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     krb5_error_code ret;
 127     krb5_storage *sp;
 128
 129     sp = krb5_storage_emem();
 130     if (sp == NULL) goto out;
 131     ret = krb5_store_uint16(sp, result_code);
 132     if (ret) goto out;
 133     ret = krb5_store_stringz(sp, expl);
 134     if (ret) goto out;
 135     ret = krb5_storage_to_data(sp, data);
 136     if (ret) goto out;
 137     krb5_storage_free(sp);
 138
 139     return 0;
 140  out:
 141     if (sp)
 142         krb5_storage_free(sp);
 143
 144     krb5_warnx (context, "Out of memory generating error reply");
 145     return 1;
 146 }
 147
 148 static void
 149 reply_error (krb5_realm realm,
 150              int s,
 151              struct sockaddr *sa,
 152              int sa_size,
 153              krb5_error_code error_code,
 154              uint16_t result_code,
 155              const char *expl)
 156 {
 157     krb5_error_code ret;
 158     krb5_data error_data;
 159     krb5_data e_data;
 160     krb5_principal server = NULL;
 161
 162     if (make_result(&e_data, result_code, expl))
 163         return;
 164
 165     if (realm) {
 166         ret = krb5_make_principal (context, &server, realm,
 167                                    "kadmin", "changepw", NULL);
 168         if (ret) {
 169             krb5_data_free (&e_data);
 170             return;
 171         }
 172     }
 173
 174     ret = krb5_mk_error (context,
 175                          error_code,
 176                          NULL,
 177                          &e_data,
 178                          NULL,
 179                          server,
 180                          NULL,
 181                          NULL,
 182                          &error_data);
 183     if (server)
 184         krb5_free_principal(context, server);
 185     krb5_data_free (&e_data);
 186     if (ret) {
 187         krb5_warn (context, ret, "Could not even generate error reply");
 188         return;
 189     }
 190     send_reply (s, sa, sa_size, NULL, &error_data);
 191     krb5_data_free (&error_data);
 192 }
 193
 194 static void
 195 reply_priv (krb5_auth_context auth_context,
 196             int s,
 197             struct sockaddr *sa,
 198             int sa_size,
 199             uint16_t result_code,
 200             const char *expl)
 201 {
 202     krb5_error_code ret;
 203     krb5_data krb_priv_data;
 204     krb5_data ap_rep_data;
 205     krb5_data e_data;
 206
 207     ret = krb5_mk_rep (context,
 208                        auth_context,
 209                        &ap_rep_data);
 210     if (ret) {
 211         krb5_warn (context, ret, "Could not even generate error reply");
 212         return;
 213     }
 214
 215     if (make_result(&e_data, result_code, expl))
 216         return;
 217
 218     ret = krb5_mk_priv (context,
 219                         auth_context,
 220                         &e_data,
 221                         &krb_priv_data,
 222                         NULL);
 223     krb5_data_free (&e_data);
 224     if (ret) {
 225         krb5_warn (context, ret, "Could not even generate error reply");
 226         return;
 227     }
 228     send_reply (s, sa, sa_size, &ap_rep_data, &krb_priv_data);
 229     krb5_data_free (&ap_rep_data);
 230     krb5_data_free (&krb_priv_data);
 231 }
 232
 233 /*
 234  * Change the password for `principal', sending the reply back on `s'
 235  * (`sa', `sa_size') to `pwd_data'.
 236  */
 237
 238 static void
 239 change (krb5_auth_context auth_context,
 240         krb5_principal admin_principal,
 241         uint16_t version,
 242         int s,
 243         struct sockaddr *sa,
 244         int sa_size,
 245         krb5_data *in_data)
 246 {
 247     krb5_error_code ret;
 248     char *client = NULL, *admin = NULL;
 249     const char *pwd_reason;
 250     kadm5_config_params conf;
 251     void *kadm5_handle = NULL;
 252     krb5_principal principal = NULL;
 253     krb5_data *pwd_data = NULL;
 254     char *tmp;
 255     ChangePasswdDataMS chpw;
 256
 257     memset (&conf, 0, sizeof(conf));
 258     memset(&chpw, 0, sizeof(chpw));
 259
 260     if (version == KRB5_KPASSWD_VERS_CHANGEPW) {
 261         ret = krb5_copy_data(context, in_data, &pwd_data);
 262         if (ret) {
 263             krb5_warn (context, ret, "krb5_copy_data");
 264             reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
 265                         "out out memory copying password");
 266             return;
 267         }
 268         principal = admin_principal;
 269     } else if (version == KRB5_KPASSWD_VERS_SETPW) {
 270         size_t len;
 271
 272         ret = decode_ChangePasswdDataMS(in_data->data, in_data->length,
 273                                         &chpw, &len);
 274         if (ret) {
 275             krb5_warn (context, ret, "decode_ChangePasswdDataMS");
 276             reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
 277                         "malformed ChangePasswdData");
 278             return;
 279         }
 280
 281
 282         ret = krb5_copy_data(context, &chpw.newpasswd, &pwd_data);
 283         if (ret) {
 284             krb5_warn (context, ret, "krb5_copy_data");
 285             reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_MALFORMED,
 286                         "out out memory copying password");
 287             goto out;
 288         }
 289
 290         if (chpw.targname == NULL && chpw.targrealm != NULL) {
 291             krb5_warn (context, ret, "kadm5_init_with_password_ctx");
 292             reply_priv (auth_context, s, sa, sa_size,
 293                         KRB5_KPASSWD_MALFORMED,
 294                         "targrealm but not targname");
 295             goto out;
 296         }
 297
 298         if (chpw.targname) {
 299             krb5_principal_data princ;
 300
 301             memset(&princ, 0, sizeof (princ));
 302             princ.name = *chpw.targname;
 303             princ.realm = *chpw.targrealm;
 304             if (princ.realm == NULL) {
 305                 ret = krb5_get_default_realm(context, &princ.realm);
 306
 307                 if (ret) {
 308                     krb5_warnx (context,
 309                                 "kadm5_init_with_password_ctx: "
 310                                 "failed to allocate realm");
 311                     reply_priv (auth_context, s, sa, sa_size,
 312                                 KRB5_KPASSWD_SOFTERROR,
 313                                 "failed to allocate realm");
 314                     goto out;
 315                 }
 316             }
 317             ret = krb5_copy_principal(context, &princ, &principal);
 318             if (*chpw.targrealm == NULL)
 319                 free(princ.realm);
 320             if (ret) {
 321                 krb5_warn(context, ret, "krb5_copy_principal");
 322                 reply_priv(auth_context, s, sa, sa_size,
 323                            KRB5_KPASSWD_HARDERROR,
 324                            "failed to allocate principal");
 325                 goto out;
 326             }
 327         } else
 328             principal = admin_principal;
 329     } else {
 330         krb5_warnx (context, "kadm5_init_with_password_ctx: unknown proto");
 331         reply_priv (auth_context, s, sa, sa_size,
 332                     KRB5_KPASSWD_HARDERROR,
 333                     "Unknown protocol used");
 334         return;
 335     }
 336
 337     ret = krb5_unparse_name (context, admin_principal, &admin);
 338     if (ret) {
 339         krb5_warn (context, ret, "unparse_name failed");
 340         reply_priv (auth_context, s, sa, sa_size,
 341                     KRB5_KPASSWD_HARDERROR, "out of memory error");
 342         goto out;
 343     }
 344
 345     conf.realm = principal->realm;
 346     conf.mask |= KADM5_CONFIG_REALM;
 347
 348     ret = kadm5_init_with_password_ctx(context,
 349                                        admin,
 350                                        NULL,
 351                                        KADM5_ADMIN_SERVICE,
 352                                        &conf, 0, 0,
 353                                        &kadm5_handle);
 354     if (ret) {
 355         krb5_warn (context, ret, "kadm5_init_with_password_ctx");
 356         reply_priv (auth_context, s, sa, sa_size, 2,
 357                     "Internal error");
 358         goto out;
 359     }
 360
 361     ret = krb5_unparse_name(context, principal, &client);
 362     if (ret) {
 363         krb5_warn (context, ret, "unparse_name failed");
 364         reply_priv (auth_context, s, sa, sa_size,
 365                     KRB5_KPASSWD_HARDERROR, "out of memory error");
 366         goto out;
 367     }
 368
 369     /*
 370      * Check password quality if not changing as administrator
 371      */
 372
 373     if (krb5_principal_compare(context, admin_principal, principal) == TRUE) {
 374
 375         pwd_reason = kadm5_check_password_quality (context, principal,
 376                                                    pwd_data);
 377         if (pwd_reason != NULL ) {
 378             krb5_warnx (context,
 379                         "%s didn't pass password quality check with error: %s",
 380                         client, pwd_reason);
 381             reply_priv (auth_context, s, sa, sa_size,
 382                         KRB5_KPASSWD_SOFTERROR, pwd_reason);
 383             goto out;
 384         }
 385         krb5_warnx (context, "Changing password for %s", client);
 386     } else {
 387         ret = _kadm5_acl_check_permission(kadm5_handle, KADM5_PRIV_CPW,
 388                                           principal);
 389         if (ret) {
 390             krb5_warn (context, ret,
 391                        "Check ACL failed for %s for changing %s password",
 392                        admin, client);
 393             reply_priv (auth_context, s, sa, sa_size,
 394                         KRB5_KPASSWD_HARDERROR, "permission denied");
 395             goto out;
 396         }
 397         krb5_warnx (context, "%s is changing password for %s", admin, client);
 398     }
 399
 400     ret = krb5_data_realloc(pwd_data, pwd_data->length + 1);
 401     if (ret) {
 402         krb5_warn (context, ret, "malloc: out of memory");
 403         reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_HARDERROR,
 404                     "Internal error");
 405         goto out;
 406     }
 407     tmp = pwd_data->data;
 408     tmp[pwd_data->length - 1] = '\0';
 409
 410     ret = kadm5_s_chpass_principal_cond (kadm5_handle, principal, 1, tmp);
 411     krb5_free_data (context, pwd_data);
 412     pwd_data = NULL;
 413     if (ret) {
 414         const char *str = krb5_get_error_message(context, ret);
 415         krb5_warnx(context, "kadm5_s_chpass_principal_cond: %s", str);
 416         reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SOFTERROR,
 417                     str ? str : "Internal error");
 418         krb5_free_error_message(context, str);
 419         goto out;
 420     }
 421     reply_priv (auth_context, s, sa, sa_size, KRB5_KPASSWD_SUCCESS,
 422                 "Password changed");
 423 out:
 424     free_ChangePasswdDataMS(&chpw);
 425     if (principal != admin_principal)
 426         krb5_free_principal(context, principal);
 427     if (admin)
 428         free(admin);
 429     if (client)
 430         free(client);
 431     if (pwd_data)
 432         krb5_free_data(context, pwd_data);
 433     if (kadm5_handle)
 434         kadm5_destroy (kadm5_handle);
 435 }
 436
 437 static int
 438 verify (krb5_auth_context *auth_context,
 439         krb5_keytab keytab,
 440         krb5_ticket **ticket,
 441         krb5_data *out_data,
 442         uint16_t *version,
 443         int s,
 444         struct sockaddr *sa,
 445         int sa_size,
 446         u_char *msg,
 447         size_t len,
 448         krb5_address *client_addr)
 449 {
 450     krb5_error_code ret;
 451     uint16_t pkt_len, pkt_ver, ap_req_len;
 452     krb5_data ap_req_data;
 453     krb5_data krb_priv_data;
 454     krb5_const_realm client_realm;
 455     krb5_principal sprinc;
 456     int same;
 457
 458     /*
 459      * Only send an error reply if the request passes basic length
 460      * verification.  Otherwise, kpasswdd would reply to every UDP packet,
 461      * allowing an attacker to set up a ping-pong DoS attack via a spoofed UDP
 462      * packet with a source address of another UDP service that also replies
 463      * to every packet.
 464      *
 465      * Also suppress the error reply if ap_req_len is 0, which indicates
 466      * either an invalid request or an error packet.  An error packet may be
 467      * the result of a ping-pong attacker pointing us at another kpasswdd.
 468      */
 469     pkt_len = (msg[0] << 8) | (msg[1]);
 470     pkt_ver = (msg[2] << 8) | (msg[3]);
 471     ap_req_len = (msg[4] << 8) | (msg[5]);
 472     if (pkt_len != len) {
 473         krb5_warnx (context, "Strange len: %ld != %ld",
 474                     (long)pkt_len, (long)len);
 475         return 1;
 476     }
 477     if (ap_req_len == 0) {
 478         krb5_warnx (context, "Request is error packet (ap_req_len == 0)");
 479         return 1;
 480     }
 481     if (pkt_ver != KRB5_KPASSWD_VERS_CHANGEPW &&
 482         pkt_ver != KRB5_KPASSWD_VERS_SETPW) {
 483         krb5_warnx (context, "Bad version (%d)", pkt_ver);
 484         reply_error (NULL, s, sa, sa_size, 0, 1, "Wrong program version");
 485         return 1;
 486     }
 487     *version = pkt_ver;
 488
 489     ap_req_data.data   = msg + 6;
 490     ap_req_data.length = ap_req_len;
 491
 492     ret = krb5_rd_req (context,
 493                        auth_context,
 494                        &ap_req_data,
 495                        NULL,
 496                        keytab,
 497                        NULL,
 498                        ticket);
 499     if (ret) {
 500         krb5_warn (context, ret, "krb5_rd_req");
 501         reply_error (NULL, s, sa, sa_size, ret, 3, "Authentication failed");
 502         return 1;
 503     }
 504
 505     if (!(*ticket)->ticket.flags.initial) {
 506         krb5_warnx(context, "initial flag not set");
 507         reply_error((*ticket)->server->realm, s, sa, sa_size, ret, 1,
 508                     "Bad request");
 509         goto out;
 510     }
 511
 512     /*
 513      * The service principal must be kadmin/changepw@CLIENT-REALM, there
 514      * is no reason to require the KDC's default realm(s) to be the same
 515      * as the realm(s) it serves. The only potential issue is when a KDC
 516      * is a master for realm A and a slave for realm B, in which case it
 517      * should not accept requests to change passwords for realm B, these
 518      * should be sent to realm B's master. This same issue is present in
 519      * the checks that only accepted local realms, there is no new risk.
 520      */
 521
 522     client_realm = krb5_principal_get_realm(context, (*ticket)->client);
 523     ret = krb5_make_principal(context, &sprinc, client_realm,
 524                               "kadmin", "changepw", NULL);
 525     if (ret)
 526         goto out;
 527     same = krb5_principal_compare(context, sprinc, (*ticket)->server);
 528     krb5_free_principal(context, sprinc);
 529
 530     if (!same) {
 531         char *sname;
 532
 533         krb5_unparse_name(context, (*ticket)->server, &sname);
 534         krb5_warnx(context, "Invalid kpasswd service principal %s", sname);
 535         free(sname);
 536         reply_error(NULL, s, sa, sa_size, ret, 1, "Bad request");
 537         goto out;
 538     }
 539     krb_priv_data.data   = msg + 6 + ap_req_len;
 540     krb_priv_data.length = len - 6 - ap_req_len;
 541
 542     /*
 543      * Only enforce client addresses on on tickets with addresses.  If
 544      * its addressless, we are guessing its behind NAT and really
 545      * can't know this information.
 546      */
 547
 548     if ((*ticket)->ticket.caddr && (*ticket)->ticket.caddr->len > 0) {
 549         ret = krb5_auth_con_setaddrs (context, *auth_context,
 550                                       NULL, client_addr);
 551         if (ret) {
 552             krb5_warn (context, ret, "krb5_auth_con_setaddr(this)");
 553             goto out;
 554         }
 555     }
 556
 557     ret = krb5_rd_priv (context,
 558                         *auth_context,
 559                         &krb_priv_data,
 560                         out_data,
 561                         NULL);
 562
 563     if (ret) {
 564         krb5_warn (context, ret, "krb5_rd_priv");
 565         reply_error ((*ticket)->server->realm, s, sa, sa_size, ret, 3,
 566                      "Bad request");
 567         goto out;
 568     }
 569     return 0;
 570 out:
 571     krb5_free_ticket (context, *ticket);
 572     ticket = NULL;
 573     return 1;
 574 }
 575
 576 static void
 577 process (krb5_keytab keytab,
 578          int s,
 579          krb5_address *this_addr,
 580          struct sockaddr *sa,
 581          int sa_size,
 582          u_char *msg,
 583          int len)
 584 {
 585     krb5_error_code ret;
 586     krb5_auth_context auth_context = NULL;
 587     krb5_data out_data;
 588     krb5_ticket *ticket;
 589     krb5_address other_addr;
 590     uint16_t version;
 591
 592     memset(&other_addr, 0, sizeof(other_addr));
 593     krb5_data_zero (&out_data);
 594
 595     ret = krb5_auth_con_init (context, &auth_context);
 596     if (ret) {
 597         krb5_warn (context, ret, "krb5_auth_con_init");
 598         return;
 599     }
 600
 601     krb5_auth_con_setflags (context, auth_context,
 602                             KRB5_AUTH_CONTEXT_DO_SEQUENCE);
 603
 604     ret = krb5_sockaddr2address (context, sa, &other_addr);
 605     if (ret) {
 606         krb5_warn (context, ret, "krb5_sockaddr2address");
 607         goto out;
 608     }
 609
 610     ret = krb5_auth_con_setaddrs (context, auth_context, this_addr, NULL);
 611     if (ret) {
 612         krb5_warn (context, ret, "krb5_auth_con_setaddr(this)");
 613         goto out;
 614     }
 615
 616     if (verify (&auth_context, keytab, &ticket, &out_data,
 617                 &version, s, sa, sa_size, msg, len, &other_addr) == 0)
 618     {
 619         /*
 620          * We always set the client_addr, to assume that the client
 621          * can ignore it if it choose to do so (just the server does
 622          * so for addressless tickets).
 623          */
 624         ret = krb5_auth_con_setaddrs (context, auth_context,
 625                                       this_addr, &other_addr);
 626         if (ret) {
 627             krb5_warn (context, ret, "krb5_auth_con_setaddr(other)");
 628             goto out;
 629         }
 630
 631         change (auth_context,
 632                 ticket->client,
 633                 version,
 634                 s,
 635                 sa, sa_size,
 636                 &out_data);
 637         memset (out_data.data, 0, out_data.length);
 638         krb5_free_ticket (context, ticket);
 639     }
 640
 641 out:
 642     krb5_free_address(context, &other_addr);
 643     krb5_data_free(&out_data);
 644     krb5_auth_con_free(context, auth_context);
 645 }
 646
 647 static const char *check_library  = NULL;
 648 static const char *check_function = NULL;
 649 static getarg_strings policy_libraries = { 0, NULL };
 650 static char sHDB[] = "HDBGET:";
 651 static char *keytab_str = sHDB;
 652 static char *realm_str;
 653 static int version_flag;
 654 static int help_flag;
 655 static int detach_from_console;
 656 static int daemon_child = -1;
 657 static char *port_str;
 658 static char *config_file;
 659
 660 struct getargs args[] = {
 661 #ifdef HAVE_DLOPEN
 662     { "check-library", 0, arg_string, &check_library,
 663       "library to load password check function from", "library" },
 664     { "check-function", 0, arg_string, &check_function,
 665       "password check function to load", "function" },
 666     { "policy-libraries", 0, arg_strings, &policy_libraries,
 667       "password check function to load", "function" },
 668 #endif
 669     { "addresses", 0, arg_strings, &addresses_str,
 670       "addresses to listen on", "list of addresses" },
 671     { "detach", 0, arg_flag, &detach_from_console,
 672       "detach from console", NULL },
 673     { "daemon-child",       0 ,      arg_integer, &daemon_child,
 674       "private argument, do not use", NULL },
 675     { "keytab", 'k', arg_string, &keytab_str,
 676       "keytab to get authentication key from", "kspec" },
 677     { "config-file", 'c', arg_string, &config_file, NULL, NULL },
 678     { "realm", 'r', arg_string, &realm_str, "default realm", "realm" },
 679     { "port",  'p', arg_string, &port_str, "port", NULL },
 680     { "version", 0, arg_flag, &version_flag, NULL, NULL },
 681     { "help", 0, arg_flag, &help_flag, NULL, NULL }
 682 };
 683 int num_args = sizeof(args) / sizeof(args[0]);
 684
 685 static int
 686 doit(krb5_keytab keytab, int port)
 687 {
 688     krb5_error_code ret;
 689     int *sockets;
 690     int maxfd;
 691     krb5_addresses addrs;
 692     unsigned n, i;
 693     fd_set real_fdset;
 694     struct sockaddr_storage __ss;
 695     struct sockaddr *sa = (struct sockaddr *)&__ss;
 696
 697     if (explicit_addresses.len) {
 698         addrs = explicit_addresses;
 699     } else {
 700         ret = krb5_get_all_server_addrs(context, &addrs);
 701         if (ret)
 702             krb5_err(context, 1, ret, "krb5_get_all_server_addrs");
 703     }
 704     n = addrs.len;
 705
 706     sockets = malloc(n * sizeof(*sockets));
 707     if (sockets == NULL)
 708         krb5_errx(context, 1, "out of memory");
 709     maxfd = -1;
 710     FD_ZERO(&real_fdset);
 711     for (i = 0; i < n; ++i) {
 712         krb5_socklen_t sa_size = sizeof(__ss);
 713
 714         krb5_addr2sockaddr(context, &addrs.val[i], sa, &sa_size, port);
 715
 716         sockets[i] = socket(__ss.ss_family, SOCK_DGRAM, 0);
 717         if (sockets[i] < 0)
 718             krb5_err(context, 1, errno, "socket");
 719         if (bind(sockets[i], sa, sa_size) < 0) {
 720             char str[128];
 721             size_t len;
 722             int save_errno = errno;
 723
 724             ret = krb5_print_address(&addrs.val[i], str, sizeof(str), &len);
 725             if (ret)
 726                 strlcpy(str, "unknown address", sizeof(str));
 727             krb5_warn(context, save_errno, "bind(%s)", str);
 728             continue;
 729         }
 730         maxfd = max(maxfd, sockets[i]);
 731         if (maxfd >= FD_SETSIZE)
 732             krb5_errx(context, 1, "fd too large");
 733         FD_SET(sockets[i], &real_fdset);
 734     }
 735     if (maxfd == -1)
 736         krb5_errx(context, 1, "No sockets!");
 737
 738     roken_detach_finish(NULL, daemon_child);
 739
 740     while (exit_flag == 0) {
 741         krb5_ssize_t retx;
 742         fd_set fdset = real_fdset;
 743
 744         retx = select(maxfd + 1, &fdset, NULL, NULL, NULL);
 745         if (retx < 0) {
 746             if (errno == EINTR)
 747                 continue;
 748             else
 749                 krb5_err(context, 1, errno, "select");
 750         }
 751         for (i = 0; i < n; ++i)
 752             if (FD_ISSET(sockets[i], &fdset)) {
 753                 u_char buf[BUFSIZ];
 754                 socklen_t addrlen = sizeof(__ss);
 755
 756                 retx = recvfrom(sockets[i], buf, sizeof(buf), 0,
 757                                 sa, &addrlen);
 758                 if (retx < 0) {
 759                     if (errno == EINTR)
 760                         break;
 761                     else
 762                         krb5_err(context, 1, errno, "recvfrom");
 763                 }
 764
 765                 process(keytab, sockets[i],
 766                          &addrs.val[i],
 767                          sa, addrlen,
 768                          buf, retx);
 769             }
 770     }
 771
 772     for (i = 0; i < n; ++i)
 773         close(sockets[i]);
 774     free(sockets);
 775
 776     krb5_free_addresses(context, &addrs);
 777     krb5_free_context(context);
 778     return 0;
 779 }
 780
 781 static RETSIGTYPE
 782 sigterm(int sig)
 783 {
 784     exit_flag = 1;
 785 }
 786
 787 int
 788 main(int argc, char **argv)
 789 {
 790     krb5_keytab keytab;
 791     krb5_error_code ret;
 792     char **files;
 793     int port, i;
 794     int aret;
 795
 796     krb5_program_setup(&context, argc, argv, args, num_args, NULL);
 797
 798     if (help_flag)
 799         krb5_std_usage(0, args, num_args);
 800
 801     if (version_flag) {
 802         print_version(NULL);
 803         exit(0);
 804     }
 805
 806     if (detach_from_console > 0 && daemon_child == -1)
 807         roken_detach_prep(argc, argv, "--daemon-child");
 808
 809     if (config_file == NULL) {
 810         aret = asprintf(&config_file, "%s/kdc.conf", hdb_db_dir(context));
 811         if (aret == -1)
 812             errx(1, "out of memory");
 813     }
 814
 815     ret = krb5_prepend_config_files_default(config_file, &files);
 816     if (ret)
 817         krb5_err(context, 1, ret, "getting configuration files");
 818
 819     ret = krb5_set_config_files(context, files);
 820     krb5_free_config_files(files);
 821     if (ret)
 822         krb5_err(context, 1, ret, "reading configuration files");
 823
 824     if (realm_str)
 825         krb5_set_default_realm(context, realm_str);
 826
 827     krb5_openlog(context, "kpasswdd", &log_facility);
 828     krb5_set_warn_dest(context, log_facility);
 829
 830     if (port_str != NULL) {
 831         struct servent *s = roken_getservbyname(port_str, "udp");
 832
 833         if (s != NULL)
 834             port = s->s_port;
 835         else {
 836             char *ptr;
 837
 838             port = strtol(port_str, &ptr, 10);
 839             if (port == 0 && ptr == port_str)
 840                 krb5_errx(context, 1, "bad port `%s'", port_str);
 841             port = htons(port);
 842         }
 843     } else
 844         port = krb5_getportbyname(context, "kpasswd", "udp", KPASSWD_PORT);
 845
 846     ret = krb5_kt_register(context, &hdb_get_kt_ops);
 847     if (ret)
 848         krb5_err(context, 1, ret, "krb5_kt_register");
 849
 850     ret = krb5_kt_resolve(context, keytab_str, &keytab);
 851     if (ret)
 852         krb5_err(context, 1, ret, "%s", keytab_str);
 853
 854     kadm5_setup_passwd_quality_check(context, check_library, check_function);
 855
 856     for (i = 0; i < policy_libraries.num_strings; i++) {
 857         ret = kadm5_add_passwd_quality_verifier(context,
 858                                                 policy_libraries.strings[i]);
 859         if (ret)
 860             krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
 861     }
 862     ret = kadm5_add_passwd_quality_verifier(context, NULL);
 863     if (ret)
 864         krb5_err(context, 1, ret, "kadm5_add_passwd_quality_verifier");
 865
 866
 867     explicit_addresses.len = 0;
 868
 869     if (addresses_str.num_strings) {
 870         int j;
 871
 872         for (j = 0; j < addresses_str.num_strings; ++j)
 873             add_one_address(addresses_str.strings[j], j == 0);
 874         free_getarg_strings(&addresses_str);
 875     } else {
 876         char **foo = krb5_config_get_strings(context, NULL,
 877                                               "kdc", "addresses", NULL);
 878
 879         if (foo != NULL) {
 880             add_one_address(*foo++, TRUE);
 881             while (*foo)
 882                 add_one_address(*foo++, FALSE);
 883         }
 884     }
 885
 886 #ifdef HAVE_SIGACTION
 887     {
 888         struct sigaction sa;
 889
 890         sa.sa_flags = 0;
 891         sa.sa_handler = sigterm;
 892         sigemptyset(&sa.sa_mask);
 893
 894         sigaction(SIGINT,  &sa, NULL);
 895         sigaction(SIGTERM, &sa, NULL);
 896     }
 897 #else
 898     signal(SIGINT,  sigterm);
 899     signal(SIGTERM, sigterm);
 900 #endif
 901
 902     pidfile(NULL);
 903
 904     return doit(keytab, port);
 905 }