source/smbd/password.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 /* users from session setup */
  24 static pstring session_users="";
  25
  26 /* this holds info on user ids that are already validated for this VC */
  27 static user_struct *validated_users;
  28 static int next_vuid = VUID_OFFSET;
  29 static int num_validated_vuids;
  30
  31 /****************************************************************************
  32 check if a uid has been validated, and return an pointer to the user_struct
  33 if it has. NULL if not. vuid is biased by an offset. This allows us to
  34 tell random client vuid's (normally zero) from valid vuids.
  35 ****************************************************************************/
  36 user_struct *get_valid_user_struct(uint16 vuid)
  37 {
  38         user_struct *usp;
  39         int count=0;
  40
  41         if (vuid == UID_FIELD_INVALID)
  42                 return NULL;
  43
  44         for (usp=validated_users;usp;usp=usp->next,count++) {
  45                 if (vuid == usp->vuid) {
  46                         if (count > 10) {
  47                                 DLIST_PROMOTE(validated_users, usp);
  48                         }
  49                         return usp;
  50                 }
  51         }
  52
  53         return NULL;
  54 }
  55
  56 /****************************************************************************
  57 invalidate a uid
  58 ****************************************************************************/
  59 void invalidate_vuid(uint16 vuid)
  60 {
  61         user_struct *vuser = get_valid_user_struct(vuid);
  62
  63         if (vuser == NULL)
  64                 return;
  65
  66         SAFE_FREE(vuser->homedir);
  67         SAFE_FREE(vuser->unix_homedir);
  68         SAFE_FREE(vuser->logon_script);
  69
  70         session_yield(vuser);
  71         SAFE_FREE(vuser->session_keystr);
  72
  73         free_server_info(&vuser->server_info);
  74
  75         DLIST_REMOVE(validated_users, vuser);
  76
  77         /* clear the vuid from the 'cache' on each connection, and
  78            from the vuid 'owner' of connections */
  79         conn_clear_vuid_cache(vuid);
  80
  81         SAFE_FREE(vuser->groups);
  82         delete_nt_token(&vuser->nt_user_token);
  83         SAFE_FREE(vuser);
  84         num_validated_vuids--;
  85 }
  86
  87 /****************************************************************************
  88 invalidate all vuid entries for this process
  89 ****************************************************************************/
  90 void invalidate_all_vuids(void)
  91 {
  92         user_struct *usp, *next=NULL;
  93
  94         for (usp=validated_users;usp;usp=next) {
  95                 next = usp->next;
  96
  97                 invalidate_vuid(usp->vuid);
  98         }
  99 }
 100
 101 /**
 102  *  register that a valid login has been performed, establish 'session'.
 103  *  @param server_info The token returned from the authentication process.
 104  *   (now 'owned' by register_vuid)
 105  *
 106  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 107  *   tell random client vuid's (normally zero) from valid vuids.)
 108  *
 109  */
 110
 111 int register_vuid(auth_serversupplied_info *server_info, const char *smb_name)
 112 {
 113         user_struct *vuser = NULL;
 114
 115         /* Ensure no vuid gets registered in share level security. */
 116         if(lp_security() == SEC_SHARE)
 117                 return UID_FIELD_INVALID;
 118
 119         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 120         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET)
 121                 return UID_FIELD_INVALID;
 122
 123         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
 124                 DEBUG(0,("Failed to malloc users struct!\n"));
 125                 return UID_FIELD_INVALID;
 126         }
 127
 128         ZERO_STRUCTP(vuser);
 129
 130         /* Allocate a free vuid. Yes this is a linear search... :-) */
 131         while( get_valid_user_struct(next_vuid) != NULL ) {
 132                 next_vuid++;
 133                 /* Check for vuid wrap. */
 134                 if (next_vuid == UID_FIELD_INVALID)
 135                         next_vuid = VUID_OFFSET;
 136         }
 137
 138         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
 139
 140         vuser->vuid = next_vuid;
 141
 142         /* the next functions should be done by a SID mapping system (SMS) as
 143          * the new real sam db won't have reference to unix uids or gids
 144          */
 145         if (!IS_SAM_UNIX_USER(server_info->sam_account)) {
 146                 DEBUG(0,("Attempted session setup with invalid user.  No uid/gid in SAM_ACCOUNT\n"));
 147                 free(vuser);
 148                 free_server_info(&server_info);
 149                 return UID_FIELD_INVALID;
 150         }
 151
 152         vuser->uid = pdb_get_uid(server_info->sam_account);
 153         vuser->gid = pdb_get_gid(server_info->sam_account);
 154
 155         vuser->n_groups = server_info->n_groups;
 156         if (vuser->n_groups) {
 157                 if (!(vuser->groups = memdup(server_info->groups, sizeof(gid_t) * vuser->n_groups))) {
 158                         DEBUG(0,("register_vuid: failed to memdup vuser->groups\n"));
 159                         free(vuser);
 160                         free_server_info(&server_info);
 161                         return UID_FIELD_INVALID;
 162                 }
 163         }
 164
 165         vuser->guest = server_info->guest;
 166         fstrcpy(vuser->user.unix_name, pdb_get_username(server_info->sam_account));
 167
 168         /* This is a potentially untrusted username */
 169         alpha_strcpy(vuser->user.smb_name, smb_name, ". _-$", sizeof(vuser->user.smb_name));
 170
 171         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
 172         fstrcpy(vuser->user.full_name, pdb_get_fullname(server_info->sam_account));
 173
 174         {
 175                 /* Keep the homedir handy */
 176                 const char *homedir = pdb_get_homedir(server_info->sam_account);
 177                 const char *unix_homedir = pdb_get_unix_homedir(server_info->sam_account);
 178                 const char *logon_script = pdb_get_logon_script(server_info->sam_account);
 179                 if (homedir) {
 180                         vuser->homedir = smb_xstrdup(homedir);
 181                 }
 182
 183                 if (unix_homedir) {
 184                         vuser->unix_homedir = smb_xstrdup(unix_homedir);
 185                 }
 186
 187                 if (logon_script) {
 188                         vuser->logon_script = smb_xstrdup(logon_script);
 189                 }
 190         }
 191
 192         memcpy(vuser->session_key, server_info->session_key, sizeof(vuser->session_key));
 193
 194         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n",
 195                   (unsigned int)vuser->uid,
 196                   (unsigned int)vuser->gid,
 197                   vuser->user.unix_name, vuser->user.smb_name, vuser->user.domain, vuser->guest ));
 198
 199         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));
 200
 201         if (server_info->ptok) {
 202                 vuser->nt_user_token = dup_nt_token(server_info->ptok);
 203         } else {
 204                 DEBUG(1, ("server_info does not contain a user_token - cannot continue\n"));
 205                 free_server_info(&server_info);
 206                 SAFE_FREE(vuser->homedir);
 207                 SAFE_FREE(vuser->unix_homedir);
 208                 SAFE_FREE(vuser->logon_script);
 209
 210                 SAFE_FREE(vuser);
 211                 return UID_FIELD_INVALID;
 212         }
 213
 214         /* use this to keep tabs on all our info from the authentication */
 215         vuser->server_info = server_info;
 216
 217         DEBUG(3,("UNIX uid %d is UNIX user %s, and will be vuid %u\n",(int)vuser->uid,vuser->user.unix_name, vuser->vuid));
 218
 219         next_vuid++;
 220         num_validated_vuids++;
 221
 222         DLIST_ADD(validated_users, vuser);
 223
 224         if (!session_claim(vuser)) {
 225                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
 226                 invalidate_vuid(vuser->vuid);
 227                 return -1;
 228         }
 229
 230         /* Register a home dir service for this user */
 231         if ((!vuser->guest) && vuser->unix_homedir && *(vuser->unix_homedir)) {
 232                 DEBUG(3, ("Adding/updating homes service for user '%s' using home direcotry: '%s'\n",
 233                           vuser->user.unix_name, vuser->unix_homedir));
 234                 vuser->homes_snum = add_home_service(vuser->user.unix_name, vuser->user.unix_name, vuser->unix_homedir);
 235         } else {
 236                 vuser->homes_snum = -1;
 237         }
 238
 239         return vuser->vuid;
 240 }
 241
 242
 243 /****************************************************************************
 244 add a name to the session users list
 245 ****************************************************************************/
 246 void add_session_user(const char *user)
 247 {
 248   fstring suser;
 249   struct passwd *passwd;
 250
 251   if (!(passwd = Get_Pwnam(user))) return;
 252
 253   fstrcpy(suser,passwd->pw_name);
 254
 255   if (suser && *suser && !in_list(suser,session_users,False))
 256     {
 257       if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring))
 258         DEBUG(1,("Too many session users??\n"));
 259       else
 260         {
 261           pstrcat(session_users," ");
 262           pstrcat(session_users,suser);
 263         }
 264     }
 265 }
 266
 267
 268 /****************************************************************************
 269 check if a username is valid
 270 ****************************************************************************/
 271 BOOL user_ok(const char *user,int snum, gid_t *groups, size_t n_groups)
 272 {
 273         char **valid, **invalid;
 274         BOOL ret;
 275
 276         valid = invalid = NULL;
 277         ret = True;
 278
 279         if (lp_invalid_users(snum)) {
 280                 str_list_copy(&invalid, lp_invalid_users(snum));
 281                 if (invalid && str_list_substitute(invalid, "%S", lp_servicename(snum))) {
 282                         ret = !user_in_list(user, (const char **)invalid, groups, n_groups);
 283                 }
 284         }
 285         if (invalid)
 286                 str_list_free (&invalid);
 287
 288         if (ret && lp_valid_users(snum)) {
 289                 str_list_copy(&valid, lp_valid_users(snum));
 290                 if (valid && str_list_substitute(valid, "%S", lp_servicename(snum))) {
 291                         ret = user_in_list(user, (const char **)valid, groups, n_groups);
 292                 }
 293         }
 294         if (valid)
 295                 str_list_free (&valid);
 296
 297         if (ret && lp_onlyuser(snum)) {
 298                 char **user_list = str_list_make (lp_username(snum), NULL);
 299                 if (user_list && str_list_substitute(user_list, "%S", lp_servicename(snum))) {
 300                         ret = user_in_list(user, (const char **)user_list, groups, n_groups);
 301                 }
 302                 if (user_list) str_list_free (&user_list);
 303         }
 304
 305         return(ret);
 306 }
 307
 308 /****************************************************************************
 309 validate a group username entry. Return the username or NULL
 310 ****************************************************************************/
 311 static char *validate_group(char *group, DATA_BLOB password,int snum)
 312 {
 313 #ifdef HAVE_NETGROUP
 314         {
 315                 char *host, *user, *domain;
 316                 setnetgrent(group);
 317                 while (getnetgrent(&host, &user, &domain)) {
 318                         if (user) {
 319                                 if (user_ok(user, snum, NULL, 0) &&
 320                                     password_ok(user,password)) {
 321                                         endnetgrent();
 322                                         return(user);
 323                                 }
 324                         }
 325                 }
 326                 endnetgrent();
 327         }
 328 #endif
 329
 330 #ifdef HAVE_GETGRENT
 331         {
 332                 struct group *gptr;
 333                 setgrent();
 334                 while ((gptr = (struct group *)getgrent())) {
 335                         if (strequal(gptr->gr_name,group))
 336                                 break;
 337                 }
 338
 339                 /*
 340                  * As user_ok can recurse doing a getgrent(), we must
 341                  * copy the member list into a pstring on the stack before
 342                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 343                  */
 344
 345                 if (gptr) {
 346                         pstring member_list;
 347                         char *member;
 348                         size_t copied_len = 0;
 349                         int i;
 350
 351                         *member_list = '\0';
 352                         member = member_list;
 353
 354                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 355                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
 356                                 if( copied_len + member_len < sizeof(pstring)) {
 357
 358                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
 359
 360                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
 361                                         copied_len += member_len;
 362                                         member += copied_len;
 363                                 } else {
 364                                         *member = '\0';
 365                                 }
 366                         }
 367
 368                         endgrent();
 369
 370                         member = member_list;
 371                         while (*member) {
 372                                 static fstring name;
 373                                 fstrcpy(name,member);
 374                                 if (user_ok(name,snum, NULL, 0) &&
 375                                     password_ok(name,password)) {
 376                                         endgrent();
 377                                         return(&name[0]);
 378                                 }
 379
 380                                 DEBUG(10,("validate_group = member = %s\n", member));
 381
 382                                 member += strlen(member) + 1;
 383                         }
 384                 } else {
 385                         endgrent();
 386                         return NULL;
 387                 }
 388         }
 389 #endif
 390         return(NULL);
 391 }
 392
 393 /****************************************************************************
 394  Check for authority to login to a service with a given username/password.
 395  Note this is *NOT* used when logging on using sessionsetup_and_X.
 396 ****************************************************************************/
 397
 398 BOOL authorise_login(int snum, fstring user, DATA_BLOB password,
 399                      BOOL *guest)
 400 {
 401         BOOL ok = False;
 402
 403 #if DEBUG_PASSWORD
 404         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s\n",
 405                    user,password.data));
 406 #endif
 407
 408         *guest = False;
 409
 410         /* there are several possibilities:
 411                 1) login as the given user with given password
 412                 2) login as a previously registered username with the given password
 413                 3) login as a session list username with the given password
 414                 4) login as a previously validated user/password pair
 415                 5) login as the "user =" user with given password
 416                 6) login as the "user =" user with no password (guest connection)
 417                 7) login as guest user with no password
 418
 419                 if the service is guest_only then steps 1 to 5 are skipped
 420         */
 421
 422         /* now check the list of session users */
 423         if (!ok) {
 424                 char *auser;
 425                 char *user_list = strdup(session_users);
 426                 if (!user_list)
 427                         return(False);
 428
 429                 for (auser=strtok(user_list,LIST_SEP); !ok && auser;
 430                      auser = strtok(NULL,LIST_SEP)) {
 431                         fstring user2;
 432                         fstrcpy(user2,auser);
 433                         if (!user_ok(user2,snum, NULL, 0))
 434                                 continue;
 435
 436                         if (password_ok(user2,password)) {
 437                                 ok = True;
 438                                 fstrcpy(user,user2);
 439                                 DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
 440 and given password ok\n", user));
 441                         }
 442                 }
 443
 444                 SAFE_FREE(user_list);
 445         }
 446
 447         /* check the user= fields and the given password */
 448         if (!ok && lp_username(snum)) {
 449                 char *auser;
 450                 pstring user_list;
 451                 pstrcpy(user_list,lp_username(snum));
 452
 453                 pstring_sub(user_list,"%S",lp_servicename(snum));
 454
 455                 for (auser=strtok(user_list,LIST_SEP); auser && !ok;
 456                      auser = strtok(NULL,LIST_SEP)) {
 457                         if (*auser == '@') {
 458                                 auser = validate_group(auser+1,password,snum);
 459                                 if (auser) {
 460                                         ok = True;
 461                                         fstrcpy(user,auser);
 462                                         DEBUG(3,("authorise_login: ACCEPTED: group username \
 463 and given password ok (%s)\n", user));
 464                                 }
 465                         } else {
 466                                 fstring user2;
 467                                 fstrcpy(user2,auser);
 468                                 if (user_ok(user2,snum, NULL, 0) && password_ok(user2,password)) {
 469                                         ok = True;
 470                                         fstrcpy(user,user2);
 471                                         DEBUG(3,("authorise_login: ACCEPTED: user list username \
 472 and given password ok (%s)\n", user));
 473                                 }
 474                         }
 475                 }
 476         }
 477
 478         /* check for a normal guest connection */
 479         if (!ok && GUEST_OK(snum)) {
 480                 fstring guestname;
 481                 fstrcpy(guestname,lp_guestaccount());
 482                 if (Get_Pwnam(guestname)) {
 483                         fstrcpy(user,guestname);
 484                         ok = True;
 485                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
 486                                         user));
 487                 } else {
 488                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
 489                 }
 490                 *guest = True;
 491         }
 492
 493         if (ok && !user_ok(user, snum, NULL, 0)) {
 494                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 495                 ok = False;
 496         }
 497
 498         return(ok);
 499 }