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 2 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, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.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 /* This implements kerberos password change protocol as specified in
  49  * kerb-chg-password-02.txt and kerberos-set-passwd-02.txt
  50  * as well as microsoft version of the protocol
  51  * as specified in kerberos-set-passwd-00.txt
  52  */
  53 static DATA_BLOB encode_krb5_setpw(const char *principal, const char *password)
  54 {
  55         char* princ_part1 = NULL;
  56         char* princ_part2 = NULL;
  57         char* realm = NULL;
  58         char* c;
  59         char* princ;
  60
  61         ASN1_DATA req;
  62         DATA_BLOB ret;
  63
  64
  65         princ = SMB_STRDUP(principal);
  66
  67         if ((c = strchr_m(princ, '/')) == NULL) {
  68                 c = princ;
  69         } else {
  70                 *c = '\0';
  71                 c++;
  72                 princ_part1 = princ;
  73         }
  74
  75         princ_part2 = c;
  76
  77         if ((c = strchr_m(c, '@')) != NULL) {
  78                 *c = '\0';
  79                 c++;
  80                 realm = c;
  81         } else {
  82                 /* We must have a realm component. */
  83                 return data_blob(NULL, 0);
  84         }
  85
  86         memset(&req, 0, sizeof(req));
  87
  88         asn1_push_tag(&req, ASN1_SEQUENCE(0));
  89         asn1_push_tag(&req, ASN1_CONTEXT(0));
  90         asn1_write_OctetString(&req, password, strlen(password));
  91         asn1_pop_tag(&req);
  92
  93         asn1_push_tag(&req, ASN1_CONTEXT(1));
  94         asn1_push_tag(&req, ASN1_SEQUENCE(0));
  95
  96         asn1_push_tag(&req, ASN1_CONTEXT(0));
  97         asn1_write_Integer(&req, 1);
  98         asn1_pop_tag(&req);
  99
 100         asn1_push_tag(&req, ASN1_CONTEXT(1));
 101         asn1_push_tag(&req, ASN1_SEQUENCE(0));
 102
 103         if (princ_part1) {
 104                 asn1_write_GeneralString(&req, princ_part1);
 105         }
 106
 107         asn1_write_GeneralString(&req, princ_part2);
 108         asn1_pop_tag(&req);
 109         asn1_pop_tag(&req);
 110         asn1_pop_tag(&req);
 111         asn1_pop_tag(&req);
 112
 113         asn1_push_tag(&req, ASN1_CONTEXT(2));
 114         asn1_write_GeneralString(&req, realm);
 115         asn1_pop_tag(&req);
 116         asn1_pop_tag(&req);
 117
 118         ret = data_blob(req.data, req.length);
 119         asn1_free(&req);
 120
 121         free(princ);
 122
 123         return ret;
 124 }
 125
 126 static krb5_error_code build_kpasswd_request(uint16 pversion,
 127                                            krb5_context context,
 128                                            krb5_auth_context auth_context,
 129                                            krb5_data *ap_req,
 130                                            const char *princ,
 131                                            const char *passwd,
 132                                            krb5_data *packet)
 133 {
 134         krb5_error_code ret;
 135         krb5_data cipherpw;
 136         krb5_data encoded_setpw;
 137         krb5_replay_data replay;
 138         char *p;
 139         DATA_BLOB setpw;
 140
 141         ret = krb5_auth_con_setflags(context,
 142                                      auth_context,KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 143         if (ret) {
 144                 DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
 145                          error_message(ret)));
 146                 return ret;
 147         }
 148
 149         /* handle protocol differences in chpw and setpw */
 150         if (pversion  == KRB5_KPASSWD_VERS_CHANGEPW)
 151                 setpw = data_blob(passwd, strlen(passwd));
 152         else if (pversion == KRB5_KPASSWD_VERS_SETPW ||
 153                  pversion == KRB5_KPASSWD_VERS_SETPW_ALT)
 154                 setpw = encode_krb5_setpw(princ, passwd);
 155         else
 156                 return EINVAL;
 157
 158         if (setpw.data == NULL || setpw.length == 0) {
 159                 return EINVAL;
 160         }
 161
 162         encoded_setpw.data = (char *)setpw.data;
 163         encoded_setpw.length = setpw.length;
 164
 165         ret = krb5_mk_priv(context, auth_context,
 166                            &encoded_setpw, &cipherpw, &replay);
 167
 168         data_blob_free(&setpw);         /*from 'encode_krb5_setpw(...)' */
 169
 170         if (ret) {
 171                 DEBUG(1,("krb5_mk_priv failed (%s)\n", error_message(ret)));
 172                 return ret;
 173         }
 174
 175         packet->data = (char *)SMB_MALLOC(ap_req->length + cipherpw.length + 6);
 176         if (!packet->data)
 177                 return -1;
 178
 179         /* see the RFC for details */
 180         p = ((char *)packet->data) + 2;
 181         RSSVAL(p, 0, pversion);
 182         p += 2;
 183         RSSVAL(p, 0, ap_req->length);
 184         p += 2;
 185         memcpy(p, ap_req->data, ap_req->length);
 186         p += ap_req->length;
 187         memcpy(p, cipherpw.data, cipherpw.length);
 188         p += cipherpw.length;
 189         packet->length = PTR_DIFF(p,packet->data);
 190         RSSVAL(packet->data, 0, packet->length);
 191
 192         free(cipherpw.data);    /* from 'krb5_mk_priv(...)' */
 193
 194         return 0;
 195 }
 196
 197 static const struct kpasswd_errors {
 198         int result_code;
 199         const char *error_string;
 200 } kpasswd_errors[] = {
 201         {KRB5_KPASSWD_MALFORMED, "Malformed request error"},
 202         {KRB5_KPASSWD_HARDERROR, "Server error"},
 203         {KRB5_KPASSWD_AUTHERROR, "Authentication error"},
 204         {KRB5_KPASSWD_SOFTERROR, "Password change rejected"},
 205         {KRB5_KPASSWD_ACCESSDENIED, "Client does not have proper authorization"},
 206         {KRB5_KPASSWD_BAD_VERSION, "Protocol version not supported"},
 207         {KRB5_KPASSWD_INITIAL_FLAG_NEEDED, "Authorization ticket must have initial flag set"},
 208         {KRB5_KPASSWD_POLICY_REJECT, "Password rejected due to policy requirements"},
 209         {KRB5_KPASSWD_BAD_PRINCIPAL, "Target principal does not exist"},
 210         {KRB5_KPASSWD_ETYPE_NOSUPP, "Unsupported encryption type"},
 211         {0, NULL}
 212 };
 213
 214 static krb5_error_code setpw_result_code_string(krb5_context context,
 215                                                 int result_code,
 216                                                 const char **code_string)
 217 {
 218         unsigned int idx = 0;
 219
 220         while (kpasswd_errors[idx].error_string != NULL) {
 221                 if (kpasswd_errors[idx].result_code ==
 222                     result_code) {
 223                         *code_string = kpasswd_errors[idx].error_string;
 224                         return 0;
 225                 }
 226                 idx++;
 227         }
 228         *code_string = "Password change failed";
 229         return (0);
 230 }
 231
 232  krb5_error_code kpasswd_err_to_krb5_err(krb5_error_code res_code)
 233 {
 234         switch(res_code) {
 235                 case KRB5_KPASSWD_ACCESSDENIED:
 236                         return KRB5KDC_ERR_BADOPTION;
 237                 case KRB5_KPASSWD_INITIAL_FLAG_NEEDED:
 238                         return KRB5KDC_ERR_BADOPTION;
 239                         /* return KV5M_ALT_METHOD; MIT-only define */
 240                 case KRB5_KPASSWD_ETYPE_NOSUPP:
 241                         return KRB5KDC_ERR_ETYPE_NOSUPP;
 242                 case KRB5_KPASSWD_BAD_PRINCIPAL:
 243                         return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 244                 case KRB5_KPASSWD_POLICY_REJECT:
 245                 case KRB5_KPASSWD_SOFTERROR:
 246                         return KRB5KDC_ERR_POLICY;
 247                 default:
 248                         return KRB5KRB_ERR_GENERIC;
 249         }
 250 }
 251 static krb5_error_code parse_setpw_reply(krb5_context context,
 252                                          krb5_auth_context auth_context,
 253                                          krb5_data *packet)
 254 {
 255         krb5_data ap_rep;
 256         char *p;
 257         int vnum, ret, res_code;
 258         krb5_data cipherresult;
 259         krb5_data clearresult;
 260         krb5_ap_rep_enc_part *ap_rep_enc;
 261         krb5_replay_data replay;
 262
 263         if (packet->length < 4) {
 264                 return KRB5KRB_AP_ERR_MODIFIED;
 265         }
 266
 267         p = packet->data;
 268
 269         if (((char *)packet->data)[0] == 0x7e || ((char *)packet->data)[0] == 0x5e) {
 270                 /* it's an error packet. We should parse it ... */
 271                 DEBUG(1,("Got error packet 0x%x from kpasswd server\n",
 272                          ((char *)packet->data)[0]));
 273                 return KRB5KRB_AP_ERR_MODIFIED;
 274         }
 275
 276         if (RSVAL(p, 0) != packet->length) {
 277                 DEBUG(1,("Bad packet length (%d/%d) from kpasswd server\n",
 278                          RSVAL(p, 0), packet->length));
 279                 return KRB5KRB_AP_ERR_MODIFIED;
 280         }
 281
 282         p += 2;
 283
 284         vnum = RSVAL(p, 0); p += 2;
 285
 286         /* FIXME: According to standard there is only one type of reply */
 287         if (vnum != KRB5_KPASSWD_VERS_SETPW &&
 288             vnum != KRB5_KPASSWD_VERS_SETPW_ALT &&
 289             vnum != KRB5_KPASSWD_VERS_CHANGEPW) {
 290                 DEBUG(1,("Bad vnum (%d) from kpasswd server\n", vnum));
 291                 return KRB5KDC_ERR_BAD_PVNO;
 292         }
 293
 294         ap_rep.length = RSVAL(p, 0); p += 2;
 295
 296         if (p + ap_rep.length >= (char *)packet->data + packet->length) {
 297                 DEBUG(1,("ptr beyond end of packet from kpasswd server\n"));
 298                 return KRB5KRB_AP_ERR_MODIFIED;
 299         }
 300
 301         if (ap_rep.length == 0) {
 302                 DEBUG(1,("got unencrypted setpw result?!\n"));
 303                 return KRB5KRB_AP_ERR_MODIFIED;
 304         }
 305
 306         /* verify ap_rep */
 307         ap_rep.data = p;
 308         p += ap_rep.length;
 309
 310         ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc);
 311         if (ret) {
 312                 DEBUG(1,("failed to rd setpw reply (%s)\n", error_message(ret)));
 313                 return KRB5KRB_AP_ERR_MODIFIED;
 314         }
 315
 316         krb5_free_ap_rep_enc_part(context, ap_rep_enc);
 317
 318         cipherresult.data = p;
 319         cipherresult.length = ((char *)packet->data + packet->length) - p;
 320
 321         ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
 322                            &replay);
 323         if (ret) {
 324                 DEBUG(1,("failed to decrypt setpw reply (%s)\n", error_message(ret)));
 325                 return KRB5KRB_AP_ERR_MODIFIED;
 326         }
 327
 328         if (clearresult.length < 2) {
 329                 free(clearresult.data);
 330                 ret = KRB5KRB_AP_ERR_MODIFIED;
 331                 return KRB5KRB_AP_ERR_MODIFIED;
 332         }
 333
 334         p = clearresult.data;
 335
 336         res_code = RSVAL(p, 0);
 337
 338         free(clearresult.data);
 339
 340         if ((res_code < KRB5_KPASSWD_SUCCESS) ||
 341             (res_code > KRB5_KPASSWD_ETYPE_NOSUPP)) {
 342                 return KRB5KRB_AP_ERR_MODIFIED;
 343         }
 344
 345         if(res_code == KRB5_KPASSWD_SUCCESS)
 346                         return 0;
 347         else {
 348                 const char *errstr;
 349                 setpw_result_code_string(context, res_code, &errstr);
 350                 DEBUG(1, ("Error changing password: %s (%d)\n", errstr, res_code));
 351
 352                 return kpasswd_err_to_krb5_err(res_code);
 353         }
 354 }
 355
 356 static ADS_STATUS do_krb5_kpasswd_request(krb5_context context,
 357                                           const char *kdc_host,
 358                                           uint16 pversion,
 359                                           krb5_creds *credsp,
 360                                           const char *princ,
 361                                           const char *newpw)
 362 {
 363         krb5_auth_context auth_context = NULL;
 364         krb5_data ap_req, chpw_req, chpw_rep;
 365         int ret, sock;
 366         socklen_t addr_len;
 367         struct sockaddr remote_addr, local_addr;
 368         krb5_address local_kaddr, remote_kaddr;
 369
 370         ret = krb5_mk_req_extended(context, &auth_context, AP_OPTS_USE_SUBKEY,
 371                                    NULL, credsp, &ap_req);
 372         if (ret) {
 373                 DEBUG(1,("krb5_mk_req_extended failed (%s)\n", error_message(ret)));
 374                 return ADS_ERROR_KRB5(ret);
 375         }
 376
 377         sock = open_udp_socket(kdc_host, DEFAULT_KPASSWD_PORT);
 378         if (sock == -1) {
 379                 int rc = errno;
 380                 free(ap_req.data);
 381                 krb5_auth_con_free(context, auth_context);
 382                 DEBUG(1,("failed to open kpasswd socket to %s (%s)\n",
 383                          kdc_host, strerror(errno)));
 384                 return ADS_ERROR_SYSTEM(rc);
 385         }
 386
 387         addr_len = sizeof(remote_addr);
 388         getpeername(sock, &remote_addr, &addr_len);
 389         addr_len = sizeof(local_addr);
 390         getsockname(sock, &local_addr, &addr_len);
 391
 392         setup_kaddr(&remote_kaddr, &remote_addr);
 393         setup_kaddr(&local_kaddr, &local_addr);
 394
 395         ret = krb5_auth_con_setaddrs(context, auth_context, &local_kaddr, NULL);
 396         if (ret) {
 397                 close(sock);
 398                 free(ap_req.data);
 399                 krb5_auth_con_free(context, auth_context);
 400                 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n", error_message(ret)));
 401                 return ADS_ERROR_KRB5(ret);
 402         }
 403
 404         ret = build_kpasswd_request(pversion, context, auth_context, &ap_req,
 405                                   princ, newpw, &chpw_req);
 406         if (ret) {
 407                 close(sock);
 408                 free(ap_req.data);
 409                 krb5_auth_con_free(context, auth_context);
 410                 DEBUG(1,("build_setpw_request failed (%s)\n", error_message(ret)));
 411                 return ADS_ERROR_KRB5(ret);
 412         }
 413
 414         if (write(sock, chpw_req.data, chpw_req.length) != chpw_req.length) {
 415                 close(sock);
 416                 free(chpw_req.data);
 417                 free(ap_req.data);
 418                 krb5_auth_con_free(context, auth_context);
 419                 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
 420                 return ADS_ERROR_SYSTEM(errno);
 421         }
 422
 423         free(chpw_req.data);
 424
 425         chpw_rep.length = 1500;
 426         chpw_rep.data = (char *) SMB_MALLOC(chpw_rep.length);
 427         if (!chpw_rep.data) {
 428                 close(sock);
 429                 free(ap_req.data);
 430                 krb5_auth_con_free(context, auth_context);
 431                 DEBUG(1,("send of chpw failed (%s)\n", strerror(errno)));
 432                 errno = ENOMEM;
 433                 return ADS_ERROR_SYSTEM(errno);
 434         }
 435
 436         ret = read(sock, chpw_rep.data, chpw_rep.length);
 437         if (ret < 0) {
 438                 close(sock);
 439                 free(chpw_rep.data);
 440                 free(ap_req.data);
 441                 krb5_auth_con_free(context, auth_context);
 442                 DEBUG(1,("recv of chpw reply failed (%s)\n", strerror(errno)));
 443                 return ADS_ERROR_SYSTEM(errno);
 444         }
 445
 446         close(sock);
 447         chpw_rep.length = ret;
 448
 449         ret = krb5_auth_con_setaddrs(context, auth_context, NULL,&remote_kaddr);
 450         if (ret) {
 451                 free(chpw_rep.data);
 452                 free(ap_req.data);
 453                 krb5_auth_con_free(context, auth_context);
 454                 DEBUG(1,("krb5_auth_con_setaddrs on reply failed (%s)\n",
 455                          error_message(ret)));
 456                 return ADS_ERROR_KRB5(ret);
 457         }
 458
 459         ret = parse_setpw_reply(context, auth_context, &chpw_rep);
 460         free(chpw_rep.data);
 461
 462         if (ret) {
 463                 free(ap_req.data);
 464                 krb5_auth_con_free(context, auth_context);
 465                 DEBUG(1,("parse_setpw_reply failed (%s)\n",
 466                          error_message(ret)));
 467                 return ADS_ERROR_KRB5(ret);
 468         }
 469
 470         free(ap_req.data);
 471         krb5_auth_con_free(context, auth_context);
 472
 473         return ADS_SUCCESS;
 474 }
 475
 476 ADS_STATUS ads_krb5_set_password(const char *kdc_host, const char *princ,
 477                                  const char *newpw, int time_offset)
 478 {
 479
 480         ADS_STATUS aret;
 481         krb5_error_code ret = 0;
 482         krb5_context context = NULL;
 483         krb5_principal principal = NULL;
 484         char *princ_name = NULL;
 485         char *realm = NULL;
 486         krb5_creds creds, *credsp = NULL;
 487 #if KRB5_PRINC_REALM_RETURNS_REALM
 488         krb5_realm orig_realm;
 489 #else
 490         krb5_data orig_realm;
 491 #endif
 492         krb5_ccache ccache = NULL;
 493
 494         ZERO_STRUCT(creds);
 495
 496         initialize_krb5_error_table();
 497         ret = krb5_init_context(&context);
 498         if (ret) {
 499                 DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
 500                 return ADS_ERROR_KRB5(ret);
 501         }
 502
 503         if (time_offset != 0) {
 504                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
 505         }
 506
 507         ret = krb5_cc_default(context, &ccache);
 508         if (ret) {
 509                 krb5_free_context(context);
 510                 DEBUG(1,("Failed to get default creds (%s)\n", error_message(ret)));
 511                 return ADS_ERROR_KRB5(ret);
 512         }
 513
 514         realm = strchr_m(princ, '@');
 515         if (!realm) {
 516                 krb5_cc_close(context, ccache);
 517                 krb5_free_context(context);
 518                 DEBUG(1,("Failed to get realm\n"));
 519                 return ADS_ERROR_KRB5(-1);
 520         }
 521         realm++;
 522
 523         asprintf(&princ_name, "kadmin/changepw@%s", realm);
 524         ret = krb5_parse_name(context, princ_name, &creds.server);
 525         if (ret) {
 526                 krb5_cc_close(context, ccache);
 527                 krb5_free_context(context);
 528                 DEBUG(1,("Failed to parse kadmin/changepw (%s)\n", error_message(ret)));
 529                 return ADS_ERROR_KRB5(ret);
 530         }
 531         free(princ_name);
 532
 533         /* parse the principal we got as a function argument */
 534         ret = krb5_parse_name(context, princ, &principal);
 535         if (ret) {
 536                 krb5_cc_close(context, ccache);
 537                 krb5_free_principal(context, creds.server);
 538                 krb5_free_context(context);
 539                 DEBUG(1,("Failed to parse %s (%s)\n", princ_name, error_message(ret)));
 540                 return ADS_ERROR_KRB5(ret);
 541         }
 542
 543         /* The creds.server principal takes ownership of this memory.
 544                 Remember to set back to original value before freeing. */
 545         orig_realm = *krb5_princ_realm(context, creds.server);
 546         krb5_princ_set_realm(context, creds.server, krb5_princ_realm(context, principal));
 547
 548         ret = krb5_cc_get_principal(context, ccache, &creds.client);
 549         if (ret) {
 550                 krb5_cc_close(context, ccache);
 551                 krb5_princ_set_realm(context, creds.server, &orig_realm);
 552                 krb5_free_principal(context, creds.server);
 553                 krb5_free_principal(context, principal);
 554                 krb5_free_context(context);
 555                 DEBUG(1,("Failed to get principal from ccache (%s)\n",
 556                          error_message(ret)));
 557                 return ADS_ERROR_KRB5(ret);
 558         }
 559
 560         ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
 561         if (ret) {
 562                 krb5_cc_close(context, ccache);
 563                 krb5_free_principal(context, creds.client);
 564                 krb5_princ_set_realm(context, creds.server, &orig_realm);
 565                 krb5_free_principal(context, creds.server);
 566                 krb5_free_principal(context, principal);
 567                 krb5_free_context(context);
 568                 DEBUG(1,("krb5_get_credentials failed (%s)\n", error_message(ret)));
 569                 return ADS_ERROR_KRB5(ret);
 570         }
 571
 572         /* we might have to call krb5_free_creds(...) from now on ... */
 573
 574         aret = do_krb5_kpasswd_request(context, kdc_host,
 575                                        KRB5_KPASSWD_VERS_SETPW,
 576                                        credsp, princ, newpw);
 577
 578         krb5_free_creds(context, credsp);
 579         krb5_free_principal(context, creds.client);
 580         krb5_princ_set_realm(context, creds.server, &orig_realm);
 581         krb5_free_principal(context, creds.server);
 582         krb5_free_principal(context, principal);
 583         krb5_cc_close(context, ccache);
 584         krb5_free_context(context);
 585
 586         return aret;
 587 }
 588
 589 /*
 590   we use a prompter to avoid a crash bug in the kerberos libs when
 591   dealing with empty passwords
 592   this prompter is just a string copy ...
 593 */
 594 static krb5_error_code
 595 kerb_prompter(krb5_context ctx, void *data,
 596                const char *name,
 597                const char *banner,
 598                int num_prompts,
 599                krb5_prompt prompts[])
 600 {
 601         if (num_prompts == 0) return 0;
 602
 603         memset(prompts[0].reply->data, 0, prompts[0].reply->length);
 604         if (prompts[0].reply->length > 0) {
 605                 if (data) {
 606                         strncpy(prompts[0].reply->data, data, prompts[0].reply->length-1);
 607                         prompts[0].reply->length = strlen(prompts[0].reply->data);
 608                 } else {
 609                         prompts[0].reply->length = 0;
 610                 }
 611         }
 612         return 0;
 613 }
 614
 615 static ADS_STATUS ads_krb5_chg_password(const char *kdc_host,
 616                                         const char *principal,
 617                                         const char *oldpw,
 618                                         const char *newpw,
 619                                         int time_offset)
 620 {
 621     ADS_STATUS aret;
 622     krb5_error_code ret;
 623     krb5_context context = NULL;
 624     krb5_principal princ;
 625     krb5_get_init_creds_opt opts;
 626     krb5_creds creds;
 627     char *chpw_princ = NULL, *password;
 628
 629     initialize_krb5_error_table();
 630     ret = krb5_init_context(&context);
 631     if (ret) {
 632         DEBUG(1,("Failed to init krb5 context (%s)\n", error_message(ret)));
 633         return ADS_ERROR_KRB5(ret);
 634     }
 635
 636     if ((ret = krb5_parse_name(context, principal,
 637                                     &princ))) {
 638         krb5_free_context(context);
 639         DEBUG(1,("Failed to parse %s (%s)\n", principal, error_message(ret)));
 640         return ADS_ERROR_KRB5(ret);
 641     }
 642
 643     krb5_get_init_creds_opt_init(&opts);
 644     krb5_get_init_creds_opt_set_tkt_life(&opts, 5*60);
 645     krb5_get_init_creds_opt_set_renew_life(&opts, 0);
 646     krb5_get_init_creds_opt_set_forwardable(&opts, 0);
 647     krb5_get_init_creds_opt_set_proxiable(&opts, 0);
 648
 649     /* We have to obtain an INITIAL changepw ticket for changing password */
 650     asprintf(&chpw_princ, "kadmin/changepw@%s",
 651                                 (char *) krb5_princ_realm(context, princ));
 652     password = SMB_STRDUP(oldpw);
 653     ret = krb5_get_init_creds_password(context, &creds, princ, password,
 654                                            kerb_prompter, NULL,
 655                                            0, chpw_princ, &opts);
 656     SAFE_FREE(chpw_princ);
 657     SAFE_FREE(password);
 658
 659     if (ret) {
 660       if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
 661         DEBUG(1,("Password incorrect while getting initial ticket"));
 662       else
 663         DEBUG(1,("krb5_get_init_creds_password failed (%s)\n", error_message(ret)));
 664
 665         krb5_free_principal(context, princ);
 666         krb5_free_context(context);
 667         return ADS_ERROR_KRB5(ret);
 668     }
 669
 670     aret = do_krb5_kpasswd_request(context, kdc_host,
 671                                    KRB5_KPASSWD_VERS_CHANGEPW,
 672                                    &creds, principal, newpw);
 673
 674     krb5_free_principal(context, princ);
 675     krb5_free_context(context);
 676
 677     return aret;
 678 }
 679
 680
 681 ADS_STATUS kerberos_set_password(const char *kpasswd_server,
 682                                  const char *auth_principal, const char *auth_password,
 683                                  const char *target_principal, const char *new_password,
 684                                  int time_offset)
 685 {
 686     int ret;
 687
 688     if ((ret = kerberos_kinit_password(auth_principal, auth_password, time_offset, NULL, NULL, NULL, False, 0))) {
 689         DEBUG(1,("Failed kinit for principal %s (%s)\n", auth_principal, error_message(ret)));
 690         return ADS_ERROR_KRB5(ret);
 691     }
 692
 693     if (!strcmp(auth_principal, target_principal))
 694         return ads_krb5_chg_password(kpasswd_server, target_principal,
 695                                      auth_password, new_password, time_offset);
 696     else
 697         return ads_krb5_set_password(kpasswd_server, target_principal,
 698                                      new_password, time_offset);
 699 }
 700
 701
 702 /**
 703  * Set the machine account password
 704  * @param ads connection to ads server
 705  * @param hostname machine whose password is being set
 706  * @param password new password
 707  * @return status of password change
 708  **/
 709 ADS_STATUS ads_set_machine_password(ADS_STRUCT *ads,
 710                                     const char *machine_account,
 711                                     const char *password)
 712 {
 713         ADS_STATUS status;
 714         char *principal = NULL;
 715
 716         /*
 717           we need to use the '$' form of the name here (the machine account name),
 718           as otherwise the server might end up setting the password for a user
 719           instead
 720          */
 721         asprintf(&principal, "%s@%s", machine_account, ads->config.realm);
 722
 723         status = ads_krb5_set_password(ads->auth.kdc_server, principal,
 724                                        password, ads->auth.time_offset);
 725
 726         free(principal);
 727
 728         return status;
 729 }
 730
 731
 732
 733 #endif