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 krb5_error_code smb_krb5_keytab_name(TALLOC_CTX *mem_ctx,
1155                                      krb5_context context,
1156                                      krb5_keytab keytab,
1157                                      const char **keytab_name)
1158 {
1159         char keytab_string[MAX_KEYTAB_NAME_LEN];
1160         krb5_error_code ret = 0;
1161
1162         ret = krb5_kt_get_name(context, keytab,
1163                                keytab_string, MAX_KEYTAB_NAME_LEN - 2);
1164         if (ret) {
1165                 return ret;
1166         }
1167
1168         *keytab_name = talloc_strdup(mem_ctx, keytab_string);
1169         if (!*keytab_name) {
1170                 return ENOMEM;
1171         }
1172
1173         return ret;
1174 }
1175
1176 /**
1177  * @brief Seek and delete old entries in a keytab based on the passed
1178  *        principal.
1179  *
1180  * @param[in]  context       The KRB5 context to use.
1181  *
1182  * @param[in]  keytab        The keytab to operate on.
1183  *
1184  * @param[in]  kvno          The kvnco to use.
1185  *
1186  * @param[in]  princ_s       The principal as a string to search for.
1187  *
1188  * @param[in]  princ         The principal as a krb5_principal to search for.
1189  *
1190  * @param[in]  flush         Weather to flush the complete keytab.
1191  *
1192  * @param[in]  keep_old_entries Keep the entry with the previous kvno.
1193  *
1194  * @retval 0 on Sucess
1195  *
1196  * @return An appropriate KRB5 error code.
1197  */
1198 krb5_error_code smb_krb5_kt_seek_and_delete_old_entries(krb5_context context,
1199                                                         krb5_keytab keytab,
1200                                                         krb5_kvno kvno,
1201                                                         krb5_enctype enctype,
1202                                                         const char *princ_s,
1203                                                         krb5_principal princ,
1204                                                         bool flush,
1205                                                         bool keep_old_entries)
1206 {
1207         krb5_error_code ret;
1208         krb5_kt_cursor cursor;
1209         krb5_kt_cursor zero_csr;
1210         krb5_keytab_entry kt_entry;
1211         krb5_keytab_entry zero_kt_entry;
1212         char *ktprinc = NULL;
1213         krb5_kvno old_kvno = kvno - 1;
1214         TALLOC_CTX *tmp_ctx;
1215
1216         ZERO_STRUCT(cursor);
1217         ZERO_STRUCT(zero_csr);
1218         ZERO_STRUCT(kt_entry);
1219         ZERO_STRUCT(zero_kt_entry);
1220
1221         ret = krb5_kt_start_seq_get(context, keytab, &cursor);
1222         if (ret == KRB5_KT_END || ret == ENOENT ) {
1223                 /* no entries */
1224                 return 0;
1225         }
1226
1227         tmp_ctx = talloc_new(NULL);
1228         if (tmp_ctx == NULL) {
1229                 return ENOMEM;
1230         }
1231
1232         DEBUG(3, (__location__ ": Will try to delete old keytab entries\n"));
1233         while (!krb5_kt_next_entry(context, keytab, &kt_entry, &cursor)) {
1234                 bool name_ok = false;
1235                 krb5_enctype kt_entry_enctype =
1236                         smb_krb5_kt_get_enctype_from_entry(&kt_entry);
1237
1238                 if (!flush && (princ_s != NULL)) {
1239                         ret = smb_krb5_unparse_name(tmp_ctx, context,
1240                                                     kt_entry.principal,
1241                                                     &ktprinc);
1242                         if (ret) {
1243                                 DEBUG(1, (__location__
1244                                           ": smb_krb5_unparse_name failed "
1245                                           "(%s)\n", error_message(ret)));
1246                                 goto out;
1247                         }
1248
1249 #ifdef HAVE_KRB5_KT_COMPARE
1250                         name_ok = krb5_kt_compare(context, &kt_entry,
1251                                                   princ, 0, 0);
1252 #else
1253                         name_ok = (strcmp(ktprinc, princ_s) == 0);
1254 #endif
1255
1256                         if (!name_ok) {
1257                                 DEBUG(10, (__location__ ": ignoring keytab "
1258                                            "entry principal %s, kvno = %d\n",
1259                                            ktprinc, kt_entry.vno));
1260
1261                                 /* Not a match,
1262                                  * just free this entry and continue. */
1263                                 ret = smb_krb5_kt_free_entry(context,
1264                                                              &kt_entry);
1265                                 ZERO_STRUCT(kt_entry);
1266                                 if (ret) {
1267                                         DEBUG(1, (__location__
1268                                                   ": smb_krb5_kt_free_entry "
1269                                                   "failed (%s)\n",
1270                                                   error_message(ret)));
1271                                         goto out;
1272                                 }
1273
1274                                 TALLOC_FREE(ktprinc);
1275                                 continue;
1276                         }
1277
1278                         TALLOC_FREE(ktprinc);
1279                 }
1280
1281                 /*------------------------------------------------------------
1282                  * Save the entries with kvno - 1. This is what microsoft does
1283                  * to allow people with existing sessions that have kvno - 1
1284                  * to still work. Otherwise, when the password for the machine
1285                  * changes, all kerberizied sessions will 'break' until either
1286                  * the client reboots or the client's session key expires and
1287                  * they get a new session ticket with the new kvno.
1288                  * Some keytab files only store the kvno in 8bits, limit
1289                  * the compare accordingly.
1290                  */
1291
1292                 if (!flush && ((kt_entry.vno & 0xff) == (old_kvno & 0xff))) {
1293                         DEBUG(5, (__location__ ": Saving previous (kvno %d) "
1294                                   "entry for principal: %s.\n",
1295                                   old_kvno, princ_s));
1296                         continue;
1297                 }
1298
1299                 if (keep_old_entries) {
1300                         DEBUG(5, (__location__ ": Saving old (kvno %d) "
1301                                   "entry for principal: %s.\n",
1302                                   kvno, princ_s));
1303                         continue;
1304                 }
1305
1306                 if (!flush &&
1307                     (kt_entry.vno == kvno) &&
1308                     (kt_entry_enctype != enctype))
1309                 {
1310                         DEBUG(5, (__location__ ": Saving entry with kvno [%d] "
1311                                   "enctype [%d] for principal: %s.\n",
1312                                   kvno, kt_entry_enctype, princ_s));
1313                         continue;
1314                 }
1315
1316                 DEBUG(5, (__location__ ": Found old entry for principal: %s "
1317                           "(kvno %d) - trying to remove it.\n",
1318                           princ_s, kt_entry.vno));
1319
1320                 ret = krb5_kt_end_seq_get(context, keytab, &cursor);
1321                 ZERO_STRUCT(cursor);
1322                 if (ret) {
1323                         DEBUG(1, (__location__ ": krb5_kt_end_seq_get() "
1324                                   "failed (%s)\n", error_message(ret)));
1325                         goto out;
1326                 }
1327                 ret = krb5_kt_remove_entry(context, keytab, &kt_entry);
1328                 if (ret) {
1329                         DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
1330                                   "failed (%s)\n", error_message(ret)));
1331                         goto out;
1332                 }
1333
1334                 DEBUG(5, (__location__ ": removed old entry for principal: "
1335                           "%s (kvno %d).\n", princ_s, kt_entry.vno));
1336
1337                 ret = krb5_kt_start_seq_get(context, keytab, &cursor);
1338                 if (ret) {
1339                         DEBUG(1, (__location__ ": krb5_kt_start_seq() failed "
1340                                   "(%s)\n", error_message(ret)));
1341                         goto out;
1342                 }
1343                 ret = smb_krb5_kt_free_entry(context, &kt_entry);
1344                 ZERO_STRUCT(kt_entry);
1345                 if (ret) {
1346                         DEBUG(1, (__location__ ": krb5_kt_remove_entry() "
1347                                   "failed (%s)\n", error_message(ret)));
1348                         goto out;
1349                 }
1350         }
1351
1352 out:
1353         talloc_free(tmp_ctx);
1354         if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
1355                 smb_krb5_kt_free_entry(context, &kt_entry);
1356         }
1357         if (memcmp(&cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) {
1358                 krb5_kt_end_seq_get(context, keytab, &cursor);
1359         }
1360         return ret;
1361 }
1362
1363 /**
1364  * @brief Add a keytab entry for the given principal
1365  *
1366  * @param[in]  context       The krb5 context to use.
1367  *
1368  * @param[in]  keytab        The keytab to add the entry to.
1369  *
1370  * @param[in]  kvno          The kvno to use.
1371  *
1372  * @param[in]  princ_s       The principal as a string.
1373  *
1374  * @param[in]  salt_principal The salt principal to salt the password with.
1375  *                            Only needed for keys which support salting.
1376  *                            If no salt is used set no_salt to false and
1377  *                            pass NULL here.
1378  *
1379  * @param[in]  enctype        The encryption type of the keytab entry.
1380  *
1381  * @param[in]  password       The password of the keytab entry.
1382  *
1383  * @param[in]  no_salt        If the password should not be salted. Normally
1384  *                            this is only set to false for encryption types
1385  *                            which do not support salting like RC4.
1386  *
1387  * @param[in]  keep_old_entries Wether to keep or delte old keytab entries.
1388  *
1389  * @retval 0 on Success
1390  *
1391  * @return A corresponding KRB5 error code.
1392  *
1393  * @see smb_krb5_kt_open()
1394  */
1395 krb5_error_code smb_krb5_kt_add_entry(krb5_context context,
1396                                       krb5_keytab keytab,
1397                                       krb5_kvno kvno,
1398                                       const char *princ_s,
1399                                       const char *salt_principal,
1400                                       krb5_enctype enctype,
1401                                       krb5_data *password,
1402                                       bool no_salt,
1403                                       bool keep_old_entries)
1404 {
1405         krb5_error_code ret;
1406         krb5_keytab_entry kt_entry;
1407         krb5_principal princ = NULL;
1408         krb5_keyblock *keyp;
1409
1410         ZERO_STRUCT(kt_entry);
1411
1412         ret = smb_krb5_parse_name(context, princ_s, &princ);
1413         if (ret) {
1414                 DEBUG(1, (__location__ ": smb_krb5_parse_name(%s) "
1415                           "failed (%s)\n", princ_s, error_message(ret)));
1416                 goto out;
1417         }
1418
1419         /* Seek and delete old keytab entries */
1420         ret = smb_krb5_kt_seek_and_delete_old_entries(context,
1421                                                       keytab,
1422                                                       kvno,
1423                                                       enctype,
1424                                                       princ_s,
1425                                                       princ,
1426                                                       false,
1427                                                       keep_old_entries);
1428         if (ret) {
1429                 goto out;
1430         }
1431
1432         /* If we get here, we have deleted all the old entries with kvno's
1433          * not equal to the current kvno-1. */
1434
1435         keyp = KRB5_KT_KEY(&kt_entry);
1436
1437         if (no_salt) {
1438                 KRB5_KEY_DATA(keyp) = (KRB5_KEY_DATA_CAST *)SMB_MALLOC(password->length);
1439                 if (KRB5_KEY_DATA(keyp) == NULL) {
1440                         ret = ENOMEM;
1441                         goto out;
1442                 }
1443                 memcpy(KRB5_KEY_DATA(keyp), password->data, password->length);
1444                 KRB5_KEY_LENGTH(keyp) = password->length;
1445                 KRB5_KEY_TYPE(keyp) = enctype;
1446         } else {
1447                 krb5_principal salt_princ = NULL;
1448
1449                 /* Now add keytab entries for all encryption types */
1450                 ret = smb_krb5_parse_name(context, salt_principal, &salt_princ);
1451                 if (ret) {
1452                         DBG_WARNING("krb5_parse_name(%s) failed (%s)\n",
1453                                     salt_principal, error_message(ret));
1454                         goto out;
1455                 }
1456
1457                 ret = smb_krb5_create_key_from_string(context,
1458                                                       salt_princ,
1459                                                       NULL,
1460                                                       password,
1461                                                       enctype,
1462                                                       keyp);
1463                 krb5_free_principal(context, salt_princ);
1464                 if (ret != 0) {
1465                         goto out;
1466                 }
1467         }
1468
1469         kt_entry.principal = princ;
1470         kt_entry.vno       = kvno;
1471
1472         DEBUG(3, (__location__ ": adding keytab entry for (%s) with "
1473                   "encryption type (%d) and version (%d)\n",
1474                   princ_s, enctype, kt_entry.vno));
1475         ret = krb5_kt_add_entry(context, keytab, &kt_entry);
1476         krb5_free_keyblock_contents(context, keyp);
1477         ZERO_STRUCT(kt_entry);
1478         if (ret) {
1479                 DEBUG(1, (__location__ ": adding entry to keytab "
1480                           "failed (%s)\n", error_message(ret)));
1481                 goto out;
1482         }
1483
1484 out:
1485         if (princ) {
1486                 krb5_free_principal(context, princ);
1487         }
1488
1489         return ret;
1490 }
1491
1492 #if defined(HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE) && \
1493     defined(HAVE_KRB5_GET_CREDS_OPT_ALLOC) && \
1494     defined(HAVE_KRB5_GET_CREDS)
1495 static krb5_error_code smb_krb5_get_credentials_for_user_opt(krb5_context context,
1496                                                              krb5_ccache ccache,
1497                                                              krb5_principal me,
1498                                                              krb5_principal server,
1499                                                              krb5_principal impersonate_princ,
1500                                                              krb5_creds **out_creds)
1501 {
1502         krb5_error_code ret;
1503         krb5_get_creds_opt opt;
1504
1505         ret = krb5_get_creds_opt_alloc(context, &opt);
1506         if (ret) {
1507                 goto done;
1508         }
1509         krb5_get_creds_opt_add_options(context, opt, KRB5_GC_FORWARDABLE);
1510
1511         if (impersonate_princ) {
1512                 ret = krb5_get_creds_opt_set_impersonate(context, opt,
1513                                                          impersonate_princ);
1514                 if (ret) {
1515                         goto done;
1516                 }
1517         }
1518
1519         ret = krb5_get_creds(context, opt, ccache, server, out_creds);
1520         if (ret) {
1521                 goto done;
1522         }
1523
1524  done:
1525         if (opt) {
1526                 krb5_get_creds_opt_free(context, opt);
1527         }
1528         return ret;
1529 }
1530 #endif /* HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE */
1531
1532 #ifdef HAVE_KRB5_GET_CREDENTIALS_FOR_USER
1533
1534 #if !HAVE_DECL_KRB5_GET_CREDENTIALS_FOR_USER
1535 krb5_error_code KRB5_CALLCONV
1536 krb5_get_credentials_for_user(krb5_context context, krb5_flags options,
1537                               krb5_ccache ccache, krb5_creds *in_creds,
1538                               krb5_data *subject_cert,
1539                               krb5_creds **out_creds);
1540 #endif /* !HAVE_DECL_KRB5_GET_CREDENTIALS_FOR_USER */
1541
1542 static krb5_error_code smb_krb5_get_credentials_for_user(krb5_context context,
1543                                                          krb5_ccache ccache,
1544                                                          krb5_principal me,
1545                                                          krb5_principal server,
1546                                                          krb5_principal impersonate_princ,
1547                                                          krb5_creds **out_creds)
1548 {
1549         krb5_error_code ret;
1550         krb5_creds in_creds;
1551
1552         ZERO_STRUCT(in_creds);
1553
1554         if (impersonate_princ) {
1555
1556                 in_creds.server = me;
1557                 in_creds.client = impersonate_princ;
1558
1559                 ret = krb5_get_credentials_for_user(context,
1560                                                     0, /* krb5_flags options */
1561                                                     ccache,
1562                                                     &in_creds,
1563                                                     NULL, /* krb5_data *subject_cert */
1564                                                     out_creds);
1565         } else {
1566                 in_creds.client = me;
1567                 in_creds.server = server;
1568
1569                 ret = krb5_get_credentials(context, 0, ccache,
1570                                            &in_creds, out_creds);
1571         }
1572
1573         return ret;
1574 }
1575 #endif /* HAVE_KRB5_GET_CREDENTIALS_FOR_USER */
1576
1577 /*
1578  * smb_krb5_get_credentials
1579  *
1580  * @brief Get krb5 credentials for a server
1581  *
1582  * @param[in] context           An initialized krb5_context
1583  * @param[in] ccache            An initialized krb5_ccache
1584  * @param[in] me                The krb5_principal of the caller
1585  * @param[in] server            The krb5_principal of the requested service
1586  * @param[in] impersonate_princ The krb5_principal of a user to impersonate as (optional)
1587  * @param[out] out_creds        The returned krb5_creds structure
1588  * @return krb5_error_code
1589  *
1590  */
1591 krb5_error_code smb_krb5_get_credentials(krb5_context context,
1592                                          krb5_ccache ccache,
1593                                          krb5_principal me,
1594                                          krb5_principal server,
1595                                          krb5_principal impersonate_princ,
1596                                          krb5_creds **out_creds)
1597 {
1598         krb5_error_code ret;
1599         krb5_creds *creds = NULL;
1600
1601         if (out_creds != NULL) {
1602                 *out_creds = NULL;
1603         }
1604
1605         if (impersonate_princ) {
1606 #ifdef HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE /* Heimdal */
1607                 ret = smb_krb5_get_credentials_for_user_opt(context, ccache, me, server, impersonate_princ, &creds);
1608 #elif defined(HAVE_KRB5_GET_CREDENTIALS_FOR_USER) /* MIT */
1609                 ret = smb_krb5_get_credentials_for_user(context, ccache, me, server, impersonate_princ, &creds);
1610 #else
1611                 ret = ENOTSUP;
1612 #endif
1613         } else {
1614                 krb5_creds in_creds;
1615
1616                 ZERO_STRUCT(in_creds);
1617
1618                 in_creds.client = me;
1619                 in_creds.server = server;
1620
1621                 ret = krb5_get_credentials(context, 0, ccache,
1622                                            &in_creds, &creds);
1623         }
1624         if (ret) {
1625                 goto done;
1626         }
1627
1628         if (out_creds) {
1629                 *out_creds = creds;
1630         }
1631
1632  done:
1633         if (creds && ret) {
1634                 krb5_free_creds(context, creds);
1635         }
1636
1637         return ret;
1638 }
1639
1640 krb5_error_code smb_krb5_keyblock_init_contents(krb5_context context,
1641                                                 krb5_enctype enctype,
1642                                                 const void *data,
1643                                                 size_t length,
1644                                                 krb5_keyblock *key)
1645 {
1646 #if defined(HAVE_KRB5_KEYBLOCK_INIT)
1647         return krb5_keyblock_init(context, enctype, data, length, key);
1648 #else
1649         memset(key, 0, sizeof(krb5_keyblock));
1650         KRB5_KEY_DATA(key) = SMB_MALLOC(length);
1651         if (NULL == KRB5_KEY_DATA(key)) {
1652                 return ENOMEM;
1653         }
1654         memcpy(KRB5_KEY_DATA(key), data, length);
1655         KRB5_KEY_LENGTH(key) = length;
1656         KRB5_KEY_TYPE(key) = enctype;
1657         return 0;
1658 #endif
1659 }
1660
1661 /*
1662   simulate a kinit, putting the tgt in the given credentials cache.
1663   Orignally by remus@snapserver.com
1664
1665   This version is built to use a keyblock, rather than needing the
1666   original password.
1667
1668   The impersonate_principal is the principal if NULL, or the principal
1669   to impersonate
1670
1671   The target_service defaults to the krbtgt if NULL, but could be
1672    kpasswd/realm or the local service (if we are doing s4u2self)
1673 */
1674 krb5_error_code kerberos_kinit_keyblock_cc(krb5_context ctx, krb5_ccache cc,
1675                                            krb5_principal principal,
1676                                            krb5_keyblock *keyblock,
1677                                            const char *target_service,
1678                                            krb5_get_init_creds_opt *krb_options,
1679                                            time_t *expire_time,
1680                                            time_t *kdc_time)
1681 {
1682         krb5_error_code code = 0;
1683         krb5_creds my_creds;
1684
1685 #if defined(HAVE_KRB5_GET_INIT_CREDS_KEYBLOCK)
1686         code = krb5_get_init_creds_keyblock(ctx, &my_creds, principal,
1687                                             keyblock, 0, target_service,
1688                                             krb_options);
1689 #elif defined(HAVE_KRB5_GET_INIT_CREDS_KEYTAB)
1690 {
1691 #define SMB_CREDS_KEYTAB "MEMORY:tmp_smb_creds_XXXXXX"
1692         char tmp_name[sizeof(SMB_CREDS_KEYTAB)];
1693         krb5_keytab_entry entry;
1694         krb5_keytab keytab;
1695         mode_t mask;
1696
1697         memset(&entry, 0, sizeof(entry));
1698         entry.principal = principal;
1699         *(KRB5_KT_KEY(&entry)) = *keyblock;
1700
1701         memcpy(tmp_name, SMB_CREDS_KEYTAB, sizeof(SMB_CREDS_KEYTAB));
1702         mask = umask(S_IRWXO | S_IRWXG);
1703         mktemp(tmp_name);
1704         umask(mask);
1705         if (tmp_name[0] == 0) {
1706                 return KRB5_KT_BADNAME;
1707         }
1708         code = krb5_kt_resolve(ctx, tmp_name, &keytab);
1709         if (code) {
1710                 return code;
1711         }
1712
1713         code = krb5_kt_add_entry(ctx, keytab, &entry);
1714         if (code) {
1715                 (void)krb5_kt_close(ctx, keytab);
1716                 goto done;
1717         }
1718
1719         code = krb5_get_init_creds_keytab(ctx, &my_creds, principal,
1720                                           keytab, 0, target_service,
1721                                           krb_options);
1722         (void)krb5_kt_close(ctx, keytab);
1723 }
1724 #else
1725 #error krb5_get_init_creds_keyblock not available!
1726 #endif
1727         if (code) {
1728                 return code;
1729         }
1730
1731 #ifndef SAMBA4_USES_HEIMDAL /* MIT */
1732         /*
1733          * We need to store the principal as returned from the KDC to the
1734          * credentials cache. If we don't do that the KRB5 library is not
1735          * able to find the tickets it is looking for
1736          */
1737         principal = my_creds.client;
1738 #endif
1739         code = krb5_cc_initialize(ctx, cc, principal);
1740         if (code) {
1741                 goto done;
1742         }
1743
1744         code = krb5_cc_store_cred(ctx, cc, &my_creds);
1745         if (code) {
1746                 goto done;
1747         }
1748
1749         if (expire_time) {
1750                 *expire_time = (time_t) my_creds.times.endtime;
1751         }
1752
1753         if (kdc_time) {
1754                 *kdc_time = (time_t) my_creds.times.starttime;
1755         }
1756
1757         code = 0;
1758 done:
1759         krb5_free_cred_contents(ctx, &my_creds);
1760         return code;
1761 }
1762
1763 krb5_error_code kerberos_kinit_password_cc(krb5_context ctx, krb5_ccache cc,
1764                                            krb5_principal principal,
1765                                            const char *password,
1766                                            const char *target_service,
1767                                            krb5_get_init_creds_opt *krb_options,
1768                                            time_t *expire_time,
1769                                            time_t *kdc_time)
1770 {
1771         krb5_error_code code = 0;
1772         krb5_creds my_creds;
1773
1774         code = krb5_get_init_creds_password(ctx, &my_creds, principal,
1775                                             password, NULL, NULL, 0,
1776                                             target_service, krb_options);
1777         if (code) {
1778                 return code;
1779         }
1780
1781 #ifndef SAMBA4_USES_HEIMDAL /* MIT */
1782         /*
1783          * We need to store the principal as returned from the KDC to the
1784          * credentials cache. If we don't do that the KRB5 library is not
1785          * able to find the tickets it is looking for
1786          */
1787         principal = my_creds.client;
1788 #endif
1789         code = krb5_cc_initialize(ctx, cc, principal);
1790         if (code) {
1791                 goto done;
1792         }
1793
1794         code = krb5_cc_store_cred(ctx, cc, &my_creds);
1795         if (code) {
1796                 goto done;
1797         }
1798
1799         if (expire_time) {
1800                 *expire_time = (time_t) my_creds.times.endtime;
1801         }
1802
1803         if (kdc_time) {
1804                 *kdc_time = (time_t) my_creds.times.starttime;
1805         }
1806
1807         code = 0;
1808 done:
1809         krb5_free_cred_contents(ctx, &my_creds);
1810         return code;
1811 }
1812
1813 #ifdef SAMBA4_USES_HEIMDAL
1814 /*
1815   simulate a kinit, putting the tgt in the given credentials cache.
1816   Orignally by remus@snapserver.com
1817
1818   The impersonate_principal is the principal
1819
1820   The self_service, should be the local service (for S4U2Self if
1821   impersonate_principal is given).
1822
1823   The target_service defaults to the krbtgt if NULL, but could be
1824   kpasswd/realm or a remote service (for S4U2Proxy)
1825
1826 */
1827 krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
1828                                         krb5_ccache store_cc,
1829                                         krb5_principal init_principal,
1830                                         const char *init_password,
1831                                         krb5_principal impersonate_principal,
1832                                         const char *self_service,
1833                                         const char *target_service,
1834                                         krb5_get_init_creds_opt *krb_options,
1835                                         time_t *expire_time,
1836                                         time_t *kdc_time)
1837 {
1838         krb5_error_code code = 0;
1839         krb5_get_creds_opt options;
1840         krb5_principal store_principal;
1841         krb5_creds store_creds;
1842         krb5_creds *s4u2self_creds;
1843         Ticket s4u2self_ticket;
1844         size_t s4u2self_ticketlen;
1845         krb5_creds *s4u2proxy_creds;
1846         krb5_principal self_princ;
1847         bool s4u2proxy;
1848         krb5_principal target_princ;
1849         krb5_ccache tmp_cc;
1850         const char *self_realm;
1851         krb5_principal blacklist_principal = NULL;
1852         krb5_principal whitelist_principal = NULL;
1853
1854         code = krb5_get_init_creds_password(ctx, &store_creds,
1855                                             init_principal,
1856                                             init_password,
1857                                             NULL, NULL,
1858                                             0,
1859                                             NULL,
1860                                             krb_options);
1861         if (code != 0) {
1862                 return code;
1863         }
1864
1865         store_principal = init_principal;
1866
1867         /*
1868          * We are trying S4U2Self now:
1869          *
1870          * As we do not want to expose our TGT in the
1871          * krb5_ccache, which is also holds the impersonated creds.
1872          *
1873          * Some low level krb5/gssapi function might use the TGT
1874          * identity and let the client act as our machine account.
1875          *
1876          * We need to avoid that and use a temporary krb5_ccache
1877          * in order to pass our TGT to the krb5_get_creds() function.
1878          */
1879         code = krb5_cc_new_unique(ctx, NULL, NULL, &tmp_cc);
1880         if (code != 0) {
1881                 krb5_free_cred_contents(ctx, &store_creds);
1882                 return code;
1883         }
1884
1885         code = krb5_cc_initialize(ctx, tmp_cc, store_creds.client);
1886         if (code != 0) {
1887                 krb5_cc_destroy(ctx, tmp_cc);
1888                 krb5_free_cred_contents(ctx, &store_creds);
1889                 return code;
1890         }
1891
1892         code = krb5_cc_store_cred(ctx, tmp_cc, &store_creds);
1893         if (code != 0) {
1894                 krb5_free_cred_contents(ctx, &store_creds);
1895                 krb5_cc_destroy(ctx, tmp_cc);
1896                 return code;
1897         }
1898
1899         /*
1900          * we need to remember the client principal of our
1901          * TGT and make sure the KDC does not return this
1902          * in the impersonated tickets. This can happen
1903          * if the KDC does not support S4U2Self and S4U2Proxy.
1904          */
1905         blacklist_principal = store_creds.client;
1906         store_creds.client = NULL;
1907         krb5_free_cred_contents(ctx, &store_creds);
1908
1909         /*
1910          * Check if we also need S4U2Proxy or if S4U2Self is
1911          * enough in order to get a ticket for the target.
1912          */
1913         if (target_service == NULL) {
1914                 s4u2proxy = false;
1915         } else if (strcmp(target_service, self_service) == 0) {
1916                 s4u2proxy = false;
1917         } else {
1918                 s4u2proxy = true;
1919         }
1920
1921         /*
1922          * For S4U2Self we need our own service principal,
1923          * which belongs to our own realm (available on
1924          * our client principal).
1925          */
1926         self_realm = krb5_principal_get_realm(ctx, init_principal);
1927
1928         code = krb5_parse_name(ctx, self_service, &self_princ);
1929         if (code != 0) {
1930                 krb5_free_principal(ctx, blacklist_principal);
1931                 krb5_cc_destroy(ctx, tmp_cc);
1932                 return code;
1933         }
1934
1935         code = krb5_principal_set_realm(ctx, self_princ, self_realm);
1936         if (code != 0) {
1937                 krb5_free_principal(ctx, blacklist_principal);
1938                 krb5_free_principal(ctx, self_princ);
1939                 krb5_cc_destroy(ctx, tmp_cc);
1940                 return code;
1941         }
1942
1943         code = krb5_get_creds_opt_alloc(ctx, &options);
1944         if (code != 0) {
1945                 krb5_free_principal(ctx, blacklist_principal);
1946                 krb5_free_principal(ctx, self_princ);
1947                 krb5_cc_destroy(ctx, tmp_cc);
1948                 return code;
1949         }
1950
1951         if (s4u2proxy) {
1952                 /*
1953                  * If we want S4U2Proxy, we need the forwardable flag
1954                  * on the S4U2Self ticket.
1955                  */
1956                 krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
1957         }
1958
1959         code = krb5_get_creds_opt_set_impersonate(ctx, options,
1960                                                   impersonate_principal);
1961         if (code != 0) {
1962                 krb5_get_creds_opt_free(ctx, options);
1963                 krb5_free_principal(ctx, blacklist_principal);
1964                 krb5_free_principal(ctx, self_princ);
1965                 krb5_cc_destroy(ctx, tmp_cc);
1966                 return code;
1967         }
1968
1969         code = krb5_get_creds(ctx, options, tmp_cc,
1970                               self_princ, &s4u2self_creds);
1971         krb5_get_creds_opt_free(ctx, options);
1972         krb5_free_principal(ctx, self_princ);
1973         if (code != 0) {
1974                 krb5_free_principal(ctx, blacklist_principal);
1975                 krb5_cc_destroy(ctx, tmp_cc);
1976                 return code;
1977         }
1978
1979         if (!s4u2proxy) {
1980                 krb5_cc_destroy(ctx, tmp_cc);
1981
1982                 /*
1983                  * Now make sure we store the impersonated principal
1984                  * and creds instead of the TGT related stuff
1985                  * in the krb5_ccache of the caller.
1986                  */
1987                 code = krb5_copy_creds_contents(ctx, s4u2self_creds,
1988                                                 &store_creds);
1989                 krb5_free_creds(ctx, s4u2self_creds);
1990                 if (code != 0) {
1991                         return code;
1992                 }
1993
1994                 /*
1995                  * It's important to store the principal the KDC
1996                  * returned, as otherwise the caller would not find
1997                  * the S4U2Self ticket in the krb5_ccache lookup.
1998                  */
1999                 store_principal = store_creds.client;
2000                 goto store;
2001         }
2002
2003         /*
2004          * We are trying S4U2Proxy:
2005          *
2006          * We need the ticket from the S4U2Self step
2007          * and our TGT in order to get the delegated ticket.
2008          */
2009         code = decode_Ticket((const uint8_t *)s4u2self_creds->ticket.data,
2010                              s4u2self_creds->ticket.length,
2011                              &s4u2self_ticket,
2012                              &s4u2self_ticketlen);
2013         if (code != 0) {
2014                 krb5_free_creds(ctx, s4u2self_creds);
2015                 krb5_free_principal(ctx, blacklist_principal);
2016                 krb5_cc_destroy(ctx, tmp_cc);
2017                 return code;
2018         }
2019
2020         /*
2021          * we need to remember the client principal of the
2022          * S4U2Self stage and as it needs to match the one we
2023          * will get for the S4U2Proxy stage. We need this
2024          * in order to detect KDCs which does not support S4U2Proxy.
2025          */
2026         whitelist_principal = s4u2self_creds->client;
2027         s4u2self_creds->client = NULL;
2028         krb5_free_creds(ctx, s4u2self_creds);
2029
2030         /*
2031          * For S4U2Proxy we also got a target service principal,
2032          * which also belongs to our own realm (available on
2033          * our client principal).
2034          */
2035         code = krb5_parse_name(ctx, target_service, &target_princ);
2036         if (code != 0) {
2037                 free_Ticket(&s4u2self_ticket);
2038                 krb5_free_principal(ctx, whitelist_principal);
2039                 krb5_free_principal(ctx, blacklist_principal);
2040                 krb5_cc_destroy(ctx, tmp_cc);
2041                 return code;
2042         }
2043
2044         code = krb5_principal_set_realm(ctx, target_princ, self_realm);
2045         if (code != 0) {
2046                 free_Ticket(&s4u2self_ticket);
2047                 krb5_free_principal(ctx, target_princ);
2048                 krb5_free_principal(ctx, whitelist_principal);
2049                 krb5_free_principal(ctx, blacklist_principal);
2050                 krb5_cc_destroy(ctx, tmp_cc);
2051                 return code;
2052         }
2053
2054         code = krb5_get_creds_opt_alloc(ctx, &options);
2055         if (code != 0) {
2056                 free_Ticket(&s4u2self_ticket);
2057                 krb5_free_principal(ctx, target_princ);
2058                 krb5_free_principal(ctx, whitelist_principal);
2059                 krb5_free_principal(ctx, blacklist_principal);
2060                 krb5_cc_destroy(ctx, tmp_cc);
2061                 return code;
2062         }
2063
2064         krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
2065         krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_CONSTRAINED_DELEGATION);
2066
2067         code = krb5_get_creds_opt_set_ticket(ctx, options, &s4u2self_ticket);
2068         free_Ticket(&s4u2self_ticket);
2069         if (code != 0) {
2070                 krb5_get_creds_opt_free(ctx, options);
2071                 krb5_free_principal(ctx, target_princ);
2072                 krb5_free_principal(ctx, whitelist_principal);
2073                 krb5_free_principal(ctx, blacklist_principal);
2074                 krb5_cc_destroy(ctx, tmp_cc);
2075                 return code;
2076         }
2077
2078         code = krb5_get_creds(ctx, options, tmp_cc,
2079                               target_princ, &s4u2proxy_creds);
2080         krb5_get_creds_opt_free(ctx, options);
2081         krb5_free_principal(ctx, target_princ);
2082         krb5_cc_destroy(ctx, tmp_cc);
2083         if (code != 0) {
2084                 krb5_free_principal(ctx, whitelist_principal);
2085                 krb5_free_principal(ctx, blacklist_principal);
2086                 return code;
2087         }
2088
2089         /*
2090          * Now make sure we store the impersonated principal
2091          * and creds instead of the TGT related stuff
2092          * in the krb5_ccache of the caller.
2093          */
2094         code = krb5_copy_creds_contents(ctx, s4u2proxy_creds,
2095                                         &store_creds);
2096         krb5_free_creds(ctx, s4u2proxy_creds);
2097         if (code != 0) {
2098                 krb5_free_principal(ctx, whitelist_principal);
2099                 krb5_free_principal(ctx, blacklist_principal);
2100                 return code;
2101         }
2102
2103         /*
2104          * It's important to store the principal the KDC
2105          * returned, as otherwise the caller would not find
2106          * the S4U2Self ticket in the krb5_ccache lookup.
2107          */
2108         store_principal = store_creds.client;
2109
2110  store:
2111         if (blacklist_principal &&
2112             krb5_principal_compare(ctx, store_creds.client, blacklist_principal)) {
2113                 char *sp = NULL;
2114                 char *ip = NULL;
2115
2116                 code = krb5_unparse_name(ctx, blacklist_principal, &sp);
2117                 if (code != 0) {
2118                         sp = NULL;
2119                 }
2120                 code = krb5_unparse_name(ctx, impersonate_principal, &ip);
2121                 if (code != 0) {
2122                         ip = NULL;
2123                 }
2124                 DEBUG(1, ("kerberos_kinit_password_cc: "
2125                           "KDC returned self principal[%s] while impersonating [%s]\n",
2126                           sp?sp:"<no memory>",
2127                           ip?ip:"<no memory>"));
2128
2129                 SAFE_FREE(sp);
2130                 SAFE_FREE(ip);
2131
2132                 krb5_free_principal(ctx, whitelist_principal);
2133                 krb5_free_principal(ctx, blacklist_principal);
2134                 krb5_free_cred_contents(ctx, &store_creds);
2135                 return KRB5_FWD_BAD_PRINCIPAL;
2136         }
2137         if (blacklist_principal) {
2138                 krb5_free_principal(ctx, blacklist_principal);
2139         }
2140
2141         if (whitelist_principal &&
2142             !krb5_principal_compare(ctx, store_creds.client, whitelist_principal)) {
2143                 char *sp = NULL;
2144                 char *ep = NULL;
2145
2146                 code = krb5_unparse_name(ctx, store_creds.client, &sp);
2147                 if (code != 0) {
2148                         sp = NULL;
2149                 }
2150                 code = krb5_unparse_name(ctx, whitelist_principal, &ep);
2151                 if (code != 0) {
2152                         ep = NULL;
2153                 }
2154                 DEBUG(1, ("kerberos_kinit_password_cc: "
2155                           "KDC returned wrong principal[%s] we expected [%s]\n",
2156                           sp?sp:"<no memory>",
2157                           ep?ep:"<no memory>"));
2158
2159                 SAFE_FREE(sp);
2160                 SAFE_FREE(ep);
2161
2162                 krb5_free_principal(ctx, whitelist_principal);
2163                 krb5_free_cred_contents(ctx, &store_creds);
2164                 return KRB5_FWD_BAD_PRINCIPAL;
2165         }
2166         if (whitelist_principal) {
2167                 krb5_free_principal(ctx, whitelist_principal);
2168         }
2169
2170         code = krb5_cc_initialize(ctx, store_cc, store_principal);
2171         if (code != 0) {
2172                 krb5_free_cred_contents(ctx, &store_creds);
2173                 return code;
2174         }
2175
2176         code = krb5_cc_store_cred(ctx, store_cc, &store_creds);
2177         if (code != 0) {
2178                 krb5_free_cred_contents(ctx, &store_creds);
2179                 return code;
2180         }
2181
2182         if (expire_time) {
2183                 *expire_time = (time_t) store_creds.times.endtime;
2184         }
2185
2186         if (kdc_time) {
2187                 *kdc_time = (time_t) store_creds.times.starttime;
2188         }
2189
2190         krb5_free_cred_contents(ctx, &store_creds);
2191
2192         return 0;
2193 }
2194 #endif
2195
2196 #if !defined(HAVE_KRB5_MAKE_PRINCIPAL) && defined(HAVE_KRB5_BUILD_PRINCIPAL_ALLOC_VA)
2197 krb5_error_code smb_krb5_make_principal(krb5_context context,
2198                                         krb5_principal *principal,
2199                                         const char *_realm, ...)
2200 {
2201         krb5_error_code code;
2202         bool free_realm;
2203         char *realm;
2204         va_list ap;
2205
2206         if (_realm) {
2207                 realm = discard_const_p(char, _realm);
2208                 free_realm = false;
2209         } else {
2210                 code = krb5_get_default_realm(context, &realm);
2211                 if (code) {
2212                         return code;
2213                 }
2214                 free_realm = true;
2215         }
2216
2217         va_start(ap, _realm);
2218         code = krb5_build_principal_alloc_va(context, principal,
2219                                              strlen(realm), realm,
2220                                              ap);
2221         va_end(ap);
2222
2223         if (free_realm) {
2224                 krb5_free_default_realm(context, realm);
2225         }
2226
2227         return code;
2228 }
2229 #endif
2230
2231 #if !defined(HAVE_KRB5_CC_GET_LIFETIME) && defined(HAVE_KRB5_CC_RETRIEVE_CRED)
2232 /**
2233  * @brief Get the lifetime of the initial ticket in the cache.
2234  *
2235  * @param[in]  context  The kerberos context.
2236  *
2237  * @param[in]  id       The credential cache to get the ticket lifetime.
2238  *
2239  * @param[out] t        A pointer to a time value to store the lifetime.
2240  *
2241  * @return              0 on success, a krb5_error_code on error.
2242  */
2243 krb5_error_code smb_krb5_cc_get_lifetime(krb5_context context,
2244                                          krb5_ccache id,
2245                                          time_t *t)
2246 {
2247         krb5_cc_cursor cursor;
2248         krb5_error_code kerr;
2249         krb5_creds cred;
2250         krb5_timestamp now;
2251
2252         *t = 0;
2253
2254         kerr = krb5_timeofday(context, &now);
2255         if (kerr) {
2256                 return kerr;
2257         }
2258
2259         kerr = krb5_cc_start_seq_get(context, id, &cursor);
2260         if (kerr) {
2261                 return kerr;
2262         }
2263
2264         while ((kerr = krb5_cc_next_cred(context, id, &cursor, &cred)) == 0) {
2265 #ifndef HAVE_FLAGS_IN_KRB5_CREDS
2266                 if (cred.ticket_flags & TKT_FLG_INITIAL) {
2267 #else
2268                 if (cred.flags.b.initial) {
2269 #endif
2270                         if (now < cred.times.endtime) {
2271                                 *t = (time_t) (cred.times.endtime - now);
2272                         }
2273                         krb5_free_cred_contents(context, &cred);
2274                         break;
2275                 }
2276                 krb5_free_cred_contents(context, &cred);
2277         }
2278
2279         krb5_cc_end_seq_get(context, id, &cursor);
2280
2281         return kerr;
2282 }
2283 #endif /* HAVE_KRB5_CC_GET_LIFETIME */
2284
2285 #if !defined(HAVE_KRB5_FREE_CHECKSUM_CONTENTS) && defined(HAVE_FREE_CHECKSUM)
2286 void smb_krb5_free_checksum_contents(krb5_context ctx, krb5_checksum *cksum)
2287 {
2288         free_Checksum(cksum);
2289 }
2290 #endif
2291
2292 krb5_error_code smb_krb5_make_pac_checksum(TALLOC_CTX *mem_ctx,
2293                                            DATA_BLOB *pac_data,
2294                                            krb5_context context,
2295                                            const krb5_keyblock *keyblock,
2296                                            uint32_t *sig_type,
2297                                            DATA_BLOB *sig_blob)
2298 {
2299         krb5_error_code ret;
2300         krb5_checksum cksum;
2301 #if defined(HAVE_KRB5_CRYPTO_INIT) && defined(HAVE_KRB5_CREATE_CHECKSUM)
2302         krb5_crypto crypto;
2303
2304
2305         ret = krb5_crypto_init(context,
2306                                keyblock,
2307                                0,
2308                                &crypto);
2309         if (ret) {
2310                 DEBUG(0,("krb5_crypto_init() failed: %s\n",
2311                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2312                 return ret;
2313         }
2314         ret = krb5_create_checksum(context,
2315                                    crypto,
2316                                    KRB5_KU_OTHER_CKSUM,
2317                                    0,
2318                                    pac_data->data,
2319                                    pac_data->length,
2320                                    &cksum);
2321         if (ret) {
2322                 DEBUG(2, ("PAC Verification failed: %s\n",
2323                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2324         }
2325
2326         krb5_crypto_destroy(context, crypto);
2327
2328         if (ret) {
2329                 return ret;
2330         }
2331
2332         *sig_type = cksum.cksumtype;
2333         *sig_blob = data_blob_talloc(mem_ctx,
2334                                         cksum.checksum.data,
2335                                         cksum.checksum.length);
2336 #elif defined(HAVE_KRB5_C_MAKE_CHECKSUM)
2337         krb5_data input;
2338
2339         input.data = (char *)pac_data->data;
2340         input.length = pac_data->length;
2341
2342         ret = krb5_c_make_checksum(context,
2343                                    0,
2344                                    keyblock,
2345                                    KRB5_KEYUSAGE_APP_DATA_CKSUM,
2346                                    &input,
2347                                    &cksum);
2348         if (ret) {
2349                 DEBUG(2, ("PAC Verification failed: %s\n",
2350                           smb_get_krb5_error_message(context, ret, mem_ctx)));
2351                 return ret;
2352         }
2353
2354         *sig_type = cksum.checksum_type;
2355         *sig_blob = data_blob_talloc(mem_ctx,
2356                                         cksum.contents,
2357                                         cksum.length);
2358
2359 #else
2360 #error krb5_create_checksum or krb5_c_make_checksum not available
2361 #endif /* HAVE_KRB5_C_MAKE_CHECKSUM */
2362         smb_krb5_free_checksum_contents(context, &cksum);
2363
2364         return 0;
2365 }
2366
2367
2368 /*
2369  * smb_krb5_principal_get_realm
2370  *
2371  * @brief Get realm of a principal
2372  *
2373  * @param[in] context           The krb5_context
2374  * @param[in] principal         The principal
2375  * @return pointer to the realm
2376  *
2377  * Caller must free if the return value is not NULL.
2378  *
2379  */
2380
2381 char *smb_krb5_principal_get_realm(krb5_context context,
2382                                    krb5_const_principal principal)
2383 {
2384 #ifdef HAVE_KRB5_PRINCIPAL_GET_REALM /* Heimdal */
2385         return strdup(discard_const_p(char, krb5_principal_get_realm(context, principal)));
2386 #elif defined(krb5_princ_realm) /* MIT */
2387         krb5_data *realm;
2388         realm = discard_const_p(krb5_data,
2389                                 krb5_princ_realm(context, principal));
2390         return strndup(realm->data, realm->length);
2391 #else
2392 #error UNKNOWN_GET_PRINC_REALM_FUNCTIONS
2393 #endif
2394 }
2395
2396 /*
2397  * smb_krb5_principal_set_realm
2398  *
2399  * @brief Get realm of a principal
2400  *
2401  * @param[in] context           The krb5_context
2402  * @param[in] principal         The principal
2403  * @param[in] realm             The realm
2404  * @return                      0 on success, a krb5_error_code on error.
2405  *
2406  */
2407
2408 krb5_error_code smb_krb5_principal_set_realm(krb5_context context,
2409                                              krb5_principal principal,
2410                                              const char *realm)
2411 {
2412 #ifdef HAVE_KRB5_PRINCIPAL_SET_REALM /* Heimdal */
2413         return krb5_principal_set_realm(context, principal, realm);
2414 #elif defined(krb5_princ_realm) && defined(krb5_princ_set_realm) /* MIT */
2415         krb5_error_code ret;
2416         krb5_data data;
2417         krb5_data *old_data;
2418
2419         old_data = krb5_princ_realm(context, principal);
2420
2421         ret = smb_krb5_copy_data_contents(&data,
2422                                           realm,
2423                                           strlen(realm));
2424         if (ret) {
2425                 return ret;
2426         }
2427
2428         /* free realm before setting */
2429         free(old_data->data);
2430
2431         krb5_princ_set_realm(context, principal, &data);
2432
2433         return ret;
2434 #else
2435 #error UNKNOWN_PRINC_SET_REALM_FUNCTION
2436 #endif
2437 }
2438
2439
2440 /************************************************************************
2441  Routine to get the default realm from the kerberos credentials cache.
2442  Caller must free if the return value is not NULL.
2443 ************************************************************************/
2444
2445 static char *smb_krb5_get_default_realm_from_ccache(TALLOC_CTX *mem_ctx)
2446 {
2447         char *realm = NULL;
2448         krb5_context ctx = NULL;
2449         krb5_ccache cc = NULL;
2450         krb5_principal princ = NULL;
2451
2452         initialize_krb5_error_table();
2453         if (krb5_init_context(&ctx)) {
2454                 return NULL;
2455         }
2456
2457         DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2458                 "Trying to read krb5 cache: %s\n",
2459                 krb5_cc_default_name(ctx)));
2460         if (krb5_cc_default(ctx, &cc)) {
2461                 DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2462                         "failed to read default cache\n"));
2463                 goto out;
2464         }
2465         if (krb5_cc_get_principal(ctx, cc, &princ)) {
2466                 DEBUG(5,("kerberos_get_default_realm_from_ccache: "
2467                         "failed to get default principal\n"));
2468                 goto out;
2469         }
2470
2471 #if defined(HAVE_KRB5_PRINCIPAL_GET_REALM)
2472         realm = talloc_strdup(mem_ctx, krb5_principal_get_realm(ctx, princ));
2473 #elif defined(HAVE_KRB5_PRINC_REALM)
2474         {
2475                 krb5_data *realm_data = krb5_princ_realm(ctx, princ);
2476                 realm = talloc_strndup(mem_ctx, realm_data->data, realm_data->length);
2477         }
2478 #endif
2479
2480   out:
2481
2482         if (ctx) {
2483                 if (princ) {
2484                         krb5_free_principal(ctx, princ);
2485                 }
2486                 if (cc) {
2487                         krb5_cc_close(ctx, cc);
2488                 }
2489                 krb5_free_context(ctx);
2490         }
2491
2492         return realm;
2493 }
2494
2495 /************************************************************************
2496  Routine to get the realm from a given DNS name.
2497 ************************************************************************/
2498
2499 static char *smb_krb5_get_realm_from_hostname(TALLOC_CTX *mem_ctx,
2500                                                 const char *hostname)
2501 {
2502 #if defined(HAVE_KRB5_REALM_TYPE)
2503         /* Heimdal. */
2504         krb5_realm *realm_list = NULL;
2505 #else
2506         /* MIT */
2507         char **realm_list = NULL;
2508 #endif
2509         char *realm = NULL;
2510         krb5_error_code kerr;
2511         krb5_context ctx = NULL;
2512
2513         initialize_krb5_error_table();
2514         if (krb5_init_context(&ctx)) {
2515                 return NULL;
2516         }
2517
2518         kerr = krb5_get_host_realm(ctx, hostname, &realm_list);
2519         if (kerr != 0) {
2520                 DEBUG(3,("kerberos_get_realm_from_hostname %s: "
2521                         "failed %s\n",
2522                         hostname ? hostname : "(NULL)",
2523                         error_message(kerr) ));
2524                 goto out;
2525         }
2526
2527         if (realm_list && realm_list[0]) {
2528                 realm = talloc_strdup(mem_ctx, realm_list[0]);
2529         }
2530
2531   out:
2532
2533         if (ctx) {
2534                 if (realm_list) {
2535                         krb5_free_host_realm(ctx, realm_list);
2536                         realm_list = NULL;
2537                 }
2538                 krb5_free_context(ctx);
2539                 ctx = NULL;
2540         }
2541         return realm;
2542 }
2543
2544 char *kerberos_get_principal_from_service_hostname(TALLOC_CTX *mem_ctx,
2545                                                    const char *service,
2546                                                    const char *remote_name,
2547                                                    const char *default_realm)
2548 {
2549         char *realm = NULL;
2550         char *host = NULL;
2551         char *principal;
2552         host = strchr_m(remote_name, '.');
2553         if (host) {
2554                 /* DNS name. */
2555                 realm = smb_krb5_get_realm_from_hostname(talloc_tos(),
2556                                                          remote_name);
2557         } else {
2558                 /* NetBIOS name - use our realm. */
2559                 realm = smb_krb5_get_default_realm_from_ccache(talloc_tos());
2560         }
2561
2562         if (realm == NULL || *realm == '\0') {
2563                 realm = talloc_strdup(talloc_tos(), default_realm);
2564                 if (!realm) {
2565                         return NULL;
2566                 }
2567                 DEBUG(3,("kerberos_get_principal_from_service_hostname: "
2568                          "cannot get realm from, "
2569                          "desthost %s or default ccache. Using default "
2570                          "smb.conf realm %s\n",
2571                          remote_name,
2572                          realm));
2573         }
2574
2575         principal = talloc_asprintf(mem_ctx,
2576                                     "%s/%s@%s",
2577                                     service, remote_name,
2578                                     realm);
2579         TALLOC_FREE(realm);
2580         return principal;
2581 }
2582
2583 char *smb_get_krb5_error_message(krb5_context context,
2584                                  krb5_error_code code,
2585                                  TALLOC_CTX *mem_ctx)
2586 {
2587         char *ret;
2588
2589 #if defined(HAVE_KRB5_GET_ERROR_MESSAGE) && defined(HAVE_KRB5_FREE_ERROR_MESSAGE)
2590         const char *context_error = krb5_get_error_message(context, code);
2591         if (context_error) {
2592                 ret = talloc_asprintf(mem_ctx, "%s: %s",
2593                                         error_message(code), context_error);
2594                 krb5_free_error_message(context, context_error);
2595                 return ret;
2596         }
2597 #endif
2598         ret = talloc_strdup(mem_ctx, error_message(code));
2599         return ret;
2600 }
2601
2602
2603 /**
2604 * @brief Return the kerberos library setting for "libdefaults:allow_weak_crypto"
2605 *
2606 * @param context        The krb5_context
2607 *
2608 * @return krb5_boolean
2609 *
2610 * Function returns true if weak crypto is allowd, false if not
2611 */
2612
2613 krb5_boolean smb_krb5_get_allowed_weak_crypto(krb5_context context)
2614 #if defined(HAVE_KRB5_CONFIG_GET_BOOL_DEFAULT)
2615 {
2616         return krb5_config_get_bool_default(context,
2617                                             NULL,
2618                                             FALSE,
2619                                             "libdefaults",
2620                                             "allow_weak_crypto",
2621                                             NULL);
2622 }
2623 #elif defined(HAVE_PROFILE_H) && defined(HAVE_KRB5_GET_PROFILE)
2624 {
2625 #include <profile.h>
2626         krb5_error_code ret;
2627         krb5_boolean ret_default = false;
2628         profile_t profile;
2629         int ret_profile;
2630
2631         ret = krb5_get_profile(context,
2632                                &profile);
2633         if (ret) {
2634                 return ret_default;
2635         }
2636
2637         ret = profile_get_boolean(profile,
2638                                   "libdefaults",
2639                                   "allow_weak_crypto",
2640                                   NULL, /* subsubname */
2641                                   ret_default, /* def_val */
2642                                   &ret_profile /* *ret_default */);
2643         if (ret) {
2644                 return ret_default;
2645         }
2646
2647         profile_release(profile);
2648
2649         return ret_profile;
2650 }
2651 #else
2652 #error UNKNOWN_KRB5_CONFIG_ROUTINES
2653 #endif
2654
2655 /**
2656 * @brief Return the type of a krb5_principal
2657 *
2658 * @param context        The krb5_context
2659 * @param principal      The const krb5_principal
2660 *
2661 * @return integer type of the principal
2662 */
2663 int smb_krb5_principal_get_type(krb5_context context,
2664                                 krb5_const_principal principal)
2665 {
2666 #ifdef HAVE_KRB5_PRINCIPAL_GET_TYPE /* Heimdal */
2667         return krb5_principal_get_type(context, principal);
2668 #elif defined(krb5_princ_type) /* MIT */
2669         return krb5_princ_type(context, principal);
2670 #else
2671 #error  UNKNOWN_PRINC_GET_TYPE_FUNCTION
2672 #endif
2673 }
2674
2675 /**
2676 * @brief Set the type of a krb5_principal
2677 *
2678 * @param context        The krb5_context
2679 * @param principal      The const krb5_principal
2680 * @param type           The principal type
2681 *
2682 */
2683 void smb_krb5_principal_set_type(krb5_context context,
2684                                  krb5_principal principal,
2685                                  int type)
2686 {
2687 #ifdef HAVE_KRB5_PRINCIPAL_SET_TYPE /* Heimdal */
2688         krb5_principal_set_type(context, principal, type);
2689 #elif defined(krb5_princ_type) /* MIT */
2690         krb5_princ_type(context, principal) = type;
2691 #else
2692 #error  UNKNOWN_PRINC_SET_TYPE_FUNCTION
2693 #endif
2694 }
2695
2696 /**
2697 * @brief Generate a krb5 warning, forwarding to com_err
2698 *
2699 * @param context        The krb5_context
2700 * @param fmt            The message format
2701 * @param ...            The message arguments
2702 *
2703 * @return
2704 */
2705 #if !defined(HAVE_KRB5_WARNX)
2706 krb5_error_code krb5_warnx(krb5_context context, const char *fmt, ...)
2707 {
2708         va_list args;
2709
2710         va_start(args, fmt);
2711         com_err_va("kdb_samba", errno, fmt, args);
2712         va_end(args);
2713
2714         return 0;
2715 }
2716 #endif
2717
2718 krb5_error_code smb_krb5_cc_copy_creds(krb5_context context,
2719                                        krb5_ccache incc, krb5_ccache outcc)
2720 {
2721 #ifdef HAVE_KRB5_CC_COPY_CACHE /* Heimdal */
2722         return krb5_cc_copy_cache(context, incc, outcc);
2723 #elif defined(HAVE_KRB5_CC_COPY_CREDS)
2724         return krb5_cc_copy_creds(context, incc, outcc);
2725 #else
2726 #error UNKNOWN_KRB5_CC_COPY_CACHE_OR_CREDS_FUNCTION
2727 #endif
2728 }
2729
2730 /**********************************************************
2731  * ADS KRB5 CALLS
2732  **********************************************************/
2733
2734 static bool ads_cleanup_expired_creds(krb5_context context,
2735                                       krb5_ccache  ccache,
2736                                       krb5_creds  *credsp)
2737 {
2738         krb5_error_code retval;
2739         const char *cc_type = krb5_cc_get_type(context, ccache);
2740
2741         DEBUG(3, ("ads_cleanup_expired_creds: Ticket in ccache[%s:%s] expiration %s\n",
2742                   cc_type, krb5_cc_get_name(context, ccache),
2743                   http_timestring(talloc_tos(), credsp->times.endtime)));
2744
2745         /* we will probably need new tickets if the current ones
2746            will expire within 10 seconds.
2747         */
2748         if (credsp->times.endtime >= (time(NULL) + 10))
2749                 return false;
2750
2751         /* heimdal won't remove creds from a file ccache, and
2752            perhaps we shouldn't anyway, since internally we
2753            use memory ccaches, and a FILE one probably means that
2754            we're using creds obtained outside of our exectuable
2755         */
2756         if (strequal(cc_type, "FILE")) {
2757                 DEBUG(5, ("ads_cleanup_expired_creds: We do not remove creds from a %s ccache\n", cc_type));
2758                 return false;
2759         }
2760
2761         retval = krb5_cc_remove_cred(context, ccache, 0, credsp);
2762         if (retval) {
2763                 DEBUG(1, ("ads_cleanup_expired_creds: krb5_cc_remove_cred failed, err %s\n",
2764                           error_message(retval)));
2765                 /* If we have an error in this, we want to display it,
2766                    but continue as though we deleted it */
2767         }
2768         return true;
2769 }
2770
2771 /* Allocate and setup the auth context into the state we need. */
2772
2773 static krb5_error_code ads_setup_auth_context(krb5_context context,
2774                                               krb5_auth_context *auth_context)
2775 {
2776         krb5_error_code retval;
2777
2778         retval = krb5_auth_con_init(context, auth_context );
2779         if (retval) {
2780                 DEBUG(1,("krb5_auth_con_init failed (%s)\n",
2781                         error_message(retval)));
2782                 return retval;
2783         }
2784
2785         /* Ensure this is an addressless ticket. */
2786         retval = krb5_auth_con_setaddrs(context, *auth_context, NULL, NULL);
2787         if (retval) {
2788                 DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n",
2789                         error_message(retval)));
2790         }
2791
2792         return retval;
2793 }
2794
2795 #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)
2796 static krb5_error_code ads_create_gss_checksum(krb5_data *in_data, /* [inout] */
2797                                                uint32_t gss_flags)
2798 {
2799         unsigned int orig_length = in_data->length;
2800         unsigned int base_cksum_size = GSSAPI_CHECKSUM_SIZE;
2801         char *gss_cksum = NULL;
2802
2803         if (orig_length) {
2804                 /* Extra length field for delgated ticket. */
2805                 base_cksum_size += 4;
2806         }
2807
2808         if ((unsigned int)base_cksum_size + orig_length <
2809                         (unsigned int)base_cksum_size) {
2810                 return EINVAL;
2811         }
2812
2813         gss_cksum = (char *)SMB_MALLOC(base_cksum_size + orig_length);
2814         if (gss_cksum == NULL) {
2815                 return ENOMEM;
2816         }
2817
2818         memset(gss_cksum, '\0', base_cksum_size + orig_length);
2819         SIVAL(gss_cksum, 0, GSSAPI_BNDLENGTH);
2820
2821         /*
2822          * GSS_C_NO_CHANNEL_BINDINGS means 16 zero bytes.
2823          * This matches the behavior of heimdal and mit.
2824          *
2825          * And it is needed to work against some closed source
2826          * SMB servers.
2827          *
2828          * See bug #7883
2829          */
2830         memset(&gss_cksum[4], 0x00, GSSAPI_BNDLENGTH);
2831
2832         SIVAL(gss_cksum, 20, gss_flags);
2833
2834         if (orig_length) {
2835                 SSVAL(gss_cksum, 24, 1); /* The Delegation Option identifier */
2836                 SSVAL(gss_cksum, 26, orig_length);
2837                 /* Copy the kerberos KRB_CRED data */
2838                 memcpy(gss_cksum + 28, in_data->data, orig_length);
2839                 free(in_data->data);
2840                 in_data->data = NULL;
2841                 in_data->length = 0;
2842         }
2843         in_data->data = gss_cksum;
2844         in_data->length = base_cksum_size + orig_length;
2845         return 0;
2846 }
2847 #endif
2848
2849 /*
2850  * We can't use krb5_mk_req because w2k wants the service to be in a particular
2851  * format.
2852  */
2853 static krb5_error_code ads_krb5_mk_req(krb5_context context,
2854                                        krb5_auth_context *auth_context,
2855                                        const krb5_flags ap_req_options,
2856                                        const char *principal,
2857                                        krb5_ccache ccache,
2858                                        krb5_data *outbuf,
2859                                        time_t *expire_time,
2860                                        const char *impersonate_princ_s)
2861 {
2862         krb5_error_code retval;
2863         krb5_principal server;
2864         krb5_principal impersonate_princ = NULL;
2865         krb5_creds *credsp;
2866         krb5_creds creds;
2867         krb5_data in_data;
2868         bool creds_ready = false;
2869         int i = 0, maxtries = 3;
2870         bool ok;
2871
2872         ZERO_STRUCT(in_data);
2873
2874         retval = smb_krb5_parse_name(context, principal, &server);
2875         if (retval != 0) {
2876                 DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", principal));
2877                 return retval;
2878         }
2879
2880         if (impersonate_princ_s) {
2881                 retval = smb_krb5_parse_name(context, impersonate_princ_s,
2882                                              &impersonate_princ);
2883                 if (retval) {
2884                         DEBUG(1,("ads_krb5_mk_req: Failed to parse principal %s\n", impersonate_princ_s));
2885                         goto cleanup_princ;
2886                 }
2887         }
2888
2889         /* obtain ticket & session key */
2890         ZERO_STRUCT(creds);
2891         if ((retval = krb5_copy_principal(context, server, &creds.server))) {
2892                 DEBUG(1,("ads_krb5_mk_req: krb5_copy_principal failed (%s)\n",
2893                          error_message(retval)));
2894                 goto cleanup_princ;
2895         }
2896
2897         retval = krb5_cc_get_principal(context, ccache, &creds.client);
2898         if (retval != 0) {
2899                 /* This can commonly fail on smbd startup with no ticket in the cache.
2900                  * Report at higher level than 1. */
2901                 DEBUG(3,("ads_krb5_mk_req: krb5_cc_get_principal failed (%s)\n",
2902                          error_message(retval)));
2903                 goto cleanup_creds;
2904         }
2905
2906         while (!creds_ready && (i < maxtries)) {
2907
2908                 retval = smb_krb5_get_credentials(context,
2909                                                   ccache,
2910                                                   creds.client,
2911                                                   creds.server,
2912                                                   impersonate_princ,
2913                                                   &credsp);
2914                 if (retval != 0) {
2915                         DBG_WARNING("smb_krb5_get_credentials failed for %s "
2916                                     "(%s)\n",
2917                                     principal,
2918                                     error_message(retval));
2919                         goto cleanup_creds;
2920                 }
2921
2922                 /* cope with ticket being in the future due to clock skew */
2923                 if ((unsigned)credsp->times.starttime > time(NULL)) {
2924                         time_t t = time(NULL);
2925                         int time_offset =(int)((unsigned)credsp->times.starttime-t);
2926                         DEBUG(4,("ads_krb5_mk_req: Advancing clock by %d seconds to cope with clock skew\n", time_offset));
2927                         krb5_set_real_time(context, t + time_offset + 1, 0);
2928                 }
2929
2930                 ok = ads_cleanup_expired_creds(context, ccache, credsp);
2931                 if (!ok) {
2932                         creds_ready = true;
2933                 }
2934
2935                 i++;
2936         }
2937
2938         DBG_DEBUG("Ticket (%s) in ccache (%s:%s) is valid until: (%s - %u)\n",
2939                   principal,
2940                   krb5_cc_get_type(context, ccache),
2941                   krb5_cc_get_name(context, ccache),
2942                   http_timestring(talloc_tos(),
2943                                   (unsigned)credsp->times.endtime),
2944                   (unsigned)credsp->times.endtime);
2945
2946         if (expire_time) {
2947                 *expire_time = (time_t)credsp->times.endtime;
2948         }
2949
2950         /* Allocate the auth_context. */
2951         retval = ads_setup_auth_context(context, auth_context);
2952         if (retval != 0) {
2953                 DBG_WARNING("ads_setup_auth_context failed (%s)\n",
2954                             error_message(retval));
2955                 goto cleanup_creds;
2956         }
2957
2958 #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)
2959         {
2960                 uint32_t gss_flags = 0;
2961
2962                 if (credsp->ticket_flags & TKT_FLG_OK_AS_DELEGATE) {
2963                         /*
2964                          * Fetch a forwarded TGT from the KDC so that we can
2965                          * hand off a 2nd ticket as part of the kerberos
2966                          * exchange.
2967                          */
2968
2969                         DBG_INFO("Server marked as OK to delegate to, building "
2970                                  "forwardable TGT\n");
2971
2972                         retval = krb5_auth_con_setuseruserkey(context,
2973                                         *auth_context,
2974                                         &credsp->keyblock );
2975                         if (retval != 0) {
2976                                 DBG_WARNING("krb5_auth_con_setuseruserkey "
2977                                             "failed (%s)\n",
2978                                             error_message(retval)));
2979                                 goto cleanup_creds;
2980                         }
2981
2982                         /* Must use a subkey for forwarded tickets. */
2983                         retval = krb5_auth_con_setflags(context,
2984                                                         *auth_context,
2985                                                         KRB5_AUTH_CONTEXT_USE_SUBKEY);
2986                         if (retval != 0) {
2987                                 DBG_WARNING("krb5_auth_con_setflags failed (%s)\n",
2988                                             error_message(retval)));
2989                                 goto cleanup_creds;
2990                         }
2991
2992                         retval = krb5_fwd_tgt_creds(context,/* Krb5 context [in] */
2993                                 *auth_context,  /* Authentication context [in] */
2994                                 discard_const_p(char, KRB5_TGS_NAME),  /* Ticket service name ("krbtgt") [in] */
2995                                 credsp->client, /* Client principal for the tgt [in] */
2996                                 credsp->server, /* Server principal for the tgt [in] */
2997                                 ccache,         /* Credential cache to use for storage [in] */
2998                                 1,              /* Turn on for "Forwardable ticket" [in] */
2999                                 &in_data );     /* Resulting response [out] */
3000
3001                         if (retval) {
3002                                 DBG_INFO("krb5_fwd_tgt_creds failed (%s)\n",
3003                                          error_message(retval));
3004
3005                                 /*
3006                                  * This is not fatal. Delete the *auth_context and continue
3007                                  * with krb5_mk_req_extended to get a non-forwardable ticket.
3008                                  */
3009
3010                                 if (in_data.data) {
3011                                         free( in_data.data );
3012                                         in_data.data = NULL;
3013                                         in_data.length = 0;
3014                                 }
3015                                 krb5_auth_con_free(context, *auth_context);
3016                                 *auth_context = NULL;
3017                                 retval = ads_setup_auth_context(context, auth_context);
3018                                 if (retval != 0) {
3019                                         DBG_WARNING("ads_setup_auth_context failed (%s)\n",
3020                                                     error_message(retval)));
3021                                         goto cleanup_creds;
3022                                 }
3023                         } else {
3024                                 /* We got a delegated ticket. */
3025                                 gss_flags |= GSS_C_DELEG_FLAG;
3026                         }
3027                 }
3028
3029                 /* Frees and reallocates in_data into a GSS checksum blob. */
3030                 retval = ads_create_gss_checksum(&in_data, gss_flags);
3031                 if (retval != 0) {
3032                         goto cleanup_data;
3033                 }
3034
3035                 /* We always want GSS-checksum types. */
3036                 retval = krb5_auth_con_set_req_cksumtype(context, *auth_context, GSSAPI_CHECKSUM );
3037                 if (retval != 0) {
3038                         DEBUG(1,("krb5_auth_con_set_req_cksumtype failed (%s)\n",
3039                                 error_message(retval)));
3040                         goto cleanup_data;
3041                 }
3042         }
3043 #endif
3044
3045         retval = krb5_mk_req_extended(context, auth_context, ap_req_options,
3046                                       &in_data, credsp, outbuf);
3047         if (retval != 0) {
3048                 DBG_WARNING("krb5_mk_req_extended failed (%s)\n",
3049                             error_message(retval));
3050         }
3051
3052 #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)
3053 cleanup_data:
3054 #endif
3055
3056         if (in_data.data) {
3057                 free( in_data.data );
3058                 in_data.length = 0;
3059         }
3060
3061         krb5_free_creds(context, credsp);
3062
3063 cleanup_creds:
3064         krb5_free_cred_contents(context, &creds);
3065
3066 cleanup_princ:
3067         krb5_free_principal(context, server);
3068         if (impersonate_princ) {
3069                 krb5_free_principal(context, impersonate_princ);
3070         }
3071
3072         return retval;
3073 }
3074
3075 /*
3076   get a kerberos5 ticket for the given service
3077 */
3078 int ads_krb5_cli_get_ticket(TALLOC_CTX *mem_ctx,
3079                             const char *principal,
3080                             time_t time_offset,
3081                             DATA_BLOB *ticket,
3082                             DATA_BLOB *session_key_krb5,
3083                             uint32_t extra_ap_opts, const char *ccname,
3084                             time_t *tgs_expire,
3085                             const char *impersonate_princ_s)
3086 {
3087         krb5_error_code retval;
3088         krb5_data packet;
3089         krb5_context context = NULL;
3090         krb5_ccache ccdef = NULL;
3091         krb5_auth_context auth_context = NULL;
3092         krb5_enctype enc_types[] = {
3093 #ifdef HAVE_ENCTYPE_AES256_CTS_HMAC_SHA1_96
3094                 ENCTYPE_AES256_CTS_HMAC_SHA1_96,
3095 #endif
3096 #ifdef HAVE_ENCTYPE_AES128_CTS_HMAC_SHA1_96
3097                 ENCTYPE_AES128_CTS_HMAC_SHA1_96,
3098 #endif
3099                 ENCTYPE_ARCFOUR_HMAC,
3100                 ENCTYPE_DES_CBC_MD5,
3101                 ENCTYPE_DES_CBC_CRC,
3102                 ENCTYPE_NULL};
3103         bool ok;
3104
3105         initialize_krb5_error_table();
3106         retval = krb5_init_context(&context);
3107         if (retval != 0) {
3108                 DBG_WARNING("krb5_init_context failed (%s)\n",
3109                             error_message(retval));
3110                 goto failed;
3111         }
3112
3113         if (time_offset != 0) {
3114                 krb5_set_real_time(context, time(NULL) + time_offset, 0);
3115         }
3116
3117         retval = krb5_cc_resolve(context,
3118                                  ccname ? ccname : krb5_cc_default_name(context),
3119                                  &ccdef);
3120         if (retval != 0) {
3121                 DBG_WARNING("krb5_cc_default failed (%s)\n",
3122                             error_message(retval));
3123                 goto failed;
3124         }
3125
3126         retval = krb5_set_default_tgs_ktypes(context, enc_types);
3127         if (retval != 0) {
3128                 DBG_WARNING("krb5_set_default_tgs_ktypes failed (%s)\n",
3129                             error_message(retval));
3130                 goto failed;
3131         }
3132
3133         retval = ads_krb5_mk_req(context,
3134                                  &auth_context,
3135                                  AP_OPTS_USE_SUBKEY | (krb5_flags)extra_ap_opts,
3136                                  principal,
3137                                  ccdef,
3138                                  &packet,
3139                                  tgs_expire,
3140                                  impersonate_princ_s);
3141         if (retval != 0) {
3142                 goto failed;
3143         }
3144
3145         ok = smb_krb5_get_smb_session_key(mem_ctx,
3146                                           context,
3147                                           auth_context,
3148                                           session_key_krb5,
3149                                           false);
3150         if (!ok) {
3151                 retval = ENOMEM;
3152                 goto failed;
3153         }
3154
3155         *ticket = data_blob_talloc(mem_ctx, packet.data, packet.length);
3156
3157         smb_krb5_free_data_contents(context, &packet);
3158
3159 failed:
3160
3161         if (context) {
3162                 if (ccdef) {
3163                         krb5_cc_close(context, ccdef);
3164                 }
3165                 if (auth_context) {
3166                         krb5_auth_con_free(context, auth_context);
3167                 }
3168                 krb5_free_context(context);
3169         }
3170
3171         return retval;
3172 }
3173
3174 #else /* HAVE_KRB5 */
3175 /* This saves a few linking headaches */
3176 int ads_krb5_cli_get_ticket(TALLOC_CTX *mem_ctx,
3177                             const char *principal,
3178                             time_t time_offset,
3179                             DATA_BLOB *ticket,
3180                             DATA_BLOB *session_key_krb5,
3181                             uint32_t extra_ap_opts, const char *ccname,
3182                             time_t *tgs_expire,
3183                             const char *impersonate_princ_s)
3184 {
3185          DEBUG(0,("NO KERBEROS SUPPORT\n"));
3186          return 1;
3187 }
3188
3189 #endif /* HAVE_KRB5 */