[openssh.git] / uidswap.c

/* $OpenBSD: uidswap.c,v 1.31 2006/07/11 20:07:25 stevesk Exp $ */
/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Code for uid-swapping.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#include "includes.h"

#include <sys/types.h>

#include <errno.h>
#include <pwd.h>

#include <grp.h>

#include "log.h"
#include "uidswap.h"
#include "xmalloc.h"

/*
 * Note: all these functions must work in all of the following cases:
 *    1. euid=0, ruid=0
 *    2. euid=0, ruid!=0
 *    3. euid!=0, ruid!=0
 * Additionally, they must work regardless of whether the system has
 * POSIX saved uids or not.
 */

#if defined(_POSIX_SAVED_IDS) && !defined(BROKEN_SAVED_UIDS)
/* Lets assume that posix saved ids also work with seteuid, even though that
   is not part of the posix specification. */
#define SAVED_IDS_WORK_WITH_SETEUID
/* Saved effective uid. */
static uid_t 	saved_euid = 0;
static gid_t	saved_egid = 0;
#endif

/* Saved effective uid. */
static int	privileged = 0;
static int	temporarily_use_uid_effective = 0;
static gid_t	*saved_egroups = NULL, *user_groups = NULL;
static int	saved_egroupslen = -1, user_groupslen = -1;

/*
 * Temporarily changes to the given uid.  If the effective user
 * id is not root, this does nothing.  This call cannot be nested.
 */
void
temporarily_use_uid(struct passwd *pw)
{
	/* Save the current euid, and egroups. */
#ifdef SAVED_IDS_WORK_WITH_SETEUID
	saved_euid = geteuid();
	saved_egid = getegid();
	debug("temporarily_use_uid: %u/%u (e=%u/%u)",
	    (u_int)pw->pw_uid, (u_int)pw->pw_gid,
	    (u_int)saved_euid, (u_int)saved_egid);
#ifndef HAVE_CYGWIN
	if (saved_euid != 0) {
		privileged = 0;
		return;
	}
#endif
#else
	if (geteuid() != 0) {
		privileged = 0;
		return;
	}
#endif /* SAVED_IDS_WORK_WITH_SETEUID */

	privileged = 1;
	temporarily_use_uid_effective = 1;

	saved_egroupslen = getgroups(0, NULL);
	if (saved_egroupslen < 0)
		fatal("getgroups: %.100s", strerror(errno));
	if (saved_egroupslen > 0) {
		saved_egroups = xrealloc(saved_egroups,
		    saved_egroupslen, sizeof(gid_t));
		if (getgroups(saved_egroupslen, saved_egroups) < 0)
			fatal("getgroups: %.100s", strerror(errno));
	} else { /* saved_egroupslen == 0 */
		if (saved_egroups != NULL)
			xfree(saved_egroups);
	}

	/* set and save the user's groups */
	if (user_groupslen == -1) {
		if (initgroups(pw->pw_name, pw->pw_gid) < 0)
			fatal("initgroups: %s: %.100s", pw->pw_name,
			    strerror(errno));

		user_groupslen = getgroups(0, NULL);
		if (user_groupslen < 0)
			fatal("getgroups: %.100s", strerror(errno));
		if (user_groupslen > 0) {
			user_groups = xrealloc(user_groups,
			    user_groupslen, sizeof(gid_t));
			if (getgroups(user_groupslen, user_groups) < 0)
				fatal("getgroups: %.100s", strerror(errno));
		} else { /* user_groupslen == 0 */
			if (user_groups)
				xfree(user_groups);
		}
	}
	/* Set the effective uid to the given (unprivileged) uid. */
	if (setgroups(user_groupslen, user_groups) < 0)
		fatal("setgroups: %.100s", strerror(errno));
#ifndef SAVED_IDS_WORK_WITH_SETEUID
	/* Propagate the privileged gid to all of our gids. */
	if (setgid(getegid()) < 0)
		debug("setgid %u: %.100s", (u_int) getegid(), strerror(errno));
	/* Propagate the privileged uid to all of our uids. */
	if (setuid(geteuid()) < 0)
		debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	if (setegid(pw->pw_gid) < 0)
		fatal("setegid %u: %.100s", (u_int)pw->pw_gid,
		    strerror(errno));
	if (seteuid(pw->pw_uid) == -1)
		fatal("seteuid %u: %.100s", (u_int)pw->pw_uid,
		    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.
 */
void
restore_uid(void)
{
	/* it's a no-op unless privileged */
	if (!privileged) {
		debug("restore_uid: (unprivileged)");
		return;
	}
	if (!temporarily_use_uid_effective)
		fatal("restore_uid: temporarily_use_uid not effective");

#ifdef SAVED_IDS_WORK_WITH_SETEUID
	debug("restore_uid: %u/%u", (u_int)saved_euid, (u_int)saved_egid);
	/* Set the effective uid back to the saved privileged uid. */
	if (seteuid(saved_euid) < 0)
		fatal("seteuid %u: %.100s", (u_int)saved_euid, strerror(errno));
	if (setegid(saved_egid) < 0)
		fatal("setegid %u: %.100s", (u_int)saved_egid, strerror(errno));
#else /* SAVED_IDS_WORK_WITH_SETEUID */
	/*
	 * We are unable to restore the real uid to its unprivileged value.
	 * Propagate the real uid (usually more privileged) to effective uid
	 * as well.
	 */
	setuid(getuid());
	setgid(getgid());
#endif /* SAVED_IDS_WORK_WITH_SETEUID */

	if (setgroups(saved_egroupslen, saved_egroups) < 0)
		fatal("setgroups: %.100s", strerror(errno));
	temporarily_use_uid_effective = 0;
}

/*
 * Permanently sets all uids to the given uid.  This cannot be
 * called while temporarily_use_uid is effective.
 */
void
permanently_set_uid(struct passwd *pw)
{
	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,
	    (u_int)pw->pw_gid);

#if defined(HAVE_SETRESGID) && !defined(BROKEN_SETRESGID)
	if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) < 0)
		fatal("setresgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
#elif defined(HAVE_SETREGID) && !defined(BROKEN_SETREGID)
	if (setregid(pw->pw_gid, pw->pw_gid) < 0)
		fatal("setregid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
#else
	if (setegid(pw->pw_gid) < 0)
		fatal("setegid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
	if (setgid(pw->pw_gid) < 0)
		fatal("setgid %u: %.100s", (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));
#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
	if (setreuid(pw->pw_uid, pw->pw_uid) < 0)
		fatal("setreuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
#else
# ifndef SETEUID_BREAKS_SETUID
	if (seteuid(pw->pw_uid) < 0)
		fatal("seteuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
# endif
	if (setuid(pw->pw_uid) < 0)
		fatal("setuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
#endif

#ifndef HAVE_CYGWIN
	/* Try restoration of GID if changed (test clearing of saved gid) */
	if (old_gid != pw->pw_gid && pw->pw_uid != 0 &&
	    (setgid(old_gid) != -1 || setegid(old_gid) != -1))
		fatal("%s: was able to restore old [e]gid", __func__);
#endif

	/* Verify GID drop was successful */
	if (getgid() != pw->pw_gid || getegid() != pw->pw_gid) {
		fatal("%s: egid incorrect gid:%u egid:%u (should be %u)",
		    __func__, (u_int)getgid(), (u_int)getegid(),
		    (u_int)pw->pw_gid);
	}

#ifndef HAVE_CYGWIN
	/* Try restoration of UID if changed (test clearing of saved uid) */
	if (old_uid != pw->pw_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() != pw->pw_uid || geteuid() != pw->pw_uid) {
		fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
		    __func__, (u_int)getuid(), (u_int)geteuid(),
		    (u_int)pw->pw_uid);
	}
}
Commit	Line	Data
028094f4	1	/* $OpenBSD: uidswap.c,v 1.31 2006/07/11 20:07:25 stevesk Exp $ */
8efc0c15	2	/*
5260325f	3	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	4	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	5	* All rights reserved
5260325f	6	* Code for uid-swapping.
bcbf86ec	7	*
	8	* As far as I am concerned, the code I have written for this software
	9	* can be used freely for any purpose. Any derived versions of this
	10	* software must be clearly marked as such, and if the derived work is
	11	* incompatible with the protocol description in the RFC file, it must be
	12	* called by a name other than "ssh" or "Secure Shell".
5260325f	13	*/
8efc0c15	14
8efc0c15	15	#include "includes.h"
8efc0c15	16
b1842393	17	#include <sys/types.h>
b1842393	18
028094f4	19	#include <errno.h>
b1842393	20	#include <pwd.h>
b1842393	21
16fbe330	22	#include <grp.h>
16fbe330	23
42f11eb2	24	#include "log.h"
8efc0c15	25	#include "uidswap.h"
13dff404	26	#include "xmalloc.h"
8efc0c15	27
5260325f	28	/*
	29	* Note: all these functions must work in all of the following cases:
	30	* 1. euid=0, ruid=0
	31	* 2. euid=0, ruid!=0
	32	* 3. euid!=0, ruid!=0
	33	* Additionally, they must work regardless of whether the system has
	34	* POSIX saved uids or not.
	35	*/
8efc0c15	36
0096ac62	37	#if defined(_POSIX_SAVED_IDS) && !defined(BROKEN_SAVED_UIDS)
8efc0c15	38	/* Lets assume that posix saved ids also work with seteuid, even though that
8efc0c15	39	is not part of the posix specification. */
0096ac62	40	#define SAVED_IDS_WORK_WITH_SETEUID
	41	/* Saved effective uid. */
	42	static uid_t saved_euid = 0;
	43	static gid_t saved_egid = 0;
	44	#endif
f8252c48	45
8efc0c15	46	/* Saved effective uid. */
63bd8c36	47	static int privileged = 0;
63bd8c36	48	static int temporarily_use_uid_effective = 0;
13dff404	49	static gid_t saved_egroups = NULL, user_groups = NULL;
63bd8c36	50	static int saved_egroupslen = -1, user_groupslen = -1;
f8252c48	51
5260325f	52	/*
	53	* Temporarily changes to the given uid. If the effective user
	54	* id is not root, this does nothing. This call cannot be nested.
	55	*/
6ae2364d	56	void
63bd8c36	57	temporarily_use_uid(struct passwd *pw)
8efc0c15	58	{
f8252c48	59	/* Save the current euid, and egroups. */
0096ac62	60	#ifdef SAVED_IDS_WORK_WITH_SETEUID
f8252c48	61	saved_euid = geteuid();
0096ac62	62	saved_egid = getegid();
0df3a240	63	debug("temporarily_use_uid: %u/%u (e=%u/%u)",
	64	(u_int)pw->pw_uid, (u_int)pw->pw_gid,
	65	(u_int)saved_euid, (u_int)saved_egid);
c2736f7f	66	#ifndef HAVE_CYGWIN
f8252c48	67	if (saved_euid != 0) {
	68	privileged = 0;
	69	return;
	70	}
c2736f7f	71	#endif
0096ac62	72	#else
	73	if (geteuid() != 0) {
	74	privileged = 0;
	75	return;
	76	}
	77	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	78
f8252c48	79	privileged = 1;
f8252c48	80	temporarily_use_uid_effective = 1;
13dff404	81
13dff404	82	saved_egroupslen = getgroups(0, NULL);
f8252c48	83	if (saved_egroupslen < 0)
f8252c48	84	fatal("getgroups: %.100s", strerror(errno));
13dff404	85	if (saved_egroupslen > 0) {
13dff404	86	saved_egroups = xrealloc(saved_egroups,
c5d10563	87	saved_egroupslen, sizeof(gid_t));
13dff404	88	if (getgroups(saved_egroupslen, saved_egroups) < 0)
	89	fatal("getgroups: %.100s", strerror(errno));
	90	} else { /* saved_egroupslen == 0 */
972fc531	91	if (saved_egroups != NULL)
13dff404	92	xfree(saved_egroups);
13dff404	93	}
f8252c48	94
	95	/* set and save the user's groups */
	96	if (user_groupslen == -1) {
	97	if (initgroups(pw->pw_name, pw->pw_gid) < 0)
	98	fatal("initgroups: %s: %.100s", pw->pw_name,
	99	strerror(errno));
13dff404	100
13dff404	101	user_groupslen = getgroups(0, NULL);
f8252c48	102	if (user_groupslen < 0)
f8252c48	103	fatal("getgroups: %.100s", strerror(errno));
13dff404	104	if (user_groupslen > 0) {
13dff404	105	user_groups = xrealloc(user_groups,
c5d10563	106	user_groupslen, sizeof(gid_t));
13dff404	107	if (getgroups(user_groupslen, user_groups) < 0)
	108	fatal("getgroups: %.100s", strerror(errno));
	109	} else { /* user_groupslen == 0 */
	110	if (user_groups)
	111	xfree(user_groups);
	112	}
f8252c48	113	}
f8252c48	114	/* Set the effective uid to the given (unprivileged) uid. */
d98d029a	115	if (setgroups(user_groupslen, user_groups) < 0)
63bd8c36	116	fatal("setgroups: %.100s", strerror(errno));
0096ac62	117	#ifndef SAVED_IDS_WORK_WITH_SETEUID
	118	/* Propagate the privileged gid to all of our gids. */
	119	if (setgid(getegid()) < 0)
	120	debug("setgid %u: %.100s", (u_int) getegid(), strerror(errno));
	121	/* Propagate the privileged uid to all of our uids. */
	122	if (setuid(geteuid()) < 0)
	123	debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
	124	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
d98d029a	125	if (setegid(pw->pw_gid) < 0)
caa49784	126	fatal("setegid %u: %.100s", (u_int)pw->pw_gid,
f8252c48	127	strerror(errno));
f8252c48	128	if (seteuid(pw->pw_uid) == -1)
caa49784	129	fatal("seteuid %u: %.100s", (u_int)pw->pw_uid,
f8252c48	130	strerror(errno));
8efc0c15	131	}
f8252c48	132
3c33c1b6	133	void
	134	permanently_drop_suid(uid_t uid)
	135	{
	136	uid_t old_uid = getuid();
	137
	138	debug("permanently_drop_suid: %u", (u_int)uid);
	139	#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
	140	if (setresuid(uid, uid, uid) < 0)
	141	fatal("setresuid %u: %.100s", (u_int)uid, strerror(errno));
	142	#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
	143	if (setreuid(uid, uid) < 0)
	144	fatal("setreuid %u: %.100s", (u_int)uid, strerror(errno));
	145	#else
	146	# ifndef SETEUID_BREAKS_SETUID
	147	if (seteuid(uid) < 0)
	148	fatal("seteuid %u: %.100s", (u_int)uid, strerror(errno));
	149	# endif
	150	if (setuid(uid) < 0)
	151	fatal("setuid %u: %.100s", (u_int)uid, strerror(errno));
	152	#endif
	153
	154	#ifndef HAVE_CYGWIN
	155	/* Try restoration of UID if changed (test clearing of saved uid) */
	156	if (old_uid != uid &&
	157	(setuid(old_uid) != -1 \|\| seteuid(old_uid) != -1))
	158	fatal("%s: was able to restore old [e]uid", __func__);
	159	#endif
	160
	161	/* Verify UID drop was successful */
	162	if (getuid() != uid \|\| geteuid() != uid) {
	163	fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
	164	__func__, (u_int)getuid(), (u_int)geteuid(), (u_int)uid);
	165	}
	166	}
	167
5260325f	168	/*
a3626e12	169	* Restores to the original (privileged) uid.
5260325f	170	*/
6ae2364d	171	void
1e3b8b07	172	restore_uid(void)
8efc0c15	173	{
63bd8c36	174	/* it's a no-op unless privileged */
0df3a240	175	if (!privileged) {
0df3a240	176	debug("restore_uid: (unprivileged)");
63bd8c36	177	return;
0df3a240	178	}
63bd8c36	179	if (!temporarily_use_uid_effective)
63bd8c36	180	fatal("restore_uid: temporarily_use_uid not effective");
0096ac62	181
0096ac62	182	#ifdef SAVED_IDS_WORK_WITH_SETEUID
13979d47	183	debug("restore_uid: %u/%u", (u_int)saved_euid, (u_int)saved_egid);
a3626e12	184	/* Set the effective uid back to the saved privileged uid. */
5260325f	185	if (seteuid(saved_euid) < 0)
caa49784	186	fatal("seteuid %u: %.100s", (u_int)saved_euid, strerror(errno));
0096ac62	187	if (setegid(saved_egid) < 0)
caa49784	188	fatal("setegid %u: %.100s", (u_int)saved_egid, strerror(errno));
0096ac62	189	#else /* SAVED_IDS_WORK_WITH_SETEUID */
	190	/*
	191	* We are unable to restore the real uid to its unprivileged value.
	192	* Propagate the real uid (usually more privileged) to effective uid
	193	* as well.
	194	*/
	195	setuid(getuid());
	196	setgid(getgid());
	197	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	198
d98d029a	199	if (setgroups(saved_egroupslen, saved_egroups) < 0)
63bd8c36	200	fatal("setgroups: %.100s", strerror(errno));
63bd8c36	201	temporarily_use_uid_effective = 0;
8efc0c15	202	}
8efc0c15	203
5260325f	204	/*
	205	* Permanently sets all uids to the given uid. This cannot be
	206	* called while temporarily_use_uid is effective.
	207	*/
6ae2364d	208	void
63bd8c36	209	permanently_set_uid(struct passwd *pw)
8efc0c15	210	{
688eed4a	211	uid_t old_uid = getuid();
	212	gid_t old_gid = getgid();
	213
82aeee5d	214	if (pw == NULL)
82aeee5d	215	fatal("permanently_set_uid: no user given");
63bd8c36	216	if (temporarily_use_uid_effective)
95f20fe8	217	fatal("permanently_set_uid: temporarily_use_uid effective");
0df3a240	218	debug("permanently_set_uid: %u/%u", (u_int)pw->pw_uid,
0df3a240	219	(u_int)pw->pw_gid);
688eed4a	220
9a3fe0e2	221	#if defined(HAVE_SETRESGID) && !defined(BROKEN_SETRESGID)
688eed4a	222	if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) < 0)
688eed4a	223	fatal("setresgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
3b8dff69	224	#elif defined(HAVE_SETREGID) && !defined(BROKEN_SETREGID)
688eed4a	225	if (setregid(pw->pw_gid, pw->pw_gid) < 0)
	226	fatal("setregid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
	227	#else
fa5120a0	228	if (setegid(pw->pw_gid) < 0)
fa5120a0	229	fatal("setegid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
63bd8c36	230	if (setgid(pw->pw_gid) < 0)
caa49784	231	fatal("setgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
688eed4a	232	#endif
688eed4a	233
9a3fe0e2	234	#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
688eed4a	235	if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) < 0)
688eed4a	236	fatal("setresuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
3b8dff69	237	#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
f5db6a03	238	if (setreuid(pw->pw_uid, pw->pw_uid) < 0)
f5db6a03	239	fatal("setreuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	240	#else
688eed4a	241	# ifndef SETEUID_BREAKS_SETUID
fa5120a0	242	if (seteuid(pw->pw_uid) < 0)
fa5120a0	243	fatal("seteuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	244	# endif
a3626e12	245	if (setuid(pw->pw_uid) < 0)
caa49784	246	fatal("setuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	247	#endif
688eed4a	248
8f817407	249	#ifndef HAVE_CYGWIN
688eed4a	250	/* Try restoration of GID if changed (test clearing of saved gid) */
8f817407	251	if (old_gid != pw->pw_gid && pw->pw_uid != 0 &&
688eed4a	252	(setgid(old_gid) != -1 \|\| setegid(old_gid) != -1))
f5db6a03	253	fatal("%s: was able to restore old [e]gid", __func__);
8f817407	254	#endif
688eed4a	255
	256	/* Verify GID drop was successful */
	257	if (getgid() != pw->pw_gid \|\| getegid() != pw->pw_gid) {
aff51935	258	fatal("%s: egid incorrect gid:%u egid:%u (should be %u)",
aff51935	259	__func__, (u_int)getgid(), (u_int)getegid(),
688eed4a	260	(u_int)pw->pw_gid);
	261	}
	262
51e7d820	263	#ifndef HAVE_CYGWIN
688eed4a	264	/* Try restoration of UID if changed (test clearing of saved uid) */
aff51935	265	if (old_uid != pw->pw_uid &&
688eed4a	266	(setuid(old_uid) != -1 \|\| seteuid(old_uid) != -1))
f5db6a03	267	fatal("%s: was able to restore old [e]uid", __func__);
51e7d820	268	#endif
688eed4a	269
	270	/* Verify UID drop was successful */
	271	if (getuid() != pw->pw_uid \|\| geteuid() != pw->pw_uid) {
aff51935	272	fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
aff51935	273	__func__, (u_int)getuid(), (u_int)geteuid(),
688eed4a	274	(u_int)pw->pw_uid);
688eed4a	275	}
8efc0c15	276	}