lib/krb5_wrap/krb5_samba.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    Copyright (C) Guenther Deschner 2005-2009
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "system/filesys.h"
  25 #include "krb5_samba.h"
  26 #include "lib/util/asn1.h"
  27
  28 #ifdef HAVE_COM_ERR_H
  29 #include <com_err.h>
  30 #endif /* HAVE_COM_ERR_H */
  31
  32 #ifndef KRB5_AUTHDATA_WIN2K_PAC
  33 #define KRB5_AUTHDATA_WIN2K_PAC 128
  34 #endif
  35
  36 #ifndef KRB5_AUTHDATA_IF_RELEVANT
  37 #define KRB5_AUTHDATA_IF_RELEVANT 1
  38 #endif
  39
  40 #ifdef HAVE_KRB5
  41
  42 #define GSSAPI_CHECKSUM      0x8003             /* Checksum type value for Kerberos */
  43 #define GSSAPI_BNDLENGTH     16                 /* Bind Length (rfc-1964 pg.3) */
  44 #define GSSAPI_CHECKSUM_SIZE (4+GSSAPI_BNDLENGTH+4) /* Length of bind length,
  45                                                         bind field, flags field. */
  46 #define GSS_C_DELEG_FLAG 1
  47
  48 /* MIT krb5 1.7beta3 (in Ubuntu Karmic) is missing the prototype,
  49    but still has the symbol */
  50 #if !HAVE_DECL_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE
  51 krb5_error_code krb5_auth_con_set_req_cksumtype(
  52         krb5_context     context,
  53         krb5_auth_context      auth_context,
  54         krb5_cksumtype     cksumtype);
  55 #endif
  56
  57 #if !defined(SMB_MALLOC)
  58 #undef malloc
  59 #define SMB_MALLOC(s) malloc((s))
  60 #endif
  61
  62 #ifndef SMB_STRDUP
  63 #define SMB_STRDUP(s) strdup(s)
  64 #endif
  65
  66 /**********************************************************
  67  * MISSING FUNCTIONS
  68  **********************************************************/
  69
  70 #if !defined(HAVE_KRB5_SET_DEFAULT_TGS_KTYPES)
  71
  72 #if defined(HAVE_KRB5_SET_DEFAULT_TGS_ENCTYPES)
  73
  74 /* With MIT kerberos, we should use krb5_set_default_tgs_enctypes in preference
  75  * to krb5_set_default_tgs_ktypes. See
  76  *         http://lists.samba.org/archive/samba-technical/2006-July/048271.html
  77  *
  78  * If the MIT libraries are not exporting internal symbols, we will end up in
  79  * this branch, which is correct. Otherwise we will continue to use the
  80  * internal symbol
  81  */
  82  krb5_error_code krb5_set_default_tgs_ktypes(krb5_context ctx, const krb5_enctype *enc)
  83 {
  84     return krb5_set_default_tgs_enctypes(ctx, enc);
  85 }
  86
  87 #elif defined(HAVE_KRB5_SET_DEFAULT_IN_TKT_ETYPES)
  88
  89 /* Heimdal */
  90  krb5_error_code krb5_set_default_tgs_ktypes(krb5_context ctx, const krb5_enctype *enc)
  91 {
  92         return krb5_set_default_in_tkt_etypes(ctx, enc);
  93 }
  94
  95 #endif /* HAVE_KRB5_SET_DEFAULT_TGS_ENCTYPES */
  96
  97 #endif /* HAVE_KRB5_SET_DEFAULT_TGS_KTYPES */
  98
  99
 100 #if defined(HAVE_KRB5_AUTH_CON_SETKEY) && !defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY)
 101 krb5_error_code krb5_auth_con_setuseruserkey(krb5_context context,
 102                                              krb5_auth_context auth_context,
 103                                              krb5_keyblock *keyblock)
 104 {
 105         return krb5_auth_con_setkey(context, auth_context, keyblock);
 106 }
 107 #endif
 108
 109 #if !defined(HAVE_KRB5_FREE_UNPARSED_NAME)
 110 void krb5_free_unparsed_name(krb5_context context, char *val)
 111 {
 112         SAFE_FREE(val);
 113 }
 114 #endif
 115
 116 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING) && !defined(HAVE_KRB5_PRINC_COMPONENT)
 117 const krb5_data *krb5_princ_component(krb5_context context,
 118                                       krb5_principal principal, int i);
 119
 120 const krb5_data *krb5_princ_component(krb5_context context,
 121                                       krb5_principal principal, int i)
 122 {
 123         static krb5_data kdata;
 124
 125         kdata.data = discard_const_p(char, krb5_principal_get_comp_string(context, principal, i));
 126         kdata.length = strlen((const char *)kdata.data);
 127         return &kdata;
 128 }
 129 #endif
 130
 131
 132 /**********************************************************
 133  * WRAPPING FUNCTIONS
 134  **********************************************************/
 135
 136 #if defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS)
 137 /* HEIMDAL */
 138
 139 /**
 140  * @brief Stores the address of a 'struct sockaddr_storage' a krb5_address
 141  *
 142  * @param[in]  paddr    A pointer to a 'struct sockaddr_storage to extract the
 143  *                      address from.
 144  *
 145  * @param[out] pkaddr   A Kerberos address to store tha address in.
 146  *
 147  * @return True on success, false if an error occured.
 148  */
 149 bool smb_krb5_sockaddr_to_kaddr(struct sockaddr_storage *paddr,
 150                                 krb5_address *pkaddr)
 151 {
 152         memset(pkaddr, '\0', sizeof(krb5_address));
 153 #if defined(HAVE_IPV6) && defined(KRB5_ADDRESS_INET6)
 154         if (paddr->ss_family == AF_INET6) {
 155                 pkaddr->addr_type = KRB5_ADDRESS_INET6;
 156                 pkaddr->address.length = sizeof(((struct sockaddr_in6 *)paddr)->sin6_addr);
 157                 pkaddr->address.data = (char *)&(((struct sockaddr_in6 *)paddr)->sin6_addr);
 158                 return true;
 159         }
 160 #endif
 161         if (paddr->ss_family == AF_INET) {
 162                 pkaddr->addr_type = KRB5_ADDRESS_INET;
 163                 pkaddr->address.length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
 164                 pkaddr->address.data = (char *)&(((struct sockaddr_in *)paddr)->sin_addr);
 165                 return true;
 166         }
 167         return false;
 168 }
 169 #elif defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS)
 170 /* MIT */
 171
 172 /**
 173  * @brief Stores the address of a 'struct sockaddr_storage' a krb5_address
 174  *
 175  * @param[in]  paddr    A pointer to a 'struct sockaddr_storage to extract the
 176  *                      address from.
 177  *
 178  * @param[in]  pkaddr A Kerberos address to store tha address in.
 179  *
 180  * @return True on success, false if an error occured.
 181  */
 182 bool smb_krb5_sockaddr_to_kaddr(struct sockaddr_storage *paddr,
 183                                 krb5_address *pkaddr)
 184 {
 185         memset(pkaddr, '\0', sizeof(krb5_address));
 186 #if defined(HAVE_IPV6) && defined(ADDRTYPE_INET6)
 187         if (paddr->ss_family == AF_INET6) {
 188                 pkaddr->addrtype = ADDRTYPE_INET6;
 189                 pkaddr->length = sizeof(((struct sockaddr_in6 *)paddr)->sin6_addr);
 190                 pkaddr->contents = (krb5_octet *)&(((struct sockaddr_in6 *)paddr)->sin6_addr);
 191                 return true;
 192         }
 193 #endif
 194         if (paddr->ss_family == AF_INET) {
 195                 pkaddr->addrtype = ADDRTYPE_INET;
 196                 pkaddr->length = sizeof(((struct sockaddr_in *)paddr)->sin_addr);
 197                 pkaddr->contents = (krb5_octet *)&(((struct sockaddr_in *)paddr)->sin_addr);
 198                 return true;
 199         }
 200         return false;
 201 }
 202 #else
 203 #error UNKNOWN_ADDRTYPE
 204 #endif
 205
 206 krb5_error_code smb_krb5_mk_error(krb5_context context,
 207                                   krb5_error_code error_code,
 208                                   const char *e_text,
 209                                   krb5_data *e_data,
 210                                   krb5_data *enc_err)
 211 {
 212         krb5_error_code code = EINVAL;
 213 #ifdef SAMBA4_USES_HEIMDAL
 214         code = krb5_mk_error(context,
 215                              error_code,
 216                              e_text,
 217                              e_data,
 218                              NULL, /* client */
 219                              NULL, /* server */
 220                              NULL, /* client_time */
 221                              NULL, /* client_usec */
 222                              enc_err);
 223 #else
 224         krb5_error dec_err = {
 225                 .error = error_code,
 226         };
 227
 228         if (e_text != NULL) {
 229                 dec_err.text.length = strlen(e_text);
 230                 dec_err.text.data = discard_const_p(char, e_text);
 231         }
 232         if (e_data != NULL) {
 233                 dec_err.e_data = *e_data;
 234         }
 235
 236         code = krb5_mk_error(context,
 237                              &dec_err,
 238                              enc_err);
 239 #endif
 240         return code;
 241 }
 242
 243 /**
 244 * @brief Create a keyblock based on input parameters
 245 *
 246 * @param context        The krb5_context
 247 * @param host_princ     The krb5_principal to use
 248 * @param salt           The optional salt, if omitted, salt is calculated with
 249 *                       the provided principal.
 250 * @param password       The krb5_data containing the password
 251 * @param enctype        The krb5_enctype to use for the keyblock generation
 252 * @param key            The returned krb5_keyblock, caller needs to free with
 253 *                       krb5_free_keyblock().
 254 *
 255 * @return krb5_error_code
 256 */
 257 int smb_krb5_create_key_from_string(krb5_context context,
 258                                     krb5_const_principal host_princ,
 259                                     krb5_data *salt,
 260                                     krb5_data *password,
 261                                     krb5_enctype enctype,
 262                                     krb5_keyblock *key)
 263 {
 264         int ret = 0;
 265
 266         if (host_princ == NULL && salt == NULL) {
 267                 return -1;
 268         }
 269
 270 #if defined(HAVE_KRB5_PRINCIPAL2SALT) && defined(HAVE_KRB5_C_STRING_TO_KEY)
 271 {/* MIT */
 272         krb5_data _salt;
 273
 274         if (salt == NULL) {
 275                 ret = krb5_principal2salt(context, host_princ, &_salt);
 276                 if (ret) {
 277                         DEBUG(1,("krb5_principal2salt failed (%s)\n", error_message(ret)));
 278                         return ret;
 279                 }
 280         } else {
 281                 _salt = *salt;
 282         }
 283         ret = krb5_c_string_to_key(context, enctype, password, &_salt, key);
 284         if (salt == NULL) {
 285                 SAFE_FREE(_salt.data);
 286         }
 287 }
 288 #elif defined(HAVE_KRB5_GET_PW_SALT) && defined(HAVE_KRB5_STRING_TO_KEY_SALT)
 289 {/* Heimdal */
 290         krb5_salt _salt;
 291
 292         if (salt == NULL) {
 293                 ret = krb5_get_pw_salt(context, host_princ, &_salt);
 294                 if (ret) {
 295                         DEBUG(1,("krb5_get_pw_salt failed (%s)\n", error_message(ret)));
 296                         return ret;
 297                 }
 298         } else {
 299                 _salt.saltvalue = *salt;
 300                 _salt.salttype = KRB5_PW_SALT;
 301         }
 302
 303         ret = krb5_string_to_key_salt(context, enctype, (const char *)password->data, _salt, key);
 304         if (salt == NULL) {
 305                 krb5_free_salt(context, _salt);
 306         }
 307 }
 308 #else
 309 #error UNKNOWN_CREATE_KEY_FUNCTIONS
 310 #endif
 311         return ret;
 312 }
 313
 314 /**
 315 * @brief Create a salt for a given principal
 316 *
 317 * @param context        The initialized krb5_context
 318 * @param host_princ     The krb5_principal to create the salt for
 319 * @param psalt          A pointer to a krb5_data struct
 320 *
 321 * caller has to free the contents of psalt with smb_krb5_free_data_contents
 322 * when function has succeeded
 323 *
 324 * @return krb5_error_code, returns 0 on success, error code otherwise
 325 */
 326
 327 int smb_krb5_get_pw_salt(krb5_context context,
 328                          krb5_const_principal host_princ,
 329                          krb5_data *psalt)
 330 #if defined(HAVE_KRB5_GET_PW_SALT)
 331 /* Heimdal */
 332 {
 333         int ret;
 334         krb5_salt salt;
 335
 336         ret = krb5_get_pw_salt(context, host_princ, &salt);
 337         if (ret) {
 338                 return ret;
 339         }
 340
 341         psalt->data = salt.saltvalue.data;
 342         psalt->length = salt.saltvalue.length;
 343
 344         return ret;
 345 }
 346 #elif defined(HAVE_KRB5_PRINCIPAL2SALT)
 347 /* MIT */
 348 {
 349         return krb5_principal2salt(context, host_princ, psalt);
 350 }
 351 #else
 352 #error UNKNOWN_SALT_FUNCTIONS
 353 #endif
 354
 355 #if defined(HAVE_KRB5_GET_PERMITTED_ENCTYPES)
 356 /**
 357  * @brief Get a list of encryption types allowed for session keys
 358  *
 359  * @param[in]  context  The library context
 360  *
 361  * @param[in]  enctypes An allocated, zero-terminated list of encryption types
 362  *
 363  * This function returns an allocated list of encryption types allowed for
 364  * session keys.
 365  *
 366  * Use free() to free the enctypes when it is no longer needed.
 367  *
 368  * @retval 0 Success; otherwise - Kerberos error codes
 369  */
 370 krb5_error_code smb_krb5_get_allowed_etypes(krb5_context context,
 371                                             krb5_enctype **enctypes)
 372 {
 373         return krb5_get_permitted_enctypes(context, enctypes);
 374 }
 375 #elif defined(HAVE_KRB5_GET_DEFAULT_IN_TKT_ETYPES)
 376 krb5_error_code smb_krb5_get_allowed_etypes(krb5_context context,
 377                                             krb5_enctype **enctypes)
 378 {
 379 #ifdef HAVE_KRB5_PDU_NONE_DECL
 380         return krb5_get_default_in_tkt_etypes(context, KRB5_PDU_NONE, enctypes);
 381 #else
 382         return krb5_get_default_in_tkt_etypes(context, enctypes);
 383 #endif
 384 }
 385 #else
 386 #error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 387 #endif
 388
 389 bool unwrap_edata_ntstatus(TALLOC_CTX *mem_ctx,
 390                            DATA_BLOB *edata,
 391                            DATA_BLOB *edata_out)
 392 {
 393         DATA_BLOB edata_contents;
 394         ASN1_DATA *data;
 395         int edata_type;
 396
 397         if (!edata->length) {
 398                 return false;
 399         }
 400
 401         data = asn1_init(mem_ctx);
 402         if (data == NULL) {
 403                 return false;
 404         }
 405
 406         if (!asn1_load(data, *edata)) goto err;
 407         if (!asn1_start_tag(data, ASN1_SEQUENCE(0))) goto err;
 408         if (!asn1_start_tag(data, ASN1_CONTEXT(1))) goto err;
 409         if (!asn1_read_Integer(data, &edata_type)) goto err;
 410
 411         if (edata_type != KRB5_PADATA_PW_SALT) {
 412                 DEBUG(0,("edata is not of required type %d but of type %d\n",
 413                         KRB5_PADATA_PW_SALT, edata_type));
 414                 goto err;
 415         }
 416
 417         if (!asn1_start_tag(data, ASN1_CONTEXT(2))) goto err;
 418         if (!asn1_read_OctetString(data, talloc_tos(), &edata_contents)) goto err;
 419         if (!asn1_end_tag(data)) goto err;
 420         if (!asn1_end_tag(data)) goto err;
 421         if (!asn1_end_tag(data)) goto err;
 422         asn1_free(data);
 423
 424         *edata_out = data_blob_talloc(mem_ctx, edata_contents.data, edata_contents.length);
 425
 426         data_blob_free(&edata_contents);
 427
 428         return true;
 429
 430   err:
 431
 432         asn1_free(data);
 433         return false;
 434 }
 435
 436
 437 /**************************************************************
 438  krb5_parse_name that takes a UNIX charset.
 439 **************************************************************/
 440
 441 krb5_error_code smb_krb5_parse_name(krb5_context context,
 442                                 const char *name, /* in unix charset */
 443                                 krb5_principal *principal)
 444 {
 445         krb5_error_code ret;
 446         char *utf8_name;
 447         size_t converted_size;
 448         TALLOC_CTX *frame = talloc_stackframe();
 449
 450         if (!push_utf8_talloc(frame, &utf8_name, name, &converted_size)) {
 451                 talloc_free(frame);
 452                 return ENOMEM;
 453         }
 454
 455         ret = krb5_parse_name(context, utf8_name, principal);
 456         TALLOC_FREE(frame);
 457         return ret;
 458 }
 459
 460 /**************************************************************
 461  krb5_parse_name that returns a UNIX charset name. Must
 462  be freed with talloc_free() call.
 463 **************************************************************/
 464
 465 krb5_error_code smb_krb5_unparse_name(TALLOC_CTX *mem_ctx,
 466                                       krb5_context context,
 467                                       krb5_const_principal principal,
 468                                       char **unix_name)
 469 {
 470         krb5_error_code ret;
 471         char *utf8_name;
 472         size_t converted_size;
 473
 474         *unix_name = NULL;
 475         ret = krb5_unparse_name(context, principal, &utf8_name);
 476         if (ret) {
 477                 return ret;
 478         }
 479
 480         if (!pull_utf8_talloc(mem_ctx, unix_name, utf8_name, &converted_size)) {
 481                 krb5_free_unparsed_name(context, utf8_name);
 482                 return ENOMEM;
 483         }
 484         krb5_free_unparsed_name(context, utf8_name);
 485         return 0;
 486 }
 487
 488 krb5_error_code smb_krb5_parse_name_norealm(krb5_context context,
 489                                             const char *name,
 490                                             krb5_principal *principal)
 491 {
 492         /* we are cheating here because parse_name will in fact set the realm.
 493          * We don't care as the only caller of smb_krb5_parse_name_norealm
 494          * ignores the realm anyway when calling
 495          * smb_krb5_principal_compare_any_realm later - Guenther */
 496
 497         return smb_krb5_parse_name(context, name, principal);
 498 }
 499
 500 bool smb_krb5_principal_compare_any_realm(krb5_context context,
 501                                           krb5_const_principal princ1,
 502                                           krb5_const_principal princ2)
 503 {
 504         return krb5_principal_compare_any_realm(context, princ1, princ2);
 505 }
 506
 507 /**
 508  * @brief Free the contents of a krb5_data structure and zero the data field.
 509  *
 510  * @param[in]  context  The krb5 context
 511  *
 512  * @param[in]  pdata    The data structure to free contents of
 513  *
 514  * This function frees the contents, not the structure itself.
 515  */
 516 void smb_krb5_free_data_contents(krb5_context context, krb5_data *pdata)
 517 {
 518 #if defined(HAVE_KRB5_FREE_DATA_CONTENTS)
 519         if (pdata->data) {
 520                 krb5_free_data_contents(context, pdata);
 521         }
 522 #elif defined(HAVE_KRB5_DATA_FREE)
 523         krb5_data_free(context, pdata);
 524 #else
 525         SAFE_FREE(pdata->data);
 526 #endif
 527 }
 528
 529 /*
 530  * @brief copy a buffer into a krb5_data struct
 531  *
 532  * @param[in] p                 The krb5_data
 533  * @param[in] data              The data to copy
 534  * @param[in] length            The length of the data to copy
 535  * @return krb5_error_code
 536  *
 537  * Caller has to free krb5_data with smb_krb5_free_data_contents().
 538  */
 539 krb5_error_code smb_krb5_copy_data_contents(krb5_data *p,
 540                                             const void *data,
 541                                             size_t len)
 542 {
 543 #if defined(HAVE_KRB5_DATA_COPY)
 544         return krb5_data_copy(p, data, len);
 545 #else
 546         if (len) {
 547                 p->data = malloc(len);
 548                 if (p->data == NULL) {
 549                         return ENOMEM;
 550                 }
 551                 memmove(p->data, data, len);
 552         } else {
 553                 p->data = NULL;
 554         }
 555         p->length = len;
 556         p->magic = KV5M_DATA;
 557         return 0;
 558 #endif
 559 }
 560
 561 bool smb_krb5_get_smb_session_key(TALLOC_CTX *mem_ctx,
 562                                   krb5_context context,
 563                                   krb5_auth_context auth_context,
 564                                   DATA_BLOB *session_key,
 565                                   bool remote)
 566 {
 567         krb5_keyblock *skey = NULL;
 568         krb5_error_code err = 0;
 569         bool ret = false;
 570
 571         if (remote) {
 572 #ifdef HAVE_KRB5_AUTH_CON_GETRECVSUBKEY
 573                 err = krb5_auth_con_getrecvsubkey(context,
 574                                                   auth_context,
 575                                                   &skey);
 576 #else /* HAVE_KRB5_AUTH_CON_GETRECVSUBKEY */
 577                 err = krb5_auth_con_getremotesubkey(context,
 578                                                     auth_context, &skey);
 579 #endif /* HAVE_KRB5_AUTH_CON_GETRECVSUBKEY */
 580         } else {
 581 #ifdef HAVE_KRB5_AUTH_CON_GETSENDSUBKEY
 582                 err = krb5_auth_con_getsendsubkey(context,
 583                                                   auth_context,
 584                                                   &skey);
 585 #else /* HAVE_KRB5_AUTH_CON_GETSENDSUBKEY */
 586                 err = krb5_auth_con_getlocalsubkey(context,
 587                                                    auth_context, &skey);
 588 #endif /* HAVE_KRB5_AUTH_CON_GETSENDSUBKEY */
 589         }
 590
 591         if (err || skey == NULL) {
 592                 DEBUG(10, ("KRB5 error getting session key %d\n", err));
 593                 goto done;
 594         }
 595
 596         DEBUG(10, ("Got KRB5 session key of length %d\n",
 597                    (int)KRB5_KEY_LENGTH(skey)));
 598
 599         *session_key = data_blob_talloc(mem_ctx,
 600                                          KRB5_KEY_DATA(skey),
 601                                          KRB5_KEY_LENGTH(skey));
 602         dump_data_pw("KRB5 Session Key:\n",
 603                      session_key->data,
 604                      session_key->length);
 605
 606         ret = true;
 607
 608 done:
 609         if (skey) {
 610                 krb5_free_keyblock(context, skey);
 611         }
 612
 613         return ret;
 614 }
 615
 616
 617 /**
 618  * @brief Get talloced string component of a principal
 619  *
 620  * @param[in] mem_ctx           The TALLOC_CTX
 621  * @param[in] context           The krb5_context
 622  * @param[in] principal         The principal
 623  * @param[in] component         The component
 624  * @return string component
 625  *
 626  * Caller must talloc_free if the return value is not NULL.
 627  *
 628  */
 629 char *smb_krb5_principal_get_comp_string(TALLOC_CTX *mem_ctx,
 630                                          krb5_context context,
 631                                          krb5_const_principal principal,
 632                                          unsigned int component)
 633 {
 634 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING)
 635         return talloc_strdup(mem_ctx, krb5_principal_get_comp_string(context, principal, component));
 636 #else
 637         krb5_data *data;
 638
 639         if (component >= krb5_princ_size(context, principal)) {
 640                 return NULL;
 641         }
 642
 643         data = krb5_princ_component(context, principal, component);
 644         if (data == NULL) {
 645                 return NULL;
 646         }
 647
 648         return talloc_strndup(mem_ctx, data->data, data->length);
 649 #endif
 650 }
 651
 652 /**
 653  * @brief
 654  *
 655  * @param[in]  ccache_string A string pointing to the cache to renew the ticket
 656  *                           (e.g. FILE:/tmp/krb5cc_0) or NULL. If the principal
 657  *                           ccache has not been specified, the default ccache
 658  *                           will be used.
 659  *
 660  * @param[in]  client_string The client principal string (e.g. user@SAMBA.SITE)
 661  *                           or NULL. If the principal string has not been
 662  *                           specified, the principal from the ccache will be
 663  *                           retrieved.
 664  *
 665  * @param[in]  service_string The service ticket string
 666  *                            (e.g. krbtgt/SAMBA.SITE@SAMBA.SITE) or NULL. If
 667  *                            the sevice ticket is specified, it is parsed (
 668  *                            with the realm part ignored) and used as the
 669  *                            server principal of the credential. Otherwise
 670  *                            the ticket-granting service is used.
 671  *
 672  * @param[in]  expire_time    A pointer to store the credentials end time or
 673  *                            NULL.
 674  *
 675  * @return 0 on Succes, a Kerberos error code otherwise.
 676  */
 677 krb5_error_code smb_krb5_renew_ticket(const char *ccache_string,
 678                                       const char *client_string,
 679                                       const char *service_string,
 680                                       time_t *expire_time)
 681 {
 682         krb5_error_code ret;
 683         krb5_context context = NULL;
 684         krb5_ccache ccache = NULL;
 685         krb5_principal client = NULL;
 686         krb5_creds creds, creds_in;
 687
 688         ZERO_STRUCT(creds);
 689         ZERO_STRUCT(creds_in);
 690
 691         initialize_krb5_error_table();
 692         ret = krb5_init_context(&context);
 693         if (ret) {
 694                 goto done;
 695         }
 696
 697         if (!ccache_string) {
 698                 ccache_string = krb5_cc_default_name(context);
 699         }
 700
 701         if (!ccache_string) {
 702                 ret = EINVAL;
 703                 goto done;
 704         }
 705
 706         DEBUG(10,("smb_krb5_renew_ticket: using %s as ccache\n", ccache_string));
 707
 708         /* FIXME: we should not fall back to defaults */
 709         ret = krb5_cc_resolve(context, discard_const_p(char, ccache_string), &ccache);
 710         if (ret) {
 711                 goto done;
 712         }
 713
 714         if (client_string) {
 715                 ret = smb_krb5_parse_name(context, client_string, &client);
 716                 if (ret) {
 717                         goto done;
 718                 }
 719         } else {
 720                 ret = krb5_cc_get_principal(context, ccache, &client);
 721                 if (ret) {
 722                         goto done;
 723                 }
 724         }
 725
 726         ret = krb5_get_renewed_creds(context, &creds, client, ccache, discard_const_p(char, service_string));
 727         if (ret) {
 728                 DEBUG(10,("smb_krb5_renew_ticket: krb5_get_kdc_cred failed: %s\n", error_message(ret)));
 729                 goto done;
 730         }
 731
 732         /* hm, doesn't that create a new one if the old one wasn't there? - Guenther */
 733         ret = krb5_cc_initialize(context, ccache, client);
 734         if (ret) {
 735                 goto done;
 736         }
 737
 738         ret = krb5_cc_store_cred(context, ccache, &creds);
 739
 740         if (expire_time) {
 741                 *expire_time = (time_t) creds.times.endtime;
 742         }
 743
 744 done:
 745         krb5_free_cred_contents(context, &creds_in);
 746         krb5_free_cred_contents(context, &creds);
 747
 748         if (client) {
 749                 krb5_free_principal(context, client);
 750         }
 751         if (ccache) {
 752                 krb5_cc_close(context, ccache);
 753         }
 754         if (context) {
 755                 krb5_free_context(context);
 756         }
 757
 758         return ret;
 759 }
 760
 761 /**
 762  * @brief Free the data stored in an smb_krb5_addresses structure.
 763  *
 764  * @param[in]  context  The library context
 765  *
 766  * @param[in]  addr     The address structure to free.
 767  *
 768  * @return 0 on success, a Kerberos error code otherwise.
 769  */
 770 krb5_error_code smb_krb5_free_addresses(krb5_context context,
 771                                         smb_krb5_addresses *addr)
 772 {
 773         krb5_error_code ret = 0;
 774         if (addr == NULL) {
 775                 return ret;
 776         }
 777 #if defined(HAVE_MAGIC_IN_KRB5_ADDRESS) && defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS) /* MIT */
 778         krb5_free_addresses(context, addr->addrs);
 779 #elif defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS) /* Heimdal */
 780         ret = krb5_free_addresses(context, addr->addrs);
 781         SAFE_FREE(addr->addrs);
 782 #endif
 783         SAFE_FREE(addr);
 784         addr = NULL;
 785         return ret;
 786 }
 787
 788 #define MAX_NETBIOSNAME_LEN 16
 789
 790 /**
 791  * @brief Add a netbios name to the array of addresses
 792  *
 793  * @param[in]  kerb_addr A pointer to the smb_krb5_addresses to add the
 794  *                       netbios name to.
 795  *
 796  * @param[in]  netbios_name The netbios name to add.
 797  *
 798  * @return 0 on success, a Kerberos error code otherwise.
 799  */
 800 krb5_error_code smb_krb5_gen_netbios_krb5_address(smb_krb5_addresses **kerb_addr,
 801                                                    const char *netbios_name)
 802 {
 803         krb5_error_code ret = 0;
 804         char buf[MAX_NETBIOSNAME_LEN];
 805         int len;
 806 #if defined(HAVE_MAGIC_IN_KRB5_ADDRESS) && defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS) /* MIT */
 807         krb5_address **addrs = NULL;
 808 #elif defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS) /* Heimdal */
 809         krb5_addresses *addrs = NULL;
 810 #endif
 811
 812         *kerb_addr = (smb_krb5_addresses *)SMB_MALLOC(sizeof(smb_krb5_addresses));
 813         if (*kerb_addr == NULL) {
 814                 return ENOMEM;
 815         }
 816
 817         /* temporarily duplicate put_name() code here to avoid dependency
 818          * issues for a 5 lines function */
 819         len = strlen(netbios_name);
 820         memcpy(buf, netbios_name,
 821                 (len < MAX_NETBIOSNAME_LEN) ? len : MAX_NETBIOSNAME_LEN - 1);
 822         if (len < MAX_NETBIOSNAME_LEN - 1) {
 823                 memset(buf + len, ' ', MAX_NETBIOSNAME_LEN - 1 - len);
 824         }
 825         buf[MAX_NETBIOSNAME_LEN - 1] = 0x20;
 826
 827 #if defined(HAVE_MAGIC_IN_KRB5_ADDRESS) && defined(HAVE_ADDRTYPE_IN_KRB5_ADDRESS) /* MIT */
 828         {
 829                 int num_addr = 2;
 830
 831                 addrs = (krb5_address **)SMB_MALLOC(sizeof(krb5_address *) * num_addr);
 832                 if (addrs == NULL) {
 833                         SAFE_FREE(*kerb_addr);
 834                         return ENOMEM;
 835                 }
 836
 837                 memset(addrs, 0, sizeof(krb5_address *) * num_addr);
 838
 839                 addrs[0] = (krb5_address *)SMB_MALLOC(sizeof(krb5_address));
 840                 if (addrs[0] == NULL) {
 841                         SAFE_FREE(addrs);
 842                         SAFE_FREE(*kerb_addr);
 843                         return ENOMEM;
 844                 }
 845
 846                 addrs[0]->magic = KV5M_ADDRESS;
 847                 addrs[0]->addrtype = KRB5_ADDR_NETBIOS;
 848                 addrs[0]->length = MAX_NETBIOSNAME_LEN;
 849                 addrs[0]->contents = (unsigned char *)SMB_MALLOC(addrs[0]->length);
 850                 if (addrs[0]->contents == NULL) {
 851                         SAFE_FREE(addrs[0]);
 852                         SAFE_FREE(addrs);
 853                         SAFE_FREE(*kerb_addr);
 854                         return ENOMEM;
 855                 }
 856
 857                 memcpy(addrs[0]->contents, buf, addrs[0]->length);
 858
 859                 addrs[1] = NULL;
 860         }
 861 #elif defined(HAVE_ADDR_TYPE_IN_KRB5_ADDRESS) /* Heimdal */
 862         {
 863                 addrs = (krb5_addresses *)SMB_MALLOC(sizeof(krb5_addresses));
 864                 if (addrs == NULL) {
 865                         SAFE_FREE(*kerb_addr);
 866                         return ENOMEM;
 867                 }
 868
 869                 memset(addrs, 0, sizeof(krb5_addresses));
 870
 871                 addrs->len = 1;
 872                 addrs->val = (krb5_address *)SMB_MALLOC(sizeof(krb5_address));
 873                 if (addrs->val == NULL) {
 874                         SAFE_FREE(addrs);
 875                         SAFE_FREE(kerb_addr);
 876                         return ENOMEM;
 877                 }
 878
 879                 addrs->val[0].addr_type = KRB5_ADDR_NETBIOS;
 880                 addrs->val[0].address.length = MAX_NETBIOSNAME_LEN;
 881                 addrs->val[0].address.data = (unsigned char *)SMB_MALLOC(addrs->val[0].address.length);
 882                 if (addrs->val[0].address.data == NULL) {
 883                         SAFE_FREE(addrs->val);
 884                         SAFE_FREE(addrs);
 885                         SAFE_FREE(*kerb_addr);
 886                         return ENOMEM;
 887                 }
 888
 889                 memcpy(addrs->val[0].address.data, buf, addrs->val[0].address.length);
 890         }
 891 #else
 892 #error UNKNOWN_KRB5_ADDRESS_FORMAT
 893 #endif
 894         (*kerb_addr)->addrs = addrs;
 895
 896         return ret;
 897 }
 898
 899 /**
 900  * @brief Get the enctype from a key table entry
 901  *
 902  * @param[in]  kt_entry Key table entry to get the enctype from.
 903  *
 904  * @return The enctype from the entry.
 905  */
 906 krb5_enctype smb_krb5_kt_get_enctype_from_entry(krb5_keytab_entry *kt_entry)
 907 {
 908         return KRB5_KEY_TYPE(KRB5_KT_KEY(kt_entry));
 909 }
 910
 911 /**
 912  * @brief Free the contents of a key table entry.
 913  *
 914  * @param[in]  context The library context.
 915  *
 916  * @param[in]  kt_entry The key table entry to free the contents of.
 917  *
 918  * @return 0 on success, a Kerberos error code otherwise.
 919  *
 920  * The pointer itself is not freed.
 921  */
 922 krb5_error_code smb_krb5_kt_free_entry(krb5_context context,
 923                                         krb5_keytab_entry *kt_entry)
 924 {
 925 /* Try krb5_free_keytab_entry_contents first, since
 926  * MIT Kerberos >= 1.7 has both krb5_free_keytab_entry_contents and
 927  * krb5_kt_free_entry but only has a prototype for the first, while the
 928  * second is considered private.
 929  */
 930 #if defined(HAVE_KRB5_FREE_KEYTAB_ENTRY_CONTENTS)
 931         return krb5_free_keytab_entry_contents(context, kt_entry);
 932 #elif defined(HAVE_KRB5_KT_FREE_ENTRY)
 933         return krb5_kt_free_entry(context, kt_entry);
 934 #else
 935 #error UNKNOWN_KT_FREE_FUNCTION
 936 #endif
 937 }
 938
 939
 940 /**
 941  * @brief Convert an encryption type to a string.
 942  *
 943  * @param[in]  context The library context.
 944  *
 945  * @param[in]  enctype The encryption type.
 946  *
 947  * @param[in]  etype_s A pointer to store the allocated encryption type as a
 948  *                     string.
 949  *
 950  * @return 0 on success, a Kerberos error code otherwise.
 951  *
 952  * The caller needs to free the allocated string etype_s.
 953  */
 954 krb5_error_code smb_krb5_enctype_to_string(krb5_context context,
 955                                            krb5_enctype enctype,
 956                                            char **etype_s)
 957 {
 958 #ifdef HAVE_KRB5_ENCTYPE_TO_STRING_WITH_KRB5_CONTEXT_ARG
 959         return krb5_enctype_to_string(context, enctype, etype_s); /* Heimdal */
 960 #elif defined(HAVE_KRB5_ENCTYPE_TO_STRING_WITH_SIZE_T_ARG)
 961         char buf[256];
 962         krb5_error_code ret = krb5_enctype_to_string(enctype, buf, 256); /* MIT */
 963         if (ret) {
 964                 return ret;
 965         }
 966         *etype_s = SMB_STRDUP(buf);
 967         if (!*etype_s) {
 968                 return ENOMEM;
 969         }
 970         return ret;
 971 #else
 972 #error UNKNOWN_KRB5_ENCTYPE_TO_STRING_FUNCTION
 973 #endif
 974 }
 975
 976 /* This MAX_NAME_LEN is a constant defined in krb5.h */
 977 #ifndef MAX_KEYTAB_NAME_LEN
 978 #define MAX_KEYTAB_NAME_LEN 1100
 979 #endif
 980
 981 /**
 982  * @brief Open a key table readonly or with readwrite access.
 983  *
 984  * Allows to use a different keytab than the default one using a relative
 985  * path to the keytab.
 986  *
 987  * @param[in]  context  The library context
 988  *
 989  * @param[in]  keytab_name_req The path to the key table.
 990  *
 991  * @param[in]  write_access Open with readwrite access.
 992  *
 993  * @param[in]  keytab A pointer o the opended key table.
 994  *
 995  * The keytab pointer should be freed using krb5_kt_close().
 996  *
 997  * @return 0 on success, a Kerberos error code otherwise.
 998  */
 999 krb5_error_code smb_krb5_kt_open_relative(krb5_context context,
1000                                           const char *keytab_name_req,
1001                                           bool write_access,
1002                                           krb5_keytab *keytab)
1003 {
1004         krb5_error_code ret = 0;
1005         TALLOC_CTX *mem_ctx;
1006         char keytab_string[MAX_KEYTAB_NAME_LEN];
1007         char *kt_str = NULL;
1008         bool found_valid_name = false;
1009         const char *pragma = "FILE";
1010         const char *tmp = NULL;
1011
1012         if (!write_access && !keytab_name_req) {
1013                 /* caller just wants to read the default keytab readonly, so be it */
1014                 return krb5_kt_default(context, keytab);
1015         }
1016
1017         mem_ctx = talloc_init("smb_krb5_open_keytab");
1018         if (!mem_ctx) {
1019                 return ENOMEM;
1020         }
1021
1022 #ifdef HAVE_WRFILE_KEYTAB
1023         if (write_access) {
1024                 pragma = "WRFILE";
1025         }
1026 #endif
1027
1028         if (keytab_name_req) {
1029
1030                 if (strlen(keytab_name_req) > MAX_KEYTAB_NAME_LEN) {
1031                         ret = KRB5_CONFIG_NOTENUFSPACE;
1032                         goto out;
1033                 }
1034
1035                 if ((strncmp(keytab_name_req, "WRFILE:/", 8) == 0) ||
1036                     (strncmp(keytab_name_req, "FILE:/", 6) == 0)) {
1037                         tmp = keytab_name_req;
1038                         goto resolve;
1039                 }
1040
1041                 tmp = talloc_asprintf(mem_ctx, "%s:%s", pragma, keytab_name_req);
1042                 if (!tmp) {
1043                         ret = ENOMEM;
1044                         goto out;
1045                 }
1046
1047                 goto resolve;
1048         }
1049
1050         /* we need to handle more complex keytab_strings, like:
1051          * "ANY:FILE:/etc/krb5.keytab,krb4:/etc/srvtab" */
1052
1053         ret = krb5_kt_default_name(context, &keytab_string[0], MAX_KEYTAB_NAME_LEN - 2);
1054         if (ret) {
1055                 goto out;
1056         }
1057
1058         DEBUG(10,("smb_krb5_open_keytab: krb5_kt_default_name returned %s\n", keytab_string));
1059
1060         tmp = talloc_strdup(mem_ctx, keytab_string);
1061         if (!tmp) {
1062                 ret = ENOMEM;
1063                 goto out;
1064         }
1065
1066         if (strncmp(tmp, "ANY:", 4) == 0) {
1067                 tmp += 4;
1068         }
1069
1070         memset(&keytab_string, '\0', sizeof(keytab_string));
1071
1072         while (next_token_talloc(mem_ctx, &tmp, &kt_str, ",")) {
1073                 if (strncmp(kt_str, "WRFILE:", 7) == 0) {
1074                         found_valid_name = true;
1075                         tmp = kt_str;
1076                         tmp += 7;
1077                 }
1078
1079                 if (strncmp(kt_str, "FILE:", 5) == 0) {
1080                         found_valid_name = true;
1081                         tmp = kt_str;
1082                         tmp += 5;
1083                 }
1084
1085                 if (tmp[0] == '/') {
1086                         /* Treat as a FILE: keytab definition. */
1087                         found_valid_name = true;
1088                 }
1089
1090                 if (found_valid_name) {
1091                         if (tmp[0] != '/') {
1092                                 ret = KRB5_KT_BADNAME;
1093                                 goto out;
1094                         }
1095
1096                         tmp = talloc_asprintf(mem_ctx, "%s:%s", pragma, tmp);
1097                         if (!tmp) {
1098                                 ret = ENOMEM;
1099                                 goto out;
1100                         }
1101                         break;
1102                 }
1103         }
1104
1105         if (!found_valid_name) {
1106                 ret = KRB5_KT_UNKNOWN_TYPE;
1107                 goto out;
1108         }
1109
1110 resolve:
1111         DEBUG(10,("smb_krb5_open_keytab: resolving: %s\n", tmp));
1112         ret = krb5_kt_resolve(context, tmp, keytab);
1113
1114 out:
1115         TALLOC_FREE(mem_ctx);
1116         return ret;
1117 }
1118
1119 /**
1120  * @brief Open a key table readonly or with readwrite access.
1121  *
1122  * Allows to use a different keytab than the default one. The path needs to be
1123  * an absolute path or an error will be returned.
1124  *
1125  * @param[in]  context  The library context
1126  *
1127  * @param[in]  keytab_name_req The path to the key table.
1128  *
1129  * @param[in]  write_access Open with readwrite access.
1130  *
1131  * @param[in]  keytab A pointer o the opended key table.
1132  *
1133  * The keytab pointer should be freed using krb5_kt_close().
1134  *
1135  * @return 0 on success, a Kerberos error code otherwise.
1136  */
1137 krb5_error_code smb_krb5_kt_open(krb5_context context,
1138                                  const char *keytab_name_req,
1139                                  bool write_access,
1140                                  krb5_keytab *keytab)
1141 {
1142         if (keytab_name_req != NULL) {
1143                 if (keytab_name_req[0] != '/') {
1144                         return KRB5_KT_BADNAME;
1145                 }
1146         }
1147
1148         return smb_krb5_kt_open_relative(context,
1149                                          keytab_name_req,
1150                                          write_access,
1151                                          keytab);
1152 }
1153
1154 /**
1155  * @brief Get a key table name.
1156  *
1157  * @param[in]  mem_ctx The talloc context to use for allocation.
1158  *
1159  * @param[in]  context The library context.
1160  *
1161  * @param[in]  keytab The key table to get the name from.
1162  *
1163  * @param[in]  keytab_name A talloc'ed string of the key table name.
1164  *
1165  * The talloc'ed name string needs to be freed with talloc_free().
1166  *
1167  * @return 0 on success, a Kerberos error code otherwise.
1168  */
1169 krb5_error_code smb_krb5_kt_get_name(TALLOC_CTX *mem_ctx,
1170                                      krb5_context context,
1171                                      krb5_keytab keytab,
1172                                      const char **keytab_name)
1173 {
1174         char keytab_string[MAX_KEYTAB_NAME_LEN];
1175         krb5_error_code ret = 0;
1176
1177         ret = krb5_kt_get_name(context, keytab,
1178                                keytab_string, MAX_KEYTAB_NAME_LEN - 2);
1179         if (ret) {
1180                 return ret;
1181         }
1182
1183         *keytab_name = talloc_strdup(mem_ctx, keytab_string);
1184         if (!*keytab_name) {
1185                 return ENOMEM;
1186         }
1187
1188         return ret;
1189 }
1190
1191 /**
1192  * @brief Seek and delete old entries in a keytab based on the passed
1193  *        principal.
1194  *
1195  * @param[in]  context       The KRB5 context to use.
1196  *
1197  * @param[in]  keytab        The keytab to operate on.
1198  *
1199  * @param[in]  kvno          The kvnco to use.
1200  *
1201  * @param[in]  princ_s       The principal as a string to search for.
1202  *
1203  * @param[in]  princ         The principal as a krb5_principal to search for.
1204  *
1205  * @param[in]  flush         Weather to flush the complete keytab.
1206  *
1207  * @param[in]  keep_old_entries Keep the entry with the previous kvno.
1208  *
1209  * @retval 0 on Sucess
1210  *
1211  * @return An appropriate KRB5 error code.
1212  */
1213 krb5_error_code smb_krb5_kt_seek_and_delete_old_entries(krb5_context context,
1214                                                         krb5_keytab keytab,
1215                                                         krb5_kvno kvno,
1216                                                         krb5_enctype enctype,
1217                                                         const char *princ_s,
1218                                                         krb5_principal princ,
1219                                                         bool flush,
1220                                                         bool keep_old_entries)
1221 {
1222         krb5_error_code ret;
1223         krb5_kt_cursor cursor;
1224         krb5_kt_cursor zero_csr;
1225         krb5_keytab_entry kt_entry;
1226         krb5_keytab_entry zero_kt_entry;
1227         char *ktprinc = NULL;
1228         krb5_kvno old_kvno = kvno - 1;
1229         TALLOC_CTX *tmp_ctx;
1230
1231         ZERO_STRUCT(cursor);
1232         ZERO_STRUCT(zero_csr);
1233         ZERO_STRUCT(kt_entry);
1234         ZERO_STRUCT(zero_kt_entry);
1235
1236         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
1237         if (ret == KRB5_KT_END || ret == ENOENT ) {
1238                 /* no entries */
1239                 return 0;
1240         }
1241
1242         tmp_ctx = talloc_new(NULL);
1243         if (tmp_ctx == NULL) {
1244                 return ENOMEM;
1245         }
1246
1247         DEBUG(3, (__location__ ": Will try to delete old keytab entries\n"));
1248         while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
1249                 bool name_ok = false;
1250                 krb5_enctype kt_entry_enctype =
1251                         smb_krb5_kt_get_enctype_from_entry(&kt_entry);
1252
1253                 if (!flush && (princ_s != NULL)) {
1254                         ret = smb_krb5_unparse_name(tmp_ctx, context,
1255                                                     kt_entry.principal,
1256                                                     &ktprinc);
1257                         if (ret) {
1258                                 DEBUG(1, (__location__
1259                                           ": smb_krb5_unparse_name failed "
1260                                           "(%s)\n", error_message(ret)));
1261                                 goto out;
1262                         }
1263
1264 #ifdef HAVE_KRB5_KT_COMPARE
1265                         name_ok = krb5_kt_compare(context, &kt_entry,
1266                                                   princ, 0, 0);
1267 #else
1268                         name_ok = (strcmp(ktprinc, princ_s) == 0);
1269 #endif
1270
1271                         if (!name_ok) {
1272                                 DEBUG(10, (__location__ ": ignoring keytab "
1273                                            "entry principal %s, kvno = %d\n",
1274                                            ktprinc, kt_entry.vno));
1275
1276                                 /* Not a match,
1277                                  * just free this entry and continue. */
1278                                 ret = smb_krb5_kt_free_entry(context,
1279                                                              &kt_entry);
1280                                 ZERO_STRUCT(kt_entry);
1281                                 if (ret) {
1282                                         DEBUG(1, (__location__
1283                                                   ": smb_krb5_kt_free_entry "
1284                                                   "failed (%s)\n",
1285                                                   error_message(ret)));
1286                                         goto out;
1287                                 }
1288
1289                                 TALLOC_FREE(ktprinc);
1290                                 continue;
1291                         }
1292
1293                         TALLOC_FREE(ktprinc);
1294                 }
1295
1296                 /*------------------------------------------------------------
1297                  * Save the entries with kvno - 1. This is what microsoft does
1298                  * to allow people with existing sessions that have kvno - 1
1299                  * to still work. Otherwise, when the password for the machine
1300                  * changes, all kerberizied sessions will 'break' until either
1301                  * the client reboots or the client's session key expires and
1302                  * they get a new session ticket with the new kvno.
1303                  * Some keytab files only store the kvno in 8bits, limit
1304                  * the compare accordingly.
1305                  */
1306
1307                 if (!flush && ((kt_entry.vno & 0xff) == (old_kvno & 0xff))) {
1308                         DEBUG(5, (__location__ ": Saving previous (kvno %d) "
1309                                   "entry for principal: %s.\n",
1310                                   old_kvno, princ_s));
1311                         continue;
1312                 }
1313
1314                 if (keep_old_entries) {
1315                         DEBUG(5, (__location__ ": Saving old (kvno %d) "
1316                                   "entry for principal: %s.\n",
1317                                   kvno, princ_s));
1318                         continue;
1319                 }
1320
1321                 if (!flush &&
1322                     (kt_entry.vno == kvno) &&
1323                     (kt_entry_enctype != enctype))
1324                 {
1325                         DEBUG(5, (__location__ ": Saving entry with kvno [%d] "
1326                                   "enctype [%d] for principal: %s.\n",
1327                                   kvno, kt_entry_enctype, princ_s));
1328                         continue;
1329                 }
1330
1331                 DEBUG(5, (__location__ ": Found old entry for principal: %s "
1332                           "(kvno %d) - trying to remove it.\n",
1333                           princ_s, kt_entry.vno));
1334
1335                 ret = krb5_kt_end_seq_get(context, keytab, &cursor);
1336                 ZERO_STRUCT(cursor);
1337                 if (ret) {
1338                         DEBUG(1, (__location__ ": krb5_kt_end_seq_get() "
1339                                   "failed (%s)\n", error_message(ret)));
1340                         goto out;
1341                 }
1342                 ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
1343                 if (ret) {
1344                         DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
1345                                   "failed (%s)\n", error_message(ret)));
1346                         goto out;
1347                 }
1348
1349                 DEBUG(5, (__location__ ": removed old entry for principal: "
1350                           "%s (kvno %d).\n", princ_s, kt_entry.vno));
1351
1352                 ret = krb5_kt_start_seq_get(context, keytab, &cursor);
1353                 if (ret) {
1354                         DEBUG(1, (__location__ ": krb5_kt_start_seq() failed "
1355                                   "(%s)\n", error_message(ret)));
1356                         goto out;
1357                 }
1358                 ret = smb_krb5_kt_free_entry(context, &kt_entry);
1359                 ZERO_STRUCT(kt_entry);
1360                 if (ret) {
1361                         DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
1362                                   "failed (%s)\n", error_message(ret)));
1363                         goto out;
1364                 }
1365         }
1366
1367 out:
1368         talloc_free(tmp_ctx);
1369         if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
1370                 smb_krb5_kt_free_entry(context, &kt_entry);
1371         }
1372         if (memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) {
1373                 krb5_kt_end_seq_get(context, keytab, &cursor);
1374         }
1375         return ret;
1376 }
1377
1378 /**
1379  * @brief Add a keytab entry for the given principal
1380  *
1381  * @param[in]  context       The krb5 context to use.
1382  *
1383  * @param[in]  keytab        The keytab to add the entry to.
1384  *
1385  * @param[in]  kvno          The kvno to use.
1386  *
1387  * @param[in]  princ_s       The principal as a string.
1388  *
1389  * @param[in]  salt_principal The salt principal to salt the password with.
1390  *                            Only needed for keys which support salting.
1391  *                            If no salt is used set no_salt to false and
1392  *                            pass NULL here.
1393  *
1394  * @param[in]  enctype        The encryption type of the keytab entry.
1395  *
1396  * @param[in]  password       The password of the keytab entry.
1397  *
1398  * @param[in]  no_salt        If the password should not be salted. Normally
1399  *                            this is only set to false for encryption types
1400  *                            which do not support salting like RC4.
1401  *
1402  * @param[in]  keep_old_entries Wether to keep or delte old keytab entries.
1403  *
1404  * @retval 0 on Success
1405  *
1406  * @return A corresponding KRB5 error code.
1407  *
1408  * @see smb_krb5_kt_open()
1409  */
1410 krb5_error_code smb_krb5_kt_add_entry(krb5_context context,
1411                                       krb5_keytab keytab,
1412                                       krb5_kvno kvno,
1413                                       const char *princ_s,
1414                                       const char *salt_principal,
1415                                       krb5_enctype enctype,
1416                                       krb5_data *password,
1417                                       bool no_salt,
1418                                       bool keep_old_entries)
1419 {
1420         krb5_error_code ret;
1421         krb5_keytab_entry kt_entry;
1422         krb5_principal princ = NULL;
1423         krb5_keyblock *keyp;
1424
1425         ZERO_STRUCT(kt_entry);
1426
1427         ret = smb_krb5_parse_name(context, princ_s, &princ);
1428         if (ret) {
1429                 DEBUG(1, (__location__ ": smb_krb5_parse_name(%s) "
1430                           "failed (%s)\n", princ_s, error_message(ret)));
1431                 goto out;
1432         }
1433
1434         /* Seek and delete old keytab entries */
1435         ret = smb_krb5_kt_seek_and_delete_old_entries(context,
1436                                                       keytab,
1437                                                       kvno,
1438                                                       enctype,
1439                                                       princ_s,
1440                                                       princ,
1441                                                       false,
1442                                                       keep_old_entries);
1443         if (ret) {
1444                 goto out;
1445         }
1446
1447         /* If we get here, we have deleted all the old entries with kvno's
1448          * not equal to the current kvno-1. */
1449
1450         keyp = KRB5_KT_KEY(&kt_entry);
1451
1452         if (no_salt) {
1453                 KRB5_KEY_DATA(keyp) = (KRB5_KEY_DATA_CAST *)SMB_MALLOC(password->length);
1454                 if (KRB5_KEY_DATA(keyp) == NULL) {
1455                         ret = ENOMEM;
1456                         goto out;
1457                 }
1458                 memcpy(KRB5_KEY_DATA(keyp), password->data, password->length);
1459                 KRB5_KEY_LENGTH(keyp) = password->length;
1460                 KRB5_KEY_TYPE(keyp) = enctype;
1461         } else {
1462                 krb5_principal salt_princ = NULL;
1463
1464                 /* Now add keytab entries for all encryption types */
1465                 ret = smb_krb5_parse_name(context, salt_principal, &salt_princ);
1466                 if (ret) {
1467                         DBG_WARNING("krb5_parse_name(%s) failed (%s)\n",
1468                                     salt_principal, error_message(ret));
1469                         goto out;
1470                 }
1471
1472                 ret = smb_krb5_create_key_from_string(context,
1473                                                       salt_princ,
1474                                                       NULL,
1475                                                       password,
1476                                                       enctype,
1477                                                       keyp);
1478                 krb5_free_principal(context, salt_princ);
1479                 if (ret != 0) {
1480                         goto out;
1481                 }
1482         }
1483
1484         kt_entry.principal = princ;
1485         kt_entry.vno       = kvno;
1486
1487         DEBUG(3, (__location__ ": adding keytab entry for (%s) with "
1488                   "encryption type (%d) and version (%d)\n",
1489                   princ_s, enctype, kt_entry.vno));
1490         ret = krb5_kt_add_entry(context, keytab, &kt_entry);
1491         krb5_free_keyblock_contents(context, keyp);
1492         ZERO_STRUCT(kt_entry);
1493         if (ret) {
1494                 DEBUG(1, (__location__ ": adding entry to keytab "
1495                           "failed (%s)\n", error_message(ret)));
1496                 goto out;
1497         }
1498
1499 out:
1500         if (princ) {
1501                 krb5_free_principal(context, princ);
1502         }
1503
1504         return ret;
1505 }
1506
1507 #if defined(HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE) && \
1508     defined(HAVE_KRB5_GET_CREDS_OPT_ALLOC) && \
1509     defined(HAVE_KRB5_GET_CREDS)
1510 static krb5_error_code smb_krb5_get_credentials_for_user_opt(krb5_context context,
1511                                                              krb5_ccache ccache,
1512                                                              krb5_principal me,
1513                                                              krb5_principal server,
1514                                                              krb5_principal impersonate_princ,
1515                                                              krb5_creds **out_creds)
1516 {
1517         krb5_error_code ret;
1518         krb5_get_creds_opt opt;
1519
1520         ret = krb5_get_creds_opt_alloc(context, &opt);
1521         if (ret) {
1522                 goto done;
1523         }
1524         krb5_get_creds_opt_add_options(context, opt, KRB5_GC_FORWARDABLE);
1525
1526         if (impersonate_princ) {
1527                 ret = krb5_get_creds_opt_set_impersonate(context, opt,
1528                                                          impersonate_princ);
1529                 if (ret) {
1530                         goto done;
1531                 }
1532         }
1533
1534         ret = krb5_get_creds(context, opt, ccache, server, out_creds);
1535         if (ret) {
1536                 goto done;
1537         }
1538
1539  done:
1540         if (opt) {
1541                 krb5_get_creds_opt_free(context, opt);
1542         }
1543         return ret;
1544 }
1545 #endif /* HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE */
1546
1547 #ifdef HAVE_KRB5_GET_CREDENTIALS_FOR_USER
1548
1549 #if !HAVE_DECL_KRB5_GET_CREDENTIALS_FOR_USER
1550 krb5_error_code KRB5_CALLCONV
1551 krb5_get_credentials_for_user(krb5_context context, krb5_flags options,
1552                               krb5_ccache ccache, krb5_creds *in_creds,
1553                               krb5_data *subject_cert,
1554                               krb5_creds **out_creds);
1555 #endif /* !HAVE_DECL_KRB5_GET_CREDENTIALS_FOR_USER */
1556
1557 static krb5_error_code smb_krb5_get_credentials_for_user(krb5_context context,
1558                                                          krb5_ccache ccache,
1559                                                          krb5_principal me,
1560                                                          krb5_principal server,
1561                                                          krb5_principal impersonate_princ,
1562                                                          krb5_creds **out_creds)
1563 {
1564         krb5_error_code ret;
1565         krb5_creds in_creds;
1566
1567         ZERO_STRUCT(in_creds);
1568
1569         if (impersonate_princ) {
1570
1571                 in_creds.server = me;
1572                 in_creds.client = impersonate_princ;
1573
1574                 ret = krb5_get_credentials_for_user(context,
1575                                                     0, /* krb5_flags options */
1576                                                     ccache,
1577                                                     &in_creds,
1578                                                     NULL, /* krb5_data *subject_cert */
1579                                                     out_creds);
1580         } else {
1581                 in_creds.client = me;
1582                 in_creds.server = server;
1583
1584                 ret = krb5_get_credentials(context, 0, ccache,
1585                                            &in_creds, out_creds);
1586         }
1587
1588         return ret;
1589 }
1590 #endif /* HAVE_KRB5_GET_CREDENTIALS_FOR_USER */
1591
1592 /*
1593  * smb_krb5_get_credentials
1594  *
1595  * @brief Get krb5 credentials for a server
1596  *
1597  * @param[in] context           An initialized krb5_context
1598  * @param[in] ccache            An initialized krb5_ccache
1599  * @param[in] me                The krb5_principal of the caller
1600  * @param[in] server            The krb5_principal of the requested service
1601  * @param[in] impersonate_princ The krb5_principal of a user to impersonate as (optional)
1602  * @param[out] out_creds        The returned krb5_creds structure
1603  * @return krb5_error_code
1604  *
1605  */
1606 krb5_error_code smb_krb5_get_credentials(krb5_context context,
1607                                          krb5_ccache ccache,
1608                                          krb5_principal me,
1609                                          krb5_principal server,
1610                                          krb5_principal impersonate_princ,
1611                                          krb5_creds **out_creds)
1612 {
1613         krb5_error_code ret;
1614         krb5_creds *creds = NULL;
1615
1616         if (out_creds != NULL) {
1617                 *out_creds = NULL;
1618         }
1619
1620         if (impersonate_princ) {
1621 #ifdef HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE /* Heimdal */
1622                 ret = smb_krb5_get_credentials_for_user_opt(context, ccache, me, server, impersonate_princ, &creds);
1623 #elif defined(HAVE_KRB5_GET_CREDENTIALS_FOR_USER) /* MIT */
1624                 ret = smb_krb5_get_credentials_for_user(context, ccache, me, server, impersonate_princ, &creds);
1625 #else
1626                 ret = ENOTSUP;
1627 #endif
1628         } else {
1629                 krb5_creds in_creds;
1630
1631                 ZERO_STRUCT(in_creds);
1632
1633                 in_creds.client = me;
1634                 in_creds.server = server;
1635
1636                 ret = krb5_get_credentials(context, 0, ccache,
1637                                            &in_creds, &creds);
1638         }
1639         if (ret) {
1640                 goto done;
1641         }
1642
1643         if (out_creds) {
1644                 *out_creds = creds;
1645         }
1646
1647  done:
1648         if (creds && ret) {
1649                 krb5_free_creds(context, creds);
1650         }
1651
1652         return ret;
1653 }
1654
1655 /**
1656  * @brief Initialize a krb5_keyblock with the given data.
1657  *
1658  * Initialized a new keyblock, allocates the contents fo the key and
1659  * copies the data into the keyblock.
1660  *
1661  * @param[in]  context  The library context
1662  *
1663  * @param[in]  enctype  The encryption type.
1664  *
1665  * @param[in]  data     The date to initialize the keyblock with.
1666  *
1667  * @param[in]  length   The length of the keyblock.
1668  *
1669  * @param[in]  key      Newly allocated keyblock structure.
1670  *
1671  * The key date must be freed using krb5_free_keyblock_contents() when it is
1672  * no longer needed.
1673  *
1674  * @return 0 on success, a Kerberos error code otherwise.
1675  */
1676 krb5_error_code smb_krb5_keyblock_init_contents(krb5_context context,
1677                                                 krb5_enctype enctype,
1678                                                 const void *data,
1679                                                 size_t length,
1680                                                 krb5_keyblock *key)
1681 {
1682 #if defined(HAVE_KRB5_KEYBLOCK_INIT)
1683         return krb5_keyblock_init(context, enctype, data, length, key);
1684 #else
1685         memset(key, 0, sizeof(krb5_keyblock));
1686         KRB5_KEY_DATA(key) = SMB_MALLOC(length);
1687         if (NULL == KRB5_KEY_DATA(key)) {
1688                 return ENOMEM;
1689         }
1690         memcpy(KRB5_KEY_DATA(key), data, length);
1691         KRB5_KEY_LENGTH(key) = length;
1692         KRB5_KEY_TYPE(key) = enctype;
1693         return 0;
1694 #endif
1695 }
1696
1697 /*
1698   simulate a kinit, putting the tgt in the given credentials cache.
1699   Orignally by remus@snapserver.com
1700
1701   This version is built to use a keyblock, rather than needing the
1702   original password.
1703
1704   The impersonate_principal is the principal if NULL, or the principal
1705   to impersonate
1706
1707   The target_service defaults to the krbtgt if NULL, but could be
1708    kpasswd/realm or the local service (if we are doing s4u2self)
1709 */
1710 krb5_error_code kerberos_kinit_keyblock_cc(krb5_context ctx, krb5_ccache cc,
1711                                            krb5_principal principal,
1712                                            krb5_keyblock *keyblock,
1713                                            const char *target_service,
1714                                            krb5_get_init_creds_opt *krb_options,
1715                                            time_t *expire_time,
1716                                            time_t *kdc_time)
1717 {
1718         krb5_error_code code = 0;
1719         krb5_creds my_creds;
1720
1721 #if defined(HAVE_KRB5_GET_INIT_CREDS_KEYBLOCK)
1722         code = krb5_get_init_creds_keyblock(ctx, &my_creds, principal,
1723                                             keyblock, 0, target_service,
1724                                             krb_options);
1725 #elif defined(HAVE_KRB5_GET_INIT_CREDS_KEYTAB)
1726 {
1727 #define SMB_CREDS_KEYTAB "MEMORY:tmp_smb_creds_XXXXXX"
1728         char tmp_name[sizeof(SMB_CREDS_KEYTAB)];
1729         krb5_keytab_entry entry;
1730         krb5_keytab keytab;
1731         mode_t mask;
1732
1733         memset(&entry, 0, sizeof(entry));
1734         entry.principal = principal;
1735         *(KRB5_KT_KEY(&entry)) = *keyblock;
1736
1737         memcpy(tmp_name, SMB_CREDS_KEYTAB, sizeof(SMB_CREDS_KEYTAB));
1738         mask = umask(S_IRWXO | S_IRWXG);
1739         mktemp(tmp_name);
1740         umask(mask);
1741         if (tmp_name[0] == 0) {
1742                 return KRB5_KT_BADNAME;
1743         }
1744         code = krb5_kt_resolve(ctx, tmp_name, &keytab);
1745         if (code) {
1746                 return code;
1747         }
1748
1749         code = krb5_kt_add_entry(ctx, keytab, &entry);
1750         if (code) {
1751                 (void)krb5_kt_close(ctx, keytab);
1752                 goto done;
1753         }
1754
1755         code = krb5_get_init_creds_keytab(ctx, &my_creds, principal,
1756                                           keytab, 0, target_service,
1757                                           krb_options);
1758         (void)krb5_kt_close(ctx, keytab);
1759 }
1760 #else
1761 #error krb5_get_init_creds_keyblock not available!
1762 #endif
1763         if (code) {
1764                 return code;
1765         }
1766
1767 #ifndef SAMBA4_USES_HEIMDAL /* MIT */
1768         /*
1769          * We need to store the principal as returned from the KDC to the
1770          * credentials cache. If we don't do that the KRB5 library is not
1771          * able to find the tickets it is looking for
1772          */
1773         principal = my_creds.client;
1774 #endif
1775         code = krb5_cc_initialize(ctx, cc, principal);
1776         if (code) {
1777                 goto done;
1778         }
1779
1780         code = krb5_cc_store_cred(ctx, cc, &my_creds);
1781         if (code) {
1782                 goto done;
1783         }
1784
1785         if (expire_time) {
1786                 *expire_time = (time_t) my_creds.times.endtime;
1787         }
1788
1789         if (kdc_time) {
1790                 *kdc_time = (time_t) my_creds.times.starttime;
1791         }
1792
1793         code = 0;
1794 done:
1795         krb5_free_cred_contents(ctx, &my_creds);
1796         return code;
1797 }
1798
1799 krb5_error_code kerberos_kinit_password_cc(krb5_context ctx, krb5_ccache cc,
1800                                            krb5_principal principal,
1801                                            const char *password,
1802                                            const char *target_service,
1803                                            krb5_get_init_creds_opt *krb_options,
1804                                            time_t *expire_time,
1805                                            time_t *kdc_time)
1806 {
1807         krb5_error_code code = 0;
1808         krb5_creds my_creds;
1809
1810         code = krb5_get_init_creds_password(ctx, &my_creds, principal,
1811                                             password, NULL, NULL, 0,
1812                                             target_service, krb_options);
1813         if (code) {
1814                 return code;
1815         }
1816
1817 #ifndef SAMBA4_USES_HEIMDAL /* MIT */
1818         /*
1819          * We need to store the principal as returned from the KDC to the
1820          * credentials cache. If we don't do that the KRB5 library is not
1821          * able to find the tickets it is looking for
1822          */
1823         principal = my_creds.client;
1824 #endif
1825         code = krb5_cc_initialize(ctx, cc, principal);
1826         if (code) {
1827                 goto done;
1828         }
1829
1830         code = krb5_cc_store_cred(ctx, cc, &my_creds);
1831         if (code) {
1832                 goto done;
1833         }
1834
1835         if (expire_time) {
1836                 *expire_time = (time_t) my_creds.times.endtime;
1837         }
1838
1839         if (kdc_time) {
1840                 *kdc_time = (time_t) my_creds.times.starttime;
1841         }
1842
1843         code = 0;
1844 done:
1845         krb5_free_cred_contents(ctx, &my_creds);
1846         return code;
1847 }
1848
1849 #ifdef SAMBA4_USES_HEIMDAL
1850 /*
1851   simulate a kinit, putting the tgt in the given credentials cache.
1852   Orignally by remus@snapserver.com
1853
1854   The impersonate_principal is the principal
1855
1856   The self_service, should be the local service (for S4U2Self if
1857   impersonate_principal is given).
1858
1859   The target_service defaults to the krbtgt if NULL, but could be
1860   kpasswd/realm or a remote service (for S4U2Proxy)
1861
1862 */
1863 krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
1864                                         krb5_ccache store_cc,
1865                                         krb5_principal init_principal,
1866                                         const char *init_password,
1867                                         krb5_principal impersonate_principal,
1868                                         const char *self_service,
1869                                         const char *target_service,
1870                                         krb5_get_init_creds_opt *krb_options,
1871                                         time_t *expire_time,
1872                                         time_t *kdc_time)
1873 {
1874         krb5_error_code code = 0;
1875         krb5_get_creds_opt options;
1876         krb5_principal store_principal;
1877         krb5_creds store_creds;
1878         krb5_creds *s4u2self_creds;
1879         Ticket s4u2self_ticket;
1880         size_t s4u2self_ticketlen;
1881         krb5_creds *s4u2proxy_creds;
1882         krb5_principal self_princ;
1883         bool s4u2proxy;
1884         krb5_principal target_princ;
1885         krb5_ccache tmp_cc;
1886         const char *self_realm;
1887         krb5_principal blacklist_principal = NULL;
1888         krb5_principal whitelist_principal = NULL;
1889
1890         code = krb5_get_init_creds_password(ctx, &store_creds,
1891                                             init_principal,
1892                                             init_password,
1893                                             NULL, NULL,
1894                                             0,
1895                                             NULL,
1896                                             krb_options);
1897         if (code != 0) {
1898                 return code;
1899         }
1900
1901         store_principal = init_principal;
1902
1903         /*
1904          * We are trying S4U2Self now:
1905          *
1906          * As we do not want to expose our TGT in the
1907          * krb5_ccache, which is also holds the impersonated creds.
1908          *
1909          * Some low level krb5/gssapi function might use the TGT
1910          * identity and let the client act as our machine account.
1911          *
1912          * We need to avoid that and use a temporary krb5_ccache
1913          * in order to pass our TGT to the krb5_get_creds() function.
1914          */
1915         code = krb5_cc_new_unique(ctx, NULL, NULL, &tmp_cc);
1916         if (code != 0) {
1917                 krb5_free_cred_contents(ctx, &store_creds);
1918                 return code;
1919         }
1920
1921         code = krb5_cc_initialize(ctx, tmp_cc, store_creds.client);
1922         if (code != 0) {
1923                 krb5_cc_destroy(ctx, tmp_cc);
1924                 krb5_free_cred_contents(ctx, &store_creds);
1925                 return code;
1926         }
1927
1928         code = krb5_cc_store_cred(ctx, tmp_cc, &store_creds);
1929         if (code != 0) {
1930                 krb5_free_cred_contents(ctx, &store_creds);
1931                 krb5_cc_destroy(ctx, tmp_cc);
1932                 return code;
1933         }
1934
1935         /*
1936          * we need to remember the client principal of our
1937          * TGT and make sure the KDC does not return this
1938          * in the impersonated tickets. This can happen
1939          * if the KDC does not support S4U2Self and S4U2Proxy.
1940          */
1941         blacklist_principal = store_creds.client;
1942         store_creds.client = NULL;
1943         krb5_free_cred_contents(ctx, &store_creds);
1944
1945         /*
1946          * Check if we also need S4U2Proxy or if S4U2Self is
1947          * enough in order to get a ticket for the target.
1948          */
1949         if (target_service == NULL) {
1950                 s4u2proxy = false;
1951         } else if (strcmp(target_service, self_service) == 0) {
1952                 s4u2proxy = false;
1953         } else {
1954                 s4u2proxy = true;
1955         }
1956
1957         /*
1958          * For S4U2Self we need our own service principal,
1959          * which belongs to our own realm (available on
1960          * our client principal).
1961          */
1962         self_realm = krb5_principal_get_realm(ctx, init_principal);
1963
1964         code = krb5_parse_name(ctx, self_service, &self_princ);
1965         if (code != 0) {
1966                 krb5_free_principal(ctx, blacklist_principal);
1967                 krb5_cc_destroy(ctx, tmp_cc);
1968                 return code;
1969         }
1970
1971         code = krb5_principal_set_realm(ctx, self_princ, self_realm);
1972         if (code != 0) {
1973                 krb5_free_principal(ctx, blacklist_principal);
1974                 krb5_free_principal(ctx, self_princ);
1975                 krb5_cc_destroy(ctx, tmp_cc);
1976                 return code;
1977         }
1978
1979         code = krb5_get_creds_opt_alloc(ctx, &options);
1980         if (code != 0) {
1981                 krb5_free_principal(ctx, blacklist_principal);
1982                 krb5_free_principal(ctx, self_princ);
1983                 krb5_cc_destroy(ctx, tmp_cc);
1984                 return code;
1985         }
1986
1987         if (s4u2proxy) {
1988                 /*
1989                  * If we want S4U2Proxy, we need the forwardable flag
1990                  * on the S4U2Self ticket.
1991                  */
1992                 krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
1993         }
1994
1995         code = krb5_get_creds_opt_set_impersonate(ctx, options,
1996                                                   impersonate_principal);
1997         if (code != 0) {
1998                 krb5_get_creds_opt_free(ctx, options);
1999                 krb5_free_principal(ctx, blacklist_principal);
2000                 krb5_free_principal(ctx, self_princ);
2001                 krb5_cc_destroy(ctx, tmp_cc);
2002                 return code;
2003         }
2004
2005         code = krb5_get_creds(ctx, options, tmp_cc,
2006                               self_princ, &s4u2self_creds);
2007         krb5_get_creds_opt_free(ctx, options);
2008         krb5_free_principal(ctx, self_princ);
2009         if (code != 0) {
2010                 krb5_free_principal(ctx, blacklist_principal);
2011                 krb5_cc_destroy(ctx, tmp_cc);
2012                 return code;
2013         }
2014
2015         if (!s4u2proxy) {
2016                 krb5_cc_destroy(ctx, tmp_cc);
2017
2018                 /*
2019                  * Now make sure we store the impersonated principal
2020                  * and creds instead of the TGT related stuff
2021                  * in the krb5_ccache of the caller.
2022                  */
2023                 code = krb5_copy_creds_contents(ctx, s4u2self_creds,
2024                                                 &store_creds);
2025                 krb5_free_creds(ctx, s4u2self_creds);
2026                 if (code != 0) {
2027                         return code;
2028                 }
2029
2030                 /*
2031                  * It's important to store the principal the KDC
2032                  * returned, as otherwise the caller would not find
2033                  * the S4U2Self ticket in the krb5_ccache lookup.
2034                  */
2035                 store_principal = store_creds.client;
2036                 goto store;
2037         }
2038
2039         /*
2040          * We are trying S4U2Proxy:
2041          *
2042          * We need the ticket from the S4U2Self step
2043          * and our TGT in order to get the delegated ticket.
2044          */
2045         code = decode_Ticket((const uint8_t *)s4u2self_creds->ticket.data,
2046                              s4u2self_creds->ticket.length,
2047                              &s4u2self_ticket,
2048                              &s4u2self_ticketlen);
2049         if (code != 0) {
2050                 krb5_free_creds(ctx, s4u2self_creds);
2051                 krb5_free_principal(ctx, blacklist_principal);
2052                 krb5_cc_destroy(ctx, tmp_cc);
2053                 return code;
2054         }
2055
2056         /*
2057          * we need to remember the client principal of the
2058          * S4U2Self stage and as it needs to match the one we
2059          * will get for the S4U2Proxy stage. We need this
2060          * in order to detect KDCs which does not support S4U2Proxy.
2061          */
2062         whitelist_principal = s4u2self_creds->client;
2063         s4u2self_creds->client = NULL;
2064         krb5_free_creds(ctx, s4u2self_creds);
2065
2066         /*
2067          * For S4U2Proxy we also got a target service principal,
2068          * which also belongs to our own realm (available on
2069          * our client principal).
2070          */
2071         code = krb5_parse_name(ctx, target_service, &target_princ);
2072         if (code != 0) {
2073                 free_Ticket(&s4u2self_ticket);
2074                 krb5_free_principal(ctx, whitelist_principal);
2075                 krb5_free_principal(ctx, blacklist_principal);
2076                 krb5_cc_destroy(ctx, tmp_cc);
2077                 return code;
2078         }
2079
2080         code = krb5_principal_set_realm(ctx, target_princ, self_realm);
2081         if (code != 0) {
2082                 free_Ticket(&s4u2self_ticket);
2083                 krb5_free_principal(ctx, target_princ);
2084                 krb5_free_principal(ctx, whitelist_principal);
2085                 krb5_free_principal(ctx, blacklist_principal);
2086                 krb5_cc_destroy(ctx, tmp_cc);
2087                 return code;
2088         }
2089
2090         code = krb5_get_creds_opt_alloc(ctx, &options);
2091         if (code != 0) {
2092                 free_Ticket(&s4u2self_ticket);
2093                 krb5_free_principal(ctx, target_princ);
2094                 krb5_free_principal(ctx, whitelist_principal);
2095                 krb5_free_principal(ctx, blacklist_principal);
2096                 krb5_cc_destroy(ctx, tmp_cc);
2097                 return code;
2098         }
2099
2100         krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
2101         krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_CONSTRAINED_DELEGATION);
2102
2103         code = krb5_get_creds_opt_set_ticket(ctx, options, &s4u2self_ticket);
2104         free_Ticket(&s4u2self_ticket);
2105         if (code != 0) {
2106                 krb5_get_creds_opt_free(ctx, options);
2107                 krb5_free_principal(ctx, target_princ);
2108                 krb5_free_principal(ctx, whitelist_principal);
2109                 krb5_free_principal(ctx, blacklist_principal);
2110                 krb5_cc_destroy(ctx, tmp_cc);
2111                 return code;
2112         }
2113
2114         code = krb5_get_creds(ctx, options, tmp_cc,
2115                               target_princ, &s4u2proxy_creds);
2116         krb5_get_creds_opt_free(ctx, options);
2117         krb5_free_principal(ctx, target_princ);
2118         krb5_cc_destroy(ctx, tmp_cc);
2119         if (code != 0) {
2120                 krb5_free_principal(ctx, whitelist_principal);
2121                 krb5_free_principal(ctx, blacklist_principal);
2122                 return code;
2123         }
2124
2125         /*
2126          * Now make sure we store the impersonated principal
2127          * and creds instead of the TGT related stuff
2128          * in the krb5_ccache of the caller.
2129          */
2130         code = krb5_copy_creds_contents(ctx, s4u2proxy_creds,
2131                                         &store_creds);
2132         krb5_free_creds(ctx, s4u2proxy_creds);
2133         if (code != 0) {
2134                 krb5_free_principal(ctx, whitelist_principal);
2135                 krb5_free_principal(ctx, blacklist_principal);
2136                 return code;
2137         }
2138
2139         /*
2140          * It's important to store the principal the KDC
2141          * returned, as otherwise the caller would not find
2142          * the S4U2Self ticket in the krb5_ccache lookup.
2143          */
2144         store_principal = store_creds.client;
2145
2146  store:
2147         if (blacklist_principal &&
2148             krb5_principal_compare(ctx, store_creds.client, blacklist_principal)) {
2149                 char *sp = NULL;
2150                 char *ip = NULL;
2151
2152                 code = krb5_unparse_name(ctx, blacklist_principal, &sp);
2153                 if (code != 0) {
2154                         sp = NULL;
2155                 }
2156                 code = krb5_unparse_name(ctx, impersonate_principal, &ip);
2157                 if (code != 0) {
2158                         ip = NULL;
2159                 }
2160                 DEBUG(1, ("kerberos_kinit_password_cc: "
2161                           "KDC returned self principal[%s] while impersonating [%s]\n",
2162                           sp?sp:"<no memory>",
2163                           ip?ip:"<no memory>"));
2164
2165                 SAFE_FREE(sp);
2166                 SAFE_FREE(ip);
2167
2168                 krb5_free_principal(ctx, whitelist_principal);
2169                 krb5_free_principal(ctx, blacklist_principal);
2170                 krb5_free_cred_contents(ctx, &store_creds);
2171                 return KRB5_FWD_BAD_PRINCIPAL;
2172         }
2173         if (blacklist_principal) {
2174                 krb5_free_principal(ctx, blacklist_principal);
2175         }
2176
2177         if (whitelist_principal &&
2178             !krb5_principal_compare(ctx, store_creds.client, whitelist_principal)) {
2179                 char *sp = NULL;
2180                 char *ep = NULL;
2181
2182                 code = krb5_unparse_name(ctx, store_creds.client, &sp);
2183                 if (code != 0) {
2184                         sp = NULL;
2185                 }
2186                 code = krb5_unparse_name(ctx, whitelist_principal, &ep);
2187                 if (code != 0) {
2188                         ep = NULL;
2189                 }
2190                 DEBUG(1, ("kerberos_kinit_password_cc: "
2191                           "KDC returned wrong principal[%s] we expected [%s]\n",
2192                           sp?sp:"<no memory>",
2193                           ep?ep:"<no memory>"));
2194
2195                 SAFE_FREE(sp);
2196                 SAFE_FREE(ep);
2197
2198                 krb5_free_principal(ctx, whitelist_principal);
2199                 krb5_free_cred_contents(ctx, &store_creds);
2200                 return KRB5_FWD_BAD_PRINCIPAL;
2201         }
2202         if (whitelist_principal) {
2203                 krb5_free_principal(ctx, whitelist_principal);
2204         }
2205
2206         code = krb5_cc_initialize(ctx, store_cc, store_principal);
2207         if (code != 0) {
2208                 krb5_free_cred_contents(ctx, &store_creds);
2209                 return code;
2210         }
2211
2212         code = krb5_cc_store_cred(ctx, store_cc, &store_creds);
2213         if (code != 0) {
2214                 krb5_free_cred_contents(ctx, &store_creds);
2215                 return code;
2216         }
2217
2218         if (expire_time) {
2219                 *expire_time = (time_t) store_creds.times.endtime;
2220         }
2221
2222         if (kdc_time) {
2223                 *kdc_time = (time_t) store_creds.times.starttime;
2224         }
2225
2226         krb5_free_cred_contents(ctx, &store_creds);
2227
2228         return 0;
2229 }
2230 #endif
2231
2232 #if !defined(HAVE_KRB5_MAKE_PRINCIPAL) && defined(HAVE_KRB5_BUILD_PRINCIPAL_ALLOC_VA)
2233 krb5_error_code smb_krb5_make_principal(krb5_context context,
2234                                         krb5_principal *principal,
2235                                         const char *_realm, ...)
2236 {
2237         krb5_error_code code;
2238         bool free_realm;
2239         char *realm;
2240         va_list ap;
2241
2242         if (_realm) {
2243                 realm = discard_const_p(char, _realm);
2244                 free_realm = false;
2245         } else {
2246                 code = krb5_get_default_realm(context, &realm);
2247                 if (code) {
2248                         return code;
2249                 }
2250                 free_realm = true;
2251         }
2252
2253         va_start(ap, _realm);
2254         code = krb5_build_principal_alloc_va(context, principal,
2255                                              strlen(realm), realm,
2256                                              ap);
2257         va_end(ap);
2258
2259         if (free_realm) {
2260                 krb5_free_default_realm(context, realm);
2261         }
2262
2263         return code;
2264 }
2265 #endif
2266
2267 #if !defined(HAVE_KRB5_CC_GET_LIFETIME) && defined(HAVE_KRB5_CC_RETRIEVE_CRED)
2268 /**
2269  * @brief Get the lifetime of the initial ticket in the cache.
2270  *
2271  * @param[in]  context  The kerberos context.
2272  *
2273  * @param[in]  id       The credential cache to get the ticket lifetime.
2274  *
2275  * @param[out] t        A pointer to a time value to store the lifetime.
2276  *
2277  * @return              0 on success, a krb5_error_code on error.
2278  */
2279 krb5_error_code smb_krb5_cc_get_lifetime(krb5_context context,
2280                                          krb5_ccache id,
2281                                          time_t *t)
2282 {
2283         krb5_cc_cursor cursor;
2284         krb5_error_code kerr;
2285         krb5_creds cred;
2286         krb5_timestamp now;
2287
2288         *t = 0;
2289
2290         kerr = krb5_timeofday(context, &now);
2291         if (kerr) {
2292                 return kerr;
2293         }
2294
2295         kerr = krb5_cc_start_seq_get(context, id, &cursor);
2296         if (kerr) {
2297                 return kerr;
2298         }
2299
2300         while ((kerr = krb5_cc_next_cred(context, id, &cursor, &cred)) == 0) {
2301 #ifndef HAVE_FLAGS_IN_KRB5_CREDS
2302                 if (cred.ticket_flags & TKT_FLG_INITIAL) {
2303 #else
2304                 if (cred.flags.b.initial) {
2305 #endif
2306                         if (now < cred.times.endtime) {
2307                                 *t = (time_t) (cred.times.endtime - now);
2308                         }
2309                         krb5_free_cred_contents(context, &cred);
2310                         break;
2311                 }
2312                 krb5_free_cred_contents(context, &cred);
2313         }
2314
2315         krb5_cc_end_seq_get(context, id, &cursor);
2316
2317         return kerr;
2318 }
2319 #endif /* HAVE_KRB5_CC_GET_LIFETIME */
2320
2321 #if !defined(HAVE_KRB5_FREE_CHECKSUM_CONTENTS) && defined(HAVE_FREE_CHECKSUM)
2322 void smb_krb5_free_checksum_contents(krb5_context ctx, krb5_checksum *cksum)
2323 {
2324         free_Checksum(cksum);
2325 }
2326 #endif
2327
2328 krb5_error_code smb_krb5_make_pac_checksum(TALLOC_CTX *mem_ctx,
2329                                            DATA_BLOB *pac_data,
2330                                            krb5_context context,
2331                                            const krb5_keyblock *keyblock,
2332                                            uint32_t *sig_type,
2333                                            DATA_BLOB *sig_blob)
2334 {
2335         krb5_error_code ret;
2336         krb5_checksum cksum;
2337 #if defined(HAVE_KRB5_CRYPTO_INIT) && defined(HAVE_KRB5_CREATE_CHECKSUM)
2338         krb5_crypto crypto;
2339
2340
2341         ret = krb5_crypto_init(context,
2342                                keyblock,
2343                                0,
2344                                &crypto);
2345         if (ret) {
2346                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
2347                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2348                 return ret;
2349         }
2350         ret = krb5_create_checksum(context,
2351                                    crypto,
2352                                    KRB5_KU_OTHER_CKSUM,
2353                                    0,
2354                                    pac_data->data,
2355                                    pac_data->length,
2356                                    &cksum);
2357         if (ret) {
2358                 DEBUG(2, ("PAC Verification failed: %s\n",
2359                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2360         }
2361
2362         krb5_crypto_destroy(context, crypto);
2363
2364         if (ret) {
2365                 return ret;
2366         }
2367
2368         *sig_type = cksum.cksumtype;
2369         *sig_blob = data_blob_talloc(mem_ctx,
2370                                         cksum.checksum.data,
2371                                         cksum.checksum.length);
2372 #elif defined(HAVE_KRB5_C_MAKE_CHECKSUM)
2373         krb5_data input;
2374
2375         input.data = (char *)pac_data->data;
2376         input.length = pac_data->length;
2377
2378         ret = krb5_c_make_checksum(context,
2379                                    0,
2380                                    keyblock,
2381                                    KRB5_KEYUSAGE_APP_DATA_CKSUM,
2382                                    &input,
2383                                    &cksum);
2384         if (ret) {
2385                 DEBUG(2, ("PAC Verification failed: %s\n",
2386                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2387                 return ret;
2388         }
2389
2390         *sig_type = cksum.checksum_type;
2391         *sig_blob = data_blob_talloc(mem_ctx,
2392                                         cksum.contents,
2393                                         cksum.length);
2394
2395 #else
2396 #error krb5_create_checksum or krb5_c_make_checksum not available
2397 #endif /* HAVE_KRB5_C_MAKE_CHECKSUM */
2398         smb_krb5_free_checksum_contents(context, &cksum);
2399
2400         return 0;
2401 }
2402
2403
2404 /*
2405  * smb_krb5_principal_get_realm
2406  *
2407  * @brief Get realm of a principal
2408  *
2409  * @param[in] context           The krb5_context
2410  * @param[in] principal         The principal
2411  * @return pointer to the realm
2412  *
2413  * Caller must free if the return value is not NULL.
2414  *
2415  */
2416
2417 char *smb_krb5_principal_get_realm(krb5_context context,
2418                                    krb5_const_principal principal)
2419 {
2420 #ifdef HAVE_KRB5_PRINCIPAL_GET_REALM /* Heimdal */
2421         return strdup(discard_const_p(char, krb5_principal_get_realm(context, principal)));
2422 #elif defined(krb5_princ_realm) /* MIT */
2423         krb5_data *realm;
2424         realm = discard_const_p(krb5_data,
2425                                 krb5_princ_realm(context, principal));
2426         return strndup(realm->data, realm->length);
2427 #else
2428 #error UNKNOWN_GET_PRINC_REALM_FUNCTIONS
2429 #endif
2430 }
2431
2432 /*
2433  * smb_krb5_principal_set_realm
2434  *
2435  * @brief Get realm of a principal
2436  *
2437  * @param[in] context           The krb5_context
2438  * @param[in] principal         The principal
2439  * @param[in] realm             The realm
2440  * @return                      0 on success, a krb5_error_code on error.
2441  *
2442  */
2443
2444 krb5_error_code smb_krb5_principal_set_realm(krb5_context context,
2445                                              krb5_principal principal,
2446                                              const char *realm)
2447 {
2448 #ifdef HAVE_KRB5_PRINCIPAL_SET_REALM /* Heimdal */
2449         return krb5_principal_set_realm(context, principal, realm);
2450 #elif defined(krb5_princ_realm) && defined(krb5_princ_set_realm) /* MIT */
2451         krb5_error_code ret;
2452         krb5_data data;
2453         krb5_data *old_data;
2454
2455         old_data = krb5_princ_realm(context, principal);
2456
2457         ret = smb_krb5_copy_data_contents(&data,
2458                                           realm,
2459                                           strlen(realm));
2460         if (ret) {
2461                 return ret;
2462         }
2463
2464         /* free realm before setting */
2465         free(old_data->data);
2466
2467         krb5_princ_set_realm(context, principal, &data);
2468
2469         return ret;
2470 #else
2471 #error UNKNOWN_PRINC_SET_REALM_FUNCTION
2472 #endif
2473 }
2474
2475
2476 /************************************************************************
2477  Routine to get the default realm from the kerberos credentials cache.
2478  Caller must free if the return value is not NULL.
2479 ************************************************************************/
2480
2481 static char *smb_krb5_get_default_realm_from_ccache(TALLOC_CTX *mem_ctx)
2482 {
2483         char *realm = NULL;
2484         krb5_context ctx = NULL;
2485         krb5_ccache cc = NULL;
2486         krb5_principal princ = NULL;
2487
2488         initialize_krb5_error_table();
2489         if (krb5_init_context(&ctx)) {
2490                 return NULL;
2491         }
2492
2493         DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2494                 "Trying to read krb5 cache: %s\n",
2495                 krb5_cc_default_name(ctx)));
2496         if (krb5_cc_default(ctx, &cc)) {
2497                 DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2498                         "failed to read default cache\n"));
2499                 goto out;
2500         }
2501         if (krb5_cc_get_principal(ctx, cc, &princ)) {
2502                 DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2503                         "failed to get default principal\n"));
2504                 goto out;
2505         }
2506
2507 #if defined(HAVE_KRB5_PRINCIPAL_GET_REALM)
2508         realm = talloc_strdup(mem_ctx, krb5_principal_get_realm(ctx, princ));
2509 #elif defined(HAVE_KRB5_PRINC_REALM)
2510         {
2511                 krb5_data *realm_data = krb5_princ_realm(ctx, princ);
2512                 realm = talloc_strndup(mem_ctx, realm_data->data, realm_data->length);
2513         }
2514 #endif
2515
2516   out:
2517
2518         if (ctx) {
2519                 if (princ) {
2520                         krb5_free_principal(ctx, princ);
2521                 }
2522                 if (cc) {
2523                         krb5_cc_close(ctx, cc);
2524                 }
2525                 krb5_free_context(ctx);
2526         }
2527
2528         return realm;
2529 }
2530
2531 /************************************************************************
2532  Routine to get the realm from a given DNS name.
2533 ************************************************************************/
2534
2535 static char *smb_krb5_get_realm_from_hostname(TALLOC_CTX *mem_ctx,
2536                                                 const char *hostname)
2537 {
2538 #if defined(HAVE_KRB5_REALM_TYPE)
2539         /* Heimdal. */
2540         krb5_realm *realm_list = NULL;
2541 #else
2542         /* MIT */
2543         char **realm_list = NULL;
2544 #endif
2545         char *realm = NULL;
2546         krb5_error_code kerr;
2547         krb5_context ctx = NULL;
2548
2549         initialize_krb5_error_table();
2550         if (krb5_init_context(&ctx)) {
2551                 return NULL;
2552         }
2553
2554         kerr = krb5_get_host_realm(ctx, hostname, &realm_list);
2555         if (kerr != 0) {
2556                 DEBUG(3,("kerberos_get_realm_from_hostname %s: "
2557                         "failed %s\n",
2558                         hostname ? hostname : "(NULL)",
2559                         error_message(kerr) ));
2560                 goto out;
2561         }
2562
2563         if (realm_list && realm_list[0]) {
2564                 realm = talloc_strdup(mem_ctx, realm_list[0]);
2565         }
2566
2567   out:
2568
2569         if (ctx) {
2570                 if (realm_list) {
2571                         krb5_free_host_realm(ctx, realm_list);
2572                         realm_list = NULL;
2573                 }
2574                 krb5_free_context(ctx);
2575                 ctx = NULL;
2576         }
2577         return realm;
2578 }
2579
2580 char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
2581                                                    const char *service,
2582                                                    const char *remote_name,
2583                                                    const char *default_realm)
2584 {
2585         char *realm = NULL;
2586         char *host = NULL;
2587         char *principal;
2588         host = strchr_m(remote_name, '.');
2589         if (host) {
2590                 /* DNS name. */
2591                 realm = smb_krb5_get_realm_from_hostname(talloc_tos(),
2592                                                          remote_name);
2593         } else {
2594                 /* NetBIOS name - use our realm. */
2595                 realm = smb_krb5_get_default_realm_from_ccache(talloc_tos());
2596         }
2597
2598         if (realm == NULL || *realm == '\0') {
2599                 realm = talloc_strdup(talloc_tos(), default_realm);
2600                 if (!realm) {
2601                         return NULL;
2602                 }
2603                 DEBUG(3,("kerberos_get_principal_from_service_hostname: "
2604                          "cannot get realm from, "
2605                          "desthost %s or default ccache. Using default "
2606                          "smb.conf realm %s\n",
2607                          remote_name,
2608                          realm));
2609         }
2610
2611         principal = talloc_asprintf(mem_ctx,
2612                                     "%s/%s@%s",
2613                                     service, remote_name,
2614                                     realm);
2615         TALLOC_FREE(realm);
2616         return principal;
2617 }
2618
2619 char *smb_get_krb5_error_message(krb5_context context,
2620                                  krb5_error_code code,
2621                                  TALLOC_CTX *mem_ctx)
2622 {
2623         char *ret;
2624
2625 #if defined(HAVE_KRB5_GET_ERROR_MESSAGE) && defined(HAVE_KRB5_FREE_ERROR_MESSAGE)
2626         const char *context_error = krb5_get_error_message(context, code);
2627         if (context_error) {
2628                 ret = talloc_asprintf(mem_ctx, "%s: %s",
2629                                         error_message(code), context_error);
2630                 krb5_free_error_message(context, context_error);
2631                 return ret;
2632         }
2633 #endif
2634         ret = talloc_strdup(mem_ctx, error_message(code));
2635         return ret;
2636 }
2637
2638
2639 /**
2640 * @brief Return the kerberos library setting for "libdefaults:allow_weak_crypto"
2641 *
2642 * @param context        The krb5_context
2643 *
2644 * @return krb5_boolean
2645 *
2646 * Function returns true if weak crypto is allowd, false if not
2647 */
2648
2649 krb5_boolean smb_krb5_get_allowed_weak_crypto(krb5_context context)
2650 #if defined(HAVE_KRB5_CONFIG_GET_BOOL_DEFAULT)
2651 {
2652         return krb5_config_get_bool_default(context,
2653                                             NULL,
2654                                             FALSE,
2655                                             "libdefaults",
2656                                             "allow_weak_crypto",
2657                                             NULL);
2658 }
2659 #elif defined(HAVE_PROFILE_H) && defined(HAVE_KRB5_GET_PROFILE)
2660 {
2661 #include <profile.h>
2662         krb5_error_code ret;
2663         krb5_boolean ret_default = false;
2664         profile_t profile;
2665         int ret_profile;
2666
2667         ret = krb5_get_profile(context,
2668                                &profile);
2669         if (ret) {
2670                 return ret_default;
2671         }
2672
2673         ret = profile_get_boolean(profile,
2674                                   "libdefaults",
2675                                   "allow_weak_crypto",
2676                                   NULL, /* subsubname */
2677                                   ret_default, /* def_val */
2678                                   &ret_profile /* *ret_default */);
2679         if (ret) {
2680                 return ret_default;
2681         }
2682
2683         profile_release(profile);
2684
2685         return ret_profile;
2686 }
2687 #else
2688 #error UNKNOWN_KRB5_CONFIG_ROUTINES
2689 #endif
2690
2691 /**
2692 * @brief Return the type of a krb5_principal
2693 *
2694 * @param context        The krb5_context
2695 * @param principal      The const krb5_principal
2696 *
2697 * @return integer type of the principal
2698 */
2699 int smb_krb5_principal_get_type(krb5_context context,
2700                                 krb5_const_principal principal)
2701 {
2702 #ifdef HAVE_KRB5_PRINCIPAL_GET_TYPE /* Heimdal */
2703         return krb5_principal_get_type(context, principal);
2704 #elif defined(krb5_princ_type) /* MIT */
2705         return krb5_princ_type(context, principal);
2706 #else
2707 #error  UNKNOWN_PRINC_GET_TYPE_FUNCTION
2708 #endif
2709 }
2710
2711 /**
2712 * @brief Set the type of a krb5_principal
2713 *
2714 * @param context        The krb5_context
2715 * @param principal      The const krb5_principal
2716 * @param type           The principal type
2717 *
2718 */
2719 void smb_krb5_principal_set_type(krb5_context context,
2720                                  krb5_principal principal,
2721                                  int type)
2722 {
2723 #ifdef HAVE_KRB5_PRINCIPAL_SET_TYPE /* Heimdal */
2724         krb5_principal_set_type(context, principal, type);
2725 #elif defined(krb5_princ_type) /* MIT */
2726         krb5_princ_type(context, principal) = type;
2727 #else
2728 #error  UNKNOWN_PRINC_SET_TYPE_FUNCTION
2729 #endif
2730 }
2731
2732 /**
2733 * @brief Generate a krb5 warning, forwarding to com_err
2734 *
2735 * @param context        The krb5_context
2736 * @param fmt            The message format
2737 * @param ...            The message arguments
2738 *
2739 * @return
2740 */
2741 #if !defined(HAVE_KRB5_WARNX)
2742 krb5_error_code krb5_warnx(krb5_context context, const char *fmt, ...)
2743 {
2744         va_list args;
2745
2746         va_start(args, fmt);
2747         com_err_va("kdb_samba", errno, fmt, args);
2748         va_end(args);
2749
2750         return 0;
2751 }
2752 #endif
2753
2754 krb5_error_code smb_krb5_cc_copy_creds(krb5_context context,
2755                                        krb5_ccache incc, krb5_ccache outcc)
2756 {
2757 #ifdef HAVE_KRB5_CC_COPY_CACHE /* Heimdal */
2758         return krb5_cc_copy_cache(context, incc, outcc);
2759 #elif defined(HAVE_KRB5_CC_COPY_CREDS)
2760         return krb5_cc_copy_creds(context, incc, outcc);
2761 #else
2762 #error UNKNOWN_KRB5_CC_COPY_CACHE_OR_CREDS_FUNCTION
2763 #endif
2764 }
2765
2766 /**********************************************************
2767  * ADS KRB5 CALLS
2768  **********************************************************/
2769
2770 static bool ads_cleanup_expired_creds(krb5_context context,
2771                                       krb5_ccache  ccache,
2772                                       krb5_creds  *credsp)
2773 {
2774         krb5_error_code retval;
2775         const char *cc_type = krb5_cc_get_type(context, ccache);
2776
2777         DEBUG(3, ("ads_cleanup_expired_creds: Ticket in ccache[%s:%s] expiration %s\n",
2778                   cc_type, krb5_cc_get_name(context, ccache),
2779                   http_timestring(talloc_tos(), credsp->times.endtime)));
2780
2781         /* we will probably need new tickets if the current ones
2782            will expire within 10 seconds.
2783         */
2784         if (credsp->times.endtime >= (time(NULL) + 10))
2785                 return false;
2786
2787         /* heimdal won't remove creds from a file ccache, and
2788            perhaps we shouldn't anyway, since internally we
2789            use memory ccaches, and a FILE one probably means that
2790            we're using creds obtained outside of our exectuable
2791         */
2792         if (strequal(cc_type, "FILE")) {
2793                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a %s ccache\n", cc_type));
2794                 return false;
2795         }
2796
2797         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
2798         if (retval) {
2799                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
2800                           error_message(retval)));
2801                 /* If we have an error in this, we want to display it,
2802                    but continue as though we deleted it */
2803         }
2804         return true;
2805 }
2806
2807 /* Allocate and setup the auth context into the state we need. */
2808
2809 static krb5_error_code ads_setup_auth_context(krb5_context context,
2810                                               krb5_auth_context *auth_context)
2811 {
2812         krb5_error_code retval;
2813
2814         retval = krb5_auth_con_init(context, auth_context );
2815         if (retval) {
2816                 DEBUG(1,("krb5_auth_con_init failed (%s)\n",
2817                         error_message(retval)));
2818                 return retval;
2819         }
2820
2821         /* Ensure this is an addressless ticket. */
2822         retval = krb5_auth_con_setaddrs(context, *auth_context, NULL, NULL);
2823         if (retval) {
2824                 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n",
2825                         error_message(retval)));
2826         }
2827
2828         return retval;
2829 }
2830
2831 #if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE)
2832 static krb5_error_code ads_create_gss_checksum(krb5_data *in_data, /* [inout] */
2833                                                uint32_t gss_flags)
2834 {
2835         unsigned int orig_length = in_data->length;
2836         unsigned int base_cksum_size = GSSAPI_CHECKSUM_SIZE;
2837         char *gss_cksum = NULL;
2838
2839         if (orig_length) {
2840                 /* Extra length field for delgated ticket. */
2841                 base_cksum_size += 4;
2842         }
2843
2844         if ((unsigned int)base_cksum_size + orig_length <
2845                         (unsigned int)base_cksum_size) {
2846                 return EINVAL;
2847         }
2848
2849         gss_cksum = (char *)SMB_MALLOC(base_cksum_size + orig_length);
2850         if (gss_cksum == NULL) {
2851                 return ENOMEM;
2852         }
2853
2854         memset(gss_cksum, '\0', base_cksum_size + orig_length);
2855         SIVAL(gss_cksum, 0, GSSAPI_BNDLENGTH);
2856
2857         /*
2858          * GSS_C_NO_CHANNEL_BINDINGS means 16 zero bytes.
2859          * This matches the behavior of heimdal and mit.
2860          *
2861          * And it is needed to work against some closed source
2862          * SMB servers.
2863          *
2864          * See bug #7883
2865          */
2866         memset(&gss_cksum[4], 0x00, GSSAPI_BNDLENGTH);
2867
2868         SIVAL(gss_cksum, 20, gss_flags);
2869
2870         if (orig_length) {
2871                 SSVAL(gss_cksum, 24, 1); /* The Delegation Option identifier */
2872                 SSVAL(gss_cksum, 26, orig_length);
2873                 /* Copy the kerberos KRB_CRED data */
2874                 memcpy(gss_cksum + 28, in_data->data, orig_length);
2875                 free(in_data->data);
2876                 in_data->data = NULL;
2877                 in_data->length = 0;
2878         }
2879         in_data->data = gss_cksum;
2880         in_data->length = base_cksum_size + orig_length;
2881         return 0;
2882 }
2883 #endif
2884
2885 /*
2886  * We can't use krb5_mk_req because w2k wants the service to be in a particular
2887  * format.
2888  */
2889 static krb5_error_code ads_krb5_mk_req(krb5_context context,
2890                                        krb5_auth_context *auth_context,
2891                                        const krb5_flags ap_req_options,
2892                                        const char *principal,
2893                                        krb5_ccache ccache,
2894                                        krb5_data *outbuf,
2895                                        time_t *expire_time,
2896                                        const char *impersonate_princ_s)
2897 {
2898         krb5_error_code retval;
2899         krb5_principal server;
2900         krb5_principal impersonate_princ = NULL;
2901         krb5_creds *credsp;
2902         krb5_creds creds;
2903         krb5_data in_data;
2904         bool creds_ready = false;
2905         int i = 0, maxtries = 3;
2906         bool ok;
2907
2908         ZERO_STRUCT(in_data);
2909
2910         retval = smb_krb5_parse_name(context, principal, &server);
2911         if (retval != 0) {
2912                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
2913                 return retval;
2914         }
2915
2916         if (impersonate_princ_s) {
2917                 retval = smb_krb5_parse_name(context, impersonate_princ_s,
2918                                              &impersonate_princ);
2919                 if (retval) {
2920                         DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", impersonate_princ_s));
2921                         goto cleanup_princ;
2922                 }
2923         }
2924
2925         /* obtain ticket & session key */
2926         ZERO_STRUCT(creds);
2927         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
2928                 DEBUG(1,("ads_krb5_mk_req: krb5_copy_principal failed (%s)\n",
2929                          error_message(retval)));
2930                 goto cleanup_princ;
2931         }
2932
2933         retval = krb5_cc_get_principal(context, ccache, &creds.client);
2934         if (retval != 0) {
2935                 /* This can commonly fail on smbd startup with no ticket in the cache.
2936                  * Report at higher level than 1. */
2937                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
2938                          error_message(retval)));
2939                 goto cleanup_creds;
2940         }
2941
2942         while (!creds_ready && (i < maxtries)) {
2943
2944                 retval = smb_krb5_get_credentials(context,
2945                                                   ccache,
2946                                                   creds.client,
2947                                                   creds.server,
2948                                                   impersonate_princ,
2949                                                   &credsp);
2950                 if (retval != 0) {
2951                         DBG_WARNING("smb_krb5_get_credentials failed for %s "
2952                                     "(%s)\n",
2953                                     principal,
2954                                     error_message(retval));
2955                         goto cleanup_creds;
2956                 }
2957
2958                 /* cope with ticket being in the future due to clock skew */
2959                 if ((unsigned)credsp->times.starttime > time(NULL)) {
2960                         time_t t = time(NULL);
2961                         int time_offset =(int)((unsigned)credsp->times.starttime-t);
2962                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
2963                         krb5_set_real_time(context, t + time_offset + 1, 0);
2964                 }
2965
2966                 ok = ads_cleanup_expired_creds(context, ccache, credsp);
2967                 if (!ok) {
2968                         creds_ready = true;
2969                 }
2970
2971                 i++;
2972         }
2973
2974         DBG_DEBUG("Ticket (%s) in ccache (%s:%s) is valid until: (%s - %u)\n",
2975                   principal,
2976                   krb5_cc_get_type(context, ccache),
2977                   krb5_cc_get_name(context, ccache),
2978                   http_timestring(talloc_tos(),
2979                                   (unsigned)credsp->times.endtime),
2980                   (unsigned)credsp->times.endtime);
2981
2982         if (expire_time) {
2983                 *expire_time = (time_t)credsp->times.endtime;
2984         }
2985
2986         /* Allocate the auth_context. */
2987         retval = ads_setup_auth_context(context, auth_context);
2988         if (retval != 0) {
2989                 DBG_WARNING("ads_setup_auth_context failed (%s)\n",
2990                             error_message(retval));
2991                 goto cleanup_creds;
2992         }
2993
2994 #if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE)
2995         {
2996                 uint32_t gss_flags = 0;
2997
2998                 if (credsp->ticket_flags & TKT_FLG_OK_AS_DELEGATE) {
2999                         /*
3000                          * Fetch a forwarded TGT from the KDC so that we can
3001                          * hand off a 2nd ticket as part of the kerberos
3002                          * exchange.
3003                          */
3004
3005                         DBG_INFO("Server marked as OK to delegate to, building "
3006                                  "forwardable TGT\n");
3007
3008                         retval = krb5_auth_con_setuseruserkey(context,
3009                                         *auth_context,
3010                                         &credsp->keyblock );
3011                         if (retval != 0) {
3012                                 DBG_WARNING("krb5_auth_con_setuseruserkey "
3013                                             "failed (%s)\n",
3014                                             error_message(retval)));
3015                                 goto cleanup_creds;
3016                         }
3017
3018                         /* Must use a subkey for forwarded tickets. */
3019                         retval = krb5_auth_con_setflags(context,
3020                                                         *auth_context,
3021                                                         KRB5_AUTH_CONTEXT_USE_SUBKEY);
3022                         if (retval != 0) {
3023                                 DBG_WARNING("krb5_auth_con_setflags failed (%s)\n",
3024                                             error_message(retval)));
3025                                 goto cleanup_creds;
3026                         }
3027
3028                         retval = krb5_fwd_tgt_creds(context,/* Krb5 context [in] */
3029                                 *auth_context,  /* Authentication context [in] */
3030                                 discard_const_p(char, KRB5_TGS_NAME),  /* Ticket service name ("krbtgt") [in] */
3031                                 credsp->client, /* Client principal for the tgt [in] */
3032                                 credsp->server, /* Server principal for the tgt [in] */
3033                                 ccache,         /* Credential cache to use for storage [in] */
3034                                 1,              /* Turn on for "Forwardable ticket" [in] */
3035                                 &in_data );     /* Resulting response [out] */
3036
3037                         if (retval) {
3038                                 DBG_INFO("krb5_fwd_tgt_creds failed (%s)\n",
3039                                          error_message(retval));
3040
3041                                 /*
3042                                  * This is not fatal. Delete the *auth_context and continue
3043                                  * with krb5_mk_req_extended to get a non-forwardable ticket.
3044                                  */
3045
3046                                 if (in_data.data) {
3047                                         free( in_data.data );
3048                                         in_data.data = NULL;
3049                                         in_data.length = 0;
3050                                 }
3051                                 krb5_auth_con_free(context, *auth_context);
3052                                 *auth_context = NULL;
3053                                 retval = ads_setup_auth_context(context, auth_context);
3054                                 if (retval != 0) {
3055                                         DBG_WARNING("ads_setup_auth_context failed (%s)\n",
3056                                                     error_message(retval)));
3057                                         goto cleanup_creds;
3058                                 }
3059                         } else {
3060                                 /* We got a delegated ticket. */
3061                                 gss_flags |= GSS_C_DELEG_FLAG;
3062                         }
3063                 }
3064
3065                 /* Frees and reallocates in_data into a GSS checksum blob. */
3066                 retval = ads_create_gss_checksum(&in_data, gss_flags);
3067                 if (retval != 0) {
3068                         goto cleanup_data;
3069                 }
3070
3071                 /* We always want GSS-checksum types. */
3072                 retval = krb5_auth_con_set_req_cksumtype(context, *auth_context, GSSAPI_CHECKSUM );
3073                 if (retval != 0) {
3074                         DEBUG(1,("krb5_auth_con_set_req_cksumtype failed (%s)\n",
3075                                 error_message(retval)));
3076                         goto cleanup_data;
3077                 }
3078         }
3079 #endif
3080
3081         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
3082                                       &in_data, credsp, outbuf);
3083         if (retval != 0) {
3084                 DBG_WARNING("krb5_mk_req_extended failed (%s)\n",
3085                             error_message(retval));
3086         }
3087
3088 #if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE)
3089 cleanup_data:
3090 #endif
3091
3092         if (in_data.data) {
3093                 free( in_data.data );
3094                 in_data.length = 0;
3095         }
3096
3097         krb5_free_creds(context, credsp);
3098
3099 cleanup_creds:
3100         krb5_free_cred_contents(context, &creds);
3101
3102 cleanup_princ:
3103         krb5_free_principal(context, server);
3104         if (impersonate_princ) {
3105                 krb5_free_principal(context, impersonate_princ);
3106         }
3107
3108         return retval;
3109 }
3110
3111 /*
3112   get a kerberos5 ticket for the given service
3113 */
3114 int ads_krb5_cli_get_ticket(TALLOC_CTX *mem_ctx,
3115                             const char *principal,
3116                             time_t time_offset,
3117                             DATA_BLOB *ticket,
3118                             DATA_BLOB *session_key_krb5,
3119                             uint32_t extra_ap_opts, const char *ccname,
3120                             time_t *tgs_expire,
3121                             const char *impersonate_princ_s)
3122 {
3123         krb5_error_code retval;
3124         krb5_data packet;
3125         krb5_context context = NULL;
3126         krb5_ccache ccdef = NULL;
3127         krb5_auth_context auth_context = NULL;
3128         krb5_enctype enc_types[] = {
3129 #ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
3130                 ENCTYPE_AES256_CTS_HMAC_SHA1_96,
3131 #endif
3132 #ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
3133                 ENCTYPE_AES128_CTS_HMAC_SHA1_96,
3134 #endif
3135                 ENCTYPE_ARCFOUR_HMAC,
3136                 ENCTYPE_DES_CBC_MD5,
3137                 ENCTYPE_DES_CBC_CRC,
3138                 ENCTYPE_NULL};
3139         bool ok;
3140
3141         initialize_krb5_error_table();
3142         retval = krb5_init_context(&context);
3143         if (retval != 0) {
3144                 DBG_WARNING("krb5_init_context failed (%s)\n",
3145                             error_message(retval));
3146                 goto failed;
3147         }
3148
3149         if (time_offset != 0) {
3150                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
3151         }
3152
3153         retval = krb5_cc_resolve(context,
3154                                  ccname ? ccname : krb5_cc_default_name(context),
3155                                  &ccdef);
3156         if (retval != 0) {
3157                 DBG_WARNING("krb5_cc_default failed (%s)\n",
3158                             error_message(retval));
3159                 goto failed;
3160         }
3161
3162         retval = krb5_set_default_tgs_ktypes(context, enc_types);
3163         if (retval != 0) {
3164                 DBG_WARNING("krb5_set_default_tgs_ktypes failed (%s)\n",
3165                             error_message(retval));
3166                 goto failed;
3167         }
3168
3169         retval = ads_krb5_mk_req(context,
3170                                  &auth_context,
3171                                  AP_OPTS_USE_SUBKEY | (krb5_flags)extra_ap_opts,
3172                                  principal,
3173                                  ccdef,
3174                                  &packet,
3175                                  tgs_expire,
3176                                  impersonate_princ_s);
3177         if (retval != 0) {
3178                 goto failed;
3179         }
3180
3181         ok = smb_krb5_get_smb_session_key(mem_ctx,
3182                                           context,
3183                                           auth_context,
3184                                           session_key_krb5,
3185                                           false);
3186         if (!ok) {
3187                 retval = ENOMEM;
3188                 goto failed;
3189         }
3190
3191         *ticket = data_blob_talloc(mem_ctx, packet.data, packet.length);
3192
3193         smb_krb5_free_data_contents(context, &packet);
3194
3195 failed:
3196
3197         if (context) {
3198                 if (ccdef) {
3199                         krb5_cc_close(context, ccdef);
3200                 }
3201                 if (auth_context) {
3202                         krb5_auth_con_free(context, auth_context);
3203                 }
3204                 krb5_free_context(context);
3205         }
3206
3207         return retval;
3208 }
3209
3210 #else /* HAVE_KRB5 */
3211 /* This saves a few linking headaches */
3212 int ads_krb5_cli_get_ticket(TALLOC_CTX *mem_ctx,
3213                             const char *principal,
3214                             time_t time_offset,
3215                             DATA_BLOB *ticket,
3216                             DATA_BLOB *session_key_krb5,
3217                             uint32_t extra_ap_opts, const char *ccname,
3218                             time_t *tgs_expire,
3219                             const char *impersonate_princ_s)
3220 {
3221          DEBUG(0,("NO KERBEROS SUPPORT\n"));
3222          return 1;
3223 }
3224
3225 #endif /* HAVE_KRB5 */