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
  68         session_yield(vuser);
  69
  70         DLIST_REMOVE(validated_users, vuser);
  71
  72         SAFE_FREE(vuser->groups);
  73         delete_nt_token(&vuser->nt_user_token);
  74         SAFE_FREE(vuser);
  75         num_validated_vuids--;
  76 }
  77
  78 /****************************************************************************
  79 invalidate all vuid entries for this process
  80 ****************************************************************************/
  81 void invalidate_all_vuids(void)
  82 {
  83         user_struct *usp, *next=NULL;
  84
  85         for (usp=validated_users;usp;usp=next) {
  86                 next = usp->next;
  87
  88                 invalidate_vuid(usp->vuid);
  89         }
  90 }
  91
  92 /****************************************************************************
  93 return a validated username
  94 ****************************************************************************/
  95 char *validated_username(uint16 vuid)
  96 {
  97         user_struct *vuser = get_valid_user_struct(vuid);
  98         if (vuser == NULL)
  99                 return 0;
 100         return(vuser->user.unix_name);
 101 }
 102
 103 /****************************************************************************
 104 return a validated domain
 105 ****************************************************************************/
 106 char *validated_domain(uint16 vuid)
 107 {
 108         user_struct *vuser = get_valid_user_struct(vuid);
 109         if (vuser == NULL)
 110                 return 0;
 111         return(vuser->user.domain);
 112 }
 113
 114
 115 /****************************************************************************
 116  Create the SID list for this user.
 117 ****************************************************************************/
 118
 119 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)
 120 {
 121         extern DOM_SID global_sid_World;
 122         extern DOM_SID global_sid_Network;
 123         extern DOM_SID global_sid_Builtin_Guests;
 124         extern DOM_SID global_sid_Authenticated_Users;
 125         NT_USER_TOKEN *token;
 126         DOM_SID *psids;
 127         int i, psid_ndx = 0;
 128         size_t num_sids = 0;
 129         fstring sid_str;
 130
 131         if ((token = (NT_USER_TOKEN *)malloc( sizeof(NT_USER_TOKEN) ) ) == NULL)
 132                 return NULL;
 133
 134         ZERO_STRUCTP(token);
 135
 136         /* We always have uid/gid plus World and Network and Authenticated Users or Guest SIDs. */
 137         num_sids = 5 + ngroups;
 138
 139         if (sup_tok && sup_tok->num_sids)
 140                 num_sids += sup_tok->num_sids;
 141
 142         if ((token->user_sids = (DOM_SID *)malloc( num_sids*sizeof(DOM_SID))) == NULL) {
 143                 SAFE_FREE(token);
 144                 return NULL;
 145         }
 146
 147         psids = token->user_sids;
 148
 149         /*
 150          * Note - user SID *MUST* be first in token !
 151          * se_access_check depends on this.
 152          */
 153
 154         uid_to_sid( &psids[PRIMARY_USER_SID_INDEX], uid);
 155         psid_ndx++;
 156
 157         /*
 158          * Primary group SID is second in token. Convention.
 159          */
 160
 161         gid_to_sid( &psids[PRIMARY_GROUP_SID_INDEX], gid);
 162         psid_ndx++;
 163
 164         /* Now add the group SIDs. */
 165
 166         for (i = 0; i < ngroups; i++) {
 167                 if (groups[i] != gid) {
 168                         gid_to_sid( &psids[psid_ndx++], groups[i]);
 169                 }
 170         }
 171
 172         if (sup_tok) {
 173                 /* Now add the additional SIDs from the supplimentary token. */
 174                 for (i = 0; i < sup_tok->num_sids; i++)
 175                         sid_copy( &psids[psid_ndx++], &sup_tok->user_sids[i] );
 176         }
 177
 178         /*
 179          * Finally add the "standard" SIDs.
 180          * The only difference between guest and "anonymous" (which we
 181          * don't really support) is the addition of Authenticated_Users.
 182          */
 183
 184         sid_copy( &psids[psid_ndx++], &global_sid_World);
 185         sid_copy( &psids[psid_ndx++], &global_sid_Network);
 186
 187         if (is_guest)
 188                 sid_copy( &psids[psid_ndx++], &global_sid_Builtin_Guests);
 189         else
 190                 sid_copy( &psids[psid_ndx++], &global_sid_Authenticated_Users);
 191
 192         token->num_sids = psid_ndx;
 193
 194         /* Dump list of sids in token */
 195
 196         for (i = 0; i < token->num_sids; i++) {
 197                 DEBUG(5, ("user token sid %s\n",
 198                           sid_to_string(sid_str, &token->user_sids[i])));
 199         }
 200
 201         return token;
 202 }
 203
 204 /****************************************************************************
 205 register a uid/name pair as being valid and that a valid password
 206 has been given. vuid is biased by an offset. This allows us to
 207 tell random client vuid's (normally zero) from valid vuids.
 208 ****************************************************************************/
 209
 210 int register_vuid(auth_serversupplied_info *server_info, char *smb_name)
 211 {
 212         user_struct *vuser = NULL;
 213         uid_t uid;
 214         gid_t gid;
 215
 216         /* Ensure no vuid gets registered in share level security. */
 217         if(lp_security() == SEC_SHARE)
 218                 return UID_FIELD_INVALID;
 219
 220         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 221         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET)
 222                 return UID_FIELD_INVALID;
 223
 224         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
 225                 DEBUG(0,("Failed to malloc users struct!\n"));
 226                 return UID_FIELD_INVALID;
 227         }
 228
 229         ZERO_STRUCTP(vuser);
 230
 231         if (!IS_SAM_UNIX_USER(server_info->sam_account)) {
 232                 DEBUG(0,("Attempted session setup with invalid user.  No uid/gid in SAM_ACCOUNT (flags:%x)\n", pdb_get_init_flag(server_info->sam_account)));
 233                 free(vuser);
 234                 return UID_FIELD_INVALID;
 235         }
 236
 237         uid = pdb_get_uid(server_info->sam_account);
 238         gid = pdb_get_gid(server_info->sam_account);
 239
 240         /* Allocate a free vuid. Yes this is a linear search... :-) */
 241         while( get_valid_user_struct(next_vuid) != NULL ) {
 242                 next_vuid++;
 243                 /* Check for vuid wrap. */
 244                 if (next_vuid == UID_FIELD_INVALID)
 245                         next_vuid = VUID_OFFSET;
 246         }
 247
 248         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
 249
 250         vuser->vuid = next_vuid;
 251         vuser->uid = uid;
 252         vuser->gid = gid;
 253         vuser->guest = server_info->guest;
 254         fstrcpy(vuser->user.unix_name, pdb_get_username(server_info->sam_account));
 255         fstrcpy(vuser->user.smb_name, smb_name);
 256         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
 257         fstrcpy(vuser->user.full_name, pdb_get_fullname(server_info->sam_account));
 258
 259         {
 260                 /* Keep the homedir handy */
 261                 const char *homedir = pdb_get_homedir(server_info->sam_account);
 262                 if (homedir) {
 263                         vuser->homedir = smb_xstrdup(homedir);
 264                 }
 265         }
 266
 267         memcpy(vuser->session_key, server_info->session_key, sizeof(vuser->session_key));
 268
 269         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n",
 270                   (unsigned int)vuser->uid,
 271                   (unsigned int)vuser->gid,
 272                   vuser->user.unix_name, vuser->user.smb_name, vuser->user.domain, vuser->guest ));
 273
 274         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));
 275
 276         vuser->n_groups = 0;
 277         vuser->groups  = NULL;
 278
 279         /* Find all the groups this uid is in and store them.
 280                 Used by change_to_user() */
 281         initialise_groups(vuser->user.unix_name, vuser->uid, vuser->gid);
 282         get_current_groups( &vuser->n_groups, &vuser->groups);
 283
 284         if (server_info->ptok)
 285                 add_supplementary_nt_login_groups(&vuser->n_groups, &vuser->groups, &server_info->ptok);
 286
 287         /* Create an NT_USER_TOKEN struct for this user. */
 288         vuser->nt_user_token = create_nt_token(vuser->uid, vuser->gid, vuser->n_groups, vuser->groups, vuser->guest, server_info->ptok);
 289
 290         DEBUG(3,("uid %d registered to name %s\n",(int)vuser->uid,vuser->user.unix_name));
 291
 292         next_vuid++;
 293         num_validated_vuids++;
 294
 295         DLIST_ADD(validated_users, vuser);
 296
 297         if (!session_claim(vuser)) {
 298                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
 299                 invalidate_vuid(vuser->vuid);
 300                 return -1;
 301         }
 302
 303         /* Register a home dir service for this user */
 304         if ((!vuser->guest) && vuser->homedir && *(vuser->homedir)
 305                 && (lp_servicenumber(vuser->user.unix_name) < 0)) {
 306                 add_home_service(vuser->user.unix_name, vuser->homedir);
 307         }
 308
 309         return vuser->vuid;
 310 }
 311
 312
 313 /****************************************************************************
 314 add a name to the session users list
 315 ****************************************************************************/
 316 void add_session_user(char *user)
 317 {
 318   fstring suser;
 319   StrnCpy(suser,user,sizeof(suser)-1);
 320
 321   if (!Get_Pwnam_Modify(suser)) return;
 322
 323   if (suser && *suser && !in_list(suser,session_users,False))
 324     {
 325       if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring))
 326         DEBUG(1,("Too many session users??\n"));
 327       else
 328         {
 329           pstrcat(session_users," ");
 330           pstrcat(session_users,suser);
 331         }
 332     }
 333 }
 334
 335
 336 /****************************************************************************
 337 check if a username is valid
 338 ****************************************************************************/
 339 BOOL user_ok(char *user,int snum)
 340 {
 341         char **valid, **invalid;
 342         BOOL ret;
 343
 344         valid = invalid = NULL;
 345         ret = True;
 346
 347         if (lp_invalid_users(snum)) {
 348                 lp_list_copy(&invalid, lp_invalid_users(snum));
 349                 if (invalid && lp_list_substitute(invalid, "%S", lp_servicename(snum))) {
 350                         ret = !user_in_list(user, invalid);
 351                 }
 352         }
 353         if (invalid) lp_list_free (&invalid);
 354
 355         if (ret && lp_valid_users(snum)) {
 356                 lp_list_copy(&valid, lp_valid_users(snum));
 357                 if (valid && lp_list_substitute(valid, "%S", lp_servicename(snum))) {
 358                         ret = user_in_list(user,valid);
 359                 }
 360         }
 361         if (valid) lp_list_free (&valid);
 362
 363         if (ret && lp_onlyuser(snum)) {
 364                 char **user_list = lp_list_make (lp_username(snum));
 365                 if (user_list && lp_list_substitute(user_list, "%S", lp_servicename(snum))) {
 366                         ret = user_in_list(user, user_list);
 367                 }
 368                 if (user_list) lp_list_free (&user_list);
 369         }
 370
 371         return(ret);
 372 }
 373
 374 /****************************************************************************
 375 validate a group username entry. Return the username or NULL
 376 ****************************************************************************/
 377 static char *validate_group(char *group, DATA_BLOB password,int snum)
 378 {
 379 #ifdef HAVE_NETGROUP
 380         {
 381                 char *host, *user, *domain;
 382                 setnetgrent(group);
 383                 while (getnetgrent(&host, &user, &domain)) {
 384                         if (user) {
 385                                 if (user_ok(user, snum) &&
 386                                     password_ok(user,password)) {
 387                                         endnetgrent();
 388                                         return(user);
 389                                 }
 390                         }
 391                 }
 392                 endnetgrent();
 393         }
 394 #endif
 395
 396 #ifdef HAVE_GETGRENT
 397         {
 398                 struct group *gptr;
 399                 setgrent();
 400                 while ((gptr = (struct group *)getgrent())) {
 401                         if (strequal(gptr->gr_name,group))
 402                                 break;
 403                 }
 404
 405                 /*
 406                  * As user_ok can recurse doing a getgrent(), we must
 407                  * copy the member list into a pstring on the stack before
 408                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 409                  */
 410
 411                 if (gptr) {
 412                         pstring member_list;
 413                         char *member;
 414                         size_t copied_len = 0;
 415                         int i;
 416
 417                         *member_list = '\0';
 418                         member = member_list;
 419
 420                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 421                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
 422                                 if( copied_len + member_len < sizeof(pstring)) {
 423
 424                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
 425
 426                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
 427                                         copied_len += member_len;
 428                                         member += copied_len;
 429                                 } else {
 430                                         *member = '\0';
 431                                 }
 432                         }
 433
 434                         endgrent();
 435
 436                         member = member_list;
 437                         while (*member) {
 438                                 static fstring name;
 439                                 fstrcpy(name,member);
 440                                 if (user_ok(name,snum) &&
 441                                     password_ok(name,password)) {
 442                                         endgrent();
 443                                         return(&name[0]);
 444                                 }
 445
 446                                 DEBUG(10,("validate_group = member = %s\n", member));
 447
 448                                 member += strlen(member) + 1;
 449                         }
 450                 } else {
 451                         endgrent();
 452                         return NULL;
 453                 }
 454         }
 455 #endif
 456         return(NULL);
 457 }
 458
 459 /****************************************************************************
 460  Check for authority to login to a service with a given username/password.
 461  Note this is *NOT* used when logging on using sessionsetup_and_X.
 462 ****************************************************************************/
 463
 464 BOOL authorise_login(int snum,char *user, DATA_BLOB password,
 465                      BOOL *guest,BOOL *force,uint16 vuid)
 466 {
 467         BOOL ok = False;
 468         user_struct *vuser = get_valid_user_struct(vuid);
 469
 470 #if DEBUG_PASSWORD
 471         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s vuid=%d\n",
 472                         user,password.data, vuid));
 473 #endif
 474
 475         *guest = False;
 476
 477         if (GUEST_ONLY(snum))
 478                 *force = True;
 479
 480         if (!GUEST_ONLY(snum) && (lp_security() > SEC_SHARE)) {
 481
 482                 /*
 483                  * We should just use the given vuid from a sessionsetup_and_X.
 484                  */
 485
 486                 if (!vuser) {
 487                         DEBUG(1,("authorise_login: refusing user '%s' with no session setup\n", user));
 488                         return False;
 489                 }
 490
 491                 if ((!vuser->guest && user_ok(vuser->user.unix_name,snum)) ||
 492                     (vuser->guest && GUEST_OK(snum))) {
 493                         fstrcpy(user,vuser->user.unix_name);
 494                         *guest = vuser->guest;
 495                         DEBUG(3,("authorise_login: ACCEPTED: validated based on vuid as %sguest \
 496 (user=%s)\n", vuser->guest ? "" : "non-", user));
 497                         return True;
 498                 }
 499         }
 500
 501         /* there are several possibilities:
 502                 1) login as the given user with given password
 503                 2) login as a previously registered username with the given password
 504                 3) login as a session list username with the given password
 505                 4) login as a previously validated user/password pair
 506                 5) login as the "user =" user with given password
 507                 6) login as the "user =" user with no password (guest connection)
 508                 7) login as guest user with no password
 509
 510                 if the service is guest_only then steps 1 to 5 are skipped
 511         */
 512
 513         if (!(GUEST_ONLY(snum) && GUEST_OK(snum))) {
 514                 /* check for a previously registered guest username */
 515                 if (!ok && (vuser != 0) && vuser->guest) {
 516                         if (user_ok(vuser->user.unix_name,snum) &&
 517                                         password_ok(vuser->user.unix_name, password)) {
 518                                 fstrcpy(user, vuser->user.unix_name);
 519                                 *guest = False;
 520                                 DEBUG(3,("authorise_login: ACCEPTED: given password with registered user %s\n", user));
 521                                 ok = True;
 522                         }
 523                 }
 524
 525                 /* now check the list of session users */
 526                 if (!ok) {
 527                         char *auser;
 528                         char *user_list = strdup(session_users);
 529                         if (!user_list)
 530                                 return(False);
 531
 532                         for (auser=strtok(user_list,LIST_SEP); !ok && auser;
 533                                                                         auser = strtok(NULL,LIST_SEP)) {
 534                                 fstring user2;
 535                                 fstrcpy(user2,auser);
 536                                 if (!user_ok(user2,snum))
 537                                         continue;
 538
 539                                 if (password_ok(user2,password)) {
 540                                         ok = True;
 541                                         fstrcpy(user,user2);
 542                                         DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
 543 and given password ok\n", user));
 544                                 }
 545                         }
 546
 547                         SAFE_FREE(user_list);
 548                 }
 549
 550                 /* check for a previously validated username/password pair */
 551                 if (!ok && (lp_security() > SEC_SHARE) && (vuser != 0) && !vuser->guest &&
 552                                                         user_ok(vuser->user.unix_name,snum)) {
 553                         fstrcpy(user,vuser->user.unix_name);
 554                         *guest = False;
 555                         DEBUG(3,("authorise_login: ACCEPTED: validated uid (%s) as non-guest\n",
 556                                 user));
 557                         ok = True;
 558                 }
 559
 560                 /* check the user= fields and the given password */
 561                 if (!ok && lp_username(snum)) {
 562                         char *auser;
 563                         pstring user_list;
 564                         StrnCpy(user_list,lp_username(snum),sizeof(pstring));
 565
 566                         pstring_sub(user_list,"%S",lp_servicename(snum));
 567
 568                         for (auser=strtok(user_list,LIST_SEP); auser && !ok;
 569                                                                                         auser = strtok(NULL,LIST_SEP)) {
 570                                 if (*auser == '@') {
 571                                         auser = validate_group(auser+1,password,snum);
 572                                         if (auser) {
 573                                                 ok = True;
 574                                                 fstrcpy(user,auser);
 575                                                 DEBUG(3,("authorise_login: ACCEPTED: group username \
 576 and given password ok (%s)\n", user));
 577                                         }
 578                                 } else {
 579                                         fstring user2;
 580                                         fstrcpy(user2,auser);
 581                                         if (user_ok(user2,snum) && password_ok(user2,password)) {
 582                                                 ok = True;
 583                                                 fstrcpy(user,user2);
 584                                                 DEBUG(3,("authorise_login: ACCEPTED: user list username \
 585 and given password ok (%s)\n", user));
 586                                         }
 587                                 }
 588                         }
 589                 }
 590         } /* not guest only */
 591
 592         /* check for a normal guest connection */
 593         if (!ok && GUEST_OK(snum)) {
 594                 fstring guestname;
 595                 StrnCpy(guestname,lp_guestaccount(),sizeof(guestname)-1);
 596                 if (Get_Pwnam(guestname)) {
 597                         fstrcpy(user,guestname);
 598                         ok = True;
 599                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
 600                                         user));
 601                 } else {
 602                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
 603                 }
 604                 *guest = True;
 605         }
 606
 607         if (ok && !user_ok(user,snum)) {
 608                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 609                 ok = False;
 610         }
 611
 612         return(ok);
 613 }