/*

   Unix SMB/CIFS implementation.

   Privileges handling functions

   Copyright (C) Jean François Micouleau 1998-2001

   Copyright (C) Simo Sorce     2002-2003

   Copyright (C) Gerald (Jerry) Carter          2005

   Copyright (C) Michael Adam     2007

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "includes.h"

#include "lib/privileges.h"

#include "dbwrap/dbwrap.h"

#include "libcli/security/privileges_private.h"

#include "../libcli/security/security.h"

#include "passdb.h"

#include "lib/util/string_wrappers.h"

#define PRIVPREFIX              "PRIV_"

typedef struct {

  uint32_t count;

  struct dom_sid *list;

} SID_LIST;

typedef struct {

  TALLOC_CTX *mem_ctx;

  uint64_t privilege;

  SID_LIST sids;

} PRIV_SID_LIST;

/*

  interpret an old style SE_PRIV structure

 */

static uint64_t map_old_SE_PRIV(unsigned char *dptr)

{

  uint32_t *old_masks = (uint32_t *)dptr;

  /*

   * the old privileges code only ever used up to 0x800, except

   * for a special case of 'SE_ALL_PRIVS' which was 0xFFFFFFFF

   */

  if (old_masks[0] == 0xFFFFFFFF) {

    /* they set all privileges */

    return SE_ALL_PRIVS;

  }

  /* the old code used the machine byte order, but we don't know

   * the byte order of the machine that wrote it. However we can

   * tell what byte order it was by taking advantage of the fact

   * that it only ever use up to 0x800

   */

  if (dptr[0] || dptr[1]) {

    /* it was little endian */

    return IVAL(dptr, 0);

  }

  /* it was either zero or big-endian */

  return RIVAL(dptr, 0);

}

static bool get_privileges( const struct dom_sid *sid, uint64_t *mask )

{

  struct db_context *db = get_account_pol_db();

  struct dom_sid_buf tmp;

  fstring keystr;

  TDB_DATA data;

  NTSTATUS status;

  /* Fail if the admin has not enable privileges */

  if ( !lp_enable_privileges() ) {

    return False;

  }

  if ( db == NULL )

    return False;

  /* PRIV_<SID> (NULL terminated) as the key */

  fstr_sprintf(keystr, "%s%s", PRIVPREFIX, dom_sid_str_buf(sid, &tmp));

  status = dbwrap_fetch_bystring(db, talloc_tos(), keystr, &data);

  if (!NT_STATUS_IS_OK(status)) {

    DEBUG(4, ("get_privileges: No privileges assigned to SID "

        "[%s]\n", tmp.buf));

    return False;

  }

  if (data.dsize == 4*4) {

    /* it's an old style SE_PRIV structure. */

    *mask = map_old_SE_PRIV(data.dptr);

  } else {

    if (data.dsize != sizeof( uint64_t ) ) {

      DEBUG(3, ("get_privileges: Invalid privileges record assigned to SID "

          "[%s]\n", tmp.buf));

      return False;

    }

    *mask = BVAL(data.dptr, 0);

  }

  TALLOC_FREE(data.dptr);

  return True;

}

/***************************************************************************

 Store the privilege mask (set) for a given SID

****************************************************************************/

static bool set_privileges( const struct dom_sid *sid, uint64_t mask )

{

  struct db_context *db = get_account_pol_db();

  uint8_t privbuf[8];

  struct dom_sid_buf tmp;

  fstring keystr;

  TDB_DATA data = { .dptr = privbuf, .dsize = sizeof(privbuf), };

  if ( !lp_enable_privileges() )

    return False;

  if ( db == NULL )

    return False;

  if ( !sid || (sid->num_auths == 0) ) {

    DEBUG(0,("set_privileges: Refusing to store empty SID!\n"));

    return False;

  }

  /* PRIV_<SID> (NULL terminated) as the key */

  fstr_sprintf(keystr, "%s%s", PRIVPREFIX, dom_sid_str_buf(sid, &tmp));

  /* This writes the 64 bit bitmask out in little endian format */

  SBVAL(privbuf,0,mask);

  return NT_STATUS_IS_OK(dbwrap_store_bystring(db, keystr, data,

                 TDB_REPLACE));

}

/*********************************************************************

 get a list of all privileges for all sids in the list

*********************************************************************/

bool get_privileges_for_sids(uint64_t *privileges, struct dom_sid *slist, int scount)

{

  uint64_t mask;

  int i;

  bool found = False;

  *privileges = 0;

  for ( i=0; i<scount; i++ ) {

    struct dom_sid_buf buf;

    /* don't add unless we actually have a privilege assigned */

    if ( !get_privileges( &slist[i], &mask ) )

      continue;

    DBG_INFO("sid = %s\nPrivilege set: 0x%"PRIx64"\n",

       dom_sid_str_buf(&slist[i], &buf),

       mask);

    *privileges |= mask;

    found = True;

  }

  return found;

}

NTSTATUS get_privileges_for_sid_as_set(TALLOC_CTX *mem_ctx, PRIVILEGE_SET **privileges, struct dom_sid *sid)

{

  uint64_t mask;

  if (!get_privileges(sid, &mask)) {

    return NT_STATUS_OBJECT_NAME_NOT_FOUND;

  }

  *privileges = talloc_zero(mem_ctx, PRIVILEGE_SET);

  if (!*privileges) {

    return NT_STATUS_NO_MEMORY;

  }

  if (!se_priv_to_privilege_set(*privileges, mask)) {

    return NT_STATUS_NO_MEMORY;

  }

  return NT_STATUS_OK;

}

/*********************************************************************

 traversal functions for privilege_enumerate_accounts

*********************************************************************/

static int priv_traverse_fn(struct db_record *rec, void *state)

{

  PRIV_SID_LIST *priv = (PRIV_SID_LIST *)state;

  int  prefixlen = strlen(PRIVPREFIX);

  struct dom_sid sid;

  fstring sid_string;

  TDB_DATA key;

  key = dbwrap_record_get_key(rec);

  /* check we have a PRIV_+SID entry */

  if (strncmp((char *)key.dptr, PRIVPREFIX, prefixlen) != 0)

    return 0;

  /* check to see if we are looking for a particular privilege */

  fstrcpy( sid_string, (char *)&(key.dptr[strlen(PRIVPREFIX)]) );

  if (priv->privilege != 0) {

    uint64_t mask;

    TDB_DATA value;

    value = dbwrap_record_get_value(rec);

    if (value.dsize == 4*4) {

      mask = map_old_SE_PRIV(value.dptr);

    } else {

      if (value.dsize != sizeof( uint64_t ) ) {

        DEBUG(3, ("get_privileges: Invalid privileges record assigned to SID "

            "[%s]\n", sid_string));

        return 0;

      }

      mask = BVAL(value.dptr, 0);

    }

    /* if the SID does not have the specified privilege

       then just return */

    if ((mask & priv->privilege) == 0) {

      return 0;

    }

  }

  /* this is a last ditch safety check to preventing returning

     and invalid SID (i've somehow run into this on development branches) */

  if ( strcmp( "S-0-0", sid_string ) == 0 )

    return 0;

  if ( !string_to_sid(&sid, sid_string) ) {

    DBG_WARNING("Could not convert SID [%s]\n", sid_string);

    return 0;

  }

  if (!NT_STATUS_IS_OK(add_sid_to_array(priv->mem_ctx, &sid,

                &priv->sids.list,

                &priv->sids.count)))

  {

    return 0;

  }

  return 0;

}

/*********************************************************************

 Retrieve list of privileged SIDs (for _lsa_enumerate_accounts()

*********************************************************************/

NTSTATUS privilege_enumerate_accounts(struct dom_sid **sids, int *num_sids)

{

  struct db_context *db = get_account_pol_db();

  PRIV_SID_LIST priv;

  NTSTATUS status;

  if (db == NULL) {

    return NT_STATUS_ACCESS_DENIED;

  }

  ZERO_STRUCT(priv);

  status = dbwrap_traverse_read(db, priv_traverse_fn, &priv, NULL);

  if (!NT_STATUS_IS_OK(status)) {

    return status;

  }

  /* give the memory away; caller will free */

  *sids      = priv.sids.list;

  *num_sids  = priv.sids.count;

  return NT_STATUS_OK;

}

/*********************************************************************

 Retrieve list of SIDs granted a particular privilege

*********************************************************************/

NTSTATUS privilege_enum_sids(enum sec_privilege privilege, TALLOC_CTX *mem_ctx,

           struct dom_sid **sids, int *num_sids)

{

  struct db_context *db = get_account_pol_db();

  PRIV_SID_LIST priv;

  NTSTATUS status;

  if (db == NULL) {

    return NT_STATUS_ACCESS_DENIED;

  }

  ZERO_STRUCT(priv);

  priv.privilege = sec_privilege_mask(privilege);

  priv.mem_ctx = mem_ctx;

  status = dbwrap_traverse_read(db, priv_traverse_fn, &priv, NULL);

  if (!NT_STATUS_IS_OK(status)) {

    return status;

  }

  /* give the memory away; caller will free */

  *sids      = priv.sids.list;

  *num_sids  = priv.sids.count;

  return NT_STATUS_OK;

}

/***************************************************************************

 Add privilege to sid

****************************************************************************/

static bool grant_privilege_bitmap(const struct dom_sid *sid, const uint64_t priv_mask)

{

  uint64_t old_mask = 0, new_mask = 0;

  struct dom_sid_buf buf;

  if ( get_privileges( sid, &old_mask ) ) {

    new_mask = old_mask;

  }

  new_mask |= priv_mask;

  DBG_DEBUG("%s\n"

      "original privilege mask: 0x%"PRIx64"\n"

      "new privilege mask:      0x%"PRIx64"\n",

      dom_sid_str_buf(sid, &buf),

      old_mask,

      new_mask);

  return set_privileges( sid, new_mask );

}

/*********************************************************************

 Add a privilege based on its name

*********************************************************************/

bool grant_privilege_by_name(const struct dom_sid *sid, const char *name)

{

  uint64_t mask;

  if (! se_priv_from_name(name, &mask)) {

          DEBUG(3, ("grant_privilege_by_name: "

        "No Such Privilege Found (%s)\n", name));

    return False;

  }

  return grant_privilege_bitmap( sid, mask );

}

/***************************************************************************

 Grant a privilege set (list of LUID values) from a sid

****************************************************************************/

bool grant_privilege_set(const struct dom_sid *sid, struct lsa_PrivilegeSet *set)

{

  uint64_t privilege_mask;

  if (!privilege_set_to_se_priv(&privilege_mask, set)) {

    return false;

  }

  return grant_privilege_bitmap(sid, privilege_mask);

}

/***************************************************************************

 Remove privilege from sid

****************************************************************************/

static bool revoke_privilege_bitmap(const struct dom_sid *sid, const uint64_t priv_mask)

{

  uint64_t mask;

  struct dom_sid_buf buf;

  /* if the user has no privileges, then we can't revoke any */

  if ( !get_privileges( sid, &mask ) )

    return True;

  DEBUG(10,("revoke_privilege: %s\n", dom_sid_str_buf(sid, &buf)));

  DEBUGADD( 10, ("original privilege mask: 0x%llx\n", (unsigned long long)mask));

  mask &= ~priv_mask;

  DEBUGADD( 10, ("new privilege mask:      0x%llx\n", (unsigned long long)mask));

  return set_privileges( sid, mask );

}

/***************************************************************************

 Remove a privilege set (list of LUID values) from a sid

****************************************************************************/

bool revoke_privilege_set(const struct dom_sid *sid, struct lsa_PrivilegeSet *set)

{

  uint64_t privilege_mask;

  if (!privilege_set_to_se_priv(&privilege_mask, set)) {

    return false;

  }

  return revoke_privilege_bitmap(sid, privilege_mask);

}

/*********************************************************************

 Revoke all privileges

*********************************************************************/

bool revoke_all_privileges( const struct dom_sid *sid )

{

  return revoke_privilege_bitmap( sid, SE_ALL_PRIVS);

}

/*********************************************************************

 Add a privilege based on its name

*********************************************************************/

bool revoke_privilege_by_name(const struct dom_sid *sid, const char *name)

{

  uint64_t mask;

  if (! se_priv_from_name(name, &mask)) {

          DEBUG(3, ("revoke_privilege_by_name: "

        "No Such Privilege Found (%s)\n", name));

          return False;

  }

  return revoke_privilege_bitmap(sid, mask);

}

/***************************************************************************

 Retrieve the SIDs assigned to a given privilege

****************************************************************************/

NTSTATUS privilege_create_account(const struct dom_sid *sid )

{

  return ( grant_privilege_bitmap(sid, 0) ? NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL);

}

/***************************************************************************

 Delete a privileged account

****************************************************************************/

NTSTATUS privilege_delete_account(const struct dom_sid *sid)

{

  struct db_context *db = get_account_pol_db();

  struct dom_sid_buf tmp;

  fstring keystr;

  if (!lp_enable_privileges()) {

    return NT_STATUS_OK;

  }

  if (!db) {

    return NT_STATUS_INVALID_HANDLE;

  }

  if (!sid || (sid->num_auths == 0)) {

    return NT_STATUS_INVALID_SID;

  }

  /* PRIV_<SID> (NULL terminated) as the key */

  fstr_sprintf(keystr, "%s%s", PRIVPREFIX, dom_sid_str_buf(sid, &tmp));

  return dbwrap_delete_bystring(db, keystr);

}

/*******************************************************************

*******************************************************************/

bool is_privileged_sid( const struct dom_sid *sid )

{

  uint64_t mask;

  return get_privileges( sid, &mask );

}

/*******************************************************************

*******************************************************************/

bool grant_all_privileges( const struct dom_sid *sid )

{

  uint64_t mask;

  se_priv_put_all_privileges(&mask);

  return grant_privilege_bitmap( sid, mask );

}