First cut as to how configure added post-/preconstruct functions.

Author: rohe

src/oidcservice/service.py

@@ -542,6 +542,32 @@ def init_services(service_definitions, service_context, state_db,
         else:
             _srv = service_configuration['class'](**kwargs)
 
+        try:
+            post_methods = service_configuration['post_functions']
+        except KeyError:
+            pass
+        else:
+            for meth in post_methods:
+                try:
+                    func = meth['function']
+                except KeyError:
+                    pass
+                else:
+                    _srv.post_construct.append(util.importer(func))
+
+        try:
+            post_methods = service_configuration['pre_functions']
+        except KeyError:
+            pass
+        else:
+            for meth in post_methods:
+                try:
+                    func = meth['function']
+                except KeyError:
+                    pass
+                else:
+                    _srv.pre_construct.append(util.importer(func))
+
         try:
             service[_srv.service_name] = _srv
         except AttributeError:

tests/test_14_pkce.py

@@ -6,6 +6,7 @@
 from oidcservice.oidc.pkce import add_code_verifier
 from oidcservice.oidc.pkce import put_state_in_post_args
 from oidcservice.service import Service
+from oidcservice.service import init_services
 from oidcservice.service_context import ServiceContext
 from oidcservice.service_factory import service_factory
 from oidcservice.state_interface import InMemoryStateDataBase
@@ -118,6 +119,54 @@ def test_access_token_and_pkce():
                                    'client_secret', 'code_verifier', 'code',
                                    'state'}
 
+
+def test_pkce_config():
+    client_config = {
+        'client_id': 'client_id',
+        'client_secret': 'password example one',
+        'redirect_uris': ['https://example.com/cli/authz_cb'],
+        'behaviour': {'response_types': ['code']}
+    }
+    service_context = ServiceContext(config=client_config)
+    db = InMemoryStateDataBase()
+    # Construct an authorization request.
+    # Gives us a state value and stores code_verifier in state_db
+    service_definitions = {
+        'authorization': {
+            'class': 'oidcservice.oidc.authorization.Authorization',
+            'kwargs': {},
+            'post_functions': [
+                {
+                    'function': 'oidcservice.oidc.pkce.add_code_challenge'
+                }
+            ]
+        },
+        'access_token': {
+            'class': 'oidcservice.oidc.access_token.AccessToken',
+            'kwargs': {},
+            'pre_functions': [
+                {
+                    'function': 'oidcservice.oidc.pkce.put_state_in_post_args'
+                }
+            ],
+            'post_functions': [
+                {'function': 'oidcservice.oidc.pkce.add_code_verifier'}
+            ]
+        }
+    }
+    service = init_services(service_definitions, service_context, db)
+
+    request = service['authorization'].construct_request()
+    _state = request['state']
+
+    auth_response = AuthorizationResponse(code='access code')
+    service['authorization'].store_item(auth_response, 'auth_response', _state)
+
+    request = service['accesstoken'].construct_request(state=_state)
+    assert set(request.keys()) == {'client_id', 'redirect_uri', 'grant_type',
+                                   'client_secret', 'code_verifier', 'code',
+                                   'state'}
+
 # class TestPKCE(object):
 #     def test_pkce_create(self):
 #         _cli = Client(