xref: /freebsd/crypto/heimdal/lib/krb5/changepw.c (revision 02e9120893770924227138ba49df1edb3896112a)
1 /*
2  * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
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.
16  *
17  * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 #include "krb5_locl.h"
35 
36 #undef __attribute__
37 #define __attribute__(X)
38 
39 
40 static void
41 str2data (krb5_data *d,
42 	  const char *fmt,
43 	  ...) __attribute__ ((format (printf, 2, 3)));
44 
45 static void
46 str2data (krb5_data *d,
47 	  const char *fmt,
48 	  ...)
49 {
50     va_list args;
51     char *str;
52 
53     va_start(args, fmt);
54     d->length = vasprintf (&str, fmt, args);
55     va_end(args);
56     d->data = str;
57 }
58 
59 /*
60  * Change password protocol defined by
61  * draft-ietf-cat-kerb-chg-password-02.txt
62  *
63  * Share the response part of the protocol with MS set password
64  * (RFC3244)
65  */
66 
67 static krb5_error_code
68 chgpw_send_request (krb5_context context,
69 		    krb5_auth_context *auth_context,
70 		    krb5_creds *creds,
71 		    krb5_principal targprinc,
72 		    int is_stream,
73 		    rk_socket_t sock,
74 		    const char *passwd,
75 		    const char *host)
76 {
77     krb5_error_code ret;
78     krb5_data ap_req_data;
79     krb5_data krb_priv_data;
80     krb5_data passwd_data;
81     size_t len;
82     u_char header[6];
83     struct iovec iov[3];
84     struct msghdr msghdr;
85 
86     if (is_stream)
87 	return KRB5_KPASSWD_MALFORMED;
88 
89     if (targprinc &&
90 	krb5_principal_compare(context, creds->client, targprinc) != TRUE)
91 	return KRB5_KPASSWD_MALFORMED;
92 
93     krb5_data_zero (&ap_req_data);
94 
95     ret = krb5_mk_req_extended (context,
96 				auth_context,
97 				AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
98 				NULL, /* in_data */
99 				creds,
100 				&ap_req_data);
101     if (ret)
102 	return ret;
103 
104     passwd_data.data   = rk_UNCONST(passwd);
105     passwd_data.length = strlen(passwd);
106 
107     krb5_data_zero (&krb_priv_data);
108 
109     ret = krb5_mk_priv (context,
110 			*auth_context,
111 			&passwd_data,
112 			&krb_priv_data,
113 			NULL);
114     if (ret)
115 	goto out2;
116 
117     len = 6 + ap_req_data.length + krb_priv_data.length;
118     header[0] = (len >> 8) & 0xFF;
119     header[1] = (len >> 0) & 0xFF;
120     header[2] = 0;
121     header[3] = 1;
122     header[4] = (ap_req_data.length >> 8) & 0xFF;
123     header[5] = (ap_req_data.length >> 0) & 0xFF;
124 
125     memset(&msghdr, 0, sizeof(msghdr));
126     msghdr.msg_name       = NULL;
127     msghdr.msg_namelen    = 0;
128     msghdr.msg_iov        = iov;
129     msghdr.msg_iovlen     = sizeof(iov)/sizeof(*iov);
130 #if 0
131     msghdr.msg_control    = NULL;
132     msghdr.msg_controllen = 0;
133 #endif
134 
135     iov[0].iov_base    = (void*)header;
136     iov[0].iov_len     = 6;
137     iov[1].iov_base    = ap_req_data.data;
138     iov[1].iov_len     = ap_req_data.length;
139     iov[2].iov_base    = krb_priv_data.data;
140     iov[2].iov_len     = krb_priv_data.length;
141 
142     if (rk_IS_SOCKET_ERROR( sendmsg (sock, &msghdr, 0) )) {
143 	ret = rk_SOCK_ERRNO;
144 	krb5_set_error_message(context, ret, "sendmsg %s: %s",
145 			       host, strerror(ret));
146     }
147 
148     krb5_data_free (&krb_priv_data);
149 out2:
150     krb5_data_free (&ap_req_data);
151     return ret;
152 }
153 
154 /*
155  * Set password protocol as defined by RFC3244 --
156  * Microsoft Windows 2000 Kerberos Change Password and Set Password Protocols
157  */
158 
159 static krb5_error_code
160 setpw_send_request (krb5_context context,
161 		    krb5_auth_context *auth_context,
162 		    krb5_creds *creds,
163 		    krb5_principal targprinc,
164 		    int is_stream,
165 		    rk_socket_t sock,
166 		    const char *passwd,
167 		    const char *host)
168 {
169     krb5_error_code ret;
170     krb5_data ap_req_data;
171     krb5_data krb_priv_data;
172     krb5_data pwd_data;
173     ChangePasswdDataMS chpw;
174     size_t len = 0;
175     u_char header[4 + 6];
176     u_char *p;
177     struct iovec iov[3];
178     struct msghdr msghdr;
179 
180     krb5_data_zero (&ap_req_data);
181 
182     ret = krb5_mk_req_extended (context,
183 				auth_context,
184 				AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
185 				NULL, /* in_data */
186 				creds,
187 				&ap_req_data);
188     if (ret)
189 	return ret;
190 
191     chpw.newpasswd.length = strlen(passwd);
192     chpw.newpasswd.data = rk_UNCONST(passwd);
193     if (targprinc) {
194 	chpw.targname = &targprinc->name;
195 	chpw.targrealm = &targprinc->realm;
196     } else {
197 	chpw.targname = NULL;
198 	chpw.targrealm = NULL;
199     }
200 
201     ASN1_MALLOC_ENCODE(ChangePasswdDataMS, pwd_data.data, pwd_data.length,
202 		       &chpw, &len, ret);
203     if (ret) {
204 	krb5_data_free (&ap_req_data);
205 	return ret;
206     }
207 
208     if(pwd_data.length != len)
209 	krb5_abortx(context, "internal error in ASN.1 encoder");
210 
211     ret = krb5_mk_priv (context,
212 			*auth_context,
213 			&pwd_data,
214 			&krb_priv_data,
215 			NULL);
216     if (ret)
217 	goto out2;
218 
219     len = 6 + ap_req_data.length + krb_priv_data.length;
220     p = header;
221     if (is_stream) {
222 	_krb5_put_int(p, len, 4);
223 	p += 4;
224     }
225     *p++ = (len >> 8) & 0xFF;
226     *p++ = (len >> 0) & 0xFF;
227     *p++ = 0xff;
228     *p++ = 0x80;
229     *p++ = (ap_req_data.length >> 8) & 0xFF;
230     *p   = (ap_req_data.length >> 0) & 0xFF;
231 
232     memset(&msghdr, 0, sizeof(msghdr));
233     msghdr.msg_name       = NULL;
234     msghdr.msg_namelen    = 0;
235     msghdr.msg_iov        = iov;
236     msghdr.msg_iovlen     = sizeof(iov)/sizeof(*iov);
237 #if 0
238     msghdr.msg_control    = NULL;
239     msghdr.msg_controllen = 0;
240 #endif
241 
242     iov[0].iov_base    = (void*)header;
243     if (is_stream)
244 	iov[0].iov_len     = 10;
245     else
246 	iov[0].iov_len     = 6;
247     iov[1].iov_base    = ap_req_data.data;
248     iov[1].iov_len     = ap_req_data.length;
249     iov[2].iov_base    = krb_priv_data.data;
250     iov[2].iov_len     = krb_priv_data.length;
251 
252     if (rk_IS_SOCKET_ERROR( sendmsg (sock, &msghdr, 0) )) {
253 	ret = rk_SOCK_ERRNO;
254 	krb5_set_error_message(context, ret, "sendmsg %s: %s",
255 			       host, strerror(ret));
256     }
257 
258     krb5_data_free (&krb_priv_data);
259 out2:
260     krb5_data_free (&ap_req_data);
261     krb5_data_free (&pwd_data);
262     return ret;
263 }
264 
265 static krb5_error_code
266 process_reply (krb5_context context,
267 	       krb5_auth_context auth_context,
268 	       int is_stream,
269 	       rk_socket_t sock,
270 	       int *result_code,
271 	       krb5_data *result_code_string,
272 	       krb5_data *result_string,
273 	       const char *host)
274 {
275     krb5_error_code ret;
276     u_char reply[1024 * 3];
277     size_t len;
278     uint16_t pkt_len, pkt_ver;
279     krb5_data ap_rep_data;
280     int save_errno;
281 
282     len = 0;
283     if (is_stream) {
284 	while (len < sizeof(reply)) {
285 	    unsigned long size;
286 
287 	    ret = recvfrom (sock, reply + len, sizeof(reply) - len,
288 			    0, NULL, NULL);
289 	    if (rk_IS_SOCKET_ERROR(ret)) {
290 		save_errno = rk_SOCK_ERRNO;
291 		krb5_set_error_message(context, save_errno,
292 				       "recvfrom %s: %s",
293 				       host, strerror(save_errno));
294 		return save_errno;
295 	    } else if (ret == 0) {
296 		krb5_set_error_message(context, 1,"recvfrom timeout %s", host);
297 		return 1;
298 	    }
299 	    len += ret;
300 	    if (len < 4)
301 		continue;
302 	    _krb5_get_int(reply, &size, 4);
303 	    if (size + 4 < len)
304 		continue;
305 	    memmove(reply, reply + 4, size);
306 	    len = size;
307 	    break;
308 	}
309 	if (len == sizeof(reply)) {
310 	    krb5_set_error_message(context, ENOMEM,
311 				   N_("Message too large from %s", "host"),
312 				   host);
313 	    return ENOMEM;
314 	}
315     } else {
316 	ret = recvfrom (sock, reply, sizeof(reply), 0, NULL, NULL);
317 	if (rk_IS_SOCKET_ERROR(ret)) {
318 	    save_errno = rk_SOCK_ERRNO;
319 	    krb5_set_error_message(context, save_errno,
320 				   "recvfrom %s: %s",
321 				   host, strerror(save_errno));
322 	    return save_errno;
323 	}
324 	len = ret;
325     }
326 
327     if (len < 6) {
328 	str2data (result_string, "server %s sent to too short message "
329 		  "(%zu bytes)", host, len);
330 	*result_code = KRB5_KPASSWD_MALFORMED;
331 	return 0;
332     }
333 
334     pkt_len = (reply[0] << 8) | (reply[1]);
335     pkt_ver = (reply[2] << 8) | (reply[3]);
336 
337     if ((pkt_len != len) || (reply[1] == 0x7e || reply[1] == 0x5e)) {
338 	KRB_ERROR error;
339 	size_t size;
340 	u_char *p;
341 
342 	memset(&error, 0, sizeof(error));
343 
344 	ret = decode_KRB_ERROR(reply, len, &error, &size);
345 	if (ret)
346 	    return ret;
347 
348 	if (error.e_data->length < 2) {
349 	    str2data(result_string, "server %s sent too short "
350 		     "e_data to print anything usable", host);
351 	    free_KRB_ERROR(&error);
352 	    *result_code = KRB5_KPASSWD_MALFORMED;
353 	    return 0;
354 	}
355 
356 	p = error.e_data->data;
357 	*result_code = (p[0] << 8) | p[1];
358 	if (error.e_data->length == 2)
359 	    str2data(result_string, "server only sent error code");
360 	else
361 	    krb5_data_copy (result_string,
362 			    p + 2,
363 			    error.e_data->length - 2);
364 	free_KRB_ERROR(&error);
365 	return 0;
366     }
367 
368     if (pkt_len != len) {
369 	str2data (result_string, "client: wrong len in reply");
370 	*result_code = KRB5_KPASSWD_MALFORMED;
371 	return 0;
372     }
373     if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW) {
374 	str2data (result_string,
375 		  "client: wrong version number (%d)", pkt_ver);
376 	*result_code = KRB5_KPASSWD_MALFORMED;
377 	return 0;
378     }
379 
380     ap_rep_data.data = reply + 6;
381     ap_rep_data.length  = (reply[4] << 8) | (reply[5]);
382 
383     if (reply + len < (u_char *)ap_rep_data.data + ap_rep_data.length) {
384 	str2data (result_string, "client: wrong AP len in reply");
385 	*result_code = KRB5_KPASSWD_MALFORMED;
386 	return 0;
387     }
388 
389     if (ap_rep_data.length) {
390 	krb5_ap_rep_enc_part *ap_rep;
391 	krb5_data priv_data;
392 	u_char *p;
393 
394 	priv_data.data   = (u_char*)ap_rep_data.data + ap_rep_data.length;
395 	priv_data.length = len - ap_rep_data.length - 6;
396 
397 	ret = krb5_rd_rep (context,
398 			   auth_context,
399 			   &ap_rep_data,
400 			   &ap_rep);
401 	if (ret)
402 	    return ret;
403 
404 	krb5_free_ap_rep_enc_part (context, ap_rep);
405 
406 	ret = krb5_rd_priv (context,
407 			    auth_context,
408 			    &priv_data,
409 			    result_code_string,
410 			    NULL);
411 	if (ret) {
412 	    krb5_data_free (result_code_string);
413 	    return ret;
414 	}
415 
416 	if (result_code_string->length < 2) {
417 	    *result_code = KRB5_KPASSWD_MALFORMED;
418 	    str2data (result_string,
419 		      "client: bad length in result");
420 	    return 0;
421 	}
422 
423         p = result_code_string->data;
424 
425         *result_code = (p[0] << 8) | p[1];
426         krb5_data_copy (result_string,
427                         (unsigned char*)result_code_string->data + 2,
428                         result_code_string->length - 2);
429         return 0;
430     } else {
431 	KRB_ERROR error;
432 	size_t size;
433 	u_char *p;
434 
435 	ret = decode_KRB_ERROR(reply + 6, len - 6, &error, &size);
436 	if (ret) {
437 	    return ret;
438 	}
439 	if (error.e_data->length < 2) {
440 	    krb5_warnx (context, "too short e_data to print anything usable");
441 	    return 1;		/* XXX */
442 	}
443 
444 	p = error.e_data->data;
445 	*result_code = (p[0] << 8) | p[1];
446 	krb5_data_copy (result_string,
447 			p + 2,
448 			error.e_data->length - 2);
449 	return 0;
450     }
451 }
452 
453 
454 /*
455  * change the password using the credentials in `creds' (for the
456  * principal indicated in them) to `newpw', storing the result of
457  * the operation in `result_*' and an error code or 0.
458  */
459 
460 typedef krb5_error_code (*kpwd_send_request) (krb5_context,
461 					      krb5_auth_context *,
462 					      krb5_creds *,
463 					      krb5_principal,
464 					      int,
465 					      rk_socket_t,
466 					      const char *,
467 					      const char *);
468 typedef krb5_error_code (*kpwd_process_reply) (krb5_context,
469 					       krb5_auth_context,
470 					       int,
471 					       rk_socket_t,
472 					       int *,
473 					       krb5_data *,
474 					       krb5_data *,
475 					       const char *);
476 
477 static struct kpwd_proc {
478     const char *name;
479     int flags;
480 #define SUPPORT_TCP	1
481 #define SUPPORT_UDP	2
482     kpwd_send_request send_req;
483     kpwd_process_reply process_rep;
484 } procs[] = {
485     {
486 	"MS set password",
487 	SUPPORT_TCP|SUPPORT_UDP,
488 	setpw_send_request,
489 	process_reply
490     },
491     {
492 	"change password",
493 	SUPPORT_UDP,
494 	chgpw_send_request,
495 	process_reply
496     },
497     { NULL, 0, NULL, NULL }
498 };
499 
500 /*
501  *
502  */
503 
504 static krb5_error_code
505 change_password_loop (krb5_context	context,
506 		      krb5_creds	*creds,
507 		      krb5_principal	targprinc,
508 		      const char	*newpw,
509 		      int		*result_code,
510 		      krb5_data		*result_code_string,
511 		      krb5_data		*result_string,
512 		      struct kpwd_proc	*proc)
513 {
514     krb5_error_code ret;
515     krb5_auth_context auth_context = NULL;
516     krb5_krbhst_handle handle = NULL;
517     krb5_krbhst_info *hi;
518     rk_socket_t sock;
519     unsigned int i;
520     int done = 0;
521     krb5_realm realm;
522 
523     if (targprinc)
524 	realm = targprinc->realm;
525     else
526 	realm = creds->client->realm;
527 
528     ret = krb5_auth_con_init (context, &auth_context);
529     if (ret)
530 	return ret;
531 
532     krb5_auth_con_setflags (context, auth_context,
533 			    KRB5_AUTH_CONTEXT_DO_SEQUENCE);
534 
535     ret = krb5_krbhst_init (context, realm, KRB5_KRBHST_CHANGEPW, &handle);
536     if (ret)
537 	goto out;
538 
539     while (!done && (ret = krb5_krbhst_next(context, handle, &hi)) == 0) {
540 	struct addrinfo *ai, *a;
541 	int is_stream;
542 
543 	switch (hi->proto) {
544 	case KRB5_KRBHST_UDP:
545 	    if ((proc->flags & SUPPORT_UDP) == 0)
546 		continue;
547 	    is_stream = 0;
548 	    break;
549 	case KRB5_KRBHST_TCP:
550 	    if ((proc->flags & SUPPORT_TCP) == 0)
551 		continue;
552 	    is_stream = 1;
553 	    break;
554 	default:
555 	    continue;
556 	}
557 
558 	ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
559 	if (ret)
560 	    continue;
561 
562 	for (a = ai; !done && a != NULL; a = a->ai_next) {
563 	    int replied = 0;
564 
565 	    sock = socket (a->ai_family, a->ai_socktype | SOCK_CLOEXEC, a->ai_protocol);
566 	    if (rk_IS_BAD_SOCKET(sock))
567 		continue;
568 	    rk_cloexec(sock);
569 
570 	    ret = connect(sock, a->ai_addr, a->ai_addrlen);
571 	    if (rk_IS_SOCKET_ERROR(ret)) {
572 		rk_closesocket (sock);
573 		goto out;
574 	    }
575 
576 	    ret = krb5_auth_con_genaddrs (context, auth_context, sock,
577 					  KRB5_AUTH_CONTEXT_GENERATE_LOCAL_ADDR);
578 	    if (ret) {
579 		rk_closesocket (sock);
580 		goto out;
581 	    }
582 
583 	    for (i = 0; !done && i < 5; ++i) {
584 		fd_set fdset;
585 		struct timeval tv;
586 
587 		if (!replied) {
588 		    replied = 0;
589 
590 		    ret = (*proc->send_req) (context,
591 					     &auth_context,
592 					     creds,
593 					     targprinc,
594 					     is_stream,
595 					     sock,
596 					     newpw,
597 					     hi->hostname);
598 		    if (ret) {
599 			rk_closesocket(sock);
600 			goto out;
601 		    }
602 		}
603 
604 #ifndef NO_LIMIT_FD_SETSIZE
605 		if (sock >= FD_SETSIZE) {
606 		    ret = ERANGE;
607 		    krb5_set_error_message(context, ret,
608 					   "fd %d too large", sock);
609 		    rk_closesocket (sock);
610 		    goto out;
611 		}
612 #endif
613 
614 		FD_ZERO(&fdset);
615 		FD_SET(sock, &fdset);
616 		tv.tv_usec = 0;
617 		tv.tv_sec  = 1 + (1 << i);
618 
619 		ret = select (sock + 1, &fdset, NULL, NULL, &tv);
620 		if (rk_IS_SOCKET_ERROR(ret) && rk_SOCK_ERRNO != EINTR) {
621 		    rk_closesocket(sock);
622 		    goto out;
623 		}
624 		if (ret == 1) {
625 		    ret = (*proc->process_rep) (context,
626 						auth_context,
627 						is_stream,
628 						sock,
629 						result_code,
630 						result_code_string,
631 						result_string,
632 						hi->hostname);
633 		    if (ret == 0)
634 			done = 1;
635 		    else if (i > 0 && ret == KRB5KRB_AP_ERR_MUT_FAIL)
636 			replied = 1;
637 		} else {
638 		    ret = KRB5_KDC_UNREACH;
639 		}
640 	    }
641 	    rk_closesocket (sock);
642 	}
643     }
644 
645  out:
646     krb5_krbhst_free (context, handle);
647     krb5_auth_con_free (context, auth_context);
648 
649     if (ret == KRB5_KDC_UNREACH) {
650 	krb5_set_error_message(context,
651 			       ret,
652 			       N_("Unable to reach any changepw server "
653 				 " in realm %s", "realm"), realm);
654 	*result_code = KRB5_KPASSWD_HARDERROR;
655     }
656     return ret;
657 }
658 
659 #ifndef HEIMDAL_SMALLER
660 
661 static struct kpwd_proc *
662 find_chpw_proto(const char *name)
663 {
664     struct kpwd_proc *p;
665     for (p = procs; p->name != NULL; p++) {
666 	if (strcmp(p->name, name) == 0)
667 	    return p;
668     }
669     return NULL;
670 }
671 
672 /**
673  * Deprecated: krb5_change_password() is deprecated, use krb5_set_password().
674  *
675  * @param context a Keberos context
676  * @param creds
677  * @param newpw
678  * @param result_code
679  * @param result_code_string
680  * @param result_string
681  *
682  * @return On sucess password is changed.
683 
684  * @ingroup @krb5_deprecated
685  */
686 
687 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
688 krb5_change_password (krb5_context	context,
689 		      krb5_creds	*creds,
690 		      const char	*newpw,
691 		      int		*result_code,
692 		      krb5_data		*result_code_string,
693 		      krb5_data		*result_string)
694     KRB5_DEPRECATED_FUNCTION("Use X instead")
695 {
696     struct kpwd_proc *p = find_chpw_proto("change password");
697 
698     *result_code = KRB5_KPASSWD_MALFORMED;
699     result_code_string->data = result_string->data = NULL;
700     result_code_string->length = result_string->length = 0;
701 
702     if (p == NULL)
703 	return KRB5_KPASSWD_MALFORMED;
704 
705     return change_password_loop(context, creds, NULL, newpw,
706 				result_code, result_code_string,
707 				result_string, p);
708 }
709 #endif /* HEIMDAL_SMALLER */
710 
711 /**
712  * Change password using creds.
713  *
714  * @param context a Keberos context
715  * @param creds The initial kadmin/passwd for the principal or an admin principal
716  * @param newpw The new password to set
717  * @param targprinc if unset, the default principal is used.
718  * @param result_code Result code, KRB5_KPASSWD_SUCCESS is when password is changed.
719  * @param result_code_string binary message from the server, contains
720  * at least the result_code.
721  * @param result_string A message from the kpasswd service or the
722  * library in human printable form. The string is NUL terminated.
723  *
724  * @return On sucess and *result_code is KRB5_KPASSWD_SUCCESS, the password is changed.
725 
726  * @ingroup @krb5
727  */
728 
729 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
730 krb5_set_password(krb5_context context,
731 		  krb5_creds *creds,
732 		  const char *newpw,
733 		  krb5_principal targprinc,
734 		  int *result_code,
735 		  krb5_data *result_code_string,
736 		  krb5_data *result_string)
737 {
738     krb5_principal principal = NULL;
739     krb5_error_code ret = 0;
740     int i;
741 
742     *result_code = KRB5_KPASSWD_MALFORMED;
743     krb5_data_zero(result_code_string);
744     krb5_data_zero(result_string);
745 
746     if (targprinc == NULL) {
747 	ret = krb5_get_default_principal(context, &principal);
748 	if (ret)
749 	    return ret;
750     } else
751 	principal = targprinc;
752 
753     for (i = 0; procs[i].name != NULL; i++) {
754 	*result_code = 0;
755 	ret = change_password_loop(context, creds, principal, newpw,
756 				   result_code, result_code_string,
757 				   result_string,
758 				   &procs[i]);
759 	if (ret == 0 && *result_code == 0)
760 	    break;
761     }
762 
763     if (targprinc == NULL)
764 	krb5_free_principal(context, principal);
765     return ret;
766 }
767 
768 /*
769  *
770  */
771 
772 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
773 krb5_set_password_using_ccache(krb5_context context,
774 			       krb5_ccache ccache,
775 			       const char *newpw,
776 			       krb5_principal targprinc,
777 			       int *result_code,
778 			       krb5_data *result_code_string,
779 			       krb5_data *result_string)
780 {
781     krb5_creds creds, *credsp;
782     krb5_error_code ret;
783     krb5_principal principal = NULL;
784 
785     *result_code = KRB5_KPASSWD_MALFORMED;
786     result_code_string->data = result_string->data = NULL;
787     result_code_string->length = result_string->length = 0;
788 
789     memset(&creds, 0, sizeof(creds));
790 
791     if (targprinc == NULL) {
792 	ret = krb5_cc_get_principal(context, ccache, &principal);
793 	if (ret)
794 	    return ret;
795     } else
796 	principal = targprinc;
797 
798     ret = krb5_make_principal(context, &creds.server,
799 			      krb5_principal_get_realm(context, principal),
800 			      "kadmin", "changepw", NULL);
801     if (ret)
802 	goto out;
803 
804     ret = krb5_cc_get_principal(context, ccache, &creds.client);
805     if (ret) {
806         krb5_free_principal(context, creds.server);
807 	goto out;
808     }
809 
810     ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
811     krb5_free_principal(context, creds.server);
812     krb5_free_principal(context, creds.client);
813     if (ret)
814 	goto out;
815 
816     ret = krb5_set_password(context,
817 			    credsp,
818 			    newpw,
819 			    principal,
820 			    result_code,
821 			    result_code_string,
822 			    result_string);
823 
824     krb5_free_creds(context, credsp);
825 
826     return ret;
827  out:
828     if (targprinc == NULL)
829 	krb5_free_principal(context, principal);
830     return ret;
831 }
832 
833 /*
834  *
835  */
836 
837 KRB5_LIB_FUNCTION const char* KRB5_LIB_CALL
838 krb5_passwd_result_to_string (krb5_context context,
839 			      int result)
840 {
841     static const char *strings[] = {
842 	"Success",
843 	"Malformed",
844 	"Hard error",
845 	"Auth error",
846 	"Soft error" ,
847 	"Access denied",
848 	"Bad version",
849 	"Initial flag needed"
850     };
851 
852     if (result < 0 || result > KRB5_KPASSWD_INITIAL_FLAG_NEEDED)
853 	return "unknown result code";
854     else
855 	return strings[result];
856 }
857