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)
  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)
 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 = malloc( sizeof(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         *addr_pp = malloc(sizeof(struct sockaddr) * num_kdcs);
 245         memset(*addr_pp, '\0', sizeof(struct sockaddr) * num_kdcs );
 246
 247         for (i = 0; i < num_kdcs && (rc = krb5_krbhst_next(ctx, hnd, &hinfo) == 0); i++) {
 248
 249 #if defined(HAVE_KRB5_KRBHST_GET_ADDRINFO)
 250                 rc = krb5_krbhst_get_addrinfo(ctx, hinfo, &ai);
 251                 if (rc) {
 252                         DEBUG(0,("krb5_krbhst_get_addrinfo failed: %s\n", error_message(rc)));
 253                         continue;
 254                 }
 255 #endif
 256                 if (hinfo->ai && hinfo->ai->ai_family == AF_INET)
 257                         memcpy(&sa[i], hinfo->ai->ai_addr, sizeof(struct sockaddr));
 258         }
 259
 260         krb5_krbhst_free(ctx, hnd);
 261
 262         *naddrs = num_kdcs;
 263         *addr_pp = sa;
 264         return 0;
 265 }
 266 #endif
 267
 268 #if !defined(HAVE_KRB5_FREE_UNPARSED_NAME)
 269  void krb5_free_unparsed_name(krb5_context context, char *val)
 270 {
 271         SAFE_FREE(val);
 272 }
 273 #endif
 274
 275  void kerberos_free_data_contents(krb5_context context, krb5_data *pdata)
 276 {
 277 #if defined(HAVE_KRB5_FREE_DATA_CONTENTS)
 278         if (pdata->data) {
 279                 krb5_free_data_contents(context, pdata);
 280         }
 281 #else
 282         SAFE_FREE(pdata->data);
 283 #endif
 284 }
 285
 286  void kerberos_set_creds_enctype(krb5_creds *pcreds, int enctype)
 287 {
 288 #if defined(HAVE_KRB5_KEYBLOCK_IN_CREDS)
 289         KRB5_KEY_TYPE((&pcreds->keyblock)) = enctype;
 290 #elif defined(HAVE_KRB5_SESSION_IN_CREDS)
 291         KRB5_KEY_TYPE((&pcreds->session)) = enctype;
 292 #else
 293 #error UNKNOWN_KEYBLOCK_MEMBER_IN_KRB5_CREDS_STRUCT
 294 #endif
 295 }
 296
 297  BOOL kerberos_compatible_enctypes(krb5_context context,
 298                                   krb5_enctype enctype1,
 299                                   krb5_enctype enctype2)
 300 {
 301 #if defined(HAVE_KRB5_C_ENCTYPE_COMPARE)
 302         krb5_boolean similar = 0;
 303
 304         krb5_c_enctype_compare(context, enctype1, enctype2, &similar);
 305         return similar ? True : False;
 306 #elif defined(HAVE_KRB5_ENCTYPES_COMPATIBLE_KEYS)
 307         return krb5_enctypes_compatible_keys(context, enctype1, enctype2) ? True : False;
 308 #endif
 309 }
 310
 311 static BOOL ads_cleanup_expired_creds(krb5_context context,
 312                                       krb5_ccache  ccache,
 313                                       krb5_creds  *credsp)
 314 {
 315         krb5_error_code retval;
 316
 317         DEBUG(3, ("Ticket in ccache[%s] expiration %s\n",
 318                   krb5_cc_default_name(context),
 319                   http_timestring(credsp->times.endtime)));
 320
 321         /* we will probably need new tickets if the current ones
 322            will expire within 10 seconds.
 323         */
 324         if (credsp->times.endtime >= (time(NULL) + 10))
 325                 return False;
 326
 327         /* heimdal won't remove creds from a file ccache, and
 328            perhaps we shouldn't anyway, since internally we
 329            use memory ccaches, and a FILE one probably means that
 330            we're using creds obtained outside of our exectuable
 331         */
 332         if (StrCaseCmp(krb5_cc_get_type(context, ccache), "FILE") == 0) {
 333                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a FILE ccache\n"));
 334                 return False;
 335         }
 336
 337         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
 338         if (retval) {
 339                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
 340                           error_message(retval)));
 341                 /* If we have an error in this, we want to display it,
 342                    but continue as though we deleted it */
 343         }
 344         return True;
 345 }
 346
 347 /*
 348   we can't use krb5_mk_req because w2k wants the service to be in a particular format
 349 */
 350 static krb5_error_code ads_krb5_mk_req(krb5_context context,
 351                                        krb5_auth_context *auth_context,
 352                                        const krb5_flags ap_req_options,
 353                                        const char *principal,
 354                                        krb5_ccache ccache,
 355                                        krb5_data *outbuf)
 356 {
 357         krb5_error_code           retval;
 358         krb5_principal    server;
 359         krb5_creds              * credsp;
 360         krb5_creds                creds;
 361         krb5_data in_data;
 362         BOOL creds_ready = False;
 363
 364         retval = krb5_parse_name(context, principal, &server);
 365         if (retval) {
 366                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
 367                 return retval;
 368         }
 369
 370         /* obtain ticket & session key */
 371         ZERO_STRUCT(creds);
 372         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
 373                 DEBUG(1,("krb5_copy_principal failed (%s)\n",
 374                          error_message(retval)));
 375                 goto cleanup_princ;
 376         }
 377
 378         if ((retval = krb5_cc_get_principal(context, ccache, &creds.client))) {
 379                 /* This can commonly fail on smbd startup with no ticket in the cache.
 380                  * Report at higher level than 1. */
 381                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
 382                          error_message(retval)));
 383                 goto cleanup_creds;
 384         }
 385
 386         while(!creds_ready) {
 387                 if ((retval = krb5_get_credentials(context, 0, ccache,
 388                                                    &creds, &credsp))) {
 389                         DEBUG(1,("ads_krb5_mk_req: krb5_get_credentials failed for %s (%s)\n",
 390                                  principal, error_message(retval)));
 391                         goto cleanup_creds;
 392                 }
 393
 394                 /* cope with ticket being in the future due to clock skew */
 395                 if ((unsigned)credsp->times.starttime > time(NULL)) {
 396                         time_t t = time(NULL);
 397                         int time_offset =(unsigned)credsp->times.starttime-t;
 398                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 399                         krb5_set_real_time(context, t + time_offset + 1, 0);
 400                 }
 401
 402                 if (!ads_cleanup_expired_creds(context, ccache, credsp))
 403                         creds_ready = True;
 404         }
 405
 406         DEBUG(10,("ads_krb5_mk_req: Ticket (%s) in ccache (%s) is valid until: (%s - %d)\n",
 407                   principal, krb5_cc_default_name(context),
 408                   http_timestring((unsigned)credsp->times.endtime),
 409                   (unsigned)credsp->times.endtime));
 410
 411         in_data.length = 0;
 412         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
 413                                       &in_data, credsp, outbuf);
 414         if (retval) {
 415                 DEBUG(1,("ads_krb5_mk_req: krb5_mk_req_extended failed (%s)\n",
 416                          error_message(retval)));
 417         }
 418
 419         krb5_free_creds(context, credsp);
 420
 421 cleanup_creds:
 422         krb5_free_cred_contents(context, &creds);
 423
 424 cleanup_princ:
 425         krb5_free_principal(context, server);
 426
 427         return retval;
 428 }
 429
 430 /*
 431   get a kerberos5 ticket for the given service
 432 */
 433 int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 434                         DATA_BLOB *ticket, DATA_BLOB *session_key_krb5)
 435 {
 436         krb5_error_code retval;
 437         krb5_data packet;
 438         krb5_context context = NULL;
 439         krb5_ccache ccdef = NULL;
 440         krb5_auth_context auth_context = NULL;
 441         krb5_enctype enc_types[] = {
 442 #ifdef ENCTYPE_ARCFOUR_HMAC
 443                 ENCTYPE_ARCFOUR_HMAC,
 444 #endif
 445                 ENCTYPE_DES_CBC_MD5,
 446                 ENCTYPE_DES_CBC_CRC,
 447                 ENCTYPE_NULL};
 448
 449         retval = krb5_init_context(&context);
 450         if (retval) {
 451                 DEBUG(1,("cli_krb5_get_ticket: krb5_init_context failed (%s)\n",
 452                          error_message(retval)));
 453                 goto failed;
 454         }
 455
 456         if (time_offset != 0) {
 457                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
 458         }
 459
 460         if ((retval = krb5_cc_default(context, &ccdef))) {
 461                 DEBUG(1,("cli_krb5_get_ticket: krb5_cc_default failed (%s)\n",
 462                          error_message(retval)));
 463                 goto failed;
 464         }
 465
 466         if ((retval = krb5_set_default_tgs_ktypes(context, enc_types))) {
 467                 DEBUG(1,("cli_krb5_get_ticket: krb5_set_default_tgs_ktypes failed (%s)\n",
 468                          error_message(retval)));
 469                 goto failed;
 470         }
 471
 472         if ((retval = ads_krb5_mk_req(context,
 473                                         &auth_context,
 474                                         AP_OPTS_USE_SUBKEY,
 475                                         principal,
 476                                         ccdef, &packet))) {
 477                 goto failed;
 478         }
 479
 480         get_krb5_smb_session_key(context, auth_context, session_key_krb5, False);
 481
 482         *ticket = data_blob(packet.data, packet.length);
 483
 484         kerberos_free_data_contents(context, &packet);
 485
 486 failed:
 487
 488         if ( context ) {
 489                 if (ccdef)
 490                         krb5_cc_close(context, ccdef);
 491                 if (auth_context)
 492                         krb5_auth_con_free(context, auth_context);
 493                 krb5_free_context(context);
 494         }
 495
 496         return retval;
 497 }
 498
 499  BOOL get_krb5_smb_session_key(krb5_context context, krb5_auth_context auth_context, DATA_BLOB *session_key, BOOL remote)
 500  {
 501         krb5_keyblock *skey;
 502         krb5_error_code err;
 503         BOOL ret = False;
 504
 505         if (remote)
 506                 err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
 507         else
 508                 err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
 509         if (err == 0 && skey != NULL) {
 510                 DEBUG(10, ("Got KRB5 session key of length %d\n",  KRB5_KEY_LENGTH(skey)));
 511                 *session_key = data_blob(KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
 512                 dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 513
 514                 ret = True;
 515
 516                 krb5_free_keyblock(context, skey);
 517         } else {
 518                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 519         }
 520
 521         return ret;
 522  }
 523
 524
 525 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING) && !defined(HAVE_KRB5_PRINC_COMPONENT)
 526  const krb5_data *krb5_princ_component(krb5_context context, krb5_principal principal, int i )
 527 {
 528         static krb5_data kdata;
 529
 530         kdata.data = krb5_principal_get_comp_string(context, principal, i);
 531         kdata.length = strlen(kdata.data);
 532         return &kdata;
 533 }
 534 #endif
 535
 536  krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry)
 537 {
 538 #if defined(HAVE_KRB5_KT_FREE_ENTRY)
 539         return krb5_kt_free_entry(context, kt_entry);
 540 #elif defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
 541         return krb5_free_keytab_entry_contents(context, kt_entry);
 542 #else
 543 #error UNKNOWN_KT_FREE_FUNCTION
 544 #endif
 545 }
 546
 547 #else /* HAVE_KRB5 */
 548  /* this saves a few linking headaches */
 549 int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 550                         DATA_BLOB *ticket, DATA_BLOB *session_key_krb5)
 551 {
 552          DEBUG(0,("NO KERBEROS SUPPORT\n"));
 553          return 1;
 554 }
 555
 556 #endif