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