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
 123         ret = krb5_string_to_key_salt(context, enctype, password->data, salt, key);
 124         krb5_free_salt(context, salt);
 125         return ret;
 126 }
 127 #else
 128 #error UNKNOWN_CREATE_KEY_FUNCTIONS
 129 #endif
 130
 131  int create_kerberos_key_from_string(krb5_context context,
 132                                         krb5_principal host_princ,
 133                                         krb5_data *password,
 134                                         krb5_keyblock *key,
 135                                         krb5_enctype enctype)
 136 {
 137         krb5_principal salt_princ = NULL;
 138         int ret;
 139         /*
 140          * Check if we've determined that the KDC is salting keys for this
 141          * principal/enctype in a non-obvious way.  If it is, try to match
 142          * its behavior.
 143          */
 144         salt_princ = kerberos_fetch_salt_princ_for_host_princ(context, host_princ, enctype);
 145         ret = create_kerberos_key_from_string_direct(context, salt_princ ? salt_princ : host_princ, password, key, enctype);
 146         if (salt_princ) {
 147                 krb5_free_principal(context, salt_princ);
 148         }
 149         return ret;
 150 }
 151
 152 #if defined(HAVE_KRB5_GET_PERMITTED_ENCTYPES)
 153  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 154                                             krb5_enctype **enctypes)
 155 {
 156         return krb5_get_permitted_enctypes(context, enctypes);
 157 }
 158 #elif defined(HAVE_KRB5_GET_DEFAULT_IN_TKT_ETYPES)
 159  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 160                                             krb5_enctype **enctypes)
 161 {
 162         return krb5_get_default_in_tkt_etypes(context, enctypes);
 163 }
 164 #else
 165 #error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 166 #endif
 167
 168  void free_kerberos_etypes(krb5_context context,
 169                            krb5_enctype *enctypes)
 170 {
 171 #if defined(HAVE_KRB5_FREE_KTYPES)
 172         krb5_free_ktypes(context, enctypes);
 173         return;
 174 #else
 175         SAFE_FREE(enctypes);
 176         return;
 177 #endif
 178 }
 179
 180 #if defined(HAVE_KRB5_AUTH_CON_SETKEY) && !defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY)
 181  krb5_error_code krb5_auth_con_setuseruserkey(krb5_context context,
 182                                         krb5_auth_context auth_context,
 183                                         krb5_keyblock *keyblock)
 184 {
 185         return krb5_auth_con_setkey(context, auth_context, keyblock);
 186 }
 187 #endif
 188
 189  void get_auth_data_from_tkt(DATA_BLOB *auth_data, krb5_ticket *tkt)
 190 {
 191 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 192         if (tkt->enc_part2 && tkt->enc_part2->authorization_data && tkt->enc_part2->authorization_data[0] && tkt->enc_part2->authorization_data[0]->length)
 193                 *auth_data = data_blob(tkt->enc_part2->authorization_data[0]->contents,
 194                         tkt->enc_part2->authorization_data[0]->length);
 195 #else
 196         if (tkt->ticket.authorization_data && tkt->ticket.authorization_data->len)
 197                 *auth_data = data_blob(tkt->ticket.authorization_data->val->ad_data.data,
 198                         tkt->ticket.authorization_data->val->ad_data.length);
 199 #endif
 200 }
 201
 202  krb5_const_principal get_principal_from_tkt(krb5_ticket *tkt)
 203 {
 204 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 205         return tkt->enc_part2->client;
 206 #else
 207         return tkt->client;
 208 #endif
 209 }
 210
 211 #if !defined(HAVE_KRB5_LOCATE_KDC)
 212  krb5_error_code krb5_locate_kdc(krb5_context ctx, const krb5_data *realm, struct sockaddr **addr_pp, int *naddrs, int get_masters)
 213 {
 214         krb5_krbhst_handle hnd;
 215         krb5_krbhst_info *hinfo;
 216         krb5_error_code rc;
 217         int num_kdcs, i;
 218         struct sockaddr *sa;
 219         struct addrinfo *ai;
 220
 221         *addr_pp = NULL;
 222         *naddrs = 0;
 223
 224         rc = krb5_krbhst_init(ctx, realm->data, KRB5_KRBHST_KDC, &hnd);
 225         if (rc) {
 226                 DEBUG(0, ("krb5_locate_kdc: krb5_krbhst_init failed (%s)\n", error_message(rc)));
 227                 return rc;
 228         }
 229
 230         for ( num_kdcs = 0; (rc = krb5_krbhst_next(ctx, hnd, &hinfo) == 0); num_kdcs++)
 231                 ;
 232
 233         krb5_krbhst_reset(ctx, hnd);
 234
 235         if (!num_kdcs) {
 236                 DEBUG(0, ("krb5_locate_kdc: zero kdcs found !\n"));
 237                 krb5_krbhst_free(ctx, hnd);
 238                 return -1;
 239         }
 240
 241         sa = SMB_MALLOC_ARRAY( struct sockaddr, num_kdcs );
 242         if (!sa) {
 243                 DEBUG(0, ("krb5_locate_kdc: malloc failed\n"));
 244                 krb5_krbhst_free(ctx, hnd);
 245                 naddrs = 0;
 246                 return -1;
 247         }
 248
 249         memset(sa, '\0', sizeof(struct sockaddr) * num_kdcs );
 250
 251         for (i = 0; i < num_kdcs && (rc = krb5_krbhst_next(ctx, hnd, &hinfo) == 0); i++) {
 252
 253 #if defined(HAVE_KRB5_KRBHST_GET_ADDRINFO)
 254                 rc = krb5_krbhst_get_addrinfo(ctx, hinfo, &ai);
 255                 if (rc) {
 256                         DEBUG(0,("krb5_krbhst_get_addrinfo failed: %s\n", error_message(rc)));
 257                         continue;
 258                 }
 259 #endif
 260                 if (hinfo->ai && hinfo->ai->ai_family == AF_INET)
 261                         memcpy(&sa[i], hinfo->ai->ai_addr, sizeof(struct sockaddr));
 262         }
 263
 264         krb5_krbhst_free(ctx, hnd);
 265
 266         *naddrs = num_kdcs;
 267         *addr_pp = sa;
 268         return 0;
 269 }
 270 #endif
 271
 272 #if !defined(HAVE_KRB5_FREE_UNPARSED_NAME)
 273  void krb5_free_unparsed_name(krb5_context context, char *val)
 274 {
 275         SAFE_FREE(val);
 276 }
 277 #endif
 278
 279  void kerberos_free_data_contents(krb5_context context, krb5_data *pdata)
 280 {
 281 #if defined(HAVE_KRB5_FREE_DATA_CONTENTS)
 282         if (pdata->data) {
 283                 krb5_free_data_contents(context, pdata);
 284         }
 285 #else
 286         SAFE_FREE(pdata->data);
 287 #endif
 288 }
 289
 290  void kerberos_set_creds_enctype(krb5_creds *pcreds, int enctype)
 291 {
 292 #if defined(HAVE_KRB5_KEYBLOCK_IN_CREDS)
 293         KRB5_KEY_TYPE((&pcreds->keyblock)) = enctype;
 294 #elif defined(HAVE_KRB5_SESSION_IN_CREDS)
 295         KRB5_KEY_TYPE((&pcreds->session)) = enctype;
 296 #else
 297 #error UNKNOWN_KEYBLOCK_MEMBER_IN_KRB5_CREDS_STRUCT
 298 #endif
 299 }
 300
 301  BOOL kerberos_compatible_enctypes(krb5_context context,
 302                                   krb5_enctype enctype1,
 303                                   krb5_enctype enctype2)
 304 {
 305 #if defined(HAVE_KRB5_C_ENCTYPE_COMPARE)
 306         krb5_boolean similar = 0;
 307
 308         krb5_c_enctype_compare(context, enctype1, enctype2, &similar);
 309         return similar ? True : False;
 310 #elif defined(HAVE_KRB5_ENCTYPES_COMPATIBLE_KEYS)
 311         return krb5_enctypes_compatible_keys(context, enctype1, enctype2) ? True : False;
 312 #endif
 313 }
 314
 315 static BOOL ads_cleanup_expired_creds(krb5_context context,
 316                                       krb5_ccache  ccache,
 317                                       krb5_creds  *credsp)
 318 {
 319         krb5_error_code retval;
 320
 321         DEBUG(3, ("Ticket in ccache[%s] expiration %s\n",
 322                   krb5_cc_default_name(context),
 323                   http_timestring(credsp->times.endtime)));
 324
 325         /* we will probably need new tickets if the current ones
 326            will expire within 10 seconds.
 327         */
 328         if (credsp->times.endtime >= (time(NULL) + 10))
 329                 return False;
 330
 331         /* heimdal won't remove creds from a file ccache, and
 332            perhaps we shouldn't anyway, since internally we
 333            use memory ccaches, and a FILE one probably means that
 334            we're using creds obtained outside of our exectuable
 335         */
 336         if (StrCaseCmp(krb5_cc_get_type(context, ccache), "FILE") == 0) {
 337                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a FILE ccache\n"));
 338                 return False;
 339         }
 340
 341         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
 342         if (retval) {
 343                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
 344                           error_message(retval)));
 345                 /* If we have an error in this, we want to display it,
 346                    but continue as though we deleted it */
 347         }
 348         return True;
 349 }
 350
 351 /*
 352   we can't use krb5_mk_req because w2k wants the service to be in a particular format
 353 */
 354 static krb5_error_code ads_krb5_mk_req(krb5_context context,
 355                                        krb5_auth_context *auth_context,
 356                                        const krb5_flags ap_req_options,
 357                                        const char *principal,
 358                                        krb5_ccache ccache,
 359                                        krb5_data *outbuf)
 360 {
 361         krb5_error_code           retval;
 362         krb5_principal    server;
 363         krb5_creds              * credsp;
 364         krb5_creds                creds;
 365         krb5_data in_data;
 366         BOOL creds_ready = False;
 367
 368         retval = krb5_parse_name(context, principal, &server);
 369         if (retval) {
 370                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
 371                 return retval;
 372         }
 373
 374         /* obtain ticket & session key */
 375         ZERO_STRUCT(creds);
 376         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
 377                 DEBUG(1,("krb5_copy_principal failed (%s)\n",
 378                          error_message(retval)));
 379                 goto cleanup_princ;
 380         }
 381
 382         if ((retval = krb5_cc_get_principal(context, ccache, &creds.client))) {
 383                 /* This can commonly fail on smbd startup with no ticket in the cache.
 384                  * Report at higher level than 1. */
 385                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
 386                          error_message(retval)));
 387                 goto cleanup_creds;
 388         }
 389
 390         while(!creds_ready) {
 391                 if ((retval = krb5_get_credentials(context, 0, ccache,
 392                                                    &creds, &credsp))) {
 393                         DEBUG(1,("ads_krb5_mk_req: krb5_get_credentials failed for %s (%s)\n",
 394                                  principal, error_message(retval)));
 395                         goto cleanup_creds;
 396                 }
 397
 398                 /* cope with ticket being in the future due to clock skew */
 399                 if ((unsigned)credsp->times.starttime > time(NULL)) {
 400                         time_t t = time(NULL);
 401                         int time_offset =(int)((unsigned)credsp->times.starttime-t);
 402                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 403                         krb5_set_real_time(context, t + time_offset + 1, 0);
 404                 }
 405
 406                 if (!ads_cleanup_expired_creds(context, ccache, credsp))
 407                         creds_ready = True;
 408         }
 409
 410         DEBUG(10,("ads_krb5_mk_req: Ticket (%s) in ccache (%s) is valid until: (%s - %u)\n",
 411                   principal, krb5_cc_default_name(context),
 412                   http_timestring((unsigned)credsp->times.endtime),
 413                   (unsigned)credsp->times.endtime));
 414
 415         in_data.length = 0;
 416         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
 417                                       &in_data, credsp, outbuf);
 418         if (retval) {
 419                 DEBUG(1,("ads_krb5_mk_req: krb5_mk_req_extended failed (%s)\n",
 420                          error_message(retval)));
 421         }
 422
 423         krb5_free_creds(context, credsp);
 424
 425 cleanup_creds:
 426         krb5_free_cred_contents(context, &creds);
 427
 428 cleanup_princ:
 429         krb5_free_principal(context, server);
 430
 431         return retval;
 432 }
 433
 434 /*
 435   get a kerberos5 ticket for the given service
 436 */
 437 int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 438                         DATA_BLOB *ticket, DATA_BLOB *session_key_krb5)
 439 {
 440         krb5_error_code retval;
 441         krb5_data packet;
 442         krb5_context context = NULL;
 443         krb5_ccache ccdef = NULL;
 444         krb5_auth_context auth_context = NULL;
 445         krb5_enctype enc_types[] = {
 446 #ifdef ENCTYPE_ARCFOUR_HMAC
 447                 ENCTYPE_ARCFOUR_HMAC,
 448 #endif
 449                 ENCTYPE_DES_CBC_MD5,
 450                 ENCTYPE_DES_CBC_CRC,
 451                 ENCTYPE_NULL};
 452
 453         retval = krb5_init_context(&context);
 454         if (retval) {
 455                 DEBUG(1,("cli_krb5_get_ticket: krb5_init_context failed (%s)\n",
 456                          error_message(retval)));
 457                 goto failed;
 458         }
 459
 460         if (time_offset != 0) {
 461                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
 462         }
 463
 464         if ((retval = krb5_cc_default(context, &ccdef))) {
 465                 DEBUG(1,("cli_krb5_get_ticket: krb5_cc_default failed (%s)\n",
 466                          error_message(retval)));
 467                 goto failed;
 468         }
 469
 470         if ((retval = krb5_set_default_tgs_ktypes(context, enc_types))) {
 471                 DEBUG(1,("cli_krb5_get_ticket: krb5_set_default_tgs_ktypes failed (%s)\n",
 472                          error_message(retval)));
 473                 goto failed;
 474         }
 475
 476         if ((retval = ads_krb5_mk_req(context,
 477                                         &auth_context,
 478                                         AP_OPTS_USE_SUBKEY,
 479                                         principal,
 480                                         ccdef, &packet))) {
 481                 goto failed;
 482         }
 483
 484         get_krb5_smb_session_key(context, auth_context, session_key_krb5, False);
 485
 486         *ticket = data_blob(packet.data, packet.length);
 487
 488         kerberos_free_data_contents(context, &packet);
 489
 490 failed:
 491
 492         if ( context ) {
 493                 if (ccdef)
 494                         krb5_cc_close(context, ccdef);
 495                 if (auth_context)
 496                         krb5_auth_con_free(context, auth_context);
 497                 krb5_free_context(context);
 498         }
 499
 500         return retval;
 501 }
 502
 503  BOOL get_krb5_smb_session_key(krb5_context context, krb5_auth_context auth_context, DATA_BLOB *session_key, BOOL remote)
 504  {
 505         krb5_keyblock *skey;
 506         krb5_error_code err;
 507         BOOL ret = False;
 508
 509         if (remote)
 510                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 511         else
 512                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 513         if (err == 0 && skey != NULL) {
 514                 DEBUG(10, ("Got KRB5 session key of length %d\n",  KRB5_KEY_LENGTH(skey)));
 515                 *session_key = data_blob(KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 516                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 517
 518                 ret = True;
 519
 520                 krb5_free_keyblock(context, skey);
 521         } else {
 522                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 523         }
 524
 525         return ret;
 526  }
 527
 528
 529 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING) && !defined(HAVE_KRB5_PRINC_COMPONENT)
 530  const krb5_data *krb5_princ_component(krb5_context context, krb5_principal principal, int i );
 531
 532  const krb5_data *krb5_princ_component(krb5_context context, krb5_principal principal, int i )
 533 {
 534         static krb5_data kdata;
 535
 536         kdata.data = (char *)krb5_principal_get_comp_string(context, principal, i);
 537         kdata.length = strlen(kdata.data);
 538         return &kdata;
 539 }
 540 #endif
 541
 542  krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry)
 543 {
 544 #if defined(HAVE_KRB5_KT_FREE_ENTRY)
 545         return krb5_kt_free_entry(context, kt_entry);
 546 #elif defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
 547         return krb5_free_keytab_entry_contents(context, kt_entry);
 548 #else
 549 #error UNKNOWN_KT_FREE_FUNCTION
 550 #endif
 551 }
 552
 553 #else /* HAVE_KRB5 */
 554  /* this saves a few linking headaches */
 555 int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 556                         DATA_BLOB *ticket, DATA_BLOB *session_key_krb5)
 557 {
 558          DEBUG(0,("NO KERBEROS SUPPORT\n"));
 559          return 1;
 560 }
 561
 562 #endif