.SubElement(
+            header, '{http://www.w3.org/2005/08/addressing}To')
+        to.set("{http://www.w3.org/2003/05/soap-envelope}mustUnderstand", "1")
+
+        security = etree.SubElement(
+            header, '{http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+            'wss-wssecurity-secext-1.0.xsd}Security',
+            nsmap=WSS_SECURITY_NAMESPACE)
+
+        security.set(
+            "{http://www.w3.org/2003/05/soap-envelope}mustUnderstand", "1")
+
+        timestamp = etree.SubElement(
+            security, ('{http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+                       'wss-wssecurity-utility-1.0.xsd}Timestamp'))
+        timestamp.set(
+            ('{http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+             'wss-wssecurity-utility-1.0.xsd}Id'), '_0')
+
+        created = etree.SubElement(
+            timestamp, ('{http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+                        'wss-wssecurity-utility-1.0.xsd}Created'))
+
+        expires = etree.SubElement(
+            timestamp, ('{http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+                        'wss-wssecurity-utility-1.0.xsd}Expires'))
+
+        created.text, expires.text = self._token_dates()
+
+        usernametoken = etree.SubElement(
+            security, '{http://docs.oasis-open.org/wss/2004/01/oasis-200401-'
+                      'wss-wssecurity-secext-1.0.xsd}UsernameToken')
+        usernametoken.set(
+            ('{http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-'
+             'wssecurity-utility-1.0.xsd}u'), "uuid-%s-1" % self._uuid4)
+
+        username = etree.SubElement(
+            usernametoken, ('{http://docs.oasis-open.org/wss/2004/01/oasis-'
+                            '200401-wss-wssecurity-secext-1.0.xsd}Username'))
+        password = etree.SubElement(
+            usernametoken, ('{http://docs.oasis-open.org/wss/2004/01/oasis-'
+                            '200401-wss-wssecurity-secext-1.0.xsd}Password'),
+            Type=('http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-'
+                  'username-token-profile-1.0#PasswordText'))
+
+        body = etree.SubElement(
+            root, "{http://www.w3.org/2003/05/soap-envelope}Body")
+
+        request_security_token = etree.SubElement(
+            body, ('{http://docs.oasis-open.org/ws-sx/ws-trust/200512}'
+                   'RequestSecurityToken'), nsmap=TRUST_NAMESPACE)
+
+        applies_to = etree.SubElement(
+            request_security_token,
+            '{http://schemas.xmlsoap.org/ws/2004/09/policy}AppliesTo',
+            nsmap=WSP_NAMESPACE)
+
+        endpoint_reference = etree.SubElement(
+            applies_to,
+            '{http://www.w3.org/2005/08/addressing}EndpointReference',
+            nsmap=WSA_NAMESPACE)
+
+        wsa_address = etree.SubElement(
+            endpoint_reference,
+            '{http://www.w3.org/2005/08/addressing}Address')
+
+        keytype = etree.SubElement(
+            request_security_token,
+            '{http://docs.oasis-open.org/ws-sx/ws-trust/200512}KeyType')
+        keytype.text = ('http://docs.oasis-open.org/ws-sx/'
+                        'ws-trust/200512/Bearer')
+
+        request_type = etree.SubElement(
+            request_security_token,
+            '{http://docs.oasis-open.org/ws-sx/ws-trust/200512}RequestType')
+        request_type.text = ('http://docs.oasis-open.org/ws-sx/'
+                             'ws-trust/200512/Issue')
+        token_type = etree.SubElement(
+            request_security_token,
+            '{http://docs.oasis-open.org/ws-sx/ws-trust/200512}TokenType')
+        token_type.text = 'urn:oasis:names:tc:SAML:1.0:assertion'
+
+        # After constructing the request, let's plug in some values
+        username.text = self.username
+        password.text = self.password
+        to.text = self.identity_provider_url
+        wsa_address.text = self.service_provider_endpoint
+
+        self.prepared_request = root
+
+    def _get_adfs_security_token(self, session):
+        """Send ADFS Security token to the ADFS server.
+
+        Store the result in the instance attribute and raise an exception in
+        case the response is not valid XML data.
+
+        If a user cannot authenticate due to providing bad credentials, the
+        ADFS2.0 server will return a HTTP 500 response and a XML Fault message.
+        If ``exceptions.InternalServerError`` is caught, the method tries to
+        parse the XML response.
+        If parsing is unsuccessful, an ``exceptions.AuthorizationFailure`` is
+        raised with a reason from the XML fault. Otherwise an original
+        ``exceptions.InternalServerError`` is re-raised.
+
+        :param session : a session object to send out HTTP requests.
+        :type session: keystoneclient.session.Session
+
+        :raises: exceptions.AuthorizationFailure when HTTP response from the
+                 ADFS server is not a valid XML ADFS security token.
+        :raises: exceptions.InternalServerError: If response status code is
+                 HTTP 500 and the response XML cannot be recognized.
+
+
+        """
+        def _get_failure(e):
+            xpath = '/s:Envelope/s:Body/s:Fault/s:Code/s:Subcode/s:Value'
+            content = e.response.content
+            try:
+                obj = self.str_to_xml(content).xpath(
+                    xpath, namespaces=self.NAMESPACES)
+                obj = self._first(obj)
+                return obj.text
+            # NOTE(marek-denis): etree.Element.xpath() doesn't raise an
+            # exception, it just returns an empty list. In that case, _first()
+            # will raise IndexError and we should treat it as an indication XML
+            # is not valid. exceptions.AuthorizationFailure can be raised from
+            # str_to_xml(), however since server returned HTTP 500 we should
+            # re-raise exceptions.InternalServerError.
+            except (IndexError, exceptions.AuthorizationFailure):
+                raise e
+
+        request_security_token = self.xml_to_str(self.prepared_request)
+        try:
+            response = session.post(
+                url=self.identity_provider_url, headers=self.HEADER_SOAP,
+                data=request_security_token, authenticated=False)
+        except exceptions.InternalServerError as e:
+            reason = _get_failure(e)
+            raise exceptions.AuthorizationFailure(reason)
+        msg = ("Error parsing XML returned from "
+               "the ADFS Identity Provider, reason: %s")
+        self.adfs_token = self.str_to_xml(response.content, msg)
+
+    def _prepare_sp_request(self):
+        """Prepare ADFS Security Token to be sent to the Service Provider.
+
+        The method works as follows:
+        * Extract SAML2 assertion from the ADFS Security Token.
+        * Replace namespaces
+        * urlencode assertion
+        * concatenate static string with the encoded assertion
+
+        """
+        assertion = self.adfs_token.xpath(
+            self.ADFS_ASSERTION_XPATH, namespaces=self.ADFS_TOKEN_NAMESPACES)
+        assertion = self._first(assertion)
+        assertion = self.xml_to_str(assertion)
+        # TODO(marek-denis): Ideally no string replacement should occur.
+        # Unfortunately lxml doesn't allow for namespaces changing in-place and
+        # probably the only solution good for now is to build the assertion
+        # from scratch and reuse values from the adfs security token.
+        assertion = assertion.replace(
+            b'http://docs.oasis-open.org/ws-sx/ws-trust/200512',
+            b'http://schemas.xmlsoap.org/ws/2005/02/trust')
+
+        encoded_assertion = urllib.parse.quote(assertion)
+        self.encoded_assertion = 'wa=wsignin1.0&wresult=' + encoded_assertion
+
+    def _send_assertion_to_service_provider(self, session):
+        """Send prepared assertion to a service provider.
+
+        As the assertion doesn't contain a protected resource, the value from
+        the ``location`` header is not valid and we should not let the Session
+        object get redirected there. The aim of this call is to get a cookie in
+        the response which is required for entering a protected endpoint.
+
+        :param session : a session object to send out HTTP requests.
+        :type session: keystoneclient.session.Session
+
+        :raises: Corresponding HTTP error exception
+
+        """
+        session.post(
+            url=self.service_provider_endpoint, data=self.encoded_assertion,
+            headers=self.HEADER_X_FORM, redirect=False, authenticated=False)
+
+    def _access_service_provider(self, session):
+        """Access protected endpoint and fetch unscoped token.
+
+        After federated authentication workflow a protected endpoint should be
+        accessible with the session object. The access is granted basing on the
+        cookies stored within the session object. If, for some reason no
+        cookies are present (quantity test) it means something went wrong and
+        user will not be able to fetch an unscoped token. In that case an
+        ``exceptions.AuthorizationFailure` exception is raised and no HTTP call
+        is even made.
+
+        :param session : a session object to send out HTTP requests.
+        :type session: keystoneclient.session.Session
+
+        :raises: exceptions.AuthorizationFailure: in case session object
+        has empty cookie jar.
+
+        """
+        if self._cookies(session) is False:
+            raise exceptions.AuthorizationFailure(
+                "Session object doesn't contain a cookie, therefore you are "
+                "not allowed to enter the Identity Provider's protected area.")
+        self.authenticated_response = session.get(self.token_url,
+                                                  authenticated=False)
+
+    def _get_unscoped_token(self, session, *kwargs):
+        """Retrieve unscoped token after authentcation with ADFS server.
+
+        This is a multistep process::
+
+        * Prepare ADFS Request Securty Token -
+        build a etree.XML object filling certain attributes with proper user
+        credentials, created/expires dates (ticket is be valid for 120 seconds
+        as currently we don't handle reusing ADFS issued security tokens) .
+        Step handled by ``ADFSUnscopedToken._prepare_adfs_request()`` method.
+
+        * Send ADFS Security token to the ADFS server. Step handled by
+        ``ADFSUnscopedToken._get_adfs_security_token()`` method.
+
+        * Receive and parse security token, extract actual SAML assertion and
+        prepare a request addressed for the Service Provider endpoint.
+        This also includes changing namespaces in the XML document. Step
+        handled by ``ADFSUnscopedToken._prepare_sp_request()`` method.
+
+        * Send prepared assertion to the Service Provider endpoint. Usually
+        the server will respond with HTTP 301 code which should be ignored as
+        the 'location' header doesn't contain protected area. The goal of this
+        operation is fetching the session cookie which later allows for
+        accessing protected URL endpoints. Step handed by
+        ``ADFSUnscopedToken._send_assertion_to_service_provider()`` method.
+
+        * Once the session cookie is issued, the protected endpoint can be
+        accessed and an unscoped token can be retrieved. Step handled by
+        ``ADFSUnscopedToken._access_service_provider()`` method.
+
+        :param session : a session object to send out HTTP requests.
+        :type session: keystoneclient.session.Session
+
+        :returns (Unscoped federated token, token JSON body)
+
+        """
+        self._prepare_adfs_request()
+        self._get_adfs_security_token(session)
+        self._prepare_sp_request()
+        self._send_assertion_to_service_provider(session)
+        self._access_service_provider(session)
+
+        try:
+            return (self.authenticated_response.headers['X-Subject-Token'],
+                    self.authenticated_response.json()['token'])
+        except (KeyError, ValueError):
+            raise exceptions.InvalidResponse(
+                response=self.authenticated_response)
+
+    def get_auth_ref(self, session, **kwargs):
+        token, token_json = self._get_unscoped_token(session)
+        return access.AccessInfoV3(token, **token_json)
+
+
 class Saml2ScopedTokenMethod(v3.TokenMethod):
     _method_name = 'saml2'