1 files changed, 70 insertions, 0 deletions
diff --git a/src/util/set_eugid.c b/src/util/set_eugid.c
new file mode 100644
index 0000000..ef35380
--- /dev/null
+++ b/src/util/set_eugid.c
@@ -0,0 +1,70 @@
+/*++
+/* NAME
+/*	set_eugid 3
+/* SUMMARY
+/*	set effective user and group attributes
+/* SYNOPSIS
+/*	#include <set_eugid.h>
+/*
+/*	void	set_eugid(euid, egid)
+/*	uid_t	euid;
+/*	gid_t	egid;
+/*
+/*	void	SAVE_AND_SET_EUGID(uid, gid)
+/*	uid_t	uid;
+/*	gid_t gid;
+/*
+/*	void	RESTORE_SAVED_EUGID()
+/* DESCRIPTION
+/*	set_eugid() sets the effective user and group process attributes
+/*	and updates the process group access list to be just the specified
+/*	effective group id.
+/*
+/*	SAVE_AND_SET_EUGID() opens a block that executes with the
+/*	specified privilege. RESTORE_SAVED_EUGID() closes the block. 
+/* DIAGNOSTICS
+/*	All system call errors are fatal.
+/* SEE ALSO
+/*	seteuid(2), setegid(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_eugid.h"
+
+/* set_eugid - set effective user and group attributes */
+
+void    set_eugid(uid_t euid, gid_t egid)
+{
+    int     saved_errno = errno;
+
+    if (geteuid() != 0)
+	if (seteuid(0))
+	    msg_fatal("set_eugid: seteuid(0): %m");
+    if (setegid(egid) < 0)
+	msg_fatal("set_eugid: setegid(%ld): %m", (long) egid);
+    if (setgroups(1, &egid) < 0)
+	msg_fatal("set_eugid: setgroups(%ld): %m", (long) egid);
+    if (euid != 0 && seteuid(euid) < 0)
+	msg_fatal("set_eugid: seteuid(%ld): %m", (long) euid);
+    if (msg_verbose)
+	msg_info("set_eugid: euid %ld egid %ld", (long) euid, (long) egid);
+    errno = saved_errno;
+}