Port over the last of the tinylogin applets

[oweals/busybox.git] / libbb / change_identity.c

diff --git a/libbb/change_identity.c b/libbb/change_identity.c
new file mode 100644 (file)
index 0000000..819b216
--- /dev/null
+++ b/libbb/change_identity.c
@@ -0,0 +1,54 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <ctype.h>
+
+#include "libbb.h"
+
+
+/* Become the user and group(s) specified by PW.  */
+void change_identity ( const struct passwd *pw )
+{
+       if ( initgroups ( pw-> pw_name, pw-> pw_gid ) == -1 )
+               perror_msg_and_die ( "cannot set groups" );
+       endgrent ( );
+
+       if ( setgid ( pw-> pw_gid ))
+               perror_msg_and_die ( "cannot set group id" );
+       if ( setuid ( pw->pw_uid ))
+               perror_msg_and_die ( "cannot set user id" );
+}
+