Packages and Binaries:

openssh-client

This is the portable version of OpenSSH, a free implementation of the Secure Shell protocol as specified by the IETF secsh working group.

Ssh (Secure Shell) is a program for logging into a remote machine and for executing commands on a remote machine. It provides secure encrypted communications between two untrusted hosts over an insecure network. X11 connections and arbitrary TCP/IP ports can also be forwarded over the secure channel. It can be used to provide applications with a secure communication channel.

This package provides the ssh, scp and sftp clients, the ssh-agent and ssh-add programs to make public key authentication more convenient, and the ssh-keygen, ssh-keyscan, ssh-copy-id and ssh-argv0 utilities.

In some countries it may be illegal to use any encryption at all without a special permit.

ssh replaces the insecure rsh, rcp and rlogin programs, which are obsolete for most purposes.

Installed size: 5.63 MB
How to install: sudo apt install openssh-client

scp

OpenSSH secure file copy

[email protected]:~# scp -h
scp: unknown option -- h
usage: scp [-346ABCOpqRrsTv] [-c cipher] [-D sftp_server_path] [-F ssh_config]
           [-i identity_file] [-J destination] [-l limit] [-o ssh_option]
           [-P port] [-S program] [-X sftp_option] source ... target

sftp

OpenSSH secure file transfer

[email protected]:~# sftp --help
unknown option -- -
usage: sftp [-46AaCfNpqrv] [-B buffer_size] [-b batchfile] [-c cipher]
          [-D sftp_server_command] [-F ssh_config] [-i identity_file]
          [-J destination] [-l limit] [-o ssh_option] [-P port]
          [-R num_requests] [-S program] [-s subsystem | sftp_server]
          [-X sftp_option] destination

slogin

OpenSSH remote login client

[email protected]:~# slogin -h
unknown option -- h
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]
           [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]
           [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]
           [-i identity_file] [-J [[email protected]]host[:port]] [-L address]
           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]
           [-Q query_option] [-R address] [-S ctl_path] [-W host:port]
           [-w local_tun[:remote_tun]] destination [command [argument ...]]

ssh

OpenSSH remote login client

[email protected]:~# ssh -h
unknown option -- h
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]
           [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]
           [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]
           [-i identity_file] [-J [[email protected]]host[:port]] [-L address]
           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]
           [-Q query_option] [-R address] [-S ctl_path] [-W host:port]
           [-w local_tun[:remote_tun]] destination [command [argument ...]]

ssh-add

Adds private key identities to the OpenSSH authentication agent

[email protected]:~# man ssh-add
SSH-ADD(1)                BSD General Commands Manual               SSH-ADD(1)

NAME
     ssh-add -- adds private key identities to the OpenSSH authentication
     agent

SYNOPSIS
     ssh-add [-cDdKkLlqvXx] [-E fingerprint_hash] [-H hostkey_file]
             [-h destination_constraint] [-S provider] [-t life] [file ...]
     ssh-add -s pkcs11
     ssh-add -e pkcs11
     ssh-add -T pubkey ...

DESCRIPTION
     ssh-add adds private key identities to the authentication agent,
     ssh-agent(1).  When run without arguments, it adds the files
     ~/.ssh/id_rsa, ~/.ssh/id_ecdsa, ~/.ssh/id_ecdsa_sk, ~/.ssh/id_ed25519,
     ~/.ssh/id_ed25519_sk, and ~/.ssh/id_dsa.  After loading a private key,
     ssh-add will try to load corresponding certificate information from the
     filename obtained by appending -cert.pub to the name of the private key
     file.  Alternative file names can be given on the command line.

     If any file requires a passphrase, ssh-add asks for the passphrase from
     the user.  The passphrase is read from the user's tty.  ssh-add retries
     the last passphrase if multiple identity files are given.

     The authentication agent must be running and the SSH_AUTH_SOCK environ-
     ment variable must contain the name of its socket for ssh-add to work.

     The options are as follows:

     -c      Indicates that added identities should be subject to confirmation
             before being used for authentication.  Confirmation is performed
             by ssh-askpass(1).  Successful confirmation is signaled by a zero
             exit status from ssh-askpass(1), rather than text entered into
             the requester.

     -D      Deletes all identities from the agent.

     -d      Instead of adding identities, removes identities from the agent.
             If ssh-add has been run without arguments, the keys for the de-
             fault identities and their corresponding certificates will be re-
             moved.  Otherwise, the argument list will be interpreted as a
             list of paths to public key files to specify keys and certifi-
             cates to be removed from the agent.  If no public key is found at
             a given path, ssh-add will append .pub and retry.  If the argu-
             ment list consists of "-" then ssh-add will read public keys to
             be removed from standard input.

     -E fingerprint_hash
             Specifies the hash algorithm used when displaying key finger-
             prints.  Valid options are: "md5" and "sha256".  The default is
             "sha256".

     -e pkcs11
             Remove keys provided by the PKCS#11 shared library pkcs11.

     -H hostkey_file
             Specifies a known hosts file to look up hostkeys when using des-
             tination-constrained keys via the -h flag.  This option may be
             specified multiple times to allow multiple files to be searched.
             If no files are specified, ssh-add will use the default
             ssh_config(5) known hosts files: ~/.ssh/known_hosts,
             ~/.ssh/known_hosts2, /etc/ssh/ssh_known_hosts, and
             /etc/ssh/ssh_known_hosts2.

     -h destination_constraint
             When adding keys, constrain them to be usable only through spe-
             cific hosts or to specific destinations.

             Destination constraints of the form '[[email protected]]dest-hostname' permit
             use of the key only from the origin host (the one running
             ssh-agent(1)) to the listed destination host, with optional user
             name.

             Constraints of the form 'src-hostname>[[email protected]]dst-hostname' allow
             a key available on a forwarded ssh-agent(1) to be used through a
             particular host (as specified by 'src-hostname') to authenticate
             to a further host, specified by 'dst-hostname'.

             Multiple destination constraints may be added when loading keys.
             When attempting authentication with a key that has destination
             constraints, the whole connection path, including ssh-agent(1)
             forwarding, is tested against those constraints and each hop must
             be permitted for the attempt to succeed.  For example, if key is
             forwarded to a remote host, 'host-b', and is attempting authenti-
             cation to another host, 'host-c', then the operation will be suc-
             cessful only if 'host-b' was permitted from the origin host and
             the subsequent 'host-b>host-c' hop is also permitted by destina-
             tion constraints.

             Hosts are identified by their host keys, and are looked up from
             known hosts files by ssh-add.  Wildcards patterns may be used for
             hostnames and certificate host keys are supported.  By default,
             keys added by ssh-add are not destination constrained.

             Destination constraints were added in OpenSSH release 8.9.  Sup-
             port in both the remote SSH client and server is required when
             using destination-constrained keys over a forwarded ssh-agent(1)
             channel.

             It is also important to note that destination constraints can
             only be enforced by ssh-agent(1) when a key is used, or when it
             is forwarded by a cooperating ssh(1).  Specifically, it does not
             prevent an attacker with access to a remote SSH_AUTH_SOCK from
             forwarding it again and using it on a different host (but only to
             a permitted destination).

     -K      Load resident keys from a FIDO authenticator.

     -k      When loading keys into or deleting keys from the agent, process
             plain private keys only and skip certificates.

     -L      Lists public key parameters of all identities currently repre-
             sented by the agent.

     -l      Lists fingerprints of all identities currently represented by the
             agent.

     -q      Be quiet after a successful operation.

     -S provider
             Specifies a path to a library that will be used when adding FIDO
             authenticator-hosted keys, overriding the default of using the
             internal USB HID support.

     -s pkcs11
             Add keys provided by the PKCS#11 shared library pkcs11.

     -T pubkey ...
             Tests whether the private keys that correspond to the specified
             pubkey files are usable by performing sign and verify operations
             on each.

     -t life
             Set a maximum lifetime when adding identities to an agent.  The
             lifetime may be specified in seconds or in a time format speci-
             fied in sshd_config(5).

     -v      Verbose mode.  Causes ssh-add to print debugging messages about
             its progress.  This is helpful in debugging problems.  Multiple
             -v options increase the verbosity.  The maximum is 3.

     -X      Unlock the agent.

     -x      Lock the agent with a password.

ENVIRONMENT
     DISPLAY, SSH_ASKPASS and SSH_ASKPASS_REQUIRE
             If ssh-add needs a passphrase, it will read the passphrase from
             the current terminal if it was run from a terminal.  If ssh-add
             does not have a terminal associated with it but DISPLAY and
             SSH_ASKPASS are set, it will execute the program specified by
             SSH_ASKPASS (by default "ssh-askpass") and open an X11 window to
             read the passphrase.  This is particularly useful when calling
             ssh-add from a .xsession or related script.

             SSH_ASKPASS_REQUIRE allows further control over the use of an
             askpass program.  If this variable is set to "never" then ssh-add
             will never attempt to use one.  If it is set to "prefer", then
             ssh-add will prefer to use the askpass program instead of the TTY
             when requesting passwords.  Finally, if the variable is set to
             "force", then the askpass program will be used for all passphrase
             input regardless of whether DISPLAY is set.

     SSH_AUTH_SOCK
             Identifies the path of a UNIX-domain socket used to communicate
             with the agent.

     SSH_SK_PROVIDER
             Specifies a path to a library that will be used when loading any
             FIDO authenticator-hosted keys, overriding the default of using
             the built-in USB HID support.

FILES
     ~/.ssh/id_dsa
     ~/.ssh/id_ecdsa
     ~/.ssh/id_ecdsa_sk
     ~/.ssh/id_ed25519
     ~/.ssh/id_ed25519_sk
     ~/.ssh/id_rsa
             Contains the DSA, ECDSA, authenticator-hosted ECDSA, Ed25519, au-
             thenticator-hosted Ed25519 or RSA authentication identity of the
             user.

     Identity files should not be readable by anyone but the user.  Note that
     ssh-add ignores identity files if they are accessible by others.

EXIT STATUS
     Exit status is 0 on success, 1 if the specified command fails, and 2 if
     ssh-add is unable to contact the authentication agent.

SEE ALSO
     ssh(1), ssh-agent(1), ssh-askpass(1), ssh-keygen(1), sshd(8)

AUTHORS
     OpenSSH is a derivative of the original and free ssh 1.2.12 release by
     Tatu Ylonen.  Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
     de Raadt and Dug Song removed many bugs, re-added newer features and cre-
     ated OpenSSH.  Markus Friedl contributed the support for SSH protocol
     versions 1.5 and 2.0.

BSD                            February 4, 2022                            BSD

ssh-agent

OpenSSH authentication agent

[email protected]:~# ssh-agent -h
unknown option -- h
usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]
                 [-O option] [-P allowed_providers] [-t life]
       ssh-agent [-a bind_address] [-E fingerprint_hash] [-O option]
                 [-P allowed_providers] [-t life] command [arg ...]
       ssh-agent [-c | -s] -k

ssh-argv0

Replaces the old ssh command-name as hostname handling

[email protected]:~# man ssh-argv0
SSH-ARGV0(1)              BSD General Commands Manual             SSH-ARGV0(1)

NAME
     ssh-argv0 -- replaces the old ssh command-name as hostname handling

SYNOPSIS
     hostname | [email protected] [-l login_name] [command]

     hostname | [email protected] [-afgknqstvxACNTX1246] [-b bind_address]
     [-c cipher_spec] [-e escape_char] [-i identity_file] [-l login_name]
     [-m mac_spec] [-o option] [-p port] [-F configfile] [-L
     port:host:hostport] [-R port:host:hostport] [-D port] [command]

DESCRIPTION
     ssh-argv0 replaces the old ssh command-name as hostname handling.  If you
     link to this script with a hostname then executing the link is equivalent
     to having executed ssh with that hostname as an argument.  All other ar-
     guments are passed to ssh and will be processed normally.

OPTIONS
     See ssh(1).

FILES
     See ssh(1).

AUTHORS
     OpenSSH is a derivative of the original and free ssh 1.2.12 release by
     Tatu Ylonen.  Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
     de Raadt and Dug Song removed many bugs, re-added newer features and cre-
     ated OpenSSH.  Markus Friedl contributed the support for SSH protocol
     versions 1.5 and 2.0.  Natalie Amery wrote this ssh-argv0 script and the
     associated documentation.

SEE ALSO
     ssh(1)

Debian Project                 September 7, 2001                Debian Project

ssh-copy-id

Use locally available keys to authorise logins on a remote machine

[email protected]:~# ssh-copy-id --help
Illegal option --
Usage: /usr/bin/ssh-copy-id [-h|-?|-f|-n|-s] [-i [identity_file]] [-p port] [-F alternative ssh_config file] [[-o <ssh -o options>] ...] [[email protected]]hostname
	-f: force mode -- copy keys without trying to check if they are already installed
	-n: dry run    -- no keys are actually copied
	-s: use sftp   -- use sftp instead of executing remote-commands. Can be useful if the remote only allows sftp
	-h|-?: print this help

ssh-keygen

OpenSSH authentication key utility

[email protected]:~# ssh-keygen --help
unknown option -- -
usage: ssh-keygen [-q] [-a rounds] [-b bits] [-C comment] [-f output_keyfile]
                  [-m format] [-N new_passphrase] [-O option]
                  [-t dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa]
                  [-w provider] [-Z cipher]
       ssh-keygen -p [-a rounds] [-f keyfile] [-m format] [-N new_passphrase]
                   [-P old_passphrase] [-Z cipher]
       ssh-keygen -i [-f input_keyfile] [-m key_format]
       ssh-keygen -e [-f input_keyfile] [-m key_format]
       ssh-keygen -y [-f input_keyfile]
       ssh-keygen -c [-a rounds] [-C comment] [-f keyfile] [-P passphrase]
       ssh-keygen -l [-v] [-E fingerprint_hash] [-f input_keyfile]
       ssh-keygen -B [-f input_keyfile]
       ssh-keygen -D pkcs11
       ssh-keygen -F hostname [-lv] [-f known_hosts_file]
       ssh-keygen -H [-f known_hosts_file]
       ssh-keygen -K [-a rounds] [-w provider]
       ssh-keygen -R hostname [-f known_hosts_file]
       ssh-keygen -r hostname [-g] [-f input_keyfile]
       ssh-keygen -M generate [-O option] output_file
       ssh-keygen -M screen [-f input_file] [-O option] output_file
       ssh-keygen -I certificate_identity -s ca_key [-hU] [-D pkcs11_provider]
                  [-n principals] [-O option] [-V validity_interval]
                  [-z serial_number] file ...
       ssh-keygen -L [-f input_keyfile]
       ssh-keygen -A [-a rounds] [-f prefix_path]
       ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]
                  file ...
       ssh-keygen -Q [-l] -f krl_file [file ...]
       ssh-keygen -Y find-principals -s signature_file -f allowed_signers_file
       ssh-keygen -Y match-principals -I signer_identity -f allowed_signers_file
       ssh-keygen -Y check-novalidate -n namespace -s signature_file
       ssh-keygen -Y sign -f key_file -n namespace file [-O option] ...
       ssh-keygen -Y verify -f allowed_signers_file -I signer_identity
                  -n namespace -s signature_file [-r krl_file] [-O option]

ssh-keyscan

Gather SSH public keys from servers

[email protected]:~# ssh-keyscan -h
unknown option -- h
usage: ssh-keyscan [-46cDHv] [-f file] [-p port] [-T timeout] [-t type]
		   [host | addrlist namelist]

openssh-server

This is the portable version of OpenSSH, a free implementation of the Secure Shell protocol as specified by the IETF secsh working group.

Ssh (Secure Shell) is a program for logging into a remote machine and for executing commands on a remote machine. It provides secure encrypted communications between two untrusted hosts over an insecure network. X11 connections and arbitrary TCP/IP ports can also be forwarded over the secure channel. It can be used to provide applications with a secure communication channel.

This package provides the sshd server.

In some countries it may be illegal to use any encryption at all without a special permit.

sshd replaces the insecure rshd program, which is obsolete for most purposes.

Installed size: 1.88 MB
How to install: sudo apt install openssh-server

sshd

OpenSSH daemon

[email protected]:~# sshd -h
option requires an argument -- h
OpenSSH_9.2p1 Debian-2, OpenSSL 3.0.8 7 Feb 2023
usage: sshd [-46DdeiqTtV] [-C connection_spec] [-c host_cert_file]
            [-E log_file] [-f config_file] [-g login_grace_time]
            [-h host_key_file] [-o option] [-p port] [-u len]

openssh-sftp-server

This is the portable version of OpenSSH, a free implementation of the Secure Shell protocol as specified by the IETF secsh working group.

Ssh (Secure Shell) is a program for logging into a remote machine and for executing commands on a remote machine. It provides secure encrypted communications between two untrusted hosts over an insecure network. X11 connections and arbitrary TCP/IP ports can also be forwarded over the secure channel. It can be used to provide applications with a secure communication channel.

This package provides the SFTP server module for the SSH server. It is needed if you want to access your SSH server with SFTP. The SFTP server module also works with other SSH daemons like dropbear.

OpenSSH’s sftp and sftp-server implement revision 3 of the SSH filexfer protocol described in:

http://www.openssh.com/txt/draft-ietf-secsh-filexfer-02.txt

Newer versions of the draft will not be supported, though some features are individually implemented as extensions.

Installed size: 217 KB
How to install: sudo apt install openssh-sftp-server

openssh-tests

This package provides OpenSSH’s regression test suite. It is mainly intended for use with the autopkgtest system, though can also be run directly using /usr/lib/openssh/regress/run-tests.

Installed size: 7.46 MB
How to install: sudo apt install openssh-tests

ssh

This metapackage is a convenient way to install both the OpenSSH client and the OpenSSH server. It provides nothing in and of itself, so you may remove it if nothing depends on it.

Installed size: 182 KB
How to install: sudo apt install ssh

ssh-askpass-gnome

This has been split out of the main openssh-client package so that openssh-client does not need to depend on GTK+.

You probably want the ssh-askpass package instead, but this is provided to add to your choice and/or confusion.

Installed size: 219 KB
How to install: sudo apt install ssh-askpass-gnome