[openssh.git] / uidswap.c

/* $OpenBSD: uidswap.c,v 1.34 2006/07/26 02:35:17 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 <sys/param.h>

#include <errno.h>
#include <pwd.h>
#include <string.h>
#include <unistd.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
536c14e8	1	/* $OpenBSD: uidswap.c,v 1.34 2006/07/26 02:35:17 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>
536c14e8	18	#include <sys/param.h>
b1842393	19
028094f4	20	#include <errno.h>
b1842393	21	#include <pwd.h>
00146caa	22	#include <string.h>
5188ba17	23	#include <unistd.h>
b1842393	24
16fbe330	25	#include <grp.h>
16fbe330	26
42f11eb2	27	#include "log.h"
8efc0c15	28	#include "uidswap.h"
13dff404	29	#include "xmalloc.h"
8efc0c15	30
5260325f	31	/*
	32	* Note: all these functions must work in all of the following cases:
	33	* 1. euid=0, ruid=0
	34	* 2. euid=0, ruid!=0
	35	* 3. euid!=0, ruid!=0
	36	* Additionally, they must work regardless of whether the system has
	37	* POSIX saved uids or not.
	38	*/
8efc0c15	39
0096ac62	40	#if defined(_POSIX_SAVED_IDS) && !defined(BROKEN_SAVED_UIDS)
8efc0c15	41	/* Lets assume that posix saved ids also work with seteuid, even though that
8efc0c15	42	is not part of the posix specification. */
0096ac62	43	#define SAVED_IDS_WORK_WITH_SETEUID
	44	/* Saved effective uid. */
	45	static uid_t saved_euid = 0;
	46	static gid_t saved_egid = 0;
	47	#endif
f8252c48	48
8efc0c15	49	/* Saved effective uid. */
63bd8c36	50	static int privileged = 0;
63bd8c36	51	static int temporarily_use_uid_effective = 0;
13dff404	52	static gid_t saved_egroups = NULL, user_groups = NULL;
63bd8c36	53	static int saved_egroupslen = -1, user_groupslen = -1;
f8252c48	54
5260325f	55	/*
	56	* Temporarily changes to the given uid. If the effective user
	57	* id is not root, this does nothing. This call cannot be nested.
	58	*/
6ae2364d	59	void
63bd8c36	60	temporarily_use_uid(struct passwd *pw)
8efc0c15	61	{
f8252c48	62	/* Save the current euid, and egroups. */
0096ac62	63	#ifdef SAVED_IDS_WORK_WITH_SETEUID
f8252c48	64	saved_euid = geteuid();
0096ac62	65	saved_egid = getegid();
0df3a240	66	debug("temporarily_use_uid: %u/%u (e=%u/%u)",
	67	(u_int)pw->pw_uid, (u_int)pw->pw_gid,
	68	(u_int)saved_euid, (u_int)saved_egid);
c2736f7f	69	#ifndef HAVE_CYGWIN
f8252c48	70	if (saved_euid != 0) {
	71	privileged = 0;
	72	return;
	73	}
c2736f7f	74	#endif
0096ac62	75	#else
	76	if (geteuid() != 0) {
	77	privileged = 0;
	78	return;
	79	}
	80	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	81
f8252c48	82	privileged = 1;
f8252c48	83	temporarily_use_uid_effective = 1;
13dff404	84
13dff404	85	saved_egroupslen = getgroups(0, NULL);
f8252c48	86	if (saved_egroupslen < 0)
f8252c48	87	fatal("getgroups: %.100s", strerror(errno));
13dff404	88	if (saved_egroupslen > 0) {
13dff404	89	saved_egroups = xrealloc(saved_egroups,
c5d10563	90	saved_egroupslen, sizeof(gid_t));
13dff404	91	if (getgroups(saved_egroupslen, saved_egroups) < 0)
	92	fatal("getgroups: %.100s", strerror(errno));
	93	} else { /* saved_egroupslen == 0 */
972fc531	94	if (saved_egroups != NULL)
13dff404	95	xfree(saved_egroups);
13dff404	96	}
f8252c48	97
	98	/* set and save the user's groups */
	99	if (user_groupslen == -1) {
	100	if (initgroups(pw->pw_name, pw->pw_gid) < 0)
	101	fatal("initgroups: %s: %.100s", pw->pw_name,
	102	strerror(errno));
13dff404	103
13dff404	104	user_groupslen = getgroups(0, NULL);
f8252c48	105	if (user_groupslen < 0)
f8252c48	106	fatal("getgroups: %.100s", strerror(errno));
13dff404	107	if (user_groupslen > 0) {
13dff404	108	user_groups = xrealloc(user_groups,
c5d10563	109	user_groupslen, sizeof(gid_t));
13dff404	110	if (getgroups(user_groupslen, user_groups) < 0)
	111	fatal("getgroups: %.100s", strerror(errno));
	112	} else { /* user_groupslen == 0 */
	113	if (user_groups)
	114	xfree(user_groups);
	115	}
f8252c48	116	}
f8252c48	117	/* Set the effective uid to the given (unprivileged) uid. */
d98d029a	118	if (setgroups(user_groupslen, user_groups) < 0)
63bd8c36	119	fatal("setgroups: %.100s", strerror(errno));
0096ac62	120	#ifndef SAVED_IDS_WORK_WITH_SETEUID
	121	/* Propagate the privileged gid to all of our gids. */
	122	if (setgid(getegid()) < 0)
	123	debug("setgid %u: %.100s", (u_int) getegid(), strerror(errno));
	124	/* Propagate the privileged uid to all of our uids. */
	125	if (setuid(geteuid()) < 0)
	126	debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
	127	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
d98d029a	128	if (setegid(pw->pw_gid) < 0)
caa49784	129	fatal("setegid %u: %.100s", (u_int)pw->pw_gid,
f8252c48	130	strerror(errno));
f8252c48	131	if (seteuid(pw->pw_uid) == -1)
caa49784	132	fatal("seteuid %u: %.100s", (u_int)pw->pw_uid,
f8252c48	133	strerror(errno));
8efc0c15	134	}
f8252c48	135
3c33c1b6	136	void
	137	permanently_drop_suid(uid_t uid)
	138	{
	139	uid_t old_uid = getuid();
	140
	141	debug("permanently_drop_suid: %u", (u_int)uid);
	142	#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
	143	if (setresuid(uid, uid, uid) < 0)
	144	fatal("setresuid %u: %.100s", (u_int)uid, strerror(errno));
	145	#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
	146	if (setreuid(uid, uid) < 0)
	147	fatal("setreuid %u: %.100s", (u_int)uid, strerror(errno));
	148	#else
	149	# ifndef SETEUID_BREAKS_SETUID
	150	if (seteuid(uid) < 0)
	151	fatal("seteuid %u: %.100s", (u_int)uid, strerror(errno));
	152	# endif
	153	if (setuid(uid) < 0)
	154	fatal("setuid %u: %.100s", (u_int)uid, strerror(errno));
	155	#endif
	156
	157	#ifndef HAVE_CYGWIN
	158	/* Try restoration of UID if changed (test clearing of saved uid) */
	159	if (old_uid != uid &&
	160	(setuid(old_uid) != -1 \|\| seteuid(old_uid) != -1))
	161	fatal("%s: was able to restore old [e]uid", __func__);
	162	#endif
	163
	164	/* Verify UID drop was successful */
	165	if (getuid() != uid \|\| geteuid() != uid) {
	166	fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
	167	__func__, (u_int)getuid(), (u_int)geteuid(), (u_int)uid);
	168	}
	169	}
	170
5260325f	171	/*
a3626e12	172	* Restores to the original (privileged) uid.
5260325f	173	*/
6ae2364d	174	void
1e3b8b07	175	restore_uid(void)
8efc0c15	176	{
63bd8c36	177	/* it's a no-op unless privileged */
0df3a240	178	if (!privileged) {
0df3a240	179	debug("restore_uid: (unprivileged)");
63bd8c36	180	return;
0df3a240	181	}
63bd8c36	182	if (!temporarily_use_uid_effective)
63bd8c36	183	fatal("restore_uid: temporarily_use_uid not effective");
0096ac62	184
0096ac62	185	#ifdef SAVED_IDS_WORK_WITH_SETEUID
13979d47	186	debug("restore_uid: %u/%u", (u_int)saved_euid, (u_int)saved_egid);
a3626e12	187	/* Set the effective uid back to the saved privileged uid. */
5260325f	188	if (seteuid(saved_euid) < 0)
caa49784	189	fatal("seteuid %u: %.100s", (u_int)saved_euid, strerror(errno));
0096ac62	190	if (setegid(saved_egid) < 0)
caa49784	191	fatal("setegid %u: %.100s", (u_int)saved_egid, strerror(errno));
0096ac62	192	#else /* SAVED_IDS_WORK_WITH_SETEUID */
	193	/*
	194	* We are unable to restore the real uid to its unprivileged value.
	195	* Propagate the real uid (usually more privileged) to effective uid
	196	* as well.
	197	*/
	198	setuid(getuid());
	199	setgid(getgid());
	200	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	201
d98d029a	202	if (setgroups(saved_egroupslen, saved_egroups) < 0)
63bd8c36	203	fatal("setgroups: %.100s", strerror(errno));
63bd8c36	204	temporarily_use_uid_effective = 0;
8efc0c15	205	}
8efc0c15	206
5260325f	207	/*
	208	* Permanently sets all uids to the given uid. This cannot be
	209	* called while temporarily_use_uid is effective.
	210	*/
6ae2364d	211	void
63bd8c36	212	permanently_set_uid(struct passwd *pw)
8efc0c15	213	{
688eed4a	214	uid_t old_uid = getuid();
	215	gid_t old_gid = getgid();
	216
82aeee5d	217	if (pw == NULL)
82aeee5d	218	fatal("permanently_set_uid: no user given");
63bd8c36	219	if (temporarily_use_uid_effective)
95f20fe8	220	fatal("permanently_set_uid: temporarily_use_uid effective");
0df3a240	221	debug("permanently_set_uid: %u/%u", (u_int)pw->pw_uid,
0df3a240	222	(u_int)pw->pw_gid);
688eed4a	223
9a3fe0e2	224	#if defined(HAVE_SETRESGID) && !defined(BROKEN_SETRESGID)
688eed4a	225	if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) < 0)
688eed4a	226	fatal("setresgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
3b8dff69	227	#elif defined(HAVE_SETREGID) && !defined(BROKEN_SETREGID)
688eed4a	228	if (setregid(pw->pw_gid, pw->pw_gid) < 0)
	229	fatal("setregid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
	230	#else
fa5120a0	231	if (setegid(pw->pw_gid) < 0)
fa5120a0	232	fatal("setegid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
63bd8c36	233	if (setgid(pw->pw_gid) < 0)
caa49784	234	fatal("setgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
688eed4a	235	#endif
688eed4a	236
9a3fe0e2	237	#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
688eed4a	238	if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) < 0)
688eed4a	239	fatal("setresuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
3b8dff69	240	#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
f5db6a03	241	if (setreuid(pw->pw_uid, pw->pw_uid) < 0)
f5db6a03	242	fatal("setreuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	243	#else
688eed4a	244	# ifndef SETEUID_BREAKS_SETUID
fa5120a0	245	if (seteuid(pw->pw_uid) < 0)
fa5120a0	246	fatal("seteuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	247	# endif
a3626e12	248	if (setuid(pw->pw_uid) < 0)
caa49784	249	fatal("setuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	250	#endif
688eed4a	251
8f817407	252	#ifndef HAVE_CYGWIN
688eed4a	253	/* Try restoration of GID if changed (test clearing of saved gid) */
8f817407	254	if (old_gid != pw->pw_gid && pw->pw_uid != 0 &&
688eed4a	255	(setgid(old_gid) != -1 \|\| setegid(old_gid) != -1))
f5db6a03	256	fatal("%s: was able to restore old [e]gid", __func__);
8f817407	257	#endif
688eed4a	258
	259	/* Verify GID drop was successful */
	260	if (getgid() != pw->pw_gid \|\| getegid() != pw->pw_gid) {
aff51935	261	fatal("%s: egid incorrect gid:%u egid:%u (should be %u)",
aff51935	262	__func__, (u_int)getgid(), (u_int)getegid(),
688eed4a	263	(u_int)pw->pw_gid);
	264	}
	265
51e7d820	266	#ifndef HAVE_CYGWIN
688eed4a	267	/* Try restoration of UID if changed (test clearing of saved uid) */
aff51935	268	if (old_uid != pw->pw_uid &&
688eed4a	269	(setuid(old_uid) != -1 \|\| seteuid(old_uid) != -1))
f5db6a03	270	fatal("%s: was able to restore old [e]uid", __func__);
51e7d820	271	#endif
688eed4a	272
	273	/* Verify UID drop was successful */
	274	if (getuid() != pw->pw_uid \|\| geteuid() != pw->pw_uid) {
aff51935	275	fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
aff51935	276	__func__, (u_int)getuid(), (u_int)geteuid(),
688eed4a	277	(u_int)pw->pw_uid);
688eed4a	278	}
8efc0c15	279	}