[gnome-initial-setup/wip/pwithnall/misc-fixes: 7/70] account-local: create a shared user account

[Philip Withnall <pwithnall src gnome org>]

commit f39821fa4e4414afb8c2ed691cafd4b8dd67c860
Author: Alessandro Puccetti <alessandro kinvolk io>
Date:   Fri May 5 12:38:45 2017 +0200

    account-local: create a shared user account
    
    The shared account can be used to log in without password.
    
    Unlike the regular user, we don't call gis_driver_set_user_permissions()
    here. The credentials passed to gis_driver_set_user_permissions()
    are used by the summary page to log into the newly-created user's
    sessions. The shared user is not the user we want to log in with!
    
    In practice, these credentials are overwritten by a subsequent call to
    gis_driver_set_user_permissions() when GisAccountPageLocal emits
    ::user-created, so the only harm is a small leak of the previous
    password (in this case, empty string, so 1 byte) in
    gis_driver_set_user_permissions().
    
    We get sporadic reports of systems which only have the shared user, and
    no administrator user. (In one case, the user reported not being asked
    to create an admin user during the FBE.) It's hard to recover from this
    state because the shared user is not an administrator and the root
    account is locked; it's also hard to get useful logs, because the shared
    user cannot read the full journal. Therefore, we take care to create the
    shared user after creating the user-specified administrator user.
    
    (Rebase 3.38: Fix minor rebase conflicts. Add g_autoptr() support and
    error propagation.)

 .../pages/account/gis-account-page-local.c         | 34 +++++++++++++++++++++-
 .../pages/account/gis-account-page.c               | 16 ++++++++++
 gnome-initial-setup/pages/account/um-utils.h       |  7 +++++
 3 files changed, 56 insertions(+), 1 deletion(-)
---
diff --git a/gnome-initial-setup/pages/account/gis-account-page-local.c 
b/gnome-initial-setup/pages/account/gis-account-page-local.c
index c858c608..f5c892bb 100644
--- a/gnome-initial-setup/pages/account/gis-account-page-local.c
+++ b/gnome-initial-setup/pages/account/gis-account-page-local.c
@@ -77,6 +77,7 @@ enum {
   VALIDATION_CHANGED,
   MAIN_USER_CREATED,
   PARENT_USER_CREATED,
+  SHARED_USER_CREATED,
   CONFIRM,
   LAST_SIGNAL,
 };
@@ -534,6 +535,33 @@ set_user_avatar (GisAccountPageLocal *page,
   g_clear_object (&file);
 }
 
+static gboolean
+create_shared_user (GisAccountPageLocal  *local,
+                    GError              **error)
+{
+  GisAccountPageLocalPrivate *priv = gis_account_page_local_get_instance_private (local);
+  g_autoptr(ActUser) shared_user = NULL;
+
+  shared_user = act_user_manager_create_user (priv->act_client,
+                                              SHARED_ACCOUNT_USERNAME,
+                                              SHARED_ACCOUNT_FULLNAME,
+                                              ACT_USER_ACCOUNT_TYPE_STANDARD,
+                                              error);
+  if (shared_user == NULL)
+    {
+        g_prefix_error (error,
+                        _("Failed to create user '%s': "),
+                        SHARED_ACCOUNT_USERNAME);
+        return FALSE;
+    }
+
+  act_user_set_password_mode (shared_user, ACT_USER_PASSWORD_MODE_NONE);
+
+  g_signal_emit (local, signals[SHARED_USER_CREATED], 0, shared_user, "");
+
+  return TRUE;
+}
+
 static gboolean
 local_create_user (GisAccountPageLocal  *local,
                    GisPage              *page,
@@ -616,7 +644,7 @@ local_create_user (GisAccountPageLocal  *local,
 
   g_signal_emit (local, signals[MAIN_USER_CREATED], 0, main_user, "");
 
-  return TRUE;
+  return create_shared_user (local, error);
 }
 
 static void
@@ -650,6 +678,10 @@ gis_account_page_local_class_init (GisAccountPageLocalClass *klass)
                                                G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
                                                G_TYPE_NONE, 2, ACT_TYPE_USER, G_TYPE_STRING);
 
+  signals[SHARED_USER_CREATED] = g_signal_new ("shared-user-created", GIS_TYPE_ACCOUNT_PAGE_LOCAL,
+                                        G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
+                                        G_TYPE_NONE, 2, ACT_TYPE_USER, G_TYPE_STRING);
+
   signals[CONFIRM] = g_signal_new ("confirm", GIS_TYPE_ACCOUNT_PAGE_LOCAL,
                                    G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
                                    G_TYPE_NONE, 0);
diff --git a/gnome-initial-setup/pages/account/gis-account-page.c 
b/gnome-initial-setup/pages/account/gis-account-page.c
index f319a267..93d9e81a 100644
--- a/gnome-initial-setup/pages/account/gis-account-page.c
+++ b/gnome-initial-setup/pages/account/gis-account-page.c
@@ -235,6 +235,19 @@ on_network_changed (GNetworkMonitor *monitor,
     gtk_stack_set_visible_child (GTK_STACK (priv->offline_stack), priv->page_toggle);
 }
 
+static void
+on_shared_user_created (GtkWidget       *page_local,
+                        ActUser         *user,
+                        char            *password,
+                        GisAccountPage  *page)
+{
+    const gchar *language;
+
+    language = gis_driver_get_user_language (GIS_PAGE (page)->driver);
+    if (language)
+        act_user_set_language (user, language);
+}
+
 static void
 gis_account_page_constructed (GObject *object)
 {
@@ -254,6 +267,9 @@ gis_account_page_constructed (GObject *object)
   g_signal_connect (priv->page_local, "confirm",
                     G_CALLBACK (on_local_page_confirmed), page);
 
+  g_signal_connect (priv->page_local, "shared-user-created",
+                    G_CALLBACK (on_shared_user_created), page);
+
   g_signal_connect (priv->page_enterprise, "validation-changed",
                     G_CALLBACK (on_validation_changed), page);
   g_signal_connect (priv->page_enterprise, "user-cached",
diff --git a/gnome-initial-setup/pages/account/um-utils.h b/gnome-initial-setup/pages/account/um-utils.h
index b0bb905b..ee86966c 100644
--- a/gnome-initial-setup/pages/account/um-utils.h
+++ b/gnome-initial-setup/pages/account/um-utils.h
@@ -27,6 +27,13 @@
 
 G_BEGIN_DECLS
 
+/* Endless-specific: username and full name for the built-in shared account, an
+ * unprivileged, passwordless user created after the administrator account on
+ * most images.
+ */
+#define SHARED_ACCOUNT_USERNAME "shared"
+#define SHARED_ACCOUNT_FULLNAME "Shared Account"
+
 void     set_entry_validation_error       (GtkEntry    *entry,
                                            const gchar *text);
 void     set_entry_validation_checkmark   (GtkEntry    *entry);