Introduce generation concept for credentials

This is needed to sanely handling added scopes in the future.

Signed-off-by: David Zeuthen <davidz@redhat.com>

3 files changed, 45 insertions, 2 deletions

diff --git a/doc/goa-sections.txt b/doc/goa-sections.txt
index f8a50f5..c253157 100644
--- a/doc/goa-sections.txt
+++ b/doc/goa-sections.txt
@@ -546,6 +546,7 @@ goa_provider_lookup_credentials_sync
 goa_provider_ensure_credentials
 goa_provider_ensure_credentials_finish
 goa_provider_ensure_credentials_sync
+goa_provider_get_credentials_generation
 GOA_PROVIDER_EXTENSION_POINT_NAME
 goa_provider_get_all
 goa_provider_get_for_provider_type
diff --git a/src/goabackend/goaprovider.c b/src/goabackend/goaprovider.c
index 706f067..d37b8e2 100644
--- a/src/goabackend/goaprovider.c
+++ b/src/goabackend/goaprovider.c
@@ -60,6 +60,8 @@ static void goa_provider_show_account_real (GoaProvider         *provider,
                                             GtkBox              *vbox,
                                             GtkTable            *table);
 
+static guint goa_provider_get_credentials_generation_real (GoaProvider *provider);
+
 G_DEFINE_ABSTRACT_TYPE (GoaProvider, goa_provider, G_TYPE_OBJECT);
 
 static void
@@ -73,6 +75,7 @@ goa_provider_class_init (GoaProviderClass *klass)
   klass->build_object = goa_provider_build_object_real;
   klass->ensure_credentials_sync = goa_provider_ensure_credentials_sync_real;
   klass->show_account = goa_provider_show_account_real;
+  klass->get_credentials_generation = goa_provider_get_credentials_generation_real;
 }
 
 /**
@@ -494,6 +497,39 @@ goa_provider_build_object_real (GoaProvider         *provider,
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+/**
+ * goa_provider_get_credentials_generation:
+ * @provider: A #GoaProvider.
+ *
+ * Gets the generation of credentials being used for the provider.
+ *
+ * Implementations should bump this number when changes are introduced
+ * that may render existing credentials unusable.
+ *
+ * For example, if an additional scope is requested (e.g. access to
+ * contacts data) while obtaining credentials, then this number needs
+ * to be bumped since existing credentials are not good for the added
+ * scope.
+ *
+ * This is a virtual method where the default implemention returns 0.
+ *
+ * Returns: The current generation of credentials.
+ */
+guint
+goa_provider_get_credentials_generation (GoaProvider *provider)
+{
+  g_return_val_if_fail (GOA_IS_PROVIDER (provider), FALSE);
+  return GOA_PROVIDER_GET_CLASS (provider)->get_credentials_generation (provider);
+}
+
+static guint
+goa_provider_get_credentials_generation_real (GoaProvider *provider)
+{
+  return 0;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
 static void
 ensure_ep_and_builtins (void)
 {
@@ -644,8 +680,9 @@ goa_provider_store_credentials_sync (GoaProvider   *provider,
   g_variant_ref_sink (credentials);
   g_variant_unref (credentials);
 
-  password_key = g_strdup_printf ("%s:%s",
+  password_key = g_strdup_printf ("%s:gen%d:%s",
                                   goa_provider_get_provider_type (GOA_PROVIDER (provider)),
+                                  goa_provider_get_credentials_generation (GOA_PROVIDER (provider)),
                                   identity);
   password_description = g_strdup_printf (_("GOA %s credentials for identity %s"),
                                           goa_provider_get_provider_type (GOA_PROVIDER (provider)),
@@ -718,8 +755,9 @@ goa_provider_lookup_credentials_sync (GoaProvider   *provider,
 
   identity = goa_account_get_id (goa_object_peek_account (object));
 
-  password_key = g_strdup_printf ("%s:%s",
+  password_key = g_strdup_printf ("%s:gen%d:%s",
                                   goa_provider_get_provider_type (GOA_PROVIDER (provider)),
+                                  goa_provider_get_credentials_generation (GOA_PROVIDER (provider)),
                                   identity);
 
   result = gnome_keyring_find_password_sync (&keyring_password_schema,
diff --git a/src/goabackend/goaprovider.h b/src/goabackend/goaprovider.h
index 3dbb888..472ec3e 100644
--- a/src/goabackend/goaprovider.h
+++ b/src/goabackend/goaprovider.h
@@ -63,6 +63,7 @@ struct _GoaProvider
  * @refresh_account: Virtual function for goa_provider_refresh_account().
  * @build_object: Virtual function for goa_provider_build_object().
  * @ensure_credentials_sync: Virtual function for goa_provider_ensure_credentials_sync().
+ * @get_credentials_generation: Virtual function for goa_provider_get_credentials_generation().
  *
  * Class structure for #GoaProvider.
  */
@@ -100,6 +101,7 @@ struct _GoaProviderClass
                                        GoaObject           *object,
                                        GtkBox              *vbox,
                                        GtkTable            *table);
+  guint    (*get_credentials_generation) (GoaProvider   *provider);
 
   /*< private >*/
   /* Padding for future expansion */
@@ -152,6 +154,8 @@ gboolean     goa_provider_ensure_credentials_sync   (GoaProvider         *provid
                                                      gint                *out_expires_in,
                                                      GCancellable        *cancellable,
                                                      GError             **error);
+guint        goa_provider_get_credentials_generation (GoaProvider        *provider);
+
 
 /**
  * GOA_PROVIDER_EXTENSION_POINT_NAME: