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         TALLOC_CTX *mem_ctx;
  32         enum schannel_position state;
  33         struct schannel_state *schannel_state;
  34         struct creds_CredentialState creds;
  35         char *account_name;
  36 };
  37
  38 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
  39                                     const char *domain,
  40                                     const char *username,
  41                                     const char *password,
  42                                     int chan_type,
  43                                     uint8_t new_session_key[16]);
  44
  45 /*
  46   wrappers for the schannel_*() functions
  47
  48   These will become static again, when we get dynamic registration, and
  49   decrpc_schannel_security_ops come back here.
  50 */
  51 static NTSTATUS dcerpc_schannel_unseal_packet(struct gensec_security *gensec_security,
  52                                               TALLOC_CTX *mem_ctx,
  53                                               uint8_t *data, size_t length,
  54                                               const uint8_t *whole_pdu, size_t pdu_length,
  55                                               DATA_BLOB *sig)
  56 {
  57         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  58
  59         return schannel_unseal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  60 }
  61
  62 static NTSTATUS dcerpc_schannel_check_packet(struct gensec_security *gensec_security,
  63                                              TALLOC_CTX *mem_ctx,
  64                                              const uint8_t *data, size_t length,
  65                                              const uint8_t *whole_pdu, size_t pdu_length,
  66                                              const DATA_BLOB *sig)
  67 {
  68         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  69
  70         return schannel_check_packet(dce_schan_state->schannel_state, data, length, sig);
  71 }
  72
  73 static NTSTATUS dcerpc_schannel_seal_packet(struct gensec_security *gensec_security,
  74                                             TALLOC_CTX *mem_ctx,
  75                                             uint8_t *data, size_t length,
  76                                             const uint8_t *whole_pdu, size_t pdu_length,
  77                                             DATA_BLOB *sig)
  78 {
  79         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  80
  81         return schannel_seal_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  82 }
  83
  84 static NTSTATUS dcerpc_schannel_sign_packet(struct gensec_security *gensec_security,
  85                                             TALLOC_CTX *mem_ctx,
  86                                             const uint8_t *data, size_t length,
  87                                             const uint8_t *whole_pdu, size_t pdu_length,
  88                                             DATA_BLOB *sig)
  89 {
  90         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
  91
  92         return schannel_sign_packet(dce_schan_state->schannel_state, mem_ctx, data, length, sig);
  93 }
  94
  95 static NTSTATUS dcerpc_schannel_session_key(struct gensec_security *gensec_security,
  96                                             DATA_BLOB *session_key)
  97 {
  98         return NT_STATUS_NOT_IMPLEMENTED;
  99 }
 100
 101 static NTSTATUS dcerpc_schannel_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
 102                                        const DATA_BLOB in, DATA_BLOB *out)
 103 {
 104         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 105         NTSTATUS status;
 106         struct schannel_bind bind_schannel;
 107         struct schannel_bind_ack bind_schannel_ack;
 108         const char *account_name;
 109         *out = data_blob(NULL, 0);
 110
 111         switch (gensec_security->gensec_role) {
 112         case GENSEC_CLIENT:
 113                 if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 114                         /* we could parse the bind ack, but we don't know what it is yet */
 115                         return NT_STATUS_OK;
 116                 }
 117
 118                 bind_schannel.unknown1 = 0;
 119 #if 0
 120                 /* to support this we'd need to have access to the full domain name */
 121                 bind_schannel.bind_type = 23;
 122                 bind_schannel.u.info23.domain = gensec_security->user.domain;
 123                 bind_schannel.u.info23.account_name = gensec_security->user.name;
 124                 bind_schannel.u.info23.dnsdomain = str_format_nbt_domain(out_mem_ctx, fulldomainname);
 125                 bind_schannel.u.info23.workstation = str_format_nbt_domain(out_mem_ctx, gensec_security->user.name);
 126 #else
 127                 bind_schannel.bind_type = 3;
 128                 bind_schannel.u.info3.domain = gensec_security->user.domain;
 129                 bind_schannel.u.info3.account_name = gensec_security->user.name;
 130 #endif
 131
 132                 status = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel,
 133                                               (ndr_push_flags_fn_t)ndr_push_schannel_bind);
 134                 if (!NT_STATUS_IS_OK(status)) {
 135                         DEBUG(3, ("Could not create schannel bind: %s\n",
 136                                   nt_errstr(status)));
 137                         return status;
 138                 }
 139
 140                 dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 141
 142                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 143         case GENSEC_SERVER:
 144
 145                 if (dce_schan_state->state != DCERPC_SCHANNEL_STATE_START) {
 146                         /* no third leg on this protocol */
 147                         return NT_STATUS_INVALID_PARAMETER;
 148                 }
 149
 150                 /* parse the schannel startup blob */
 151                 status = ndr_pull_struct_blob(&in, out_mem_ctx, &bind_schannel,
 152                                               (ndr_pull_flags_fn_t)ndr_pull_schannel_bind);
 153                 if (!NT_STATUS_IS_OK(status)) {
 154                         return status;
 155                 }
 156
 157                 if (bind_schannel.bind_type == 23) {
 158                         account_name = bind_schannel.u.info23.account_name;
 159                 } else {
 160                         account_name = bind_schannel.u.info3.account_name;
 161                 }
 162
 163                 /* pull the session key for this client */
 164                 status = schannel_fetch_session_key(out_mem_ctx, account_name, &dce_schan_state->creds);
 165                 if (!NT_STATUS_IS_OK(status)) {
 166                         DEBUG(3, ("Could not find session key for attempted schannel connection on %s: %s\n",
 167                                   account_name, nt_errstr(status)));
 168                         return status;
 169                 }
 170
 171                 dce_schan_state->account_name = talloc_strdup(dce_schan_state->mem_ctx, account_name);
 172
 173                 /* start up the schannel server code */
 174                 status = schannel_start(&dce_schan_state->schannel_state,
 175                                         dce_schan_state->creds.session_key, False);
 176                 if (!NT_STATUS_IS_OK(status)) {
 177                         DEBUG(3, ("Could not initialise schannel state for account %s: %s\n",
 178                                   account_name, nt_errstr(status)));
 179                         return status;
 180                 }
 181
 182                 bind_schannel_ack.unknown1 = 1;
 183                 bind_schannel_ack.unknown2 = 0;
 184                 bind_schannel_ack.unknown3 = 0x6c0000;
 185
 186                 status = ndr_push_struct_blob(out, out_mem_ctx, &bind_schannel_ack,
 187                                               (ndr_push_flags_fn_t)ndr_push_schannel_bind_ack);
 188                 if (!NT_STATUS_IS_OK(status)) {
 189                         DEBUG(3, ("Could not return schannel bind ack for account %s: %s\n",
 190                                   account_name, nt_errstr(status)));
 191                         return status;
 192                 }
 193
 194                 dce_schan_state->state = DCERPC_SCHANNEL_STATE_UPDATE_1;
 195
 196                 return NT_STATUS_OK;
 197         }
 198         return NT_STATUS_INVALID_PARAMETER;
 199 }
 200
 201 /**
 202  * Return the credentials of a logged on user, including session keys
 203  * etc.
 204  *
 205  * Only valid after a successful authentication
 206  *
 207  * May only be called once per authentication.
 208  *
 209  */
 210
 211 NTSTATUS dcerpc_schannel_session_info(struct gensec_security *gensec_security,
 212                                       struct auth_session_info **session_info)
 213 {
 214         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 215         TALLOC_CTX *mem_ctx;
 216         mem_ctx = talloc_init("dcerpc_schannel_start");
 217         if (!mem_ctx) {
 218                 return NT_STATUS_NO_MEMORY;
 219         }
 220
 221         (*session_info) = talloc_p(mem_ctx, struct auth_session_info);
 222         if (*session_info == NULL) {
 223                 talloc_destroy(mem_ctx);
 224                 return NT_STATUS_NO_MEMORY;
 225         }
 226
 227         ZERO_STRUCTP(*session_info);
 228         (*session_info)->mem_ctx = mem_ctx;
 229         (*session_info)->refcount = 1;
 230
 231         (*session_info)->workstation = talloc_strdup(mem_ctx, dce_schan_state->account_name);
 232         if ((*session_info)->workstation == NULL) {
 233                 talloc_destroy(mem_ctx);
 234                 return NT_STATUS_NO_MEMORY;
 235         }
 236         return NT_STATUS_OK;
 237 }
 238
 239
 240 /**
 241  * Return the struct creds_CredentialState.
 242  *
 243  * Make sure not to call this unless gensec is using schannel...
 244  */
 245
 246 NTSTATUS dcerpc_schannel_creds(struct gensec_security *gensec_security,
 247                                TALLOC_CTX *mem_ctx,
 248                                struct creds_CredentialState **creds)
 249 {
 250         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 251
 252         *creds = talloc_p(mem_ctx, struct creds_CredentialState);
 253         if (!*creds) {
 254                 return NT_STATUS_NO_MEMORY;
 255         }
 256
 257         **creds = dce_schan_state->creds;
 258         return NT_STATUS_OK;
 259 }
 260
 261
 262 static NTSTATUS dcerpc_schannel_start(struct gensec_security *gensec_security)
 263 {
 264         struct dcerpc_schannel_state *dce_schan_state;
 265         TALLOC_CTX *mem_ctx;
 266         mem_ctx = talloc_init("dcerpc_schannel_start");
 267         if (!mem_ctx) {
 268                 return NT_STATUS_NO_MEMORY;
 269         }
 270
 271         dce_schan_state = talloc_p(mem_ctx, struct dcerpc_schannel_state);
 272         if (!dce_schan_state) {
 273                 talloc_destroy(mem_ctx);
 274                 return NT_STATUS_NO_MEMORY;
 275         }
 276
 277         dce_schan_state->mem_ctx = mem_ctx;
 278         dce_schan_state->state = DCERPC_SCHANNEL_STATE_START;
 279
 280
 281         gensec_security->private_data = dce_schan_state;
 282
 283         return NT_STATUS_OK;
 284 }
 285
 286 static NTSTATUS dcerpc_schannel_server_start(struct gensec_security *gensec_security)
 287 {
 288         NTSTATUS status;
 289
 290         status = dcerpc_schannel_start(gensec_security);
 291
 292         if (!NT_STATUS_IS_OK(status)) {
 293                 return status;
 294         }
 295         return NT_STATUS_OK;
 296 }
 297
 298 static NTSTATUS dcerpc_schannel_client_start(struct gensec_security *gensec_security)
 299 {
 300         NTSTATUS status;
 301         struct dcerpc_schannel_state *dce_schan_state;
 302
 303         status = dcerpc_schannel_start(gensec_security);
 304         if (!NT_STATUS_IS_OK(status)) {
 305                 return status;
 306         }
 307         dce_schan_state = gensec_security->private_data;
 308
 309         status = schannel_start(&dce_schan_state->schannel_state,
 310                                 gensec_security->user.schan_session_key,
 311                                 True);
 312         if (!NT_STATUS_IS_OK(status)) {
 313                 DEBUG(1, ("Failed to start schannel client\n"));
 314                 return status;
 315         }
 316
 317         dump_data_pw("session key:\n", dce_schan_state->schannel_state->session_key, 16);
 318         return NT_STATUS_OK;
 319 }
 320
 321 /*
 322   end crypto state
 323 */
 324 static void dcerpc_schannel_end(struct gensec_security *gensec_security)
 325 {
 326         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 327
 328         schannel_end(&dce_schan_state->schannel_state);
 329
 330         talloc_destroy(dce_schan_state->mem_ctx);
 331
 332         gensec_security->private_data = NULL;
 333 }
 334
 335
 336 /*
 337   get a schannel key using a netlogon challenge on a secondary pipe
 338 */
 339 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
 340                                     const char *domain,
 341                                     const char *username,
 342                                     const char *password,
 343                                     int chan_type,
 344                                     uint8_t new_session_key[16])
 345 {
 346         NTSTATUS status;
 347         struct dcerpc_pipe *p2;
 348         struct netr_ServerReqChallenge r;
 349         struct netr_ServerAuthenticate2 a;
 350         struct netr_Credential credentials1, credentials2, credentials3;
 351         struct samr_Password mach_pwd;
 352         struct creds_CredentialState creds;
 353         const char *workgroup, *workstation;
 354         uint32_t negotiate_flags;
 355
 356         if (p->flags & DCERPC_SCHANNEL_128) {
 357                 negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 358         } else {
 359                 negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
 360         }
 361
 362         workstation = username;
 363         workgroup = domain;
 364
 365         /*
 366           step 1 - establish a netlogon connection, with no authentication
 367         */
 368         status = dcerpc_secondary_connection(p, &p2,
 369                                              DCERPC_NETLOGON_NAME,
 370                                              DCERPC_NETLOGON_UUID,
 371                                              DCERPC_NETLOGON_VERSION);
 372
 373
 374         /*
 375           step 2 - request a netlogon challenge
 376         */
 377         r.in.server_name = talloc_asprintf(p, "\\\\%s", dcerpc_server_name(p));
 378         r.in.computer_name = workstation;
 379         r.in.credentials = &credentials1;
 380         r.out.credentials = &credentials2;
 381
 382         generate_random_buffer(credentials1.data, sizeof(credentials1.data));
 383
 384         status = dcerpc_netr_ServerReqChallenge(p2, p, &r);
 385         if (!NT_STATUS_IS_OK(status)) {
 386                 return status;
 387         }
 388
 389         /*
 390           step 3 - authenticate on the netlogon pipe
 391         */
 392         E_md4hash(password, mach_pwd.hash);
 393         creds_client_init(&creds, &credentials1, &credentials2, &mach_pwd, &credentials3,
 394                           negotiate_flags);
 395
 396         a.in.server_name = r.in.server_name;
 397         a.in.account_name = talloc_asprintf(p, "%s$", workstation);
 398         a.in.secure_channel_type = chan_type;
 399         a.in.computer_name = workstation;
 400         a.in.negotiate_flags = &negotiate_flags;
 401         a.out.negotiate_flags = &negotiate_flags;
 402         a.in.credentials = &credentials3;
 403         a.out.credentials = &credentials3;
 404
 405         status = dcerpc_netr_ServerAuthenticate2(p2, p, &a);
 406         if (!NT_STATUS_IS_OK(status)) {
 407                 return status;
 408         }
 409
 410         if (!creds_client_check(&creds, a.out.credentials)) {
 411                 return NT_STATUS_UNSUCCESSFUL;
 412         }
 413
 414         /*
 415           the schannel session key is now in creds.session_key
 416
 417           we no longer need the netlogon pipe open
 418         */
 419         dcerpc_pipe_close(p2);
 420
 421         memcpy(new_session_key, creds.session_key, 16);
 422
 423         return NT_STATUS_OK;
 424 }
 425
 426 /*
 427   do a schannel style bind on a dcerpc pipe. The username is usually
 428   of the form HOSTNAME$ and the password is the domain trust password
 429 */
 430 NTSTATUS dcerpc_bind_auth_schannel(struct dcerpc_pipe *p,
 431                                    const char *uuid, uint_t version,
 432                                    const char *domain,
 433                                    const char *username,
 434                                    const char *password)
 435 {
 436         NTSTATUS status;
 437         int chan_type = 0;
 438
 439         status = gensec_client_start(&p->security_state.generic_state);
 440         if (!NT_STATUS_IS_OK(status)) {
 441                 return status;
 442         }
 443
 444         if (p->flags & DCERPC_SCHANNEL_BDC) {
 445                 chan_type = SEC_CHAN_BDC;
 446         } else if (p->flags & DCERPC_SCHANNEL_WORKSTATION) {
 447                 chan_type = SEC_CHAN_WKSTA;
 448         } else if (p->flags & DCERPC_SCHANNEL_DOMAIN) {
 449                 chan_type = SEC_CHAN_DOMAIN;
 450         }
 451
 452         status = dcerpc_schannel_key(p, domain,
 453                                      username,
 454                                      password,
 455                                      chan_type,
 456                                      p->security_state.generic_state->user.schan_session_key);
 457         if (!NT_STATUS_IS_OK(status)) {
 458                 DEBUG(1, ("Failed to fetch schannel session key: %s\n", nt_errstr(status)));
 459                 gensec_end(&p->security_state.generic_state);
 460                 return status;
 461         }
 462
 463         status = gensec_set_username(p->security_state.generic_state, username);
 464         if (!NT_STATUS_IS_OK(status)) {
 465                 DEBUG(1, ("Failed to set schannel username to %s: %s\n", username, nt_errstr(status)));
 466                 gensec_end(&p->security_state.generic_state);
 467                 return status;
 468         }
 469
 470         status = gensec_set_domain(p->security_state.generic_state, domain);
 471         if (!NT_STATUS_IS_OK(status)) {
 472                 DEBUG(1, ("Failed to set schannel domain to %s: %s\n", domain, nt_errstr(status)));
 473                 gensec_end(&p->security_state.generic_state);
 474                 return status;
 475         }
 476
 477         status = gensec_start_mech_by_authtype(p->security_state.generic_state, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p));
 478
 479         if (!NT_STATUS_IS_OK(status)) {
 480                 DEBUG(1, ("Failed to start SCHANNEL GENSEC backend: %s\n", nt_errstr(status)));
 481                 gensec_end(&p->security_state.generic_state);
 482                 return status;
 483         }
 484
 485         status = dcerpc_bind_auth3(p, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p),
 486                                   uuid, version);
 487
 488         if (!NT_STATUS_IS_OK(status)) {
 489                 DEBUG(1, ("Failed to bind to pipe with SCHANNEL: %s\n", nt_errstr(status)));
 490                 gensec_end(&p->security_state.generic_state);
 491                 return status;
 492         }
 493
 494         return NT_STATUS_OK;
 495 }
 496
 497
 498 static const struct gensec_security_ops gensec_dcerpc_schannel_security_ops = {
 499         .name           = "dcerpc_schannel",
 500         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 501         .client_start   = dcerpc_schannel_client_start,
 502         .server_start   = dcerpc_schannel_server_start,
 503         .update         = dcerpc_schannel_update,
 504         .seal_packet    = dcerpc_schannel_seal_packet,
 505         .sign_packet    = dcerpc_schannel_sign_packet,
 506         .check_packet   = dcerpc_schannel_check_packet,
 507         .unseal_packet  = dcerpc_schannel_unseal_packet,
 508         .session_key    = dcerpc_schannel_session_key,
 509         .session_info   = dcerpc_schannel_session_info,
 510         .end            = dcerpc_schannel_end
 511 };
 512
 513 NTSTATUS gensec_dcerpc_schannel_init(void)
 514 {
 515         NTSTATUS ret;
 516         ret = register_backend("gensec", &gensec_dcerpc_schannel_security_ops);
 517         if (!NT_STATUS_IS_OK(ret)) {
 518                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 519                         gensec_dcerpc_schannel_security_ops.name));
 520                 return ret;
 521         }
 522
 523         return ret;
 524 }