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