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