lib/krb5/changepw.c

   1 /*
   2  * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 #undef __attribute__
  37 #define __attribute__(X)
  38
  39
  40 static void
  41 str2data (krb5_data *d,
  42           const char *fmt,
  43           ...) __attribute__ ((format (printf, 2, 3)));
  44
  45 static void
  46 str2data (krb5_data *d,
  47           const char *fmt,
  48           ...)
  49 {
  50     va_list args;
  51     char *str;
  52
  53     va_start(args, fmt);
  54     d->length = vasprintf (&str, fmt, args);
  55     va_end(args);
  56     d->data = str;
  57 }
  58
  59 /*
  60  * Change password protocol defined by
  61  * draft-ietf-cat-kerb-chg-password-02.txt
  62  *
  63  * Share the response part of the protocol with MS set password
  64  * (RFC3244)
  65  */
  66
  67 static krb5_error_code
  68 chgpw_send_request (krb5_context context,
  69                     krb5_auth_context *auth_context,
  70                     krb5_creds *creds,
  71                     krb5_principal targprinc,
  72                     int is_stream,
  73                     rk_socket_t sock,
  74                     const char *passwd,
  75                     const char *host)
  76 {
  77     krb5_error_code ret;
  78     krb5_data ap_req_data;
  79     krb5_data krb_priv_data;
  80     krb5_data passwd_data;
  81     size_t len;
  82     u_char header[6];
  83     struct iovec iov[3];
  84     struct msghdr msghdr;
  85
  86     if (is_stream)
  87         return KRB5_KPASSWD_MALFORMED;
  88
  89     if (targprinc &&
  90         krb5_principal_compare(context, creds->client, targprinc) != TRUE)
  91         return KRB5_KPASSWD_MALFORMED;
  92
  93     krb5_data_zero (&ap_req_data);
  94
  95     ret = krb5_mk_req_extended (context,
  96                                 auth_context,
  97                                 AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
  98                                 NULL, /* in_data */
  99                                 creds,
 100                                 &ap_req_data);
 101     if (ret)
 102         return ret;
 103
 104     passwd_data.data   = rk_UNCONST(passwd);
 105     passwd_data.length = strlen(passwd);
 106
 107     krb5_data_zero (&krb_priv_data);
 108
 109     ret = krb5_mk_priv (context,
 110                         *auth_context,
 111                         &passwd_data,
 112                         &krb_priv_data,
 113                         NULL);
 114     if (ret)
 115         goto out2;
 116
 117     len = 6 + ap_req_data.length + krb_priv_data.length;
 118     header[0] = (len >> 8) & 0xFF;
 119     header[1] = (len >> 0) & 0xFF;
 120     header[2] = 0;
 121     header[3] = 1;
 122     header[4] = (ap_req_data.length >> 8) & 0xFF;
 123     header[5] = (ap_req_data.length >> 0) & 0xFF;
 124
 125     memset(&msghdr, 0, sizeof(msghdr));
 126     msghdr.msg_name       = NULL;
 127     msghdr.msg_namelen    = 0;
 128     msghdr.msg_iov        = iov;
 129     msghdr.msg_iovlen     = sizeof(iov)/sizeof(*iov);
 130 #if 0
 131     msghdr.msg_control    = NULL;
 132     msghdr.msg_controllen = 0;
 133 #endif
 134
 135     iov[0].iov_base    = (void*)header;
 136     iov[0].iov_len     = 6;
 137     iov[1].iov_base    = ap_req_data.data;
 138     iov[1].iov_len     = ap_req_data.length;
 139     iov[2].iov_base    = krb_priv_data.data;
 140     iov[2].iov_len     = krb_priv_data.length;
 141
 142     if (rk_IS_SOCKET_ERROR( sendmsg (sock, &msghdr, 0) )) {
 143         ret = rk_SOCK_ERRNO;
 144         krb5_set_error_message(context, ret, "sendmsg %s: %s",
 145                                host, strerror(ret));
 146     }
 147
 148     krb5_data_free (&krb_priv_data);
 149 out2:
 150     krb5_data_free (&ap_req_data);
 151     return ret;
 152 }
 153
 154 /*
 155  * Set password protocol as defined by RFC3244 --
 156  * Microsoft Windows 2000 Kerberos Change Password and Set Password Protocols
 157  */
 158
 159 static krb5_error_code
 160 setpw_send_request (krb5_context context,
 161                     krb5_auth_context *auth_context,
 162                     krb5_creds *creds,
 163                     krb5_principal targprinc,
 164                     int is_stream,
 165                     rk_socket_t sock,
 166                     const char *passwd,
 167                     const char *host)
 168 {
 169     krb5_error_code ret;
 170     krb5_data ap_req_data;
 171     krb5_data krb_priv_data;
 172     krb5_data pwd_data;
 173     ChangePasswdDataMS chpw;
 174     size_t len = 0;
 175     u_char header[4 + 6];
 176     u_char *p;
 177     struct iovec iov[3];
 178     struct msghdr msghdr;
 179
 180     krb5_data_zero (&ap_req_data);
 181
 182     ret = krb5_mk_req_extended (context,
 183                                 auth_context,
 184                                 AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
 185                                 NULL, /* in_data */
 186                                 creds,
 187                                 &ap_req_data);
 188     if (ret)
 189         return ret;
 190
 191     chpw.newpasswd.length = strlen(passwd);
 192     chpw.newpasswd.data = rk_UNCONST(passwd);
 193     if (targprinc) {
 194         chpw.targname = &targprinc->name;
 195         chpw.targrealm = &targprinc->realm;
 196     } else {
 197         chpw.targname = NULL;
 198         chpw.targrealm = NULL;
 199     }
 200
 201     ASN1_MALLOC_ENCODE(ChangePasswdDataMS, pwd_data.data, pwd_data.length,
 202                        &chpw, &len, ret);
 203     if (ret) {
 204         krb5_data_free (&ap_req_data);
 205         return ret;
 206     }
 207
 208     if(pwd_data.length != len)
 209         krb5_abortx(context, "internal error in ASN.1 encoder");
 210
 211     ret = krb5_mk_priv (context,
 212                         *auth_context,
 213                         &pwd_data,
 214                         &krb_priv_data,
 215                         NULL);
 216     if (ret)
 217         goto out2;
 218
 219     len = 6 + ap_req_data.length + krb_priv_data.length;
 220     p = header;
 221     if (is_stream) {
 222         _krb5_put_int(p, len, 4);
 223         p += 4;
 224     }
 225     *p++ = (len >> 8) & 0xFF;
 226     *p++ = (len >> 0) & 0xFF;
 227     *p++ = 0xff;
 228     *p++ = 0x80;
 229     *p++ = (ap_req_data.length >> 8) & 0xFF;
 230     *p   = (ap_req_data.length >> 0) & 0xFF;
 231
 232     memset(&msghdr, 0, sizeof(msghdr));
 233     msghdr.msg_name       = NULL;
 234     msghdr.msg_namelen    = 0;
 235     msghdr.msg_iov        = iov;
 236     msghdr.msg_iovlen     = sizeof(iov)/sizeof(*iov);
 237 #if 0
 238     msghdr.msg_control    = NULL;
 239     msghdr.msg_controllen = 0;
 240 #endif
 241
 242     iov[0].iov_base    = (void*)header;
 243     if (is_stream)
 244         iov[0].iov_len     = 10;
 245     else
 246         iov[0].iov_len     = 6;
 247     iov[1].iov_base    = ap_req_data.data;
 248     iov[1].iov_len     = ap_req_data.length;
 249     iov[2].iov_base    = krb_priv_data.data;
 250     iov[2].iov_len     = krb_priv_data.length;
 251
 252     if (rk_IS_SOCKET_ERROR( sendmsg (sock, &msghdr, 0) )) {
 253         ret = rk_SOCK_ERRNO;
 254         krb5_set_error_message(context, ret, "sendmsg %s: %s",
 255                                host, strerror(ret));
 256     }
 257
 258     krb5_data_free (&krb_priv_data);
 259 out2:
 260     krb5_data_free (&ap_req_data);
 261     krb5_data_free (&pwd_data);
 262     return ret;
 263 }
 264
 265 static krb5_error_code
 266 process_reply (krb5_context context,
 267                krb5_auth_context auth_context,
 268                int is_stream,
 269                rk_socket_t sock,
 270                int *result_code,
 271                krb5_data *result_code_string,
 272                krb5_data *result_string,
 273                const char *host)
 274 {
 275     krb5_error_code ret;
 276     u_char reply[1024 * 3];
 277     size_t len;
 278     uint16_t pkt_len, pkt_ver;
 279     krb5_data ap_rep_data;
 280     int save_errno;
 281
 282     len = 0;
 283     if (is_stream) {
 284         while (len < sizeof(reply)) {
 285             unsigned long size;
 286
 287             ret = recvfrom (sock, reply + len, sizeof(reply) - len,
 288                             0, NULL, NULL);
 289             if (rk_IS_SOCKET_ERROR(ret)) {
 290                 save_errno = rk_SOCK_ERRNO;
 291                 krb5_set_error_message(context, save_errno,
 292                                        "recvfrom %s: %s",
 293                                        host, strerror(save_errno));
 294                 return save_errno;
 295             } else if (ret == 0) {
 296                 krb5_set_error_message(context, 1,"recvfrom timeout %s", host);
 297                 return 1;
 298             }
 299             len += ret;
 300             if (len < 4)
 301                 continue;
 302             _krb5_get_int(reply, &size, 4);
 303             if (size + 4 < len)
 304                 continue;
 305             memmove(reply, reply + 4, size);
 306             len = size;
 307             break;
 308         }
 309         if (len == sizeof(reply)) {
 310             krb5_set_error_message(context, ENOMEM,
 311                                    N_("Message too large from %s", "host"),
 312                                    host);
 313             return ENOMEM;
 314         }
 315     } else {
 316         ret = recvfrom (sock, reply, sizeof(reply), 0, NULL, NULL);
 317         if (rk_IS_SOCKET_ERROR(ret)) {
 318             save_errno = rk_SOCK_ERRNO;
 319             krb5_set_error_message(context, save_errno,
 320                                    "recvfrom %s: %s",
 321                                    host, strerror(save_errno));
 322             return save_errno;
 323         }
 324         len = ret;
 325     }
 326
 327     if (len < 6) {
 328         str2data (result_string, "server %s sent to too short message "
 329                   "(%zu bytes)", host, len);
 330         *result_code = KRB5_KPASSWD_MALFORMED;
 331         return 0;
 332     }
 333
 334     pkt_len = (reply[0] << 8) | (reply[1]);
 335     pkt_ver = (reply[2] << 8) | (reply[3]);
 336
 337     if ((pkt_len != len) || (reply[1] == 0x7e || reply[1] == 0x5e)) {
 338         KRB_ERROR error;
 339         size_t size;
 340         u_char *p;
 341
 342         memset(&error, 0, sizeof(error));
 343
 344         ret = decode_KRB_ERROR(reply, len, &error, &size);
 345         if (ret)
 346             return ret;
 347
 348         if (error.e_data->length < 2) {
 349             str2data(result_string, "server %s sent too short "
 350                      "e_data to print anything usable", host);
 351             free_KRB_ERROR(&error);
 352             *result_code = KRB5_KPASSWD_MALFORMED;
 353             return 0;
 354         }
 355
 356         p = error.e_data->data;
 357         *result_code = (p[0] << 8) | p[1];
 358         if (error.e_data->length == 2)
 359             str2data(result_string, "server only sent error code");
 360         else
 361             krb5_data_copy (result_string,
 362                             p + 2,
 363                             error.e_data->length - 2);
 364         free_KRB_ERROR(&error);
 365         return 0;
 366     }
 367
 368     if (pkt_len != len) {
 369         str2data (result_string, "client: wrong len in reply");
 370         *result_code = KRB5_KPASSWD_MALFORMED;
 371         return 0;
 372     }
 373     if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW) {
 374         str2data (result_string,
 375                   "client: wrong version number (%d)", pkt_ver);
 376         *result_code = KRB5_KPASSWD_MALFORMED;
 377         return 0;
 378     }
 379
 380     ap_rep_data.data = reply + 6;
 381     ap_rep_data.length  = (reply[4] << 8) | (reply[5]);
 382
 383     if (reply + len < (u_char *)ap_rep_data.data + ap_rep_data.length) {
 384         str2data (result_string, "client: wrong AP len in reply");
 385         *result_code = KRB5_KPASSWD_MALFORMED;
 386         return 0;
 387     }
 388
 389     if (ap_rep_data.length) {
 390         krb5_ap_rep_enc_part *ap_rep;
 391         krb5_data priv_data;
 392         u_char *p;
 393
 394         priv_data.data   = (u_char*)ap_rep_data.data + ap_rep_data.length;
 395         priv_data.length = len - ap_rep_data.length - 6;
 396
 397         ret = krb5_rd_rep (context,
 398                            auth_context,
 399                            &ap_rep_data,
 400                            &ap_rep);
 401         if (ret)
 402             return ret;
 403
 404         krb5_free_ap_rep_enc_part (context, ap_rep);
 405
 406         ret = krb5_rd_priv (context,
 407                             auth_context,
 408                             &priv_data,
 409                             result_code_string,
 410                             NULL);
 411         if (ret) {
 412             krb5_data_free (result_code_string);
 413             return ret;
 414         }
 415
 416         if (result_code_string->length < 2) {
 417             *result_code = KRB5_KPASSWD_MALFORMED;
 418             str2data (result_string,
 419                       "client: bad length in result");
 420             return 0;
 421         }
 422
 423         p = result_code_string->data;
 424
 425         *result_code = (p[0] << 8) | p[1];
 426         krb5_data_copy (result_string,
 427                         (unsigned char*)result_code_string->data + 2,
 428                         result_code_string->length - 2);
 429         return 0;
 430     } else {
 431         KRB_ERROR error;
 432         size_t size;
 433         u_char *p;
 434
 435         ret = decode_KRB_ERROR(reply + 6, len - 6, &error, &size);
 436         if (ret) {
 437             return ret;
 438         }
 439         if (error.e_data->length < 2) {
 440             krb5_warnx (context, "too short e_data to print anything usable");
 441             return 1;           /* XXX */
 442         }
 443
 444         p = error.e_data->data;
 445         *result_code = (p[0] << 8) | p[1];
 446         krb5_data_copy (result_string,
 447                         p + 2,
 448                         error.e_data->length - 2);
 449         return 0;
 450     }
 451 }
 452
 453
 454 /*
 455  * change the password using the credentials in `creds' (for the
 456  * principal indicated in them) to `newpw', storing the result of
 457  * the operation in `result_*' and an error code or 0.
 458  */
 459
 460 typedef krb5_error_code (*kpwd_send_request) (krb5_context,
 461                                               krb5_auth_context *,
 462                                               krb5_creds *,
 463                                               krb5_principal,
 464                                               int,
 465                                               rk_socket_t,
 466                                               const char *,
 467                                               const char *);
 468 typedef krb5_error_code (*kpwd_process_reply) (krb5_context,
 469                                                krb5_auth_context,
 470                                                int,
 471                                                rk_socket_t,
 472                                                int *,
 473                                                krb5_data *,
 474                                                krb5_data *,
 475                                                const char *);
 476
 477 static struct kpwd_proc {
 478     const char *name;
 479     int flags;
 480 #define SUPPORT_TCP     1
 481 #define SUPPORT_UDP     2
 482     kpwd_send_request send_req;
 483     kpwd_process_reply process_rep;
 484 } procs[] = {
 485     {
 486         "MS set password",
 487         SUPPORT_TCP|SUPPORT_UDP,
 488         setpw_send_request,
 489         process_reply
 490     },
 491     {
 492         "change password",
 493         SUPPORT_UDP,
 494         chgpw_send_request,
 495         process_reply
 496     },
 497     { NULL, 0, NULL, NULL }
 498 };
 499
 500 /*
 501  *
 502  */
 503
 504 static krb5_error_code
 505 change_password_loop (krb5_context      context,
 506                       krb5_creds        *creds,
 507                       krb5_principal    targprinc,
 508                       const char        *newpw,
 509                       int               *result_code,
 510                       krb5_data         *result_code_string,
 511                       krb5_data         *result_string,
 512                       struct kpwd_proc  *proc)
 513 {
 514     krb5_error_code ret;
 515     krb5_auth_context auth_context = NULL;
 516     krb5_krbhst_handle handle = NULL;
 517     krb5_krbhst_info *hi;
 518     rk_socket_t sock;
 519     unsigned int i;
 520     int done = 0;
 521     krb5_realm realm;
 522
 523     if (targprinc)
 524         realm = targprinc->realm;
 525     else
 526         realm = creds->client->realm;
 527
 528     ret = krb5_auth_con_init (context, &auth_context);
 529     if (ret)
 530         return ret;
 531
 532     krb5_auth_con_setflags (context, auth_context,
 533                             KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 534
 535     ret = krb5_krbhst_init (context, realm, KRB5_KRBHST_CHANGEPW, &handle);
 536     if (ret)
 537         goto out;
 538
 539     while (!done && (ret = krb5_krbhst_next(context, handle, &hi)) == 0) {
 540         struct addrinfo *ai, *a;
 541         int is_stream;
 542
 543         switch (hi->proto) {
 544         case KRB5_KRBHST_UDP:
 545             if ((proc->flags & SUPPORT_UDP) == 0)
 546                 continue;
 547             is_stream = 0;
 548             break;
 549         case KRB5_KRBHST_TCP:
 550             if ((proc->flags & SUPPORT_TCP) == 0)
 551                 continue;
 552             is_stream = 1;
 553             break;
 554         default:
 555             continue;
 556         }
 557
 558         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
 559         if (ret)
 560             continue;
 561
 562         for (a = ai; !done && a != NULL; a = a->ai_next) {
 563             int replied = 0;
 564
 565             sock = socket (a->ai_family, a->ai_socktype | SOCK_CLOEXEC, a->ai_protocol);
 566             if (rk_IS_BAD_SOCKET(sock))
 567                 continue;
 568             rk_cloexec(sock);
 569
 570             ret = connect(sock, a->ai_addr, a->ai_addrlen);
 571             if (rk_IS_SOCKET_ERROR(ret)) {
 572                 rk_closesocket (sock);
 573                 goto out;
 574             }
 575
 576             ret = krb5_auth_con_genaddrs (context, auth_context, sock,
 577                                           KRB5_AUTH_CONTEXT_GENERATE_LOCAL_ADDR);
 578             if (ret) {
 579                 rk_closesocket (sock);
 580                 goto out;
 581             }
 582
 583             for (i = 0; !done && i < 5; ++i) {
 584                 fd_set fdset;
 585                 struct timeval tv;
 586
 587                 if (!replied) {
 588                     replied = 0;
 589
 590                     ret = (*proc->send_req) (context,
 591                                              &auth_context,
 592                                              creds,
 593                                              targprinc,
 594                                              is_stream,
 595                                              sock,
 596                                              newpw,
 597                                              hi->hostname);
 598                     if (ret) {
 599                         rk_closesocket(sock);
 600                         goto out;
 601                     }
 602                 }
 603
 604 #ifndef NO_LIMIT_FD_SETSIZE
 605                 if (sock >= FD_SETSIZE) {
 606                     ret = ERANGE;
 607                     krb5_set_error_message(context, ret,
 608                                            "fd %d too large", sock);
 609                     rk_closesocket (sock);
 610                     goto out;
 611                 }
 612 #endif
 613
 614                 FD_ZERO(&fdset);
 615                 FD_SET(sock, &fdset);
 616                 tv.tv_usec = 0;
 617                 tv.tv_sec  = 1 + (1 << i);
 618
 619                 ret = select (sock + 1, &fdset, NULL, NULL, &tv);
 620                 if (rk_IS_SOCKET_ERROR(ret) && rk_SOCK_ERRNO != EINTR) {
 621                     rk_closesocket(sock);
 622                     goto out;
 623                 }
 624                 if (ret == 1) {
 625                     ret = (*proc->process_rep) (context,
 626                                                 auth_context,
 627                                                 is_stream,
 628                                                 sock,
 629                                                 result_code,
 630                                                 result_code_string,
 631                                                 result_string,
 632                                                 hi->hostname);
 633                     if (ret == 0)
 634                         done = 1;
 635                     else if (i > 0 && ret == KRB5KRB_AP_ERR_MUT_FAIL)
 636                         replied = 1;
 637                 } else {
 638                     ret = KRB5_KDC_UNREACH;
 639                 }
 640             }
 641             rk_closesocket (sock);
 642         }
 643     }
 644
 645  out:
 646     krb5_krbhst_free (context, handle);
 647     krb5_auth_con_free (context, auth_context);
 648
 649     if (ret == KRB5_KDC_UNREACH) {
 650         krb5_set_error_message(context,
 651                                ret,
 652                                N_("Unable to reach any changepw server "
 653                                  " in realm %s", "realm"), realm);
 654         *result_code = KRB5_KPASSWD_HARDERROR;
 655     }
 656     return ret;
 657 }
 658
 659 #ifndef HEIMDAL_SMALLER
 660
 661 static struct kpwd_proc *
 662 find_chpw_proto(const char *name)
 663 {
 664     struct kpwd_proc *p;
 665     for (p = procs; p->name != NULL; p++) {
 666         if (strcmp(p->name, name) == 0)
 667             return p;
 668     }
 669     return NULL;
 670 }
 671
 672 /**
 673  * Deprecated: krb5_change_password() is deprecated, use krb5_set_password().
 674  *
 675  * @param context a Keberos context
 676  * @param creds
 677  * @param newpw
 678  * @param result_code
 679  * @param result_code_string
 680  * @param result_string
 681  *
 682  * @return On sucess password is changed.
 683
 684  * @ingroup @krb5_deprecated
 685  */
 686
 687 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 688 krb5_change_password (krb5_context      context,
 689                       krb5_creds        *creds,
 690                       const char        *newpw,
 691                       int               *result_code,
 692                       krb5_data         *result_code_string,
 693                       krb5_data         *result_string)
 694     KRB5_DEPRECATED_FUNCTION("Use X instead")
 695 {
 696     struct kpwd_proc *p = find_chpw_proto("change password");
 697
 698     *result_code = KRB5_KPASSWD_MALFORMED;
 699     result_code_string->data = result_string->data = NULL;
 700     result_code_string->length = result_string->length = 0;
 701
 702     if (p == NULL)
 703         return KRB5_KPASSWD_MALFORMED;
 704
 705     return change_password_loop(context, creds, NULL, newpw,
 706                                 result_code, result_code_string,
 707                                 result_string, p);
 708 }
 709 #endif /* HEIMDAL_SMALLER */
 710
 711 /**
 712  * Change password using creds.
 713  *
 714  * @param context a Keberos context
 715  * @param creds The initial kadmin/passwd for the principal or an admin principal
 716  * @param newpw The new password to set
 717  * @param targprinc if unset, the default principal is used.
 718  * @param result_code Result code, KRB5_KPASSWD_SUCCESS is when password is changed.
 719  * @param result_code_string binary message from the server, contains
 720  * at least the result_code.
 721  * @param result_string A message from the kpasswd service or the
 722  * library in human printable form. The string is NUL terminated.
 723  *
 724  * @return On sucess and *result_code is KRB5_KPASSWD_SUCCESS, the password is changed.
 725
 726  * @ingroup @krb5
 727  */
 728
 729 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 730 krb5_set_password(krb5_context context,
 731                   krb5_creds *creds,
 732                   const char *newpw,
 733                   krb5_principal targprinc,
 734                   int *result_code,
 735                   krb5_data *result_code_string,
 736                   krb5_data *result_string)
 737 {
 738     krb5_principal principal = NULL;
 739     krb5_error_code ret = 0;
 740     int i;
 741
 742     *result_code = KRB5_KPASSWD_MALFORMED;
 743     krb5_data_zero(result_code_string);
 744     krb5_data_zero(result_string);
 745
 746     if (targprinc == NULL) {
 747         ret = krb5_get_default_principal(context, &principal);
 748         if (ret)
 749             return ret;
 750     } else
 751         principal = targprinc;
 752
 753     for (i = 0; procs[i].name != NULL; i++) {
 754         *result_code = 0;
 755         ret = change_password_loop(context, creds, principal, newpw,
 756                                    result_code, result_code_string,
 757                                    result_string,
 758                                    &procs[i]);
 759         if (ret == 0 && *result_code == 0)
 760             break;
 761     }
 762
 763     if (targprinc == NULL)
 764         krb5_free_principal(context, principal);
 765     return ret;
 766 }
 767
 768 /*
 769  *
 770  */
 771
 772 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 773 krb5_set_password_using_ccache(krb5_context context,
 774                                krb5_ccache ccache,
 775                                const char *newpw,
 776                                krb5_principal targprinc,
 777                                int *result_code,
 778                                krb5_data *result_code_string,
 779                                krb5_data *result_string)
 780 {
 781     krb5_creds creds, *credsp;
 782     krb5_error_code ret;
 783     krb5_principal principal = NULL;
 784
 785     *result_code = KRB5_KPASSWD_MALFORMED;
 786     result_code_string->data = result_string->data = NULL;
 787     result_code_string->length = result_string->length = 0;
 788
 789     memset(&creds, 0, sizeof(creds));
 790
 791     if (targprinc == NULL) {
 792         ret = krb5_cc_get_principal(context, ccache, &principal);
 793         if (ret)
 794             return ret;
 795     } else
 796         principal = targprinc;
 797
 798     ret = krb5_make_principal(context, &creds.server,
 799                               krb5_principal_get_realm(context, principal),
 800                               "kadmin", "changepw", NULL);
 801     if (ret)
 802         goto out;
 803
 804     ret = krb5_cc_get_principal(context, ccache, &creds.client);
 805     if (ret) {
 806         krb5_free_principal(context, creds.server);
 807         goto out;
 808     }
 809
 810     ret = krb5_get_credentials(context, 0, ccache, &creds, &credsp);
 811     krb5_free_principal(context, creds.server);
 812     krb5_free_principal(context, creds.client);
 813     if (ret)
 814         goto out;
 815
 816     ret = krb5_set_password(context,
 817                             credsp,
 818                             newpw,
 819                             principal,
 820                             result_code,
 821                             result_code_string,
 822                             result_string);
 823
 824     krb5_free_creds(context, credsp);
 825
 826     return ret;
 827  out:
 828     if (targprinc == NULL)
 829         krb5_free_principal(context, principal);
 830     return ret;
 831 }
 832
 833 /*
 834  *
 835  */
 836
 837 KRB5_LIB_FUNCTION const char* KRB5_LIB_CALL
 838 krb5_passwd_result_to_string (krb5_context context,
 839                               int result)
 840 {
 841     static const char *strings[] = {
 842         "Success",
 843         "Malformed",
 844         "Hard error",
 845         "Auth error",
 846         "Soft error" ,
 847         "Access denied",
 848         "Bad version",
 849         "Initial flag needed"
 850     };
 851
 852     if (result < 0 || result > KRB5_KPASSWD_INITIAL_FLAG_NEEDED)
 853         return "unknown result code";
 854     else
 855         return strings[result];
 856 }