ndr: add ndr_pull_charset_to_null()

[Samba.git] / source3 / auth / auth_domain.c

/* 
   Unix SMB/CIFS implementation.
   Authenticate against a remote domain
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Andrew Bartlett 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/>.
*/

#include "includes.h"
#include "auth.h"
#include "../libcli/auth/libcli_auth.h"
#include "../librpc/gen_ndr/ndr_netlogon.h"
#include "rpc_client/cli_pipe.h"
#include "rpc_client/cli_netlogon.h"
#include "secrets.h"
#include "passdb.h"
#include "libsmb/libsmb.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

extern bool global_machine_password_needs_changing;
static struct named_mutex *mutex;

/*
 * Change machine password (called from main loop
 * idle timeout. Must be done as root.
 */

void attempt_machine_password_change(void)
{
        unsigned char trust_passwd_hash[16];
        time_t lct;
        void *lock;

        if (!global_machine_password_needs_changing) {
                return;
        }

        if (lp_security() != SEC_DOMAIN) {
                return;
        }

        /*
         * We're in domain level security, and the code that
         * read the machine password flagged that the machine
         * password needs changing.
         */

        /*
         * First, open the machine password file with an exclusive lock.
         */

        lock = secrets_get_trust_account_lock(NULL, lp_workgroup());

        if (lock == NULL) {
                DEBUG(0,("attempt_machine_password_change: unable to lock "
                        "the machine account password for machine %s in "
                        "domain %s.\n",
                        global_myname(), lp_workgroup() ));
                return;
        }

        if(!secrets_fetch_trust_account_password(lp_workgroup(),
                        trust_passwd_hash, &lct, NULL)) {
                DEBUG(0,("attempt_machine_password_change: unable to read the "
                        "machine account password for %s in domain %s.\n",
                        global_myname(), lp_workgroup()));
                TALLOC_FREE(lock);
                return;
        }

        /*
         * Make sure someone else hasn't already done this.
         */

        if(time(NULL) < lct + lp_machine_password_timeout()) {
                global_machine_password_needs_changing = false;
                TALLOC_FREE(lock);
                return;
        }

        /* always just contact the PDC here */

        change_trust_account_password( lp_workgroup(), NULL);
        global_machine_password_needs_changing = false;
        TALLOC_FREE(lock);
}

/**
 * Connect to a remote server for (inter)domain security authenticaion.
 *
 * @param cli the cli to return containing the active connection
 * @param server either a machine name or text IP address to
 *               connect to.
 * @param setup_creds_as domain account to setup credentials as
 * @param sec_chan a switch value to distinguish between domain
 *                 member and interdomain authentication
 * @param trust_passwd the trust password to establish the
 *                     credentials with.
 *
 **/

static NTSTATUS connect_to_domain_password_server(struct cli_state **cli,
                                                const char *domain,
                                                const char *dc_name,
                                                struct sockaddr_storage *dc_ss, 
                                                struct rpc_pipe_client **pipe_ret)
{
        NTSTATUS result;
        struct rpc_pipe_client *netlogon_pipe = NULL;

        *cli = NULL;

        *pipe_ret = NULL;

        /* TODO: Send a SAMLOGON request to determine whether this is a valid
           logonserver.  We can avoid a 30-second timeout if the DC is down
           if the SAMLOGON request fails as it is only over UDP. */

        /* we use a mutex to prevent two connections at once - when a 
           Win2k PDC get two connections where one hasn't completed a 
           session setup yet it will send a TCP reset to the first 
           connection (tridge) */

        /*
         * With NT4.x DC's *all* authentication must be serialized to avoid
         * ACCESS_DENIED errors if 2 auths are done from the same machine. JRA.
         */

        mutex = grab_named_mutex(NULL, dc_name, 10);
        if (mutex == NULL) {
                return NT_STATUS_NO_LOGON_SERVERS;
        }

        /* Attempt connection */
        result = cli_full_connection(cli, global_myname(), dc_name, dc_ss, 0, 
                "IPC$", "IPC", "", "", "", 0, Undefined);

        if (!NT_STATUS_IS_OK(result)) {
                /* map to something more useful */
                if (NT_STATUS_EQUAL(result, NT_STATUS_UNSUCCESSFUL)) {
                        result = NT_STATUS_NO_LOGON_SERVERS;
                }

                if (*cli) {
                        cli_shutdown(*cli);
                        *cli = NULL;
                }

                TALLOC_FREE(mutex);
                return result;
        }

        /*
         * We now have an anonymous connection to IPC$ on the domain password server.
         */

        /*
         * Even if the connect succeeds we need to setup the netlogon
         * pipe here. We do this as we may just have changed the domain
         * account password on the PDC and yet we may be talking to
         * a BDC that doesn't have this replicated yet. In this case
         * a successful connect to a DC needs to take the netlogon connect
         * into account also. This patch from "Bjart Kvarme" <bjart.kvarme@usit.uio.no>.
         */

        /* open the netlogon pipe. */
        if (lp_client_schannel()) {
                /* We also setup the creds chain in the open_schannel call. */
                result = cli_rpc_pipe_open_schannel(
                        *cli, &ndr_table_netlogon.syntax_id, NCACN_NP,
                        DCERPC_AUTH_LEVEL_PRIVACY, domain, &netlogon_pipe);
        } else {
                result = cli_rpc_pipe_open_noauth(
                        *cli, &ndr_table_netlogon.syntax_id, &netlogon_pipe);
        }

        if (!NT_STATUS_IS_OK(result)) {
                DEBUG(0,("connect_to_domain_password_server: unable to open the domain client session to \
machine %s. Error was : %s.\n", dc_name, nt_errstr(result)));
                cli_shutdown(*cli);
                *cli = NULL;
                TALLOC_FREE(mutex);
                return result;
        }

        if (!lp_client_schannel()) {
                /* We need to set up a creds chain on an unauthenticated netlogon pipe. */
                uint32_t neg_flags = NETLOGON_NEG_AUTH2_ADS_FLAGS;
                enum netr_SchannelType sec_chan_type = 0;
                unsigned char machine_pwd[16];
                const char *account_name;

                if (!get_trust_pw_hash(domain, machine_pwd, &account_name,
                                       &sec_chan_type))
                {
                        DEBUG(0, ("connect_to_domain_password_server: could not fetch "
                        "trust account password for domain '%s'\n",
                                domain));
                        cli_shutdown(*cli);
                        *cli = NULL;
                        TALLOC_FREE(mutex);
                        return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
                }

                result = rpccli_netlogon_setup_creds(netlogon_pipe,
                                        dc_name, /* server name */
                                        domain, /* domain */
                                        global_myname(), /* client name */
                                        account_name, /* machine account name */
                                        machine_pwd,
                                        sec_chan_type,
                                        &neg_flags);

                if (!NT_STATUS_IS_OK(result)) {
                        cli_shutdown(*cli);
                        *cli = NULL;
                        TALLOC_FREE(mutex);
                        return result;
                }
        }

        if(!netlogon_pipe) {
                DEBUG(0,("connect_to_domain_password_server: unable to open the domain client session to \
machine %s. Error was : %s.\n", dc_name, cli_errstr(*cli)));
                cli_shutdown(*cli);
                *cli = NULL;
                TALLOC_FREE(mutex);
                return NT_STATUS_NO_LOGON_SERVERS;
        }

        /* We exit here with the mutex *locked*. JRA */

        *pipe_ret = netlogon_pipe;

        return NT_STATUS_OK;
}

/***********************************************************************
 Do the same as security=server, but using NT Domain calls and a session
 key from the machine password.  If the server parameter is specified
 use it, otherwise figure out a server from the 'password server' param.
************************************************************************/

static NTSTATUS domain_client_validate(TALLOC_CTX *mem_ctx,
                                        const struct auth_usersupplied_info *user_info,
                                        const char *domain,
                                        uchar chal[8],
                                        struct auth_serversupplied_info **server_info,
                                        const char *dc_name,
                                        struct sockaddr_storage *dc_ss)

{
        struct netr_SamInfo3 *info3 = NULL;
        struct cli_state *cli = NULL;
        struct rpc_pipe_client *netlogon_pipe = NULL;
        NTSTATUS nt_status = NT_STATUS_NO_LOGON_SERVERS;
        int i;

        /*
         * At this point, smb_apasswd points to the lanman response to
         * the challenge in local_challenge, and smb_ntpasswd points to
         * the NT response to the challenge in local_challenge. Ship
         * these over the secure channel to a domain controller and
         * see if they were valid.
         */

        /* rety loop for robustness */

        for (i = 0; !NT_STATUS_IS_OK(nt_status) && (i < 3); i++) {
                nt_status = connect_to_domain_password_server(&cli,
                                                        domain,
                                                        dc_name,
                                                        dc_ss,
                                                        &netlogon_pipe);
        }

        if ( !NT_STATUS_IS_OK(nt_status) ) {
                DEBUG(0,("domain_client_validate: Domain password server not available.\n"));
                if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCESS_DENIED)) {
                        return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
                }
                return nt_status;
        }

        /* store a successful connection */

        saf_store( domain, cli->desthost );

        /*
         * If this call succeeds, we now have lots of info about the user
         * in the info3 structure.  
         */

        nt_status = rpccli_netlogon_sam_network_logon(netlogon_pipe,
                                                      mem_ctx,
                                                      user_info->logon_parameters,         /* flags such as 'allow workstation logon' */
                                                      dc_name,                             /* server name */
                                                      user_info->client.account_name,      /* user name logging on. */
                                                      user_info->client.domain_name,       /* domain name */
                                                      user_info->workstation_name,         /* workstation name */
                                                      chal,                                /* 8 byte challenge. */
                                                      3,                                   /* validation level */
                                                      user_info->password.response.lanman, /* lanman 24 byte response */
                                                      user_info->password.response.nt,     /* nt 24 byte response */
                                                      &info3);                             /* info3 out */

        /* Let go as soon as possible so we avoid any potential deadlocks
           with winbind lookup up users or groups. */

        TALLOC_FREE(mutex);

        if (!NT_STATUS_IS_OK(nt_status)) {
                DEBUG(0,("domain_client_validate: unable to validate password "
                         "for user %s in domain %s to Domain controller %s. "
                         "Error was %s.\n", user_info->client.account_name,
                         user_info->client.domain_name, dc_name,
                         nt_errstr(nt_status)));

                /* map to something more useful */
                if (NT_STATUS_EQUAL(nt_status, NT_STATUS_UNSUCCESSFUL)) {
                        nt_status = NT_STATUS_NO_LOGON_SERVERS;
                }
        } else {
                nt_status = make_server_info_info3(mem_ctx,
                                                   user_info->client.account_name,
                                                   domain,
                                                   server_info,
                                                   info3);

                if (NT_STATUS_IS_OK(nt_status)) {
                        (*server_info)->nss_token |= user_info->was_mapped;
                        netsamlogon_cache_store(user_info->client.account_name, info3);
                        TALLOC_FREE(info3);
                }
        }

        /* Note - once the cli stream is shutdown the mem_ctx used
           to allocate the other_sids and gids structures has been deleted - so
           these pointers are no longer valid..... */

        cli_shutdown(cli);
        return nt_status;
}

/****************************************************************************
 Check for a valid username and password in security=domain mode.
****************************************************************************/

static NTSTATUS check_ntdomain_security(const struct auth_context *auth_context,
                                        void *my_private_data, 
                                        TALLOC_CTX *mem_ctx,
                                        const struct auth_usersupplied_info *user_info,
                                        struct auth_serversupplied_info **server_info)
{
        NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
        const char *domain = lp_workgroup();
        fstring dc_name;
        struct sockaddr_storage dc_ss;

        if ( lp_server_role() != ROLE_DOMAIN_MEMBER ) {
                DEBUG(0,("check_ntdomain_security: Configuration error!  Cannot use "
                        "ntdomain auth method when not a member of a domain.\n"));
                return NT_STATUS_NOT_IMPLEMENTED;
        }

        if (!user_info || !server_info || !auth_context) {
                DEBUG(1,("check_ntdomain_security: Critical variables not present.  Failing.\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        DEBUG(10, ("Check auth for: [%s]\n", user_info->mapped.account_name));

        /* 
         * Check that the requested domain is not our own machine name.
         * If it is, we should never check the PDC here, we use our own local
         * password file.
         */

        if(strequal(get_global_sam_name(), user_info->mapped.domain_name)) {
                DEBUG(3,("check_ntdomain_security: Requested domain was for this machine.\n"));
                return NT_STATUS_NOT_IMPLEMENTED;
        }

        /* we need our DC to send the net_sam_logon() request to */

        if ( !get_dc_name(domain, NULL, dc_name, &dc_ss) ) {
                DEBUG(5,("check_ntdomain_security: unable to locate a DC for domain %s\n",
                        user_info->mapped.domain_name));
                return NT_STATUS_NO_LOGON_SERVERS;
        }

        nt_status = domain_client_validate(mem_ctx,
                                        user_info,
                                        domain,
                                        (uchar *)auth_context->challenge.data,
                                        server_info,
                                        dc_name,
                                        &dc_ss);

        return nt_status;
}

/* module initialisation */
static NTSTATUS auth_init_ntdomain(struct auth_context *auth_context, const char* param, auth_methods **auth_method) 
{
        struct auth_methods *result;

        result = TALLOC_ZERO_P(auth_context, struct auth_methods);
        if (result == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        result->name = "ntdomain";
        result->auth = check_ntdomain_security;

        *auth_method = result;
        return NT_STATUS_OK;
}


/****************************************************************************
 Check for a valid username and password in a trusted domain
****************************************************************************/

static NTSTATUS check_trustdomain_security(const struct auth_context *auth_context,
                                           void *my_private_data, 
                                           TALLOC_CTX *mem_ctx,
                                           const struct auth_usersupplied_info *user_info,
                                           struct auth_serversupplied_info **server_info)
{
        NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
        unsigned char trust_md4_password[16];
        char *trust_password;
        fstring dc_name;
        struct sockaddr_storage dc_ss;

        if (!user_info || !server_info || !auth_context) {
                DEBUG(1,("check_trustdomain_security: Critical variables not present.  Failing.\n"));
                return NT_STATUS_INVALID_PARAMETER;
        }

        DEBUG(10, ("Check auth for: [%s]\n", user_info->mapped.account_name));

        /* 
         * Check that the requested domain is not our own machine name or domain name.
         */

        if( strequal(get_global_sam_name(), user_info->mapped.domain_name)) {
                DEBUG(3,("check_trustdomain_security: Requested domain [%s] was for this machine.\n",
                        user_info->mapped.domain_name));
                return NT_STATUS_NOT_IMPLEMENTED;
        }

        /* No point is bothering if this is not a trusted domain.
           This return makes "map to guest = bad user" work again.
           The logic is that if we know nothing about the domain, that
           user is not known to us and does not exist */

        if ( !is_trusted_domain( user_info->mapped.domain_name ) )
                return NT_STATUS_NOT_IMPLEMENTED;

        /*
         * Get the trusted account password for the trusted domain
         * No need to become_root() as secrets_init() is done at startup.
         */

        if (!pdb_get_trusteddom_pw(user_info->mapped.domain_name, &trust_password,
                                   NULL, NULL)) {
                DEBUG(0, ("check_trustdomain_security: could not fetch trust "
                          "account password for domain %s\n",
                          user_info->mapped.domain_name));
                return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
        }

#ifdef DEBUG_PASSWORD
        DEBUG(100, ("Trust password for domain %s is %s\n", user_info->mapped.domain_name,
                    trust_password));
#endif
        E_md4hash(trust_password, trust_md4_password);
        SAFE_FREE(trust_password);

#if 0
        /* Test if machine password is expired and need to be changed */
        if (time(NULL) > last_change_time + (time_t)lp_machine_password_timeout())
        {
                global_machine_password_needs_changing = True;
        }
#endif

        /* use get_dc_name() for consistency even through we know that it will be 
           a netbios name */

        if ( !get_dc_name(user_info->mapped.domain_name, NULL, dc_name, &dc_ss) ) {
                DEBUG(5,("check_trustdomain_security: unable to locate a DC for domain %s\n",
                        user_info->mapped.domain_name));
                return NT_STATUS_NO_LOGON_SERVERS;
        }

        nt_status = domain_client_validate(mem_ctx,
                                           user_info,
                                           user_info->mapped.domain_name,
                                           (uchar *)auth_context->challenge.data,
                                           server_info,
                                           dc_name,
                                           &dc_ss);

        return nt_status;
}

/* module initialisation */
static NTSTATUS auth_init_trustdomain(struct auth_context *auth_context, const char* param, auth_methods **auth_method) 
{
        struct auth_methods *result;

        result = TALLOC_ZERO_P(auth_context, struct auth_methods);
        if (result == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        result->name = "trustdomain";
        result->auth = check_trustdomain_security;

        *auth_method = result;
        return NT_STATUS_OK;
}

NTSTATUS auth_domain_init(void) 
{
        smb_register_auth(AUTH_INTERFACE_VERSION, "trustdomain", auth_init_trustdomain);
        smb_register_auth(AUTH_INTERFACE_VERSION, "ntdomain", auth_init_ntdomain);
        return NT_STATUS_OK;
}