/* 
   Unix SMB/CIFS implementation.
 
   Generic Authentication Interface for Samba Servers

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 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/>.
*/

/* This code sets up GENSEC in the way that all Samba servers want
 * (because they have presumed access to the sam.ldb etc */

#include "includes.h"
#include "auth/auth.h"
#include "auth/gensec/gensec.h"
#include "param/param.h"

static NTSTATUS samba_server_gensec_start_settings(TALLOC_CTX *mem_ctx,
				   struct tevent_context *event_ctx,
				   struct imessaging_context *msg_ctx,
				   struct loadparm_context *lp_ctx,
				   struct gensec_settings *settings,
				   struct cli_credentials *server_credentials,
				   const char *target_service,
				   struct gensec_security **gensec_context)
{ 
	NTSTATUS nt_status;
	struct gensec_security *gensec_ctx;
	struct auth4_context *auth_context;

	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	if (!tmp_ctx) {
		return NT_STATUS_NO_MEMORY;
	}
	
	nt_status = auth_context_create(tmp_ctx,
					event_ctx, 
					msg_ctx, 
					lp_ctx,
					&auth_context);
	
	if (!NT_STATUS_IS_OK(nt_status)) {
		DEBUG(1, ("Failed to start auth server code: %s\n", nt_errstr(nt_status)));
		talloc_free(tmp_ctx);
		return nt_status;
	}

	nt_status = gensec_server_start(tmp_ctx,
					settings,
					auth_context,
					&gensec_ctx);
	if (!NT_STATUS_IS_OK(nt_status)) {
		talloc_free(tmp_ctx);
		DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(nt_status)));
		return nt_status;
	}
	
	gensec_set_credentials(gensec_ctx, server_credentials);

	if (target_service) {
		gensec_set_target_service(gensec_ctx, target_service);
	}
	*gensec_context = talloc_steal(mem_ctx, gensec_ctx);
	talloc_free(tmp_ctx);
	return nt_status;
}

NTSTATUS samba_server_gensec_start(TALLOC_CTX *mem_ctx,
				   struct tevent_context *event_ctx,
				   struct imessaging_context *msg_ctx,
				   struct loadparm_context *lp_ctx,
				   struct cli_credentials *server_credentials,
				   const char *target_service,
				   struct gensec_security **gensec_context)
{
	struct gensec_settings *settings = NULL;
	NTSTATUS status;

	settings = lpcfg_gensec_settings(mem_ctx, lp_ctx);
	if (settings == NULL) {
		return NT_STATUS_NO_MEMORY;
	}
	status = samba_server_gensec_start_settings(mem_ctx, event_ctx,
						    msg_ctx, lp_ctx,
						    settings, server_credentials,
						    target_service,
						    gensec_context);
	if (!NT_STATUS_IS_OK(status)) {
		TALLOC_FREE(settings);
		return status;
	}

	talloc_reparent(mem_ctx, *gensec_context, settings);
	return NT_STATUS_OK;
}

NTSTATUS samba_server_gensec_krb5_start(TALLOC_CTX *mem_ctx,
					struct tevent_context *event_ctx,
					struct imessaging_context *msg_ctx,
					struct loadparm_context *lp_ctx,
					struct cli_credentials *server_credentials,
					const char *target_service,
					struct gensec_security **gensec_context)
{
	struct gensec_settings *settings = NULL;
	const struct gensec_security_ops **backends = NULL;
	size_t idx = 0;
	NTSTATUS status;

	settings = lpcfg_gensec_settings(mem_ctx, lp_ctx);
	if (settings == NULL) {
		return NT_STATUS_NO_MEMORY;
	}
	backends = talloc_zero_array(settings,
				     const struct gensec_security_ops *, 3);
	if (backends == NULL) {
			TALLOC_FREE(settings);
		return NT_STATUS_NO_MEMORY;
	}
	settings->backends = backends;

	gensec_init();

	backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_KERBEROS5);

	backends[idx++] = gensec_security_by_oid(NULL, GENSEC_OID_SPNEGO);

	status = samba_server_gensec_start_settings(mem_ctx, event_ctx,
						    msg_ctx, lp_ctx,
						    settings, server_credentials,
						    target_service,
						    gensec_context);
	if (!NT_STATUS_IS_OK(status)) {
		TALLOC_FREE(settings);
		return status;
	}

	talloc_reparent(mem_ctx, *gensec_context, settings);
	return NT_STATUS_OK;
}