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