source/auth/kerberos/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    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "system/network.h"
  25 #include "system/kerberos.h"
  26 #include "system/time.h"
  27 #include "auth/kerberos/kerberos.h"
  28
  29 #ifdef HAVE_KRB5
  30
  31 #ifndef HAVE_KRB5_SET_REAL_TIME
  32 /*
  33  * This function is not in the Heimdal mainline.
  34  */
  35  krb5_error_code krb5_set_real_time(krb5_context context, int32_t seconds, int32_t microseconds)
  36 {
  37         krb5_error_code ret;
  38         int32_t sec, usec;
  39
  40         ret = krb5_us_timeofday(context, &sec, &usec);
  41         if (ret)
  42                 return ret;
  43
  44         context->kdc_sec_offset = seconds - sec;
  45         context->kdc_usec_offset = microseconds - usec;
  46
  47         return 0;
  48 }
  49 #endif
  50
  51 #if defined(HAVE_KRB5_SET_DEFAULT_IN_TKT_ETYPES) && !defined(HAVE_KRB5_SET_DEFAULT_TGS_KTYPES)
  52  krb5_error_code krb5_set_default_tgs_ktypes(krb5_context ctx, const krb5_enctype *enc)
  53 {
  54         return krb5_set_default_in_tkt_etypes(ctx, enc);
  55 }
  56 #endif
  57
  58 #if defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS)
  59 /* HEIMDAL */
  60  void setup_kaddr( krb5_address *pkaddr, struct sockaddr *paddr)
  61 {
  62         pkaddr->addr_type = KRB5_ADDRESS_INET;
  63         pkaddr->address.length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
  64         pkaddr->address.data = (char *)&(((struct sockaddr_in *)paddr)->sin_addr);
  65 }
  66 #elif defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS)
  67 /* MIT */
  68  void setup_kaddr( krb5_address *pkaddr, struct sockaddr *paddr)
  69 {
  70         pkaddr->addrtype = ADDRTYPE_INET;
  71         pkaddr->length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
  72         pkaddr->contents = (krb5_octet *)&(((struct sockaddr_in *)paddr)->sin_addr);
  73 }
  74 #else
  75 #error UNKNOWN_ADDRTYPE
  76 #endif
  77
  78 #if defined(HAVE_KRB5_PRINCIPAL2SALT) && defined(HAVE_KRB5_USE_ENCTYPE) && defined(HAVE_KRB5_STRING_TO_KEY) && defined(HAVE_KRB5_ENCRYPT_BLOCK)
  79  int create_kerberos_key_from_string(krb5_context context,
  80                                         krb5_principal host_princ,
  81                                         krb5_data *password,
  82                                         krb5_keyblock *key,
  83                                         krb5_enctype enctype)
  84 {
  85         int ret;
  86         krb5_data salt;
  87         krb5_encrypt_block eblock;
  88
  89         ret = krb5_principal2salt(context, host_princ, &salt);
  90         if (ret) {
  91                 DEBUG(1,("krb5_principal2salt failed (%s)\n", error_message(ret)));
  92                 return ret;
  93         }
  94         krb5_use_enctype(context, &eblock, enctype);
  95         ret = krb5_string_to_key(context, &eblock, key, password, &salt);
  96         SAFE_FREE(salt.data);
  97         return ret;
  98 }
  99 #elif defined(HAVE_KRB5_GET_PW_SALT) && defined(HAVE_KRB5_STRING_TO_KEY_SALT)
 100  int create_kerberos_key_from_string(krb5_context context,
 101                                         krb5_principal host_princ,
 102                                         krb5_data *password,
 103                                         krb5_keyblock *key,
 104                                         krb5_enctype enctype)
 105 {
 106         int ret;
 107         krb5_salt salt;
 108
 109         ret = krb5_get_pw_salt(context, host_princ, &salt);
 110         if (ret) {
 111                 DEBUG(1,("krb5_get_pw_salt failed (%s)\n", error_message(ret)));
 112                 return ret;
 113         }
 114         return krb5_string_to_key_salt(context, enctype, password->data,
 115                 salt, key);
 116 }
 117 #else
 118 #error UNKNOWN_CREATE_KEY_FUNCTIONS
 119 #endif
 120
 121 #if defined(HAVE_KRB5_GET_PERMITTED_ENCTYPES)
 122  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 123                                             krb5_enctype **enctypes)
 124 {
 125         return krb5_get_permitted_enctypes(context, enctypes);
 126 }
 127 #elif defined(HAVE_KRB5_GET_DEFAULT_IN_TKT_ETYPES)
 128  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 129                                             krb5_enctype **enctypes)
 130 {
 131         return krb5_get_default_in_tkt_etypes(context, enctypes);
 132 }
 133 #else
 134 #error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 135 #endif
 136
 137  void free_kerberos_etypes(krb5_context context,
 138                            krb5_enctype *enctypes)
 139 {
 140 #if defined(HAVE_KRB5_FREE_KTYPES)
 141         krb5_free_ktypes(context, enctypes);
 142         return;
 143 #else
 144         SAFE_FREE(enctypes);
 145         return;
 146 #endif
 147 }
 148
 149 #if defined(HAVE_KRB5_AUTH_CON_SETKEY) && !defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY)
 150  krb5_error_code krb5_auth_con_setuseruserkey(krb5_context context,
 151                                         krb5_auth_context auth_context,
 152                                         krb5_keyblock *keyblock)
 153 {
 154         return krb5_auth_con_setkey(context, auth_context, keyblock);
 155 }
 156 #endif
 157
 158  DATA_BLOB get_auth_data_from_tkt(TALLOC_CTX *mem_ctx,
 159                             krb5_ticket *tkt)
 160 {
 161         DATA_BLOB auth_data = data_blob(NULL, 0);
 162 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 163         if (tkt && tkt->enc_part2
 164             && tkt->enc_part2->authorization_data
 165             && tkt->enc_part2->authorization_data[0]
 166             && tkt->enc_part2->authorization_data[0]->length)
 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 && 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         return auth_data;
 175 }
 176
 177  krb5_const_principal get_principal_from_tkt(krb5_ticket *tkt)
 178 {
 179 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 180         return tkt->enc_part2->client;
 181 #else
 182         return tkt->client;
 183 #endif
 184 }
 185
 186 #if !defined(HAVE_KRB5_FREE_UNPARSED_NAME)
 187  void krb5_free_unparsed_name(krb5_context context, char *val)
 188 {
 189         SAFE_FREE(val);
 190 }
 191 #endif
 192
 193  void kerberos_free_data_contents(krb5_context context, krb5_data *pdata)
 194 {
 195 #if defined(HAVE_KRB5_FREE_DATA_CONTENTS)
 196         if (pdata->data) {
 197                 krb5_free_data_contents(context, pdata);
 198         }
 199 #else
 200         SAFE_FREE(pdata->data);
 201 #endif
 202 }
 203
 204  void kerberos_set_creds_enctype(krb5_creds *pcreds, int enctype)
 205 {
 206 #if defined(HAVE_KRB5_KEYBLOCK_IN_CREDS)
 207         KRB5_KEY_TYPE((&pcreds->keyblock)) = enctype;
 208 #elif defined(HAVE_KRB5_SESSION_IN_CREDS)
 209         KRB5_KEY_TYPE((&pcreds->session)) = enctype;
 210 #else
 211 #error UNKNOWN_KEYBLOCK_MEMBER_IN_KRB5_CREDS_STRUCT
 212 #endif
 213 }
 214
 215  BOOL kerberos_compatible_enctypes(krb5_context context,
 216                                   krb5_enctype enctype1,
 217                                   krb5_enctype enctype2)
 218 {
 219 #if defined(HAVE_KRB5_C_ENCTYPE_COMPARE)
 220         krb5_boolean similar = 0;
 221
 222         krb5_c_enctype_compare(context, enctype1, enctype2, &similar);
 223         return similar ? True : False;
 224 #elif defined(HAVE_KRB5_ENCTYPES_COMPATIBLE_KEYS)
 225         return krb5_enctypes_compatible_keys(context, enctype1, enctype2) ? True : False;
 226 #endif
 227 }
 228
 229 static BOOL ads_cleanup_expired_creds(krb5_context context,
 230                                       krb5_ccache  ccache,
 231                                       krb5_creds  *credsp)
 232 {
 233         krb5_error_code retval;
 234         TALLOC_CTX *mem_ctx = talloc_init("ticket expied time");
 235         if (!mem_ctx) {
 236                 return False;
 237         }
 238
 239         DEBUG(3, ("Ticket in ccache[%s] expiration %s\n",
 240                   krb5_cc_default_name(context),
 241                   http_timestring(mem_ctx, credsp->times.endtime)));
 242
 243         talloc_free(mem_ctx);
 244
 245         /* we will probably need new tickets if the current ones
 246            will expire within 10 seconds.
 247         */
 248         if (credsp->times.endtime >= (time(NULL) + 10))
 249                 return False;
 250
 251         /* heimdal won't remove creds from a file ccache, and
 252            perhaps we shouldn't anyway, since internally we
 253            use memory ccaches, and a FILE one probably means that
 254            we're using creds obtained outside of our exectuable
 255         */
 256         if (StrCaseCmp(krb5_cc_get_type(context, ccache), "FILE") == 0) {
 257                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a FILE ccache\n"));
 258                 return False;
 259         }
 260
 261         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
 262         if (retval) {
 263                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
 264                           error_message(retval)));
 265                 /* If we have an error in this, we want to display it,
 266                    but continue as though we deleted it */
 267         }
 268         return True;
 269 }
 270
 271 /*
 272   we can't use krb5_mk_req because w2k wants the service to be in a particular format
 273 */
 274 krb5_error_code ads_krb5_mk_req(krb5_context context,
 275                                 krb5_auth_context *auth_context,
 276                                 const krb5_flags ap_req_options,
 277                                 const char *principal,
 278                                 krb5_ccache ccache,
 279                                 krb5_data *outbuf)
 280 {
 281         krb5_error_code           retval;
 282         krb5_principal    server;
 283         krb5_creds              * credsp;
 284         krb5_creds                creds;
 285         krb5_data in_data;
 286         BOOL creds_ready = False;
 287
 288         TALLOC_CTX *mem_ctx = NULL;
 289
 290         retval = krb5_parse_name(context, principal, &server);
 291         if (retval) {
 292                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
 293                 return retval;
 294         }
 295
 296         /* obtain ticket & session key */
 297         ZERO_STRUCT(creds);
 298         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
 299                 DEBUG(1,("krb5_copy_principal failed (%s)\n",
 300                          error_message(retval)));
 301                 goto cleanup_princ;
 302         }
 303
 304         if ((retval = krb5_cc_get_principal(context, ccache, &creds.client))) {
 305                 /* This can commonly fail on smbd startup with no ticket in the cache.
 306                  * Report at higher level than 1. */
 307                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
 308                          error_message(retval)));
 309                 goto cleanup_creds;
 310         }
 311
 312         while(!creds_ready) {
 313                 if ((retval = krb5_get_credentials(context, 0, ccache,
 314                                                    &creds, &credsp))) {
 315                         DEBUG(1,("ads_krb5_mk_req: krb5_get_credentials failed for %s (%s)\n",
 316                                  principal, error_message(retval)));
 317                         goto cleanup_creds;
 318                 }
 319
 320                 /* cope with ticket being in the future due to clock skew */
 321                 if ((unsigned)credsp->times.starttime > time(NULL)) {
 322                         time_t t = time(NULL);
 323                         int time_offset =(unsigned)credsp->times.starttime-t;
 324                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 325                         krb5_set_real_time(context, t + time_offset + 1, 0);
 326                 }
 327
 328                 if (!ads_cleanup_expired_creds(context, ccache, credsp))
 329                         creds_ready = True;
 330         }
 331
 332         mem_ctx = talloc_init("ticket expied time");
 333         if (!mem_ctx) {
 334                 retval = ENOMEM;
 335                 goto cleanup_creds;
 336         }
 337         DEBUG(10,("Ticket (%s) in ccache (%s) is valid until: (%s - %d)\n",
 338                   principal, krb5_cc_default_name(context),
 339                   http_timestring(mem_ctx, (unsigned)credsp->times.endtime),
 340                   (unsigned)credsp->times.endtime));
 341
 342         in_data.length = 0;
 343         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
 344                                       &in_data, credsp, outbuf);
 345         if (retval) {
 346                 DEBUG(1,("ads_krb5_mk_req: krb5_mk_req_extended failed (%s)\n",
 347                          error_message(retval)));
 348         }
 349
 350         krb5_free_creds(context, credsp);
 351
 352 cleanup_creds:
 353         krb5_free_cred_contents(context, &creds);
 354
 355 cleanup_princ:
 356         krb5_free_principal(context, server);
 357
 358         return retval;
 359 }
 360
 361  krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry)
 362 {
 363 #if defined(HAVE_KRB5_KT_FREE_ENTRY)
 364         return krb5_kt_free_entry(context, kt_entry);
 365 #elif defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
 366         return krb5_free_keytab_entry_contents(context, kt_entry);
 367 #else
 368 #error UNKNOWN_KT_FREE_FUNCTION
 369 #endif
 370 }
 371
 372  char *smb_get_krb5_error_message(krb5_context context, krb5_error_code code, TALLOC_CTX *mem_ctx)
 373 {
 374         char *ret;
 375
 376 #if defined(HAVE_KRB5_GET_ERROR_STRING) && defined(HAVE_KRB5_FREE_ERROR_STRING)
 377         char *context_error = krb5_get_error_string(context);
 378         ret = talloc_asprintf(mem_ctx, "%s: %s", error_message(code), context_error);
 379         krb5_free_error_string(context, context_error);
 380 #else
 381         ret = talloc_strdup(mem_ctx, error_message(code));
 382 #endif
 383         return ret;
 384 }
 385
 386
 387 static int smb_krb5_context_destory_1(void *ptr)
 388 {
 389         struct smb_krb5_context *ctx = ptr;
 390         krb5_free_context(ctx->krb5_context);
 391         return 0;
 392 }
 393
 394 #ifdef HAVE_KRB5_LOG_CONTROL
 395 static int smb_krb5_context_destory_2(void *ptr)
 396 {
 397         struct smb_krb5_context *ctx = ptr;
 398
 399         /* Otherwise krb5_free_context will try and close what we have already free()ed */
 400         krb5_set_warn_dest(ctx->krb5_context, NULL);
 401         krb5_closelog(ctx->krb5_context, ctx->logf);
 402         smb_krb5_context_destory_1(ptr);
 403         return 0;
 404 }
 405
 406 /* We never close down the DEBUG system, and no need to unreference the use */
 407 static void smb_krb5_debug_close(void *private) {
 408         return;
 409 }
 410
 411 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private)
 412 {
 413         DEBUG(3, ("Kerberos: %s\n", msg));
 414 }
 415
 416 #endif
 417
 418  krb5_error_code smb_krb5_init_context(TALLOC_CTX *parent_ctx,
 419                                        struct smb_krb5_context **smb_krb5_context)
 420 {
 421         krb5_error_code ret;
 422         TALLOC_CTX *tmp_ctx;
 423
 424         initialize_krb5_error_table();
 425
 426         *smb_krb5_context = talloc(parent_ctx, struct smb_krb5_context);
 427         tmp_ctx = talloc_new(*smb_krb5_context);
 428
 429         if (!*smb_krb5_context || !tmp_ctx) {
 430                 talloc_free(*smb_krb5_context);
 431                 talloc_free(tmp_ctx);
 432                 return ENOMEM;
 433         }
 434
 435         ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
 436         if (ret) {
 437                 DEBUG(1,("krb5_init_context failed (%s)\n",
 438                          error_message(ret)));
 439                 return ret;
 440         }
 441
 442         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destory_1);
 443
 444         if (lp_realm() && *lp_realm()) {
 445                 char *upper_realm = strupper_talloc(tmp_ctx, lp_realm());
 446                 if (!upper_realm) {
 447                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm()));
 448                         return ENOMEM;
 449                 }
 450                 ret = krb5_set_default_realm((*smb_krb5_context)->krb5_context, lp_realm());
 451                 if (ret) {
 452                         DEBUG(1,("krb5_set_default_realm failed (%s)\n",
 453                                  smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 454                         talloc_free(*smb_krb5_context);
 455                         return ret;
 456                 }
 457         }
 458
 459 #ifdef HAVE_KRB5_LOG_CONTROL
 460         /* TODO: Should we have a different name here? */
 461         ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
 462
 463         if (ret) {
 464                 DEBUG(1,("krb5_initlog failed (%s)\n",
 465                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 466                 talloc_free(*smb_krb5_context);
 467                 return ret;
 468         }
 469
 470         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destory_2);
 471
 472         ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */,
 473                                smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
 474         if (ret) {
 475                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
 476                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 477                 talloc_free(*smb_krb5_context);
 478                 return ret;
 479         }
 480         krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
 481
 482 #endif
 483         talloc_free(tmp_ctx);
 484         return 0;
 485 }
 486
 487 #endif