xref: /netbsd-src/crypto/external/bsd/heimdal/dist/kpasswd/kpasswdd.c (revision 63aea4bd5b445e491ff0389fe27ec78b3099dba3)
1 /*	$NetBSD: kpasswdd.c,v 1.3 2014/04/24 13:45:34 pettai Exp $	*/
2 
3 /*
4  * Copyright (c) 1997-2005 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "kpasswd_locl.h"
37 __RCSID("NetBSD");
38 
39 #include <kadm5/admin.h>
40 #ifdef HAVE_SYS_UN_H
41 #include <sys/un.h>
42 #endif
43 #include <krb5/hdb.h>
44 #include <kadm5/private.h>
45 
46 static krb5_context context;
47 static krb5_log_facility *log_facility;
48 
49 static struct getarg_strings addresses_str;
50 krb5_addresses explicit_addresses;
51 
52 static sig_atomic_t exit_flag = 0;
53 
54 static void
55 add_one_address (const char *str, int first)
56 {
57     krb5_error_code ret;
58     krb5_addresses tmp;
59 
60     ret = krb5_parse_address (context, str, &tmp);
61     if (ret)
62 	krb5_err (context, 1, ret, "parse_address `%s'", str);
63     if (first)
64 	krb5_copy_addresses(context, &tmp, &explicit_addresses);
65     else
66 	krb5_append_addresses(context, &explicit_addresses, &tmp);
67     krb5_free_addresses (context, &tmp);
68 }
69 
70 static void
71 send_reply (int s,
72 	    struct sockaddr *sa,
73 	    int sa_size,
74 	    krb5_data *ap_rep,
75 	    krb5_data *rest)
76 {
77     struct msghdr msghdr;
78     struct iovec iov[3];
79     uint16_t len, ap_rep_len;
80     u_char header[6];
81     u_char *p;
82 
83     if (ap_rep)
84 	ap_rep_len = ap_rep->length;
85     else
86 	ap_rep_len = 0;
87 
88     len = 6 + ap_rep_len + rest->length;
89     p = header;
90     *p++ = (len >> 8) & 0xFF;
91     *p++ = (len >> 0) & 0xFF;
92     *p++ = 0;
93     *p++ = 1;
94     *p++ = (ap_rep_len >> 8) & 0xFF;
95     *p++ = (ap_rep_len >> 0) & 0xFF;
96 
97     memset (&msghdr, 0, sizeof(msghdr));
98     msghdr.msg_name       = (void *)sa;
99     msghdr.msg_namelen    = sa_size;
100     msghdr.msg_iov        = iov;
101     msghdr.msg_iovlen     = sizeof(iov)/sizeof(*iov);
102 #if 0
103     msghdr.msg_control    = NULL;
104     msghdr.msg_controllen = 0;
105 #endif
106 
107     iov[0].iov_base       = (char *)header;
108     iov[0].iov_len        = 6;
109     if (ap_rep_len) {
110 	iov[1].iov_base   = ap_rep->data;
111 	iov[1].iov_len    = ap_rep->length;
112     } else {
113 	iov[1].iov_base   = NULL;
114 	iov[1].iov_len    = 0;
115     }
116     iov[2].iov_base       = rest->data;
117     iov[2].iov_len        = rest->length;
118 
119     if (sendmsg (s, &msghdr, 0) < 0)
120 	krb5_warn (context, errno, "sendmsg");
121 }
122 
123 static int
124 make_result (krb5_data *data,
125 	     uint16_t result_code,
126 	     const char *expl)
127 {
128     krb5_error_code ret;
129     krb5_storage *sp;
130 
131     sp = krb5_storage_emem();
132     if (sp == NULL) goto out;
133     ret = krb5_store_uint16(sp, result_code);
134     if (ret) goto out;
135     ret = krb5_store_stringz(sp, expl);
136     if (ret) goto out;
137     ret = krb5_storage_to_data(sp, data);
138     if (ret) goto out;
139     krb5_storage_free(sp);
140 
141     return 0;
142  out:
143     if (sp)
144 	krb5_storage_free(sp);
145 
146     krb5_warnx (context, "Out of memory generating error reply");
147     return 1;
148 }
149 
150 static void
151 reply_error (krb5_realm realm,
152 	     int s,
153 	     struct sockaddr *sa,
154 	     int sa_size,
155 	     krb5_error_code error_code,
156 	     uint16_t result_code,
157 	     const char *expl)
158 {
159     krb5_error_code ret;
160     krb5_data error_data;
161     krb5_data e_data;
162     krb5_principal server = NULL;
163 
164     if (make_result(&e_data, result_code, expl))
165 	return;
166 
167     if (realm) {
168 	ret = krb5_make_principal (context, &server, realm,
169 				   "kadmin", "changepw", NULL);
170 	if (ret) {
171 	    krb5_data_free (&e_data);
172 	    return;
173 	}
174     }
175 
176     ret = krb5_mk_error (context,
177 			 error_code,
178 			 NULL,
179 			 &e_data,
180 			 NULL,
181 			 server,
182 			 NULL,
183 			 NULL,
184 			 &error_data);
185     if (server)
186 	krb5_free_principal(context, server);
187     krb5_data_free (&e_data);
188     if (ret) {
189 	krb5_warn (context, ret, "Could not even generate error reply");
190 	return;
191     }
192     send_reply (s, sa, sa_size, NULL, &error_data);
193     krb5_data_free (&error_data);
194 }
195 
196 static void
197 reply_priv (krb5_auth_context auth_context,
198 	    int s,
199 	    struct sockaddr *sa,
200 	    int sa_size,
201 	    uint16_t result_code,
202 	    const char *expl)
203 {
204     krb5_error_code ret;
205     krb5_data krb_priv_data;
206     krb5_data ap_rep_data;
207     krb5_data e_data;
208 
209     ret = krb5_mk_rep (context,
210 		       auth_context,
211 		       &ap_rep_data);
212     if (ret) {
213 	krb5_warn (context, ret, "Could not even generate error reply");
214 	return;
215     }
216 
217     if (make_result(&e_data, result_code, expl))
218 	return;
219 
220     ret = krb5_mk_priv (context,
221 			auth_context,
222 			&e_data,
223 			&krb_priv_data,
224 			NULL);
225     krb5_data_free (&e_data);
226     if (ret) {
227 	krb5_warn (context, ret, "Could not even generate error reply");
228 	return;
229     }
230     send_reply (s, sa, sa_size, &ap_rep_data, &krb_priv_data);
231     krb5_data_free (&ap_rep_data);
232     krb5_data_free (&krb_priv_data);
233 }
234 
235 /*
236  * Change the password for `principal', sending the reply back on `s'
237  * (`sa', `sa_size') to `pwd_data'.
238  */
239 
240 static void
241 change (krb5_auth_context auth_context,
242 	krb5_principal admin_principal,
243 	uint16_t version,
244 	int s,
245 	struct sockaddr *sa,
246 	int sa_size,
247 	krb5_data *in_data)
248 {
249     krb5_error_code ret;
250     char *client = NULL, *admin = NULL;
251     const char *pwd_reason;
252     kadm5_config_params conf;
253     void *kadm5_handle = NULL;
254     krb5_principal principal = NULL;
255     krb5_data *pwd_data = NULL;
256     char *tmp;
257     ChangePasswdDataMS chpw;
258 
259     memset (&conf, 0, sizeof(conf));
260     memset(&chpw, 0, sizeof(chpw));
261 
262     if (version == KRB5_KPASSWD_VERS_CHANGEPW) {
263 	ret = krb5_copy_data(context, in_data, &pwd_data);
264 	if (ret) {
265 	    krb5_warn (context, ret, "krb5_copy_data");
266 	    reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
267 			"out out memory copying password");
268 	    return;
269 	}
270 	principal = admin_principal;
271     } else if (version == KRB5_KPASSWD_VERS_SETPW) {
272 	size_t len;
273 
274 	ret = decode_ChangePasswdDataMS(in_data->data, in_data->length,
275 					&chpw, &len);
276 	if (ret) {
277 	    krb5_warn (context, ret, "decode_ChangePasswdDataMS");
278 	    reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
279 			"malformed ChangePasswdData");
280 	    return;
281 	}
282 
283 
284 	ret = krb5_copy_data(context, &chpw.newpasswd, &pwd_data);
285 	if (ret) {
286 	    krb5_warn (context, ret, "krb5_copy_data");
287 	    reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
288 			"out out memory copying password");
289 	    goto out;
290 	}
291 
292 	if (chpw.targname == NULL && chpw.targrealm != NULL) {
293 	    krb5_warn (context, ret, "kadm5_init_with_password_ctx");
294 	    reply_priv (auth_context, s, sa, sa_size,
295 			KRB5_KPASSWD_MALFORMED,
296 			"targrealm but not targname");
297 	    goto out;
298 	}
299 
300 	if (chpw.targname) {
301 	    krb5_principal_data princ;
302 
303 	    princ.name = *chpw.targname;
304 	    princ.realm = *chpw.targrealm;
305 	    if (princ.realm == NULL) {
306 		ret = krb5_get_default_realm(context, &princ.realm);
307 
308 		if (ret) {
309 		    krb5_warnx (context,
310 				"kadm5_init_with_password_ctx: "
311 				"failed to allocate realm");
312 		    reply_priv (auth_context, s, sa, sa_size,
313 				KRB5_KPASSWD_SOFTERROR,
314 				"failed to allocate realm");
315 		    goto out;
316 		}
317 	    }
318 	    ret = krb5_copy_principal(context, &princ, &principal);
319 	    if (*chpw.targrealm == NULL)
320 		free(princ.realm);
321 	    if (ret) {
322 		krb5_warn(context, ret, "krb5_copy_principal");
323 		reply_priv(auth_context, s, sa, sa_size,
324 			   KRB5_KPASSWD_HARDERROR,
325 			   "failed to allocate principal");
326 		goto out;
327 	    }
328 	} else
329 	    principal = admin_principal;
330     } else {
331 	krb5_warnx (context, "kadm5_init_with_password_ctx: unknown proto");
332 	reply_priv (auth_context, s, sa, sa_size,
333 		    KRB5_KPASSWD_HARDERROR,
334 		    "Unknown protocol used");
335 	return;
336     }
337 
338     ret = krb5_unparse_name (context, admin_principal, &admin);
339     if (ret) {
340 	krb5_warn (context, ret, "unparse_name failed");
341 	reply_priv (auth_context, s, sa, sa_size,
342 		    KRB5_KPASSWD_HARDERROR, "out of memory error");
343 	goto out;
344     }
345 
346     conf.realm = principal->realm;
347     conf.mask |= KADM5_CONFIG_REALM;
348 
349     ret = kadm5_init_with_password_ctx(context,
350 				       admin,
351 				       NULL,
352 				       KADM5_ADMIN_SERVICE,
353 				       &conf, 0, 0,
354 				       &kadm5_handle);
355     if (ret) {
356 	krb5_warn (context, ret, "kadm5_init_with_password_ctx");
357 	reply_priv (auth_context, s, sa, sa_size, 2,
358 		    "Internal error");
359 	goto out;
360     }
361 
362     ret = krb5_unparse_name(context, principal, &client);
363     if (ret) {
364 	krb5_warn (context, ret, "unparse_name failed");
365 	reply_priv (auth_context, s, sa, sa_size,
366 		    KRB5_KPASSWD_HARDERROR, "out of memory error");
367 	goto out;
368     }
369 
370     /*
371      * Check password quality if not changing as administrator
372      */
373 
374     if (krb5_principal_compare(context, admin_principal, principal) == TRUE) {
375 
376 	pwd_reason = kadm5_check_password_quality (context, principal,
377 						   pwd_data);
378 	if (pwd_reason != NULL ) {
379 	    krb5_warnx (context,
380 			"%s didn't pass password quality check with error: %s",
381 			client, pwd_reason);
382 	    reply_priv (auth_context, s, sa, sa_size,
383 			KRB5_KPASSWD_SOFTERROR, pwd_reason);
384 	    goto out;
385 	}
386 	krb5_warnx (context, "Changing password for %s", client);
387     } else {
388 	ret = _kadm5_acl_check_permission(kadm5_handle, KADM5_PRIV_CPW,
389 					  principal);
390 	if (ret) {
391 	    krb5_warn (context, ret,
392 		       "Check ACL failed for %s for changing %s password",
393 		       admin, client);
394 	    reply_priv (auth_context, s, sa, sa_size,
395 			KRB5_KPASSWD_HARDERROR, "permission denied");
396 	    goto out;
397 	}
398 	krb5_warnx (context, "%s is changing password for %s", admin, client);
399     }
400 
401     ret = krb5_data_realloc(pwd_data, pwd_data->length + 1);
402     if (ret) {
403 	krb5_warn (context, ret, "malloc: out of memory");
404 	reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_HARDERROR,
405 		    "Internal error");
406 	goto out;
407     }
408     tmp = pwd_data->data;
409     tmp[pwd_data->length - 1] = '\0';
410 
411     ret = kadm5_s_chpass_principal_cond (kadm5_handle, principal, tmp);
412     krb5_free_data (context, pwd_data);
413     pwd_data = NULL;
414     if (ret) {
415 	const char *str = krb5_get_error_message(context, ret);
416 	krb5_warnx(context, "kadm5_s_chpass_principal_cond: %s", str);
417 	reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SOFTERROR,
418 		    str ? str : "Internal error");
419 	krb5_free_error_message(context, str);
420 	goto out;
421     }
422     reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SUCCESS,
423 		"Password changed");
424 out:
425     free_ChangePasswdDataMS(&chpw);
426     if (principal != admin_principal)
427 	krb5_free_principal(context, principal);
428     if (admin)
429 	free(admin);
430     if (client)
431 	free(client);
432     if (pwd_data)
433 	krb5_free_data(context, pwd_data);
434     if (kadm5_handle)
435 	kadm5_destroy (kadm5_handle);
436 }
437 
438 static int
439 verify (krb5_auth_context *auth_context,
440 	krb5_realm *realms,
441 	krb5_keytab keytab,
442 	krb5_ticket **ticket,
443 	krb5_data *out_data,
444 	uint16_t *version,
445 	int s,
446 	struct sockaddr *sa,
447 	int sa_size,
448 	u_char *msg,
449 	size_t len,
450 	krb5_address *client_addr)
451 {
452     krb5_error_code ret;
453     uint16_t pkt_len, pkt_ver, ap_req_len;
454     krb5_data ap_req_data;
455     krb5_data krb_priv_data;
456     krb5_realm *r;
457 
458     /*
459      * Only send an error reply if the request passes basic length
460      * verification.  Otherwise, kpasswdd would reply to every UDP packet,
461      * allowing an attacker to set up a ping-pong DoS attack via a spoofed UDP
462      * packet with a source address of another UDP service that also replies
463      * to every packet.
464      *
465      * Also suppress the error reply if ap_req_len is 0, which indicates
466      * either an invalid request or an error packet.  An error packet may be
467      * the result of a ping-pong attacker pointing us at another kpasswdd.
468      */
469     pkt_len = (msg[0] << 8) | (msg[1]);
470     pkt_ver = (msg[2] << 8) | (msg[3]);
471     ap_req_len = (msg[4] << 8) | (msg[5]);
472     if (pkt_len != len) {
473 	krb5_warnx (context, "Strange len: %ld != %ld",
474 		    (long)pkt_len, (long)len);
475 	return 1;
476     }
477     if (ap_req_len == 0) {
478 	krb5_warnx (context, "Request is error packet (ap_req_len == 0)");
479 	return 1;
480     }
481     if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW &&
482 	pkt_ver != KRB5_KPASSWD_VERS_SETPW) {
483 	krb5_warnx (context, "Bad version (%d)", pkt_ver);
484 	reply_error (NULL, s, sa, sa_size, 0, 1, "Wrong program version");
485 	return 1;
486     }
487     *version = pkt_ver;
488 
489     ap_req_data.data   = msg + 6;
490     ap_req_data.length = ap_req_len;
491 
492     ret = krb5_rd_req (context,
493 		       auth_context,
494 		       &ap_req_data,
495 		       NULL,
496 		       keytab,
497 		       NULL,
498 		       ticket);
499     if (ret) {
500 	krb5_warn (context, ret, "krb5_rd_req");
501 	reply_error (NULL, s, sa, sa_size, ret, 3, "Authentication failed");
502 	return 1;
503     }
504 
505     /* verify realm and principal */
506     for (r = realms; *r != NULL; r++) {
507 	krb5_principal principal;
508 	krb5_boolean same;
509 
510 	ret = krb5_make_principal (context,
511 				   &principal,
512 				   *r,
513 				   "kadmin",
514 				   "changepw",
515 				   NULL);
516 	if (ret)
517 	    krb5_err (context, 1, ret, "krb5_make_principal");
518 
519 	same = krb5_principal_compare(context, principal, (*ticket)->server);
520 	krb5_free_principal(context, principal);
521 	if (same == TRUE)
522 	    break;
523     }
524     if (*r == NULL) {
525 	char *str;
526 	krb5_unparse_name(context, (*ticket)->server, &str);
527 	krb5_warnx (context, "client used not valid principal %s", str);
528 	free(str);
529 	reply_error (NULL, s, sa, sa_size, ret, 1,
530 		     "Bad request");
531 	goto out;
532     }
533 
534     if (strcmp((*ticket)->server->realm, (*ticket)->client->realm) != 0) {
535 	krb5_warnx (context, "server realm (%s) not same a client realm (%s)",
536 		    (*ticket)->server->realm, (*ticket)->client->realm);
537 	reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 1,
538 		     "Bad request");
539 	goto out;
540     }
541 
542     if (!(*ticket)->ticket.flags.initial) {
543 	krb5_warnx (context, "initial flag not set");
544 	reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 1,
545 		     "Bad request");
546 	goto out;
547     }
548     krb_priv_data.data   = msg + 6 + ap_req_len;
549     krb_priv_data.length = len - 6 - ap_req_len;
550 
551     /*
552      * Only enforce client addresses on on tickets with addresses.  If
553      * its addressless, we are guessing its behind NAT and really
554      * can't know this information.
555      */
556 
557     if ((*ticket)->ticket.caddr && (*ticket)->ticket.caddr->len > 0) {
558 	ret = krb5_auth_con_setaddrs (context, *auth_context,
559 				      NULL, client_addr);
560 	if (ret) {
561 	    krb5_warn (context, ret, "krb5_auth_con_setaddr(this)");
562 	    goto out;
563 	}
564     }
565 
566     ret = krb5_rd_priv (context,
567 			*auth_context,
568 			&krb_priv_data,
569 			out_data,
570 			NULL);
571 
572     if (ret) {
573 	krb5_warn (context, ret, "krb5_rd_priv");
574 	reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 3,
575 		     "Bad request");
576 	goto out;
577     }
578     return 0;
579 out:
580     krb5_free_ticket (context, *ticket);
581     ticket = NULL;
582     return 1;
583 }
584 
585 static void
586 process (krb5_realm *realms,
587 	 krb5_keytab keytab,
588 	 int s,
589 	 krb5_address *this_addr,
590 	 struct sockaddr *sa,
591 	 int sa_size,
592 	 u_char *msg,
593 	 int len)
594 {
595     krb5_error_code ret;
596     krb5_auth_context auth_context = NULL;
597     krb5_data out_data;
598     krb5_ticket *ticket;
599     krb5_address other_addr;
600     uint16_t version;
601 
602     memset(&other_addr, 0, sizeof(other_addr));
603     krb5_data_zero (&out_data);
604 
605     ret = krb5_auth_con_init (context, &auth_context);
606     if (ret) {
607 	krb5_warn (context, ret, "krb5_auth_con_init");
608 	return;
609     }
610 
611     krb5_auth_con_setflags (context, auth_context,
612 			    KRB5_AUTH_CONTEXT_DO_SEQUENCE);
613 
614     ret = krb5_sockaddr2address (context, sa, &other_addr);
615     if (ret) {
616 	krb5_warn (context, ret, "krb5_sockaddr2address");
617 	goto out;
618     }
619 
620     ret = krb5_auth_con_setaddrs (context, auth_context, this_addr, NULL);
621     if (ret) {
622 	krb5_warn (context, ret, "krb5_auth_con_setaddr(this)");
623 	goto out;
624     }
625 
626     if (verify (&auth_context, realms, keytab, &ticket, &out_data,
627 		&version, s, sa, sa_size, msg, len, &other_addr) == 0)
628     {
629 	/*
630 	 * We always set the client_addr, to assume that the client
631 	 * can ignore it if it choose to do so (just the server does
632 	 * so for addressless tickets).
633 	 */
634 	ret = krb5_auth_con_setaddrs (context, auth_context,
635 				      this_addr, &other_addr);
636 	if (ret) {
637 	    krb5_warn (context, ret, "krb5_auth_con_setaddr(other)");
638 	    goto out;
639 	}
640 
641 	change (auth_context,
642 		ticket->client,
643 		version,
644 		s,
645 		sa, sa_size,
646 		&out_data);
647 	memset (out_data.data, 0, out_data.length);
648 	krb5_free_ticket (context, ticket);
649     }
650 
651 out:
652     krb5_free_address(context, &other_addr);
653     krb5_data_free(&out_data);
654     krb5_auth_con_free(context, auth_context);
655 }
656 
657 #ifdef INETD_SUPPORT
658 /*
659  * XXX this code relies on getsockname() returning a valid local
660  * address for a "connected" DGRAM socket. This is true for most, but
661  * probably not all systems. For some systems, this could be done
662  * cleaner by using the IP_RECVDSTADDR option + recvmsg().
663  */
664 static int
665 get_local_addr(struct sockaddr *remote, int remlen,
666 	       struct sockaddr *local, socklen_t *loclen)
667 {
668 	int s, ret;
669 
670 	s = socket(remote->sa_family, SOCK_DGRAM, 0);
671 	if (s < 0)
672 		return -1;
673 
674 	if (connect(s, remote, remlen) < 0) {
675 		close(s);
676 		return -1;
677 	}
678 
679 	ret = getsockname(s, local, loclen);
680 	close(s);
681 	return ret;
682 }
683 #endif
684 
685 static int
686 doit (krb5_keytab keytab, int port)
687 {
688     krb5_error_code ret;
689     int *sockets;
690     int maxfd;
691     krb5_realm *realms;
692     krb5_addresses addrs;
693     krb5_address *my_addrp;
694     unsigned n, i;
695     fd_set real_fdset;
696     struct sockaddr_storage __ss;
697     struct sockaddr *sa = (struct sockaddr *)&__ss;
698 #ifdef INETD_SUPPORT
699     int fdz;
700     int from_inetd;
701     socklen_t fromlen;
702     krb5_address my_addr;
703     struct sockaddr_storage __local;
704     struct sockaddr *localsa = (struct sockaddr *)&__local;
705 #endif
706 
707     ret = krb5_get_default_realms(context, &realms);
708     if (ret)
709 	krb5_err (context, 1, ret, "krb5_get_default_realms");
710 
711 #ifdef INETD_SUPPORT
712     fromlen = sizeof __ss;
713     from_inetd = (getsockname(0, sa, &fromlen) == 0);
714 
715     if (!from_inetd) {
716 #endif
717     if (explicit_addresses.len) {
718 	addrs = explicit_addresses;
719     } else {
720 	ret = krb5_get_all_server_addrs (context, &addrs);
721 	if (ret)
722 	    krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
723     }
724     n = addrs.len;
725 
726     sockets = malloc (n * sizeof(*sockets));
727     if (sockets == NULL)
728 	krb5_errx (context, 1, "out of memory");
729     maxfd = -1;
730     FD_ZERO(&real_fdset);
731     for (i = 0; i < n; ++i) {
732 	krb5_socklen_t sa_size = sizeof(__ss);
733 
734 	krb5_addr2sockaddr (context, &addrs.val[i], sa, &sa_size, port);
735 
736 	sockets[i] = socket (sa->sa_family, SOCK_DGRAM, 0);
737 	if (sockets[i] < 0)
738 	    krb5_err (context, 1, errno, "socket");
739 	if (bind (sockets[i], sa, sa_size) < 0) {
740 	    char str[128];
741 	    size_t len;
742 	    int save_errno = errno;
743 
744 	    ret = krb5_print_address (&addrs.val[i], str, sizeof(str), &len);
745 	    if (ret)
746 		strlcpy(str, "unknown address", sizeof(str));
747 	    krb5_warn (context, save_errno, "bind(%s)", str);
748 	    continue;
749 	}
750 	maxfd = max (maxfd, sockets[i]);
751 	if (maxfd >= FD_SETSIZE)
752 	    krb5_errx (context, 1, "fd too large");
753 	FD_SET(sockets[i], &real_fdset);
754     }
755 #ifdef INETD_SUPPORT
756     } else {
757         n = 1;
758         maxfd = 0;
759 	fdz = 0;
760         sockets = &fdz;
761         FD_ZERO(&real_fdset);
762         FD_SET(0, &real_fdset);
763     }
764 #endif
765     if (maxfd == -1)
766 	krb5_errx (context, 1, "No sockets!");
767 
768     while(exit_flag == 0) {
769 	krb5_ssize_t retx;
770 	fd_set fdset = real_fdset;
771 
772 	retx = select (maxfd + 1, &fdset, NULL, NULL, NULL);
773 	if (retx < 0) {
774 	    if (errno == EINTR)
775 		continue;
776 	    else
777 		krb5_err (context, 1, errno, "select");
778 	}
779 	for (i = 0; i < n; ++i)
780 	    if (FD_ISSET(sockets[i], &fdset)) {
781 		u_char buf[BUFSIZ];
782 		socklen_t addrlen = sizeof(__ss);
783 
784 		retx = recvfrom(sockets[i], buf, sizeof(buf), 0,
785 				sa, &addrlen);
786 		if (retx < 0) {
787 		    if(errno == EINTR)
788 			break;
789 		    else
790 			krb5_err (context, 1, errno, "recvfrom");
791 		}
792 #ifdef INETD_SUPPORT
793 		if (from_inetd) {
794 			socklen_t loclen = sizeof(__local);
795 			int ret2;
796 
797 			ret2 = get_local_addr(sa, addrlen, localsa, &loclen);
798 			if (ret2 < 0)
799 				krb5_errx (context, errno, "get_local_addr");
800 			ret2 = krb5_sockaddr2address(context, localsa,
801 			    &my_addr);
802 			if (ret2)
803 				krb5_errx (context, ret2,
804 				    "krb5_sockaddr2address");
805 			my_addrp = &my_addr;
806 		} else
807 #endif
808 		my_addrp = &addrs.val[i];
809 
810 		process (realms, keytab, sockets[i],
811 			 my_addrp,
812 			 sa, addrlen,
813 			 buf, retx);
814 #ifdef INETD_SUPPORT
815 		if (from_inetd) {
816 		    krb5_free_address(context, &my_addr);
817 		}
818 #endif
819 	    }
820 #ifdef INETD_SUPPORT
821 	if (from_inetd)
822 	    break;
823 #endif
824     }
825 
826     for (i = 0; i < n; ++i)
827 	close(sockets[i]);
828     free(sockets);
829 
830 #ifdef INETD_SUPPORT
831     if (!from_inetd)
832 #endif
833 	krb5_free_addresses (context, &addrs);
834     krb5_free_host_realm (context, realms);
835     krb5_free_context (context);
836     return 0;
837 }
838 
839 static RETSIGTYPE
840 sigterm(int sig)
841 {
842     exit_flag = 1;
843 }
844 
845 static const char *check_library  = NULL;
846 static const char *check_function = NULL;
847 static getarg_strings policy_libraries = { 0, NULL };
848 static char sHDB[] = "HDB:";
849 static char *keytab_str = sHDB;
850 static char *realm_str;
851 static int version_flag;
852 static int help_flag;
853 static char *port_str;
854 static char *config_file;
855 
856 struct getargs args[] = {
857 #ifdef HAVE_DLOPEN
858     { "check-library", 0, arg_string, &check_library,
859       "library to load password check function from", "library" },
860     { "check-function", 0, arg_string, &check_function,
861       "password check function to load", "function" },
862     { "policy-libraries", 0, arg_strings, &policy_libraries,
863       "password check function to load", "function" },
864 #endif
865     { "addresses",	0,	arg_strings, &addresses_str,
866       "addresses to listen on", "list of addresses" },
867     { "keytab", 'k', arg_string, &keytab_str,
868       "keytab to get authentication key from", "kspec" },
869     { "config-file", 'c', arg_string, &config_file, NULL, NULL },
870     { "realm", 'r', arg_string, &realm_str, "default realm", "realm" },
871     { "port",  'p', arg_string, &port_str, "port", NULL },
872     { "version", 0, arg_flag, &version_flag, NULL, NULL },
873     { "help", 0, arg_flag, &help_flag, NULL, NULL }
874 };
875 int num_args = sizeof(args) / sizeof(args[0]);
876 
877 int
878 main (int argc, char **argv)
879 {
880     krb5_keytab keytab;
881     krb5_error_code ret;
882     char **files;
883     int port, i;
884 
885     krb5_program_setup(&context, argc, argv, args, num_args, NULL);
886 
887     if(help_flag)
888 	krb5_std_usage(0, args, num_args);
889     if(version_flag) {
890 	print_version(NULL);
891 	exit(0);
892     }
893 
894     if (config_file == NULL) {
895 	asprintf(&config_file, "%s/kdc.conf", hdb_db_dir(context));
896 	if (config_file == NULL)
897 	    errx(1, "out of memory");
898     }
899 
900     ret = krb5_prepend_config_files_default(config_file, &files);
901     if (ret)
902 	krb5_err(context, 1, ret, "getting configuration files");
903 
904     ret = krb5_set_config_files(context, files);
905     krb5_free_config_files(files);
906     if (ret)
907 	krb5_err(context, 1, ret, "reading configuration files");
908 
909     if(realm_str)
910 	krb5_set_default_realm(context, realm_str);
911 
912     krb5_openlog (context, "kpasswdd", &log_facility);
913     krb5_set_warn_dest(context, log_facility);
914 
915     if (port_str != NULL) {
916 	struct servent *s = roken_getservbyname (port_str, "udp");
917 
918 	if (s != NULL)
919 	    port = s->s_port;
920 	else {
921 	    char *ptr;
922 
923 	    port = strtol (port_str, &ptr, 10);
924 	    if (port == 0 && ptr == port_str)
925 		krb5_errx (context, 1, "bad port `%s'", port_str);
926 	    port = htons(port);
927 	}
928     } else
929 	port = krb5_getportbyname (context, "kpasswd", "udp", KPASSWD_PORT);
930 
931     ret = krb5_kt_register(context, &hdb_kt_ops);
932     if(ret)
933 	krb5_err(context, 1, ret, "krb5_kt_register");
934 
935     ret = krb5_kt_resolve(context, keytab_str, &keytab);
936     if(ret)
937 	krb5_err(context, 1, ret, "%s", keytab_str);
938 
939     kadm5_setup_passwd_quality_check (context, check_library, check_function);
940 
941     for (i = 0; i < policy_libraries.num_strings; i++) {
942 	ret = kadm5_add_passwd_quality_verifier(context,
943 						policy_libraries.strings[i]);
944 	if (ret)
945 	    krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
946     }
947     ret = kadm5_add_passwd_quality_verifier(context, NULL);
948     if (ret)
949 	krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
950 
951 
952     explicit_addresses.len = 0;
953 
954     if (addresses_str.num_strings) {
955 	int j;
956 
957 	for (j = 0; j < addresses_str.num_strings; ++j)
958 	    add_one_address (addresses_str.strings[j], j == 0);
959 	free_getarg_strings (&addresses_str);
960     } else {
961 	char **foo = krb5_config_get_strings (context, NULL,
962 					      "kdc", "addresses", NULL);
963 
964 	if (foo != NULL) {
965 	    add_one_address (*foo++, TRUE);
966 	    while (*foo)
967 		add_one_address (*foo++, FALSE);
968 	}
969     }
970 
971 #ifdef HAVE_SIGACTION
972     {
973 	struct sigaction sa;
974 
975 	sa.sa_flags = 0;
976 	sa.sa_handler = sigterm;
977 	sigemptyset(&sa.sa_mask);
978 
979 	sigaction(SIGINT,  &sa, NULL);
980 	sigaction(SIGTERM, &sa, NULL);
981     }
982 #else
983     signal(SIGINT,  sigterm);
984     signal(SIGTERM, sigterm);
985 #endif
986 
987     pidfile(NULL);
988 
989     return doit (keytab, port);
990 }
991