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 = dce_schan_state->creds;
 262         return NT_STATUS_OK;
 263 }
 264
 265
 266 static NTSTATUS dcerpc_schannel_start(struct gensec_security *gensec_security)
 267 {
 268         struct dcerpc_schannel_state *dce_schan_state;
 269
 270         dce_schan_state = talloc_p(gensec_security, struct dcerpc_schannel_state);
 271         if (!dce_schan_state) {
 272                 return NT_STATUS_NO_MEMORY;
 273         }
 274
 275         dce_schan_state->state = DCERPC_SCHANNEL_STATE_START;
 276         gensec_security->private_data = dce_schan_state;
 277
 278         return NT_STATUS_OK;
 279 }
 280
 281 static NTSTATUS dcerpc_schannel_server_start(struct gensec_security *gensec_security)
 282 {
 283         NTSTATUS status;
 284
 285         status = dcerpc_schannel_start(gensec_security);
 286         if (!NT_STATUS_IS_OK(status)) {
 287                 return status;
 288         }
 289
 290         return NT_STATUS_OK;
 291 }
 292
 293 static NTSTATUS dcerpc_schannel_client_start(struct gensec_security *gensec_security)
 294 {
 295         NTSTATUS status;
 296
 297         status = dcerpc_schannel_start(gensec_security);
 298         if (!NT_STATUS_IS_OK(status)) {
 299                 return status;
 300         }
 301
 302         return NT_STATUS_OK;
 303 }
 304
 305 /*
 306   end crypto state
 307 */
 308 static void dcerpc_schannel_end(struct gensec_security *gensec_security)
 309 {
 310         struct dcerpc_schannel_state *dce_schan_state = gensec_security->private_data;
 311
 312         schannel_end(&dce_schan_state->schannel_state);
 313
 314         talloc_free(dce_schan_state);
 315
 316         gensec_security->private_data = NULL;
 317 }
 318
 319
 320 /*
 321   get a schannel key using a netlogon challenge on a secondary pipe
 322 */
 323 static NTSTATUS dcerpc_schannel_key(struct dcerpc_pipe *p,
 324                                     const char *domain,
 325                                     const char *username,
 326                                     const char *password,
 327                                     int chan_type,
 328                                     struct creds_CredentialState *creds)
 329 {
 330         NTSTATUS status;
 331         struct dcerpc_pipe *p2;
 332         struct netr_ServerReqChallenge r;
 333         struct netr_ServerAuthenticate2 a;
 334         struct netr_Credential credentials1, credentials2, credentials3;
 335         struct samr_Password mach_pwd;
 336         const char *workgroup, *workstation;
 337         uint32_t negotiate_flags;
 338
 339         if (p->flags & DCERPC_SCHANNEL_128) {
 340                 negotiate_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
 341         } else {
 342                 negotiate_flags = NETLOGON_NEG_AUTH2_FLAGS;
 343         }
 344
 345         workstation = username;
 346         workgroup = domain;
 347
 348         /*
 349           step 1 - establish a netlogon connection, with no authentication
 350         */
 351         status = dcerpc_secondary_connection(p, &p2,
 352                                              DCERPC_NETLOGON_NAME,
 353                                              DCERPC_NETLOGON_UUID,
 354                                              DCERPC_NETLOGON_VERSION);
 355         if (!NT_STATUS_IS_OK(status)) {
 356                 return status;
 357         }
 358
 359
 360         /*
 361           step 2 - request a netlogon challenge
 362         */
 363         r.in.server_name = talloc_asprintf(p, "\\\\%s", dcerpc_server_name(p));
 364         r.in.computer_name = workstation;
 365         r.in.credentials = &credentials1;
 366         r.out.credentials = &credentials2;
 367
 368         generate_random_buffer(credentials1.data, sizeof(credentials1.data));
 369
 370         status = dcerpc_netr_ServerReqChallenge(p2, p, &r);
 371         if (!NT_STATUS_IS_OK(status)) {
 372                 return status;
 373         }
 374
 375         /*
 376           step 3 - authenticate on the netlogon pipe
 377         */
 378         E_md4hash(password, mach_pwd.hash);
 379         creds_client_init(creds, &credentials1, &credentials2, &mach_pwd, &credentials3,
 380                           negotiate_flags);
 381
 382         a.in.server_name = r.in.server_name;
 383         a.in.account_name = talloc_asprintf(p, "%s$", workstation);
 384         a.in.secure_channel_type = chan_type;
 385         a.in.computer_name = workstation;
 386         a.in.negotiate_flags = &negotiate_flags;
 387         a.out.negotiate_flags = &negotiate_flags;
 388         a.in.credentials = &credentials3;
 389         a.out.credentials = &credentials3;
 390
 391         status = dcerpc_netr_ServerAuthenticate2(p2, p, &a);
 392         if (!NT_STATUS_IS_OK(status)) {
 393                 return status;
 394         }
 395
 396         if (!creds_client_check(creds, a.out.credentials)) {
 397                 return NT_STATUS_UNSUCCESSFUL;
 398         }
 399
 400         /*
 401           the schannel session key is now in creds.session_key
 402
 403           we no longer need the netlogon pipe open
 404         */
 405         dcerpc_pipe_close(p2);
 406
 407         return NT_STATUS_OK;
 408 }
 409
 410 /*
 411   do a schannel style bind on a dcerpc pipe. The username is usually
 412   of the form HOSTNAME$ and the password is the domain trust password
 413 */
 414 NTSTATUS dcerpc_bind_auth_schannel_withkey(struct dcerpc_pipe *p,
 415                                            const char *uuid, uint_t version,
 416                                            const char *domain,
 417                                            const char *username,
 418                                            const char *password,
 419                                            struct creds_CredentialState *creds)
 420 {
 421         NTSTATUS status;
 422         struct dcerpc_schannel_state *dce_schan_state;
 423
 424         status = gensec_client_start(p, &p->security_state.generic_state);
 425         if (!NT_STATUS_IS_OK(status)) {
 426                 return status;
 427         }
 428
 429         status = gensec_set_username(p->security_state.generic_state, username);
 430         if (!NT_STATUS_IS_OK(status)) {
 431                 DEBUG(1, ("Failed to set schannel username to %s: %s\n", username, nt_errstr(status)));
 432                 gensec_end(&p->security_state.generic_state);
 433                 return status;
 434         }
 435
 436         status = gensec_set_domain(p->security_state.generic_state, domain);
 437         if (!NT_STATUS_IS_OK(status)) {
 438                 DEBUG(1, ("Failed to set schannel domain to %s: %s\n", domain, nt_errstr(status)));
 439                 gensec_end(&p->security_state.generic_state);
 440                 return status;
 441         }
 442
 443         status = gensec_start_mech_by_authtype(p->security_state.generic_state, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p));
 444
 445         if (!NT_STATUS_IS_OK(status)) {
 446                 DEBUG(1, ("Failed to start SCHANNEL GENSEC backend: %s\n", nt_errstr(status)));
 447                 gensec_end(&p->security_state.generic_state);
 448                 return status;
 449         }
 450
 451         dce_schan_state = p->security_state.generic_state->private_data;
 452         dce_schan_state->creds = talloc_reference(dce_schan_state, creds);
 453
 454         status = dcerpc_bind_auth3(p, DCERPC_AUTH_TYPE_SCHANNEL, dcerpc_auth_level(p),
 455                                   uuid, version);
 456
 457         if (!NT_STATUS_IS_OK(status)) {
 458                 DEBUG(1, ("Failed to bind to pipe with SCHANNEL: %s\n", nt_errstr(status)));
 459                 gensec_end(&p->security_state.generic_state);
 460                 return status;
 461         }
 462
 463         return NT_STATUS_OK;
 464 }
 465
 466 NTSTATUS dcerpc_bind_auth_schannel(struct dcerpc_pipe *p,
 467                                    const char *uuid, uint_t version,
 468                                    const char *domain,
 469                                    const char *username,
 470                                    const char *password)
 471 {
 472         NTSTATUS status;
 473         int chan_type = 0;
 474         struct creds_CredentialState *creds;
 475         creds = talloc_p(p, struct creds_CredentialState);
 476         if (!creds) {
 477                 return NT_STATUS_NO_MEMORY;
 478         }
 479
 480         if (p->flags & DCERPC_SCHANNEL_BDC) {
 481                 chan_type = SEC_CHAN_BDC;
 482         } else if (p->flags & DCERPC_SCHANNEL_WORKSTATION) {
 483                 chan_type = SEC_CHAN_WKSTA;
 484         } else if (p->flags & DCERPC_SCHANNEL_DOMAIN) {
 485                 chan_type = SEC_CHAN_DOMAIN;
 486         }
 487
 488         status = dcerpc_schannel_key(p, domain,
 489                                      username,
 490                                      password,
 491                                      chan_type,
 492                                      creds);
 493
 494         if (!NT_STATUS_IS_OK(status)) {
 495                 DEBUG(1, ("Failed to fetch schannel session key: %s\n",
 496                           nt_errstr(status)));
 497                 return status;
 498         }
 499
 500         return dcerpc_bind_auth_schannel_withkey(p, uuid, version, domain,
 501                                                  username, password,
 502                                                  creds);
 503 }
 504
 505 static const struct gensec_security_ops gensec_dcerpc_schannel_security_ops = {
 506         .name           = "dcerpc_schannel",
 507         .auth_type      = DCERPC_AUTH_TYPE_SCHANNEL,
 508         .client_start   = dcerpc_schannel_client_start,
 509         .server_start   = dcerpc_schannel_server_start,
 510         .update         = dcerpc_schannel_update,
 511         .seal_packet    = dcerpc_schannel_seal_packet,
 512         .sign_packet    = dcerpc_schannel_sign_packet,
 513         .check_packet   = dcerpc_schannel_check_packet,
 514         .unseal_packet  = dcerpc_schannel_unseal_packet,
 515         .session_key    = dcerpc_schannel_session_key,
 516         .session_info   = dcerpc_schannel_session_info,
 517         .sig_size       = dcerpc_schannel_sig_size,
 518         .end            = dcerpc_schannel_end
 519 };
 520
 521 NTSTATUS gensec_dcerpc_schannel_init(void)
 522 {
 523         NTSTATUS ret;
 524         ret = gensec_register(&gensec_dcerpc_schannel_security_ops);
 525         if (!NT_STATUS_IS_OK(ret)) {
 526                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 527                         gensec_dcerpc_schannel_security_ops.name));
 528                 return ret;
 529         }
 530
 531         return ret;
 532 }