source3/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 #include "smb_krb5.h"
  23
  24 #ifdef HAVE_KRB5
  25
  26 #define DEFAULT_KPASSWD_PORT    464
  27
  28 #define KRB5_KPASSWD_VERS_CHANGEPW              1
  29
  30 #define KRB5_KPASSWD_VERS_SETPW                 0xff80
  31 #define KRB5_KPASSWD_VERS_SETPW_ALT             2
  32
  33 #define KRB5_KPASSWD_SUCCESS                    0
  34 #define KRB5_KPASSWD_MALFORMED                  1
  35 #define KRB5_KPASSWD_HARDERROR                  2
  36 #define KRB5_KPASSWD_AUTHERROR                  3
  37 #define KRB5_KPASSWD_SOFTERROR                  4
  38 #define KRB5_KPASSWD_ACCESSDENIED               5
  39 #define KRB5_KPASSWD_BAD_VERSION                6
  40 #define KRB5_KPASSWD_INITIAL_FLAG_NEEDED        7
  41
  42 /* Those are defined by kerberos-set-passwd-02.txt and are probably
  43  * not supported by M$ implementation */
  44 #define KRB5_KPASSWD_POLICY_REJECT              8
  45 #define KRB5_KPASSWD_BAD_PRINCIPAL              9
  46 #define KRB5_KPASSWD_ETYPE_NOSUPP               10
  47
  48 /*
  49  * we've got to be able to distinguish KRB_ERRORs from other
  50  * requests - valid response for CHPW v2 replies.
  51  */
  52
  53 #define krb5_is_krb_error(packet) \
  54         ( packet && packet->length && (((char *)packet->data)[0] == 0x7e || ((char *)packet->data)[0] == 0x5e))
  55
  56 /* This implements kerberos password change protocol as specified in
  57  * kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
  58  * as well as microsoft version of the protocol
  59  * as specified in kerberos-set-passwd-00.txt
  60  */
  61 static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
  62 {
  63         char* princ_part1 = NULL;
  64         char* princ_part2 = NULL;
  65         char* realm = NULL;
  66         char* c;
  67         char* princ;
  68
  69         ASN1_DATA *req;
  70         DATA_BLOB ret;
  71
  72
  73         princ = SMB_STRDUP(principal);
  74
  75         if ((c = strchr_m(princ, '/')) == NULL) {
  76                 c = princ;
  77         } else {
  78                 *c = '\0';
  79                 c++;
  80                 princ_part1 = princ;
  81         }
  82
  83         princ_part2 = c;
  84
  85         if ((c = strchr_m(c, '@')) != NULL) {
  86                 *c = '\0';
  87                 c++;
  88                 realm = c;
  89         } else {
  90                 /* We must have a realm component. */
  91                 return data_blob_null;
  92         }
  93
  94         req = asn1_init(talloc_tos());
  95         if (req == NULL) {
  96                 return data_blob_null;
  97         }
  98
  99         asn1_push_tag(req, ASN1_SEQUENCE(0));
 100         asn1_push_tag(req, ASN1_CONTEXT(0));
 101         asn1_write_OctetString(req, password, strlen(password));
 102         asn1_pop_tag(req);
 103
 104         asn1_push_tag(req, ASN1_CONTEXT(1));
 105         asn1_push_tag(req, ASN1_SEQUENCE(0));
 106
 107         asn1_push_tag(req, ASN1_CONTEXT(0));
 108         asn1_write_Integer(req, 1);
 109         asn1_pop_tag(req);
 110
 111         asn1_push_tag(req, ASN1_CONTEXT(1));
 112         asn1_push_tag(req, ASN1_SEQUENCE(0));
 113
 114         if (princ_part1) {
 115                 asn1_write_GeneralString(req, princ_part1);
 116         }
 117
 118         asn1_write_GeneralString(req, princ_part2);
 119         asn1_pop_tag(req);
 120         asn1_pop_tag(req);
 121         asn1_pop_tag(req);
 122         asn1_pop_tag(req);
 123
 124         asn1_push_tag(req, ASN1_CONTEXT(2));
 125         asn1_write_GeneralString(req, realm);
 126         asn1_pop_tag(req);
 127         asn1_pop_tag(req);
 128
 129         ret = data_blob(req->data, req->length);
 130         asn1_free(req);
 131
 132         free(princ);
 133
 134         return ret;
 135 }
 136
 137 static krb5_error_code build_kpasswd_request(uint16 pversion,
 138                                            krb5_context context,
 139                                            krb5_auth_context auth_context,
 140                                            krb5_data *ap_req,
 141                                            const char *princ,
 142                                            const char *passwd,
 143                                            bool use_tcp,
 144                                            krb5_data *packet)
 145 {
 146         krb5_error_code ret;
 147         krb5_data cipherpw;
 148         krb5_data encoded_setpw;
 149         krb5_replay_data replay;
 150         char *p, *msg_start;
 151         DATA_BLOB setpw;
 152         unsigned int msg_length;
 153
 154         ret = krb5_auth_con_setflags(context,
 155                                      auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 156         if (ret) {
 157                 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
 158                          error_message(ret)));
 159                 return ret;
 160         }
 161
 162         /* handle protocol differences in chpw and setpw */
 163         if (pversion  == KRB5_KPASSWD_VERS_CHANGEPW)
 164                 setpw = data_blob(passwd, strlen(passwd));
 165         else if (pversion == KRB5_KPASSWD_VERS_SETPW ||
 166                  pversion == KRB5_KPASSWD_VERS_SETPW_ALT)
 167                 setpw = encode_krb5_setpw(princ, passwd);
 168         else
 169                 return EINVAL;
 170
 171         if (setpw.data == NULL || setpw.length == 0) {
 172                 return EINVAL;
 173         }
 174
 175         encoded_setpw.data = (char *)setpw.data;
 176         encoded_setpw.length = setpw.length;
 177
 178         ret = krb5_mk_priv(context, auth_context,
 179                            &encoded_setpw, &cipherpw, &replay);
 180
 181         data_blob_free(&setpw);         /*from 'encode_krb5_setpw(...)' */
 182
 183         if (ret) {
 184                 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
 185                 return ret;
 186         }
 187
 188         packet->data = (char *)SMB_MALLOC(ap_req->length + cipherpw.length + (use_tcp ? 10 : 6 ));
 189         if (!packet->data)
 190                 return -1;
 191
 192
 193
 194         /* see the RFC for details */
 195
 196         msg_start = p = ((char *)packet->data) + (use_tcp ? 4 : 0);
 197         p += 2;
 198         RSSVAL(p, 0, pversion);
 199         p += 2;
 200         RSSVAL(p, 0, ap_req->length);
 201         p += 2;
 202         memcpy(p, ap_req->data, ap_req->length);
 203         p += ap_req->length;
 204         memcpy(p, cipherpw.data, cipherpw.length);
 205         p += cipherpw.length;
 206         packet->length = PTR_DIFF(p,packet->data);
 207         msg_length = PTR_DIFF(p,msg_start);
 208
 209         if (use_tcp) {
 210                 RSIVAL(packet->data, 0, msg_length);
 211         }
 212         RSSVAL(msg_start, 0, msg_length);
 213
 214         free(cipherpw.data);    /* from 'krb5_mk_priv(...)' */
 215
 216         return 0;
 217 }
 218
 219 static const struct kpasswd_errors {
 220         int result_code;
 221         const char *error_string;
 222 } kpasswd_errors[] = {
 223         {KRB5_KPASSWD_MALFORMED, "Malformed request error"},
 224         {KRB5_KPASSWD_HARDERROR, "Server error"},
 225         {KRB5_KPASSWD_AUTHERROR, "Authentication error"},
 226         {KRB5_KPASSWD_SOFTERROR, "Password change rejected"},
 227         {KRB5_KPASSWD_ACCESSDENIED, "Client does not have proper authorization"},
 228         {KRB5_KPASSWD_BAD_VERSION, "Protocol version not supported"},
 229         {KRB5_KPASSWD_INITIAL_FLAG_NEEDED, "Authorization ticket must have initial flag set"},
 230         {KRB5_KPASSWD_POLICY_REJECT, "Password rejected due to policy requirements"},
 231         {KRB5_KPASSWD_BAD_PRINCIPAL, "Target principal does not exist"},
 232         {KRB5_KPASSWD_ETYPE_NOSUPP, "Unsupported encryption type"},
 233         {0, NULL}
 234 };
 235
 236 static krb5_error_code setpw_result_code_string(krb5_context context,
 237                                                 int result_code,
 238                                                 const char **code_string)
 239 {
 240         unsigned int idx = 0;
 241
 242         while (kpasswd_errors[idx].error_string != NULL) {
 243                 if (kpasswd_errors[idx].result_code ==
 244                     result_code) {
 245                         *code_string = kpasswd_errors[idx].error_string;
 246                         return 0;
 247                 }
 248                 idx++;
 249         }
 250         *code_string = "Password change failed";
 251         return (0);
 252 }
 253
 254  krb5_error_code kpasswd_err_to_krb5_err(krb5_error_code res_code)
 255 {
 256         switch(res_code) {
 257                 case KRB5_KPASSWD_ACCESSDENIED:
 258                         return KRB5KDC_ERR_BADOPTION;
 259                 case KRB5_KPASSWD_INITIAL_FLAG_NEEDED:
 260                         return KRB5KDC_ERR_BADOPTION;
 261                         /* return KV5M_ALT_METHOD; MIT-only define */
 262                 case KRB5_KPASSWD_ETYPE_NOSUPP:
 263                         return KRB5KDC_ERR_ETYPE_NOSUPP;
 264                 case KRB5_KPASSWD_BAD_PRINCIPAL:
 265                         return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 266                 case KRB5_KPASSWD_POLICY_REJECT:
 267                 case KRB5_KPASSWD_SOFTERROR:
 268                         return KRB5KDC_ERR_POLICY;
 269                 default:
 270                         return KRB5KRB_ERR_GENERIC;
 271         }
 272 }
 273 static krb5_error_code parse_setpw_reply(krb5_context context,
 274                                          bool use_tcp,
 275                                          krb5_auth_context auth_context,
 276                                          krb5_data *packet)
 277 {
 278         krb5_data ap_rep;
 279         char *p;
 280         int vnum, ret, res_code;
 281         krb5_data cipherresult;
 282         krb5_data clearresult;
 283         krb5_ap_rep_enc_part *ap_rep_enc;
 284         krb5_replay_data replay;
 285         unsigned int msg_length = packet->length;
 286
 287
 288         if (packet->length < (use_tcp ? 8 : 4)) {
 289                 return KRB5KRB_AP_ERR_MODIFIED;
 290         }
 291
 292         p = (char *)packet->data;
 293         /*
 294         ** see if it is an error
 295         */
 296         if (krb5_is_krb_error(packet)) {
 297
 298                 ret = handle_krberror_packet(context, packet);
 299                 if (ret) {
 300                         return ret;
 301                 }
 302         }
 303
 304
 305         /* tcp... */
 306         if (use_tcp) {
 307                 msg_length -= 4;
 308                 if (RIVAL(p, 0) != msg_length) {
 309                         DEBUG(1,("Bad TCP packet length (%d/%d) from kpasswd server\n",
 310                         RIVAL(p, 0), msg_length));
 311                         return KRB5KRB_AP_ERR_MODIFIED;
 312                 }
 313
 314                 p += 4;
 315         }
 316
 317         if (RSVAL(p, 0) != msg_length) {
 318                 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
 319                          RSVAL(p, 0), msg_length));
 320                 return KRB5KRB_AP_ERR_MODIFIED;
 321         }
 322
 323         p += 2;
 324
 325         vnum = RSVAL(p, 0); p += 2;
 326
 327         /* FIXME: According to standard there is only one type of reply */
 328         if (vnum != KRB5_KPASSWD_VERS_SETPW &&
 329             vnum != KRB5_KPASSWD_VERS_SETPW_ALT &&
 330             vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
 331                 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
 332                 return KRB5KDC_ERR_BAD_PVNO;
 333         }
 334
 335         ap_rep.length = RSVAL(p, 0); p += 2;
 336
 337         if (p + ap_rep.length >= (char *)packet->data + packet->length) {
 338                 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
 339                 return KRB5KRB_AP_ERR_MODIFIED;
 340         }
 341
 342         if (ap_rep.length == 0) {
 343                 DEBUG(1,("got unencrypted setpw result?!\n"));
 344                 return KRB5KRB_AP_ERR_MODIFIED;
 345         }
 346
 347         /* verify ap_rep */
 348         ap_rep.data = p;
 349         p += ap_rep.length;
 350
 351         ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
 352         if (ret) {
 353                 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
 354                 return KRB5KRB_AP_ERR_MODIFIED;
 355         }
 356
 357         krb5_free_ap_rep_enc_part(context, ap_rep_enc);
 358
 359         cipherresult.data = p;
 360         cipherresult.length = ((char *)packet->data + packet->length) - p;
 361
 362         ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
 363                            &replay);
 364         if (ret) {
 365                 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
 366                 return KRB5KRB_AP_ERR_MODIFIED;
 367         }
 368
 369         if (clearresult.length < 2) {
 370                 free(clearresult.data);
 371                 ret = KRB5KRB_AP_ERR_MODIFIED;
 372                 return KRB5KRB_AP_ERR_MODIFIED;
 373         }
 374
 375         p = (char *)clearresult.data;
 376
 377         res_code = RSVAL(p, 0);
 378
 379         free(clearresult.data);
 380
 381         if ((res_code < KRB5_KPASSWD_SUCCESS) ||
 382             (res_code > KRB5_KPASSWD_ETYPE_NOSUPP)) {
 383                 return KRB5KRB_AP_ERR_MODIFIED;
 384         }
 385
 386         if (res_code == KRB5_KPASSWD_SUCCESS) {
 387                 return 0;
 388         } else {
 389                 const char *errstr;
 390                 setpw_result_code_string(context, res_code, &errstr);
 391                 DEBUG(1, ("Error changing password: %s (%d)\n", errstr, res_code));
 392
 393                 return kpasswd_err_to_krb5_err(res_code);
 394         }
 395 }
 396
 397 static ADS_STATUS do_krb5_kpasswd_request(krb5_context context,
 398                                           const char *kdc_host,
 399                                           uint16 pversion,
 400                                           krb5_creds *credsp,
 401                                           const char *princ,
 402                                           const char *newpw)
 403 {
 404         krb5_auth_context auth_context = NULL;
 405         krb5_data ap_req, chpw_req, chpw_rep;
 406         int ret, sock;
 407         socklen_t addr_len;
 408         struct sockaddr_storage remote_addr, local_addr;
 409         struct sockaddr_storage addr;
 410         krb5_address local_kaddr, remote_kaddr;
 411         bool use_tcp = False;
 412
 413
 414         if (!interpret_string_addr(&addr, kdc_host, 0)) {
 415         }
 416
 417         ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
 418                                    NULL, credsp, &ap_req);
 419         if (ret) {
 420                 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
 421                 return ADS_ERROR_KRB5(ret);
 422         }
 423
 424         do {
 425
 426                 if (!use_tcp) {
 427
 428                         sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
 429                         if (sock == -1) {
 430                                 int rc = errno;
 431                                 SAFE_FREE(ap_req.data);
 432                                 krb5_auth_con_free(context, auth_context);
 433                                 DEBUG(1,("failed to open kpasswd socket to %s "
 434                                          "(%s)\n", kdc_host, strerror(errno)));
 435                                 return ADS_ERROR_SYSTEM(rc);
 436                         }
 437                 } else {
 438                         NTSTATUS status;
 439                         status = open_socket_out(&addr, DEFAULT_KPASSWD_PORT,
 440                                                  LONG_CONNECT_TIMEOUT, &sock);
 441                         if (!NT_STATUS_IS_OK(status)) {
 442                                 SAFE_FREE(ap_req.data);
 443                                 krb5_auth_con_free(context, auth_context);
 444                                 DEBUG(1,("failed to open kpasswd socket to %s "
 445                                          "(%s)\n", kdc_host,
 446                                          nt_errstr(status)));
 447                                 return ADS_ERROR_NT(status);
 448                         }
 449                 }
 450
 451                 addr_len = sizeof(remote_addr);
 452                 if (getpeername(sock, (struct sockaddr *)&remote_addr, &addr_len) != 0) {
 453                         close(sock);
 454                         SAFE_FREE(ap_req.data);
 455                         krb5_auth_con_free(context, auth_context);
 456                         DEBUG(1,("getpeername() failed (%s)\n", error_message(errno)));
 457                         return ADS_ERROR_SYSTEM(errno);
 458                 }
 459                 addr_len = sizeof(local_addr);
 460                 if (getsockname(sock, (struct sockaddr *)&local_addr, &addr_len) != 0) {
 461                         close(sock);
 462                         SAFE_FREE(ap_req.data);
 463                         krb5_auth_con_free(context, auth_context);
 464                         DEBUG(1,("getsockname() failed (%s)\n", error_message(errno)));
 465                         return ADS_ERROR_SYSTEM(errno);
 466                 }
 467                 if (!setup_kaddr(&remote_kaddr, &remote_addr) ||
 468                                 !setup_kaddr(&local_kaddr, &local_addr)) {
 469                         DEBUG(1,("do_krb5_kpasswd_request: "
 470                                 "Failed to setup addresses.\n"));
 471                         close(sock);
 472                         SAFE_FREE(ap_req.data);
 473                         krb5_auth_con_free(context, auth_context);
 474                         errno = EINVAL;
 475                         return ADS_ERROR_SYSTEM(EINVAL);
 476                 }
 477
 478                 ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
 479                 if (ret) {
 480                         close(sock);
 481                         SAFE_FREE(ap_req.data);
 482                         krb5_auth_con_free(context, auth_context);
 483                         DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
 484                         return ADS_ERROR_KRB5(ret);
 485                 }
 486
 487                 ret = build_kpasswd_request(pversion, context, auth_context, &ap_req,
 488                                           princ, newpw, use_tcp, &chpw_req);
 489                 if (ret) {
 490                         close(sock);
 491                         SAFE_FREE(ap_req.data);
 492                         krb5_auth_con_free(context, auth_context);
 493                         DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
 494                         return ADS_ERROR_KRB5(ret);
 495                 }
 496
 497                 ret = write(sock, chpw_req.data, chpw_req.length);
 498
 499                 if (ret != chpw_req.length) {
 500                         close(sock);
 501                         SAFE_FREE(chpw_req.data);
 502                         SAFE_FREE(ap_req.data);
 503                         krb5_auth_con_free(context, auth_context);
 504                         DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
 505                         return ADS_ERROR_SYSTEM(errno);
 506                 }
 507
 508                 SAFE_FREE(chpw_req.data);
 509
 510                 chpw_rep.length = 1500;
 511                 chpw_rep.data = (char *) SMB_MALLOC(chpw_rep.length);
 512                 if (!chpw_rep.data) {
 513                         close(sock);
 514                         SAFE_FREE(ap_req.data);
 515                         krb5_auth_con_free(context, auth_context);
 516                         DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
 517                         errno = ENOMEM;
 518                         return ADS_ERROR_SYSTEM(errno);
 519                 }
 520
 521                 ret = read(sock, chpw_rep.data, chpw_rep.length);
 522                 if (ret < 0) {
 523                         close(sock);
 524                         SAFE_FREE(chpw_rep.data);
 525                         SAFE_FREE(ap_req.data);
 526                         krb5_auth_con_free(context, auth_context);
 527                         DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
 528                         return ADS_ERROR_SYSTEM(errno);
 529                 }
 530
 531                 close(sock);
 532                 chpw_rep.length = ret;
 533
 534                 ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
 535                 if (ret) {
 536                         SAFE_FREE(chpw_rep.data);
 537                         SAFE_FREE(ap_req.data);
 538                         krb5_auth_con_free(context, auth_context);
 539                         DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
 540                                  error_message(ret)));
 541                         return ADS_ERROR_KRB5(ret);
 542                 }
 543
 544                 ret = parse_setpw_reply(context, use_tcp, auth_context, &chpw_rep);
 545                 SAFE_FREE(chpw_rep.data);
 546
 547                 if (ret) {
 548
 549                         if (ret == KRB5KRB_ERR_RESPONSE_TOO_BIG && !use_tcp) {
 550                                 DEBUG(5, ("Trying setpw with TCP!!!\n"));
 551                                 use_tcp = True;
 552                                 continue;
 553                         }
 554
 555                         SAFE_FREE(ap_req.data);
 556                         krb5_auth_con_free(context, auth_context);
 557                         DEBUG(1,("parse_setpw_reply failed (%s)\n",
 558                                  error_message(ret)));
 559                         return ADS_ERROR_KRB5(ret);
 560                 }
 561
 562                 SAFE_FREE(ap_req.data);
 563                 krb5_auth_con_free(context, auth_context);
 564         } while ( ret );
 565
 566         return ADS_SUCCESS;
 567 }
 568
 569 ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *princ,
 570                                  const char *newpw, int time_offset)
 571 {
 572
 573         ADS_STATUS aret;
 574         krb5_error_code ret = 0;
 575         krb5_context context = NULL;
 576         krb5_principal principal = NULL;
 577         char *princ_name = NULL;
 578         char *realm = NULL;
 579         krb5_creds creds, *credsp = NULL;
 580 #if KRB5_PRINC_REALM_RETURNS_REALM
 581         krb5_realm orig_realm;
 582 #else
 583         krb5_data orig_realm;
 584 #endif
 585         krb5_ccache ccache = NULL;
 586
 587         ZERO_STRUCT(creds);
 588
 589         initialize_krb5_error_table();
 590         ret = krb5_init_context(&context);
 591         if (ret) {
 592                 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
 593                 return ADS_ERROR_KRB5(ret);
 594         }
 595
 596         if (time_offset != 0) {
 597                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
 598         }
 599
 600         ret = krb5_cc_default(context, &ccache);
 601         if (ret) {
 602                 krb5_free_context(context);
 603                 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
 604                 return ADS_ERROR_KRB5(ret);
 605         }
 606
 607         realm = strchr_m(princ, '@');
 608         if (!realm) {
 609                 krb5_cc_close(context, ccache);
 610                 krb5_free_context(context);
 611                 DEBUG(1,("Failed to get realm\n"));
 612                 return ADS_ERROR_KRB5(-1);
 613         }
 614         realm++;
 615
 616         if (asprintf(&princ_name, "kadmin/changepw@%s", realm) == -1) {
 617                 krb5_cc_close(context, ccache);
 618                 krb5_free_context(context);
 619                 DEBUG(1,("asprintf failed\n"));
 620                 return ADS_ERROR_NT(NT_STATUS_NO_MEMORY);
 621         }
 622
 623         ret = smb_krb5_parse_name(context, princ_name, &creds.server);
 624         if (ret) {
 625                 krb5_cc_close(context, ccache);
 626                 krb5_free_context(context);
 627                 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
 628                 return ADS_ERROR_KRB5(ret);
 629         }
 630
 631         /* parse the principal we got as a function argument */
 632         ret = smb_krb5_parse_name(context, princ, &principal);
 633         if (ret) {
 634                 krb5_cc_close(context, ccache);
 635                 krb5_free_principal(context, creds.server);
 636                 krb5_free_context(context);
 637                 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
 638                 free(princ_name);
 639                 return ADS_ERROR_KRB5(ret);
 640         }
 641
 642         free(princ_name);
 643
 644         /* The creds.server principal takes ownership of this memory.
 645                 Remember to set back to original value before freeing. */
 646         orig_realm = *krb5_princ_realm(context, creds.server);
 647         krb5_princ_set_realm(context, creds.server, krb5_princ_realm(context, principal));
 648
 649         ret = krb5_cc_get_principal(context, ccache, &creds.client);
 650         if (ret) {
 651                 krb5_cc_close(context, ccache);
 652                 krb5_princ_set_realm(context, creds.server, &orig_realm);
 653                 krb5_free_principal(context, creds.server);
 654                 krb5_free_principal(context, principal);
 655                 krb5_free_context(context);
 656                 DEBUG(1,("Failed to get principal from ccache (%s)\n",
 657                          error_message(ret)));
 658                 return ADS_ERROR_KRB5(ret);
 659         }
 660
 661         ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
 662         if (ret) {
 663                 krb5_cc_close(context, ccache);
 664                 krb5_free_principal(context, creds.client);
 665                 krb5_princ_set_realm(context, creds.server, &orig_realm);
 666                 krb5_free_principal(context, creds.server);
 667                 krb5_free_principal(context, principal);
 668                 krb5_free_context(context);
 669                 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
 670                 return ADS_ERROR_KRB5(ret);
 671         }
 672
 673         /* we might have to call krb5_free_creds(...) from now on ... */
 674
 675         aret = do_krb5_kpasswd_request(context, kdc_host,
 676                                        KRB5_KPASSWD_VERS_SETPW,
 677                                        credsp, princ, newpw);
 678
 679         krb5_free_creds(context, credsp);
 680         krb5_free_principal(context, creds.client);
 681         krb5_princ_set_realm(context, creds.server, &orig_realm);
 682         krb5_free_principal(context, creds.server);
 683         krb5_free_principal(context, principal);
 684         krb5_cc_close(context, ccache);
 685         krb5_free_context(context);
 686
 687         return aret;
 688 }
 689
 690 /*
 691   we use a prompter to avoid a crash bug in the kerberos libs when
 692   dealing with empty passwords
 693   this prompter is just a string copy ...
 694 */
 695 static krb5_error_code
 696 kerb_prompter(krb5_context ctx, void *data,
 697                const char *name,
 698                const char *banner,
 699                int num_prompts,
 700                krb5_prompt prompts[])
 701 {
 702         if (num_prompts == 0) return 0;
 703
 704         memset(prompts[0].reply->data, 0, prompts[0].reply->length);
 705         if (prompts[0].reply->length > 0) {
 706                 if (data) {
 707                         strncpy((char *)prompts[0].reply->data,
 708                                 (const char *)data,
 709                                 prompts[0].reply->length-1);
 710                         prompts[0].reply->length = strlen((const char *)prompts[0].reply->data);
 711                 } else {
 712                         prompts[0].reply->length = 0;
 713                 }
 714         }
 715         return 0;
 716 }
 717
 718 static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
 719                                         const char *principal,
 720                                         const char *oldpw,
 721                                         const char *newpw,
 722                                         int time_offset)
 723 {
 724     ADS_STATUS aret;
 725     krb5_error_code ret;
 726     krb5_context context = NULL;
 727     krb5_principal princ;
 728     krb5_get_init_creds_opt opts;
 729     krb5_creds creds;
 730     char *chpw_princ = NULL, *password;
 731
 732     initialize_krb5_error_table();
 733     ret = krb5_init_context(&context);
 734     if (ret) {
 735         DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
 736         return ADS_ERROR_KRB5(ret);
 737     }
 738
 739     if ((ret = smb_krb5_parse_name(context, principal,
 740                                     &princ))) {
 741         krb5_free_context(context);
 742         DEBUG(1,("Failed to parse %s (%s)\n", principal, error_message(ret)));
 743         return ADS_ERROR_KRB5(ret);
 744     }
 745
 746     krb5_get_init_creds_opt_init(&opts);
 747     krb5_get_init_creds_opt_set_tkt_life(&opts, 5*60);
 748     krb5_get_init_creds_opt_set_renew_life(&opts, 0);
 749     krb5_get_init_creds_opt_set_forwardable(&opts, 0);
 750     krb5_get_init_creds_opt_set_proxiable(&opts, 0);
 751
 752     /* We have to obtain an INITIAL changepw ticket for changing password */
 753     if (asprintf(&chpw_princ, "kadmin/changepw@%s",
 754                                 (char *) krb5_princ_realm(context, princ)) == -1) {
 755         krb5_free_context(context);
 756         DEBUG(1,("ads_krb5_chg_password: asprintf fail\n"));
 757         return ADS_ERROR_NT(NT_STATUS_NO_MEMORY);
 758     }
 759
 760     password = SMB_STRDUP(oldpw);
 761     ret = krb5_get_init_creds_password(context, &creds, princ, password,
 762                                            kerb_prompter, NULL,
 763                                            0, chpw_princ, &opts);
 764     SAFE_FREE(chpw_princ);
 765     SAFE_FREE(password);
 766
 767     if (ret) {
 768       if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
 769         DEBUG(1,("Password incorrect while getting initial ticket"));
 770       else
 771         DEBUG(1,("krb5_get_init_creds_password failed (%s)\n", error_message(ret)));
 772
 773         krb5_free_principal(context, princ);
 774         krb5_free_context(context);
 775         return ADS_ERROR_KRB5(ret);
 776     }
 777
 778     aret = do_krb5_kpasswd_request(context, kdc_host,
 779                                    KRB5_KPASSWD_VERS_CHANGEPW,
 780                                    &creds, principal, newpw);
 781
 782     krb5_free_principal(context, princ);
 783     krb5_free_context(context);
 784
 785     return aret;
 786 }
 787
 788
 789 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
 790                                  const char *auth_principal, const char *auth_password,
 791                                  const char *target_principal, const char *new_password,
 792                                  int time_offset)
 793 {
 794     int ret;
 795
 796     if ((ret = kerberos_kinit_password(auth_principal, auth_password, time_offset, NULL))) {
 797         DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
 798         return ADS_ERROR_KRB5(ret);
 799     }
 800
 801     if (!strcmp(auth_principal, target_principal))
 802         return ads_krb5_chg_password(kpasswd_server, target_principal,
 803                                      auth_password, new_password, time_offset);
 804     else
 805         return ads_krb5_set_password(kpasswd_server, target_principal,
 806                                      new_password, time_offset);
 807 }
 808
 809
 810 /**
 811  * Set the machine account password
 812  * @param ads connection to ads server
 813  * @param hostname machine whose password is being set
 814  * @param password new password
 815  * @return status of password change
 816  **/
 817 ADS_STATUS ads_set_machine_password(ADS_STRUCT *ads,
 818                                     const char *machine_account,
 819                                     const char *password)
 820 {
 821         ADS_STATUS status;
 822         char *principal = NULL;
 823
 824         /*
 825           we need to use the '$' form of the name here (the machine account name),
 826           as otherwise the server might end up setting the password for a user
 827           instead
 828          */
 829         if (asprintf(&principal, "%s@%s", machine_account, ads->config.realm) < 0) {
 830                 return ADS_ERROR_NT(NT_STATUS_NO_MEMORY);
 831         }
 832
 833         status = ads_krb5_set_password(ads->auth.kdc_server, principal,
 834                                        password, ads->auth.time_offset);
 835
 836         SAFE_FREE(principal);
 837         return status;
 838 }
 839 #endif