source3/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 extern struct in_addr ipzero;
  25
  26 /* users from session setup */
  27 static pstring session_users="";
  28
  29 /* this holds info on user ids that are already validated for this VC */
  30 static user_struct *validated_users;
  31 static int next_vuid = VUID_OFFSET;
  32 static int num_validated_vuids;
  33
  34 /****************************************************************************
  35 check if a uid has been validated, and return an pointer to the user_struct
  36 if it has. NULL if not. vuid is biased by an offset. This allows us to
  37 tell random client vuid's (normally zero) from valid vuids.
  38 ****************************************************************************/
  39 user_struct *get_valid_user_struct(uint16 vuid)
  40 {
  41         user_struct *usp;
  42         int count=0;
  43
  44         if (vuid == UID_FIELD_INVALID)
  45                 return NULL;
  46
  47         for (usp=validated_users;usp;usp=usp->next,count++) {
  48                 if (vuid == usp->vuid) {
  49                         if (count > 10) {
  50                                 DLIST_PROMOTE(validated_users, usp);
  51                         }
  52                         return usp;
  53                 }
  54         }
  55
  56         return NULL;
  57 }
  58
  59 /****************************************************************************
  60 invalidate a uid
  61 ****************************************************************************/
  62 void invalidate_vuid(uint16 vuid)
  63 {
  64         user_struct *vuser = get_valid_user_struct(vuid);
  65
  66         if (vuser == NULL)
  67                 return;
  68
  69         session_yield(vuid);
  70
  71         DLIST_REMOVE(validated_users, vuser);
  72
  73         SAFE_FREE(vuser->groups);
  74         delete_nt_token(&vuser->nt_user_token);
  75         SAFE_FREE(vuser);
  76         num_validated_vuids--;
  77 }
  78
  79 /****************************************************************************
  80 invalidate all vuid entries for this process
  81 ****************************************************************************/
  82 void invalidate_all_vuids(void)
  83 {
  84         user_struct *usp, *next=NULL;
  85
  86         for (usp=validated_users;usp;usp=next) {
  87                 next = usp->next;
  88
  89                 invalidate_vuid(usp->vuid);
  90         }
  91 }
  92
  93 /****************************************************************************
  94 return a validated username
  95 ****************************************************************************/
  96 char *validated_username(uint16 vuid)
  97 {
  98         user_struct *vuser = get_valid_user_struct(vuid);
  99         if (vuser == NULL)
 100                 return 0;
 101         return(vuser->user.unix_name);
 102 }
 103
 104 /****************************************************************************
 105 return a validated domain
 106 ****************************************************************************/
 107 char *validated_domain(uint16 vuid)
 108 {
 109         user_struct *vuser = get_valid_user_struct(vuid);
 110         if (vuser == NULL)
 111                 return 0;
 112         return(vuser->user.domain);
 113 }
 114
 115
 116 /****************************************************************************
 117  Create the SID list for this user.
 118 ****************************************************************************/
 119
 120 NT_USER_TOKEN *create_nt_token(uid_t uid, gid_t gid, int ngroups, gid_t *groups, BOOL is_guest)
 121 {
 122         extern DOM_SID global_sid_World;
 123         extern DOM_SID global_sid_Network;
 124         extern DOM_SID global_sid_Builtin_Guests;
 125         extern DOM_SID global_sid_Authenticated_Users;
 126         NT_USER_TOKEN *token;
 127         DOM_SID *psids;
 128         int i, psid_ndx = 0;
 129         size_t num_sids = 0;
 130         fstring sid_str;
 131
 132         if ((token = (NT_USER_TOKEN *)malloc( sizeof(NT_USER_TOKEN) ) ) == NULL)
 133                 return NULL;
 134
 135         ZERO_STRUCTP(token);
 136
 137         /* We always have uid/gid plus World and Network and Authenticated Users or Guest SIDs. */
 138         num_sids = 5 + ngroups;
 139
 140         if ((token->user_sids = (DOM_SID *)malloc( num_sids*sizeof(DOM_SID))) == NULL) {
 141                 SAFE_FREE(token);
 142                 return NULL;
 143         }
 144
 145         psids = token->user_sids;
 146
 147         /*
 148          * Note - user SID *MUST* be first in token !
 149          * se_access_check depends on this.
 150          */
 151
 152         uid_to_sid( &psids[psid_ndx++], uid);
 153
 154         /*
 155          * Primary group SID is second in token. Convention.
 156          */
 157
 158         gid_to_sid( &psids[psid_ndx++], gid);
 159
 160         /* Now add the group SIDs. */
 161
 162         for (i = 0; i < ngroups; i++) {
 163                 if (groups[i] != gid) {
 164                         gid_to_sid( &psids[psid_ndx++], groups[i]);
 165                 }
 166         }
 167
 168         /*
 169          * Finally add the "standard" SIDs.
 170          * The only difference between guest and "anonymous" (which we
 171          * don't really support) is the addition of Authenticated_Users.
 172          */
 173
 174         sid_copy( &psids[psid_ndx++], &global_sid_World);
 175         sid_copy( &psids[psid_ndx++], &global_sid_Network);
 176
 177         if (is_guest)
 178                 sid_copy( &psids[psid_ndx++], &global_sid_Builtin_Guests);
 179         else
 180                 sid_copy( &psids[psid_ndx++], &global_sid_Authenticated_Users);
 181
 182         token->num_sids = psid_ndx;
 183
 184         /* Dump list of sids in token */
 185
 186         for (i = 0; i < token->num_sids; i++) {
 187                 DEBUG(5, ("user token sid %s\n",
 188                           sid_to_string(sid_str, &token->user_sids[i])));
 189         }
 190
 191         return token;
 192 }
 193
 194 /****************************************************************************
 195 register a uid/name pair as being valid and that a valid password
 196 has been given. vuid is biased by an offset. This allows us to
 197 tell random client vuid's (normally zero) from valid vuids.
 198 ****************************************************************************/
 199
 200 int register_vuid(uid_t uid,gid_t gid, char *unix_name, char *requested_name,
 201                   char *domain,BOOL guest, char *full_name)
 202 {
 203         user_struct *vuser = NULL;
 204
 205         /* Ensure no vuid gets registered in share level security. */
 206         if(lp_security() == SEC_SHARE)
 207                 return UID_FIELD_INVALID;
 208
 209         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 210         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET)
 211                 return UID_FIELD_INVALID;
 212
 213         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
 214                 DEBUG(0,("Failed to malloc users struct!\n"));
 215                 return UID_FIELD_INVALID;
 216         }
 217
 218         ZERO_STRUCTP(vuser);
 219
 220         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n", (unsigned int)uid, (unsigned int)gid,
 221                                 unix_name, requested_name, domain, guest ));
 222
 223         /* Allocate a free vuid. Yes this is a linear search... :-) */
 224         while( get_valid_user_struct(next_vuid) != NULL ) {
 225                 next_vuid++;
 226                 /* Check for vuid wrap. */
 227                 if (next_vuid == UID_FIELD_INVALID)
 228                         next_vuid = VUID_OFFSET;
 229         }
 230
 231         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
 232
 233         vuser->vuid = next_vuid;
 234         vuser->uid = uid;
 235         vuser->gid = gid;
 236         vuser->guest = guest;
 237         fstrcpy(vuser->user.unix_name,unix_name);
 238         fstrcpy(vuser->user.smb_name,requested_name);
 239         fstrcpy(vuser->user.domain,domain);
 240         fstrcpy(vuser->user.full_name, full_name);
 241         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));
 242
 243         vuser->n_groups = 0;
 244         vuser->groups  = NULL;
 245
 246         /* Find all the groups this uid is in and store them.
 247                 Used by become_user() */
 248         initialise_groups(vuser->user.unix_name, vuser->uid, vuser->gid);
 249         get_current_groups( &vuser->n_groups, &vuser->groups);
 250
 251         /* Create an NT_USER_TOKEN struct for this user. */
 252         vuser->nt_user_token = create_nt_token(vuser->uid, vuser->gid, vuser->n_groups, vuser->groups, guest);
 253
 254         DEBUG(3,("uid %d registered to name %s\n",(int)vuser->uid,vuser->user.unix_name));
 255
 256         next_vuid++;
 257         num_validated_vuids++;
 258
 259         DLIST_ADD(validated_users, vuser);
 260
 261         if (!session_claim(vuser->vuid)) {
 262                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
 263                 invalidate_vuid(vuser->vuid);
 264                 return -1;
 265         }
 266
 267         return vuser->vuid;
 268 }
 269
 270
 271 /****************************************************************************
 272 add a name to the session users list
 273 ****************************************************************************/
 274 void add_session_user(char *user)
 275 {
 276   fstring suser;
 277   StrnCpy(suser,user,sizeof(suser)-1);
 278
 279   if (!Get_Pwnam(suser,True)) return;
 280
 281   if (suser && *suser && !in_list(suser,session_users,False))
 282     {
 283       if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring))
 284         DEBUG(1,("Too many session users??\n"));
 285       else
 286         {
 287           pstrcat(session_users," ");
 288           pstrcat(session_users,suser);
 289         }
 290     }
 291 }
 292
 293
 294 /****************************************************************************
 295 check if a username is valid
 296 ****************************************************************************/
 297 BOOL user_ok(char *user,int snum)
 298 {
 299         char **valid, **invalid;
 300         BOOL ret;
 301
 302         valid = invalid = NULL;
 303         ret = True;
 304
 305         if (lp_invalid_users(snum)) {
 306                 lp_list_copy(&invalid, lp_invalid_users(snum));
 307                 if (invalid && lp_list_substitute(invalid, "%S", lp_servicename(snum))) {
 308                         ret = !user_in_list(user, invalid);
 309                 }
 310         }
 311         if (invalid) lp_list_free (&invalid);
 312
 313         if (ret && lp_valid_users(snum)) {
 314                 lp_list_copy(&valid, lp_valid_users(snum));
 315                 if (valid && lp_list_substitute(valid, "%S", lp_servicename(snum))) {
 316                         ret = user_in_list(user,valid);
 317                 }
 318         }
 319         if (valid) lp_list_free (&valid);
 320
 321         if (ret && lp_onlyuser(snum)) {
 322                 char **user_list = lp_list_make (lp_username(snum));
 323                 if (user_list && lp_list_substitute(user_list, "%S", lp_servicename(snum))) {
 324                         ret = user_in_list(user, user_list);
 325                 }
 326                 if (user_list) lp_list_free (&user_list);
 327         }
 328
 329         return(ret);
 330 }
 331
 332 /****************************************************************************
 333 validate a group username entry. Return the username or NULL
 334 ****************************************************************************/
 335 static char *validate_group(char *group,char *password,int pwlen,int snum)
 336 {
 337 #ifdef HAVE_NETGROUP
 338         {
 339                 char *host, *user, *domain;
 340                 setnetgrent(group);
 341                 while (getnetgrent(&host, &user, &domain)) {
 342                         if (user) {
 343                                 if (user_ok(user, snum) &&
 344                                     password_ok(user,password,pwlen)) {
 345                                         endnetgrent();
 346                                         return(user);
 347                                 }
 348                         }
 349                 }
 350                 endnetgrent();
 351         }
 352 #endif
 353
 354 #ifdef HAVE_GETGRENT
 355         {
 356                 struct group *gptr;
 357                 setgrent();
 358                 while ((gptr = (struct group *)getgrent())) {
 359                         if (strequal(gptr->gr_name,group))
 360                                 break;
 361                 }
 362
 363                 /*
 364                  * As user_ok can recurse doing a getgrent(), we must
 365                  * copy the member list into a pstring on the stack before
 366                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 367                  */
 368
 369                 if (gptr) {
 370                         pstring member_list;
 371                         char *member;
 372                         size_t copied_len = 0;
 373                         int i;
 374
 375                         *member_list = '\0';
 376                         member = member_list;
 377
 378                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 379                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
 380                                 if( copied_len + member_len < sizeof(pstring)) {
 381
 382                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
 383
 384                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
 385                                         copied_len += member_len;
 386                                         member += copied_len;
 387                                 } else {
 388                                         *member = '\0';
 389                                 }
 390                         }
 391
 392                         endgrent();
 393
 394                         member = member_list;
 395                         while (*member) {
 396                                 static fstring name;
 397                                 fstrcpy(name,member);
 398                                 if (user_ok(name,snum) &&
 399                                     password_ok(name,password,pwlen)) {
 400                                         endgrent();
 401                                         return(&name[0]);
 402                                 }
 403
 404                                 DEBUG(10,("validate_group = member = %s\n", member));
 405
 406                                 member += strlen(member) + 1;
 407                         }
 408                 } else {
 409                         endgrent();
 410                         return NULL;
 411                 }
 412         }
 413 #endif
 414         return(NULL);
 415 }
 416
 417 /****************************************************************************
 418  Check for authority to login to a service with a given username/password.
 419  Note this is *NOT* used when logging on using sessionsetup_and_X.
 420 ****************************************************************************/
 421
 422 BOOL authorise_login(int snum,char *user,char *password, int pwlen,
 423                      BOOL *guest,BOOL *force,uint16 vuid)
 424 {
 425         BOOL ok = False;
 426         user_struct *vuser = get_valid_user_struct(vuid);
 427
 428 #if DEBUG_PASSWORD
 429         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s\n",
 430                         user,password));
 431 #endif
 432
 433         *guest = False;
 434
 435         if (GUEST_ONLY(snum))
 436                 *force = True;
 437
 438         if (!GUEST_ONLY(snum) && (lp_security() > SEC_SHARE)) {
 439
 440                 /*
 441                  * We should just use the given vuid from a sessionsetup_and_X.
 442                  */
 443
 444                 if (!vuser) {
 445                         DEBUG(1,("authorise_login: refusing user %s with no session setup\n",
 446                                         user));
 447                         return False;
 448                 }
 449
 450                 if (!vuser->guest && user_ok(vuser->user.unix_name,snum)) {
 451                         fstrcpy(user,vuser->user.unix_name);
 452                         *guest = False;
 453                         DEBUG(3,("authorise_login: ACCEPTED: validated uid ok as non-guest \
 454 (user=%s)\n", user));
 455                         return True;
 456                 }
 457         }
 458
 459         /* there are several possibilities:
 460                 1) login as the given user with given password
 461                 2) login as a previously registered username with the given password
 462                 3) login as a session list username with the given password
 463                 4) login as a previously validated user/password pair
 464                 5) login as the "user =" user with given password
 465                 6) login as the "user =" user with no password (guest connection)
 466                 7) login as guest user with no password
 467
 468                 if the service is guest_only then steps 1 to 5 are skipped
 469         */
 470
 471         if (!(GUEST_ONLY(snum) && GUEST_OK(snum))) {
 472                 /* check for a previously registered guest username */
 473                 if (!ok && (vuser != 0) && vuser->guest) {
 474                         if (user_ok(vuser->user.unix_name,snum) &&
 475                                         password_ok(vuser->user.unix_name, password, pwlen)) {
 476                                 fstrcpy(user, vuser->user.unix_name);
 477                                 vuser->guest = False;
 478                                 DEBUG(3,("authorise_login: ACCEPTED: given password with registered user %s\n", user));
 479                                 ok = True;
 480                         }
 481                 }
 482
 483                 /* now check the list of session users */
 484                 if (!ok) {
 485                         char *auser;
 486                         char *user_list = strdup(session_users);
 487                         if (!user_list)
 488                                 return(False);
 489
 490                         for (auser=strtok(user_list,LIST_SEP); !ok && auser;
 491                                                                         auser = strtok(NULL,LIST_SEP)) {
 492                                 fstring user2;
 493                                 fstrcpy(user2,auser);
 494                                 if (!user_ok(user2,snum))
 495                                         continue;
 496
 497                                 if (password_ok(user2,password, pwlen)) {
 498                                         ok = True;
 499                                         fstrcpy(user,user2);
 500                                         DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
 501 and given password ok\n", user));
 502                                 }
 503                         }
 504
 505                         SAFE_FREE(user_list);
 506                 }
 507
 508                 /* check for a previously validated username/password pair */
 509                 if (!ok && (lp_security() > SEC_SHARE) && (vuser != 0) && !vuser->guest &&
 510                                                         user_ok(vuser->user.unix_name,snum)) {
 511                         fstrcpy(user,vuser->user.unix_name);
 512                         *guest = False;
 513                         DEBUG(3,("authorise_login: ACCEPTED: validated uid (%s) as non-guest\n",
 514                                 user));
 515                         ok = True;
 516                 }
 517
 518                 /* check the user= fields and the given password */
 519                 if (!ok && lp_username(snum)) {
 520                         char *auser;
 521                         pstring user_list;
 522                         StrnCpy(user_list,lp_username(snum),sizeof(pstring));
 523
 524                         pstring_sub(user_list,"%S",lp_servicename(snum));
 525
 526                         for (auser=strtok(user_list,LIST_SEP); auser && !ok;
 527                                                                                         auser = strtok(NULL,LIST_SEP)) {
 528                                 if (*auser == '@') {
 529                                         auser = validate_group(auser+1,password,pwlen,snum);
 530                                         if (auser) {
 531                                                 ok = True;
 532                                                 fstrcpy(user,auser);
 533                                                 DEBUG(3,("authorise_login: ACCEPTED: group username \
 534 and given password ok (%s)\n", user));
 535                                         }
 536                                 } else {
 537                                         fstring user2;
 538                                         fstrcpy(user2,auser);
 539                                         if (user_ok(user2,snum) && password_ok(user2,password,pwlen)) {
 540                                                 ok = True;
 541                                                 fstrcpy(user,user2);
 542                                                 DEBUG(3,("authorise_login: ACCEPTED: user list username \
 543 and given password ok (%s)\n", user));
 544                                         }
 545                                 }
 546                         }
 547                 }
 548         } /* not guest only */
 549
 550         /* check for a normal guest connection */
 551         if (!ok && GUEST_OK(snum)) {
 552                 fstring guestname;
 553                 StrnCpy(guestname,lp_guestaccount(snum),sizeof(guestname)-1);
 554                 if (Get_Pwnam(guestname,True)) {
 555                         fstrcpy(user,guestname);
 556                         ok = True;
 557                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
 558                                         user));
 559                 } else {
 560                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
 561                 }
 562                 *guest = True;
 563         }
 564
 565         if (ok && !user_ok(user,snum)) {
 566                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 567                 ok = False;
 568         }
 569
 570         return(ok);
 571 }