[openssh.git] / uidswap.c

/* $OpenBSD: uidswap.c,v 1.30 2006/07/06 16:03:53 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 <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
b1842393	1	/* $OpenBSD: uidswap.c,v 1.30 2006/07/06 16:03:53 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>
	18
	19	#include <pwd.h>
	20
16fbe330	21	#include <grp.h>
16fbe330	22
42f11eb2	23	#include "log.h"
8efc0c15	24	#include "uidswap.h"
13dff404	25	#include "xmalloc.h"
8efc0c15	26
5260325f	27	/*
	28	* Note: all these functions must work in all of the following cases:
	29	* 1. euid=0, ruid=0
	30	* 2. euid=0, ruid!=0
	31	* 3. euid!=0, ruid!=0
	32	* Additionally, they must work regardless of whether the system has
	33	* POSIX saved uids or not.
	34	*/
8efc0c15	35
0096ac62	36	#if defined(_POSIX_SAVED_IDS) && !defined(BROKEN_SAVED_UIDS)
8efc0c15	37	/* Lets assume that posix saved ids also work with seteuid, even though that
8efc0c15	38	is not part of the posix specification. */
0096ac62	39	#define SAVED_IDS_WORK_WITH_SETEUID
	40	/* Saved effective uid. */
	41	static uid_t saved_euid = 0;
	42	static gid_t saved_egid = 0;
	43	#endif
f8252c48	44
8efc0c15	45	/* Saved effective uid. */
63bd8c36	46	static int privileged = 0;
63bd8c36	47	static int temporarily_use_uid_effective = 0;
13dff404	48	static gid_t saved_egroups = NULL, user_groups = NULL;
63bd8c36	49	static int saved_egroupslen = -1, user_groupslen = -1;
f8252c48	50
5260325f	51	/*
	52	* Temporarily changes to the given uid. If the effective user
	53	* id is not root, this does nothing. This call cannot be nested.
	54	*/
6ae2364d	55	void
63bd8c36	56	temporarily_use_uid(struct passwd *pw)
8efc0c15	57	{
f8252c48	58	/* Save the current euid, and egroups. */
0096ac62	59	#ifdef SAVED_IDS_WORK_WITH_SETEUID
f8252c48	60	saved_euid = geteuid();
0096ac62	61	saved_egid = getegid();
0df3a240	62	debug("temporarily_use_uid: %u/%u (e=%u/%u)",
	63	(u_int)pw->pw_uid, (u_int)pw->pw_gid,
	64	(u_int)saved_euid, (u_int)saved_egid);
c2736f7f	65	#ifndef HAVE_CYGWIN
f8252c48	66	if (saved_euid != 0) {
	67	privileged = 0;
	68	return;
	69	}
c2736f7f	70	#endif
0096ac62	71	#else
	72	if (geteuid() != 0) {
	73	privileged = 0;
	74	return;
	75	}
	76	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	77
f8252c48	78	privileged = 1;
f8252c48	79	temporarily_use_uid_effective = 1;
13dff404	80
13dff404	81	saved_egroupslen = getgroups(0, NULL);
f8252c48	82	if (saved_egroupslen < 0)
f8252c48	83	fatal("getgroups: %.100s", strerror(errno));
13dff404	84	if (saved_egroupslen > 0) {
13dff404	85	saved_egroups = xrealloc(saved_egroups,
c5d10563	86	saved_egroupslen, sizeof(gid_t));
13dff404	87	if (getgroups(saved_egroupslen, saved_egroups) < 0)
	88	fatal("getgroups: %.100s", strerror(errno));
	89	} else { /* saved_egroupslen == 0 */
972fc531	90	if (saved_egroups != NULL)
13dff404	91	xfree(saved_egroups);
13dff404	92	}
f8252c48	93
	94	/* set and save the user's groups */
	95	if (user_groupslen == -1) {
	96	if (initgroups(pw->pw_name, pw->pw_gid) < 0)
	97	fatal("initgroups: %s: %.100s", pw->pw_name,
	98	strerror(errno));
13dff404	99
13dff404	100	user_groupslen = getgroups(0, NULL);
f8252c48	101	if (user_groupslen < 0)
f8252c48	102	fatal("getgroups: %.100s", strerror(errno));
13dff404	103	if (user_groupslen > 0) {
13dff404	104	user_groups = xrealloc(user_groups,
c5d10563	105	user_groupslen, sizeof(gid_t));
13dff404	106	if (getgroups(user_groupslen, user_groups) < 0)
	107	fatal("getgroups: %.100s", strerror(errno));
	108	} else { /* user_groupslen == 0 */
	109	if (user_groups)
	110	xfree(user_groups);
	111	}
f8252c48	112	}
f8252c48	113	/* Set the effective uid to the given (unprivileged) uid. */
d98d029a	114	if (setgroups(user_groupslen, user_groups) < 0)
63bd8c36	115	fatal("setgroups: %.100s", strerror(errno));
0096ac62	116	#ifndef SAVED_IDS_WORK_WITH_SETEUID
	117	/* Propagate the privileged gid to all of our gids. */
	118	if (setgid(getegid()) < 0)
	119	debug("setgid %u: %.100s", (u_int) getegid(), strerror(errno));
	120	/* Propagate the privileged uid to all of our uids. */
	121	if (setuid(geteuid()) < 0)
	122	debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
	123	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
d98d029a	124	if (setegid(pw->pw_gid) < 0)
caa49784	125	fatal("setegid %u: %.100s", (u_int)pw->pw_gid,
f8252c48	126	strerror(errno));
f8252c48	127	if (seteuid(pw->pw_uid) == -1)
caa49784	128	fatal("seteuid %u: %.100s", (u_int)pw->pw_uid,
f8252c48	129	strerror(errno));
8efc0c15	130	}
f8252c48	131
3c33c1b6	132	void
	133	permanently_drop_suid(uid_t uid)
	134	{
	135	uid_t old_uid = getuid();
	136
	137	debug("permanently_drop_suid: %u", (u_int)uid);
	138	#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
	139	if (setresuid(uid, uid, uid) < 0)
	140	fatal("setresuid %u: %.100s", (u_int)uid, strerror(errno));
	141	#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
	142	if (setreuid(uid, uid) < 0)
	143	fatal("setreuid %u: %.100s", (u_int)uid, strerror(errno));
	144	#else
	145	# ifndef SETEUID_BREAKS_SETUID
	146	if (seteuid(uid) < 0)
	147	fatal("seteuid %u: %.100s", (u_int)uid, strerror(errno));
	148	# endif
	149	if (setuid(uid) < 0)
	150	fatal("setuid %u: %.100s", (u_int)uid, strerror(errno));
	151	#endif
	152
	153	#ifndef HAVE_CYGWIN
	154	/* Try restoration of UID if changed (test clearing of saved uid) */
	155	if (old_uid != uid &&
	156	(setuid(old_uid) != -1 \|\| seteuid(old_uid) != -1))
	157	fatal("%s: was able to restore old [e]uid", __func__);
	158	#endif
	159
	160	/* Verify UID drop was successful */
	161	if (getuid() != uid \|\| geteuid() != uid) {
	162	fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
	163	__func__, (u_int)getuid(), (u_int)geteuid(), (u_int)uid);
	164	}
	165	}
	166
5260325f	167	/*
a3626e12	168	* Restores to the original (privileged) uid.
5260325f	169	*/
6ae2364d	170	void
1e3b8b07	171	restore_uid(void)
8efc0c15	172	{
63bd8c36	173	/* it's a no-op unless privileged */
0df3a240	174	if (!privileged) {
0df3a240	175	debug("restore_uid: (unprivileged)");
63bd8c36	176	return;
0df3a240	177	}
63bd8c36	178	if (!temporarily_use_uid_effective)
63bd8c36	179	fatal("restore_uid: temporarily_use_uid not effective");
0096ac62	180
0096ac62	181	#ifdef SAVED_IDS_WORK_WITH_SETEUID
13979d47	182	debug("restore_uid: %u/%u", (u_int)saved_euid, (u_int)saved_egid);
a3626e12	183	/* Set the effective uid back to the saved privileged uid. */
5260325f	184	if (seteuid(saved_euid) < 0)
caa49784	185	fatal("seteuid %u: %.100s", (u_int)saved_euid, strerror(errno));
0096ac62	186	if (setegid(saved_egid) < 0)
caa49784	187	fatal("setegid %u: %.100s", (u_int)saved_egid, strerror(errno));
0096ac62	188	#else /* SAVED_IDS_WORK_WITH_SETEUID */
	189	/*
	190	* We are unable to restore the real uid to its unprivileged value.
	191	* Propagate the real uid (usually more privileged) to effective uid
	192	* as well.
	193	*/
	194	setuid(getuid());
	195	setgid(getgid());
	196	#endif /* SAVED_IDS_WORK_WITH_SETEUID */
	197
d98d029a	198	if (setgroups(saved_egroupslen, saved_egroups) < 0)
63bd8c36	199	fatal("setgroups: %.100s", strerror(errno));
63bd8c36	200	temporarily_use_uid_effective = 0;
8efc0c15	201	}
8efc0c15	202
5260325f	203	/*
	204	* Permanently sets all uids to the given uid. This cannot be
	205	* called while temporarily_use_uid is effective.
	206	*/
6ae2364d	207	void
63bd8c36	208	permanently_set_uid(struct passwd *pw)
8efc0c15	209	{
688eed4a	210	uid_t old_uid = getuid();
	211	gid_t old_gid = getgid();
	212
82aeee5d	213	if (pw == NULL)
82aeee5d	214	fatal("permanently_set_uid: no user given");
63bd8c36	215	if (temporarily_use_uid_effective)
95f20fe8	216	fatal("permanently_set_uid: temporarily_use_uid effective");
0df3a240	217	debug("permanently_set_uid: %u/%u", (u_int)pw->pw_uid,
0df3a240	218	(u_int)pw->pw_gid);
688eed4a	219
9a3fe0e2	220	#if defined(HAVE_SETRESGID) && !defined(BROKEN_SETRESGID)
688eed4a	221	if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) < 0)
688eed4a	222	fatal("setresgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
3b8dff69	223	#elif defined(HAVE_SETREGID) && !defined(BROKEN_SETREGID)
688eed4a	224	if (setregid(pw->pw_gid, pw->pw_gid) < 0)
	225	fatal("setregid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
	226	#else
fa5120a0	227	if (setegid(pw->pw_gid) < 0)
fa5120a0	228	fatal("setegid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
63bd8c36	229	if (setgid(pw->pw_gid) < 0)
caa49784	230	fatal("setgid %u: %.100s", (u_int)pw->pw_gid, strerror(errno));
688eed4a	231	#endif
688eed4a	232
9a3fe0e2	233	#if defined(HAVE_SETRESUID) && !defined(BROKEN_SETRESUID)
688eed4a	234	if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) < 0)
688eed4a	235	fatal("setresuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
3b8dff69	236	#elif defined(HAVE_SETREUID) && !defined(BROKEN_SETREUID)
f5db6a03	237	if (setreuid(pw->pw_uid, pw->pw_uid) < 0)
f5db6a03	238	fatal("setreuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	239	#else
688eed4a	240	# ifndef SETEUID_BREAKS_SETUID
fa5120a0	241	if (seteuid(pw->pw_uid) < 0)
fa5120a0	242	fatal("seteuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	243	# endif
a3626e12	244	if (setuid(pw->pw_uid) < 0)
caa49784	245	fatal("setuid %u: %.100s", (u_int)pw->pw_uid, strerror(errno));
688eed4a	246	#endif
688eed4a	247
8f817407	248	#ifndef HAVE_CYGWIN
688eed4a	249	/* Try restoration of GID if changed (test clearing of saved gid) */
8f817407	250	if (old_gid != pw->pw_gid && pw->pw_uid != 0 &&
688eed4a	251	(setgid(old_gid) != -1 \|\| setegid(old_gid) != -1))
f5db6a03	252	fatal("%s: was able to restore old [e]gid", __func__);
8f817407	253	#endif
688eed4a	254
	255	/* Verify GID drop was successful */
	256	if (getgid() != pw->pw_gid \|\| getegid() != pw->pw_gid) {
aff51935	257	fatal("%s: egid incorrect gid:%u egid:%u (should be %u)",
aff51935	258	__func__, (u_int)getgid(), (u_int)getegid(),
688eed4a	259	(u_int)pw->pw_gid);
	260	}
	261
51e7d820	262	#ifndef HAVE_CYGWIN
688eed4a	263	/* Try restoration of UID if changed (test clearing of saved uid) */
aff51935	264	if (old_uid != pw->pw_uid &&
688eed4a	265	(setuid(old_uid) != -1 \|\| seteuid(old_uid) != -1))
f5db6a03	266	fatal("%s: was able to restore old [e]uid", __func__);
51e7d820	267	#endif
688eed4a	268
	269	/* Verify UID drop was successful */
	270	if (getuid() != pw->pw_uid \|\| geteuid() != pw->pw_uid) {
aff51935	271	fatal("%s: euid incorrect uid:%u euid:%u (should be %u)",
aff51935	272	__func__, (u_int)getuid(), (u_int)geteuid(),
688eed4a	273	(u_int)pw->pw_uid);
688eed4a	274	}
8efc0c15	275	}