source/libads/krb5_setpw.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    krb5 set password implementation
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Remus Koos 2001 (remuskoos@yahoo.com)
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 #ifdef HAVE_KRB5
  24
  25 #define DEFAULT_KPASSWD_PORT    464
  26
  27 #define KRB5_KPASSWD_VERS_CHANGEPW              1
  28
  29 #define KRB5_KPASSWD_VERS_SETPW                 0xff80
  30 #define KRB5_KPASSWD_VERS_SETPW_ALT             2
  31
  32 #define KRB5_KPASSWD_SUCCESS                    0
  33 #define KRB5_KPASSWD_MALFORMED                  1
  34 #define KRB5_KPASSWD_HARDERROR                  2
  35 #define KRB5_KPASSWD_AUTHERROR                  3
  36 #define KRB5_KPASSWD_SOFTERROR                  4
  37 #define KRB5_KPASSWD_ACCESSDENIED               5
  38 #define KRB5_KPASSWD_BAD_VERSION                6
  39 #define KRB5_KPASSWD_INITIAL_FLAG_NEEDED        7
  40
  41 /* Those are defined by kerberos-set-passwd-02.txt and are probably
  42  * not supported by M$ implementation */
  43 #define KRB5_KPASSWD_POLICY_REJECT              8
  44 #define KRB5_KPASSWD_BAD_PRINCIPAL              9
  45 #define KRB5_KPASSWD_ETYPE_NOSUPP               10
  46
  47 /*
  48  * we've got to be able to distinguish KRB_ERRORs from other
  49  * requests - valid response for CHPW v2 replies.
  50  */
  51
  52 #define krb5_is_krb_error(packet) \
  53         ( packet && packet->length && (((char *)packet->data)[0] == 0x7e || ((char *)packet->data)[0] == 0x5e))
  54
  55 /* This implements kerberos password change protocol as specified in
  56  * kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
  57  * as well as microsoft version of the protocol
  58  * as specified in kerberos-set-passwd-00.txt
  59  */
  60 static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
  61 {
  62         char* princ_part1 = NULL;
  63         char* princ_part2 = NULL;
  64         char* realm = NULL;
  65         char* c;
  66         char* princ;
  67
  68         ASN1_DATA req;
  69         DATA_BLOB ret;
  70
  71
  72         princ = SMB_STRDUP(principal);
  73
  74         if ((c = strchr_m(princ, '/')) == NULL) {
  75                 c = princ;
  76         } else {
  77                 *c = '\0';
  78                 c++;
  79                 princ_part1 = princ;
  80         }
  81
  82         princ_part2 = c;
  83
  84         if ((c = strchr_m(c, '@')) != NULL) {
  85                 *c = '\0';
  86                 c++;
  87                 realm = c;
  88         } else {
  89                 /* We must have a realm component. */
  90                 return data_blob_null;
  91         }
  92
  93         memset(&req, 0, sizeof(req));
  94
  95         asn1_push_tag(&req, ASN1_SEQUENCE(0));
  96         asn1_push_tag(&req, ASN1_CONTEXT(0));
  97         asn1_write_OctetString(&req, password, strlen(password));
  98         asn1_pop_tag(&req);
  99
 100         asn1_push_tag(&req, ASN1_CONTEXT(1));
 101         asn1_push_tag(&req, ASN1_SEQUENCE(0));
 102
 103         asn1_push_tag(&req, ASN1_CONTEXT(0));
 104         asn1_write_Integer(&req, 1);
 105         asn1_pop_tag(&req);
 106
 107         asn1_push_tag(&req, ASN1_CONTEXT(1));
 108         asn1_push_tag(&req, ASN1_SEQUENCE(0));
 109
 110         if (princ_part1) {
 111                 asn1_write_GeneralString(&req, princ_part1);
 112         }
 113
 114         asn1_write_GeneralString(&req, princ_part2);
 115         asn1_pop_tag(&req);
 116         asn1_pop_tag(&req);
 117         asn1_pop_tag(&req);
 118         asn1_pop_tag(&req);
 119
 120         asn1_push_tag(&req, ASN1_CONTEXT(2));
 121         asn1_write_GeneralString(&req, realm);
 122         asn1_pop_tag(&req);
 123         asn1_pop_tag(&req);
 124
 125         ret = data_blob(req.data, req.length);
 126         asn1_free(&req);
 127
 128         free(princ);
 129
 130         return ret;
 131 }
 132
 133 static krb5_error_code build_kpasswd_request(uint16 pversion,
 134                                            krb5_context context,
 135                                            krb5_auth_context auth_context,
 136                                            krb5_data *ap_req,
 137                                            const char *princ,
 138                                            const char *passwd,
 139                                            bool use_tcp,
 140                                            krb5_data *packet)
 141 {
 142         krb5_error_code ret;
 143         krb5_data cipherpw;
 144         krb5_data encoded_setpw;
 145         krb5_replay_data replay;
 146         char *p, *msg_start;
 147         DATA_BLOB setpw;
 148         unsigned int msg_length;
 149
 150         ret = krb5_auth_con_setflags(context,
 151                                      auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 152         if (ret) {
 153                 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
 154                          error_message(ret)));
 155                 return ret;
 156         }
 157
 158         /* handle protocol differences in chpw and setpw */
 159         if (pversion  == KRB5_KPASSWD_VERS_CHANGEPW)
 160                 setpw = data_blob(passwd, strlen(passwd));
 161         else if (pversion == KRB5_KPASSWD_VERS_SETPW ||
 162                  pversion == KRB5_KPASSWD_VERS_SETPW_ALT)
 163                 setpw = encode_krb5_setpw(princ, passwd);
 164         else
 165                 return EINVAL;
 166
 167         if (setpw.data == NULL || setpw.length == 0) {
 168                 return EINVAL;
 169         }
 170
 171         encoded_setpw.data = (char *)setpw.data;
 172         encoded_setpw.length = setpw.length;
 173
 174         ret = krb5_mk_priv(context, auth_context,
 175                            &encoded_setpw, &cipherpw, &replay);
 176
 177         data_blob_free(&setpw);         /*from 'encode_krb5_setpw(...)' */
 178
 179         if (ret) {
 180                 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
 181                 return ret;
 182         }
 183
 184         packet->data = (char *)SMB_MALLOC(ap_req->length + cipherpw.length + (use_tcp ? 10 : 6 ));
 185         if (!packet->data)
 186                 return -1;
 187
 188
 189
 190         /* see the RFC for details */
 191
 192         msg_start = p = ((char *)packet->data) + (use_tcp ? 4 : 0);
 193         p += 2;
 194         RSSVAL(p, 0, pversion);
 195         p += 2;
 196         RSSVAL(p, 0, ap_req->length);
 197         p += 2;
 198         memcpy(p, ap_req->data, ap_req->length);
 199         p += ap_req->length;
 200         memcpy(p, cipherpw.data, cipherpw.length);
 201         p += cipherpw.length;
 202         packet->length = PTR_DIFF(p,packet->data);
 203         msg_length = PTR_DIFF(p,msg_start);
 204
 205         if (use_tcp) {
 206                 RSIVAL(packet->data, 0, msg_length);
 207         }
 208         RSSVAL(msg_start, 0, msg_length);
 209
 210         free(cipherpw.data);    /* from 'krb5_mk_priv(...)' */
 211
 212         return 0;
 213 }
 214
 215 static const struct kpasswd_errors {
 216         int result_code;
 217         const char *error_string;
 218 } kpasswd_errors[] = {
 219         {KRB5_KPASSWD_MALFORMED, "Malformed request error"},
 220         {KRB5_KPASSWD_HARDERROR, "Server error"},
 221         {KRB5_KPASSWD_AUTHERROR, "Authentication error"},
 222         {KRB5_KPASSWD_SOFTERROR, "Password change rejected"},
 223         {KRB5_KPASSWD_ACCESSDENIED, "Client does not have proper authorization"},
 224         {KRB5_KPASSWD_BAD_VERSION, "Protocol version not supported"},
 225         {KRB5_KPASSWD_INITIAL_FLAG_NEEDED, "Authorization ticket must have initial flag set"},
 226         {KRB5_KPASSWD_POLICY_REJECT, "Password rejected due to policy requirements"},
 227         {KRB5_KPASSWD_BAD_PRINCIPAL, "Target principal does not exist"},
 228         {KRB5_KPASSWD_ETYPE_NOSUPP, "Unsupported encryption type"},
 229         {0, NULL}
 230 };
 231
 232 static krb5_error_code setpw_result_code_string(krb5_context context,
 233                                                 int result_code,
 234                                                 const char **code_string)
 235 {
 236         unsigned int idx = 0;
 237
 238         while (kpasswd_errors[idx].error_string != NULL) {
 239                 if (kpasswd_errors[idx].result_code ==
 240                     result_code) {
 241                         *code_string = kpasswd_errors[idx].error_string;
 242                         return 0;
 243                 }
 244                 idx++;
 245         }
 246         *code_string = "Password change failed";
 247         return (0);
 248 }
 249
 250  krb5_error_code kpasswd_err_to_krb5_err(krb5_error_code res_code)
 251 {
 252         switch(res_code) {
 253                 case KRB5_KPASSWD_ACCESSDENIED:
 254                         return KRB5KDC_ERR_BADOPTION;
 255                 case KRB5_KPASSWD_INITIAL_FLAG_NEEDED:
 256                         return KRB5KDC_ERR_BADOPTION;
 257                         /* return KV5M_ALT_METHOD; MIT-only define */
 258                 case KRB5_KPASSWD_ETYPE_NOSUPP:
 259                         return KRB5KDC_ERR_ETYPE_NOSUPP;
 260                 case KRB5_KPASSWD_BAD_PRINCIPAL:
 261                         return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 262                 case KRB5_KPASSWD_POLICY_REJECT:
 263                 case KRB5_KPASSWD_SOFTERROR:
 264                         return KRB5KDC_ERR_POLICY;
 265                 default:
 266                         return KRB5KRB_ERR_GENERIC;
 267         }
 268 }
 269 static krb5_error_code parse_setpw_reply(krb5_context context,
 270                                          bool use_tcp,
 271                                          krb5_auth_context auth_context,
 272                                          krb5_data *packet)
 273 {
 274         krb5_data ap_rep;
 275         char *p;
 276         int vnum, ret, res_code;
 277         krb5_data cipherresult;
 278         krb5_data clearresult;
 279         krb5_ap_rep_enc_part *ap_rep_enc;
 280         krb5_replay_data replay;
 281         unsigned int msg_length = packet->length;
 282
 283
 284         if (packet->length < (use_tcp ? 8 : 4)) {
 285                 return KRB5KRB_AP_ERR_MODIFIED;
 286         }
 287
 288         p = packet->data;
 289         /*
 290         ** see if it is an error
 291         */
 292         if (krb5_is_krb_error(packet)) {
 293
 294                 ret = handle_krberror_packet(context, packet);
 295                 if (ret) {
 296                         return ret;
 297                 }
 298         }
 299
 300
 301         /* tcp... */
 302         if (use_tcp) {
 303                 msg_length -= 4;
 304                 if (RIVAL(p, 0) != msg_length) {
 305                         DEBUG(1,("Bad TCP packet length (%d/%d) from kpasswd server\n",
 306                         RIVAL(p, 0), msg_length));
 307                         return KRB5KRB_AP_ERR_MODIFIED;
 308                 }
 309
 310                 p += 4;
 311         }
 312
 313         if (RSVAL(p, 0) != msg_length) {
 314                 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
 315                          RSVAL(p, 0), msg_length));
 316                 return KRB5KRB_AP_ERR_MODIFIED;
 317         }
 318
 319         p += 2;
 320
 321         vnum = RSVAL(p, 0); p += 2;
 322
 323         /* FIXME: According to standard there is only one type of reply */
 324         if (vnum != KRB5_KPASSWD_VERS_SETPW &&
 325             vnum != KRB5_KPASSWD_VERS_SETPW_ALT &&
 326             vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
 327                 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
 328                 return KRB5KDC_ERR_BAD_PVNO;
 329         }
 330
 331         ap_rep.length = RSVAL(p, 0); p += 2;
 332
 333         if (p + ap_rep.length >= (char *)packet->data + packet->length) {
 334                 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
 335                 return KRB5KRB_AP_ERR_MODIFIED;
 336         }
 337
 338         if (ap_rep.length == 0) {
 339                 DEBUG(1,("got unencrypted setpw result?!\n"));
 340                 return KRB5KRB_AP_ERR_MODIFIED;
 341         }
 342
 343         /* verify ap_rep */
 344         ap_rep.data = p;
 345         p += ap_rep.length;
 346
 347         ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
 348         if (ret) {
 349                 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
 350                 return KRB5KRB_AP_ERR_MODIFIED;
 351         }
 352
 353         krb5_free_ap_rep_enc_part(context, ap_rep_enc);
 354
 355         cipherresult.data = p;
 356         cipherresult.length = ((char *)packet->data + packet->length) - p;
 357
 358         ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
 359                            &replay);
 360         if (ret) {
 361                 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
 362                 return KRB5KRB_AP_ERR_MODIFIED;
 363         }
 364
 365         if (clearresult.length < 2) {
 366                 free(clearresult.data);
 367                 ret = KRB5KRB_AP_ERR_MODIFIED;
 368                 return KRB5KRB_AP_ERR_MODIFIED;
 369         }
 370
 371         p = clearresult.data;
 372
 373         res_code = RSVAL(p, 0);
 374
 375         free(clearresult.data);
 376
 377         if ((res_code < KRB5_KPASSWD_SUCCESS) ||
 378             (res_code > KRB5_KPASSWD_ETYPE_NOSUPP)) {
 379                 return KRB5KRB_AP_ERR_MODIFIED;
 380         }
 381
 382         if (res_code == KRB5_KPASSWD_SUCCESS) {
 383                 return 0;
 384         } else {
 385                 const char *errstr;
 386                 setpw_result_code_string(context, res_code, &errstr);
 387                 DEBUG(1, ("Error changing password: %s (%d)\n", errstr, res_code));
 388
 389                 return kpasswd_err_to_krb5_err(res_code);
 390         }
 391 }
 392
 393 static ADS_STATUS do_krb5_kpasswd_request(krb5_context context,
 394                                           const char *kdc_host,
 395                                           uint16 pversion,
 396                                           krb5_creds *credsp,
 397                                           const char *princ,
 398                                           const char *newpw)
 399 {
 400         krb5_auth_context auth_context = NULL;
 401         krb5_data ap_req, chpw_req, chpw_rep;
 402         int ret, sock;
 403         socklen_t addr_len;
 404         struct sockaddr_storage remote_addr, local_addr;
 405         struct sockaddr_storage addr;
 406         krb5_address local_kaddr, remote_kaddr;
 407         bool use_tcp = False;
 408
 409
 410         if (!interpret_string_addr(&addr, kdc_host, 0)) {
 411         }
 412
 413         ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
 414                                    NULL, credsp, &ap_req);
 415         if (ret) {
 416                 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
 417                 return ADS_ERROR_KRB5(ret);
 418         }
 419
 420         do {
 421
 422                 if (!use_tcp) {
 423
 424                         sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
 425
 426                 } else {
 427
 428                         sock = open_socket_out(SOCK_STREAM, &addr, DEFAULT_KPASSWD_PORT,
 429                                                LONG_CONNECT_TIMEOUT);
 430                 }
 431
 432                 if (sock == -1) {
 433                         int rc = errno;
 434                         SAFE_FREE(ap_req.data);
 435                         krb5_auth_con_free(context, auth_context);
 436                         DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
 437                                  kdc_host, strerror(errno)));
 438                         return ADS_ERROR_SYSTEM(rc);
 439                 }
 440                 addr_len = sizeof(remote_addr);
 441                 if (getpeername(sock, (struct sockaddr *)&remote_addr, &addr_len) != 0) {
 442                         close(sock);
 443                         SAFE_FREE(ap_req.data);
 444                         krb5_auth_con_free(context, auth_context);
 445                         DEBUG(1,("getpeername() failed (%s)\n", error_message(errno)));
 446                         return ADS_ERROR_SYSTEM(errno);
 447                 }
 448                 addr_len = sizeof(local_addr);
 449                 if (getsockname(sock, (struct sockaddr *)&local_addr, &addr_len) != 0) {
 450                         close(sock);
 451                         SAFE_FREE(ap_req.data);
 452                         krb5_auth_con_free(context, auth_context);
 453                         DEBUG(1,("getsockname() failed (%s)\n", error_message(errno)));
 454                         return ADS_ERROR_SYSTEM(errno);
 455                 }
 456                 if (!setup_kaddr(&remote_kaddr, &remote_addr) ||
 457                                 !setup_kaddr(&local_kaddr, &local_addr)) {
 458                         DEBUG(1,("do_krb5_kpasswd_request: "
 459                                 "Failed to setup addresses.\n"));
 460                         close(sock);
 461                         SAFE_FREE(ap_req.data);
 462                         krb5_auth_con_free(context, auth_context);
 463                         errno = EINVAL;
 464                         return ADS_ERROR_SYSTEM(EINVAL);
 465                 }
 466
 467                 ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
 468                 if (ret) {
 469                         close(sock);
 470                         SAFE_FREE(ap_req.data);
 471                         krb5_auth_con_free(context, auth_context);
 472                         DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
 473                         return ADS_ERROR_KRB5(ret);
 474                 }
 475
 476                 ret = build_kpasswd_request(pversion, context, auth_context, &ap_req,
 477                                           princ, newpw, use_tcp, &chpw_req);
 478                 if (ret) {
 479                         close(sock);
 480                         SAFE_FREE(ap_req.data);
 481                         krb5_auth_con_free(context, auth_context);
 482                         DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
 483                         return ADS_ERROR_KRB5(ret);
 484                 }
 485
 486                 ret = write(sock, chpw_req.data, chpw_req.length);
 487
 488                 if (ret != chpw_req.length) {
 489                         close(sock);
 490                         SAFE_FREE(chpw_req.data);
 491                         SAFE_FREE(ap_req.data);
 492                         krb5_auth_con_free(context, auth_context);
 493                         DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
 494                         return ADS_ERROR_SYSTEM(errno);
 495                 }
 496
 497                 SAFE_FREE(chpw_req.data);
 498
 499                 chpw_rep.length = 1500;
 500                 chpw_rep.data = (char *) SMB_MALLOC(chpw_rep.length);
 501                 if (!chpw_rep.data) {
 502                         close(sock);
 503                         SAFE_FREE(ap_req.data);
 504                         krb5_auth_con_free(context, auth_context);
 505                         DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
 506                         errno = ENOMEM;
 507                         return ADS_ERROR_SYSTEM(errno);
 508                 }
 509
 510                 ret = read(sock, chpw_rep.data, chpw_rep.length);
 511                 if (ret < 0) {
 512                         close(sock);
 513                         SAFE_FREE(chpw_rep.data);
 514                         SAFE_FREE(ap_req.data);
 515                         krb5_auth_con_free(context, auth_context);
 516                         DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
 517                         return ADS_ERROR_SYSTEM(errno);
 518                 }
 519
 520                 close(sock);
 521                 chpw_rep.length = ret;
 522
 523                 ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
 524                 if (ret) {
 525                         SAFE_FREE(chpw_rep.data);
 526                         SAFE_FREE(ap_req.data);
 527                         krb5_auth_con_free(context, auth_context);
 528                         DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
 529                                  error_message(ret)));
 530                         return ADS_ERROR_KRB5(ret);
 531                 }
 532
 533                 ret = parse_setpw_reply(context, use_tcp, auth_context, &chpw_rep);
 534                 SAFE_FREE(chpw_rep.data);
 535
 536                 if (ret) {
 537
 538                         if (ret == KRB5KRB_ERR_RESPONSE_TOO_BIG && !use_tcp) {
 539                                 DEBUG(5, ("Trying setpw with TCP!!!\n"));
 540                                 use_tcp = True;
 541                                 continue;
 542                         }
 543
 544                         SAFE_FREE(ap_req.data);
 545                         krb5_auth_con_free(context, auth_context);
 546                         DEBUG(1,("parse_setpw_reply failed (%s)\n",
 547                                  error_message(ret)));
 548                         return ADS_ERROR_KRB5(ret);
 549                 }
 550
 551                 SAFE_FREE(ap_req.data);
 552                 krb5_auth_con_free(context, auth_context);
 553         } while ( ret );
 554
 555         return ADS_SUCCESS;
 556 }
 557
 558 ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *princ,
 559                                  const char *newpw, int time_offset)
 560 {
 561
 562         ADS_STATUS aret;
 563         krb5_error_code ret = 0;
 564         krb5_context context = NULL;
 565         krb5_principal principal = NULL;
 566         char *princ_name = NULL;
 567         char *realm = NULL;
 568         krb5_creds creds, *credsp = NULL;
 569 #if KRB5_PRINC_REALM_RETURNS_REALM
 570         krb5_realm orig_realm;
 571 #else
 572         krb5_data orig_realm;
 573 #endif
 574         krb5_ccache ccache = NULL;
 575
 576         ZERO_STRUCT(creds);
 577
 578         initialize_krb5_error_table();
 579         ret = krb5_init_context(&context);
 580         if (ret) {
 581                 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
 582                 return ADS_ERROR_KRB5(ret);
 583         }
 584
 585         if (time_offset != 0) {
 586                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
 587         }
 588
 589         ret = krb5_cc_default(context, &ccache);
 590         if (ret) {
 591                 krb5_free_context(context);
 592                 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
 593                 return ADS_ERROR_KRB5(ret);
 594         }
 595
 596         realm = strchr_m(princ, '@');
 597         if (!realm) {
 598                 krb5_cc_close(context, ccache);
 599                 krb5_free_context(context);
 600                 DEBUG(1,("Failed to get realm\n"));
 601                 return ADS_ERROR_KRB5(-1);
 602         }
 603         realm++;
 604
 605         asprintf(&princ_name, "kadmin/changepw@%s", realm);
 606         ret = smb_krb5_parse_name(context, princ_name, &creds.server);
 607         if (ret) {
 608                 krb5_cc_close(context, ccache);
 609                 krb5_free_context(context);
 610                 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
 611                 return ADS_ERROR_KRB5(ret);
 612         }
 613
 614         /* parse the principal we got as a function argument */
 615         ret = smb_krb5_parse_name(context, princ, &principal);
 616         if (ret) {
 617                 krb5_cc_close(context, ccache);
 618                 krb5_free_principal(context, creds.server);
 619                 krb5_free_context(context);
 620                 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
 621                 free(princ_name);
 622                 return ADS_ERROR_KRB5(ret);
 623         }
 624
 625         free(princ_name);
 626
 627         /* The creds.server principal takes ownership of this memory.
 628                 Remember to set back to original value before freeing. */
 629         orig_realm = *krb5_princ_realm(context, creds.server);
 630         krb5_princ_set_realm(context, creds.server, krb5_princ_realm(context, principal));
 631
 632         ret = krb5_cc_get_principal(context, ccache, &creds.client);
 633         if (ret) {
 634                 krb5_cc_close(context, ccache);
 635                 krb5_princ_set_realm(context, creds.server, &orig_realm);
 636                 krb5_free_principal(context, creds.server);
 637                 krb5_free_principal(context, principal);
 638                 krb5_free_context(context);
 639                 DEBUG(1,("Failed to get principal from ccache (%s)\n",
 640                          error_message(ret)));
 641                 return ADS_ERROR_KRB5(ret);
 642         }
 643
 644         ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
 645         if (ret) {
 646                 krb5_cc_close(context, ccache);
 647                 krb5_free_principal(context, creds.client);
 648                 krb5_princ_set_realm(context, creds.server, &orig_realm);
 649                 krb5_free_principal(context, creds.server);
 650                 krb5_free_principal(context, principal);
 651                 krb5_free_context(context);
 652                 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
 653                 return ADS_ERROR_KRB5(ret);
 654         }
 655
 656         /* we might have to call krb5_free_creds(...) from now on ... */
 657
 658         aret = do_krb5_kpasswd_request(context, kdc_host,
 659                                        KRB5_KPASSWD_VERS_SETPW,
 660                                        credsp, princ, newpw);
 661
 662         krb5_free_creds(context, credsp);
 663         krb5_free_principal(context, creds.client);
 664         krb5_princ_set_realm(context, creds.server, &orig_realm);
 665         krb5_free_principal(context, creds.server);
 666         krb5_free_principal(context, principal);
 667         krb5_cc_close(context, ccache);
 668         krb5_free_context(context);
 669
 670         return aret;
 671 }
 672
 673 /*
 674   we use a prompter to avoid a crash bug in the kerberos libs when
 675   dealing with empty passwords
 676   this prompter is just a string copy ...
 677 */
 678 static krb5_error_code
 679 kerb_prompter(krb5_context ctx, void *data,
 680                const char *name,
 681                const char *banner,
 682                int num_prompts,
 683                krb5_prompt prompts[])
 684 {
 685         if (num_prompts == 0) return 0;
 686
 687         memset(prompts[0].reply->data, 0, prompts[0].reply->length);
 688         if (prompts[0].reply->length > 0) {
 689                 if (data) {
 690                         strncpy(prompts[0].reply->data,
 691                                 (const char *)data,
 692                                 prompts[0].reply->length-1);
 693                         prompts[0].reply->length = strlen(prompts[0].reply->data);
 694                 } else {
 695                         prompts[0].reply->length = 0;
 696                 }
 697         }
 698         return 0;
 699 }
 700
 701 static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
 702                                         const char *principal,
 703                                         const char *oldpw,
 704                                         const char *newpw,
 705                                         int time_offset)
 706 {
 707     ADS_STATUS aret;
 708     krb5_error_code ret;
 709     krb5_context context = NULL;
 710     krb5_principal princ;
 711     krb5_get_init_creds_opt opts;
 712     krb5_creds creds;
 713     char *chpw_princ = NULL, *password;
 714
 715     initialize_krb5_error_table();
 716     ret = krb5_init_context(&context);
 717     if (ret) {
 718         DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
 719         return ADS_ERROR_KRB5(ret);
 720     }
 721
 722     if ((ret = smb_krb5_parse_name(context, principal,
 723                                     &princ))) {
 724         krb5_free_context(context);
 725         DEBUG(1,("Failed to parse %s (%s)\n", principal, error_message(ret)));
 726         return ADS_ERROR_KRB5(ret);
 727     }
 728
 729     krb5_get_init_creds_opt_init(&opts);
 730     krb5_get_init_creds_opt_set_tkt_life(&opts, 5*60);
 731     krb5_get_init_creds_opt_set_renew_life(&opts, 0);
 732     krb5_get_init_creds_opt_set_forwardable(&opts, 0);
 733     krb5_get_init_creds_opt_set_proxiable(&opts, 0);
 734
 735     /* We have to obtain an INITIAL changepw ticket for changing password */
 736     asprintf(&chpw_princ, "kadmin/changepw@%s",
 737                                 (char *) krb5_princ_realm(context, princ));
 738     password = SMB_STRDUP(oldpw);
 739     ret = krb5_get_init_creds_password(context, &creds, princ, password,
 740                                            kerb_prompter, NULL,
 741                                            0, chpw_princ, &opts);
 742     SAFE_FREE(chpw_princ);
 743     SAFE_FREE(password);
 744
 745     if (ret) {
 746       if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
 747         DEBUG(1,("Password incorrect while getting initial ticket"));
 748       else
 749         DEBUG(1,("krb5_get_init_creds_password failed (%s)\n", error_message(ret)));
 750
 751         krb5_free_principal(context, princ);
 752         krb5_free_context(context);
 753         return ADS_ERROR_KRB5(ret);
 754     }
 755
 756     aret = do_krb5_kpasswd_request(context, kdc_host,
 757                                    KRB5_KPASSWD_VERS_CHANGEPW,
 758                                    &creds, principal, newpw);
 759
 760     krb5_free_principal(context, princ);
 761     krb5_free_context(context);
 762
 763     return aret;
 764 }
 765
 766
 767 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
 768                                  const char *auth_principal, const char *auth_password,
 769                                  const char *target_principal, const char *new_password,
 770                                  int time_offset)
 771 {
 772     int ret;
 773
 774     if ((ret = kerberos_kinit_password(auth_principal, auth_password, time_offset, NULL))) {
 775         DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
 776         return ADS_ERROR_KRB5(ret);
 777     }
 778
 779     if (!strcmp(auth_principal, target_principal))
 780         return ads_krb5_chg_password(kpasswd_server, target_principal,
 781                                      auth_password, new_password, time_offset);
 782     else
 783         return ads_krb5_set_password(kpasswd_server, target_principal,
 784                                      new_password, time_offset);
 785 }
 786
 787
 788 /**
 789  * Set the machine account password
 790  * @param ads connection to ads server
 791  * @param hostname machine whose password is being set
 792  * @param password new password
 793  * @return status of password change
 794  **/
 795 ADS_STATUS ads_set_machine_password(ADS_STRUCT *ads,
 796                                     const char *machine_account,
 797                                     const char *password)
 798 {
 799         ADS_STATUS status;
 800         char *principal = NULL;
 801
 802         /*
 803           we need to use the '$' form of the name here (the machine account name),
 804           as otherwise the server might end up setting the password for a user
 805           instead
 806          */
 807         asprintf(&principal, "%s@%s", machine_account, ads->config.realm);
 808
 809         status = ads_krb5_set_password(ads->auth.kdc_server, principal,
 810                                        password, ads->auth.time_offset);
 811
 812         free(principal);
 813
 814         return status;
 815 }
 816
 817
 818
 819 #endif