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