[unix-history] / usr.bin / su / su.c

/*
 * Copyright (c) 1988 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)su.c	5.26 (Berkeley) 7/6/91";
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <syslog.h>
#include <stdio.h>
#include <pwd.h>
#include <grp.h>
#include <string.h>
#include <unistd.h>
#include <paths.h>

#ifdef KERBEROS
#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>
#include <netdb.h>

#define	ARGSTR	"-Kflm"

int use_kerberos = 1;
#else
#define	ARGSTR	"-flm"
#endif

main(argc, argv)
	int argc;
	char **argv;
{
	extern char **environ;
	extern int errno, optind;
	register struct passwd *pwd;
	register char *p, **g;
	struct group *gr;
	uid_t ruid, getuid();
	int asme, ch, asthem, fastlogin, prio;
	enum { UNSET, YES, NO } iscsh = UNSET;
	char *user, *shell, *username, *cleanenv[2], *nargv[4], **np;
	char shellbuf[MAXPATHLEN];
	char *crypt(), *getpass(), *getenv(), *getlogin(), *ontty();

	np = &nargv[3];
	*np-- = NULL;
	asme = asthem = fastlogin = 0;
	while ((ch = getopt(argc, argv, ARGSTR)) != EOF)
		switch((char)ch) {
#ifdef KERBEROS
		case 'K':
			use_kerberos = 0;
			break;
#endif
		case 'f':
			fastlogin = 1;
			break;
		case '-':
		case 'l':
			asme = 0;
			asthem = 1;
			break;
		case 'm':
			asme = 1;
			asthem = 0;
			break;
		case '?':
		default:
			(void)fprintf(stderr, "usage: su [%s] [login]\n",
			    ARGSTR);
			exit(1);
		}
	argv += optind;

	errno = 0;
	prio = getpriority(PRIO_PROCESS, 0);
	if (errno)
		prio = 0;
	(void)setpriority(PRIO_PROCESS, 0, -2);
	openlog("su", LOG_CONS, 0);

	/* get current login name and shell */
	ruid = getuid();
	username = getlogin();
	if (username == NULL || (pwd = getpwnam(username)) == NULL ||
	    pwd->pw_uid != ruid)
		pwd = getpwuid(ruid);
	if (pwd == NULL) {
		fprintf(stderr, "su: who are you?\n");
		exit(1);
	}
	username = strdup(pwd->pw_name);
	if (asme)
		if (pwd->pw_shell && *pwd->pw_shell)
			shell = strcpy(shellbuf,  pwd->pw_shell);
		else {
			shell = _PATH_BSHELL;
			iscsh = NO;
		}

	/* get target login information, default to root */
	user = *argv ? *argv : "root";
	if ((pwd = getpwnam(user)) == NULL) {
		fprintf(stderr, "su: unknown login %s\n", user);
		exit(1);
	}

	if (ruid) {
#ifdef KERBEROS
	    if (!use_kerberos || kerberos(username, user, pwd->pw_uid))
#endif
	    {
		/* only allow those in group zero to su to root. */
		if (pwd->pw_uid == 0 && (gr = getgrgid((gid_t)0)))
			for (g = gr->gr_mem;; ++g) {
				if (!*g) {
					(void)fprintf(stderr,
			    "su: you are not in the correct group to su %s.\n",
					    user);
					exit(1);
				}
				if (!strcmp(username, *g))
					break;
		}
		/* if target requires a password, verify it */
		if (*pwd->pw_passwd) {
			p = getpass("Password:");
			if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) {
				fprintf(stderr, "Sorry\n");
				syslog(LOG_AUTH|LOG_WARNING,
					"BAD SU %s to %s%s", username,
					user, ontty());
				exit(1);
			}
		}
	    }
	}

	if (asme) {
		/* if asme and non-standard target shell, must be root */
		if (!chshell(pwd->pw_shell) && ruid) {
			(void)fprintf(stderr,
				"su: permission denied (shell).\n");
			exit(1);
		}
	} else if (pwd->pw_shell && *pwd->pw_shell) {
		shell = pwd->pw_shell;
		iscsh = UNSET;
	} else {
		shell = _PATH_BSHELL;
		iscsh = NO;
	}

	/* if we're forking a csh, we want to slightly muck the args */
	if (iscsh == UNSET) {
		if (p = rindex(shell, '/'))
			++p;
		else
			p = shell;
		iscsh = strcmp(p, "csh") ? NO : YES;
	}

	/* set permissions */
	if (setgid(pwd->pw_gid) < 0) {
		perror("su: setgid");
		exit(1);
	}
	if (initgroups(user, pwd->pw_gid)) {
		(void)fprintf(stderr, "su: initgroups failed.\n");
		exit(1);
	}
	if (setuid(pwd->pw_uid) < 0) {
		perror("su: setuid");
		exit(1);
	}

	if (!asme) {
		if (asthem) {
			p = getenv("TERM");
			cleanenv[0] = _PATH_DEFPATH;
			cleanenv[1] = NULL;
			environ = cleanenv;
			(void)setenv("TERM", p, 1);
			if (chdir(pwd->pw_dir) < 0) {
				fprintf(stderr, "su: no directory\n");
				exit(1);
			}
		}
		if (asthem || pwd->pw_uid)
			(void)setenv("USER", pwd->pw_name, 1);
		(void)setenv("HOME", pwd->pw_dir, 1);
		(void)setenv("SHELL", shell, 1);
	}

	if (iscsh == YES) {
		if (fastlogin)
			*np-- = "-f";
		if (asme)
			*np-- = "-m";
	}

	/* csh strips the first character... */
	*np = asthem ? "-su" : iscsh == YES ? "_su" : "su";

	if (ruid != 0)
		syslog(LOG_NOTICE|LOG_AUTH, "%s to %s%s",
		    username, user, ontty());

	(void)setpriority(PRIO_PROCESS, 0, prio);

	execv(shell, np);
	(void)fprintf(stderr, "su: %s not found.\n", shell);
	exit(1);
}

chshell(sh)
	char *sh;
{
	register char *cp;
	char *getusershell();

	while ((cp = getusershell()) != NULL)
		if (!strcmp(cp, sh))
			return (1);
	return (0);
}

char *
ontty()
{
	char *p, *ttyname();
	static char buf[MAXPATHLEN + 4];

	buf[0] = 0;
	if (p = ttyname(STDERR_FILENO))
		sprintf(buf, " on %s", p);
	return (buf);
}

#ifdef KERBEROS
kerberos(username, user, uid)
	char *username, *user;
	int uid;
{
	extern char *krb_err_txt[];
	KTEXT_ST ticket;
	AUTH_DAT authdata;
	struct hostent *hp;
	register char *p;
	int kerno;
	u_long faddr;
	char lrealm[REALM_SZ], krbtkfile[MAXPATHLEN];
	char hostname[MAXHOSTNAMELEN], savehost[MAXHOSTNAMELEN];
	char *ontty(), *krb_get_phost();

	if (krb_get_lrealm(lrealm, 1) != KSUCCESS)
		return (1);
	if (koktologin(username, lrealm, user) && !uid) {
		(void)fprintf(stderr, "kerberos su: not in %s's ACL.\n", user);
		return (1);
	}
	(void)sprintf(krbtkfile, "%s_%s_%d", TKT_ROOT, user, getuid());

	(void)setenv("KRBTKFILE", krbtkfile, 1);
	(void)krb_set_tkt_string(krbtkfile);
	/*
	 * Set real as well as effective ID to 0 for the moment,
	 * to make the kerberos library do the right thing.
	 */
	if (setuid(0) < 0) {
		perror("su: setuid");
		return (1);
	}

	/*
	 * Little trick here -- if we are su'ing to root,
	 * we need to get a ticket for "xxx.root", where xxx represents
	 * the name of the person su'ing.  Otherwise (non-root case),
	 * we need to get a ticket for "yyy.", where yyy represents
	 * the name of the person being su'd to, and the instance is null
	 *
	 * We should have a way to set the ticket lifetime,
	 * with a system default for root.
	 */
	kerno = krb_get_pw_in_tkt((uid == 0 ? username : user),
		(uid == 0 ? "root" : ""), lrealm,
	    	"krbtgt", lrealm, DEFAULT_TKT_LIFE, 0);

	if (kerno != KSUCCESS) {
		if (kerno == KDC_PR_UNKNOWN) {
			fprintf(stderr, "principal unknown: %s.%s@%s\n",
				(uid == 0 ? username : user),
				(uid == 0 ? "root" : ""), lrealm);
			return (1);
		}
		(void)fprintf(stderr, "su: unable to su: %s\n",
		    krb_err_txt[kerno]);
		syslog(LOG_NOTICE|LOG_AUTH,
		    "BAD Kerberos SU: %s to %s%s: %s",
		    username, user, ontty(), krb_err_txt[kerno]);
		return (1);
	}

	if (chown(krbtkfile, uid, -1) < 0) {
		perror("su: chown:");
		(void)unlink(krbtkfile);
		return (1);
	}

	(void)setpriority(PRIO_PROCESS, 0, -2);

	if (gethostname(hostname, sizeof(hostname)) == -1) {
		perror("su: gethostname");
		dest_tkt();
		return (1);
	}

	(void)strncpy(savehost, krb_get_phost(hostname), sizeof(savehost));
	savehost[sizeof(savehost) - 1] = '\0';

	kerno = krb_mk_req(&ticket, "rcmd", savehost, lrealm, 33);

	if (kerno == KDC_PR_UNKNOWN) {
		(void)fprintf(stderr, "Warning: TGT not verified.\n");
		syslog(LOG_NOTICE|LOG_AUTH,
		    "%s to %s%s, TGT not verified (%s); %s.%s not registered?",
		    username, user, ontty(), krb_err_txt[kerno],
		    "rcmd", savehost);
	} else if (kerno != KSUCCESS) {
		(void)fprintf(stderr, "Unable to use TGT: %s\n",
		    krb_err_txt[kerno]);
		syslog(LOG_NOTICE|LOG_AUTH, "failed su: %s to %s%s: %s",
		    username, user, ontty(), krb_err_txt[kerno]);
		dest_tkt();
		return (1);
	} else {
		if (!(hp = gethostbyname(hostname))) {
			(void)fprintf(stderr, "su: can't get addr of %s\n",
			    hostname);
			dest_tkt();
			return (1);
		}
		(void)bcopy((char *)hp->h_addr, (char *)&faddr, sizeof(faddr));

		if ((kerno = krb_rd_req(&ticket, "rcmd", savehost, faddr,
		    &authdata, "")) != KSUCCESS) {
			(void)fprintf(stderr,
			    "su: unable to verify rcmd ticket: %s\n",
			    krb_err_txt[kerno]);
			syslog(LOG_NOTICE|LOG_AUTH,
			    "failed su: %s to %s%s: %s", username,
			     user, ontty(), krb_err_txt[kerno]);
			dest_tkt();
			return (1);
		}
	}
	return (0);
}

koktologin(name, realm, toname)
	char *name, *realm, *toname;
{
	register AUTH_DAT *kdata;
	AUTH_DAT kdata_st;

	kdata = &kdata_st;
	bzero((caddr_t) kdata, sizeof(*kdata));
	(void)strcpy(kdata->pname, name);
	(void)strcpy(kdata->pinst,
	    ((strcmp(toname, "root") == 0) ? "root" : ""));
	(void)strcpy(kdata->prealm, realm);
	return (kuserok(kdata, toname));
}
#endif
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1988 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#ifndef lint
	35	char copyright[] =
	36	"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
	37	All rights reserved.\n";
	38	#endif /* not lint */
	39
	40	#ifndef lint
	41	static char sccsid[] = "@(#)su.c 5.26 (Berkeley) 7/6/91";
	42	#endif /* not lint */
	43
	44	#include <sys/param.h>
	45	#include <sys/time.h>
	46	#include <sys/resource.h>
	47	#include <syslog.h>
	48	#include <stdio.h>
	49	#include <pwd.h>
	50	#include <grp.h>
	51	#include <string.h>
	52	#include <unistd.h>
	53	#include <paths.h>
	54
	55	#ifdef KERBEROS
	56	#include <kerberosIV/des.h>
	57	#include <kerberosIV/krb.h>
	58	#include <netdb.h>
	59
	60	#define ARGSTR "-Kflm"
	61
	62	int use_kerberos = 1;
	63	#else
	64	#define ARGSTR "-flm"
65	#endif
66
67	main(argc, argv)
68	int argc;
69	char **argv;
70	{
71	extern char **environ;
72	extern int errno, optind;
73	register struct passwd *pwd;
74	register char p, *g;
75	struct group *gr;
76	uid_t ruid, getuid();
77	int asme, ch, asthem, fastlogin, prio;
78	enum { UNSET, YES, NO } iscsh = UNSET;
79	char user, shell, username, cleanenv[2], nargv[4], *np;
80	char shellbuf[MAXPATHLEN];
81	char crypt(), getpass(), getenv(), getlogin(), *ontty();
82
83	np = &nargv[3];
84	*np-- = NULL;
85	asme = asthem = fastlogin = 0;
86	while ((ch = getopt(argc, argv, ARGSTR)) != EOF)
87	switch((char)ch) {
88	#ifdef KERBEROS
89	case 'K':
90	use_kerberos = 0;
91	break;
92	#endif
93	case 'f':
94	fastlogin = 1;
95	break;
96	case '-':
97	case 'l':
98	asme = 0;
99	asthem = 1;
100	break;
101	case 'm':
102	asme = 1;
103	asthem = 0;
104	break;
105	case '?':
106	default:
107	(void)fprintf(stderr, "usage: su [%s] [login]\n",
108	ARGSTR);
109	exit(1);
110	}
111	argv += optind;
112
113	errno = 0;
114	prio = getpriority(PRIO_PROCESS, 0);
115	if (errno)
116	prio = 0;
117	(void)setpriority(PRIO_PROCESS, 0, -2);
118	openlog("su", LOG_CONS, 0);
119
120	/* get current login name and shell */
121	ruid = getuid();
122	username = getlogin();
123	if (username == NULL \|\| (pwd = getpwnam(username)) == NULL \|\|
124	pwd->pw_uid != ruid)
125	pwd = getpwuid(ruid);
126	if (pwd == NULL) {
127	fprintf(stderr, "su: who are you?\n");
128	exit(1);
129	}
130	username = strdup(pwd->pw_name);
131	if (asme)
132	if (pwd->pw_shell && *pwd->pw_shell)
133	shell = strcpy(shellbuf, pwd->pw_shell);
134	else {
135	shell = _PATH_BSHELL;
136	iscsh = NO;
137	}
138
139	/* get target login information, default to root */
140	user = argv ? argv : "root";
141	if ((pwd = getpwnam(user)) == NULL) {
142	fprintf(stderr, "su: unknown login %s\n", user);
143	exit(1);
144	}
145
146	if (ruid) {
147	#ifdef KERBEROS
148	if (!use_kerberos \|\| kerberos(username, user, pwd->pw_uid))
149	#endif
150	{
151	/* only allow those in group zero to su to root. */
152	if (pwd->pw_uid == 0 && (gr = getgrgid((gid_t)0)))
153	for (g = gr->gr_mem;; ++g) {
154	if (!*g) {
155	(void)fprintf(stderr,
156	"su: you are not in the correct group to su %s.\n",
157	user);
158	exit(1);
159	}
160	if (!strcmp(username, *g))
161	break;
162	}
163	/* if target requires a password, verify it */
164	if (*pwd->pw_passwd) {
165	p = getpass("Password:");
15637ed4	166	if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) {
15637ed4 RG	167	fprintf(stderr, "Sorry\n");
	168	syslog(LOG_AUTH\|LOG_WARNING,
	169	"BAD SU %s to %s%s", username,
	170	user, ontty());
	171	exit(1);
	172	}
	173	}
	174	}
	175	}
	176
	177	if (asme) {
	178	/* if asme and non-standard target shell, must be root */
	179	if (!chshell(pwd->pw_shell) && ruid) {
	180	(void)fprintf(stderr,
	181	"su: permission denied (shell).\n");
	182	exit(1);
	183	}
	184	} else if (pwd->pw_shell && *pwd->pw_shell) {
	185	shell = pwd->pw_shell;
	186	iscsh = UNSET;
	187	} else {
	188	shell = _PATH_BSHELL;
	189	iscsh = NO;
	190	}
	191
	192	/* if we're forking a csh, we want to slightly muck the args */
	193	if (iscsh == UNSET) {
	194	if (p = rindex(shell, '/'))
	195	++p;
	196	else
	197	p = shell;
	198	iscsh = strcmp(p, "csh") ? NO : YES;
	199	}
	200
	201	/* set permissions */
	202	if (setgid(pwd->pw_gid) < 0) {
	203	perror("su: setgid");
	204	exit(1);
	205	}
	206	if (initgroups(user, pwd->pw_gid)) {
	207	(void)fprintf(stderr, "su: initgroups failed.\n");
	208	exit(1);
	209	}
	210	if (setuid(pwd->pw_uid) < 0) {
	211	perror("su: setuid");
	212	exit(1);
	213	}
	214
	215	if (!asme) {
	216	if (asthem) {
	217	p = getenv("TERM");
	218	cleanenv[0] = _PATH_DEFPATH;
	219	cleanenv[1] = NULL;
	220	environ = cleanenv;
	221	(void)setenv("TERM", p, 1);
	222	if (chdir(pwd->pw_dir) < 0) {
	223	fprintf(stderr, "su: no directory\n");
	224	exit(1);
	225	}
	226	}
	227	if (asthem \|\| pwd->pw_uid)
	228	(void)setenv("USER", pwd->pw_name, 1);
	229	(void)setenv("HOME", pwd->pw_dir, 1);
	230	(void)setenv("SHELL", shell, 1);
231	}
232
233	if (iscsh == YES) {
234	if (fastlogin)
235	*np-- = "-f";
236	if (asme)
237	*np-- = "-m";
238	}
239
240	/* csh strips the first character... */
241	*np = asthem ? "-su" : iscsh == YES ? "_su" : "su";
242
243	if (ruid != 0)
244	syslog(LOG_NOTICE\|LOG_AUTH, "%s to %s%s",
245	username, user, ontty());
246
247	(void)setpriority(PRIO_PROCESS, 0, prio);
248
249	execv(shell, np);
250	(void)fprintf(stderr, "su: %s not found.\n", shell);
251	exit(1);
252	}
253
254	chshell(sh)
255	char *sh;
256	{
257	register char *cp;
258	char *getusershell();
259
260	while ((cp = getusershell()) != NULL)
261	if (!strcmp(cp, sh))
262	return (1);
263	return (0);
264	}
265
266	char *
267	ontty()
268	{
269	char p, ttyname();
270	static char buf[MAXPATHLEN + 4];
271
272	buf[0] = 0;
273	if (p = ttyname(STDERR_FILENO))
274	sprintf(buf, " on %s", p);
275	return (buf);
276	}
277
278	#ifdef KERBEROS
279	kerberos(username, user, uid)
280	char username, user;
281	int uid;
282	{
283	extern char *krb_err_txt[];
284	KTEXT_ST ticket;
285	AUTH_DAT authdata;
286	struct hostent *hp;
287	register char *p;
288	int kerno;
289	u_long faddr;
290	char lrealm[REALM_SZ], krbtkfile[MAXPATHLEN];
291	char hostname[MAXHOSTNAMELEN], savehost[MAXHOSTNAMELEN];
292	char ontty(), krb_get_phost();
293
294	if (krb_get_lrealm(lrealm, 1) != KSUCCESS)
295	return (1);
296	if (koktologin(username, lrealm, user) && !uid) {
297	(void)fprintf(stderr, "kerberos su: not in %s's ACL.\n", user);
298	return (1);
299	}
300	(void)sprintf(krbtkfile, "%s_%s_%d", TKT_ROOT, user, getuid());
301
302	(void)setenv("KRBTKFILE", krbtkfile, 1);
303	(void)krb_set_tkt_string(krbtkfile);
304	/*
305	* Set real as well as effective ID to 0 for the moment,
306	* to make the kerberos library do the right thing.
307	*/
308	if (setuid(0) < 0) {
309	perror("su: setuid");
310	return (1);
311	}
312
313	/*
314	* Little trick here -- if we are su'ing to root,
315	* we need to get a ticket for "xxx.root", where xxx represents
316	* the name of the person su'ing. Otherwise (non-root case),
317	* we need to get a ticket for "yyy.", where yyy represents
318	* the name of the person being su'd to, and the instance is null
319	*
320	* We should have a way to set the ticket lifetime,
321	* with a system default for root.
322	*/
323	kerno = krb_get_pw_in_tkt((uid == 0 ? username : user),
324	(uid == 0 ? "root" : ""), lrealm,
325	"krbtgt", lrealm, DEFAULT_TKT_LIFE, 0);
326
327	if (kerno != KSUCCESS) {
328	if (kerno == KDC_PR_UNKNOWN) {
329	fprintf(stderr, "principal unknown: %s.%s@%s\n",
330	(uid == 0 ? username : user),
331	(uid == 0 ? "root" : ""), lrealm);
332	return (1);
333	}
334	(void)fprintf(stderr, "su: unable to su: %s\n",
335	krb_err_txt[kerno]);
336	syslog(LOG_NOTICE\|LOG_AUTH,
337	"BAD Kerberos SU: %s to %s%s: %s",
338	username, user, ontty(), krb_err_txt[kerno]);
339	return (1);
340	}
341
342	if (chown(krbtkfile, uid, -1) < 0) {
343	perror("su: chown:");
344	(void)unlink(krbtkfile);
345	return (1);
346	}
347
348	(void)setpriority(PRIO_PROCESS, 0, -2);
349
350	if (gethostname(hostname, sizeof(hostname)) == -1) {
351	perror("su: gethostname");
352	dest_tkt();
353	return (1);
354	}
355
356	(void)strncpy(savehost, krb_get_phost(hostname), sizeof(savehost));
357	savehost[sizeof(savehost) - 1] = '\0';
358
359	kerno = krb_mk_req(&ticket, "rcmd", savehost, lrealm, 33);
360
361	if (kerno == KDC_PR_UNKNOWN) {
362	(void)fprintf(stderr, "Warning: TGT not verified.\n");
363	syslog(LOG_NOTICE\|LOG_AUTH,
364	"%s to %s%s, TGT not verified (%s); %s.%s not registered?",
365	username, user, ontty(), krb_err_txt[kerno],
366	"rcmd", savehost);
367	} else if (kerno != KSUCCESS) {
368	(void)fprintf(stderr, "Unable to use TGT: %s\n",
369	krb_err_txt[kerno]);
370	syslog(LOG_NOTICE\|LOG_AUTH, "failed su: %s to %s%s: %s",
371	username, user, ontty(), krb_err_txt[kerno]);
372	dest_tkt();
373	return (1);
374	} else {
375	if (!(hp = gethostbyname(hostname))) {
376	(void)fprintf(stderr, "su: can't get addr of %s\n",
377	hostname);
378	dest_tkt();
379	return (1);
380	}
381	(void)bcopy((char )hp->h_addr, (char )&faddr, sizeof(faddr));
382
383	if ((kerno = krb_rd_req(&ticket, "rcmd", savehost, faddr,
384	&authdata, "")) != KSUCCESS) {
385	(void)fprintf(stderr,
386	"su: unable to verify rcmd ticket: %s\n",
387	krb_err_txt[kerno]);
388	syslog(LOG_NOTICE\|LOG_AUTH,
389	"failed su: %s to %s%s: %s", username,
390	user, ontty(), krb_err_txt[kerno]);
391	dest_tkt();
392	return (1);
393	}
394	}
395	return (0);
396	}
397
398	koktologin(name, realm, toname)
399	char name, realm, *toname;
400	{
401	register AUTH_DAT *kdata;
402	AUTH_DAT kdata_st;
403
404	kdata = &kdata_st;
405	bzero((caddr_t) kdata, sizeof(*kdata));
406	(void)strcpy(kdata->pname, name);
407	(void)strcpy(kdata->pinst,
408	((strcmp(toname, "root") == 0) ? "root" : ""));
409	(void)strcpy(kdata->prealm, realm);
410	return (kuserok(kdata, toname));
411	}
412	#endif