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
  25 enum schannel_position {
  26         DCERPC_SCHANNEL_STATE_START = 0,
  27         DCERPC_SCHANNEL_STATE_UPDATE_1
  28 };
  29
  30 struct dcerpc_schannel_state {
  31         enum schannel_position state;
  32         struct schannel_state *schannel_state;
  33         struct creds_CredentialState creds;
  34         char *account_name;
  35 };
  36
  37 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
  38                                     const char *domain,
  39                                     const char *username,
  40                                     const char *password,
  41                                     int chan_type,
  42                                     uint8_t new_session_key[16]);
  43
  44 /*
  45   wrappers for the schannel_*() functions
  46
  47   These will become static again, when we get dynamic registration, and
  48   decrpc_schannel_security_ops come back here.
  49 */
  50 static NTSTATUS dcerpc_schannel_unseal_packet(struct gensec_security *gensec_security,
  51                                               TALLOC_CTX *mem_ctx,
  52                                               uint8_t *data, size_t length,
  53                                               const uint8_t *whole_pdu, size_t pdu_length,
  54                                               DATA_BLOB *sig)
  55 {
  56         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  57
  58         return schannel_unseal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  59 }
  60
  61 static NTSTATUS dcerpc_schannel_check_packet(struct gensec_security *gensec_security,
  62                                              TALLOC_CTX *mem_ctx,
  63                                              const uint8_t *data, size_t length,
  64                                              const uint8_t *whole_pdu, size_t pdu_length,
  65                                              const DATA_BLOB *sig)
  66 {
  67         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  68
  69         return schannel_check_packet(dce_schan_state->schannel_state, data, length, sig);
  70 }
  71
  72 static NTSTATUS dcerpc_schannel_seal_packet(struct gensec_security *gensec_security,
  73                                             TALLOC_CTX *mem_ctx,
  74                                             uint8_t *data, size_t length,
  75                                             const uint8_t *whole_pdu, size_t pdu_length,
  76                                             DATA_BLOB *sig)
  77 {
  78         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  79
  80         return schannel_seal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  81 }
  82
  83 static NTSTATUS dcerpc_schannel_sign_packet(struct gensec_security *gensec_security,
  84                                             TALLOC_CTX *mem_ctx,
  85                                             const uint8_t *data, size_t length,
  86                                             const uint8_t *whole_pdu, size_t pdu_length,
  87                                             DATA_BLOB *sig)
  88 {
  89         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  90
  91         return schannel_sign_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  92 }
  93
  94 static size_t dcerpc_schannel_sig_size(struct gensec_security *gensec_security)
  95 {
  96         return 32;
  97 }
  98
  99 static NTSTATUS dcerpc_schannel_session_key(struct gensec_security *gensec_security,
 100                                             DATA_BLOB *session_key)
 101 {
 102         return NT_STATUS_NOT_IMPLEMENTED;
 103 }
 104
 105 static NTSTATUS dcerpc_schannel_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
 106                                        const DATA_BLOB in, DATA_BLOB *out)
 107 {
 108         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 109         NTSTATUS status;
 110         struct schannel_bind bind_schannel;
 111         struct schannel_bind_ack bind_schannel_ack;
 112         const char *account_name;
 113         *out = data_blob(NULL, 0);
 114
 115         switch (gensec_security->gensec_role) {
 116         case GENSEC_CLIENT:
 117                 if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 118                         /* we could parse the bind ack, but we don't know what it is yet */
 119                         return NT_STATUS_OK;
 120                 }
 121
 122                 bind_schannel.unknown1 = 0;
 123 #if 0
 124                 /* to support this we'd need to have access to the full domain name */
 125                 bind_schannel.bind_type = 23;
 126                 bind_schannel.u.info23.domain = gensec_security->user.domain;
 127                 bind_schannel.u.info23.account_name = gensec_security->user.name;
 128                 bind_schannel.u.info23.dnsdomain = str_format_nbt_domain(out_mem_ctx, fulldomainname);
 129                 bind_schannel.u.info23.workstation = str_format_nbt_domain(out_mem_ctx, gensec_security->user.name);
 130 #else
 131                 bind_schannel.bind_type = 3;
 132                 bind_schannel.u.info3.domain = gensec_security->user.domain;
 133                 bind_schannel.u.info3.account_name = gensec_security->user.name;
 134 #endif
 135
 136                 status = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
 137                                               (ndr_push_flags_fn_t)ndr_push_schannel_bind);
 138                 if (!NT_STATUS_IS_OK(status)) {
 139                         DEBUG(3, ("Could not create schannel bind: %s\n",
 140                                   nt_errstr(status)));
 141                         return status;
 142                 }
 143
 144                 dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 145
 146                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 147         case GENSEC_SERVER:
 148
 149                 if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 150                         /* no third leg on this protocol */
 151                         return NT_STATUS_INVALID_PARAMETER;
 152                 }
 153
 154                 /* parse the schannel startup blob */
 155                 status = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
 156                                               (ndr_pull_flags_fn_t)ndr_pull_schannel_bind);
 157                 if (!NT_STATUS_IS_OK(status)) {
 158                         return status;
 159                 }
 160
 161                 if (bind_schannel.bind_type == 23) {
 162                         account_name = bind_schannel.u.info23.account_name;
 163                 } else {
 164                         account_name = bind_schannel.u.info3.account_name;
 165                 }
 166
 167                 /* pull the session key for this client */
 168                 status = schannel_fetch_session_key(out_mem_ctx, account_name, &dce_schan_state->creds);
 169                 if (!NT_STATUS_IS_OK(status)) {
 170                         DEBUG(3, ("Could not find session key for attempted schannel connection on %s: %s\n",
 171                                   account_name, nt_errstr(status)));
 172                         return status;
 173                 }
 174
 175                 dce_schan_state->account_name = talloc_strdup(dce_schan_state, account_name);
 176
 177                 /* start up the schannel server code */
 178                 status = schannel_start(&dce_schan_state->schannel_state,
 179                                         dce_schan_state->creds.session_key, False);
 180                 if (!NT_STATUS_IS_OK(status)) {
 181                         DEBUG(3, ("Could not initialise schannel state for account %s: %s\n",
 182                                   account_name, nt_errstr(status)));
 183                         return status;
 184                 }
 185                 talloc_steal(dce_schan_state, dce_schan_state->schannel_state);
 186
 187                 bind_schannel_ack.unknown1 = 1;
 188                 bind_schannel_ack.unknown2 = 0;
 189                 bind_schannel_ack.unknown3 = 0x6c0000;
 190
 191                 status = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
 192                                               (ndr_push_flags_fn_t)ndr_push_schannel_bind_ack);
 193                 if (!NT_STATUS_IS_OK(status)) {
 194                         DEBUG(3, ("Could not return schannel bind ack for account %s: %s\n",
 195                                   account_name, nt_errstr(status)));
 196                         return status;
 197                 }
 198
 199                 dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 200
 201                 return NT_STATUS_OK;
 202         }
 203         return NT_STATUS_INVALID_PARAMETER;
 204 }
 205
 206 /**
 207  * Return the credentials of a logged on user, including session keys
 208  * etc.
 209  *
 210  * Only valid after a successful authentication
 211  *
 212  * May only be called once per authentication.
 213  *
 214  */
 215
 216 NTSTATUS dcerpc_schannel_session_info(struct gensec_security *gensec_security,
 217                                       struct auth_session_info **session_info)
 218 {
 219         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 220
 221         (*session_info) = talloc_p(gensec_security, struct auth_session_info);
 222         if (*session_info == NULL) {
 223                 return NT_STATUS_NO_MEMORY;
 224         }
 225
 226         ZERO_STRUCTP(*session_info);
 227         (*session_info)->refcount = 1;
 228
 229         (*session_info)->workstation = talloc_strdup(*session_info, dce_schan_state->account_name);
 230         if ((*session_info)->workstation == NULL) {
 231                 talloc_free(*session_info);
 232                 return NT_STATUS_NO_MEMORY;
 233         }
 234         return NT_STATUS_OK;
 235 }
 236
 237
 238 /**
 239  * Return the struct creds_CredentialState.
 240  *
 241  * Make sure not to call this unless gensec is using schannel...
 242  */
 243
 244 NTSTATUS dcerpc_schannel_creds(struct gensec_security *gensec_security,
 245                                TALLOC_CTX *mem_ctx,
 246                                struct creds_CredentialState **creds)
 247 {
 248         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 249
 250         *creds = talloc_p(mem_ctx, struct creds_CredentialState);
 251         if (!*creds) {
 252                 return NT_STATUS_NO_MEMORY;
 253         }
 254
 255         **creds = dce_schan_state->creds;
 256         return NT_STATUS_OK;
 257 }
 258
 259
 260 static NTSTATUS dcerpc_schannel_start(struct gensec_security *gensec_security)
 261 {
 262         struct dcerpc_schannel_state *dce_schan_state;
 263
 264         dce_schan_state = talloc_p(gensec_security, struct dcerpc_schannel_state);
 265         if (!dce_schan_state) {
 266                 return NT_STATUS_NO_MEMORY;
 267         }
 268
 269         dce_schan_state->state = DCERPC_SCHANNEL_STATE_START;
 270         gensec_security->private_data = dce_schan_state;
 271
 272         return NT_STATUS_OK;
 273 }
 274
 275 static NTSTATUS dcerpc_schannel_server_start(struct gensec_security *gensec_security)
 276 {
 277         NTSTATUS status;
 278         struct dcerpc_schannel_state *dce_schan_state;
 279
 280         status = dcerpc_schannel_start(gensec_security);
 281
 282         dce_schan_state = gensec_security->private_data;
 283         dce_schan_state->schannel_state = NULL;
 284
 285         if (!NT_STATUS_IS_OK(status)) {
 286                 return status;
 287         }
 288         return NT_STATUS_OK;
 289 }
 290
 291 static NTSTATUS dcerpc_schannel_client_start(struct gensec_security *gensec_security)
 292 {
 293         NTSTATUS status;
 294         struct dcerpc_schannel_state *dce_schan_state;
 295
 296         status = dcerpc_schannel_start(gensec_security);
 297         if (!NT_STATUS_IS_OK(status)) {
 298                 return status;
 299         }
 300         dce_schan_state = gensec_security->private_data;
 301
 302         status = schannel_start(&dce_schan_state->schannel_state,
 303                                 gensec_security->user.schan_session_key,
 304                                 True);
 305         if (!NT_STATUS_IS_OK(status)) {
 306                 DEBUG(1, ("Failed to start schannel client\n"));
 307                 return status;
 308         }
 309         talloc_steal(dce_schan_state, dce_schan_state->schannel_state);
 310
 311         return NT_STATUS_OK;
 312 }
 313
 314 /*
 315   end crypto state
 316 */
 317 static void dcerpc_schannel_end(struct gensec_security *gensec_security)
 318 {
 319         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 320
 321         schannel_end(&dce_schan_state->schannel_state);
 322
 323         talloc_free(dce_schan_state);
 324
 325         gensec_security->private_data = NULL;
 326 }
 327
 328
 329 /*
 330   get a schannel key using a netlogon challenge on a secondary pipe
 331 */
 332 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
 333                                     const char *domain,
 334                                     const char *username,
 335                                     const char *password,
 336                                     int chan_type,
 337                                     uint8_t new_session_key[16])
 338 {
 339         NTSTATUS status;
 340         struct dcerpc_pipe *p2;
 341         struct netr_ServerReqChallenge r;
 342         struct netr_ServerAuthenticate2 a;
 343         struct netr_Credential credentials1, credentials2, credentials3;
 344         struct samr_Password mach_pwd;
 345         struct creds_CredentialState creds;
 346         const char *workgroup, *workstation;
 347         uint32_t negotiate_flags;
 348
 349         if (p->flags & DCERPC_SCHANNEL_128) {
 350                 negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 351         } else {
 352                 negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
 353         }
 354
 355         workstation = username;
 356         workgroup = domain;
 357
 358         /*
 359           step 1 - establish a netlogon connection, with no authentication
 360         */
 361         status = dcerpc_secondary_connection(p, &p2,
 362                                              DCERPC_NETLOGON_NAME,
 363                                              DCERPC_NETLOGON_UUID,
 364                                              DCERPC_NETLOGON_VERSION);
 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$", workstation);
 391         a.in.secure_channel_type = chan_type;
 392         a.in.computer_name = workstation;
 393         a.in.negotiate_flags = &negotiate_flags;
 394         a.out.negotiate_flags = &negotiate_flags;
 395         a.in.credentials = &credentials3;
 396         a.out.credentials = &credentials3;
 397
 398         status = dcerpc_netr_ServerAuthenticate2(p2, p, &a);
 399         if (!NT_STATUS_IS_OK(status)) {
 400                 return status;
 401         }
 402
 403         if (!creds_client_check(&creds, a.out.credentials)) {
 404                 return NT_STATUS_UNSUCCESSFUL;
 405         }
 406
 407         /*
 408           the schannel session key is now in creds.session_key
 409
 410           we no longer need the netlogon pipe open
 411         */
 412         dcerpc_pipe_close(p2);
 413
 414         memcpy(new_session_key, creds.session_key, 16);
 415
 416         return NT_STATUS_OK;
 417 }
 418
 419 /*
 420   do a schannel style bind on a dcerpc pipe. The username is usually
 421   of the form HOSTNAME$ and the password is the domain trust password
 422 */
 423 NTSTATUS dcerpc_bind_auth_schannel(struct dcerpc_pipe *p,
 424                                    const char *uuid, uint_t version,
 425                                    const char *domain,
 426                                    const char *username,
 427                                    const char *password)
 428 {
 429         NTSTATUS status;
 430         int chan_type = 0;
 431
 432         status = gensec_client_start(p, &p->security_state.generic_state);
 433         if (!NT_STATUS_IS_OK(status)) {
 434                 return status;
 435         }
 436
 437         if (p->flags & DCERPC_SCHANNEL_BDC) {
 438                 chan_type = SEC_CHAN_BDC;
 439         } else if (p->flags & DCERPC_SCHANNEL_WORKSTATION) {
 440                 chan_type = SEC_CHAN_WKSTA;
 441         } else if (p->flags & DCERPC_SCHANNEL_DOMAIN) {
 442                 chan_type = SEC_CHAN_DOMAIN;
 443         }
 444
 445         status = dcerpc_schannel_key(p, domain,
 446                                      username,
 447                                      password,
 448                                      chan_type,
 449                                      p->security_state.generic_state->user.schan_session_key);
 450         if (!NT_STATUS_IS_OK(status)) {
 451                 DEBUG(1, ("Failed to fetch schannel session key: %s\n", nt_errstr(status)));
 452                 gensec_end(&p->security_state.generic_state);
 453                 return status;
 454         }
 455
 456         status = gensec_set_username(p->security_state.generic_state, username);
 457         if (!NT_STATUS_IS_OK(status)) {
 458                 DEBUG(1, ("Failed to set schannel username to %s: %s\n", username, nt_errstr(status)));
 459                 gensec_end(&p->security_state.generic_state);
 460                 return status;
 461         }
 462
 463         status = gensec_set_domain(p->security_state.generic_state, domain);
 464         if (!NT_STATUS_IS_OK(status)) {
 465                 DEBUG(1, ("Failed to set schannel domain to %s: %s\n", domain, nt_errstr(status)));
 466                 gensec_end(&p->security_state.generic_state);
 467                 return status;
 468         }
 469
 470         status = gensec_start_mech_by_authtype(p->security_state.generic_state, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p));
 471
 472         if (!NT_STATUS_IS_OK(status)) {
 473                 DEBUG(1, ("Failed to start SCHANNEL GENSEC backend: %s\n", nt_errstr(status)));
 474                 gensec_end(&p->security_state.generic_state);
 475                 return status;
 476         }
 477
 478         status = dcerpc_bind_auth3(p, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p),
 479                                   uuid, version);
 480
 481         if (!NT_STATUS_IS_OK(status)) {
 482                 DEBUG(1, ("Failed to bind to pipe with SCHANNEL: %s\n", nt_errstr(status)));
 483                 gensec_end(&p->security_state.generic_state);
 484                 return status;
 485         }
 486
 487         return NT_STATUS_OK;
 488 }
 489
 490
 491 static const struct gensec_security_ops gensec_dcerpc_schannel_security_ops = {
 492         .name           = "dcerpc_schannel",
 493         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 494         .client_start   = dcerpc_schannel_client_start,
 495         .server_start   = dcerpc_schannel_server_start,
 496         .update         = dcerpc_schannel_update,
 497         .seal_packet    = dcerpc_schannel_seal_packet,
 498         .sign_packet    = dcerpc_schannel_sign_packet,
 499         .check_packet   = dcerpc_schannel_check_packet,
 500         .unseal_packet  = dcerpc_schannel_unseal_packet,
 501         .session_key    = dcerpc_schannel_session_key,
 502         .session_info   = dcerpc_schannel_session_info,
 503         .sig_size       = dcerpc_schannel_sig_size,
 504         .end            = dcerpc_schannel_end
 505 };
 506
 507 NTSTATUS gensec_dcerpc_schannel_init(void)
 508 {
 509         NTSTATUS ret;
 510         ret = register_backend("gensec", &gensec_dcerpc_schannel_security_ops);
 511         if (!NT_STATUS_IS_OK(ret)) {
 512                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 513                         gensec_dcerpc_schannel_security_ops.name));
 514                 return ret;
 515         }
 516
 517         return ret;
 518 }