libmlsvc/common/mlsvc_util.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
 */

/*
 * Utility functions to support the RPC interface library.
 */

#include <stdio.h>
#include <stdarg.h>
#include <strings.h>
#include <unistd.h>
#include <netdb.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <note.h>
#include <syslog.h>

#include <smbsrv/libsmb.h>
#include <smbsrv/libsmbns.h>
#include <smbsrv/libmlsvc.h>
#include <smbsrv/ntaccess.h>
#include <smbsrv/smbinfo.h>
#include <smbsrv/netrauth.h>
#include <libsmbrdr.h>
#include <lsalib.h>
#include <samlib.h>
#include <mlsvc.h>

static DWORD
mlsvc_join_rpc(smb_domainex_t *dxi,
    char *admin_user, char *admin_pw,
    char *machine_name, char *machine_pw);
static DWORD
mlsvc_join_noauth(smb_domainex_t *dxi,
    char *machine_name, char *machine_pw);


DWORD
mlsvc_netlogon(char *server, char *domain)
{
    mlsvc_handle_t netr_handle;
    DWORD status;

    status = netr_open(server, domain, &netr_handle);
    if (status != 0) {
        syslog(LOG_NOTICE, "Failed to connect to %s "
            "for domain %s (%s)", server, domain,
            xlate_nt_status(status));
        return (status);
    }

    status = netlogon_auth(server, &netr_handle, NETR_FLG_INIT);
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_NOTICE, "Failed to establish NETLOGON "
            "credential chain with DC: %s (%s)", server,
            xlate_nt_status(status));
        syslog(LOG_NOTICE, "The machine account information on the "
            "domain controller does not match the local storage.");
        syslog(LOG_NOTICE, "To correct this, use 'smbadm join'");
    }
    (void) netr_close(&netr_handle);

    return (status);
}

/*
 * Join the specified domain.  The method varies depending on whether
 * we're using "secure join" (using an administrative account to join)
 * or "unsecure join" (using a pre-created machine account).  In the
 * latter case, the machine account is created "by hand" before this
 * machine attempts to join, and we just change the password from the
 * (weak) default password for a new machine account to a random one.
 *
 * Returns NT status codes.
 */
void
mlsvc_join(smb_joininfo_t *info, smb_joinres_t *res)
{
    static unsigned char zero_hash[SMBAUTH_HASH_SZ];
    char machine_name[SMB_SAMACCT_MAXLEN];
    char machine_pw[NETR_MACHINE_ACCT_PASSWD_MAX];
    unsigned char passwd_hash[SMBAUTH_HASH_SZ];
    smb_domainex_t dxi;
    smb_domain_t *di = &dxi.d_primary;
    DWORD status;
    int rc;

    bzero(&dxi, sizeof (dxi));

    /*
     * Domain join support: AD (Kerberos+LDAP) or MS-RPC?
     */
    boolean_t ads_enabled = smb_config_get_ads_enable();

    if (smb_getsamaccount(machine_name, sizeof (machine_name)) != 0) {
        res->status = NT_STATUS_INVALID_COMPUTER_NAME;
        return;
    }

    (void) smb_gen_random_passwd(machine_pw, sizeof (machine_pw));

    /*
     * Ensure that any previous membership of this domain has
     * been cleared from the environment before we start. This
     * will ensure that we don't attempt a NETLOGON_SAMLOGON
     * when attempting to find the PDC.
     */
    (void) smb_config_setbool(SMB_CI_DOMAIN_MEMB, B_FALSE);

    if (info->domain_username[0] != '\0') {
        (void) smb_auth_ntlm_hash(info->domain_passwd, passwd_hash);
        smb_ipc_set(info->domain_username, passwd_hash);
    } else {
        smb_ipc_set(MLSVC_ANON_USER, zero_hash);
    }

    /*
     * Tentatively set the idmap domain to the one we're joining,
     * so that the DC locator in idmap knows what to look for.
     * Ditto the SMB server domain.
     */
    if (smb_config_set_idmap_domain(info->domain_name) != 0)
        syslog(LOG_NOTICE, "Failed to set idmap domain name");
    if (smb_config_refresh_idmap() != 0)
        syslog(LOG_NOTICE, "Failed to refresh idmap service");

    /* Clear DNS local (ADS) lookup cache. */
    smb_ads_refresh(B_FALSE);

    /*
     * Locate a DC for this domain.  Intentionally bypass the
     * ddiscover service here because we're still joining.
     * This also allows better reporting of any failures.
     */
    status = smb_ads_lookup_msdcs(info->domain_name, &dxi.d_dci);
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_ERR,
            "smbd: failed to locate AD server for domain %s (%s)",
            info->domain_name, xlate_nt_status(status));
        goto out;
    }

    /*
     * Found a DC.  Report what we found along with the return status
     * so that admin will know which AD server we were talking to.
     */
    (void) strlcpy(res->dc_name, dxi.d_dci.dc_name, MAXHOSTNAMELEN);
    syslog(LOG_INFO, "smbd: found AD server %s", dxi.d_dci.dc_name);

    /*
     * Domain discovery needs to authenticate with the AD server.
     * Disconnect any existing connection with the domain controller
     * to make sure we won't use any prior authentication context
     * our redirector might have.
     */
    mlsvc_disconnect(dxi.d_dci.dc_name);

    /*
     * Get the domain policy info (domain SID etc).
     * Here too, bypass the smb_ddiscover_service.
     */
    status = smb_ddiscover_main(info->domain_name, &dxi);
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_ERR,
            "smbd: failed getting domain info for %s (%s)",
            info->domain_name, xlate_nt_status(status));
        goto out;
    }
    /*
     * After a successful smbd_ddiscover_main() call
     * we should call smb_domain_save() to update the
     * data shown by smbadm list.  Do that at the end,
     * only if all goes well with joining the domain.
     */

    /*
     * Create or update our machine account on the DC.
     * A non-null user means we do "secure join".
     */
    if (info->domain_username[0] != '\0') {
        /*
         * If enabled, try to join using AD Services.
         */
        status = NT_STATUS_UNSUCCESSFUL;
        if (ads_enabled) {
            res->join_err = smb_ads_join(di->di_fqname,
                info->domain_username, info->domain_passwd,
                machine_pw);
            if (res->join_err == SMB_ADS_SUCCESS) {
                status = NT_STATUS_SUCCESS;
            }
        } else {
            syslog(LOG_DEBUG, "use_ads=false (do RPC join)");

            /*
             * If ADS was disabled, join using RPC.
             */
            status = mlsvc_join_rpc(&dxi,
                info->domain_username,
                info->domain_passwd,
                machine_name, machine_pw);
        }

    } else {
        /*
         * Doing "Unsecure join" (pre-created account)
         */
        status = mlsvc_join_noauth(&dxi, machine_name, machine_pw);
    }

    if (status != NT_STATUS_SUCCESS)
        goto out;

    /*
     * Make sure we can authenticate using the
     * (new, or updated) machine account.
     */
    (void) smb_auth_ntlm_hash(machine_pw, passwd_hash);
    smb_ipc_set(machine_name, passwd_hash);
    rc = smbrdr_logon(dxi.d_dci.dc_name, di->di_nbname, machine_name);
    if (rc != 0) {
        syslog(LOG_NOTICE, "Authenticate with "
            "new/updated machine account: %s",
            strerror(rc));
        res->join_err = SMB_ADJOIN_ERR_AUTH_NETLOGON;
        status = NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
        goto out;
    }

    /*
     * Store the new machine account password, and
     * SMB_CI_DOMAIN_MEMB etc.
     */
    rc = smb_setdomainprops(NULL, dxi.d_dci.dc_name, machine_pw);
    if (rc != 0) {
        syslog(LOG_NOTICE,
            "Failed to save machine account password");
        res->join_err = SMB_ADJOIN_ERR_STORE_PROPS;
        status = NT_STATUS_INTERNAL_DB_ERROR;
        goto out;
    }

    /*
     * Update idmap config?
     * Already set the domain_name above.
     */

    /*
     * Save the SMB server config.  Sets: SMB_CI_DOMAIN_*
     * Should unify SMB vs idmap configs.
     */
    smb_config_setdomaininfo(di->di_nbname, di->di_fqname,
        di->di_sid,
        di->di_u.di_dns.ddi_forest,
        di->di_u.di_dns.ddi_guid);
    smb_ipc_commit();
    smb_domain_save();

    status = 0;

out:

    if (status != 0) {
        /*
         * Undo the tentative domain settings.
         */
        (void) smb_config_set_idmap_domain("");
        (void) smb_config_refresh_idmap();
        smb_ipc_rollback();
    }

    /* Avoid leaving cleartext passwords around. */
    bzero(machine_pw, sizeof (machine_pw));
    bzero(passwd_hash, sizeof (passwd_hash));

    res->status = status;
}

static DWORD
mlsvc_join_rpc(smb_domainex_t *dxi,
    char *admin_user, char *admin_pw,
    char *machine_name,  char *machine_pw)
{
    mlsvc_handle_t samr_handle;
    mlsvc_handle_t domain_handle;
    mlsvc_handle_t user_handle;
    smb_account_t ainfo;
    char *server = dxi->d_dci.dc_name;
    smb_domain_t *di = &dxi->d_primary;
    DWORD account_flags;
    DWORD rid;
    DWORD status;
    int rc;

    /* Caller did smb_ipc_set() so we don't need the pw for now. */
    _NOTE(ARGUNUSED(admin_pw));

    rc = samr_open(server, di->di_nbname, admin_user,
        MAXIMUM_ALLOWED, &samr_handle);
    if (rc != 0) {
        syslog(LOG_NOTICE, "sam_connect to server %s failed", server);
        return (RPC_NT_SERVER_UNAVAILABLE);
    }
    /* have samr_handle */

    status = samr_open_domain(&samr_handle, MAXIMUM_ALLOWED,
        (struct samr_sid *)di->di_binsid, &domain_handle);
    if (status != NT_STATUS_SUCCESS)
        goto out_samr_handle;
    /* have domain_handle */

    account_flags = SAMR_AF_WORKSTATION_TRUST_ACCOUNT;
    status = samr_create_user(&domain_handle, machine_name,
        account_flags, &rid, &user_handle);
    if (status == NT_STATUS_USER_EXISTS) {
        status = samr_lookup_domain_names(&domain_handle,
            machine_name, &ainfo);
        if (status != NT_STATUS_SUCCESS)
            goto out_domain_handle;
        status = samr_open_user(&domain_handle, MAXIMUM_ALLOWED,
            ainfo.a_rid, &user_handle);
    }
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_NOTICE,
            "smbd: failed to open machine account (%s)",
            xlate_nt_status(status));
        goto out_domain_handle;
    }

    /*
     * The account exists, and we have user_handle open
     * on that account.  Set the password and flags.
     */

    status = netr_set_user_password(&user_handle, machine_pw);
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_NOTICE,
            "smbd: failed to set machine account password (%s)",
            xlate_nt_status(status));
        goto out_user_handle;
    }

    account_flags |= SAMR_AF_DONT_EXPIRE_PASSWD;
    status = netr_set_user_control(&user_handle, account_flags);
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_NOTICE,
            "Set machine account control flags: %s",
            xlate_nt_status(status));
        goto out_user_handle;
    }

out_user_handle:
    (void) samr_close_handle(&user_handle);
out_domain_handle:
    (void) samr_close_handle(&domain_handle);
out_samr_handle:
    (void) samr_close_handle(&samr_handle);

    return (status);
}

/*
 * Doing "Unsecure join" (using a pre-created machine account).
 * All we need to do is change the password from the default
 * to a random string.
 *
 * Note: this is a work in progres.  Nexenta issue 11960
 * (allow joining an AD domain using a pre-created computer account)
 * It turns out that to change the machine account password,
 * we need to use a different RPC call, performed over the
 * NetLogon secure channel.  (See netr_server_password_set2)
 */
static DWORD
mlsvc_join_noauth(smb_domainex_t *dxi,
    char *machine_name, char *machine_pw)
{
    char old_pw[SMB_SAMACCT_MAXLEN];
    DWORD status;

    /*
     * Compose the current (default) password for the
     * pre-created machine account, which is just the
     * account name in lower case, truncated to 14
     * characters.
     */
    if (smb_gethostname(old_pw, sizeof (old_pw), SMB_CASE_LOWER) != 0)
        return (NT_STATUS_INTERNAL_ERROR);
    old_pw[14] = '\0';

    status = netr_change_password(dxi->d_dci.dc_name, machine_name,
        old_pw, machine_pw);
    if (status != NT_STATUS_SUCCESS) {
        syslog(LOG_NOTICE,
            "Change machine account password: %s",
            xlate_nt_status(status));
    }
    return (status);
}

void
mlsvc_disconnect(const char *server)
{
    smbrdr_disconnect(server);
}