sms: prevent crash if date is out of range

g_date_time_new, and g_date_time_new_utc return NULL if inputs are out
of range, and currently mm_new_iso8601_time passes the GDateTime created
by those two functions to date_time_format_iso8601 without checking for
NULL values, causing a g_date_time_format_iso8601 crash if PDU data is
corrupted with wrong date.

To prevent this, mm_new_iso8601_time now can return NULL and set a new
GError if GDateTime created by g_date_time_new is NULL.

Fixes #546

3 files changed, 36 insertions, 4 deletions

diff --git a/libmm-glib/mm-common-helpers.c b/libmm-glib/mm-common-helpers.c
index b7883b26..085177b7 100644
--- a/libmm-glib/mm-common-helpers.c
+++ b/libmm-glib/mm-common-helpers.c
@@ -1769,7 +1769,8 @@ mm_new_iso8601_time (guint    year,
                      guint    minute,
                      guint    second,
                      gboolean have_offset,
-                     gint     offset_minutes)
+                     gint     offset_minutes,
+                     GError **error)
 {
     g_autoptr(GDateTime) dt = NULL;
 
@@ -1781,6 +1782,14 @@ mm_new_iso8601_time (guint    year,
     } else
         dt = g_date_time_new_utc (year, month, day, hour, minute, second);
 
+    if (dt == NULL) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_INVALID_ARGS,
+                     "Invalid input for date: got year:%u, month:%u, day:%u, hour:%u, minute:%u, second:%u",
+                     year, month, day, hour, minute, second);
+        return NULL;
+    }
     return date_time_format_iso8601 (dt);
 }
 
diff --git a/libmm-glib/mm-common-helpers.h b/libmm-glib/mm-common-helpers.h
index d444012c..490f882d 100644
--- a/libmm-glib/mm-common-helpers.h
+++ b/libmm-glib/mm-common-helpers.h
@@ -216,7 +216,8 @@ gchar    *mm_new_iso8601_time                    (guint    year,
                                                   guint    minute,
                                                   guint    second,
                                                   gboolean have_offset,
-                                                  gint     offset_minutes);
+                                                  gint     offset_minutes,
+                                                  GError **error);
 
 /******************************************************************************/
 /* Type checkers and conversion utilities */
diff --git a/libmm-glib/tests/test-common-helpers.c b/libmm-glib/tests/test-common-helpers.c
index 69b95cb1..a1a2e61e 100644
--- a/libmm-glib/tests/test-common-helpers.c
+++ b/libmm-glib/tests/test-common-helpers.c
@@ -602,18 +602,40 @@ static void
 date_time_iso8601 (void)
 {
     gchar *date = NULL;
+    GError *error = NULL;
 
     date = mm_new_iso8601_time_from_unix_time (1634307342);
     g_assert_cmpstr (date, ==, "2021-10-15T14:15:42Z");
     g_free (date);
 
-    date = mm_new_iso8601_time (2021, 10, 15, 16, 15, 42, FALSE, 0);
+    date = mm_new_iso8601_time (2021, 10, 15, 16, 15, 42, FALSE, 0, &error);
+    g_assert_no_error (error);
     g_assert_cmpstr (date, ==, "2021-10-15T16:15:42Z");
     g_free (date);
 
-    date = mm_new_iso8601_time (2021, 10, 15, 16, 15, 42, TRUE, 120);
+    date = mm_new_iso8601_time (2021, 10, 15, 16, 15, 42, TRUE, 120, &error);
+    g_assert_no_error (error);
     g_assert_cmpstr (date, ==, "2021-10-15T16:15:42+02");
     g_free (date);
+
+    /* Valid args:
+     * - Year:[1-9999]
+     * - Month:[1-12]
+     * - Day:[1-28|29|30|31] according to year and month
+     * - Hour: [0-23]
+     * - Minute: [0-59]
+     * - Seconds: [0.0-60.0)
+     * */
+    date = mm_new_iso8601_time (2021, 13, 15, 16, 15, 42, TRUE, 120, &error);
+    g_assert_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS);
+    g_assert_null (date);
+    g_clear_error (&error);
+
+    /* No February 29 in 2021 */
+    date = mm_new_iso8601_time (2021, 2, 29, 16, 15, 42, TRUE, 120, &error);
+    g_assert_error (error, MM_CORE_ERROR, MM_CORE_ERROR_INVALID_ARGS);
+    g_assert_null (date);
+    g_clear_error (&error);
 }
 
 /**************************************************************/