CVE-2020-12689

@@ -60,30 +60,41 @@ def _blob_to_json(ref):
             ref['blob'] = jsonutils.dumps(blob)
         return ref
 
-    def _assign_unique_id(self, ref, trust_id=None):
+    def _validate_blob_json(self, ref):
+        try:
+            blob = jsonutils.loads(ref.get('blob'))
+        except (ValueError, TabError):
+            raise exception.ValidationError(
+                message=_('Invalid blob in credential'))
+        if not blob or not isinstance(blob, dict):
+            raise exception.ValidationError(attribute='blob',
+                                            target='credential')
+        if blob.get('access') is None:
+            raise exception.ValidationError(attribute='access',
+                                            target='credential')
+        return blob
+
+    def _assign_unique_id(
+            self, ref, trust_id=None, app_cred_id=None, access_token_id=None):
         # Generates an assigns a unique identifier to a credential reference.
         if ref.get('type', '').lower() == 'ec2':
-            try:
-                blob = jsonutils.loads(ref.get('blob'))
-            except (ValueError, TabError):
-                raise exception.ValidationError(
-                    message=_('Invalid blob in credential'))
-            if not blob or not isinstance(blob, dict):
-                raise exception.ValidationError(attribute='blob',
-                                                target='credential')
-            if blob.get('access') is None:
-                raise exception.ValidationError(attribute='access',
-                                                target='credential')
-
+            blob = self._validate_blob_json(ref)
             ref = ref.copy()
             ref['id'] = hashlib.sha256(
                 blob['access'].encode('utf8')).hexdigest()
-            # update the blob with the trust_id, so credentials created with
-            # a trust scoped token will result in trust scoped tokens when
-            # authentication via ec2tokens happens
+            # update the blob with the trust_id or app_cred_id, so credentials
+            # created with a trust- or app cred-scoped token will result in
+            # trust- or app cred-scoped tokens when authentication via
+            # ec2tokens happens
             if trust_id is not None:
                 blob['trust_id'] = trust_id
                 ref['blob'] = jsonutils.dumps(blob)
+            if app_cred_id is not None:
+                blob['app_cred_id'] = app_cred_id
+                ref['blob'] = jsonutils.dumps(blob)
+            if access_token_id is not None:
+                blob['access_token_id'] = access_token_id
+                ref['blob'] = jsonutils.dumps(blob)
             return ref
         else:
             return super(CredentialResource, self)._assign_unique_id(ref)
@@ -146,23 +157,47 @@ def post(self):
         )
         validation.lazy_validate(schema.credential_create, credential)
         trust_id = getattr(self.oslo_context, 'trust_id', None)
+        app_cred_id = getattr(
+            self.auth_context['token'], 'application_credential_id', None)
+        access_token_id = getattr(
+            self.auth_context['token'], 'access_token_id', None)
         ref = self._assign_unique_id(
-            self._normalize_dict(credential), trust_id=trust_id)
+            self._normalize_dict(credential),
+            trust_id=trust_id, app_cred_id=app_cred_id,
+            access_token_id=access_token_id)
         ref = PROVIDERS.credential_api.create_credential(
             ref['id'], ref, initiator=self.audit_initiator)
         return self.wrap_member(ref), http.client.CREATED
 
+    def _validate_blob_update_keys(self, credential, ref):
+        if credential.get('type', '').lower() == 'ec2':
+            new_blob = self._validate_blob_json(ref)
+            old_blob = credential.get('blob')
+            if isinstance(old_blob, str):
+                old_blob = jsonutils.loads(old_blob)
+            # if there was a scope set, prevent changing it or unsetting it
+            for key in ['trust_id', 'app_cred_id', 'access_token_id']:
+                if old_blob.get(key) != new_blob.get(key):
+                    message = _('%s can not be updated for credential') % key
+                    raise exception.ValidationError(message=message)
+
     def patch(self, credential_id):
         # Update Credential
         ENFORCER.enforce_call(
             action='identity:update_credential',
             build_target=_build_target_enforcement
         )
-        PROVIDERS.credential_api.get_credential(credential_id)
+        current = PROVIDERS.credential_api.get_credential(credential_id)
 
         credential = self.request_body_json.get('credential', {})
         validation.lazy_validate(schema.credential_update, credential)
+        self._validate_blob_update_keys(current.copy(), credential.copy())
         self._require_matching_id(credential)
+        # Check that the user hasn't illegally modified the owner or scope
+        target = {'credential': dict(current, **credential)}
+        ENFORCER.enforce_call(
+            action='identity:update_credential', target_attr=target
+        )
         ref = PROVIDERS.credential_api.update_credential(
             credential_id, credential)
         return self.wrap_member(ref)

@@ -113,7 +113,9 @@ def handle_authenticate(self):
             project_id=cred.get('project_id'),
             access=loaded.get('access'),
             secret=loaded.get('secret'),
-            trust_id=loaded.get('trust_id')
+            trust_id=loaded.get('trust_id'),
+            app_cred_id=loaded.get('app_cred_id'),
+            access_token_id=loaded.get('access_token_id')
         )
 
         # validate the signature
@@ -132,8 +134,34 @@ def handle_authenticate(self):
             raise ks_exceptions.Unauthorized from e
 
         self._check_timestamp(credentials)
-        roles = PROVIDERS.assignment_api.get_roles_for_user_and_project(
-            user_ref['id'], project_ref['id'])
+
+        trustee_user_id = None
+        auth_context = None
+        if cred_data['trust_id']:
+            trust = PROVIDERS.trust_api.get_trust(cred_data['trust_id'])
+            roles = [r['id'] for r in trust['roles']]
+            # NOTE(cmurphy): if this credential was created using a
+            # trust-scoped token with impersonation, the user_id will be for
+            # the trustor, not the trustee. In this case, issuing a
+            # trust-scoped token to the trustor will fail. In order to get a
+            # trust-scoped token, use the user ID of the trustee. With
+            # impersonation, the resulting token will still be for the trustor.
+            # Without impersonation, the token will be for the trustee.
+            if trust['impersonation'] is True:
+                trustee_user_id = trust['trustee_user_id']
+        elif cred_data['app_cred_id']:
+            ac_client = PROVIDERS.application_credential_api
+            app_cred = ac_client.get_application_credential(
+                cred_data['app_cred_id'])
+            roles = [r['id'] for r in app_cred['roles']]
+        elif cred_data['access_token_id']:
+            access_token = PROVIDERS.oauth_api.get_access_token(
+                cred_data['access_token_id'])
+            roles = jsonutils.loads(access_token['role_ids'])
+            auth_context = {'access_token_id': cred_data['access_token_id']}
+        else:
+            roles = PROVIDERS.assignment_api.get_roles_for_user_and_project(
+                user_ref['id'], project_ref['id'])
 
         if not roles:
             raise ks_exceptions.Unauthorized(_('User not valid for project.'))
@@ -144,7 +172,14 @@ def handle_authenticate(self):
 
         method_names = ['ec2credential']
 
+        if trustee_user_id:
+            user_id = trustee_user_id
+        else:
+            user_id = user_ref['id']
         token = PROVIDERS.token_provider_api.issue_token(
-            user_id=user_ref['id'], method_names=method_names,
-            project_id=project_ref['id'])
+            user_id=user_id, method_names=method_names,
+            project_id=project_ref['id'],
+            trust_id=cred_data['trust_id'],
+            app_cred_id=cred_data['app_cred_id'],
+            auth_context=auth_context)
         return token

@@ -559,6 +559,25 @@ def _normalize_role_list(app_cred_roles):
                     role['name']))
         return roles
 
+    def _get_roles(self, app_cred_data, token):
+        if app_cred_data.get('roles'):
+            roles = self._normalize_role_list(app_cred_data['roles'])
+            # NOTE(cmurphy): The user is not allowed to add a role that is not
+            # in their token. This is to prevent trustees or application
+            # credential users from escallating their privileges to include
+            # additional roles that the trustor or application credential
+            # creator has assigned on the project.
+            token_roles = [r['id'] for r in token.roles]
+            for role in roles:
+                if role['id'] not in token_roles:
+                    detail = _('Cannot create an application credential with '
+                               'unassigned role')
+                    raise ks_exception.ApplicationCredentialValidationError(
+                        detail=detail)
+        else:
+            roles = token.roles
+        return roles
+
     def get(self, user_id):
         """List application credentials for user.
 
@@ -594,8 +613,7 @@ def post(self, user_id):
             app_cred_data['secret'] = self._generate_secret()
         app_cred_data['user_id'] = user_id
         app_cred_data['project_id'] = project_id
-        app_cred_data['roles'] = self._normalize_role_list(
-            app_cred_data.get('roles', token.roles))
+        app_cred_data['roles'] = self._get_roles(app_cred_data, token)
         if app_cred_data.get('expires_at'):
             app_cred_data['expires_at'] = utils.parse_expiration_date(
                 app_cred_data['expires_at'])

@@ -174,6 +174,37 @@ def test_create_application_credential_with_application_credential(self):
                    expected_status_code=http.client.FORBIDDEN,
                    headers={'X-Auth-Token': token})
 
+    def test_create_application_credential_with_trust(self):
+        second_role = unit.new_role_ref(name='reader')
+        PROVIDERS.role_api.create_role(second_role['id'], second_role)
+        PROVIDERS.assignment_api.add_role_to_user_and_project(
+            self.user_id, self.project_id, second_role['id'])
+        with self.test_client() as c:
+            pw_token = self.get_scoped_token()
+            # create a self-trust - only the roles are important for this test
+            trust_ref = unit.new_trust_ref(
+                trustor_user_id=self.user_id,
+                trustee_user_id=self.user_id,
+                project_id=self.project_id,
+                role_ids=[second_role['id']])
+            resp = c.post('/v3/OS-TRUST/trusts',
+                          headers={'X-Auth-Token': pw_token},
+                          json={'trust': trust_ref})
+            trust_id = resp.json['trust']['id']
+            trust_auth = self.build_authentication_request(
+                user_id=self.user_id,
+                password=self.user['password'],
+                trust_id=trust_id)
+            trust_token = self.v3_create_token(
+                trust_auth).headers['X-Subject-Token']
+            app_cred = self._app_cred_body(roles=[{'id': self.role_id}])
+            # only the roles from the trust token should be allowed, even if
+            # the user has the role assigned on the project
+            c.post('/v3/users/%s/application_credentials' % self.user_id,
+                   headers={'X-Auth-Token': trust_token},
+                   json=app_cred,
+                   expected_status_code=http.client.BAD_REQUEST)
+
     def test_create_application_credential_allow_recursion(self):
         with self.test_client() as c:
             roles = [{'id': self.role_id}]

@@ -21,12 +21,14 @@
 from keystoneclient.contrib.ec2 import utils as ec2_utils
 from oslo_db import exception as oslo_db_exception
 from testtools import matchers
+import urllib
 
 from keystone.api import ec2tokens
 from keystone.common import provider_api
 from keystone.common import utils
 from keystone.credential.providers import fernet as credential_fernet
 from keystone import exception
+from keystone import oauth1
 from keystone.tests import unit
 from keystone.tests.unit import ksfixtures
 from keystone.tests.unit import test_v3
@@ -63,6 +65,33 @@ def _create_dict_blob_credential(self):
 
         return json.dumps(blob), credential_id
 
+    def _test_get_token(self, access, secret):
+        """Test signature validation with the access/secret provided."""
+        signer = ec2_utils.Ec2Signer(secret)
+        params = {'SignatureMethod': 'HmacSHA256',
+                  'SignatureVersion': '2',
+                  'AWSAccessKeyId': access}
+        request = {'host': 'foo',
+                   'verb': 'GET',
+                   'path': '/bar',
+                   'params': params}
+        signature = signer.generate(request)
+
+        # Now make a request to validate the signed dummy request via the
+        # ec2tokens API.  This proves the v3 ec2 credentials actually work.
+        sig_ref = {'access': access,
+                   'signature': signature,
+                   'host': 'foo',
+                   'verb': 'GET',
+                   'path': '/bar',
+                   'params': params}
+        r = self.post(
+            '/ec2tokens',
+            body={'ec2Credentials': sig_ref},
+            expected_status=http.client.OK)
+        self.assertValidTokenResponse(r)
+        return r.result['token']
+
 
 class CredentialTestCase(CredentialBaseTestCase):
     """Test credential CRUD."""
@@ -258,6 +287,126 @@ def test_update_credential_to_ec2_with_previously_set_project_id(self):
                 'credential_id': credential_id},
             body={'credential': update_ref})
 
+    def test_update_credential_non_owner(self):
+        """Call ``PATCH /credentials/{credential_id}``."""
+        alt_user = unit.create_user(
+            PROVIDERS.identity_api, domain_id=self.domain_id)
+        alt_user_id = alt_user['id']
+        alt_project = unit.new_project_ref(domain_id=self.domain_id)
+        alt_project_id = alt_project['id']
+        PROVIDERS.resource_api.create_project(
+            alt_project['id'], alt_project)
+        alt_role = unit.new_role_ref(name='reader')
+        alt_role_id = alt_role['id']
+        PROVIDERS.role_api.create_role(alt_role_id, alt_role)
+        PROVIDERS.assignment_api.add_role_to_user_and_project(
+            alt_user_id, alt_project_id, alt_role_id)
+        auth = self.build_authentication_request(
+            user_id=alt_user_id,
+            password=alt_user['password'],
+            project_id=alt_project_id)
+        ref = unit.new_credential_ref(user_id=alt_user_id,
+                                      project_id=alt_project_id)
+        r = self.post(
+            '/credentials',
+            auth=auth,
+            body={'credential': ref})
+        self.assertValidCredentialResponse(r, ref)
+        credential_id = r.result.get('credential')['id']
+
+        # Cannot change the credential to be owned by another user
+        update_ref = {'user_id': self.user_id, 'project_id': self.project_id}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            expected_status=403,
+            auth=auth,
+            body={'credential': update_ref})
+
+    def test_update_ec2_credential_change_trust_id(self):
+        """Call ``PATCH /credentials/{credential_id}``."""
+        blob, ref = unit.new_ec2_credential(user_id=self.user['id'],
+                                            project_id=self.project_id)
+        blob['trust_id'] = uuid.uuid4().hex
+        ref['blob'] = json.dumps(blob)
+        r = self.post(
+            '/credentials',
+            body={'credential': ref})
+        self.assertValidCredentialResponse(r, ref)
+        credential_id = r.result.get('credential')['id']
+        # Try changing to a different trust
+        blob['trust_id'] = uuid.uuid4().hex
+        update_ref = {'blob': json.dumps(blob)}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            body={'credential': update_ref},
+            expected_status=http.client.BAD_REQUEST)
+        # Try removing the trust
+        del blob['trust_id']
+        update_ref = {'blob': json.dumps(blob)}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            body={'credential': update_ref},
+            expected_status=http.client.BAD_REQUEST)
+
+    def test_update_ec2_credential_change_app_cred_id(self):
+        """Call ``PATCH /credentials/{credential_id}``."""
+        blob, ref = unit.new_ec2_credential(user_id=self.user['id'],
+                                            project_id=self.project_id)
+        blob['app_cred_id'] = uuid.uuid4().hex
+        ref['blob'] = json.dumps(blob)
+        r = self.post(
+            '/credentials',
+            body={'credential': ref})
+        self.assertValidCredentialResponse(r, ref)
+        credential_id = r.result.get('credential')['id']
+        # Try changing to a different app cred
+        blob['app_cred_id'] = uuid.uuid4().hex
+        update_ref = {'blob': json.dumps(blob)}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            body={'credential': update_ref},
+            expected_status=http.client.BAD_REQUEST)
+        # Try removing the app cred
+        del blob['app_cred_id']
+        update_ref = {'blob': json.dumps(blob)}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            body={'credential': update_ref},
+            expected_status=http.client.BAD_REQUEST)
+
+    def test_update_ec2_credential_change_access_token_id(self):
+        """Call ``PATCH /credentials/{credential_id}``."""
+        blob, ref = unit.new_ec2_credential(user_id=self.user['id'],
+                                            project_id=self.project_id)
+        blob['access_token_id'] = uuid.uuid4().hex
+        ref['blob'] = json.dumps(blob)
+        r = self.post(
+            '/credentials',
+            body={'credential': ref})
+        self.assertValidCredentialResponse(r, ref)
+        credential_id = r.result.get('credential')['id']
+        # Try changing to a different access token
+        blob['access_token_id'] = uuid.uuid4().hex
+        update_ref = {'blob': json.dumps(blob)}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            body={'credential': update_ref},
+            expected_status=http.client.BAD_REQUEST)
+        # Try removing the access token
+        del blob['access_token_id']
+        update_ref = {'blob': json.dumps(blob)}
+        self.patch(
+            '/credentials/%(credential_id)s' % {
+                'credential_id': credential_id},
+            body={'credential': update_ref},
+            expected_status=http.client.BAD_REQUEST)
+
     def test_delete_credential(self):
         """Call ``DELETE /credentials/{credential_id}``."""
         self.delete(
@@ -393,7 +542,7 @@ def test_create_credential_with_admin_token(self):
         self.assertValidCredentialResponse(r, ref)
 
 
-class TestCredentialTrustScoped(test_v3.RestfulTestCase):
+class TestCredentialTrustScoped(CredentialBaseTestCase):
     """Test credential with trust scoped token."""
 
     def setUp(self):
@@ -446,7 +595,7 @@ def test_trust_scoped_ec2_credential(self):
         token_id = r.headers.get('X-Subject-Token')
 
         # Create the credential with the trust scoped token
-        blob, ref = unit.new_ec2_credential(user_id=self.user['id'],
+        blob, ref = unit.new_ec2_credential(user_id=self.user_id,
                                             project_id=self.project_id)
         r = self.post('/credentials', body={'credential': ref}, token=token_id)
 
@@ -463,6 +612,21 @@ def test_trust_scoped_ec2_credential(self):
         self.assertEqual(hashlib.sha256(access).hexdigest(),
                          r.result['credential']['id'])
 
+        # Create a role assignment to ensure that it is ignored and only the
+        # trust-delegated roles are used
+        role = unit.new_role_ref(name='reader')
+        role_id = role['id']
+        PROVIDERS.role_api.create_role(role_id, role)
+        PROVIDERS.assignment_api.add_role_to_user_and_project(
+            self.user_id, self.project_id, role_id)
+
+        ret_blob = json.loads(r.result['credential']['blob'])
+        ec2token = self._test_get_token(
+            access=ret_blob['access'], secret=ret_blob['secret'])
+        ec2_roles = [role['id'] for role in ec2token['roles']]
+        self.assertIn(self.role_id, ec2_roles)
+        self.assertNotIn(role_id, ec2_roles)
+
         # Create second ec2 credential with the same access key id and check
         # for conflict.
         self.post(
@@ -472,34 +636,229 @@ def test_trust_scoped_ec2_credential(self):
             expected_status=http.client.CONFLICT)
 
 
-class TestCredentialEc2(CredentialBaseTestCase):
-    """Test v3 credential compatibility with ec2tokens."""
+class TestCredentialAppCreds(CredentialBaseTestCase):
+    """Test credential with application credential token."""
 
-    def _validate_signature(self, access, secret):
-        """Test signature validation with the access/secret provided."""
-        signer = ec2_utils.Ec2Signer(secret)
-        params = {'SignatureMethod': 'HmacSHA256',
-                  'SignatureVersion': '2',
-                  'AWSAccessKeyId': access}
-        request = {'host': 'foo',
-                   'verb': 'GET',
-                   'path': '/bar',
-                   'params': params}
-        signature = signer.generate(request)
+    def setUp(self):
+        super(TestCredentialAppCreds, self).setUp()
+        self.useFixture(
+            ksfixtures.KeyRepository(
+                self.config_fixture,
+                'credential',
+                credential_fernet.MAX_ACTIVE_KEYS
+            )
+        )
 
-        # Now make a request to validate the signed dummy request via the
-        # ec2tokens API.  This proves the v3 ec2 credentials actually work.
-        sig_ref = {'access': access,
-                   'signature': signature,
-                   'host': 'foo',
-                   'verb': 'GET',
-                   'path': '/bar',
-                   'params': params}
-        r = self.post(
-            '/ec2tokens',
-            body={'ec2Credentials': sig_ref},
-            expected_status=http.client.OK)
-        self.assertValidTokenResponse(r)
+    def test_app_cred_ec2_credential(self):
+        """Test creating ec2 credential from an application credential.
+
+        Call ``POST /credentials``.
+        """
+        # Create the app cred
+        ref = unit.new_application_credential_ref(roles=[{'id': self.role_id}])
+        del ref['id']
+        r = self.post('/users/%s/application_credentials' % self.user_id,
+                      body={'application_credential': ref})
+        app_cred = r.result['application_credential']
+
+        # Get an application credential token
+        auth_data = self.build_authentication_request(
+            app_cred_id=app_cred['id'],
+            secret=app_cred['secret'])
+        r = self.v3_create_token(auth_data)
+        token_id = r.headers.get('X-Subject-Token')
+
+        # Create the credential with the app cred token
+        blob, ref = unit.new_ec2_credential(user_id=self.user_id,
+                                            project_id=self.project_id)
+        r = self.post('/credentials', body={'credential': ref}, token=token_id)
+
+        # We expect the response blob to contain the app_cred_id
+        ret_ref = ref.copy()
+        ret_blob = blob.copy()
+        ret_blob['app_cred_id'] = app_cred['id']
+        ret_ref['blob'] = json.dumps(ret_blob)
+        self.assertValidCredentialResponse(r, ref=ret_ref)
+
+        # Assert credential id is same as hash of access key id for
+        # ec2 credentials
+        access = blob['access'].encode('utf-8')
+        self.assertEqual(hashlib.sha256(access).hexdigest(),
+                         r.result['credential']['id'])
+
+        # Create a role assignment to ensure that it is ignored and only the
+        # roles in the app cred are used
+        role = unit.new_role_ref(name='reader')
+        role_id = role['id']
+        PROVIDERS.role_api.create_role(role_id, role)
+        PROVIDERS.assignment_api.add_role_to_user_and_project(
+            self.user_id, self.project_id, role_id)
+
+        ret_blob = json.loads(r.result['credential']['blob'])
+        ec2token = self._test_get_token(
+            access=ret_blob['access'], secret=ret_blob['secret'])
+        ec2_roles = [role['id'] for role in ec2token['roles']]
+        self.assertIn(self.role_id, ec2_roles)
+        self.assertNotIn(role_id, ec2_roles)
+
+        # Create second ec2 credential with the same access key id and check
+        # for conflict.
+        self.post(
+            '/credentials',
+            body={'credential': ref},
+            token=token_id,
+            expected_status=http.client.CONFLICT)
+
+
+class TestCredentialAccessToken(CredentialBaseTestCase):
+    """Test credential with access token."""
+
+    def setUp(self):
+        super(TestCredentialAccessToken, self).setUp()
+        self.useFixture(
+            ksfixtures.KeyRepository(
+                self.config_fixture,
+                'credential',
+                credential_fernet.MAX_ACTIVE_KEYS
+            )
+        )
+        self.base_url = 'http://localhost/v3'
+
+    def _urllib_parse_qs_text_keys(self, content):
+        results = urllib.parse.parse_qs(content)
+        return {key.decode('utf-8'): value for key, value in results.items()}
+
+    def _create_single_consumer(self):
+        endpoint = '/OS-OAUTH1/consumers'
+
+        ref = {'description': uuid.uuid4().hex}
+        resp = self.post(endpoint, body={'consumer': ref})
+        return resp.result['consumer']
+
+    def _create_request_token(self, consumer, project_id, base_url=None):
+        endpoint = '/OS-OAUTH1/request_token'
+        client = oauth1.Client(consumer['key'],
+                               client_secret=consumer['secret'],
+                               signature_method=oauth1.SIG_HMAC,
+                               callback_uri="oob")
+        headers = {'requested_project_id': project_id}
+        if not base_url:
+            base_url = self.base_url
+        url, headers, body = client.sign(base_url + endpoint,
+                                         http_method='POST',
+                                         headers=headers)
+        return endpoint, headers
+
+    def _create_access_token(self, consumer, token, base_url=None):
+        endpoint = '/OS-OAUTH1/access_token'
+        client = oauth1.Client(consumer['key'],
+                               client_secret=consumer['secret'],
+                               resource_owner_key=token.key,
+                               resource_owner_secret=token.secret,
+                               signature_method=oauth1.SIG_HMAC,
+                               verifier=token.verifier)
+        if not base_url:
+            base_url = self.base_url
+        url, headers, body = client.sign(base_url + endpoint,
+                                         http_method='POST')
+        headers.update({'Content-Type': 'application/json'})
+        return endpoint, headers
+
+    def _get_oauth_token(self, consumer, token):
+        client = oauth1.Client(consumer['key'],
+                               client_secret=consumer['secret'],
+                               resource_owner_key=token.key,
+                               resource_owner_secret=token.secret,
+                               signature_method=oauth1.SIG_HMAC)
+        endpoint = '/auth/tokens'
+        url, headers, body = client.sign(self.base_url + endpoint,
+                                         http_method='POST')
+        headers.update({'Content-Type': 'application/json'})
+        ref = {'auth': {'identity': {'oauth1': {}, 'methods': ['oauth1']}}}
+        return endpoint, headers, ref
+
+    def _authorize_request_token(self, request_id):
+        if isinstance(request_id, bytes):
+            request_id = request_id.decode()
+        return '/OS-OAUTH1/authorize/%s' % (request_id)
+
+    def _get_access_token(self):
+        consumer = self._create_single_consumer()
+        consumer_id = consumer['id']
+        consumer_secret = consumer['secret']
+        consumer = {'key': consumer_id, 'secret': consumer_secret}
+
+        url, headers = self._create_request_token(consumer, self.project_id)
+        content = self.post(
+            url, headers=headers,
+            response_content_type='application/x-www-form-urlencoded')
+        credentials = self._urllib_parse_qs_text_keys(content.result)
+        request_key = credentials['oauth_token'][0]
+        request_secret = credentials['oauth_token_secret'][0]
+        request_token = oauth1.Token(request_key, request_secret)
+
+        url = self._authorize_request_token(request_key)
+        body = {'roles': [{'id': self.role_id}]}
+        resp = self.put(url, body=body, expected_status=http.client.OK)
+        verifier = resp.result['token']['oauth_verifier']
+
+        request_token.set_verifier(verifier)
+        url, headers = self._create_access_token(consumer, request_token)
+        content = self.post(
+            url, headers=headers,
+            response_content_type='application/x-www-form-urlencoded')
+        credentials = self._urllib_parse_qs_text_keys(content.result)
+        access_key = credentials['oauth_token'][0]
+        access_secret = credentials['oauth_token_secret'][0]
+        access_token = oauth1.Token(access_key, access_secret)
+
+        url, headers, body = self._get_oauth_token(consumer, access_token)
+        content = self.post(url, headers=headers, body=body)
+        return access_key, content.headers['X-Subject-Token']
+
+    def test_access_token_ec2_credential(self):
+        """Test creating ec2 credential from an oauth access token.
+
+        Call ``POST /credentials``.
+        """
+        access_key, token_id = self._get_access_token()
+
+        # Create the credential with the access token
+        blob, ref = unit.new_ec2_credential(user_id=self.user_id,
+                                            project_id=self.project_id)
+        r = self.post('/credentials', body={'credential': ref}, token=token_id)
+
+        # We expect the response blob to contain the access_token_id
+        ret_ref = ref.copy()
+        ret_blob = blob.copy()
+        ret_blob['access_token_id'] = access_key.decode('utf-8')
+        ret_ref['blob'] = json.dumps(ret_blob)
+        self.assertValidCredentialResponse(r, ref=ret_ref)
+
+        # Assert credential id is same as hash of access key id for
+        # ec2 credentials
+        access = blob['access'].encode('utf-8')
+        self.assertEqual(hashlib.sha256(access).hexdigest(),
+                         r.result['credential']['id'])
+
+        # Create a role assignment to ensure that it is ignored and only the
+        # roles in the access token are used
+        role = unit.new_role_ref(name='reader')
+        role_id = role['id']
+        PROVIDERS.role_api.create_role(role_id, role)
+        PROVIDERS.assignment_api.add_role_to_user_and_project(
+            self.user_id, self.project_id, role_id)
+
+        ret_blob = json.loads(r.result['credential']['blob'])
+        ec2token = self._test_get_token(
+            access=ret_blob['access'], secret=ret_blob['secret'])
+        ec2_roles = [role['id'] for role in ec2token['roles']]
+        self.assertIn(self.role_id, ec2_roles)
+        self.assertNotIn(role_id, ec2_roles)
+
+
+class TestCredentialEc2(CredentialBaseTestCase):
+    """Test v3 credential compatibility with ec2tokens."""
 
     def test_ec2_credential_signature_validate(self):
         """Test signature validation with a v3 ec2 credential."""
@@ -514,15 +873,15 @@ def test_ec2_credential_signature_validate(self):
 
         cred_blob = json.loads(r.result['credential']['blob'])
         self.assertEqual(blob, cred_blob)
-        self._validate_signature(access=cred_blob['access'],
-                                 secret=cred_blob['secret'])
+        self._test_get_token(access=cred_blob['access'],
+                             secret=cred_blob['secret'])
 
     def test_ec2_credential_signature_validate_legacy(self):
         """Test signature validation with a legacy v3 ec2 credential."""
         cred_json, _ = self._create_dict_blob_credential()
         cred_blob = json.loads(cred_json)
-        self._validate_signature(access=cred_blob['access'],
-                                 secret=cred_blob['secret'])
+        self._test_get_token(access=cred_blob['access'],
+                             secret=cred_blob['secret'])
 
     def _get_ec2_cred_uri(self):
         return '/users/%s/credentials/OS-EC2' % self.user_id
@@ -538,8 +897,8 @@ def test_ec2_create_credential(self):
         self.assertEqual(self.user_id, ec2_cred['user_id'])
         self.assertEqual(self.project_id, ec2_cred['tenant_id'])
         self.assertIsNone(ec2_cred['trust_id'])
-        self._validate_signature(access=ec2_cred['access'],
-                                 secret=ec2_cred['secret'])
+        self._test_get_token(access=ec2_cred['access'],
+                             secret=ec2_cred['secret'])
         uri = '/'.join([self._get_ec2_cred_uri(), ec2_cred['access']])
         self.assertThat(ec2_cred['links']['self'],
                         matchers.EndsWith(uri))

@@ -0,0 +1,16 @@
+---
+critical:
+  - |
+    [`bug 1872733 <https://bugs.launchpad.net/keystone/+bug/1872733>`_]
+    Fixed a critical security issue in which an authenticated user could
+    escalate their privileges by altering a valid EC2 credential.
+security:
+  - |
+    [`bug 1872733 <https://bugs.launchpad.net/keystone/+bug/1872733>`_]
+    Fixed a critical security issue in which an authenticated user could
+    escalate their privileges by altering a valid EC2 credential.
+fixes:
+  - |
+    [`bug 1872733 <https://bugs.launchpad.net/keystone/+bug/1872733>`_]
+    Fixed a critical security issue in which an authenticated user could
+    escalate their privileges by altering a valid EC2 credential.

@@ -0,0 +1,31 @@
+---
+critical:
+  - |
+    [`bug 1872735 <https://bugs.launchpad.net/keystone/+bug/1872735>`_]
+    Fixed a security issue in which a trustee or an application credential user
+    could create an EC2 credential or an application credential that would
+    permit them to get a token that elevated their role assignments beyond the
+    subset delegated to them in the trust or application credential. A new
+    attribute ``app_cred_id`` is now automatically added to the access blob of
+    an EC2 credential and the role list in the trust or application credential
+    is respected.
+security:
+  - |
+    [`bug 1872735 <https://bugs.launchpad.net/keystone/+bug/1872735>`_]
+    Fixed a security issue in which a trustee or an application credential user
+    could create an EC2 credential or an application credential that would
+    permit them to get a token that elevated their role assignments beyond the
+    subset delegated to them in the trust or application credential. A new
+    attribute ``app_cred_id`` is now automatically added to the access blob of
+    an EC2 credential and the role list in the trust or application credential
+    is respected.
+fixes:
+  - |
+    [`bug 1872735 <https://bugs.launchpad.net/keystone/+bug/1872735>`_]
+    Fixed a security issue in which a trustee or an application credential user
+    could create an EC2 credential or an application credential that would
+    permit them to get a token that elevated their role assignments beyond the
+    subset delegated to them in the trust or application credential. A new
+    attribute ``app_cred_id`` is now automatically added to the access blob of
+    an EC2 credential and the role list in the trust or application credential
+    is respected.

@@ -0,0 +1,19 @@
+---
+security:
+  - |
+    [`bug 1872755 <https://bugs.launchpad.net/keystone/+bug/1872755>`_]
+    Added validation to the EC2 credentials update API to ensure the metadata
+    labels 'trust_id' and 'app_cred_id' are not altered by the user. These
+    labels are used by keystone to determine the scope allowed by the
+    credential, and altering these automatic labels could enable an EC2
+    credential holder to elevate their access beyond what is permitted by the
+    application credential or trust that was used to create the EC2 credential.
+fixes:
+  - |
+    [`bug 1872755 <https://bugs.launchpad.net/keystone/+bug/1872755>`_]
+    Added validation to the EC2 credentials update API to ensure the metadata
+    labels 'trust_id' and 'app_cred_id' are not altered by the user. These
+    labels are used by keystone to determine the scope allowed by the
+    credential, and altering these automatic labels could enable an EC2
+    credential holder to elevate their access beyond what is permitted by the
+    application credential or trust that was used to create the EC2 credential.