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 #undef DBGC_CLASS
  38 #define DBGC_CLASS DBGC_AUTH
  39
  40 _PUBLIC_ struct auth_session_info *anonymous_session(TALLOC_CTX *mem_ctx,
  41                                             struct loadparm_context *lp_ctx)
  42 {
  43         NTSTATUS nt_status;
  44         struct auth_session_info *session_info = NULL;
  45         nt_status = auth_anonymous_session_info(mem_ctx, lp_ctx, &session_info);
  46         if (!NT_STATUS_IS_OK(nt_status)) {
  47                 return NULL;
  48         }
  49         return session_info;
  50 }
  51
  52 _PUBLIC_ NTSTATUS auth_generate_session_info(TALLOC_CTX *mem_ctx,
  53                                              struct loadparm_context *lp_ctx, /* Optional, if you don't want privilages */
  54                                              struct ldb_context *sam_ctx, /* Optional, if you don't want local groups */
  55                                              struct auth_user_info_dc *user_info_dc,
  56                                              uint32_t session_info_flags,
  57                                              struct auth_session_info **_session_info)
  58 {
  59         struct auth_session_info *session_info;
  60         NTSTATUS nt_status;
  61         unsigned int i, num_sids = 0;
  62
  63         const char *filter;
  64
  65         struct dom_sid *sids = NULL;
  66         const struct dom_sid *anonymous_sid, *system_sid;
  67
  68         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  69         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
  70
  71         session_info = talloc_zero(tmp_ctx, struct auth_session_info);
  72         if (session_info == NULL) {
  73                 TALLOC_FREE(tmp_ctx);
  74                 return NT_STATUS_NO_MEMORY;
  75         }
  76
  77         session_info->info = talloc_reference(session_info, user_info_dc->info);
  78
  79         session_info->torture = talloc_zero(session_info, struct auth_user_info_torture);
  80         if (session_info->torture == NULL) {
  81                 TALLOC_FREE(tmp_ctx);
  82                 return NT_STATUS_NO_MEMORY;
  83         }
  84         session_info->torture->num_dc_sids = user_info_dc->num_sids;
  85         session_info->torture->dc_sids = talloc_reference(session_info, user_info_dc->sids);
  86         if (session_info->torture->dc_sids == NULL) {
  87                 TALLOC_FREE(tmp_ctx);
  88                 return NT_STATUS_NO_MEMORY;
  89         }
  90
  91         /* unless set otherwise, the session key is the user session
  92          * key from the auth subsystem */
  93         session_info->session_key = data_blob_talloc(session_info, user_info_dc->user_session_key.data, user_info_dc->user_session_key.length);
  94         if (!session_info->session_key.data && session_info->session_key.length) {
  95                 if (session_info->session_key.data == NULL) {
  96                         TALLOC_FREE(tmp_ctx);
  97                         return NT_STATUS_NO_MEMORY;
  98                 }
  99         }
 100
 101         anonymous_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_ANONYMOUS);
 102         if (anonymous_sid == NULL) {
 103                 TALLOC_FREE(tmp_ctx);
 104                 return NT_STATUS_NO_MEMORY;
 105         }
 106
 107         system_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_SYSTEM);
 108         if (system_sid == NULL) {
 109                 TALLOC_FREE(tmp_ctx);
 110                 return NT_STATUS_NO_MEMORY;
 111         }
 112
 113         sids = talloc_array(tmp_ctx, struct dom_sid, user_info_dc->num_sids);
 114         if (sids == NULL) {
 115                 TALLOC_FREE(tmp_ctx);
 116                 return NT_STATUS_NO_MEMORY;
 117         }
 118
 119         num_sids = user_info_dc->num_sids;
 120
 121         for (i=0; i < user_info_dc->num_sids; i++) {
 122                 sids[i] = user_info_dc->sids[i];
 123         }
 124
 125         /*
 126          * Finally add the "standard" sids.
 127          * The only difference between guest and "anonymous"
 128          * is the addition of Authenticated_Users.
 129          */
 130
 131         if (session_info_flags & AUTH_SESSION_INFO_DEFAULT_GROUPS) {
 132                 sids = talloc_realloc(tmp_ctx, sids, struct dom_sid, num_sids + 2);
 133                 if (sids == NULL) {
 134                         TALLOC_FREE(tmp_ctx);
 135                         return NT_STATUS_NO_MEMORY;
 136                 }
 137
 138                 sid_copy(&sids[num_sids], &global_sid_World);
 139                 num_sids++;
 140
 141                 sid_copy(&sids[num_sids], &global_sid_Network);
 142                 num_sids++;
 143         }
 144
 145         if (session_info_flags & AUTH_SESSION_INFO_AUTHENTICATED) {
 146                 sids = talloc_realloc(tmp_ctx, sids, struct dom_sid, num_sids + 1);
 147                 if (sids == NULL) {
 148                         TALLOC_FREE(tmp_ctx);
 149                         return NT_STATUS_NO_MEMORY;
 150                 }
 151
 152                 sid_copy(&sids[num_sids], &global_sid_Authenticated_Users);
 153                 num_sids++;
 154         }
 155
 156         if (session_info_flags & AUTH_SESSION_INFO_NTLM) {
 157                 sids = talloc_realloc(tmp_ctx, sids, struct dom_sid, num_sids + 1);
 158                 if (sids == NULL) {
 159                         TALLOC_FREE(tmp_ctx);
 160                         return NT_STATUS_NO_MEMORY;
 161                 }
 162
 163                 if (!dom_sid_parse(SID_NT_NTLM_AUTHENTICATION, &sids[num_sids])) {
 164                         TALLOC_FREE(tmp_ctx);
 165                         return NT_STATUS_INTERNAL_ERROR;
 166                 }
 167                 num_sids++;
 168         }
 169
 170
 171         if (num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(anonymous_sid, &sids[PRIMARY_USER_SID_INDEX])) {
 172                 /* Don't expand nested groups of system, anonymous etc*/
 173         } else if (num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(system_sid, &sids[PRIMARY_USER_SID_INDEX])) {
 174                 /* Don't expand nested groups of system, anonymous etc*/
 175         } else if (sam_ctx) {
 176                 filter = talloc_asprintf(tmp_ctx, "(&(objectClass=group)(groupType:1.2.840.113556.1.4.803:=%u))",
 177                                          GROUP_TYPE_BUILTIN_LOCAL_GROUP);
 178
 179                 /* Search for each group in the token */
 180                 for (i = 0; i < num_sids; i++) {
 181                         struct dom_sid_buf buf;
 182                         const char *sid_dn;
 183                         DATA_BLOB sid_blob;
 184
 185                         sid_dn = talloc_asprintf(
 186                                 tmp_ctx,
 187                                 "<SID=%s>",
 188                                 dom_sid_str_buf(&sids[i], &buf));
 189                         if (sid_dn == NULL) {
 190                                 TALLOC_FREE(tmp_ctx);
 191                                 return NT_STATUS_NO_MEMORY;
 192                         }
 193                         sid_blob = data_blob_string_const(sid_dn);
 194
 195                         /* This function takes in memberOf values and expands
 196                          * them, as long as they meet the filter - so only
 197                          * builtin groups
 198                          *
 199                          * We already have the SID in the token, so set
 200                          * 'only childs' flag to true */
 201                         nt_status = dsdb_expand_nested_groups(sam_ctx, &sid_blob, true, filter,
 202                                                               tmp_ctx, &sids, &num_sids);
 203                         if (!NT_STATUS_IS_OK(nt_status)) {
 204                                 talloc_free(tmp_ctx);
 205                                 return nt_status;
 206                         }
 207                 }
 208         }
 209
 210         nt_status = security_token_create(session_info,
 211                                           lp_ctx,
 212                                           num_sids,
 213                                           sids,
 214                                           session_info_flags,
 215                                           &session_info->security_token);
 216         if (!NT_STATUS_IS_OK(nt_status)) {
 217                 TALLOC_FREE(tmp_ctx);
 218                 return nt_status;
 219         }
 220
 221         session_info->unique_session_token = GUID_random();
 222
 223         session_info->credentials = NULL;
 224
 225         talloc_steal(mem_ctx, session_info);
 226         *_session_info = session_info;
 227         talloc_free(tmp_ctx);
 228         return NT_STATUS_OK;
 229 }
 230
 231
 232 /* Fill out the auth_session_info with a cli_credentials based on the
 233  * auth_session_info we were forwarded over named pipe forwarding.
 234  *
 235  * NOTE: The stucture members of session_info_transport are stolen
 236  * with talloc_move() into auth_session_info for long term use
 237  */
 238 struct auth_session_info *auth_session_info_from_transport(TALLOC_CTX *mem_ctx,
 239                                                            struct auth_session_info_transport *session_info_transport,
 240                                                            struct loadparm_context *lp_ctx,
 241                                                            const char **reason)
 242 {
 243         struct auth_session_info *session_info;
 244         session_info = talloc_steal(mem_ctx, session_info_transport->session_info);
 245         /*
 246          * This is to allow us to check the type of this pointer using
 247          * talloc_get_type()
 248          */
 249         talloc_set_name(session_info, "struct auth_session_info");
 250 #ifdef HAVE_GSS_IMPORT_CRED
 251         if (session_info_transport->exported_gssapi_credentials.length) {
 252                 struct cli_credentials *creds;
 253                 OM_uint32 minor_status;
 254                 gss_buffer_desc cred_token;
 255                 gss_cred_id_t cred_handle;
 256                 const char *error_string;
 257                 int ret;
 258                 bool ok;
 259
 260                 DEBUG(10, ("Delegated credentials supplied by client\n"));
 261
 262                 cred_token.value = session_info_transport->exported_gssapi_credentials.data;
 263                 cred_token.length = session_info_transport->exported_gssapi_credentials.length;
 264
 265                 ret = gss_import_cred(&minor_status,
 266                                       &cred_token,
 267                                       &cred_handle);
 268                 if (ret != GSS_S_COMPLETE) {
 269                         *reason = "Internal error in gss_import_cred()";
 270                         return NULL;
 271                 }
 272
 273                 creds = cli_credentials_init(session_info);
 274                 if (!creds) {
 275                         *reason = "Out of memory in cli_credentials_init()";
 276                         return NULL;
 277                 }
 278                 session_info->credentials = creds;
 279
 280                 ok = cli_credentials_set_conf(creds, lp_ctx);
 281                 if (!ok) {
 282                         *reason = "Failed to load smb.conf";
 283                         return NULL;
 284                 }
 285
 286                 /* Just so we don't segfault trying to get at a username */
 287                 cli_credentials_set_anonymous(creds);
 288
 289                 ret = cli_credentials_set_client_gss_creds(creds,
 290                                                            lp_ctx,
 291                                                            cred_handle,
 292                                                            CRED_SPECIFIED,
 293                                                            &error_string);
 294                 if (ret) {
 295                         *reason = talloc_asprintf(mem_ctx,
 296                                                   "Failed to set pipe forwarded"
 297                                                   "creds: %s\n", error_string);
 298                         return NULL;
 299                 }
 300
 301                 /* This credential handle isn't useful for password
 302                  * authentication, so ensure nobody tries to do that */
 303                 cli_credentials_set_kerberos_state(creds,
 304                                                    CRED_USE_KERBEROS_REQUIRED,
 305                                                    CRED_SPECIFIED);
 306
 307         }
 308 #endif
 309         return session_info;
 310 }
 311
 312
 313 /* Create a auth_session_info_transport from an auth_session_info.
 314  *
 315  * NOTE: Members of the auth_session_info_transport structure are
 316  * talloc_referenced() into this structure, and should not be changed.
 317  */
 318 NTSTATUS auth_session_info_transport_from_session(TALLOC_CTX *mem_ctx,
 319                                                   struct auth_session_info *session_info,
 320                                                   struct tevent_context *event_ctx,
 321                                                   struct loadparm_context *lp_ctx,
 322                                                   struct auth_session_info_transport **transport_out)
 323 {
 324
 325         struct auth_session_info_transport *session_info_transport
 326                 = talloc_zero(mem_ctx, struct auth_session_info_transport);
 327         if (!session_info_transport) {
 328                 return NT_STATUS_NO_MEMORY;
 329         };
 330         session_info_transport->session_info = talloc_reference(session_info_transport, session_info);
 331         if (!session_info_transport->session_info) {
 332                 return NT_STATUS_NO_MEMORY;
 333         };
 334 #ifdef HAVE_GSS_EXPORT_CRED
 335         if (session_info->credentials) {
 336                 struct gssapi_creds_container *gcc;
 337                 OM_uint32 gret;
 338                 OM_uint32 minor_status;
 339                 gss_buffer_desc cred_token;
 340                 const char *error_string;
 341                 int ret;
 342
 343                 ret = cli_credentials_get_client_gss_creds(session_info->credentials,
 344                                                            event_ctx,
 345                                                            lp_ctx,
 346                                                            &gcc, &error_string);
 347                 if (ret != 0) {
 348                         *transport_out = session_info_transport;
 349                         return NT_STATUS_OK;
 350                 }
 351
 352                 gret = gss_export_cred(&minor_status,
 353                                        gcc->creds,
 354                                        &cred_token);
 355                 if (gret != GSS_S_COMPLETE) {
 356                         return NT_STATUS_INTERNAL_ERROR;
 357                 }
 358
 359                 if (cred_token.length) {
 360                         session_info_transport->exported_gssapi_credentials
 361                                 = data_blob_talloc(session_info_transport,
 362                                                    cred_token.value,
 363                                                    cred_token.length);
 364                         gss_release_buffer(&minor_status, &cred_token);
 365                         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->exported_gssapi_credentials.data);
 366                 }
 367         }
 368 #endif
 369         *transport_out = session_info_transport;
 370         return NT_STATUS_OK;
 371 }
 372
 373
 374 /* Produce a session_info for an arbitary DN or principal in the local
 375  * DB, assuming the local DB holds all the groups
 376  *
 377  * Supply either a principal or a DN
 378  */
 379 NTSTATUS authsam_get_session_info_principal(TALLOC_CTX *mem_ctx,
 380                                             struct loadparm_context *lp_ctx,
 381                                             struct ldb_context *sam_ctx,
 382                                             const char *principal,
 383                                             struct ldb_dn *user_dn,
 384                                             uint32_t session_info_flags,
 385                                             struct auth_session_info **session_info)
 386 {
 387         NTSTATUS nt_status;
 388         struct auth_user_info_dc *user_info_dc;
 389         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 390         if (!tmp_ctx) {
 391                 return NT_STATUS_NO_MEMORY;
 392         }
 393         nt_status = authsam_get_user_info_dc_principal(tmp_ctx, lp_ctx, sam_ctx,
 394                                                       principal, user_dn,
 395                                                       &user_info_dc);
 396         if (!NT_STATUS_IS_OK(nt_status)) {
 397                 talloc_free(tmp_ctx);
 398                 return nt_status;
 399         }
 400
 401         nt_status = auth_generate_session_info(tmp_ctx, lp_ctx, sam_ctx,
 402                                                user_info_dc, session_info_flags,
 403                                                session_info);
 404
 405         if (NT_STATUS_IS_OK(nt_status)) {
 406                 talloc_steal(mem_ctx, *session_info);
 407         }
 408         talloc_free(tmp_ctx);
 409         return nt_status;
 410 }
 411
 412 /**
 413  * prints a struct auth_session_info security token to debug output.
 414  */
 415 void auth_session_info_debug(int dbg_lev,
 416                              const struct auth_session_info *session_info)
 417 {
 418         if (!session_info) {
 419                 DEBUG(dbg_lev, ("Session Info: (NULL)\n"));
 420                 return;
 421         }
 422
 423         security_token_debug(DBGC_AUTH, dbg_lev,
 424                              session_info->security_token);
 425 }