source3/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. If at first we don't succeed,
 297  try lower case.
 298 ****************************************************************************/
 299
 300 static BOOL user_in_netgroup_list(const char *user, const char *ngname)
 301 {
 302 #ifdef HAVE_NETGROUP
 303         static char *mydomain = NULL;
 304         fstring lowercase_user, lowercase_ngname;
 305
 306         if (mydomain == NULL)
 307                 yp_get_default_domain(&mydomain);
 308
 309         if(mydomain == NULL) {
 310                 DEBUG(5,("Unable to get default yp domain\n"));
 311                 return False;
 312         }
 313
 314         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 315                 user, mydomain, ngname));
 316         DEBUG(5,("innetgr is %s\n", innetgr(ngname, NULL, user, mydomain)
 317                 ? "TRUE" : "FALSE"));
 318
 319         if (innetgr(ngname, NULL, user, mydomain))
 320                 return (True);
 321
 322         /*
 323          * Ok, innetgr is case sensitive. Try once more with lowercase
 324          * just in case. Attempt to fix #703. JRA.
 325          */
 326
 327         fstrcpy(lowercase_user, user);
 328         strlower_m(lowercase_user);
 329         fstrcpy(lowercase_ngname, ngname);
 330         strlower_m(lowercase_ngname);
 331
 332         if (innetgr(lowercase_ngname, NULL, lowercase_user, mydomain))
 333                 return (True);
 334
 335 #endif /* HAVE_NETGROUP */
 336         return False;
 337 }
 338
 339 /****************************************************************************
 340  Check if a user is in a winbind group.
 341 ****************************************************************************/
 342
 343 static BOOL user_in_winbind_group_list(const char *user, const char *gname, BOOL *winbind_answered)
 344 {
 345         int i;
 346         gid_t gid, gid_low, gid_high;
 347         BOOL ret = False;
 348         static gid_t *groups = NULL;
 349         static int num_groups = 0;
 350         static fstring last_user = "";
 351
 352         *winbind_answered = False;
 353
 354         if ((gid = nametogid(gname)) == (gid_t)-1) {
 355                 DEBUG(0,("user_in_winbind_group_list: nametogid for group %s failed.\n",
 356                         gname ));
 357                 goto err;
 358         }
 359
 360         if (!lp_idmap_gid(&gid_low, &gid_high)) {
 361                 DEBUG(4, ("winbind gid range not configured, therefore %s cannot be a winbind group\n", gname));
 362                 goto err;
 363         }
 364
 365         if (gid < gid_low || gid > gid_high) {
 366                 DEBUG(4, ("group %s is not a winbind group\n", gname));
 367                 goto err;
 368         }
 369
 370         /* try to user the last user we looked up */
 371         /* otherwise fall back to lookups */
 372
 373         if ( !strequal( last_user, user ) || !groups )
 374         {
 375                 /* clear any cached information */
 376
 377                 SAFE_FREE(groups);
 378                 fstrcpy( last_user, "" );
 379
 380                 /*
 381                  * Get the gid's that this user belongs to.
 382                  */
 383
 384                 if ((num_groups = winbind_getgroups(user, &groups)) == -1)
 385                         return False;
 386
 387                 if ( num_groups == -1 )
 388                         return False;
 389
 390                 if ( num_groups == 0 ) {
 391                         *winbind_answered = True;
 392                         return False;
 393                 }
 394
 395                 /* save the last username */
 396
 397                 fstrcpy( last_user, user );
 398
 399         }
 400         else
 401                 DEBUG(10,("user_in_winbind_group_list: using cached user groups for [%s]\n", user));
 402
 403         if ( DEBUGLEVEL >= 10 ) {
 404                 DEBUG(10,("user_in_winbind_group_list: using groups -- "));
 405                 for ( i=0; i<num_groups; i++ )
 406                         DEBUGADD(10,("%lu ", (unsigned long)groups[i]));
 407                 DEBUGADD(10,("\n"));
 408         }
 409
 410         /*
 411          * Now we have the gid list for this user - convert the gname
 412          * to a gid_t via either winbind or the local UNIX lookup and do the comparison.
 413          */
 414
 415         for (i = 0; i < num_groups; i++) {
 416                 if (gid == groups[i]) {
 417                         ret = True;
 418                         break;
 419                 }
 420         }
 421
 422         *winbind_answered = True;
 423         SAFE_FREE(groups);
 424         return ret;
 425
 426    err:
 427
 428         *winbind_answered = False;
 429         SAFE_FREE(groups);
 430         return False;
 431 }
 432
 433 /****************************************************************************
 434  Check if a user is in a UNIX group.
 435 ****************************************************************************/
 436
 437 BOOL user_in_unix_group_list(const char *user,const char *gname)
 438 {
 439         struct passwd *pass = Get_Pwnam(user);
 440         struct sys_userlist *user_list;
 441         struct sys_userlist *member;
 442
 443         DEBUG(10,("user_in_unix_group_list: checking user %s in group %s\n", user, gname));
 444
 445         /*
 446          * We need to check the users primary group as this
 447          * group is implicit and often not listed in the group database.
 448          */
 449
 450         if (pass) {
 451                 if (strequal(gname,gidtoname(pass->pw_gid))) {
 452                         DEBUG(10,("user_in_unix_group_list: group %s is primary group.\n", gname ));
 453                         return True;
 454                 }
 455         }
 456
 457         user_list = get_users_in_group(gname);
 458         if (user_list == NULL) {
 459                 DEBUG(10,("user_in_unix_group_list: no such group %s\n", gname ));
 460                 return False;
 461         }
 462
 463         for (member = user_list; member; member = member->next) {
 464                 DEBUG(10,("user_in_unix_group_list: checking user %s against member %s\n",
 465                         user, member->unix_name ));
 466                 if (strequal(member->unix_name,user)) {
 467                         free_userlist(user_list);
 468                         return(True);
 469                 }
 470         }
 471
 472         free_userlist(user_list);
 473         return False;
 474 }
 475
 476 /****************************************************************************
 477  Check if a user is in a group list. Ask winbind first, then use UNIX.
 478 ****************************************************************************/
 479
 480 BOOL user_in_group_list(const char *user, const char *gname, gid_t *groups, size_t n_groups)
 481 {
 482         BOOL winbind_answered = False;
 483         BOOL ret;
 484         gid_t gid;
 485         unsigned i;
 486
 487         gid = nametogid(gname);
 488         if (gid == (gid_t)-1)
 489                 return False;
 490
 491         if (groups && n_groups > 0) {
 492                 for (i=0; i < n_groups; i++) {
 493                         if (groups[i] == gid) {
 494                                 return True;
 495                         }
 496                 }
 497                 return False;
 498         }
 499
 500         /* fallback if we don't yet have the group list */
 501
 502         ret = user_in_winbind_group_list(user, gname, &winbind_answered);
 503         if (!winbind_answered)
 504                 ret = user_in_unix_group_list(user, gname);
 505
 506         if (ret)
 507                 DEBUG(10,("user_in_group_list: user |%s| is in group |%s|\n", user, gname));
 508         return ret;
 509 }
 510
 511 /****************************************************************************
 512  Check if a user is in a user list - can check combinations of UNIX
 513  and netgroup lists.
 514 ****************************************************************************/
 515
 516 BOOL user_in_list(const char *user,const char **list, gid_t *groups, size_t n_groups)
 517 {
 518         if (!list || !*list)
 519                 return False;
 520
 521         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 522
 523         while (*list) {
 524
 525                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n", user, *list));
 526
 527                 /*
 528                  * Check raw username.
 529                  */
 530                 if (strequal(user, *list))
 531                         return(True);
 532
 533                 /*
 534                  * Now check to see if any combination
 535                  * of UNIX and netgroups has been specified.
 536                  */
 537
 538                 if(**list == '@') {
 539                         /*
 540                          * Old behaviour. Check netgroup list
 541                          * followed by UNIX list.
 542                          */
 543                         if(user_in_netgroup_list(user, *list +1))
 544                                 return True;
 545                         if(user_in_group_list(user, *list +1, groups, n_groups))
 546                                 return True;
 547                 } else if (**list == '+') {
 548
 549                         if((*(*list +1)) == '&') {
 550                                 /*
 551                                  * Search UNIX list followed by netgroup.
 552                                  */
 553                                 if(user_in_group_list(user, *list +2, groups, n_groups))
 554                                         return True;
 555                                 if(user_in_netgroup_list(user, *list +2))
 556                                         return True;
 557
 558                         } else {
 559
 560                                 /*
 561                                  * Just search UNIX list.
 562                                  */
 563
 564                                 if(user_in_group_list(user, *list +1, groups, n_groups))
 565                                         return True;
 566                         }
 567
 568                 } else if (**list == '&') {
 569
 570                         if(*(*list +1) == '+') {
 571                                 /*
 572                                  * Search netgroup list followed by UNIX list.
 573                                  */
 574                                 if(user_in_netgroup_list(user, *list +2))
 575                                         return True;
 576                                 if(user_in_group_list(user, *list +2, groups, n_groups))
 577                                         return True;
 578                         } else {
 579                                 /*
 580                                  * Just search netgroup list.
 581                                  */
 582                                 if(user_in_netgroup_list(user, *list +1))
 583                                         return True;
 584                         }
 585                 } else if (!name_is_local(*list)) {
 586                         /*
 587                          * If user name did not match and token is not
 588                          * a unix group and the token has a winbind separator in the
 589                          * name then see if it is a Windows group.
 590                          */
 591
 592                         DOM_SID g_sid;
 593                         enum SID_NAME_USE name_type;
 594                         BOOL winbind_answered = False;
 595                         BOOL ret;
 596                         fstring groupname, domain;
 597
 598                         /* Parse a string of the form DOMAIN/user into a domain and a user */
 599
 600                         char *p = strchr(*list,*lp_winbind_separator());
 601
 602                         DEBUG(10,("user_in_list: checking if user |%s| is in winbind group |%s|\n", user, *list));
 603
 604                         if (p) {
 605                                 fstrcpy(groupname, p+1);
 606                                 fstrcpy(domain, *list);
 607                                 domain[PTR_DIFF(p, *list)] = 0;
 608
 609                                 /* Check to see if name is a Windows group;  Win2k native mode DCs
 610                                    will return domain local groups; while NT4 or mixed mode 2k DCs
 611                                    will not */
 612
 613                                 if ( winbind_lookup_name(domain, groupname, &g_sid, &name_type)
 614                                         && ( name_type==SID_NAME_DOM_GRP ||
 615                                            (strequal(lp_workgroup(), domain) && name_type==SID_NAME_ALIAS) ) )
 616                                 {
 617
 618                                         /* Check if user name is in the Windows group */
 619                                         ret = user_in_winbind_group_list(user, *list, &winbind_answered);
 620
 621                                         if (winbind_answered && ret == True) {
 622                                                 DEBUG(10,("user_in_list: user |%s| is in winbind group |%s|\n", user, *list));
 623                                                 return ret;
 624                                         }
 625                                 }
 626                         }
 627                 }
 628
 629                 list++;
 630         }
 631         return(False);
 632 }
 633
 634 /* The functions below have been taken from password.c and slightly modified */
 635 /****************************************************************************
 636  Apply a function to upper/lower case combinations
 637  of a string and return true if one of them returns true.
 638  Try all combinations with N uppercase letters.
 639  offset is the first char to try and change (start with 0)
 640  it assumes the string starts lowercased
 641 ****************************************************************************/
 642
 643 static struct passwd *uname_string_combinations2(char *s,int offset,struct passwd *(*fn)(const char *),int N)
 644 {
 645         ssize_t len = (ssize_t)strlen(s);
 646         int i;
 647         struct passwd *ret;
 648
 649         if (N <= 0 || offset >= len)
 650                 return(fn(s));
 651
 652         for (i=offset;i<(len-(N-1));i++) {
 653                 char c = s[i];
 654                 if (!islower((int)c))
 655                         continue;
 656                 s[i] = toupper(c);
 657                 ret = uname_string_combinations2(s,i+1,fn,N-1);
 658                 if(ret)
 659                         return(ret);
 660                 s[i] = c;
 661         }
 662         return(NULL);
 663 }
 664
 665 /****************************************************************************
 666  Apply a function to upper/lower case combinations
 667  of a string and return true if one of them returns true.
 668  Try all combinations with up to N uppercase letters.
 669  offset is the first char to try and change (start with 0)
 670  it assumes the string starts lowercased
 671 ****************************************************************************/
 672
 673 static struct passwd * uname_string_combinations(char *s,struct passwd * (*fn)(const char *),int N)
 674 {
 675         int n;
 676         struct passwd *ret;
 677
 678         for (n=1;n<=N;n++) {
 679                 ret = uname_string_combinations2(s,0,fn,n);
 680                 if(ret)
 681                         return(ret);
 682         }
 683         return(NULL);
 684 }
 685