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