kdc/kaserver.c

   1 /*
   2  * Copyright (c) 1997 - 2002 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 "kdc_locl.h"
  35
  36 RCSID("$Id$");
  37
  38
  39 #include <rx.h>
  40
  41 #define KA_AUTHENTICATION_SERVICE 731
  42 #define KA_TICKET_GRANTING_SERVICE 732
  43 #define KA_MAINTENANCE_SERVICE 733
  44
  45 #define AUTHENTICATE_OLD         1
  46 #define CHANGEPASSWORD           2
  47 #define GETTICKET_OLD            3
  48 #define SETPASSWORD              4
  49 #define SETFIELDS                5
  50 #define CREATEUSER               6
  51 #define DELETEUSER               7
  52 #define GETENTRY                 8
  53 #define LISTENTRY                9
  54 #define GETSTATS                10
  55 #define DEBUG                   11
  56 #define GETPASSWORD             12
  57 #define GETRANDOMKEY            13
  58 #define AUTHENTICATE            21
  59 #define AUTHENTICATE_V2         22
  60 #define GETTICKET               23
  61
  62 /* XXX - Where do we get these? */
  63
  64 #define RXGEN_OPCODE (-455)
  65
  66 #define KADATABASEINCONSISTENT                   (180480L)
  67 #define KAEXIST                                  (180481L)
  68 #define KAIO                                     (180482L)
  69 #define KACREATEFAIL                             (180483L)
  70 #define KANOENT                                  (180484L)
  71 #define KAEMPTY                                  (180485L)
  72 #define KABADNAME                                (180486L)
  73 #define KABADINDEX                               (180487L)
  74 #define KANOAUTH                                 (180488L)
  75 #define KAANSWERTOOLONG                          (180489L)
  76 #define KABADREQUEST                             (180490L)
  77 #define KAOLDINTERFACE                           (180491L)
  78 #define KABADARGUMENT                            (180492L)
  79 #define KABADCMD                                 (180493L)
  80 #define KANOKEYS                                 (180494L)
  81 #define KAREADPW                                 (180495L)
  82 #define KABADKEY                                 (180496L)
  83 #define KAUBIKINIT                               (180497L)
  84 #define KAUBIKCALL                               (180498L)
  85 #define KABADPROTOCOL                            (180499L)
  86 #define KANOCELLS                                (180500L)
  87 #define KANOCELL                                 (180501L)
  88 #define KATOOMANYUBIKS                           (180502L)
  89 #define KATOOMANYKEYS                            (180503L)
  90 #define KABADTICKET                              (180504L)
  91 #define KAUNKNOWNKEY                             (180505L)
  92 #define KAKEYCACHEINVALID                        (180506L)
  93 #define KABADSERVER                              (180507L)
  94 #define KABADUSER                                (180508L)
  95 #define KABADCPW                                 (180509L)
  96 #define KABADCREATE                              (180510L)
  97 #define KANOTICKET                               (180511L)
  98 #define KAASSOCUSER                              (180512L)
  99 #define KANOTSPECIAL                             (180513L)
 100 #define KACLOCKSKEW                              (180514L)
 101 #define KANORECURSE                              (180515L)
 102 #define KARXFAIL                                 (180516L)
 103 #define KANULLPASSWORD                           (180517L)
 104 #define KAINTERNALERROR                          (180518L)
 105 #define KAPWEXPIRED                              (180519L)
 106 #define KAREUSED                                 (180520L)
 107 #define KATOOSOON                                (180521L)
 108 #define KALOCKED                                 (180522L)
 109
 110 static void
 111 decode_rx_header (krb5_storage *sp,
 112                   struct rx_header *h)
 113 {
 114     krb5_ret_int32(sp, &h->epoch);
 115     krb5_ret_int32(sp, &h->connid);
 116     krb5_ret_int32(sp, &h->callid);
 117     krb5_ret_int32(sp, &h->seqno);
 118     krb5_ret_int32(sp, &h->serialno);
 119     krb5_ret_int8(sp,  &h->type);
 120     krb5_ret_int8(sp,  &h->flags);
 121     krb5_ret_int8(sp,  &h->status);
 122     krb5_ret_int8(sp,  &h->secindex);
 123     krb5_ret_int16(sp, &h->reserved);
 124     krb5_ret_int16(sp, &h->serviceid);
 125 }
 126
 127 static void
 128 encode_rx_header (struct rx_header *h,
 129                   krb5_storage *sp)
 130 {
 131     krb5_store_int32(sp, h->epoch);
 132     krb5_store_int32(sp, h->connid);
 133     krb5_store_int32(sp, h->callid);
 134     krb5_store_int32(sp, h->seqno);
 135     krb5_store_int32(sp, h->serialno);
 136     krb5_store_int8(sp,  h->type);
 137     krb5_store_int8(sp,  h->flags);
 138     krb5_store_int8(sp,  h->status);
 139     krb5_store_int8(sp,  h->secindex);
 140     krb5_store_int16(sp, h->reserved);
 141     krb5_store_int16(sp, h->serviceid);
 142 }
 143
 144 static void
 145 init_reply_header (struct rx_header *hdr,
 146                    struct rx_header *reply_hdr,
 147                    u_char type,
 148                    u_char flags)
 149 {
 150     reply_hdr->epoch     = hdr->epoch;
 151     reply_hdr->connid    = hdr->connid;
 152     reply_hdr->callid    = hdr->callid;
 153     reply_hdr->seqno     = 1;
 154     reply_hdr->serialno  = 1;
 155     reply_hdr->type      = type;
 156     reply_hdr->flags     = flags;
 157     reply_hdr->status    = 0;
 158     reply_hdr->secindex  = 0;
 159     reply_hdr->reserved  = 0;
 160     reply_hdr->serviceid = hdr->serviceid;
 161 }
 162
 163 static void
 164 make_error_reply (struct rx_header *hdr,
 165                   u_int32_t ret,
 166                   krb5_data *reply)
 167
 168 {
 169     krb5_storage *sp;
 170     struct rx_header reply_hdr;
 171
 172     init_reply_header (hdr, &reply_hdr, HT_ABORT, HF_LAST);
 173     sp = krb5_storage_emem();
 174     encode_rx_header (&reply_hdr, sp);
 175     krb5_store_int32(sp, ret);
 176     krb5_storage_to_data (sp, reply);
 177     krb5_storage_free (sp);
 178 }
 179
 180 static krb5_error_code
 181 krb5_ret_xdr_data(krb5_storage *sp,
 182                   krb5_data *data)
 183 {
 184     int ret;
 185     int size;
 186     ret = krb5_ret_int32(sp, &size);
 187     if(ret)
 188         return ret;
 189     if(size < 0)
 190         return ERANGE;
 191     data->length = size;
 192     if (size) {
 193         u_char foo[4];
 194         size_t pad = (4 - size % 4) % 4;
 195
 196         data->data = malloc(size);
 197         if (data->data == NULL)
 198             return ENOMEM;
 199         ret = krb5_storage_read(sp, data->data, size);
 200         if(ret != size)
 201             return (ret < 0)? errno : KRB5_CC_END;
 202         if (pad) {
 203             ret = krb5_storage_read(sp, foo, pad);
 204             if (ret != pad)
 205                 return (ret < 0)? errno : KRB5_CC_END;
 206         }
 207     } else
 208         data->data = NULL;
 209     return 0;
 210 }
 211
 212 static krb5_error_code
 213 krb5_store_xdr_data(krb5_storage *sp,
 214                     krb5_data data)
 215 {
 216     u_char zero[4] = {0, 0, 0, 0};
 217     int ret;
 218     size_t pad;
 219
 220     ret = krb5_store_int32(sp, data.length);
 221     if(ret < 0)
 222         return ret;
 223     ret = krb5_storage_write(sp, data.data, data.length);
 224     if(ret != data.length){
 225         if(ret < 0)
 226             return errno;
 227         return KRB5_CC_END;
 228     }
 229     pad = (4 - data.length % 4) % 4;
 230     if (pad) {
 231         ret = krb5_storage_write(sp, zero, pad);
 232         if (ret != pad) {
 233             if (ret < 0)
 234                 return errno;
 235             return KRB5_CC_END;
 236         }
 237     }
 238     return 0;
 239 }
 240
 241
 242 static krb5_error_code
 243 create_reply_ticket (struct rx_header *hdr,
 244                      Key *skey,
 245                      char *name, char *instance, char *realm,
 246                      struct sockaddr_in *addr,
 247                      int life,
 248                      int kvno,
 249                      int32_t max_seq_len,
 250                      const char *sname, const char *sinstance,
 251                      u_int32_t challenge,
 252                      const char *label,
 253                      des_cblock *key,
 254                      krb5_data *reply)
 255 {
 256     KTEXT_ST ticket;
 257     des_cblock session;
 258     krb5_storage *sp;
 259     krb5_data enc_data;
 260     des_key_schedule schedule;
 261     struct rx_header reply_hdr;
 262     des_cblock zero;
 263     size_t pad;
 264     unsigned fyrtiosjuelva;
 265
 266     /* create the ticket */
 267
 268     des_new_random_key(&session);
 269
 270     krb_create_ticket (&ticket, 0, name, instance, realm,
 271                        addr->sin_addr.s_addr,
 272                        &session, life, kdc_time,
 273                        sname, sinstance, skey->key.keyvalue.data);
 274
 275     /* create the encrypted part of the reply */
 276     sp = krb5_storage_emem ();
 277     krb5_generate_random_block(&fyrtiosjuelva, sizeof(fyrtiosjuelva));
 278     fyrtiosjuelva &= 0xffffffff;
 279     krb5_store_int32 (sp, fyrtiosjuelva);
 280     krb5_store_int32 (sp, challenge);
 281     krb5_storage_write  (sp, session, 8);
 282     memset (&session, 0, sizeof(session));
 283     krb5_store_int32 (sp, kdc_time);
 284     krb5_store_int32 (sp, kdc_time + krb_life_to_time (0, life));
 285     krb5_store_int32 (sp, kvno);
 286     krb5_store_int32 (sp, ticket.length);
 287     krb5_store_stringz (sp, name);
 288     krb5_store_stringz (sp, instance);
 289 #if 1 /* XXX - Why shouldn't the realm go here? */
 290     krb5_store_stringz (sp, "");
 291 #else
 292     krb5_store_stringz (sp, realm);
 293 #endif
 294     krb5_store_stringz (sp, sname);
 295     krb5_store_stringz (sp, sinstance);
 296     krb5_storage_write (sp, ticket.dat, ticket.length);
 297     krb5_storage_write (sp, label, strlen(label));
 298
 299     /* pad to DES block */
 300     memset (zero, 0, sizeof(zero));
 301     pad = (8 - krb5_storage_seek (sp, 0, SEEK_CUR) % 8) % 8;
 302     krb5_storage_write (sp, zero, pad);
 303
 304     krb5_storage_to_data (sp, &enc_data);
 305     krb5_storage_free (sp);
 306
 307     if (enc_data.length > max_seq_len) {
 308         krb5_data_free (&enc_data);
 309         make_error_reply (hdr, KAANSWERTOOLONG, reply);
 310         return 0;
 311     }
 312
 313     /* encrypt it */
 314     des_set_key (key, schedule);
 315     des_pcbc_encrypt (enc_data.data,
 316                       enc_data.data,
 317                       enc_data.length,
 318                       schedule,
 319                       key,
 320                       DES_ENCRYPT);
 321     memset (&schedule, 0, sizeof(schedule));
 322
 323     /* create the reply packet */
 324     init_reply_header (hdr, &reply_hdr, HT_DATA, HF_LAST);
 325     sp = krb5_storage_emem ();
 326     encode_rx_header (&reply_hdr, sp);
 327     krb5_store_int32 (sp, max_seq_len);
 328     krb5_store_xdr_data (sp, enc_data);
 329     krb5_data_free (&enc_data);
 330     krb5_storage_to_data (sp, reply);
 331     krb5_storage_free (sp);
 332     return 0;
 333 }
 334
 335 static krb5_error_code
 336 unparse_auth_args (krb5_storage *sp,
 337                    char **name,
 338                    char **instance,
 339                    time_t *start_time,
 340                    time_t *end_time,
 341                    krb5_data *request,
 342                    int32_t *max_seq_len)
 343 {
 344     krb5_data data;
 345     int32_t tmp;
 346
 347     krb5_ret_xdr_data (sp, &data);
 348     *name = malloc(data.length + 1);
 349     if (*name == NULL)
 350         return ENOMEM;
 351     memcpy (*name, data.data, data.length);
 352     (*name)[data.length] = '\0';
 353     krb5_data_free (&data);
 354
 355     krb5_ret_xdr_data (sp, &data);
 356     *instance = malloc(data.length + 1);
 357     if (*instance == NULL) {
 358         free (*name);
 359         return ENOMEM;
 360     }
 361     memcpy (*instance, data.data, data.length);
 362     (*instance)[data.length] = '\0';
 363     krb5_data_free (&data);
 364
 365     krb5_ret_int32 (sp, &tmp);
 366     *start_time = tmp;
 367     krb5_ret_int32 (sp, &tmp);
 368     *end_time = tmp;
 369     krb5_ret_xdr_data (sp, request);
 370     krb5_ret_int32 (sp, max_seq_len);
 371     /* ignore the rest */
 372     return 0;
 373 }
 374
 375 static void
 376 do_authenticate (struct rx_header *hdr,
 377                  krb5_storage *sp,
 378                  struct sockaddr_in *addr,
 379                  krb5_data *reply)
 380 {
 381     krb5_error_code ret;
 382     char *name = NULL;
 383     char *instance = NULL;
 384     time_t start_time;
 385     time_t end_time;
 386     krb5_data request;
 387     int32_t max_seq_len;
 388     hdb_entry *client_entry = NULL;
 389     hdb_entry *server_entry = NULL;
 390     Key *ckey = NULL;
 391     Key *skey = NULL;
 392     des_cblock key;
 393     des_key_schedule schedule;
 394     krb5_storage *reply_sp;
 395     time_t max_life;
 396     u_int8_t life;
 397     int32_t chal;
 398     char client_name[256];
 399     char server_name[256];
 400
 401     krb5_data_zero (&request);
 402
 403     unparse_auth_args (sp, &name, &instance, &start_time, &end_time,
 404                        &request, &max_seq_len);
 405
 406     snprintf (client_name, sizeof(client_name), "%s.%s@%s",
 407               name, instance, v4_realm);
 408
 409     ret = db_fetch4 (name, instance, v4_realm, &client_entry);
 410     if (ret) {
 411         kdc_log(0, "Client not found in database: %s: %s",
 412                 client_name, krb5_get_err_text(context, ret));
 413         make_error_reply (hdr, KANOENT, reply);
 414         goto out;
 415     }
 416
 417     snprintf (server_name, sizeof(server_name), "%s.%s@%s",
 418               "krbtgt", v4_realm, v4_realm);
 419
 420     ret = db_fetch4 ("krbtgt", v4_realm, v4_realm, &server_entry);
 421     if (ret) {
 422         kdc_log(0, "Server not found in database: %s: %s",
 423                 server_name, krb5_get_err_text(context, ret));
 424         make_error_reply (hdr, KANOENT, reply);
 425         goto out;
 426     }
 427
 428     ret = check_flags (client_entry, client_name,
 429                        server_entry, server_name,
 430                        TRUE);
 431     if (ret) {
 432         make_error_reply (hdr, KAPWEXPIRED, reply);
 433         goto out;
 434     }
 435
 436     /* find a DES key */
 437     ret = get_des_key(client_entry, FALSE, TRUE, &ckey);
 438     if(ret){
 439         kdc_log(0, "no suitable DES key for client");
 440         make_error_reply (hdr, KANOKEYS, reply);
 441         goto out;
 442     }
 443
 444     /* find a DES key */
 445     ret = get_des_key(server_entry, TRUE, TRUE, &skey);
 446     if(ret){
 447         kdc_log(0, "no suitable DES key for server");
 448         make_error_reply (hdr, KANOKEYS, reply);
 449         goto out;
 450     }
 451
 452     /* try to decode the `request' */
 453     memcpy (&key, ckey->key.keyvalue.data, sizeof(key));
 454     des_set_key (&key, schedule);
 455     des_pcbc_encrypt (request.data,
 456                       request.data,
 457                       request.length,
 458                       schedule,
 459                       &key,
 460                       DES_DECRYPT);
 461     memset (&schedule, 0, sizeof(schedule));
 462
 463     /* check for the magic label */
 464     if (memcmp ((char *)request.data + 4, "gTGS", 4) != 0) {
 465         make_error_reply (hdr, KABADREQUEST, reply);
 466         goto out;
 467     }
 468
 469     reply_sp = krb5_storage_from_mem (request.data, 4);
 470     krb5_ret_int32 (reply_sp, &chal);
 471     krb5_storage_free (reply_sp);
 472
 473     if (abs(chal - kdc_time) > context->max_skew) {
 474         make_error_reply (hdr, KACLOCKSKEW, reply);
 475         goto out;
 476     }
 477
 478     /* life */
 479     max_life = end_time - kdc_time;
 480     /* end_time - kdc_time can sometimes be non-positive due to slight
 481        time skew between client and server. Let's make sure it is postive */
 482     if(max_life < 1)
 483         max_life = 1;
 484     if (client_entry->max_life)
 485         max_life = min(max_life, *client_entry->max_life);
 486     if (server_entry->max_life)
 487         max_life = min(max_life, *server_entry->max_life);
 488
 489     life = krb_time_to_life(kdc_time, kdc_time + max_life);
 490
 491     create_reply_ticket (hdr, skey,
 492                          name, instance, v4_realm,
 493                          addr, life, server_entry->kvno,
 494                          max_seq_len,
 495                          "krbtgt", v4_realm,
 496                          chal + 1, "tgsT",
 497                          &key, reply);
 498     memset (&key, 0, sizeof(key));
 499
 500 out:
 501     if (request.length) {
 502         memset (request.data, 0, request.length);
 503         krb5_data_free (&request);
 504     }
 505     if (name)
 506         free (name);
 507     if (instance)
 508         free (instance);
 509     if (client_entry)
 510         free_ent (client_entry);
 511     if (server_entry)
 512         free_ent (server_entry);
 513 }
 514
 515 static krb5_error_code
 516 unparse_getticket_args (krb5_storage *sp,
 517                         int *kvno,
 518                         char **auth_domain,
 519                         krb5_data *ticket,
 520                         char **name,
 521                         char **instance,
 522                         krb5_data *times,
 523                         int32_t *max_seq_len)
 524 {
 525     krb5_data data;
 526     int32_t tmp;
 527
 528     krb5_ret_int32 (sp, &tmp);
 529     *kvno = tmp;
 530
 531     krb5_ret_xdr_data (sp, &data);
 532     *auth_domain = malloc(data.length + 1);
 533     if (*auth_domain == NULL)
 534         return ENOMEM;
 535     memcpy (*auth_domain, data.data, data.length);
 536     (*auth_domain)[data.length] = '\0';
 537     krb5_data_free (&data);
 538
 539     krb5_ret_xdr_data (sp, ticket);
 540
 541     krb5_ret_xdr_data (sp, &data);
 542     *name = malloc(data.length + 1);
 543     if (*name == NULL) {
 544         free (*auth_domain);
 545         return ENOMEM;
 546     }
 547     memcpy (*name, data.data, data.length);
 548     (*name)[data.length] = '\0';
 549     krb5_data_free (&data);
 550
 551     krb5_ret_xdr_data (sp, &data);
 552     *instance = malloc(data.length + 1);
 553     if (*instance == NULL) {
 554         free (*auth_domain);
 555         free (*name);
 556         return ENOMEM;
 557     }
 558     memcpy (*instance, data.data, data.length);
 559     (*instance)[data.length] = '\0';
 560     krb5_data_free (&data);
 561
 562     krb5_ret_xdr_data (sp, times);
 563
 564     krb5_ret_int32 (sp, max_seq_len);
 565     /* ignore the rest */
 566     return 0;
 567 }
 568
 569 static void
 570 do_getticket (struct rx_header *hdr,
 571               krb5_storage *sp,
 572               struct sockaddr_in *addr,
 573               krb5_data *reply)
 574 {
 575     krb5_error_code ret;
 576     int kvno;
 577     char *auth_domain = NULL;
 578     krb5_data aticket;
 579     char *name = NULL;
 580     char *instance = NULL;
 581     krb5_data times;
 582     int32_t max_seq_len;
 583     hdb_entry *server_entry = NULL;
 584     hdb_entry *krbtgt_entry = NULL;
 585     Key *kkey = NULL;
 586     Key *skey = NULL;
 587     des_cblock key;
 588     des_key_schedule schedule;
 589     des_cblock session;
 590     time_t max_life;
 591     int8_t life;
 592     time_t start_time, end_time;
 593     char pname[ANAME_SZ];
 594     char pinst[INST_SZ];
 595     char prealm[REALM_SZ];
 596     char server_name[256];
 597
 598     krb5_data_zero (&aticket);
 599     krb5_data_zero (&times);
 600
 601     unparse_getticket_args (sp, &kvno, &auth_domain, &aticket,
 602                             &name, &instance, &times, &max_seq_len);
 603
 604     snprintf (server_name, sizeof(server_name),
 605               "%s.%s@%s", name, instance, v4_realm);
 606
 607     ret = db_fetch4 (name, instance, v4_realm, &server_entry);
 608     if (ret) {
 609         kdc_log(0, "Server not found in database: %s: %s",
 610                 server_name, krb5_get_err_text(context, ret));
 611         make_error_reply (hdr, KANOENT, reply);
 612         goto out;
 613     }
 614
 615     ret = check_flags (NULL, NULL,
 616                        server_entry, server_name,
 617                        FALSE);
 618     if (ret) {
 619         make_error_reply (hdr, KAPWEXPIRED, reply);
 620         goto out;
 621     }
 622
 623     ret = db_fetch4 ("krbtgt", v4_realm, v4_realm, &krbtgt_entry);
 624     if (ret) {
 625         kdc_log(0, "Server not found in database: %s.%s@%s: %s",
 626                 "krbtgt", v4_realm, v4_realm, krb5_get_err_text(context, ret));
 627         make_error_reply (hdr, KANOENT, reply);
 628         goto out;
 629     }
 630
 631     /* find a DES key */
 632     ret = get_des_key(krbtgt_entry, TRUE, TRUE, &kkey);
 633     if(ret){
 634         kdc_log(0, "no suitable DES key for krbtgt");
 635         make_error_reply (hdr, KANOKEYS, reply);
 636         goto out;
 637     }
 638
 639     /* find a DES key */
 640     ret = get_des_key(server_entry, TRUE, TRUE, &skey);
 641     if(ret){
 642         kdc_log(0, "no suitable DES key for server");
 643         make_error_reply (hdr, KANOKEYS, reply);
 644         goto out;
 645     }
 646
 647     /* decrypt the incoming ticket */
 648     memcpy (&key, kkey->key.keyvalue.data, sizeof(key));
 649
 650     /* unpack the ticket */
 651     {
 652         KTEXT_ST ticket;
 653         u_char flags;
 654         int life;
 655         u_int32_t time_sec;
 656         char sname[ANAME_SZ];
 657         char sinstance[SNAME_SZ];
 658         u_int32_t paddress;
 659
 660         if (aticket.length > sizeof(ticket.dat)) {
 661             kdc_log(0, "ticket too long (%u > %u)",
 662                     (unsigned)aticket.length,
 663                     (unsigned)sizeof(ticket.dat));
 664             make_error_reply (hdr, KABADTICKET, reply);
 665             goto out;
 666         }
 667
 668         ticket.length = aticket.length;
 669         memcpy (ticket.dat, aticket.data, ticket.length);
 670
 671         des_set_key (&key, schedule);
 672         decomp_ticket (&ticket, &flags, pname, pinst, prealm,
 673                        &paddress, session, &life, &time_sec,
 674                        sname, sinstance,
 675                        &key, schedule);
 676
 677         if (strcmp (sname, "krbtgt") != 0
 678             || strcmp (sinstance, v4_realm) != 0) {
 679             kdc_log(0, "no TGT: %s.%s for %s.%s@%s",
 680                     sname, sinstance,
 681                     pname, pinst, prealm);
 682             make_error_reply (hdr, KABADTICKET, reply);
 683             goto out;
 684         }
 685
 686         if (kdc_time > krb_life_to_time(time_sec, life)) {
 687             kdc_log(0, "TGT expired: %s.%s@%s",
 688                     pname, pinst, prealm);
 689             make_error_reply (hdr, KABADTICKET, reply);
 690             goto out;
 691         }
 692     }
 693
 694     /* decrypt the times */
 695     des_set_key (&session, schedule);
 696     des_ecb_encrypt (times.data,
 697                      times.data,
 698                      schedule,
 699                      DES_DECRYPT);
 700     memset (&schedule, 0, sizeof(schedule));
 701
 702     /* and extract them */
 703     {
 704         krb5_storage *sp;
 705         int32_t tmp;
 706
 707         sp = krb5_storage_from_mem (times.data, times.length);
 708         krb5_ret_int32 (sp, &tmp);
 709         start_time = tmp;
 710         krb5_ret_int32 (sp, &tmp);
 711         end_time = tmp;
 712         krb5_storage_free (sp);
 713     }
 714
 715     /* life */
 716     max_life = end_time - kdc_time;
 717     /* end_time - kdc_time can sometimes be non-positive due to slight
 718        time skew between client and server. Let's make sure it is postive */
 719     if(max_life < 1)
 720         max_life = 1;
 721     if (krbtgt_entry->max_life)
 722         max_life = min(max_life, *krbtgt_entry->max_life);
 723     if (server_entry->max_life)
 724         max_life = min(max_life, *server_entry->max_life);
 725
 726     life = krb_time_to_life(kdc_time, kdc_time + max_life);
 727
 728     create_reply_ticket (hdr, skey,
 729                          pname, pinst, prealm,
 730                          addr, life, server_entry->kvno,
 731                          max_seq_len,
 732                          name, instance,
 733                          0, "gtkt",
 734                          &session, reply);
 735     memset (&session, 0, sizeof(session));
 736
 737 out:
 738     if (aticket.length) {
 739         memset (aticket.data, 0, aticket.length);
 740         krb5_data_free (&aticket);
 741     }
 742     if (times.length) {
 743         memset (times.data, 0, times.length);
 744         krb5_data_free (&times);
 745     }
 746     if (auth_domain)
 747         free (auth_domain);
 748     if (name)
 749         free (name);
 750     if (instance)
 751         free (instance);
 752     if (krbtgt_entry)
 753         free_ent (krbtgt_entry);
 754     if (server_entry)
 755         free_ent (server_entry);
 756 }
 757
 758 krb5_error_code
 759 do_kaserver(unsigned char *buf,
 760             size_t len,
 761             krb5_data *reply,
 762             const char *from,
 763             struct sockaddr_in *addr)
 764 {
 765     krb5_error_code ret = 0;
 766     struct rx_header hdr;
 767     u_int32_t op;
 768     krb5_storage *sp;
 769
 770     if (len < RX_HEADER_SIZE)
 771         return -1;
 772     sp = krb5_storage_from_mem (buf, len);
 773
 774     decode_rx_header (sp, &hdr);
 775     buf += RX_HEADER_SIZE;
 776     len -= RX_HEADER_SIZE;
 777
 778     switch (hdr.type) {
 779     case HT_DATA :
 780         break;
 781     case HT_ACK :
 782     case HT_BUSY :
 783     case HT_ABORT :
 784     case HT_ACKALL :
 785     case HT_CHAL :
 786     case HT_RESP :
 787     case HT_DEBUG :
 788     default:
 789         /* drop */
 790         goto out;
 791     }
 792
 793
 794     if (hdr.serviceid != KA_AUTHENTICATION_SERVICE
 795         && hdr.serviceid != KA_TICKET_GRANTING_SERVICE) {
 796         ret = -1;
 797         goto out;
 798     }
 799
 800     krb5_ret_int32(sp, &op);
 801     switch (op) {
 802     case AUTHENTICATE :
 803         do_authenticate (&hdr, sp, addr, reply);
 804         break;
 805     case GETTICKET :
 806         do_getticket (&hdr, sp, addr, reply);
 807         break;
 808     case AUTHENTICATE_OLD :
 809     case CHANGEPASSWORD :
 810     case GETTICKET_OLD :
 811     case SETPASSWORD :
 812     case SETFIELDS :
 813     case CREATEUSER :
 814     case DELETEUSER :
 815     case GETENTRY :
 816     case LISTENTRY :
 817     case GETSTATS :
 818     case DEBUG :
 819     case GETPASSWORD :
 820     case GETRANDOMKEY :
 821     case AUTHENTICATE_V2 :
 822     default :
 823         make_error_reply (&hdr, RXGEN_OPCODE, reply);
 824         break;
 825     }
 826
 827 out:
 828     krb5_storage_free (sp);
 829     return ret;
 830 }