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 /****************************************************************************
  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
  37 user_struct *get_valid_user_struct(uint16 vuid)
  38 {
  39         user_struct *usp;
  40         int count=0;
  41
  42         if (vuid == UID_FIELD_INVALID)
  43                 return NULL;
  44
  45         for (usp=validated_users;usp;usp=usp->next,count++) {
  46                 if (vuid == usp->vuid) {
  47                         if (count > 10) {
  48                                 DLIST_PROMOTE(validated_users, usp);
  49                         }
  50                         return usp;
  51                 }
  52         }
  53
  54         return NULL;
  55 }
  56
  57 /****************************************************************************
  58  Invalidate a uid.
  59 ****************************************************************************/
  60
  61 void invalidate_vuid(uint16 vuid)
  62 {
  63         user_struct *vuser = get_valid_user_struct(vuid);
  64
  65         if (vuser == NULL)
  66                 return;
  67
  68         SAFE_FREE(vuser->homedir);
  69         SAFE_FREE(vuser->unix_homedir);
  70         SAFE_FREE(vuser->logon_script);
  71
  72         session_yield(vuser);
  73         SAFE_FREE(vuser->session_keystr);
  74
  75         free_server_info(&vuser->server_info);
  76
  77         DLIST_REMOVE(validated_users, vuser);
  78
  79         /* clear the vuid from the 'cache' on each connection, and
  80            from the vuid 'owner' of connections */
  81         conn_clear_vuid_cache(vuid);
  82
  83         SAFE_FREE(vuser->groups);
  84         delete_nt_token(&vuser->nt_user_token);
  85         SAFE_FREE(vuser);
  86         num_validated_vuids--;
  87 }
  88
  89 /****************************************************************************
  90  Invalidate all vuid entries for this process.
  91 ****************************************************************************/
  92
  93 void invalidate_all_vuids(void)
  94 {
  95         user_struct *usp, *next=NULL;
  96
  97         for (usp=validated_users;usp;usp=next) {
  98                 next = usp->next;
  99
 100                 invalidate_vuid(usp->vuid);
 101         }
 102 }
 103
 104 /**
 105  *  register that a valid login has been performed, establish 'session'.
 106  *  @param server_info The token returned from the authentication process.
 107  *   (now 'owned' by register_vuid)
 108  *
 109  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 110  *   tell random client vuid's (normally zero) from valid vuids.)
 111  *
 112  */
 113
 114 int register_vuid(auth_serversupplied_info *server_info, DATA_BLOB response_blob, const char *smb_name)
 115 {
 116         user_struct *vuser = NULL;
 117
 118         /* Ensure no vuid gets registered in share level security. */
 119         if(lp_security() == SEC_SHARE)
 120                 return UID_FIELD_INVALID;
 121
 122         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 123         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET)
 124                 return UID_FIELD_INVALID;
 125
 126         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
 127                 DEBUG(0,("Failed to malloc users struct!\n"));
 128                 return UID_FIELD_INVALID;
 129         }
 130
 131         ZERO_STRUCTP(vuser);
 132
 133         /* Allocate a free vuid. Yes this is a linear search... :-) */
 134         while( get_valid_user_struct(next_vuid) != NULL ) {
 135                 next_vuid++;
 136                 /* Check for vuid wrap. */
 137                 if (next_vuid == UID_FIELD_INVALID)
 138                         next_vuid = VUID_OFFSET;
 139         }
 140
 141         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
 142
 143         vuser->vuid = next_vuid;
 144
 145         /* the next functions should be done by a SID mapping system (SMS) as
 146          * the new real sam db won't have reference to unix uids or gids
 147          */
 148
 149         vuser->uid = server_info->uid;
 150         vuser->gid = server_info->gid;
 151
 152         vuser->n_groups = server_info->n_groups;
 153         if (vuser->n_groups) {
 154                 if (!(vuser->groups = memdup(server_info->groups, sizeof(gid_t) * vuser->n_groups))) {
 155                         DEBUG(0,("register_vuid: failed to memdup vuser->groups\n"));
 156                         free(vuser);
 157                         free_server_info(&server_info);
 158                         return UID_FIELD_INVALID;
 159                 }
 160         }
 161
 162         vuser->guest = server_info->guest;
 163         fstrcpy(vuser->user.unix_name, server_info->unix_name);
 164
 165         /* This is a potentially untrusted username */
 166         alpha_strcpy(vuser->user.smb_name, smb_name, ". _-$", sizeof(vuser->user.smb_name));
 167
 168         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
 169         fstrcpy(vuser->user.full_name, pdb_get_fullname(server_info->sam_account));
 170
 171         {
 172                 /* Keep the homedir handy */
 173                 const char *homedir = pdb_get_homedir(server_info->sam_account);
 174                 const char *logon_script = pdb_get_logon_script(server_info->sam_account);
 175
 176                 if (!IS_SAM_DEFAULT(server_info->sam_account, PDB_UNIXHOMEDIR)) {
 177                         const char *unix_homedir = pdb_get_unix_homedir(server_info->sam_account);
 178                         if (unix_homedir) {
 179                                 vuser->unix_homedir = smb_xstrdup(unix_homedir);
 180                         }
 181                 } else {
 182                         struct passwd *passwd = getpwnam_alloc(vuser->user.unix_name);
 183                         if (passwd) {
 184                                 vuser->unix_homedir = smb_xstrdup(passwd->pw_dir);
 185                                 passwd_free(&passwd);
 186                         }
 187                 }
 188
 189                 if (homedir) {
 190                         vuser->homedir = smb_xstrdup(homedir);
 191                 }
 192                 if (logon_script) {
 193                         vuser->logon_script = smb_xstrdup(logon_script);
 194                 }
 195         }
 196
 197         memcpy(vuser->session_key, server_info->session_key, sizeof(vuser->session_key));
 198
 199         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n",
 200                   (unsigned int)vuser->uid,
 201                   (unsigned int)vuser->gid,
 202                   vuser->user.unix_name, vuser->user.smb_name, vuser->user.domain, vuser->guest ));
 203
 204         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));
 205
 206         if (server_info->ptok) {
 207                 vuser->nt_user_token = dup_nt_token(server_info->ptok);
 208         } else {
 209                 DEBUG(1, ("server_info does not contain a user_token - cannot continue\n"));
 210                 free_server_info(&server_info);
 211                 SAFE_FREE(vuser->homedir);
 212                 SAFE_FREE(vuser->unix_homedir);
 213                 SAFE_FREE(vuser->logon_script);
 214
 215                 SAFE_FREE(vuser);
 216                 return UID_FIELD_INVALID;
 217         }
 218
 219         /* use this to keep tabs on all our info from the authentication */
 220         vuser->server_info = server_info;
 221
 222         DEBUG(3,("UNIX uid %d is UNIX user %s, and will be vuid %u\n",(int)vuser->uid,vuser->user.unix_name, vuser->vuid));
 223
 224         next_vuid++;
 225         num_validated_vuids++;
 226
 227         DLIST_ADD(validated_users, vuser);
 228
 229         if (!session_claim(vuser)) {
 230                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
 231                 invalidate_vuid(vuser->vuid);
 232                 return -1;
 233         }
 234
 235         /* Register a home dir service for this user */
 236         if ((!vuser->guest) && vuser->unix_homedir && *(vuser->unix_homedir)) {
 237                 DEBUG(3, ("Adding/updating homes service for user '%s' using home directory: '%s'\n",
 238                           vuser->user.unix_name, vuser->unix_homedir));
 239                 vuser->homes_snum = add_home_service(vuser->user.unix_name, vuser->user.unix_name, vuser->unix_homedir);
 240         } else {
 241                 vuser->homes_snum = -1;
 242         }
 243
 244         if (lp_server_signing() && !vuser->guest && !srv_is_signing_active()) {
 245                 /* Try and turn on server signing on the first non-guest sessionsetup. */
 246                 srv_set_signing(vuser->session_key, response_blob);
 247         }
 248
 249         return vuser->vuid;
 250 }
 251
 252 /****************************************************************************
 253  Add a name to the session users list.
 254 ****************************************************************************/
 255
 256 void add_session_user(const char *user)
 257 {
 258         fstring suser;
 259         struct passwd *passwd;
 260
 261         if (!(passwd = Get_Pwnam(user)))
 262                 return;
 263
 264         fstrcpy(suser,passwd->pw_name);
 265
 266         if (suser && *suser && !in_list(suser,session_users,False)) {
 267                 if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring)) {
 268                         DEBUG(1,("Too many session users??\n"));
 269                 } else {
 270                         pstrcat(session_users," ");
 271                         pstrcat(session_users,suser);
 272                 }
 273         }
 274 }
 275
 276 /****************************************************************************
 277  Check if a username is valid.
 278 ****************************************************************************/
 279
 280 BOOL user_ok(const char *user,int snum, gid_t *groups, size_t n_groups)
 281 {
 282         char **valid, **invalid;
 283         BOOL ret;
 284
 285         valid = invalid = NULL;
 286         ret = True;
 287
 288         if (lp_invalid_users(snum)) {
 289                 str_list_copy(&invalid, lp_invalid_users(snum));
 290                 if (invalid && str_list_substitute(invalid, "%S", lp_servicename(snum))) {
 291                         ret = !user_in_list(user, (const char **)invalid, groups, n_groups);
 292                 }
 293         }
 294         if (invalid)
 295                 str_list_free (&invalid);
 296
 297         if (ret && lp_valid_users(snum)) {
 298                 str_list_copy(&valid, lp_valid_users(snum));
 299                 if (valid && str_list_substitute(valid, "%S", lp_servicename(snum))) {
 300                         ret = user_in_list(user, (const char **)valid, groups, n_groups);
 301                 }
 302         }
 303         if (valid)
 304                 str_list_free (&valid);
 305
 306         if (ret && lp_onlyuser(snum)) {
 307                 char **user_list = str_list_make (lp_username(snum), NULL);
 308                 if (user_list && str_list_substitute(user_list, "%S", lp_servicename(snum))) {
 309                         ret = user_in_list(user, (const char **)user_list, groups, n_groups);
 310                 }
 311                 if (user_list) str_list_free (&user_list);
 312         }
 313
 314         return(ret);
 315 }
 316
 317 /****************************************************************************
 318  Validate a group username entry. Return the username or NULL.
 319 ****************************************************************************/
 320
 321 static char *validate_group(char *group, DATA_BLOB password,int snum)
 322 {
 323 #ifdef HAVE_NETGROUP
 324         {
 325                 char *host, *user, *domain;
 326                 setnetgrent(group);
 327                 while (getnetgrent(&host, &user, &domain)) {
 328                         if (user) {
 329                                 if (user_ok(user, snum, NULL, 0) &&
 330                                     password_ok(user,password)) {
 331                                         endnetgrent();
 332                                         return(user);
 333                                 }
 334                         }
 335                 }
 336                 endnetgrent();
 337         }
 338 #endif
 339
 340 #ifdef HAVE_GETGRENT
 341         {
 342                 struct group *gptr;
 343                 setgrent();
 344                 while ((gptr = (struct group *)getgrent())) {
 345                         if (strequal(gptr->gr_name,group))
 346                                 break;
 347                 }
 348
 349                 /*
 350                  * As user_ok can recurse doing a getgrent(), we must
 351                  * copy the member list into a pstring on the stack before
 352                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 353                  */
 354
 355                 if (gptr) {
 356                         pstring member_list;
 357                         char *member;
 358                         size_t copied_len = 0;
 359                         int i;
 360
 361                         *member_list = '\0';
 362                         member = member_list;
 363
 364                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 365                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
 366                                 if( copied_len + member_len < sizeof(pstring)) {
 367
 368                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
 369
 370                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
 371                                         copied_len += member_len;
 372                                         member += copied_len;
 373                                 } else {
 374                                         *member = '\0';
 375                                 }
 376                         }
 377
 378                         endgrent();
 379
 380                         member = member_list;
 381                         while (*member) {
 382                                 static fstring name;
 383                                 fstrcpy(name,member);
 384                                 if (user_ok(name,snum, NULL, 0) &&
 385                                     password_ok(name,password)) {
 386                                         endgrent();
 387                                         return(&name[0]);
 388                                 }
 389
 390                                 DEBUG(10,("validate_group = member = %s\n", member));
 391
 392                                 member += strlen(member) + 1;
 393                         }
 394                 } else {
 395                         endgrent();
 396                         return NULL;
 397                 }
 398         }
 399 #endif
 400         return(NULL);
 401 }
 402
 403 /****************************************************************************
 404  Check for authority to login to a service with a given username/password.
 405  Note this is *NOT* used when logging on using sessionsetup_and_X.
 406 ****************************************************************************/
 407
 408 BOOL authorise_login(int snum, fstring user, DATA_BLOB password,
 409                      BOOL *guest)
 410 {
 411         BOOL ok = False;
 412
 413 #if DEBUG_PASSWORD
 414         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s\n",
 415                    user,password.data));
 416 #endif
 417
 418         *guest = False;
 419
 420         /* there are several possibilities:
 421                 1) login as the given user with given password
 422                 2) login as a previously registered username with the given password
 423                 3) login as a session list username with the given password
 424                 4) login as a previously validated user/password pair
 425                 5) login as the "user =" user with given password
 426                 6) login as the "user =" user with no password (guest connection)
 427                 7) login as guest user with no password
 428
 429                 if the service is guest_only then steps 1 to 5 are skipped
 430         */
 431
 432         /* now check the list of session users */
 433         if (!ok) {
 434                 char *auser;
 435                 char *user_list = strdup(session_users);
 436                 if (!user_list)
 437                         return(False);
 438
 439                 for (auser=strtok(user_list,LIST_SEP); !ok && auser;
 440                      auser = strtok(NULL,LIST_SEP)) {
 441                         fstring user2;
 442                         fstrcpy(user2,auser);
 443                         if (!user_ok(user2,snum, NULL, 0))
 444                                 continue;
 445
 446                         if (password_ok(user2,password)) {
 447                                 ok = True;
 448                                 fstrcpy(user,user2);
 449                                 DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
 450 and given password ok\n", user));
 451                         }
 452                 }
 453
 454                 SAFE_FREE(user_list);
 455         }
 456
 457         /* check the user= fields and the given password */
 458         if (!ok && lp_username(snum)) {
 459                 char *auser;
 460                 pstring user_list;
 461                 pstrcpy(user_list,lp_username(snum));
 462
 463                 pstring_sub(user_list,"%S",lp_servicename(snum));
 464
 465                 for (auser=strtok(user_list,LIST_SEP); auser && !ok;
 466                      auser = strtok(NULL,LIST_SEP)) {
 467                         if (*auser == '@') {
 468                                 auser = validate_group(auser+1,password,snum);
 469                                 if (auser) {
 470                                         ok = True;
 471                                         fstrcpy(user,auser);
 472                                         DEBUG(3,("authorise_login: ACCEPTED: group username \
 473 and given password ok (%s)\n", user));
 474                                 }
 475                         } else {
 476                                 fstring user2;
 477                                 fstrcpy(user2,auser);
 478                                 if (user_ok(user2,snum, NULL, 0) && password_ok(user2,password)) {
 479                                         ok = True;
 480                                         fstrcpy(user,user2);
 481                                         DEBUG(3,("authorise_login: ACCEPTED: user list username \
 482 and given password ok (%s)\n", user));
 483                                 }
 484                         }
 485                 }
 486         }
 487
 488         /* check for a normal guest connection */
 489         if (!ok && GUEST_OK(snum)) {
 490                 fstring guestname;
 491                 fstrcpy(guestname,lp_guestaccount());
 492                 if (Get_Pwnam(guestname)) {
 493                         fstrcpy(user,guestname);
 494                         ok = True;
 495                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
 496                                         user));
 497                 } else {
 498                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
 499                 }
 500                 *guest = True;
 501         }
 502
 503         if (ok && !user_ok(user, snum, NULL, 0)) {
 504                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 505                 ok = False;
 506         }
 507
 508         return(ok);
 509 }