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