[seed] Add a very documented test to demonstrate sandboxing

[Mathieu Duponchelle <mathieudu src gnome org>]

commit 941a8c530469e7a85b65b48549d6b782105074a7
Author: Mathieu Duponchelle <mathieu duponchelle opencreed com>
Date:   Fri Sep 16 11:22:53 2016 +0200

    Add a very documented test to demonstrate sandboxing
    
    .. of the engine using mostly existing API.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=771520

 tests/c/Makefile.am             |   31 +++++++--
 tests/c/test-module-whitelist.c |  137 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 162 insertions(+), 6 deletions(-)
---
diff --git a/tests/c/Makefile.am b/tests/c/Makefile.am
index 6c69e20..ae76259 100644
--- a/tests/c/Makefile.am
+++ b/tests/c/Makefile.am
@@ -4,20 +4,20 @@ TESTS_ENVIRONMENT = \
        SEED_MODULE_PATH=$(top_srcdir)/modules:$$SEED_MODULE_PATH \
        $(NULL)
 
-noinst_PROGRAMS = test
+noinst_PROGRAMS =
+TESTS =
 
-TESTS = test
+noinst_PROGRAMS += test test-module-whitelist
+TESTS += test test-module-whitelist
 
 test_SOURCES =                                 \
        main.c                                          \
        basic.c                                         \
        api-types.c                                     \
        api-closure.c                           \
-       api-js-signal-from-c.c
+       api-js-signal-from-c.c                  \
+       $(NULL)
 
-EXTRA_DIST =                                   \
-       test-common.h
-       
 test_CFLAGS = \
        -Wall \
        $(GOBJECT_INTROSPECTION_CFLAGS)
@@ -28,5 +28,24 @@ test_LDFLAGS = \
 test_LDADD = \
        ../../libseed/libseed@SEED_GTK_VERSION@.la
 
+noinst_PROGRAMS += test-module-whitelist
+TESTS += test-module-whitelist
+
+test_module_whitelist_SOURCES = \
+       test-module-whitelist.c \
+       $(NULL)
+
+test_module_whitelist_CFLAGS = \
+       -Wall \
+       $(GOBJECT_INTROSPECTION_CFLAGS)
+
+test_module_whitelist_LDFLAGS = \
+       $(GOBJECT_INTROSPECTION_LIBS)
+
+test_module_whitelist_LDADD = \
+       ../../libseed/libseed@SEED_GTK_VERSION@.la
+
+EXTRA_DIST =                                   \
+       test-common.h
 
 -include $(top_srcdir)/git.mk
diff --git a/tests/c/test-module-whitelist.c b/tests/c/test-module-whitelist.c
new file mode 100644
index 0000000..d47a971
--- /dev/null
+++ b/tests/c/test-module-whitelist.c
@@ -0,0 +1,137 @@
+/* -*- mode: C; indent-tabs-mode: t; tab-width: 8; c-basic-offset: 2; -*- */
+
+/*
+ * This file is part of Seed, the GObject Introspection<->Javascript bindings.
+ *
+ * Seed is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 2 of
+ * the License, or (at your option) any later version.
+ * Seed is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Seed.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright © 2016 Robert Bosch Car Multimedia GmbH
+ */
+
+#include "../../libseed/seed.h"
+
+static void
+test_module_whitelist(void)
+{
+    SeedEngine* engine;
+    SeedValue* val;
+    SeedException exception = NULL;
+
+    engine = seed_init_constrained(NULL, NULL);
+
+    /* In the initial state, the engine is completely sandboxed
+     */
+    val = seed_simple_evaluate(engine->context, "Os = imports.os;", &exception);
+    g_assert(val == NULL);
+    g_assert_cmpstr(seed_exception_get_message(engine->context, exception), ==,
+                    "Can't find variable: imports");
+    exception = NULL;
+
+    /* Even printing is impossible */
+    val = seed_simple_evaluate(engine->context, "print (\"Hello world!\");",
+                               &exception);
+    g_assert(val == NULL);
+    g_assert_cmpstr(seed_exception_get_message(engine->context, exception), ==,
+                    "Can't find variable: print");
+    exception = NULL;
+
+    /* Let's fix that */
+    seed_init_builtins(engine, NULL, NULL);
+    val = seed_simple_evaluate(engine->context, "print (\"Hello world!\");",
+                               &exception);
+    g_assert(val != NULL);
+    g_assert(exception == NULL);
+
+    /* imports is not a builtin, and thus should not yet be available */
+    val = seed_simple_evaluate(engine->context, "Os = imports.os;", &exception);
+    g_assert(val == NULL);
+    g_assert_cmpstr(seed_exception_get_message(engine->context, exception), ==,
+                    "Can't find variable: imports");
+    exception = NULL;
+
+    /* Let's fix that */
+    seed_engine_initialize_importer(engine);
+    val = seed_simple_evaluate(engine->context, "Os = imports.os;", &exception);
+    g_assert(exception == NULL);
+    g_assert(val != NULL);
+
+    /* As imports is now available, seed doesn't raise an exception anymore,
+     * however as the search path for modules is currently empty, the type of
+     * val should be undefined.
+     */
+    g_assert(seed_value_get_type(engine->context, val) == SEED_TYPE_UNDEFINED);
+
+    /* Let's update the search path, this is set in Makefile.am
+     * to an uninstalled location which is guaranteed to contain an
+     * os module
+     */
+    {
+        const gchar* env_paths = g_getenv("SEED_MODULE_PATH");
+        g_assert(env_paths != NULL);
+        gchar** paths = g_strsplit(env_paths, ":", -1);
+        seed_importer_set_search_path(engine->context, paths);
+        g_strfreev(paths);
+    }
+
+    val = seed_simple_evaluate(engine->context, "Os = imports.os;", &exception);
+    g_assert(exception == NULL);
+    g_assert(val != NULL);
+    /* imports.os is no longer undefined, but an actual object */
+    g_assert(seed_value_get_type(engine->context, val) == SEED_TYPE_OBJECT);
+
+    /* We're now less sandboxed, but there are still some things we can't do,
+     * for example importing any gi module */
+    val = seed_simple_evaluate(engine->context, "GObject = imports.gi.GObject;",
+                               &exception);
+    g_assert(val == NULL);
+
+    /* Pretty obscure error message, but the idea is there */
+    g_assert_cmpstr(
+      seed_exception_get_message(engine->context, exception), ==,
+      "undefined is not an object (evaluating 'imports.extensions.GObject')");
+    exception = NULL;
+
+    /* Let's now authorize GObject and GObject only */
+    val = seed_engine_expose_namespace(engine, "GObject", exception);
+    g_assert(val != NULL);
+    g_assert(exception == NULL);
+
+    /* Seed tells us all went well, let's try anyway */
+    val = seed_simple_evaluate(engine->context, "GObject = imports.gi.GObject;",
+                               &exception);
+    g_assert(val != NULL);
+    g_assert(exception == NULL);
+
+    /* Only need to check whether another module which we know
+     * would be available if the engine was not constrained is indeed
+     * still unavailable
+     */
+    val = seed_simple_evaluate(engine->context, "GLib = imports.gi.GLib;",
+                               &exception);
+    g_assert(val == NULL);
+
+    /* The error message isn't any clearer since last time */
+    g_assert_cmpstr(
+      seed_exception_get_message(engine->context, exception), ==,
+      "undefined is not an object (evaluating 'imports.extensions.GLib')");
+    exception = NULL;
+
+    seed_engine_destroy(engine);
+}
+
+int
+main(int argc, char** argv)
+{
+    g_test_init(&argc, &argv, NULL);
+    g_test_add_func("/module-whitelist", test_module_whitelist);
+    return g_test_run();
+}