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 #elif defined(HAVE_KRB5_INIT_KEYBLOCK)
1685         krb5_error_code code;
1686
1687         code = krb5_init_keyblock(context,
1688                                   enctype,
1689                                   length,
1690                                   key);
1691         if (code != 0) {
1692                 return code;
1693         }
1694
1695         if (length != 0) {
1696                 memcpy(KRB5_KEY_DATA(key), data, length);
1697         }
1698
1699         return 0;
1700 #else
1701         memset(key, 0, sizeof(krb5_keyblock));
1702         KRB5_KEY_DATA(key) = SMB_MALLOC(length);
1703         if (NULL == KRB5_KEY_DATA(key)) {
1704                 return ENOMEM;
1705         }
1706         memcpy(KRB5_KEY_DATA(key), data, length);
1707         KRB5_KEY_LENGTH(key) = length;
1708         KRB5_KEY_TYPE(key) = enctype;
1709         return 0;
1710 #endif
1711 }
1712
1713 /*
1714   simulate a kinit, putting the tgt in the given credentials cache.
1715   Orignally by remus@snapserver.com
1716
1717   This version is built to use a keyblock, rather than needing the
1718   original password.
1719
1720   The impersonate_principal is the principal if NULL, or the principal
1721   to impersonate
1722
1723   The target_service defaults to the krbtgt if NULL, but could be
1724    kpasswd/realm or the local service (if we are doing s4u2self)
1725 */
1726 krb5_error_code smb_krb5_kinit_keyblock_ccache(krb5_context ctx,
1727                                                krb5_ccache cc,
1728                                                krb5_principal principal,
1729                                                krb5_keyblock *keyblock,
1730                                                const char *target_service,
1731                                                krb5_get_init_creds_opt *krb_options,
1732                                                time_t *expire_time,
1733                                                time_t *kdc_time)
1734 {
1735         krb5_error_code code = 0;
1736         krb5_creds my_creds;
1737
1738 #if defined(HAVE_KRB5_GET_INIT_CREDS_KEYBLOCK)
1739         code = krb5_get_init_creds_keyblock(ctx, &my_creds, principal,
1740                                             keyblock, 0, target_service,
1741                                             krb_options);
1742 #elif defined(HAVE_KRB5_GET_INIT_CREDS_KEYTAB)
1743 {
1744 #define SMB_CREDS_KEYTAB "MEMORY:tmp_smb_creds_XXXXXX"
1745         char tmp_name[sizeof(SMB_CREDS_KEYTAB)];
1746         krb5_keytab_entry entry;
1747         krb5_keytab keytab;
1748         mode_t mask;
1749
1750         memset(&entry, 0, sizeof(entry));
1751         entry.principal = principal;
1752         *(KRB5_KT_KEY(&entry)) = *keyblock;
1753
1754         memcpy(tmp_name, SMB_CREDS_KEYTAB, sizeof(SMB_CREDS_KEYTAB));
1755         mask = umask(S_IRWXO | S_IRWXG);
1756         mktemp(tmp_name);
1757         umask(mask);
1758         if (tmp_name[0] == 0) {
1759                 return KRB5_KT_BADNAME;
1760         }
1761         code = krb5_kt_resolve(ctx, tmp_name, &keytab);
1762         if (code) {
1763                 return code;
1764         }
1765
1766         code = krb5_kt_add_entry(ctx, keytab, &entry);
1767         if (code) {
1768                 (void)krb5_kt_close(ctx, keytab);
1769                 goto done;
1770         }
1771
1772         code = krb5_get_init_creds_keytab(ctx, &my_creds, principal,
1773                                           keytab, 0, target_service,
1774                                           krb_options);
1775         (void)krb5_kt_close(ctx, keytab);
1776 }
1777 #else
1778 #error krb5_get_init_creds_keyblock not available!
1779 #endif
1780         if (code) {
1781                 return code;
1782         }
1783
1784 #ifndef SAMBA4_USES_HEIMDAL /* MIT */
1785         /*
1786          * We need to store the principal as returned from the KDC to the
1787          * credentials cache. If we don't do that the KRB5 library is not
1788          * able to find the tickets it is looking for
1789          */
1790         principal = my_creds.client;
1791 #endif
1792         code = krb5_cc_initialize(ctx, cc, principal);
1793         if (code) {
1794                 goto done;
1795         }
1796
1797         code = krb5_cc_store_cred(ctx, cc, &my_creds);
1798         if (code) {
1799                 goto done;
1800         }
1801
1802         if (expire_time) {
1803                 *expire_time = (time_t) my_creds.times.endtime;
1804         }
1805
1806         if (kdc_time) {
1807                 *kdc_time = (time_t) my_creds.times.starttime;
1808         }
1809
1810         code = 0;
1811 done:
1812         krb5_free_cred_contents(ctx, &my_creds);
1813         return code;
1814 }
1815
1816 krb5_error_code kerberos_kinit_password_cc(krb5_context ctx, krb5_ccache cc,
1817                                            krb5_principal principal,
1818                                            const char *password,
1819                                            const char *target_service,
1820                                            krb5_get_init_creds_opt *krb_options,
1821                                            time_t *expire_time,
1822                                            time_t *kdc_time)
1823 {
1824         krb5_error_code code = 0;
1825         krb5_creds my_creds;
1826
1827         code = krb5_get_init_creds_password(ctx, &my_creds, principal,
1828                                             password, NULL, NULL, 0,
1829                                             target_service, krb_options);
1830         if (code) {
1831                 return code;
1832         }
1833
1834 #ifndef SAMBA4_USES_HEIMDAL /* MIT */
1835         /*
1836          * We need to store the principal as returned from the KDC to the
1837          * credentials cache. If we don't do that the KRB5 library is not
1838          * able to find the tickets it is looking for
1839          */
1840         principal = my_creds.client;
1841 #endif
1842         code = krb5_cc_initialize(ctx, cc, principal);
1843         if (code) {
1844                 goto done;
1845         }
1846
1847         code = krb5_cc_store_cred(ctx, cc, &my_creds);
1848         if (code) {
1849                 goto done;
1850         }
1851
1852         if (expire_time) {
1853                 *expire_time = (time_t) my_creds.times.endtime;
1854         }
1855
1856         if (kdc_time) {
1857                 *kdc_time = (time_t) my_creds.times.starttime;
1858         }
1859
1860         code = 0;
1861 done:
1862         krb5_free_cred_contents(ctx, &my_creds);
1863         return code;
1864 }
1865
1866 #ifdef SAMBA4_USES_HEIMDAL
1867 /*
1868   simulate a kinit, putting the tgt in the given credentials cache.
1869   Orignally by remus@snapserver.com
1870
1871   The impersonate_principal is the principal
1872
1873   The self_service, should be the local service (for S4U2Self if
1874   impersonate_principal is given).
1875
1876   The target_service defaults to the krbtgt if NULL, but could be
1877   kpasswd/realm or a remote service (for S4U2Proxy)
1878
1879 */
1880 krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
1881                                         krb5_ccache store_cc,
1882                                         krb5_principal init_principal,
1883                                         const char *init_password,
1884                                         krb5_principal impersonate_principal,
1885                                         const char *self_service,
1886                                         const char *target_service,
1887                                         krb5_get_init_creds_opt *krb_options,
1888                                         time_t *expire_time,
1889                                         time_t *kdc_time)
1890 {
1891         krb5_error_code code = 0;
1892         krb5_get_creds_opt options;
1893         krb5_principal store_principal;
1894         krb5_creds store_creds;
1895         krb5_creds *s4u2self_creds;
1896         Ticket s4u2self_ticket;
1897         size_t s4u2self_ticketlen;
1898         krb5_creds *s4u2proxy_creds;
1899         krb5_principal self_princ;
1900         bool s4u2proxy;
1901         krb5_principal target_princ;
1902         krb5_ccache tmp_cc;
1903         const char *self_realm;
1904         krb5_principal blacklist_principal = NULL;
1905         krb5_principal whitelist_principal = NULL;
1906
1907         code = krb5_get_init_creds_password(ctx, &store_creds,
1908                                             init_principal,
1909                                             init_password,
1910                                             NULL, NULL,
1911                                             0,
1912                                             NULL,
1913                                             krb_options);
1914         if (code != 0) {
1915                 return code;
1916         }
1917
1918         store_principal = init_principal;
1919
1920         /*
1921          * We are trying S4U2Self now:
1922          *
1923          * As we do not want to expose our TGT in the
1924          * krb5_ccache, which is also holds the impersonated creds.
1925          *
1926          * Some low level krb5/gssapi function might use the TGT
1927          * identity and let the client act as our machine account.
1928          *
1929          * We need to avoid that and use a temporary krb5_ccache
1930          * in order to pass our TGT to the krb5_get_creds() function.
1931          */
1932         code = krb5_cc_new_unique(ctx, NULL, NULL, &tmp_cc);
1933         if (code != 0) {
1934                 krb5_free_cred_contents(ctx, &store_creds);
1935                 return code;
1936         }
1937
1938         code = krb5_cc_initialize(ctx, tmp_cc, store_creds.client);
1939         if (code != 0) {
1940                 krb5_cc_destroy(ctx, tmp_cc);
1941                 krb5_free_cred_contents(ctx, &store_creds);
1942                 return code;
1943         }
1944
1945         code = krb5_cc_store_cred(ctx, tmp_cc, &store_creds);
1946         if (code != 0) {
1947                 krb5_free_cred_contents(ctx, &store_creds);
1948                 krb5_cc_destroy(ctx, tmp_cc);
1949                 return code;
1950         }
1951
1952         /*
1953          * we need to remember the client principal of our
1954          * TGT and make sure the KDC does not return this
1955          * in the impersonated tickets. This can happen
1956          * if the KDC does not support S4U2Self and S4U2Proxy.
1957          */
1958         blacklist_principal = store_creds.client;
1959         store_creds.client = NULL;
1960         krb5_free_cred_contents(ctx, &store_creds);
1961
1962         /*
1963          * Check if we also need S4U2Proxy or if S4U2Self is
1964          * enough in order to get a ticket for the target.
1965          */
1966         if (target_service == NULL) {
1967                 s4u2proxy = false;
1968         } else if (strcmp(target_service, self_service) == 0) {
1969                 s4u2proxy = false;
1970         } else {
1971                 s4u2proxy = true;
1972         }
1973
1974         /*
1975          * For S4U2Self we need our own service principal,
1976          * which belongs to our own realm (available on
1977          * our client principal).
1978          */
1979         self_realm = krb5_principal_get_realm(ctx, init_principal);
1980
1981         code = krb5_parse_name(ctx, self_service, &self_princ);
1982         if (code != 0) {
1983                 krb5_free_principal(ctx, blacklist_principal);
1984                 krb5_cc_destroy(ctx, tmp_cc);
1985                 return code;
1986         }
1987
1988         code = krb5_principal_set_realm(ctx, self_princ, self_realm);
1989         if (code != 0) {
1990                 krb5_free_principal(ctx, blacklist_principal);
1991                 krb5_free_principal(ctx, self_princ);
1992                 krb5_cc_destroy(ctx, tmp_cc);
1993                 return code;
1994         }
1995
1996         code = krb5_get_creds_opt_alloc(ctx, &options);
1997         if (code != 0) {
1998                 krb5_free_principal(ctx, blacklist_principal);
1999                 krb5_free_principal(ctx, self_princ);
2000                 krb5_cc_destroy(ctx, tmp_cc);
2001                 return code;
2002         }
2003
2004         if (s4u2proxy) {
2005                 /*
2006                  * If we want S4U2Proxy, we need the forwardable flag
2007                  * on the S4U2Self ticket.
2008                  */
2009                 krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
2010         }
2011
2012         code = krb5_get_creds_opt_set_impersonate(ctx, options,
2013                                                   impersonate_principal);
2014         if (code != 0) {
2015                 krb5_get_creds_opt_free(ctx, options);
2016                 krb5_free_principal(ctx, blacklist_principal);
2017                 krb5_free_principal(ctx, self_princ);
2018                 krb5_cc_destroy(ctx, tmp_cc);
2019                 return code;
2020         }
2021
2022         code = krb5_get_creds(ctx, options, tmp_cc,
2023                               self_princ, &s4u2self_creds);
2024         krb5_get_creds_opt_free(ctx, options);
2025         krb5_free_principal(ctx, self_princ);
2026         if (code != 0) {
2027                 krb5_free_principal(ctx, blacklist_principal);
2028                 krb5_cc_destroy(ctx, tmp_cc);
2029                 return code;
2030         }
2031
2032         if (!s4u2proxy) {
2033                 krb5_cc_destroy(ctx, tmp_cc);
2034
2035                 /*
2036                  * Now make sure we store the impersonated principal
2037                  * and creds instead of the TGT related stuff
2038                  * in the krb5_ccache of the caller.
2039                  */
2040                 code = krb5_copy_creds_contents(ctx, s4u2self_creds,
2041                                                 &store_creds);
2042                 krb5_free_creds(ctx, s4u2self_creds);
2043                 if (code != 0) {
2044                         return code;
2045                 }
2046
2047                 /*
2048                  * It's important to store the principal the KDC
2049                  * returned, as otherwise the caller would not find
2050                  * the S4U2Self ticket in the krb5_ccache lookup.
2051                  */
2052                 store_principal = store_creds.client;
2053                 goto store;
2054         }
2055
2056         /*
2057          * We are trying S4U2Proxy:
2058          *
2059          * We need the ticket from the S4U2Self step
2060          * and our TGT in order to get the delegated ticket.
2061          */
2062         code = decode_Ticket((const uint8_t *)s4u2self_creds->ticket.data,
2063                              s4u2self_creds->ticket.length,
2064                              &s4u2self_ticket,
2065                              &s4u2self_ticketlen);
2066         if (code != 0) {
2067                 krb5_free_creds(ctx, s4u2self_creds);
2068                 krb5_free_principal(ctx, blacklist_principal);
2069                 krb5_cc_destroy(ctx, tmp_cc);
2070                 return code;
2071         }
2072
2073         /*
2074          * we need to remember the client principal of the
2075          * S4U2Self stage and as it needs to match the one we
2076          * will get for the S4U2Proxy stage. We need this
2077          * in order to detect KDCs which does not support S4U2Proxy.
2078          */
2079         whitelist_principal = s4u2self_creds->client;
2080         s4u2self_creds->client = NULL;
2081         krb5_free_creds(ctx, s4u2self_creds);
2082
2083         /*
2084          * For S4U2Proxy we also got a target service principal,
2085          * which also belongs to our own realm (available on
2086          * our client principal).
2087          */
2088         code = krb5_parse_name(ctx, target_service, &target_princ);
2089         if (code != 0) {
2090                 free_Ticket(&s4u2self_ticket);
2091                 krb5_free_principal(ctx, whitelist_principal);
2092                 krb5_free_principal(ctx, blacklist_principal);
2093                 krb5_cc_destroy(ctx, tmp_cc);
2094                 return code;
2095         }
2096
2097         code = krb5_principal_set_realm(ctx, target_princ, self_realm);
2098         if (code != 0) {
2099                 free_Ticket(&s4u2self_ticket);
2100                 krb5_free_principal(ctx, target_princ);
2101                 krb5_free_principal(ctx, whitelist_principal);
2102                 krb5_free_principal(ctx, blacklist_principal);
2103                 krb5_cc_destroy(ctx, tmp_cc);
2104                 return code;
2105         }
2106
2107         code = krb5_get_creds_opt_alloc(ctx, &options);
2108         if (code != 0) {
2109                 free_Ticket(&s4u2self_ticket);
2110                 krb5_free_principal(ctx, target_princ);
2111                 krb5_free_principal(ctx, whitelist_principal);
2112                 krb5_free_principal(ctx, blacklist_principal);
2113                 krb5_cc_destroy(ctx, tmp_cc);
2114                 return code;
2115         }
2116
2117         krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
2118         krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_CONSTRAINED_DELEGATION);
2119
2120         code = krb5_get_creds_opt_set_ticket(ctx, options, &s4u2self_ticket);
2121         free_Ticket(&s4u2self_ticket);
2122         if (code != 0) {
2123                 krb5_get_creds_opt_free(ctx, options);
2124                 krb5_free_principal(ctx, target_princ);
2125                 krb5_free_principal(ctx, whitelist_principal);
2126                 krb5_free_principal(ctx, blacklist_principal);
2127                 krb5_cc_destroy(ctx, tmp_cc);
2128                 return code;
2129         }
2130
2131         code = krb5_get_creds(ctx, options, tmp_cc,
2132                               target_princ, &s4u2proxy_creds);
2133         krb5_get_creds_opt_free(ctx, options);
2134         krb5_free_principal(ctx, target_princ);
2135         krb5_cc_destroy(ctx, tmp_cc);
2136         if (code != 0) {
2137                 krb5_free_principal(ctx, whitelist_principal);
2138                 krb5_free_principal(ctx, blacklist_principal);
2139                 return code;
2140         }
2141
2142         /*
2143          * Now make sure we store the impersonated principal
2144          * and creds instead of the TGT related stuff
2145          * in the krb5_ccache of the caller.
2146          */
2147         code = krb5_copy_creds_contents(ctx, s4u2proxy_creds,
2148                                         &store_creds);
2149         krb5_free_creds(ctx, s4u2proxy_creds);
2150         if (code != 0) {
2151                 krb5_free_principal(ctx, whitelist_principal);
2152                 krb5_free_principal(ctx, blacklist_principal);
2153                 return code;
2154         }
2155
2156         /*
2157          * It's important to store the principal the KDC
2158          * returned, as otherwise the caller would not find
2159          * the S4U2Self ticket in the krb5_ccache lookup.
2160          */
2161         store_principal = store_creds.client;
2162
2163  store:
2164         if (blacklist_principal &&
2165             krb5_principal_compare(ctx, store_creds.client, blacklist_principal)) {
2166                 char *sp = NULL;
2167                 char *ip = NULL;
2168
2169                 code = krb5_unparse_name(ctx, blacklist_principal, &sp);
2170                 if (code != 0) {
2171                         sp = NULL;
2172                 }
2173                 code = krb5_unparse_name(ctx, impersonate_principal, &ip);
2174                 if (code != 0) {
2175                         ip = NULL;
2176                 }
2177                 DEBUG(1, ("kerberos_kinit_password_cc: "
2178                           "KDC returned self principal[%s] while impersonating [%s]\n",
2179                           sp?sp:"<no memory>",
2180                           ip?ip:"<no memory>"));
2181
2182                 SAFE_FREE(sp);
2183                 SAFE_FREE(ip);
2184
2185                 krb5_free_principal(ctx, whitelist_principal);
2186                 krb5_free_principal(ctx, blacklist_principal);
2187                 krb5_free_cred_contents(ctx, &store_creds);
2188                 return KRB5_FWD_BAD_PRINCIPAL;
2189         }
2190         if (blacklist_principal) {
2191                 krb5_free_principal(ctx, blacklist_principal);
2192         }
2193
2194         if (whitelist_principal &&
2195             !krb5_principal_compare(ctx, store_creds.client, whitelist_principal)) {
2196                 char *sp = NULL;
2197                 char *ep = NULL;
2198
2199                 code = krb5_unparse_name(ctx, store_creds.client, &sp);
2200                 if (code != 0) {
2201                         sp = NULL;
2202                 }
2203                 code = krb5_unparse_name(ctx, whitelist_principal, &ep);
2204                 if (code != 0) {
2205                         ep = NULL;
2206                 }
2207                 DEBUG(1, ("kerberos_kinit_password_cc: "
2208                           "KDC returned wrong principal[%s] we expected [%s]\n",
2209                           sp?sp:"<no memory>",
2210                           ep?ep:"<no memory>"));
2211
2212                 SAFE_FREE(sp);
2213                 SAFE_FREE(ep);
2214
2215                 krb5_free_principal(ctx, whitelist_principal);
2216                 krb5_free_cred_contents(ctx, &store_creds);
2217                 return KRB5_FWD_BAD_PRINCIPAL;
2218         }
2219         if (whitelist_principal) {
2220                 krb5_free_principal(ctx, whitelist_principal);
2221         }
2222
2223         code = krb5_cc_initialize(ctx, store_cc, store_principal);
2224         if (code != 0) {
2225                 krb5_free_cred_contents(ctx, &store_creds);
2226                 return code;
2227         }
2228
2229         code = krb5_cc_store_cred(ctx, store_cc, &store_creds);
2230         if (code != 0) {
2231                 krb5_free_cred_contents(ctx, &store_creds);
2232                 return code;
2233         }
2234
2235         if (expire_time) {
2236                 *expire_time = (time_t) store_creds.times.endtime;
2237         }
2238
2239         if (kdc_time) {
2240                 *kdc_time = (time_t) store_creds.times.starttime;
2241         }
2242
2243         krb5_free_cred_contents(ctx, &store_creds);
2244
2245         return 0;
2246 }
2247 #endif
2248
2249 #if !defined(HAVE_KRB5_MAKE_PRINCIPAL) && defined(HAVE_KRB5_BUILD_PRINCIPAL_ALLOC_VA)
2250 krb5_error_code smb_krb5_make_principal(krb5_context context,
2251                                         krb5_principal *principal,
2252                                         const char *_realm, ...)
2253 {
2254         krb5_error_code code;
2255         bool free_realm;
2256         char *realm;
2257         va_list ap;
2258
2259         if (_realm) {
2260                 realm = discard_const_p(char, _realm);
2261                 free_realm = false;
2262         } else {
2263                 code = krb5_get_default_realm(context, &realm);
2264                 if (code) {
2265                         return code;
2266                 }
2267                 free_realm = true;
2268         }
2269
2270         va_start(ap, _realm);
2271         code = krb5_build_principal_alloc_va(context, principal,
2272                                              strlen(realm), realm,
2273                                              ap);
2274         va_end(ap);
2275
2276         if (free_realm) {
2277                 krb5_free_default_realm(context, realm);
2278         }
2279
2280         return code;
2281 }
2282 #endif
2283
2284 #if !defined(HAVE_KRB5_CC_GET_LIFETIME) && defined(HAVE_KRB5_CC_RETRIEVE_CRED)
2285 /**
2286  * @brief Get the lifetime of the initial ticket in the cache.
2287  *
2288  * @param[in]  context  The kerberos context.
2289  *
2290  * @param[in]  id       The credential cache to get the ticket lifetime.
2291  *
2292  * @param[out] t        A pointer to a time value to store the lifetime.
2293  *
2294  * @return              0 on success, a krb5_error_code on error.
2295  */
2296 krb5_error_code smb_krb5_cc_get_lifetime(krb5_context context,
2297                                          krb5_ccache id,
2298                                          time_t *t)
2299 {
2300         krb5_cc_cursor cursor;
2301         krb5_error_code kerr;
2302         krb5_creds cred;
2303         krb5_timestamp now;
2304
2305         *t = 0;
2306
2307         kerr = krb5_timeofday(context, &now);
2308         if (kerr) {
2309                 return kerr;
2310         }
2311
2312         kerr = krb5_cc_start_seq_get(context, id, &cursor);
2313         if (kerr) {
2314                 return kerr;
2315         }
2316
2317         while ((kerr = krb5_cc_next_cred(context, id, &cursor, &cred)) == 0) {
2318 #ifndef HAVE_FLAGS_IN_KRB5_CREDS
2319                 if (cred.ticket_flags & TKT_FLG_INITIAL) {
2320 #else
2321                 if (cred.flags.b.initial) {
2322 #endif
2323                         if (now < cred.times.endtime) {
2324                                 *t = (time_t) (cred.times.endtime - now);
2325                         }
2326                         krb5_free_cred_contents(context, &cred);
2327                         break;
2328                 }
2329                 krb5_free_cred_contents(context, &cred);
2330         }
2331
2332         krb5_cc_end_seq_get(context, id, &cursor);
2333
2334         return kerr;
2335 }
2336 #endif /* HAVE_KRB5_CC_GET_LIFETIME */
2337
2338 #if !defined(HAVE_KRB5_FREE_CHECKSUM_CONTENTS) && defined(HAVE_FREE_CHECKSUM)
2339 void smb_krb5_free_checksum_contents(krb5_context ctx, krb5_checksum *cksum)
2340 {
2341         free_Checksum(cksum);
2342 }
2343 #endif
2344
2345 krb5_error_code smb_krb5_make_pac_checksum(TALLOC_CTX *mem_ctx,
2346                                            DATA_BLOB *pac_data,
2347                                            krb5_context context,
2348                                            const krb5_keyblock *keyblock,
2349                                            uint32_t *sig_type,
2350                                            DATA_BLOB *sig_blob)
2351 {
2352         krb5_error_code ret;
2353         krb5_checksum cksum;
2354 #if defined(HAVE_KRB5_CRYPTO_INIT) && defined(HAVE_KRB5_CREATE_CHECKSUM)
2355         krb5_crypto crypto;
2356
2357
2358         ret = krb5_crypto_init(context,
2359                                keyblock,
2360                                0,
2361                                &crypto);
2362         if (ret) {
2363                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
2364                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2365                 return ret;
2366         }
2367         ret = krb5_create_checksum(context,
2368                                    crypto,
2369                                    KRB5_KU_OTHER_CKSUM,
2370                                    0,
2371                                    pac_data->data,
2372                                    pac_data->length,
2373                                    &cksum);
2374         if (ret) {
2375                 DEBUG(2, ("PAC Verification failed: %s\n",
2376                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2377         }
2378
2379         krb5_crypto_destroy(context, crypto);
2380
2381         if (ret) {
2382                 return ret;
2383         }
2384
2385         *sig_type = cksum.cksumtype;
2386         *sig_blob = data_blob_talloc(mem_ctx,
2387                                         cksum.checksum.data,
2388                                         cksum.checksum.length);
2389 #elif defined(HAVE_KRB5_C_MAKE_CHECKSUM)
2390         krb5_data input;
2391
2392         input.data = (char *)pac_data->data;
2393         input.length = pac_data->length;
2394
2395         ret = krb5_c_make_checksum(context,
2396                                    0,
2397                                    keyblock,
2398                                    KRB5_KEYUSAGE_APP_DATA_CKSUM,
2399                                    &input,
2400                                    &cksum);
2401         if (ret) {
2402                 DEBUG(2, ("PAC Verification failed: %s\n",
2403                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2404                 return ret;
2405         }
2406
2407         *sig_type = cksum.checksum_type;
2408         *sig_blob = data_blob_talloc(mem_ctx,
2409                                         cksum.contents,
2410                                         cksum.length);
2411
2412 #else
2413 #error krb5_create_checksum or krb5_c_make_checksum not available
2414 #endif /* HAVE_KRB5_C_MAKE_CHECKSUM */
2415         smb_krb5_free_checksum_contents(context, &cksum);
2416
2417         return 0;
2418 }
2419
2420
2421 /*
2422  * smb_krb5_principal_get_realm
2423  *
2424  * @brief Get realm of a principal
2425  *
2426  * @param[in] context           The krb5_context
2427  * @param[in] principal         The principal
2428  * @return pointer to the realm
2429  *
2430  * Caller must free if the return value is not NULL.
2431  *
2432  */
2433
2434 char *smb_krb5_principal_get_realm(krb5_context context,
2435                                    krb5_const_principal principal)
2436 {
2437 #ifdef HAVE_KRB5_PRINCIPAL_GET_REALM /* Heimdal */
2438         return strdup(discard_const_p(char, krb5_principal_get_realm(context, principal)));
2439 #elif defined(krb5_princ_realm) /* MIT */
2440         krb5_data *realm;
2441         realm = discard_const_p(krb5_data,
2442                                 krb5_princ_realm(context, principal));
2443         return strndup(realm->data, realm->length);
2444 #else
2445 #error UNKNOWN_GET_PRINC_REALM_FUNCTIONS
2446 #endif
2447 }
2448
2449 /*
2450  * smb_krb5_principal_set_realm
2451  *
2452  * @brief Get realm of a principal
2453  *
2454  * @param[in] context           The krb5_context
2455  * @param[in] principal         The principal
2456  * @param[in] realm             The realm
2457  * @return                      0 on success, a krb5_error_code on error.
2458  *
2459  */
2460
2461 krb5_error_code smb_krb5_principal_set_realm(krb5_context context,
2462                                              krb5_principal principal,
2463                                              const char *realm)
2464 {
2465 #ifdef HAVE_KRB5_PRINCIPAL_SET_REALM /* Heimdal */
2466         return krb5_principal_set_realm(context, principal, realm);
2467 #elif defined(krb5_princ_realm) && defined(krb5_princ_set_realm) /* MIT */
2468         krb5_error_code ret;
2469         krb5_data data;
2470         krb5_data *old_data;
2471
2472         old_data = krb5_princ_realm(context, principal);
2473
2474         ret = smb_krb5_copy_data_contents(&data,
2475                                           realm,
2476                                           strlen(realm));
2477         if (ret) {
2478                 return ret;
2479         }
2480
2481         /* free realm before setting */
2482         free(old_data->data);
2483
2484         krb5_princ_set_realm(context, principal, &data);
2485
2486         return ret;
2487 #else
2488 #error UNKNOWN_PRINC_SET_REALM_FUNCTION
2489 #endif
2490 }
2491
2492
2493 /************************************************************************
2494  Routine to get the default realm from the kerberos credentials cache.
2495  Caller must free if the return value is not NULL.
2496 ************************************************************************/
2497
2498 static char *smb_krb5_get_default_realm_from_ccache(TALLOC_CTX *mem_ctx)
2499 {
2500         char *realm = NULL;
2501         krb5_context ctx = NULL;
2502         krb5_ccache cc = NULL;
2503         krb5_principal princ = NULL;
2504
2505         initialize_krb5_error_table();
2506         if (krb5_init_context(&ctx)) {
2507                 return NULL;
2508         }
2509
2510         DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2511                 "Trying to read krb5 cache: %s\n",
2512                 krb5_cc_default_name(ctx)));
2513         if (krb5_cc_default(ctx, &cc)) {
2514                 DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2515                         "failed to read default cache\n"));
2516                 goto out;
2517         }
2518         if (krb5_cc_get_principal(ctx, cc, &princ)) {
2519                 DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2520                         "failed to get default principal\n"));
2521                 goto out;
2522         }
2523
2524 #if defined(HAVE_KRB5_PRINCIPAL_GET_REALM)
2525         realm = talloc_strdup(mem_ctx, krb5_principal_get_realm(ctx, princ));
2526 #elif defined(HAVE_KRB5_PRINC_REALM)
2527         {
2528                 krb5_data *realm_data = krb5_princ_realm(ctx, princ);
2529                 realm = talloc_strndup(mem_ctx, realm_data->data, realm_data->length);
2530         }
2531 #endif
2532
2533   out:
2534
2535         if (ctx) {
2536                 if (princ) {
2537                         krb5_free_principal(ctx, princ);
2538                 }
2539                 if (cc) {
2540                         krb5_cc_close(ctx, cc);
2541                 }
2542                 krb5_free_context(ctx);
2543         }
2544
2545         return realm;
2546 }
2547
2548 /************************************************************************
2549  Routine to get the realm from a given DNS name.
2550 ************************************************************************/
2551
2552 static char *smb_krb5_get_realm_from_hostname(TALLOC_CTX *mem_ctx,
2553                                                 const char *hostname)
2554 {
2555 #if defined(HAVE_KRB5_REALM_TYPE)
2556         /* Heimdal. */
2557         krb5_realm *realm_list = NULL;
2558 #else
2559         /* MIT */
2560         char **realm_list = NULL;
2561 #endif
2562         char *realm = NULL;
2563         krb5_error_code kerr;
2564         krb5_context ctx = NULL;
2565
2566         initialize_krb5_error_table();
2567         if (krb5_init_context(&ctx)) {
2568                 return NULL;
2569         }
2570
2571         kerr = krb5_get_host_realm(ctx, hostname, &realm_list);
2572         if (kerr != 0) {
2573                 DEBUG(3,("kerberos_get_realm_from_hostname %s: "
2574                         "failed %s\n",
2575                         hostname ? hostname : "(NULL)",
2576                         error_message(kerr) ));
2577                 goto out;
2578         }
2579
2580         if (realm_list && realm_list[0]) {
2581                 realm = talloc_strdup(mem_ctx, realm_list[0]);
2582         }
2583
2584   out:
2585
2586         if (ctx) {
2587                 if (realm_list) {
2588                         krb5_free_host_realm(ctx, realm_list);
2589                         realm_list = NULL;
2590                 }
2591                 krb5_free_context(ctx);
2592                 ctx = NULL;
2593         }
2594         return realm;
2595 }
2596
2597 char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
2598                                                    const char *service,
2599                                                    const char *remote_name,
2600                                                    const char *default_realm)
2601 {
2602         char *realm = NULL;
2603         char *host = NULL;
2604         char *principal;
2605         host = strchr_m(remote_name, '.');
2606         if (host) {
2607                 /* DNS name. */
2608                 realm = smb_krb5_get_realm_from_hostname(talloc_tos(),
2609                                                          remote_name);
2610         } else {
2611                 /* NetBIOS name - use our realm. */
2612                 realm = smb_krb5_get_default_realm_from_ccache(talloc_tos());
2613         }
2614
2615         if (realm == NULL || *realm == '\0') {
2616                 realm = talloc_strdup(talloc_tos(), default_realm);
2617                 if (!realm) {
2618                         return NULL;
2619                 }
2620                 DEBUG(3,("kerberos_get_principal_from_service_hostname: "
2621                          "cannot get realm from, "
2622                          "desthost %s or default ccache. Using default "
2623                          "smb.conf realm %s\n",
2624                          remote_name,
2625                          realm));
2626         }
2627
2628         principal = talloc_asprintf(mem_ctx,
2629                                     "%s/%s@%s",
2630                                     service, remote_name,
2631                                     realm);
2632         TALLOC_FREE(realm);
2633         return principal;
2634 }
2635
2636 char *smb_get_krb5_error_message(krb5_context context,
2637                                  krb5_error_code code,
2638                                  TALLOC_CTX *mem_ctx)
2639 {
2640         char *ret;
2641
2642 #if defined(HAVE_KRB5_GET_ERROR_MESSAGE) && defined(HAVE_KRB5_FREE_ERROR_MESSAGE)
2643         const char *context_error = krb5_get_error_message(context, code);
2644         if (context_error) {
2645                 ret = talloc_asprintf(mem_ctx, "%s: %s",
2646                                         error_message(code), context_error);
2647                 krb5_free_error_message(context, context_error);
2648                 return ret;
2649         }
2650 #endif
2651         ret = talloc_strdup(mem_ctx, error_message(code));
2652         return ret;
2653 }
2654
2655
2656 /**
2657 * @brief Return the kerberos library setting for "libdefaults:allow_weak_crypto"
2658 *
2659 * @param context        The krb5_context
2660 *
2661 * @return krb5_boolean
2662 *
2663 * Function returns true if weak crypto is allowd, false if not
2664 */
2665
2666 krb5_boolean smb_krb5_get_allowed_weak_crypto(krb5_context context)
2667 #if defined(HAVE_KRB5_CONFIG_GET_BOOL_DEFAULT)
2668 {
2669         return krb5_config_get_bool_default(context,
2670                                             NULL,
2671                                             FALSE,
2672                                             "libdefaults",
2673                                             "allow_weak_crypto",
2674                                             NULL);
2675 }
2676 #elif defined(HAVE_PROFILE_H) && defined(HAVE_KRB5_GET_PROFILE)
2677 {
2678 #include <profile.h>
2679         krb5_error_code ret;
2680         krb5_boolean ret_default = false;
2681         profile_t profile;
2682         int ret_profile;
2683
2684         ret = krb5_get_profile(context,
2685                                &profile);
2686         if (ret) {
2687                 return ret_default;
2688         }
2689
2690         ret = profile_get_boolean(profile,
2691                                   "libdefaults",
2692                                   "allow_weak_crypto",
2693                                   NULL, /* subsubname */
2694                                   ret_default, /* def_val */
2695                                   &ret_profile /* *ret_default */);
2696         if (ret) {
2697                 return ret_default;
2698         }
2699
2700         profile_release(profile);
2701
2702         return ret_profile;
2703 }
2704 #else
2705 #error UNKNOWN_KRB5_CONFIG_ROUTINES
2706 #endif
2707
2708 /**
2709 * @brief Return the type of a krb5_principal
2710 *
2711 * @param context        The krb5_context
2712 * @param principal      The const krb5_principal
2713 *
2714 * @return integer type of the principal
2715 */
2716 int smb_krb5_principal_get_type(krb5_context context,
2717                                 krb5_const_principal principal)
2718 {
2719 #ifdef HAVE_KRB5_PRINCIPAL_GET_TYPE /* Heimdal */
2720         return krb5_principal_get_type(context, principal);
2721 #elif defined(krb5_princ_type) /* MIT */
2722         return krb5_princ_type(context, principal);
2723 #else
2724 #error  UNKNOWN_PRINC_GET_TYPE_FUNCTION
2725 #endif
2726 }
2727
2728 /**
2729 * @brief Set the type of a krb5_principal
2730 *
2731 * @param context        The krb5_context
2732 * @param principal      The const krb5_principal
2733 * @param type           The principal type
2734 *
2735 */
2736 void smb_krb5_principal_set_type(krb5_context context,
2737                                  krb5_principal principal,
2738                                  int type)
2739 {
2740 #ifdef HAVE_KRB5_PRINCIPAL_SET_TYPE /* Heimdal */
2741         krb5_principal_set_type(context, principal, type);
2742 #elif defined(krb5_princ_type) /* MIT */
2743         krb5_princ_type(context, principal) = type;
2744 #else
2745 #error  UNKNOWN_PRINC_SET_TYPE_FUNCTION
2746 #endif
2747 }
2748
2749 /**
2750 * @brief Generate a krb5 warning, forwarding to com_err
2751 *
2752 * @param context        The krb5_context
2753 * @param fmt            The message format
2754 * @param ...            The message arguments
2755 *
2756 * @return
2757 */
2758 #if !defined(HAVE_KRB5_WARNX)
2759 krb5_error_code krb5_warnx(krb5_context context, const char *fmt, ...)
2760 {
2761         va_list args;
2762
2763         va_start(args, fmt);
2764         com_err_va("kdb_samba", errno, fmt, args);
2765         va_end(args);
2766
2767         return 0;
2768 }
2769 #endif
2770
2771 krb5_error_code smb_krb5_cc_copy_creds(krb5_context context,
2772                                        krb5_ccache incc, krb5_ccache outcc)
2773 {
2774 #ifdef HAVE_KRB5_CC_COPY_CACHE /* Heimdal */
2775         return krb5_cc_copy_cache(context, incc, outcc);
2776 #elif defined(HAVE_KRB5_CC_COPY_CREDS)
2777         return krb5_cc_copy_creds(context, incc, outcc);
2778 #else
2779 #error UNKNOWN_KRB5_CC_COPY_CACHE_OR_CREDS_FUNCTION
2780 #endif
2781 }
2782
2783 /**********************************************************
2784  * ADS KRB5 CALLS
2785  **********************************************************/
2786
2787 static bool ads_cleanup_expired_creds(krb5_context context,
2788                                       krb5_ccache  ccache,
2789                                       krb5_creds  *credsp)
2790 {
2791         krb5_error_code retval;
2792         const char *cc_type = krb5_cc_get_type(context, ccache);
2793
2794         DEBUG(3, ("ads_cleanup_expired_creds: Ticket in ccache[%s:%s] expiration %s\n",
2795                   cc_type, krb5_cc_get_name(context, ccache),
2796                   http_timestring(talloc_tos(), credsp->times.endtime)));
2797
2798         /* we will probably need new tickets if the current ones
2799            will expire within 10 seconds.
2800         */
2801         if (credsp->times.endtime >= (time(NULL) + 10))
2802                 return false;
2803
2804         /* heimdal won't remove creds from a file ccache, and
2805            perhaps we shouldn't anyway, since internally we
2806            use memory ccaches, and a FILE one probably means that
2807            we're using creds obtained outside of our exectuable
2808         */
2809         if (strequal(cc_type, "FILE")) {
2810                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a %s ccache\n", cc_type));
2811                 return false;
2812         }
2813
2814         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
2815         if (retval) {
2816                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
2817                           error_message(retval)));
2818                 /* If we have an error in this, we want to display it,
2819                    but continue as though we deleted it */
2820         }
2821         return true;
2822 }
2823
2824 /* Allocate and setup the auth context into the state we need. */
2825
2826 static krb5_error_code ads_setup_auth_context(krb5_context context,
2827                                               krb5_auth_context *auth_context)
2828 {
2829         krb5_error_code retval;
2830
2831         retval = krb5_auth_con_init(context, auth_context );
2832         if (retval) {
2833                 DEBUG(1,("krb5_auth_con_init failed (%s)\n",
2834                         error_message(retval)));
2835                 return retval;
2836         }
2837
2838         /* Ensure this is an addressless ticket. */
2839         retval = krb5_auth_con_setaddrs(context, *auth_context, NULL, NULL);
2840         if (retval) {
2841                 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n",
2842                         error_message(retval)));
2843         }
2844
2845         return retval;
2846 }
2847
2848 #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)
2849 static krb5_error_code ads_create_gss_checksum(krb5_data *in_data, /* [inout] */
2850                                                uint32_t gss_flags)
2851 {
2852         unsigned int orig_length = in_data->length;
2853         unsigned int base_cksum_size = GSSAPI_CHECKSUM_SIZE;
2854         char *gss_cksum = NULL;
2855
2856         if (orig_length) {
2857                 /* Extra length field for delgated ticket. */
2858                 base_cksum_size += 4;
2859         }
2860
2861         if ((unsigned int)base_cksum_size + orig_length <
2862                         (unsigned int)base_cksum_size) {
2863                 return EINVAL;
2864         }
2865
2866         gss_cksum = (char *)SMB_MALLOC(base_cksum_size + orig_length);
2867         if (gss_cksum == NULL) {
2868                 return ENOMEM;
2869         }
2870
2871         memset(gss_cksum, '\0', base_cksum_size + orig_length);
2872         SIVAL(gss_cksum, 0, GSSAPI_BNDLENGTH);
2873
2874         /*
2875          * GSS_C_NO_CHANNEL_BINDINGS means 16 zero bytes.
2876          * This matches the behavior of heimdal and mit.
2877          *
2878          * And it is needed to work against some closed source
2879          * SMB servers.
2880          *
2881          * See bug #7883
2882          */
2883         memset(&gss_cksum[4], 0x00, GSSAPI_BNDLENGTH);
2884
2885         SIVAL(gss_cksum, 20, gss_flags);
2886
2887         if (orig_length) {
2888                 SSVAL(gss_cksum, 24, 1); /* The Delegation Option identifier */
2889                 SSVAL(gss_cksum, 26, orig_length);
2890                 /* Copy the kerberos KRB_CRED data */
2891                 memcpy(gss_cksum + 28, in_data->data, orig_length);
2892                 free(in_data->data);
2893                 in_data->data = NULL;
2894                 in_data->length = 0;
2895         }
2896         in_data->data = gss_cksum;
2897         in_data->length = base_cksum_size + orig_length;
2898         return 0;
2899 }
2900 #endif
2901
2902 /*
2903  * We can't use krb5_mk_req because w2k wants the service to be in a particular
2904  * format.
2905  */
2906 static krb5_error_code ads_krb5_mk_req(krb5_context context,
2907                                        krb5_auth_context *auth_context,
2908                                        const krb5_flags ap_req_options,
2909                                        const char *principal,
2910                                        krb5_ccache ccache,
2911                                        krb5_data *outbuf,
2912                                        time_t *expire_time,
2913                                        const char *impersonate_princ_s)
2914 {
2915         krb5_error_code retval;
2916         krb5_principal server;
2917         krb5_principal impersonate_princ = NULL;
2918         krb5_creds *credsp;
2919         krb5_creds creds;
2920         krb5_data in_data;
2921         bool creds_ready = false;
2922         int i = 0, maxtries = 3;
2923         bool ok;
2924
2925         ZERO_STRUCT(in_data);
2926
2927         retval = smb_krb5_parse_name(context, principal, &server);
2928         if (retval != 0) {
2929                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
2930                 return retval;
2931         }
2932
2933         if (impersonate_princ_s) {
2934                 retval = smb_krb5_parse_name(context, impersonate_princ_s,
2935                                              &impersonate_princ);
2936                 if (retval) {
2937                         DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", impersonate_princ_s));
2938                         goto cleanup_princ;
2939                 }
2940         }
2941
2942         /* obtain ticket & session key */
2943         ZERO_STRUCT(creds);
2944         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
2945                 DEBUG(1,("ads_krb5_mk_req: krb5_copy_principal failed (%s)\n",
2946                          error_message(retval)));
2947                 goto cleanup_princ;
2948         }
2949
2950         retval = krb5_cc_get_principal(context, ccache, &creds.client);
2951         if (retval != 0) {
2952                 /* This can commonly fail on smbd startup with no ticket in the cache.
2953                  * Report at higher level than 1. */
2954                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
2955                          error_message(retval)));
2956                 goto cleanup_creds;
2957         }
2958
2959         while (!creds_ready && (i < maxtries)) {
2960
2961                 retval = smb_krb5_get_credentials(context,
2962                                                   ccache,
2963                                                   creds.client,
2964                                                   creds.server,
2965                                                   impersonate_princ,
2966                                                   &credsp);
2967                 if (retval != 0) {
2968                         DBG_WARNING("smb_krb5_get_credentials failed for %s "
2969                                     "(%s)\n",
2970                                     principal,
2971                                     error_message(retval));
2972                         goto cleanup_creds;
2973                 }
2974
2975                 /* cope with ticket being in the future due to clock skew */
2976                 if ((unsigned)credsp->times.starttime > time(NULL)) {
2977                         time_t t = time(NULL);
2978                         int time_offset =(int)((unsigned)credsp->times.starttime-t);
2979                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
2980                         krb5_set_real_time(context, t + time_offset + 1, 0);
2981                 }
2982
2983                 ok = ads_cleanup_expired_creds(context, ccache, credsp);
2984                 if (!ok) {
2985                         creds_ready = true;
2986                 }
2987
2988                 i++;
2989         }
2990
2991         DBG_DEBUG("Ticket (%s) in ccache (%s:%s) is valid until: (%s - %u)\n",
2992                   principal,
2993                   krb5_cc_get_type(context, ccache),
2994                   krb5_cc_get_name(context, ccache),
2995                   http_timestring(talloc_tos(),
2996                                   (unsigned)credsp->times.endtime),
2997                   (unsigned)credsp->times.endtime);
2998
2999         if (expire_time) {
3000                 *expire_time = (time_t)credsp->times.endtime;
3001         }
3002
3003         /* Allocate the auth_context. */
3004         retval = ads_setup_auth_context(context, auth_context);
3005         if (retval != 0) {
3006                 DBG_WARNING("ads_setup_auth_context failed (%s)\n",
3007                             error_message(retval));
3008                 goto cleanup_creds;
3009         }
3010
3011 #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)
3012         {
3013                 uint32_t gss_flags = 0;
3014
3015                 if (credsp->ticket_flags & TKT_FLG_OK_AS_DELEGATE) {
3016                         /*
3017                          * Fetch a forwarded TGT from the KDC so that we can
3018                          * hand off a 2nd ticket as part of the kerberos
3019                          * exchange.
3020                          */
3021
3022                         DBG_INFO("Server marked as OK to delegate to, building "
3023                                  "forwardable TGT\n");
3024
3025                         retval = krb5_auth_con_setuseruserkey(context,
3026                                         *auth_context,
3027                                         &credsp->keyblock );
3028                         if (retval != 0) {
3029                                 DBG_WARNING("krb5_auth_con_setuseruserkey "
3030                                             "failed (%s)\n",
3031                                             error_message(retval)));
3032                                 goto cleanup_creds;
3033                         }
3034
3035                         /* Must use a subkey for forwarded tickets. */
3036                         retval = krb5_auth_con_setflags(context,
3037                                                         *auth_context,
3038                                                         KRB5_AUTH_CONTEXT_USE_SUBKEY);
3039                         if (retval != 0) {
3040                                 DBG_WARNING("krb5_auth_con_setflags failed (%s)\n",
3041                                             error_message(retval)));
3042                                 goto cleanup_creds;
3043                         }
3044
3045                         retval = krb5_fwd_tgt_creds(context,/* Krb5 context [in] */
3046                                 *auth_context,  /* Authentication context [in] */
3047                                 discard_const_p(char, KRB5_TGS_NAME),  /* Ticket service name ("krbtgt") [in] */
3048                                 credsp->client, /* Client principal for the tgt [in] */
3049                                 credsp->server, /* Server principal for the tgt [in] */
3050                                 ccache,         /* Credential cache to use for storage [in] */
3051                                 1,              /* Turn on for "Forwardable ticket" [in] */
3052                                 &in_data );     /* Resulting response [out] */
3053
3054                         if (retval) {
3055                                 DBG_INFO("krb5_fwd_tgt_creds failed (%s)\n",
3056                                          error_message(retval));
3057
3058                                 /*
3059                                  * This is not fatal. Delete the *auth_context and continue
3060                                  * with krb5_mk_req_extended to get a non-forwardable ticket.
3061                                  */
3062
3063                                 if (in_data.data) {
3064                                         free( in_data.data );
3065                                         in_data.data = NULL;
3066                                         in_data.length = 0;
3067                                 }
3068                                 krb5_auth_con_free(context, *auth_context);
3069                                 *auth_context = NULL;
3070                                 retval = ads_setup_auth_context(context, auth_context);
3071                                 if (retval != 0) {
3072                                         DBG_WARNING("ads_setup_auth_context failed (%s)\n",
3073                                                     error_message(retval)));
3074                                         goto cleanup_creds;
3075                                 }
3076                         } else {
3077                                 /* We got a delegated ticket. */
3078                                 gss_flags |= GSS_C_DELEG_FLAG;
3079                         }
3080                 }
3081
3082                 /* Frees and reallocates in_data into a GSS checksum blob. */
3083                 retval = ads_create_gss_checksum(&in_data, gss_flags);
3084                 if (retval != 0) {
3085                         goto cleanup_data;
3086                 }
3087
3088                 /* We always want GSS-checksum types. */
3089                 retval = krb5_auth_con_set_req_cksumtype(context, *auth_context, GSSAPI_CHECKSUM );
3090                 if (retval != 0) {
3091                         DEBUG(1,("krb5_auth_con_set_req_cksumtype failed (%s)\n",
3092                                 error_message(retval)));
3093                         goto cleanup_data;
3094                 }
3095         }
3096 #endif
3097
3098         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
3099                                       &in_data, credsp, outbuf);
3100         if (retval != 0) {
3101                 DBG_WARNING("krb5_mk_req_extended failed (%s)\n",
3102                             error_message(retval));
3103         }
3104
3105 #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)
3106 cleanup_data:
3107 #endif
3108
3109         if (in_data.data) {
3110                 free( in_data.data );
3111                 in_data.length = 0;
3112         }
3113
3114         krb5_free_creds(context, credsp);
3115
3116 cleanup_creds:
3117         krb5_free_cred_contents(context, &creds);
3118
3119 cleanup_princ:
3120         krb5_free_principal(context, server);
3121         if (impersonate_princ) {
3122                 krb5_free_principal(context, impersonate_princ);
3123         }
3124
3125         return retval;
3126 }
3127
3128 /*
3129   get a kerberos5 ticket for the given service
3130 */
3131 int ads_krb5_cli_get_ticket(TALLOC_CTX *mem_ctx,
3132                             const char *principal,
3133                             time_t time_offset,
3134                             DATA_BLOB *ticket,
3135                             DATA_BLOB *session_key_krb5,
3136                             uint32_t extra_ap_opts, const char *ccname,
3137                             time_t *tgs_expire,
3138                             const char *impersonate_princ_s)
3139 {
3140         krb5_error_code retval;
3141         krb5_data packet;
3142         krb5_context context = NULL;
3143         krb5_ccache ccdef = NULL;
3144         krb5_auth_context auth_context = NULL;
3145         krb5_enctype enc_types[] = {
3146 #ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
3147                 ENCTYPE_AES256_CTS_HMAC_SHA1_96,
3148 #endif
3149 #ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
3150                 ENCTYPE_AES128_CTS_HMAC_SHA1_96,
3151 #endif
3152                 ENCTYPE_ARCFOUR_HMAC,
3153                 ENCTYPE_DES_CBC_MD5,
3154                 ENCTYPE_DES_CBC_CRC,
3155                 ENCTYPE_NULL};
3156         bool ok;
3157
3158         initialize_krb5_error_table();
3159         retval = krb5_init_context(&context);
3160         if (retval != 0) {
3161                 DBG_WARNING("krb5_init_context failed (%s)\n",
3162                             error_message(retval));
3163                 goto failed;
3164         }
3165
3166         if (time_offset != 0) {
3167                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
3168         }
3169
3170         retval = krb5_cc_resolve(context,
3171                                  ccname ? ccname : krb5_cc_default_name(context),
3172                                  &ccdef);
3173         if (retval != 0) {
3174                 DBG_WARNING("krb5_cc_default failed (%s)\n",
3175                             error_message(retval));
3176                 goto failed;
3177         }
3178
3179         retval = krb5_set_default_tgs_ktypes(context, enc_types);
3180         if (retval != 0) {
3181                 DBG_WARNING("krb5_set_default_tgs_ktypes failed (%s)\n",
3182                             error_message(retval));
3183                 goto failed;
3184         }
3185
3186         retval = ads_krb5_mk_req(context,
3187                                  &auth_context,
3188                                  AP_OPTS_USE_SUBKEY | (krb5_flags)extra_ap_opts,
3189                                  principal,
3190                                  ccdef,
3191                                  &packet,
3192                                  tgs_expire,
3193                                  impersonate_princ_s);
3194         if (retval != 0) {
3195                 goto failed;
3196         }
3197
3198         ok = smb_krb5_get_smb_session_key(mem_ctx,
3199                                           context,
3200                                           auth_context,
3201                                           session_key_krb5,
3202                                           false);
3203         if (!ok) {
3204                 retval = ENOMEM;
3205                 goto failed;
3206         }
3207
3208         *ticket = data_blob_talloc(mem_ctx, packet.data, packet.length);
3209
3210         smb_krb5_free_data_contents(context, &packet);
3211
3212 failed:
3213
3214         if (context) {
3215                 if (ccdef) {
3216                         krb5_cc_close(context, ccdef);
3217                 }
3218                 if (auth_context) {
3219                         krb5_auth_con_free(context, auth_context);
3220                 }
3221                 krb5_free_context(context);
3222         }
3223
3224         return retval;
3225 }
3226
3227 #else /* HAVE_KRB5 */
3228 /* This saves a few linking headaches */
3229 int ads_krb5_cli_get_ticket(TALLOC_CTX *mem_ctx,
3230                             const char *principal,
3231                             time_t time_offset,
3232                             DATA_BLOB *ticket,
3233                             DATA_BLOB *session_key_krb5,
3234                             uint32_t extra_ap_opts, const char *ccname,
3235                             time_t *tgs_expire,
3236                             const char *impersonate_princ_s)
3237 {
3238          DEBUG(0,("NO KERBEROS SUPPORT\n"));
3239          return 1;
3240 }
3241
3242 #endif /* HAVE_KRB5 */