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