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