source3/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 #define SECURITY_NULL_SID_AUTHORITY    0
  79 #define SECURITY_WORLD_SID_AUTHORITY   1
  80 #define SECURITY_LOCAL_SID_AUTHORITY   2
  81 #define SECURITY_CREATOR_SID_AUTHORITY 3
  82 #define SECURITY_NT_AUTHORITY          5
  83
  84 /*
  85  * An NT compatible anonymous token.
  86  */
  87
  88 static DOM_SID anon_sid_array[3] =
  89 { { 1, 1, {0,0,0,0,0,1}, {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}},
  90   { 1, 1, {0,0,0,0,0,5}, {2,0,0,0,0,0,0,0,0,0,0,0,0,0,0}},
  91   { 1, 1, {0,0,0,0,0,5}, {7,0,0,0,0,0,0,0,0,0,0,0,0,0,0}} };
  92 NT_USER_TOKEN anonymous_token = { 3, anon_sid_array, SE_NONE };
  93
  94 static DOM_SID system_sid_array[1] =
  95 { { 1, 1, {0,0,0,0,0,5}, {18,0,0,0,0,0,0,0,0,0,0,0,0,0,0}} };
  96 NT_USER_TOKEN system_token = { 1, system_sid_array, SE_ALL_PRIVS };
  97
  98 /****************************************************************************
  99  Lookup string names for SID types.
 100 ****************************************************************************/
 101
 102 static const struct {
 103         enum SID_NAME_USE sid_type;
 104         const char *string;
 105 } sid_name_type[] = {
 106         {SID_NAME_USER, "User"},
 107         {SID_NAME_DOM_GRP, "Domain Group"},
 108         {SID_NAME_DOMAIN, "Domain"},
 109         {SID_NAME_ALIAS, "Local Group"},
 110         {SID_NAME_WKN_GRP, "Well-known Group"},
 111         {SID_NAME_DELETED, "Deleted Account"},
 112         {SID_NAME_INVALID, "Invalid Account"},
 113         {SID_NAME_UNKNOWN, "UNKNOWN"},
 114         {SID_NAME_COMPUTER, "Computer"},
 115
 116         {(enum SID_NAME_USE)0, NULL}
 117 };
 118
 119 const char *sid_type_lookup(uint32 sid_type)
 120 {
 121         int i = 0;
 122
 123         /* Look through list */
 124         while(sid_name_type[i].sid_type != 0) {
 125                 if (sid_name_type[i].sid_type == sid_type)
 126                         return sid_name_type[i].string;
 127                 i++;
 128         }
 129
 130         /* Default return */
 131         return "SID *TYPE* is INVALID";
 132 }
 133
 134 /**************************************************************************
 135  Create the SYSTEM token.
 136 ***************************************************************************/
 137
 138 NT_USER_TOKEN *get_system_token(void)
 139 {
 140         return &system_token;
 141 }
 142
 143 /******************************************************************
 144  get the default domain/netbios name to be used when dealing
 145  with our passdb list of accounts
 146 ******************************************************************/
 147
 148 const char *get_global_sam_name(void)
 149 {
 150         if ((lp_server_role() == ROLE_DOMAIN_PDC) || (lp_server_role() == ROLE_DOMAIN_BDC)) {
 151                 return lp_workgroup();
 152         }
 153         return global_myname();
 154 }
 155
 156 /**************************************************************************
 157  Splits a name of format \DOMAIN\name or name into its two components.
 158  Sets the DOMAIN name to global_myname() if it has not been specified.
 159 ***************************************************************************/
 160
 161 void split_domain_name(const char *fullname, char *domain, char *name)
 162 {
 163         pstring full_name;
 164         const char *sep;
 165         char *p;
 166
 167         sep = lp_winbind_separator();
 168
 169         *domain = *name = '\0';
 170
 171         if (fullname[0] == sep[0] || fullname[0] == '\\')
 172                 fullname++;
 173
 174         pstrcpy(full_name, fullname);
 175         p = strchr_m(full_name+1, '\\');
 176         if (!p) p = strchr_m(full_name+1, sep[0]);
 177
 178         if (p != NULL) {
 179                 *p = 0;
 180                 fstrcpy(domain, full_name);
 181                 fstrcpy(name, p+1);
 182         } else {
 183                 fstrcpy(domain, get_global_sam_name());
 184                 fstrcpy(name, full_name);
 185         }
 186
 187         DEBUG(10,("split_domain_name:name '%s' split into domain :'%s' and user :'%s'\n",
 188                         fullname, domain, name));
 189 }
 190
 191 /****************************************************************************
 192  Test if a SID is wellknown and resolvable.
 193 ****************************************************************************/
 194
 195 BOOL resolvable_wellknown_sid(DOM_SID *sid)
 196 {
 197         uint32 ia = (sid->id_auth[5]) +
 198                         (sid->id_auth[4] << 8 ) +
 199                         (sid->id_auth[3] << 16) +
 200                         (sid->id_auth[2] << 24);
 201
 202         if (sid->sid_rev_num != SEC_DESC_REVISION || sid->num_auths < 1)
 203                 return False;
 204
 205         return (ia == SECURITY_WORLD_SID_AUTHORITY ||
 206                 ia == SECURITY_CREATOR_SID_AUTHORITY);
 207 }
 208
 209 /*****************************************************************
 210  Convert a SID to an ascii string.
 211 *****************************************************************/
 212
 213 char *sid_to_string(fstring sidstr_out, const DOM_SID *sid)
 214 {
 215         char subauth[16];
 216         int i;
 217         uint32 ia;
 218
 219         if (!sid) {
 220                 fstrcpy(sidstr_out, "(NULL SID)");
 221                 return sidstr_out;
 222         }
 223
 224         /*
 225          * BIG NOTE: this function only does SIDS where the identauth is not >= 2^32
 226          * in a range of 2^48.
 227          */
 228         ia = (sid->id_auth[5]) +
 229                 (sid->id_auth[4] << 8 ) +
 230                 (sid->id_auth[3] << 16) +
 231                 (sid->id_auth[2] << 24);
 232
 233         slprintf(sidstr_out, sizeof(fstring) - 1, "S-%u-%lu", (unsigned int)sid->sid_rev_num, (unsigned long)ia);
 234
 235         for (i = 0; i < sid->num_auths; i++) {
 236                 slprintf(subauth, sizeof(subauth)-1, "-%lu", (unsigned long)sid->sub_auths[i]);
 237                 fstrcat(sidstr_out, subauth);
 238         }
 239
 240         return sidstr_out;
 241 }
 242
 243 /*****************************************************************
 244  Useful function for debug lines.
 245 *****************************************************************/
 246
 247 const char *sid_string_static(const DOM_SID *sid)
 248 {
 249         static fstring sid_str;
 250         sid_to_string(sid_str, sid);
 251         return sid_str;
 252 }
 253
 254 /*****************************************************************
 255  Convert a string to a SID. Returns True on success, False on fail.
 256 *****************************************************************/
 257
 258 BOOL string_to_sid(DOM_SID *sidout, const char *sidstr)
 259 {
 260         const char *p;
 261         char *q;
 262         /* BIG NOTE: this function only does SIDS where the identauth is not >= 2^32 */
 263         uint32 conv;
 264
 265         if (StrnCaseCmp( sidstr, "S-", 2)) {
 266                 DEBUG(0,("string_to_sid: Sid %s does not start with 'S-'.\n", sidstr));
 267                 return False;
 268         }
 269
 270         ZERO_STRUCTP(sidout);
 271
 272         /* Get the revision number. */
 273         p = sidstr + 2;
 274         conv = (uint32) strtoul(p, &q, 10);
 275         if (!q || (*q != '-')) {
 276                 DEBUG(0,("string_to_sid: Sid %s is not in a valid format.\n", sidstr));
 277                 return False;
 278         }
 279         sidout->sid_rev_num = (uint8) conv;
 280         q++;
 281
 282         /* get identauth */
 283         conv = (uint32) strtoul(q, &q, 10);
 284         if (!q || (*q != '-')) {
 285                 DEBUG(0,("string_to_sid: Sid %s is not in a valid format.\n", sidstr));
 286                 return False;
 287         }
 288         /* identauth in decimal should be <  2^32 */
 289         /* NOTE - the conv value is in big-endian format. */
 290         sidout->id_auth[0] = 0;
 291         sidout->id_auth[1] = 0;
 292         sidout->id_auth[2] = (conv & 0xff000000) >> 24;
 293         sidout->id_auth[3] = (conv & 0x00ff0000) >> 16;
 294         sidout->id_auth[4] = (conv & 0x0000ff00) >> 8;
 295         sidout->id_auth[5] = (conv & 0x000000ff);
 296
 297         q++;
 298         sidout->num_auths = 0;
 299
 300         for(conv = (uint32) strtoul(q, &q, 10);
 301             q && (*q =='-' || *q =='\0') && (sidout->num_auths < MAXSUBAUTHS);
 302             conv = (uint32) strtoul(q, &q, 10)) {
 303                 sid_append_rid(sidout, conv);
 304                 if (*q == '\0')
 305                         break;
 306                 q++;
 307         }
 308
 309         return True;
 310 }
 311
 312 DOM_SID *string_sid_talloc(TALLOC_CTX *mem_ctx, const char *sidstr)
 313 {
 314         DOM_SID *result = TALLOC_P(mem_ctx, DOM_SID);
 315
 316         if (result == NULL)
 317                 return NULL;
 318
 319         if (!string_to_sid(result, sidstr))
 320                 return NULL;
 321
 322         return result;
 323 }
 324
 325 /*****************************************************************
 326  Add a rid to the end of a sid
 327 *****************************************************************/
 328
 329 BOOL sid_append_rid(DOM_SID *sid, uint32 rid)
 330 {
 331         if (sid->num_auths < MAXSUBAUTHS) {
 332                 sid->sub_auths[sid->num_auths++] = rid;
 333                 return True;
 334         }
 335         return False;
 336 }
 337
 338 BOOL sid_compose(DOM_SID *dst, const DOM_SID *domain_sid, uint32 rid)
 339 {
 340         sid_copy(dst, domain_sid);
 341         return sid_append_rid(dst, rid);
 342 }
 343
 344 /*****************************************************************
 345  Removes the last rid from the end of a sid
 346 *****************************************************************/
 347
 348 BOOL sid_split_rid(DOM_SID *sid, uint32 *rid)
 349 {
 350         if (sid->num_auths > 0) {
 351                 sid->num_auths--;
 352                 *rid = sid->sub_auths[sid->num_auths];
 353                 return True;
 354         }
 355         return False;
 356 }
 357
 358 /*****************************************************************
 359  Return the last rid from the end of a sid
 360 *****************************************************************/
 361
 362 BOOL sid_peek_rid(const DOM_SID *sid, uint32 *rid)
 363 {
 364         if (!sid || !rid)
 365                 return False;
 366
 367         if (sid->num_auths > 0) {
 368                 *rid = sid->sub_auths[sid->num_auths - 1];
 369                 return True;
 370         }
 371         return False;
 372 }
 373
 374 /*****************************************************************
 375  Return the last rid from the end of a sid
 376  and check the sid against the exp_dom_sid
 377 *****************************************************************/
 378
 379 BOOL sid_peek_check_rid(const DOM_SID *exp_dom_sid, const DOM_SID *sid, uint32 *rid)
 380 {
 381         if (!exp_dom_sid || !sid || !rid)
 382                 return False;
 383
 384         if (sid->num_auths != (exp_dom_sid->num_auths+1)) {
 385                 return False;
 386         }
 387
 388         if (sid_compare_domain(exp_dom_sid, sid)!=0){
 389                 *rid=(-1);
 390                 return False;
 391         }
 392
 393         return sid_peek_rid(sid, rid);
 394 }
 395
 396 /*****************************************************************
 397  Copies a sid
 398 *****************************************************************/
 399
 400 void sid_copy(DOM_SID *dst, const DOM_SID *src)
 401 {
 402         int i;
 403
 404         ZERO_STRUCTP(dst);
 405
 406         dst->sid_rev_num = src->sid_rev_num;
 407         dst->num_auths = src->num_auths;
 408
 409         memcpy(&dst->id_auth[0], &src->id_auth[0], sizeof(src->id_auth));
 410
 411         for (i = 0; i < src->num_auths; i++)
 412                 dst->sub_auths[i] = src->sub_auths[i];
 413 }
 414
 415 /*****************************************************************
 416  Write a sid out into on-the-wire format.
 417 *****************************************************************/
 418
 419 BOOL sid_linearize(char *outbuf, size_t len, const DOM_SID *sid)
 420 {
 421         size_t i;
 422
 423         if (len < sid_size(sid))
 424                 return False;
 425
 426         SCVAL(outbuf,0,sid->sid_rev_num);
 427         SCVAL(outbuf,1,sid->num_auths);
 428         memcpy(&outbuf[2], sid->id_auth, 6);
 429         for(i = 0; i < sid->num_auths; i++)
 430                 SIVAL(outbuf, 8 + (i*4), sid->sub_auths[i]);
 431
 432         return True;
 433 }
 434
 435 /*****************************************************************
 436  Parse a on-the-wire SID to a DOM_SID.
 437 *****************************************************************/
 438
 439 BOOL sid_parse(const char *inbuf, size_t len, DOM_SID *sid)
 440 {
 441         int i;
 442         if (len < 8)
 443                 return False;
 444
 445         ZERO_STRUCTP(sid);
 446
 447         sid->sid_rev_num = CVAL(inbuf, 0);
 448         sid->num_auths = CVAL(inbuf, 1);
 449         memcpy(sid->id_auth, inbuf+2, 6);
 450         if (len < 8 + sid->num_auths*4)
 451                 return False;
 452         for (i=0;i<sid->num_auths;i++)
 453                 sid->sub_auths[i] = IVAL(inbuf, 8+i*4);
 454         return True;
 455 }
 456
 457 /*****************************************************************
 458  Compare the auth portion of two sids.
 459 *****************************************************************/
 460
 461 static int sid_compare_auth(const DOM_SID *sid1, const DOM_SID *sid2)
 462 {
 463         int i;
 464
 465         if (sid1 == sid2)
 466                 return 0;
 467         if (!sid1)
 468                 return -1;
 469         if (!sid2)
 470                 return 1;
 471
 472         if (sid1->sid_rev_num != sid2->sid_rev_num)
 473                 return sid1->sid_rev_num - sid2->sid_rev_num;
 474
 475         for (i = 0; i < 6; i++)
 476                 if (sid1->id_auth[i] != sid2->id_auth[i])
 477                         return sid1->id_auth[i] - sid2->id_auth[i];
 478
 479         return 0;
 480 }
 481
 482 /*****************************************************************
 483  Compare two sids.
 484 *****************************************************************/
 485
 486 int sid_compare(const DOM_SID *sid1, const DOM_SID *sid2)
 487 {
 488         int i;
 489
 490         if (sid1 == sid2)
 491                 return 0;
 492         if (!sid1)
 493                 return -1;
 494         if (!sid2)
 495                 return 1;
 496
 497         /* Compare most likely different rids, first: i.e start at end */
 498         if (sid1->num_auths != sid2->num_auths)
 499                 return sid1->num_auths - sid2->num_auths;
 500
 501         for (i = sid1->num_auths-1; i >= 0; --i)
 502                 if (sid1->sub_auths[i] != sid2->sub_auths[i])
 503                         return sid1->sub_auths[i] - sid2->sub_auths[i];
 504
 505         return sid_compare_auth(sid1, sid2);
 506 }
 507
 508 /*****************************************************************
 509  See if 2 SIDs are in the same domain
 510  this just compares the leading sub-auths
 511 *****************************************************************/
 512
 513 int sid_compare_domain(const DOM_SID *sid1, const DOM_SID *sid2)
 514 {
 515         int n, i;
 516
 517         n = MIN(sid1->num_auths, sid2->num_auths);
 518
 519         for (i = n-1; i >= 0; --i)
 520                 if (sid1->sub_auths[i] != sid2->sub_auths[i])
 521                         return sid1->sub_auths[i] - sid2->sub_auths[i];
 522
 523         return sid_compare_auth(sid1, sid2);
 524 }
 525
 526 /*****************************************************************
 527  Compare two sids.
 528 *****************************************************************/
 529
 530 BOOL sid_equal(const DOM_SID *sid1, const DOM_SID *sid2)
 531 {
 532         return sid_compare(sid1, sid2) == 0;
 533 }
 534
 535 /*****************************************************************
 536  Check if the SID is the builtin SID (S-1-5-32).
 537 *****************************************************************/
 538
 539 BOOL sid_check_is_builtin(const DOM_SID *sid)
 540 {
 541         return sid_equal(sid, &global_sid_Builtin);
 542 }
 543
 544 /*****************************************************************
 545  Check if the SID is one of the builtin SIDs (S-1-5-32-a).
 546 *****************************************************************/
 547
 548 BOOL sid_check_is_in_builtin(const DOM_SID *sid)
 549 {
 550         DOM_SID dom_sid;
 551         uint32 rid;
 552
 553         sid_copy(&dom_sid, sid);
 554         sid_split_rid(&dom_sid, &rid);
 555
 556         return sid_equal(&dom_sid, &global_sid_Builtin);
 557 }
 558
 559 /*****************************************************************
 560  Calculates size of a sid.
 561 *****************************************************************/
 562
 563 size_t sid_size(const DOM_SID *sid)
 564 {
 565         if (sid == NULL)
 566                 return 0;
 567
 568         return sid->num_auths * sizeof(uint32) + 8;
 569 }
 570
 571 /*****************************************************************
 572  Returns true if SID is internal (and non-mappable).
 573 *****************************************************************/
 574
 575 BOOL non_mappable_sid(DOM_SID *sid)
 576 {
 577         DOM_SID dom;
 578         uint32 rid;
 579
 580         sid_copy(&dom, sid);
 581         sid_split_rid(&dom, &rid);
 582
 583         if (sid_equal(&dom, &global_sid_Builtin))
 584                 return True;
 585
 586         if (sid_equal(&dom, &global_sid_NT_Authority))
 587                 return True;
 588
 589         return False;
 590 }
 591
 592 /*****************************************************************
 593  Return the binary string representation of a DOM_SID.
 594  Caller must free.
 595 *****************************************************************/
 596
 597 char *sid_binstring(const DOM_SID *sid)
 598 {
 599         char *buf, *s;
 600         int len = sid_size(sid);
 601         buf = SMB_MALLOC(len);
 602         if (!buf)
 603                 return NULL;
 604         sid_linearize(buf, len, sid);
 605         s = binary_string(buf, len);
 606         free(buf);
 607         return s;
 608 }
 609
 610 /*******************************************************************
 611  Tallocs a duplicate SID.
 612 ********************************************************************/
 613
 614 DOM_SID *sid_dup_talloc(TALLOC_CTX *ctx, const DOM_SID *src)
 615 {
 616         DOM_SID *dst;
 617
 618         if(!src)
 619                 return NULL;
 620
 621         if((dst = TALLOC_ZERO_P(ctx, DOM_SID)) != NULL) {
 622                 sid_copy( dst, src);
 623         }
 624
 625         return dst;
 626 }
 627
 628 /********************************************************************
 629  Add SID to an array SIDs
 630 ********************************************************************/
 631
 632 void add_sid_to_array(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
 633                       DOM_SID **sids, size_t *num)
 634 {
 635         if (mem_ctx != NULL)
 636                 *sids = TALLOC_REALLOC_ARRAY(mem_ctx, *sids, DOM_SID,
 637                                              (*num)+1);
 638         else
 639                 *sids = SMB_REALLOC_ARRAY(*sids, DOM_SID, (*num)+1);
 640
 641         if (*sids == NULL)
 642                 return;
 643
 644         sid_copy(&((*sids)[*num]), sid);
 645         *num += 1;
 646
 647         return;
 648 }
 649
 650
 651 /********************************************************************
 652  Add SID to an array SIDs ensuring that it is not already there
 653 ********************************************************************/
 654
 655 void add_sid_to_array_unique(TALLOC_CTX *mem_ctx, const DOM_SID *sid,
 656                              DOM_SID **sids, size_t *num_sids)
 657 {
 658         size_t i;
 659
 660         for (i=0; i<(*num_sids); i++) {
 661                 if (sid_compare(sid, &(*sids)[i]) == 0)
 662                         return;
 663         }
 664
 665         add_sid_to_array(mem_ctx, sid, sids, num_sids);
 666 }
 667
 668 /********************************************************************
 669  Remove SID from an array
 670 ********************************************************************/
 671
 672 void del_sid_from_array(const DOM_SID *sid, DOM_SID **sids, size_t *num)
 673 {
 674         DOM_SID *sid_list = *sids;
 675         size_t i;
 676
 677         for ( i=0; i<*num; i++ ) {
 678
 679                 /* if we find the SID, then decrement the count
 680                    and break out of the loop */
 681
 682                 if ( sid_equal(sid, &sid_list[i]) ) {
 683                         *num -= 1;
 684                         break;
 685                 }
 686         }
 687
 688         /* This loop will copy the remainder of the array
 689            if i < num of sids ni the array */
 690
 691         for ( ; i<*num; i++ )
 692                 sid_copy( &sid_list[i], &sid_list[i+1] );
 693
 694         return;
 695 }