ctdb-failover: Split statd_callout add-client/del-client

[Samba.git] / auth / credentials / credentials_secrets.c

/*
   Unix SMB/CIFS implementation.

   User credentials handling (as regards on-disk files)

   Copyright (C) Jelmer Vernooij 2005
   Copyright (C) Tim Potter 2001
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "lib/events/events.h"
#include <ldb.h>
#include "librpc/gen_ndr/samr.h" /* for struct samrPassword */
#include "param/secrets.h"
#include "system/filesys.h"
#include "auth/credentials/credentials.h"
#include "auth/credentials/credentials_internal.h"
#include "auth/credentials/credentials_krb5.h"
#include "auth/kerberos/kerberos_util.h"
#include "param/param.h"
#include "lib/events/events.h"
#include "dsdb/samdb/samdb.h"
#include "source3/include/secrets.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_open.h"
#include "lib/util/util_tdb.h"
#include "libds/common/roles.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

/**
 * Fill in credentials for the machine trust account, from the secrets database.
 *
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
static NTSTATUS cli_credentials_set_secrets_lct(struct cli_credentials *cred,
                                                struct loadparm_context *lp_ctx,
                                                struct ldb_context *ldb,
                                                const char *base,
                                                const char *filter,
                                                time_t secrets_tdb_last_change_time,
                                                const char *secrets_tdb_password,
                                                char **error_string)
{
        TALLOC_CTX *mem_ctx;

        int ldb_ret;
        struct ldb_message *msg;

        const char *machine_account;
        const char *password;
        const char *domain;
        const char *realm;
        enum netr_SchannelType sct;
        const char *salt_principal;
        char *keytab;
        const struct ldb_val *whenChanged;
        time_t lct;

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

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

        mem_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");

        if (!ldb) {
                /* Local secrets are stored in secrets.ldb */
                ldb = secrets_db_connect(mem_ctx, lp_ctx);
                if (!ldb) {
                        *error_string = talloc_strdup(cred, "Could not open secrets.ldb");
                        talloc_free(mem_ctx);
                        return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
                }
        }

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

        if (ldb_ret != LDB_SUCCESS) {
                *error_string = talloc_asprintf(cred, "Could not find entry to match filter: '%s' base: '%s': %s: %s",
                                                filter, base ? base : "",
                                                ldb_strerror(ldb_ret), ldb_errstring(ldb));
                talloc_free(mem_ctx);
                return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
        }

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

        whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
        if (!whenChanged || ldb_val_to_time(whenChanged, &lct) != LDB_SUCCESS) {
                /* This attribute is mandatory */
                talloc_free(mem_ctx);
                return NT_STATUS_NOT_FOUND;
        }

        /* Don't set secrets.ldb info if the secrets.tdb entry was more recent */
        if (lct < secrets_tdb_last_change_time) {
                talloc_free(mem_ctx);
                return NT_STATUS_NOT_FOUND;
        }

        if ((lct == secrets_tdb_last_change_time) &&
            (secrets_tdb_password != NULL) &&
            (password != NULL) &&
            (strcmp(password, secrets_tdb_password) != 0)) {
                talloc_free(mem_ctx);
                return NT_STATUS_NOT_FOUND;
        }

        cli_credentials_set_password_last_changed_time(cred, lct);

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

        if (!machine_account) {
                machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);

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

        salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
        cli_credentials_set_salt_principal(cred, salt_principal);

        sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
        if (sct) {
                cli_credentials_set_secure_channel_type(cred, sct);
        }

        if (!password) {
                const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
                struct samr_Password hash;
                ZERO_STRUCT(hash);
                if (nt_password_hash) {
                        memcpy(hash.hash, nt_password_hash->data,
                               MIN(nt_password_hash->length, sizeof(hash.hash)));

                        cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
                } else {
                        cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
                }
        } else {
                cli_credentials_set_password(cred, password, CRED_SPECIFIED);
        }

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

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

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

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

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

        return NT_STATUS_OK;
}


/**
 * Fill in credentials for the machine trust account, from the secrets database.
 *
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
                                              struct loadparm_context *lp_ctx,
                                              struct ldb_context *ldb,
                                              const char *base,
                                              const char *filter,
                                              char **error_string)
{
        NTSTATUS status = cli_credentials_set_secrets_lct(cred, lp_ctx, ldb, base, filter, 0, NULL, error_string);
        if (!NT_STATUS_IS_OK(status)) {
                /* set anonymous as the fallback, if the machine account won't work */
                cli_credentials_set_anonymous(cred);
        }
        return status;
}

/**
 * Fill in credentials for the machine trust account, from the secrets database.
 *
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
                                                      struct loadparm_context *lp_ctx)
{
        struct db_context *db_ctx;
        char *secrets_tdb_path;
        int hash_size, tdb_flags;

        secrets_tdb_path = lpcfg_private_db_path(cred, lp_ctx, "secrets");
        if (secrets_tdb_path == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        hash_size = lpcfg_tdb_hash_size(lp_ctx, secrets_tdb_path);
        tdb_flags = lpcfg_tdb_flags(lp_ctx, TDB_DEFAULT);

        db_ctx = dbwrap_local_open(
                cred,
                secrets_tdb_path,
                hash_size,
                tdb_flags,
                O_RDWR,
                0600,
                DBWRAP_LOCK_ORDER_1,
                DBWRAP_FLAG_NONE);
        TALLOC_FREE(secrets_tdb_path);

        /*
         * We do not check for errors here, we might not have a
         * secrets.tdb at all, and so we just need to check the
         * secrets.ldb
         */
        return cli_credentials_set_machine_account_db_ctx(cred, lp_ctx, db_ctx);
}

/**
 * Fill in credentials for the machine trust account, from the
 * secrets.ldb or passed in handle to secrets.tdb (perhaps in CTDB).
 *
 * This version is used in parts of the code that can link in the
 * CTDB dbwrap backend, by passing down the already open handle.
 *
 * @param cred Credentials structure to fill in
 * @param db_ctx dbwrap context for secrets.tdb
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_machine_account_db_ctx(struct cli_credentials *cred,
                                                             struct loadparm_context *lp_ctx,
                                                             struct db_context *db_ctx)
{
        NTSTATUS status;
        char *filter;
        char *error_string = NULL;
        const char *domain;
        bool secrets_tdb_password_more_recent;
        time_t secrets_tdb_lct = 0;
        char *secrets_tdb_password = NULL;
        char *secrets_tdb_old_password = NULL;
        uint32_t secrets_tdb_secure_channel_type = SEC_CHAN_NULL;
        int server_role = lpcfg_server_role(lp_ctx);
        int security = lpcfg_security(lp_ctx);
        char *keystr;
        char *keystr_upper = NULL;
        TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
        if (!tmp_ctx) {
                return NT_STATUS_NO_MEMORY;
        }

        /* Bleh, nasty recursion issues: We are setting a machine
         * account here, so we don't want the 'pending' flag around
         * any more */
        cred->machine_account_pending = false;

        /* We have to do this, as the fallback in
         * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
        domain = cli_credentials_get_domain(cred);

        if (db_ctx) {
                TDB_DATA dbuf;
                keystr = talloc_asprintf(tmp_ctx, "%s/%s",
                                         SECRETS_MACHINE_LAST_CHANGE_TIME,
                                         domain);
                keystr_upper = strupper_talloc(tmp_ctx, keystr);
                status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
                                      &dbuf);
                if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
                        secrets_tdb_lct = IVAL(dbuf.dptr,0);
                }

                keystr = talloc_asprintf(tmp_ctx, "%s/%s",
                                         SECRETS_MACHINE_PASSWORD,
                                         domain);
                keystr_upper = strupper_talloc(tmp_ctx, keystr);
                status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
                                      &dbuf);
                if (NT_STATUS_IS_OK(status)) {
                        secrets_tdb_password = (char *)dbuf.dptr;
                }

                keystr = talloc_asprintf(tmp_ctx, "%s/%s",
                                         SECRETS_MACHINE_PASSWORD_PREV,
                                         domain);
                keystr_upper = strupper_talloc(tmp_ctx, keystr);
                status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
                                      &dbuf);
                if (NT_STATUS_IS_OK(status)) {
                        secrets_tdb_old_password = (char *)dbuf.dptr;
                }

                keystr = talloc_asprintf(tmp_ctx, "%s/%s",
                                         SECRETS_MACHINE_SEC_CHANNEL_TYPE,
                                         domain);
                keystr_upper = strupper_talloc(tmp_ctx, keystr);
                status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
                                      &dbuf);
                if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
                        secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
                }
        }

        filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER, 
                                 domain);
        status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
                                                 SECRETS_PRIMARY_DOMAIN_DN,
                                                 filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
        if (secrets_tdb_password == NULL) {
                secrets_tdb_password_more_recent = false;
        } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
            || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
                secrets_tdb_password_more_recent = true;
        } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
                secrets_tdb_password_more_recent = true;
        } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
                secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
        } else {
                secrets_tdb_password_more_recent = false;
        }

        if (secrets_tdb_password_more_recent) {
                char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
                cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
                cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
                cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
                if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
                        enum credentials_use_kerberos use_kerberos =
                                cli_credentials_get_kerberos_state(cred);
                        enum credentials_obtained use_kerberos_obtained =
                                cli_credentials_get_kerberos_state_obtained(cred);
                        bool is_ad = false;

                        cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);

                        switch (server_role) {
                        case ROLE_DOMAIN_MEMBER:
                                if (security != SEC_ADS) {
                                        break;
                                }

                                FALL_THROUGH;
                        case ROLE_ACTIVE_DIRECTORY_DC:
                        case ROLE_IPA_DC:
                                is_ad = true;
                                break;
                        }

                        if (use_kerberos != CRED_USE_KERBEROS_DESIRED || is_ad) {
                                /*
                                 * Keep an explicit selection
                                 *
                                 * For AD domains we also keep
                                 * CRED_USE_KERBEROS_DESIRED
                                 */
                        } else if (use_kerberos_obtained <= CRED_SMB_CONF) {
                                /*
                                 * Disable kerberos by default within
                                 * an NT4 domain.
                                 */
                                cli_credentials_set_kerberos_state(cred,
                                                CRED_USE_KERBEROS_DISABLED,
                                                CRED_SMB_CONF);
                        }
                }

                cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
                cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
                cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
                status = NT_STATUS_OK;
        } else if (!NT_STATUS_IS_OK(status)) {
                if (db_ctx) {
                        error_string
                                = talloc_asprintf(cred,
                                                  "Failed to fetch machine account password for %s from both "
                                                  "secrets.ldb (%s) and from %s",
                                                  domain,
                                                  error_string == NULL ? "error" : error_string,
                                                  dbwrap_name(db_ctx));
                } else {
                        char *secrets_tdb_path;

                        secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
                                                                 lp_ctx,
                                                                 "secrets");
                        if (secrets_tdb_path == NULL) {
                                return NT_STATUS_NO_MEMORY;
                        }

                        error_string = talloc_asprintf(cred,
                                                       "Failed to fetch machine account password from "
                                                       "secrets.ldb: %s and failed to open %s",
                                                       error_string == NULL ? "error" : error_string,
                                                       secrets_tdb_path);
                }
                DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
                          error_string == NULL ? "error" : error_string,
                          nt_errstr(status)));
                /* set anonymous as the fallback, if the machine account won't work */
                cli_credentials_set_anonymous(cred);
        }

        TALLOC_FREE(tmp_ctx);
        return status;
}

/**
 * Fill in credentials for a particular principal, from the secrets database.
 *
 * @param cred Credentials structure to fill in
 * @retval NTSTATUS error detailing any failure
 */
_PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
                                              struct loadparm_context *lp_ctx,
                                              const char *serviceprincipal)
{
        NTSTATUS status;
        char *filter;
        char *error_string = NULL;
        /* Bleh, nasty recursion issues: We are setting a machine
         * account here, so we don't want the 'pending' flag around
         * any more */
        cred->machine_account_pending = false;
        filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
                                 cli_credentials_get_realm(cred),
                                 cli_credentials_get_domain(cred),
                                 serviceprincipal);
        status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
                                             SECRETS_PRINCIPALS_DN, filter,
                                             0, NULL, &error_string);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
                          serviceprincipal, nt_errstr(status),
                          error_string ? error_string : "<no error>"));
        }
        return status;
}

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