/*
 * session handling routines
 *
 * Copyright (C) 2014-2018 LastPass.
 *
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 *
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 *
 * See LICENSE.OpenSSL for more details regarding this exception.
 */
#include "xml.h"
#include "config.h"
#include "util.h"
#include "cipher.h"
#include "agent.h"
#include "upload-queue.h"
#include <sys/mman.h>
#include <string.h>

struct session *session_new(void)
{
	return new0(struct session, 1);
}
void session_free(struct session *session)
{
	if (!session)
		return;
	free(session->uid);
	free(session->sessionid);
	free(session->token);
	free(session->private_key.key);
	free(session->server);
	free(session);
}
bool session_is_valid(struct session *session)
{
	return session && session->uid && session->sessionid && session->token;
}

void session_set_private_key(struct session *session, unsigned const char key[KDF_HASH_LEN], const char *key_hex)
{
	cipher_decrypt_private_key(key_hex, key, &session->private_key);
}

void session_save(struct session *session, unsigned const char key[KDF_HASH_LEN])
{
	config_write_encrypted_string("session_uid", session->uid, key);
	config_write_encrypted_string("session_sessionid", session->sessionid, key);
	config_write_encrypted_string("session_token", session->token, key);
	config_write_encrypted_buffer("session_privatekey", (char *)session->private_key.key, session->private_key.len, key);

	/*
	 * existing sessions may not have a server yet; they will fall back
	 * to lastpass.com.
	 */
	if (session->server)
		config_write_string("session_server", session->server);
}
struct session *session_load(unsigned const char key[KDF_HASH_LEN])
{
	struct session *session = session_new();
	session->uid = config_read_encrypted_string("session_uid", key);
	session->sessionid = config_read_encrypted_string("session_sessionid", key);
	session->token = config_read_encrypted_string("session_token", key);
	session->server = config_read_string("session_server");
	session->private_key.len = config_read_encrypted_buffer("session_privatekey", &session->private_key.key, key);
	mlock(session->private_key.key, session->private_key.len);

	if (session_is_valid(session))
		return session;
	else {
		session_free(session);
		return NULL;
	}
}

void session_kill()
{
	config_unlink("verify");
	config_unlink("username");
	config_unlink("session_sessionid");
	config_unlink("iterations");

	config_unlink("blob");
	config_unlink("session_token");
	config_unlink("session_uid");
	config_unlink("session_privatekey");
	config_unlink("session_server");
	config_unlink("plaintext_key");
	agent_kill();
	upload_queue_kill();
}