/*
 * Remmina - The GTK+ Remote Desktop Client
 * Copyright (C) 2009-2011 Vic Lee
 * Copyright (C) 2014-2015 Antenore Gatta, Fabio Castelli, Giovanni Panozzo
 * Copyright (C) 2016-2019 Antenore Gatta, Giovanni Panozzo
 *
 * 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.
 *
 */

#pragma once

#include "config.h"

#ifdef HAVE_LIBSSH

#define LIBSSH_STATIC 1
#include <libssh/libssh.h>
#include <libssh/callbacks.h>
#include <libssh/sftp.h>
#include <pthread.h>
#include "remmina_file.h"
#include "rcw.h"

G_BEGIN_DECLS

/*-----------------------------------------------------------------------------*
*                           SSH Base                                          *
*-----------------------------------------------------------------------------*/

#define REMMINA_SSH(a) ((RemminaSSH*)a)

typedef struct _RemminaSSH {
	ssh_session session;
	ssh_callbacks callback;
	gboolean authenticated;

	gchar *server;
	gint port;
	gchar *user;
	gint auth;
	gchar *password;
	gchar *privkeyfile;

	gchar *charset;
	const gchar *kex_algorithms;
	gchar *ciphers;
        gchar *hostkeytypes;
        gchar *proxycommand;
        gint stricthostkeycheck;
        const gchar *compression;

	gchar *error;

	pthread_mutex_t ssh_mutex;

	gchar *passphrase;
} RemminaSSH;

gchar* remmina_ssh_identity_path(const gchar *id);

/* Auto-detect commonly used private key identities */
gchar* remmina_ssh_find_identity(void);

/* Initialize the ssh object */
gboolean remmina_ssh_init_from_file(RemminaSSH *ssh, RemminaFile *remminafile);

/* Initialize the SSH session */
gboolean remmina_ssh_init_session(RemminaSSH *ssh);

/* Authenticate SSH session */
/* -1: Require password; 0: Failed; 1: Succeeded */
gint remmina_ssh_auth(RemminaSSH *ssh, const gchar *password);

/* -1: Cancelled; 0: Failed; 1: Succeeded */
gint remmina_ssh_auth_gui(RemminaSSH *ssh, RemminaProtocolWidget *gp, RemminaFile *remminafile);

/* Error handling */
#define remmina_ssh_has_error(ssh) (((RemminaSSH*)ssh)->error != NULL)
void remmina_ssh_set_error(RemminaSSH *ssh, const gchar *fmt);
void remmina_ssh_set_application_error(RemminaSSH *ssh, const gchar *fmt, ...);

/* Converts a string to/from UTF-8, or simply duplicate it if no conversion */
gchar* remmina_ssh_convert(RemminaSSH *ssh, const gchar *from);
gchar* remmina_ssh_unconvert(RemminaSSH *ssh, const gchar *from);

void remmina_ssh_free(RemminaSSH *ssh);

/*-----------------------------------------------------------------------------*
*                           SSH Tunnel                                        *
*-----------------------------------------------------------------------------*/
typedef struct _RemminaSSHTunnel RemminaSSHTunnel;
typedef struct _RemminaSSHTunnelBuffer RemminaSSHTunnelBuffer;

typedef gboolean (*RemminaSSHTunnelCallback) (RemminaSSHTunnel*, gpointer);

enum {
	REMMINA_SSH_TUNNEL_OPEN,
	REMMINA_SSH_TUNNEL_X11,
	REMMINA_SSH_TUNNEL_XPORT,
	REMMINA_SSH_TUNNEL_REVERSE
};

struct _RemminaSSHTunnel {
	RemminaSSH ssh;

	gint tunnel_type;

	ssh_channel *channels;
	gint *sockets;
	RemminaSSHTunnelBuffer **socketbuffers;
	gint num_channels;
	gint max_channels;

	ssh_channel x11_channel;

	pthread_t thread;
	gboolean running;

	gchar *buffer;
	gint buffer_len;
	ssh_channel *channels_out;

	gint server_sock;
	gchar *dest;
	gint port;
	gint localport;

	gint remotedisplay;
	gboolean bindlocalhost;
	gchar *localdisplay;

	RemminaSSHTunnelCallback init_func;
	RemminaSSHTunnelCallback connect_func;
	RemminaSSHTunnelCallback disconnect_func;
	gpointer callback_data;
};

/* Create a new SSH Tunnel session and connects to the SSH server */
RemminaSSHTunnel* remmina_ssh_tunnel_new_from_file(RemminaFile *remminafile);

/* Open the tunnel. A new thread will be started and listen on a local port.
 * dest: The host:port of the remote destination
 * local_port: The listening local port for the tunnel
 */
gboolean remmina_ssh_tunnel_open(RemminaSSHTunnel *tunnel, const gchar *host, gint port, gint local_port);

/* Cancel accepting any incoming tunnel request.
 * Typically called after the connection has already been establish.
 */
void remmina_ssh_tunnel_cancel_accept(RemminaSSHTunnel *tunnel);

/* Accept the X11 tunnel. A new thread will be started and connect to local display.
 * cmd: The remote X11 application to be executed
 */
gboolean remmina_ssh_tunnel_x11(RemminaSSHTunnel *tunnel, const gchar *cmd);

/* start X Port Forwarding */
gboolean remmina_ssh_tunnel_xport(RemminaSSHTunnel *tunnel, gboolean bindlocalhost);

/* start reverse tunnel. A new thread will be started and waiting for incoming connection.
 * port: the port listening on the remote server side.
 * local_port: the port listening on the local side. When connection on the server side comes
 *             in, it will connect to the local port and create the tunnel. The caller should
 *             start listening on the local port before calling it or in connect_func callback.
 */
gboolean remmina_ssh_tunnel_reverse(RemminaSSHTunnel *tunnel, gint port, gint local_port);

/* Tells if the tunnel is terminated after start */
gboolean remmina_ssh_tunnel_terminated(RemminaSSHTunnel *tunnel);

/* Free the tunnel */
void remmina_ssh_tunnel_free(RemminaSSHTunnel *tunnel);

/*-----------------------------------------------------------------------------*
*                           SSH sFTP                                          *
*-----------------------------------------------------------------------------*/

typedef struct _RemminaSFTP {
	RemminaSSH ssh;

	sftp_session sftp_sess;
} RemminaSFTP;

/* Create a new SFTP session object from RemminaFile */
RemminaSFTP* remmina_sftp_new_from_file(RemminaFile *remminafile);

/* Create a new SFTP session object from existing SSH session */
RemminaSFTP* remmina_sftp_new_from_ssh(RemminaSSH *ssh);

/* open the SFTP session, assuming the session already authenticated */
gboolean remmina_sftp_open(RemminaSFTP *sftp);

/* Free the SFTP session */
void remmina_sftp_free(RemminaSFTP *sftp);

/*-----------------------------------------------------------------------------*
*                           SSH Shell                                         *
*-----------------------------------------------------------------------------*/
typedef void (*RemminaSSHExitFunc) (gpointer data);

typedef struct _RemminaSSHShell {
	RemminaSSH ssh;

	gint master;
	gint slave;
	gchar *exec;
	pthread_t thread;
	ssh_channel channel;
	gboolean closed;
	RemminaSSHExitFunc exit_callback;
	gpointer user_data;
} RemminaSSHShell;

/* Create a new SSH Shell session object from RemminaFile */
RemminaSSHShell* remmina_ssh_shell_new_from_file(RemminaFile *remminafile);

/* Create a new SSH Shell session object from existing SSH session */
RemminaSSHShell* remmina_ssh_shell_new_from_ssh(RemminaSSH *ssh);

/* open the SSH Shell, assuming the session already authenticated */
gboolean remmina_ssh_shell_open(RemminaSSHShell *shell, RemminaSSHExitFunc exit_callback, gpointer data);

/* Change the SSH Shell terminal size */
void remmina_ssh_shell_set_size(RemminaSSHShell *shell, gint columns, gint rows);

/* Free the SFTP session */
void remmina_ssh_shell_free(RemminaSSHShell *shell);

G_END_DECLS

#else

#define RemminaSSH void
#define RemminaSSHTunnel void
#define RemminaSFTP void
#define RemminaSSHShell void
typedef void (*RemminaSSHTunnelCallback)(void);

#endif /* HAVE_LIBSSH */


