source/smbd/password.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    Password and authentication handling
   5    Copyright (C) Andrew Tridgell 1992-1998
   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 /* users from session setup */
  25 static pstring session_users="";
  26
  27 /* this holds info on user ids that are already validated for this VC */
  28 static user_struct *validated_users;
  29 static int next_vuid = VUID_OFFSET;
  30 static int num_validated_vuids;
  31
  32 /****************************************************************************
  33 check if a uid has been validated, and return an pointer to the user_struct
  34 if it has. NULL if not. vuid is biased by an offset. This allows us to
  35 tell random client vuid's (normally zero) from valid vuids.
  36 ****************************************************************************/
  37 user_struct *get_valid_user_struct(uint16 vuid)
  38 {
  39         user_struct *usp;
  40         int count=0;
  41
  42         if (vuid == UID_FIELD_INVALID)
  43                 return NULL;
  44
  45         for (usp=validated_users;usp;usp=usp->next,count++) {
  46                 if (vuid == usp->vuid) {
  47                         if (count > 10) {
  48                                 DLIST_PROMOTE(validated_users, usp);
  49                         }
  50                         return usp;
  51                 }
  52         }
  53
  54         return NULL;
  55 }
  56
  57 /****************************************************************************
  58 invalidate a uid
  59 ****************************************************************************/
  60 void invalidate_vuid(uint16 vuid)
  61 {
  62         user_struct *vuser = get_valid_user_struct(vuid);
  63
  64         if (vuser == NULL)
  65                 return;
  66
  67         session_yield(vuser);
  68
  69         DLIST_REMOVE(validated_users, vuser);
  70
  71         SAFE_FREE(vuser->groups);
  72         delete_nt_token(&vuser->nt_user_token);
  73         SAFE_FREE(vuser);
  74         num_validated_vuids--;
  75 }
  76
  77 /****************************************************************************
  78 invalidate all vuid entries for this process
  79 ****************************************************************************/
  80 void invalidate_all_vuids(void)
  81 {
  82         user_struct *usp, *next=NULL;
  83
  84         for (usp=validated_users;usp;usp=next) {
  85                 next = usp->next;
  86
  87                 invalidate_vuid(usp->vuid);
  88         }
  89 }
  90
  91 /****************************************************************************
  92 return a validated username
  93 ****************************************************************************/
  94 char *validated_username(uint16 vuid)
  95 {
  96         user_struct *vuser = get_valid_user_struct(vuid);
  97         if (vuser == NULL)
  98                 return 0;
  99         return(vuser->user.unix_name);
 100 }
 101
 102 /****************************************************************************
 103 return a validated domain
 104 ****************************************************************************/
 105 char *validated_domain(uint16 vuid)
 106 {
 107         user_struct *vuser = get_valid_user_struct(vuid);
 108         if (vuser == NULL)
 109                 return 0;
 110         return(vuser->user.domain);
 111 }
 112
 113
 114 /****************************************************************************
 115  Create the SID list for this user.
 116 ****************************************************************************/
 117
 118 NT_USER_TOKEN *create_nt_token(uid_t uid, gid_t gid, int ngroups, gid_t *groups, BOOL is_guest, NT_USER_TOKEN *sup_tok)
 119 {
 120         extern DOM_SID global_sid_World;
 121         extern DOM_SID global_sid_Network;
 122         extern DOM_SID global_sid_Builtin_Guests;
 123         extern DOM_SID global_sid_Authenticated_Users;
 124         NT_USER_TOKEN *token;
 125         DOM_SID *psids;
 126         int i, psid_ndx = 0;
 127         size_t num_sids = 0;
 128         fstring sid_str;
 129
 130         if ((token = (NT_USER_TOKEN *)malloc( sizeof(NT_USER_TOKEN) ) ) == NULL)
 131                 return NULL;
 132
 133         ZERO_STRUCTP(token);
 134
 135         /* We always have uid/gid plus World and Network and Authenticated Users or Guest SIDs. */
 136         num_sids = 5 + ngroups;
 137
 138         if (sup_tok && sup_tok->num_sids)
 139                 num_sids += sup_tok->num_sids;
 140
 141         if ((token->user_sids = (DOM_SID *)malloc( num_sids*sizeof(DOM_SID))) == NULL) {
 142                 SAFE_FREE(token);
 143                 return NULL;
 144         }
 145
 146         psids = token->user_sids;
 147
 148         /*
 149          * Note - user SID *MUST* be first in token !
 150          * se_access_check depends on this.
 151          */
 152
 153         uid_to_sid( &psids[PRIMARY_USER_SID_INDEX], uid);
 154         psid_ndx++;
 155
 156         /*
 157          * Primary group SID is second in token. Convention.
 158          */
 159
 160         gid_to_sid( &psids[PRIMARY_GROUP_SID_INDEX], gid);
 161         psid_ndx++;
 162
 163         /* Now add the group SIDs. */
 164
 165         for (i = 0; i < ngroups; i++) {
 166                 if (groups[i] != gid) {
 167                         gid_to_sid( &psids[psid_ndx++], groups[i]);
 168                 }
 169         }
 170
 171         if (sup_tok) {
 172                 /* Now add the additional SIDs from the supplimentary token. */
 173                 for (i = 0; i < sup_tok->num_sids; i++)
 174                         sid_copy( &psids[psid_ndx++], &sup_tok->user_sids[i] );
 175         }
 176
 177         /*
 178          * Finally add the "standard" SIDs.
 179          * The only difference between guest and "anonymous" (which we
 180          * don't really support) is the addition of Authenticated_Users.
 181          */
 182
 183         sid_copy( &psids[psid_ndx++], &global_sid_World);
 184         sid_copy( &psids[psid_ndx++], &global_sid_Network);
 185
 186         if (is_guest)
 187                 sid_copy( &psids[psid_ndx++], &global_sid_Builtin_Guests);
 188         else
 189                 sid_copy( &psids[psid_ndx++], &global_sid_Authenticated_Users);
 190
 191         token->num_sids = psid_ndx;
 192
 193         /* Dump list of sids in token */
 194
 195         for (i = 0; i < token->num_sids; i++) {
 196                 DEBUG(5, ("user token sid %s\n",
 197                           sid_to_string(sid_str, &token->user_sids[i])));
 198         }
 199
 200         return token;
 201 }
 202
 203 /****************************************************************************
 204 register a uid/name pair as being valid and that a valid password
 205 has been given. vuid is biased by an offset. This allows us to
 206 tell random client vuid's (normally zero) from valid vuids.
 207 ****************************************************************************/
 208
 209 int register_vuid(auth_serversupplied_info *server_info, char *smb_name)
 210 {
 211         user_struct *vuser = NULL;
 212         uid_t *puid;
 213         gid_t *pgid;
 214
 215         /* Ensure no vuid gets registered in share level security. */
 216         if(lp_security() == SEC_SHARE)
 217                 return UID_FIELD_INVALID;
 218
 219         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 220         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET)
 221                 return UID_FIELD_INVALID;
 222
 223         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
 224                 DEBUG(0,("Failed to malloc users struct!\n"));
 225                 return UID_FIELD_INVALID;
 226         }
 227
 228         ZERO_STRUCTP(vuser);
 229
 230         puid = pdb_get_uid(server_info->sam_account);
 231         pgid = pdb_get_gid(server_info->sam_account);
 232
 233         if (!puid || !pgid) {
 234                 DEBUG(0,("Attempted session setup with invalid user.  No uid/gid in SAM_ACCOUNT\n"));
 235                 free(vuser);
 236                 return UID_FIELD_INVALID;
 237         }
 238
 239         /* Allocate a free vuid. Yes this is a linear search... :-) */
 240         while( get_valid_user_struct(next_vuid) != NULL ) {
 241                 next_vuid++;
 242                 /* Check for vuid wrap. */
 243                 if (next_vuid == UID_FIELD_INVALID)
 244                         next_vuid = VUID_OFFSET;
 245         }
 246
 247         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
 248
 249         vuser->vuid = next_vuid;
 250         vuser->uid = *puid;
 251         vuser->gid = *pgid;
 252         vuser->guest = server_info->guest;
 253         fstrcpy(vuser->user.unix_name, pdb_get_username(server_info->sam_account));
 254         fstrcpy(vuser->user.smb_name, smb_name);
 255         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
 256         fstrcpy(vuser->user.full_name, pdb_get_fullname(server_info->sam_account));
 257
 258         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n",
 259                   (unsigned int)vuser->uid,
 260                   (unsigned int)vuser->gid,
 261                   vuser->user.unix_name, vuser->user.smb_name, vuser->user.domain, vuser->guest ));
 262
 263         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));
 264
 265         vuser->n_groups = 0;
 266         vuser->groups  = NULL;
 267
 268         /* Find all the groups this uid is in and store them.
 269                 Used by change_to_user() */
 270         initialise_groups(vuser->user.unix_name, vuser->uid, vuser->gid);
 271         get_current_groups( &vuser->n_groups, &vuser->groups);
 272
 273         if (server_info->ptok)
 274                 add_supplementary_nt_login_groups(&vuser->n_groups, &vuser->groups, &server_info->ptok);
 275
 276         /* Create an NT_USER_TOKEN struct for this user. */
 277         vuser->nt_user_token = create_nt_token(vuser->uid, vuser->gid, vuser->n_groups, vuser->groups, vuser->guest, server_info->ptok);
 278
 279         DEBUG(3,("uid %d registered to name %s\n",(int)vuser->uid,vuser->user.unix_name));
 280
 281         next_vuid++;
 282         num_validated_vuids++;
 283
 284         DLIST_ADD(validated_users, vuser);
 285
 286         if (!session_claim(vuser)) {
 287                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
 288                 invalidate_vuid(vuser->vuid);
 289                 return -1;
 290         }
 291
 292         return vuser->vuid;
 293 }
 294
 295
 296 /****************************************************************************
 297 add a name to the session users list
 298 ****************************************************************************/
 299 void add_session_user(char *user)
 300 {
 301   fstring suser;
 302   StrnCpy(suser,user,sizeof(suser)-1);
 303
 304   if (!Get_Pwnam_Modify(suser)) return;
 305
 306   if (suser && *suser && !in_list(suser,session_users,False))
 307     {
 308       if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring))
 309         DEBUG(1,("Too many session users??\n"));
 310       else
 311         {
 312           pstrcat(session_users," ");
 313           pstrcat(session_users,suser);
 314         }
 315     }
 316 }
 317
 318
 319 /****************************************************************************
 320 check if a username is valid
 321 ****************************************************************************/
 322 BOOL user_ok(char *user,int snum)
 323 {
 324         char **valid, **invalid;
 325         BOOL ret;
 326
 327         valid = invalid = NULL;
 328         ret = True;
 329
 330         if (lp_invalid_users(snum)) {
 331                 lp_list_copy(&invalid, lp_invalid_users(snum));
 332                 if (invalid && lp_list_substitute(invalid, "%S", lp_servicename(snum))) {
 333                         ret = !user_in_list(user, invalid);
 334                 }
 335         }
 336         if (invalid) lp_list_free (&invalid);
 337
 338         if (ret && lp_valid_users(snum)) {
 339                 lp_list_copy(&valid, lp_valid_users(snum));
 340                 if (valid && lp_list_substitute(valid, "%S", lp_servicename(snum))) {
 341                         ret = user_in_list(user,valid);
 342                 }
 343         }
 344         if (valid) lp_list_free (&valid);
 345
 346         if (ret && lp_onlyuser(snum)) {
 347                 char **user_list = lp_list_make (lp_username(snum));
 348                 if (user_list && lp_list_substitute(user_list, "%S", lp_servicename(snum))) {
 349                         ret = user_in_list(user, user_list);
 350                 }
 351                 if (user_list) lp_list_free (&user_list);
 352         }
 353
 354         return(ret);
 355 }
 356
 357 /****************************************************************************
 358 validate a group username entry. Return the username or NULL
 359 ****************************************************************************/
 360 static char *validate_group(char *group, DATA_BLOB password,int snum)
 361 {
 362 #ifdef HAVE_NETGROUP
 363         {
 364                 char *host, *user, *domain;
 365                 setnetgrent(group);
 366                 while (getnetgrent(&host, &user, &domain)) {
 367                         if (user) {
 368                                 if (user_ok(user, snum) &&
 369                                     password_ok(user,password)) {
 370                                         endnetgrent();
 371                                         return(user);
 372                                 }
 373                         }
 374                 }
 375                 endnetgrent();
 376         }
 377 #endif
 378
 379 #ifdef HAVE_GETGRENT
 380         {
 381                 struct group *gptr;
 382                 setgrent();
 383                 while ((gptr = (struct group *)getgrent())) {
 384                         if (strequal(gptr->gr_name,group))
 385                                 break;
 386                 }
 387
 388                 /*
 389                  * As user_ok can recurse doing a getgrent(), we must
 390                  * copy the member list into a pstring on the stack before
 391                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 392                  */
 393
 394                 if (gptr) {
 395                         pstring member_list;
 396                         char *member;
 397                         size_t copied_len = 0;
 398                         int i;
 399
 400                         *member_list = '\0';
 401                         member = member_list;
 402
 403                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 404                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
 405                                 if( copied_len + member_len < sizeof(pstring)) {
 406
 407                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
 408
 409                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
 410                                         copied_len += member_len;
 411                                         member += copied_len;
 412                                 } else {
 413                                         *member = '\0';
 414                                 }
 415                         }
 416
 417                         endgrent();
 418
 419                         member = member_list;
 420                         while (*member) {
 421                                 static fstring name;
 422                                 fstrcpy(name,member);
 423                                 if (user_ok(name,snum) &&
 424                                     password_ok(name,password)) {
 425                                         endgrent();
 426                                         return(&name[0]);
 427                                 }
 428
 429                                 DEBUG(10,("validate_group = member = %s\n", member));
 430
 431                                 member += strlen(member) + 1;
 432                         }
 433                 } else {
 434                         endgrent();
 435                         return NULL;
 436                 }
 437         }
 438 #endif
 439         return(NULL);
 440 }
 441
 442 /****************************************************************************
 443  Check for authority to login to a service with a given username/password.
 444  Note this is *NOT* used when logging on using sessionsetup_and_X.
 445 ****************************************************************************/
 446
 447 BOOL authorise_login(int snum,char *user, DATA_BLOB password,
 448                      BOOL *guest,BOOL *force,uint16 vuid)
 449 {
 450         BOOL ok = False;
 451         user_struct *vuser = get_valid_user_struct(vuid);
 452
 453 #if DEBUG_PASSWORD
 454         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s vuid=%d\n",
 455                         user,password.data, vuid));
 456 #endif
 457
 458         *guest = False;
 459
 460         if (GUEST_ONLY(snum))
 461                 *force = True;
 462
 463         if (!GUEST_ONLY(snum) && (lp_security() > SEC_SHARE)) {
 464
 465                 /*
 466                  * We should just use the given vuid from a sessionsetup_and_X.
 467                  */
 468
 469                 if (!vuser) {
 470                         DEBUG(1,("authorise_login: refusing user '%s' with no session setup\n", user));
 471                         return False;
 472                 }
 473
 474                 if ((!vuser->guest && user_ok(vuser->user.unix_name,snum)) ||
 475                     (vuser->guest && GUEST_OK(snum))) {
 476                         fstrcpy(user,vuser->user.unix_name);
 477                         *guest = vuser->guest;
 478                         DEBUG(3,("authorise_login: ACCEPTED: validated based on vuid as %sguest \
 479 (user=%s)\n", vuser->guest ? "" : "non-", user));
 480                         return True;
 481                 }
 482         }
 483
 484         /* there are several possibilities:
 485                 1) login as the given user with given password
 486                 2) login as a previously registered username with the given password
 487                 3) login as a session list username with the given password
 488                 4) login as a previously validated user/password pair
 489                 5) login as the "user =" user with given password
 490                 6) login as the "user =" user with no password (guest connection)
 491                 7) login as guest user with no password
 492
 493                 if the service is guest_only then steps 1 to 5 are skipped
 494         */
 495
 496         if (!(GUEST_ONLY(snum) && GUEST_OK(snum))) {
 497                 /* check for a previously registered guest username */
 498                 if (!ok && (vuser != 0) && vuser->guest) {
 499                         if (user_ok(vuser->user.unix_name,snum) &&
 500                                         password_ok(vuser->user.unix_name, password)) {
 501                                 fstrcpy(user, vuser->user.unix_name);
 502                                 *guest = False;
 503                                 DEBUG(3,("authorise_login: ACCEPTED: given password with registered user %s\n", user));
 504                                 ok = True;
 505                         }
 506                 }
 507
 508                 /* now check the list of session users */
 509                 if (!ok) {
 510                         char *auser;
 511                         char *user_list = strdup(session_users);
 512                         if (!user_list)
 513                                 return(False);
 514
 515                         for (auser=strtok(user_list,LIST_SEP); !ok && auser;
 516                                                                         auser = strtok(NULL,LIST_SEP)) {
 517                                 fstring user2;
 518                                 fstrcpy(user2,auser);
 519                                 if (!user_ok(user2,snum))
 520                                         continue;
 521
 522                                 if (password_ok(user2,password)) {
 523                                         ok = True;
 524                                         fstrcpy(user,user2);
 525                                         DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
 526 and given password ok\n", user));
 527                                 }
 528                         }
 529
 530                         SAFE_FREE(user_list);
 531                 }
 532
 533                 /* check for a previously validated username/password pair */
 534                 if (!ok && (lp_security() > SEC_SHARE) && (vuser != 0) && !vuser->guest &&
 535                                                         user_ok(vuser->user.unix_name,snum)) {
 536                         fstrcpy(user,vuser->user.unix_name);
 537                         *guest = False;
 538                         DEBUG(3,("authorise_login: ACCEPTED: validated uid (%s) as non-guest\n",
 539                                 user));
 540                         ok = True;
 541                 }
 542
 543                 /* check the user= fields and the given password */
 544                 if (!ok && lp_username(snum)) {
 545                         char *auser;
 546                         pstring user_list;
 547                         StrnCpy(user_list,lp_username(snum),sizeof(pstring));
 548
 549                         pstring_sub(user_list,"%S",lp_servicename(snum));
 550
 551                         for (auser=strtok(user_list,LIST_SEP); auser && !ok;
 552                                                                                         auser = strtok(NULL,LIST_SEP)) {
 553                                 if (*auser == '@') {
 554                                         auser = validate_group(auser+1,password,snum);
 555                                         if (auser) {
 556                                                 ok = True;
 557                                                 fstrcpy(user,auser);
 558                                                 DEBUG(3,("authorise_login: ACCEPTED: group username \
 559 and given password ok (%s)\n", user));
 560                                         }
 561                                 } else {
 562                                         fstring user2;
 563                                         fstrcpy(user2,auser);
 564                                         if (user_ok(user2,snum) && password_ok(user2,password)) {
 565                                                 ok = True;
 566                                                 fstrcpy(user,user2);
 567                                                 DEBUG(3,("authorise_login: ACCEPTED: user list username \
 568 and given password ok (%s)\n", user));
 569                                         }
 570                                 }
 571                         }
 572                 }
 573         } /* not guest only */
 574
 575         /* check for a normal guest connection */
 576         if (!ok && GUEST_OK(snum)) {
 577                 fstring guestname;
 578                 StrnCpy(guestname,lp_guestaccount(),sizeof(guestname)-1);
 579                 if (Get_Pwnam(guestname)) {
 580                         fstrcpy(user,guestname);
 581                         ok = True;
 582                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
 583                                         user));
 584                 } else {
 585                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
 586                 }
 587                 *guest = True;
 588         }
 589
 590         if (ok && !user_ok(user,snum)) {
 591                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 592                 ok = False;
 593         }
 594
 595         return(ok);
 596 }