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