#ifndef DROPBEAR_DEFAULT_OPTIONS_H_ #define DROPBEAR_DEFAULT_OPTIONS_H_ /* > > > Read This < < < default_options.h.in (this file) 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 (#ifndef guards added by ifndef_wrapper.sh). 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 /* Setting this disables the fast exptmod bignum code. It saves ~5kB, but is * perhaps 20% slower for pubkey operations (it is probably worth experimenting * if you want to use this) */ /*#define NO_FAST_EXPTMOD*/ /* 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 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 ENABLE_USER_ALGO_LIST #define ENABLE_USER_ALGO_LIST 1 #endif /* Encryption - at least one required. * Protocol RFC requires 3DES and recommends AES128 for interoperability. * Including multiple keysize variants the same cipher * (eg AES256 as well as AES128) 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 /* Compiling in Blowfish will add ~6kB to runtime heap memory usage */ /*#define DROPBEAR_BLOWFISH*/ #ifndef DROPBEAR_TWOFISH256 #define DROPBEAR_TWOFISH256 1 #endif #ifndef DROPBEAR_TWOFISH128 #define DROPBEAR_TWOFISH128 1 #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 normal * 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 is 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 */ /* 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. */ /* This requires crypt() */ #ifdef HAVE_CRYPT #ifndef DROPBEAR_SVR_PASSWORD_AUTH #define DROPBEAR_SVR_PASSWORD_AUTH 1 #endif #else #ifndef DROPBEAR_SVR_PASSWORD_AUTH #define DROPBEAR_SVR_PASSWORD_AUTH 0 #endif #endif /* PAM requires ./configure --enable-pam */ #ifndef DROPBEAR_SVR_PAM_AUTH #define DROPBEAR_SVR_PAM_AUTH 0 #endif #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 /* This requires getpass. */ #ifdef HAVE_GETPASS #ifndef DROPBEAR_CLI_PASSWORD_AUTH #define DROPBEAR_CLI_PASSWORD_AUTH 1 #endif #ifndef DROPBEAR_CLI_INTERACT_AUTH #define DROPBEAR_CLI_INTERACT_AUTH 1 #endif #endif #ifndef DROPBEAR_CLI_PUBKEY_AUTH #define DROPBEAR_CLI_PUBKEY_AUTH 1 #endif /* A default argument for dbclient -i . Homedir is prepended unless path begins with / */ #ifndef DROPBEAR_DEFAULT_CLI_AUTHKEY #define DROPBEAR_DEFAULT_CLI_AUTHKEY ".ssh/id_dropbear" #endif /* This variable can be used to set a password for client * authentication on the commandline. Beware of platforms * that don't protect environment variables of processes etc. Also * note that it will be provided for all "hidden" client-interactive * style prompts - if you want something more sophisticated, use * SSH_ASKPASS instead. Comment out this var to remove this functionality.*/ #ifndef DROPBEAR_PASSWORD_ENV #define DROPBEAR_PASSWORD_ENV "DROPBEAR_PASSWORD" #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. It is at the expense of < 100 * bytes of extra network traffic. This is not yet enabled by default since it * could cause problems with non-compliant servers */ #ifndef DROPBEAR_CLI_IMMEDIATE_AUTH #define DROPBEAR_CLI_IMMEDIATE_AUTH 0 #endif /* Source for randomness. This must be able to provide hundreds of bytes per SSH * connection without blocking. In addition /dev/random is used for seeding * rsa/dss key generation */ #ifndef DROPBEAR_URANDOM_DEV #define DROPBEAR_URANDOM_DEV "/dev/urandom" #endif /* Set this to use PRNGD or EGD instead of /dev/urandom or /dev/random */ /*#define DROPBEAR_PRNGD_SOCKET "/var/run/dropbear-rng"*/ /* 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 runtime 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. If the path isn't defined, sftp will not * be enabled */ #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_ */