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