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[Samba.git] / source4 / auth / sam.c

/*
   Unix SMB/CIFS implementation.
   Password and authentication handling
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2010
   Copyright (C) Gerald Carter                             2003
   Copyright (C) Stefan Metzmacher                         2005
   Copyright (C) Matthias Dieter Wallnöfer                 2009

   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 "system/time.h"
#include "auth/auth.h"
#include <ldb.h>
#include "dsdb/samdb/samdb.h"
#include "libcli/security/security.h"
#include "auth/auth_sam.h"
#include "dsdb/common/util.h"
#include "libcli/ldap/ldap_ndr.h"
#include "param/param.h"
#include "librpc/gen_ndr/ndr_winbind_c.h"
#include "lib/dbwrap/dbwrap.h"
#include "cluster/cluster.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

#define KRBTGT_ATTRS                            \
        /* required for the krb5 kdc */         \
        "objectClass",                          \
        "sAMAccountName",                       \
        "userPrincipalName",                    \
        "servicePrincipalName",                 \
        "msDS-KeyVersionNumber",                \
        "msDS-SecondaryKrbTgtNumber",           \
        "msDS-SupportedEncryptionTypes",        \
        "supplementalCredentials",              \
        "msDS-AllowedToDelegateTo",             \
        "msDS-AllowedToActOnBehalfOfOtherIdentity", \
                                                \
        /* passwords */                         \
        "unicodePwd",                           \
                                                \
        "userAccountControl",                   \
        "msDS-User-Account-Control-Computed",   \
        "objectSid",                            \
                                                \
        "pwdLastSet",                           \
        "msDS-UserPasswordExpiryTimeComputed",  \
        "accountExpires",                       \
                                                \
        /* Needed for RODC rule processing */   \
        "msDS-KrbTgtLinkBL"

#define AUTHN_POLICY_ATTRS                     \
        /* Required for authentication policies / silos */ \
        "msDS-AssignedAuthNPolicy",             \
        "msDS-AssignedAuthNPolicySilo"

const char *krbtgt_attrs[] = {
        /*
         * Authentication policies will not be enforced on the TGS
         * account. Don’t include the relevant attributes in the account search.
         */
        KRBTGT_ATTRS, NULL
};

const char *server_attrs[] = {
        KRBTGT_ATTRS,
        AUTHN_POLICY_ATTRS,
        NULL
};

const char *user_attrs[] = {
        /*
         * This ordering (having msDS-ResultantPSO first) is
         * important.  By processing this attribute first it is
         * available in the operational module for the other PSO
         * attribute calcuations to use.
         */
        "msDS-ResultantPSO",

        KRBTGT_ATTRS,
        AUTHN_POLICY_ATTRS,

        "logonHours",

        /*
         * To allow us to zero the badPwdCount and lockoutTime on
         * successful logon, without database churn
         */
        "lockoutTime",

        /*
         * Needed for SendToSAM requests
         */
        "objectGUID",

        /* check 'allowed workstations' */
        "userWorkstations",

        /* required for user_info_dc, not access control: */
        "displayName",
        "scriptPath",
        "profilePath",
        "homeDirectory",
        "homeDrive",
        "lastLogon",
        "lastLogonTimestamp",
        "lastLogoff",
        "accountExpires",
        "badPwdCount",
        "logonCount",
        "primaryGroupID",
        "memberOf",
        "badPasswordTime",
        "lmPwdHistory",
        "ntPwdHistory",
        NULL,
};

/****************************************************************************
 Check if a user is allowed to logon at this time. Note this is the
 servers local time, as logon hours are just specified as a weekly
 bitmask.
****************************************************************************/

static bool logon_hours_ok(struct ldb_message *msg, const char *name_for_logs)
{
        /* In logon hours first bit is Sunday from 12AM to 1AM */
        const struct ldb_val *hours;
        struct tm *utctime;
        time_t lasttime;
        const char *asct;
        uint8_t bitmask, bitpos;

        hours = ldb_msg_find_ldb_val(msg, "logonHours");
        if (!hours) {
                DEBUG(5,("logon_hours_ok: No hours restrictions for user %s\n", name_for_logs));
                return true;
        }

        if (hours->length != 168/8) {
                DEBUG(5,("logon_hours_ok: malformed logon hours restrictions for user %s\n", name_for_logs));
                return true;
        }

        lasttime = time(NULL);
        utctime = gmtime(&lasttime);
        if (!utctime) {
                DEBUG(1, ("logon_hours_ok: failed to get gmtime. Failing logon for user %s\n",
                        name_for_logs));
                return false;
        }

        /* find the corresponding byte and bit */
        bitpos = (utctime->tm_wday * 24 + utctime->tm_hour) % 168;
        bitmask = 1 << (bitpos % 8);

        if (! (hours->data[bitpos/8] & bitmask)) {
                struct tm *t = localtime(&lasttime);
                if (!t) {
                        asct = "INVALID TIME";
                } else {
                        asct = asctime(t);
                        if (!asct) {
                                asct = "INVALID TIME";
                        }
                }

                DEBUG(1, ("logon_hours_ok: Account for user %s not allowed to "
                          "logon at this time (%s).\n",
                          name_for_logs, asct ));
                return false;
        }

        asct = asctime(utctime);
        DEBUG(5,("logon_hours_ok: user %s allowed to logon at this time (%s)\n",
                name_for_logs, asct ? asct : "UNKNOWN TIME" ));

        return true;
}

/****************************************************************************
 Do a specific test for a SAM_ACCOUNT being valid for this connection
 (ie not disabled, expired and the like).
****************************************************************************/
_PUBLIC_ NTSTATUS authsam_account_ok(TALLOC_CTX *mem_ctx,
                                     struct ldb_context *sam_ctx,
                                     uint32_t logon_parameters,
                                     struct ldb_dn *domain_dn,
                                     struct ldb_message *msg,
                                     const char *logon_workstation,
                                     const char *name_for_logs,
                                     bool allow_domain_trust,
                                     bool password_change)
{
        uint16_t acct_flags;
        const char *workstation_list;
        NTTIME acct_expiry;
        NTTIME must_change_time;
        struct timeval tv_now = timeval_current();
        NTTIME now = timeval_to_nttime(&tv_now);

        DEBUG(4,("authsam_account_ok: Checking SMB password for user %s\n", name_for_logs));

        acct_flags = samdb_result_acct_flags(msg, "msDS-User-Account-Control-Computed");

        acct_expiry = samdb_result_account_expires(msg);

        /* Check for when we must change this password, taking the
         * userAccountControl flags into account */
        must_change_time = samdb_result_nttime(msg,
                        "msDS-UserPasswordExpiryTimeComputed", 0);

        workstation_list = ldb_msg_find_attr_as_string(msg, "userWorkstations", NULL);

        /* Quit if the account was disabled. */
        if (acct_flags & ACB_DISABLED) {
                DEBUG(2,("authsam_account_ok: Account for user '%s' was disabled.\n", name_for_logs));
                return NT_STATUS_ACCOUNT_DISABLED;
        }

        /* Quit if the account was locked out. */
        if (acct_flags & ACB_AUTOLOCK) {
                DEBUG(2,("authsam_account_ok: Account for user %s was locked out.\n", name_for_logs));
                return NT_STATUS_ACCOUNT_LOCKED_OUT;
        }

        /* Test account expire time */
        if (now > acct_expiry) {
                DEBUG(2,("authsam_account_ok: Account for user '%s' has expired.\n", name_for_logs));
                DEBUG(3,("authsam_account_ok: Account expired at '%s'.\n",
                         nt_time_string(mem_ctx, acct_expiry)));
                return NT_STATUS_ACCOUNT_EXPIRED;
        }

        /* check for immediate expiry "must change at next logon" (but not if this is a password change request) */
        if ((must_change_time == 0) && !password_change) {
                DEBUG(2,("sam_account_ok: Account for user '%s' password must change!.\n",
                         name_for_logs));
                return NT_STATUS_PASSWORD_MUST_CHANGE;
        }

        /* check for expired password (but not if this is a password change request) */
        if ((must_change_time < now) && !password_change) {
                DEBUG(2,("sam_account_ok: Account for user '%s' password expired!.\n",
                         name_for_logs));
                DEBUG(2,("sam_account_ok: Password expired at '%s' unix time.\n",
                         nt_time_string(mem_ctx, must_change_time)));
                return NT_STATUS_PASSWORD_EXPIRED;
        }

        /* Test workstation. Workstation list is comma separated. */
        if (logon_workstation && workstation_list && *workstation_list) {
                bool invalid_ws = true;
                int i;
                char **workstations = str_list_make(mem_ctx, workstation_list, ",");

                for (i = 0; workstations && workstations[i]; i++) {
                        DEBUG(10,("sam_account_ok: checking for workstation match '%s' and '%s'\n",
                                  workstations[i], logon_workstation));

                        if (strequal(workstations[i], logon_workstation)) {
                                invalid_ws = false;
                                break;
                        }
                }

                talloc_free(workstations);

                if (invalid_ws) {
                        return NT_STATUS_INVALID_WORKSTATION;
                }
        }

        if (!logon_hours_ok(msg, name_for_logs)) {
                return NT_STATUS_INVALID_LOGON_HOURS;
        }

        if (!allow_domain_trust) {
                if (acct_flags & ACB_DOMTRUST) {
                        DEBUG(2,("sam_account_ok: Domain trust account %s denied by server\n", name_for_logs));
                        return NT_STATUS_NOLOGON_INTERDOMAIN_TRUST_ACCOUNT;
                }
        }
        if (!(logon_parameters & MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT)) {
                if (acct_flags & ACB_SVRTRUST) {
                        DEBUG(2,("sam_account_ok: Server trust account %s denied by server\n", name_for_logs));
                        return NT_STATUS_NOLOGON_SERVER_TRUST_ACCOUNT;
                }
        }
        if (!(logon_parameters & MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT)) {
                /* TODO: this fails with current solaris client. We
                   need to work with Gordon to work out why */
                if (acct_flags & ACB_WSTRUST) {
                        DEBUG(4,("sam_account_ok: Wksta trust account %s denied by server\n", name_for_logs));
                        return NT_STATUS_NOLOGON_WORKSTATION_TRUST_ACCOUNT;
                }
        }

        return NT_STATUS_OK;
}

static NTSTATUS authsam_domain_group_filter(TALLOC_CTX *mem_ctx,
                                            char **_filter)
{
        char *filter = NULL;

        *_filter = NULL;

        filter = talloc_strdup(mem_ctx, "(&(objectClass=group)");

        /*
         * Skip all builtin groups, they're added later.
         */
        talloc_asprintf_addbuf(&filter,
                               "(!(groupType:"LDB_OID_COMPARATOR_AND":=%u))",
                               GROUP_TYPE_BUILTIN_LOCAL_GROUP);
        /*
         * Only include security groups.
         */
        talloc_asprintf_addbuf(&filter,
                               "(groupType:"LDB_OID_COMPARATOR_AND":=%u))",
                               GROUP_TYPE_SECURITY_ENABLED);
        if (filter == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        *_filter = filter;
        return NT_STATUS_OK;
}

_PUBLIC_ NTSTATUS authsam_make_user_info_dc(TALLOC_CTX *mem_ctx,
                                           struct ldb_context *sam_ctx,
                                           const char *netbios_name,
                                           const char *domain_name,
                                           const char *dns_domain_name,
                                           struct ldb_dn *domain_dn,
                                           const struct ldb_message *msg,
                                           DATA_BLOB user_sess_key,
                                           DATA_BLOB lm_sess_key,
                                           struct auth_user_info_dc **_user_info_dc)
{
        NTSTATUS status;
        int ret;
        struct auth_user_info_dc *user_info_dc;
        struct auth_user_info *info;
        const char *str = NULL;
        char *filter = NULL;
        /* SIDs for the account and his primary group */
        struct dom_sid *account_sid;
        struct dom_sid_buf buf;
        const char *primary_group_dn_str = NULL;
        DATA_BLOB primary_group_blob;
        struct ldb_dn *primary_group_dn = NULL;
        struct ldb_message *primary_group_msg = NULL;
        unsigned primary_group_type;
        /* SID structures for the expanded group memberships */
        struct auth_SidAttr *sids = NULL;
        uint32_t num_sids = 0;
        unsigned int i;
        struct dom_sid *domain_sid;
        TALLOC_CTX *tmp_ctx;
        struct ldb_message_element *el;
        static const char * const group_type_attrs[] = { "groupType", NULL };

        user_info_dc = talloc_zero(mem_ctx, struct auth_user_info_dc);
        NT_STATUS_HAVE_NO_MEMORY(user_info_dc);

        tmp_ctx = talloc_new(user_info_dc);
        if (tmp_ctx == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        /*
         * We'll typically store three SIDs: the SID of the user, the SID of the
         * primary group, and a copy of the latter if it's not a resource
         * group. Allocate enough memory for these three SIDs.
         */
        sids = talloc_zero_array(user_info_dc, struct auth_SidAttr, 3);
        if (sids == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        num_sids = 2;

        account_sid = samdb_result_dom_sid(tmp_ctx, msg, "objectSid");
        if (account_sid == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        status = dom_sid_split_rid(tmp_ctx, account_sid, &domain_sid, NULL);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(user_info_dc);
                return status;
        }

        sids[PRIMARY_USER_SID_INDEX].sid = *account_sid;
        sids[PRIMARY_USER_SID_INDEX].attrs = SE_GROUP_DEFAULT_FLAGS;
        sids[PRIMARY_GROUP_SID_INDEX].sid = *domain_sid;
        sid_append_rid(&sids[PRIMARY_GROUP_SID_INDEX].sid, ldb_msg_find_attr_as_uint(msg, "primaryGroupID", ~0));
        sids[PRIMARY_GROUP_SID_INDEX].attrs = SE_GROUP_DEFAULT_FLAGS;

        /*
         * Filter out builtin groups from this token. We will search
         * for builtin groups later, and not include them in the PAC
         * or SamLogon validation info.
         */
        status = authsam_domain_group_filter(tmp_ctx, &filter);
        if (!NT_STATUS_IS_OK(status)) {
                TALLOC_FREE(user_info_dc);
                return status;
        }

        primary_group_dn_str = talloc_asprintf(
                tmp_ctx,
                "<SID=%s>",
                dom_sid_str_buf(&sids[PRIMARY_GROUP_SID_INDEX].sid, &buf));
        if (primary_group_dn_str == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        /* Get the DN of the primary group. */
        primary_group_dn = ldb_dn_new(tmp_ctx, sam_ctx, primary_group_dn_str);
        if (primary_group_dn == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        /*
         * Do a search for the primary group, for the purpose of checking
         * whether it's a resource group.
         */
        ret = dsdb_search_one(sam_ctx, tmp_ctx,
                              &primary_group_msg,
                              primary_group_dn,
                              LDB_SCOPE_BASE,
                              group_type_attrs,
                              0,
                              NULL);
        if (ret != LDB_SUCCESS) {
                talloc_free(user_info_dc);
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }

        /* Check the type of the primary group. */
        primary_group_type = ldb_msg_find_attr_as_uint(primary_group_msg, "groupType", 0);
        if (primary_group_type & GROUP_TYPE_RESOURCE_GROUP) {
                /*
                 * If it's a resource group, we might as well indicate that in
                 * its attributes. At any rate, the primary group's attributes
                 * are unlikely to be used in the code, as there's nowhere to
                 * store them.
                 */
                sids[PRIMARY_GROUP_SID_INDEX].attrs |= SE_GROUP_RESOURCE;
        } else {
                /*
                 * The primary group is not a resource group. Make a copy of its
                 * SID to ensure it is added to the Base SIDs in the PAC.
                 */
                sids[REMAINING_SIDS_INDEX] = sids[PRIMARY_GROUP_SID_INDEX];
                ++num_sids;
        }

        primary_group_blob = data_blob_string_const(primary_group_dn_str);

        /* Expands the primary group - this function takes in
         * memberOf-like values, so we fake one up with the
         * <SID=S-...> format of DN and then let it expand
         * them, as long as they meet the filter - so only
         * domain groups, not builtin groups
         *
         * The primary group is still treated specially, so we set the
         * 'only childs' flag to true
         */
        status = dsdb_expand_nested_groups(sam_ctx, &primary_group_blob, true, filter,
                                           user_info_dc, &sids, &num_sids);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(user_info_dc);
                return status;
        }

        /* Expands the additional groups */
        el = ldb_msg_find_element(msg, "memberOf");
        for (i = 0; el && i < el->num_values; i++) {
                /* This function takes in memberOf values and expands
                 * them, as long as they meet the filter - so only
                 * domain groups, not builtin groups */
                status = dsdb_expand_nested_groups(sam_ctx, &el->values[i], false, filter,
                                                   user_info_dc, &sids, &num_sids);
                if (!NT_STATUS_IS_OK(status)) {
                        talloc_free(user_info_dc);
                        return status;
                }
        }

        user_info_dc->sids = sids;
        user_info_dc->num_sids = num_sids;

        user_info_dc->info = info = talloc_zero(user_info_dc, struct auth_user_info);
        if (user_info_dc->info == NULL) {
                talloc_free(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        str = ldb_msg_find_attr_as_string(msg, "sAMAccountName", NULL);
        info->account_name = talloc_strdup(info, str);
        if (info->account_name == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        str = ldb_msg_find_attr_as_string(msg, "userPrincipalName", NULL);
        if (str == NULL && dns_domain_name != NULL) {
                info->user_principal_name = talloc_asprintf(info, "%s@%s",
                                        info->account_name,
                                        dns_domain_name);
                if (info->user_principal_name == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
                info->user_principal_constructed = true;
        } else if (str != NULL) {
                info->user_principal_name = talloc_strdup(info, str);
                if (info->user_principal_name == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
        }

        info->domain_name = talloc_strdup(info, domain_name);
        if (info->domain_name == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        if (dns_domain_name != NULL) {
                info->dns_domain_name = talloc_strdup(info, dns_domain_name);
                if (info->dns_domain_name == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
        }

        str = ldb_msg_find_attr_as_string(msg, "displayName", "");
        info->full_name = talloc_strdup(info, str);
        if (info->full_name == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        str = ldb_msg_find_attr_as_string(msg, "scriptPath", "");
        info->logon_script = talloc_strdup(info, str);
        if (info->logon_script == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        str = ldb_msg_find_attr_as_string(msg, "profilePath", "");
        info->profile_path = talloc_strdup(info, str);
        if (info->profile_path == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        str = ldb_msg_find_attr_as_string(msg, "homeDirectory", "");
        info->home_directory = talloc_strdup(info, str);
        if (info->home_directory == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        str = ldb_msg_find_attr_as_string(msg, "homeDrive", "");
        info->home_drive = talloc_strdup(info, str);
        if (info->home_drive == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        info->logon_server = talloc_strdup(info, netbios_name);
        if (info->logon_server == NULL) {
                TALLOC_FREE(user_info_dc);
                return NT_STATUS_NO_MEMORY;
        }

        info->last_logon = samdb_result_nttime(msg, "lastLogon", 0);
        info->last_logoff = samdb_result_last_logoff(msg);
        info->acct_expiry = samdb_result_account_expires(msg);
        info->last_password_change = samdb_result_nttime(msg,
                "pwdLastSet", 0);
        info->allow_password_change
                = samdb_result_allow_password_change(sam_ctx, mem_ctx,
                        domain_dn, msg, "pwdLastSet");
        info->force_password_change = samdb_result_nttime(msg,
                "msDS-UserPasswordExpiryTimeComputed", 0);
        info->logon_count = ldb_msg_find_attr_as_uint(msg, "logonCount", 0);
        info->bad_password_count = ldb_msg_find_attr_as_uint(msg, "badPwdCount",
                0);

        info->acct_flags = samdb_result_acct_flags(msg, "msDS-User-Account-Control-Computed");

        user_info_dc->user_session_key = data_blob_talloc(user_info_dc,
                                                         user_sess_key.data,
                                                         user_sess_key.length);
        if (user_sess_key.data) {
                if (user_info_dc->user_session_key.data == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
        }
        user_info_dc->lm_session_key = data_blob_talloc(user_info_dc,
                                                       lm_sess_key.data,
                                                       lm_sess_key.length);
        if (lm_sess_key.data) {
                if (user_info_dc->lm_session_key.data == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
        }

        if (info->acct_flags & ACB_SVRTRUST) {
                /* the SID_NT_ENTERPRISE_DCS SID gets added into the
                   PAC */
                user_info_dc->sids = talloc_realloc(user_info_dc,
                                                   user_info_dc->sids,
                                                   struct auth_SidAttr,
                                                   user_info_dc->num_sids+1);
                if (user_info_dc->sids == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
                user_info_dc->sids[user_info_dc->num_sids].sid = global_sid_Enterprise_DCs;
                user_info_dc->sids[user_info_dc->num_sids].attrs = SE_GROUP_DEFAULT_FLAGS;
                user_info_dc->num_sids++;
        }

        if ((info->acct_flags & (ACB_PARTIAL_SECRETS_ACCOUNT | ACB_WSTRUST)) ==
            (ACB_PARTIAL_SECRETS_ACCOUNT | ACB_WSTRUST)) {
                /* the DOMAIN_RID_ENTERPRISE_READONLY_DCS PAC */
                user_info_dc->sids = talloc_realloc(user_info_dc,
                                                   user_info_dc->sids,
                                                   struct auth_SidAttr,
                                                   user_info_dc->num_sids+1);
                if (user_info_dc->sids == NULL) {
                        TALLOC_FREE(user_info_dc);
                        return NT_STATUS_NO_MEMORY;
                }
                user_info_dc->sids[user_info_dc->num_sids].sid = *domain_sid;
                sid_append_rid(&user_info_dc->sids[user_info_dc->num_sids].sid,
                            DOMAIN_RID_ENTERPRISE_READONLY_DCS);
                user_info_dc->sids[user_info_dc->num_sids].attrs = SE_GROUP_DEFAULT_FLAGS;
                user_info_dc->num_sids++;
        }

        info->user_flags = 0;

        talloc_free(tmp_ctx);
        *_user_info_dc = user_info_dc;

        return NT_STATUS_OK;
}

_PUBLIC_ NTSTATUS authsam_update_user_info_dc(TALLOC_CTX *mem_ctx,
                        struct ldb_context *sam_ctx,
                        struct auth_user_info_dc *user_info_dc)
{
        char *filter = NULL;
        NTSTATUS status;
        uint32_t i;
        uint32_t n = 0;

        /*
         * This function exists to expand group memberships
         * in the local domain (forest), as the token
         * may come from a different domain.
         */

        /*
         * Filter out builtin groups from this token. We will search
         * for builtin groups later.
         */
        status = authsam_domain_group_filter(mem_ctx, &filter);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /*
         * We loop only over the existing number of
         * sids.
         */
        n = user_info_dc->num_sids;
        for (i = 0; i < n; i++) {
                struct dom_sid *sid = &user_info_dc->sids[i].sid;
                struct dom_sid_buf sid_buf;
                char dn_str[sizeof(sid_buf.buf)*2];
                DATA_BLOB dn_blob = data_blob_null;

                snprintf(dn_str,
                        sizeof(dn_str),
                        "<SID=%s>",
                        dom_sid_str_buf(sid, &sid_buf));
                dn_blob = data_blob_string_const(dn_str);

                /*
                 * We already have the SID in the token, so set
                 * 'only childs' flag to true and add all
                 * groups which match the filter.
                 */
                status = dsdb_expand_nested_groups(sam_ctx, &dn_blob,
                                                   true, filter,
                                                   user_info_dc,
                                                   &user_info_dc->sids,
                                                   &user_info_dc->num_sids);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
        }

        return NT_STATUS_OK;
}

/*
 * Make a shallow copy of a talloc-allocated user_info_dc structure, holding a
 * reference to each of the original fields.
 */
NTSTATUS authsam_shallow_copy_user_info_dc(TALLOC_CTX *mem_ctx,
                                           const struct auth_user_info_dc *user_info_dc_in,
                                           struct auth_user_info_dc **user_info_dc_out)
{
        struct auth_user_info_dc *user_info_dc = NULL;
        NTSTATUS status = NT_STATUS_OK;

        user_info_dc = talloc_zero(mem_ctx, struct auth_user_info_dc);
        if (user_info_dc == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto out;
        }

        *user_info_dc = *user_info_dc_in;

        if (user_info_dc->info != NULL) {
                if (talloc_reference(user_info_dc, user_info_dc->info) == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto out;
                }
        }

        if (user_info_dc->user_session_key.data != NULL) {
                if (talloc_reference(user_info_dc, user_info_dc->user_session_key.data) == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto out;
                }
        }

        if (user_info_dc->lm_session_key.data != NULL) {
                if (talloc_reference(user_info_dc, user_info_dc->lm_session_key.data) == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto out;
                }
        }

        if (user_info_dc->sids != NULL) {
                /*
                 * Because we want to modify the SIDs in the user_info_dc
                 * structure, adding various well-known SIDs such as Asserted
                 * Identity or Claims Valid, make a copy of the SID array to
                 * guard against modification of the original.
                 *
                 * It’s better not to make a reference, because anything that
                 * tries to call talloc_realloc() on the original or the copy
                 * will fail when called for any referenced talloc context.
                 */
                user_info_dc->sids = talloc_memdup(user_info_dc,
                                                   user_info_dc->sids,
                                                   talloc_get_size(user_info_dc->sids));
                if (user_info_dc->sids == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto out;
                }
        }

        *user_info_dc_out = user_info_dc;
        user_info_dc = NULL;

out:
        talloc_free(user_info_dc);
        return status;
}

NTSTATUS sam_get_results_principal(struct ldb_context *sam_ctx,
                                   TALLOC_CTX *mem_ctx, const char *principal,
                                   const char **attrs,
                                   struct ldb_dn **domain_dn,
                                   struct ldb_message **msg)
{
        struct ldb_dn *user_dn;
        NTSTATUS nt_status;
        TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
        int ret;

        if (!tmp_ctx) {
                return NT_STATUS_NO_MEMORY;
        }

        nt_status = crack_user_principal_name(sam_ctx, tmp_ctx, principal,
                                              &user_dn, domain_dn);
        if (!NT_STATUS_IS_OK(nt_status)) {
                talloc_free(tmp_ctx);
                return nt_status;
        }

        /* pull the user attributes */
        ret = dsdb_search_one(sam_ctx, tmp_ctx, msg, user_dn,
                              LDB_SCOPE_BASE, attrs,
                              DSDB_SEARCH_SHOW_EXTENDED_DN | DSDB_SEARCH_NO_GLOBAL_CATALOG,
                              "(objectClass=*)");
        if (ret != LDB_SUCCESS) {
                talloc_free(tmp_ctx);
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }
        talloc_steal(mem_ctx, *msg);
        talloc_steal(mem_ctx, *domain_dn);
        talloc_free(tmp_ctx);

        return NT_STATUS_OK;
}

/* Used in the gensec_gssapi and gensec_krb5 server-side code, where the PAC isn't available, and for tokenGroups in the DSDB stack.

 Supply either a principal or a DN
*/
NTSTATUS authsam_get_user_info_dc_principal(TALLOC_CTX *mem_ctx,
                                           struct loadparm_context *lp_ctx,
                                           struct ldb_context *sam_ctx,
                                           const char *principal,
                                           struct ldb_dn *user_dn,
                                           struct auth_user_info_dc **user_info_dc)
{
        NTSTATUS nt_status;
        DATA_BLOB user_sess_key = data_blob(NULL, 0);
        DATA_BLOB lm_sess_key = data_blob(NULL, 0);

        struct ldb_message *msg;
        struct ldb_dn *domain_dn;

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

        if (principal) {
                nt_status = sam_get_results_principal(sam_ctx, tmp_ctx, principal,
                                                      user_attrs, &domain_dn, &msg);
                if (!NT_STATUS_IS_OK(nt_status)) {
                        talloc_free(tmp_ctx);
                        return nt_status;
                }
        } else if (user_dn) {
                struct dom_sid *user_sid, *domain_sid;
                int ret;
                /* pull the user attributes */
                ret = dsdb_search_one(sam_ctx, tmp_ctx, &msg, user_dn,
                                      LDB_SCOPE_BASE, user_attrs,
                                      DSDB_SEARCH_SHOW_EXTENDED_DN | DSDB_SEARCH_NO_GLOBAL_CATALOG,
                                      "(objectClass=*)");
                if (ret == LDB_ERR_NO_SUCH_OBJECT) {
                        talloc_free(tmp_ctx);
                        return NT_STATUS_NO_SUCH_USER;
                } else if (ret != LDB_SUCCESS) {
                        talloc_free(tmp_ctx);
                        return NT_STATUS_INTERNAL_DB_CORRUPTION;
                }

                user_sid = samdb_result_dom_sid(msg, msg, "objectSid");

                nt_status = dom_sid_split_rid(tmp_ctx, user_sid, &domain_sid, NULL);
                if (!NT_STATUS_IS_OK(nt_status)) {
                        return nt_status;
                }

                domain_dn = samdb_search_dn(sam_ctx, mem_ctx, NULL,
                                          "(&(objectSid=%s)(objectClass=domain))",
                                            ldap_encode_ndr_dom_sid(tmp_ctx, domain_sid));
                if (!domain_dn) {
                        struct dom_sid_buf buf;
                        DEBUG(3, ("authsam_get_user_info_dc_principal: Failed to find domain with: SID %s\n",
                                  dom_sid_str_buf(domain_sid, &buf)));
                        return NT_STATUS_NO_SUCH_USER;
                }

        } else {
                return NT_STATUS_INVALID_PARAMETER;
        }

        nt_status = authsam_make_user_info_dc(tmp_ctx, sam_ctx,
                                             lpcfg_netbios_name(lp_ctx),
                                             lpcfg_sam_name(lp_ctx),
                                             lpcfg_sam_dnsname(lp_ctx),
                                             domain_dn,
                                             msg,
                                             user_sess_key, lm_sess_key,
                                             user_info_dc);
        if (!NT_STATUS_IS_OK(nt_status)) {
                talloc_free(tmp_ctx);
                return nt_status;
        }

        talloc_steal(mem_ctx, *user_info_dc);
        talloc_free(tmp_ctx);

        return NT_STATUS_OK;
}

/*
 * Returns the details for the Password Settings Object (PSO), if one applies
 * the user.
 */
static int authsam_get_user_pso(struct ldb_context *sam_ctx,
                                TALLOC_CTX *mem_ctx,
                                struct ldb_message *user_msg,
                                struct ldb_message **pso_msg)
{
        const char *attrs[] = { "msDS-LockoutThreshold",
                                "msDS-LockoutObservationWindow",
                                NULL };
        struct ldb_dn *pso_dn = NULL;
        struct ldb_result *res = NULL;
        int ret;

        /* check if the user has a PSO that applies to it */
        pso_dn = ldb_msg_find_attr_as_dn(sam_ctx, mem_ctx, user_msg,
                                         "msDS-ResultantPSO");

        if (pso_dn != NULL) {
                ret = dsdb_search_dn(sam_ctx, mem_ctx, &res, pso_dn, attrs, 0);
                if (ret != LDB_SUCCESS) {
                        return ret;
                }

                *pso_msg = res->msgs[0];
        }

        return LDB_SUCCESS;
}

/*
 * Re-read the bad password and successful logon data for a user.
 *
 * The DN in the passed user record should contain the "objectGUID" in case the
 * object DN has changed.
 */
NTSTATUS authsam_reread_user_logon_data(
        struct ldb_context *sam_ctx,
        TALLOC_CTX *mem_ctx,
        const struct ldb_message *user_msg,
        struct ldb_message **current)
{
        const struct ldb_val *v = NULL;
        struct ldb_result *res = NULL;
        uint16_t acct_flags = 0;
        const char *attr_name = "msDS-User-Account-Control-Computed";

        int ret;

        /*
         * Re-read the account details, using the GUID in case the DN
         * is being changed (this is automatic in LDB because the
         * original search also used DSDB_SEARCH_SHOW_EXTENDED_DN)
         *
         * We re read all the attributes in user_attrs, rather than using a
         * subset to ensure that we can reuse existing validation code.
         */
        ret = dsdb_search_dn(sam_ctx,
                             mem_ctx,
                             &res,
                             user_msg->dn,
                             user_attrs,
                             DSDB_SEARCH_SHOW_EXTENDED_DN);
        if (ret != LDB_SUCCESS) {
                DBG_ERR("Unable to re-read account control data for %s\n",
                        ldb_dn_get_linearized(user_msg->dn));
                return NT_STATUS_INTERNAL_ERROR;
        }

        /*
         * Ensure the account has not been locked out by another request
         */
        v = ldb_msg_find_ldb_val(res->msgs[0], attr_name);
        if (v == NULL || v->data == NULL) {
                DBG_ERR("No %s attribute for %s\n",
                        attr_name,
                        ldb_dn_get_linearized(user_msg->dn));
                TALLOC_FREE(res);
                return NT_STATUS_INTERNAL_ERROR;
        }
        acct_flags = samdb_result_acct_flags(res->msgs[0], attr_name);
        if (acct_flags & ACB_AUTOLOCK) {
                DBG_WARNING(
                        "Account for user %s was locked out.\n",
                        ldb_dn_get_linearized(user_msg->dn));
                TALLOC_FREE(res);
                return NT_STATUS_ACCOUNT_LOCKED_OUT;
        }
        *current = talloc_steal(mem_ctx, res->msgs[0]);
        TALLOC_FREE(res);
        return NT_STATUS_OK;
}

static struct db_context *authsam_get_bad_password_db(
        TALLOC_CTX *mem_ctx,
        struct ldb_context *sam_ctx)
{
        struct loadparm_context *lp_ctx = NULL;
        const char *db_name = "bad_password";
        struct db_context *db_ctx =  NULL;

        lp_ctx = ldb_get_opaque(sam_ctx, "loadparm");
        if (lp_ctx == NULL) {
                DBG_ERR("Unable to get loadparm_context\n");
                return NULL;
        }

        db_ctx = cluster_db_tmp_open(mem_ctx, lp_ctx, db_name, TDB_DEFAULT);
        if (db_ctx == NULL) {
                DBG_ERR("Unable to open bad password attempts database\n");
                return NULL;
        }
        return db_ctx;
}

static NTSTATUS get_object_sid_as_tdb_data(
        TALLOC_CTX *mem_ctx,
        const struct ldb_message *msg,
        struct dom_sid_buf *buf,
        TDB_DATA *key)
{
        struct dom_sid *objectsid = NULL;

        /*
         * Convert the objectSID to a human readable form to
         * make debugging easier
         */
        objectsid = samdb_result_dom_sid(mem_ctx, msg, "objectSID");
        if (objectsid == NULL) {
                DBG_ERR("Unable to extract objectSID\n");
                return NT_STATUS_INTERNAL_ERROR;
        }
        dom_sid_str_buf(objectsid, buf);
        key->dptr = (unsigned char *)buf->buf;
        key->dsize = strlen(buf->buf);

        talloc_free(objectsid);

        return NT_STATUS_OK;
}

/*
 * Add the users objectSID to the bad password attempt database
 * to indicate that last authentication failed due to a bad password
 */
static NTSTATUS authsam_set_bad_password_indicator(
        struct ldb_context *sam_ctx,
        TALLOC_CTX *mem_ctx,
        const struct ldb_message *msg)
{
        NTSTATUS status = NT_STATUS_OK;
        struct dom_sid_buf buf;
        TDB_DATA key = {0};
        TDB_DATA value = {0};
        struct db_context *db = NULL;

        TALLOC_CTX *ctx = talloc_new(mem_ctx);
        if (ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        db = authsam_get_bad_password_db(ctx, sam_ctx);
        if (db == NULL) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto exit;
        }

        status = get_object_sid_as_tdb_data(ctx, msg, &buf, &key);
        if (!NT_STATUS_IS_OK(status)) {
                goto exit;
        }

        status = dbwrap_store(db, key, value, 0);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_ERR("Unable to store bad password indicator\n");
        }
exit:
        talloc_free(ctx);
        return status;
}

/*
 * see if the users objectSID is in the bad password attempt database
 */
static NTSTATUS authsam_check_bad_password_indicator(
        struct ldb_context *sam_ctx,
        TALLOC_CTX *mem_ctx,
        bool *exists,
        const struct ldb_message *msg)
{
        NTSTATUS status = NT_STATUS_OK;
        struct dom_sid_buf buf;
        TDB_DATA key = {0};
        struct db_context *db = NULL;

        TALLOC_CTX *ctx = talloc_new(mem_ctx);
        if (ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        db = authsam_get_bad_password_db(ctx, sam_ctx);
        if (db == NULL) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto exit;
        }

        status = get_object_sid_as_tdb_data(ctx, msg, &buf, &key);
        if (!NT_STATUS_IS_OK(status)) {
                goto exit;
        }

        *exists = dbwrap_exists(db, key);
exit:
        talloc_free(ctx);
        return status;
}

/*
 * Remove the users objectSID to the bad password attempt database
 * to indicate that last authentication succeeded.
 */
static NTSTATUS authsam_clear_bad_password_indicator(
        struct ldb_context *sam_ctx,
        TALLOC_CTX *mem_ctx,
        const struct ldb_message *msg)
{
        NTSTATUS status = NT_STATUS_OK;
        struct dom_sid_buf buf;
        TDB_DATA key = {0};
        struct db_context *db = NULL;

        TALLOC_CTX *ctx = talloc_new(mem_ctx);
        if (ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        db = authsam_get_bad_password_db(ctx, sam_ctx);
        if (db == NULL) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto exit;
        }

        status = get_object_sid_as_tdb_data(ctx, msg, &buf, &key);
        if (!NT_STATUS_IS_OK(status)) {
                goto exit;
        }

        status = dbwrap_delete(db, key);
        if (NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
                /*
                 * Ok there was no bad password indicator this is expected
                 */
                status = NT_STATUS_OK;
        }
        if (NT_STATUS_IS_ERR(status)) {
                DBG_ERR("Unable to delete bad password indicator, %s %s\n",
                        nt_errstr(status),
                        get_friendly_nt_error_msg(status));
        }
exit:
        talloc_free(ctx);
        return status;
}

NTSTATUS authsam_update_bad_pwd_count(struct ldb_context *sam_ctx,
                                      struct ldb_message *msg,
                                      struct ldb_dn *domain_dn)
{
        const char *attrs[] = { "lockoutThreshold",
                                "lockOutObservationWindow",
                                "lockoutDuration",
                                "pwdProperties",
                                NULL };
        int ret;
        NTSTATUS status;
        struct ldb_result *domain_res;
        struct ldb_message *msg_mod = NULL;
        struct ldb_message *current = NULL;
        struct ldb_message *pso_msg = NULL;
        bool txn_active = false;
        TALLOC_CTX *mem_ctx;

        mem_ctx = talloc_new(msg);
        if (mem_ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        ret = dsdb_search_dn(sam_ctx, mem_ctx, &domain_res, domain_dn, attrs, 0);
        if (ret != LDB_SUCCESS) {
                TALLOC_FREE(mem_ctx);
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }

        ret = authsam_get_user_pso(sam_ctx, mem_ctx, msg, &pso_msg);
        if (ret != LDB_SUCCESS) {

                /*
                 * fallback to using the domain defaults so that we still
                 * record the bad password attempt
                 */
                DBG_ERR("Error (%d) checking PSO for %s\n",
                        ret, ldb_dn_get_linearized(msg->dn));
        }

        /*
         * To ensure that the bad password count is updated atomically,
         * we need to:
         *    begin a transaction
         *       re-read the account details,
         *         using the <GUID= part of the DN
         *       update the bad password count
         *    commit the transaction.
         */

        /*
         * Start a new transaction
         */
        ret = ldb_transaction_start(sam_ctx);
        if (ret != LDB_SUCCESS) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto error;
        }
        txn_active = true;

        /*
         * Re-read the account details, using the GUID in case the DN
         * is being changed.
         */
        status = authsam_reread_user_logon_data(
                sam_ctx, mem_ctx, msg, &current);
        if (!NT_STATUS_IS_OK(status)) {
                /* The re-read can return account locked out, as well
                 * as an internal error
                 */
                if (NT_STATUS_EQUAL(status, NT_STATUS_ACCOUNT_LOCKED_OUT)) {
                        /*
                         * For NT_STATUS_ACCOUNT_LOCKED_OUT we want to commit
                         * the transaction. Again to avoid cluttering the
                         * audit logs with spurious errors
                         */
                        goto exit;
                }
                goto error;
        }

        /*
         * Update the bad password count and if required lock the account
         */
        status = dsdb_update_bad_pwd_count(
                mem_ctx,
                sam_ctx,
                current,
                domain_res->msgs[0],
                pso_msg,
                &msg_mod);
        if (!NT_STATUS_IS_OK(status)) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto error;
        }

        /*
         * Write the data back to disk if required.
         */
        if (msg_mod != NULL) {
                struct ldb_request *req;

                ret = ldb_build_mod_req(&req, sam_ctx, sam_ctx,
                                        msg_mod,
                                        NULL,
                                        NULL,
                                        ldb_op_default_callback,
                                        NULL);
                if (ret != LDB_SUCCESS) {
                        TALLOC_FREE(msg_mod);
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }

                ret = ldb_request_add_control(req,
                                              DSDB_CONTROL_FORCE_RODC_LOCAL_CHANGE,
                                              false, NULL);
                if (ret != LDB_SUCCESS) {
                        talloc_free(req);
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }

                /*
                 * As we're in a transaction, make the ldb request directly
                 * to avoid the nested transaction that would result if we
                 * called dsdb_autotransaction_request
                 */
                ret = ldb_request(sam_ctx, req);
                if (ret == LDB_SUCCESS) {
                        ret = ldb_wait(req->handle, LDB_WAIT_ALL);
                }
                talloc_free(req);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }
                status = authsam_set_bad_password_indicator(
                        sam_ctx, mem_ctx, msg);
                if (!NT_STATUS_IS_OK(status)) {
                        goto error;
                }
        }
        /*
         * Note that we may not have updated the user record, but
         * committing the transaction in that case is still the correct
         * thing to do.
         * If the transaction was cancelled, this would be logged by
         * the dsdb audit log as a failure. When in fact it is expected
         * behaviour.
         */
exit:
        TALLOC_FREE(mem_ctx);
        ret = ldb_transaction_commit(sam_ctx);
        if (ret != LDB_SUCCESS) {
                DBG_ERR("Error (%d) %s, committing transaction,"
                        " while updating bad password count"
                        " for (%s)\n",
                        ret,
                        ldb_errstring(sam_ctx),
                        ldb_dn_get_linearized(msg->dn));
                return NT_STATUS_INTERNAL_ERROR;
        }
        return status;

error:
        DBG_ERR("Failed to update badPwdCount, badPasswordTime or "
                "set lockoutTime on %s: %s\n",
                ldb_dn_get_linearized(msg->dn),
                ldb_errstring(sam_ctx) != NULL ?
                        ldb_errstring(sam_ctx) :nt_errstr(status));
        if (txn_active) {
                ret = ldb_transaction_cancel(sam_ctx);
                if (ret != LDB_SUCCESS) {
                        DBG_ERR("Error rolling back transaction,"
                                " while updating bad password count"
                                " on %s: %s\n",
                                ldb_dn_get_linearized(msg->dn),
                                ldb_errstring(sam_ctx));
                }
        }
        TALLOC_FREE(mem_ctx);
        return status;

}

/*
 * msDS-LogonTimeSyncInterval is an int32_t number of days.
 *
 * The docs say: "the initial update, after the domain functional
 * level is raised to DS_BEHAVIOR_WIN2003 or higher, is calculated as
 * 14 days minus a random percentage of 5 days", but we aren't doing
 * that. The blogosphere seems to think that this randomised update
 * happens everytime, but [MS-ADA1] doesn't agree.
 *
 * Dochelp referred us to the following blog post:
 * http://blogs.technet.com/b/askds/archive/2009/04/15/the-lastlogontimestamp-attribute-what-it-was-designed-for-and-how-it-works.aspx
 *
 * when msDS-LogonTimeSyncInterval is zero, the lastLogonTimestamp is
 * not changed.
 */

static NTSTATUS authsam_calculate_lastlogon_sync_interval(
        struct ldb_context *sam_ctx,
        TALLOC_CTX *ctx,
        struct ldb_dn *domain_dn,
        NTTIME *sync_interval_nt)
{
        static const char *attrs[] = { "msDS-LogonTimeSyncInterval",
                                        NULL };
        int ret;
        struct ldb_result *domain_res = NULL;
        TALLOC_CTX *mem_ctx = NULL;
        uint32_t sync_interval;

        mem_ctx = talloc_new(ctx);
        if (mem_ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        ret = dsdb_search_dn(sam_ctx, mem_ctx, &domain_res, domain_dn, attrs,
                             0);
        if (ret != LDB_SUCCESS || domain_res->count != 1) {
                TALLOC_FREE(mem_ctx);
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }

        sync_interval = ldb_msg_find_attr_as_int(domain_res->msgs[0],
                                                 "msDS-LogonTimeSyncInterval",
                                                 14);
        DEBUG(5, ("sync interval is %d\n", sync_interval));
        if (sync_interval >= 5){
                /*
                 * Subtract "a random percentage of 5" days. Presumably this
                 * percentage is between 0 and 100, and modulus is accurate
                 * enough.
                 */
                uint32_t r = generate_random() % 6;
                sync_interval -= r;
                DBG_INFO("randomised sync interval is %d (-%d)\n", sync_interval, r);
        }
        /* In the case where sync_interval < 5 there is no randomisation */

        /*
         * msDS-LogonTimeSyncInterval is an int32_t number of days,
         * while lastLogonTimestamp (to be updated) is in the 64 bit
         * 100ns NTTIME format so we must convert.
         */
        *sync_interval_nt = sync_interval * 24LL * 3600LL * 10000000LL;
        TALLOC_FREE(mem_ctx);
        return NT_STATUS_OK;
}


/*
 * We only set lastLogonTimestamp if the current value is older than
 * now - msDS-LogonTimeSyncInterval days.
 *
 * lastLogonTimestamp is in the 64 bit 100ns NTTIME format
 */
static NTSTATUS authsam_update_lastlogon_timestamp(struct ldb_context *sam_ctx,
                                                   struct ldb_message *msg_mod,
                                                   struct ldb_dn *domain_dn,
                                                   NTTIME old_timestamp,
                                                   NTTIME now,
                                                   NTTIME sync_interval_nt)
{
        int ret;
        DEBUG(5, ("old timestamp is %lld, threshold %lld, diff %lld\n",
                  (long long int)old_timestamp,
                  (long long int)(now - sync_interval_nt),
                  (long long int)(old_timestamp - now + sync_interval_nt)));

        if (sync_interval_nt == 0){
                /*
                 * Setting msDS-LogonTimeSyncInterval to zero is how you ask
                 * that nothing happens here.
                 */
                return NT_STATUS_OK;
        }
        if (old_timestamp > now){
                DEBUG(0, ("lastLogonTimestamp is in the future! (%lld > %lld)\n",
                          (long long int)old_timestamp, (long long int)now));
                /* then what? */

        } else if (old_timestamp < now - sync_interval_nt){
                DEBUG(5, ("updating lastLogonTimestamp to %lld\n",
                          (long long int)now));

                /* The time has come to update lastLogonTimestamp */
                ret = samdb_msg_add_int64(sam_ctx, msg_mod, msg_mod,
                                          "lastLogonTimestamp", now);

                if (ret != LDB_SUCCESS) {
                        return NT_STATUS_NO_MEMORY;
                }
        }
        return NT_STATUS_OK;
}

/****************************************************************************
 Look for the specified user in the sam, return ldb result structures
****************************************************************************/

NTSTATUS authsam_search_account(TALLOC_CTX *mem_ctx, struct ldb_context *sam_ctx,
                                         const char *account_name,
                                         struct ldb_dn *domain_dn,
                                         struct ldb_message **ret_msg)
{
        int ret;
        char *account_name_encoded = NULL;

        account_name_encoded = ldb_binary_encode_string(mem_ctx, account_name);
        if (account_name_encoded == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        /* pull the user attributes */
        ret = dsdb_search_one(sam_ctx, mem_ctx, ret_msg, domain_dn, LDB_SCOPE_SUBTREE,
                              user_attrs,
                              DSDB_SEARCH_SHOW_EXTENDED_DN,
                              "(&(sAMAccountName=%s)(objectclass=user))",
                              account_name_encoded);
        if (ret == LDB_ERR_NO_SUCH_OBJECT) {
                DEBUG(3,("authsam_search_account: Couldn't find user [%s] in samdb, under %s\n",
                         account_name, ldb_dn_get_linearized(domain_dn)));
                return NT_STATUS_NO_SUCH_USER;
        }
        if (ret != LDB_SUCCESS) {
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }

        return NT_STATUS_OK;
}


/* Reset the badPwdCount to zero and update the lastLogon time. */
NTSTATUS authsam_logon_success_accounting(struct ldb_context *sam_ctx,
                                          const struct ldb_message *msg,
                                          struct ldb_dn *domain_dn,
                                          bool interactive_or_kerberos,
                                          TALLOC_CTX *send_to_sam_mem_ctx,
                                          struct netr_SendToSamBase **send_to_sam)
{
        int ret;
        NTSTATUS status;
        int badPwdCount;
        int dbBadPwdCount;
        int64_t lockoutTime;
        struct ldb_message *msg_mod;
        TALLOC_CTX *mem_ctx;
        struct timeval tv_now;
        NTTIME now;
        NTTIME lastLogonTimestamp;
        int64_t lockOutObservationWindow;
        NTTIME sync_interval_nt = 0;
        bool am_rodc = false;
        bool txn_active = false;
        bool need_db_reread;

        mem_ctx = talloc_new(msg);
        if (mem_ctx == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        /*
         * Any update of the last logon data, needs to be done inside a
         * transaction.
         * And the user data needs to be re-read, and the account re-checked
         * for lockout.
         *
         * Howevver we have long-running transactions like replication
         * that could otherwise grind the system to a halt so we first
         * determine if *this* account has seen a bad password,
         * otherwise we only start a transaction if there was a need
         * (because a change was to be made).
         */

        status = authsam_check_bad_password_indicator(
                sam_ctx, mem_ctx, &need_db_reread, msg);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        if (interactive_or_kerberos == false) {
                /*
                 * Avoid calculating this twice, it reads the PSO.  A
                 * race on this is unimportant.
                 */
                lockOutObservationWindow
                        = samdb_result_msds_LockoutObservationWindow(
                                sam_ctx, mem_ctx, domain_dn, msg);
        }

        ret = samdb_rodc(sam_ctx, &am_rodc);
        if (ret != LDB_SUCCESS) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto error;
        }

        if (!am_rodc) {
                /*
                 * Avoid reading the main domain DN twice.  A race on
                 * this is unimportant.
                 */
                status = authsam_calculate_lastlogon_sync_interval(
                        sam_ctx, mem_ctx, domain_dn, &sync_interval_nt);

                if (!NT_STATUS_IS_OK(status)) {
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }
        }

get_transaction:

        if (need_db_reread) {
                struct ldb_message *current = NULL;

                /*
                 * Start a new transaction
                 */
                ret = ldb_transaction_start(sam_ctx);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }

                txn_active = true;

                /*
                 * Re-read the account details, using the GUID
                 * embedded in DN so this is safe against a race where
                 * it is being renamed.
                 */
                status = authsam_reread_user_logon_data(
                        sam_ctx, mem_ctx, msg, &current);
                if (!NT_STATUS_IS_OK(status)) {
                        /*
                         * The re-read can return account locked out, as well
                         * as an internal error
                         */
                        if (NT_STATUS_EQUAL(status, NT_STATUS_ACCOUNT_LOCKED_OUT)) {
                                /*
                                 * For NT_STATUS_ACCOUNT_LOCKED_OUT we want to commit
                                 * the transaction. Again to avoid cluttering the
                                 * audit logs with spurious errors
                                 */
                                goto exit;
                        }
                        goto error;
                }
                msg = current;
        }

        lockoutTime = ldb_msg_find_attr_as_int64(msg, "lockoutTime", 0);
        dbBadPwdCount = ldb_msg_find_attr_as_int(msg, "badPwdCount", 0);
        tv_now = timeval_current();
        now = timeval_to_nttime(&tv_now);

        if (interactive_or_kerberos) {
                badPwdCount = dbBadPwdCount;
        } else {
                /*
                 * We get lockOutObservationWindow above, before the
                 * transaction
                 */
                badPwdCount = dsdb_effective_badPwdCount(
                        msg, lockOutObservationWindow, now);
        }
        lastLogonTimestamp =
                ldb_msg_find_attr_as_int64(msg, "lastLogonTimestamp", 0);

        DEBUG(5, ("lastLogonTimestamp is %lld\n",
                  (long long int)lastLogonTimestamp));

        msg_mod = ldb_msg_new(mem_ctx);
        if (msg_mod == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto error;
        }

        /*
         * By using the DN from msg->dn directly, we allow LDB to
         * prefer the embedded GUID form, so this is actually quite
         * safe even in the case where DN has been changed
         */
        msg_mod->dn = msg->dn;

        if (lockoutTime != 0) {
                /*
                 * This implies "badPwdCount" = 0, see samldb_lockout_time()
                 */
                ret = samdb_msg_add_int(sam_ctx, msg_mod, msg_mod, "lockoutTime", 0);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_NO_MEMORY;
                        goto error;
                }
        } else if (badPwdCount != 0) {
                ret = samdb_msg_add_int(sam_ctx, msg_mod, msg_mod, "badPwdCount", 0);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_NO_MEMORY;
                        goto error;
                }
        }

        if (interactive_or_kerberos ||
            (badPwdCount != 0 && lockoutTime == 0)) {
                ret = samdb_msg_add_int64(sam_ctx, msg_mod, msg_mod,
                                          "lastLogon", now);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_NO_MEMORY;
                        goto error;
                }
        }

        if (interactive_or_kerberos) {
                int logonCount;

                logonCount = ldb_msg_find_attr_as_int(msg, "logonCount", 0);

                logonCount += 1;

                ret = samdb_msg_add_int(sam_ctx, msg_mod, msg_mod,
                                        "logonCount", logonCount);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_NO_MEMORY;
                        goto error;
                }
        } else {
                /* Set an unset logonCount to 0 on first successful login */
                if (ldb_msg_find_ldb_val(msg, "logonCount") == NULL) {
                        ret = samdb_msg_add_int(sam_ctx, msg_mod, msg_mod,
                                                "logonCount", 0);
                        if (ret != LDB_SUCCESS) {
                                TALLOC_FREE(mem_ctx);
                                return NT_STATUS_NO_MEMORY;
                        }
                }
        }

        if (!am_rodc) {
                status = authsam_update_lastlogon_timestamp(
                        sam_ctx,
                        msg_mod,
                        domain_dn,
                        lastLogonTimestamp,
                        now,
                        sync_interval_nt);
                if (!NT_STATUS_IS_OK(status)) {
                        status = NT_STATUS_NO_MEMORY;
                        goto error;
                }
        } else {
                /* Perform the (async) SendToSAM calls for MS-SAMS */
                if (dbBadPwdCount != 0 && send_to_sam != NULL) {
                        struct netr_SendToSamBase *base_msg;
                        struct GUID guid = samdb_result_guid(msg, "objectGUID");

                        base_msg = talloc_zero(send_to_sam_mem_ctx,
                                               struct netr_SendToSamBase);
                        if (base_msg == NULL) {
                                status = NT_STATUS_NO_MEMORY;
                                goto error;
                        }

                        base_msg->message_type = SendToSamResetBadPasswordCount;
                        base_msg->message_size = 16;
                        base_msg->message.reset_bad_password.guid = guid;
                        *send_to_sam = base_msg;
                }
        }

        if (msg_mod->num_elements > 0) {
                unsigned int i;
                struct ldb_request *req;

                /*
                 * If it turns out we are going to update the DB, go
                 * back to the start, get a transaction and the
                 * current DB state and try again
                 */
                if (txn_active == false) {
                        need_db_reread = true;
                        goto get_transaction;
                }

                /* mark all the message elements as LDB_FLAG_MOD_REPLACE */
                for (i=0;i<msg_mod->num_elements;i++) {
                        msg_mod->elements[i].flags = LDB_FLAG_MOD_REPLACE;
                }

                ret = ldb_build_mod_req(&req, sam_ctx, sam_ctx,
                                        msg_mod,
                                        NULL,
                                        NULL,
                                        ldb_op_default_callback,
                                        NULL);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }

                ret = ldb_request_add_control(req,
                                              DSDB_CONTROL_FORCE_RODC_LOCAL_CHANGE,
                                              false, NULL);
                if (ret != LDB_SUCCESS) {
                        TALLOC_FREE(req);
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }
                /*
                 * As we're in a transaction, make the ldb request directly
                 * to avoid the nested transaction that would result if we
                 * called dsdb_autotransaction_request
                 */
                ret = ldb_request(sam_ctx, req);
                if (ret == LDB_SUCCESS) {
                        ret = ldb_wait(req->handle, LDB_WAIT_ALL);
                }
                TALLOC_FREE(req);
                if (ret != LDB_SUCCESS) {
                        status = NT_STATUS_INTERNAL_ERROR;
                        goto error;
                }
        }
        status = authsam_clear_bad_password_indicator(sam_ctx, mem_ctx, msg);
        if (!NT_STATUS_IS_OK(status)) {
                goto error;
        }

        /*
         * Note that we may not have updated the user record, but
         * committing the transaction in that case is still the correct
         * thing to do.
         * If the transaction was cancelled, this would be logged by
         * the dsdb audit log as a failure. When in fact it is expected
         * behaviour.
         *
         * Thankfully both TDB and LMDB seem to optimise for the empty
         * transaction case
         */
exit:
        TALLOC_FREE(mem_ctx);

        if (txn_active == false) {
                return status;
        }

        ret = ldb_transaction_commit(sam_ctx);
        if (ret != LDB_SUCCESS) {
                DBG_ERR("Error (%d) %s, committing transaction,"
                        " while updating successful logon accounting"
                        " for (%s)\n",
                        ret,
                        ldb_errstring(sam_ctx),
                        ldb_dn_get_linearized(msg->dn));
                return NT_STATUS_INTERNAL_ERROR;
        }
        return status;

error:
        DBG_ERR("Failed to update badPwdCount, badPasswordTime or "
                "set lockoutTime on %s: %s\n",
                ldb_dn_get_linearized(msg->dn),
                ldb_errstring(sam_ctx) != NULL ?
                        ldb_errstring(sam_ctx) :nt_errstr(status));
        if (txn_active) {
                ret = ldb_transaction_cancel(sam_ctx);
                if (ret != LDB_SUCCESS) {
                        DBG_ERR("Error rolling back transaction,"
                                " while updating bad password count"
                                " on %s: %s\n",
                                ldb_dn_get_linearized(msg->dn),
                                ldb_errstring(sam_ctx));
                }
        }
        TALLOC_FREE(mem_ctx);
        return status;
}