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, dosuserlist)) {
 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(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(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(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 num_groups;
 329         int i;
 330         gid_t *groups = NULL;
 331         gid_t gid;
 332         BOOL ret = False;
 333
 334         *winbind_answered = False;
 335
 336         /*
 337          * Get the gid's that this user belongs to.
 338          */
 339
 340         if ((num_groups = winbind_getgroups(user, 0, NULL)) == -1)
 341                 return False;
 342
 343         if (num_groups == 0) {
 344                 *winbind_answered = True;
 345                 return False;
 346         }
 347
 348         if ((groups = (gid_t *)malloc(sizeof(gid_t) * num_groups )) == NULL) {
 349                 DEBUG(0,("user_in_winbind_group_list: malloc fail.\n"));
 350                 goto err;
 351         }
 352
 353         if ((num_groups = winbind_getgroups(user, num_groups, groups)) == -1) {
 354                 DEBUG(0,("user_in_winbind_group_list: second winbind_getgroups call \
 355 failed with error %s\n", strerror(errno) ));
 356                 goto err;
 357         }
 358
 359         /*
 360          * Now we have the gid list for this user - convert the gname
 361          * to a gid_t via either winbind or the local UNIX lookup and do the comparison.
 362          */
 363
 364         if ((gid = nametogid(gname)) == (gid_t)-1) {
 365                 DEBUG(0,("user_in_winbind_group_list: winbind_lookup_name for group %s failed.\n",
 366                         gname ));
 367                 goto err;
 368         }
 369
 370         for (i = 0; i < num_groups; i++) {
 371                 if (gid == groups[i]) {
 372                         ret = True;
 373                         break;
 374                 }
 375         }
 376
 377         *winbind_answered = True;
 378         SAFE_FREE(groups);
 379         return ret;
 380
 381    err:
 382
 383         *winbind_answered = False;
 384         SAFE_FREE(groups);
 385         return False;
 386 }
 387
 388 /****************************************************************************
 389  Check if a user is in a UNIX group.
 390 ****************************************************************************/
 391
 392 static BOOL user_in_unix_group_list(const char *user,const char *gname)
 393 {
 394         struct passwd *pass = Get_Pwnam(user);
 395         struct sys_userlist *user_list;
 396         struct sys_userlist *member;
 397
 398         DEBUG(10,("user_in_unix_group_list: checking user %s in group %s\n", user, gname));
 399
 400         /*
 401          * We need to check the users primary group as this
 402          * group is implicit and often not listed in the group database.
 403          */
 404
 405         if (pass) {
 406                 if (strequal(gname,gidtoname(pass->pw_gid))) {
 407                         DEBUG(10,("user_in_unix_group_list: group %s is primary group.\n", gname ));
 408                         return True;
 409                 }
 410         }
 411
 412         user_list = get_users_in_group(gname);
 413         if (user_list == NULL) {
 414                 DEBUG(10,("user_in_unix_group_list: no such group %s\n", gname ));
 415                 return False;
 416         }
 417
 418         for (member = user_list; member; member = member->next) {
 419                 DEBUG(10,("user_in_unix_group_list: checking user %s against member %s\n",
 420                         user, member->unix_name ));
 421                 if (strequal(member->unix_name,user)) {
 422                         free_userlist(user_list);
 423                         return(True);
 424                 }
 425         }
 426
 427         free_userlist(user_list);
 428         return False;
 429 }
 430
 431 /****************************************************************************
 432  Check if a user is in a group list. Ask winbind first, then use UNIX.
 433 ****************************************************************************/
 434
 435 BOOL user_in_group_list(const char *user, const char *gname)
 436 {
 437         BOOL winbind_answered = False;
 438         BOOL ret;
 439
 440         ret = user_in_winbind_group_list(user, gname, &winbind_answered);
 441         if (!winbind_answered)
 442                 ret = user_in_unix_group_list(user, gname);
 443
 444         if (ret)
 445                 DEBUG(10,("user_in_group_list: user |%s| is in group |%s|\n", user, gname));
 446         return ret;
 447 }
 448
 449 /****************************************************************************
 450  Check if a user is in a user list - can check combinations of UNIX
 451  and netgroup lists.
 452 ****************************************************************************/
 453
 454 BOOL user_in_list(const char *user,char **list)
 455 {
 456         if (!list || !*list)
 457                 return False;
 458
 459         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 460
 461         while (*list) {
 462
 463                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n", user, *list));
 464
 465                 /*
 466                  * Check raw username.
 467                  */
 468                 if (strequal(user, *list))
 469                         return(True);
 470
 471                 /*
 472                  * Now check to see if any combination
 473                  * of UNIX and netgroups has been specified.
 474                  */
 475
 476                 if(**list == '@') {
 477                         /*
 478                          * Old behaviour. Check netgroup list
 479                          * followed by UNIX list.
 480                          */
 481                         if(user_in_netgroup_list(user, *list +1))
 482                                 return True;
 483                         if(user_in_group_list(user, *list +1))
 484                                 return True;
 485                 } else if (**list == '+') {
 486
 487                         if((*(*list +1)) == '&') {
 488                                 /*
 489                                  * Search UNIX list followed by netgroup.
 490                                  */
 491                                 if(user_in_group_list(user, *list +2))
 492                                         return True;
 493                                 if(user_in_netgroup_list(user, *list +2))
 494                                         return True;
 495
 496                         } else {
 497
 498                                 /*
 499                                  * Just search UNIX list.
 500                                  */
 501
 502                                 if(user_in_group_list(user, *list +1))
 503                                         return True;
 504                         }
 505
 506                 } else if (**list == '&') {
 507
 508                         if(*(*list +1) == '+') {
 509                                 /*
 510                                  * Search netgroup list followed by UNIX list.
 511                                  */
 512                                 if(user_in_netgroup_list(user, *list +2))
 513                                         return True;
 514                                 if(user_in_group_list(user, *list +2))
 515                                         return True;
 516                         } else {
 517                                 /*
 518                                  * Just search netgroup list.
 519                                  */
 520                                 if(user_in_netgroup_list(user, *list +1))
 521                                         return True;
 522                         }
 523                 } else if (!name_is_local(*list)) {
 524                         /*
 525                          * If user name did not match and token is not
 526                          * a unix group and the token has a winbind separator in the
 527                          * name then see if it is a Windows group.
 528                          */
 529
 530                         DOM_SID g_sid;
 531                         enum SID_NAME_USE name_type;
 532                         BOOL winbind_answered = False;
 533                         BOOL ret;
 534                         fstring groupname, domain;
 535
 536                         /* Parse a string of the form DOMAIN/user into a domain and a user */
 537
 538                         char *p = strchr(*list,*lp_winbind_separator());
 539
 540                         DEBUG(10,("user_in_list: checking if user |%s| is in winbind group |%s|\n", user, *list));
 541
 542                         if (p) {
 543                                 fstrcpy(groupname, p+1);
 544                                 fstrcpy(domain, *list);
 545                                 domain[PTR_DIFF(p, *list)] = 0;
 546
 547                                 /* Check to see if name is a Windows group */
 548                                 if (winbind_lookup_name(domain, groupname, &g_sid, &name_type) && name_type == SID_NAME_DOM_GRP) {
 549
 550                                 /* Check if user name is in the Windows group */
 551                                         ret = user_in_winbind_group_list(user, *list, &winbind_answered);
 552
 553                                         if (winbind_answered && ret == True) {
 554                                                 DEBUG(10,("user_in_list: user |%s| is in winbind group |%s|\n", user, *list));
 555                                                 return ret;
 556                                         }
 557                                 }
 558                         }
 559                 }
 560
 561                 list++;
 562         }
 563         return(False);
 564 }
 565
 566 /* The functions below have been taken from password.c and slightly modified */
 567 /****************************************************************************
 568  Apply a function to upper/lower case combinations
 569  of a string and return true if one of them returns true.
 570  Try all combinations with N uppercase letters.
 571  offset is the first char to try and change (start with 0)
 572  it assumes the string starts lowercased
 573 ****************************************************************************/
 574
 575 static struct passwd *uname_string_combinations2(char *s,int offset,struct passwd *(*fn)(const char *),int N)
 576 {
 577         ssize_t len = (ssize_t)strlen(s);
 578         int i;
 579         struct passwd *ret;
 580
 581         if (N <= 0 || offset >= len)
 582                 return(fn(s));
 583
 584         for (i=offset;i<(len-(N-1));i++) {
 585                 char c = s[i];
 586                 if (!islower((int)c))
 587                         continue;
 588                 s[i] = toupper(c);
 589                 ret = uname_string_combinations2(s,i+1,fn,N-1);
 590                 if(ret)
 591                         return(ret);
 592                 s[i] = c;
 593         }
 594         return(NULL);
 595 }
 596
 597 /****************************************************************************
 598  Apply a function to upper/lower case combinations
 599  of a string and return true if one of them returns true.
 600  Try all combinations with up to N uppercase letters.
 601  offset is the first char to try and change (start with 0)
 602  it assumes the string starts lowercased
 603 ****************************************************************************/
 604
 605 static struct passwd * uname_string_combinations(char *s,struct passwd * (*fn)(const char *),int N)
 606 {
 607         int n;
 608         struct passwd *ret;
 609
 610         for (n=1;n<=N;n++) {
 611                 ret = uname_string_combinations2(s,0,fn,n);
 612                 if(ret)
 613                         return(ret);
 614         }
 615         return(NULL);
 616 }
 617