source/libsmb/clikrb5.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    simple kerberos5 routines for active directory
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Luke Howard 2002-2003
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #define KRB5_PRIVATE    1       /* this file uses PRIVATE interfaces! */
  23 #define KRB5_DEPRECATED 1       /* this file uses DEPRECATED interfaces! */
  24
  25 #include "includes.h"
  26
  27 #ifdef HAVE_KRB5
  28
  29 #ifdef HAVE_KRB5_KEYBLOCK_KEYVALUE
  30 #define KRB5_KEY_TYPE(k)        ((k)->keytype)
  31 #define KRB5_KEY_LENGTH(k)      ((k)->keyvalue.length)
  32 #define KRB5_KEY_DATA(k)        ((k)->keyvalue.data)
  33 #else
  34 #define KRB5_KEY_TYPE(k)        ((k)->enctype)
  35 #define KRB5_KEY_LENGTH(k)      ((k)->length)
  36 #define KRB5_KEY_DATA(k)        ((k)->contents)
  37 #endif /* HAVE_KRB5_KEYBLOCK_KEYVALUE */
  38
  39 #ifndef HAVE_KRB5_SET_REAL_TIME
  40 /*
  41  * This function is not in the Heimdal mainline.
  42  */
  43  krb5_error_code krb5_set_real_time(krb5_context context, int32_t seconds, int32_t microseconds)
  44 {
  45         krb5_error_code ret;
  46         int32_t sec, usec;
  47
  48         ret = krb5_us_timeofday(context, &sec, &usec);
  49         if (ret)
  50                 return ret;
  51
  52         context->kdc_sec_offset = seconds - sec;
  53         context->kdc_usec_offset = microseconds - usec;
  54
  55         return 0;
  56 }
  57 #endif
  58
  59 #if defined(HAVE_KRB5_SET_DEFAULT_IN_TKT_ETYPES) && !defined(HAVE_KRB5_SET_DEFAULT_TGS_KTYPES)
  60  krb5_error_code krb5_set_default_tgs_ktypes(krb5_context ctx, const krb5_enctype *enc)
  61 {
  62         return krb5_set_default_in_tkt_etypes(ctx, enc);
  63 }
  64 #endif
  65
  66 #if defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS)
  67 /* HEIMDAL */
  68  void setup_kaddr( krb5_address *pkaddr, struct sockaddr *paddr)
  69 {
  70         pkaddr->addr_type = KRB5_ADDRESS_INET;
  71         pkaddr->address.length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
  72         pkaddr->address.data = (char *)&(((struct sockaddr_in *)paddr)->sin_addr);
  73 }
  74 #elif defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS)
  75 /* MIT */
  76  void setup_kaddr( krb5_address *pkaddr, struct sockaddr *paddr)
  77 {
  78         pkaddr->addrtype = ADDRTYPE_INET;
  79         pkaddr->length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
  80         pkaddr->contents = (krb5_octet *)&(((struct sockaddr_in *)paddr)->sin_addr);
  81 }
  82 #else
  83 #error UNKNOWN_ADDRTYPE
  84 #endif
  85
  86 #if defined(HAVE_KRB5_PRINCIPAL2SALT) && defined(HAVE_KRB5_USE_ENCTYPE) && defined(HAVE_KRB5_STRING_TO_KEY) && defined(HAVE_KRB5_ENCRYPT_BLOCK)
  87  int create_kerberos_key_from_string_direct(krb5_context context,
  88                                         krb5_principal host_princ,
  89                                         krb5_data *password,
  90                                         krb5_keyblock *key,
  91                                         krb5_enctype enctype)
  92 {
  93         int ret;
  94         krb5_data salt;
  95         krb5_encrypt_block eblock;
  96
  97         ret = krb5_principal2salt(context, host_princ, &salt);
  98         if (ret) {
  99                 DEBUG(1,("krb5_principal2salt failed (%s)\n", error_message(ret)));
 100                 return ret;
 101         }
 102         krb5_use_enctype(context, &eblock, enctype);
 103         ret = krb5_string_to_key(context, &eblock, key, password, &salt);
 104         SAFE_FREE(salt.data);
 105         return ret;
 106 }
 107 #elif defined(HAVE_KRB5_GET_PW_SALT) && defined(HAVE_KRB5_STRING_TO_KEY_SALT)
 108  int create_kerberos_key_from_string_direct(krb5_context context,
 109                                         krb5_principal host_princ,
 110                                         krb5_data *password,
 111                                         krb5_keyblock *key,
 112                                         krb5_enctype enctype)
 113 {
 114         int ret;
 115         krb5_salt salt;
 116
 117         ret = krb5_get_pw_salt(context, host_princ, &salt);
 118         if (ret) {
 119                 DEBUG(1,("krb5_get_pw_salt failed (%s)\n", error_message(ret)));
 120                 return ret;
 121         }
 122         return krb5_string_to_key_salt(context, enctype, password->data,
 123                 salt, key);
 124 }
 125 #else
 126 #error UNKNOWN_CREATE_KEY_FUNCTIONS
 127 #endif
 128
 129  int create_kerberos_key_from_string(krb5_context context,
 130                                         krb5_principal host_princ,
 131                                         krb5_data *password,
 132                                         krb5_keyblock *key,
 133                                         krb5_enctype enctype)
 134 {
 135         krb5_principal salt_princ = NULL;
 136         int ret;
 137         /*
 138          * Check if we've determined that the KDC is salting keys for this
 139          * principal/enctype in a non-obvious way.  If it is, try to match
 140          * its behavior.
 141          */
 142         salt_princ = kerberos_fetch_salt_princ_for_host_princ(context, host_princ, enctype);
 143         ret = create_kerberos_key_from_string_direct(context, salt_princ ? salt_princ : host_princ, password, key, enctype);
 144         if (salt_princ) {
 145                 krb5_free_principal(context, salt_princ);
 146         }
 147         return ret;
 148 }
 149
 150 #if defined(HAVE_KRB5_GET_PERMITTED_ENCTYPES)
 151  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 152                                             krb5_enctype **enctypes)
 153 {
 154         return krb5_get_permitted_enctypes(context, enctypes);
 155 }
 156 #elif defined(HAVE_KRB5_GET_DEFAULT_IN_TKT_ETYPES)
 157  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 158                                             krb5_enctype **enctypes)
 159 {
 160         return krb5_get_default_in_tkt_etypes(context, enctypes);
 161 }
 162 #else
 163 #error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 164 #endif
 165
 166  void free_kerberos_etypes(krb5_context context,
 167                            krb5_enctype *enctypes)
 168 {
 169 #if defined(HAVE_KRB5_FREE_KTYPES)
 170         krb5_free_ktypes(context, enctypes);
 171         return;
 172 #else
 173         SAFE_FREE(enctypes);
 174         return;
 175 #endif
 176 }
 177
 178 #if defined(HAVE_KRB5_AUTH_CON_SETKEY) && !defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY)
 179  krb5_error_code krb5_auth_con_setuseruserkey(krb5_context context,
 180                                         krb5_auth_context auth_context,
 181                                         krb5_keyblock *keyblock)
 182 {
 183         return krb5_auth_con_setkey(context, auth_context, keyblock);
 184 }
 185 #endif
 186
 187  void get_auth_data_from_tkt(DATA_BLOB *auth_data, krb5_ticket *tkt)
 188 {
 189 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 190         if (tkt->enc_part2 && tkt->enc_part2->authorization_data && tkt->enc_part2->authorization_data[0] && tkt->enc_part2->authorization_data[0]->length)
 191                 *auth_data = data_blob(tkt->enc_part2->authorization_data[0]->contents,
 192                         tkt->enc_part2->authorization_data[0]->length);
 193 #else
 194         if (tkt->ticket.authorization_data && tkt->ticket.authorization_data->len)
 195                 *auth_data = data_blob(tkt->ticket.authorization_data->val->ad_data.data,
 196                         tkt->ticket.authorization_data->val->ad_data.length);
 197 #endif
 198 }
 199
 200  krb5_const_principal get_principal_from_tkt(krb5_ticket *tkt)
 201 {
 202 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 203         return tkt->enc_part2->client;
 204 #else
 205         return tkt->client;
 206 #endif
 207 }
 208
 209 #if !defined(HAVE_KRB5_LOCATE_KDC)
 210  krb5_error_code krb5_locate_kdc(krb5_context ctx, const krb5_data *realm, struct sockaddr **addr_pp, int *naddrs, int get_masters)
 211 {
 212         krb5_krbhst_handle hnd;
 213         krb5_krbhst_info *hinfo;
 214         krb5_error_code rc;
 215         int num_kdcs, i;
 216         struct sockaddr *sa;
 217         struct addrinfo *ai;
 218
 219         *addr_pp = NULL;
 220         *naddrs = 0;
 221
 222         rc = krb5_krbhst_init(ctx, realm->data, KRB5_KRBHST_KDC, &hnd);
 223         if (rc) {
 224                 DEBUG(0, ("krb5_locate_kdc: krb5_krbhst_init failed (%s)\n", error_message(rc)));
 225                 return rc;
 226         }
 227
 228         for ( num_kdcs = 0; (rc = krb5_krbhst_next(ctx, hnd, &hinfo) == 0); num_kdcs++)
 229                 ;
 230
 231         krb5_krbhst_reset(ctx, hnd);
 232
 233         if (!num_kdcs) {
 234                 DEBUG(0, ("krb5_locate_kdc: zero kdcs found !\n"));
 235                 krb5_krbhst_free(ctx, hnd);
 236                 return -1;
 237         }
 238
 239         sa = SMB_MALLOC_ARRAY( struct sockaddr, num_kdcs );
 240         if (!sa) {
 241                 DEBUG(0, ("krb5_locate_kdc: malloc failed\n"));
 242                 krb5_krbhst_free(ctx, hnd);
 243                 naddrs = 0;
 244                 return -1;
 245         }
 246
 247         memset(sa, '\0', sizeof(struct sockaddr) * num_kdcs );
 248
 249         for (i = 0; i < num_kdcs && (rc = krb5_krbhst_next(ctx, hnd, &hinfo) == 0); i++) {
 250
 251 #if defined(HAVE_KRB5_KRBHST_GET_ADDRINFO)
 252                 rc = krb5_krbhst_get_addrinfo(ctx, hinfo, &ai);
 253                 if (rc) {
 254                         DEBUG(0,("krb5_krbhst_get_addrinfo failed: %s\n", error_message(rc)));
 255                         continue;
 256                 }
 257 #endif
 258                 if (hinfo->ai && hinfo->ai->ai_family == AF_INET)
 259                         memcpy(&sa[i], hinfo->ai->ai_addr, sizeof(struct sockaddr));
 260         }
 261
 262         krb5_krbhst_free(ctx, hnd);
 263
 264         *naddrs = num_kdcs;
 265         *addr_pp = sa;
 266         return 0;
 267 }
 268 #endif
 269
 270 #if !defined(HAVE_KRB5_FREE_UNPARSED_NAME)
 271  void krb5_free_unparsed_name(krb5_context context, char *val)
 272 {
 273         SAFE_FREE(val);
 274 }
 275 #endif
 276
 277  void kerberos_free_data_contents(krb5_context context, krb5_data *pdata)
 278 {
 279 #if defined(HAVE_KRB5_FREE_DATA_CONTENTS)
 280         if (pdata->data) {
 281                 krb5_free_data_contents(context, pdata);
 282         }
 283 #else
 284         SAFE_FREE(pdata->data);
 285 #endif
 286 }
 287
 288  void kerberos_set_creds_enctype(krb5_creds *pcreds, int enctype)
 289 {
 290 #if defined(HAVE_KRB5_KEYBLOCK_IN_CREDS)
 291         KRB5_KEY_TYPE((&pcreds->keyblock)) = enctype;
 292 #elif defined(HAVE_KRB5_SESSION_IN_CREDS)
 293         KRB5_KEY_TYPE((&pcreds->session)) = enctype;
 294 #else
 295 #error UNKNOWN_KEYBLOCK_MEMBER_IN_KRB5_CREDS_STRUCT
 296 #endif
 297 }
 298
 299  BOOL kerberos_compatible_enctypes(krb5_context context,
 300                                   krb5_enctype enctype1,
 301                                   krb5_enctype enctype2)
 302 {
 303 #if defined(HAVE_KRB5_C_ENCTYPE_COMPARE)
 304         krb5_boolean similar = 0;
 305
 306         krb5_c_enctype_compare(context, enctype1, enctype2, &similar);
 307         return similar ? True : False;
 308 #elif defined(HAVE_KRB5_ENCTYPES_COMPATIBLE_KEYS)
 309         return krb5_enctypes_compatible_keys(context, enctype1, enctype2) ? True : False;
 310 #endif
 311 }
 312
 313 static BOOL ads_cleanup_expired_creds(krb5_context context,
 314                                       krb5_ccache  ccache,
 315                                       krb5_creds  *credsp)
 316 {
 317         krb5_error_code retval;
 318
 319         DEBUG(3, ("Ticket in ccache[%s] expiration %s\n",
 320                   krb5_cc_default_name(context),
 321                   http_timestring(credsp->times.endtime)));
 322
 323         /* we will probably need new tickets if the current ones
 324            will expire within 10 seconds.
 325         */
 326         if (credsp->times.endtime >= (time(NULL) + 10))
 327                 return False;
 328
 329         /* heimdal won't remove creds from a file ccache, and
 330            perhaps we shouldn't anyway, since internally we
 331            use memory ccaches, and a FILE one probably means that
 332            we're using creds obtained outside of our exectuable
 333         */
 334         if (StrCaseCmp(krb5_cc_get_type(context, ccache), "FILE") == 0) {
 335                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a FILE ccache\n"));
 336                 return False;
 337         }
 338
 339         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
 340         if (retval) {
 341                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
 342                           error_message(retval)));
 343                 /* If we have an error in this, we want to display it,
 344                    but continue as though we deleted it */
 345         }
 346         return True;
 347 }
 348
 349 /*
 350   we can't use krb5_mk_req because w2k wants the service to be in a particular format
 351 */
 352 static krb5_error_code ads_krb5_mk_req(krb5_context context,
 353                                        krb5_auth_context *auth_context,
 354                                        const krb5_flags ap_req_options,
 355                                        const char *principal,
 356                                        krb5_ccache ccache,
 357                                        krb5_data *outbuf)
 358 {
 359         krb5_error_code           retval;
 360         krb5_principal    server;
 361         krb5_creds              * credsp;
 362         krb5_creds                creds;
 363         krb5_data in_data;
 364         BOOL creds_ready = False;
 365
 366         retval = krb5_parse_name(context, principal, &server);
 367         if (retval) {
 368                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
 369                 return retval;
 370         }
 371
 372         /* obtain ticket & session key */
 373         ZERO_STRUCT(creds);
 374         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
 375                 DEBUG(1,("krb5_copy_principal failed (%s)\n",
 376                          error_message(retval)));
 377                 goto cleanup_princ;
 378         }
 379
 380         if ((retval = krb5_cc_get_principal(context, ccache, &creds.client))) {
 381                 /* This can commonly fail on smbd startup with no ticket in the cache.
 382                  * Report at higher level than 1. */
 383                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
 384                          error_message(retval)));
 385                 goto cleanup_creds;
 386         }
 387
 388         while(!creds_ready) {
 389                 if ((retval = krb5_get_credentials(context, 0, ccache,
 390                                                    &creds, &credsp))) {
 391                         DEBUG(1,("ads_krb5_mk_req: krb5_get_credentials failed for %s (%s)\n",
 392                                  principal, error_message(retval)));
 393                         goto cleanup_creds;
 394                 }
 395
 396                 /* cope with ticket being in the future due to clock skew */
 397                 if ((unsigned)credsp->times.starttime > time(NULL)) {
 398                         time_t t = time(NULL);
 399                         int time_offset =(unsigned)credsp->times.starttime-t;
 400                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 401                         krb5_set_real_time(context, t + time_offset + 1, 0);
 402                 }
 403
 404                 if (!ads_cleanup_expired_creds(context, ccache, credsp))
 405                         creds_ready = True;
 406         }
 407
 408         DEBUG(10,("ads_krb5_mk_req: Ticket (%s) in ccache (%s) is valid until: (%s - %d)\n",
 409                   principal, krb5_cc_default_name(context),
 410                   http_timestring((unsigned)credsp->times.endtime),
 411                   (unsigned)credsp->times.endtime));
 412
 413         in_data.length = 0;
 414         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
 415                                       &in_data, credsp, outbuf);
 416         if (retval) {
 417                 DEBUG(1,("ads_krb5_mk_req: krb5_mk_req_extended failed (%s)\n",
 418                          error_message(retval)));
 419         }
 420
 421         krb5_free_creds(context, credsp);
 422
 423 cleanup_creds:
 424         krb5_free_cred_contents(context, &creds);
 425
 426 cleanup_princ:
 427         krb5_free_principal(context, server);
 428
 429         return retval;
 430 }
 431
 432 /*
 433   get a kerberos5 ticket for the given service
 434 */
 435 int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 436                         DATA_BLOB *ticket, DATA_BLOB *session_key_krb5)
 437 {
 438         krb5_error_code retval;
 439         krb5_data packet;
 440         krb5_context context = NULL;
 441         krb5_ccache ccdef = NULL;
 442         krb5_auth_context auth_context = NULL;
 443         krb5_enctype enc_types[] = {
 444 #ifdef ENCTYPE_ARCFOUR_HMAC
 445                 ENCTYPE_ARCFOUR_HMAC,
 446 #endif
 447                 ENCTYPE_DES_CBC_MD5,
 448                 ENCTYPE_DES_CBC_CRC,
 449                 ENCTYPE_NULL};
 450
 451         retval = krb5_init_context(&context);
 452         if (retval) {
 453                 DEBUG(1,("cli_krb5_get_ticket: krb5_init_context failed (%s)\n",
 454                          error_message(retval)));
 455                 goto failed;
 456         }
 457
 458         if (time_offset != 0) {
 459                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
 460         }
 461
 462         if ((retval = krb5_cc_default(context, &ccdef))) {
 463                 DEBUG(1,("cli_krb5_get_ticket: krb5_cc_default failed (%s)\n",
 464                          error_message(retval)));
 465                 goto failed;
 466         }
 467
 468         if ((retval = krb5_set_default_tgs_ktypes(context, enc_types))) {
 469                 DEBUG(1,("cli_krb5_get_ticket: krb5_set_default_tgs_ktypes failed (%s)\n",
 470                          error_message(retval)));
 471                 goto failed;
 472         }
 473
 474         if ((retval = ads_krb5_mk_req(context,
 475                                         &auth_context,
 476                                         AP_OPTS_USE_SUBKEY,
 477                                         principal,
 478                                         ccdef, &packet))) {
 479                 goto failed;
 480         }
 481
 482         get_krb5_smb_session_key(context, auth_context, session_key_krb5, False);
 483
 484         *ticket = data_blob(packet.data, packet.length);
 485
 486         kerberos_free_data_contents(context, &packet);
 487
 488 failed:
 489
 490         if ( context ) {
 491                 if (ccdef)
 492                         krb5_cc_close(context, ccdef);
 493                 if (auth_context)
 494                         krb5_auth_con_free(context, auth_context);
 495                 krb5_free_context(context);
 496         }
 497
 498         return retval;
 499 }
 500
 501  BOOL get_krb5_smb_session_key(krb5_context context, krb5_auth_context auth_context, DATA_BLOB *session_key, BOOL remote)
 502  {
 503         krb5_keyblock *skey;
 504         krb5_error_code err;
 505         BOOL ret = False;
 506
 507         if (remote)
 508                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 509         else
 510                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 511         if (err == 0 && skey != NULL) {
 512                 DEBUG(10, ("Got KRB5 session key of length %d\n",  KRB5_KEY_LENGTH(skey)));
 513                 *session_key = data_blob(KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 514                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 515
 516                 ret = True;
 517
 518                 krb5_free_keyblock(context, skey);
 519         } else {
 520                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 521         }
 522
 523         return ret;
 524  }
 525
 526
 527 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING) && !defined(HAVE_KRB5_PRINC_COMPONENT)
 528  const krb5_data *krb5_princ_component(krb5_context context, krb5_principal principal, int i )
 529 {
 530         static krb5_data kdata;
 531
 532         kdata.data = krb5_principal_get_comp_string(context, principal, i);
 533         kdata.length = strlen(kdata.data);
 534         return &kdata;
 535 }
 536 #endif
 537
 538  krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry)
 539 {
 540 #if defined(HAVE_KRB5_KT_FREE_ENTRY)
 541         return krb5_kt_free_entry(context, kt_entry);
 542 #elif defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
 543         return krb5_free_keytab_entry_contents(context, kt_entry);
 544 #else
 545 #error UNKNOWN_KT_FREE_FUNCTION
 546 #endif
 547 }
 548
 549 #else /* HAVE_KRB5 */
 550  /* this saves a few linking headaches */
 551 int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 552                         DATA_BLOB *ticket, DATA_BLOB *session_key_krb5)
 553 {
 554          DEBUG(0,("NO KERBEROS SUPPORT\n"));
 555          return 1;
 556 }
 557
 558 #endif