-/* $OpenBSD: uidswap.c,v 1.27 2006/04/22 04:06:51 djm Exp $ */
+/* $OpenBSD: uidswap.c,v 1.35 2006/08/03 03:34:42 deraadt Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
#include "includes.h"
+#include <sys/param.h>
+#include <errno.h>
+#include <pwd.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#include <grp.h>
+
#include "log.h"
#include "uidswap.h"
#include "xmalloc.h"
strerror(errno));
}
+void
+permanently_drop_suid(uid_t uid)
+{
+ uid_t old_uid = getuid();
+
+ debug("permanently_drop_suid: %u", (u_int)uid);
+#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
+ if (setresuid(uid, uid, uid) < 0)
+ fatal("setresuid %u: %.100s", (u_int)uid, strerror(errno));
+#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
+ if (setreuid(uid, uid) < 0)
+ fatal("setreuid %u: %.100s", (u_int)uid, strerror(errno));
+#else
+# ifndef SETEUID_BREAKS_SETUID
+ if (seteuid(uid) < 0)
+ fatal("seteuid %u: %.100s", (u_int)uid, strerror(errno));
+# endif
+ if (setuid(uid) < 0)
+ fatal("setuid %u: %.100s", (u_int)uid, strerror(errno));
+#endif
+
+#ifndef HAVE_CYGWIN
+ /* Try restoration of UID if changed (test clearing of saved uid) */
+ if (old_uid != uid &&
+ (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
+ fatal("%s: was able to restore old [e]uid", __func__);
+#endif
+
+ /* Verify UID drop was successful */
+ if (getuid() != uid || geteuid() != uid) {
+ fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
+ __func__, (u_int)getuid(), (u_int)geteuid(), (u_int)uid);
+ }
+}
+
/*
* Restores to the original (privileged) uid.
*/
uid_t old_uid = getuid();
gid_t old_gid = getgid();
+ if (pw == NULL)
+ fatal("permanently_set_uid: no user given");
if (temporarily_use_uid_effective)
fatal("permanently_set_uid: temporarily_use_uid effective");
debug("permanently_set_uid: %u/%u", (u_int)pw->pw_uid,
fatal("setgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
#endif
+#ifdef __APPLE__
+ /*
+ * OS X requires initgroups after setgid to opt back into
+ * memberd support for >16 supplemental groups.
+ */
+ if (initgroups(pw->pw_name, pw->pw_gid) < 0)
+ fatal("initgroups %.100s %u: %.100s",
+ pw->pw_name, (u_int)pw->pw_gid, strerror(errno));
+#endif
+
#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) < 0)
fatal("setresuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));