source: trunk/server/source4/kdc/mit_samba.c

/*
   MIT-Samba4 library

   Copyright (c) 2010, Simo Sorce <idra@samba.org>

   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/>.
 */

#define TEVENT_DEPRECATED 1

#include "includes.h"
#include "param/param.h"
#include "dsdb/samdb/samdb.h"
#include "system/kerberos.h"
#include <hdb.h>
#include "mit_samba_interface.h"
#include "auth/kerberos/kerberos.h"
#include "kdc/samba_kdc.h"
#include "kdc/pac-glue.h"
#include "kdc/db-glue.h"

const int mit_samba_interface_version = MIT_SAMBA_INTERFACE_VERSION;

struct mit_samba_context {
        struct auth_session_info *session_info;

        /* for compat with hdb plugin common code */
        krb5_context context;
        struct samba_kdc_db_context *db_ctx;
};

static void mit_samba_context_free(struct mit_samba_context *ctx)
{
        /* free heimdal's krb5_context */
        if (ctx->context) {
                krb5_free_context(ctx->context);
        }

        /* then free everything else */
        talloc_free(ctx);
}

static int mit_samba_context_init(struct mit_samba_context **_ctx)
{
        NTSTATUS status;
        struct mit_samba_context *ctx;
        const char *s4_conf_file;
        int ret;
        struct samba_kdc_base_context base_ctx;

        ctx = talloc(NULL, struct mit_samba_context);
        if (!ctx) {
                ret = ENOMEM;
                goto done;
        }

        base_ctx.ev_ctx = tevent_context_init(ctx);
        if (!base_ctx.ev_ctx) {
                ret = ENOMEM;
                goto done;
        }
        tevent_loop_allow_nesting(base_ctx.ev_ctx);
        base_ctx.lp_ctx = loadparm_init_global(false);
        if (!base_ctx.lp_ctx) {
                ret = ENOMEM;
                goto done;
        }
        /* init s4 configuration */
        s4_conf_file = lpcfg_configfile(base_ctx.lp_ctx);
        if (s4_conf_file) {
                lpcfg_load(base_ctx.lp_ctx, s4_conf_file);
        } else {
                lpcfg_load_default(base_ctx.lp_ctx);
        }

        status = samba_kdc_setup_db_ctx(ctx, &base_ctx, &ctx->db_ctx);
        if (!NT_STATUS_IS_OK(status)) {
                ret = EINVAL;
                goto done;
        }

        /* init heimdal's krb_context and log facilities */
        ret = smb_krb5_init_context_basic(ctx,
                                          ctx->db_ctx->lp_ctx,
                                          &ctx->context);
        if (ret) {
                goto done;
        }

        ret = 0;

done:
        if (ret) {
                mit_samba_context_free(ctx);
        } else {
                *_ctx = ctx;
        }
        return ret;
}


static int mit_samba_get_principal(struct mit_samba_context *ctx,
                                   char *principal_string,
                                   unsigned int flags,
                                   hdb_entry_ex **_hentry)
{
        krb5_principal principal;
        hdb_entry_ex *hentry;
        int ret;

        hentry = talloc(ctx, hdb_entry_ex);
        if (!hentry) {
                return ENOMEM;
        }

        ret = krb5_parse_name(ctx->context, principal_string, &principal);
        if (ret) {
                goto done;
        }

        ret = samba_kdc_fetch(ctx->context, ctx->db_ctx,
                              principal, flags, 0, hentry);

        krb5_free_principal(ctx->context, principal);

done:
        if (ret) {
                talloc_free(hentry);
        } else {
                talloc_steal(hentry->ctx, hentry);
                *_hentry = hentry;
        }
        return ret;
}

static int mit_samba_get_firstkey(struct mit_samba_context *ctx,
                                  hdb_entry_ex **_hentry)
{
        hdb_entry_ex *hentry;
        int ret;

        hentry = talloc(ctx, hdb_entry_ex);
        if (!hentry) {
                return ENOMEM;
        }

        ret = samba_kdc_firstkey(ctx->context, ctx->db_ctx, hentry);

        if (ret) {
                talloc_free(hentry);
        } else {
                talloc_steal(hentry->ctx, hentry);
                *_hentry = hentry;
        }
        return ret;
}

static int mit_samba_get_nextkey(struct mit_samba_context *ctx,
                                 hdb_entry_ex **_hentry)
{
        hdb_entry_ex *hentry;
        int ret;

        hentry = talloc(ctx, hdb_entry_ex);
        if (!hentry) {
                return ENOMEM;
        }

        ret = samba_kdc_nextkey(ctx->context, ctx->db_ctx, hentry);

        if (ret) {
                talloc_free(hentry);
        } else {
                talloc_steal(hentry->ctx, hentry);
                *_hentry = hentry;
        }
        return ret;
}

static int mit_samba_get_pac_data(struct mit_samba_context *ctx,
                                  hdb_entry_ex *client,
                                  DATA_BLOB *data)
{
        TALLOC_CTX *tmp_ctx;
        DATA_BLOB *pac_blob;
        NTSTATUS nt_status;

        tmp_ctx = talloc_named(ctx, 0, "mit_samba_get_pac_data context");
        if (!tmp_ctx) {
                return ENOMEM;
        }

        nt_status = samba_kdc_get_pac_blob(tmp_ctx, client, &pac_blob);
        if (!NT_STATUS_IS_OK(nt_status)) {
                talloc_free(tmp_ctx);
                return EINVAL;
        }

        data->data = (uint8_t *)malloc(pac_blob->length);
        if (!data->data) {
                talloc_free(tmp_ctx);
                return ENOMEM;
        }
        memcpy(data->data, pac_blob->data, pac_blob->length);
        data->length = pac_blob->length;

        talloc_free(tmp_ctx);
        return 0;
}

static int mit_samba_update_pac_data(struct mit_samba_context *ctx,
                                     hdb_entry_ex *client,
                                     DATA_BLOB *pac_data,
                                     DATA_BLOB *logon_data)
{
        TALLOC_CTX *tmp_ctx;
        DATA_BLOB *logon_blob;
        krb5_error_code code;
        NTSTATUS nt_status;
        krb5_pac pac = NULL;
        int ret;

        /* The user account may be set not to want the PAC */
        if (client && !samba_princ_needs_pac(client)) {
                return EINVAL;
        }

        tmp_ctx = talloc_named(ctx, 0, "mit_samba_update_pac_data context");
        if (!tmp_ctx) {
                return ENOMEM;
        }

        logon_blob = talloc_zero(tmp_ctx, DATA_BLOB);
        if (!logon_blob) {
                ret = ENOMEM;
                goto done;
        }

        code = krb5_pac_parse(ctx->context,
                              pac_data->data, pac_data->length, &pac);
        if (code) {
                ret = EINVAL;
                goto done;
        }

        nt_status = samba_kdc_update_pac_blob(tmp_ctx, ctx->context,
                                              &pac, logon_blob);
        if (!NT_STATUS_IS_OK(nt_status)) {
                DEBUG(0, ("Building PAC failed: %s\n",
                          nt_errstr(nt_status)));
                ret = EINVAL;
                goto done;
        }

        logon_data->data = (uint8_t *)malloc(logon_blob->length);
        if (!logon_data->data) {
                ret = ENOMEM;
                goto done;
        }
        memcpy(logon_data->data, logon_blob->data, logon_blob->length);
        logon_data->length = logon_blob->length;

        ret = 0;

done:
        if (pac) krb5_pac_free(ctx->context, pac);
        talloc_free(tmp_ctx);
        return ret;
}

static int mit_samba_check_client_access(struct mit_samba_context *ctx,
                                         hdb_entry_ex *client,
                                         const char *client_name,
                                         hdb_entry_ex *server,
                                         const char *server_name,
                                         const char *netbios_name,
                                         bool password_change,
                                         DATA_BLOB *e_data)
{
        struct samba_kdc_entry *kdc_entry;
        NTSTATUS nt_status;

        kdc_entry = talloc_get_type(client->ctx, struct samba_kdc_entry);

        nt_status = samba_kdc_check_client_access(kdc_entry,
                                                  client_name,
                                                  netbios_name,
                                                  password_change);

        if (!NT_STATUS_IS_OK(nt_status)) {
                if (NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_MEMORY)) {
                        return ENOMEM;
                }

                samba_kdc_build_edata_reply(nt_status, e_data);

                return samba_kdc_map_policy_err(nt_status);
        }

        return 0;
}

static int mit_samba_check_s4u2proxy(struct mit_samba_context *ctx,
                                     hdb_entry_ex *entry,
                                     const char *target_name,
                                     bool is_nt_enterprise_name)
{
        krb5_principal target_principal;
        int flags = 0;
        int ret;

        if (is_nt_enterprise_name) {
                flags = KRB5_PRINCIPAL_PARSE_ENTERPRISE;
        }

        ret = krb5_parse_name_flags(ctx->context, target_name,
                                    flags, &target_principal);
        if (ret) {
                return ret;
        }

        ret = samba_kdc_check_identical_client_and_server(ctx->context,
                                                          ctx->db_ctx,
                                                          entry,
                                                          target_principal);

        krb5_free_principal(ctx->context, target_principal);

        return ret;
}

struct mit_samba_function_table mit_samba_function_table = {
        mit_samba_context_init,
        mit_samba_context_free,
        mit_samba_get_principal,
        mit_samba_get_firstkey,
        mit_samba_get_nextkey,
        mit_samba_get_pac_data,
        mit_samba_update_pac_data,
        mit_samba_check_client_access,
        mit_samba_check_s4u2proxy
};