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