source3/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 extern userdom_struct current_user_info;
  32
  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
  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
  64 void invalidate_vuid(uint16 vuid)
  65 {
  66         user_struct *vuser = get_valid_user_struct(vuid);
  67
  68         if (vuser == NULL)
  69                 return;
  70
  71         SAFE_FREE(vuser->homedir);
  72         SAFE_FREE(vuser->unix_homedir);
  73         SAFE_FREE(vuser->logon_script);
  74
  75         session_yield(vuser);
  76         SAFE_FREE(vuser->session_keystr);
  77
  78         free_server_info(&vuser->server_info);
  79
  80         DLIST_REMOVE(validated_users, vuser);
  81
  82         /* clear the vuid from the 'cache' on each connection, and
  83            from the vuid 'owner' of connections */
  84         conn_clear_vuid_cache(vuid);
  85
  86         SAFE_FREE(vuser->groups);
  87         delete_nt_token(&vuser->nt_user_token);
  88         SAFE_FREE(vuser);
  89         num_validated_vuids--;
  90 }
  91
  92 /****************************************************************************
  93  Invalidate all vuid entries for this process.
  94 ****************************************************************************/
  95
  96 void invalidate_all_vuids(void)
  97 {
  98         user_struct *usp, *next=NULL;
  99
 100         for (usp=validated_users;usp;usp=next) {
 101                 next = usp->next;
 102
 103                 invalidate_vuid(usp->vuid);
 104         }
 105 }
 106
 107 /**
 108  *  register that a valid login has been performed, establish 'session'.
 109  *  @param server_info The token returned from the authentication process.
 110  *   (now 'owned' by register_vuid)
 111  *
 112  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 113  *   tell random client vuid's (normally zero) from valid vuids.)
 114  *
 115  */
 116
 117 int register_vuid(auth_serversupplied_info *server_info, DATA_BLOB response_blob, const char *smb_name)
 118 {
 119         user_struct *vuser = NULL;
 120
 121         /* Ensure no vuid gets registered in share level security. */
 122         if(lp_security() == SEC_SHARE)
 123                 return UID_FIELD_INVALID;
 124
 125         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 126         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET)
 127                 return UID_FIELD_INVALID;
 128
 129         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
 130                 DEBUG(0,("Failed to malloc users struct!\n"));
 131                 return UID_FIELD_INVALID;
 132         }
 133
 134         ZERO_STRUCTP(vuser);
 135
 136         /* Allocate a free vuid. Yes this is a linear search... :-) */
 137         while( get_valid_user_struct(next_vuid) != NULL ) {
 138                 next_vuid++;
 139                 /* Check for vuid wrap. */
 140                 if (next_vuid == UID_FIELD_INVALID)
 141                         next_vuid = VUID_OFFSET;
 142         }
 143
 144         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
 145
 146         vuser->vuid = next_vuid;
 147
 148         /* the next functions should be done by a SID mapping system (SMS) as
 149          * the new real sam db won't have reference to unix uids or gids
 150          */
 151
 152         vuser->uid = server_info->uid;
 153         vuser->gid = server_info->gid;
 154
 155         vuser->n_groups = server_info->n_groups;
 156         if (vuser->n_groups) {
 157                 if (!(vuser->groups = memdup(server_info->groups, sizeof(gid_t) * vuser->n_groups))) {
 158                         DEBUG(0,("register_vuid: failed to memdup vuser->groups\n"));
 159                         free(vuser);
 160                         free_server_info(&server_info);
 161                         return UID_FIELD_INVALID;
 162                 }
 163         }
 164
 165         vuser->guest = server_info->guest;
 166         fstrcpy(vuser->user.unix_name, server_info->unix_name);
 167
 168         /* This is a potentially untrusted username */
 169         alpha_strcpy(vuser->user.smb_name, smb_name, ". _-$", sizeof(vuser->user.smb_name));
 170
 171         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
 172         fstrcpy(vuser->user.full_name, pdb_get_fullname(server_info->sam_account));
 173
 174         {
 175                 /* Keep the homedir handy */
 176                 const char *homedir = pdb_get_homedir(server_info->sam_account);
 177                 const char *logon_script = pdb_get_logon_script(server_info->sam_account);
 178
 179                 if (!IS_SAM_DEFAULT(server_info->sam_account, PDB_UNIXHOMEDIR)) {
 180                         const char *unix_homedir = pdb_get_unix_homedir(server_info->sam_account);
 181                         if (unix_homedir) {
 182                                 vuser->unix_homedir = smb_xstrdup(unix_homedir);
 183                         }
 184                 } else {
 185                         struct passwd *passwd = getpwnam_alloc(vuser->user.unix_name);
 186                         if (passwd) {
 187                                 vuser->unix_homedir = smb_xstrdup(passwd->pw_dir);
 188                                 passwd_free(&passwd);
 189                         }
 190                 }
 191
 192                 if (homedir) {
 193                         vuser->homedir = smb_xstrdup(homedir);
 194                 }
 195                 if (logon_script) {
 196                         vuser->logon_script = smb_xstrdup(logon_script);
 197                 }
 198         }
 199
 200         memcpy(vuser->session_key, server_info->session_key, sizeof(vuser->session_key));
 201
 202         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n",
 203                   (unsigned int)vuser->uid,
 204                   (unsigned int)vuser->gid,
 205                   vuser->user.unix_name, vuser->user.smb_name, vuser->user.domain, vuser->guest ));
 206
 207         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));
 208
 209         if (server_info->ptok) {
 210                 vuser->nt_user_token = dup_nt_token(server_info->ptok);
 211         } else {
 212                 DEBUG(1, ("server_info does not contain a user_token - cannot continue\n"));
 213                 free_server_info(&server_info);
 214                 SAFE_FREE(vuser->homedir);
 215                 SAFE_FREE(vuser->unix_homedir);
 216                 SAFE_FREE(vuser->logon_script);
 217
 218                 SAFE_FREE(vuser);
 219                 return UID_FIELD_INVALID;
 220         }
 221
 222         /* use this to keep tabs on all our info from the authentication */
 223         vuser->server_info = server_info;
 224
 225         DEBUG(3,("UNIX uid %d is UNIX user %s, and will be vuid %u\n",(int)vuser->uid,vuser->user.unix_name, vuser->vuid));
 226
 227         next_vuid++;
 228         num_validated_vuids++;
 229
 230         DLIST_ADD(validated_users, vuser);
 231
 232         if (!session_claim(vuser)) {
 233                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
 234                 invalidate_vuid(vuser->vuid);
 235                 return -1;
 236         }
 237
 238         /* Register a home dir service for this user */
 239         if ((!vuser->guest) && vuser->unix_homedir && *(vuser->unix_homedir)) {
 240                 DEBUG(3, ("Adding/updating homes service for user '%s' using home directory: '%s'\n",
 241                           vuser->user.unix_name, vuser->unix_homedir));
 242                 vuser->homes_snum = add_home_service(vuser->user.unix_name, vuser->user.unix_name, vuser->unix_homedir);
 243         } else {
 244                 vuser->homes_snum = -1;
 245         }
 246
 247         if (lp_server_signing() && !vuser->guest && !srv_is_signing_active()) {
 248                 /* Try and turn on server signing on the first non-guest sessionsetup. */
 249                 srv_set_signing(vuser->session_key, response_blob);
 250         }
 251
 252         return vuser->vuid;
 253 }
 254
 255 /****************************************************************************
 256  Add a name to the session users list.
 257 ****************************************************************************/
 258
 259 void add_session_user(const char *user)
 260 {
 261         fstring suser;
 262         struct passwd *passwd;
 263
 264         if (!(passwd = Get_Pwnam(user)))
 265                 return;
 266
 267         fstrcpy(suser,passwd->pw_name);
 268
 269         if (suser && *suser && !in_list(suser,session_users,False)) {
 270                 if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring)) {
 271                         DEBUG(1,("Too many session users??\n"));
 272                 } else {
 273                         pstrcat(session_users," ");
 274                         pstrcat(session_users,suser);
 275                 }
 276         }
 277 }
 278
 279 /****************************************************************************
 280  Check if a username is valid.
 281 ****************************************************************************/
 282
 283 BOOL user_ok(const char *user,int snum, gid_t *groups, size_t n_groups)
 284 {
 285         char **valid, **invalid;
 286         BOOL ret;
 287
 288         valid = invalid = NULL;
 289         ret = True;
 290
 291         if (lp_invalid_users(snum)) {
 292                 str_list_copy(&invalid, lp_invalid_users(snum));
 293                 if (invalid && str_list_substitute(invalid, "%S", lp_servicename(snum))) {
 294                         ret = !user_in_list(user, (const char **)invalid, groups, n_groups);
 295                 }
 296         }
 297         if (invalid)
 298                 str_list_free (&invalid);
 299
 300         if (ret && lp_valid_users(snum)) {
 301                 str_list_copy(&valid, lp_valid_users(snum));
 302                 if ( valid && str_list_sub_basic(valid, current_user_info.smb_name) ) {
 303                         ret = user_in_list(user, (const char **)valid, groups, n_groups);
 304                 }
 305         }
 306         if (valid)
 307                 str_list_free (&valid);
 308
 309         if (ret && lp_onlyuser(snum)) {
 310                 char **user_list = str_list_make (lp_username(snum), NULL);
 311                 if (user_list && str_list_substitute(user_list, "%S", lp_servicename(snum))) {
 312                         ret = user_in_list(user, (const char **)user_list, groups, n_groups);
 313                 }
 314                 if (user_list) str_list_free (&user_list);
 315         }
 316
 317         return(ret);
 318 }
 319
 320 /****************************************************************************
 321  Validate a group username entry. Return the username or NULL.
 322 ****************************************************************************/
 323
 324 static char *validate_group(char *group, DATA_BLOB password,int snum)
 325 {
 326 #ifdef HAVE_NETGROUP
 327         {
 328                 char *host, *user, *domain;
 329                 setnetgrent(group);
 330                 while (getnetgrent(&host, &user, &domain)) {
 331                         if (user) {
 332                                 if (user_ok(user, snum, NULL, 0) &&
 333                                     password_ok(user,password)) {
 334                                         endnetgrent();
 335                                         return(user);
 336                                 }
 337                         }
 338                 }
 339                 endnetgrent();
 340         }
 341 #endif
 342
 343 #ifdef HAVE_GETGRENT
 344         {
 345                 struct group *gptr;
 346                 setgrent();
 347                 while ((gptr = (struct group *)getgrent())) {
 348                         if (strequal(gptr->gr_name,group))
 349                                 break;
 350                 }
 351
 352                 /*
 353                  * As user_ok can recurse doing a getgrent(), we must
 354                  * copy the member list into a pstring on the stack before
 355                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 356                  */
 357
 358                 if (gptr) {
 359                         pstring member_list;
 360                         char *member;
 361                         size_t copied_len = 0;
 362                         int i;
 363
 364                         *member_list = '\0';
 365                         member = member_list;
 366
 367                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 368                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
 369                                 if( copied_len + member_len < sizeof(pstring)) {
 370
 371                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
 372
 373                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
 374                                         copied_len += member_len;
 375                                         member += copied_len;
 376                                 } else {
 377                                         *member = '\0';
 378                                 }
 379                         }
 380
 381                         endgrent();
 382
 383                         member = member_list;
 384                         while (*member) {
 385                                 static fstring name;
 386                                 fstrcpy(name,member);
 387                                 if (user_ok(name,snum, NULL, 0) &&
 388                                     password_ok(name,password)) {
 389                                         endgrent();
 390                                         return(&name[0]);
 391                                 }
 392
 393                                 DEBUG(10,("validate_group = member = %s\n", member));
 394
 395                                 member += strlen(member) + 1;
 396                         }
 397                 } else {
 398                         endgrent();
 399                         return NULL;
 400                 }
 401         }
 402 #endif
 403         return(NULL);
 404 }
 405
 406 /****************************************************************************
 407  Check for authority to login to a service with a given username/password.
 408  Note this is *NOT* used when logging on using sessionsetup_and_X.
 409 ****************************************************************************/
 410
 411 BOOL authorise_login(int snum, fstring user, DATA_BLOB password,
 412                      BOOL *guest)
 413 {
 414         BOOL ok = False;
 415
 416 #if DEBUG_PASSWORD
 417         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s\n",
 418                    user,password.data));
 419 #endif
 420
 421         *guest = False;
 422
 423         /* there are several possibilities:
 424                 1) login as the given user with given password
 425                 2) login as a previously registered username with the given password
 426                 3) login as a session list username with the given password
 427                 4) login as a previously validated user/password pair
 428                 5) login as the "user =" user with given password
 429                 6) login as the "user =" user with no password (guest connection)
 430                 7) login as guest user with no password
 431
 432                 if the service is guest_only then steps 1 to 5 are skipped
 433         */
 434
 435         /* now check the list of session users */
 436         if (!ok) {
 437                 char *auser;
 438                 char *user_list = strdup(session_users);
 439                 if (!user_list)
 440                         return(False);
 441
 442                 for (auser=strtok(user_list,LIST_SEP); !ok && auser;
 443                      auser = strtok(NULL,LIST_SEP)) {
 444                         fstring user2;
 445                         fstrcpy(user2,auser);
 446                         if (!user_ok(user2,snum, NULL, 0))
 447                                 continue;
 448
 449                         if (password_ok(user2,password)) {
 450                                 ok = True;
 451                                 fstrcpy(user,user2);
 452                                 DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
 453 and given password ok\n", user));
 454                         }
 455                 }
 456
 457                 SAFE_FREE(user_list);
 458         }
 459
 460         /* check the user= fields and the given password */
 461         if (!ok && lp_username(snum)) {
 462                 char *auser;
 463                 pstring user_list;
 464                 pstrcpy(user_list,lp_username(snum));
 465
 466                 pstring_sub(user_list,"%S",lp_servicename(snum));
 467
 468                 for (auser=strtok(user_list,LIST_SEP); auser && !ok;
 469                      auser = strtok(NULL,LIST_SEP)) {
 470                         if (*auser == '@') {
 471                                 auser = validate_group(auser+1,password,snum);
 472                                 if (auser) {
 473                                         ok = True;
 474                                         fstrcpy(user,auser);
 475                                         DEBUG(3,("authorise_login: ACCEPTED: group username \
 476 and given password ok (%s)\n", user));
 477                                 }
 478                         } else {
 479                                 fstring user2;
 480                                 fstrcpy(user2,auser);
 481                                 if (user_ok(user2,snum, NULL, 0) && password_ok(user2,password)) {
 482                                         ok = True;
 483                                         fstrcpy(user,user2);
 484                                         DEBUG(3,("authorise_login: ACCEPTED: user list username \
 485 and given password ok (%s)\n", user));
 486                                 }
 487                         }
 488                 }
 489         }
 490
 491         /* check for a normal guest connection */
 492         if (!ok && GUEST_OK(snum)) {
 493                 fstring guestname;
 494                 fstrcpy(guestname,lp_guestaccount());
 495                 if (Get_Pwnam(guestname)) {
 496                         fstrcpy(user,guestname);
 497                         ok = True;
 498                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
 499                                         user));
 500                 } else {
 501                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
 502                 }
 503                 *guest = True;
 504         }
 505
 506         if (ok && !user_ok(user, snum, NULL, 0)) {
 507                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 508                 ok = False;
 509         }
 510
 511         return(ok);
 512 }