source/libcli/auth/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 #include "system/network.h"
  24 #include "system/kerberos.h"
  25 #include "libcli/auth/kerberos.h"
  26 #include "system/time.h"
  27
  28 #ifdef HAVE_KRB5
  29
  30 #ifndef HAVE_KRB5_SET_REAL_TIME
  31 /*
  32  * This function is not in the Heimdal mainline.
  33  */
  34  krb5_error_code krb5_set_real_time(krb5_context context, int32_t seconds, int32_t microseconds)
  35 {
  36         krb5_error_code ret;
  37         int32_t sec, usec;
  38
  39         ret = krb5_us_timeofday(context, &sec, &usec);
  40         if (ret)
  41                 return ret;
  42
  43         context->kdc_sec_offset = seconds - sec;
  44         context->kdc_usec_offset = microseconds - usec;
  45
  46         return 0;
  47 }
  48 #endif
  49
  50 #if defined(HAVE_KRB5_SET_DEFAULT_IN_TKT_ETYPES) && !defined(HAVE_KRB5_SET_DEFAULT_TGS_KTYPES)
  51  krb5_error_code krb5_set_default_tgs_ktypes(krb5_context ctx, const krb5_enctype *enc)
  52 {
  53         return krb5_set_default_in_tkt_etypes(ctx, enc);
  54 }
  55 #endif
  56
  57 #if defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS)
  58 /* HEIMDAL */
  59  void setup_kaddr( krb5_address *pkaddr, struct sockaddr *paddr)
  60 {
  61         pkaddr->addr_type = KRB5_ADDRESS_INET;
  62         pkaddr->address.length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
  63         pkaddr->address.data = (char *)&(((struct sockaddr_in *)paddr)->sin_addr);
  64 }
  65 #elif defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS)
  66 /* MIT */
  67  void setup_kaddr( krb5_address *pkaddr, struct sockaddr *paddr)
  68 {
  69         pkaddr->addrtype = ADDRTYPE_INET;
  70         pkaddr->length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
  71         pkaddr->contents = (krb5_octet *)&(((struct sockaddr_in *)paddr)->sin_addr);
  72 }
  73 #else
  74 #error UNKNOWN_ADDRTYPE
  75 #endif
  76
  77 #if defined(HAVE_KRB5_PRINCIPAL2SALT) && defined(HAVE_KRB5_USE_ENCTYPE) && defined(HAVE_KRB5_STRING_TO_KEY) && defined(HAVE_KRB5_ENCRYPT_BLOCK)
  78  int create_kerberos_key_from_string_direct(krb5_context context,
  79                                         krb5_principal host_princ,
  80                                         krb5_data *password,
  81                                         krb5_keyblock *key,
  82                                         krb5_enctype enctype)
  83 {
  84         int ret;
  85         krb5_data salt;
  86         krb5_encrypt_block eblock;
  87
  88         ret = krb5_principal2salt(context, host_princ, &salt);
  89         if (ret) {
  90                 DEBUG(1,("krb5_principal2salt failed (%s)\n", error_message(ret)));
  91                 return ret;
  92         }
  93         krb5_use_enctype(context, &eblock, enctype);
  94         ret = krb5_string_to_key(context, &eblock, key, password, &salt);
  95         SAFE_FREE(salt.data);
  96         return ret;
  97 }
  98 #elif defined(HAVE_KRB5_GET_PW_SALT) && defined(HAVE_KRB5_STRING_TO_KEY_SALT)
  99  int create_kerberos_key_from_string_direct(krb5_context context,
 100                                         krb5_principal host_princ,
 101                                         krb5_data *password,
 102                                         krb5_keyblock *key,
 103                                         krb5_enctype enctype)
 104 {
 105         int ret;
 106         krb5_salt salt;
 107
 108         ret = krb5_get_pw_salt(context, host_princ, &salt);
 109         if (ret) {
 110                 DEBUG(1,("krb5_get_pw_salt failed (%s)\n", error_message(ret)));
 111                 return ret;
 112         }
 113         return krb5_string_to_key_salt(context, enctype, password->data,
 114                 salt, key);
 115 }
 116 #else
 117 #error UNKNOWN_CREATE_KEY_FUNCTIONS
 118 #endif
 119
 120  int create_kerberos_key_from_string(krb5_context context,
 121                                         krb5_principal host_princ,
 122                                         krb5_data *password,
 123                                         krb5_keyblock *key,
 124                                         krb5_enctype enctype)
 125 {
 126         krb5_principal salt_princ = NULL;
 127         int ret;
 128         /*
 129          * Check if we've determined that the KDC is salting keys for this
 130          * principal/enctype in a non-obvious way.  If it is, try to match
 131          * its behavior.
 132          */
 133         salt_princ = kerberos_fetch_salt_princ_for_host_princ(context, host_princ, enctype);
 134         ret = create_kerberos_key_from_string_direct(context, salt_princ ? salt_princ : host_princ, password, key, enctype);
 135         if (salt_princ) {
 136                 krb5_free_principal(context, salt_princ);
 137         }
 138         return ret;
 139 }
 140
 141 #if defined(HAVE_KRB5_GET_PERMITTED_ENCTYPES)
 142  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 143                                             krb5_enctype **enctypes)
 144 {
 145         return krb5_get_permitted_enctypes(context, enctypes);
 146 }
 147 #elif defined(HAVE_KRB5_GET_DEFAULT_IN_TKT_ETYPES)
 148  krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 149                                             krb5_enctype **enctypes)
 150 {
 151         return krb5_get_default_in_tkt_etypes(context, enctypes);
 152 }
 153 #else
 154 #error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 155 #endif
 156
 157  void free_kerberos_etypes(krb5_context context,
 158                            krb5_enctype *enctypes)
 159 {
 160 #if defined(HAVE_KRB5_FREE_KTYPES)
 161         krb5_free_ktypes(context, enctypes);
 162         return;
 163 #else
 164         SAFE_FREE(enctypes);
 165         return;
 166 #endif
 167 }
 168
 169 #if defined(HAVE_KRB5_AUTH_CON_SETKEY) && !defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY)
 170  krb5_error_code krb5_auth_con_setuseruserkey(krb5_context context,
 171                                         krb5_auth_context auth_context,
 172                                         krb5_keyblock *keyblock)
 173 {
 174         return krb5_auth_con_setkey(context, auth_context, keyblock);
 175 }
 176 #endif
 177
 178  DATA_BLOB get_auth_data_from_tkt(TALLOC_CTX *mem_ctx,
 179                             krb5_ticket *tkt)
 180 {
 181         DATA_BLOB auth_data = data_blob(NULL, 0);
 182 #if defined(HAVE_KRB5_TKT_ENC_PART2)
 183         if (tkt && tkt->enc_part2
 184             && tkt->enc_part2->authorization_data
 185             && tkt->enc_part2->authorization_data[0]
 186             && tkt->enc_part2->authorization_data[0]->length)
 187                 auth_data = data_blob(tkt->enc_part2->authorization_data[0]->contents,
 188                         tkt->enc_part2->authorization_data[0]->length);
 189 #else
 190         if (tkt && tkt->ticket.authorization_data && tkt->ticket.authorization_data->len)
 191                 auth_data = data_blob(tkt->ticket.authorization_data->val->ad_data.data,
 192                         tkt->ticket.authorization_data->val->ad_data.length);
 193 #endif
 194         return auth_data;
 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_array_p(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         TALLOC_CTX *mem_ctx = talloc_init("ticket expied time");
 316         if (!mem_ctx) {
 317                 return False;
 318         }
 319
 320         DEBUG(3, ("Ticket in ccache[%s] expiration %s\n",
 321                   krb5_cc_default_name(context),
 322                   http_timestring(mem_ctx, credsp->times.endtime)));
 323
 324         talloc_free(mem_ctx);
 325
 326         /* we will probably need new tickets if the current ones
 327            will expire within 10 seconds.
 328         */
 329         if (credsp->times.endtime >= (time(NULL) + 10))
 330                 return False;
 331
 332         /* heimdal won't remove creds from a file ccache, and
 333            perhaps we shouldn't anyway, since internally we
 334            use memory ccaches, and a FILE one probably means that
 335            we're using creds obtained outside of our exectuable
 336         */
 337         if (StrCaseCmp(krb5_cc_get_type(context, ccache), "FILE") == 0) {
 338                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a FILE ccache\n"));
 339                 return False;
 340         }
 341
 342         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
 343         if (retval) {
 344                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
 345                           error_message(retval)));
 346                 /* If we have an error in this, we want to display it,
 347                    but continue as though we deleted it */
 348         }
 349         return True;
 350 }
 351
 352 /*
 353   we can't use krb5_mk_req because w2k wants the service to be in a particular format
 354 */
 355 krb5_error_code ads_krb5_mk_req(krb5_context context,
 356                                 krb5_auth_context *auth_context,
 357                                 const krb5_flags ap_req_options,
 358                                 const char *principal,
 359                                 krb5_ccache ccache,
 360                                 krb5_data *outbuf)
 361 {
 362         krb5_error_code           retval;
 363         krb5_principal    server;
 364         krb5_creds              * credsp;
 365         krb5_creds                creds;
 366         krb5_data in_data;
 367         BOOL creds_ready = False;
 368
 369         TALLOC_CTX *mem_ctx = NULL;
 370
 371         retval = krb5_parse_name(context, principal, &server);
 372         if (retval) {
 373                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
 374                 return retval;
 375         }
 376
 377         /* obtain ticket & session key */
 378         ZERO_STRUCT(creds);
 379         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
 380                 DEBUG(1,("krb5_copy_principal failed (%s)\n",
 381                          error_message(retval)));
 382                 goto cleanup_princ;
 383         }
 384
 385         if ((retval = krb5_cc_get_principal(context, ccache, &creds.client))) {
 386                 /* This can commonly fail on smbd startup with no ticket in the cache.
 387                  * Report at higher level than 1. */
 388                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
 389                          error_message(retval)));
 390                 goto cleanup_creds;
 391         }
 392
 393         while(!creds_ready) {
 394                 if ((retval = krb5_get_credentials(context, 0, ccache,
 395                                                    &creds, &credsp))) {
 396                         DEBUG(1,("ads_krb5_mk_req: krb5_get_credentials failed for %s (%s)\n",
 397                                  principal, error_message(retval)));
 398                         goto cleanup_creds;
 399                 }
 400
 401                 /* cope with ticket being in the future due to clock skew */
 402                 if ((unsigned)credsp->times.starttime > time(NULL)) {
 403                         time_t t = time(NULL);
 404                         int time_offset =(unsigned)credsp->times.starttime-t;
 405                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
 406                         krb5_set_real_time(context, t + time_offset + 1, 0);
 407                 }
 408
 409                 if (!ads_cleanup_expired_creds(context, ccache, credsp))
 410                         creds_ready = True;
 411         }
 412
 413         mem_ctx = talloc_init("ticket expied time");
 414         if (!mem_ctx) {
 415                 retval = ENOMEM;
 416                 goto cleanup_creds;
 417         }
 418         DEBUG(10,("Ticket (%s) in ccache (%s) is valid until: (%s - %d)\n",
 419                   principal, krb5_cc_default_name(context),
 420                   http_timestring(mem_ctx, (unsigned)credsp->times.endtime),
 421                   (unsigned)credsp->times.endtime));
 422
 423         in_data.length = 0;
 424         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
 425                                       &in_data, credsp, outbuf);
 426         if (retval) {
 427                 DEBUG(1,("ads_krb5_mk_req: krb5_mk_req_extended failed (%s)\n",
 428                          error_message(retval)));
 429         }
 430
 431         krb5_free_creds(context, credsp);
 432
 433 cleanup_creds:
 434         krb5_free_cred_contents(context, &creds);
 435
 436 cleanup_princ:
 437         krb5_free_principal(context, server);
 438
 439         return retval;
 440 }
 441
 442 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING) && !defined(HAVE_KRB5_PRINC_COMPONENT)
 443  const krb5_data *krb5_princ_component(krb5_context context, krb5_principal principal, int i )
 444 {
 445         static krb5_data kdata;
 446
 447         kdata.data = discard_const(krb5_principal_get_comp_string(context, principal, i));
 448         kdata.length = strlen(kdata.data);
 449         return &kdata;
 450 }
 451 #endif
 452
 453  krb5_error_code smb_krb5_kt_free_entry(krb5_context context, krb5_keytab_entry *kt_entry)
 454 {
 455 #if defined(HAVE_KRB5_KT_FREE_ENTRY)
 456         return krb5_kt_free_entry(context, kt_entry);
 457 #elif defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
 458         return krb5_free_keytab_entry_contents(context, kt_entry);
 459 #else
 460 #error UNKNOWN_KT_FREE_FUNCTION
 461 #endif
 462 }
 463
 464 #endif