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_security_token(TALLOC_CTX *mem_ctx,
  53                                                struct loadparm_context *lp_ctx, /* Optional, if you don't want privileges */
  54                                                struct ldb_context *sam_ctx, /* Optional, if you don't want local groups */
  55                                                const struct auth_user_info_dc *user_info_dc,
  56                                                uint32_t session_info_flags,
  57                                                struct security_token **_security_token)
  58 {
  59         struct security_token *security_token = NULL;
  60         NTSTATUS nt_status;
  61         uint32_t i;
  62         uint32_t num_sids = 0;
  63         const char *filter = NULL;
  64         struct auth_SidAttr *sids = NULL;
  65         const struct dom_sid *anonymous_sid = NULL;
  66         const struct dom_sid *system_sid = NULL;
  67
  68         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  69         if (tmp_ctx == NULL) {
  70                 return NT_STATUS_NO_MEMORY;
  71         }
  72
  73         anonymous_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_ANONYMOUS);
  74         if (anonymous_sid == NULL) {
  75                 TALLOC_FREE(tmp_ctx);
  76                 return NT_STATUS_NO_MEMORY;
  77         }
  78
  79         system_sid = dom_sid_parse_talloc(tmp_ctx, SID_NT_SYSTEM);
  80         if (system_sid == NULL) {
  81                 TALLOC_FREE(tmp_ctx);
  82                 return NT_STATUS_NO_MEMORY;
  83         }
  84
  85         sids = talloc_array(tmp_ctx, struct auth_SidAttr, user_info_dc->num_sids);
  86         if (sids == NULL) {
  87                 TALLOC_FREE(tmp_ctx);
  88                 return NT_STATUS_NO_MEMORY;
  89         }
  90
  91         num_sids = user_info_dc->num_sids;
  92
  93         for (i=0; i < user_info_dc->num_sids; i++) {
  94                 sids[i] = user_info_dc->sids[i];
  95         }
  96
  97         /*
  98          * Finally add the "standard" sids.
  99          * The only difference between guest and "anonymous"
 100          * is the addition of Authenticated_Users.
 101          */
 102
 103         if (session_info_flags & AUTH_SESSION_INFO_DEFAULT_GROUPS) {
 104                 sids = talloc_realloc(tmp_ctx, sids, struct auth_SidAttr, num_sids + 2);
 105                 if (sids == NULL) {
 106                         TALLOC_FREE(tmp_ctx);
 107                         return NT_STATUS_NO_MEMORY;
 108                 }
 109
 110                 sid_copy(&sids[num_sids].sid, &global_sid_World);
 111                 sids[num_sids].attrs = SE_GROUP_DEFAULT_FLAGS;
 112                 num_sids++;
 113
 114                 sid_copy(&sids[num_sids].sid, &global_sid_Network);
 115                 sids[num_sids].attrs = SE_GROUP_DEFAULT_FLAGS;
 116                 num_sids++;
 117         }
 118
 119         if (session_info_flags & AUTH_SESSION_INFO_AUTHENTICATED) {
 120                 sids = talloc_realloc(tmp_ctx, sids, struct auth_SidAttr, num_sids + 1);
 121                 if (sids == NULL) {
 122                         TALLOC_FREE(tmp_ctx);
 123                         return NT_STATUS_NO_MEMORY;
 124                 }
 125
 126                 sid_copy(&sids[num_sids].sid, &global_sid_Authenticated_Users);
 127                 sids[num_sids].attrs = SE_GROUP_DEFAULT_FLAGS;
 128                 num_sids++;
 129         }
 130
 131         if (session_info_flags & AUTH_SESSION_INFO_NTLM) {
 132                 sids = talloc_realloc(tmp_ctx, sids, struct auth_SidAttr, num_sids + 1);
 133                 if (sids == NULL) {
 134                         TALLOC_FREE(tmp_ctx);
 135                         return NT_STATUS_NO_MEMORY;
 136                 }
 137
 138                 if (!dom_sid_parse(SID_NT_NTLM_AUTHENTICATION, &sids[num_sids].sid)) {
 139                         TALLOC_FREE(tmp_ctx);
 140                         return NT_STATUS_INTERNAL_ERROR;
 141                 }
 142                 sids[num_sids].attrs = SE_GROUP_DEFAULT_FLAGS;
 143                 num_sids++;
 144         }
 145
 146
 147         if (num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(anonymous_sid, &sids[PRIMARY_USER_SID_INDEX].sid)) {
 148                 /* Don't expand nested groups of system, anonymous etc*/
 149         } else if (num_sids > PRIMARY_USER_SID_INDEX && dom_sid_equal(system_sid, &sids[PRIMARY_USER_SID_INDEX].sid)) {
 150                 /* Don't expand nested groups of system, anonymous etc*/
 151         } else if (sam_ctx != NULL) {
 152                 filter = talloc_asprintf(tmp_ctx, "(&(objectClass=group)(groupType:"LDB_OID_COMPARATOR_AND":=%u))",
 153                                          GROUP_TYPE_BUILTIN_LOCAL_GROUP);
 154
 155                 /* Search for each group in the token */
 156                 for (i = 0; i < num_sids; i++) {
 157                         struct dom_sid_buf buf;
 158                         const char *sid_dn;
 159                         DATA_BLOB sid_blob;
 160
 161                         sid_dn = talloc_asprintf(
 162                                 tmp_ctx,
 163                                 "<SID=%s>",
 164                                 dom_sid_str_buf(&sids[i].sid, &buf));
 165                         if (sid_dn == NULL) {
 166                                 TALLOC_FREE(tmp_ctx);
 167                                 return NT_STATUS_NO_MEMORY;
 168                         }
 169                         sid_blob = data_blob_string_const(sid_dn);
 170
 171                         /* This function takes in memberOf values and expands
 172                          * them, as long as they meet the filter - so only
 173                          * builtin groups
 174                          *
 175                          * We already have the SID in the token, so set
 176                          * 'only childs' flag to true */
 177                         nt_status = dsdb_expand_nested_groups(sam_ctx, &sid_blob, true, filter,
 178                                                               tmp_ctx, &sids, &num_sids);
 179                         if (!NT_STATUS_IS_OK(nt_status)) {
 180                                 talloc_free(tmp_ctx);
 181                                 return nt_status;
 182                         }
 183                 }
 184         }
 185
 186         nt_status = security_token_create(mem_ctx,
 187                                           lp_ctx,
 188                                           num_sids,
 189                                           sids,
 190                                           session_info_flags,
 191                                           &security_token);
 192         if (!NT_STATUS_IS_OK(nt_status)) {
 193                 TALLOC_FREE(tmp_ctx);
 194                 return nt_status;
 195         }
 196
 197         talloc_steal(mem_ctx, security_token);
 198         *_security_token = security_token;
 199         talloc_free(tmp_ctx);
 200         return NT_STATUS_OK;
 201 }
 202
 203 _PUBLIC_ NTSTATUS auth_generate_session_info(TALLOC_CTX *mem_ctx,
 204                                              struct loadparm_context *lp_ctx, /* Optional, if you don't want privileges */
 205                                              struct ldb_context *sam_ctx, /* Optional, if you don't want local groups */
 206                                              const struct auth_user_info_dc *user_info_dc,
 207                                              uint32_t session_info_flags,
 208                                              struct auth_session_info **_session_info)
 209 {
 210         struct auth_session_info *session_info;
 211         NTSTATUS nt_status;
 212
 213         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 214         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 215
 216         session_info = talloc_zero(tmp_ctx, struct auth_session_info);
 217         if (session_info == NULL) {
 218                 TALLOC_FREE(tmp_ctx);
 219                 return NT_STATUS_NO_MEMORY;
 220         }
 221
 222         session_info->info = talloc_reference(session_info, user_info_dc->info);
 223
 224         session_info->torture = talloc_zero(session_info, struct auth_user_info_torture);
 225         if (session_info->torture == NULL) {
 226                 TALLOC_FREE(tmp_ctx);
 227                 return NT_STATUS_NO_MEMORY;
 228         }
 229         session_info->torture->num_dc_sids = user_info_dc->num_sids;
 230         session_info->torture->dc_sids = talloc_reference(session_info, user_info_dc->sids);
 231         if (session_info->torture->dc_sids == NULL) {
 232                 TALLOC_FREE(tmp_ctx);
 233                 return NT_STATUS_NO_MEMORY;
 234         }
 235
 236         /* unless set otherwise, the session key is the user session
 237          * key from the auth subsystem */
 238         session_info->session_key = data_blob_talloc(session_info, user_info_dc->user_session_key.data, user_info_dc->user_session_key.length);
 239         if (!session_info->session_key.data && session_info->session_key.length) {
 240                 if (session_info->session_key.data == NULL) {
 241                         TALLOC_FREE(tmp_ctx);
 242                         return NT_STATUS_NO_MEMORY;
 243                 }
 244         }
 245
 246         nt_status = auth_generate_security_token(session_info,
 247                                                  lp_ctx,
 248                                                  sam_ctx,
 249                                                  user_info_dc,
 250                                                  session_info_flags,
 251                                                  &session_info->security_token);
 252         if (!NT_STATUS_IS_OK(nt_status)) {
 253                 TALLOC_FREE(tmp_ctx);
 254                 return nt_status;
 255         }
 256
 257         session_info->unique_session_token = GUID_random();
 258
 259         session_info->credentials = NULL;
 260
 261         session_info->ticket_type = user_info_dc->ticket_type;
 262
 263         talloc_steal(mem_ctx, session_info);
 264         *_session_info = session_info;
 265         talloc_free(tmp_ctx);
 266         return NT_STATUS_OK;
 267 }
 268
 269
 270 /* Fill out the auth_session_info with a cli_credentials based on the
 271  * auth_session_info we were forwarded over named pipe forwarding.
 272  *
 273  * NOTE: The stucture members of session_info_transport are stolen
 274  * with talloc_move() into auth_session_info for long term use
 275  */
 276 struct auth_session_info *auth_session_info_from_transport(TALLOC_CTX *mem_ctx,
 277                                                            struct auth_session_info_transport *session_info_transport,
 278                                                            struct loadparm_context *lp_ctx,
 279                                                            const char **reason)
 280 {
 281         struct auth_session_info *session_info;
 282         session_info = talloc_steal(mem_ctx, session_info_transport->session_info);
 283         /*
 284          * This is to allow us to check the type of this pointer using
 285          * talloc_get_type()
 286          */
 287         talloc_set_name(session_info, "struct auth_session_info");
 288 #ifdef HAVE_GSS_IMPORT_CRED
 289         if (session_info_transport->exported_gssapi_credentials.length) {
 290                 struct cli_credentials *creds;
 291                 OM_uint32 minor_status;
 292                 gss_buffer_desc cred_token;
 293                 gss_cred_id_t cred_handle;
 294                 const char *error_string;
 295                 int ret;
 296                 bool ok;
 297
 298                 DEBUG(10, ("Delegated credentials supplied by client\n"));
 299
 300                 cred_token.value = session_info_transport->exported_gssapi_credentials.data;
 301                 cred_token.length = session_info_transport->exported_gssapi_credentials.length;
 302
 303                 ret = gss_import_cred(&minor_status,
 304                                       &cred_token,
 305                                       &cred_handle);
 306                 if (ret != GSS_S_COMPLETE) {
 307                         *reason = "Internal error in gss_import_cred()";
 308                         return NULL;
 309                 }
 310
 311                 creds = cli_credentials_init(session_info);
 312                 if (!creds) {
 313                         *reason = "Out of memory in cli_credentials_init()";
 314                         return NULL;
 315                 }
 316                 session_info->credentials = creds;
 317
 318                 ok = cli_credentials_set_conf(creds, lp_ctx);
 319                 if (!ok) {
 320                         *reason = "Failed to load smb.conf";
 321                         return NULL;
 322                 }
 323
 324                 /* Just so we don't segfault trying to get at a username */
 325                 cli_credentials_set_anonymous(creds);
 326
 327                 ret = cli_credentials_set_client_gss_creds(creds,
 328                                                            lp_ctx,
 329                                                            cred_handle,
 330                                                            CRED_SPECIFIED,
 331                                                            &error_string);
 332                 if (ret) {
 333                         *reason = talloc_asprintf(mem_ctx,
 334                                                   "Failed to set pipe forwarded"
 335                                                   "creds: %s\n", error_string);
 336                         return NULL;
 337                 }
 338
 339                 /* This credential handle isn't useful for password
 340                  * authentication, so ensure nobody tries to do that */
 341                 cli_credentials_set_kerberos_state(creds,
 342                                                    CRED_USE_KERBEROS_REQUIRED,
 343                                                    CRED_SPECIFIED);
 344
 345         }
 346 #endif
 347         return session_info;
 348 }
 349
 350
 351 /* Create a auth_session_info_transport from an auth_session_info.
 352  *
 353  * NOTE: Members of the auth_session_info_transport structure are
 354  * talloc_referenced() into this structure, and should not be changed.
 355  */
 356 NTSTATUS auth_session_info_transport_from_session(TALLOC_CTX *mem_ctx,
 357                                                   struct auth_session_info *session_info,
 358                                                   struct tevent_context *event_ctx,
 359                                                   struct loadparm_context *lp_ctx,
 360                                                   struct auth_session_info_transport **transport_out)
 361 {
 362
 363         struct auth_session_info_transport *session_info_transport
 364                 = talloc_zero(mem_ctx, struct auth_session_info_transport);
 365         if (!session_info_transport) {
 366                 return NT_STATUS_NO_MEMORY;
 367         };
 368         session_info_transport->session_info = talloc_reference(session_info_transport, session_info);
 369         if (!session_info_transport->session_info) {
 370                 return NT_STATUS_NO_MEMORY;
 371         };
 372 #ifdef HAVE_GSS_EXPORT_CRED
 373         if (session_info->credentials) {
 374                 struct gssapi_creds_container *gcc;
 375                 OM_uint32 gret;
 376                 OM_uint32 minor_status;
 377                 gss_buffer_desc cred_token;
 378                 const char *error_string;
 379                 int ret;
 380
 381                 ret = cli_credentials_get_client_gss_creds(session_info->credentials,
 382                                                            event_ctx,
 383                                                            lp_ctx,
 384                                                            &gcc, &error_string);
 385                 if (ret != 0) {
 386                         *transport_out = session_info_transport;
 387                         return NT_STATUS_OK;
 388                 }
 389
 390                 gret = gss_export_cred(&minor_status,
 391                                        gcc->creds,
 392                                        &cred_token);
 393                 if (gret != GSS_S_COMPLETE) {
 394                         return NT_STATUS_INTERNAL_ERROR;
 395                 }
 396
 397                 if (cred_token.length) {
 398                         session_info_transport->exported_gssapi_credentials
 399                                 = data_blob_talloc(session_info_transport,
 400                                                    cred_token.value,
 401                                                    cred_token.length);
 402                         gss_release_buffer(&minor_status, &cred_token);
 403                         NT_STATUS_HAVE_NO_MEMORY(session_info_transport->exported_gssapi_credentials.data);
 404                 }
 405         }
 406 #endif
 407         *transport_out = session_info_transport;
 408         return NT_STATUS_OK;
 409 }
 410
 411
 412 /* Produce a session_info for an arbitary DN or principal in the local
 413  * DB, assuming the local DB holds all the groups
 414  *
 415  * Supply either a principal or a DN
 416  */
 417 NTSTATUS authsam_get_session_info_principal(TALLOC_CTX *mem_ctx,
 418                                             struct loadparm_context *lp_ctx,
 419                                             struct ldb_context *sam_ctx,
 420                                             const char *principal,
 421                                             struct ldb_dn *user_dn,
 422                                             uint32_t session_info_flags,
 423                                             struct auth_session_info **session_info)
 424 {
 425         NTSTATUS nt_status;
 426         struct auth_user_info_dc *user_info_dc;
 427         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 428         if (!tmp_ctx) {
 429                 return NT_STATUS_NO_MEMORY;
 430         }
 431         nt_status = authsam_get_user_info_dc_principal(tmp_ctx, lp_ctx, sam_ctx,
 432                                                       principal, user_dn,
 433                                                       &user_info_dc);
 434         if (!NT_STATUS_IS_OK(nt_status)) {
 435                 talloc_free(tmp_ctx);
 436                 return nt_status;
 437         }
 438
 439         nt_status = auth_generate_session_info(tmp_ctx, lp_ctx, sam_ctx,
 440                                                user_info_dc, session_info_flags,
 441                                                session_info);
 442
 443         if (NT_STATUS_IS_OK(nt_status)) {
 444                 talloc_steal(mem_ctx, *session_info);
 445         }
 446         talloc_free(tmp_ctx);
 447         return nt_status;
 448 }
 449
 450 /**
 451  * prints a struct auth_session_info security token to debug output.
 452  */
 453 void auth_session_info_debug(int dbg_lev,
 454                              const struct auth_session_info *session_info)
 455 {
 456         if (!session_info) {
 457                 DEBUG(dbg_lev, ("Session Info: (NULL)\n"));
 458                 return;
 459         }
 460
 461         security_token_debug(DBGC_AUTH, dbg_lev,
 462                              session_info->security_token);
 463 }