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         if ( *user == '\0' ) {
 287                 DEBUG(10,("Get_Pwnam: empty username!\n"));
 288                 return NULL;
 289         }
 290
 291         fstrcpy(user2, user);
 292
 293         DEBUG(5,("Finding user %s\n", user));
 294
 295         ret = Get_Pwnam_internals(user, user2);
 296
 297         return ret;
 298 }
 299
 300 /****************************************************************************
 301  Check if a user is in a netgroup user list. If at first we don't succeed,
 302  try lower case.
 303 ****************************************************************************/
 304
 305 static BOOL user_in_netgroup_list(const char *user, const char *ngname)
 306 {
 307 #ifdef HAVE_NETGROUP
 308         static char *mydomain = NULL;
 309         fstring lowercase_user;
 310
 311         if (mydomain == NULL)
 312                 yp_get_default_domain(&mydomain);
 313
 314         if(mydomain == NULL) {
 315                 DEBUG(5,("Unable to get default yp domain\n"));
 316                 return False;
 317         }
 318
 319         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 320                 user, mydomain, ngname));
 321
 322         if (innetgr(ngname, NULL, user, mydomain)) {
 323                 DEBUG(5,("user_in_netgroup_list: Found\n"));
 324                 return (True);
 325         } else {
 326
 327                 /*
 328                  * Ok, innetgr is case sensitive. Try once more with lowercase
 329                  * just in case. Attempt to fix #703. JRA.
 330                  */
 331
 332                 fstrcpy(lowercase_user, user);
 333                 strlower_m(lowercase_user);
 334
 335                 DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 336                         lowercase_user, mydomain, ngname));
 337
 338                 if (innetgr(ngname, NULL, lowercase_user, mydomain)) {
 339                         DEBUG(5,("user_in_netgroup_list: Found\n"));
 340                         return (True);
 341                 }
 342         }
 343 #endif /* HAVE_NETGROUP */
 344         return False;
 345 }
 346
 347 /****************************************************************************
 348  Check if a user is in a winbind group.
 349 ****************************************************************************/
 350
 351 static BOOL user_in_winbind_group_list(const char *user, const char *gname, BOOL *winbind_answered)
 352 {
 353         int i;
 354         gid_t gid, gid_low, gid_high;
 355         BOOL ret = False;
 356         static gid_t *groups = NULL;
 357         static int num_groups = 0;
 358         static fstring last_user = "";
 359
 360         *winbind_answered = False;
 361
 362         if ((gid = nametogid(gname)) == (gid_t)-1) {
 363                 DEBUG(0,("user_in_winbind_group_list: nametogid for group %s failed.\n",
 364                         gname ));
 365                 goto err;
 366         }
 367
 368         if (!lp_idmap_gid(&gid_low, &gid_high)) {
 369                 DEBUG(4, ("winbind gid range not configured, therefore %s cannot be a winbind group\n", gname));
 370                 goto err;
 371         }
 372
 373         if (gid < gid_low || gid > gid_high) {
 374                 DEBUG(4, ("group %s is not a winbind group\n", gname));
 375                 goto err;
 376         }
 377
 378         /* try to user the last user we looked up */
 379         /* otherwise fall back to lookups */
 380
 381         if ( !strequal( last_user, user ) || !groups )
 382         {
 383                 /* clear any cached information */
 384
 385                 SAFE_FREE(groups);
 386                 fstrcpy( last_user, "" );
 387
 388                 /*
 389                  * Get the gid's that this user belongs to.
 390                  */
 391
 392                 if ((num_groups = winbind_getgroups(user, &groups)) == -1)
 393                         return False;
 394
 395                 if ( num_groups == -1 )
 396                         return False;
 397
 398                 if ( num_groups == 0 ) {
 399                         *winbind_answered = True;
 400                         return False;
 401                 }
 402
 403                 /* save the last username */
 404
 405                 fstrcpy( last_user, user );
 406
 407         }
 408         else
 409                 DEBUG(10,("user_in_winbind_group_list: using cached user groups for [%s]\n", user));
 410
 411         if ( DEBUGLEVEL >= 10 ) {
 412                 DEBUG(10,("user_in_winbind_group_list: using groups -- "));
 413                 for ( i=0; i<num_groups; i++ )
 414                         DEBUGADD(10,("%lu ", (unsigned long)groups[i]));
 415                 DEBUGADD(10,("\n"));
 416         }
 417
 418         /*
 419          * Now we have the gid list for this user - convert the gname
 420          * to a gid_t via either winbind or the local UNIX lookup and do the comparison.
 421          */
 422
 423         for (i = 0; i < num_groups; i++) {
 424                 if (gid == groups[i]) {
 425                         ret = True;
 426                         break;
 427                 }
 428         }
 429
 430         *winbind_answered = True;
 431         SAFE_FREE(groups);
 432         return ret;
 433
 434    err:
 435
 436         *winbind_answered = False;
 437         SAFE_FREE(groups);
 438         return False;
 439 }
 440
 441 /****************************************************************************
 442  Check if a user is in a UNIX group.
 443 ****************************************************************************/
 444
 445 BOOL user_in_unix_group_list(const char *user,const char *gname)
 446 {
 447         struct passwd *pass = Get_Pwnam(user);
 448         struct sys_userlist *user_list;
 449         struct sys_userlist *member;
 450
 451         DEBUG(10,("user_in_unix_group_list: checking user %s in group %s\n", user, gname));
 452
 453         /*
 454          * We need to check the users primary group as this
 455          * group is implicit and often not listed in the group database.
 456          */
 457
 458         if (pass) {
 459                 if (strequal(gname,gidtoname(pass->pw_gid))) {
 460                         DEBUG(10,("user_in_unix_group_list: group %s is primary group.\n", gname ));
 461                         return True;
 462                 }
 463         }
 464
 465         user_list = get_users_in_group(gname);
 466         if (user_list == NULL) {
 467                 DEBUG(10,("user_in_unix_group_list: no such group %s\n", gname ));
 468                 return False;
 469         }
 470
 471         for (member = user_list; member; member = member->next) {
 472                 DEBUG(10,("user_in_unix_group_list: checking user %s against member %s\n",
 473                         user, member->unix_name ));
 474                 if (strequal(member->unix_name,user)) {
 475                         free_userlist(user_list);
 476                         return(True);
 477                 }
 478         }
 479
 480         free_userlist(user_list);
 481         return False;
 482 }
 483
 484 /****************************************************************************
 485  Check if a user is in a group list. Ask winbind first, then use UNIX.
 486 ****************************************************************************/
 487
 488 BOOL user_in_group_list(const char *user, const char *gname, gid_t *groups, size_t n_groups)
 489 {
 490         BOOL winbind_answered = False;
 491         BOOL ret;
 492         gid_t gid;
 493         unsigned i;
 494
 495         gid = nametogid(gname);
 496         if (gid == (gid_t)-1)
 497                 return False;
 498
 499         if (groups && n_groups > 0) {
 500                 for (i=0; i < n_groups; i++) {
 501                         if (groups[i] == gid) {
 502                                 return True;
 503                         }
 504                 }
 505                 return False;
 506         }
 507
 508         /* fallback if we don't yet have the group list */
 509
 510         ret = user_in_winbind_group_list(user, gname, &winbind_answered);
 511         if (!winbind_answered)
 512                 ret = user_in_unix_group_list(user, gname);
 513
 514         if (ret)
 515                 DEBUG(10,("user_in_group_list: user |%s| is in group |%s|\n", user, gname));
 516         return ret;
 517 }
 518
 519 /****************************************************************************
 520  Check if a user is in a user list - can check combinations of UNIX
 521  and netgroup lists.
 522 ****************************************************************************/
 523
 524 BOOL user_in_list(const char *user,const char **list, gid_t *groups, size_t n_groups)
 525 {
 526         if (!list || !*list)
 527                 return False;
 528
 529         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 530
 531         while (*list) {
 532
 533                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n", user, *list));
 534
 535                 /*
 536                  * Check raw username.
 537                  */
 538                 if (strequal(user, *list))
 539                         return(True);
 540
 541                 /*
 542                  * Now check to see if any combination
 543                  * of UNIX and netgroups has been specified.
 544                  */
 545
 546                 if(**list == '@') {
 547                         /*
 548                          * Old behaviour. Check netgroup list
 549                          * followed by UNIX list.
 550                          */
 551                         if(user_in_netgroup_list(user, *list +1))
 552                                 return True;
 553                         if(user_in_group_list(user, *list +1, groups, n_groups))
 554                                 return True;
 555                 } else if (**list == '+') {
 556
 557                         if((*(*list +1)) == '&') {
 558                                 /*
 559                                  * Search UNIX list followed by netgroup.
 560                                  */
 561                                 if(user_in_group_list(user, *list +2, groups, n_groups))
 562                                         return True;
 563                                 if(user_in_netgroup_list(user, *list +2))
 564                                         return True;
 565
 566                         } else {
 567
 568                                 /*
 569                                  * Just search UNIX list.
 570                                  */
 571
 572                                 if(user_in_group_list(user, *list +1, groups, n_groups))
 573                                         return True;
 574                         }
 575
 576                 } else if (**list == '&') {
 577
 578                         if(*(*list +1) == '+') {
 579                                 /*
 580                                  * Search netgroup list followed by UNIX list.
 581                                  */
 582                                 if(user_in_netgroup_list(user, *list +2))
 583                                         return True;
 584                                 if(user_in_group_list(user, *list +2, groups, n_groups))
 585                                         return True;
 586                         } else {
 587                                 /*
 588                                  * Just search netgroup list.
 589                                  */
 590                                 if(user_in_netgroup_list(user, *list +1))
 591                                         return True;
 592                         }
 593                 } else if (!name_is_local(*list)) {
 594                         /*
 595                          * If user name did not match and token is not
 596                          * a unix group and the token has a winbind separator in the
 597                          * name then see if it is a Windows group.
 598                          */
 599
 600                         DOM_SID g_sid;
 601                         enum SID_NAME_USE name_type;
 602                         BOOL winbind_answered = False;
 603                         BOOL ret;
 604                         fstring groupname, domain;
 605
 606                         /* Parse a string of the form DOMAIN/user into a domain and a user */
 607
 608                         char *p = strchr(*list,*lp_winbind_separator());
 609
 610                         DEBUG(10,("user_in_list: checking if user |%s| is in winbind group |%s|\n", user, *list));
 611
 612                         if (p) {
 613                                 fstrcpy(groupname, p+1);
 614                                 fstrcpy(domain, *list);
 615                                 domain[PTR_DIFF(p, *list)] = 0;
 616
 617                                 /* Check to see if name is a Windows group;  Win2k native mode DCs
 618                                    will return domain local groups; while NT4 or mixed mode 2k DCs
 619                                    will not */
 620
 621                                 if ( winbind_lookup_name(domain, groupname, &g_sid, &name_type)
 622                                         && ( name_type==SID_NAME_DOM_GRP ||
 623                                            (strequal(lp_workgroup(), domain) && name_type==SID_NAME_ALIAS) ) )
 624                                 {
 625
 626                                         /* Check if user name is in the Windows group */
 627                                         ret = user_in_winbind_group_list(user, *list, &winbind_answered);
 628
 629                                         if (winbind_answered && ret == True) {
 630                                                 DEBUG(10,("user_in_list: user |%s| is in winbind group |%s|\n", user, *list));
 631                                                 return ret;
 632                                         }
 633                                 }
 634                         }
 635                 }
 636
 637                 list++;
 638         }
 639         return(False);
 640 }
 641
 642 /* The functions below have been taken from password.c and slightly modified */
 643 /****************************************************************************
 644  Apply a function to upper/lower case combinations
 645  of a string and return true if one of them returns true.
 646  Try all combinations with N uppercase letters.
 647  offset is the first char to try and change (start with 0)
 648  it assumes the string starts lowercased
 649 ****************************************************************************/
 650
 651 static struct passwd *uname_string_combinations2(char *s,int offset,struct passwd *(*fn)(const char *),int N)
 652 {
 653         ssize_t len = (ssize_t)strlen(s);
 654         int i;
 655         struct passwd *ret;
 656
 657         if (N <= 0 || offset >= len)
 658                 return(fn(s));
 659
 660         for (i=offset;i<(len-(N-1));i++) {
 661                 char c = s[i];
 662                 if (!islower((int)c))
 663                         continue;
 664                 s[i] = toupper(c);
 665                 ret = uname_string_combinations2(s,i+1,fn,N-1);
 666                 if(ret)
 667                         return(ret);
 668                 s[i] = c;
 669         }
 670         return(NULL);
 671 }
 672
 673 /****************************************************************************
 674  Apply a function to upper/lower case combinations
 675  of a string and return true if one of them returns true.
 676  Try all combinations with up to N uppercase letters.
 677  offset is the first char to try and change (start with 0)
 678  it assumes the string starts lowercased
 679 ****************************************************************************/
 680
 681 static struct passwd * uname_string_combinations(char *s,struct passwd * (*fn)(const char *),int N)
 682 {
 683         int n;
 684         struct passwd *ret;
 685
 686         for (n=1;n<=N;n++) {
 687                 ret = uname_string_combinations2(s,0,fn,n);
 688                 if(ret)
 689                         return(ret);
 690         }
 691         return(NULL);
 692 }
 693