s4:librpc/rpc: use talloc_zero for 'struct rpc_request'

[Samba/gebeck_regimport.git] / source3 / auth / auth_util.c

/*
   Unix SMB/CIFS implementation.
   Authentication utility functions
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Andrew Bartlett 2001-2011
   Copyright (C) Jeremy Allison 2000-2001
   Copyright (C) Rafal Szczesniak 2002
   Copyright (C) Volker Lendecke 2006-2008

   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 "../lib/crypto/arcfour.h"
#include "rpc_client/init_lsa.h"
#include "../libcli/security/security.h"
#include "../lib/util/util_pw.h"
#include "lib/winbind_util.h"
#include "passdb.h"
#include "../librpc/gen_ndr/ndr_auth.h"
#include "../auth/auth_sam_reply.h"
#include "../librpc/gen_ndr/idmap.h"
#include "lib/param/loadparm.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

/****************************************************************************
 Create a UNIX user on demand.
****************************************************************************/

static int _smb_create_user(const char *domain, const char *unix_username, const char *homedir)
{
        TALLOC_CTX *ctx = talloc_tos();
        char *add_script;
        int ret;

        add_script = lp_adduser_script(ctx);
        if (!add_script || !*add_script) {
                return -1;
        }
        add_script = talloc_all_string_sub(ctx,
                                add_script,
                                "%u",
                                unix_username);
        if (!add_script) {
                return -1;
        }
        if (domain) {
                add_script = talloc_all_string_sub(ctx,
                                        add_script,
                                        "%D",
                                        domain);
                if (!add_script) {
                        return -1;
                }
        }
        if (homedir) {
                add_script = talloc_all_string_sub(ctx,
                                add_script,
                                "%H",
                                homedir);
                if (!add_script) {
                        return -1;
                }
        }
        ret = smbrun(add_script,NULL);
        flush_pwnam_cache();
        DEBUG(ret ? 0 : 3,
                ("smb_create_user: Running the command `%s' gave %d\n",
                 add_script,ret));
        return ret;
}

/****************************************************************************
 Create an auth_usersupplied_data structure after appropriate mapping.
****************************************************************************/

NTSTATUS make_user_info_map(struct auth_usersupplied_info **user_info,
                            const char *smb_name,
                            const char *client_domain,
                            const char *workstation_name,
                            const struct tsocket_address *remote_address,
                            const DATA_BLOB *lm_pwd,
                            const DATA_BLOB *nt_pwd,
                            const struct samr_Password *lm_interactive_pwd,
                            const struct samr_Password *nt_interactive_pwd,
                            const char *plaintext,
                            enum auth_password_state password_state)
{
        const char *domain;
        NTSTATUS result;
        bool was_mapped;
        char *internal_username = NULL;

        was_mapped = map_username(talloc_tos(), smb_name, &internal_username);
        if (!internal_username) {
                return NT_STATUS_NO_MEMORY;
        }

        DEBUG(5, ("Mapping user [%s]\\[%s] from workstation [%s]\n",
                 client_domain, smb_name, workstation_name));

        domain = client_domain;

        /* If you connect to a Windows domain member using a bogus domain name,
         * the Windows box will map the BOGUS\user to SAMNAME\user.  Thus, if
         * the Windows box is a DC the name will become DOMAIN\user and be
         * authenticated against AD, if the Windows box is a member server but
         * not a DC the name will become WORKSTATION\user.  A standalone
         * non-domain member box will also map to WORKSTATION\user.
         * This also deals with the client passing in a "" domain */

        if (!is_trusted_domain(domain) &&
            !strequal(domain, my_sam_name()))
        {
                if (lp_map_untrusted_to_domain())
                        domain = my_sam_name();
                else
                        domain = get_global_sam_name();
                DEBUG(5, ("Mapped domain from [%s] to [%s] for user [%s] from "
                          "workstation [%s]\n",
                          client_domain, domain, smb_name, workstation_name));
        }

        /* We know that the given domain is trusted (and we are allowing them),
         * it is our global SAM name, or for legacy behavior it is our
         * primary domain name */

        result = make_user_info(user_info, smb_name, internal_username,
                              client_domain, domain, workstation_name,
                              remote_address, lm_pwd, nt_pwd,
                              lm_interactive_pwd, nt_interactive_pwd,
                              plaintext, password_state);
        if (NT_STATUS_IS_OK(result)) {
                /* We have tried mapping */
                (*user_info)->mapped_state = true;
                /* did we actually map the user to a different name? */
                (*user_info)->was_mapped = was_mapped;
        }
        return result;
}

/****************************************************************************
 Create an auth_usersupplied_data, making the DATA_BLOBs here. 
 Decrypt and encrypt the passwords.
****************************************************************************/

bool make_user_info_netlogon_network(struct auth_usersupplied_info **user_info,
                                     const char *smb_name, 
                                     const char *client_domain, 
                                     const char *workstation_name,
                                     const struct tsocket_address *remote_address,
                                     uint32 logon_parameters,
                                     const uchar *lm_network_pwd,
                                     int lm_pwd_len,
                                     const uchar *nt_network_pwd,
                                     int nt_pwd_len)
{
        bool ret;
        NTSTATUS status;
        DATA_BLOB lm_blob = data_blob(lm_network_pwd, lm_pwd_len);
        DATA_BLOB nt_blob = data_blob(nt_network_pwd, nt_pwd_len);

        status = make_user_info_map(user_info,
                                    smb_name, client_domain, 
                                    workstation_name,
                                    remote_address,
                                    lm_pwd_len ? &lm_blob : NULL, 
                                    nt_pwd_len ? &nt_blob : NULL,
                                    NULL, NULL, NULL,
                                    AUTH_PASSWORD_RESPONSE);

        if (NT_STATUS_IS_OK(status)) {
                (*user_info)->logon_parameters = logon_parameters;
        }
        ret = NT_STATUS_IS_OK(status) ? true : false;

        data_blob_free(&lm_blob);
        data_blob_free(&nt_blob);
        return ret;
}

/****************************************************************************
 Create an auth_usersupplied_data, making the DATA_BLOBs here. 
 Decrypt and encrypt the passwords.
****************************************************************************/

bool make_user_info_netlogon_interactive(struct auth_usersupplied_info **user_info,
                                         const char *smb_name, 
                                         const char *client_domain, 
                                         const char *workstation_name,
                                         const struct tsocket_address *remote_address,
                                         uint32 logon_parameters,
                                         const uchar chal[8], 
                                         const uchar lm_interactive_pwd[16], 
                                         const uchar nt_interactive_pwd[16], 
                                         const uchar *dc_sess_key)
{
        struct samr_Password lm_pwd;
        struct samr_Password nt_pwd;
        unsigned char local_lm_response[24];
        unsigned char local_nt_response[24];
        unsigned char key[16];

        memcpy(key, dc_sess_key, 16);

        if (lm_interactive_pwd)
                memcpy(lm_pwd.hash, lm_interactive_pwd, sizeof(lm_pwd.hash));

        if (nt_interactive_pwd)
                memcpy(nt_pwd.hash, nt_interactive_pwd, sizeof(nt_pwd.hash));

#ifdef DEBUG_PASSWORD
        DEBUG(100,("key:"));
        dump_data(100, key, sizeof(key));

        DEBUG(100,("lm owf password:"));
        dump_data(100, lm_pwd.hash, sizeof(lm_pwd.hash));

        DEBUG(100,("nt owf password:"));
        dump_data(100, nt_pwd.hash, sizeof(nt_pwd.hash));
#endif

        if (lm_interactive_pwd)
                arcfour_crypt(lm_pwd.hash, key, sizeof(lm_pwd.hash));

        if (nt_interactive_pwd)
                arcfour_crypt(nt_pwd.hash, key, sizeof(nt_pwd.hash));

#ifdef DEBUG_PASSWORD
        DEBUG(100,("decrypt of lm owf password:"));
        dump_data(100, lm_pwd.hash, sizeof(lm_pwd));

        DEBUG(100,("decrypt of nt owf password:"));
        dump_data(100, nt_pwd.hash, sizeof(nt_pwd));
#endif

        if (lm_interactive_pwd)
                SMBOWFencrypt(lm_pwd.hash, chal,
                              local_lm_response);

        if (nt_interactive_pwd)
                SMBOWFencrypt(nt_pwd.hash, chal,
                              local_nt_response);

        /* Password info paranoia */
        ZERO_STRUCT(key);

        {
                bool ret;
                NTSTATUS nt_status;
                DATA_BLOB local_lm_blob;
                DATA_BLOB local_nt_blob;

                if (lm_interactive_pwd) {
                        local_lm_blob = data_blob(local_lm_response,
                                                  sizeof(local_lm_response));
                }

                if (nt_interactive_pwd) {
                        local_nt_blob = data_blob(local_nt_response,
                                                  sizeof(local_nt_response));
                }

                nt_status = make_user_info_map(
                        user_info, 
                        smb_name, client_domain, workstation_name,
                        remote_address,
                        lm_interactive_pwd ? &local_lm_blob : NULL,
                        nt_interactive_pwd ? &local_nt_blob : NULL,
                        lm_interactive_pwd ? &lm_pwd : NULL,
                        nt_interactive_pwd ? &nt_pwd : NULL,
                        NULL, AUTH_PASSWORD_HASH);

                if (NT_STATUS_IS_OK(nt_status)) {
                        (*user_info)->logon_parameters = logon_parameters;
                }

                ret = NT_STATUS_IS_OK(nt_status) ? true : false;
                data_blob_free(&local_lm_blob);
                data_blob_free(&local_nt_blob);
                return ret;
        }
}


/****************************************************************************
 Create an auth_usersupplied_data structure
****************************************************************************/

bool make_user_info_for_reply(struct auth_usersupplied_info **user_info,
                              const char *smb_name, 
                              const char *client_domain,
                              const struct tsocket_address *remote_address,
                              const uint8 chal[8],
                              DATA_BLOB plaintext_password)
{

        DATA_BLOB local_lm_blob;
        DATA_BLOB local_nt_blob;
        NTSTATUS ret = NT_STATUS_UNSUCCESSFUL;
        char *plaintext_password_string;
        /*
         * Not encrypted - do so.
         */

        DEBUG(5,("make_user_info_for_reply: User passwords not in encrypted "
                 "format.\n"));
        if (plaintext_password.data && plaintext_password.length) {
                unsigned char local_lm_response[24];

#ifdef DEBUG_PASSWORD
                DEBUG(10,("Unencrypted password (len %d):\n",
                          (int)plaintext_password.length));
                dump_data(100, plaintext_password.data,
                          plaintext_password.length);
#endif

                SMBencrypt( (const char *)plaintext_password.data,
                            (const uchar*)chal, local_lm_response);
                local_lm_blob = data_blob(local_lm_response, 24);

                /* We can't do an NT hash here, as the password needs to be
                   case insensitive */
                local_nt_blob = data_blob_null; 
        } else {
                local_lm_blob = data_blob_null; 
                local_nt_blob = data_blob_null; 
        }

        plaintext_password_string = talloc_strndup(talloc_tos(),
                                                   (const char *)plaintext_password.data,
                                                   plaintext_password.length);
        if (!plaintext_password_string) {
                return false;
        }

        ret = make_user_info(
                user_info, smb_name, smb_name, client_domain, client_domain, 
                get_remote_machine_name(),
                remote_address,
                local_lm_blob.data ? &local_lm_blob : NULL,
                local_nt_blob.data ? &local_nt_blob : NULL,
                NULL, NULL,
                plaintext_password_string,
                AUTH_PASSWORD_PLAIN);

        if (plaintext_password_string) {
                memset(plaintext_password_string, '\0', strlen(plaintext_password_string));
                talloc_free(plaintext_password_string);
        }

        data_blob_free(&local_lm_blob);
        return NT_STATUS_IS_OK(ret) ? true : false;
}

/****************************************************************************
 Create an auth_usersupplied_data structure
****************************************************************************/

NTSTATUS make_user_info_for_reply_enc(struct auth_usersupplied_info **user_info,
                                      const char *smb_name,
                                      const char *client_domain,
                                      const struct tsocket_address *remote_address,
                                      DATA_BLOB lm_resp, DATA_BLOB nt_resp)
{
        return make_user_info(user_info, smb_name, smb_name, 
                              client_domain, client_domain, 
                              get_remote_machine_name(),
                              remote_address,
                              lm_resp.data && (lm_resp.length > 0) ? &lm_resp : NULL,
                              nt_resp.data && (nt_resp.length > 0) ? &nt_resp : NULL,
                              NULL, NULL, NULL,
                              AUTH_PASSWORD_RESPONSE);
}

/****************************************************************************
 Create a guest user_info blob, for anonymous authentication.
****************************************************************************/

bool make_user_info_guest(const struct tsocket_address *remote_address,
                          struct auth_usersupplied_info **user_info)
{
        NTSTATUS nt_status;

        nt_status = make_user_info(user_info, 
                                   "","", 
                                   "","", 
                                   "", 
                                   remote_address,
                                   NULL, NULL, 
                                   NULL, NULL, 
                                   NULL,
                                   AUTH_PASSWORD_RESPONSE);

        return NT_STATUS_IS_OK(nt_status) ? true : false;
}

static NTSTATUS log_nt_token(struct security_token *token)
{
        TALLOC_CTX *frame = talloc_stackframe();
        char *command;
        char *group_sidstr;
        size_t i;

        if ((lp_log_nt_token_command(frame) == NULL) ||
            (strlen(lp_log_nt_token_command(frame)) == 0)) {
                TALLOC_FREE(frame);
                return NT_STATUS_OK;
        }

        group_sidstr = talloc_strdup(frame, "");
        for (i=1; i<token->num_sids; i++) {
                group_sidstr = talloc_asprintf(
                        frame, "%s %s", group_sidstr,
                        sid_string_talloc(frame, &token->sids[i]));
        }

        command = talloc_string_sub(
                frame, lp_log_nt_token_command(frame),
                "%s", sid_string_talloc(frame, &token->sids[0]));
        command = talloc_string_sub(frame, command, "%t", group_sidstr);

        if (command == NULL) {
                TALLOC_FREE(frame);
                return NT_STATUS_NO_MEMORY;
        }

        DEBUG(8, ("running command: [%s]\n", command));
        if (smbrun(command, NULL) != 0) {
                DEBUG(0, ("Could not log NT token\n"));
                TALLOC_FREE(frame);
                return NT_STATUS_ACCESS_DENIED;
        }

        TALLOC_FREE(frame);
        return NT_STATUS_OK;
}

/*
 * Create the token to use from server_info->info3 and
 * server_info->sids (the info3/sam groups). Find the unix gids.
 */

NTSTATUS create_local_token(TALLOC_CTX *mem_ctx,
                            const struct auth_serversupplied_info *server_info,
                            DATA_BLOB *session_key,
                            const char *smb_username, /* for ->sanitized_username, for %U subs */
                            struct auth_session_info **session_info_out)
{
        struct security_token *t;
        NTSTATUS status;
        size_t i;
        struct dom_sid tmp_sid;
        struct auth_session_info *session_info;
        struct unixid *ids;
        fstring tmp;

        /* Ensure we can't possible take a code path leading to a
         * null defref. */
        if (!server_info) {
                return NT_STATUS_LOGON_FAILURE;
        }

        session_info = talloc_zero(mem_ctx, struct auth_session_info);
        if (!session_info) {
                return NT_STATUS_NO_MEMORY;
        }

        session_info->unix_token = talloc_zero(session_info, struct security_unix_token);
        if (!session_info->unix_token) {
                TALLOC_FREE(session_info);
                return NT_STATUS_NO_MEMORY;
        }

        session_info->unix_token->uid = server_info->utok.uid;
        session_info->unix_token->gid = server_info->utok.gid;

        session_info->unix_info = talloc_zero(session_info, struct auth_user_info_unix);
        if (!session_info->unix_info) {
                TALLOC_FREE(session_info);
                return NT_STATUS_NO_MEMORY;
        }

        session_info->unix_info->unix_name = talloc_strdup(session_info, server_info->unix_name);
        if (!session_info->unix_info->unix_name) {
                TALLOC_FREE(session_info);
                return NT_STATUS_NO_MEMORY;
        }

        /* This is a potentially untrusted username for use in %U */
        alpha_strcpy(tmp, smb_username, ". _-$", sizeof(tmp));
        session_info->unix_info->sanitized_username =
                                talloc_strdup(session_info->unix_info, tmp);

        if (session_key) {
                data_blob_free(&session_info->session_key);
                session_info->session_key = data_blob_talloc(session_info,
                                                                  session_key->data,
                                                                  session_key->length);
                if (!session_info->session_key.data && session_key->length) {
                        return NT_STATUS_NO_MEMORY;
                }
        } else {
                session_info->session_key = data_blob_talloc( session_info, server_info->session_key.data,
                                                              server_info->session_key.length);
        }

        /* We need to populate session_info->info with the information found in server_info->info3 */
        status = make_user_info_SamBaseInfo(session_info, "", &server_info->info3->base,
                                            server_info->guest == false,
                                            &session_info->info);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("conversion of info3 into auth_user_info failed!\n"));
                TALLOC_FREE(session_info);
                return status;
        }

        if (server_info->security_token) {
                /* Just copy the token, it has already been finalised
                 * (nasty hack to support a cached guest/system session_info
                 */

                session_info->security_token = dup_nt_token(session_info, server_info->security_token);
                if (!session_info->security_token) {
                        TALLOC_FREE(session_info);
                        return NT_STATUS_NO_MEMORY;
                }

                session_info->unix_token->ngroups = server_info->utok.ngroups;
                if (server_info->utok.ngroups != 0) {
                        session_info->unix_token->groups = (gid_t *)talloc_memdup(
                                session_info->unix_token, server_info->utok.groups,
                                sizeof(gid_t)*session_info->unix_token->ngroups);
                } else {
                        session_info->unix_token->groups = NULL;
                }

                *session_info_out = session_info;
                return NT_STATUS_OK;
        }

        /*
         * If winbind is not around, we can not make much use of the SIDs the
         * domain controller provided us with. Likewise if the user name was
         * mapped to some local unix user.
         */

        if (((lp_server_role() == ROLE_DOMAIN_MEMBER) && !winbind_ping()) ||
            (server_info->nss_token)) {
                char *found_username = NULL;
                status = create_token_from_username(session_info,
                                                    server_info->unix_name,
                                                    server_info->guest,
                                                    &session_info->unix_token->uid,
                                                    &session_info->unix_token->gid,
                                                    &found_username,
                                                    &session_info->security_token);
                if (NT_STATUS_IS_OK(status)) {
                        session_info->unix_info->unix_name = found_username;
                }
        } else {
                status = create_local_nt_token_from_info3(session_info,
                                                          server_info->guest,
                                                          server_info->info3,
                                                          &server_info->extra,
                                                          &session_info->security_token);
        }

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* Convert the SIDs to gids. */

        session_info->unix_token->ngroups = 0;
        session_info->unix_token->groups = NULL;

        t = session_info->security_token;

        ids = talloc_array(talloc_tos(), struct unixid,
                           t->num_sids);
        if (ids == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        if (!sids_to_unixids(t->sids, t->num_sids, ids)) {
                TALLOC_FREE(ids);
                return NT_STATUS_NO_MEMORY;
        }

        for (i=0; i<t->num_sids; i++) {

                if (i == 0 && ids[i].type != ID_TYPE_BOTH) {
                        continue;
                }

                if (ids[i].type != ID_TYPE_GID &&
                    ids[i].type != ID_TYPE_BOTH) {
                        DEBUG(10, ("Could not convert SID %s to gid, "
                                   "ignoring it\n",
                                   sid_string_dbg(&t->sids[i])));
                        continue;
                }
                if (!add_gid_to_array_unique(session_info, ids[i].id,
                                             &session_info->unix_token->groups,
                                             &session_info->unix_token->ngroups)) {
                        return NT_STATUS_NO_MEMORY;
                }
        }

        /*
         * Add the "Unix Group" SID for each gid to catch mapped groups
         * and their Unix equivalent.  This is to solve the backwards
         * compatibility problem of 'valid users = +ntadmin' where
         * ntadmin has been paired with "Domain Admins" in the group
         * mapping table.  Otherwise smb.conf would need to be changed
         * to 'valid user = "Domain Admins"'.  --jerry
         *
         * For consistency we also add the "Unix User" SID,
         * so that the complete unix token is represented within
         * the nt token.
         */

        uid_to_unix_users_sid(session_info->unix_token->uid, &tmp_sid);

        add_sid_to_array_unique(session_info->security_token, &tmp_sid,
                                &session_info->security_token->sids,
                                &session_info->security_token->num_sids);

        for ( i=0; i<session_info->unix_token->ngroups; i++ ) {
                gid_to_unix_groups_sid(session_info->unix_token->groups[i], &tmp_sid);
                add_sid_to_array_unique(session_info->security_token, &tmp_sid,
                                        &session_info->security_token->sids,
                                        &session_info->security_token->num_sids);
        }

        security_token_debug(DBGC_AUTH, 10, session_info->security_token);
        debug_unix_user_token(DBGC_AUTH, 10,
                              session_info->unix_token->uid,
                              session_info->unix_token->gid,
                              session_info->unix_token->ngroups,
                              session_info->unix_token->groups);

        status = log_nt_token(session_info->security_token);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        *session_info_out = session_info;
        return NT_STATUS_OK;
}

/***************************************************************************
 Make (and fill) a server_info struct from a 'struct passwd' by conversion
 to a struct samu
***************************************************************************/

NTSTATUS make_server_info_pw(struct auth_serversupplied_info **server_info,
                             char *unix_username,
                             struct passwd *pwd)
{
        NTSTATUS status;
        struct samu *sampass = NULL;
        char *qualified_name = NULL;
        TALLOC_CTX *mem_ctx = NULL;
        struct dom_sid u_sid;
        enum lsa_SidType type;
        struct auth_serversupplied_info *result;

        /*
         * The SID returned in server_info->sam_account is based
         * on our SAM sid even though for a pure UNIX account this should
         * not be the case as it doesn't really exist in the SAM db.
         * This causes lookups on "[in]valid users" to fail as they
         * will lookup this name as a "Unix User" SID to check against
         * the user token. Fix this by adding the "Unix User"\unix_username
         * SID to the sid array. The correct fix should probably be
         * changing the server_info->sam_account user SID to be a
         * S-1-22 Unix SID, but this might break old configs where
         * plaintext passwords were used with no SAM backend.
         */

        mem_ctx = talloc_init("make_server_info_pw_tmp");
        if (!mem_ctx) {
                return NT_STATUS_NO_MEMORY;
        }

        qualified_name = talloc_asprintf(mem_ctx, "%s\\%s",
                                        unix_users_domain_name(),
                                        unix_username );
        if (!qualified_name) {
                TALLOC_FREE(mem_ctx);
                return NT_STATUS_NO_MEMORY;
        }

        if (!lookup_name(mem_ctx, qualified_name, LOOKUP_NAME_ALL,
                                                NULL, NULL,
                                                &u_sid, &type)) {
                TALLOC_FREE(mem_ctx);
                return NT_STATUS_NO_SUCH_USER;
        }

        TALLOC_FREE(mem_ctx);

        if (type != SID_NAME_USER) {
                return NT_STATUS_NO_SUCH_USER;
        }

        if ( !(sampass = samu_new( NULL )) ) {
                return NT_STATUS_NO_MEMORY;
        }

        status = samu_set_unix( sampass, pwd );
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* In pathological cases the above call can set the account
         * name to the DOMAIN\username form. Reset the account name
         * using unix_username */
        pdb_set_username(sampass, unix_username, PDB_SET);

        /* set the user sid to be the calculated u_sid */
        pdb_set_user_sid(sampass, &u_sid, PDB_SET);

        result = make_server_info(NULL);
        if (result == NULL) {
                TALLOC_FREE(sampass);
                return NT_STATUS_NO_MEMORY;
        }

        status = samu_to_SamInfo3(result, sampass, lp_netbios_name(),
                                  &result->info3, &result->extra);
        TALLOC_FREE(sampass);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("Failed to convert samu to info3: %s\n",
                           nt_errstr(status)));
                TALLOC_FREE(result);
                return status;
        }

        result->unix_name = talloc_strdup(result, unix_username);

        if (result->unix_name == NULL) {
                TALLOC_FREE(result);
                return NT_STATUS_NO_MEMORY;
        }

        result->utok.uid = pwd->pw_uid;
        result->utok.gid = pwd->pw_gid;

        *server_info = result;

        return NT_STATUS_OK;
}

static NTSTATUS get_system_info3(TALLOC_CTX *mem_ctx,
                                 struct netr_SamInfo3 *info3)
{
        NTSTATUS status;
        struct dom_sid *system_sid;

        /* Set account name */
        init_lsa_String(&info3->base.account_name, "SYSTEM");

        /* Set domain name */
        init_lsa_StringLarge(&info3->base.logon_domain, "NT AUTHORITY");


        /* The SID set here will be overwirtten anyway, but try and make it SID_NT_SYSTEM anyway */
        /* Domain sid is NT_AUTHORITY */
        
        system_sid = dom_sid_parse_talloc(mem_ctx, SID_NT_SYSTEM);
        if (system_sid == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        
        status = dom_sid_split_rid(mem_ctx, system_sid, &info3->base.domain_sid, 
                                   &info3->base.rid);
        TALLOC_FREE(system_sid);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }
        
        /* Primary gid is the same */
        info3->base.primary_gid = info3->base.rid;

        return NT_STATUS_OK;
}

static NTSTATUS get_guest_info3(TALLOC_CTX *mem_ctx,
                                struct netr_SamInfo3 *info3)
{
        const char *guest_account = lp_guestaccount();
        struct dom_sid domain_sid;
        struct passwd *pwd;
        const char *tmp;

        pwd = Get_Pwnam_alloc(mem_ctx, guest_account);
        if (pwd == NULL) {
                DEBUG(0,("SamInfo3_for_guest: Unable to locate guest "
                         "account [%s]!\n", guest_account));
                return NT_STATUS_NO_SUCH_USER;
        }

        /* Set account name */
        tmp = talloc_strdup(mem_ctx, pwd->pw_name);
        if (tmp == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        init_lsa_String(&info3->base.account_name, tmp);

        /* Set domain name */
        tmp = talloc_strdup(mem_ctx, get_global_sam_name());
        if (tmp == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        init_lsa_StringLarge(&info3->base.logon_domain, tmp);

        /* Domain sid */
        sid_copy(&domain_sid, get_global_sam_sid());

        info3->base.domain_sid = dom_sid_dup(mem_ctx, &domain_sid);
        if (info3->base.domain_sid == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        /* Guest rid */
        info3->base.rid = DOMAIN_RID_GUEST;

        /* Primary gid */
        info3->base.primary_gid = DOMAIN_RID_GUESTS;

        /* Set as guest */
        info3->base.user_flags = NETLOGON_GUEST;

        TALLOC_FREE(pwd);
        return NT_STATUS_OK;
}

/***************************************************************************
 Make (and fill) a user_info struct for a guest login.
 This *must* succeed for smbd to start. If there is no mapping entry for
 the guest gid, then create one.

 The resulting structure is a 'session_info' because
 create_local_token() has already been called on it.  This is quite
 nasty, as the auth subsystem isn't expect this, but the behavior is
 left as-is for now.
***************************************************************************/

static NTSTATUS make_new_session_info_guest(struct auth_session_info **session_info, struct auth_serversupplied_info **server_info)
{
        static const char zeros[16] = {0};
        const char *guest_account = lp_guestaccount();
        const char *domain = lp_netbios_name();
        struct netr_SamInfo3 info3;
        TALLOC_CTX *tmp_ctx;
        NTSTATUS status;

        tmp_ctx = talloc_stackframe();
        if (tmp_ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        ZERO_STRUCT(info3);

        status = get_guest_info3(tmp_ctx, &info3);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("get_guest_info3 failed with %s\n",
                          nt_errstr(status)));
                goto done;
        }

        status = make_server_info_info3(tmp_ctx,
                                        guest_account,
                                        domain,
                                        server_info,
                                        &info3);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("make_server_info_info3 failed with %s\n",
                          nt_errstr(status)));
                goto done;
        }

        (*server_info)->guest = true;

        /* This should not be done here (we should produce a server
         * info, and later construct a session info from it), but for
         * now this does not change the previous behavior */
        status = create_local_token(tmp_ctx, *server_info, NULL,
                                    (*server_info)->info3->base.account_name.string,
                                    session_info);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("create_local_token failed: %s\n",
                          nt_errstr(status)));
                goto done;
        }
        talloc_steal(NULL, *session_info);
        talloc_steal(NULL, *server_info);

        /* annoying, but the Guest really does have a session key, and it is
           all zeros! */
        (*session_info)->session_key = data_blob(zeros, sizeof(zeros));

        status = NT_STATUS_OK;
done:
        TALLOC_FREE(tmp_ctx);
        return status;
}

/***************************************************************************
 Make (and fill) a auth_session_info struct for a system user login.
 This *must* succeed for smbd to start.
***************************************************************************/

static NTSTATUS make_new_session_info_system(TALLOC_CTX *mem_ctx,
                                            struct auth_session_info **session_info)
{
        NTSTATUS status;
        struct auth_serversupplied_info *server_info;
        TALLOC_CTX *tmp_ctx;

        tmp_ctx = talloc_stackframe();
        if (tmp_ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        server_info = make_server_info(tmp_ctx);
        if (!server_info) {
                status = NT_STATUS_NO_MEMORY;
                DEBUG(0, ("failed making server_info\n"));
                goto done;
        }

        server_info->info3 = talloc_zero(server_info, struct netr_SamInfo3);
        if (!server_info->info3) {
                status = NT_STATUS_NO_MEMORY;
                DEBUG(0, ("talloc failed setting info3\n"));
                goto done;
        }

        status = get_system_info3(server_info, server_info->info3);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("Failed creating system info3 with %s\n",
                          nt_errstr(status)));
                goto done;
        }

        server_info->utok.uid = sec_initial_uid();
        server_info->utok.gid = sec_initial_gid();
        server_info->unix_name = talloc_asprintf(server_info,
                                                 "NT AUTHORITY%cSYSTEM",
                                                 *lp_winbind_separator());

        if (!server_info->unix_name) {
                status = NT_STATUS_NO_MEMORY;
                DEBUG(0, ("talloc_asprintf failed setting unix_name\n"));
                goto done;
        }

        server_info->security_token = talloc_zero(server_info, struct security_token);
        if (!server_info->security_token) {
                status = NT_STATUS_NO_MEMORY;
                DEBUG(0, ("talloc failed setting security token\n"));
                goto done;
        }

        status = add_sid_to_array_unique(server_info->security_token->sids,
                                         &global_sid_System,
                                         &server_info->security_token->sids,
                                         &server_info->security_token->num_sids);
        if (!NT_STATUS_IS_OK(status)) {
                goto done;
        }

        /* SYSTEM has all privilages */
        server_info->security_token->privilege_mask = ~0;

        /* Now turn the server_info into a session_info with the full token etc */
        status = create_local_token(mem_ctx, server_info, NULL, "SYSTEM", session_info);
        talloc_free(server_info);

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0, ("create_local_token failed: %s\n",
                          nt_errstr(status)));
                goto done;
        }

        talloc_steal(mem_ctx, *session_info);

done:
        TALLOC_FREE(tmp_ctx);
        return status;
}

/****************************************************************************
  Fake a auth_session_info just from a username (as a
  session_info structure, with create_local_token() already called on
  it.
****************************************************************************/

NTSTATUS make_session_info_from_username(TALLOC_CTX *mem_ctx,
                                         const char *username,
                                         bool is_guest,
                                         struct auth_session_info **session_info)
{
        struct passwd *pwd;
        NTSTATUS status;
        struct auth_serversupplied_info *result;

        pwd = Get_Pwnam_alloc(talloc_tos(), username);
        if (pwd == NULL) {
                return NT_STATUS_NO_SUCH_USER;
        }

        status = make_server_info_pw(&result, pwd->pw_name, pwd);

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        result->nss_token = true;
        result->guest = is_guest;

        /* Now turn the server_info into a session_info with the full token etc */
        status = create_local_token(mem_ctx, result, NULL, pwd->pw_name, session_info);
        TALLOC_FREE(result);
        TALLOC_FREE(pwd);

        return status;
}

/* This function MUST only used to create the cached server_info for
 * guest.
 *
 * This is a lossy conversion.  Variables known to be lost so far
 * include:
 *
 * - nss_token (not needed because the only read doesn't happen
 * for the GUEST user, as this routine populates ->security_token
 *
 * - extra (not needed because the guest account must have valid RIDs per the output of get_guest_info3())
 *
 * - The 'server_info' parameter allows the missing 'info3' to be copied across.
 */
static struct auth_serversupplied_info *copy_session_info_serverinfo_guest(TALLOC_CTX *mem_ctx,
                                                                           const struct auth_session_info *src,
                                                                           struct auth_serversupplied_info *server_info)
{
        struct auth_serversupplied_info *dst;

        dst = make_server_info(mem_ctx);
        if (dst == NULL) {
                return NULL;
        }

        /* This element must be provided to convert back to an auth_serversupplied_info */
        SMB_ASSERT(src->unix_info);

        dst->guest = true;
        dst->system = false;

        /* This element must be provided to convert back to an
         * auth_serversupplied_info.  This needs to be from the
         * auth_session_info because the group values in particular
         * may change during create_local_token() processing */
        SMB_ASSERT(src->unix_token);
        dst->utok.uid = src->unix_token->uid;
        dst->utok.gid = src->unix_token->gid;
        dst->utok.ngroups = src->unix_token->ngroups;
        if (src->unix_token->ngroups != 0) {
                dst->utok.groups = (gid_t *)talloc_memdup(
                        dst, src->unix_token->groups,
                        sizeof(gid_t)*dst->utok.ngroups);
        } else {
                dst->utok.groups = NULL;
        }

        /* We must have a security_token as otherwise the lossy
         * conversion without nss_token would cause create_local_token
         * to take the wrong path */
        SMB_ASSERT(src->security_token);

        dst->security_token = dup_nt_token(dst, src->security_token);
        if (!dst->security_token) {
                TALLOC_FREE(dst);
                return NULL;
        }

        dst->session_key = data_blob_talloc( dst, src->session_key.data,
                                                src->session_key.length);

        /* This is OK because this functions is only used for the
         * GUEST account, which has all-zero keys for both values */
        dst->lm_session_key = data_blob_talloc(dst, src->session_key.data,
                                                src->session_key.length);

        dst->info3 = copy_netr_SamInfo3(dst, server_info->info3);
        if (!dst->info3) {
                TALLOC_FREE(dst);
                return NULL;
        }

        dst->unix_name = talloc_strdup(dst, src->unix_info->unix_name);
        if (!dst->unix_name) {
                TALLOC_FREE(dst);
                return NULL;
        }

        return dst;
}

struct auth_session_info *copy_session_info(TALLOC_CTX *mem_ctx,
                                             const struct auth_session_info *src)
{
        struct auth_session_info *dst;
        DATA_BLOB blob;
        enum ndr_err_code ndr_err;

        ndr_err = ndr_push_struct_blob(
                &blob, talloc_tos(), src,
                (ndr_push_flags_fn_t)ndr_push_auth_session_info);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(0, ("copy_session_info(): ndr_push_auth_session_info failed: "
                           "%s\n", ndr_errstr(ndr_err)));
                return NULL;
        }

        dst = talloc(mem_ctx, struct auth_session_info);
        if (dst == NULL) {
                DEBUG(0, ("talloc failed\n"));
                TALLOC_FREE(blob.data);
                return NULL;
        }

        ndr_err = ndr_pull_struct_blob(
                &blob, dst, dst,
                (ndr_pull_flags_fn_t)ndr_pull_auth_session_info);
        TALLOC_FREE(blob.data);

        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                DEBUG(0, ("copy_session_info(): ndr_pull_auth_session_info failed: "
                           "%s\n", ndr_errstr(ndr_err)));
                TALLOC_FREE(dst);
                return NULL;
        }

        return dst;
}

/*
 * Set a new session key. Used in the rpc server where we have to override the
 * SMB level session key with SystemLibraryDTC
 */

bool session_info_set_session_key(struct auth_session_info *info,
                                 DATA_BLOB session_key)
{
        TALLOC_FREE(info->session_key.data);

        info->session_key = data_blob_talloc(
                info, session_key.data, session_key.length);

        return (info->session_key.data != NULL);
}

static struct auth_session_info *guest_info = NULL;

static struct auth_serversupplied_info *guest_server_info = NULL;

bool init_guest_info(void)
{
        if (guest_info != NULL)
                return true;

        return NT_STATUS_IS_OK(make_new_session_info_guest(&guest_info, &guest_server_info));
}

NTSTATUS make_server_info_guest(TALLOC_CTX *mem_ctx,
                                struct auth_serversupplied_info **server_info)
{
        /* This is trickier than it would appear to need to be because
         * we are trying to avoid certain costly operations when the
         * structure is converted to a 'auth_session_info' again in
         * create_local_token() */
        *server_info = copy_session_info_serverinfo_guest(mem_ctx, guest_info, guest_server_info);
        return (*server_info != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
}

NTSTATUS make_session_info_guest(TALLOC_CTX *mem_ctx,
                                struct auth_session_info **session_info)
{
        *session_info = copy_session_info(mem_ctx, guest_info);
        return (*session_info != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
}

static struct auth_session_info *system_info = NULL;

NTSTATUS init_system_session_info(void)
{
        if (system_info != NULL)
                return NT_STATUS_OK;

        return make_new_session_info_system(NULL, &system_info);
}

NTSTATUS make_session_info_system(TALLOC_CTX *mem_ctx,
                                struct auth_session_info **session_info)
{
        if (system_info == NULL) return NT_STATUS_UNSUCCESSFUL;
        *session_info = copy_session_info(mem_ctx, system_info);
        return (*session_info != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
}

const struct auth_session_info *get_session_info_system(void)
{
    return system_info;
}

/***************************************************************************
 Purely internal function for make_server_info_info3
***************************************************************************/

static NTSTATUS check_account(TALLOC_CTX *mem_ctx, const char *domain,
                              const char *username, char **found_username,
                              struct passwd **pwd,
                              bool *username_was_mapped)
{
        char *orig_dom_user = NULL;
        char *dom_user = NULL;
        char *lower_username = NULL;
        char *real_username = NULL;
        struct passwd *passwd;

        lower_username = talloc_strdup(mem_ctx, username);
        if (!lower_username) {
                return NT_STATUS_NO_MEMORY;
        }
        if (!strlower_m( lower_username )) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        orig_dom_user = talloc_asprintf(mem_ctx,
                                "%s%c%s",
                                domain,
                                *lp_winbind_separator(),
                                lower_username);
        if (!orig_dom_user) {
                return NT_STATUS_NO_MEMORY;
        }

        /* Get the passwd struct.  Try to create the account if necessary. */

        *username_was_mapped = map_username(mem_ctx, orig_dom_user, &dom_user);
        if (!dom_user) {
                return NT_STATUS_NO_MEMORY;
        }

        passwd = smb_getpwnam(mem_ctx, dom_user, &real_username, true );
        if (!passwd) {
                DEBUG(3, ("Failed to find authenticated user %s via "
                          "getpwnam(), denying access.\n", dom_user));
                return NT_STATUS_NO_SUCH_USER;
        }

        if (!real_username) {
                return NT_STATUS_NO_MEMORY;
        }

        *pwd = passwd;

        /* This is pointless -- there is no support for differing
           unix and windows names.  Make sure to always store the 
           one we actually looked up and succeeded. Have I mentioned
           why I hate the 'winbind use default domain' parameter?   
                                         --jerry              */

        *found_username = talloc_strdup( mem_ctx, real_username );

        return NT_STATUS_OK;
}

/****************************************************************************
 Wrapper to allow the getpwnam() call to strip the domain name and 
 try again in case a local UNIX user is already there.  Also run through 
 the username if we fallback to the username only.
 ****************************************************************************/

struct passwd *smb_getpwnam( TALLOC_CTX *mem_ctx, const char *domuser,
                             char **p_save_username, bool create )
{
        struct passwd *pw = NULL;
        char *p = NULL;
        char *username = NULL;

        /* we only save a copy of the username it has been mangled 
           by winbindd use default domain */
        *p_save_username = NULL;

        /* don't call map_username() here since it has to be done higher 
           up the stack so we don't call it multiple times */

        username = talloc_strdup(mem_ctx, domuser);
        if (!username) {
                return NULL;
        }

        p = strchr_m( username, *lp_winbind_separator() );

        /* code for a DOMAIN\user string */

        if ( p ) {
                pw = Get_Pwnam_alloc( mem_ctx, domuser );
                if ( pw ) {
                        /* make sure we get the case of the username correct */
                        /* work around 'winbind use default domain = yes' */

                        if ( !strchr_m( pw->pw_name, *lp_winbind_separator() ) ) {
                                char *domain;

                                /* split the domain and username into 2 strings */
                                *p = '\0';
                                domain = username;

                                *p_save_username = talloc_asprintf(mem_ctx,
                                                                "%s%c%s",
                                                                domain,
                                                                *lp_winbind_separator(),
                                                                pw->pw_name);
                                if (!*p_save_username) {
                                        TALLOC_FREE(pw);
                                        return NULL;
                                }
                        } else {
                                *p_save_username = talloc_strdup(mem_ctx, pw->pw_name);
                        }

                        /* whew -- done! */
                        return pw;
                }

                /* setup for lookup of just the username */
                /* remember that p and username are overlapping memory */

                p++;
                username = talloc_strdup(mem_ctx, p);
                if (!username) {
                        return NULL;
                }
        }

        /* just lookup a plain username */

        pw = Get_Pwnam_alloc(mem_ctx, username);

        /* Create local user if requested but only if winbindd
           is not running.  We need to protect against cases
           where winbindd is failing and then prematurely
           creating users in /etc/passwd */

        if ( !pw && create && !winbind_ping() ) {
                /* Don't add a machine account. */
                if (username[strlen(username)-1] == '$')
                        return NULL;

                _smb_create_user(NULL, username, NULL);
                pw = Get_Pwnam_alloc(mem_ctx, username);
        }

        /* one last check for a valid passwd struct */

        if (pw) {
                *p_save_username = talloc_strdup(mem_ctx, pw->pw_name);
        }
        return pw;
}

/***************************************************************************
 Make a server_info struct from the info3 returned by a domain logon 
***************************************************************************/

NTSTATUS make_server_info_info3(TALLOC_CTX *mem_ctx, 
                                const char *sent_nt_username,
                                const char *domain,
                                struct auth_serversupplied_info **server_info,
                                struct netr_SamInfo3 *info3)
{
        static const char zeros[16] = {0, };

        NTSTATUS nt_status = NT_STATUS_OK;
        char *found_username = NULL;
        const char *nt_domain;
        const char *nt_username;
        struct dom_sid user_sid;
        struct dom_sid group_sid;
        bool username_was_mapped;
        struct passwd *pwd;
        struct auth_serversupplied_info *result;

        /* 
           Here is where we should check the list of
           trusted domains, and verify that the SID 
           matches.
        */

        if (!sid_compose(&user_sid, info3->base.domain_sid, info3->base.rid)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (!sid_compose(&group_sid, info3->base.domain_sid,
                         info3->base.primary_gid)) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        nt_username = talloc_strdup(mem_ctx, info3->base.account_name.string);
        if (!nt_username) {
                /* If the server didn't give us one, just use the one we sent
                 * them */
                nt_username = sent_nt_username;
        }

        nt_domain = talloc_strdup(mem_ctx, info3->base.logon_domain.string);
        if (!nt_domain) {
                /* If the server didn't give us one, just use the one we sent
                 * them */
                nt_domain = domain;
        }

        /* If getpwnam() fails try the add user script (2.2.x behavior).

           We use the _unmapped_ username here in an attempt to provide
           consistent username mapping behavior between kerberos and NTLM[SSP]
           authentication in domain mode security.  I.E. Username mapping
           should be applied to the fully qualified username
           (e.g. DOMAIN\user) and not just the login name.  Yes this means we
           called map_username() unnecessarily in make_user_info_map() but
           that is how the current code is designed.  Making the change here
           is the least disruptive place.  -- jerry */

        /* this call will try to create the user if necessary */

        nt_status = check_account(mem_ctx, nt_domain, sent_nt_username,
                                     &found_username, &pwd,
                                     &username_was_mapped);

        if (!NT_STATUS_IS_OK(nt_status)) {
                return nt_status;
        }

        result = make_server_info(NULL);
        if (result == NULL) {
                DEBUG(4, ("make_server_info failed!\n"));
                return NT_STATUS_NO_MEMORY;
        }

        result->unix_name = talloc_strdup(result, found_username);

        /* copy in the info3 */
        result->info3 = copy_netr_SamInfo3(result, info3);
        if (result->info3 == NULL) {
                TALLOC_FREE(result);
                return NT_STATUS_NO_MEMORY;
        }

        /* Fill in the unix info we found on the way */

        result->utok.uid = pwd->pw_uid;
        result->utok.gid = pwd->pw_gid;

        /* ensure we are never given NULL session keys */

        if (memcmp(info3->base.key.key, zeros, sizeof(zeros)) == 0) {
                result->session_key = data_blob_null;
        } else {
                result->session_key = data_blob_talloc(
                        result, info3->base.key.key,
                        sizeof(info3->base.key.key));
        }

        if (memcmp(info3->base.LMSessKey.key, zeros, 8) == 0) {
                result->lm_session_key = data_blob_null;
        } else {
                result->lm_session_key = data_blob_talloc(
                        result, info3->base.LMSessKey.key,
                        sizeof(info3->base.LMSessKey.key));
        }

        result->nss_token |= username_was_mapped;

        result->guest = (info3->base.user_flags & NETLOGON_GUEST);

        *server_info = result;

        return NT_STATUS_OK;
}

/*****************************************************************************
 Make a server_info struct from the wbcAuthUserInfo returned by a domain logon
******************************************************************************/

NTSTATUS make_server_info_wbcAuthUserInfo(TALLOC_CTX *mem_ctx,
                                          const char *sent_nt_username,
                                          const char *domain,
                                          const struct wbcAuthUserInfo *info,
                                          struct auth_serversupplied_info **server_info)
{
        struct netr_SamInfo3 *info3;

        info3 = wbcAuthUserInfo_to_netr_SamInfo3(mem_ctx, info);
        if (!info3) {
                return NT_STATUS_NO_MEMORY;
        }

        return make_server_info_info3(mem_ctx,
                                      sent_nt_username, domain,
                                      server_info, info3);
}

/**
 * Verify whether or not given domain is trusted.
 *
 * @param domain_name name of the domain to be verified
 * @return true if domain is one of the trusted ones or
 *         false if otherwise
 **/

bool is_trusted_domain(const char* dom_name)
{
        struct dom_sid trustdom_sid;
        bool ret;

        /* no trusted domains for a standalone server */

        if ( lp_server_role() == ROLE_STANDALONE )
                return false;

        if (dom_name == NULL || dom_name[0] == '\0') {
                return false;
        }

        if (strequal(dom_name, get_global_sam_name())) {
                return false;
        }

        /* if we are a DC, then check for a direct trust relationships */

        if ( IS_DC ) {
                become_root();
                DEBUG (5,("is_trusted_domain: Checking for domain trust with "
                          "[%s]\n", dom_name ));
                ret = pdb_get_trusteddom_pw(dom_name, NULL, NULL, NULL);
                unbecome_root();
                if (ret)
                        return true;
        }
        else {
                wbcErr result;

                /* If winbind is around, ask it */

                result = wb_is_trusted_domain(dom_name);

                if (result == WBC_ERR_SUCCESS) {
                        return true;
                }

                if (result == WBC_ERR_DOMAIN_NOT_FOUND) {
                        /* winbind could not find the domain */
                        return false;
                }

                /* The only other possible result is that winbind is not up
                   and running. We need to update the trustdom_cache
                   ourselves */

                update_trustdom_cache();
        }

        /* now the trustdom cache should be available a DC could still
         * have a transitive trust so fall back to the cache of trusted
         * domains (like a domain member would use  */

        if ( trustdom_cache_fetch(dom_name, &trustdom_sid) ) {
                return true;
        }

        return false;
}



/*
  on a logon error possibly map the error to success if "map to guest"
  is set approriately
*/
NTSTATUS do_map_to_guest_server_info(NTSTATUS status,
                                     struct auth_serversupplied_info **server_info,
                                     const char *user, const char *domain)
{
        user = user ? user : "";
        domain = domain ? domain : "";

        if (NT_STATUS_EQUAL(status, NT_STATUS_NO_SUCH_USER)) {
                if ((lp_map_to_guest() == MAP_TO_GUEST_ON_BAD_USER) ||
                    (lp_map_to_guest() == MAP_TO_GUEST_ON_BAD_PASSWORD)) {
                        DEBUG(3,("No such user %s [%s] - using guest account\n",
                                 user, domain));
                        return make_server_info_guest(NULL, server_info);
                }
        } else if (NT_STATUS_EQUAL(status, NT_STATUS_WRONG_PASSWORD)) {
                if (lp_map_to_guest() == MAP_TO_GUEST_ON_BAD_PASSWORD) {
                        DEBUG(3,("Registered username %s for guest access\n",
                                user));
                        return make_server_info_guest(NULL, server_info);
                }
        }

        return status;
}

/*
  Extract session key from a session info and return it in a blob
  if intent is KEY_USE_16BYTES, truncate it to 16 bytes

  See sections 3.2.4.15 and 3.3.4.2 of MS-SMB
  Also see https://lists.samba.org/archive/cifs-protocol/2012-January/002265.html for details

  Note that returned session_key is referencing the original key, it is supposed to be
  short-lived. If original session_info->session_key is gone, the reference will be broken.
*/
NTSTATUS session_extract_session_key(const struct auth_session_info *session_info, DATA_BLOB *session_key, enum session_key_use_intent intent)
{

        if (session_key == NULL || session_info == NULL) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (session_info->session_key.length == 0) {
                return NT_STATUS_NO_USER_SESSION_KEY;
        }

        *session_key = session_info->session_key;
        if (intent == KEY_USE_16BYTES) {
                session_key->length = MIN(session_info->session_key.length, 16);
        }
        return NT_STATUS_OK;
}