source/lib/username.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Username handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1997-2001.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 /* internal functions */
  25 static struct passwd *uname_string_combinations(char *s, struct passwd * (*fn) (const char *), int N);
  26 static struct passwd *uname_string_combinations2(char *s, int offset, struct passwd * (*fn) (const char *), int N);
  27
  28 /*****************************************************************
  29  Check if a user or group name is local (this is a *local* name for
  30  *local* people, there's nothing for you here...).
  31 *****************************************************************/
  32
  33 static BOOL name_is_local(const char *name)
  34 {
  35         return !(strchr_m(name, *lp_winbind_separator()));
  36 }
  37
  38 /*****************************************************************
  39  Splits passed user or group name to domain and user/group name parts
  40  Returns True if name was splitted and False otherwise.
  41 *****************************************************************/
  42
  43 BOOL split_domain_and_name(const char *name, char *domain, char* username)
  44 {
  45         char *p = strchr(name,*lp_winbind_separator());
  46
  47
  48         /* Parse a string of the form DOMAIN/user into a domain and a user */
  49         DEBUG(10,("split_domain_and_name: checking whether name |%s| local or not\n", name));
  50
  51         if (p) {
  52                 fstrcpy(username, p+1);
  53                 fstrcpy(domain, name);
  54                 domain[PTR_DIFF(p, name)] = 0;
  55         } else if (lp_winbind_use_default_domain()) {
  56                 fstrcpy(username, name);
  57                 fstrcpy(domain, lp_workgroup());
  58         } else {
  59                 return False;
  60         }
  61
  62         DEBUG(10,("split_domain_and_name: all is fine, domain is |%s| and name is |%s|\n", domain, username));
  63         return True;
  64 }
  65
  66 /****************************************************************************
  67  Get a users home directory.
  68 ****************************************************************************/
  69
  70 char *get_user_home_dir(const char *user)
  71 {
  72         static struct passwd *pass;
  73
  74         /* Ensure the user exists. */
  75
  76         pass = Get_Pwnam(user);
  77
  78         if (!pass)
  79                 return(NULL);
  80         /* Return home directory from struct passwd. */
  81
  82         return(pass->pw_dir);
  83 }
  84
  85 /*******************************************************************
  86  Map a username from a dos name to a unix name by looking in the username
  87  map. Note that this modifies the name in place.
  88  This is the main function that should be called *once* on
  89  any incoming or new username - in order to canonicalize the name.
  90  This is being done to de-couple the case conversions from the user mapping
  91  function. Previously, the map_username was being called
  92  every time Get_Pwnam was called.
  93  Returns True if username was changed, false otherwise.
  94 ********************************************************************/
  95
  96 BOOL map_username(char *user)
  97 {
  98         static BOOL initialised=False;
  99         static fstring last_from,last_to;
 100         XFILE *f;
 101         char *mapfile = lp_username_map();
 102         char *s;
 103         pstring buf;
 104         BOOL mapped_user = False;
 105
 106         if (!*user)
 107                 return False;
 108
 109         if (!*mapfile)
 110                 return False;
 111
 112         if (!initialised) {
 113                 *last_from = *last_to = 0;
 114                 initialised = True;
 115         }
 116
 117         if (strequal(user,last_to))
 118                 return False;
 119
 120         if (strequal(user,last_from)) {
 121                 DEBUG(3,("Mapped user %s to %s\n",user,last_to));
 122                 fstrcpy(user,last_to);
 123                 return True;
 124         }
 125
 126         f = x_fopen(mapfile,O_RDONLY, 0);
 127         if (!f) {
 128                 DEBUG(0,("can't open username map %s. Error %s\n",mapfile, strerror(errno) ));
 129                 return False;
 130         }
 131
 132         DEBUG(4,("Scanning username map %s\n",mapfile));
 133
 134         while((s=fgets_slash(buf,sizeof(buf),f))!=NULL) {
 135                 char *unixname = s;
 136                 char *dosname = strchr_m(unixname,'=');
 137                 char **dosuserlist;
 138                 BOOL return_if_mapped = False;
 139
 140                 if (!dosname)
 141                         continue;
 142
 143                 *dosname++ = 0;
 144
 145                 while (isspace((int)*unixname))
 146                         unixname++;
 147
 148                 if ('!' == *unixname) {
 149                         return_if_mapped = True;
 150                         unixname++;
 151                         while (*unixname && isspace((int)*unixname))
 152                                 unixname++;
 153                 }
 154
 155                 if (!*unixname || strchr_m("#;",*unixname))
 156                         continue;
 157
 158                 {
 159                         int l = strlen(unixname);
 160                         while (l && isspace((int)unixname[l-1])) {
 161                                 unixname[l-1] = 0;
 162                                 l--;
 163                         }
 164                 }
 165
 166                 dosuserlist = str_list_make(dosname, NULL);
 167                 if (!dosuserlist) {
 168                         DEBUG(0,("Unable to build user list\n"));
 169                         return False;
 170                 }
 171
 172                 if (strchr_m(dosname,'*') || user_in_list(user, (const char **)dosuserlist, NULL, 0)) {
 173                         DEBUG(3,("Mapped user %s to %s\n",user,unixname));
 174                         mapped_user = True;
 175                         fstrcpy(last_from,user);
 176                         sscanf(unixname,"%s",user);
 177                         fstrcpy(last_to,user);
 178                         if(return_if_mapped) {
 179                                 str_list_free (&dosuserlist);
 180                                 x_fclose(f);
 181                                 return True;
 182                         }
 183                 }
 184
 185                 str_list_free (&dosuserlist);
 186         }
 187
 188         x_fclose(f);
 189
 190         /*
 191          * Setup the last_from and last_to as an optimization so
 192          * that we don't scan the file again for the same user.
 193          */
 194         fstrcpy(last_from,user);
 195         fstrcpy(last_to,user);
 196
 197         return mapped_user;
 198 }
 199
 200 /****************************************************************************
 201  * A wrapper for sys_getpwnam().  The following variations are tried:
 202  *   - as transmitted
 203  *   - in all lower case if this differs from transmitted
 204  *   - in all upper case if this differs from transmitted
 205  *   - using lp_usernamelevel() for permutations.
 206 ****************************************************************************/
 207
 208 static struct passwd *Get_Pwnam_ret = NULL;
 209
 210 static struct passwd *Get_Pwnam_internals(const char *user, char *user2)
 211 {
 212         struct passwd *ret = NULL;
 213
 214         if (!user2 || !(*user2))
 215                 return(NULL);
 216
 217         if (!user || !(*user))
 218                 return(NULL);
 219
 220         /* Try in all lower case first as this is the most
 221            common case on UNIX systems */
 222         strlower_m(user2);
 223         DEBUG(5,("Trying _Get_Pwnam(), username as lowercase is %s\n",user2));
 224         ret = getpwnam_alloc(user2);
 225         if(ret)
 226                 goto done;
 227
 228         /* Try as given, if username wasn't originally lowercase */
 229         if(strcmp(user, user2) != 0) {
 230                 DEBUG(5,("Trying _Get_Pwnam(), username as given is %s\n", user));
 231                 ret = getpwnam_alloc(user);
 232                 if(ret)
 233                         goto done;
 234         }
 235
 236         /* Try as uppercase, if username wasn't originally uppercase */
 237         strupper_m(user2);
 238         if(strcmp(user, user2) != 0) {
 239                 DEBUG(5,("Trying _Get_Pwnam(), username as uppercase is %s\n", user2));
 240                 ret = getpwnam_alloc(user2);
 241                 if(ret)
 242                         goto done;
 243         }
 244
 245         /* Try all combinations up to usernamelevel */
 246         strlower_m(user2);
 247         DEBUG(5,("Checking combinations of %d uppercase letters in %s\n", lp_usernamelevel(), user2));
 248         ret = uname_string_combinations(user2, getpwnam_alloc, lp_usernamelevel());
 249
 250 done:
 251         DEBUG(5,("Get_Pwnam_internals %s find user [%s]!\n",ret ? "did":"didn't", user));
 252
 253         /* This call used to just return the 'passwd' static buffer.
 254            This could then have accidental reuse implications, so
 255            we now malloc a copy, and free it in the next use.
 256
 257            This should cause the (ab)user to segfault if it
 258            uses an old struct.
 259
 260            This is better than useing the wrong data in security
 261            critical operations.
 262
 263            The real fix is to make the callers free the returned
 264            malloc'ed data.
 265         */
 266
 267         if (Get_Pwnam_ret) {
 268                 passwd_free(&Get_Pwnam_ret);
 269         }
 270
 271         Get_Pwnam_ret = ret;
 272
 273         return ret;
 274 }
 275
 276 /****************************************************************************
 277  Get_Pwnam wrapper without modification.
 278   NOTE: This with NOT modify 'user'!
 279 ****************************************************************************/
 280
 281 struct passwd *Get_Pwnam(const char *user)
 282 {
 283         fstring user2;
 284         struct passwd *ret;
 285
 286         fstrcpy(user2, user);
 287
 288         DEBUG(5,("Finding user %s\n", user));
 289
 290         ret = Get_Pwnam_internals(user, user2);
 291
 292         return ret;
 293 }
 294
 295 /****************************************************************************
 296  Check if a user is in a netgroup user list.
 297 ****************************************************************************/
 298
 299 static BOOL user_in_netgroup_list(const char *user, const char *ngname)
 300 {
 301 #ifdef HAVE_NETGROUP
 302         static char *mydomain = NULL;
 303         if (mydomain == NULL)
 304                 yp_get_default_domain(&mydomain);
 305
 306         if(mydomain == NULL) {
 307                 DEBUG(5,("Unable to get default yp domain\n"));
 308                 return False;
 309         }
 310
 311         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 312                 user, mydomain, ngname));
 313         DEBUG(5,("innetgr is %s\n", innetgr(ngname, NULL, user, mydomain)
 314                 ? "TRUE" : "FALSE"));
 315
 316         if (innetgr(ngname, NULL, user, mydomain))
 317                 return (True);
 318 #endif /* HAVE_NETGROUP */
 319         return False;
 320 }
 321
 322 /****************************************************************************
 323  Check if a user is in a winbind group.
 324 ****************************************************************************/
 325
 326 static BOOL user_in_winbind_group_list(const char *user, const char *gname, BOOL *winbind_answered)
 327 {
 328         int i;
 329         gid_t gid, gid_low, gid_high;
 330         BOOL ret = False;
 331         static gid_t *groups = NULL;
 332         static int num_groups = 0;
 333         static fstring last_user = "";
 334
 335         *winbind_answered = False;
 336
 337         if ((gid = nametogid(gname)) == (gid_t)-1) {
 338                 DEBUG(0,("user_in_winbind_group_list: nametogid for group %s failed.\n",
 339                         gname ));
 340                 goto err;
 341         }
 342
 343         if (!lp_idmap_gid(&gid_low, &gid_high)) {
 344                 DEBUG(4, ("winbind gid range not configured, therefore %s cannot be a winbind group\n", gname));
 345                 goto err;
 346         }
 347
 348         if (gid < gid_low || gid > gid_high) {
 349                 DEBUG(4, ("group %s is not a winbind group\n", gname));
 350                 goto err;
 351         }
 352
 353         /* try to user the last user we looked up */
 354         /* otherwise fall back to lookups */
 355
 356         if ( !strequal( last_user, user ) || !groups )
 357         {
 358                 /* clear any cached information */
 359
 360                 SAFE_FREE(groups);
 361                 fstrcpy( last_user, "" );
 362
 363                 /*
 364                  * Get the gid's that this user belongs to.
 365                  */
 366
 367                 if ((num_groups = winbind_getgroups(user, &groups)) == -1)
 368                         return False;
 369
 370                 if ( num_groups == -1 )
 371                         return False;
 372
 373                 if ( num_groups == 0 ) {
 374                         *winbind_answered = True;
 375                         return False;
 376                 }
 377
 378                 /* save the last username */
 379
 380                 fstrcpy( last_user, user );
 381
 382         }
 383         else
 384                 DEBUG(10,("user_in_winbind_group_list: using cached user groups for [%s]\n", user));
 385
 386         if ( DEBUGLEVEL >= 10 ) {
 387                 DEBUG(10,("user_in_winbind_group_list: using groups -- "));
 388                 for ( i=0; i<num_groups; i++ )
 389                         DEBUGADD(10,("%lu ", (unsigned long)groups[i]));
 390                 DEBUGADD(10,("\n"));
 391         }
 392
 393         /*
 394          * Now we have the gid list for this user - convert the gname
 395          * to a gid_t via either winbind or the local UNIX lookup and do the comparison.
 396          */
 397
 398         for (i = 0; i < num_groups; i++) {
 399                 if (gid == groups[i]) {
 400                         ret = True;
 401                         break;
 402                 }
 403         }
 404
 405         *winbind_answered = True;
 406         SAFE_FREE(groups);
 407         return ret;
 408
 409    err:
 410
 411         *winbind_answered = False;
 412         SAFE_FREE(groups);
 413         return False;
 414 }
 415
 416 /****************************************************************************
 417  Check if a user is in a UNIX group.
 418 ****************************************************************************/
 419
 420 BOOL user_in_unix_group_list(const char *user,const char *gname)
 421 {
 422         struct passwd *pass = Get_Pwnam(user);
 423         struct sys_userlist *user_list;
 424         struct sys_userlist *member;
 425
 426         DEBUG(10,("user_in_unix_group_list: checking user %s in group %s\n", user, gname));
 427
 428         /*
 429          * We need to check the users primary group as this
 430          * group is implicit and often not listed in the group database.
 431          */
 432
 433         if (pass) {
 434                 if (strequal(gname,gidtoname(pass->pw_gid))) {
 435                         DEBUG(10,("user_in_unix_group_list: group %s is primary group.\n", gname ));
 436                         return True;
 437                 }
 438         }
 439
 440         user_list = get_users_in_group(gname);
 441         if (user_list == NULL) {
 442                 DEBUG(10,("user_in_unix_group_list: no such group %s\n", gname ));
 443                 return False;
 444         }
 445
 446         for (member = user_list; member; member = member->next) {
 447                 DEBUG(10,("user_in_unix_group_list: checking user %s against member %s\n",
 448                         user, member->unix_name ));
 449                 if (strequal(member->unix_name,user)) {
 450                         free_userlist(user_list);
 451                         return(True);
 452                 }
 453         }
 454
 455         free_userlist(user_list);
 456         return False;
 457 }
 458
 459 /****************************************************************************
 460  Check if a user is in a group list. Ask winbind first, then use UNIX.
 461 ****************************************************************************/
 462
 463 BOOL user_in_group_list(const char *user, const char *gname, gid_t *groups, size_t n_groups)
 464 {
 465         BOOL winbind_answered = False;
 466         BOOL ret;
 467         gid_t gid;
 468         unsigned i;
 469
 470         gid = nametogid(gname);
 471         if (gid == (gid_t)-1)
 472                 return False;
 473
 474         if (groups && n_groups > 0) {
 475                 for (i=0; i < n_groups; i++) {
 476                         if (groups[i] == gid) {
 477                                 return True;
 478                         }
 479                 }
 480                 return False;
 481         }
 482
 483         /* fallback if we don't yet have the group list */
 484
 485         ret = user_in_winbind_group_list(user, gname, &winbind_answered);
 486         if (!winbind_answered)
 487                 ret = user_in_unix_group_list(user, gname);
 488
 489         if (ret)
 490                 DEBUG(10,("user_in_group_list: user |%s| is in group |%s|\n", user, gname));
 491         return ret;
 492 }
 493
 494 /****************************************************************************
 495  Check if a user is in a user list - can check combinations of UNIX
 496  and netgroup lists.
 497 ****************************************************************************/
 498
 499 BOOL user_in_list(const char *user,const char **list, gid_t *groups, size_t n_groups)
 500 {
 501         if (!list || !*list)
 502                 return False;
 503
 504         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 505
 506         while (*list) {
 507
 508                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n", user, *list));
 509
 510                 /*
 511                  * Check raw username.
 512                  */
 513                 if (strequal(user, *list))
 514                         return(True);
 515
 516                 /*
 517                  * Now check to see if any combination
 518                  * of UNIX and netgroups has been specified.
 519                  */
 520
 521                 if(**list == '@') {
 522                         /*
 523                          * Old behaviour. Check netgroup list
 524                          * followed by UNIX list.
 525                          */
 526                         if(user_in_netgroup_list(user, *list +1))
 527                                 return True;
 528                         if(user_in_group_list(user, *list +1, groups, n_groups))
 529                                 return True;
 530                 } else if (**list == '+') {
 531
 532                         if((*(*list +1)) == '&') {
 533                                 /*
 534                                  * Search UNIX list followed by netgroup.
 535                                  */
 536                                 if(user_in_group_list(user, *list +2, groups, n_groups))
 537                                         return True;
 538                                 if(user_in_netgroup_list(user, *list +2))
 539                                         return True;
 540
 541                         } else {
 542
 543                                 /*
 544                                  * Just search UNIX list.
 545                                  */
 546
 547                                 if(user_in_group_list(user, *list +1, groups, n_groups))
 548                                         return True;
 549                         }
 550
 551                 } else if (**list == '&') {
 552
 553                         if(*(*list +1) == '+') {
 554                                 /*
 555                                  * Search netgroup list followed by UNIX list.
 556                                  */
 557                                 if(user_in_netgroup_list(user, *list +2))
 558                                         return True;
 559                                 if(user_in_group_list(user, *list +2, groups, n_groups))
 560                                         return True;
 561                         } else {
 562                                 /*
 563                                  * Just search netgroup list.
 564                                  */
 565                                 if(user_in_netgroup_list(user, *list +1))
 566                                         return True;
 567                         }
 568                 } else if (!name_is_local(*list)) {
 569                         /*
 570                          * If user name did not match and token is not
 571                          * a unix group and the token has a winbind separator in the
 572                          * name then see if it is a Windows group.
 573                          */
 574
 575                         DOM_SID g_sid;
 576                         enum SID_NAME_USE name_type;
 577                         BOOL winbind_answered = False;
 578                         BOOL ret;
 579                         fstring groupname, domain;
 580
 581                         /* Parse a string of the form DOMAIN/user into a domain and a user */
 582
 583                         char *p = strchr(*list,*lp_winbind_separator());
 584
 585                         DEBUG(10,("user_in_list: checking if user |%s| is in winbind group |%s|\n", user, *list));
 586
 587                         if (p) {
 588                                 fstrcpy(groupname, p+1);
 589                                 fstrcpy(domain, *list);
 590                                 domain[PTR_DIFF(p, *list)] = 0;
 591
 592                                 /* Check to see if name is a Windows group;  Win2k native mode DCs
 593                                    will return domain local groups; while NT4 or mixed mode 2k DCs
 594                                    will not */
 595
 596                                 if ( winbind_lookup_name(domain, groupname, &g_sid, &name_type)
 597                                         && ( name_type==SID_NAME_DOM_GRP ||
 598                                            (strequal(lp_workgroup(), domain) && name_type==SID_NAME_ALIAS) ) )
 599                                 {
 600
 601                                         /* Check if user name is in the Windows group */
 602                                         ret = user_in_winbind_group_list(user, *list, &winbind_answered);
 603
 604                                         if (winbind_answered && ret == True) {
 605                                                 DEBUG(10,("user_in_list: user |%s| is in winbind group |%s|\n", user, *list));
 606                                                 return ret;
 607                                         }
 608                                 }
 609                         }
 610                 }
 611
 612                 list++;
 613         }
 614         return(False);
 615 }
 616
 617 /* The functions below have been taken from password.c and slightly modified */
 618 /****************************************************************************
 619  Apply a function to upper/lower case combinations
 620  of a string and return true if one of them returns true.
 621  Try all combinations with N uppercase letters.
 622  offset is the first char to try and change (start with 0)
 623  it assumes the string starts lowercased
 624 ****************************************************************************/
 625
 626 static struct passwd *uname_string_combinations2(char *s,int offset,struct passwd *(*fn)(const char *),int N)
 627 {
 628         ssize_t len = (ssize_t)strlen(s);
 629         int i;
 630         struct passwd *ret;
 631
 632         if (N <= 0 || offset >= len)
 633                 return(fn(s));
 634
 635         for (i=offset;i<(len-(N-1));i++) {
 636                 char c = s[i];
 637                 if (!islower((int)c))
 638                         continue;
 639                 s[i] = toupper(c);
 640                 ret = uname_string_combinations2(s,i+1,fn,N-1);
 641                 if(ret)
 642                         return(ret);
 643                 s[i] = c;
 644         }
 645         return(NULL);
 646 }
 647
 648 /****************************************************************************
 649  Apply a function to upper/lower case combinations
 650  of a string and return true if one of them returns true.
 651  Try all combinations with up to N uppercase letters.
 652  offset is the first char to try and change (start with 0)
 653  it assumes the string starts lowercased
 654 ****************************************************************************/
 655
 656 static struct passwd * uname_string_combinations(char *s,struct passwd * (*fn)(const char *),int N)
 657 {
 658         int n;
 659         struct passwd *ret;
 660
 661         for (n=1;n<=N;n++) {
 662                 ret = uname_string_combinations2(s,0,fn,n);
 663                 if(ret)
 664                         return(ret);
 665         }
 666         return(NULL);
 667 }
 668