view default_options.h @ 1517:7c7c5326ad73

clean up some default options - move hmac-sha2-512, hmac-md5, twofish_ctr to sysoptions.h, off by default - try and improve text for KEX methods
author Matt Johnston <matt@ucc.asn.au>
date Sun, 18 Feb 2018 22:27:51 +0800
parents 6c16a05023aa
children 2f4d52b1334e
line wrap: on
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/*
 > > > Do not edit this file (default_options.h) < < <
Generated from ../default_options.h.in
Local customisation goes in localoptions.h
*/


#ifndef DROPBEAR_DEFAULT_OPTIONS_H_
#define DROPBEAR_DEFAULT_OPTIONS_H_
/*
                     > > > Read This < < <

default_options.h.in  documents compile-time options, and provides default values.

Local customisation should be added to localoptions.h which is
used if it exists. Options defined there will override any options in this
file.

Options can also be defined with -DDROPBEAR_XXX in Makefile CFLAGS

IMPORTANT: Many options will require "make clean" after changes */

#ifndef DROPBEAR_DEFPORT
#define DROPBEAR_DEFPORT "22"
#endif

/* Listen on all interfaces */
#ifndef DROPBEAR_DEFADDRESS
#define DROPBEAR_DEFADDRESS ""
#endif

/* Default hostkey paths - these can be specified on the command line */
#ifndef DSS_PRIV_FILENAME
#define DSS_PRIV_FILENAME "/etc/dropbear/dropbear_dss_host_key"
#endif
#ifndef RSA_PRIV_FILENAME
#define RSA_PRIV_FILENAME "/etc/dropbear/dropbear_rsa_host_key"
#endif
#ifndef ECDSA_PRIV_FILENAME
#define ECDSA_PRIV_FILENAME "/etc/dropbear/dropbear_ecdsa_host_key"
#endif

/* Set NON_INETD_MODE if you require daemon functionality (ie Dropbear listens
 * on chosen ports and keeps accepting connections. This is the default.
 *
 * Set INETD_MODE if you want to be able to run Dropbear with inetd (or
 * similar), where it will use stdin/stdout for connections, and each process
 * lasts for a single connection. Dropbear should be invoked with the -i flag
 * for inetd, and can only accept IPv4 connections.
 *
 * Both of these flags can be defined at once, don't compile without at least
 * one of them. */
#ifndef NON_INETD_MODE
#define NON_INETD_MODE 1
#endif
#ifndef INETD_MODE
#define INETD_MODE 1
#endif

/* Include verbose debug output, enabled with -v at runtime. 
 * This will add a reasonable amount to your executable size. */
#ifndef DEBUG_TRACE
#define DEBUG_TRACE 0
#endif

/* Set this if you want to use the DROPBEAR_SMALL_CODE option. This can save
several kB in binary size however will make the symmetrical ciphers and hashes
slower, perhaps by 50%. Recommended for small systems that aren't doing
much traffic. */
#ifndef DROPBEAR_SMALL_CODE
#define DROPBEAR_SMALL_CODE 1
#endif

/* Enable X11 Forwarding - server only */
#ifndef DROPBEAR_X11FWD
#define DROPBEAR_X11FWD 1
#endif

/* Enable TCP Fowarding */
/* 'Local' is "-L" style (client listening port forwarded via server)
 * 'Remote' is "-R" style (server listening port forwarded via client) */

#ifndef DROPBEAR_CLI_LOCALTCPFWD
#define DROPBEAR_CLI_LOCALTCPFWD 1
#endif
#ifndef DROPBEAR_CLI_REMOTETCPFWD
#define DROPBEAR_CLI_REMOTETCPFWD 1
#endif

#ifndef DROPBEAR_SVR_LOCALTCPFWD
#define DROPBEAR_SVR_LOCALTCPFWD 1
#endif
#ifndef DROPBEAR_SVR_REMOTETCPFWD
#define DROPBEAR_SVR_REMOTETCPFWD 1
#endif

/* Enable Authentication Agent Forwarding */
#ifndef DROPBEAR_SVR_AGENTFWD
#define DROPBEAR_SVR_AGENTFWD 1
#endif
#ifndef DROPBEAR_CLI_AGENTFWD
#define DROPBEAR_CLI_AGENTFWD 1
#endif

/* Note: Both DROPBEAR_CLI_PROXYCMD and DROPBEAR_CLI_NETCAT must be set to
 * allow multihop dbclient connections */

/* Allow using -J <proxycommand> to run the connection through a 
   pipe to a program, rather the normal TCP connection */
#ifndef DROPBEAR_CLI_PROXYCMD
#define DROPBEAR_CLI_PROXYCMD 1
#endif

/* Enable "Netcat mode" option. This will forward standard input/output
 * to a remote TCP-forwarded connection */
#ifndef DROPBEAR_CLI_NETCAT
#define DROPBEAR_CLI_NETCAT 1
#endif

/* Whether to support "-c" and "-m" flags to choose ciphers/MACs at runtime */
#ifndef DROPBEAR_USER_ALGO_LIST
#define DROPBEAR_USER_ALGO_LIST 1
#endif

/* Encryption - at least one required.
 * AES128 should be enabled, some very old implementations might only
 * support 3DES.
 * Including both AES keysize variants (128 and 256) will result in 
 * a minimal size increase */
#ifndef DROPBEAR_AES128
#define DROPBEAR_AES128 1
#endif
#ifndef DROPBEAR_3DES
#define DROPBEAR_3DES 1
#endif
#ifndef DROPBEAR_AES256
#define DROPBEAR_AES256 1
#endif
#ifndef DROPBEAR_TWOFISH256
#define DROPBEAR_TWOFISH256 1
#endif
#ifndef DROPBEAR_TWOFISH128
#define DROPBEAR_TWOFISH128 1
#endif
/* Compiling in Blowfish will add ~6kB to runtime heap memory usage */
#ifndef DROPBEAR_BLOWFISH
#define DROPBEAR_BLOWFISH 0
#endif

/* Enable CBC mode for ciphers. This has security issues though
 * is the most compatible with older SSH implementations */
#ifndef DROPBEAR_ENABLE_CBC_MODE
#define DROPBEAR_ENABLE_CBC_MODE 1
#endif

/* Enable "Counter Mode" for ciphers. This is more secure than
 * CBC mode against certain attacks. It is recommended for security
 * and forwards compatibility */
#ifndef DROPBEAR_ENABLE_CTR_MODE
#define DROPBEAR_ENABLE_CTR_MODE 1
#endif

/* Twofish counter mode is disabled by default because it 
has not been tested for interoperability with other SSH implementations.
If you test it please contact the Dropbear author */
#ifndef DROPBEAR_TWOFISH_CTR
#define DROPBEAR_TWOFISH_CTR 0
#endif

/* Message integrity. sha2-256 is recommended as a default, 
   sha1 for compatibility */
#ifndef DROPBEAR_SHA1_HMAC
#define DROPBEAR_SHA1_HMAC 1
#endif
#ifndef DROPBEAR_SHA1_96_HMAC
#define DROPBEAR_SHA1_96_HMAC 1
#endif
#ifndef DROPBEAR_SHA2_256_HMAC
#define DROPBEAR_SHA2_256_HMAC 1
#endif
/* Default is to include it if sha512 is being compiled in for ECDSA */
#ifndef DROPBEAR_SHA2_512_HMAC
#define DROPBEAR_SHA2_512_HMAC (DROPBEAR_ECDSA)
#endif

/* XXX needed for fingerprints */
#ifndef DROPBEAR_MD5_HMAC
#define DROPBEAR_MD5_HMAC 0
#endif

/* Hostkey/public key algorithms - at least one required, these are used
 * for hostkey as well as for verifying signatures with pubkey auth.
 * Removing either of these won't save very much space.
 * RSA is recommended
 * DSS may be necessary to connect to some systems though
   is not recommended for new keys */
#ifndef DROPBEAR_RSA
#define DROPBEAR_RSA 1
#endif
#ifndef DROPBEAR_DSS
#define DROPBEAR_DSS 1
#endif
/* ECDSA is significantly faster than RSA or DSS. Compiling in ECC
 * code (either ECDSA or ECDH) increases binary size - around 30kB
 * on x86-64 */
#ifndef DROPBEAR_ECDSA
#define DROPBEAR_ECDSA 1
#endif

/* RSA must be >=1024 */
#ifndef DROPBEAR_DEFAULT_RSA_SIZE
#define DROPBEAR_DEFAULT_RSA_SIZE 2048
#endif
/* DSS is always 1024 */
/* ECDSA defaults to largest size configured, usually 521 */

/* Add runtime flag "-R" to generate hostkeys as-needed when the first 
   connection using that key type occurs.
   This avoids the need to otherwise run "dropbearkey" and avoids some problems
   with badly seeded /dev/urandom when systems first boot. */
#ifndef DROPBEAR_DELAY_HOSTKEY
#define DROPBEAR_DELAY_HOSTKEY 1
#endif

/* Enable Curve25519 for key exchange. This is another elliptic
 * curve method with good security properties. Increases binary size
 * by ~8kB on x86-64 */
#ifndef DROPBEAR_CURVE25519
#define DROPBEAR_CURVE25519 1
#endif

/* Enable elliptic curve Diffie Hellman key exchange, see note about
 * ECDSA above */
#ifndef DROPBEAR_ECDH
#define DROPBEAR_ECDH 1
#endif

/* Key exchange algorithm.
 * group14_sha1 - 2048 bit, sha1
 * group14_sha256 - 2048 bit, sha2-256
 * group16 - 4096 bit, sha2-512
 * group1 - 1024 bit, sha1
 *
 * group14 is supported by most implementations.
 * group16 provides a greater strength level but is slower and increases binary size
 * group1 is too small for security though is necessary if you need 
     compatibility with some implementations such as Dropbear versions < 0.53
 */ 
#ifndef DROPBEAR_DH_GROUP1
#define DROPBEAR_DH_GROUP1 1
#endif
#ifndef DROPBEAR_DH_GROUP14_SHA1
#define DROPBEAR_DH_GROUP14_SHA1 1
#endif
#ifndef DROPBEAR_DH_GROUP14_SHA256
#define DROPBEAR_DH_GROUP14_SHA256 1
#endif
#ifndef DROPBEAR_DH_GROUP16
#define DROPBEAR_DH_GROUP16 0
#endif

/* Control the memory/performance/compression tradeoff for zlib.
 * Set windowBits=8 for least memory usage, see your system's
 * zlib.h for full details.
 * Default settings (windowBits=15) will use 256kB for compression
 * windowBits=8 will use 129kB for compression.
 * Both modes will use ~35kB for decompression (using windowBits=15 for
 * interoperability) */
#ifndef DROPBEAR_ZLIB_WINDOW_BITS
#define DROPBEAR_ZLIB_WINDOW_BITS 15 
#endif

/* Whether to do reverse DNS lookups. */
#ifndef DO_HOST_LOOKUP
#define DO_HOST_LOOKUP 0
#endif

/* Whether to print the message of the day (MOTD). */
#ifndef DO_MOTD
#define DO_MOTD 0
#endif

/* The MOTD file path */
#ifndef MOTD_FILENAME
#define MOTD_FILENAME "/etc/motd"
#endif

/* Authentication Types - at least one required.
   RFC Draft requires pubkey auth, and recommends password */
#ifndef DROPBEAR_SVR_PASSWORD_AUTH
#define DROPBEAR_SVR_PASSWORD_AUTH 1
#endif

/* Note: PAM auth is quite simple and only works for PAM modules which just do
 * a simple "Login: " "Password: " (you can edit the strings in svr-authpam.c).
 * It's useful for systems like OS X where standard password crypts don't work
 * but there's an interface via a PAM module. It won't work for more complex
 * PAM challenge/response.
 * You can't enable both PASSWORD and PAM. */
#ifndef DROPBEAR_SVR_PAM_AUTH
#define DROPBEAR_SVR_PAM_AUTH 0
#endif

/* ~/.ssh/authorized_keys authentication */
#ifndef DROPBEAR_SVR_PUBKEY_AUTH
#define DROPBEAR_SVR_PUBKEY_AUTH 1
#endif

/* Whether to take public key options in 
 * authorized_keys file into account */
#ifndef DROPBEAR_SVR_PUBKEY_OPTIONS
#define DROPBEAR_SVR_PUBKEY_OPTIONS 1
#endif

/* Client authentication options */
#ifndef DROPBEAR_CLI_PASSWORD_AUTH
#define DROPBEAR_CLI_PASSWORD_AUTH 1
#endif
#ifndef DROPBEAR_CLI_PUBKEY_AUTH
#define DROPBEAR_CLI_PUBKEY_AUTH 1
#endif

/* A default argument for dbclient -i <privatekey>. 
Homedir is prepended unless path begins with / */
#ifndef DROPBEAR_DEFAULT_CLI_AUTHKEY
#define DROPBEAR_DEFAULT_CLI_AUTHKEY ".ssh/id_dropbear"
#endif

/* Allow specifying the password for dbclient via the DROPBEAR_PASSWORD
 * environment variable. */
#ifndef DROPBEAR_USE_PASSWORD_ENV
#define DROPBEAR_USE_PASSWORD_ENV 1
#endif

/* Define this (as well as DROPBEAR_CLI_PASSWORD_AUTH) to allow the use of
 * a helper program for the ssh client. The helper program should be
 * specified in the SSH_ASKPASS environment variable, and dbclient
 * should be run with DISPLAY set and no tty. The program should
 * return the password on standard output */
#ifndef DROPBEAR_CLI_ASKPASS_HELPER
#define DROPBEAR_CLI_ASKPASS_HELPER 0
#endif

/* Save a network roundtrip by sendng a real auth request immediately after
 * sending a query for the available methods. This is not yet enabled by default 
 since it could cause problems with non-compliant servers */ 
 #define DROPBEAR_CLI_IMMEDIATE_AUTH 0

/* Set this to use PRNGD or EGD instead of /dev/urandom */
#ifndef DROPBEAR_USE_PRNGD
#define DROPBEAR_USE_PRNGD 0
#endif
#ifndef DROPBEAR_PRNGD_SOCKET
#define DROPBEAR_PRNGD_SOCKET "/var/run/dropbear-rng"
#endif

/* Specify the number of clients we will allow to be connected but
 * not yet authenticated. After this limit, connections are rejected */
/* The first setting is per-IP, to avoid denial of service */
#ifndef MAX_UNAUTH_PER_IP
#define MAX_UNAUTH_PER_IP 5
#endif

/* And then a global limit to avoid chewing memory if connections 
 * come from many IPs */
#ifndef MAX_UNAUTH_CLIENTS
#define MAX_UNAUTH_CLIENTS 30
#endif

/* Default maximum number of failed authentication tries (server option) */
/* -T server option overrides */
#ifndef MAX_AUTH_TRIES
#define MAX_AUTH_TRIES 10
#endif

/* The default file to store the daemon's process ID, for shutdown
   scripts etc. This can be overridden with the -P flag */
#ifndef DROPBEAR_PIDFILE
#define DROPBEAR_PIDFILE "/var/run/dropbear.pid"
#endif

/* The command to invoke for xauth when using X11 forwarding.
 * "-q" for quiet */
#ifndef XAUTH_COMMAND
#define XAUTH_COMMAND "/usr/bin/xauth -q"
#endif


/* if you want to enable running an sftp server (such as the one included with
 * OpenSSH), set the path below and set DROPBEAR_SFTPSERVER. 
 * The sftp-server program is not provided by Dropbear itself */
#ifndef DROPBEAR_SFTPSERVER
#define DROPBEAR_SFTPSERVER 1
#endif
#ifndef SFTPSERVER_PATH
#define SFTPSERVER_PATH "/usr/libexec/sftp-server"
#endif

/* This is used by the scp binary when used as a client binary. If you're
 * not using the Dropbear client, you'll need to change it */
#ifndef DROPBEAR_PATH_SSH_PROGRAM
#define DROPBEAR_PATH_SSH_PROGRAM "/usr/bin/dbclient"
#endif

/* Whether to log commands executed by a client. This only logs the 
 * (single) command sent to the server, not what a user did in a 
 * shell/sftp session etc. */
#ifndef LOG_COMMANDS
#define LOG_COMMANDS 0
#endif

/* Window size limits. These tend to be a trade-off between memory
   usage and network performance: */
/* Size of the network receive window. This amount of memory is allocated
   as a per-channel receive buffer. Increasing this value can make a
   significant difference to network performance. 24kB was empirically
   chosen for a 100mbit ethernet network. The value can be altered at
   runtime with the -W argument. */
#ifndef DEFAULT_RECV_WINDOW
#define DEFAULT_RECV_WINDOW 24576
#endif
/* Maximum size of a received SSH data packet - this _MUST_ be >= 32768
   in order to interoperate with other implementations */
#ifndef RECV_MAX_PAYLOAD_LEN
#define RECV_MAX_PAYLOAD_LEN 32768
#endif
/* Maximum size of a transmitted data packet - this can be any value,
   though increasing it may not make a significant difference. */
#ifndef TRANS_MAX_PAYLOAD_LEN
#define TRANS_MAX_PAYLOAD_LEN 16384
#endif

/* Ensure that data is transmitted every KEEPALIVE seconds. This can
be overridden at runtime with -K. 0 disables keepalives */
#ifndef DEFAULT_KEEPALIVE
#define DEFAULT_KEEPALIVE 0
#endif

/* If this many KEEPALIVES are sent with no packets received from the
other side, exit. Not run-time configurable - if you have a need
for runtime configuration please mail the Dropbear list */
#ifndef DEFAULT_KEEPALIVE_LIMIT
#define DEFAULT_KEEPALIVE_LIMIT 3
#endif

/* Ensure that data is received within IDLE_TIMEOUT seconds. This can
be overridden at runtime with -I. 0 disables idle timeouts */
#ifndef DEFAULT_IDLE_TIMEOUT
#define DEFAULT_IDLE_TIMEOUT 0
#endif

/* The default path. This will often get replaced by the shell */
#ifndef DEFAULT_PATH
#define DEFAULT_PATH "/usr/bin:/bin"
#endif

#endif /* DROPBEAR_DEFAULT_OPTIONS_H_ */