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 /* Fill out the auth_session_info with a cli_credentials based on the
 160  * auth_session_info we were forwarded over named pipe 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_steal(mem_ctx, session_info_transport->session_info);
 172
 173         if (session_info_transport->exported_gssapi_credentials.length) {
 174                 struct cli_credentials *creds;
 175                 OM_uint32 minor_status;
 176                 gss_buffer_desc cred_token;
 177                 gss_cred_id_t cred_handle;
 178                 const char *error_string;
 179                 int ret;
 180
 181                 DEBUG(10, ("Delegated credentials supplied by client\n"));
 182
 183                 cred_token.value = session_info_transport->exported_gssapi_credentials.data;
 184                 cred_token.length = session_info_transport->exported_gssapi_credentials.length;
 185
 186                 ret = gss_import_cred(&minor_status,
 187                                       &cred_token,
 188                                       &cred_handle);
 189                 if (ret != GSS_S_COMPLETE) {
 190                         *reason = "Internal error in gss_import_cred()";
 191                         return NULL;
 192                 }
 193
 194                 creds = cli_credentials_init(session_info);
 195                 if (!creds) {
 196                         *reason = "Out of memory in cli_credentials_init()";
 197                         return NULL;
 198                 }
 199                 session_info->credentials = creds;
 200
 201                 cli_credentials_set_conf(creds, lp_ctx);
 202                 /* Just so we don't segfault trying to get at a username */
 203                 cli_credentials_set_anonymous(creds);
 204
 205                 ret = cli_credentials_set_client_gss_creds(creds,
 206                                                            lp_ctx,
 207                                                            cred_handle,
 208                                                            CRED_SPECIFIED,
 209                                                            &error_string);
 210                 if (ret) {
 211                         *reason = talloc_asprintf(mem_ctx,
 212                                                   "Failed to set pipe forwarded"
 213                                                   "creds: %s\n", error_string);
 214                         return NULL;
 215                 }
 216
 217                 /* This credential handle isn't useful for password
 218                  * authentication, so ensure nobody tries to do that */
 219                 cli_credentials_set_kerberos_state(creds,
 220                                                    CRED_MUST_USE_KERBEROS);
 221
 222         }
 223
 224         return session_info;
 225 }
 226
 227
 228 /* Create a auth_session_info_transport from an auth_session_info.
 229  *
 230  * NOTE: Members of the auth_session_info_transport structure are
 231  * talloc_referenced() into this structure, and should not be changed.
 232  */
 233 NTSTATUS auth_session_info_transport_from_session(TALLOC_CTX *mem_ctx,
 234                                                   struct auth_session_info *session_info,
 235                                                   struct tevent_context *event_ctx,
 236                                                   struct loadparm_context *lp_ctx,
 237                                                   struct auth_session_info_transport **transport_out)
 238 {
 239
 240         struct auth_session_info_transport *session_info_transport
 241                 = talloc_zero(mem_ctx, struct auth_session_info_transport);
 242         if (!session_info_transport) {
 243                 return NT_STATUS_NO_MEMORY;
 244         };
 245         session_info_transport->session_info = talloc_reference(session_info_transport, session_info);
 246         if (!session_info_transport->session_info) {
 247                 return NT_STATUS_NO_MEMORY;
 248         };
 249
 250         if (session_info->credentials) {
 251                 struct gssapi_creds_container *gcc;
 252                 OM_uint32 gret;
 253                 OM_uint32 minor_status;
 254                 gss_buffer_desc cred_token;
 255                 const char *error_string;
 256                 int ret;
 257
 258                 ret = cli_credentials_get_client_gss_creds(session_info->credentials,
 259                                                            event_ctx,
 260                                                            lp_ctx,
 261                                                            &gcc, &error_string);
 262                 if (ret != 0) {
 263                         *transport_out = session_info_transport;
 264                         return NT_STATUS_OK;
 265                 }
 266
 267                 gret = gss_export_cred(&minor_status,
 268                                        gcc->creds,
 269                                        &cred_token);
 270                 if (gret != GSS_S_COMPLETE) {
 271                         return NT_STATUS_INTERNAL_ERROR;
 272                 }
 273
 274                 if (cred_token.length) {
 275                         session_info_transport->exported_gssapi_credentials
 276                                 = data_blob_talloc(session_info_transport,
 277                                                    cred_token.value,
 278                                                    cred_token.length);
 279                         gss_release_buffer(&minor_status, &cred_token);
 280                         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->exported_gssapi_credentials.data);
 281                 }
 282         }
 283         *transport_out = session_info_transport;
 284         return NT_STATUS_OK;
 285 }
 286
 287
 288 /* Produce a session_info for an arbitary DN or principal in the local
 289  * DB, assuming the local DB holds all the groups
 290  *
 291  * Supply either a principal or a DN
 292  */
 293 NTSTATUS authsam_get_session_info_principal(TALLOC_CTX *mem_ctx,
 294                                             struct loadparm_context *lp_ctx,
 295                                             struct ldb_context *sam_ctx,
 296                                             const char *principal,
 297                                             struct ldb_dn *user_dn,
 298                                             uint32_t session_info_flags,
 299                                             struct auth_session_info **session_info)
 300 {
 301         NTSTATUS nt_status;
 302         struct auth_user_info_dc *user_info_dc;
 303         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 304         if (!tmp_ctx) {
 305                 return NT_STATUS_NO_MEMORY;
 306         }
 307         nt_status = authsam_get_user_info_dc_principal(tmp_ctx, lp_ctx, sam_ctx,
 308                                                       principal, user_dn,
 309                                                       &user_info_dc);
 310         if (!NT_STATUS_IS_OK(nt_status)) {
 311                 talloc_free(tmp_ctx);
 312                 return nt_status;
 313         }
 314
 315         nt_status = auth_generate_session_info(tmp_ctx, lp_ctx, sam_ctx,
 316                                                user_info_dc, session_info_flags,
 317                                                session_info);
 318
 319         if (NT_STATUS_IS_OK(nt_status)) {
 320                 talloc_steal(mem_ctx, *session_info);
 321         }
 322         talloc_free(tmp_ctx);
 323         return nt_status;
 324 }
 325
 326 /**
 327  * prints a struct auth_session_info security token to debug output.
 328  */
 329 void auth_session_info_debug(int dbg_lev,
 330                              const struct auth_session_info *session_info)
 331 {
 332         if (!session_info) {
 333                 DEBUG(dbg_lev, ("Session Info: (NULL)\n"));
 334                 return;
 335         }
 336
 337         security_token_debug(0, dbg_lev, session_info->security_token);
 338 }