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
  36 _PUBLIC_ struct auth_session_info *anonymous_session(TALLOC_CTX *mem_ctx,
  37                                             struct loadparm_context *lp_ctx)
  38 {
  39         NTSTATUS nt_status;
  40         struct auth_session_info *session_info = NULL;
  41         nt_status = auth_anonymous_session_info(mem_ctx, lp_ctx, &session_info);
  42         if (!NT_STATUS_IS_OK(nt_status)) {
  43                 return NULL;
  44         }
  45         return session_info;
  46 }
  47
  48 _PUBLIC_ NTSTATUS auth_generate_session_info(TALLOC_CTX *mem_ctx,
  49                                              struct loadparm_context *lp_ctx, /* Optional, if you don't want privilages */
  50                                              struct ldb_context *sam_ctx, /* Optional, if you don't want local groups */
  51                                              struct auth_user_info_dc *user_info_dc,
  52                                              uint32_t session_info_flags,
  53                                              struct auth_session_info **_session_info)
  54 {
  55         struct auth_session_info *session_info;
  56         NTSTATUS nt_status;
  57         unsigned int i, num_sids = 0;
  58
  59         const char *filter;
  60
  61         struct dom_sid *sids = NULL;
  62         const struct dom_sid *anonymous_sid, *system_sid;
  63
  64         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  65         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
  66
  67         session_info = talloc(tmp_ctx, struct auth_session_info);
  68         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(session_info, tmp_ctx);
  69
  70         session_info->info = talloc_reference(session_info, user_info_dc->info);
  71
  72         session_info->torture = talloc_zero(session_info, struct auth_user_info_torture);
  73         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(session_info->torture, tmp_ctx);
  74         session_info->torture->num_dc_sids = user_info_dc->num_sids;
  75         session_info->torture->dc_sids = talloc_reference(session_info, user_info_dc->sids);
  76         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(session_info->torture->dc_sids, tmp_ctx);
  77
  78         /* unless set otherwise, the session key is the user session
  79          * key from the auth subsystem */
  80         session_info->session_key = data_blob_talloc(session_info, user_info_dc->user_session_key.data, user_info_dc->user_session_key.length);
  81         if (!session_info->session_key.data && session_info->session_key.length) {
  82                 NT_STATUS_HAVE_NO_MEMORY_AND_FREE(session_info->session_key.data, tmp_ctx);
  83         }
  84
  85         anonymous_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_ANONYMOUS);
  86         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(anonymous_sid, tmp_ctx);
  87
  88         system_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_SYSTEM);
  89         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(system_sid, tmp_ctx);
  90
  91         sids = talloc_array(tmp_ctx, struct dom_sid, user_info_dc->num_sids);
  92         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(sids, tmp_ctx);
  93         if (!sids) {
  94                 talloc_free(tmp_ctx);
  95                 return NT_STATUS_NO_MEMORY;
  96         }
  97
  98         num_sids = user_info_dc->num_sids;
  99
 100         for (i=0; i < user_info_dc->num_sids; i++) {
 101                 sids[i] = user_info_dc->sids[i];
 102         }
 103
 104         if (user_info_dc->num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(anonymous_sid, &user_info_dc->sids[PRIMARY_USER_SID_INDEX])) {
 105                 /* Don't expand nested groups of system, anonymous etc*/
 106         } else if (user_info_dc->num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(system_sid, &user_info_dc->sids[PRIMARY_USER_SID_INDEX])) {
 107                 /* Don't expand nested groups of system, anonymous etc*/
 108         } else if (sam_ctx) {
 109                 filter = talloc_asprintf(tmp_ctx, "(&(objectClass=group)(groupType:1.2.840.113556.1.4.803:=%u))",
 110                                          GROUP_TYPE_BUILTIN_LOCAL_GROUP);
 111
 112                 /* Search for each group in the token */
 113                 for (i = 0; i < user_info_dc->num_sids; i++) {
 114                         char *sid_string;
 115                         const char *sid_dn;
 116                         DATA_BLOB sid_blob;
 117
 118                         sid_string = dom_sid_string(tmp_ctx,
 119                                                       &user_info_dc->sids[i]);
 120                         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(sid_string, user_info_dc);
 121
 122                         sid_dn = talloc_asprintf(tmp_ctx, "<SID=%s>", sid_string);
 123                         talloc_free(sid_string);
 124                         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(sid_dn, user_info_dc);
 125                         sid_blob = data_blob_string_const(sid_dn);
 126
 127                         /* This function takes in memberOf values and expands
 128                          * them, as long as they meet the filter - so only
 129                          * builtin groups
 130                          *
 131                          * We already have the SID in the token, so set
 132                          * 'only childs' flag to true */
 133                         nt_status = dsdb_expand_nested_groups(sam_ctx, &sid_blob, true, filter,
 134                                                               tmp_ctx, &sids, &num_sids);
 135                         if (!NT_STATUS_IS_OK(nt_status)) {
 136                                 talloc_free(tmp_ctx);
 137                                 return nt_status;
 138                         }
 139                 }
 140         }
 141
 142         nt_status = security_token_create(session_info,
 143                                           lp_ctx,
 144                                           num_sids,
 145                                           sids,
 146                                           session_info_flags,
 147                                           &session_info->security_token);
 148         NT_STATUS_NOT_OK_RETURN_AND_FREE(nt_status, tmp_ctx);
 149
 150         session_info->credentials = NULL;
 151
 152         talloc_steal(mem_ctx, session_info);
 153         *_session_info = session_info;
 154         talloc_free(tmp_ctx);
 155         return NT_STATUS_OK;
 156 }
 157
 158 /* Create a session_info structure from the
 159  * auth_session_info_transport we were forwarded over named pipe
 160  * forwarding.
 161  *
 162  * NOTE: The stucture members of session_info_transport are stolen
 163  * with talloc_move() into auth_session_info for long term use
 164  */
 165 struct auth_session_info *auth_session_info_from_transport(TALLOC_CTX *mem_ctx,
 166                                                            struct auth_session_info_transport *session_info_transport,
 167                                                            struct loadparm_context *lp_ctx,
 168                                                            const char **reason)
 169 {
 170         struct auth_session_info *session_info;
 171         session_info = talloc_zero(mem_ctx, struct auth_session_info);
 172         if (!session_info) {
 173                 *reason = "failed to allocate session_info";
 174                 return NULL;
 175         }
 176
 177         session_info->security_token = talloc_move(session_info, &session_info_transport->security_token);
 178         session_info->info = talloc_move(session_info, &session_info_transport->info);
 179         session_info->session_key = session_info_transport->session_key;
 180         session_info->session_key.data = talloc_move(session_info, &session_info_transport->session_key.data);
 181
 182         if (session_info_transport->exported_gssapi_credentials.length) {
 183                 struct cli_credentials *creds;
 184                 OM_uint32 minor_status;
 185                 gss_buffer_desc cred_token;
 186                 gss_cred_id_t cred_handle;
 187                 const char *error_string;
 188                 int ret;
 189
 190                 DEBUG(10, ("Delegated credentials supplied by client\n"));
 191
 192                 cred_token.value = session_info_transport->exported_gssapi_credentials.data;
 193                 cred_token.length = session_info_transport->exported_gssapi_credentials.length;
 194
 195                 ret = gss_import_cred(&minor_status,
 196                                       &cred_token,
 197                                       &cred_handle);
 198                 if (ret != GSS_S_COMPLETE) {
 199                         *reason = "Internal error in gss_import_cred()";
 200                         return NULL;
 201                 }
 202
 203                 creds = cli_credentials_init(session_info);
 204                 if (!creds) {
 205                         *reason = "Out of memory in cli_credentials_init()";
 206                         return NULL;
 207                 }
 208                 session_info->credentials = creds;
 209
 210                 cli_credentials_set_conf(creds, lp_ctx);
 211                 /* Just so we don't segfault trying to get at a username */
 212                 cli_credentials_set_anonymous(creds);
 213
 214                 ret = cli_credentials_set_client_gss_creds(creds,
 215                                                            lp_ctx,
 216                                                            cred_handle,
 217                                                            CRED_SPECIFIED,
 218                                                            &error_string);
 219                 if (ret) {
 220                         *reason = talloc_asprintf(mem_ctx,
 221                                                   "Failed to set pipe forwarded"
 222                                                   "creds: %s\n", error_string);
 223                         return NULL;
 224                 }
 225
 226                 /* This credential handle isn't useful for password
 227                  * authentication, so ensure nobody tries to do that */
 228                 cli_credentials_set_kerberos_state(creds,
 229                                                    CRED_MUST_USE_KERBEROS);
 230
 231         }
 232
 233         return session_info;
 234 }
 235
 236
 237 /* Create a auth_session_info_transport from an auth_session_info.
 238  *
 239  * NOTE: Members of the auth_session_info_transport structure are not talloc_referenced, but simply assigned.  They are only valid for the lifetime of the struct auth_session_info
 240  *
 241  * This isn't normally an issue, as the auth_session_info has a very long typical life
 242  */
 243 NTSTATUS auth_session_info_transport_from_session(TALLOC_CTX *mem_ctx,
 244                                                   struct auth_session_info *session_info,
 245                                                   struct tevent_context *event_ctx,
 246                                                   struct loadparm_context *lp_ctx,
 247                                                   struct auth_session_info_transport **transport_out)
 248 {
 249
 250         struct auth_session_info_transport *session_info_transport = talloc_zero(mem_ctx, struct auth_session_info_transport);
 251         session_info_transport->security_token = talloc_reference(session_info, session_info->security_token);
 252         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->security_token);
 253
 254         session_info_transport->info = talloc_reference(session_info, session_info->info);
 255         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->info);
 256
 257         session_info_transport->session_key = session_info->session_key;
 258         session_info_transport->session_key.data = talloc_reference(session_info, session_info->session_key.data);
 259         if (!session_info_transport->session_key.data && session_info->session_key.length) {
 260                 return NT_STATUS_NO_MEMORY;
 261         }
 262
 263         if (session_info->credentials) {
 264                 struct gssapi_creds_container *gcc;
 265                 OM_uint32 gret;
 266                 OM_uint32 minor_status;
 267                 gss_buffer_desc cred_token;
 268                 const char *error_string;
 269                 int ret;
 270
 271                 ret = cli_credentials_get_client_gss_creds(session_info->credentials,
 272                                                            event_ctx,
 273                                                            lp_ctx,
 274                                                            &gcc, &error_string);
 275                 if (ret != 0) {
 276                         *transport_out = session_info_transport;
 277                         return NT_STATUS_OK;
 278                 }
 279
 280                 gret = gss_export_cred(&minor_status,
 281                                        gcc->creds,
 282                                        &cred_token);
 283                 if (gret != GSS_S_COMPLETE) {
 284                         return NT_STATUS_INTERNAL_ERROR;
 285                 }
 286
 287                 if (cred_token.length) {
 288                         session_info_transport->exported_gssapi_credentials
 289                                 = data_blob_talloc(session_info_transport,
 290                                                    cred_token.value,
 291                                                    cred_token.length);
 292                         gss_release_buffer(&minor_status, &cred_token);
 293                         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->exported_gssapi_credentials.data);
 294                 }
 295         }
 296         *transport_out = session_info_transport;
 297         return NT_STATUS_OK;
 298 }
 299
 300
 301 /* Produce a session_info for an arbitary DN or principal in the local
 302  * DB, assuming the local DB holds all the groups
 303  *
 304  * Supply either a principal or a DN
 305  */
 306 NTSTATUS authsam_get_session_info_principal(TALLOC_CTX *mem_ctx,
 307                                             struct loadparm_context *lp_ctx,
 308                                             struct ldb_context *sam_ctx,
 309                                             const char *principal,
 310                                             struct ldb_dn *user_dn,
 311                                             uint32_t session_info_flags,
 312                                             struct auth_session_info **session_info)
 313 {
 314         NTSTATUS nt_status;
 315         struct auth_user_info_dc *user_info_dc;
 316         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 317         if (!tmp_ctx) {
 318                 return NT_STATUS_NO_MEMORY;
 319         }
 320         nt_status = authsam_get_user_info_dc_principal(tmp_ctx, lp_ctx, sam_ctx,
 321                                                       principal, user_dn,
 322                                                       &user_info_dc);
 323         if (!NT_STATUS_IS_OK(nt_status)) {
 324                 talloc_free(tmp_ctx);
 325                 return nt_status;
 326         }
 327
 328         nt_status = auth_generate_session_info(tmp_ctx, lp_ctx, sam_ctx,
 329                                                user_info_dc, session_info_flags,
 330                                                session_info);
 331
 332         if (NT_STATUS_IS_OK(nt_status)) {
 333                 talloc_steal(mem_ctx, *session_info);
 334         }
 335         talloc_free(tmp_ctx);
 336         return nt_status;
 337 }
 338
 339 /**
 340  * prints a struct auth_session_info security token to debug output.
 341  */
 342 void auth_session_info_debug(int dbg_lev,
 343                              const struct auth_session_info *session_info)
 344 {
 345         if (!session_info) {
 346                 DEBUG(dbg_lev, ("Session Info: (NULL)\n"));
 347                 return;
 348         }
 349
 350         security_token_debug(0, dbg_lev, session_info->security_token);
 351 }
 352