r20257: Hey, change_owner_to_parent is now static :-)

[Samba.git] / source / passdb / 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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

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

#include "includes.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_PASSDB

static TDB_CONTEXT *tdb;

/* Urrrg. global.... */
BOOL global_machine_password_needs_changing;

/**
 * Use a TDB to store an incrementing random seed.
 *
 * Initialised to the current pid, the very first time Samba starts,
 * and incremented by one each time it is needed.  
 * 
 * @note Not called by systems with a working /dev/urandom.
 */
static void get_rand_seed(int *new_seed) 
{
        *new_seed = sys_getpid();
        if (tdb) {
                tdb_change_int32_atomic(tdb, "INFO/random_seed", new_seed, 1);
        }
}

/* open up the secrets database */
BOOL secrets_init(void)
{
        pstring fname;
        unsigned char dummy;

        if (tdb)
                return True;

        pstrcpy(fname, lp_private_dir());
        pstrcat(fname,"/secrets.tdb");

        tdb = tdb_open_log(fname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);

        if (!tdb) {
                DEBUG(0,("Failed to open %s\n", fname));
                return False;
        }

        /**
         * Set a reseed function for the crypto random generator 
         * 
         * This avoids a problem where systems without /dev/urandom
         * could send the same challenge to multiple clients
         */
        set_rand_reseed_callback(get_rand_seed);

        /* Ensure that the reseed is done now, while we are root, etc */
        generate_random_buffer(&dummy, sizeof(dummy));

        return True;
}

/* read a entry from the secrets database - the caller must free the result
   if size is non-null then the size of the entry is put in there
 */
void *secrets_fetch(const char *key, size_t *size)
{
        TDB_DATA dbuf;
        secrets_init();
        if (!tdb)
                return NULL;
        dbuf = tdb_fetch(tdb, string_tdb_data(key));
        if (size)
                *size = dbuf.dsize;
        return dbuf.dptr;
}

/* store a secrets entry 
 */
BOOL secrets_store(const char *key, const void *data, size_t size)
{
        secrets_init();
        if (!tdb)
                return False;
        return tdb_trans_store(tdb, string_tdb_data(key),
                               make_tdb_data((const char *)data, size),
                               TDB_REPLACE) == 0;
}


/* delete a secets database entry
 */
BOOL secrets_delete(const char *key)
{
        secrets_init();
        if (!tdb)
                return False;
        return tdb_delete(tdb, string_tdb_data(key)) == 0;
}

BOOL secrets_store_domain_sid(const char *domain, const DOM_SID *sid)
{
        fstring key;
        BOOL ret;

        slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_DOMAIN_SID, domain);
        strupper_m(key);
        ret = secrets_store(key, sid, sizeof(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, DOM_SID *sid)
{
        DOM_SID *dyn_sid;
        fstring key;
        size_t size = 0;

        slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_DOMAIN_SID, domain);
        strupper_m(key);
        dyn_sid = (DOM_SID *)secrets_fetch(key, &size);

        if (dyn_sid == NULL)
                return False;

        if (size != sizeof(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) {
                        smb_uuid_generate_random(&new_guid);
                        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 password
 *
 * @param domain domain name
 *
 * @return stored password's key
 **/
const char *trust_keystr(const char *domain)
{
        static fstring keystr;

        slprintf(keystr,sizeof(keystr)-1,"%s/%s", 
                 SECRETS_MACHINE_ACCT_PASS, domain);
        strupper_m(keystr);

        return keystr;
}

/**
 * Form a key for fetching a trusted domain password
 *
 * @param domain trusted domain name
 *
 * @return stored password's key
 **/
static char *trustdom_keystr(const char *domain)
{
        static pstring keystr;

        pstr_sprintf(keystr, "%s/%s", SECRETS_DOMTRUST_ACCT_PASS, domain);
        strupper_m(keystr);
                
        return keystr;
}

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

BOOL secrets_lock_trust_account_password(const char *domain, BOOL dolock)
{
        if (!tdb)
                return False;

        if (dolock)
                return (tdb_lock_bystring(tdb, trust_keystr(domain)) == 0);
        else
                tdb_unlock_bystring(tdb, trust_keystr(domain));
        return True;
}

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

uint32 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.
 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,
                                          uint32 *channel)
{
        struct machine_acct_pass *pass;
        char *plaintext;
        size_t size = 0;

        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;
        }

        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"));
                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;
}

/**
 * Pack SID passed by pointer
 *
 * @param pack_buf pointer to buffer which is to be filled with packed data
 * @param bufsize size of packing buffer
 * @param sid pointer to sid to be packed
 *
 * @return length of the packed representation of the whole structure
 **/
static size_t tdb_sid_pack(char* pack_buf, int bufsize, DOM_SID* sid)
{
        int idx;
        size_t len = 0;
        
        if (!sid || !pack_buf) return -1;
        
        len += tdb_pack(pack_buf + len, bufsize - len, "bb", sid->sid_rev_num,
                        sid->num_auths);
        
        for (idx = 0; idx < 6; idx++) {
                len += tdb_pack(pack_buf + len, bufsize - len, "b",
                                sid->id_auth[idx]);
        }
        
        for (idx = 0; idx < MAXSUBAUTHS; idx++) {
                len += tdb_pack(pack_buf + len, bufsize - len, "d",
                                sid->sub_auths[idx]);
        }
        
        return len;
}

/**
 * Unpack SID into a pointer
 *
 * @param pack_buf pointer to buffer with packed representation
 * @param bufsize size of the buffer
 * @param sid pointer to sid structure to be filled with unpacked data
 *
 * @return size of structure unpacked from buffer
 **/
static size_t tdb_sid_unpack(char* pack_buf, int bufsize, DOM_SID* sid)
{
        int idx, len = 0;
        
        if (!sid || !pack_buf) return -1;

        len += tdb_unpack(pack_buf + len, bufsize - len, "bb",
                          &sid->sid_rev_num, &sid->num_auths);
                          
        for (idx = 0; idx < 6; idx++) {
                len += tdb_unpack(pack_buf + len, bufsize - len, "b",
                                  &sid->id_auth[idx]);
        }
        
        for (idx = 0; idx < MAXSUBAUTHS; idx++) {
                len += tdb_unpack(pack_buf + len, bufsize - len, "d",
                                  &sid->sub_auths[idx]);
        }
        
        return len;
}

/**
 * Pack TRUSTED_DOM_PASS passed by pointer
 *
 * @param pack_buf pointer to buffer which is to be filled with packed data
 * @param bufsize size of the buffer
 * @param pass pointer to trusted domain password to be packed
 *
 * @return length of the packed representation of the whole structure
 **/
static size_t tdb_trusted_dom_pass_pack(char* pack_buf, int bufsize,
                                        TRUSTED_DOM_PASS* pass)
{
        int idx, len = 0;
        
        if (!pack_buf || !pass) return -1;
        
        /* packing unicode domain name and password */
        len += tdb_pack(pack_buf + len, bufsize - len, "d",
                        pass->uni_name_len);
        
        for (idx = 0; idx < 32; idx++)
                len +=  tdb_pack(pack_buf + len, bufsize - len, "w",
                                 pass->uni_name[idx]);
        
        len += tdb_pack(pack_buf + len, bufsize - len, "dPd", pass->pass_len,
                             pass->pass, pass->mod_time);

        /* packing SID structure */
        len += tdb_sid_pack(pack_buf + len, bufsize - len, &pass->domain_sid);

        return len;
}


/**
 * Unpack TRUSTED_DOM_PASS passed by pointer
 *
 * @param pack_buf pointer to buffer with packed representation
 * @param bufsize size of the buffer
 * @param pass pointer to trusted domain password to be filled with unpacked data
 *
 * @return size of structure unpacked from buffer
 **/
size_t tdb_trusted_dom_pass_unpack(char* pack_buf, int bufsize,
                                   TRUSTED_DOM_PASS* pass)
{
        int idx, len = 0;
        
        if (!pack_buf || !pass) return -1;

        /* unpack unicode domain name and plaintext password */
        len += tdb_unpack(pack_buf, bufsize - len, "d", &pass->uni_name_len);
        
        for (idx = 0; idx < 32; idx++)
                len +=  tdb_unpack(pack_buf + len, bufsize - len, "w",
                                   &pass->uni_name[idx]);

        len += tdb_unpack(pack_buf + len, bufsize - len, "dPd",
                          &pass->pass_len, &pass->pass, &pass->mod_time);
        
        /* unpack domain sid */
        len += tdb_sid_unpack(pack_buf + len, bufsize - len,
                              &pass->domain_sid);
        
        return len;     
}

/************************************************************************
 Routine to get account password to trusted domain
************************************************************************/

BOOL secrets_fetch_trusted_domain_password(const char *domain, char** pwd,
                                           DOM_SID *sid, time_t *pass_last_set_time)
{
        struct trusted_dom_pass pass;
        size_t size = 0;
        
        /* unpacking structures */
        char* pass_buf;
        int pass_len = 0;

        ZERO_STRUCT(pass);

        /* fetching trusted domain password structure */
        if (!(pass_buf = (char *)secrets_fetch(trustdom_keystr(domain),
                                               &size))) {
                DEBUG(5, ("secrets_fetch failed!\n"));
                return False;
        }

        /* unpack trusted domain password */
        pass_len = tdb_trusted_dom_pass_unpack(pass_buf, size, &pass);
        SAFE_FREE(pass_buf);

        if (pass_len != size) {
                DEBUG(5, ("Invalid secrets size. Unpacked data doesn't match trusted_dom_pass structure.\n"));
                return False;
        }
                        
        /* the trust's password */      
        if (pwd) {
                *pwd = SMB_STRDUP(pass.pass);
                if (!*pwd) {
                        return False;
                }
        }

        /* last change time */
        if (pass_last_set_time) *pass_last_set_time = pass.mod_time;

        /* domain sid */
        if (sid != NULL) sid_copy(sid, &pass.domain_sid);
                
        return True;
}

/************************************************************************
 Routine to set the trust account password for a domain.
************************************************************************/

BOOL secrets_store_trust_account_password(const char *domain, uint8 new_pwd[16])
{
        struct machine_acct_pass pass;

        pass.mod_time = time(NULL);
        memcpy(pass.hash, new_pwd, 16);

        return secrets_store(trust_keystr(domain), (void *)&pass, sizeof(pass));
}

/**
 * Routine to store the password for trusted domain
 *
 * @param domain remote domain name
 * @param pwd plain text password of trust relationship
 * @param sid remote domain sid
 *
 * @return true if succeeded
 **/

BOOL secrets_store_trusted_domain_password(const char* domain, const char* pwd,
                                           const DOM_SID *sid)
{
        smb_ucs2_t *uni_dom_name;

        /* packing structures */
        pstring pass_buf;
        int pass_len = 0;
        int pass_buf_len = sizeof(pass_buf);
        
        struct trusted_dom_pass pass;
        ZERO_STRUCT(pass);

        if (push_ucs2_allocate(&uni_dom_name, domain) == (size_t)-1) {
                DEBUG(0, ("Could not convert domain name %s to unicode\n",
                          domain));
                return False;
        }
        
        strncpy_w(pass.uni_name, uni_dom_name, sizeof(pass.uni_name) - 1);
        pass.uni_name_len = strlen_w(uni_dom_name)+1;
        SAFE_FREE(uni_dom_name);

        /* last change time */
        pass.mod_time = time(NULL);

        /* password of the trust */
        pass.pass_len = strlen(pwd);
        fstrcpy(pass.pass, pwd);

        /* domain sid */
        sid_copy(&pass.domain_sid, sid);
        
        pass_len = tdb_trusted_dom_pass_pack(pass_buf, pass_buf_len, &pass);

        return secrets_store(trustdom_keystr(domain), (void *)&pass_buf, pass_len);
}

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

BOOL secrets_store_machine_password(const char *pass, const char *domain, uint32 sec_channel)
{
        char *key = NULL;
        BOOL ret;
        uint32 last_change_time;
        uint32 sec_channel_type;

        asprintf(&key, "%s/%s", SECRETS_MACHINE_PASSWORD, domain);
        if (!key) 
                return False;
        strupper_m(key);

        ret = secrets_store(key, pass, strlen(pass)+1);
        SAFE_FREE(key);

        if (!ret)
                return ret;
        
        asprintf(&key, "%s/%s", SECRETS_MACHINE_LAST_CHANGE_TIME, domain);
        if (!key) 
                return False;
        strupper_m(key);

        SIVAL(&last_change_time, 0, time(NULL));
        ret = secrets_store(key, &last_change_time, sizeof(last_change_time));
        SAFE_FREE(key);

        asprintf(&key, "%s/%s", SECRETS_MACHINE_SEC_CHANNEL_TYPE, domain);
        if (!key) 
                return False;
        strupper_m(key);

        SIVAL(&sec_channel_type, 0, sec_channel);
        ret = secrets_store(key, &sec_channel_type, sizeof(sec_channel_type));
        SAFE_FREE(key);

        return ret;
}

/************************************************************************
 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,
                                     uint32 *channel)
{
        char *key = NULL;
        char *ret;
        asprintf(&key, "%s/%s", SECRETS_MACHINE_PASSWORD, domain);
        strupper_m(key);
        ret = (char *)secrets_fetch(key, NULL);
        SAFE_FREE(key);
        
        if (pass_last_set_time) {
                size_t size;
                uint32 *last_set_time;
                asprintf(&key, "%s/%s", SECRETS_MACHINE_LAST_CHANGE_TIME, domain);
                strupper_m(key);
                last_set_time = (unsigned int *)secrets_fetch(key, &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;
                }
                SAFE_FREE(key);
        }
        
        if (channel) {
                size_t size;
                uint32 *channel_type;
                asprintf(&key, "%s/%s", SECRETS_MACHINE_SEC_CHANNEL_TYPE, domain);
                strupper_m(key);
                channel_type = (unsigned int *)secrets_fetch(key, &size);
                if (channel_type) {
                        *channel = IVAL(channel_type,0);
                        SAFE_FREE(channel_type);
                } else {
                        *channel = get_default_sec_channel();
                }
                SAFE_FREE(key);
        }
        
        return ret;
}

/*******************************************************************
 Wrapper around retrieving the trust account password
*******************************************************************/
                                                                                                                     
BOOL get_trust_pw(const char *domain, uint8 ret_pwd[16], uint32 *channel)
{
        DOM_SID sid;
        char *pwd;
        time_t last_set_time;
                                                                                                                     
        /* if we are a DC and this is not our domain, then lookup an account
                for the domain trust */
                                                                                                                     
        if ( IS_DC && !strequal(domain, lp_workgroup()) && lp_allow_trusted_domains() ) {
                if (!secrets_fetch_trusted_domain_password(domain, &pwd, &sid,
                                                        &last_set_time)) {
                        DEBUG(0, ("get_trust_pw: could not fetch trust "
                                "account password for trusted domain %s\n",
                                domain));
                        return False;
                }
                                                                                                                     
                *channel = SEC_CHAN_DOMAIN;
                E_md4hash(pwd, ret_pwd);
                SAFE_FREE(pwd);

                return True;
        }
                                                                                                                     
        /* Just get the account for the requested domain. In the future this
         * might also cover to be member of more than one domain. */
                                                                                                                     
        if (secrets_fetch_trust_account_password(domain, ret_pwd,
                                                &last_set_time, channel))
                return True;

        DEBUG(5, ("get_trust_pw: could not fetch trust account "
                "password for domain %s\n", domain));
        return False;
}

/************************************************************************
 Routine to delete the machine trust account password file for a domain.
************************************************************************/

BOOL trust_password_delete(const char *domain)
{
        return secrets_delete(trust_keystr(domain));
}

/************************************************************************
 Routine to delete the password for trusted domain
************************************************************************/

BOOL trusted_domain_password_delete(const char *domain)
{
        return secrets_delete(trustdom_keystr(domain));
}

BOOL secrets_store_ldap_pw(const char* dn, char* pw)
{
        char *key = NULL;
        BOOL ret;
        
        if (asprintf(&key, "%s/%s", SECRETS_LDAP_BIND_PW, dn) < 0) {
                DEBUG(0, ("secrets_store_ldap_pw: asprintf failed!\n"));
                return False;
        }
                
        ret = secrets_store(key, pw, strlen(pw)+1);
        
        SAFE_FREE(key);
        return ret;
}

/*******************************************************************
 Find the ldap password.
******************************************************************/

BOOL fetch_ldap_pw(char **dn, char** pw)
{
        char *key = NULL;
        size_t size = 0;
        
        *dn = smb_xstrdup(lp_ldap_admin_dn());
        
        if (asprintf(&key, "%s/%s", SECRETS_LDAP_BIND_PW, *dn) < 0) {
                SAFE_FREE(*dn);
                DEBUG(0, ("fetch_ldap_pw: asprintf failed!\n"));
        }
        
        *pw=(char *)secrets_fetch(key, &size);
        SAFE_FREE(key);

        if (!size) {
                /* Upgrade 2.2 style entry */
                char *p;
                char* old_style_key = SMB_STRDUP(*dn);
                char *data;
                fstring old_style_pw;
                
                if (!old_style_key) {
                        DEBUG(0, ("fetch_ldap_pw: strdup failed!\n"));
                        return False;
                }

                for (p=old_style_key; *p; p++)
                        if (*p == ',') *p = '/';
        
                data=(char *)secrets_fetch(old_style_key, &size);
                if (!size && size < sizeof(old_style_pw)) {
                        DEBUG(0,("fetch_ldap_pw: neither ldap secret retrieved!\n"));
                        SAFE_FREE(old_style_key);
                        SAFE_FREE(*dn);
                        return False;
                }

                size = MIN(size, sizeof(fstring)-1);
                strncpy(old_style_pw, data, size);
                old_style_pw[size] = 0;

                SAFE_FREE(data);

                if (!secrets_store_ldap_pw(*dn, old_style_pw)) {
                        DEBUG(0,("fetch_ldap_pw: ldap secret could not be upgraded!\n"));
                        SAFE_FREE(old_style_key);
                        SAFE_FREE(*dn);
                        return False;                   
                }
                if (!secrets_delete(old_style_key)) {
                        DEBUG(0,("fetch_ldap_pw: old ldap secret could not be deleted!\n"));
                }

                SAFE_FREE(old_style_key);

                *pw = smb_xstrdup(old_style_pw);                
        }
        
        return True;
}

/**
 * Get trusted domains info from secrets.tdb.
 **/ 

NTSTATUS secrets_trusted_domains(TALLOC_CTX *mem_ctx, uint32 *num_domains,
                                 struct trustdom_info ***domains)
{
        TDB_LIST_NODE *keys, *k;
        char *pattern;
        TALLOC_CTX *tmp_ctx;

        if (!(tmp_ctx = talloc_new(mem_ctx))) {
                return NT_STATUS_NO_MEMORY;
        }

        if (!secrets_init()) return NT_STATUS_ACCESS_DENIED;
        
        /* generate searching pattern */
        pattern = talloc_asprintf(tmp_ctx, "%s/*", SECRETS_DOMTRUST_ACCT_PASS);
        if (pattern == NULL) {
                DEBUG(0, ("secrets_trusted_domains: talloc_asprintf() "
                          "failed!\n"));
                TALLOC_FREE(tmp_ctx);
                return NT_STATUS_NO_MEMORY;
        }

        *num_domains = 0;

        /*
         * Make sure that a talloc context for the trustdom_info structs
         * exists
         */

        if (!(*domains = TALLOC_ARRAY(mem_ctx, struct trustdom_info *, 1))) {
                TALLOC_FREE(tmp_ctx);
                return NT_STATUS_NO_MEMORY;
        }

        /* fetching trusted domains' data and collecting them in a list */
        keys = tdb_search_keys(tdb, pattern);

        /* searching for keys in secrets db -- way to go ... */
        for (k = keys; k; k = k->next) {
                char *packed_pass;
                size_t size = 0, packed_size = 0;
                struct trusted_dom_pass pass;
                char *secrets_key;
                struct trustdom_info *dom_info;
                
                /* important: ensure null-termination of the key string */
                secrets_key = talloc_strndup(tmp_ctx,
                                             k->node_key.dptr,
                                             k->node_key.dsize);
                if (!secrets_key) {
                        DEBUG(0, ("strndup failed!\n"));
                        tdb_search_list_free(keys);
                        TALLOC_FREE(tmp_ctx);
                        return NT_STATUS_NO_MEMORY;
                }

                packed_pass = (char *)secrets_fetch(secrets_key, &size);
                packed_size = tdb_trusted_dom_pass_unpack(packed_pass, size,
                                                          &pass);
                /* packed representation isn't needed anymore */
                SAFE_FREE(packed_pass);
                
                if (size != packed_size) {
                        DEBUG(2, ("Secrets record %s is invalid!\n",
                                  secrets_key));
                        continue;
                }

                if (pass.domain_sid.num_auths != 4) {
                        DEBUG(0, ("SID %s is not a domain sid, has %d "
                                  "auths instead of 4\n",
                                  sid_string_static(&pass.domain_sid),
                                  pass.domain_sid.num_auths));
                        continue;
                }

                if (!(dom_info = TALLOC_P(*domains, struct trustdom_info))) {
                        DEBUG(0, ("talloc failed\n"));
                        tdb_search_list_free(keys);
                        TALLOC_FREE(tmp_ctx);
                        return NT_STATUS_NO_MEMORY;
                }

                if (pull_ucs2_talloc(dom_info, &dom_info->name,
                                     pass.uni_name) == (size_t)-1) {
                        DEBUG(2, ("pull_ucs2_talloc failed\n"));
                        tdb_search_list_free(keys);
                        TALLOC_FREE(tmp_ctx);
                        return NT_STATUS_NO_MEMORY;
                }

                sid_copy(&dom_info->sid, &pass.domain_sid);

                ADD_TO_ARRAY(*domains, struct trustdom_info *, dom_info,
                             domains, num_domains);

                if (*domains == NULL) {
                        tdb_search_list_free(keys);
                        TALLOC_FREE(tmp_ctx);
                        return NT_STATUS_NO_MEMORY;
                }
        }
        
        DEBUG(5, ("secrets_get_trusted_domains: got %d domains\n",
                  *num_domains));

        /* free the results of searching the keys */
        tdb_search_list_free(keys);
        TALLOC_FREE(tmp_ctx);

        return NT_STATUS_OK;
}

/*******************************************************************************
 Lock the secrets tdb based on a string - this is used as a primitive form of mutex
 between smbd instances.
*******************************************************************************/

BOOL secrets_named_mutex(const char *name, unsigned int timeout)
{
        int ret = 0;

        if (!secrets_init())
                return False;

        ret = tdb_lock_bystring_with_timeout(tdb, name, timeout);
        if (ret == 0)
                DEBUG(10,("secrets_named_mutex: got mutex for %s\n", name ));

        return (ret == 0);
}

/*******************************************************************************
 Unlock a named mutex.
*******************************************************************************/

void secrets_named_mutex_release(const char *name)
{
        tdb_unlock_bystring(tdb, name);
        DEBUG(10,("secrets_named_mutex: released mutex for %s\n", name ));
}

/*******************************************************************************
 Store a complete AFS keyfile into secrets.tdb.
*******************************************************************************/

BOOL secrets_store_afs_keyfile(const char *cell, const struct afs_keyfile *keyfile)
{
        fstring key;

        if ((cell == NULL) || (keyfile == NULL))
                return False;

        if (ntohl(keyfile->nkeys) > SECRETS_AFS_MAXKEYS)
                return False;

        slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_AFS_KEYFILE, cell);
        return secrets_store(key, keyfile, sizeof(struct afs_keyfile));
}

/*******************************************************************************
 Fetch the current (highest) AFS key from secrets.tdb
*******************************************************************************/
BOOL secrets_fetch_afs_key(const char *cell, struct afs_key *result)
{
        fstring key;
        struct afs_keyfile *keyfile;
        size_t size = 0;
        uint32 i;

        slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_AFS_KEYFILE, cell);

        keyfile = (struct afs_keyfile *)secrets_fetch(key, &size);

        if (keyfile == NULL)
                return False;

        if (size != sizeof(struct afs_keyfile)) {
                SAFE_FREE(keyfile);
                return False;
        }

        i = ntohl(keyfile->nkeys);

        if (i > SECRETS_AFS_MAXKEYS) {
                SAFE_FREE(keyfile);
                return False;
        }

        *result = keyfile->entry[i-1];

        result->kvno = ntohl(result->kvno);

        return True;
}

/******************************************************************************
  When kerberos is not available, choose between anonymous or
  authenticated connections.  

  We need to use an authenticated connection if DCs have the
  RestrictAnonymous registry entry set > 0, or the "Additional
  restrictions for anonymous connections" set in the win2k Local
  Security Policy.

  Caller to free() result in domain, username, password
*******************************************************************************/
void secrets_fetch_ipc_userpass(char **username, char **domain, char **password)
{
        *username = (char *)secrets_fetch(SECRETS_AUTH_USER, NULL);
        *domain = (char *)secrets_fetch(SECRETS_AUTH_DOMAIN, NULL);
        *password = (char *)secrets_fetch(SECRETS_AUTH_PASSWORD, NULL);
        
        if (*username && **username) {

                if (!*domain || !**domain)
                        *domain = smb_xstrdup(lp_workgroup());
                
                if (!*password || !**password)
                        *password = smb_xstrdup("");

                DEBUG(3, ("IPC$ connections done by user %s\\%s\n", 
                          *domain, *username));

        } else {
                DEBUG(3, ("IPC$ connections done anonymously\n"));
                *username = smb_xstrdup("");
                *domain = smb_xstrdup("");
                *password = smb_xstrdup("");
        }
}

/******************************************************************************
 Open or create the schannel session store tdb.
*******************************************************************************/

static TDB_CONTEXT *open_schannel_session_store(TALLOC_CTX *mem_ctx)
{
        TDB_DATA vers;
        uint32 ver;
        TDB_CONTEXT *tdb_sc = NULL;
        char *fname = talloc_asprintf(mem_ctx, "%s/schannel_store.tdb", lp_private_dir());

        if (!fname) {
                return NULL;
        }

        tdb_sc = tdb_open_log(fname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);

        if (!tdb_sc) {
                DEBUG(0,("open_schannel_session_store: Failed to open %s\n", fname));
                TALLOC_FREE(fname);
                return NULL;
        }

        vers = tdb_fetch_bystring(tdb_sc, "SCHANNEL_STORE_VERSION");
        if (vers.dptr == NULL) {
                /* First opener, no version. */
                SIVAL(&ver,0,1);
                vers.dptr = (char *)&ver;
                vers.dsize = 4;
                tdb_store_bystring(tdb_sc, "SCHANNEL_STORE_VERSION", vers, TDB_REPLACE);
                vers.dptr = NULL;
        } else if (vers.dsize == 4) {
                ver = IVAL(vers.dptr,0);
                if (ver != 1) {
                        tdb_close(tdb_sc);
                        tdb_sc = NULL;
                        DEBUG(0,("open_schannel_session_store: wrong version number %d in %s\n",
                                (int)ver, fname ));
                }
        } else {
                tdb_close(tdb_sc);
                tdb_sc = NULL;
                DEBUG(0,("open_schannel_session_store: wrong version number size %d in %s\n",
                        (int)vers.dsize, fname ));
        }

        SAFE_FREE(vers.dptr);
        TALLOC_FREE(fname);

        return tdb_sc;
}

/******************************************************************************
 Store the schannel state after an AUTH2 call.
 Note we must be root here.
*******************************************************************************/

BOOL secrets_store_schannel_session_info(TALLOC_CTX *mem_ctx,
                                const char *remote_machine,
                                const struct dcinfo *pdc)
{
        TDB_CONTEXT *tdb_sc = NULL;
        TDB_DATA value;
        BOOL ret;
        char *keystr = talloc_asprintf(mem_ctx, "%s/%s", SECRETS_SCHANNEL_STATE,
                                remote_machine);
        if (!keystr) {
                return False;
        }

        strupper_m(keystr);

        /* Work out how large the record is. */
        value.dsize = tdb_pack(NULL, 0, "dBBBBBfff",
                                pdc->sequence,
                                8, pdc->seed_chal.data,
                                8, pdc->clnt_chal.data,
                                8, pdc->srv_chal.data,
                                16, pdc->sess_key,
                                16, pdc->mach_pw,
                                pdc->mach_acct,
                                pdc->remote_machine,
                                pdc->domain);

        value.dptr = (char *)TALLOC(mem_ctx, value.dsize);
        if (!value.dptr) {
                TALLOC_FREE(keystr);
                return False;
        }

        value.dsize = tdb_pack(value.dptr, value.dsize, "dBBBBBfff",
                                pdc->sequence,
                                8, pdc->seed_chal.data,
                                8, pdc->clnt_chal.data,
                                8, pdc->srv_chal.data,
                                16, pdc->sess_key,
                                16, pdc->mach_pw,
                                pdc->mach_acct,
                                pdc->remote_machine,
                                pdc->domain);

        tdb_sc = open_schannel_session_store(mem_ctx);
        if (!tdb_sc) {
                TALLOC_FREE(keystr);
                TALLOC_FREE(value.dptr);
                return False;
        }

        ret = (tdb_store_bystring(tdb_sc, keystr, value, TDB_REPLACE) == 0 ? True : False);

        DEBUG(3,("secrets_store_schannel_session_info: stored schannel info with key %s\n",
                keystr ));

        tdb_close(tdb_sc);
        TALLOC_FREE(keystr);
        TALLOC_FREE(value.dptr);
        return ret;
}

/******************************************************************************
 Restore the schannel state on a client reconnect.
 Note we must be root here.
*******************************************************************************/

BOOL secrets_restore_schannel_session_info(TALLOC_CTX *mem_ctx,
                                const char *remote_machine,
                                struct dcinfo **ppdc)
{
        TDB_CONTEXT *tdb_sc = NULL;
        TDB_DATA value;
        unsigned char *pseed_chal = NULL;
        unsigned char *pclnt_chal = NULL;
        unsigned char *psrv_chal = NULL;
        unsigned char *psess_key = NULL;
        unsigned char *pmach_pw = NULL;
        uint32 l1, l2, l3, l4, l5;
        int ret;
        struct dcinfo *pdc = NULL;
        char *keystr = talloc_asprintf(mem_ctx, "%s/%s", SECRETS_SCHANNEL_STATE,
                                remote_machine);

        *ppdc = NULL;

        if (!keystr) {
                return False;
        }

        strupper_m(keystr);

        tdb_sc = open_schannel_session_store(mem_ctx);
        if (!tdb_sc) {
                TALLOC_FREE(keystr);
                return False;
        }

        value = tdb_fetch_bystring(tdb_sc, keystr);
        if (!value.dptr) {
                DEBUG(0,("secrets_restore_schannel_session_info: Failed to find entry with key %s\n",
                        keystr ));
                tdb_close(tdb_sc);
                return False;
        }

        pdc = TALLOC_ZERO_P(mem_ctx, struct dcinfo);

        /* Retrieve the record. */
        ret = tdb_unpack(value.dptr, value.dsize, "dBBBBBfff",
                                &pdc->sequence,
                                &l1, &pseed_chal,
                                &l2, &pclnt_chal,
                                &l3, &psrv_chal,
                                &l4, &psess_key,
                                &l5, &pmach_pw,
                                &pdc->mach_acct,
                                &pdc->remote_machine,
                                &pdc->domain);

        if (ret == -1 || l1 != 8 || l2 != 8 || l3 != 8 || l4 != 16 || l5 != 16) {
                /* Bad record - delete it. */
                tdb_delete_bystring(tdb_sc, keystr);
                tdb_close(tdb_sc);
                TALLOC_FREE(keystr);
                TALLOC_FREE(pdc);
                SAFE_FREE(pseed_chal);
                SAFE_FREE(pclnt_chal);
                SAFE_FREE(psrv_chal);
                SAFE_FREE(psess_key);
                SAFE_FREE(pmach_pw);
                SAFE_FREE(value.dptr);
                return False;
        }

        tdb_close(tdb_sc);

        memcpy(pdc->seed_chal.data, pseed_chal, 8);
        memcpy(pdc->clnt_chal.data, pclnt_chal, 8);
        memcpy(pdc->srv_chal.data, psrv_chal, 8);
        memcpy(pdc->sess_key, psess_key, 16);
        memcpy(pdc->mach_pw, pmach_pw, 16);

        /* We know these are true so didn't bother to store them. */
        pdc->challenge_sent = True;
        pdc->authenticated = True;

        DEBUG(3,("secrets_restore_schannel_session_info: restored schannel info key %s\n",
                keystr ));

        SAFE_FREE(pseed_chal);
        SAFE_FREE(pclnt_chal);
        SAFE_FREE(psrv_chal);
        SAFE_FREE(psess_key);
        SAFE_FREE(pmach_pw);

        TALLOC_FREE(keystr);
        SAFE_FREE(value.dptr);

        *ppdc = pdc;

        return True;
}