kpasswd/kpasswdd.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 "kpasswd_locl.h"
  35 RCSID("$Id$");
  36
  37 #include <kadm5/admin.h>
  38 #ifdef HAVE_SYS_UN_H
  39 #include <sys/un.h>
  40 #endif
  41 #include <hdb.h>
  42 #include <kadm5/private.h>
  43
  44 static krb5_context context;
  45 static krb5_log_facility *log_facility;
  46
  47 static struct getarg_strings addresses_str;
  48 krb5_addresses explicit_addresses;
  49
  50 static sig_atomic_t exit_flag = 0;
  51
  52 static void
  53 add_one_address (const char *str, int first)
  54 {
  55     krb5_error_code ret;
  56     krb5_addresses tmp;
  57
  58     ret = krb5_parse_address (context, str, &tmp);
  59     if (ret)
  60         krb5_err (context, 1, ret, "parse_address `%s'", str);
  61     if (first)
  62         krb5_copy_addresses(context, &tmp, &explicit_addresses);
  63     else
  64         krb5_append_addresses(context, &explicit_addresses, &tmp);
  65     krb5_free_addresses (context, &tmp);
  66 }
  67
  68 static void
  69 send_reply (int s,
  70             struct sockaddr *sa,
  71             int sa_size,
  72             krb5_data *ap_rep,
  73             krb5_data *rest)
  74 {
  75     struct msghdr msghdr;
  76     struct iovec iov[3];
  77     uint16_t len, ap_rep_len;
  78     u_char header[6];
  79     u_char *p;
  80
  81     if (ap_rep)
  82         ap_rep_len = ap_rep->length;
  83     else
  84         ap_rep_len = 0;
  85
  86     len = 6 + ap_rep_len + rest->length;
  87     p = header;
  88     *p++ = (len >> 8) & 0xFF;
  89     *p++ = (len >> 0) & 0xFF;
  90     *p++ = 0;
  91     *p++ = 1;
  92     *p++ = (ap_rep_len >> 8) & 0xFF;
  93     *p++ = (ap_rep_len >> 0) & 0xFF;
  94
  95     memset (&msghdr, 0, sizeof(msghdr));
  96     msghdr.msg_name       = (void *)sa;
  97     msghdr.msg_namelen    = sa_size;
  98     msghdr.msg_iov        = iov;
  99     msghdr.msg_iovlen     = sizeof(iov)/sizeof(*iov);
 100 #if 0
 101     msghdr.msg_control    = NULL;
 102     msghdr.msg_controllen = 0;
 103 #endif
 104
 105     iov[0].iov_base       = (char *)header;
 106     iov[0].iov_len        = 6;
 107     if (ap_rep_len) {
 108         iov[1].iov_base   = ap_rep->data;
 109         iov[1].iov_len    = ap_rep->length;
 110     } else {
 111         iov[1].iov_base   = NULL;
 112         iov[1].iov_len    = 0;
 113     }
 114     iov[2].iov_base       = rest->data;
 115     iov[2].iov_len        = rest->length;
 116
 117     if (sendmsg (s, &msghdr, 0) < 0)
 118         krb5_warn (context, errno, "sendmsg");
 119 }
 120
 121 static int
 122 make_result (krb5_data *data,
 123              uint16_t result_code,
 124              const char *expl)
 125 {
 126     char *str;
 127     krb5_data_zero (data);
 128
 129     data->length = asprintf (&str,
 130                              "%c%c%s",
 131                              (result_code >> 8) & 0xFF,
 132                              result_code & 0xFF,
 133                              expl);
 134
 135     if (str == NULL) {
 136         krb5_warnx (context, "Out of memory generating error reply");
 137         return 1;
 138     }
 139     data->data = str;
 140     return 0;
 141 }
 142
 143 static void
 144 reply_error (krb5_realm realm,
 145              int s,
 146              struct sockaddr *sa,
 147              int sa_size,
 148              krb5_error_code error_code,
 149              uint16_t result_code,
 150              const char *expl)
 151 {
 152     krb5_error_code ret;
 153     krb5_data error_data;
 154     krb5_data e_data;
 155     krb5_principal server = NULL;
 156
 157     if (make_result(&e_data, result_code, expl))
 158         return;
 159
 160     if (realm) {
 161         ret = krb5_make_principal (context, &server, realm,
 162                                    "kadmin", "changepw", NULL);
 163         if (ret) {
 164             krb5_data_free (&e_data);
 165             return;
 166         }
 167     }
 168
 169     ret = krb5_mk_error (context,
 170                          error_code,
 171                          NULL,
 172                          &e_data,
 173                          NULL,
 174                          server,
 175                          NULL,
 176                          NULL,
 177                          &error_data);
 178     if (server)
 179         krb5_free_principal(context, server);
 180     krb5_data_free (&e_data);
 181     if (ret) {
 182         krb5_warn (context, ret, "Could not even generate error reply");
 183         return;
 184     }
 185     send_reply (s, sa, sa_size, NULL, &error_data);
 186     krb5_data_free (&error_data);
 187 }
 188
 189 static void
 190 reply_priv (krb5_auth_context auth_context,
 191             int s,
 192             struct sockaddr *sa,
 193             int sa_size,
 194             uint16_t result_code,
 195             const char *expl)
 196 {
 197     krb5_error_code ret;
 198     krb5_data krb_priv_data;
 199     krb5_data ap_rep_data;
 200     krb5_data e_data;
 201
 202     ret = krb5_mk_rep (context,
 203                        auth_context,
 204                        &ap_rep_data);
 205     if (ret) {
 206         krb5_warn (context, ret, "Could not even generate error reply");
 207         return;
 208     }
 209
 210     if (make_result(&e_data, result_code, expl))
 211         return;
 212
 213     ret = krb5_mk_priv (context,
 214                         auth_context,
 215                         &e_data,
 216                         &krb_priv_data,
 217                         NULL);
 218     krb5_data_free (&e_data);
 219     if (ret) {
 220         krb5_warn (context, ret, "Could not even generate error reply");
 221         return;
 222     }
 223     send_reply (s, sa, sa_size, &ap_rep_data, &krb_priv_data);
 224     krb5_data_free (&ap_rep_data);
 225     krb5_data_free (&krb_priv_data);
 226 }
 227
 228 /*
 229  * Change the password for `principal', sending the reply back on `s'
 230  * (`sa', `sa_size') to `pwd_data'.
 231  */
 232
 233 static void
 234 change (krb5_auth_context auth_context,
 235         krb5_principal admin_principal,
 236         uint16_t version,
 237         int s,
 238         struct sockaddr *sa,
 239         int sa_size,
 240         krb5_data *in_data)
 241 {
 242     krb5_error_code ret;
 243     char *client = NULL, *admin = NULL;
 244     const char *pwd_reason;
 245     kadm5_config_params conf;
 246     void *kadm5_handle = NULL;
 247     krb5_principal principal = NULL;
 248     krb5_data *pwd_data = NULL;
 249     char *tmp;
 250     ChangePasswdDataMS chpw;
 251
 252     memset (&conf, 0, sizeof(conf));
 253     memset(&chpw, 0, sizeof(chpw));
 254
 255     if (version == KRB5_KPASSWD_VERS_CHANGEPW) {
 256         ret = krb5_copy_data(context, in_data, &pwd_data);
 257         if (ret) {
 258             krb5_warn (context, ret, "krb5_copy_data");
 259             reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
 260                         "out out memory copying password");
 261             return;
 262         }
 263         principal = admin_principal;
 264     } else if (version == KRB5_KPASSWD_VERS_SETPW) {
 265         size_t len;
 266
 267         ret = decode_ChangePasswdDataMS(in_data->data, in_data->length,
 268                                         &chpw, &len);
 269         if (ret) {
 270             krb5_warn (context, ret, "decode_ChangePasswdDataMS");
 271             reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
 272                         "malformed ChangePasswdData");
 273             return;
 274         }
 275
 276
 277         ret = krb5_copy_data(context, &chpw.newpasswd, &pwd_data);
 278         if (ret) {
 279             krb5_warn (context, ret, "krb5_copy_data");
 280             reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
 281                         "out out memory copying password");
 282             goto out;
 283         }
 284
 285         if (chpw.targname == NULL && chpw.targrealm != NULL) {
 286             krb5_warn (context, ret, "kadm5_init_with_password_ctx");
 287             reply_priv (auth_context, s, sa, sa_size,
 288                         KRB5_KPASSWD_MALFORMED,
 289                         "targrealm but not targname");
 290             goto out;
 291         }
 292
 293         if (chpw.targname) {
 294             krb5_principal_data princ;
 295
 296             princ.name = *chpw.targname;
 297             princ.realm = *chpw.targrealm;
 298             if (princ.realm == NULL) {
 299                 ret = krb5_get_default_realm(context, &princ.realm);
 300
 301                 if (ret) {
 302                     krb5_warnx (context,
 303                                 "kadm5_init_with_password_ctx: "
 304                                 "failed to allocate realm");
 305                     reply_priv (auth_context, s, sa, sa_size,
 306                                 KRB5_KPASSWD_SOFTERROR,
 307                                 "failed to allocate realm");
 308                     goto out;
 309                 }
 310             }
 311             ret = krb5_copy_principal(context, &princ, &principal);
 312             if (*chpw.targrealm == NULL)
 313                 free(princ.realm);
 314             if (ret) {
 315                 krb5_warn(context, ret, "krb5_copy_principal");
 316                 reply_priv(auth_context, s, sa, sa_size,
 317                            KRB5_KPASSWD_HARDERROR,
 318                            "failed to allocate principal");
 319                 goto out;
 320             }
 321         } else
 322             principal = admin_principal;
 323     } else {
 324         krb5_warnx (context, "kadm5_init_with_password_ctx: unknown proto");
 325         reply_priv (auth_context, s, sa, sa_size,
 326                     KRB5_KPASSWD_HARDERROR,
 327                     "Unknown protocol used");
 328         return;
 329     }
 330
 331     ret = krb5_unparse_name (context, admin_principal, &admin);
 332     if (ret) {
 333         krb5_warn (context, ret, "unparse_name failed");
 334         reply_priv (auth_context, s, sa, sa_size,
 335                     KRB5_KPASSWD_HARDERROR, "out of memory error");
 336         goto out;
 337     }
 338
 339     conf.realm = principal->realm;
 340     conf.mask |= KADM5_CONFIG_REALM;
 341
 342     ret = kadm5_init_with_password_ctx(context,
 343                                        admin,
 344                                        NULL,
 345                                        KADM5_ADMIN_SERVICE,
 346                                        &conf, 0, 0,
 347                                        &kadm5_handle);
 348     if (ret) {
 349         krb5_warn (context, ret, "kadm5_init_with_password_ctx");
 350         reply_priv (auth_context, s, sa, sa_size, 2,
 351                     "Internal error");
 352         goto out;
 353     }
 354
 355     ret = krb5_unparse_name(context, principal, &client);
 356     if (ret) {
 357         krb5_warn (context, ret, "unparse_name failed");
 358         reply_priv (auth_context, s, sa, sa_size,
 359                     KRB5_KPASSWD_HARDERROR, "out of memory error");
 360         goto out;
 361     }
 362
 363     /*
 364      * Check password quality if not changing as administrator
 365      */
 366
 367     if (krb5_principal_compare(context, admin_principal, principal) == TRUE) {
 368
 369         pwd_reason = kadm5_check_password_quality (context, principal,
 370                                                    pwd_data);
 371         if (pwd_reason != NULL ) {
 372             krb5_warnx (context,
 373                         "%s didn't pass password quality check with error: %s",
 374                         client, pwd_reason);
 375             reply_priv (auth_context, s, sa, sa_size,
 376                         KRB5_KPASSWD_SOFTERROR, pwd_reason);
 377             goto out;
 378         }
 379         krb5_warnx (context, "Changing password for %s", client);
 380     } else {
 381         ret = _kadm5_acl_check_permission(kadm5_handle, KADM5_PRIV_CPW,
 382                                           principal);
 383         if (ret) {
 384             krb5_warn (context, ret,
 385                        "Check ACL failed for %s for changing %s password",
 386                        admin, client);
 387             reply_priv (auth_context, s, sa, sa_size,
 388                         KRB5_KPASSWD_HARDERROR, "permission denied");
 389             goto out;
 390         }
 391         krb5_warnx (context, "%s is changing password for %s", admin, client);
 392     }
 393
 394     ret = krb5_data_realloc(pwd_data, pwd_data->length + 1);
 395     if (ret) {
 396         krb5_warn (context, ret, "malloc: out of memory");
 397         reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_HARDERROR,
 398                     "Internal error");
 399         goto out;
 400     }
 401     tmp = pwd_data->data;
 402     tmp[pwd_data->length - 1] = '\0';
 403
 404     ret = kadm5_s_chpass_principal_cond (kadm5_handle, principal, tmp);
 405     krb5_free_data (context, pwd_data);
 406     pwd_data = NULL;
 407     if (ret) {
 408         const char *str = krb5_get_error_message(context, ret);
 409         krb5_warnx(context, "kadm5_s_chpass_principal_cond: %s", str);
 410         reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SOFTERROR,
 411                     str ? str : "Internal error");
 412         krb5_free_error_message(context, str);
 413         goto out;
 414     }
 415     reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SUCCESS,
 416                 "Password changed");
 417 out:
 418     free_ChangePasswdDataMS(&chpw);
 419     if (principal != admin_principal)
 420         krb5_free_principal(context, principal);
 421     if (admin)
 422         free(admin);
 423     if (client)
 424         free(client);
 425     if (pwd_data)
 426         krb5_free_data(context, pwd_data);
 427     if (kadm5_handle)
 428         kadm5_destroy (kadm5_handle);
 429 }
 430
 431 static int
 432 verify (krb5_auth_context *auth_context,
 433         krb5_realm *realms,
 434         krb5_keytab keytab,
 435         krb5_ticket **ticket,
 436         krb5_data *out_data,
 437         uint16_t *version,
 438         int s,
 439         struct sockaddr *sa,
 440         int sa_size,
 441         u_char *msg,
 442         size_t len)
 443 {
 444     krb5_error_code ret;
 445     uint16_t pkt_len, pkt_ver, ap_req_len;
 446     krb5_data ap_req_data;
 447     krb5_data krb_priv_data;
 448     krb5_realm *r;
 449
 450     /*
 451      * Only send an error reply if the request passes basic length
 452      * verification.  Otherwise, kpasswdd would reply to every UDP packet,
 453      * allowing an attacker to set up a ping-pong DoS attack via a spoofed UDP
 454      * packet with a source address of another UDP service that also replies
 455      * to every packet.
 456      *
 457      * Also suppress the error reply if ap_req_len is 0, which indicates
 458      * either an invalid request or an error packet.  An error packet may be
 459      * the result of a ping-pong attacker pointing us at another kpasswdd.
 460      */
 461     pkt_len = (msg[0] << 8) | (msg[1]);
 462     pkt_ver = (msg[2] << 8) | (msg[3]);
 463     ap_req_len = (msg[4] << 8) | (msg[5]);
 464     if (pkt_len != len) {
 465         krb5_warnx (context, "Strange len: %ld != %ld",
 466                     (long)pkt_len, (long)len);
 467         return 1;
 468     }
 469     if (ap_req_len == 0) {
 470         krb5_warnx (context, "Request is error packet (ap_req_len == 0)");
 471         return 1;
 472     }
 473     if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW &&
 474         pkt_ver != KRB5_KPASSWD_VERS_SETPW) {
 475         krb5_warnx (context, "Bad version (%d)", pkt_ver);
 476         reply_error (NULL, s, sa, sa_size, 0, 1, "Wrong program version");
 477         return 1;
 478     }
 479     *version = pkt_ver;
 480
 481     ap_req_data.data   = msg + 6;
 482     ap_req_data.length = ap_req_len;
 483
 484     ret = krb5_rd_req (context,
 485                        auth_context,
 486                        &ap_req_data,
 487                        NULL,
 488                        keytab,
 489                        NULL,
 490                        ticket);
 491     if (ret) {
 492         krb5_warn (context, ret, "krb5_rd_req");
 493         reply_error (NULL, s, sa, sa_size, ret, 3, "Authentication failed");
 494         return 1;
 495     }
 496
 497     /* verify realm and principal */
 498     for (r = realms; *r != NULL; r++) {
 499         krb5_principal principal;
 500         krb5_boolean same;
 501
 502         ret = krb5_make_principal (context,
 503                                    &principal,
 504                                    *r,
 505                                    "kadmin",
 506                                    "changepw",
 507                                    NULL);
 508         if (ret)
 509             krb5_err (context, 1, ret, "krb5_make_principal");
 510
 511         same = krb5_principal_compare(context, principal, (*ticket)->server);
 512         krb5_free_principal(context, principal);
 513         if (same == TRUE)
 514             break;
 515     }
 516     if (*r == NULL) {
 517         char *str;
 518         krb5_unparse_name(context, (*ticket)->server, &str);
 519         krb5_warnx (context, "client used not valid principal %s", str);
 520         free(str);
 521         reply_error (NULL, s, sa, sa_size, ret, 1,
 522                      "Bad request");
 523         goto out;
 524     }
 525
 526     if (strcmp((*ticket)->server->realm, (*ticket)->client->realm) != 0) {
 527         krb5_warnx (context, "server realm (%s) not same a client realm (%s)",
 528                     (*ticket)->server->realm, (*ticket)->client->realm);
 529         reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 1,
 530                      "Bad request");
 531         goto out;
 532     }
 533
 534     if (!(*ticket)->ticket.flags.initial) {
 535         krb5_warnx (context, "initial flag not set");
 536         reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 1,
 537                      "Bad request");
 538         goto out;
 539     }
 540     krb_priv_data.data   = msg + 6 + ap_req_len;
 541     krb_priv_data.length = len - 6 - ap_req_len;
 542
 543     ret = krb5_rd_priv (context,
 544                         *auth_context,
 545                         &krb_priv_data,
 546                         out_data,
 547                         NULL);
 548
 549     if (ret) {
 550         krb5_warn (context, ret, "krb5_rd_priv");
 551         reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 3,
 552                      "Bad request");
 553         goto out;
 554     }
 555     return 0;
 556 out:
 557     krb5_free_ticket (context, *ticket);
 558     ticket = NULL;
 559     return 1;
 560 }
 561
 562 static void
 563 process (krb5_realm *realms,
 564          krb5_keytab keytab,
 565          int s,
 566          krb5_address *this_addr,
 567          struct sockaddr *sa,
 568          int sa_size,
 569          u_char *msg,
 570          int len)
 571 {
 572     krb5_error_code ret;
 573     krb5_auth_context auth_context = NULL;
 574     krb5_data out_data;
 575     krb5_ticket *ticket;
 576     krb5_address other_addr;
 577     uint16_t version;
 578
 579
 580     krb5_data_zero (&out_data);
 581
 582     ret = krb5_auth_con_init (context, &auth_context);
 583     if (ret) {
 584         krb5_warn (context, ret, "krb5_auth_con_init");
 585         return;
 586     }
 587
 588     krb5_auth_con_setflags (context, auth_context,
 589                             KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 590
 591     ret = krb5_sockaddr2address (context, sa, &other_addr);
 592     if (ret) {
 593         krb5_warn (context, ret, "krb5_sockaddr2address");
 594         goto out;
 595     }
 596
 597     ret = krb5_auth_con_setaddrs (context,
 598                                   auth_context,
 599                                   this_addr,
 600                                   &other_addr);
 601     krb5_free_address (context, &other_addr);
 602     if (ret) {
 603         krb5_warn (context, ret, "krb5_auth_con_setaddr");
 604         goto out;
 605     }
 606
 607     if (verify (&auth_context, realms, keytab, &ticket, &out_data,
 608                 &version, s, sa, sa_size, msg, len) == 0) {
 609         change (auth_context,
 610                 ticket->client,
 611                 version,
 612                 s,
 613                 sa, sa_size,
 614                 &out_data);
 615         memset (out_data.data, 0, out_data.length);
 616         krb5_free_ticket (context, ticket);
 617     }
 618
 619 out:
 620     krb5_data_free (&out_data);
 621     krb5_auth_con_free (context, auth_context);
 622 }
 623
 624 static int
 625 doit (krb5_keytab keytab, int port)
 626 {
 627     krb5_error_code ret;
 628     int *sockets;
 629     int maxfd;
 630     krb5_realm *realms;
 631     krb5_addresses addrs;
 632     unsigned n, i;
 633     fd_set real_fdset;
 634     struct sockaddr_storage __ss;
 635     struct sockaddr *sa = (struct sockaddr *)&__ss;
 636
 637     ret = krb5_get_default_realms(context, &realms);
 638     if (ret)
 639         krb5_err (context, 1, ret, "krb5_get_default_realms");
 640
 641     if (explicit_addresses.len) {
 642         addrs = explicit_addresses;
 643     } else {
 644         ret = krb5_get_all_server_addrs (context, &addrs);
 645         if (ret)
 646             krb5_err (context, 1, ret, "krb5_get_all_server_addrs");
 647     }
 648     n = addrs.len;
 649
 650     sockets = malloc (n * sizeof(*sockets));
 651     if (sockets == NULL)
 652         krb5_errx (context, 1, "out of memory");
 653     maxfd = -1;
 654     FD_ZERO(&real_fdset);
 655     for (i = 0; i < n; ++i) {
 656         krb5_socklen_t sa_size = sizeof(__ss);
 657
 658         krb5_addr2sockaddr (context, &addrs.val[i], sa, &sa_size, port);
 659
 660         sockets[i] = socket (sa->sa_family, SOCK_DGRAM, 0);
 661         if (sockets[i] < 0)
 662             krb5_err (context, 1, errno, "socket");
 663         if (bind (sockets[i], sa, sa_size) < 0) {
 664             char str[128];
 665             size_t len;
 666             int save_errno = errno;
 667
 668             ret = krb5_print_address (&addrs.val[i], str, sizeof(str), &len);
 669             if (ret)
 670                 strlcpy(str, "unknown address", sizeof(str));
 671             krb5_warn (context, save_errno, "bind(%s)", str);
 672             continue;
 673         }
 674         maxfd = max (maxfd, sockets[i]);
 675         if (maxfd >= FD_SETSIZE)
 676             krb5_errx (context, 1, "fd too large");
 677         FD_SET(sockets[i], &real_fdset);
 678     }
 679     if (maxfd == -1)
 680         krb5_errx (context, 1, "No sockets!");
 681
 682     while(exit_flag == 0) {
 683         int ret;
 684         fd_set fdset = real_fdset;
 685
 686         ret = select (maxfd + 1, &fdset, NULL, NULL, NULL);
 687         if (ret < 0) {
 688             if (errno == EINTR)
 689                 continue;
 690             else
 691                 krb5_err (context, 1, errno, "select");
 692         }
 693         for (i = 0; i < n; ++i)
 694             if (FD_ISSET(sockets[i], &fdset)) {
 695                 u_char buf[BUFSIZ];
 696                 socklen_t addrlen = sizeof(__ss);
 697
 698                 ret = recvfrom (sockets[i], buf, sizeof(buf), 0,
 699                                 sa, &addrlen);
 700                 if (ret < 0) {
 701                     if(errno == EINTR)
 702                         break;
 703                     else
 704                         krb5_err (context, 1, errno, "recvfrom");
 705                 }
 706
 707                 process (realms, keytab, sockets[i],
 708                          &addrs.val[i],
 709                          sa, addrlen,
 710                          buf, ret);
 711             }
 712     }
 713
 714     for (i = 0; i < n; ++i)
 715         close(sockets[i]);
 716     free(sockets);
 717
 718     krb5_free_addresses (context, &addrs);
 719     krb5_free_host_realm (context, realms);
 720     krb5_free_context (context);
 721     return 0;
 722 }
 723
 724 static RETSIGTYPE
 725 sigterm(int sig)
 726 {
 727     exit_flag = 1;
 728 }
 729
 730 static const char *check_library  = NULL;
 731 static const char *check_function = NULL;
 732 static getarg_strings policy_libraries = { 0, NULL };
 733 static char *keytab_str = "HDB:";
 734 static char *realm_str;
 735 static int version_flag;
 736 static int help_flag;
 737 static char *port_str;
 738 static char *config_file;
 739
 740 struct getargs args[] = {
 741 #ifdef HAVE_DLOPEN
 742     { "check-library", 0, arg_string, &check_library,
 743       "library to load password check function from", "library" },
 744     { "check-function", 0, arg_string, &check_function,
 745       "password check function to load", "function" },
 746     { "policy-libraries", 0, arg_strings, &policy_libraries,
 747       "password check function to load", "function" },
 748 #endif
 749     { "addresses",      0,      arg_strings, &addresses_str,
 750       "addresses to listen on", "list of addresses" },
 751     { "keytab", 'k', arg_string, &keytab_str,
 752       "keytab to get authentication key from", "kspec" },
 753     { "config-file", 'c', arg_string, &config_file },
 754     { "realm", 'r', arg_string, &realm_str, "default realm", "realm" },
 755     { "port",  'p', arg_string, &port_str, "port" },
 756     { "version", 0, arg_flag, &version_flag },
 757     { "help", 0, arg_flag, &help_flag }
 758 };
 759 int num_args = sizeof(args) / sizeof(args[0]);
 760
 761 int
 762 main (int argc, char **argv)
 763 {
 764     krb5_keytab keytab;
 765     krb5_error_code ret;
 766     char **files;
 767     int port, i;
 768
 769     krb5_program_setup(&context, argc, argv, args, num_args, NULL);
 770
 771     if(help_flag)
 772         krb5_std_usage(0, args, num_args);
 773     if(version_flag) {
 774         print_version(NULL);
 775         exit(0);
 776     }
 777
 778     if (config_file == NULL) {
 779         asprintf(&config_file, "%s/kdc.conf", hdb_db_dir(context));
 780         if (config_file == NULL)
 781             errx(1, "out of memory");
 782     }
 783
 784     ret = krb5_prepend_config_files_default(config_file, &files);
 785     if (ret)
 786         krb5_err(context, 1, ret, "getting configuration files");
 787
 788     ret = krb5_set_config_files(context, files);
 789     krb5_free_config_files(files);
 790     if (ret)
 791         krb5_err(context, 1, ret, "reading configuration files");
 792
 793     if(realm_str)
 794         krb5_set_default_realm(context, realm_str);
 795
 796     krb5_openlog (context, "kpasswdd", &log_facility);
 797     krb5_set_warn_dest(context, log_facility);
 798
 799     if (port_str != NULL) {
 800         struct servent *s = roken_getservbyname (port_str, "udp");
 801
 802         if (s != NULL)
 803             port = s->s_port;
 804         else {
 805             char *ptr;
 806
 807             port = strtol (port_str, &ptr, 10);
 808             if (port == 0 && ptr == port_str)
 809                 krb5_errx (context, 1, "bad port `%s'", port_str);
 810             port = htons(port);
 811         }
 812     } else
 813         port = krb5_getportbyname (context, "kpasswd", "udp", KPASSWD_PORT);
 814
 815     ret = krb5_kt_register(context, &hdb_kt_ops);
 816     if(ret)
 817         krb5_err(context, 1, ret, "krb5_kt_register");
 818
 819     ret = krb5_kt_resolve(context, keytab_str, &keytab);
 820     if(ret)
 821         krb5_err(context, 1, ret, "%s", keytab_str);
 822
 823     kadm5_setup_passwd_quality_check (context, check_library, check_function);
 824
 825     for (i = 0; i < policy_libraries.num_strings; i++) {
 826         ret = kadm5_add_passwd_quality_verifier(context,
 827                                                 policy_libraries.strings[i]);
 828         if (ret)
 829             krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
 830     }
 831     ret = kadm5_add_passwd_quality_verifier(context, NULL);
 832     if (ret)
 833         krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
 834
 835
 836     explicit_addresses.len = 0;
 837
 838     if (addresses_str.num_strings) {
 839         int i;
 840
 841         for (i = 0; i < addresses_str.num_strings; ++i)
 842             add_one_address (addresses_str.strings[i], i == 0);
 843         free_getarg_strings (&addresses_str);
 844     } else {
 845         char **foo = krb5_config_get_strings (context, NULL,
 846                                               "kdc", "addresses", NULL);
 847
 848         if (foo != NULL) {
 849             add_one_address (*foo++, TRUE);
 850             while (*foo)
 851                 add_one_address (*foo++, FALSE);
 852         }
 853     }
 854
 855 #ifdef HAVE_SIGACTION
 856     {
 857         struct sigaction sa;
 858
 859         sa.sa_flags = 0;
 860         sa.sa_handler = sigterm;
 861         sigemptyset(&sa.sa_mask);
 862
 863         sigaction(SIGINT,  &sa, NULL);
 864         sigaction(SIGTERM, &sa, NULL);
 865     }
 866 #else
 867     signal(SIGINT,  sigterm);
 868     signal(SIGTERM, sigterm);
 869 #endif
 870
 871     pidfile(NULL);
 872
 873     return doit (keytab, port);
 874 }