source4/auth/session.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Authentication utility functions
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Andrew Bartlett 2001-2010
   6    Copyright (C) Jeremy Allison 2000-2001
   7    Copyright (C) Rafal Szczesniak 2002
   8    Copyright (C) Stefan Metzmacher 2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "auth/auth.h"
  26 #include "auth/auth_sam.h"
  27 #include "auth/credentials/credentials.h"
  28 #include "auth/credentials/credentials_krb5.h"
  29 #include "libcli/security/security.h"
  30 #include "libcli/auth/libcli_auth.h"
  31 #include "dsdb/samdb/samdb.h"
  32 #include "auth/session_proto.h"
  33 #include "system/kerberos.h"
  34 #include <gssapi/gssapi.h>
  35 #include "libcli/wbclient/wbclient.h"
  36
  37 _PUBLIC_ struct auth_session_info *anonymous_session(TALLOC_CTX *mem_ctx,
  38                                             struct loadparm_context *lp_ctx)
  39 {
  40         NTSTATUS nt_status;
  41         struct auth_session_info *session_info = NULL;
  42         nt_status = auth_anonymous_session_info(mem_ctx, lp_ctx, &session_info);
  43         if (!NT_STATUS_IS_OK(nt_status)) {
  44                 return NULL;
  45         }
  46         return session_info;
  47 }
  48
  49 _PUBLIC_ NTSTATUS auth_generate_session_info(TALLOC_CTX *mem_ctx,
  50                                              struct loadparm_context *lp_ctx, /* Optional, if you don't want privilages */
  51                                              struct ldb_context *sam_ctx, /* Optional, if you don't want local groups */
  52                                              struct auth_user_info_dc *user_info_dc,
  53                                              uint32_t session_info_flags,
  54                                              struct auth_session_info **_session_info)
  55 {
  56         struct auth_session_info *session_info;
  57         NTSTATUS nt_status;
  58         unsigned int i, num_sids = 0;
  59
  60         const char *filter;
  61
  62         struct dom_sid *sids = NULL;
  63         const struct dom_sid *anonymous_sid, *system_sid;
  64
  65         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  66         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
  67
  68         session_info = talloc_zero(tmp_ctx, struct auth_session_info);
  69         if (session_info == NULL) {
  70                 TALLOC_FREE(tmp_ctx);
  71                 return NT_STATUS_NO_MEMORY;
  72         }
  73
  74         session_info->info = talloc_reference(session_info, user_info_dc->info);
  75
  76         session_info->torture = talloc_zero(session_info, struct auth_user_info_torture);
  77         if (session_info->torture == NULL) {
  78                 TALLOC_FREE(tmp_ctx);
  79                 return NT_STATUS_NO_MEMORY;
  80         }
  81         session_info->torture->num_dc_sids = user_info_dc->num_sids;
  82         session_info->torture->dc_sids = talloc_reference(session_info, user_info_dc->sids);
  83         if (session_info->torture->dc_sids == NULL) {
  84                 TALLOC_FREE(tmp_ctx);
  85                 return NT_STATUS_NO_MEMORY;
  86         }
  87
  88         /* unless set otherwise, the session key is the user session
  89          * key from the auth subsystem */
  90         session_info->session_key = data_blob_talloc(session_info, user_info_dc->user_session_key.data, user_info_dc->user_session_key.length);
  91         if (!session_info->session_key.data && session_info->session_key.length) {
  92                 if (session_info->session_key.data == NULL) {
  93                         TALLOC_FREE(tmp_ctx);
  94                         return NT_STATUS_NO_MEMORY;
  95                 }
  96         }
  97
  98         anonymous_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_ANONYMOUS);
  99         if (anonymous_sid == NULL) {
 100                 TALLOC_FREE(tmp_ctx);
 101                 return NT_STATUS_NO_MEMORY;
 102         }
 103
 104         system_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_SYSTEM);
 105         if (system_sid == NULL) {
 106                 TALLOC_FREE(tmp_ctx);
 107                 return NT_STATUS_NO_MEMORY;
 108         }
 109
 110         sids = talloc_array(tmp_ctx, struct dom_sid, user_info_dc->num_sids);
 111         if (sids == NULL) {
 112                 TALLOC_FREE(tmp_ctx);
 113                 return NT_STATUS_NO_MEMORY;
 114         }
 115         if (!sids) {
 116                 talloc_free(tmp_ctx);
 117                 return NT_STATUS_NO_MEMORY;
 118         }
 119
 120         num_sids = user_info_dc->num_sids;
 121
 122         for (i=0; i < user_info_dc->num_sids; i++) {
 123                 sids[i] = user_info_dc->sids[i];
 124         }
 125
 126         /*
 127          * Finally add the "standard" sids.
 128          * The only difference between guest and "anonymous"
 129          * is the addition of Authenticated_Users.
 130          */
 131
 132         if (session_info_flags & AUTH_SESSION_INFO_DEFAULT_GROUPS) {
 133                 sids = talloc_realloc(tmp_ctx, sids, struct dom_sid, num_sids + 2);
 134                 NT_STATUS_HAVE_NO_MEMORY(sids);
 135
 136                 if (!dom_sid_parse(SID_WORLD, &sids[num_sids])) {
 137                         return NT_STATUS_INTERNAL_ERROR;
 138                 }
 139                 num_sids++;
 140
 141                 if (!dom_sid_parse(SID_NT_NETWORK, &sids[num_sids])) {
 142                         return NT_STATUS_INTERNAL_ERROR;
 143                 }
 144                 num_sids++;
 145         }
 146
 147         if (session_info_flags & AUTH_SESSION_INFO_AUTHENTICATED) {
 148                 sids = talloc_realloc(tmp_ctx, sids, struct dom_sid, num_sids + 1);
 149                 NT_STATUS_HAVE_NO_MEMORY(sids);
 150
 151                 if (!dom_sid_parse(SID_NT_AUTHENTICATED_USERS, &sids[num_sids])) {
 152                         return NT_STATUS_INTERNAL_ERROR;
 153                 }
 154                 num_sids++;
 155         }
 156
 157
 158
 159         if (num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(anonymous_sid, &sids[PRIMARY_USER_SID_INDEX])) {
 160                 /* Don't expand nested groups of system, anonymous etc*/
 161         } else if (num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(system_sid, &sids[PRIMARY_USER_SID_INDEX])) {
 162                 /* Don't expand nested groups of system, anonymous etc*/
 163         } else if (sam_ctx) {
 164                 filter = talloc_asprintf(tmp_ctx, "(&(objectClass=group)(groupType:1.2.840.113556.1.4.803:=%u))",
 165                                          GROUP_TYPE_BUILTIN_LOCAL_GROUP);
 166
 167                 /* Search for each group in the token */
 168                 for (i = 0; i < num_sids; i++) {
 169                         char *sid_string;
 170                         const char *sid_dn;
 171                         DATA_BLOB sid_blob;
 172
 173                         sid_string = dom_sid_string(tmp_ctx,
 174                                                       &sids[i]);
 175                         if (sid_string == NULL) {
 176                                 TALLOC_FREE(user_info_dc);
 177                                 return NT_STATUS_NO_MEMORY;
 178                         }
 179
 180                         sid_dn = talloc_asprintf(tmp_ctx, "<SID=%s>", sid_string);
 181                         talloc_free(sid_string);
 182                         if (sid_dn == NULL) {
 183                                 TALLOC_FREE(user_info_dc);
 184                                 return NT_STATUS_NO_MEMORY;
 185                         }
 186                         sid_blob = data_blob_string_const(sid_dn);
 187
 188                         /* This function takes in memberOf values and expands
 189                          * them, as long as they meet the filter - so only
 190                          * builtin groups
 191                          *
 192                          * We already have the SID in the token, so set
 193                          * 'only childs' flag to true */
 194                         nt_status = dsdb_expand_nested_groups(sam_ctx, &sid_blob, true, filter,
 195                                                               tmp_ctx, &sids, &num_sids);
 196                         if (!NT_STATUS_IS_OK(nt_status)) {
 197                                 talloc_free(tmp_ctx);
 198                                 return nt_status;
 199                         }
 200                 }
 201         }
 202
 203         nt_status = security_token_create(session_info,
 204                                           lp_ctx,
 205                                           num_sids,
 206                                           sids,
 207                                           session_info_flags,
 208                                           &session_info->security_token);
 209         if (!NT_STATUS_IS_OK(nt_status)) {
 210                 TALLOC_FREE(tmp_ctx);
 211                 return nt_status;
 212         }
 213
 214         session_info->credentials = NULL;
 215
 216         talloc_steal(mem_ctx, session_info);
 217         *_session_info = session_info;
 218         talloc_free(tmp_ctx);
 219         return NT_STATUS_OK;
 220 }
 221
 222
 223 /* Fill out the auth_session_info with a cli_credentials based on the
 224  * auth_session_info we were forwarded over named pipe forwarding.
 225  *
 226  * NOTE: The stucture members of session_info_transport are stolen
 227  * with talloc_move() into auth_session_info for long term use
 228  */
 229 struct auth_session_info *auth_session_info_from_transport(TALLOC_CTX *mem_ctx,
 230                                                            struct auth_session_info_transport *session_info_transport,
 231                                                            struct loadparm_context *lp_ctx,
 232                                                            const char **reason)
 233 {
 234         struct auth_session_info *session_info;
 235         session_info = talloc_steal(mem_ctx, session_info_transport->session_info);
 236         /*
 237          * This is to allow us to check the type of this pointer using
 238          * talloc_get_type()
 239          */
 240         talloc_set_name(session_info, "struct auth_session_info");
 241 #ifdef HAVE_GSS_IMPORT_CRED
 242         if (session_info_transport->exported_gssapi_credentials.length) {
 243                 struct cli_credentials *creds;
 244                 OM_uint32 minor_status;
 245                 gss_buffer_desc cred_token;
 246                 gss_cred_id_t cred_handle;
 247                 const char *error_string;
 248                 int ret;
 249
 250                 DEBUG(10, ("Delegated credentials supplied by client\n"));
 251
 252                 cred_token.value = session_info_transport->exported_gssapi_credentials.data;
 253                 cred_token.length = session_info_transport->exported_gssapi_credentials.length;
 254
 255                 ret = gss_import_cred(&minor_status,
 256                                       &cred_token,
 257                                       &cred_handle);
 258                 if (ret != GSS_S_COMPLETE) {
 259                         *reason = "Internal error in gss_import_cred()";
 260                         return NULL;
 261                 }
 262
 263                 creds = cli_credentials_init(session_info);
 264                 if (!creds) {
 265                         *reason = "Out of memory in cli_credentials_init()";
 266                         return NULL;
 267                 }
 268                 session_info->credentials = creds;
 269
 270                 cli_credentials_set_conf(creds, lp_ctx);
 271                 /* Just so we don't segfault trying to get at a username */
 272                 cli_credentials_set_anonymous(creds);
 273
 274                 ret = cli_credentials_set_client_gss_creds(creds,
 275                                                            lp_ctx,
 276                                                            cred_handle,
 277                                                            CRED_SPECIFIED,
 278                                                            &error_string);
 279                 if (ret) {
 280                         *reason = talloc_asprintf(mem_ctx,
 281                                                   "Failed to set pipe forwarded"
 282                                                   "creds: %s\n", error_string);
 283                         return NULL;
 284                 }
 285
 286                 /* This credential handle isn't useful for password
 287                  * authentication, so ensure nobody tries to do that */
 288                 cli_credentials_set_kerberos_state(creds,
 289                                                    CRED_MUST_USE_KERBEROS);
 290
 291         }
 292 #endif
 293         return session_info;
 294 }
 295
 296
 297 /* Create a auth_session_info_transport from an auth_session_info.
 298  *
 299  * NOTE: Members of the auth_session_info_transport structure are
 300  * talloc_referenced() into this structure, and should not be changed.
 301  */
 302 NTSTATUS auth_session_info_transport_from_session(TALLOC_CTX *mem_ctx,
 303                                                   struct auth_session_info *session_info,
 304                                                   struct tevent_context *event_ctx,
 305                                                   struct loadparm_context *lp_ctx,
 306                                                   struct auth_session_info_transport **transport_out)
 307 {
 308
 309         struct auth_session_info_transport *session_info_transport
 310                 = talloc_zero(mem_ctx, struct auth_session_info_transport);
 311         if (!session_info_transport) {
 312                 return NT_STATUS_NO_MEMORY;
 313         };
 314         session_info_transport->session_info = talloc_reference(session_info_transport, session_info);
 315         if (!session_info_transport->session_info) {
 316                 return NT_STATUS_NO_MEMORY;
 317         };
 318 #ifdef HAVE_GSS_EXPORT_CRED
 319         if (session_info->credentials) {
 320                 struct gssapi_creds_container *gcc;
 321                 OM_uint32 gret;
 322                 OM_uint32 minor_status;
 323                 gss_buffer_desc cred_token;
 324                 const char *error_string;
 325                 int ret;
 326
 327                 ret = cli_credentials_get_client_gss_creds(session_info->credentials,
 328                                                            event_ctx,
 329                                                            lp_ctx,
 330                                                            &gcc, &error_string);
 331                 if (ret != 0) {
 332                         *transport_out = session_info_transport;
 333                         return NT_STATUS_OK;
 334                 }
 335
 336                 gret = gss_export_cred(&minor_status,
 337                                        gcc->creds,
 338                                        &cred_token);
 339                 if (gret != GSS_S_COMPLETE) {
 340                         return NT_STATUS_INTERNAL_ERROR;
 341                 }
 342
 343                 if (cred_token.length) {
 344                         session_info_transport->exported_gssapi_credentials
 345                                 = data_blob_talloc(session_info_transport,
 346                                                    cred_token.value,
 347                                                    cred_token.length);
 348                         gss_release_buffer(&minor_status, &cred_token);
 349                         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->exported_gssapi_credentials.data);
 350                 }
 351         }
 352 #endif
 353         *transport_out = session_info_transport;
 354         return NT_STATUS_OK;
 355 }
 356
 357
 358 /* Produce a session_info for an arbitary DN or principal in the local
 359  * DB, assuming the local DB holds all the groups
 360  *
 361  * Supply either a principal or a DN
 362  */
 363 NTSTATUS authsam_get_session_info_principal(TALLOC_CTX *mem_ctx,
 364                                             struct loadparm_context *lp_ctx,
 365                                             struct ldb_context *sam_ctx,
 366                                             const char *principal,
 367                                             struct ldb_dn *user_dn,
 368                                             uint32_t session_info_flags,
 369                                             struct auth_session_info **session_info)
 370 {
 371         NTSTATUS nt_status;
 372         struct auth_user_info_dc *user_info_dc;
 373         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 374         if (!tmp_ctx) {
 375                 return NT_STATUS_NO_MEMORY;
 376         }
 377         nt_status = authsam_get_user_info_dc_principal(tmp_ctx, lp_ctx, sam_ctx,
 378                                                       principal, user_dn,
 379                                                       &user_info_dc);
 380         if (!NT_STATUS_IS_OK(nt_status)) {
 381                 talloc_free(tmp_ctx);
 382                 return nt_status;
 383         }
 384
 385         nt_status = auth_generate_session_info(tmp_ctx, lp_ctx, sam_ctx,
 386                                                user_info_dc, session_info_flags,
 387                                                session_info);
 388
 389         if (NT_STATUS_IS_OK(nt_status)) {
 390                 talloc_steal(mem_ctx, *session_info);
 391         }
 392         talloc_free(tmp_ctx);
 393         return nt_status;
 394 }
 395
 396 /**
 397  * prints a struct auth_session_info security token to debug output.
 398  */
 399 void auth_session_info_debug(int dbg_lev,
 400                              const struct auth_session_info *session_info)
 401 {
 402         if (!session_info) {
 403                 DEBUG(dbg_lev, ("Session Info: (NULL)\n"));
 404                 return;
 405         }
 406
 407         security_token_debug(0, dbg_lev, session_info->security_token);
 408 }