source3/libsmb/clispnego.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    simple kerberos5/SPNEGO routines
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
   6    Copyright (C) Luke Howard     2003
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "../libcli/auth/spnego.h"
  24
  25 /*
  26   generate a negTokenInit packet given a GUID, a list of supported
  27   OIDs (the mechanisms) and a principal name string
  28 */
  29 DATA_BLOB spnego_gen_negTokenInit(char guid[16],
  30                                   const char *OIDs[],
  31                                   const char *principal)
  32 {
  33         int i;
  34         ASN1_DATA *data;
  35         DATA_BLOB ret;
  36
  37         data = asn1_init(talloc_tos());
  38         if (data == NULL) {
  39                 return data_blob_null;
  40         }
  41
  42         asn1_write(data, guid, 16);
  43         asn1_push_tag(data,ASN1_APPLICATION(0));
  44         asn1_write_OID(data,OID_SPNEGO);
  45         asn1_push_tag(data,ASN1_CONTEXT(0));
  46         asn1_push_tag(data,ASN1_SEQUENCE(0));
  47
  48         asn1_push_tag(data,ASN1_CONTEXT(0));
  49         asn1_push_tag(data,ASN1_SEQUENCE(0));
  50         for (i=0; OIDs[i]; i++) {
  51                 asn1_write_OID(data,OIDs[i]);
  52         }
  53         asn1_pop_tag(data);
  54         asn1_pop_tag(data);
  55
  56         asn1_push_tag(data, ASN1_CONTEXT(3));
  57         asn1_push_tag(data, ASN1_SEQUENCE(0));
  58         asn1_push_tag(data, ASN1_CONTEXT(0));
  59         asn1_write_GeneralString(data,principal);
  60         asn1_pop_tag(data);
  61         asn1_pop_tag(data);
  62         asn1_pop_tag(data);
  63
  64         asn1_pop_tag(data);
  65         asn1_pop_tag(data);
  66
  67         asn1_pop_tag(data);
  68
  69         if (data->has_error) {
  70                 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
  71         }
  72
  73         ret = data_blob(data->data, data->length);
  74         asn1_free(data);
  75
  76         return ret;
  77 }
  78
  79 /*
  80   Generate a negTokenInit as used by the client side ... It has a mechType
  81   (OID), and a mechToken (a security blob) ...
  82
  83   Really, we need to break out the NTLMSSP stuff as well, because it could be
  84   raw in the packets!
  85 */
  86 DATA_BLOB gen_negTokenInit(const char *OID, DATA_BLOB blob)
  87 {
  88         ASN1_DATA *data;
  89         DATA_BLOB ret;
  90
  91         data = asn1_init(talloc_tos());
  92         if (data == NULL) {
  93                 return data_blob_null;
  94         }
  95
  96         asn1_push_tag(data, ASN1_APPLICATION(0));
  97         asn1_write_OID(data,OID_SPNEGO);
  98         asn1_push_tag(data, ASN1_CONTEXT(0));
  99         asn1_push_tag(data, ASN1_SEQUENCE(0));
 100
 101         asn1_push_tag(data, ASN1_CONTEXT(0));
 102         asn1_push_tag(data, ASN1_SEQUENCE(0));
 103         asn1_write_OID(data, OID);
 104         asn1_pop_tag(data);
 105         asn1_pop_tag(data);
 106
 107         asn1_push_tag(data, ASN1_CONTEXT(2));
 108         asn1_write_OctetString(data,blob.data,blob.length);
 109         asn1_pop_tag(data);
 110
 111         asn1_pop_tag(data);
 112         asn1_pop_tag(data);
 113
 114         asn1_pop_tag(data);
 115
 116         if (data->has_error) {
 117                 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs));
 118         }
 119
 120         ret = data_blob(data->data, data->length);
 121         asn1_free(data);
 122
 123         return ret;
 124 }
 125
 126 /*
 127   parse a negTokenInit packet giving a GUID, a list of supported
 128   OIDs (the mechanisms) and a principal name string
 129 */
 130 bool spnego_parse_negTokenInit(DATA_BLOB blob,
 131                                char *OIDs[ASN1_MAX_OIDS],
 132                                char **principal)
 133 {
 134         int i;
 135         bool ret;
 136         ASN1_DATA *data;
 137
 138         data = asn1_init(talloc_tos());
 139         if (data == NULL) {
 140                 return false;
 141         }
 142
 143         asn1_load(data, blob);
 144
 145         asn1_start_tag(data,ASN1_APPLICATION(0));
 146
 147         asn1_check_OID(data,OID_SPNEGO);
 148         asn1_start_tag(data,ASN1_CONTEXT(0));
 149         asn1_start_tag(data,ASN1_SEQUENCE(0));
 150
 151         asn1_start_tag(data,ASN1_CONTEXT(0));
 152         asn1_start_tag(data,ASN1_SEQUENCE(0));
 153         for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
 154                 const char *oid_str = NULL;
 155                 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
 156                 OIDs[i] = CONST_DISCARD(char *, oid_str);
 157         }
 158         OIDs[i] = NULL;
 159         asn1_end_tag(data);
 160         asn1_end_tag(data);
 161
 162         *principal = NULL;
 163         if (asn1_tag_remaining(data) > 0) {
 164                 asn1_start_tag(data, ASN1_CONTEXT(3));
 165                 asn1_start_tag(data, ASN1_SEQUENCE(0));
 166                 asn1_start_tag(data, ASN1_CONTEXT(0));
 167                 asn1_read_GeneralString(data,talloc_autofree_context(),principal);
 168                 asn1_end_tag(data);
 169                 asn1_end_tag(data);
 170                 asn1_end_tag(data);
 171         }
 172
 173         asn1_end_tag(data);
 174         asn1_end_tag(data);
 175
 176         asn1_end_tag(data);
 177
 178         ret = !data->has_error;
 179         if (data->has_error) {
 180                 int j;
 181                 TALLOC_FREE(*principal);
 182                 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
 183                         TALLOC_FREE(OIDs[j]);
 184                 }
 185         }
 186
 187         asn1_free(data);
 188         return ret;
 189 }
 190
 191 /*
 192   generate a negTokenTarg packet given a list of OIDs and a security blob
 193 */
 194 DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob)
 195 {
 196         int i;
 197         ASN1_DATA *data;
 198         DATA_BLOB ret;
 199
 200         data = asn1_init(talloc_tos());
 201         if (data == NULL) {
 202                 return data_blob_null;
 203         }
 204
 205         asn1_push_tag(data, ASN1_APPLICATION(0));
 206         asn1_write_OID(data,OID_SPNEGO);
 207         asn1_push_tag(data, ASN1_CONTEXT(0));
 208         asn1_push_tag(data, ASN1_SEQUENCE(0));
 209
 210         asn1_push_tag(data, ASN1_CONTEXT(0));
 211         asn1_push_tag(data, ASN1_SEQUENCE(0));
 212         for (i=0; OIDs[i]; i++) {
 213                 asn1_write_OID(data,OIDs[i]);
 214         }
 215         asn1_pop_tag(data);
 216         asn1_pop_tag(data);
 217
 218         asn1_push_tag(data, ASN1_CONTEXT(2));
 219         asn1_write_OctetString(data,blob.data,blob.length);
 220         asn1_pop_tag(data);
 221
 222         asn1_pop_tag(data);
 223         asn1_pop_tag(data);
 224
 225         asn1_pop_tag(data);
 226
 227         if (data->has_error) {
 228                 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs));
 229         }
 230
 231         ret = data_blob(data->data, data->length);
 232         asn1_free(data);
 233
 234         return ret;
 235 }
 236
 237 /*
 238   parse a negTokenTarg packet giving a list of OIDs and a security blob
 239 */
 240 bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob)
 241 {
 242         int i;
 243         ASN1_DATA *data;
 244
 245         data = asn1_init(talloc_tos());
 246         if (data == NULL) {
 247                 return false;
 248         }
 249
 250         asn1_load(data, blob);
 251         asn1_start_tag(data, ASN1_APPLICATION(0));
 252         asn1_check_OID(data,OID_SPNEGO);
 253         asn1_start_tag(data, ASN1_CONTEXT(0));
 254         asn1_start_tag(data, ASN1_SEQUENCE(0));
 255
 256         asn1_start_tag(data, ASN1_CONTEXT(0));
 257         asn1_start_tag(data, ASN1_SEQUENCE(0));
 258         for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
 259                 const char *oid_str = NULL;
 260                 asn1_read_OID(data,talloc_autofree_context(),&oid_str);
 261                 OIDs[i] = CONST_DISCARD(char *, oid_str);
 262         }
 263         OIDs[i] = NULL;
 264         asn1_end_tag(data);
 265         asn1_end_tag(data);
 266
 267         /* Skip any optional req_flags that are sent per RFC 4178 */
 268         if (asn1_peek_tag(data, ASN1_CONTEXT(1))) {
 269                 uint8 flags;
 270
 271                 asn1_start_tag(data, ASN1_CONTEXT(1));
 272                 asn1_start_tag(data, ASN1_BIT_STRING);
 273                 while (asn1_tag_remaining(data) > 0)
 274                         asn1_read_uint8(data, &flags);
 275                 asn1_end_tag(data);
 276                 asn1_end_tag(data);
 277         }
 278
 279         asn1_start_tag(data, ASN1_CONTEXT(2));
 280         asn1_read_OctetString(data,talloc_autofree_context(),secblob);
 281         asn1_end_tag(data);
 282
 283         asn1_end_tag(data);
 284         asn1_end_tag(data);
 285
 286         asn1_end_tag(data);
 287
 288         if (data->has_error) {
 289                 int j;
 290                 data_blob_free(secblob);
 291                 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
 292                         TALLOC_FREE(OIDs[j]);
 293                 }
 294                 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs));
 295                 asn1_free(data);
 296                 return False;
 297         }
 298
 299         asn1_free(data);
 300         return True;
 301 }
 302
 303 /*
 304   generate a krb5 GSS-API wrapper packet given a ticket
 305 */
 306 DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2])
 307 {
 308         ASN1_DATA *data;
 309         DATA_BLOB ret;
 310
 311         data = asn1_init(talloc_tos());
 312         if (data == NULL) {
 313                 return data_blob_null;
 314         }
 315
 316         asn1_push_tag(data, ASN1_APPLICATION(0));
 317         asn1_write_OID(data, OID_KERBEROS5);
 318
 319         asn1_write(data, tok_id, 2);
 320         asn1_write(data, ticket.data, ticket.length);
 321         asn1_pop_tag(data);
 322
 323         if (data->has_error) {
 324                 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
 325         }
 326
 327         ret = data_blob(data->data, data->length);
 328         asn1_free(data);
 329
 330         return ret;
 331 }
 332
 333 /*
 334   parse a krb5 GSS-API wrapper packet giving a ticket
 335 */
 336 bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
 337 {
 338         bool ret;
 339         ASN1_DATA *data;
 340         int data_remaining;
 341
 342         data = asn1_init(talloc_tos());
 343         if (data == NULL) {
 344                 return false;
 345         }
 346
 347         asn1_load(data, blob);
 348         asn1_start_tag(data, ASN1_APPLICATION(0));
 349         asn1_check_OID(data, OID_KERBEROS5);
 350
 351         data_remaining = asn1_tag_remaining(data);
 352
 353         if (data_remaining < 3) {
 354                 data->has_error = True;
 355         } else {
 356                 asn1_read(data, tok_id, 2);
 357                 data_remaining -= 2;
 358                 *ticket = data_blob(NULL, data_remaining);
 359                 asn1_read(data, ticket->data, ticket->length);
 360         }
 361
 362         asn1_end_tag(data);
 363
 364         ret = !data->has_error;
 365
 366         if (data->has_error) {
 367                 data_blob_free(ticket);
 368         }
 369
 370         asn1_free(data);
 371
 372         return ret;
 373 }
 374
 375
 376 /*
 377    generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY
 378    kerberos session setup
 379 */
 380 int spnego_gen_negTokenTarg(const char *principal, int time_offset,
 381                             DATA_BLOB *targ,
 382                             DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
 383                             time_t *expire_time)
 384 {
 385         int retval;
 386         DATA_BLOB tkt, tkt_wrapped;
 387         const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL};
 388
 389         /* get a kerberos ticket for the service and extract the session key */
 390         retval = cli_krb5_get_ticket(principal, time_offset,
 391                                         &tkt, session_key_krb5, extra_ap_opts, NULL,
 392                                         expire_time);
 393
 394         if (retval)
 395                 return retval;
 396
 397         /* wrap that up in a nice GSS-API wrapping */
 398         tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
 399
 400         /* and wrap that in a shiny SPNEGO wrapper */
 401         *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
 402
 403         data_blob_free(&tkt_wrapped);
 404         data_blob_free(&tkt);
 405
 406         return retval;
 407 }
 408
 409
 410 /*
 411   parse a spnego NTLMSSP challenge packet giving two security blobs
 412 */
 413 bool spnego_parse_challenge(const DATA_BLOB blob,
 414                             DATA_BLOB *chal1, DATA_BLOB *chal2)
 415 {
 416         bool ret;
 417         ASN1_DATA *data;
 418
 419         ZERO_STRUCTP(chal1);
 420         ZERO_STRUCTP(chal2);
 421
 422         data = asn1_init(talloc_tos());
 423         if (data == NULL) {
 424                 return false;
 425         }
 426
 427         asn1_load(data, blob);
 428         asn1_start_tag(data,ASN1_CONTEXT(1));
 429         asn1_start_tag(data,ASN1_SEQUENCE(0));
 430
 431         asn1_start_tag(data,ASN1_CONTEXT(0));
 432         asn1_check_enumerated(data,1);
 433         asn1_end_tag(data);
 434
 435         asn1_start_tag(data,ASN1_CONTEXT(1));
 436         asn1_check_OID(data, OID_NTLMSSP);
 437         asn1_end_tag(data);
 438
 439         asn1_start_tag(data,ASN1_CONTEXT(2));
 440         asn1_read_OctetString(data, talloc_autofree_context(), chal1);
 441         asn1_end_tag(data);
 442
 443         /* the second challenge is optional (XP doesn't send it) */
 444         if (asn1_tag_remaining(data)) {
 445                 asn1_start_tag(data,ASN1_CONTEXT(3));
 446                 asn1_read_OctetString(data, talloc_autofree_context(), chal2);
 447                 asn1_end_tag(data);
 448         }
 449
 450         asn1_end_tag(data);
 451         asn1_end_tag(data);
 452
 453         ret = !data->has_error;
 454
 455         if (data->has_error) {
 456                 data_blob_free(chal1);
 457                 data_blob_free(chal2);
 458         }
 459
 460         asn1_free(data);
 461         return ret;
 462 }
 463
 464
 465 /*
 466  generate a SPNEGO auth packet. This will contain the encrypted passwords
 467 */
 468 DATA_BLOB spnego_gen_auth(DATA_BLOB blob)
 469 {
 470         ASN1_DATA *data;
 471         DATA_BLOB ret;
 472
 473         data = asn1_init(talloc_tos());
 474         if (data == NULL) {
 475                 return data_blob_null;
 476         }
 477
 478         asn1_push_tag(data, ASN1_CONTEXT(1));
 479         asn1_push_tag(data, ASN1_SEQUENCE(0));
 480         asn1_push_tag(data, ASN1_CONTEXT(2));
 481         asn1_write_OctetString(data,blob.data,blob.length);
 482         asn1_pop_tag(data);
 483         asn1_pop_tag(data);
 484         asn1_pop_tag(data);
 485
 486         ret = data_blob(data->data, data->length);
 487
 488         asn1_free(data);
 489
 490         return ret;
 491 }
 492
 493 /*
 494  parse a SPNEGO auth packet. This contains the encrypted passwords
 495 */
 496 bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
 497 {
 498         ASN1_DATA *data;
 499
 500         data = asn1_init(talloc_tos());
 501         if (data == NULL) {
 502                 return false;
 503         }
 504
 505         asn1_load(data, blob);
 506         asn1_start_tag(data, ASN1_CONTEXT(1));
 507         asn1_start_tag(data, ASN1_SEQUENCE(0));
 508         asn1_start_tag(data, ASN1_CONTEXT(2));
 509         asn1_read_OctetString(data, talloc_autofree_context(), auth);
 510         asn1_end_tag(data);
 511         asn1_end_tag(data);
 512         asn1_end_tag(data);
 513
 514         if (data->has_error) {
 515                 DEBUG(3,("spnego_parse_auth failed at %d\n", (int)data->ofs));
 516                 data_blob_free(auth);
 517                 asn1_free(data);
 518                 return False;
 519         }
 520
 521         asn1_free(data);
 522         return True;
 523 }
 524
 525 /*
 526   generate a minimal SPNEGO response packet.  Doesn't contain much.
 527 */
 528 DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
 529                                    const char *mechOID)
 530 {
 531         ASN1_DATA *data;
 532         DATA_BLOB ret;
 533         uint8 negResult;
 534
 535         if (NT_STATUS_IS_OK(nt_status)) {
 536                 negResult = SPNEGO_ACCEPT_COMPLETED;
 537         } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 538                 negResult = SPNEGO_ACCEPT_INCOMPLETE;
 539         } else {
 540                 negResult = SPNEGO_REJECT;
 541         }
 542
 543         data = asn1_init(talloc_tos());
 544         if (data == NULL) {
 545                 return data_blob_null;
 546         }
 547
 548         asn1_push_tag(data, ASN1_CONTEXT(1));
 549         asn1_push_tag(data, ASN1_SEQUENCE(0));
 550         asn1_push_tag(data, ASN1_CONTEXT(0));
 551         asn1_write_enumerated(data, negResult);
 552         asn1_pop_tag(data);
 553
 554         if (mechOID) {
 555                 asn1_push_tag(data,ASN1_CONTEXT(1));
 556                 asn1_write_OID(data, mechOID);
 557                 asn1_pop_tag(data);
 558         }
 559
 560         if (reply && reply->data != NULL) {
 561                 asn1_push_tag(data,ASN1_CONTEXT(2));
 562                 asn1_write_OctetString(data, reply->data, reply->length);
 563                 asn1_pop_tag(data);
 564         }
 565
 566         asn1_pop_tag(data);
 567         asn1_pop_tag(data);
 568
 569         ret = data_blob(data->data, data->length);
 570         asn1_free(data);
 571         return ret;
 572 }
 573
 574 /*
 575  parse a SPNEGO auth packet. This contains the encrypted passwords
 576 */
 577 bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
 578                                 const char *mechOID,
 579                                 DATA_BLOB *auth)
 580 {
 581         ASN1_DATA *data;
 582         uint8 negResult;
 583
 584         if (NT_STATUS_IS_OK(nt_status)) {
 585                 negResult = SPNEGO_ACCEPT_COMPLETED;
 586         } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 587                 negResult = SPNEGO_ACCEPT_INCOMPLETE;
 588         } else {
 589                 negResult = SPNEGO_REJECT;
 590         }
 591
 592         data = asn1_init(talloc_tos());
 593         if (data == NULL) {
 594                 return false;
 595         }
 596
 597         asn1_load(data, blob);
 598         asn1_start_tag(data, ASN1_CONTEXT(1));
 599         asn1_start_tag(data, ASN1_SEQUENCE(0));
 600         asn1_start_tag(data, ASN1_CONTEXT(0));
 601         asn1_check_enumerated(data, negResult);
 602         asn1_end_tag(data);
 603
 604         *auth = data_blob_null;
 605
 606         if (asn1_tag_remaining(data)) {
 607                 asn1_start_tag(data,ASN1_CONTEXT(1));
 608                 asn1_check_OID(data, mechOID);
 609                 asn1_end_tag(data);
 610
 611                 if (asn1_tag_remaining(data)) {
 612                         asn1_start_tag(data,ASN1_CONTEXT(2));
 613                         asn1_read_OctetString(data, talloc_autofree_context(), auth);
 614                         asn1_end_tag(data);
 615                 }
 616         } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) {
 617                 data->has_error = 1;
 618         }
 619
 620         /* Binding against Win2K DC returns a duplicate of the responseToken in
 621          * the optional mechListMIC field. This is a bug in Win2K. We ignore
 622          * this field if it exists. Win2K8 may return a proper mechListMIC at
 623          * which point we need to implement the integrity checking. */
 624         if (asn1_tag_remaining(data)) {
 625                 DATA_BLOB mechList = data_blob_null;
 626                 asn1_start_tag(data, ASN1_CONTEXT(3));
 627                 asn1_read_OctetString(data, talloc_autofree_context(), &mechList);
 628                 asn1_end_tag(data);
 629                 data_blob_free(&mechList);
 630                 DEBUG(5,("spnego_parse_auth_response received mechListMIC, "
 631                     "ignoring.\n"));
 632         }
 633
 634         asn1_end_tag(data);
 635         asn1_end_tag(data);
 636
 637         if (data->has_error) {
 638                 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs));
 639                 asn1_free(data);
 640                 data_blob_free(auth);
 641                 return False;
 642         }
 643
 644         asn1_free(data);
 645         return True;
 646 }