1 files changed, 61 insertions, 0 deletions
diff --git a/src/util/set_ugid.c b/src/util/set_ugid.c
new file mode 100644
index 0000000..bbcb901
--- /dev/null
+++ b/src/util/set_ugid.c
@@ -0,0 +1,61 @@
+/*++
+/* NAME
+/*	set_ugid 3
+/* SUMMARY
+/*	set real, effective and saved user and group attributes
+/* SYNOPSIS
+/*	#include <set_ugid.h>
+/*
+/*	void	set_ugid(uid, gid)
+/*	uid_t	uid;
+/*	gid_t	gid;
+/* DESCRIPTION
+/*	set_ugid() sets the real, effective and saved user and group process
+/*	attributes and updates the process group access list to be just the
+/*	user's primary group. This operation is irreversible.
+/* DIAGNOSTICS
+/*	All system call errors are fatal.
+/* SEE ALSO
+/*	setuid(2), setgid(2), setgroups(2)
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <unistd.h>
+#include <grp.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include "msg.h"
+#include "set_ugid.h"
+
+/* set_ugid - set real, effective and saved user and group attributes */
+
+void    set_ugid(uid_t uid, gid_t gid)
+{
+    int     saved_errno = errno;
+
+    if (geteuid() != 0)
+	if (seteuid(0) < 0)
+	    msg_fatal("seteuid(0): %m");
+    if (setgid(gid) < 0)
+	msg_fatal("setgid(%ld): %m", (long) gid);
+    if (setgroups(1, &gid) < 0)
+	msg_fatal("setgroups(1, &%ld): %m", (long) gid);
+    if (setuid(uid) < 0)
+	msg_fatal("setuid(%ld): %m", (long) uid);
+    if (msg_verbose > 1)
+	msg_info("setugid: uid %ld gid %ld", (long) uid, (long) gid);
+    errno = saved_errno;
+}