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#include "smb_krb5.h" 25 26/* 27 generate a negTokenInit packet given a GUID, a list of supported 28 OIDs (the mechanisms) and a principal name string 29*/ 30DATA_BLOB spnego_gen_negTokenInit(char guid[16], 31 const char *OIDs[], 32 const char *principal) 33{ 34 int i; 35 ASN1_DATA *data; 36 DATA_BLOB ret; 37 38 data = asn1_init(talloc_tos()); 39 if (data == NULL) { 40 return data_blob_null; 41 } 42 43 asn1_write(data, guid, 16); 44 asn1_push_tag(data,ASN1_APPLICATION(0)); 45 asn1_write_OID(data,OID_SPNEGO); 46 asn1_push_tag(data,ASN1_CONTEXT(0)); 47 asn1_push_tag(data,ASN1_SEQUENCE(0)); 48 49 asn1_push_tag(data,ASN1_CONTEXT(0)); 50 asn1_push_tag(data,ASN1_SEQUENCE(0)); 51 for (i=0; OIDs[i]; i++) { 52 asn1_write_OID(data,OIDs[i]); 53 } 54 asn1_pop_tag(data); 55 asn1_pop_tag(data); 56 57 asn1_push_tag(data, ASN1_CONTEXT(3)); 58 asn1_push_tag(data, ASN1_SEQUENCE(0)); 59 asn1_push_tag(data, ASN1_CONTEXT(0)); 60 asn1_write_GeneralString(data,principal); 61 asn1_pop_tag(data); 62 asn1_pop_tag(data); 63 asn1_pop_tag(data); 64 65 asn1_pop_tag(data); 66 asn1_pop_tag(data); 67 68 asn1_pop_tag(data); 69 70 if (data->has_error) { 71 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs)); 72 } 73 74 ret = data_blob(data->data, data->length); 75 asn1_free(data); 76 77 return ret; 78} 79 80/* 81 Generate a negTokenInit as used by the client side ... It has a mechType 82 (OID), and a mechToken (a security blob) ... 83 84 Really, we need to break out the NTLMSSP stuff as well, because it could be 85 raw in the packets! 86*/ 87DATA_BLOB gen_negTokenInit(const char *OID, DATA_BLOB blob) 88{ 89 ASN1_DATA *data; 90 DATA_BLOB ret; 91 92 data = asn1_init(talloc_tos()); 93 if (data == NULL) { 94 return data_blob_null; 95 } 96 97 asn1_push_tag(data, ASN1_APPLICATION(0)); 98 asn1_write_OID(data,OID_SPNEGO); 99 asn1_push_tag(data, ASN1_CONTEXT(0)); 100 asn1_push_tag(data, ASN1_SEQUENCE(0)); 101 102 asn1_push_tag(data, ASN1_CONTEXT(0)); 103 asn1_push_tag(data, ASN1_SEQUENCE(0)); 104 asn1_write_OID(data, OID); 105 asn1_pop_tag(data); 106 asn1_pop_tag(data); 107 108 asn1_push_tag(data, ASN1_CONTEXT(2)); 109 asn1_write_OctetString(data,blob.data,blob.length); 110 asn1_pop_tag(data); 111 112 asn1_pop_tag(data); 113 asn1_pop_tag(data); 114 115 asn1_pop_tag(data); 116 117 if (data->has_error) { 118 DEBUG(1,("Failed to build negTokenInit at offset %d\n", (int)data->ofs)); 119 } 120 121 ret = data_blob(data->data, data->length); 122 asn1_free(data); 123 124 return ret; 125} 126 127/* 128 parse a negTokenInit packet giving a GUID, a list of supported 129 OIDs (the mechanisms) and a principal name string 130*/ 131bool spnego_parse_negTokenInit(DATA_BLOB blob, 132 char *OIDs[ASN1_MAX_OIDS], 133 char **principal) 134{ 135 int i; 136 bool ret; 137 ASN1_DATA *data; 138 139 data = asn1_init(talloc_tos()); 140 if (data == NULL) { 141 return false; 142 } 143 144 asn1_load(data, blob); 145 146 asn1_start_tag(data,ASN1_APPLICATION(0)); 147 148 asn1_check_OID(data,OID_SPNEGO); 149 150 /* negTokenInit [0] NegTokenInit */ 151 asn1_start_tag(data,ASN1_CONTEXT(0)); 152 asn1_start_tag(data,ASN1_SEQUENCE(0)); 153 154 /* mechTypes [0] MechTypeList OPTIONAL */ 155 156 /* Not really optional, we depend on this to decide 157 * what mechanisms we have to work with. */ 158 159 asn1_start_tag(data,ASN1_CONTEXT(0)); 160 asn1_start_tag(data,ASN1_SEQUENCE(0)); 161 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) { 162 const char *oid_str = NULL; 163 asn1_read_OID(data,talloc_autofree_context(),&oid_str); 164 OIDs[i] = CONST_DISCARD(char *, oid_str); 165 } 166 OIDs[i] = NULL; 167 asn1_end_tag(data); 168 asn1_end_tag(data); 169 170 *principal = NULL; 171 172 /* 173 Win7 + Live Sign-in Assistant attaches a mechToken 174 ASN1_CONTEXT(2) to the negTokenInit packet 175 which breaks our negotiation if we just assume 176 the next tag is ASN1_CONTEXT(3). 177 */ 178 179 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) { 180 uint8 flags; 181 182 /* reqFlags [1] ContextFlags OPTIONAL */ 183 asn1_start_tag(data, ASN1_CONTEXT(1)); 184 asn1_start_tag(data, ASN1_BIT_STRING); 185 while (asn1_tag_remaining(data) > 0) { 186 asn1_read_uint8(data, &flags); 187 } 188 asn1_end_tag(data); 189 asn1_end_tag(data); 190 } 191 192 if (asn1_peek_tag(data, ASN1_CONTEXT(2))) { 193 /* mechToken [2] OCTET STRING OPTIONAL */ 194 DATA_BLOB token; 195 asn1_start_tag(data, ASN1_CONTEXT(2)); 196 asn1_read_OctetString(data, talloc_autofree_context(), 197 &token); 198 asn1_end_tag(data); 199 /* Throw away the token - not used. */ 200 data_blob_free(&token); 201 } 202 203 if (asn1_peek_tag(data, ASN1_CONTEXT(3))) { 204 /* mechListMIC [3] OCTET STRING OPTIONAL */ 205 asn1_start_tag(data, ASN1_CONTEXT(3)); 206 asn1_start_tag(data, ASN1_SEQUENCE(0)); 207 asn1_start_tag(data, ASN1_CONTEXT(0)); 208 asn1_read_GeneralString(data,talloc_autofree_context(), 209 principal); 210 asn1_end_tag(data); 211 asn1_end_tag(data); 212 asn1_end_tag(data); 213 } 214 215 asn1_end_tag(data); 216 asn1_end_tag(data); 217 218 asn1_end_tag(data); 219 220 ret = !data->has_error; 221 if (data->has_error) { 222 int j; 223 TALLOC_FREE(*principal); 224 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) { 225 TALLOC_FREE(OIDs[j]); 226 } 227 } 228 229 asn1_free(data); 230 return ret; 231} 232 233/* 234 generate a negTokenTarg packet given a list of OIDs and a security blob 235*/ 236DATA_BLOB gen_negTokenTarg(const char *OIDs[], DATA_BLOB blob) 237{ 238 int i; 239 ASN1_DATA *data; 240 DATA_BLOB ret; 241 242 data = asn1_init(talloc_tos()); 243 if (data == NULL) { 244 return data_blob_null; 245 } 246 247 asn1_push_tag(data, ASN1_APPLICATION(0)); 248 asn1_write_OID(data,OID_SPNEGO); 249 asn1_push_tag(data, ASN1_CONTEXT(0)); 250 asn1_push_tag(data, ASN1_SEQUENCE(0)); 251 252 asn1_push_tag(data, ASN1_CONTEXT(0)); 253 asn1_push_tag(data, ASN1_SEQUENCE(0)); 254 for (i=0; OIDs[i]; i++) { 255 asn1_write_OID(data,OIDs[i]); 256 } 257 asn1_pop_tag(data); 258 asn1_pop_tag(data); 259 260 asn1_push_tag(data, ASN1_CONTEXT(2)); 261 asn1_write_OctetString(data,blob.data,blob.length); 262 asn1_pop_tag(data); 263 264 asn1_pop_tag(data); 265 asn1_pop_tag(data); 266 267 asn1_pop_tag(data); 268 269 if (data->has_error) { 270 DEBUG(1,("Failed to build negTokenTarg at offset %d\n", (int)data->ofs)); 271 } 272 273 ret = data_blob(data->data, data->length); 274 asn1_free(data); 275 276 return ret; 277} 278 279/* 280 parse a negTokenTarg packet giving a list of OIDs and a security blob 281*/ 282bool parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *secblob) 283{ 284 int i; 285 ASN1_DATA *data; 286 287 data = asn1_init(talloc_tos()); 288 if (data == NULL) { 289 return false; 290 } 291 292 asn1_load(data, blob); 293 asn1_start_tag(data, ASN1_APPLICATION(0)); 294 asn1_check_OID(data,OID_SPNEGO); 295 asn1_start_tag(data, ASN1_CONTEXT(0)); 296 asn1_start_tag(data, ASN1_SEQUENCE(0)); 297 298 asn1_start_tag(data, ASN1_CONTEXT(0)); 299 asn1_start_tag(data, ASN1_SEQUENCE(0)); 300 for (i=0; asn1_tag_remaining(data) > 0 && i < ASN1_MAX_OIDS-1; i++) { 301 const char *oid_str = NULL; 302 asn1_read_OID(data,talloc_autofree_context(),&oid_str); 303 OIDs[i] = CONST_DISCARD(char *, oid_str); 304 } 305 OIDs[i] = NULL; 306 asn1_end_tag(data); 307 asn1_end_tag(data); 308 309 /* Skip any optional req_flags that are sent per RFC 4178 */ 310 if (asn1_peek_tag(data, ASN1_CONTEXT(1))) { 311 uint8 flags; 312 313 asn1_start_tag(data, ASN1_CONTEXT(1)); 314 asn1_start_tag(data, ASN1_BIT_STRING); 315 while (asn1_tag_remaining(data) > 0) 316 asn1_read_uint8(data, &flags); 317 asn1_end_tag(data); 318 asn1_end_tag(data); 319 } 320 321 asn1_start_tag(data, ASN1_CONTEXT(2)); 322 asn1_read_OctetString(data,talloc_autofree_context(),secblob); 323 asn1_end_tag(data); 324 325 asn1_end_tag(data); 326 asn1_end_tag(data); 327 328 asn1_end_tag(data); 329 330 if (data->has_error) { 331 int j; 332 data_blob_free(secblob); 333 for(j = 0; j < i && j < ASN1_MAX_OIDS-1; j++) { 334 TALLOC_FREE(OIDs[j]); 335 } 336 DEBUG(1,("Failed to parse negTokenTarg at offset %d\n", (int)data->ofs)); 337 asn1_free(data); 338 return False; 339 } 340 341 asn1_free(data); 342 return True; 343} 344 345/* 346 generate a krb5 GSS-API wrapper packet given a ticket 347*/ 348DATA_BLOB spnego_gen_krb5_wrap(const DATA_BLOB ticket, const uint8 tok_id[2]) 349{ 350 ASN1_DATA *data; 351 DATA_BLOB ret; 352 353 data = asn1_init(talloc_tos()); 354 if (data == NULL) { 355 return data_blob_null; 356 } 357 358 asn1_push_tag(data, ASN1_APPLICATION(0)); 359 asn1_write_OID(data, OID_KERBEROS5); 360 361 asn1_write(data, tok_id, 2); 362 asn1_write(data, ticket.data, ticket.length); 363 asn1_pop_tag(data); 364 365 if (data->has_error) { 366 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs)); 367 } 368 369 ret = data_blob(data->data, data->length); 370 asn1_free(data); 371 372 return ret; 373} 374 375/* 376 parse a krb5 GSS-API wrapper packet giving a ticket 377*/ 378bool spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2]) 379{ 380 bool ret; 381 ASN1_DATA *data; 382 int data_remaining; 383 384 data = asn1_init(talloc_tos()); 385 if (data == NULL) { 386 return false; 387 } 388 389 asn1_load(data, blob); 390 asn1_start_tag(data, ASN1_APPLICATION(0)); 391 asn1_check_OID(data, OID_KERBEROS5); 392 393 data_remaining = asn1_tag_remaining(data); 394 395 if (data_remaining < 3) { 396 data->has_error = True; 397 } else { 398 asn1_read(data, tok_id, 2); 399 data_remaining -= 2; 400 *ticket = data_blob(NULL, data_remaining); 401 asn1_read(data, ticket->data, ticket->length); 402 } 403 404 asn1_end_tag(data); 405 406 ret = !data->has_error; 407 408 if (data->has_error) { 409 data_blob_free(ticket); 410 } 411 412 asn1_free(data); 413 414 return ret; 415} 416 417 418/* 419 generate a SPNEGO negTokenTarg packet, ready for a EXTENDED_SECURITY 420 kerberos session setup 421*/ 422int spnego_gen_negTokenTarg(const char *principal, int time_offset, 423 DATA_BLOB *targ, 424 DATA_BLOB *session_key_krb5, uint32 extra_ap_opts, 425 time_t *expire_time) 426{ 427 int retval; 428 DATA_BLOB tkt, tkt_wrapped; 429 const char *krb_mechs[] = {OID_KERBEROS5_OLD, OID_KERBEROS5, OID_NTLMSSP, NULL}; 430 431 /* get a kerberos ticket for the service and extract the session key */ 432 retval = cli_krb5_get_ticket(principal, time_offset, 433 &tkt, session_key_krb5, extra_ap_opts, NULL, 434 expire_time, NULL); 435 436 if (retval) 437 return retval; 438 439 /* wrap that up in a nice GSS-API wrapping */ 440 tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ); 441 442 /* and wrap that in a shiny SPNEGO wrapper */ 443 *targ = gen_negTokenTarg(krb_mechs, tkt_wrapped); 444 445 data_blob_free(&tkt_wrapped); 446 data_blob_free(&tkt); 447 448 return retval; 449} 450 451 452/* 453 parse a spnego NTLMSSP challenge packet giving two security blobs 454*/ 455bool spnego_parse_challenge(const DATA_BLOB blob, 456 DATA_BLOB *chal1, DATA_BLOB *chal2) 457{ 458 bool ret; 459 ASN1_DATA *data; 460 461 ZERO_STRUCTP(chal1); 462 ZERO_STRUCTP(chal2); 463 464 data = asn1_init(talloc_tos()); 465 if (data == NULL) { 466 return false; 467 } 468 469 asn1_load(data, blob); 470 asn1_start_tag(data,ASN1_CONTEXT(1)); 471 asn1_start_tag(data,ASN1_SEQUENCE(0)); 472 473 asn1_start_tag(data,ASN1_CONTEXT(0)); 474 asn1_check_enumerated(data,1); 475 asn1_end_tag(data); 476 477 asn1_start_tag(data,ASN1_CONTEXT(1)); 478 asn1_check_OID(data, OID_NTLMSSP); 479 asn1_end_tag(data); 480 481 asn1_start_tag(data,ASN1_CONTEXT(2)); 482 asn1_read_OctetString(data, talloc_autofree_context(), chal1); 483 asn1_end_tag(data); 484 485 /* the second challenge is optional (XP doesn't send it) */ 486 if (asn1_tag_remaining(data)) { 487 asn1_start_tag(data,ASN1_CONTEXT(3)); 488 asn1_read_OctetString(data, talloc_autofree_context(), chal2); 489 asn1_end_tag(data); 490 } 491 492 asn1_end_tag(data); 493 asn1_end_tag(data); 494 495 ret = !data->has_error; 496 497 if (data->has_error) { 498 data_blob_free(chal1); 499 data_blob_free(chal2); 500 } 501 502 asn1_free(data); 503 return ret; 504} 505 506 507/* 508 generate a SPNEGO auth packet. This will contain the encrypted passwords 509*/ 510DATA_BLOB spnego_gen_auth(DATA_BLOB blob) 511{ 512 ASN1_DATA *data; 513 DATA_BLOB ret; 514 515 data = asn1_init(talloc_tos()); 516 if (data == NULL) { 517 return data_blob_null; 518 } 519 520 asn1_push_tag(data, ASN1_CONTEXT(1)); 521 asn1_push_tag(data, ASN1_SEQUENCE(0)); 522 asn1_push_tag(data, ASN1_CONTEXT(2)); 523 asn1_write_OctetString(data,blob.data,blob.length); 524 asn1_pop_tag(data); 525 asn1_pop_tag(data); 526 asn1_pop_tag(data); 527 528 ret = data_blob(data->data, data->length); 529 530 asn1_free(data); 531 532 return ret; 533} 534 535/* 536 parse a SPNEGO auth packet. This contains the encrypted passwords 537*/ 538bool spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth) 539{ 540 ssize_t len; 541 struct spnego_data token; 542 543 len = spnego_read_data(talloc_tos(), blob, &token); 544 if (len == -1) { 545 DEBUG(3,("spnego_parse_auth: spnego_read_data failed\n")); 546 return false; 547 } 548 549 if (token.type != SPNEGO_NEG_TOKEN_TARG) { 550 DEBUG(3,("spnego_parse_auth: wrong token type: %d\n", 551 token.type)); 552 spnego_free_data(&token); 553 return false; 554 } 555 556 *auth = data_blob_talloc(talloc_tos(), 557 token.negTokenTarg.responseToken.data, 558 token.negTokenTarg.responseToken.length); 559 spnego_free_data(&token); 560 561 return true; 562} 563 564/* 565 generate a minimal SPNEGO response packet. Doesn't contain much. 566*/ 567DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status, 568 const char *mechOID) 569{ 570 ASN1_DATA *data; 571 DATA_BLOB ret; 572 uint8 negResult; 573 574 if (NT_STATUS_IS_OK(nt_status)) { 575 negResult = SPNEGO_ACCEPT_COMPLETED; 576 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { 577 negResult = SPNEGO_ACCEPT_INCOMPLETE; 578 } else { 579 negResult = SPNEGO_REJECT; 580 } 581 582 data = asn1_init(talloc_tos()); 583 if (data == NULL) { 584 return data_blob_null; 585 } 586 587 asn1_push_tag(data, ASN1_CONTEXT(1)); 588 asn1_push_tag(data, ASN1_SEQUENCE(0)); 589 asn1_push_tag(data, ASN1_CONTEXT(0)); 590 asn1_write_enumerated(data, negResult); 591 asn1_pop_tag(data); 592 593 if (mechOID) { 594 asn1_push_tag(data,ASN1_CONTEXT(1)); 595 asn1_write_OID(data, mechOID); 596 asn1_pop_tag(data); 597 } 598 599 if (reply && reply->data != NULL) { 600 asn1_push_tag(data,ASN1_CONTEXT(2)); 601 asn1_write_OctetString(data, reply->data, reply->length); 602 asn1_pop_tag(data); 603 } 604 605 asn1_pop_tag(data); 606 asn1_pop_tag(data); 607 608 ret = data_blob(data->data, data->length); 609 asn1_free(data); 610 return ret; 611} 612 613/* 614 parse a SPNEGO auth packet. This contains the encrypted passwords 615*/ 616bool spnego_parse_auth_response(DATA_BLOB blob, NTSTATUS nt_status, 617 const char *mechOID, 618 DATA_BLOB *auth) 619{ 620 ASN1_DATA *data; 621 uint8 negResult; 622 623 if (NT_STATUS_IS_OK(nt_status)) { 624 negResult = SPNEGO_ACCEPT_COMPLETED; 625 } else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { 626 negResult = SPNEGO_ACCEPT_INCOMPLETE; 627 } else { 628 negResult = SPNEGO_REJECT; 629 } 630 631 data = asn1_init(talloc_tos()); 632 if (data == NULL) { 633 return false; 634 } 635 636 asn1_load(data, blob); 637 asn1_start_tag(data, ASN1_CONTEXT(1)); 638 asn1_start_tag(data, ASN1_SEQUENCE(0)); 639 asn1_start_tag(data, ASN1_CONTEXT(0)); 640 asn1_check_enumerated(data, negResult); 641 asn1_end_tag(data); 642 643 *auth = data_blob_null; 644 645 if (asn1_tag_remaining(data)) { 646 asn1_start_tag(data,ASN1_CONTEXT(1)); 647 asn1_check_OID(data, mechOID); 648 asn1_end_tag(data); 649 650 if (asn1_tag_remaining(data)) { 651 asn1_start_tag(data,ASN1_CONTEXT(2)); 652 asn1_read_OctetString(data, talloc_autofree_context(), auth); 653 asn1_end_tag(data); 654 } 655 } else if (negResult == SPNEGO_ACCEPT_INCOMPLETE) { 656 data->has_error = 1; 657 } 658 659 /* Binding against Win2K DC returns a duplicate of the responseToken in 660 * the optional mechListMIC field. This is a bug in Win2K. We ignore 661 * this field if it exists. Win2K8 may return a proper mechListMIC at 662 * which point we need to implement the integrity checking. */ 663 if (asn1_tag_remaining(data)) { 664 DATA_BLOB mechList = data_blob_null; 665 asn1_start_tag(data, ASN1_CONTEXT(3)); 666 asn1_read_OctetString(data, talloc_autofree_context(), &mechList); 667 asn1_end_tag(data); 668 data_blob_free(&mechList); 669 DEBUG(5,("spnego_parse_auth_response received mechListMIC, " 670 "ignoring.\n")); 671 } 672 673 asn1_end_tag(data); 674 asn1_end_tag(data); 675 676 if (data->has_error) { 677 DEBUG(3,("spnego_parse_auth_response failed at %d\n", (int)data->ofs)); 678 asn1_free(data); 679 data_blob_free(auth); 680 return False; 681 } 682 683 asn1_free(data); 684 return True; 685} 686