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.1,v 1.175 2003/07/22 13:35:22 markus Exp $
38 .Dd September 25, 1999
43 .Nd OpenSSH SSH client (remote login program)
46 .Op Fl l Ar login_name
47 .Ar hostname | user@hostname
52 .Op Fl afgknqstvxACNTVX1246
53 .Op Fl b Ar bind_address
54 .Op Fl c Ar cipher_spec
55 .Op Fl e Ar escape_char
56 .Op Fl i Ar identity_file
57 .Op Fl l Ar login_name
61 .Op Fl F Ar configfile
81 .Ar hostname | user@hostname
86 (SSH client) is a program for logging into a remote machine and for
87 executing commands on a remote machine.
88 It is intended to replace
89 rlogin and rsh, and provide secure encrypted communications between
90 two untrusted hosts over an insecure network.
92 arbitrary TCP/IP ports can also be forwarded over the secure channel.
95 connects and logs into the specified
98 his/her identity to the remote machine using one of several methods
99 depending on the protocol version used:
101 .Ss SSH protocol version 1
103 First, if the machine the user logs in from is listed in
106 .Pa /etc/shosts.equiv
107 on the remote machine, and the user names are
108 the same on both sides, the user is immediately permitted to log in.
113 exists in the user's home directory on the
114 remote machine and contains a line containing the name of the client
115 machine and the name of the user on that machine, the user is
117 This form of authentication alone is normally not
118 allowed by the server because it is not secure.
120 The second authentication method is the
124 method combined with RSA-based host authentication.
125 It means that if the login would be permitted by
128 .Pa /etc/hosts.equiv ,
130 .Pa /etc/shosts.equiv ,
131 and if additionally the server can verify the client's
133 .Pa /etc/ssh/ssh_known_hosts
135 .Pa $HOME/.ssh/known_hosts
138 section), only then login is permitted.
139 This authentication method closes security holes due to IP
140 spoofing, DNS spoofing and routing spoofing.
141 [Note to the administrator:
142 .Pa /etc/hosts.equiv ,
144 and the rlogin/rsh protocol in general, are inherently insecure and should be
145 disabled if security is desired.]
147 As a third authentication method,
149 supports RSA based authentication.
150 The scheme is based on public-key cryptography: there are cryptosystems
151 where encryption and decryption are done using separate keys, and it
152 is not possible to derive the decryption key from the encryption key.
153 RSA is one such system.
154 The idea is that each user creates a public/private
155 key pair for authentication purposes.
156 The server knows the public key, and only the user knows the private key.
158 .Pa $HOME/.ssh/authorized_keys
159 lists the public keys that are permitted for logging
161 When the user logs in, the
163 program tells the server which key pair it would like to use for
165 The server checks if this key is permitted, and if
166 so, sends the user (actually the
168 program running on behalf of the user) a challenge, a random number,
169 encrypted by the user's public key.
170 The challenge can only be
171 decrypted using the proper private key.
172 The user's client then decrypts the
173 challenge using the private key, proving that he/she knows the private
174 key but without disclosing it to the server.
177 implements the RSA authentication protocol automatically.
178 The user creates his/her RSA key pair by running
180 This stores the private key in
181 .Pa $HOME/.ssh/identity
182 and the public key in
183 .Pa $HOME/.ssh/identity.pub
184 in the user's home directory.
185 The user should then copy the
188 .Pa $HOME/.ssh/authorized_keys
189 in his/her home directory on the remote machine (the
191 file corresponds to the conventional
193 file, and has one key
194 per line, though the lines can be very long).
195 After this, the user can log in without giving the password.
196 RSA authentication is much
197 more secure than rhosts authentication.
199 The most convenient way to use RSA authentication may be with an
200 authentication agent.
203 for more information.
205 If other authentication methods fail,
207 prompts the user for a password.
208 The password is sent to the remote
209 host for checking; however, since all communications are encrypted,
210 the password cannot be seen by someone listening on the network.
212 .Ss SSH protocol version 2
214 When a user connects using protocol version 2
215 similar authentication methods are available.
216 Using the default values for
217 .Cm PreferredAuthentications ,
218 the client will try to authenticate first using the hostbased method;
219 if this method fails public key authentication is attempted,
220 and finally if this method fails keyboard-interactive and
221 password authentication are tried.
223 The public key method is similar to RSA authentication described
224 in the previous section and allows the RSA or DSA algorithm to be used:
225 The client uses his private key,
226 .Pa $HOME/.ssh/id_dsa
228 .Pa $HOME/.ssh/id_rsa ,
229 to sign the session identifier and sends the result to the server.
230 The server checks whether the matching public key is listed in
231 .Pa $HOME/.ssh/authorized_keys
232 and grants access if both the key is found and the signature is correct.
233 The session identifier is derived from a shared Diffie-Hellman value
234 and is only known to the client and the server.
236 If public key authentication fails or is not available a password
237 can be sent encrypted to the remote host for proving the user's identity.
241 supports hostbased or challenge response authentication.
243 Protocol 2 provides additional mechanisms for confidentiality
244 (the traffic is encrypted using 3DES, Blowfish, CAST128 or Arcfour)
245 and integrity (hmac-md5, hmac-sha1).
246 Note that protocol 1 lacks a strong mechanism for ensuring the
247 integrity of the connection.
249 .Ss Login session and remote execution
251 When the user's identity has been accepted by the server, the server
252 either executes the given command, or logs into the machine and gives
253 the user a normal shell on the remote machine.
254 All communication with
255 the remote command or shell will be automatically encrypted.
257 If a pseudo-terminal has been allocated (normal login session), the
258 user may use the escape characters noted below.
260 If no pseudo tty has been allocated, the
261 session is transparent and can be used to reliably transfer binary
263 On most systems, setting the escape character to
265 will also make the session transparent even if a tty is used.
267 The session terminates when the command or shell on the remote
268 machine exits and all X11 and TCP/IP connections have been closed.
269 The exit status of the remote program is returned as the exit status
273 .Ss Escape Characters
275 When a pseudo terminal has been requested, ssh supports a number of functions
276 through the use of an escape character.
278 A single tilde character can be sent as
280 or by following the tilde by a character other than those described below.
281 The escape character must always follow a newline to be interpreted as
283 The escape character can be changed in configuration files using the
285 configuration directive or on the command line by the
289 The supported escapes (assuming the default
298 List forwarded connections
300 Background ssh at logout when waiting for forwarded connection / X11 sessions
303 Display a list of escape characters
305 Send a BREAK to the remote system (only useful for SSH protocol version 2
306 and if the peer supports it)
308 Open command line (only useful for adding port forwardings using the
314 Request rekeying of the connection (only useful for SSH protocol version 2
315 and if the peer supports it)
318 .Ss X11 and TCP forwarding
324 (or, see the description of the
328 options described later)
329 and the user is using X11 (the
331 environment variable is set), the connection to the X11 display is
332 automatically forwarded to the remote side in such a way that any X11
333 programs started from the shell (or command) will go through the
334 encrypted channel, and the connection to the real X server will be made
335 from the local machine.
336 The user should not manually set
338 Forwarding of X11 connections can be
339 configured on the command line or in configuration files.
345 will point to the server machine, but with a display number greater
347 This is normal, and happens because
351 X server on the server machine for forwarding the
352 connections over the encrypted channel.
355 will also automatically set up Xauthority data on the server machine.
356 For this purpose, it will generate a random authorization cookie,
357 store it in Xauthority on the server, and verify that any forwarded
358 connections carry this cookie and replace it by the real cookie when
359 the connection is opened.
360 The real authentication cookie is never
361 sent to the server machine (and no cookies are sent in the plain).
367 (or, see the description of the
371 options described later) and
372 the user is using an authentication agent, the connection to the agent
373 is automatically forwarded to the remote side.
375 Forwarding of arbitrary TCP/IP connections over the secure channel can
376 be specified either on the command line or in a configuration file.
377 One possible application of TCP/IP forwarding is a secure connection to an
378 electronic purse; another is going through firewalls.
380 .Ss Server authentication
383 automatically maintains and checks a database containing
384 identifications for all hosts it has ever been used with.
385 Host keys are stored in
386 .Pa $HOME/.ssh/known_hosts
387 in the user's home directory.
388 Additionally, the file
389 .Pa /etc/ssh/ssh_known_hosts
390 is automatically checked for known hosts.
391 Any new hosts are automatically added to the user's file.
392 If a host's identification
395 warns about this and disables password authentication to prevent a
396 trojan horse from getting the user's password.
398 this mechanism is to prevent man-in-the-middle attacks which could
399 otherwise be used to circumvent the encryption.
401 .Cm StrictHostKeyChecking
402 option can be used to prevent logins to machines whose
403 host key is not known or has changed.
405 The options are as follows:
408 Disables forwarding of the authentication agent connection.
410 Enables forwarding of the authentication agent connection.
411 This can also be specified on a per-host basis in a configuration file.
413 Agent forwarding should be enabled with caution.
414 Users with the ability to bypass file permissions on the remote host
415 (for the agent's Unix-domain socket)
416 can access the local agent through the forwarded connection.
417 An attacker cannot obtain key material from the agent,
418 however they can perform operations on the keys that enable them to
419 authenticate using the identities loaded into the agent.
420 .It Fl b Ar bind_address
421 Specify the interface to transmit from on machines with multiple
422 interfaces or aliased addresses.
423 .It Fl c Ar blowfish|3des|des
424 Selects the cipher to use for encrypting the session.
427 It is believed to be secure.
429 (triple-des) is an encrypt-decrypt-encrypt triple with three different keys.
431 is a fast block cipher, it appears very secure and is much faster than
434 is only supported in the
436 client for interoperability with legacy protocol 1 implementations
437 that do not support the
440 Its use is strongly discouraged due to cryptographic weaknesses.
441 .It Fl c Ar cipher_spec
442 Additionally, for protocol version 2 a comma-separated list of ciphers can
443 be specified in order of preference.
446 for more information.
447 .It Fl e Ar ch|^ch|none
448 Sets the escape character for sessions with a pty (default:
450 The escape character is only recognized at the beginning of a line.
451 The escape character followed by a dot
453 closes the connection, followed
454 by control-Z suspends the connection, and followed by itself sends the
455 escape character once.
456 Setting the character to
458 disables any escapes and makes the session fully transparent.
462 to go to background just before command execution.
465 is going to ask for passwords or passphrases, but the user
466 wants it in the background.
469 The recommended way to start X11 programs at a remote site is with
471 .Ic ssh -f host xterm .
473 Allows remote hosts to connect to local forwarded ports.
474 .It Fl i Ar identity_file
475 Selects a file from which the identity (private key) for
476 RSA or DSA authentication is read.
478 .Pa $HOME/.ssh/identity
479 for protocol version 1, and
480 .Pa $HOME/.ssh/id_rsa
482 .Pa $HOME/.ssh/id_dsa
483 for protocol version 2.
484 Identity files may also be specified on
485 a per-host basis in the configuration file.
486 It is possible to have multiple
488 options (and multiple identities specified in
489 configuration files).
490 .It Fl I Ar smartcard_device
491 Specifies which smartcard device to use.
492 The argument is the device
494 should use to communicate with a smartcard used for storing the user's
497 Disables forwarding of Kerberos tickets.
498 This may also be specified on a per-host basis in the configuration file.
499 .It Fl l Ar login_name
500 Specifies the user to log in as on the remote machine.
501 This also may be specified on a per-host basis in the configuration file.
503 Additionally, for protocol version 2 a comma-separated list of MAC
504 (message authentication code) algorithms can
505 be specified in order of preference.
508 keyword for more information.
512 (actually, prevents reading from stdin).
513 This must be used when
515 is run in the background.
516 A common trick is to use this to run X11 programs on a remote machine.
518 .Ic ssh -n shadows.cs.hut.fi emacs &
519 will start an emacs on shadows.cs.hut.fi, and the X11
520 connection will be automatically forwarded over an encrypted channel.
523 program will be put in the background.
524 (This does not work if
526 needs to ask for a password or passphrase; see also the
530 Do not execute a remote command.
531 This is useful for just forwarding ports
532 (protocol version 2 only).
534 Can be used to give options in the format used in the configuration file.
535 This is useful for specifying options for which there is no separate
538 Port to connect to on the remote host.
539 This can be specified on a
540 per-host basis in the configuration file.
543 Causes all warning and diagnostic messages to be suppressed.
545 May be used to request invocation of a subsystem on the remote system.
546 Subsystems are a feature of the SSH2 protocol which facilitate the use
547 of SSH as a secure transport for other applications (eg. sftp).
548 The subsystem is specified as the remote command.
550 Force pseudo-tty allocation.
551 This can be used to execute arbitrary
552 screen-based programs on a remote machine, which can be very useful,
553 e.g., when implementing menu services.
556 options force tty allocation, even if
560 Disable pseudo-tty allocation.
565 to print debugging messages about its progress.
567 debugging connection, authentication, and configuration problems.
570 options increase the verbosity.
573 Display the version number and exit.
575 Disables X11 forwarding.
577 Enables X11 forwarding.
578 This can also be specified on a per-host basis in a configuration file.
580 X11 forwarding should be enabled with caution.
581 Users with the ability to bypass file permissions on the remote host
582 (for the user's X authorization database)
583 can access the local X11 display through the forwarded connection.
584 An attacker may then be able to perform activities such as keystroke monitoring.
586 Requests compression of all data (including stdin, stdout, stderr, and
587 data for forwarded X11 and TCP/IP connections).
588 The compression algorithm is the same used by
592 can be controlled by the
594 option for protocol version 1.
595 Compression is desirable on modem lines and other
596 slow connections, but will only slow down things on fast networks.
597 The default value can be set on a host-by-host basis in the
598 configuration files; see the
601 .It Fl F Ar configfile
602 Specifies an alternative per-user configuration file.
603 If a configuration file is given on the command line,
604 the system-wide configuration file
605 .Pq Pa /etc/ssh/ssh_config
607 The default for the per-user configuration file is
608 .Pa $HOME/.ssh/config .
609 .It Fl L Ar port:host:hostport
610 Specifies that the given port on the local (client) host is to be
611 forwarded to the given host and port on the remote side.
612 This works by allocating a socket to listen to
614 on the local side, and whenever a connection is made to this port, the
615 connection is forwarded over the secure channel, and a connection is
620 from the remote machine.
621 Port forwardings can also be specified in the configuration file.
622 Only root can forward privileged ports.
623 IPv6 addresses can be specified with an alternative syntax:
624 .Ar port/host/hostport
625 .It Fl R Ar port:host:hostport
626 Specifies that the given port on the remote (server) host is to be
627 forwarded to the given host and port on the local side.
628 This works by allocating a socket to listen to
630 on the remote side, and whenever a connection is made to this port, the
631 connection is forwarded over the secure channel, and a connection is
636 from the local machine.
637 Port forwardings can also be specified in the configuration file.
638 Privileged ports can be forwarded only when
639 logging in as root on the remote machine.
640 IPv6 addresses can be specified with an alternative syntax:
641 .Ar port/host/hostport
645 application-level port forwarding.
646 This works by allocating a socket to listen to
648 on the local side, and whenever a connection is made to this port, the
649 connection is forwarded over the secure channel, and the application
650 protocol is then used to determine where to connect to from the
652 Currently the SOCKS4 and SOCKS5 protocols are supported, and
654 will act as a SOCKS server.
655 Only root can forward privileged ports.
656 Dynamic port forwardings can also be specified in the configuration file.
660 to try protocol version 1 only.
664 to try protocol version 2 only.
668 to use IPv4 addresses only.
672 to use IPv6 addresses only.
674 .Sh CONFIGURATION FILES
676 may additionally obtain configuration data from
677 a per-user configuration file and a system-wide configuration file.
678 The file format and configuration options are described in
682 will normally set the following environment variables:
687 variable indicates the location of the X11 server.
688 It is automatically set by
690 to point to a value of the form
692 where hostname indicates
693 the host where the shell runs, and n is an integer >= 1.
695 uses this special value to forward X11 connections over the secure
697 The user should normally not set
700 will render the X11 connection insecure (and will require the user to
701 manually copy any required authorization cookies).
703 Set to the path of the user's home directory.
707 set for compatibility with systems that use this variable.
709 Set to the path of the user's mailbox.
713 as specified when compiling
718 needs a passphrase, it will read the passphrase from the current
719 terminal if it was run from a terminal.
722 does not have a terminal associated with it but
726 are set, it will execute the program specified by
728 and open an X11 window to read the passphrase.
729 This is particularly useful when calling
734 (Note that on some machines it
735 may be necessary to redirect the input from
739 Identifies the path of a unix-domain socket used to communicate with the
741 .It Ev SSH_CONNECTION
742 Identifies the client and server ends of the connection.
743 The variable contains
744 four space-separated values: client ip-address, client port number,
745 server ip-address and server port number.
746 .It Ev SSH_ORIGINAL_COMMAND
747 The variable contains the original command line if a forced command
749 It can be used to extract the original arguments.
751 This is set to the name of the tty (path to the device) associated
752 with the current shell or command.
753 If the current session has no tty,
754 this variable is not set.
756 The timezone variable is set to indicate the present timezone if it
757 was set when the daemon was started (i.e., the daemon passes the value
758 on to new connections).
760 Set to the name of the user logging in.
766 .Pa $HOME/.ssh/environment ,
767 and adds lines of the format
769 to the environment if the file exists and if users are allowed to
770 change their environment.
772 .Cm PermitUserEnvironment
777 .It Pa $HOME/.ssh/known_hosts
778 Records host keys for all hosts the user has logged into that are not
780 .Pa /etc/ssh/ssh_known_hosts .
783 .It Pa $HOME/.ssh/identity, $HOME/.ssh/id_dsa, $HOME/.ssh/id_rsa
784 Contains the authentication identity of the user.
785 They are for protocol 1 RSA, protocol 2 DSA, and protocol 2 RSA, respectively.
787 contain sensitive data and should be readable by the user but not
788 accessible by others (read/write/execute).
791 ignores a private key file if it is accessible by others.
792 It is possible to specify a passphrase when
793 generating the key; the passphrase will be used to encrypt the
794 sensitive part of this file using 3DES.
795 .It Pa $HOME/.ssh/identity.pub, $HOME/.ssh/id_dsa.pub, $HOME/.ssh/id_rsa.pub
796 Contains the public key for authentication (public part of the
797 identity file in human-readable form).
799 .Pa $HOME/.ssh/identity.pub
800 file should be added to
801 .Pa $HOME/.ssh/authorized_keys
803 where the user wishes to log in using protocol version 1 RSA authentication.
805 .Pa $HOME/.ssh/id_dsa.pub
807 .Pa $HOME/.ssh/id_rsa.pub
808 file should be added to
809 .Pa $HOME/.ssh/authorized_keys
811 where the user wishes to log in using protocol version 2 DSA/RSA authentication.
813 sensitive and can (but need not) be readable by anyone.
815 never used automatically and are not necessary; they are only provided for
816 the convenience of the user.
817 .It Pa $HOME/.ssh/config
818 This is the per-user configuration file.
819 The file format and configuration options are described in
821 .It Pa $HOME/.ssh/authorized_keys
822 Lists the public keys (RSA/DSA) that can be used for logging in as this user.
823 The format of this file is described in the
826 In the simplest form the format is the same as the .pub
828 This file is not highly sensitive, but the recommended
829 permissions are read/write for the user, and not accessible by others.
830 .It Pa /etc/ssh/ssh_known_hosts
831 Systemwide list of known host keys.
832 This file should be prepared by the
833 system administrator to contain the public host keys of all machines in the
835 This file should be world-readable.
837 public keys, one per line, in the following format (fields separated
838 by spaces): system name, public key and optional comment field.
839 When different names are used
840 for the same machine, all such names should be listed, separated by
842 The format is described on the
846 The canonical system name (as returned by name servers) is used by
848 to verify the client host when logging in; other names are needed because
850 does not convert the user-supplied name to a canonical name before
851 checking the key, because someone with access to the name servers
852 would then be able to fool host authentication.
853 .It Pa /etc/ssh/ssh_config
854 Systemwide configuration file.
855 The file format and configuration options are described in
857 .It Pa /etc/ssh/ssh_host_key, /etc/ssh/ssh_host_dsa_key, /etc/ssh/ssh_host_rsa_key
858 These three files contain the private parts of the host keys
860 .Cm RhostsRSAAuthentication
862 .Cm HostbasedAuthentication .
863 If the protocol version 1
864 .Cm RhostsRSAAuthentication
867 must be setuid root, since the host key is readable only by root.
868 For protocol version 2,
872 to access the host keys for
873 .Cm HostbasedAuthentication .
874 This eliminates the requirement that
876 be setuid root when that authentication method is used.
883 authentication to list the
884 host/user pairs that are permitted to log in.
885 (Note that this file is
886 also used by rlogin and rsh, which makes using this file insecure.)
887 Each line of the file contains a host name (in the canonical form
888 returned by name servers), and then a user name on that host,
889 separated by a space.
890 On some machines this file may need to be
891 world-readable if the user's home directory is on a NFS partition,
895 Additionally, this file must be owned by the user,
896 and must not have write permissions for anyone else.
898 permission for most machines is read/write for the user, and not
899 accessible by others.
903 will be installed so that it requires successful RSA host
904 authentication before permitting \s+2.\s0rhosts authentication.
905 If the server machine does not have the client's host key in
906 .Pa /etc/ssh/ssh_known_hosts ,
908 .Pa $HOME/.ssh/known_hosts .
909 The easiest way to do this is to
910 connect back to the client from the server machine using ssh; this
911 will automatically add the host key to
912 .Pa $HOME/.ssh/known_hosts .
914 This file is used exactly the same way as
917 having this file is to be able to use rhosts authentication with
919 without permitting login with
923 .It Pa /etc/hosts.equiv
924 This file is used during
928 canonical hosts names, one per line (the full format is described on
932 If the client host is found in this file, login is
933 automatically permitted provided client and server user names are the
935 Additionally, successful RSA host authentication is normally
937 This file should only be writable by root.
938 .It Pa /etc/shosts.equiv
939 This file is processed exactly as
940 .Pa /etc/hosts.equiv .
941 This file may be useful to permit logins using
943 but not using rsh/rlogin.
944 .It Pa /etc/ssh/sshrc
945 Commands in this file are executed by
947 when the user logs in just before the user's shell (or command) is started.
950 manual page for more information.
952 Commands in this file are executed by
954 when the user logs in just before the user's shell (or command) is
958 manual page for more information.
959 .It Pa $HOME/.ssh/environment
960 Contains additional definitions for environment variables, see section
966 exits with the exit status of the remote command or with 255
967 if an error occurred.
985 .%T "SSH Protocol Architecture"
986 .%N draft-ietf-secsh-architecture-12.txt
988 .%O work in progress material
991 OpenSSH is a derivative of the original and free
992 ssh 1.2.12 release by Tatu Ylonen.
993 Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
994 Theo de Raadt and Dug Song
995 removed many bugs, re-added newer features and
997 Markus Friedl contributed the support for SSH
998 protocol versions 1.5 and 2.0.
andersk / gssapi-openssh.git / blob