view runopts.h @ 1930:299f4f19ba19

Add /usr/sbin and /sbin to default root PATH When dropbear is used in a very restricted environment (such as in a initrd), the default user shell is often also very restricted and doesn't take care of setting the PATH so the user ends up with the PATH set by dropbear. Unfortunately, dropbear always sets "/usr/bin:/bin" as default PATH even for the root user which should have /usr/sbin and /sbin too. For a concrete instance of this problem, see the "Remote Unlocking" section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/ It speaks of a bug in the initramfs script because it's written "blkid" instead of "/sbin/blkid"... this is just because the scripts from the initramfs do not expect to have a PATH without the sbin directories and because dropbear is not setting the PATH appropriately for the root user. I'm thus suggesting to use the attached patch to fix this misbehaviour (I did not test it, but it's easy enough). It might seem anecdotic but multiple Kali users have been bitten by this. From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
author Raphael Hertzog <hertzog@debian.org>
date Mon, 09 Jul 2018 16:27:53 +0200
parents bfd0f3248df3
children 4528afefe45d
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/*
 * Dropbear - a SSH2 server
 * 
 * Copyright (c) 2002,2003 Matt Johnston
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

#ifndef DROPBEAR_RUNOPTS_H_
#define DROPBEAR_RUNOPTS_H_

#include "includes.h"
#include "signkey.h"
#include "buffer.h"
#include "auth.h"
#include "tcpfwd.h"

typedef struct runopts {

#if DROPBEAR_SVR_REMOTETCPFWD || DROPBEAR_CLI_LOCALTCPFWD \
    || DROPBEAR_CLI_REMOTETCPFWD
	int listen_fwd_all;
#endif
	unsigned int recv_window;
	time_t keepalive_secs; /* Time between sending keepalives. 0 is off */
	time_t idle_timeout_secs; /* Exit if no traffic is sent/received in this time */
	int usingsyslog;

#ifndef DISABLE_ZLIB
	/* TODO: add a commandline flag. Currently this is on by default if compression
	 * is compiled in, but disabled for a client's non-final multihop stages. (The
	 * intermediate stages are compressed streams, so are uncompressible. */
	enum {
		DROPBEAR_COMPRESS_DELAYED, /* Server only */
		DROPBEAR_COMPRESS_ON,
		DROPBEAR_COMPRESS_OFF,
	} compress_mode;
#endif

#if DROPBEAR_USER_ALGO_LIST
	char *cipher_list;
	char *mac_list;
#endif

} runopts;

extern runopts opts;

int readhostkey(const char * filename, sign_key * hostkey, 
	enum signkey_type *type);
void load_all_hostkeys(void);

typedef struct svr_runopts {

	char * bannerfile;

	int forkbg;

	/* ports and addresses are arrays of the portcount
	listening ports. strings are malloced. */
	char *ports[DROPBEAR_MAX_PORTS];
	unsigned int portcount;
	char *addresses[DROPBEAR_MAX_PORTS];

	int inetdmode;
	/* Hidden "-2" flag indicates it's re-executing itself */
	int reexec_child;

	/* Flags indicating whether to use ipv4 and ipv6 */
	/* not used yet
	int ipv4;
	int ipv6;
	*/

#if DO_MOTD
	/* whether to print the MOTD */
	int domotd;
#endif
	int norootlogin;

#ifdef HAVE_GETGROUPLIST
	/* restrict_group is the group name if group restriction was enabled, 
	NULL otherwise */
	char *restrict_group;
	/* restrict_group_gid is only valid if restrict_group is set */
	gid_t restrict_group_gid;
#endif

	int noauthpass;
	int norootpass;
	int allowblankpass;
	unsigned int maxauthtries;

#if DROPBEAR_SVR_REMOTETCPFWD
	int noremotetcp;
#endif
#if DROPBEAR_SVR_LOCALTCPFWD
	int nolocaltcp;
#endif

	sign_key *hostkey;

	int delay_hostkey;

	char *hostkey_files[MAX_HOSTKEYS];
	int num_hostkey_files;

	buffer * banner;
	char * pidfile;

	char * forced_command;

#if DROPBEAR_PLUGIN 
        char *pubkey_plugin;
        char *pubkey_plugin_options;
#endif

	int pass_on_env;

} svr_runopts;

extern svr_runopts svr_opts;

void svr_getopts(int argc, char ** argv);
void loadhostkeys(void);

typedef struct cli_runopts {

	char *progname;
	char *remotehost;
	const char *remoteport;

	char *own_user;
	char *username;

	char *cmd;
	int wantpty;
	int always_accept_key;
	int no_hostkey_check;
	int no_cmd;
	int quiet;
	int backgrounded;
	int is_subsystem;
#if DROPBEAR_CLI_PUBKEY_AUTH
	m_list *privkeys; /* Keys to use for public-key auth */
#endif
#if DROPBEAR_CLI_ANYTCPFWD
	int exit_on_fwd_failure;
#endif
	int disable_trivial_auth;
#if DROPBEAR_CLI_REMOTETCPFWD
	m_list * remotefwds;
#endif
#if DROPBEAR_CLI_LOCALTCPFWD
	m_list * localfwds;
#endif
#if DROPBEAR_CLI_AGENTFWD
	int agent_fwd;
	int agent_keys_loaded; /* whether pubkeys has been populated with a 
							  list of keys held by the agent */
	int agent_fd; /* The agent fd is only set during authentication. Forwarded
	                 agent sessions have their own file descriptors */
#endif

#if DROPBEAR_CLI_NETCAT
	char *netcat_host;
	unsigned int netcat_port;
#endif
#if DROPBEAR_CLI_PROXYCMD
	char *proxycmd;
#endif
	char *bind_address;
	char *bind_port;
} cli_runopts;

extern cli_runopts cli_opts;
void cli_getopts(int argc, char ** argv);

#if DROPBEAR_USER_ALGO_LIST
void parse_ciphers_macs(void);
#endif

void print_version(void);
void parse_recv_window(const char* recv_window_arg);

#endif /* DROPBEAR_RUNOPTS_H_ */