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