source4/librpc/rpc/dcerpc_schannel.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    dcerpc schannel operations
   5
   6    Copyright (C) Andrew Tridgell 2004
   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 #include "librpc/gen_ndr/ndr_schannel.h"
  25 #include "auth/auth.h"
  26
  27 enum schannel_position {
  28         DCERPC_SCHANNEL_STATE_START = 0,
  29         DCERPC_SCHANNEL_STATE_UPDATE_1
  30 };
  31
  32 struct dcerpc_schannel_state {
  33         enum schannel_position state;
  34         struct schannel_state *schannel_state;
  35         struct creds_CredentialState *creds;
  36         char *account_name;
  37 };
  38
  39 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
  40                                     const char *domain,
  41                                     const char *username,
  42                                     const char *password,
  43                                     int chan_type,
  44                                     struct creds_CredentialState *creds);
  45
  46 /*
  47   wrappers for the schannel_*() functions
  48
  49   These will become static again, when we get dynamic registration, and
  50   decrpc_schannel_security_ops come back here.
  51 */
  52 static NTSTATUS dcerpc_schannel_unseal_packet(struct gensec_security *gensec_security,
  53                                               TALLOC_CTX *mem_ctx,
  54                                               uint8_t *data, size_t length,
  55                                               const uint8_t *whole_pdu, size_t pdu_length,
  56                                               DATA_BLOB *sig)
  57 {
  58         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  59
  60         return schannel_unseal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  61 }
  62
  63 static NTSTATUS dcerpc_schannel_check_packet(struct gensec_security *gensec_security,
  64                                              TALLOC_CTX *mem_ctx,
  65                                              const uint8_t *data, size_t length,
  66                                              const uint8_t *whole_pdu, size_t pdu_length,
  67                                              const DATA_BLOB *sig)
  68 {
  69         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  70
  71         return schannel_check_packet(dce_schan_state->schannel_state, data, length, sig);
  72 }
  73
  74 static NTSTATUS dcerpc_schannel_seal_packet(struct gensec_security *gensec_security,
  75                                             TALLOC_CTX *mem_ctx,
  76                                             uint8_t *data, size_t length,
  77                                             const uint8_t *whole_pdu, size_t pdu_length,
  78                                             DATA_BLOB *sig)
  79 {
  80         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  81
  82         return schannel_seal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  83 }
  84
  85 static NTSTATUS dcerpc_schannel_sign_packet(struct gensec_security *gensec_security,
  86                                             TALLOC_CTX *mem_ctx,
  87                                             const uint8_t *data, size_t length,
  88                                             const uint8_t *whole_pdu, size_t pdu_length,
  89                                             DATA_BLOB *sig)
  90 {
  91         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  92
  93         return schannel_sign_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  94 }
  95
  96 static size_t dcerpc_schannel_sig_size(struct gensec_security *gensec_security)
  97 {
  98         return 32;
  99 }
 100
 101 static NTSTATUS dcerpc_schannel_session_key(struct gensec_security *gensec_security,
 102                                             DATA_BLOB *session_key)
 103 {
 104         return NT_STATUS_NOT_IMPLEMENTED;
 105 }
 106
 107 static NTSTATUS dcerpc_schannel_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
 108                                        const DATA_BLOB in, DATA_BLOB *out)
 109 {
 110         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 111         NTSTATUS status;
 112         struct schannel_bind bind_schannel;
 113         struct schannel_bind_ack bind_schannel_ack;
 114         const char *account_name;
 115         *out = data_blob(NULL, 0);
 116
 117         switch (gensec_security->gensec_role) {
 118         case GENSEC_CLIENT:
 119                 if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 120                         /* we could parse the bind ack, but we don't know what it is yet */
 121                         return NT_STATUS_OK;
 122                 }
 123
 124                 status = schannel_start(&dce_schan_state->schannel_state,
 125                                         dce_schan_state->creds->session_key,
 126                                         True);
 127                 if (!NT_STATUS_IS_OK(status)) {
 128                         DEBUG(1, ("Failed to start schannel client\n"));
 129                         return status;
 130                 }
 131                 talloc_steal(dce_schan_state, dce_schan_state->schannel_state);
 132
 133                 bind_schannel.unknown1 = 0;
 134 #if 0
 135                 /* to support this we'd need to have access to the full domain name */
 136                 bind_schannel.bind_type = 23;
 137                 bind_schannel.u.info23.domain = gensec_security->user.domain;
 138                 bind_schannel.u.info23.account_name = gensec_security->user.name;
 139                 bind_schannel.u.info23.dnsdomain = str_format_nbt_domain(out_mem_ctx, fulldomainname);
 140                 bind_schannel.u.info23.workstation = str_format_nbt_domain(out_mem_ctx, gensec_security->user.name);
 141 #else
 142                 bind_schannel.bind_type = 3;
 143                 bind_schannel.u.info3.domain = gensec_security->user.domain;
 144                 bind_schannel.u.info3.account_name = gensec_security->user.name;
 145 #endif
 146
 147                 status = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
 148                                               (ndr_push_flags_fn_t)ndr_push_schannel_bind);
 149                 if (!NT_STATUS_IS_OK(status)) {
 150                         DEBUG(3, ("Could not create schannel bind: %s\n",
 151                                   nt_errstr(status)));
 152                         return status;
 153                 }
 154
 155                 dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 156
 157                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 158         case GENSEC_SERVER:
 159
 160                 if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 161                         /* no third leg on this protocol */
 162                         return NT_STATUS_INVALID_PARAMETER;
 163                 }
 164
 165                 /* parse the schannel startup blob */
 166                 status = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
 167                                               (ndr_pull_flags_fn_t)ndr_pull_schannel_bind);
 168                 if (!NT_STATUS_IS_OK(status)) {
 169                         return status;
 170                 }
 171
 172                 if (bind_schannel.bind_type == 23) {
 173                         account_name = bind_schannel.u.info23.account_name;
 174                 } else {
 175                         account_name = bind_schannel.u.info3.account_name;
 176                 }
 177
 178                 /* pull the session key for this client */
 179                 status = schannel_fetch_session_key(out_mem_ctx, account_name, &dce_schan_state->creds);
 180                 if (!NT_STATUS_IS_OK(status)) {
 181                         DEBUG(3, ("Could not find session key for attempted schannel connection on %s: %s\n",
 182                                   account_name, nt_errstr(status)));
 183                         return status;
 184                 }
 185
 186                 dce_schan_state->account_name = talloc_strdup(dce_schan_state, account_name);
 187
 188                 /* start up the schannel server code */
 189                 status = schannel_start(&dce_schan_state->schannel_state,
 190                                         dce_schan_state->creds->session_key, False);
 191                 if (!NT_STATUS_IS_OK(status)) {
 192                         DEBUG(3, ("Could not initialise schannel state for account %s: %s\n",
 193                                   account_name, nt_errstr(status)));
 194                         return status;
 195                 }
 196                 talloc_steal(dce_schan_state, dce_schan_state->schannel_state);
 197
 198                 bind_schannel_ack.unknown1 = 1;
 199                 bind_schannel_ack.unknown2 = 0;
 200                 bind_schannel_ack.unknown3 = 0x6c0000;
 201
 202                 status = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
 203                                               (ndr_push_flags_fn_t)ndr_push_schannel_bind_ack);
 204                 if (!NT_STATUS_IS_OK(status)) {
 205                         DEBUG(3, ("Could not return schannel bind ack for account %s: %s\n",
 206                                   account_name, nt_errstr(status)));
 207                         return status;
 208                 }
 209
 210                 dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 211
 212                 return NT_STATUS_OK;
 213         }
 214         return NT_STATUS_INVALID_PARAMETER;
 215 }
 216
 217 /**
 218  * Return the credentials of a logged on user, including session keys
 219  * etc.
 220  *
 221  * Only valid after a successful authentication
 222  *
 223  * May only be called once per authentication.
 224  *
 225  */
 226
 227 NTSTATUS dcerpc_schannel_session_info(struct gensec_security *gensec_security,
 228                                       struct auth_session_info **session_info)
 229 {
 230         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 231
 232         (*session_info) = talloc_p(gensec_security, struct auth_session_info);
 233         if (*session_info == NULL) {
 234                 return NT_STATUS_NO_MEMORY;
 235         }
 236
 237         ZERO_STRUCTP(*session_info);
 238         (*session_info)->refcount = 1;
 239
 240         (*session_info)->workstation = talloc_strdup(*session_info, dce_schan_state->account_name);
 241         if ((*session_info)->workstation == NULL) {
 242                 talloc_free(*session_info);
 243                 return NT_STATUS_NO_MEMORY;
 244         }
 245         return NT_STATUS_OK;
 246 }
 247
 248
 249 /**
 250  * Return the struct creds_CredentialState.
 251  *
 252  * Make sure not to call this unless gensec is using schannel...
 253  */
 254
 255 NTSTATUS dcerpc_schannel_creds(struct gensec_security *gensec_security,
 256                                TALLOC_CTX *mem_ctx,
 257                                struct creds_CredentialState **creds)
 258 {
 259         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 260
 261         *creds = talloc_reference(mem_ctx, dce_schan_state->creds);
 262         if (!*creds) {
 263                 return NT_STATUS_NO_MEMORY;
 264         }
 265         return NT_STATUS_OK;
 266 }
 267
 268
 269 /*
 270   end crypto state
 271 */
 272 static int dcerpc_schannel_destroy(void *ptr)
 273 {
 274         struct dcerpc_schannel_state *dce_schan_state = ptr;
 275
 276         schannel_end(&dce_schan_state->schannel_state);
 277
 278         return 0;
 279 }
 280
 281 static NTSTATUS dcerpc_schannel_start(struct gensec_security *gensec_security)
 282 {
 283         struct dcerpc_schannel_state *dce_schan_state;
 284
 285         dce_schan_state = talloc_p(gensec_security, struct dcerpc_schannel_state);
 286         if (!dce_schan_state) {
 287                 return NT_STATUS_NO_MEMORY;
 288         }
 289
 290         dce_schan_state->state = DCERPC_SCHANNEL_STATE_START;
 291         gensec_security->private_data = dce_schan_state;
 292         gensec_security->have_features =
 293                 GENSEC_FEATURE_SESSION_KEY |
 294                 GENSEC_FEATURE_SIGN |
 295                 GENSEC_FEATURE_SEAL;
 296
 297         talloc_set_destructor(dce_schan_state, dcerpc_schannel_destroy);
 298
 299         return NT_STATUS_OK;
 300 }
 301
 302 static NTSTATUS dcerpc_schannel_server_start(struct gensec_security *gensec_security)
 303 {
 304         NTSTATUS status;
 305
 306         status = dcerpc_schannel_start(gensec_security);
 307         if (!NT_STATUS_IS_OK(status)) {
 308                 return status;
 309         }
 310
 311         return NT_STATUS_OK;
 312 }
 313
 314 static NTSTATUS dcerpc_schannel_client_start(struct gensec_security *gensec_security)
 315 {
 316         NTSTATUS status;
 317
 318         status = dcerpc_schannel_start(gensec_security);
 319         if (!NT_STATUS_IS_OK(status)) {
 320                 return status;
 321         }
 322
 323         return NT_STATUS_OK;
 324 }
 325
 326
 327 /*
 328   get a schannel key using a netlogon challenge on a secondary pipe
 329 */
 330 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
 331                                     const char *domain,
 332                                     const char *username,
 333                                     const char *password,
 334                                     int chan_type,
 335                                     struct creds_CredentialState *creds)
 336 {
 337         NTSTATUS status;
 338         struct dcerpc_pipe *p2;
 339         struct netr_ServerReqChallenge r;
 340         struct netr_ServerAuthenticate2 a;
 341         struct netr_Credential credentials1, credentials2, credentials3;
 342         struct samr_Password mach_pwd;
 343         const char *workgroup, *workstation;
 344         uint32_t negotiate_flags;
 345
 346         if (p->flags & DCERPC_SCHANNEL_128) {
 347                 negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 348         } else {
 349                 negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
 350         }
 351
 352         workstation = username;
 353         workgroup = domain;
 354
 355         /*
 356           step 1 - establish a netlogon connection, with no authentication
 357         */
 358         status = dcerpc_secondary_connection(p, &p2,
 359                                              DCERPC_NETLOGON_NAME,
 360                                              DCERPC_NETLOGON_UUID,
 361                                              DCERPC_NETLOGON_VERSION);
 362         if (!NT_STATUS_IS_OK(status)) {
 363                 return status;
 364         }
 365
 366
 367         /*
 368           step 2 - request a netlogon challenge
 369         */
 370         r.in.server_name = talloc_asprintf(p, "\\\\%s", dcerpc_server_name(p));
 371         r.in.computer_name = workstation;
 372         r.in.credentials = &credentials1;
 373         r.out.credentials = &credentials2;
 374
 375         generate_random_buffer(credentials1.data, sizeof(credentials1.data));
 376
 377         status = dcerpc_netr_ServerReqChallenge(p2, p, &r);
 378         if (!NT_STATUS_IS_OK(status)) {
 379                 return status;
 380         }
 381
 382         /*
 383           step 3 - authenticate on the netlogon pipe
 384         */
 385         E_md4hash(password, mach_pwd.hash);
 386         creds_client_init(creds, &credentials1, &credentials2, &mach_pwd, &credentials3,
 387                           negotiate_flags);
 388
 389         a.in.server_name = r.in.server_name;
 390         a.in.account_name = talloc_asprintf(p, "%s$", workstation);
 391         a.in.secure_channel_type = chan_type;
 392         a.in.computer_name = workstation;
 393         a.in.negotiate_flags = &negotiate_flags;
 394         a.out.negotiate_flags = &negotiate_flags;
 395         a.in.credentials = &credentials3;
 396         a.out.credentials = &credentials3;
 397
 398         status = dcerpc_netr_ServerAuthenticate2(p2, p, &a);
 399         if (!NT_STATUS_IS_OK(status)) {
 400                 return status;
 401         }
 402
 403         if (!creds_client_check(creds, a.out.credentials)) {
 404                 return NT_STATUS_UNSUCCESSFUL;
 405         }
 406
 407         /*
 408           the schannel session key is now in creds.session_key
 409
 410           we no longer need the netlogon pipe open
 411         */
 412         dcerpc_pipe_close(p2);
 413
 414         return NT_STATUS_OK;
 415 }
 416
 417 /*
 418   do a schannel style bind on a dcerpc pipe. The username is usually
 419   of the form HOSTNAME$ and the password is the domain trust password
 420 */
 421 NTSTATUS dcerpc_bind_auth_schannel_withkey(struct dcerpc_pipe *p,
 422                                            const char *uuid, uint_t version,
 423                                            const char *domain,
 424                                            const char *username,
 425                                            const char *password,
 426                                            struct creds_CredentialState *creds)
 427 {
 428         NTSTATUS status;
 429         struct dcerpc_schannel_state *dce_schan_state;
 430
 431         status = gensec_client_start(p, &p->security_state.generic_state);
 432         if (!NT_STATUS_IS_OK(status)) {
 433                 return status;
 434         }
 435
 436         status = gensec_set_username(p->security_state.generic_state, username);
 437         if (!NT_STATUS_IS_OK(status)) {
 438                 DEBUG(1, ("Failed to set schannel username to %s: %s\n", username, nt_errstr(status)));
 439                 talloc_free(p->security_state.generic_state);
 440                 p->security_state.generic_state = NULL;
 441                 return status;
 442         }
 443
 444         status = gensec_set_domain(p->security_state.generic_state, domain);
 445         if (!NT_STATUS_IS_OK(status)) {
 446                 DEBUG(1, ("Failed to set schannel domain to %s: %s\n", domain, nt_errstr(status)));
 447                 talloc_free(p->security_state.generic_state);
 448                 p->security_state.generic_state = NULL;
 449                 return status;
 450         }
 451
 452         status = gensec_start_mech_by_authtype(p->security_state.generic_state, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p));
 453
 454         if (!NT_STATUS_IS_OK(status)) {
 455                 DEBUG(1, ("Failed to start SCHANNEL GENSEC backend: %s\n", nt_errstr(status)));
 456                 talloc_free(p->security_state.generic_state);
 457                 p->security_state.generic_state = NULL;
 458                 return status;
 459         }
 460
 461         dce_schan_state = p->security_state.generic_state->private_data;
 462         dce_schan_state->creds = talloc_reference(dce_schan_state, creds);
 463
 464         status = dcerpc_bind_auth3(p, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p),
 465                                   uuid, version);
 466
 467         if (!NT_STATUS_IS_OK(status)) {
 468                 DEBUG(1, ("Failed to bind to pipe with SCHANNEL: %s\n", nt_errstr(status)));
 469                 talloc_free(p->security_state.generic_state);
 470                 p->security_state.generic_state = NULL;
 471                 return status;
 472         }
 473
 474         return NT_STATUS_OK;
 475 }
 476
 477 NTSTATUS dcerpc_bind_auth_schannel(struct dcerpc_pipe *p,
 478                                    const char *uuid, uint_t version,
 479                                    const char *domain,
 480                                    const char *username,
 481                                    const char *password)
 482 {
 483         NTSTATUS status;
 484         int chan_type = 0;
 485         struct creds_CredentialState *creds;
 486         creds = talloc_p(p, struct creds_CredentialState);
 487         if (!creds) {
 488                 return NT_STATUS_NO_MEMORY;
 489         }
 490
 491         if (p->flags & DCERPC_SCHANNEL_BDC) {
 492                 chan_type = SEC_CHAN_BDC;
 493         } else if (p->flags & DCERPC_SCHANNEL_WORKSTATION) {
 494                 chan_type = SEC_CHAN_WKSTA;
 495         } else if (p->flags & DCERPC_SCHANNEL_DOMAIN) {
 496                 chan_type = SEC_CHAN_DOMAIN;
 497         }
 498
 499         status = dcerpc_schannel_key(p, domain,
 500                                      username,
 501                                      password,
 502                                      chan_type,
 503                                      creds);
 504
 505         if (!NT_STATUS_IS_OK(status)) {
 506                 DEBUG(1, ("Failed to fetch schannel session key: %s\n",
 507                           nt_errstr(status)));
 508                 return status;
 509         }
 510
 511         return dcerpc_bind_auth_schannel_withkey(p, uuid, version, domain,
 512                                                  username, password,
 513                                                  creds);
 514 }
 515
 516 static const struct gensec_security_ops gensec_dcerpc_schannel_security_ops = {
 517         .name           = "dcerpc_schannel",
 518         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 519         .client_start   = dcerpc_schannel_client_start,
 520         .server_start   = dcerpc_schannel_server_start,
 521         .update         = dcerpc_schannel_update,
 522         .seal_packet    = dcerpc_schannel_seal_packet,
 523         .sign_packet    = dcerpc_schannel_sign_packet,
 524         .check_packet   = dcerpc_schannel_check_packet,
 525         .unseal_packet  = dcerpc_schannel_unseal_packet,
 526         .session_key    = dcerpc_schannel_session_key,
 527         .session_info   = dcerpc_schannel_session_info,
 528         .sig_size       = dcerpc_schannel_sig_size,
 529 };
 530
 531 NTSTATUS gensec_dcerpc_schannel_init(void)
 532 {
 533         NTSTATUS ret;
 534         ret = gensec_register(&gensec_dcerpc_schannel_security_ops);
 535         if (!NT_STATUS_IS_OK(ret)) {
 536                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 537                         gensec_dcerpc_schannel_security_ops.name));
 538                 return ret;
 539         }
 540
 541         return ret;
 542 }