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