source: trunk/server/source3/passdb/machine_account_secrets.c

/*
   Unix SMB/CIFS implementation.
   Copyright (C) Andrew Tridgell 1992-2001
   Copyright (C) Andrew Bartlett      2002
   Copyright (C) Rafal Szczesniak     2002
   Copyright (C) Tim Potter           2001

   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/>.
*/

/* the Samba secrets database stores any generated, private information
   such as the local SID and machine trust password */

#include "includes.h"
#include "passdb.h"
#include "../libcli/auth/libcli_auth.h"
#include "secrets.h"
#include "dbwrap.h"
#include "../librpc/ndr/libndr.h"
#include "util_tdb.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_PASSDB

/* Urrrg. global.... */
bool global_machine_password_needs_changing;

/**
 * Form a key for fetching the domain sid
 *
 * @param domain domain name
 *
 * @return keystring
 **/
static const char *domain_sid_keystr(const char *domain)
{
        char *keystr;

        keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
                                            SECRETS_DOMAIN_SID, domain);
        SMB_ASSERT(keystr != NULL);
        return keystr;
}

bool secrets_store_domain_sid(const char *domain, const struct dom_sid  *sid)
{
        bool ret;

        ret = secrets_store(domain_sid_keystr(domain), sid, sizeof(struct dom_sid ));

        /* Force a re-query, in case we modified our domain */
        if (ret)
                reset_global_sam_sid();
        return ret;
}

bool secrets_fetch_domain_sid(const char *domain, struct dom_sid  *sid)
{
        struct dom_sid  *dyn_sid;
        size_t size = 0;

        dyn_sid = (struct dom_sid  *)secrets_fetch(domain_sid_keystr(domain), &size);

        if (dyn_sid == NULL)
                return False;

        if (size != sizeof(struct dom_sid)) {
                SAFE_FREE(dyn_sid);
                return False;
        }

        *sid = *dyn_sid;
        SAFE_FREE(dyn_sid);
        return True;
}

bool secrets_store_domain_guid(const char *domain, struct GUID *guid)
{
        fstring key;

        slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_DOMAIN_GUID, domain);
        strupper_m(key);
        return secrets_store(key, guid, sizeof(struct GUID));
}

bool secrets_fetch_domain_guid(const char *domain, struct GUID *guid)
{
        struct GUID *dyn_guid;
        fstring key;
        size_t size = 0;
        struct GUID new_guid;

        slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_DOMAIN_GUID, domain);
        strupper_m(key);
        dyn_guid = (struct GUID *)secrets_fetch(key, &size);

        if (!dyn_guid) {
                if (lp_server_role() == ROLE_DOMAIN_PDC) {
                        new_guid = GUID_random();
                        if (!secrets_store_domain_guid(domain, &new_guid))
                                return False;
                        dyn_guid = (struct GUID *)secrets_fetch(key, &size);
                }
                if (dyn_guid == NULL) {
                        return False;
                }
        }

        if (size != sizeof(struct GUID)) {
                DEBUG(1,("UUID size %d is wrong!\n", (int)size));
                SAFE_FREE(dyn_guid);
                return False;
        }

        *guid = *dyn_guid;
        SAFE_FREE(dyn_guid);
        return True;
}

/**
 * Form a key for fetching the machine trust account sec channel type
 *
 * @param domain domain name
 *
 * @return keystring
 **/
static const char *machine_sec_channel_type_keystr(const char *domain)
{
        char *keystr;

        keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
                                            SECRETS_MACHINE_SEC_CHANNEL_TYPE,
                                            domain);
        SMB_ASSERT(keystr != NULL);
        return keystr;
}

/**
 * Form a key for fetching the machine trust account last change time
 *
 * @param domain domain name
 *
 * @return keystring
 **/
static const char *machine_last_change_time_keystr(const char *domain)
{
        char *keystr;

        keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
                                            SECRETS_MACHINE_LAST_CHANGE_TIME,
                                            domain);
        SMB_ASSERT(keystr != NULL);
        return keystr;
}


/**
 * Form a key for fetching the machine previous trust account password
 *
 * @param domain domain name
 *
 * @return keystring
 **/
static const char *machine_prev_password_keystr(const char *domain)
{
        char *keystr;

        keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
                                            SECRETS_MACHINE_PASSWORD_PREV, domain);
        SMB_ASSERT(keystr != NULL);
        return keystr;
}

/**
 * Form a key for fetching the machine trust account password
 *
 * @param domain domain name
 *
 * @return keystring
 **/
static const char *machine_password_keystr(const char *domain)
{
        char *keystr;

        keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
                                            SECRETS_MACHINE_PASSWORD, domain);
        SMB_ASSERT(keystr != NULL);
        return keystr;
}

/**
 * Form a key for fetching the machine trust account password
 *
 * @param domain domain name
 *
 * @return stored password's key
 **/
static const char *trust_keystr(const char *domain)
{
        char *keystr;

        keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
                                            SECRETS_MACHINE_ACCT_PASS, domain);
        SMB_ASSERT(keystr != NULL);
        return keystr;
}

/************************************************************************
 Lock the trust password entry.
************************************************************************/

void *secrets_get_trust_account_lock(TALLOC_CTX *mem_ctx, const char *domain)
{
        struct db_context *db_ctx;
        if (!secrets_init()) {
                return NULL;
        }

        db_ctx = secrets_db_ctx();

        return db_ctx->fetch_locked(
                db_ctx, mem_ctx, string_term_tdb_data(trust_keystr(domain)));
}

/************************************************************************
 Routine to get the default secure channel type for trust accounts
************************************************************************/

enum netr_SchannelType get_default_sec_channel(void)
{
        if (lp_server_role() == ROLE_DOMAIN_BDC ||
            lp_server_role() == ROLE_DOMAIN_PDC) {
                return SEC_CHAN_BDC;
        } else {
                return SEC_CHAN_WKSTA;
        }
}

/************************************************************************
 Routine to get the trust account password for a domain.
 This only tries to get the legacy hashed version of the password.
 The user of this function must have locked the trust password file using
 the above secrets_lock_trust_account_password().
************************************************************************/

bool secrets_fetch_trust_account_password_legacy(const char *domain,
                                                 uint8 ret_pwd[16],
                                                 time_t *pass_last_set_time,
                                                 enum netr_SchannelType *channel)
{
        struct machine_acct_pass *pass;
        size_t size = 0;

        if (!(pass = (struct machine_acct_pass *)secrets_fetch(
                      trust_keystr(domain), &size))) {
                DEBUG(5, ("secrets_fetch failed!\n"));
                return False;
        }

        if (size != sizeof(*pass)) {
                DEBUG(0, ("secrets were of incorrect size!\n"));
                SAFE_FREE(pass);
                return False;
        }

        if (pass_last_set_time) {
                *pass_last_set_time = pass->mod_time;
        }
        memcpy(ret_pwd, pass->hash, 16);

        if (channel) {
                *channel = get_default_sec_channel();
        }

        /* Test if machine password has expired and needs to be changed */
        if (lp_machine_password_timeout()) {
                if (pass->mod_time > 0 && time(NULL) > (pass->mod_time +
                                (time_t)lp_machine_password_timeout())) {
                        global_machine_password_needs_changing = True;
                }
        }

        SAFE_FREE(pass);
        return True;
}

/************************************************************************
 Routine to get the trust account password for a domain.
 The user of this function must have locked the trust password file using
 the above secrets_lock_trust_account_password().
************************************************************************/

bool secrets_fetch_trust_account_password(const char *domain, uint8 ret_pwd[16],
                                          time_t *pass_last_set_time,
                                          enum netr_SchannelType *channel)
{
        char *plaintext;

        plaintext = secrets_fetch_machine_password(domain, pass_last_set_time,
                                                   channel);
        if (plaintext) {
                DEBUG(4,("Using cleartext machine password\n"));
                E_md4hash(plaintext, ret_pwd);
                SAFE_FREE(plaintext);
                return True;
        }

        return secrets_fetch_trust_account_password_legacy(domain, ret_pwd,
                                                           pass_last_set_time,
                                                           channel);
}

/************************************************************************
 Routine to delete the old plaintext machine account password if any
************************************************************************/

static bool secrets_delete_prev_machine_password(const char *domain)
{
        char *oldpass = (char *)secrets_fetch(machine_prev_password_keystr(domain), NULL);
        if (oldpass == NULL) {
                return true;
        }
        SAFE_FREE(oldpass);
        return secrets_delete(machine_prev_password_keystr(domain));
}

/************************************************************************
 Routine to delete the plaintext machine account password and old
 password if any
************************************************************************/

bool secrets_delete_machine_password(const char *domain)
{
        if (!secrets_delete_prev_machine_password(domain)) {
                return false;
        }
        return secrets_delete(machine_password_keystr(domain));
}

/************************************************************************
 Routine to delete the plaintext machine account password, old password,
 sec channel type and last change time from secrets database
************************************************************************/

bool secrets_delete_machine_password_ex(const char *domain)
{
        if (!secrets_delete_prev_machine_password(domain)) {
                return false;
        }
        if (!secrets_delete(machine_password_keystr(domain))) {
                return false;
        }
        if (!secrets_delete(machine_sec_channel_type_keystr(domain))) {
                return false;
        }
        return secrets_delete(machine_last_change_time_keystr(domain));
}

/************************************************************************
 Routine to delete the domain sid
************************************************************************/

bool secrets_delete_domain_sid(const char *domain)
{
        return secrets_delete(domain_sid_keystr(domain));
}

/************************************************************************
 Routine to store the previous machine password (by storing the current password
 as the old)
************************************************************************/

static bool secrets_store_prev_machine_password(const char *domain)
{
        char *oldpass;
        bool ret;

        oldpass = (char *)secrets_fetch(machine_password_keystr(domain), NULL);
        if (oldpass == NULL) {
                return true;
        }
        ret = secrets_store(machine_prev_password_keystr(domain), oldpass, strlen(oldpass)+1);
        SAFE_FREE(oldpass);
        return ret;
}

/************************************************************************
 Routine to set the plaintext machine account password for a realm
 the password is assumed to be a null terminated ascii string.
 Before storing
************************************************************************/

bool secrets_store_machine_password(const char *pass, const char *domain,
                                    enum netr_SchannelType sec_channel)
{
        bool ret;
        uint32 last_change_time;
        uint32 sec_channel_type;

        if (!secrets_store_prev_machine_password(domain)) {
                return false;
        }

        ret = secrets_store(machine_password_keystr(domain), pass, strlen(pass)+1);
        if (!ret)
                return ret;

        SIVAL(&last_change_time, 0, time(NULL));
        ret = secrets_store(machine_last_change_time_keystr(domain), &last_change_time, sizeof(last_change_time));

        SIVAL(&sec_channel_type, 0, sec_channel);
        ret = secrets_store(machine_sec_channel_type_keystr(domain), &sec_channel_type, sizeof(sec_channel_type));

        return ret;
}


/************************************************************************
 Routine to fetch the previous plaintext machine account password for a realm
 the password is assumed to be a null terminated ascii string.
************************************************************************/

char *secrets_fetch_prev_machine_password(const char *domain)
{
        return (char *)secrets_fetch(machine_prev_password_keystr(domain), NULL);
}

/************************************************************************
 Routine to fetch the plaintext machine account password for a realm
 the password is assumed to be a null terminated ascii string.
************************************************************************/

char *secrets_fetch_machine_password(const char *domain,
                                     time_t *pass_last_set_time,
                                     enum netr_SchannelType *channel)
{
        char *ret;
        ret = (char *)secrets_fetch(machine_password_keystr(domain), NULL);

        if (pass_last_set_time) {
                size_t size;
                uint32 *last_set_time;
                last_set_time = (unsigned int *)secrets_fetch(machine_last_change_time_keystr(domain), &size);
                if (last_set_time) {
                        *pass_last_set_time = IVAL(last_set_time,0);
                        SAFE_FREE(last_set_time);
                } else {
                        *pass_last_set_time = 0;
                }
        }

        if (channel) {
                size_t size;
                uint32 *channel_type;
                channel_type = (unsigned int *)secrets_fetch(machine_sec_channel_type_keystr(domain), &size);
                if (channel_type) {
                        *channel = IVAL(channel_type,0);
                        SAFE_FREE(channel_type);
                } else {
                        *channel = get_default_sec_channel();
                }
        }

        return ret;
}