Line data    Source code

       1             : /*
       2             :    Unix SMB/CIFS implementation.
       3             :    Password and authentication handling
       4             :    Copyright (C) Jeremy Allison                 1996-2002
       5             :    Copyright (C) Andrew Tridgell                2002
       6             :    Copyright (C) Gerald (Jerry) Carter          2000
       7             :    Copyright (C) Stefan (metze) Metzmacher      2002
       8             : 
       9             :    This program is free software; you can redistribute it and/or modify
      10             :    it under the terms of the GNU General Public License as published by
      11             :    the Free Software Foundation; either version 3 of the License, or
      12             :    (at your option) any later version.
      13             : 
      14             :    This program is distributed in the hope that it will be useful,
      15             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      16             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      17             :    GNU General Public License for more details.
      18             : 
      19             :    You should have received a copy of the GNU General Public License
      20             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      21             : */
      22             : 
      23             : #include "includes.h"
      24             : #include "passdb/machine_sid.h"
      25             : #include "secrets.h"
      26             : #include "dbwrap/dbwrap.h"
      27             : #include "../libcli/security/security.h"
      28             : 
      29             : /* NOTE! the global_sam_sid is the SID of our local SAM. This is only
      30             :    equal to the domain SID when we are a DC, otherwise its our
      31             :    workstation SID */
      32             : static struct dom_sid *global_sam_sid=NULL;
      33             : 
      34             : #undef DBGC_CLASS
      35             : #define DBGC_CLASS DBGC_PASSDB
      36             : 
      37             : /****************************************************************************
      38             :  Read a SID from a file. This is for compatibility with the old MACHINE.SID
      39             :  style of SID storage
      40             : ****************************************************************************/
      41             : 
      42          20 : static bool read_sid_from_file(const char *fname, struct dom_sid *sid)
      43             : {
      44          20 :         char *line = NULL;
      45           2 :         size_t n;
      46           2 :         ssize_t len;
      47          20 :         bool ret = false;
      48          20 :         FILE *f = NULL;
      49             : 
      50          20 :         f = fopen(fname, "r");
      51          20 :         if (f == NULL) {
      52          18 :                 return false;
      53             :         }
      54             : 
      55           0 :         len = getline(&line, &n, f);
      56           0 :         if (len >= 0) {
      57           0 :                 ret = string_to_sid(sid, line);
      58           0 :                 SAFE_FREE(line);
      59             :         }
      60             : 
      61           0 :         fclose(f);
      62           0 :         return ret;
      63             : }
      64             : 
      65             : /*
      66             :   generate a random sid - used to build our own sid if we don't have one
      67             : */
      68          20 : static void generate_random_sid(struct dom_sid *sid)
      69             : {
      70           2 :         int i;
      71           2 :         uchar raw_sid_data[12];
      72             : 
      73          20 :         *sid = (struct dom_sid) {
      74             :                 .sid_rev_num = 1,
      75             :                 .id_auth[5] = 5,
      76             :         };
      77             : 
      78          20 :         sid->sub_auths[sid->num_auths++] = 21;
      79             : 
      80          20 :         generate_random_buffer(raw_sid_data, 12);
      81          82 :         for (i = 0; i < 3; i++)
      82          60 :                 sid->sub_auths[sid->num_auths++] = IVAL(raw_sid_data, i*4);
      83          20 : }
      84             : 
      85             : /****************************************************************************
      86             :  Generate the global machine sid.
      87             : ****************************************************************************/
      88             : 
      89        1681 : static struct dom_sid *pdb_generate_sam_sid(void)
      90             : {
      91          17 :         struct dom_sid domain_sid;
      92        1681 :         char *fname = NULL;
      93          17 :         struct dom_sid *sam_sid;
      94             : 
      95        1681 :         if(!(sam_sid=SMB_MALLOC_P(struct dom_sid)))
      96           0 :                 return NULL;
      97             : 
      98        1681 :         if ( IS_DC ) {
      99         812 :                 if (secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
     100         797 :                         sid_copy(sam_sid, &domain_sid);
     101         797 :                         return sam_sid;
     102             :                 }
     103             :         }
     104             : 
     105         884 :         if (secrets_fetch_domain_sid(lp_netbios_name(), sam_sid)) {
     106             : 
     107             :                 /* We got our sid. If not a pdc/bdc, we're done. */
     108         864 :                 if ( !IS_DC )
     109         847 :                         return sam_sid;
     110             : 
     111          15 :                 if (!secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
     112             : 
     113             :                         /* No domain sid and we're a pdc/bdc. Store it */
     114             : 
     115          15 :                         if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
     116           0 :                                 DEBUG(0,("pdb_generate_sam_sid: Can't store domain SID as a pdc/bdc.\n"));
     117           0 :                                 SAFE_FREE(sam_sid);
     118           0 :                                 return NULL;
     119             :                         }
     120          14 :                         return sam_sid;
     121             :                 }
     122             : 
     123           0 :                 if (!dom_sid_equal(&domain_sid, sam_sid)) {
     124             : 
     125             :                         /* Domain name sid doesn't match global sam sid. Re-store domain sid as 'local' sid. */
     126             : 
     127           0 :                         DEBUG(0,("pdb_generate_sam_sid: Mismatched SIDs as a pdc/bdc.\n"));
     128           0 :                         if (!secrets_store_domain_sid(lp_netbios_name(), &domain_sid)) {
     129           0 :                                 DEBUG(0,("pdb_generate_sam_sid: Can't re-store domain SID for local sid as PDC/BDC.\n"));
     130           0 :                                 SAFE_FREE(sam_sid);
     131           0 :                                 return NULL;
     132             :                         }
     133           0 :                         return sam_sid;
     134             :                 }
     135             : 
     136           0 :                 return sam_sid;
     137             :         }
     138             : 
     139             :         /* check for an old MACHINE.SID file for backwards compatibility */
     140          20 :         if (asprintf(&fname, "%s/MACHINE.SID", lp_private_dir()) == -1) {
     141           0 :                 SAFE_FREE(sam_sid);
     142           0 :                 return NULL;
     143             :         }
     144             : 
     145          20 :         if (read_sid_from_file(fname, sam_sid)) {
     146             :                 /* remember it for future reference and unlink the old MACHINE.SID */
     147           0 :                 if (!secrets_store_domain_sid(lp_netbios_name(), sam_sid)) {
     148           0 :                         DEBUG(0,("pdb_generate_sam_sid: Failed to store SID from file.\n"));
     149           0 :                         SAFE_FREE(fname);
     150           0 :                         SAFE_FREE(sam_sid);
     151           0 :                         return NULL;
     152             :                 }
     153           0 :                 unlink(fname);
     154           0 :                 if ( !IS_DC ) {
     155           0 :                         if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
     156           0 :                                 DEBUG(0,("pdb_generate_sam_sid: Failed to store domain SID from file.\n"));
     157           0 :                                 SAFE_FREE(fname);
     158           0 :                                 SAFE_FREE(sam_sid);
     159           0 :                                 return NULL;
     160             :                         }
     161             :                 }
     162             : 
     163             :                 /* Stored the old sid from MACHINE.SID successfully.*/
     164           0 :                 SAFE_FREE(fname);
     165           0 :                 return sam_sid;
     166             :         }
     167             : 
     168          20 :         SAFE_FREE(fname);
     169             : 
     170             :         /* we don't have the SID in secrets.tdb, we will need to
     171             :            generate one and save it */
     172          20 :         generate_random_sid(sam_sid);
     173             : 
     174          20 :         if (!secrets_store_domain_sid(lp_netbios_name(), sam_sid)) {
     175           0 :                 DEBUG(0,("pdb_generate_sam_sid: Failed to store generated machine SID.\n"));
     176           0 :                 SAFE_FREE(sam_sid);
     177           0 :                 return NULL;
     178             :         }
     179          20 :         if ( IS_DC ) {
     180           0 :                 if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
     181           0 :                         DEBUG(0,("pdb_generate_sam_sid: Failed to store generated domain SID.\n"));
     182           0 :                         SAFE_FREE(sam_sid);
     183           0 :                         return NULL;
     184             :                 }
     185             :         }
     186             : 
     187          18 :         return sam_sid;
     188             : }
     189             : 
     190             : /* return our global_sam_sid */
     191      691434 : struct dom_sid *get_global_sam_sid(void)
     192             : {
     193        1536 :         struct db_context *db;
     194             : 
     195      691434 :         if (global_sam_sid != NULL)
     196      688234 :                 return global_sam_sid;
     197             : 
     198             :         /*
     199             :          * memory for global_sam_sid is allocated in
     200             :          * pdb_generate_sam_sid() as needed
     201             :          *
     202             :          * Note: this is guarded by a transaction
     203             :          *       to prevent races on startup which
     204             :          *       can happen with some dbwrap backends
     205             :          */
     206             : 
     207        1681 :         db = secrets_db_ctx();
     208        1681 :         if (!db) {
     209           0 :                 smb_panic("could not open secrets db");
     210             :         }
     211             : 
     212        1681 :         if (dbwrap_transaction_start(db) != 0) {
     213           0 :                 smb_panic("could not start transaction on secrets db");
     214             :         }
     215             : 
     216        1681 :         if (!(global_sam_sid = pdb_generate_sam_sid())) {
     217           0 :                 dbwrap_transaction_cancel(db);
     218           0 :                 smb_panic("could not generate a machine SID");
     219             :         }
     220             : 
     221        1681 :         if (dbwrap_transaction_commit(db) != 0) {
     222           0 :                 smb_panic("could not start commit secrets db");
     223             :         }
     224             : 
     225        1681 :         return global_sam_sid;
     226             : }
     227             : 
     228             : /**
     229             :  * Force get_global_sam_sid to requery the backends
     230             :  */
     231         487 : void reset_global_sam_sid(void) 
     232             : {
     233         487 :         SAFE_FREE(global_sam_sid);
     234         487 : }
     235             : 
     236             : /*****************************************************************
     237             :  Check if the SID is our sam SID (S-1-5-21-x-y-z).
     238             : *****************************************************************/
     239             : 
     240      203315 : bool sid_check_is_our_sam(const struct dom_sid *sid)
     241             : {
     242      203315 :         return dom_sid_equal(sid, get_global_sam_sid());
     243             : }
     244             : 
     245             : /*****************************************************************
     246             :  Check if the SID is our domain SID (S-1-5-21-x-y-z).
     247             : *****************************************************************/
     248             : 
     249      129510 : bool sid_check_is_in_our_sam(const struct dom_sid *sid)
     250             : {
     251         325 :         struct dom_sid dom_sid;
     252             : 
     253      129510 :         sid_copy(&dom_sid, sid);
     254      129510 :         sid_split_rid(&dom_sid, NULL);
     255      129510 :         return sid_check_is_our_sam(&dom_sid);
     256             : }