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System Administration Commands sshd(1M)
NAME
sshd - secure shell daemon
SYNOPSIS
sshd [-deiqtD46] [-b bits] [-f config_file] [-g
login_grace_time] [-h host_key_file] [-k key_gen_time] [-p
port] [-V client_protocol_id]
DESCRIPTION
The sshd (Secure Shell daemon) is the daemon program for
ssh(1). Together these programs replace rlogin and rsh, and
provide secure encrypted communications between two
untrusted hosts over an insecure network. The programs are
intended to be as easy to install and use as possible.
sshd is the daemon that listens for connections from
clients. It forks a new daemon for each incoming connection.
The forked daemons handle key exchange, encryption, authen-
tication, command execution, and data exchange.
This implementation of sshd supports both SSH protocol ver-
sions 1 and 2 simultaneously. Because of security weaknesses
in the v1 protocol, sites should run only v2, if possible.
In the default configuration, only protocol v2 is enabled
for the server. To enable v1 and v2 simultaneously, see the
instructions in sshd_config(4).
Support for v1 is provided to help sites with existing ssh
v1 clients and servers to transition to v2. v1 might not be
supported in a future release.
SSH Protocol Version 1
Each host has a host-specific RSA key (normally 1024 bits)
used to identify the host. Additionally, when the daemon
starts, it generates a server RSA key (normally 768 bits).
This key is normally regenerated every hour if it has been
used, and is never stored on disk.
Whenever a client connects the daemon responds with its pub-
lic host and server keys. The client compares the RSA host
key against its own database to verify that it has not
changed. The client then generates a 256-bit random number.
It encrypts this random number using both the host key and
the server key, and sends the encrypted number to the
server. Both sides then use this random number as a session
key which is used to encrypt all further communications in
the session. The rest of the session is encrypted using a
conventional cipher, currently Blowfish or 3DES, with 3DES
being used by default. The client selects the encryption
algorithm to use from those offered by the server.
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System Administration Commands sshd(1M)
Next, the server and the client enter an authentication dia-
log. The client tries to authenticate itself using .rhosts
authentication, .rhosts authentication combined with RSA
host authentication, RSA challenge-response authentication,
or password-based authentication.
Rhosts authentication is normally disabled because it is
fundamentally insecure, but can be enabled in the server
configuration file if desired. System security is not
improved unless rshd(1M), rlogind(1M), rexecd(1M), and
rexd(1M) are disabled (thus completely disabling rlogin(1)
and rsh(1) into the machine).
SSH Protocol Version 2
Version 2 works similarly to version 1: Each host has a
host-specific DSA/RSA key. However, when the daemon starts,
it does not generate a server key. Forward security is pro-
vided through a Diffie-Hellman key agreement. This key
agreement results in a shared session key. The rest of the
session is encrypted using a symmetric cipher, currently
128-bit AES, Blowfish, 3DES, or AES. The client selects the
encryption algorithm to use from those offered by the
server. Additionally, session integrity is provided through
a cryptographic message authentication code (hmac-sha1 or
hmac-md5).
Protocol version 2 provides a public key based user authen-
tication method (PubKeyAuthentication) GSS-API based user
authentication, conventional password authentication, and a
generic prompt/reply protocol for password-based authentica-
tion.
Command Execution and Data Forwarding
If the client successfully authenticates itself, a dialog
for preparing the session is entered. At this time the
client can request things like allocating a pseudo-tty, for-
warding X11 connections, forwarding TCP/IP connections, or
forwarding the authentication agent connection over the
secure channel.
Finally, the client either requests a shell or execution of
a command. The sides then enter session mode. In this mode,
either side may send data at any time, and such data is for-
warded to/from the shell or command on the server side, and
the user terminal on the client side.
When the user program terminates and all forwarded X11 and
other connections have been closed, the server sends command
exit status to the client, and both sides exit.
sshd can be configured using command-line options or the
configuration file /etc/ssh/ssh_config, described in
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ssh_config(4). Command-line options override values speci-
fied in the configuration file.
sshd rereads its configuration file when it receives a
hangup signal, SIGHUP, by executing itself with the name it
was started as, that is, /usr/lib/ssh/sshd.
Host Access Control
The sshd daemon uses TCP Wrappers to restrict access to
hosts. It uses the service name of sshd for hosts_access().
For more information on TCP Wrappers see tcpd(1M) and
hosts_access(3) man pages, which are part of the SUNWsfman
package (they are not SunOS man pages). TCP wrappers
binaries, including libwrap, are in SUNWtcpd, a required
package for SUNWsshdu, the package containing sshd.
OPTIONS
The options for sshd are as follows:
-b bits
Specifies the number of bits in the server key (the
default is 768).
-d
Debug mode. The server sends verbose debug output to the
system log, and does not put itself in the background.
The server also will not fork and will only process one
connection. This option is only intended for debugging
for the server. Multiple -d options increase the debug-
ging level. Maximum is 3.
-e
When this option is specified, sshd will send the output
to standard error instead of to the system log.
-f configuration_file
Specifies the name of the configuration file. The
default is /etc/ssh/sshd_config. sshd refuses to start
if there is no configuration file.
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System Administration Commands sshd(1M)
-g login_grace_time
Gives the grace time for clients to authenticate them-
selves (the default is 300 seconds). If the client fails
to authenticate the user within this number of seconds,
the server disconnects and exits. A value of zero indi-
cates no limit.
-h host_key_file
Specifies a file from which a host key is read. This
option must be given if sshd is not run as root (as the
normal host key files are normally not readable by any-
one but root). The default is /etc/ssh/ssh_host_key for
protocol version 1, and /etc/ssh/ssh_host_rsa_key and
/etc/ssh/ssh_host_dsa_key for protocol version 2. It is
possible to have multiple host key files for the dif-
ferent protocol versions and host key algorithms.
-i
Specifies that sshd is being run from inetd. sshd is
normally not run from inetd because it needs to generate
the server key before it can respond to the client, and
this may take tens of seconds. Clients would have to
wait too long if the key was regenerated every time.
However, with small key sizes (for example, 512) using
sshd from inetd may be reasonable.
-k key_gen_time
(SSHv1-specific) Specifies how often the server key is
regenerated (the default is 3600 seconds, or one hour).
The motivation for regenerating the key fairly often is
that the key is not stored anywhere, and after about an
hour, it becomes impossible to recover the key for
decrypting intercepted communications even if the
machine is cracked into or physically seized. A value of
zero indicates that the key will never be regenerated.
-o option
Can be used to specify options in the format used in the
configuration file. This is useful for specifying
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options for which there are no separate command-line
flags.
-p port
Specifies the port on which the server listens for con-
nections (the default is 22).
-q
Quiet mode. Nothing is sent to the system log. Normally
the beginning, authentication, and termination of each
connection is logged.
-t
Test mode. Check only the validity of the configuration
file and the sanity of the keys. This is useful for
updating sshd reliably as configuration options might
change.
-D
When this option is specified sshd does not detach and
does not become a daemon. This allows easy monitoring of
sshd.
-4
Forces sshd to use IPv4 addresses only.
-6
Forces sshd to use IPv6 addresses only.
EXTENDED DESCRIPTION
authorized_keys File Format
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The $HOME/.ssh/authorized_keys file lists the public keys
that are permitted for RSA authentication in protocol ver-
sion 1 and for public key authentication (PubkeyAuthentica-
tion) in protocol version 2. The AuthorizedKeysFile confi-
guration option can be used to specify an alternative file.
Each line of the file contains one key (empty lines and
lines starting with a hash mark [#] are ignored as com-
ments).
Each RSA public key consists of the following, space-
separated fields:
o options
o bits
o exponent
o modulus
o comment
The options field is optional; its presence is determined by
whether the line starts with a number. (The option field
never starts with a number.) The bits, exponent, and modulus
fields give the RSA key; the comment field is a convenient
place for you to identify the key.
Lines in this file are usually several hundred bytes long
(because of the size of the RSA key modulus). You will find
it very inconvenient to type them in; instead, copy the
identity.pub file and edit it.
Permissions of this file must be set so that it is not world
or group writable. See the StrickModes option of
sshd_config(4).
The options (if present) consist of comma-separated option
specifications. No spaces are permitted, except within dou-
ble quotes. The following option specifications are sup-
ported:
from="pattern-list"
Specifies that, in addition to public key authentica-
tion, the canonical name of the remote host must be
present in the comma-separated list of patterns (`*' and
`?' serve as wildcards). The list can also contain
negated patterns by prefixing the patterns with `!'. If
the canonical host name matches a negated pattern, the
key is not accepted.
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The purpose of this option is to give you the option of
increasing security: public key authentication by itself
does not trust the network or name servers or anything
but the key. However, if someone manages to steal the
key, possession of the key would permit the intruder to
log in from anywhere in the world. This option makes
using a stolen key more difficult, because name servers
and routers would have to be compromised, in addition to
just the key.
command="command"
Specifies that the command is executed whenever this key
is used for authentication. The command supplied by the
user (if any) is ignored. The command is run on a pty if
the client requests a pty; otherwise it is run without a
tty. If an 8-bit clean channel is required, one must not
request a pty or should specify no-pty. You can include
a quote in the command by escaping it with a backslash.
This option might be useful to restrict certain public
keys from performing a specific operation. An example is
a key that permits remote backups but nothing else. Note
that the client can specify TCP/IP and/or X11 forwarding
unless they are explicitly prohibited from doing so.
Also note that this option applies to shell, command, or
subsystem execution.
environment="NAME=value"
Specifies that the string NAME=value is to be added to
the environment when logging in using this key. Environ-
ment variables set this way override other default
environment values. Multiple options of this type are
permitted. Environment processing is disabled by default
and is controlled via the PermitUserEnvironment option.
no-port-forwarding
Forbids TCP/IP forwarding when this key is used for
authentication. Any port forward requests by the client
will return an error. This might be used, for example,
in connection with the command option.
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no-X11-forwarding
Forbids X11 forwarding when this key is used for authen-
tication. Any X11 forward requests by the client will
return an error.
no-agent-forwarding
Forbids authentication agent forwarding when this key is
used for authentication.
no-pty
Prevents tty allocation (a request to allocate a pty
will fail).
permitopen="host:port"
Limit local ssh -L port forwarding such that it can con-
nect only to the specified host and port. IPv6 addresses
can be specified with an alternative syntax: host/port.
You can invoke multiple permitopen options, with each
instance separated by a comma. No pattern matching is
performed on the specified hostnames. They must be
literal domains or addresses.
ssh_known_hosts File Format
The /etc/ssh/ssh_known_hosts and $HOME/.ssh/known_hosts
files contain host public keys for all known hosts. The glo-
bal file should be prepared by the administrator (optional),
and the per-user file is maintained automatically: whenever
the user connects from an unknown host its key is added to
the per-user file.
Each line in these files contains the following fields:
hostnames, bits, exponent, modulus, comment. The fields are
separated by spaces.
Hostnames is a comma-separated list of patterns (* and ? act
as wildcards); each pattern in turn is matched against the
canonical host name (when authenticating a client) or
against the user-supplied name (when authenticating a
server). A pattern can also be preceded by ! to indicate
negation: if the host name matches a negated pattern, it is
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not accepted (by that line) even if it matched another pat-
tern on the line.
Bits, exponent, and modulus are taken directly from the RSA
host key; they can be obtained, for example, from
/etc/ssh/ssh_host_rsa_key.pub. The optional comment field
continues to the end of the line, and is not used.
Lines starting with a hash mark (#) and empty lines are
ignored as comments.
When performing host authentication, authentication is
accepted if any matching line has the proper key. It is thus
permissible (but not recommended) to have several lines or
different host keys for the same names. This will inevitably
happen when short forms of host names from different domains
are put in the file. It is possible that the files contain
conflicting information; authentication is accepted if valid
information can be found from either file.
The lines in these files are typically hundreds of charac-
ters long. You should definitely not type in the host keys
by hand. Rather, generate them by a script or by taking
/etc/ssh/ssh_host_rsa_key.pub and adding the host names at
the front.
ENVIRONMENT VARIABLES
sshd sets the following environment variables for commands
executed by ssh users:
DISPLAY
Indicates the location of the X11 server. It is automat-
ically set by sshd to point to a value of the form
hostname:n, where hostname indicates the host where the
shell runs, and n is an integer greater than or equal to
1. ssh uses this special value to forward X11 connec-
tions over the secure channel. Unless you have important
reasons to do otherwise, you should not set DISPLAY
explicitly, as that will render the X11 connection
insecure and will require you to manually copy any
required authorization cookies.
HOME
Set to the path of the user's home directory.
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LOGNAME
Synonym for USER. Set for compatibility with systems
that use this variable.
MAIL
Set to point to the user's mailbox.
SSH_AUTH_SOCK
Indicates the path of a unix-domain socket used to com-
municate with the agent.
SSH_CONNECTION
Identifies the client and server ends of the connection.
The variable contains four space-separated values:
client IP address, client port number, server IP address
and server port number.
SSH_CLIENT
Identifies the client end of the connection. The vari-
able contains three space-separated values: client IP
address, client port number, and server port number.
SSH_TTY
Set to the name of the tty (path to the device) associ-
ated with the current shell or command. If the current
session has no tty, this variable is not set.
TZ
Indicates the present timezone, if TIMEZONE is set in
/etc/default/login or if TZ was set when the daemon was
started.
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HZ
If set in /etc/default/login, the daemon sets it to the
same value.
SHELL
The user's shell, if ALTSHELL=YES in /etc/default/login.
PATH
Set to the value of PATH or SUPATH (see login(1)) in
/etc/default/login, or, if not set, to
/usr/bin:/bin:/usr/sbin:/sbin.
USER
Set to the name of the user logging in.
Additionally, sshd reads $HOME/.ssh/environment and adds
lines of the format VARNAME=value to the environment.
EXAMPLES
Example 1: authorized_key File Entries
The following are examples of authorized_key file entries.
1024 33 12121...312314325 ylo@foo.bar
from="*.niksula.hut.fi,!pc.niksula.hut.fi" 1024 35 23...2334 ylo@niksula
command="dump /home",no-pty,no-port-forwarding 1024 33 23...2323
backup.hut.fi
Example 2: ssh_known_hosts File Entries
The following are examples of ssh_known_hosts file entries.
closenet,closenet.hut.fi,...,130.233.208.41 1024 37 159...93
closenet.hut.fi
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EXIT STATUS
The following exit values are returned:
0 Successful completion.
>0 An error occurred.
FILES
/etc/default/login
Contains defaults for several sshd_config parameters,
environment variables, and other environmental factors.
The following parameters affect environment variables
(see login(1) and descriptions of these variables,
above):
o TIMEZONE
o HZ
o ALTSHELL
o PATH
o SUPATH
The following /etc/default/login parameters supply
default values for corresponding sshd_config(4) parame-
ters:
o CONSOLE (see PermitRootLogin in sshd_config(4))
o PASSREQ (see PermitEmptyPasswords in
sshd_config(4))
o TIMEOUT (see LoginGraceTime in sshd_config(4))
The following /etc/default/login parameters:
o UMASK
o ULIMIT
...set the umask(2) and file size limit of,
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respectively, the shells and commands spawned by sshd.
Finally, two /etc/default/login parameters affect the
maximum allowed login attempts per-connection using
interactive user authentication methods (for example,
keyboard-interactive but not publickey), as per
login(1):
o RETRIES
o SYSLOG_FAILED_LOGINS
/etc/ssh/sshd_config
Contains configuration data for sshd. This file should
be writable by root only, but it is recommended (though
not necessary) that it be world-readable.
/etc/ssh/ssh_host_key
/etc/ssh/ssh_host_dsa_key
/etc/ssh/ssh_host_rsa_key
Contains the private part of the host key. This file
should only be owned by root, readable only by root, and
not accessible to others. sshd does not start if this
file is group/world-accessible.
/etc/ssh/ssh_host_key.pub
/etc/ssh/ssh_host_dsa_key.pub
/etc/ssh/ssh_host_rsa_key.pub
Contains the public part of the host key. This file
should be world-readable but writable only by root. Its
contents should match the private part. This file is not
used for encryption; it is provided only for the con-
venience of the user so its contents can be copied to
known hosts files. These two files are created using
ssh-keygen(1).
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/var/run/sshd.pid
Contains the process ID of the sshd listening for con-
nections. If there are several daemons running con-
currently for different ports, this contains the pid of
the one started last. The content of this file is not
sensitive; it can be world-readable. You can use the
PidFile keyword in sshd_config to specify a file other
than /var/run/sshd.pid. See sshd_config(4).
/etc/ssh/ssh_known_hosts and $HOME/.ssh/known_hosts
These files are consulted when using rhosts with public
key host authentication to check the public key of the
host. The key must be listed in one of these files to be
accepted. The client uses the same files to verify that
the remote host is the one it intended to connect. These
files should be writable only by root or the owner.
/etc/ssh/ssh_known_hosts should be world-readable, and
$HOME/.ssh/known_hosts can but need not be world-
readable.
/etc/nologin
If this file exists, sshd refuses to let anyone except
root log in. The contents of the file are displayed to
anyone trying to log in, and non-root connections are
refused. The file should be world-readable.
$HOME/.ssh/authorized_keys
Lists the public keys (RSA or DSA) that can be used to
log into the user's account. This file must be readable
by root. This might, on some machines, imply that it is
world-readable if the user's home directory resides on
an NFS volume. It is recommended that it not be accessi-
ble by others. The format of this file is described
above. Users will place the contents of their
identity.pub, id_dsa.pub and/or id_rsa.pub files into
this file, as described in ssh-keygen(1).
$HOME/.rhosts
This file contains host-username pairs, separated by a
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System Administration Commands sshd(1M)
space, one per line. The given user on the corresponding
host is permitted to log in without password. The same
file is used by rlogind and rshd. The file must be writ-
able only by the user; it is recommended that it not be
accessible by others. It is also possible to use net-
groups in the file. Either host or user name may be of
the form +@groupname to specify all hosts or all users
in the group.
$HOME/.shosts
For ssh, this file is exactly the same as for .rhosts.
However, this file is not used by rlogin and rshd, so
using this permits access using SSH only.
/etc/hosts.equiv
This file is used during .rhosts authentication. In its
simplest form, this file contains host names, one per
line. Users on these hosts are permitted to log in
without a password, provided they have the same user
name on both machines. The host name can also be fol-
lowed by a user name; such users are permitted to log in
as any user on this machine (except root). Additionally,
the syntax +@group can be used to specify netgroups.
Negated entries start with a hyphen (-).
If the client host/user is successfully matched in this
file, login is automatically permitted, provided the
client and server user names are the same. Additionally,
successful RSA host authentication is normally required.
This file must be writable only by root; it is recom-
mended that it be world-readable.
Warning: It is almost never a good idea to use user
names in hosts.equiv. Beware that it really means that
the named user(s) can log in as anybody, which includes
bin, daemon, adm, and other accounts that own critical
binaries and directories. For practical purposes, using
a user name grants the user root access. Probably the
only valid use for user names is in negative entries.
This warning also applies to rsh/rlogin.
/etc/ssh/moduli
A private file.
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/etc/ssh/shosts.equiv
This file is processed exactly as /etc/hosts.equiv. How-
ever, this file might be useful in environments that
want to run both rsh/rlogin and ssh.
$HOME/.ssh/environment
This file is read into the environment at login (if it
exists). It can contain only empty lines, comment lines
(that start with #), and assignment lines of the form
name=value. The file should be writable only by the
user; it need not be readable by anyone else. Environ-
ment processing is disabled by default and is controlled
by means of the PermitUserEnvironment option.
$HOME/.ssh/rc
If this file exists, it is run with /bin/sh after read-
ing the environment files but before starting the user's
shell or command. If X11 spoofing is in use, this will
receive the proto cookie pair in standard input (and
DISPLAY in environment). This must call xauth in that
case.
The primary purpose of $HOME/.ssh/rc is to run any ini-
tialization routines that might be needed before the
user's home directory becomes accessible; AFS is a par-
ticular example of such an environment. If this file
exists, it is run with /bin/sh after reading the
environment files, but before starting the user's shell
or command. It must not produce any output on stdout;
stderr must be used instead. If X11 forwarding is in
use, it will receive the proto cookie pair in its stan-
dard input and DISPLAY in its environment. The script
must call xauth because sshd will not run xauth automat-
ically to add X11 cookies.
This file will probably contain some initialization code
followed by something similar to:
if read proto cookie && [ -n "$DISPLAY" ]
then
if [ `echo $DISPLAY | cut -c1-10` = 'localhost:' ]
then
# X11UseLocalhost=yes
echo add unix:`echo $DISPLAY |
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System Administration Commands sshd(1M)
cut -c11-` $proto $cookie
else
# X11UseLocalhost=no
echo add $DISPLAY $proto $cookie
fi | xauth -q -
fi
If this file does not exist, /etc/ssh/sshrc is run, and
if that does not exist, xauth is used to store the
cookie. $HOME/.ssh/rc should be writable only by the
user, and need not be readable by anyone else.
/etc/ssh/sshrc
Similar to $HOME/.ssh/rc. This can be used to specify
machine-specific login-time initializations globally.
This file should be writable only by root, and should be
world-readable.
SECURITY
sshd supports the use of several user authentication mechan-
isms: a public key system where keys are associated with
users (through users' authorized_keys files), a public key
system where keys are associated with hosts (see the Host-
basedAuthentication configuration parameter), a GSS-API
based method (see the GssAuthentication and GssKeyEx confi-
guration parameters) and three initial authentication
methods: none, password, and a generic prompt/reply proto-
col, keyboard-interactive.
sshd negotiates the use of the GSS-API with clients only if
it has a GSS-API acceptor credential for the "host" service.
This means that, for GSS-API based authentication, the
server must have a Kerberos V keytab entry (see below) or
the equivalent for any other GSS-API mechanism that might be
installed.
In order for Kerberos authentication to work, a host/<FQDN>
Kerberos principal must exist for each Fully Qualified
Domain Name associated with the in.sshd server. Each of
these host/<FQDN> principals must have a keytab entry in the
/etc/krb5/krb5.keytab file on the in.sshd server. An example
principal might be:
host/bigmachine.eng.example.com
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See kadmin(1M) or gkadmin(1M) for instructions on adding a
principal to a krb5.keytab file. See System Administration
Guide: Security Services for a discussion of Kerberos
authentication.
GSS-API authorization is covered in gss_auth_rules(5).
sshd uses pam(3PAM) for the three initial authentication
methods as well as for account management, session manage-
ment, and password management for all authentication methods
Specifically, sshd calls pam_authenticate() for the "none,"
"password" and "keyboard-interactive" SSHv2 userauth types,
as well as for for the null and password authentication
methods for SSHv1. Other SSHv2 authentication methods do not
call pam_authenticate(). pam_acct_mgmt() is called for each
authentication method that succeeds.
pam_setcred() and pam_open_session() are called when authen-
tication succeeds and pam_close_session() is called when
connections are closed.
pam_open_session() and pam_close_session() are also called
when SSHv2 channels with ptys are opened and closed.
Each SSHv2 userauth type has its own PAM service name:
____________________________________________________________
| SSHv2 Userauth | PAM Service Name |
|_____________________________|_____________________________|
| none | sshd-none |
|_____________________________|_____________________________|
| password | sshd-password |
|_____________________________|_____________________________|
| keyboard-interactive | sshd-kbdint |
|_____________________________|_____________________________|
| pubkey | sshd-pubkey |
|_____________________________|_____________________________|
| hostbased | sshd-hostbased |
|_____________________________|_____________________________|
| gssgssapi-with-mic | sshd-gssapi |
|_____________________________|_____________________________|
| gssapi-keyex | sshd-gssapi |
|_____________________________|_____________________________|
For SSHv1, sshd-v1 is always used.
If pam_acct_mgmt() returns PAM_NEW_AUTHTOK_REQD (indicating
that the user's authentication tokens have expired), then
sshd forces the use of "keyboard-interactive" userauth, if
version 2 of the protocol is in use. The "keyboard-
SunOS 5.10 Last change: 10 Nov 2005 18
System Administration Commands sshd(1M)
interactive" userauth will call pam_chauthtok() if
pam_acct_mgmt() once again returns PAM_NEW_AUTHTOK_REQD. By
this means, administrators are able to control what authen-
tication methods are allowed for SSHv2 on a per-user basis.
Setting up Host-based Authentication
To establish host-based authentication, you must perform the
following steps:
o Configure the client.
o Configure the server.
o Publish known hosts.
o Make appropriate entries in /etc/shosts.equiv and
~/.shosts.
These steps are expanded in the following paragraphs.
o On a client machine, in the system-wide client confi-
guration file, /etc/ssh/ssh_config, you must have the
entry:
HostbasedAuthentication yes
See ssh_config(4) and ssh-keysign(1M).
o On the server, in the system-wide server configuration
file, /etc/ssh/sshd_config, you must have the entry:
HostbasedAuthentication yes
If per-user .shost files are to be allowed (see last
step), in the same file, you must have:
IgnoreRhosts no
See sshd_config(4) for a description of these keywords.
o To publish known hosts, you must have entries for the
clients from which users will be allowed host-based
authentication. Make these entries in either or both of
the system-wide file (/etc/ssh/ssh_known_hosts) or the
per-user file (~/.ssh/known_hosts).
o Note that sshd uses .shosts, not .rhosts. If you want
the functionality provided by .rhosts, but do not want
SunOS 5.10 Last change: 10 Nov 2005 19
System Administration Commands sshd(1M)
to use rlogin or rsh because of their security
shortcomings, you can use .shosts in conjunction with
sshd. To use this feature, make appropriate entries in
/etc/shosts.equiv and ~/.shosts, in the format speci-
fied in rhosts(4).
For the vast majority of network environments, .shosts
is preferred over .rhosts.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWsshdu |
|_____________________________|_____________________________|
| Interface Stability | Evolving |
|_____________________________|_____________________________|
The interface stability of /etc/ssh/moduli is Private.
SEE ALSO
login(1), scp(1), ssh(1), ssh-add(1), ssh-agent(1), ssh-
keygen(1), svcs(1), gkadmin(1M), kadmin(1M), sftp-
server(1M), sshd(1M), ssh-keysign(1M), svcadm(1M),
pam(3PAM), rhosts(4), ssh_config(4), sshd_config(4), attri-
butes(5), gss_auth_rules(5), kerberos(5), smf(5)
System Administration Guide: Security Services
To view license terms, attribution, and copyright for
OpenSSH, the default path is
/var/sadm/pkg/SUNWsshdr/install/copyright. If the Solaris
operating environment has been installed anywhere other than
the default, modify the given path to access the file at the
installed location.
NOTES
The sshd service is managed by the service management facil-
ity, smf(5), under the service identifier:
svc:/network/ssh:default
Administrative actions on this service, such as enabling,
disabling, or requesting restart, can be performed using
svcadm(1M). The service's status can be queried using the
svcs(1) command.
SunOS 5.10 Last change: 10 Nov 2005 20
System Administration Commands sshd(1M)
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, added newer features and created Open SSH. Markus
Friedl contributed the support for SSH protocol versions 1.5
and 2.0.
SunOS 5.10 Last change: 10 Nov 2005 21
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