3 .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
4 .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 .\" All rights reserved
7 .\" As far as I am concerned, the code I have written for this software
8 .\" can be used freely for any purpose. Any derived versions of this
9 .\" software must be clearly marked as such, and if the derived work is
10 .\" incompatible with the protocol description in the RFC file, it must be
11 .\" called by a name other than "ssh" or "Secure Shell".
13 .\" Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
14 .\" Copyright (c) 1999 Aaron Campbell. All rights reserved.
15 .\" Copyright (c) 1999 Theo de Raadt. All rights reserved.
17 .\" Redistribution and use in source and binary forms, with or without
18 .\" modification, are permitted provided that the following conditions
20 .\" 1. Redistributions of source code must retain the above copyright
21 .\" notice, this list of conditions and the following disclaimer.
22 .\" 2. Redistributions in binary form must reproduce the above copyright
23 .\" notice, this list of conditions and the following disclaimer in the
24 .\" documentation and/or other materials provided with the distribution.
26 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 .\" $OpenBSD: ssh_config.5,v 1.119 2009/02/22 23:50:57 djm Exp $
38 .Dd $Mdocdate: February 22 2009 $
43 .Nd OpenSSH SSH client configuration files
46 .Nm /etc/ssh/ssh_config
49 obtains configuration data from the following sources in
52 .Bl -enum -offset indent -compact
56 user's configuration file
59 GSSAPI configuration file
60 .Pq Pa $HOME/.ssh/config.gssapi
62 Kerberos configuration file
63 .Pq Pa $HOME/.ssh/config.krb
65 system-wide configuration file
66 .Pq Pa /etc/ssh/ssh_config
69 For each parameter, the first obtained value
71 The configuration files contain sections separated by
73 specifications, and that section is only applied for hosts that
74 match one of the patterns given in the specification.
75 The matched host name is the one given on the command line.
77 Since the first obtained value for each parameter is used, more
78 host-specific declarations should be given near the beginning of the
79 file, and general defaults at the end.
81 The configuration file has the following format:
83 Empty lines and lines starting with
86 Otherwise a line is of the format
87 .Dq keyword arguments .
88 Configuration options may be separated by whitespace or
89 optional whitespace and exactly one
91 the latter format is useful to avoid the need to quote whitespace
92 when specifying configuration options using the
99 Arguments may optionally be enclosed in double quotes
101 in order to represent arguments containing spaces.
104 keywords and their meanings are as follows (note that
105 keywords are case-insensitive and arguments are case-sensitive):
108 Restricts the following declarations (up to the next
110 keyword) to be only for those hosts that match one of the patterns
111 given after the keyword.
112 If more than one pattern is provided, they should be separated by whitespace.
115 as a pattern can be used to provide global
116 defaults for all hosts.
119 argument given on the command line (i.e. the name is not converted to
120 a canonicalized host name before matching).
124 for more information on patterns.
126 Specifies which address family to use when connecting.
136 passphrase/password querying will be disabled.
137 This option is useful in scripts and other batch jobs where no user
138 is present to supply the password.
146 Use the specified address on the local machine as the source address of
148 Only useful on systems with more than one address.
149 Note that this option does not work if
150 .Cm UsePrivilegedPort
153 .It Cm ChallengeResponseAuthentication
154 Specifies whether to use challenge-response authentication.
155 The argument to this keyword must be
162 If this flag is set to
165 will additionally check the host IP address in the
168 This allows ssh to detect if a host key changed due to DNS spoofing.
169 If the option is set to
171 the check will not be executed.
175 Specifies the cipher to use for encrypting the session
176 in protocol version 1.
184 is only supported in the
186 client for interoperability with legacy protocol 1 implementations
187 that do not support the
190 Its use is strongly discouraged due to cryptographic weaknesses.
194 Specifies the ciphers allowed for protocol version 2
195 in order of preference.
196 Multiple ciphers must be comma-separated.
197 The supported ciphers are
212 .Bd -literal -offset 3n
213 aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,
214 aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,
217 .It Cm ClearAllForwardings
218 Specifies that all local, remote, and dynamic port forwardings
219 specified in the configuration files or on the command line be
221 This option is primarily useful when used from the
223 command line to clear port forwardings set in
224 configuration files, and is automatically set by
235 Specifies whether to use compression.
242 .It Cm CompressionLevel
243 Specifies the compression level to use if compression is enabled.
244 The argument must be an integer from 1 (fast) to 9 (slow, best).
245 The default level is 6, which is good for most applications.
246 The meaning of the values is the same as in
248 Note that this option applies to protocol version 1 only.
249 .It Cm ConnectionAttempts
250 Specifies the number of tries (one per second) to make before exiting.
251 The argument must be an integer.
252 This may be useful in scripts if the connection sometimes fails.
254 .It Cm ConnectTimeout
255 Specifies the timeout (in seconds) used when connecting to the
256 SSH server, instead of using the default system TCP timeout.
257 This value is used only when the target is down or really unreachable,
258 not when it refuses the connection.
260 Enables the sharing of multiple sessions over a single network connection.
264 will listen for connections on a control socket specified using the
267 Additional sessions can connect to this socket using the same
274 These sessions will try to reuse the master instance's network connection
275 rather than initiating new ones, but will fall back to connecting normally
276 if the control socket does not exist, or is not listening.
281 to listen for control connections, but require confirmation using the
283 program before they are accepted (see
289 ssh will continue without connecting to a master instance.
293 forwarding is supported over these multiplexed connections, however the
294 display and agent forwarded will be the one belonging to the master
295 connection i.e. it is not possible to forward multiple displays or agents.
297 Two additional options allow for opportunistic multiplexing: try to use a
298 master connection but fall back to creating a new one if one does not already
304 The latter requires confirmation like the
308 Specify the path to the control socket used for connection sharing as described
311 section above or the string
313 to disable connection sharing.
316 will be substituted by the local host name,
318 will be substituted by the target host name,
322 by the remote login username.
323 It is recommended that any
325 used for opportunistic connection sharing include
326 at least %h, %p, and %r.
327 This ensures that shared connections are uniquely identified.
328 .It Cm DynamicForward
329 Specifies that a TCP port on the local machine be forwarded
330 over the secure channel, and the application
331 protocol is then used to determine where to connect to from the
336 .Oo Ar bind_address : Oc Ar port .
338 IPv6 addresses can be specified by enclosing addresses in square brackets or
339 by using an alternative syntax:
340 .Oo Ar bind_address Ns / Oc Ns Ar port .
341 By default, the local port is bound in accordance with the
346 may be used to bind the connection to a specific address.
351 indicates that the listening port be bound for local use only, while an
354 indicates that the port should be available from all interfaces.
356 Currently the SOCKS4 and SOCKS5 protocols are supported, and
358 will act as a SOCKS server.
359 Multiple forwardings may be specified, and
360 additional forwardings can be given on the command line.
361 Only the superuser can forward privileged ports.
362 .It Cm EnableSSHKeysign
363 Setting this option to
365 in the global client configuration file
366 .Pa /etc/ssh/ssh_config
367 enables the use of the helper program
370 .Cm HostbasedAuthentication .
377 This option should be placed in the non-hostspecific section.
380 for more information.
382 Sets the escape character (default:
384 The escape character can also
385 be set on the command line.
386 The argument should be a single character,
388 followed by a letter, or
390 to disable the escape
391 character entirely (making the connection transparent for binary
393 .It Cm ExitOnForwardFailure
396 should terminate the connection if it cannot set up all requested
397 dynamic, tunnel, local, and remote port forwardings.
405 Specifies whether the connection to the authentication agent (if any)
406 will be forwarded to the remote machine.
414 Agent forwarding should be enabled with caution.
415 Users with the ability to bypass file permissions on the remote host
416 (for the agent's Unix-domain socket)
417 can access the local agent through the forwarded connection.
418 An attacker cannot obtain key material from the agent,
419 however they can perform operations on the keys that enable them to
420 authenticate using the identities loaded into the agent.
422 Specifies whether X11 connections will be automatically redirected
423 over the secure channel and
433 X11 forwarding should be enabled with caution.
434 Users with the ability to bypass file permissions on the remote host
435 (for the user's X11 authorization database)
436 can access the local X11 display through the forwarded connection.
437 An attacker may then be able to perform activities such as keystroke monitoring
439 .Cm ForwardX11Trusted
440 option is also enabled.
441 .It Cm ForwardX11Trusted
442 If this option is set to
444 remote X11 clients will have full access to the original X11 display.
446 If this option is set to
448 remote X11 clients will be considered untrusted and prevented
449 from stealing or tampering with data belonging to trusted X11
453 token used for the session will be set to expire after 20 minutes.
454 Remote clients will be refused access after this time.
459 See the X11 SECURITY extension specification for full details on
460 the restrictions imposed on untrusted clients.
462 Specifies whether remote hosts are allowed to connect to local
466 binds local port forwardings to the loopback address.
467 This prevents other remote hosts from connecting to forwarded ports.
469 can be used to specify that ssh
470 should bind local port forwardings to the wildcard address,
471 thus allowing remote hosts to connect to forwarded ports.
478 .It Cm GlobalKnownHostsFile
479 Specifies a file to use for the global
480 host key database instead of
481 .Pa /etc/ssh/ssh_known_hosts .
482 .It Cm GSSAPIAuthentication
483 Specifies whether user authentication based on GSSAPI is allowed.
486 Note that this option applies to protocol version 2 only.
487 .It Cm GSSAPIKeyExchange
488 Specifies whether key exchange based on GSSAPI may be used. When using
489 GSSAPI key exchange the server need not have a host key.
492 Note that this option applies to protocol version 2 only.
493 .It Cm GSSAPIDelegateCredentials
494 Forward (delegate) credentials to the server.
497 Note that this option applies to protocol version 2 only.
498 .It Cm GSSAPITrustDns
501 to indicate that the DNS is trusted to securely canonicalize
502 the name of the host being connected to. If
504 the hostname entered on the
505 command line will be passed untouched to the GSSAPI library.
508 This option only applies to protocol version 2 connections using GSSAPI.
509 .It Cm HashKnownHosts
512 should hash host names and addresses when they are added to
513 .Pa ~/.ssh/known_hosts .
514 These hashed names may be used normally by
518 but they do not reveal identifying information should the file's contents
522 Note that existing names and addresses in known hosts files
523 will not be converted automatically,
524 but may be manually hashed using
526 .It Cm HostbasedAuthentication
527 Specifies whether to try rhosts based authentication with public key
535 This option applies to protocol version 2 only and
537 .Cm RhostsRSAAuthentication .
538 .It Cm HostKeyAlgorithms
539 Specifies the protocol version 2 host key algorithms
540 that the client wants to use in order of preference.
541 The default for this option is:
542 .Dq ssh-rsa,ssh-dss .
544 Specifies an alias that should be used instead of the
545 real host name when looking up or saving the host key
546 in the host key database files.
547 This option is useful for tunneling SSH connections
548 or for multiple servers running on a single host.
550 Specifies the real host name to log into.
551 This can be used to specify nicknames or abbreviations for hosts.
552 The default is the name given on the command line.
553 Numeric IP addresses are also permitted (both on the command line and in
556 .It Cm IdentitiesOnly
559 should only use the authentication identity files configured in the
564 offers more identities.
565 The argument to this keyword must be
569 This option is intended for situations where ssh-agent
570 offers many different identities.
574 Specifies a file from which the user's RSA or DSA authentication identity
578 for protocol version 1, and
582 for protocol version 2.
583 Additionally, any identities represented by the authentication agent
584 will be used for authentication.
586 The file name may use the tilde
587 syntax to refer to a user's home directory or one of the following
590 (local user's home directory),
596 (remote host name) or
600 It is possible to have
601 multiple identity files specified in configuration files; all these
602 identities will be tried in sequence.
603 .It Cm KbdInteractiveAuthentication
604 Specifies whether to use keyboard-interactive authentication.
605 The argument to this keyword must be
611 .It Cm KbdInteractiveDevices
612 Specifies the list of methods to use in keyboard-interactive authentication.
613 Multiple method names must be comma-separated.
614 The default is to use the server specified list.
615 The methods available vary depending on what the server supports.
616 For an OpenSSH server,
617 it may be zero or more of:
623 Specifies a command to execute on the local machine after successfully
624 connecting to the server.
625 The command string extends to the end of the line, and is executed with
627 The following escape character substitutions will be performed:
629 (local user's home directory),
635 (host name as provided on the command line),
639 (remote user name) or
642 This directive is ignored unless
643 .Cm PermitLocalCommand
646 Specifies that a TCP port on the local machine be forwarded over
647 the secure channel to the specified host and port from the remote machine.
648 The first argument must be
650 .Oo Ar bind_address : Oc Ar port
652 and the second argument must be
653 .Ar host : Ns Ar hostport .
654 IPv6 addresses can be specified by enclosing addresses in square brackets or
655 by using an alternative syntax:
656 .Oo Ar bind_address Ns / Oc Ns Ar port
658 .Ar host Ns / Ns Ar hostport .
659 Multiple forwardings may be specified, and additional forwardings can be
660 given on the command line.
661 Only the superuser can forward privileged ports.
662 By default, the local port is bound in accordance with the
667 may be used to bind the connection to a specific address.
672 indicates that the listening port be bound for local use only, while an
675 indicates that the port should be available from all interfaces.
677 Gives the verbosity level that is used when logging messages from
679 The possible values are:
680 QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3.
682 DEBUG and DEBUG1 are equivalent.
683 DEBUG2 and DEBUG3 each specify higher levels of verbose output.
685 Specifies the MAC (message authentication code) algorithms
686 in order of preference.
687 The MAC algorithm is used in protocol version 2
688 for data integrity protection.
689 Multiple algorithms must be comma-separated.
691 .Bd -literal -offset indent
692 hmac-md5,hmac-sha1,umac-64@openssh.com,
693 hmac-ripemd160,hmac-sha1-96,hmac-md5-96
695 .It Cm NoHostAuthenticationForLocalhost
696 This option can be used if the home directory is shared across machines.
697 In this case localhost will refer to a different machine on each of
698 the machines and the user will get many warnings about changed host keys.
699 However, this option disables host authentication for localhost.
700 The argument to this keyword must be
704 The default is to check the host key for localhost.
705 .It Cm NumberOfPasswordPrompts
706 Specifies the number of password prompts before giving up.
707 The argument to this keyword must be an integer.
709 .It Cm PasswordAuthentication
710 Specifies whether to use password authentication.
711 The argument to this keyword must be
717 .It Cm PermitLocalCommand
718 Allow local command execution via the
721 .Ic !\& Ns Ar command
731 Specifies the port number to connect on the remote host.
733 .It Cm PreferredAuthentications
734 Specifies the order in which the client should try protocol 2
735 authentication methods.
736 This allows a client to prefer one method (e.g.\&
737 .Cm keyboard-interactive )
738 over another method (e.g.\&
740 The default for this option is:
746 keyboard-interactive,
750 Specifies the protocol versions
752 should support in order of preference.
753 The possible values are
757 Multiple versions must be comma-separated.
761 tries version 2 and falls back to version 1
762 if version 2 is not available.
764 Specifies the command to use to connect to the server.
766 string extends to the end of the line, and is executed with
768 In the command string,
770 will be substituted by the host name to
774 The command can be basically anything,
775 and should read from its standard input and write to its standard output.
776 It should eventually connect an
778 server running on some machine, or execute
781 Host key management will be done using the
782 HostName of the host being connected (defaulting to the name typed by
784 Setting the command to
786 disables this option entirely.
789 is not available for connects with a proxy command.
791 This directive is useful in conjunction with
793 and its proxy support.
794 For example, the following directive would connect via an HTTP proxy at
796 .Bd -literal -offset 3n
797 ProxyCommand /usr/bin/nc -X connect -x 192.0.2.0:8080 %h %p
799 .It Cm PubkeyAuthentication
800 Specifies whether to try public key authentication.
801 The argument to this keyword must be
807 This option applies to protocol version 2 only.
809 Specifies the maximum amount of data that may be transmitted before the
810 session key is renegotiated.
811 The argument is the number of bytes, with an optional suffix of
816 to indicate Kilobytes, Megabytes, or Gigabytes, respectively.
817 The default is between
821 depending on the cipher.
822 This option applies to protocol version 2 only.
824 Specifies that a TCP port on the remote machine be forwarded over
825 the secure channel to the specified host and port from the local machine.
826 The first argument must be
828 .Oo Ar bind_address : Oc Ar port
830 and the second argument must be
831 .Ar host : Ns Ar hostport .
832 IPv6 addresses can be specified by enclosing addresses in square brackets
833 or by using an alternative syntax:
834 .Oo Ar bind_address Ns / Oc Ns Ar port
836 .Ar host Ns / Ns Ar hostport .
837 Multiple forwardings may be specified, and additional
838 forwardings can be given on the command line.
839 Privileged ports can be forwarded only when
840 logging in as root on the remote machine.
846 the listen port will be dynamically allocated on the server and reported
847 to the client at run time.
851 is not specified, the default is to only bind to loopback addresses.
856 or an empty string, then the forwarding is requested to listen on all
860 will only succeed if the server's
862 option is enabled (see
863 .Xr sshd_config 5 ) .
864 .It Cm RhostsRSAAuthentication
865 Specifies whether to try rhosts based authentication with RSA host
873 This option applies to protocol version 1 only and requires
876 .It Cm RSAAuthentication
877 Specifies whether to try RSA authentication.
878 The argument to this keyword must be
882 RSA authentication will only be
883 attempted if the identity file exists, or an authentication agent is
887 Note that this option applies to protocol version 1 only.
889 Specifies what variables from the local
891 should be sent to the server.
892 Note that environment passing is only supported for protocol 2.
893 The server must also support it, and the server must be configured to
894 accept these environment variables.
899 for how to configure the server.
900 Variables are specified by name, which may contain wildcard characters.
901 Multiple environment variables may be separated by whitespace or spread
905 The default is not to send any environment variables.
909 for more information on patterns.
910 .It Cm ServerAliveCountMax
911 Sets the number of server alive messages (see below) which may be
914 receiving any messages back from the server.
915 If this threshold is reached while server alive messages are being sent,
916 ssh will disconnect from the server, terminating the session.
917 It is important to note that the use of server alive messages is very
921 The server alive messages are sent through the encrypted channel
922 and therefore will not be spoofable.
923 The TCP keepalive option enabled by
926 The server alive mechanism is valuable when the client or
927 server depend on knowing when a connection has become inactive.
929 The default value is 3.
931 .Cm ServerAliveInterval
932 (see below) is set to 15 and
933 .Cm ServerAliveCountMax
934 is left at the default, if the server becomes unresponsive,
935 ssh will disconnect after approximately 45 seconds.
936 This option applies to protocol version 2 only.
937 .It Cm ServerAliveInterval
938 Sets a timeout interval in seconds after which if no data has been received
941 will send a message through the encrypted
942 channel to request a response from the server.
944 is 0, indicating that these messages will not be sent to the server.
945 This option applies to protocol version 2 only.
946 .It Cm SmartcardDevice
947 Specifies which smartcard device to use.
948 The argument to this keyword is the device
950 should use to communicate with a smartcard used for storing the user's
952 By default, no device is specified and smartcard support is not activated.
953 .It Cm StrictHostKeyChecking
954 If this flag is set to
957 will never automatically add host keys to the
958 .Pa ~/.ssh/known_hosts
959 file, and refuses to connect to hosts whose host key has changed.
960 This provides maximum protection against trojan horse attacks,
961 though it can be annoying when the
962 .Pa /etc/ssh/ssh_known_hosts
963 file is poorly maintained or when connections to new hosts are
965 This option forces the user to manually
967 If this flag is set to
969 ssh will automatically add new host keys to the
970 user known hosts files.
971 If this flag is set to
974 will be added to the user known host files only after the user
975 has confirmed that is what they really want to do, and
976 ssh will refuse to connect to hosts whose host key has changed.
978 known hosts will be verified automatically in all cases.
987 Specifies whether the system should send TCP keepalive messages to the
989 If they are sent, death of the connection or crash of one
990 of the machines will be properly noticed.
991 However, this means that
992 connections will die if the route is down temporarily, and some people
997 (to send TCP keepalive messages), and the client will notice
998 if the network goes down or the remote host dies.
999 This is important in scripts, and many users want it too.
1001 To disable TCP keepalive messages, the value should be set to
1006 device forwarding between the client and the server.
1007 The argument must be
1017 requests the default tunnel mode, which is
1018 .Dq point-to-point .
1024 devices to open on the client
1029 The argument must be
1031 .Ar local_tun Op : Ar remote_tun .
1033 The devices may be specified by numerical ID or the keyword
1035 which uses the next available tunnel device.
1038 is not specified, it defaults to
1042 .It Cm UsePrivilegedPort
1043 Specifies whether to use a privileged port for outgoing connections.
1044 The argument must be
1053 must be setuid root.
1054 Note that this option must be set to
1057 .Cm RhostsRSAAuthentication
1060 Specifies the user to log in as.
1061 This can be useful when a different user name is used on different machines.
1062 This saves the trouble of
1063 having to remember to give the user name on the command line.
1064 .It Cm UserKnownHostsFile
1065 Specifies a file to use for the user
1066 host key database instead of
1067 .Pa ~/.ssh/known_hosts .
1068 .It Cm VerifyHostKeyDNS
1069 Specifies whether to verify the remote key using DNS and SSHFP resource
1071 If this option is set to
1073 the client will implicitly trust keys that match a secure fingerprint
1075 Insecure fingerprints will be handled as if this option was set to
1077 If this option is set to
1079 information on fingerprint match will be displayed, but the user will still
1080 need to confirm new host keys according to the
1081 .Cm StrictHostKeyChecking
1083 The argument must be
1090 Note that this option applies to protocol version 2 only.
1093 .Sx VERIFYING HOST KEYS
1096 .It Cm VisualHostKey
1097 If this flag is set to
1099 an ASCII art representation of the remote host key fingerprint is
1100 printed in addition to the hex fingerprint string at login and
1101 for unknown host keys.
1102 If this flag is set to
1104 no fingerprint strings are printed at login and
1105 only the hex fingerprint string will be printed for unknown host keys.
1108 .It Cm XAuthLocation
1109 Specifies the full pathname of the
1113 .Pa /usr/X11R6/bin/xauth .
1118 consists of zero or more non-whitespace characters,
1120 (a wildcard that matches zero or more characters),
1123 (a wildcard that matches exactly one character).
1124 For example, to specify a set of declarations for any host in the
1127 the following pattern could be used:
1131 The following pattern
1132 would match any host in the 192.168.0.[0-9] network range:
1134 .Dl Host 192.168.0.?
1138 is a comma-separated list of patterns.
1139 Patterns within pattern-lists may be negated
1140 by preceding them with an exclamation mark
1143 to allow a key to be used from anywhere within an organisation
1147 the following entry (in authorized_keys) could be used:
1149 .Dl from=\&"!*.dialup.example.com,*.example.com\&"
1152 .It Pa ~/.ssh/config
1153 This is the per-user configuration file.
1154 The format of this file is described above.
1155 This file is used by the SSH client.
1156 Because of the potential for abuse, this file must have strict permissions:
1157 read/write for the user, and not accessible by others.
1158 .It Pa /etc/ssh/ssh_config
1159 Systemwide configuration file.
1160 This file provides defaults for those
1161 values that are not specified in the user's configuration file, and
1162 for those users who do not have a configuration file.
1163 This file must be world-readable.
1168 OpenSSH is a derivative of the original and free
1169 ssh 1.2.12 release by Tatu Ylonen.
1170 Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
1171 Theo de Raadt and Dug Song
1172 removed many bugs, re-added newer features and
1174 Markus Friedl contributed the support for SSH
1175 protocol versions 1.5 and 2.0.
andersk / gssapi-openssh.git / blob