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 2 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, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.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         memset(&data, 0, sizeof(data));
  38
  39         asn1_write(&data, guid, 16);
  40         asn1_push_tag(&data,ASN1_APPLICATION(0));
  41         asn1_write_OID(&data,OID_SPNEGO);
  42         asn1_push_tag(&data,ASN1_CONTEXT(0));
  43         asn1_push_tag(&data,ASN1_SEQUENCE(0));
  44
  45         asn1_push_tag(&data,ASN1_CONTEXT(0));
  46         asn1_push_tag(&data,ASN1_SEQUENCE(0));
  47         for (i=0; OIDs[i]; i++) {
  48                 asn1_write_OID(&data,OIDs[i]);
  49         }
  50         asn1_pop_tag(&data);
  51         asn1_pop_tag(&data);
  52
  53         asn1_push_tag(&data, ASN1_CONTEXT(3));
  54         asn1_push_tag(&data, ASN1_SEQUENCE(0));
  55         asn1_push_tag(&data, ASN1_CONTEXT(0));
  56         asn1_write_GeneralString(&data,principal);
  57         asn1_pop_tag(&data);
  58         asn1_pop_tag(&data);
  59         asn1_pop_tag(&data);
  60
  61         asn1_pop_tag(&data);
  62         asn1_pop_tag(&data);
  63
  64         asn1_pop_tag(&data);
  65
  66         if (data.has_error) {
  67                 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data.ofs));
  68                 asn1_free(&data);
  69         }
  70
  71         ret = data_blob(data.data, data.length);
  72         asn1_free(&data);
  73
  74         return ret;
  75 }
  76
  77 /*
  78   Generate a negTokenInit as used by the client side ... It has a mechType
  79   (OID), and a mechToken (a security blob) ...
  80
  81   Really, we need to break out the NTLMSSP stuff as well, because it could be
  82   raw in the packets!
  83 */
  84 DATA_BLOB gen_negTokenInit(const char *OID, DATA_BLOB blob)
  85 {
  86         ASN1_DATA data;
  87         DATA_BLOB ret;
  88
  89         memset(&data, 0, sizeof(data));
  90
  91         asn1_push_tag(&data, ASN1_APPLICATION(0));
  92         asn1_write_OID(&data,OID_SPNEGO);
  93         asn1_push_tag(&data, ASN1_CONTEXT(0));
  94         asn1_push_tag(&data, ASN1_SEQUENCE(0));
  95
  96         asn1_push_tag(&data, ASN1_CONTEXT(0));
  97         asn1_push_tag(&data, ASN1_SEQUENCE(0));
  98         asn1_write_OID(&data, OID);
  99         asn1_pop_tag(&data);
 100         asn1_pop_tag(&data);
 101
 102         asn1_push_tag(&data, ASN1_CONTEXT(2));
 103         asn1_write_OctetString(&data,blob.data,blob.length);
 104         asn1_pop_tag(&data);
 105
 106         asn1_pop_tag(&data);
 107         asn1_pop_tag(&data);
 108
 109         asn1_pop_tag(&data);
 110
 111         if (data.has_error) {
 112                 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data.ofs));
 113                 asn1_free(&data);
 114         }
 115
 116         ret = data_blob(data.data, data.length);
 117         asn1_free(&data);
 118
 119         return ret;
 120 }
 121
 122 /*
 123   parse a negTokenInit packet giving a GUID, a list of supported
 124   OIDs (the mechanisms) and a principal name string
 125 */
 126 BOOL spnego_parse_negTokenInit(DATA_BLOB blob,
 127                                char *OIDs[ASN1_MAX_OIDS],
 128                                char **principal)
 129 {
 130         int i;
 131         BOOL ret;
 132         ASN1_DATA data;
 133
 134         asn1_load(&data, blob);
 135
 136         asn1_start_tag(&data,ASN1_APPLICATION(0));
 137         asn1_check_OID(&data,OID_SPNEGO);
 138         asn1_start_tag(&data,ASN1_CONTEXT(0));
 139         asn1_start_tag(&data,ASN1_SEQUENCE(0));
 140
 141         asn1_start_tag(&data,ASN1_CONTEXT(0));
 142         asn1_start_tag(&data,ASN1_SEQUENCE(0));
 143         for (i=0; asn1_tag_remaining(&data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
 144                 char *oid_str = NULL;
 145                 asn1_read_OID(&data,&oid_str);
 146                 OIDs[i] = oid_str;
 147         }
 148         OIDs[i] = NULL;
 149         asn1_end_tag(&data);
 150         asn1_end_tag(&data);
 151
 152         *principal = NULL;
 153         if (asn1_tag_remaining(&data) > 0) {
 154                 asn1_start_tag(&data, ASN1_CONTEXT(3));
 155                 asn1_start_tag(&data, ASN1_SEQUENCE(0));
 156                 asn1_start_tag(&data, ASN1_CONTEXT(0));
 157                 asn1_read_GeneralString(&data,principal);
 158                 asn1_end_tag(&data);
 159                 asn1_end_tag(&data);
 160                 asn1_end_tag(&data);
 161         }
 162
 163         asn1_end_tag(&data);
 164         asn1_end_tag(&data);
 165
 166         asn1_end_tag(&data);
 167
 168         ret = !data.has_error;
 169         if (data.has_error) {
 170                 int j;
 171                 SAFE_FREE(*principal);
 172                 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
 173                         SAFE_FREE(OIDs[j]);
 174                 }
 175         }
 176
 177         asn1_free(&data);
 178         return ret;
 179 }
 180
 181 /*
 182   generate a negTokenTarg packet given a list of OIDs and a security blob
 183 */
 184 DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob)
 185 {
 186         int i;
 187         ASN1_DATA data;
 188         DATA_BLOB ret;
 189
 190         memset(&data, 0, sizeof(data));
 191
 192         asn1_push_tag(&data, ASN1_APPLICATION(0));
 193         asn1_write_OID(&data,OID_SPNEGO);
 194         asn1_push_tag(&data, ASN1_CONTEXT(0));
 195         asn1_push_tag(&data, ASN1_SEQUENCE(0));
 196
 197         asn1_push_tag(&data, ASN1_CONTEXT(0));
 198         asn1_push_tag(&data, ASN1_SEQUENCE(0));
 199         for (i=0; OIDs[i]; i++) {
 200                 asn1_write_OID(&data,OIDs[i]);
 201         }
 202         asn1_pop_tag(&data);
 203         asn1_pop_tag(&data);
 204
 205         asn1_push_tag(&data, ASN1_CONTEXT(2));
 206         asn1_write_OctetString(&data,blob.data,blob.length);
 207         asn1_pop_tag(&data);
 208
 209         asn1_pop_tag(&data);
 210         asn1_pop_tag(&data);
 211
 212         asn1_pop_tag(&data);
 213
 214         if (data.has_error) {
 215                 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data.ofs));
 216                 asn1_free(&data);
 217         }
 218
 219         ret = data_blob(data.data, data.length);
 220         asn1_free(&data);
 221
 222         return ret;
 223 }
 224
 225 /*
 226   parse a negTokenTarg packet giving a list of OIDs and a security blob
 227 */
 228 BOOL parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob)
 229 {
 230         int i;
 231         ASN1_DATA data;
 232
 233         asn1_load(&data, blob);
 234         asn1_start_tag(&data, ASN1_APPLICATION(0));
 235         asn1_check_OID(&data,OID_SPNEGO);
 236         asn1_start_tag(&data, ASN1_CONTEXT(0));
 237         asn1_start_tag(&data, ASN1_SEQUENCE(0));
 238
 239         asn1_start_tag(&data, ASN1_CONTEXT(0));
 240         asn1_start_tag(&data, ASN1_SEQUENCE(0));
 241         for (i=0; asn1_tag_remaining(&data) > 0 && i < ASN1_MAX_OIDS-1; i++) {
 242                 char *oid_str = NULL;
 243                 asn1_read_OID(&data,&oid_str);
 244                 OIDs[i] = oid_str;
 245         }
 246         OIDs[i] = NULL;
 247         asn1_end_tag(&data);
 248         asn1_end_tag(&data);
 249
 250         asn1_start_tag(&data, ASN1_CONTEXT(2));
 251         asn1_read_OctetString(&data,secblob);
 252         asn1_end_tag(&data);
 253
 254         asn1_end_tag(&data);
 255         asn1_end_tag(&data);
 256
 257         asn1_end_tag(&data);
 258
 259         if (data.has_error) {
 260                 int j;
 261                 data_blob_free(secblob);
 262                 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) {
 263                         SAFE_FREE(OIDs[j]);
 264                 }
 265                 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data.ofs));
 266                 asn1_free(&data);
 267                 return False;
 268         }
 269
 270         asn1_free(&data);
 271         return True;
 272 }
 273
 274 /*
 275   generate a krb5 GSS-API wrapper packet given a ticket
 276 */
 277 DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2])
 278 {
 279         ASN1_DATA data;
 280         DATA_BLOB ret;
 281
 282         memset(&data, 0, sizeof(data));
 283
 284         asn1_push_tag(&data, ASN1_APPLICATION(0));
 285         asn1_write_OID(&data, OID_KERBEROS5);
 286
 287         asn1_write(&data, tok_id, 2);
 288         asn1_write(&data, ticket.data, ticket.length);
 289         asn1_pop_tag(&data);
 290
 291         if (data.has_error) {
 292                 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data.ofs));
 293                 asn1_free(&data);
 294         }
 295
 296         ret = data_blob(data.data, data.length);
 297         asn1_free(&data);
 298
 299         return ret;
 300 }
 301
 302 /*
 303   parse a krb5 GSS-API wrapper packet giving a ticket
 304 */
 305 BOOL spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
 306 {
 307         BOOL ret;
 308         ASN1_DATA data;
 309         int data_remaining;
 310
 311         asn1_load(&data, blob);
 312         asn1_start_tag(&data, ASN1_APPLICATION(0));
 313         asn1_check_OID(&data, OID_KERBEROS5);
 314
 315         data_remaining = asn1_tag_remaining(&data);
 316
 317         if (data_remaining < 3) {
 318                 data.has_error = True;
 319         } else {
 320                 asn1_read(&data, tok_id, 2);
 321                 data_remaining -= 2;
 322                 *ticket = data_blob(NULL, data_remaining);
 323                 asn1_read(&data, ticket->data, ticket->length);
 324         }
 325
 326         asn1_end_tag(&data);
 327
 328         ret = !data.has_error;
 329
 330         if (data.has_error) {
 331                 data_blob_free(ticket);
 332         }
 333
 334         asn1_free(&data);
 335
 336         return ret;
 337 }
 338
 339
 340 /*
 341    generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY
 342    kerberos session setup
 343 */
 344 int spnego_gen_negTokenTarg(const char *principal, int time_offset,
 345                             DATA_BLOB *targ,
 346                             DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
 347                             time_t *expire_time)
 348 {
 349         int retval;
 350         DATA_BLOB tkt, tkt_wrapped;
 351         const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_NTLMSSP, NULL};
 352
 353         /* get a kerberos ticket for the service and extract the session key */
 354         retval = cli_krb5_get_ticket(principal, time_offset,
 355                                         &tkt, session_key_krb5, extra_ap_opts, NULL,
 356                                         expire_time);
 357
 358         if (retval)
 359                 return retval;
 360
 361         /* wrap that up in a nice GSS-API wrapping */
 362         tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
 363
 364         /* and wrap that in a shiny SPNEGO wrapper */
 365         *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
 366
 367         data_blob_free(&tkt_wrapped);
 368         data_blob_free(&tkt);
 369
 370         return retval;
 371 }
 372
 373
 374 /*
 375   parse a spnego NTLMSSP challenge packet giving two security blobs
 376 */
 377 BOOL spnego_parse_challenge(const DATA_BLOB blob,
 378                             DATA_BLOB *chal1, DATA_BLOB *chal2)
 379 {
 380         BOOL ret;
 381         ASN1_DATA data;
 382
 383         ZERO_STRUCTP(chal1);
 384         ZERO_STRUCTP(chal2);
 385
 386         asn1_load(&data, blob);
 387         asn1_start_tag(&data,ASN1_CONTEXT(1));
 388         asn1_start_tag(&data,ASN1_SEQUENCE(0));
 389
 390         asn1_start_tag(&data,ASN1_CONTEXT(0));
 391         asn1_check_enumerated(&data,1);
 392         asn1_end_tag(&data);
 393
 394         asn1_start_tag(&data,ASN1_CONTEXT(1));
 395         asn1_check_OID(&data, OID_NTLMSSP);
 396         asn1_end_tag(&data);
 397
 398         asn1_start_tag(&data,ASN1_CONTEXT(2));
 399         asn1_read_OctetString(&data, chal1);
 400         asn1_end_tag(&data);
 401
 402         /* the second challenge is optional (XP doesn't send it) */
 403         if (asn1_tag_remaining(&data)) {
 404                 asn1_start_tag(&data,ASN1_CONTEXT(3));
 405                 asn1_read_OctetString(&data, chal2);
 406                 asn1_end_tag(&data);
 407         }
 408
 409         asn1_end_tag(&data);
 410         asn1_end_tag(&data);
 411
 412         ret = !data.has_error;
 413
 414         if (data.has_error) {
 415                 data_blob_free(chal1);
 416                 data_blob_free(chal2);
 417         }
 418
 419         asn1_free(&data);
 420         return ret;
 421 }
 422
 423
 424 /*
 425  generate a SPNEGO auth packet. This will contain the encrypted passwords
 426 */
 427 DATA_BLOB spnego_gen_auth(DATA_BLOB blob)
 428 {
 429         ASN1_DATA data;
 430         DATA_BLOB ret;
 431
 432         memset(&data, 0, sizeof(data));
 433
 434         asn1_push_tag(&data, ASN1_CONTEXT(1));
 435         asn1_push_tag(&data, ASN1_SEQUENCE(0));
 436         asn1_push_tag(&data, ASN1_CONTEXT(2));
 437         asn1_write_OctetString(&data,blob.data,blob.length);
 438         asn1_pop_tag(&data);
 439         asn1_pop_tag(&data);
 440         asn1_pop_tag(&data);
 441
 442         ret = data_blob(data.data, data.length);
 443
 444         asn1_free(&data);
 445
 446         return ret;
 447 }
 448
 449 /*
 450  parse a SPNEGO auth packet. This contains the encrypted passwords
 451 */
 452 BOOL spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
 453 {
 454         ASN1_DATA data;
 455
 456         asn1_load(&data, blob);
 457         asn1_start_tag(&data, ASN1_CONTEXT(1));
 458         asn1_start_tag(&data, ASN1_SEQUENCE(0));
 459         asn1_start_tag(&data, ASN1_CONTEXT(2));
 460         asn1_read_OctetString(&data,auth);
 461         asn1_end_tag(&data);
 462         asn1_end_tag(&data);
 463         asn1_end_tag(&data);
 464
 465         if (data.has_error) {
 466                 DEBUG(3,("spnego_parse_auth failed at %d\n", (int)data.ofs));
 467                 data_blob_free(auth);
 468                 asn1_free(&data);
 469                 return False;
 470         }
 471
 472         asn1_free(&data);
 473         return True;
 474 }
 475
 476 /*
 477   generate a minimal SPNEGO response packet.  Doesn't contain much.
 478 */
 479 DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
 480                                    const char *mechOID)
 481 {
 482         ASN1_DATA data;
 483         DATA_BLOB ret;
 484         uint8 negResult;
 485
 486         if (NT_STATUS_IS_OK(nt_status)) {
 487                 negResult = SPNEGO_NEG_RESULT_ACCEPT;
 488         } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 489                 negResult = SPNEGO_NEG_RESULT_INCOMPLETE;
 490         } else {
 491                 negResult = SPNEGO_NEG_RESULT_REJECT;
 492         }
 493
 494         ZERO_STRUCT(data);
 495
 496         asn1_push_tag(&data, ASN1_CONTEXT(1));
 497         asn1_push_tag(&data, ASN1_SEQUENCE(0));
 498         asn1_push_tag(&data, ASN1_CONTEXT(0));
 499         asn1_write_enumerated(&data, negResult);
 500         asn1_pop_tag(&data);
 501
 502         if (reply->data != NULL) {
 503                 asn1_push_tag(&data,ASN1_CONTEXT(1));
 504                 asn1_write_OID(&data, mechOID);
 505                 asn1_pop_tag(&data);
 506
 507                 asn1_push_tag(&data,ASN1_CONTEXT(2));
 508                 asn1_write_OctetString(&data, reply->data, reply->length);
 509                 asn1_pop_tag(&data);
 510         }
 511
 512         asn1_pop_tag(&data);
 513         asn1_pop_tag(&data);
 514
 515         ret = data_blob(data.data, data.length);
 516         asn1_free(&data);
 517         return ret;
 518 }
 519
 520 /*
 521  parse a SPNEGO NTLMSSP auth packet. This contains the encrypted passwords
 522 */
 523 BOOL spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status,
 524                                 DATA_BLOB *auth)
 525 {
 526         ASN1_DATA data;
 527         uint8 negResult;
 528
 529         if (NT_STATUS_IS_OK(nt_status)) {
 530                 negResult = SPNEGO_NEG_RESULT_ACCEPT;
 531         } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 532                 negResult = SPNEGO_NEG_RESULT_INCOMPLETE;
 533         } else {
 534                 negResult = SPNEGO_NEG_RESULT_REJECT;
 535         }
 536
 537         asn1_load(&data, blob);
 538         asn1_start_tag(&data, ASN1_CONTEXT(1));
 539         asn1_start_tag(&data, ASN1_SEQUENCE(0));
 540         asn1_start_tag(&data, ASN1_CONTEXT(0));
 541         asn1_check_enumerated(&data, negResult);
 542         asn1_end_tag(&data);
 543
 544         if (negResult == SPNEGO_NEG_RESULT_INCOMPLETE) {
 545                 asn1_start_tag(&data,ASN1_CONTEXT(1));
 546                 asn1_check_OID(&data, OID_NTLMSSP);
 547                 asn1_end_tag(&data);
 548
 549                 asn1_start_tag(&data,ASN1_CONTEXT(2));
 550                 asn1_read_OctetString(&data, auth);
 551                 asn1_end_tag(&data);
 552         }
 553
 554         asn1_end_tag(&data);
 555         asn1_end_tag(&data);
 556
 557         if (data.has_error) {
 558                 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data.ofs));
 559                 asn1_free(&data);
 560                 data_blob_free(auth);
 561                 return False;
 562         }
 563
 564         asn1_free(&data);
 565         return True;
 566 }