source/lib/util_sid.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright (C) Andrew Tridgell                1992-1998
   5    Copyright (C) Luke Kenneth Caseson Leighton  1998-1999
   6    Copyright (C) Jeremy Allison                 1999
   7    Copyright (C) Stefan (metze) Metzmacher      2002
   8    Copyright (C) Simo Sorce                     2002
   9    Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2005
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 */
  25
  26 #include "includes.h"
  27
  28 /*
  29  * Some useful sids
  30  */
  31
  32
  33 const DOM_SID global_sid_World_Domain =               /* Everyone domain */
  34 { 1, 0, {0,0,0,0,0,1}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  35 const DOM_SID global_sid_World =                      /* Everyone */
  36 { 1, 1, {0,0,0,0,0,1}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  37 const DOM_SID global_sid_Creator_Owner_Domain =       /* Creator Owner domain */
  38 { 1, 0, {0,0,0,0,0,3}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  39 const DOM_SID global_sid_NT_Authority =                 /* NT Authority */
  40 { 1, 0, {0,0,0,0,0,5}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  41 const DOM_SID global_sid_System =                       /* System */
  42 { 1, 1, {0,0,0,0,0,5}, {18,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  43 const DOM_SID global_sid_NULL =                         /* NULL sid */
  44 { 1, 1, {0,0,0,0,0,0}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  45 const DOM_SID global_sid_Authenticated_Users =  /* All authenticated rids */
  46 { 1, 1, {0,0,0,0,0,5}, {11,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  47 const DOM_SID global_sid_Network =                      /* Network rids */
  48 { 1, 1, {0,0,0,0,0,5}, {2,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  49
  50 const DOM_SID global_sid_Creator_Owner =                /* Creator Owner */
  51 { 1, 1, {0,0,0,0,0,3}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  52 const DOM_SID global_sid_Creator_Group =                /* Creator Group */
  53 { 1, 1, {0,0,0,0,0,3}, {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  54 const DOM_SID global_sid_Anonymous =                    /* Anonymous login */
  55 { 1, 1, {0,0,0,0,0,5}, {7,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  56
  57 const DOM_SID global_sid_Builtin =                      /* Local well-known domain */
  58 { 1, 1, {0,0,0,0,0,5}, {32,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  59 const DOM_SID global_sid_Builtin_Administrators =       /* Builtin administrators */
  60 { 1, 2, {0,0,0,0,0,5}, {32,544,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  61 const DOM_SID global_sid_Builtin_Users =                /* Builtin users */
  62 { 1, 2, {0,0,0,0,0,5}, {32,545,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  63 const DOM_SID global_sid_Builtin_Guests =               /* Builtin guest users */
  64 { 1, 2, {0,0,0,0,0,5}, {32,546,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  65 const DOM_SID global_sid_Builtin_Power_Users =  /* Builtin power users */
  66 { 1, 2, {0,0,0,0,0,5}, {32,547,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  67 const DOM_SID global_sid_Builtin_Account_Operators =    /* Builtin account operators */
  68 { 1, 2, {0,0,0,0,0,5}, {32,548,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  69 const DOM_SID global_sid_Builtin_Server_Operators =     /* Builtin server operators */
  70 { 1, 2, {0,0,0,0,0,5}, {32,549,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  71 const DOM_SID global_sid_Builtin_Print_Operators =      /* Builtin print operators */
  72 { 1, 2, {0,0,0,0,0,5}, {32,550,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  73 const DOM_SID global_sid_Builtin_Backup_Operators =     /* Builtin backup operators */
  74 { 1, 2, {0,0,0,0,0,5}, {32,551,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  75 const DOM_SID global_sid_Builtin_Replicator =           /* Builtin replicator */
  76 { 1, 2, {0,0,0,0,0,5}, {32,552,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  77
  78 const DOM_SID global_sid_Unix_Users =                   /* Unmapped Unix users */
  79 { 1, 1, {0,0,0,0,0,22}, {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  80 const DOM_SID global_sid_Unix_Groups =                  /* Unmapped Unix groups */
  81 { 1, 1, {0,0,0,0,0,22}, {2,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
  82
  83 /* Unused, left here for documentary purposes */
  84 #if 0
  85 #define SECURITY_NULL_SID_AUTHORITY    0
  86 #define SECURITY_WORLD_SID_AUTHORITY   1
  87 #define SECURITY_LOCAL_SID_AUTHORITY   2
  88 #define SECURITY_CREATOR_SID_AUTHORITY 3
  89 #define SECURITY_NT_AUTHORITY          5
  90 #endif
  91
  92 /*
  93  * An NT compatible anonymous token.
  94  */
  95
  96 static DOM_SID anon_sid_array[3] =
  97 { { 1, 1, {0,0,0,0,0,1}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}},
  98   { 1, 1, {0,0,0,0,0,5}, {2,0,0,0,0,0,0,0,0,0,0,0,0,0,0}},
  99   { 1, 1, {0,0,0,0,0,5}, {7,0,0,0,0,0,0,0,0,0,0,0,0,0,0}} };
 100 NT_USER_TOKEN anonymous_token = { 3, anon_sid_array, SE_NONE };
 101
 102 static DOM_SID system_sid_array[1] =
 103 { { 1, 1, {0,0,0,0,0,5}, {18,0,0,0,0,0,0,0,0,0,0,0,0,0,0}} };
 104 NT_USER_TOKEN system_token = { 1, system_sid_array, SE_ALL_PRIVS };
 105
 106 /****************************************************************************
 107  Lookup string names for SID types.
 108 ****************************************************************************/
 109
 110 static const struct {
 111         enum SID_NAME_USE sid_type;
 112         const char *string;
 113 } sid_name_type[] = {
 114         {SID_NAME_USER, "User"},
 115         {SID_NAME_DOM_GRP, "Domain Group"},
 116         {SID_NAME_DOMAIN, "Domain"},
 117         {SID_NAME_ALIAS, "Local Group"},
 118         {SID_NAME_WKN_GRP, "Well-known Group"},
 119         {SID_NAME_DELETED, "Deleted Account"},
 120         {SID_NAME_INVALID, "Invalid Account"},
 121         {SID_NAME_UNKNOWN, "UNKNOWN"},
 122         {SID_NAME_COMPUTER, "Computer"},
 123
 124         {(enum SID_NAME_USE)0, NULL}
 125 };
 126
 127 const char *sid_type_lookup(uint32 sid_type)
 128 {
 129         int i = 0;
 130
 131         /* Look through list */
 132         while(sid_name_type[i].sid_type != 0) {
 133                 if (sid_name_type[i].sid_type == sid_type)
 134                         return sid_name_type[i].string;
 135                 i++;
 136         }
 137
 138         /* Default return */
 139         return "SID *TYPE* is INVALID";
 140 }
 141
 142 /**************************************************************************
 143  Create the SYSTEM token.
 144 ***************************************************************************/
 145
 146 NT_USER_TOKEN *get_system_token(void)
 147 {
 148         return &system_token;
 149 }
 150
 151 /******************************************************************
 152  get the default domain/netbios name to be used when dealing
 153  with our passdb list of accounts
 154 ******************************************************************/
 155
 156 const char *get_global_sam_name(void)
 157 {
 158         if ((lp_server_role() == ROLE_DOMAIN_PDC) || (lp_server_role() == ROLE_DOMAIN_BDC)) {
 159                 return lp_workgroup();
 160         }
 161         return global_myname();
 162 }
 163
 164 /*****************************************************************
 165  Convert a SID to an ascii string.
 166 *****************************************************************/
 167
 168 char *sid_to_string(fstring sidstr_out, const DOM_SID *sid)
 169 {
 170         char subauth[16];
 171         int i;
 172         uint32 ia;
 173
 174         if (!sid) {
 175                 fstrcpy(sidstr_out, "(NULL SID)");
 176                 return sidstr_out;
 177         }
 178
 179         /*
 180          * BIG NOTE: this function only does SIDS where the identauth is not >= 2^32
 181          * in a range of 2^48.
 182          */
 183         ia = (sid->id_auth[5]) +
 184                 (sid->id_auth[4] << 8 ) +
 185                 (sid->id_auth[3] << 16) +
 186                 (sid->id_auth[2] << 24);
 187
 188         slprintf(sidstr_out, sizeof(fstring) - 1, "S-%u-%lu", (unsigned int)sid->sid_rev_num, (unsigned long)ia);
 189
 190         for (i = 0; i < sid->num_auths; i++) {
 191                 slprintf(subauth, sizeof(subauth)-1, "-%lu", (unsigned long)sid->sub_auths[i]);
 192                 fstrcat(sidstr_out, subauth);
 193         }
 194
 195         return sidstr_out;
 196 }
 197
 198 /*****************************************************************
 199  Useful function for debug lines.
 200 *****************************************************************/
 201
 202 const char *sid_string_static(const DOM_SID *sid)
 203 {
 204         static fstring sid_str;
 205         sid_to_string(sid_str, sid);
 206         return sid_str;
 207 }
 208
 209 /*****************************************************************
 210  Convert a string to a SID. Returns True on success, False on fail.
 211 *****************************************************************/
 212
 213 BOOL string_to_sid(DOM_SID *sidout, const char *sidstr)
 214 {
 215         const char *p;
 216         char *q;
 217         /* BIG NOTE: this function only does SIDS where the identauth is not >= 2^32 */
 218         uint32 conv;
 219
 220         if ((sidstr[0] != 'S' && sidstr[0] != 's') || sidstr[1] != '-') {
 221                 DEBUG(3,("string_to_sid: Sid %s does not start with 'S-'.\n", sidstr));
 222                 return False;
 223         }
 224
 225         ZERO_STRUCTP(sidout);
 226
 227         /* Get the revision number. */
 228         p = sidstr + 2;
 229         conv = (uint32) strtoul(p, &q, 10);
 230         if (!q || (*q != '-')) {
 231                 DEBUG(3,("string_to_sid: Sid %s is not in a valid format.\n", sidstr));
 232                 return False;
 233         }
 234         sidout->sid_rev_num = (uint8) conv;
 235         q++;
 236
 237         /* get identauth */
 238         conv = (uint32) strtoul(q, &q, 10);
 239         if (!q || (*q != '-')) {
 240                 DEBUG(0,("string_to_sid: Sid %s is not in a valid format.\n", sidstr));
 241                 return False;
 242         }
 243         /* identauth in decimal should be <  2^32 */
 244         /* NOTE - the conv value is in big-endian format. */
 245         sidout->id_auth[0] = 0;
 246         sidout->id_auth[1] = 0;
 247         sidout->id_auth[2] = (conv & 0xff000000) >> 24;
 248         sidout->id_auth[3] = (conv & 0x00ff0000) >> 16;
 249         sidout->id_auth[4] = (conv & 0x0000ff00) >> 8;
 250         sidout->id_auth[5] = (conv & 0x000000ff);
 251
 252         q++;
 253         sidout->num_auths = 0;
 254
 255         for(conv = (uint32) strtoul(q, &q, 10);
 256             q && (*q =='-' || *q =='\0') && (sidout->num_auths < MAXSUBAUTHS);
 257             conv = (uint32) strtoul(q, &q, 10)) {
 258                 sid_append_rid(sidout, conv);
 259                 if (*q == '\0')
 260                         break;
 261                 q++;
 262         }
 263
 264         return True;
 265 }
 266
 267 DOM_SID *string_sid_talloc(TALLOC_CTX *mem_ctx, const char *sidstr)
 268 {
 269         DOM_SID *result = TALLOC_P(mem_ctx, DOM_SID);
 270
 271         if (result == NULL)
 272                 return NULL;
 273
 274         if (!string_to_sid(result, sidstr))
 275                 return NULL;
 276
 277         return result;
 278 }
 279
 280 /*****************************************************************
 281  Add a rid to the end of a sid
 282 *****************************************************************/
 283
 284 BOOL sid_append_rid(DOM_SID *sid, uint32 rid)
 285 {
 286         if (sid->num_auths < MAXSUBAUTHS) {
 287                 sid->sub_auths[sid->num_auths++] = rid;
 288                 return True;
 289         }
 290         return False;
 291 }
 292
 293 BOOL sid_compose(DOM_SID *dst, const DOM_SID *domain_sid, uint32 rid)
 294 {
 295         sid_copy(dst, domain_sid);
 296         return sid_append_rid(dst, rid);
 297 }
 298
 299 /*****************************************************************
 300  Removes the last rid from the end of a sid
 301 *****************************************************************/
 302
 303 BOOL sid_split_rid(DOM_SID *sid, uint32 *rid)
 304 {
 305         if (sid->num_auths > 0) {
 306                 sid->num_auths--;
 307                 *rid = sid->sub_auths[sid->num_auths];
 308                 return True;
 309         }
 310         return False;
 311 }
 312
 313 /*****************************************************************
 314  Return the last rid from the end of a sid
 315 *****************************************************************/
 316
 317 BOOL sid_peek_rid(const DOM_SID *sid, uint32 *rid)
 318 {
 319         if (!sid || !rid)
 320                 return False;
 321
 322         if (sid->num_auths > 0) {
 323                 *rid = sid->sub_auths[sid->num_auths - 1];
 324                 return True;
 325         }
 326         return False;
 327 }
 328
 329 /*****************************************************************
 330  Return the last rid from the end of a sid
 331  and check the sid against the exp_dom_sid
 332 *****************************************************************/
 333
 334 BOOL sid_peek_check_rid(const DOM_SID *exp_dom_sid, const DOM_SID *sid, uint32 *rid)
 335 {
 336         if (!exp_dom_sid || !sid || !rid)
 337                 return False;
 338
 339         if (sid->num_auths != (exp_dom_sid->num_auths+1)) {
 340                 return False;
 341         }
 342
 343         if (sid_compare_domain(exp_dom_sid, sid)!=0){
 344                 *rid=(-1);
 345                 return False;
 346         }
 347
 348         return sid_peek_rid(sid, rid);
 349 }
 350
 351 /*****************************************************************
 352  Copies a sid
 353 *****************************************************************/
 354
 355 void sid_copy(DOM_SID *dst, const DOM_SID *src)
 356 {
 357         int i;
 358
 359         ZERO_STRUCTP(dst);
 360
 361         dst->sid_rev_num = src->sid_rev_num;
 362         dst->num_auths = src->num_auths;
 363
 364         memcpy(&dst->id_auth[0], &src->id_auth[0], sizeof(src->id_auth));
 365
 366         for (i = 0; i < src->num_auths; i++)
 367                 dst->sub_auths[i] = src->sub_auths[i];
 368 }
 369
 370 /*****************************************************************
 371  Write a sid out into on-the-wire format.
 372 *****************************************************************/
 373
 374 BOOL sid_linearize(char *outbuf, size_t len, const DOM_SID *sid)
 375 {
 376         size_t i;
 377
 378         if (len < sid_size(sid))
 379                 return False;
 380
 381         SCVAL(outbuf,0,sid->sid_rev_num);
 382         SCVAL(outbuf,1,sid->num_auths);
 383         memcpy(&outbuf[2], sid->id_auth, 6);
 384         for(i = 0; i < sid->num_auths; i++)
 385                 SIVAL(outbuf, 8 + (i*4), sid->sub_auths[i]);
 386
 387         return True;
 388 }
 389
 390 /*****************************************************************
 391  Parse a on-the-wire SID to a DOM_SID.
 392 *****************************************************************/
 393
 394 BOOL sid_parse(const char *inbuf, size_t len, DOM_SID *sid)
 395 {
 396         int i;
 397         if (len < 8)
 398                 return False;
 399
 400         ZERO_STRUCTP(sid);
 401
 402         sid->sid_rev_num = CVAL(inbuf, 0);
 403         sid->num_auths = CVAL(inbuf, 1);
 404         memcpy(sid->id_auth, inbuf+2, 6);
 405         if (len < 8 + sid->num_auths*4)
 406                 return False;
 407         for (i=0;i<sid->num_auths;i++)
 408                 sid->sub_auths[i] = IVAL(inbuf, 8+i*4);
 409         return True;
 410 }
 411
 412 /*****************************************************************
 413  Compare the auth portion of two sids.
 414 *****************************************************************/
 415
 416 static int sid_compare_auth(const DOM_SID *sid1, const DOM_SID *sid2)
 417 {
 418         int i;
 419
 420         if (sid1 == sid2)
 421                 return 0;
 422         if (!sid1)
 423                 return -1;
 424         if (!sid2)
 425                 return 1;
 426
 427         if (sid1->sid_rev_num != sid2->sid_rev_num)
 428                 return sid1->sid_rev_num - sid2->sid_rev_num;
 429
 430         for (i = 0; i < 6; i++)
 431                 if (sid1->id_auth[i] != sid2->id_auth[i])
 432                         return sid1->id_auth[i] - sid2->id_auth[i];
 433
 434         return 0;
 435 }
 436
 437 /*****************************************************************
 438  Compare two sids.
 439 *****************************************************************/
 440
 441 int sid_compare(const DOM_SID *sid1, const DOM_SID *sid2)
 442 {
 443         int i;
 444
 445         if (sid1 == sid2)
 446                 return 0;
 447         if (!sid1)
 448                 return -1;
 449         if (!sid2)
 450                 return 1;
 451
 452         /* Compare most likely different rids, first: i.e start at end */
 453         if (sid1->num_auths != sid2->num_auths)
 454                 return sid1->num_auths - sid2->num_auths;
 455
 456         for (i = sid1->num_auths-1; i >= 0; --i)
 457                 if (sid1->sub_auths[i] != sid2->sub_auths[i])
 458                         return sid1->sub_auths[i] - sid2->sub_auths[i];
 459
 460         return sid_compare_auth(sid1, sid2);
 461 }
 462
 463 /*****************************************************************
 464  See if 2 SIDs are in the same domain
 465  this just compares the leading sub-auths
 466 *****************************************************************/
 467
 468 int sid_compare_domain(const DOM_SID *sid1, const DOM_SID *sid2)
 469 {
 470         int n, i;
 471
 472         n = MIN(sid1->num_auths, sid2->num_auths);
 473
 474         for (i = n-1; i >= 0; --i)
 475                 if (sid1->sub_auths[i] != sid2->sub_auths[i])
 476                         return sid1->sub_auths[i] - sid2->sub_auths[i];
 477
 478         return sid_compare_auth(sid1, sid2);
 479 }
 480
 481 /*****************************************************************
 482  Compare two sids.
 483 *****************************************************************/
 484
 485 BOOL sid_equal(const DOM_SID *sid1, const DOM_SID *sid2)
 486 {
 487         return sid_compare(sid1, sid2) == 0;
 488 }
 489
 490 /*****************************************************************
 491  Calculates size of a sid.
 492 *****************************************************************/
 493
 494 size_t sid_size(const DOM_SID *sid)
 495 {
 496         if (sid == NULL)
 497                 return 0;
 498
 499         return sid->num_auths * sizeof(uint32) + 8;
 500 }
 501
 502 /*****************************************************************
 503  Returns true if SID is internal (and non-mappable).
 504 *****************************************************************/
 505
 506 BOOL non_mappable_sid(DOM_SID *sid)
 507 {
 508         DOM_SID dom;
 509         uint32 rid;
 510
 511         sid_copy(&dom, sid);
 512         sid_split_rid(&dom, &rid);
 513
 514         if (sid_equal(&dom, &global_sid_Builtin))
 515                 return True;
 516
 517         if (sid_equal(&dom, &global_sid_NT_Authority))
 518                 return True;
 519
 520         return False;
 521 }
 522
 523 /*****************************************************************
 524  Return the binary string representation of a DOM_SID.
 525  Caller must free.
 526 *****************************************************************/
 527
 528 char *sid_binstring(const DOM_SID *sid)
 529 {
 530         char *buf, *s;
 531         int len = sid_size(sid);
 532         buf = SMB_MALLOC(len);
 533         if (!buf)
 534                 return NULL;
 535         sid_linearize(buf, len, sid);
 536         s = binary_string(buf, len);
 537         free(buf);
 538         return s;
 539 }
 540
 541 /*******************************************************************
 542  Tallocs a duplicate SID.
 543 ********************************************************************/
 544
 545 DOM_SID *sid_dup_talloc(TALLOC_CTX *ctx, const DOM_SID *src)
 546 {
 547         DOM_SID *dst;
 548
 549         if(!src)
 550                 return NULL;
 551
 552         if((dst = TALLOC_ZERO_P(ctx, DOM_SID)) != NULL) {
 553                 sid_copy( dst, src);
 554         }
 555
 556         return dst;
 557 }
 558
 559 /********************************************************************
 560  Add SID to an array SIDs
 561 ********************************************************************/
 562
 563 void add_sid_to_array(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
 564                       DOM_SID **sids, size_t *num)
 565 {
 566         if (mem_ctx != NULL)
 567                 *sids = TALLOC_REALLOC_ARRAY(mem_ctx, *sids, DOM_SID,
 568                                              (*num)+1);
 569         else
 570                 *sids = SMB_REALLOC_ARRAY(*sids, DOM_SID, (*num)+1);
 571
 572         if (*sids == NULL)
 573                 return;
 574
 575         sid_copy(&((*sids)[*num]), sid);
 576         *num += 1;
 577
 578         return;
 579 }
 580
 581
 582 /********************************************************************
 583  Add SID to an array SIDs ensuring that it is not already there
 584 ********************************************************************/
 585
 586 void add_sid_to_array_unique(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
 587                              DOM_SID **sids, size_t *num_sids)
 588 {
 589         size_t i;
 590
 591         for (i=0; i<(*num_sids); i++) {
 592                 if (sid_compare(sid, &(*sids)[i]) == 0)
 593                         return;
 594         }
 595
 596         add_sid_to_array(mem_ctx, sid, sids, num_sids);
 597 }
 598
 599 /********************************************************************
 600  Remove SID from an array
 601 ********************************************************************/
 602
 603 void del_sid_from_array(const DOM_SID *sid, DOM_SID **sids, size_t *num)
 604 {
 605         DOM_SID *sid_list = *sids;
 606         size_t i;
 607
 608         for ( i=0; i<*num; i++ ) {
 609
 610                 /* if we find the SID, then decrement the count
 611                    and break out of the loop */
 612
 613                 if ( sid_equal(sid, &sid_list[i]) ) {
 614                         *num -= 1;
 615                         break;
 616                 }
 617         }
 618
 619         /* This loop will copy the remainder of the array
 620            if i < num of sids ni the array */
 621
 622         for ( ; i<*num; i++ )
 623                 sid_copy( &sid_list[i], &sid_list[i+1] );
 624
 625         return;
 626 }
 627
 628 BOOL is_null_sid(const DOM_SID *sid)
 629 {
 630         static const DOM_SID null_sid = {0};
 631         return sid_equal(sid, &null_sid);
 632 }