source: trunk/server/source4/auth/credentials/credentials_secrets.c

/* 
   Unix SMB/CIFS implementation.

   User credentials handling (as regards on-disk files)

   Copyright (C) Jelmer Vernooij 2005
   Copyright (C) Tim Potter 2001
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   
   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/events/events.h"
#include <ldb.h>
#include "librpc/gen_ndr/samr.h" /* for struct samrPassword */
#include "param/secrets.h"
#include "system/filesys.h"
#include "auth/credentials/credentials.h"
#include "auth/credentials/credentials_krb5.h"
#include "auth/kerberos/kerberos_util.h"
#include "param/param.h"
#include "lib/events/events.h"
#include "dsdb/samdb/samdb.h"

/**
 * Fill in credentials for the machine trust account, from the secrets database.
 * 
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred, 
                                              struct loadparm_context *lp_ctx,
                                              struct ldb_context *ldb,
                                              const char *base,
                                              const char *filter, 
                                              char **error_string)
{
        TALLOC_CTX *mem_ctx;
        
        int ldb_ret;
        struct ldb_message *msg;
        
        const char *machine_account;
        const char *password;
        const char *old_password;
        const char *domain;
        const char *realm;
        enum netr_SchannelType sct;
        const char *salt_principal;
        char *keytab;
        const struct ldb_val *whenChanged;

        /* ok, we are going to get it now, don't recurse back here */
        cred->machine_account_pending = false;

        /* some other parts of the system will key off this */
        cred->machine_account = true;

        mem_ctx = talloc_named(cred, 0, "cli_credentials fetch machine password");

        if (!ldb) {
                /* Local secrets are stored in secrets.ldb */
                ldb = secrets_db_connect(mem_ctx, lp_ctx);
                if (!ldb) {
                        /* set anonymous as the fallback, if the machine account won't work */
                        cli_credentials_set_anonymous(cred);
                        *error_string = talloc_strdup(cred, "Could not open secrets.ldb");
                        talloc_free(mem_ctx);
                        return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
                }
        }

        ldb_ret = dsdb_search_one(ldb, mem_ctx, &msg,
                                  ldb_dn_new(mem_ctx, ldb, base),
                                  LDB_SCOPE_SUBTREE,
                                  NULL, 0, "%s", filter);

        if (ldb_ret != LDB_SUCCESS) {
                *error_string = talloc_asprintf(cred, "Could not find entry to match filter: '%s' base: '%s': %s: %s\n",
                                                filter, base ? base : "",
                                                ldb_strerror(ldb_ret), ldb_errstring(ldb));
                /* set anonymous as the fallback, if the machine account won't work */
                cli_credentials_set_anonymous(cred);
                talloc_free(mem_ctx);
                return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
        }

        password = ldb_msg_find_attr_as_string(msg, "secret", NULL);
        old_password = ldb_msg_find_attr_as_string(msg, "priorSecret", NULL);

        machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);

        if (!machine_account) {
                machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
                
                if (!machine_account) {
                        const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
                        if (!ldap_bind_dn) {
                                *error_string = talloc_asprintf(cred, 
                                                                "Could not find 'samAccountName', "
                                                                "'servicePrincipalName' or "
                                                                "'ldapBindDn' in secrets record: %s",
                                                                ldb_dn_get_linearized(msg->dn));
                                /* set anonymous as the fallback, if the machine account won't work */
                                cli_credentials_set_anonymous(cred);
                                talloc_free(mem_ctx);
                                return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
                        } else {
                                /* store bind dn in credentials */
                                cli_credentials_set_bind_dn(cred, ldap_bind_dn);
                        }
                }
        }

        salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
        cli_credentials_set_salt_principal(cred, salt_principal);
        
        sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
        if (sct) { 
                cli_credentials_set_secure_channel_type(cred, sct);
        }
        
        if (!password) {
                const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
                struct samr_Password hash;
                ZERO_STRUCT(hash);
                if (nt_password_hash) {
                        memcpy(hash.hash, nt_password_hash->data, 
                               MIN(nt_password_hash->length, sizeof(hash.hash)));
                
                        cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
                } else {
                        cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
                }
        } else {
                cli_credentials_set_password(cred, password, CRED_SPECIFIED);
        }

        
        domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
        if (domain) {
                cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
        }

        realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
        if (realm) {
                cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
        }

        if (machine_account) {
                cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
        }

        cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));

        whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
        if (whenChanged) {
                time_t lct;
                if (ldb_val_to_time(whenChanged, &lct) == LDB_SUCCESS) {
                        cli_credentials_set_password_last_changed_time(cred, lct);
                }
        }
        
        /* If there was an external keytab specified by reference in
         * the LDB, then use this.  Otherwise we will make one up
         * (chewing CPU time) from the password */
        keytab = keytab_name_from_msg(cred, ldb, msg);
        if (keytab) {
                cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
                talloc_free(keytab);
        }
        talloc_free(mem_ctx);
        
        return NT_STATUS_OK;
}

/**
 * Fill in credentials for the machine trust account, from the secrets database.
 * 
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
                                                      struct loadparm_context *lp_ctx)
{
        NTSTATUS status;
        char *filter;
        char *error_string;
        /* Bleh, nasty recursion issues: We are setting a machine
         * account here, so we don't want the 'pending' flag around
         * any more */
        cred->machine_account_pending = false;
        filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER, 
                                 cli_credentials_get_domain(cred));
        status = cli_credentials_set_secrets(cred, lp_ctx, NULL,
                                             SECRETS_PRIMARY_DOMAIN_DN,
                                             filter, &error_string);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("Could not find machine account in secrets database: %s: %s", nt_errstr(status), error_string));
                talloc_free(error_string);
        }
        return status;
}

/**
 * Fill in credentials for the machine trust account, from the secrets database.
 * 
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
NTSTATUS cli_credentials_set_krbtgt(struct cli_credentials *cred,
                                    struct loadparm_context *lp_ctx)
{
        NTSTATUS status;
        char *filter;
        char *error_string;
        /* Bleh, nasty recursion issues: We are setting a machine
         * account here, so we don't want the 'pending' flag around
         * any more */
        cred->machine_account_pending = false;
        filter = talloc_asprintf(cred, SECRETS_KRBTGT_SEARCH,
                                       cli_credentials_get_realm(cred),
                                       cli_credentials_get_domain(cred));
        status = cli_credentials_set_secrets(cred, lp_ctx, NULL,
                                             SECRETS_PRINCIPALS_DN,
                                             filter, &error_string);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("Could not find krbtgt (master Kerberos) account in secrets database: %s: %s", nt_errstr(status), error_string));
                talloc_free(error_string);
        }
        return status;
}

/**
 * Fill in credentials for a particular prinicpal, from the secrets database.
 * 
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
                                              struct loadparm_context *lp_ctx,
                                              const char *serviceprincipal)
{
        NTSTATUS status;
        char *filter;
        char *error_string;
        /* Bleh, nasty recursion issues: We are setting a machine
         * account here, so we don't want the 'pending' flag around
         * any more */
        cred->machine_account_pending = false;
        filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
                                 cli_credentials_get_realm(cred),
                                 cli_credentials_get_domain(cred),
                                 serviceprincipal);
        status = cli_credentials_set_secrets(cred, lp_ctx, NULL,
                                             SECRETS_PRINCIPALS_DN, filter,
                                             &error_string);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("Could not find %s principal in secrets database: %s: %s", serviceprincipal, nt_errstr(status), error_string));
        }
        return status;
}

/**
 * Ask that when required, the credentials system will be filled with
 * machine trust account, from the secrets database.
 * 
 * @param cred Credentials structure to fill in
 * @note This function is used to call the above function after, rather 
 *       than during, popt processing.
 *
 */
_PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
                                                 struct loadparm_context *lp_ctx)
{
        cred->machine_account_pending = true;
        cred->machine_account_pending_lp_ctx = lp_ctx;
}