source4/auth/ntlm/auth.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Bartlett         2001-2002
   5    Copyright (C) Stefan Metzmacher       2005
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include <tevent.h>
  23 #include "../lib/util/tevent_ntstatus.h"
  24 #include "../lib/util/dlinklist.h"
  25 #include "auth/auth.h"
  26 #include "auth/ntlm/auth_proto.h"
  27 #include "param/param.h"
  28 #include "dsdb/samdb/samdb.h"
  29 #include "libcli/wbclient/wbclient.h"
  30 #include "lib/util/samba_modules.h"
  31 #include "auth/credentials/credentials.h"
  32 #include "system/kerberos.h"
  33 #include "auth/kerberos/kerberos.h"
  34 #include "auth/kerberos/kerberos_util.h"
  35
  36 static NTSTATUS auth_generate_session_info_wrapper(struct auth4_context *auth_context,
  37                                                    TALLOC_CTX *mem_ctx,
  38                                                   void *server_returned_info,
  39                                                    const char *original_user_name,
  40                                                    uint32_t session_info_flags,
  41                                                    struct auth_session_info **session_info);
  42
  43 /***************************************************************************
  44  Set a fixed challenge
  45 ***************************************************************************/
  46 _PUBLIC_ NTSTATUS auth_context_set_challenge(struct auth4_context *auth_ctx, const uint8_t chal[8], const char *set_by)
  47 {
  48         auth_ctx->challenge.set_by = talloc_strdup(auth_ctx, set_by);
  49         NT_STATUS_HAVE_NO_MEMORY(auth_ctx->challenge.set_by);
  50
  51         auth_ctx->challenge.data = data_blob_talloc(auth_ctx, chal, 8);
  52         NT_STATUS_HAVE_NO_MEMORY(auth_ctx->challenge.data.data);
  53
  54         return NT_STATUS_OK;
  55 }
  56
  57 /****************************************************************************
  58  Try to get a challenge out of the various authentication modules.
  59  Returns a const char of length 8 bytes.
  60 ****************************************************************************/
  61 _PUBLIC_ NTSTATUS auth_get_challenge(struct auth4_context *auth_ctx, uint8_t chal[8])
  62 {
  63
  64         if (auth_ctx->challenge.data.length == 8) {
  65                 DEBUG(5, ("auth_get_challenge: returning previous challenge by module %s (normal)\n",
  66                           auth_ctx->challenge.set_by));
  67                 memcpy(chal, auth_ctx->challenge.data.data, 8);
  68                 return NT_STATUS_OK;
  69         }
  70
  71         if (!auth_ctx->challenge.set_by) {
  72                 generate_random_buffer(chal, 8);
  73
  74                 auth_ctx->challenge.data                = data_blob_talloc(auth_ctx, chal, 8);
  75                 NT_STATUS_HAVE_NO_MEMORY(auth_ctx->challenge.data.data);
  76                 auth_ctx->challenge.set_by              = "random";
  77         }
  78
  79         DEBUG(10,("auth_get_challenge: challenge set by %s\n",
  80                  auth_ctx->challenge.set_by));
  81
  82         return NT_STATUS_OK;
  83 }
  84
  85 /****************************************************************************
  86 Used in the gensec_gssapi and gensec_krb5 server-side code, where the
  87 PAC isn't available, and for tokenGroups in the DSDB stack.
  88
  89  Supply either a principal or a DN
  90 ****************************************************************************/
  91 static NTSTATUS auth_generate_session_info_principal(struct auth4_context *auth_ctx,
  92                                                   TALLOC_CTX *mem_ctx,
  93                                                   const char *principal,
  94                                                   struct ldb_dn *user_dn,
  95                                                   uint32_t session_info_flags,
  96                                                   struct auth_session_info **session_info)
  97 {
  98         NTSTATUS nt_status;
  99         struct auth_method_context *method;
 100         struct auth_user_info_dc *user_info_dc;
 101
 102         for (method = auth_ctx->methods; method; method = method->next) {
 103                 if (!method->ops->get_user_info_dc_principal) {
 104                         continue;
 105                 }
 106
 107                 nt_status = method->ops->get_user_info_dc_principal(mem_ctx, auth_ctx, principal, user_dn, &user_info_dc);
 108                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NOT_IMPLEMENTED)) {
 109                         continue;
 110                 }
 111                 if (!NT_STATUS_IS_OK(nt_status)) {
 112                         return nt_status;
 113                 }
 114
 115                 nt_status = auth_generate_session_info_wrapper(auth_ctx, mem_ctx,
 116                                                                user_info_dc,
 117                                                                user_info_dc->info->account_name,
 118                                                                session_info_flags, session_info);
 119                 talloc_free(user_info_dc);
 120
 121                 return nt_status;
 122         }
 123
 124         return NT_STATUS_NOT_IMPLEMENTED;
 125 }
 126
 127 /**
 128  * Check a user's Plaintext, LM or NTLM password.
 129  * (sync version)
 130  *
 131  * Check a user's password, as given in the user_info struct and return various
 132  * interesting details in the user_info_dc struct.
 133  *
 134  * The return value takes precedence over the contents of the user_info_dc
 135  * struct.  When the return is other than NT_STATUS_OK the contents
 136  * of that structure is undefined.
 137  *
 138  * @param auth_ctx Supplies the challenges and some other data.
 139  *                  Must be created with auth_context_create(), and the challenges should be
 140  *                  filled in, either at creation or by calling the challenge geneation
 141  *                  function auth_get_challenge().
 142  *
 143  * @param user_info Contains the user supplied components, including the passwords.
 144  *
 145  * @param mem_ctx The parent memory context for the user_info_dc structure
 146  *
 147  * @param user_info_dc If successful, contains information about the authentication,
 148  *                    including a SAM_ACCOUNT struct describing the user.
 149  *
 150  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 151  *
 152  **/
 153
 154 _PUBLIC_ NTSTATUS auth_check_password(struct auth4_context *auth_ctx,
 155                              TALLOC_CTX *mem_ctx,
 156                              const struct auth_usersupplied_info *user_info,
 157                              struct auth_user_info_dc **user_info_dc)
 158 {
 159         struct tevent_req *subreq;
 160         struct tevent_context *ev;
 161         bool ok;
 162         NTSTATUS status;
 163
 164         /*TODO: create a new event context here! */
 165         ev = auth_ctx->event_ctx;
 166
 167         subreq = auth_check_password_send(mem_ctx,
 168                                           ev,
 169                                           auth_ctx,
 170                                           user_info);
 171         if (subreq == NULL) {
 172                 return NT_STATUS_NO_MEMORY;
 173         }
 174
 175         ok = tevent_req_poll(subreq, ev);
 176         if (!ok) {
 177                 return NT_STATUS_INTERNAL_ERROR;
 178         }
 179
 180         status = auth_check_password_recv(subreq, mem_ctx, user_info_dc);
 181         TALLOC_FREE(subreq);
 182
 183         return status;
 184 }
 185
 186 _PUBLIC_ NTSTATUS auth_check_password_wrapper(struct auth4_context *auth_ctx,
 187                                               TALLOC_CTX *mem_ctx,
 188                                               const struct auth_usersupplied_info *user_info,
 189                                               void **server_returned_info,
 190                                               DATA_BLOB *user_session_key, DATA_BLOB *lm_session_key)
 191 {
 192         struct auth_user_info_dc *user_info_dc;
 193         NTSTATUS status = auth_check_password(auth_ctx, mem_ctx, user_info, &user_info_dc);
 194
 195         if (NT_STATUS_IS_OK(status)) {
 196                 *server_returned_info = user_info_dc;
 197
 198                 if (user_session_key) {
 199                         DEBUG(10, ("Got NT session key of length %u\n",
 200                                    (unsigned)user_info_dc->user_session_key.length));
 201                         *user_session_key = user_info_dc->user_session_key;
 202                         talloc_steal(mem_ctx, user_session_key->data);
 203                         user_info_dc->user_session_key = data_blob_null;
 204                 }
 205
 206                 if (lm_session_key) {
 207                         DEBUG(10, ("Got LM session key of length %u\n",
 208                                    (unsigned)user_info_dc->lm_session_key.length));
 209                         *lm_session_key = user_info_dc->lm_session_key;
 210                         talloc_steal(mem_ctx, lm_session_key->data);
 211                         user_info_dc->lm_session_key = data_blob_null;
 212                 }
 213         }
 214
 215         return status;
 216 }
 217
 218 struct auth_check_password_state {
 219         struct auth4_context *auth_ctx;
 220         const struct auth_usersupplied_info *user_info;
 221         struct auth_user_info_dc *user_info_dc;
 222         struct auth_method_context *method;
 223 };
 224
 225 static void auth_check_password_async_trigger(struct tevent_context *ev,
 226                                               struct tevent_immediate *im,
 227                                               void *private_data);
 228 /**
 229  * Check a user's Plaintext, LM or NTLM password.
 230  * async send hook
 231  *
 232  * Check a user's password, as given in the user_info struct and return various
 233  * interesting details in the user_info_dc struct.
 234  *
 235  * The return value takes precedence over the contents of the user_info_dc
 236  * struct.  When the return is other than NT_STATUS_OK the contents
 237  * of that structure is undefined.
 238  *
 239  * @param mem_ctx The memory context the request should operate on
 240  *
 241  * @param ev The tevent context the request should operate on
 242  *
 243  * @param auth_ctx Supplies the challenges and some other data.
 244  *                  Must be created with make_auth_context(), and the challenges should be
 245  *                  filled in, either at creation or by calling the challenge geneation
 246  *                  function auth_get_challenge().
 247  *
 248  * @param user_info Contains the user supplied components, including the passwords.
 249  *
 250  * @return The request handle or NULL on no memory error.
 251  *
 252  **/
 253
 254 _PUBLIC_ struct tevent_req *auth_check_password_send(TALLOC_CTX *mem_ctx,
 255                                 struct tevent_context *ev,
 256                                 struct auth4_context *auth_ctx,
 257                                 const struct auth_usersupplied_info *user_info)
 258 {
 259         struct tevent_req *req;
 260         struct auth_check_password_state *state;
 261         /* if all the modules say 'not for me' this is reasonable */
 262         NTSTATUS nt_status;
 263         uint8_t chal[8];
 264         struct auth_usersupplied_info *user_info_tmp;
 265         struct tevent_immediate *im;
 266
 267         DEBUG(3,("auth_check_password_send: "
 268                  "Checking password for unmapped user [%s]\\[%s]@[%s]\n",
 269                  user_info->client.domain_name, user_info->client.account_name,
 270                  user_info->workstation_name));
 271
 272         req = tevent_req_create(mem_ctx, &state,
 273                                 struct auth_check_password_state);
 274         if (req == NULL) {
 275                 return NULL;
 276         }
 277
 278         state->auth_ctx         = auth_ctx;
 279         state->user_info        = user_info;
 280
 281         if (!user_info->mapped_state) {
 282                 nt_status = map_user_info(auth_ctx->sam_ctx, req, lpcfg_workgroup(auth_ctx->lp_ctx),
 283                                           user_info, &user_info_tmp);
 284                 if (tevent_req_nterror(req, nt_status)) {
 285                         return tevent_req_post(req, ev);
 286                 }
 287                 user_info = user_info_tmp;
 288                 state->user_info = user_info_tmp;
 289         }
 290
 291         DEBUGADD(3,("auth_check_password_send: "
 292                     "mapped user is: [%s]\\[%s]@[%s]\n",
 293                     user_info->mapped.domain_name,
 294                     user_info->mapped.account_name,
 295                     user_info->workstation_name));
 296
 297         nt_status = auth_get_challenge(auth_ctx, chal);
 298         if (tevent_req_nterror(req, nt_status)) {
 299                 DEBUG(0,("auth_check_password_send: "
 300                          "Invalid challenge (length %u) stored for "
 301                          "this auth context set_by %s - cannot continue: %s\n",
 302                         (unsigned)auth_ctx->challenge.data.length,
 303                         auth_ctx->challenge.set_by,
 304                         nt_errstr(nt_status)));
 305                 return tevent_req_post(req, ev);
 306         }
 307
 308         if (auth_ctx->challenge.set_by) {
 309                 DEBUG(10,("auth_check_password_send: "
 310                           "auth_context challenge created by %s\n",
 311                           auth_ctx->challenge.set_by));
 312         }
 313
 314         DEBUG(10, ("auth_check_password_send: challenge is: \n"));
 315         dump_data(5, auth_ctx->challenge.data.data,
 316                   auth_ctx->challenge.data.length);
 317
 318         im = tevent_create_immediate(state);
 319         if (tevent_req_nomem(im, req)) {
 320                 return tevent_req_post(req, ev);
 321         }
 322
 323         tevent_schedule_immediate(im,
 324                                   auth_ctx->event_ctx,
 325                                   auth_check_password_async_trigger,
 326                                   req);
 327         return req;
 328 }
 329
 330 static void auth_check_password_async_trigger(struct tevent_context *ev,
 331                                               struct tevent_immediate *im,
 332                                               void *private_data)
 333 {
 334         struct tevent_req *req =
 335                 talloc_get_type_abort(private_data, struct tevent_req);
 336         struct auth_check_password_state *state =
 337                 tevent_req_data(req, struct auth_check_password_state);
 338         NTSTATUS status;
 339         struct auth_method_context *method;
 340
 341         status = NT_STATUS_OK;
 342
 343         for (method=state->auth_ctx->methods; method; method = method->next) {
 344
 345                 /* we fill in state->method here so debug messages in
 346                    the callers know which method failed */
 347                 state->method = method;
 348
 349                 /* check if the module wants to check the password */
 350                 status = method->ops->want_check(method, req, state->user_info);
 351                 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_IMPLEMENTED)) {
 352                         DEBUG(11,("auth_check_password_send: "
 353                                   "%s had nothing to say\n",
 354                                   method->ops->name));
 355                         continue;
 356                 }
 357
 358                 if (tevent_req_nterror(req, status)) {
 359                         return;
 360                 }
 361
 362                 status = method->ops->check_password(method,
 363                                                      state,
 364                                                      state->user_info,
 365                                                      &state->user_info_dc);
 366                 if (!NT_STATUS_EQUAL(status, NT_STATUS_NOT_IMPLEMENTED)) {
 367                         /* the backend has handled the request */
 368                         break;
 369                 }
 370         }
 371
 372         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_IMPLEMENTED)) {
 373                 /* don't expose the NT_STATUS_NOT_IMPLEMENTED
 374                    internals */
 375                 status = NT_STATUS_NO_SUCH_USER;
 376         }
 377
 378         if (tevent_req_nterror(req, status)) {
 379                 return;
 380         }
 381
 382         tevent_req_done(req);
 383 }
 384
 385 /**
 386  * Check a user's Plaintext, LM or NTLM password.
 387  * async receive function
 388  *
 389  * The return value takes precedence over the contents of the user_info_dc
 390  * struct.  When the return is other than NT_STATUS_OK the contents
 391  * of that structure is undefined.
 392  *
 393  *
 394  * @param req The async request state
 395  *
 396  * @param mem_ctx The parent memory context for the user_info_dc structure
 397  *
 398  * @param user_info_dc If successful, contains information about the authentication,
 399  *                    including a SAM_ACCOUNT struct describing the user.
 400  *
 401  * @return An NTSTATUS with NT_STATUS_OK or an appropriate error.
 402  *
 403  **/
 404
 405 _PUBLIC_ NTSTATUS auth_check_password_recv(struct tevent_req *req,
 406                                   TALLOC_CTX *mem_ctx,
 407                                   struct auth_user_info_dc **user_info_dc)
 408 {
 409         struct auth_check_password_state *state =
 410                 tevent_req_data(req, struct auth_check_password_state);
 411         NTSTATUS status;
 412
 413         if (tevent_req_is_nterror(req, &status)) {
 414                 DEBUG(2,("auth_check_password_recv: "
 415                          "%s authentication for user [%s\\%s] "
 416                          "FAILED with error %s\n",
 417                          (state->method ? state->method->ops->name : "NO_METHOD"),
 418                          state->user_info->mapped.domain_name,
 419                          state->user_info->mapped.account_name,
 420                          nt_errstr(status)));
 421                 tevent_req_received(req);
 422                 return status;
 423         }
 424
 425         DEBUG(5,("auth_check_password_recv: "
 426                  "%s authentication for user [%s\\%s] succeeded\n",
 427                  state->method->ops->name,
 428                  state->user_info_dc->info->domain_name,
 429                  state->user_info_dc->info->account_name));
 430
 431         *user_info_dc = talloc_move(mem_ctx, &state->user_info_dc);
 432
 433         tevent_req_received(req);
 434         return NT_STATUS_OK;
 435 }
 436
 437  /* Wrapper because we don't want to expose all callers to needing to
 438   * know that session_info is generated from the main ldb, and because
 439   * we need to break a depenency loop between the DCE/RPC layer and the
 440   * generation of unix tokens via IRPC */
 441 static NTSTATUS auth_generate_session_info_wrapper(struct auth4_context *auth_context,
 442                                                    TALLOC_CTX *mem_ctx,
 443                                                    void *server_returned_info,
 444                                                    const char *original_user_name,
 445                                                   uint32_t session_info_flags,
 446                                                   struct auth_session_info **session_info)
 447 {
 448         NTSTATUS status;
 449         struct auth_user_info_dc *user_info_dc = talloc_get_type_abort(server_returned_info, struct auth_user_info_dc);
 450
 451         if (user_info_dc->info->authenticated) {
 452                 session_info_flags |= AUTH_SESSION_INFO_AUTHENTICATED;
 453         }
 454
 455         status = auth_generate_session_info(mem_ctx, auth_context->lp_ctx,
 456                                             auth_context->sam_ctx, user_info_dc,
 457                                             session_info_flags, session_info);
 458         if (!NT_STATUS_IS_OK(status)) {
 459                 return status;
 460         }
 461
 462         if ((session_info_flags & AUTH_SESSION_INFO_UNIX_TOKEN)
 463             && NT_STATUS_IS_OK(status)) {
 464                 status = auth_session_info_fill_unix(auth_context->event_ctx,
 465                                                      auth_context->lp_ctx,
 466                                                      original_user_name, *session_info);
 467                 if (!NT_STATUS_IS_OK(status)) {
 468                         TALLOC_FREE(*session_info);
 469                 }
 470         }
 471         return status;
 472 }
 473
 474 /* Wrapper because we don't want to expose all callers to needing to
 475  * know anything about the PAC or auth subsystem internal structures
 476  * before we output a struct auth session_info */
 477 static NTSTATUS auth_generate_session_info_pac(struct auth4_context *auth_ctx,
 478                                                TALLOC_CTX *mem_ctx,
 479                                                struct smb_krb5_context *smb_krb5_context,
 480                                                DATA_BLOB *pac_blob,
 481                                                const char *principal_name,
 482                                                const struct tsocket_address *remote_address,
 483                                                uint32_t session_info_flags,
 484                                                struct auth_session_info **session_info)
 485 {
 486         NTSTATUS status;
 487         struct auth_user_info_dc *user_info_dc;
 488         TALLOC_CTX *tmp_ctx;
 489
 490         if (!pac_blob) {
 491                 return auth_generate_session_info_principal(auth_ctx, mem_ctx, principal_name,
 492                                                        NULL, session_info_flags, session_info);
 493         }
 494
 495         tmp_ctx = talloc_named(mem_ctx, 0, "gensec_gssapi_session_info context");
 496         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 497
 498         status = kerberos_pac_blob_to_user_info_dc(tmp_ctx,
 499                                                    *pac_blob,
 500                                                    smb_krb5_context->krb5_context,
 501                                                    &user_info_dc, NULL, NULL);
 502         if (!NT_STATUS_IS_OK(status)) {
 503                 talloc_free(tmp_ctx);
 504                 return status;
 505         }
 506
 507         if (user_info_dc->info->authenticated) {
 508                 session_info_flags |= AUTH_SESSION_INFO_AUTHENTICATED;
 509         }
 510
 511         status = auth_generate_session_info_wrapper(auth_ctx, mem_ctx,
 512                                                     user_info_dc,
 513                                                     user_info_dc->info->account_name,
 514                                                     session_info_flags, session_info);
 515         talloc_free(tmp_ctx);
 516         return status;
 517 }
 518
 519 /***************************************************************************
 520  Make a auth_info struct for the auth subsystem
 521  - Allow the caller to specify the methods to use, including optionally the SAM to use
 522 ***************************************************************************/
 523 _PUBLIC_ NTSTATUS auth_context_create_methods(TALLOC_CTX *mem_ctx, const char **methods,
 524                                               struct tevent_context *ev,
 525                                               struct imessaging_context *msg,
 526                                               struct loadparm_context *lp_ctx,
 527                                               struct ldb_context *sam_ctx,
 528                                               struct auth4_context **auth_ctx)
 529 {
 530         int i;
 531         struct auth4_context *ctx;
 532
 533         auth4_init();
 534
 535         if (!ev) {
 536                 DEBUG(0,("auth_context_create: called with out event context\n"));
 537                 return NT_STATUS_INTERNAL_ERROR;
 538         }
 539
 540         ctx = talloc_zero(mem_ctx, struct auth4_context);
 541         NT_STATUS_HAVE_NO_MEMORY(ctx);
 542         ctx->challenge.data             = data_blob(NULL, 0);
 543         ctx->methods                    = NULL;
 544         ctx->event_ctx                  = ev;
 545         ctx->msg_ctx                    = msg;
 546         ctx->lp_ctx                     = lp_ctx;
 547
 548         if (sam_ctx) {
 549                 ctx->sam_ctx = sam_ctx;
 550         } else {
 551                 ctx->sam_ctx = samdb_connect(ctx, ctx->event_ctx, ctx->lp_ctx, system_session(ctx->lp_ctx), 0);
 552         }
 553
 554         for (i=0; methods && methods[i] ; i++) {
 555                 struct auth_method_context *method;
 556
 557                 method = talloc(ctx, struct auth_method_context);
 558                 NT_STATUS_HAVE_NO_MEMORY(method);
 559
 560                 method->ops = auth_backend_byname(methods[i]);
 561                 if (!method->ops) {
 562                         DEBUG(1,("auth_context_create: failed to find method=%s\n",
 563                                 methods[i]));
 564                         return NT_STATUS_INTERNAL_ERROR;
 565                 }
 566                 method->auth_ctx        = ctx;
 567                 method->depth           = i;
 568                 DLIST_ADD_END(ctx->methods, method, struct auth_method_context *);
 569         }
 570
 571         ctx->check_ntlm_password = auth_check_password_wrapper;
 572         ctx->get_ntlm_challenge = auth_get_challenge;
 573         ctx->set_ntlm_challenge = auth_context_set_challenge;
 574         ctx->generate_session_info = auth_generate_session_info_wrapper;
 575         ctx->generate_session_info_pac = auth_generate_session_info_pac;
 576
 577         *auth_ctx = ctx;
 578
 579         return NT_STATUS_OK;
 580 }
 581
 582 const char **auth_methods_from_lp(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
 583 {
 584         char **auth_methods = NULL;
 585
 586         switch (lpcfg_server_role(lp_ctx)) {
 587         case ROLE_STANDALONE:
 588                 auth_methods = str_list_make(mem_ctx, "anonymous sam_ignoredomain", NULL);
 589                 break;
 590         case ROLE_DOMAIN_MEMBER:
 591                 auth_methods = str_list_make(mem_ctx, "anonymous sam winbind", NULL);
 592                 break;
 593         case ROLE_DOMAIN_BDC:
 594         case ROLE_DOMAIN_PDC:
 595         case ROLE_ACTIVE_DIRECTORY_DC:
 596                 auth_methods = str_list_make(mem_ctx, "anonymous sam_ignoredomain winbind", NULL);
 597                 break;
 598         }
 599         return (const char **) auth_methods;
 600 }
 601
 602 /***************************************************************************
 603  Make a auth_info struct for the auth subsystem
 604  - Uses default auth_methods, depending on server role and smb.conf settings
 605 ***************************************************************************/
 606 _PUBLIC_ NTSTATUS auth_context_create(TALLOC_CTX *mem_ctx,
 607                              struct tevent_context *ev,
 608                              struct imessaging_context *msg,
 609                              struct loadparm_context *lp_ctx,
 610                              struct auth4_context **auth_ctx)
 611 {
 612         NTSTATUS status;
 613         const char **auth_methods;
 614         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 615         if (!tmp_ctx) {
 616                 return NT_STATUS_NO_MEMORY;
 617         }
 618
 619         auth_methods = auth_methods_from_lp(tmp_ctx, lp_ctx);
 620         if (!auth_methods) {
 621                 return NT_STATUS_INVALID_PARAMETER;
 622         }
 623         status = auth_context_create_methods(mem_ctx, auth_methods, ev, msg, lp_ctx, NULL, auth_ctx);
 624         talloc_free(tmp_ctx);
 625         return status;
 626 }
 627
 628 /* the list of currently registered AUTH backends */
 629 static struct auth_backend {
 630         const struct auth_operations *ops;
 631 } *backends = NULL;
 632 static int num_backends;
 633
 634 /*
 635   register a AUTH backend.
 636
 637   The 'name' can be later used by other backends to find the operations
 638   structure for this backend.
 639 */
 640 _PUBLIC_ NTSTATUS auth_register(const struct auth_operations *ops)
 641 {
 642         struct auth_operations *new_ops;
 643
 644         if (auth_backend_byname(ops->name) != NULL) {
 645                 /* its already registered! */
 646                 DEBUG(0,("AUTH backend '%s' already registered\n",
 647                          ops->name));
 648                 return NT_STATUS_OBJECT_NAME_COLLISION;
 649         }
 650
 651         backends = talloc_realloc(talloc_autofree_context(), backends,
 652                                   struct auth_backend, num_backends+1);
 653         NT_STATUS_HAVE_NO_MEMORY(backends);
 654
 655         new_ops = (struct auth_operations *)talloc_memdup(backends, ops, sizeof(*ops));
 656         NT_STATUS_HAVE_NO_MEMORY(new_ops);
 657         new_ops->name = talloc_strdup(new_ops, ops->name);
 658         NT_STATUS_HAVE_NO_MEMORY(new_ops->name);
 659
 660         backends[num_backends].ops = new_ops;
 661
 662         num_backends++;
 663
 664         DEBUG(3,("AUTH backend '%s' registered\n",
 665                  ops->name));
 666
 667         return NT_STATUS_OK;
 668 }
 669
 670 /*
 671   return the operations structure for a named backend of the specified type
 672 */
 673 const struct auth_operations *auth_backend_byname(const char *name)
 674 {
 675         int i;
 676
 677         for (i=0;i<num_backends;i++) {
 678                 if (strcmp(backends[i].ops->name, name) == 0) {
 679                         return backends[i].ops;
 680                 }
 681         }
 682
 683         return NULL;
 684 }
 685
 686 /*
 687   return the AUTH interface version, and the size of some critical types
 688   This can be used by backends to either detect compilation errors, or provide
 689   multiple implementations for different smbd compilation options in one module
 690 */
 691 const struct auth_critical_sizes *auth_interface_version(void)
 692 {
 693         static const struct auth_critical_sizes critical_sizes = {
 694                 AUTH4_INTERFACE_VERSION,
 695                 sizeof(struct auth_operations),
 696                 sizeof(struct auth_method_context),
 697                 sizeof(struct auth4_context),
 698                 sizeof(struct auth_usersupplied_info),
 699                 sizeof(struct auth_user_info_dc)
 700         };
 701
 702         return &critical_sizes;
 703 }
 704
 705 _PUBLIC_ NTSTATUS auth4_init(void)
 706 {
 707         static bool initialized = false;
 708 #define _MODULE_PROTO(init) extern NTSTATUS init(void);
 709         STATIC_auth4_MODULES_PROTO;
 710         init_module_fn static_init[] = { STATIC_auth4_MODULES };
 711
 712         if (initialized) return NT_STATUS_OK;
 713         initialized = true;
 714
 715         run_init_functions(static_init);
 716
 717         return NT_STATUS_OK;
 718 }