2 * Copyright (c) 1999 - 2003 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of KTH nor the names of its contributors may be
18 * used to endorse or promote products derived from this software without
19 * specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY KTH AND ITS CONTRIBUTORS ``AS IS'' AND ANY
22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KTH OR ITS CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
35 RCSID("$Id: su.c,v 1.26.2.1 2003/05/06 12:06:44 joda Exp $");
53 #include "crypto-headers.h"
66 #define _PATH_DEFPATH "/usr/bin:/bin"
70 #define _PATH_BSHELL "/bin/sh"
73 int kerberos_flag = 1;
77 char *kerberos_instance = "root";
83 struct getargs args[] = {
84 { "kerberos", 'K', arg_negative_flag, &kerberos_flag,
85 "don't use kerberos" },
86 { NULL, 'f', arg_flag, &csh_f_flag,
87 "don't read .cshrc" },
88 { "full", 'l', arg_flag, &full_login,
89 "simulate full login" },
90 { NULL, 'm', arg_flag, &env_flag,
91 "leave environment unmodified" },
92 { "instance", 'i', arg_string, &kerberos_instance,
93 "root instance to use" },
94 { "command", 'c', arg_string, &cmd,
95 "command to execute" },
96 { "help", 'h', arg_flag, &help_flag },
97 { "version", 0, arg_flag, &version_flag },
104 arg_printusage (args,
105 sizeof(args)/sizeof(*args),
107 "[login [shell arguments]]");
112 free_info(struct passwd *p)
121 static struct passwd*
122 dup_info(const struct passwd *pwd)
126 info = malloc(sizeof(*info));
129 info->pw_name = strdup(pwd->pw_name);
130 info->pw_passwd = strdup(pwd->pw_passwd);
131 info->pw_uid = pwd->pw_uid;
132 info->pw_gid = pwd->pw_gid;
133 info->pw_dir = strdup(pwd->pw_dir);
134 info->pw_shell = strdup(pwd->pw_shell);
135 if(info->pw_name == NULL || info->pw_passwd == NULL ||
136 info->pw_dir == NULL || info->pw_shell == NULL) {
143 #if defined(KRB4) || defined(KRB5)
148 #define TKT_ROOT "/tmp/tkt"
153 snprintf(tkfile, sizeof(tkfile), "%s_XXXXXX", TKT_ROOT);
154 fd = mkstemp(tkfile);
158 krb_set_tkt_string(tkfile);
164 static krb5_context context;
165 static krb5_ccache ccache;
168 krb5_verify(const struct passwd *login_info,
169 const struct passwd *su_info,
170 const char *kerberos_instance)
174 char *login_name = NULL;
176 #if defined(HAVE_GETLOGIN) && !defined(POSIX_GETLOGIN)
177 login_name = getlogin();
179 ret = krb5_init_context (&context);
182 warnx("krb5_init_context failed: %d", ret);
187 if (login_name == NULL || strcmp (login_name, "root") == 0)
188 login_name = login_info->pw_name;
189 if (strcmp (su_info->pw_name, "root") == 0)
190 ret = krb5_make_principal(context, &p, NULL,
195 ret = krb5_make_principal(context, &p, NULL,
201 if(su_info->pw_uid != 0 || krb5_kuserok(context, p, su_info->pw_name)) {
202 ret = krb5_cc_gen_new(context, &krb5_mcc_ops, &ccache);
205 krb5_warn(context, ret, "krb5_cc_gen_new");
207 krb5_free_principal (context, p);
210 ret = krb5_verify_user_lrealm(context, p, ccache, NULL, TRUE, NULL);
211 krb5_free_principal (context, p);
213 krb5_cc_destroy(context, ccache);
215 case KRB5_LIBOS_PWDINTR :
217 case KRB5KRB_AP_ERR_BAD_INTEGRITY:
218 case KRB5KRB_AP_ERR_MODIFIED:
219 krb5_warnx(context, "Password incorrect");
222 krb5_warn(context, ret, "krb5_verify_user");
229 krb5_free_principal (context, p);
234 krb5_start_session(void)
240 ret = krb5_cc_gen_new(context, &krb5_fcc_ops, &ccache2);
242 krb5_cc_destroy(context, ccache);
246 ret = krb5_cc_copy_cache(context, ccache, ccache2);
248 asprintf(&cc_name, "%s:%s", krb5_cc_get_type(context, ccache2),
249 krb5_cc_get_name(context, ccache2));
250 esetenv("KRB5CCNAME", cc_name, 1);
252 /* we want to export this even if we don't directly support KRB4 */
254 esetenv("KRBTKFILE", tkfile, 1);
259 krb5_afslog(context, ccache2, NULL, NULL);
262 krb5_cc_close(context, ccache2);
263 krb5_cc_destroy(context, ccache);
271 krb_verify(const struct passwd *login_info,
272 const struct passwd *su_info,
273 const char *kerberos_instance)
276 char *login_name = NULL;
277 char *name, *instance, realm[REALM_SZ];
279 #if defined(HAVE_GETLOGIN) && !defined(POSIX_GETLOGIN)
280 login_name = getlogin();
283 ret = krb_get_lrealm(realm, 1);
285 if (login_name == NULL || strcmp (login_name, "root") == 0)
286 login_name = login_info->pw_name;
287 if (strcmp (su_info->pw_name, "root") == 0) {
289 instance = (char*)kerberos_instance;
291 name = su_info->pw_name;
295 if(su_info->pw_uid != 0 ||
296 krb_kuserok(name, instance, realm, su_info->pw_name) == 0) {
301 krb_unparse_name_long (name, instance, realm));
302 if (des_read_pw_string (password, sizeof (password), prompt, 0)) {
303 memset (password, 0, sizeof (password));
308 if (strlen(password) == 0)
309 return (1); /* Empty passwords are not allowed */
311 setuid(geteuid()); /* need to run as root here */
312 ret = krb_verify_user(name, instance, realm, password,
313 KRB_VERIFY_SECURE, NULL);
314 memset(password, 0, sizeof(password));
317 warnx("%s", krb_get_err_text(ret));
320 chown (tkt_string(), su_info->pw_uid, su_info->pw_gid);
328 krb_start_session(void)
330 esetenv("KRBTKFILE", tkfile, 1);
333 if(k_hasafs() && k_setpag() == 0)
334 krb_afslog(NULL, NULL);
341 verify_unix(struct passwd *su)
347 if(su->pw_passwd != NULL && *su->pw_passwd != '\0') {
348 snprintf(prompt, sizeof(prompt), "%s's password: ", su->pw_name);
349 r = des_read_pw_string(pw_buf, sizeof(pw_buf), prompt, 0);
352 pw = crypt(pw_buf, su->pw_passwd);
353 memset(pw_buf, 0, sizeof(pw_buf));
354 if(strcmp(pw, su->pw_passwd) != 0)
361 main(int argc, char **argv)
365 struct passwd *su_info;
366 struct passwd *login_info;
373 int kerberos_error=1;
375 setprogname (argv[0]);
377 if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &optind))
380 for (i=0; i < optind; i++)
381 if (strcmp(argv[i], "-") == 0) {
395 su_user = argv[optind++];
397 pwd = k_getpwnam(su_user);
399 errx (1, "unknown login %s", su_user);
400 if (pwd->pw_uid == 0 && strcmp ("root", su_user) != 0) {
401 syslog (LOG_ALERT, "NIS attack, user %s has uid 0", su_user);
402 errx (1, "unknown login %s", su_user);
404 su_info = dup_info(pwd);
406 errx (1, "malloc: out of memory");
408 pwd = getpwuid(getuid());
410 errx(1, "who are you?");
411 login_info = dup_info(pwd);
412 if (login_info == NULL)
413 errx (1, "malloc: out of memory");
415 shell = login_info->pw_shell;
417 shell = su_info->pw_shell;
418 if(shell == NULL || *shell == '\0')
419 shell = _PATH_BSHELL;
423 if(kerberos_flag && ok == 0 &&
424 (kerberos_error=krb5_verify(login_info, su_info, kerberos_instance)) == 0)
428 if(kerberos_flag && ok == 0 &&
429 (kerberos_error = krb_verify(login_info, su_info, kerberos_instance)) == 0)
433 if(ok == 0 && login_info->pw_uid && verify_unix(su_info) != 0) {
442 sp = getspnam(su_info->pw_name);
444 today = time(0)/(24L * 60 * 60);
445 if (sp->sp_expire > 0) {
446 if (today >= sp->sp_expire) {
447 if (login_info->pw_uid)
448 errx(1,"Your account has expired.");
450 printf("Your account has expired.");
452 else if (sp->sp_expire - today < 14)
453 printf("Your account will expire in %d days.\n",
454 (int)(sp->sp_expire - today));
456 if (sp->sp_max > 0) {
457 if (today >= sp->sp_lstchg + sp->sp_max) {
458 if (login_info->pw_uid)
459 errx(1,"Your password has expired. Choose a new one.");
461 printf("Your password has expired. Choose a new one.");
463 else if (today >= sp->sp_lstchg + sp->sp_max - sp->sp_warn)
464 printf("Your account will expire in %d days.\n",
465 (int)(sp->sp_lstchg + sp->sp_max -today));
471 char *tty = ttyname (STDERR_FILENO);
472 syslog (LOG_NOTICE | LOG_AUTH, tty ? "%s to %s" : "%s to %s on %s",
473 login_info->pw_name, su_info->pw_name, tty);
479 char *t = getenv ("TERM");
481 environ = malloc (10 * sizeof (char *));
485 esetenv ("PATH", _PATH_DEFPATH, 1);
487 esetenv ("TERM", t, 1);
488 if (chdir (su_info->pw_dir) < 0)
489 errx (1, "no directory");
491 if (full_login || su_info->pw_uid)
492 esetenv ("USER", su_info->pw_name, 1);
493 esetenv("HOME", su_info->pw_dir, 1);
494 esetenv("SHELL", shell, 1);
502 p = strrchr(shell, '/');
508 if (strcmp(p, "csh") != 0)
511 args = malloc(((cmd ? 2 : 0) + 1 + argc - optind + 1 + csh_f_flag) * sizeof(*args));
516 asprintf(&args[i++], "-%s", p);
527 for (argv += optind; *argv; ++argv)
531 if(setgid(su_info->pw_gid) < 0)
533 if (initgroups (su_info->pw_name, su_info->pw_gid) < 0)
534 err (1, "initgroups");
535 if(setuid(su_info->pw_uid) < 0
536 || (su_info->pw_uid != 0 && setuid(0) == 0))
541 krb5_start_session();