1 files changed, 90 insertions, 0 deletions
diff --git a/utils/nullauth.c b/utils/nullauth.c
new file mode 100644
index 00000000..a0d5d1b8
--- /dev/null
+++ b/utils/nullauth.c
@@ -0,0 +1,90 @@
+/* Utility to drop all authentication credentials.
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+
+   Written by Justus Winter <4winter@informatik.uni-hamburg.de>
+
+   This file is part of the GNU Hurd.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program 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
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <argp.h>
+#include <error.h>
+#include <nullauth.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <version.h>
+
+static char **args;
+
+const char const *argp_program_version = STANDARD_HURD_VERSION (nullauth);
+
+static const struct argp_option const options[] =
+{
+  { 0 }
+};
+
+static const char const doc[] =
+  "Drop all authentication credentials and run the given program.";
+static const char const args_doc[] =
+  "PROGRAM [ARGUMENTS...]\tThe program to run";
+
+error_t
+parse_opt (int key, char *arg, struct argp_state *state)
+{
+  switch (key)
+    {
+    case ARGP_KEY_ARGS:
+      args = state->argv + state->next;
+      break;
+
+    case ARGP_KEY_NO_ARGS:
+      argp_error (state, "expected program to run");
+      return EINVAL;
+
+    default:
+      return ARGP_ERR_UNKNOWN;
+    }
+
+  return 0;
+}
+
+static struct argp argp = {
+  options,
+  parse_opt,
+  args_doc,
+  doc,
+  NULL,
+};
+
+int
+main (int argc, char *argv[])
+{
+  error_t err;
+
+  /* Parse our command line.  This shouldn't ever return an error.  */
+  argp_parse (&argp, argc, argv, 0, 0, NULL);
+
+  /* Drop all privileges.  */
+  err = setnullauth();
+  if (err)
+    error (1, err, "Could not drop privileges");
+
+  execv (args[0], args);
+  error (1, errno, "execv");
+
+  /* Not reached.  */
+  return EXIT_FAILURE;
+}