source3/passdb/machine_sid.c

   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 "secrets.h"
  25 #include "dbwrap.h"
  26
  27 /* NOTE! the global_sam_sid is the SID of our local SAM. This is only
  28    equal to the domain SID when we are a DC, otherwise its our
  29    workstation SID */
  30 static struct dom_sid *global_sam_sid=NULL;
  31
  32 #undef DBGC_CLASS
  33 #define DBGC_CLASS DBGC_PASSDB
  34
  35 /****************************************************************************
  36  Read a SID from a file. This is for compatibility with the old MACHINE.SID
  37  style of SID storage
  38 ****************************************************************************/
  39
  40 static bool read_sid_from_file(const char *fname, struct dom_sid *sid)
  41 {
  42         char **lines;
  43         int numlines;
  44         bool ret;
  45
  46         lines = file_lines_load(fname, &numlines,0, NULL);
  47
  48         if (!lines || numlines < 1) {
  49                 TALLOC_FREE(lines);
  50                 return False;
  51         }
  52
  53         ret = string_to_sid(sid, lines[0]);
  54         TALLOC_FREE(lines);
  55         return ret;
  56 }
  57
  58 /*
  59   generate a random sid - used to build our own sid if we don't have one
  60 */
  61 static void generate_random_sid(struct dom_sid *sid)
  62 {
  63         int i;
  64         uchar raw_sid_data[12];
  65
  66         ZERO_STRUCTP(sid);
  67
  68         sid->sid_rev_num = 1;
  69         sid->id_auth[5] = 5;
  70         sid->num_auths = 0;
  71         sid->sub_auths[sid->num_auths++] = 21;
  72
  73         generate_random_buffer(raw_sid_data, 12);
  74         for (i = 0; i < 3; i++)
  75                 sid->sub_auths[sid->num_auths++] = IVAL(raw_sid_data, i*4);
  76 }
  77
  78 /****************************************************************************
  79  Generate the global machine sid.
  80 ****************************************************************************/
  81
  82 static struct dom_sid *pdb_generate_sam_sid(void)
  83 {
  84         struct dom_sid domain_sid;
  85         char *fname = NULL;
  86         struct dom_sid *sam_sid;
  87
  88         if(!(sam_sid=SMB_MALLOC_P(struct dom_sid)))
  89                 return NULL;
  90
  91         if ( IS_DC ) {
  92                 if (secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
  93                         sid_copy(sam_sid, &domain_sid);
  94                         return sam_sid;
  95                 }
  96         }
  97
  98         if (secrets_fetch_domain_sid(global_myname(), sam_sid)) {
  99
 100                 /* We got our sid. If not a pdc/bdc, we're done. */
 101                 if ( !IS_DC )
 102                         return sam_sid;
 103
 104                 if (!secrets_fetch_domain_sid(lp_workgroup(), &domain_sid)) {
 105
 106                         /* No domain sid and we're a pdc/bdc. Store it */
 107
 108                         if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
 109                                 DEBUG(0,("pdb_generate_sam_sid: Can't store domain SID as a pdc/bdc.\n"));
 110                                 SAFE_FREE(sam_sid);
 111                                 return NULL;
 112                         }
 113                         return sam_sid;
 114                 }
 115
 116                 if (!sid_equal(&domain_sid, sam_sid)) {
 117
 118                         /* Domain name sid doesn't match global sam sid. Re-store domain sid as 'local' sid. */
 119
 120                         DEBUG(0,("pdb_generate_sam_sid: Mismatched SIDs as a pdc/bdc.\n"));
 121                         if (!secrets_store_domain_sid(global_myname(), &domain_sid)) {
 122                                 DEBUG(0,("pdb_generate_sam_sid: Can't re-store domain SID for local sid as PDC/BDC.\n"));
 123                                 SAFE_FREE(sam_sid);
 124                                 return NULL;
 125                         }
 126                         return sam_sid;
 127                 }
 128
 129                 return sam_sid;
 130         }
 131
 132         /* check for an old MACHINE.SID file for backwards compatibility */
 133         if (asprintf(&fname, "%s/MACHINE.SID", lp_private_dir()) == -1) {
 134                 SAFE_FREE(sam_sid);
 135                 return NULL;
 136         }
 137
 138         if (read_sid_from_file(fname, sam_sid)) {
 139                 /* remember it for future reference and unlink the old MACHINE.SID */
 140                 if (!secrets_store_domain_sid(global_myname(), sam_sid)) {
 141                         DEBUG(0,("pdb_generate_sam_sid: Failed to store SID from file.\n"));
 142                         SAFE_FREE(fname);
 143                         SAFE_FREE(sam_sid);
 144                         return NULL;
 145                 }
 146                 unlink(fname);
 147                 if ( !IS_DC ) {
 148                         if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
 149                                 DEBUG(0,("pdb_generate_sam_sid: Failed to store domain SID from file.\n"));
 150                                 SAFE_FREE(fname);
 151                                 SAFE_FREE(sam_sid);
 152                                 return NULL;
 153                         }
 154                 }
 155
 156                 /* Stored the old sid from MACHINE.SID successfully.*/
 157                 SAFE_FREE(fname);
 158                 return sam_sid;
 159         }
 160
 161         SAFE_FREE(fname);
 162
 163         /* we don't have the SID in secrets.tdb, we will need to
 164            generate one and save it */
 165         generate_random_sid(sam_sid);
 166
 167         if (!secrets_store_domain_sid(global_myname(), sam_sid)) {
 168                 DEBUG(0,("pdb_generate_sam_sid: Failed to store generated machine SID.\n"));
 169                 SAFE_FREE(sam_sid);
 170                 return NULL;
 171         }
 172         if ( IS_DC ) {
 173                 if (!secrets_store_domain_sid(lp_workgroup(), sam_sid)) {
 174                         DEBUG(0,("pdb_generate_sam_sid: Failed to store generated domain SID.\n"));
 175                         SAFE_FREE(sam_sid);
 176                         return NULL;
 177                 }
 178         }
 179
 180         return sam_sid;
 181 }
 182
 183 /* return our global_sam_sid */
 184 struct dom_sid *get_global_sam_sid(void)
 185 {
 186         struct db_context *db;
 187
 188         if (global_sam_sid != NULL)
 189                 return global_sam_sid;
 190
 191         /*
 192          * memory for global_sam_sid is allocated in
 193          * pdb_generate_sam_sid() as needed
 194          *
 195          * Note: this is garded by a transaction
 196          *       to prevent races on startup which
 197          *       can happen with some dbwrap backends
 198          */
 199
 200         db = secrets_db_ctx();
 201         if (!db) {
 202                 smb_panic("could not open secrets db");
 203         }
 204
 205         if (db->transaction_start(db) != 0) {
 206                 smb_panic("could not start transaction on secrets db");
 207         }
 208
 209         if (!(global_sam_sid = pdb_generate_sam_sid())) {
 210                 db->transaction_cancel(db);
 211                 smb_panic("could not generate a machine SID");
 212         }
 213
 214         if (db->transaction_commit(db) != 0) {
 215                 smb_panic("could not start commit secrets db");
 216         }
 217
 218         return global_sam_sid;
 219 }
 220
 221 /**
 222  * Force get_global_sam_sid to requery the backends
 223  */
 224 void reset_global_sam_sid(void)
 225 {
 226         SAFE_FREE(global_sam_sid);
 227 }
 228
 229 /*****************************************************************
 230  Check if the SID is our domain SID (S-1-5-21-x-y-z).
 231 *****************************************************************/
 232
 233 bool sid_check_is_domain(const struct dom_sid *sid)
 234 {
 235         return sid_equal(sid, get_global_sam_sid());
 236 }
 237
 238 /*****************************************************************
 239  Check if the SID is our domain SID (S-1-5-21-x-y-z).
 240 *****************************************************************/
 241
 242 bool sid_check_is_in_our_domain(const struct dom_sid *sid)
 243 {
 244         struct dom_sid dom_sid;
 245         uint32 rid;
 246
 247         sid_copy(&dom_sid, sid);
 248         sid_split_rid(&dom_sid, &rid);
 249         return sid_check_is_domain(&dom_sid);
 250 }