auth/gensec/schannel.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    dcerpc schannel operations
   5
   6    Copyright (C) Andrew Tridgell 2004
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   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 <tevent.h>
  25 #include "lib/util/tevent_ntstatus.h"
  26 #include "librpc/gen_ndr/ndr_schannel.h"
  27 #include "auth/auth.h"
  28 #include "auth/credentials/credentials.h"
  29 #include "auth/gensec/gensec.h"
  30 #include "auth/gensec/gensec_internal.h"
  31 #include "auth/gensec/gensec_proto.h"
  32 #include "../libcli/auth/schannel.h"
  33 #include "librpc/gen_ndr/dcerpc.h"
  34 #include "param/param.h"
  35 #include "auth/gensec/gensec_toplevel_proto.h"
  36 #include "lib/crypto/crypto.h"
  37 #include "libds/common/roles.h"
  38
  39 #undef DBGC_CLASS
  40 #define DBGC_CLASS DBGC_AUTH
  41
  42 struct schannel_state {
  43         struct gensec_security *gensec;
  44         uint64_t seq_num;
  45         bool initiator;
  46         struct netlogon_creds_CredentialState *creds;
  47         struct auth_user_info_dc *user_info_dc;
  48 };
  49
  50 #define SETUP_SEQNUM(state, buf, initiator) do { \
  51         uint8_t *_buf = buf; \
  52         uint32_t _seq_num_low = (state)->seq_num & UINT32_MAX; \
  53         uint32_t _seq_num_high = (state)->seq_num >> 32; \
  54         if (initiator) { \
  55                 _seq_num_high |= 0x80000000; \
  56         } \
  57         RSIVAL(_buf, 0, _seq_num_low); \
  58         RSIVAL(_buf, 4, _seq_num_high); \
  59 } while(0)
  60
  61 static struct schannel_state *netsec_create_state(
  62                                 struct gensec_security *gensec,
  63                                 struct netlogon_creds_CredentialState *creds,
  64                                 bool initiator)
  65 {
  66         struct schannel_state *state;
  67
  68         state = talloc_zero(gensec, struct schannel_state);
  69         if (state == NULL) {
  70                 return NULL;
  71         }
  72
  73         state->gensec = gensec;
  74         state->initiator = initiator;
  75         state->creds = netlogon_creds_copy(state, creds);
  76         if (state->creds == NULL) {
  77                 talloc_free(state);
  78                 return NULL;
  79         }
  80
  81         gensec->private_data = state;
  82
  83         return state;
  84 }
  85
  86 static void netsec_offset_and_sizes(struct schannel_state *state,
  87                                     bool do_seal,
  88                                     uint32_t *_min_sig_size,
  89                                     uint32_t *_used_sig_size,
  90                                     uint32_t *_checksum_length,
  91                                     uint32_t *_confounder_ofs)
  92 {
  93         uint32_t min_sig_size;
  94         uint32_t used_sig_size;
  95         uint32_t checksum_length;
  96         uint32_t confounder_ofs;
  97
  98         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
  99                 min_sig_size = 48;
 100                 used_sig_size = 56;
 101                 /*
 102                  * Note: windows has a bug here and uses the old values...
 103                  *
 104                  * checksum_length = 32;
 105                  * confounder_ofs = 48;
 106                  */
 107                 checksum_length = 8;
 108                 confounder_ofs = 24;
 109         } else {
 110                 min_sig_size = 24;
 111                 used_sig_size = 32;
 112                 checksum_length = 8;
 113                 confounder_ofs = 24;
 114         }
 115
 116         if (do_seal) {
 117                 min_sig_size += 8;
 118         }
 119
 120         if (_min_sig_size) {
 121                 *_min_sig_size = min_sig_size;
 122         }
 123
 124         if (_used_sig_size) {
 125                 *_used_sig_size = used_sig_size;
 126         }
 127
 128         if (_checksum_length) {
 129                 *_checksum_length = checksum_length;
 130         }
 131
 132         if (_confounder_ofs) {
 133                 *_confounder_ofs = confounder_ofs;
 134         }
 135 }
 136
 137 /*******************************************************************
 138  Encode or Decode the sequence number (which is symmetric)
 139  ********************************************************************/
 140 static void netsec_do_seq_num(struct schannel_state *state,
 141                               const uint8_t *checksum,
 142                               uint32_t checksum_length,
 143                               uint8_t seq_num[8])
 144 {
 145         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
 146                 AES_KEY key;
 147                 uint8_t iv[AES_BLOCK_SIZE];
 148
 149                 AES_set_encrypt_key(state->creds->session_key, 128, &key);
 150                 ZERO_STRUCT(iv);
 151                 memcpy(iv+0, checksum, 8);
 152                 memcpy(iv+8, checksum, 8);
 153
 154                 aes_cfb8_encrypt(seq_num, seq_num, 8, &key, iv, AES_ENCRYPT);
 155         } else {
 156                 static const uint8_t zeros[4];
 157                 uint8_t sequence_key[16];
 158                 uint8_t digest1[16];
 159
 160                 hmac_md5(state->creds->session_key, zeros, sizeof(zeros), digest1);
 161                 hmac_md5(digest1, checksum, checksum_length, sequence_key);
 162                 arcfour_crypt(seq_num, sequence_key, 8);
 163         }
 164
 165         state->seq_num++;
 166 }
 167
 168 static void netsec_do_seal(struct schannel_state *state,
 169                            const uint8_t seq_num[8],
 170                            uint8_t confounder[8],
 171                            uint8_t *data, uint32_t length,
 172                            bool forward)
 173 {
 174         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
 175                 AES_KEY key;
 176                 uint8_t iv[AES_BLOCK_SIZE];
 177                 uint8_t sess_kf0[16];
 178                 int i;
 179
 180                 for (i = 0; i < 16; i++) {
 181                         sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
 182                 }
 183
 184                 AES_set_encrypt_key(sess_kf0, 128, &key);
 185                 ZERO_STRUCT(iv);
 186                 memcpy(iv+0, seq_num, 8);
 187                 memcpy(iv+8, seq_num, 8);
 188
 189                 if (forward) {
 190                         aes_cfb8_encrypt(confounder, confounder, 8, &key, iv, AES_ENCRYPT);
 191                         aes_cfb8_encrypt(data, data, length, &key, iv, AES_ENCRYPT);
 192                 } else {
 193                         aes_cfb8_encrypt(confounder, confounder, 8, &key, iv, AES_DECRYPT);
 194                         aes_cfb8_encrypt(data, data, length, &key, iv, AES_DECRYPT);
 195                 }
 196         } else {
 197                 uint8_t sealing_key[16];
 198                 static const uint8_t zeros[4];
 199                 uint8_t digest2[16];
 200                 uint8_t sess_kf0[16];
 201                 int i;
 202
 203                 for (i = 0; i < 16; i++) {
 204                         sess_kf0[i] = state->creds->session_key[i] ^ 0xf0;
 205                 }
 206
 207                 hmac_md5(sess_kf0, zeros, 4, digest2);
 208                 hmac_md5(digest2, seq_num, 8, sealing_key);
 209
 210                 arcfour_crypt(confounder, sealing_key, 8);
 211                 arcfour_crypt(data, sealing_key, length);
 212         }
 213 }
 214
 215 /*******************************************************************
 216  Create a digest over the entire packet (including the data), and
 217  MD5 it with the session key.
 218  ********************************************************************/
 219 static void netsec_do_sign(struct schannel_state *state,
 220                            const uint8_t *confounder,
 221                            const uint8_t *data, size_t length,
 222                            uint8_t header[8],
 223                            uint8_t *checksum)
 224 {
 225         if (state->creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
 226                 struct HMACSHA256Context ctx;
 227
 228                 hmac_sha256_init(state->creds->session_key,
 229                                  sizeof(state->creds->session_key),
 230                                  &ctx);
 231
 232                 if (confounder) {
 233                         SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
 234                         SSVAL(header, 2, NL_SEAL_AES128);
 235                         SSVAL(header, 4, 0xFFFF);
 236                         SSVAL(header, 6, 0x0000);
 237
 238                         hmac_sha256_update(header, 8, &ctx);
 239                         hmac_sha256_update(confounder, 8, &ctx);
 240                 } else {
 241                         SSVAL(header, 0, NL_SIGN_HMAC_SHA256);
 242                         SSVAL(header, 2, NL_SEAL_NONE);
 243                         SSVAL(header, 4, 0xFFFF);
 244                         SSVAL(header, 6, 0x0000);
 245
 246                         hmac_sha256_update(header, 8, &ctx);
 247                 }
 248
 249                 hmac_sha256_update(data, length, &ctx);
 250
 251                 hmac_sha256_final(checksum, &ctx);
 252         } else {
 253                 uint8_t packet_digest[16];
 254                 static const uint8_t zeros[4];
 255                 MD5_CTX ctx;
 256
 257                 MD5Init(&ctx);
 258                 MD5Update(&ctx, zeros, 4);
 259                 if (confounder) {
 260                         SSVAL(header, 0, NL_SIGN_HMAC_MD5);
 261                         SSVAL(header, 2, NL_SEAL_RC4);
 262                         SSVAL(header, 4, 0xFFFF);
 263                         SSVAL(header, 6, 0x0000);
 264
 265                         MD5Update(&ctx, header, 8);
 266                         MD5Update(&ctx, confounder, 8);
 267                 } else {
 268                         SSVAL(header, 0, NL_SIGN_HMAC_MD5);
 269                         SSVAL(header, 2, NL_SEAL_NONE);
 270                         SSVAL(header, 4, 0xFFFF);
 271                         SSVAL(header, 6, 0x0000);
 272
 273                         MD5Update(&ctx, header, 8);
 274                 }
 275                 MD5Update(&ctx, data, length);
 276                 MD5Final(packet_digest, &ctx);
 277
 278                 hmac_md5(state->creds->session_key,
 279                          packet_digest, sizeof(packet_digest),
 280                          checksum);
 281         }
 282 }
 283
 284 static NTSTATUS netsec_incoming_packet(struct schannel_state *state,
 285                                 bool do_unseal,
 286                                 uint8_t *data, size_t length,
 287                                 const uint8_t *whole_pdu, size_t pdu_length,
 288                                 const DATA_BLOB *sig)
 289 {
 290         uint32_t min_sig_size = 0;
 291         uint8_t header[8];
 292         uint8_t checksum[32];
 293         uint32_t checksum_length = sizeof(checksum_length);
 294         uint8_t _confounder[8];
 295         uint8_t *confounder = NULL;
 296         uint32_t confounder_ofs = 0;
 297         uint8_t seq_num[8];
 298         int ret;
 299         const uint8_t *sign_data = NULL;
 300         size_t sign_length = 0;
 301
 302         netsec_offset_and_sizes(state,
 303                                 do_unseal,
 304                                 &min_sig_size,
 305                                 NULL,
 306                                 &checksum_length,
 307                                 &confounder_ofs);
 308
 309         if (sig->length < min_sig_size) {
 310                 return NT_STATUS_ACCESS_DENIED;
 311         }
 312
 313         if (do_unseal) {
 314                 confounder = _confounder;
 315                 memcpy(confounder, sig->data+confounder_ofs, 8);
 316         } else {
 317                 confounder = NULL;
 318         }
 319
 320         SETUP_SEQNUM(state, seq_num, !state->initiator);
 321
 322         if (do_unseal) {
 323                 netsec_do_seal(state, seq_num,
 324                                confounder,
 325                                data, length,
 326                                false);
 327         }
 328
 329         if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
 330                 sign_data = whole_pdu;
 331                 sign_length = pdu_length;
 332         } else {
 333                 sign_data = data;
 334                 sign_length = length;
 335         }
 336
 337         netsec_do_sign(state, confounder,
 338                        sign_data, sign_length,
 339                        header, checksum);
 340
 341         ret = memcmp(checksum, sig->data+16, checksum_length);
 342         if (ret != 0) {
 343                 dump_data_pw("calc digest:", checksum, checksum_length);
 344                 dump_data_pw("wire digest:", sig->data+16, checksum_length);
 345                 return NT_STATUS_ACCESS_DENIED;
 346         }
 347
 348         netsec_do_seq_num(state, checksum, checksum_length, seq_num);
 349
 350         ret = memcmp(seq_num, sig->data+8, 8);
 351         if (ret != 0) {
 352                 dump_data_pw("calc seq num:", seq_num, 8);
 353                 dump_data_pw("wire seq num:", sig->data+8, 8);
 354                 return NT_STATUS_ACCESS_DENIED;
 355         }
 356
 357         return NT_STATUS_OK;
 358 }
 359
 360 static uint32_t netsec_outgoing_sig_size(struct schannel_state *state)
 361 {
 362         uint32_t sig_size = 0;
 363
 364         netsec_offset_and_sizes(state,
 365                                 true,
 366                                 NULL,
 367                                 &sig_size,
 368                                 NULL,
 369                                 NULL);
 370
 371         return sig_size;
 372 }
 373
 374 static NTSTATUS netsec_outgoing_packet(struct schannel_state *state,
 375                                 TALLOC_CTX *mem_ctx,
 376                                 bool do_seal,
 377                                 uint8_t *data, size_t length,
 378                                 const uint8_t *whole_pdu, size_t pdu_length,
 379                                 DATA_BLOB *sig)
 380 {
 381         uint32_t min_sig_size = 0;
 382         uint32_t used_sig_size = 0;
 383         uint8_t header[8];
 384         uint8_t checksum[32];
 385         uint32_t checksum_length = sizeof(checksum_length);
 386         uint8_t _confounder[8];
 387         uint8_t *confounder = NULL;
 388         uint32_t confounder_ofs = 0;
 389         uint8_t seq_num[8];
 390         const uint8_t *sign_data = NULL;
 391         size_t sign_length = 0;
 392
 393         netsec_offset_and_sizes(state,
 394                                 do_seal,
 395                                 &min_sig_size,
 396                                 &used_sig_size,
 397                                 &checksum_length,
 398                                 &confounder_ofs);
 399
 400         SETUP_SEQNUM(state, seq_num, state->initiator);
 401
 402         if (do_seal) {
 403                 confounder = _confounder;
 404                 generate_random_buffer(confounder, 8);
 405         } else {
 406                 confounder = NULL;
 407         }
 408
 409         if (state->gensec->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
 410                 sign_data = whole_pdu;
 411                 sign_length = pdu_length;
 412         } else {
 413                 sign_data = data;
 414                 sign_length = length;
 415         }
 416
 417         netsec_do_sign(state, confounder,
 418                        sign_data, sign_length,
 419                        header, checksum);
 420
 421         if (do_seal) {
 422                 netsec_do_seal(state, seq_num,
 423                                confounder,
 424                                data, length,
 425                                true);
 426         }
 427
 428         netsec_do_seq_num(state, checksum, checksum_length, seq_num);
 429
 430         (*sig) = data_blob_talloc_zero(mem_ctx, used_sig_size);
 431
 432         memcpy(sig->data, header, 8);
 433         memcpy(sig->data+8, seq_num, 8);
 434         memcpy(sig->data+16, checksum, checksum_length);
 435
 436         if (confounder) {
 437                 memcpy(sig->data+confounder_ofs, confounder, 8);
 438         }
 439
 440         dump_data_pw("signature:", sig->data+ 0, 8);
 441         dump_data_pw("seq_num  :", sig->data+ 8, 8);
 442         dump_data_pw("digest   :", sig->data+16, checksum_length);
 443         dump_data_pw("confound :", sig->data+confounder_ofs, 8);
 444
 445         return NT_STATUS_OK;
 446 }
 447
 448 _PUBLIC_ NTSTATUS gensec_schannel_init(TALLOC_CTX *ctx);
 449
 450 static size_t schannel_sig_size(struct gensec_security *gensec_security, size_t data_size)
 451 {
 452         struct schannel_state *state =
 453                 talloc_get_type_abort(gensec_security->private_data,
 454                 struct schannel_state);
 455
 456         return netsec_outgoing_sig_size(state);
 457 }
 458
 459 struct schannel_update_state {
 460         NTSTATUS status;
 461         DATA_BLOB out;
 462 };
 463
 464 static NTSTATUS schannel_update_internal(struct gensec_security *gensec_security,
 465                                          TALLOC_CTX *out_mem_ctx,
 466                                          const DATA_BLOB in, DATA_BLOB *out);
 467
 468 static struct tevent_req *schannel_update_send(TALLOC_CTX *mem_ctx,
 469                                                struct tevent_context *ev,
 470                                                struct gensec_security *gensec_security,
 471                                                const DATA_BLOB in)
 472 {
 473         struct tevent_req *req;
 474         struct schannel_update_state *state = NULL;
 475         NTSTATUS status;
 476
 477         req = tevent_req_create(mem_ctx, &state,
 478                                 struct schannel_update_state);
 479         if (req == NULL) {
 480                 return NULL;
 481         }
 482
 483         status = schannel_update_internal(gensec_security,
 484                                           state, in,
 485                                           &state->out);
 486         state->status = status;
 487         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 488                 status = NT_STATUS_OK;
 489         }
 490         if (tevent_req_nterror(req, status)) {
 491                 return tevent_req_post(req, ev);
 492         }
 493
 494         tevent_req_done(req);
 495         return tevent_req_post(req, ev);
 496 }
 497
 498 static NTSTATUS schannel_update_internal(struct gensec_security *gensec_security,
 499                                          TALLOC_CTX *out_mem_ctx,
 500                                          const DATA_BLOB in, DATA_BLOB *out)
 501 {
 502         struct schannel_state *state =
 503                 talloc_get_type(gensec_security->private_data,
 504                 struct schannel_state);
 505         NTSTATUS status;
 506         enum ndr_err_code ndr_err;
 507         struct NL_AUTH_MESSAGE bind_schannel = {};
 508         struct NL_AUTH_MESSAGE bind_schannel_ack;
 509         struct netlogon_creds_CredentialState *creds;
 510         const char *workstation;
 511         const char *domain;
 512
 513         *out = data_blob(NULL, 0);
 514
 515         if (gensec_security->dcerpc_auth_level < DCERPC_AUTH_LEVEL_INTEGRITY) {
 516                 switch (gensec_security->gensec_role) {
 517                 case GENSEC_CLIENT:
 518                         return NT_STATUS_INVALID_PARAMETER_MIX;
 519                 case GENSEC_SERVER:
 520                         return NT_STATUS_INVALID_PARAMETER;
 521                 }
 522                 return NT_STATUS_INTERNAL_ERROR;
 523         }
 524
 525         switch (gensec_security->gensec_role) {
 526         case GENSEC_CLIENT:
 527                 if (state != NULL) {
 528                         /* we could parse the bind ack, but we don't know what it is yet */
 529                         return NT_STATUS_OK;
 530                 }
 531
 532                 creds = cli_credentials_get_netlogon_creds(gensec_security->credentials);
 533                 if (creds == NULL) {
 534                         return NT_STATUS_INVALID_PARAMETER_MIX;
 535                 }
 536
 537                 state = netsec_create_state(gensec_security,
 538                                             creds, true /* initiator */);
 539                 if (state == NULL) {
 540                         return NT_STATUS_NO_MEMORY;
 541                 }
 542
 543                 bind_schannel.MessageType = NL_NEGOTIATE_REQUEST;
 544
 545                 bind_schannel.Flags = NL_FLAG_OEM_NETBIOS_DOMAIN_NAME |
 546                                       NL_FLAG_OEM_NETBIOS_COMPUTER_NAME;
 547                 bind_schannel.oem_netbios_domain.a = cli_credentials_get_domain(gensec_security->credentials);
 548                 bind_schannel.oem_netbios_computer.a = creds->computer_name;
 549
 550                 if (creds->secure_channel_type == SEC_CHAN_DNS_DOMAIN) {
 551                         bind_schannel.Flags |= NL_FLAG_UTF8_DNS_DOMAIN_NAME;
 552                         bind_schannel.utf8_dns_domain.u = cli_credentials_get_realm(gensec_security->credentials);
 553
 554                         bind_schannel.Flags |= NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME;
 555                         bind_schannel.utf8_netbios_computer.u = creds->computer_name;
 556                 }
 557
 558                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
 559                                                (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
 560                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 561                         status = ndr_map_error2ntstatus(ndr_err);
 562                         DEBUG(3, ("Could not create schannel bind: %s\n",
 563                                   nt_errstr(status)));
 564                         return status;
 565                 }
 566
 567                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 568         case GENSEC_SERVER:
 569
 570                 if (state != NULL) {
 571                         /* no third leg on this protocol */
 572                         return NT_STATUS_INVALID_PARAMETER;
 573                 }
 574
 575                 /* parse the schannel startup blob */
 576                 ndr_err = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
 577                         (ndr_pull_flags_fn_t)ndr_pull_NL_AUTH_MESSAGE);
 578                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 579                         status = ndr_map_error2ntstatus(ndr_err);
 580                         DEBUG(3, ("Could not parse incoming schannel bind: %s\n",
 581                                   nt_errstr(status)));
 582                         return status;
 583                 }
 584
 585                 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_DOMAIN_NAME) {
 586                         domain = bind_schannel.oem_netbios_domain.a;
 587                         if (strcasecmp_m(domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)) != 0) {
 588                                 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
 589                                           domain, lpcfg_workgroup(gensec_security->settings->lp_ctx)));
 590                                 return NT_STATUS_LOGON_FAILURE;
 591                         }
 592                 } else if (bind_schannel.Flags & NL_FLAG_UTF8_DNS_DOMAIN_NAME) {
 593                         domain = bind_schannel.utf8_dns_domain.u;
 594                         if (strcasecmp_m(domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)) != 0) {
 595                                 DEBUG(3, ("Request for schannel to incorrect domain: %s != our domain %s\n",
 596                                           domain, lpcfg_dnsdomain(gensec_security->settings->lp_ctx)));
 597                                 return NT_STATUS_LOGON_FAILURE;
 598                         }
 599                 } else {
 600                         DEBUG(3, ("Request for schannel to without domain\n"));
 601                         return NT_STATUS_LOGON_FAILURE;
 602                 }
 603
 604                 if (bind_schannel.Flags & NL_FLAG_OEM_NETBIOS_COMPUTER_NAME) {
 605                         workstation = bind_schannel.oem_netbios_computer.a;
 606                 } else if (bind_schannel.Flags & NL_FLAG_UTF8_NETBIOS_COMPUTER_NAME) {
 607                         workstation = bind_schannel.utf8_netbios_computer.u;
 608                 } else {
 609                         DEBUG(3, ("Request for schannel to without netbios workstation\n"));
 610                         return NT_STATUS_LOGON_FAILURE;
 611                 }
 612
 613                 status = schannel_get_creds_state(out_mem_ctx,
 614                                                   gensec_security->settings->lp_ctx,
 615                                                   workstation, &creds);
 616                 if (!NT_STATUS_IS_OK(status)) {
 617                         DEBUG(3, ("Could not find session key for attempted schannel connection from %s: %s\n",
 618                                   workstation, nt_errstr(status)));
 619                         if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
 620                                 return NT_STATUS_LOGON_FAILURE;
 621                         }
 622                         return status;
 623                 }
 624
 625                 state = netsec_create_state(gensec_security,
 626                                             creds, false /* not initiator */);
 627                 if (state == NULL) {
 628                         return NT_STATUS_NO_MEMORY;
 629                 }
 630
 631                 status = auth_anonymous_user_info_dc(state,
 632                                 lpcfg_netbios_name(gensec_security->settings->lp_ctx),
 633                                 &state->user_info_dc);
 634                 if (!NT_STATUS_IS_OK(status)) {
 635                         return status;
 636                 }
 637
 638                 bind_schannel_ack.MessageType = NL_NEGOTIATE_RESPONSE;
 639                 bind_schannel_ack.Flags = 0;
 640                 bind_schannel_ack.Buffer.dummy = 0x6c0000; /* actually I think
 641                                                             * this does not have
 642                                                             * any meaning here
 643                                                             * - gd */
 644
 645                 ndr_err = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
 646                                                (ndr_push_flags_fn_t)ndr_push_NL_AUTH_MESSAGE);
 647                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 648                         status = ndr_map_error2ntstatus(ndr_err);
 649                         DEBUG(3, ("Could not return schannel bind ack for client %s: %s\n",
 650                                   workstation, nt_errstr(status)));
 651                         return status;
 652                 }
 653
 654                 return NT_STATUS_OK;
 655         }
 656         return NT_STATUS_INVALID_PARAMETER;
 657 }
 658
 659 static NTSTATUS schannel_update_recv(struct tevent_req *req,
 660                                      TALLOC_CTX *out_mem_ctx,
 661                                      DATA_BLOB *out)
 662 {
 663         struct schannel_update_state *state =
 664                 tevent_req_data(req,
 665                 struct schannel_update_state);
 666         NTSTATUS status;
 667
 668         *out = data_blob_null;
 669
 670         if (tevent_req_is_nterror(req, &status)) {
 671                 tevent_req_received(req);
 672                 return status;
 673         }
 674
 675         status = state->status;
 676         talloc_steal(out_mem_ctx, state->out.data);
 677         *out = state->out;
 678         tevent_req_received(req);
 679         return status;
 680 }
 681
 682 /**
 683  * Returns anonymous credentials for schannel, matching Win2k3.
 684  *
 685  */
 686
 687 static NTSTATUS schannel_session_info(struct gensec_security *gensec_security,
 688                                       TALLOC_CTX *mem_ctx,
 689                                       struct auth_session_info **_session_info)
 690 {
 691         struct schannel_state *state =
 692                 talloc_get_type(gensec_security->private_data,
 693                 struct schannel_state);
 694         struct auth4_context *auth_ctx = gensec_security->auth_context;
 695         struct auth_session_info *session_info = NULL;
 696         uint32_t session_info_flags = 0;
 697         NTSTATUS status;
 698
 699         if (auth_ctx == NULL) {
 700                 DEBUG(0, ("Cannot generate a session_info without the auth_context\n"));
 701                 return NT_STATUS_INTERNAL_ERROR;
 702         }
 703
 704         if (auth_ctx->generate_session_info == NULL) {
 705                 DEBUG(0, ("Cannot generate a session_info without the generate_session_info hook\n"));
 706                 return NT_STATUS_INTERNAL_ERROR;
 707         }
 708
 709         if (gensec_security->want_features & GENSEC_FEATURE_UNIX_TOKEN) {
 710                 session_info_flags |= AUTH_SESSION_INFO_UNIX_TOKEN;
 711         }
 712
 713         session_info_flags |= AUTH_SESSION_INFO_SIMPLE_PRIVILEGES;
 714
 715         status = auth_ctx->generate_session_info(
 716                                 auth_ctx,
 717                                 mem_ctx,
 718                                 state->user_info_dc,
 719                                 state->user_info_dc->info->account_name,
 720                                 session_info_flags,
 721                                 &session_info);
 722         if (!NT_STATUS_IS_OK(status)) {
 723                 return status;
 724         }
 725
 726         *_session_info = session_info;
 727         return NT_STATUS_OK;
 728 }
 729
 730 /*
 731  * Reduce the attack surface by ensuring schannel is not availble when
 732  * we are not a DC
 733  */
 734 static NTSTATUS schannel_server_start(struct gensec_security *gensec_security)
 735 {
 736         enum server_role server_role
 737                 = lpcfg_server_role(gensec_security->settings->lp_ctx);
 738
 739         switch (server_role) {
 740         case ROLE_DOMAIN_BDC:
 741         case ROLE_DOMAIN_PDC:
 742         case ROLE_ACTIVE_DIRECTORY_DC:
 743                 return NT_STATUS_OK;
 744         default:
 745                 return NT_STATUS_NOT_IMPLEMENTED;
 746         }
 747 }
 748
 749 static NTSTATUS schannel_client_start(struct gensec_security *gensec_security)
 750 {
 751         return NT_STATUS_OK;
 752 }
 753
 754 static bool schannel_have_feature(struct gensec_security *gensec_security,
 755                                          uint32_t feature)
 756 {
 757         if (gensec_security->dcerpc_auth_level >= DCERPC_AUTH_LEVEL_INTEGRITY) {
 758                 if (feature & GENSEC_FEATURE_SIGN) {
 759                         return true;
 760                 }
 761         }
 762         if (gensec_security->dcerpc_auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
 763                 if (feature & GENSEC_FEATURE_SEAL) {
 764                         return true;
 765                 }
 766         }
 767         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 768                 return true;
 769         }
 770         if (feature & GENSEC_FEATURE_SIGN_PKT_HEADER) {
 771                 return true;
 772         }
 773         return false;
 774 }
 775
 776 /*
 777   unseal a packet
 778 */
 779 static NTSTATUS schannel_unseal_packet(struct gensec_security *gensec_security,
 780                                        uint8_t *data, size_t length,
 781                                        const uint8_t *whole_pdu, size_t pdu_length,
 782                                        const DATA_BLOB *sig)
 783 {
 784         struct schannel_state *state =
 785                 talloc_get_type_abort(gensec_security->private_data,
 786                 struct schannel_state);
 787
 788         return netsec_incoming_packet(state, true,
 789                                       discard_const_p(uint8_t, data),
 790                                       length,
 791                                       whole_pdu, pdu_length,
 792                                       sig);
 793 }
 794
 795 /*
 796   check the signature on a packet
 797 */
 798 static NTSTATUS schannel_check_packet(struct gensec_security *gensec_security,
 799                                       const uint8_t *data, size_t length,
 800                                       const uint8_t *whole_pdu, size_t pdu_length,
 801                                       const DATA_BLOB *sig)
 802 {
 803         struct schannel_state *state =
 804                 talloc_get_type_abort(gensec_security->private_data,
 805                 struct schannel_state);
 806
 807         return netsec_incoming_packet(state, false,
 808                                       discard_const_p(uint8_t, data),
 809                                       length,
 810                                       whole_pdu, pdu_length,
 811                                       sig);
 812 }
 813 /*
 814   seal a packet
 815 */
 816 static NTSTATUS schannel_seal_packet(struct gensec_security *gensec_security,
 817                                      TALLOC_CTX *mem_ctx,
 818                                      uint8_t *data, size_t length,
 819                                      const uint8_t *whole_pdu, size_t pdu_length,
 820                                      DATA_BLOB *sig)
 821 {
 822         struct schannel_state *state =
 823                 talloc_get_type_abort(gensec_security->private_data,
 824                 struct schannel_state);
 825
 826         return netsec_outgoing_packet(state, mem_ctx, true,
 827                                       data, length,
 828                                       whole_pdu, pdu_length,
 829                                       sig);
 830 }
 831
 832 /*
 833   sign a packet
 834 */
 835 static NTSTATUS schannel_sign_packet(struct gensec_security *gensec_security,
 836                                      TALLOC_CTX *mem_ctx,
 837                                      const uint8_t *data, size_t length,
 838                                      const uint8_t *whole_pdu, size_t pdu_length,
 839                                      DATA_BLOB *sig)
 840 {
 841         struct schannel_state *state =
 842                 talloc_get_type_abort(gensec_security->private_data,
 843                 struct schannel_state);
 844
 845         return netsec_outgoing_packet(state, mem_ctx, false,
 846                                       discard_const_p(uint8_t, data),
 847                                       length,
 848                                       whole_pdu, pdu_length,
 849                                       sig);
 850 }
 851
 852 static const struct gensec_security_ops gensec_schannel_security_ops = {
 853         .name           = "schannel",
 854         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 855         .client_start   = schannel_client_start,
 856         .server_start   = schannel_server_start,
 857         .update_send    = schannel_update_send,
 858         .update_recv    = schannel_update_recv,
 859         .seal_packet    = schannel_seal_packet,
 860         .sign_packet    = schannel_sign_packet,
 861         .check_packet   = schannel_check_packet,
 862         .unseal_packet  = schannel_unseal_packet,
 863         .session_info   = schannel_session_info,
 864         .sig_size       = schannel_sig_size,
 865         .have_feature   = schannel_have_feature,
 866         .enabled        = true,
 867         .priority       = GENSEC_SCHANNEL
 868 };
 869
 870 _PUBLIC_ NTSTATUS gensec_schannel_init(TALLOC_CTX *ctx)
 871 {
 872         NTSTATUS ret;
 873         ret = gensec_register(ctx, &gensec_schannel_security_ops);
 874         if (!NT_STATUS_IS_OK(ret)) {
 875                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 876                         gensec_schannel_security_ops.name));
 877                 return ret;
 878         }
 879
 880         return ret;
 881 }