source3/smbd/password.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 2007.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/passwd.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "../librpc/gen_ndr/netlogon.h"
  26 #include "auth.h"
  27 #include "../libcli/security/security.h"
  28
  29 /* Fix up prototypes for OSX 10.4, where they're missing */
  30 #ifndef HAVE_SETNETGRENT_PROTOTYPE
  31 extern int setnetgrent(const char* netgroup);
  32 #endif
  33 #ifndef HAVE_GETNETGRENT_PROTOTYPE
  34 extern int getnetgrent(char **host, char **user, char **domain);
  35 #endif
  36 #ifndef HAVE_ENDNETGRENT_PROTOTYPE
  37 extern void endnetgrent(void);
  38 #endif
  39
  40 enum server_allocated_state { SERVER_ALLOCATED_REQUIRED_YES,
  41                                 SERVER_ALLOCATED_REQUIRED_NO,
  42                                 SERVER_ALLOCATED_REQUIRED_ANY};
  43
  44 static user_struct *get_valid_user_struct_internal(
  45                         struct smbd_server_connection *sconn,
  46                         uint16 vuid,
  47                         enum server_allocated_state server_allocated)
  48 {
  49         user_struct *usp;
  50         int count=0;
  51
  52         if (vuid == UID_FIELD_INVALID)
  53                 return NULL;
  54
  55         usp=sconn->users;
  56         for (;usp;usp=usp->next,count++) {
  57                 if (vuid == usp->vuid) {
  58                         switch (server_allocated) {
  59                                 case SERVER_ALLOCATED_REQUIRED_YES:
  60                                         if (usp->session_info == NULL) {
  61                                                 continue;
  62                                         }
  63                                         break;
  64                                 case SERVER_ALLOCATED_REQUIRED_NO:
  65                                         if (usp->session_info != NULL) {
  66                                                 continue;
  67                                         }
  68                                 case SERVER_ALLOCATED_REQUIRED_ANY:
  69                                         break;
  70                         }
  71                         if (count > 10) {
  72                                 DLIST_PROMOTE(sconn->users, usp);
  73                         }
  74                         return usp;
  75                 }
  76         }
  77
  78         return NULL;
  79 }
  80
  81 /****************************************************************************
  82  Check if a uid has been validated, and return an pointer to the user_struct
  83  if it has. NULL if not. vuid is biased by an offset. This allows us to
  84  tell random client vuid's (normally zero) from valid vuids.
  85 ****************************************************************************/
  86
  87 user_struct *get_valid_user_struct(struct smbd_server_connection *sconn,
  88                                    uint16 vuid)
  89 {
  90         return get_valid_user_struct_internal(sconn, vuid,
  91                         SERVER_ALLOCATED_REQUIRED_YES);
  92 }
  93
  94 bool is_partial_auth_vuid(struct smbd_server_connection *sconn, uint16 vuid)
  95 {
  96         return (get_partial_auth_user_struct(sconn, vuid) != NULL);
  97 }
  98
  99 /****************************************************************************
 100  Get the user struct of a partial NTLMSSP login
 101 ****************************************************************************/
 102
 103 user_struct *get_partial_auth_user_struct(struct smbd_server_connection *sconn,
 104                                           uint16 vuid)
 105 {
 106         return get_valid_user_struct_internal(sconn, vuid,
 107                         SERVER_ALLOCATED_REQUIRED_NO);
 108 }
 109
 110 /****************************************************************************
 111  Invalidate a uid.
 112 ****************************************************************************/
 113
 114 void invalidate_vuid(struct smbd_server_connection *sconn, uint16 vuid)
 115 {
 116         user_struct *vuser = NULL;
 117
 118         vuser = get_valid_user_struct_internal(sconn, vuid,
 119                         SERVER_ALLOCATED_REQUIRED_ANY);
 120         if (vuser == NULL) {
 121                 return;
 122         }
 123
 124         session_yield(vuser);
 125
 126         if (vuser->gensec_security) {
 127                 TALLOC_FREE(vuser->gensec_security);
 128         }
 129
 130         DLIST_REMOVE(sconn->users, vuser);
 131         SMB_ASSERT(sconn->num_users > 0);
 132         sconn->num_users--;
 133
 134         /* clear the vuid from the 'cache' on each connection, and
 135            from the vuid 'owner' of connections */
 136         conn_clear_vuid_caches(sconn, vuid);
 137
 138         TALLOC_FREE(vuser);
 139 }
 140
 141 /****************************************************************************
 142  Invalidate all vuid entries for this process.
 143 ****************************************************************************/
 144
 145 void invalidate_all_vuids(struct smbd_server_connection *sconn)
 146 {
 147         if (sconn->using_smb2) {
 148                 return;
 149         }
 150
 151         while (sconn->users != NULL) {
 152                 invalidate_vuid(sconn, sconn->users->vuid);
 153         }
 154 }
 155
 156 static void increment_next_vuid(uint16_t *vuid)
 157 {
 158         *vuid += 1;
 159
 160         /* Check for vuid wrap. */
 161         if (*vuid == UID_FIELD_INVALID) {
 162                 *vuid = VUID_OFFSET;
 163         }
 164 }
 165
 166 /****************************************************
 167  Create a new partial auth user struct.
 168 *****************************************************/
 169
 170 int register_initial_vuid(struct smbd_server_connection *sconn)
 171 {
 172         user_struct *vuser;
 173
 174         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 175         if (sconn->num_users >= 0xFFFF-VUID_OFFSET) {
 176                 return UID_FIELD_INVALID;
 177         }
 178
 179         if((vuser = talloc_zero(NULL, user_struct)) == NULL) {
 180                 DEBUG(0,("register_initial_vuid: "
 181                                 "Failed to talloc users struct!\n"));
 182                 return UID_FIELD_INVALID;
 183         }
 184
 185         /* Allocate a free vuid. Yes this is a linear search... */
 186         while( get_valid_user_struct_internal(sconn,
 187                         sconn->smb1.sessions.next_vuid,
 188                         SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) {
 189                 increment_next_vuid(&sconn->smb1.sessions.next_vuid);
 190         }
 191
 192         DEBUG(10,("register_initial_vuid: allocated vuid = %u\n",
 193                 (unsigned int)sconn->smb1.sessions.next_vuid ));
 194
 195         vuser->vuid = sconn->smb1.sessions.next_vuid;
 196
 197         /*
 198          * This happens in an unfinished NTLMSSP session setup. We
 199          * need to allocate a vuid between the first and second calls
 200          * to NTLMSSP.
 201          */
 202         increment_next_vuid(&sconn->smb1.sessions.next_vuid);
 203
 204         sconn->num_users++;
 205         DLIST_ADD(sconn->users, vuser);
 206
 207         return vuser->vuid;
 208 }
 209
 210 int register_homes_share(const char *username)
 211 {
 212         int result;
 213         struct passwd *pwd;
 214
 215         result = lp_servicenumber(username);
 216         if (result != -1) {
 217                 DEBUG(3, ("Using static (or previously created) service for "
 218                           "user '%s'; path = '%s'\n", username,
 219                           lp_pathname(result)));
 220                 return result;
 221         }
 222
 223         pwd = Get_Pwnam_alloc(talloc_tos(), username);
 224
 225         if ((pwd == NULL) || (pwd->pw_dir[0] == '\0')) {
 226                 DEBUG(3, ("No home directory defined for user '%s'\n",
 227                           username));
 228                 TALLOC_FREE(pwd);
 229                 return -1;
 230         }
 231
 232         DEBUG(3, ("Adding homes service for user '%s' using home directory: "
 233                   "'%s'\n", username, pwd->pw_dir));
 234
 235         result = add_home_service(username, username, pwd->pw_dir);
 236
 237         TALLOC_FREE(pwd);
 238         return result;
 239 }
 240
 241 /**
 242  *  register that a valid login has been performed, establish 'session'.
 243  *  @param session_info The token returned from the authentication process.
 244  *   (now 'owned' by register_existing_vuid)
 245  *
 246  *  @param session_key The User session key for the login session (now also
 247  *  'owned' by register_existing_vuid)
 248  *
 249  *  @param respose_blob The NT challenge-response, if available.  (May be
 250  *  freed after this call)
 251  *
 252  *  @param smb_name The untranslated name of the user
 253  *
 254  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 255  *   tell random client vuid's (normally zero) from valid vuids.)
 256  *
 257  */
 258
 259 int register_existing_vuid(struct smbd_server_connection *sconn,
 260                         uint16 vuid,
 261                         struct auth_session_info *session_info,
 262                         DATA_BLOB response_blob)
 263 {
 264         user_struct *vuser;
 265         bool guest = security_session_user_level(session_info, NULL) < SECURITY_USER;
 266
 267         vuser = get_partial_auth_user_struct(sconn, vuid);
 268         if (!vuser) {
 269                 goto fail;
 270         }
 271
 272         /* Use this to keep tabs on all our info from the authentication */
 273         vuser->session_info = talloc_move(vuser, &session_info);
 274
 275         /* Make clear that we require the optional unix_token and unix_info in the source3 code */
 276         SMB_ASSERT(vuser->session_info->unix_token);
 277         SMB_ASSERT(vuser->session_info->unix_info);
 278
 279         DEBUG(10,("register_existing_vuid: (%u,%u) %s %s %s guest=%d\n",
 280                   (unsigned int)vuser->session_info->unix_token->uid,
 281                   (unsigned int)vuser->session_info->unix_token->gid,
 282                   vuser->session_info->unix_info->unix_name,
 283                   vuser->session_info->unix_info->sanitized_username,
 284                   vuser->session_info->info->domain_name,
 285                   guest));
 286
 287         DEBUG(3, ("register_existing_vuid: User name: %s\t"
 288                   "Real name: %s\n", vuser->session_info->unix_info->unix_name,
 289                   vuser->session_info->info->full_name));
 290
 291         if (!vuser->session_info->security_token) {
 292                 DEBUG(1, ("register_existing_vuid: session_info does not "
 293                         "contain a user_token - cannot continue\n"));
 294                 goto fail;
 295         }
 296
 297         /* Make clear that we require the optional unix_token in the source3 code */
 298         SMB_ASSERT(vuser->session_info->unix_token);
 299
 300         DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
 301                 "and will be vuid %u\n", (int)vuser->session_info->unix_token->uid,
 302                  vuser->session_info->unix_info->unix_name, vuser->vuid));
 303
 304         if (!session_claim(sconn, vuser)) {
 305                 DEBUG(1, ("register_existing_vuid: Failed to claim session "
 306                         "for vuid=%d\n",
 307                         vuser->vuid));
 308                 goto fail;
 309         }
 310
 311         /* Register a home dir service for this user if
 312         (a) This is not a guest connection,
 313         (b) we have a home directory defined
 314         (c) there s not an existing static share by that name
 315         If a share exists by this name (autoloaded or not) reuse it . */
 316
 317         vuser->homes_snum = -1;
 318
 319
 320         if (!guest) {
 321                 vuser->homes_snum = register_homes_share(
 322                         vuser->session_info->unix_info->unix_name);
 323         }
 324
 325         if (srv_is_signing_negotiated(sconn) &&
 326             !guest) {
 327                 /* Try and turn on server signing on the first non-guest
 328                  * sessionsetup. */
 329                 srv_set_signing(sconn,
 330                                 vuser->session_info->session_key,
 331                                 response_blob);
 332         }
 333
 334         /* fill in the current_user_info struct */
 335         set_current_user_info(
 336                 vuser->session_info->unix_info->sanitized_username,
 337                 vuser->session_info->unix_info->unix_name,
 338                 vuser->session_info->info->domain_name);
 339
 340         return vuser->vuid;
 341
 342   fail:
 343
 344         if (vuser) {
 345                 invalidate_vuid(sconn, vuid);
 346         }
 347         return UID_FIELD_INVALID;
 348 }