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