SYNOPSIS
sshd [-deiqD46] [-b bits] [-f config_file] [-g lo-
gin_grace_time] [-h
host_key_file] [-k key_gen_time] [-p port] [-u len] [-V
client_protocol_id]
DESCRIPTION
sshd (SSH Daemon) is the daemon program for ssh(1). Togeth-
er these proM--
grams 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 is norM--
mally started at boot from /etc/rc. It forks a new daemon
for each incomM--
ing connection. The forked daemons handle key exchange, en-
cryption, auM--
thentication, command execution, and data exchange. This
implementation
of sshd supports both SSH protocol version 1 and 2 simulta-
neously. sshd
works as follows.
SSH protocol version 1
Each host has a host-specific RSA key (normally 1024 bits)
used to idenM--
tify the host. Additionally, when the daemon starts, it
generates a
server RSA key (normally 768 bits). This key is normally
regenerated evM--
ery 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 servM--
er. 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, cur-
fundamentally
insecure, but can be enabled in the server configuration
file if desired.
System security is not improved unless rshd(8), rlogind(8),
rexecd(8),
and rexd(8) are disabled (thus completely disabling
rlogin(1) and rsh(1)
into the machine).
SSH protocol version 2
Version 2 works similarly: Each host has a host-specific DSA
key used to
identify the host. However, when the daemon starts, it does
not generate
a server key. Forward security is provided 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 ci-
pher, currently
128 bit AES, Blowfish, 3DES, CAST128, Arcfour, 192 bit AES,
or 256 bit
AES. The client selects the encryption algorithm to use
from those ofM--
fered 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 (Pub-
keyAuthenticaM--
tion) or client host (HostbasedAuthentication) authentica-
tion method,
conventional password authentication and challenge response
based methM--
ods.
Command execution and data forwarding
If the client successfully authenticates itself, a dialog
for preparing
the session is entered. At this time the client may request
things like
allocating a pseudo-tty, forwarding X11 connections, for-
warding TCP/IP
connections, or forwarding the authentication agent connec-
tion over the
secure channel.
Finally, the client either requests a shell or execution of
sshd can be configured using command-line options or a con-
figuration
file. Command-line options override values specified in the
configuraM--
tion file.
sshd rereads its configuration file when it receives a
hangup signal,
SIGHUP, by executing itself with the name it was started as,
ie.
/usr/sbin/sshd.
The options are as follows:
-b bits
Specifies the number of bits in the ephemeral proto-
col version 1
server key (default 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. Mul-
tiple -d opM--
tions increase the debugging level. Maximum is 3.
-e When this option is specified, sshd will send the
output to the
standard error instead of the system log.
-f configuration_file
Specifies the name of the configuration file. The
default is
/etc/sshd_config. sshd refuses to start if there is
no configuraM--
tion file.
-g login_grace_time
Gives the grace time for clients to authenticate
themselves (deM--
fault 600 seconds). If the client fails to authen-
ticate the user
within this many seconds, the server disconnects and
exits. A
value of zero indicates no limit.
-h host_key_file
Specifies the file from which the host key is read
(default
take tens of
seconds. Clients would have to wait too long if the
key was reM--
generated every time. However, with small key sizes
(e.g., 512)
using sshd from inetd may be feasible.
-k key_gen_time
Specifies how often the ephemeral protocol version 1
server key
is regenerated (default 3600 seconds, or one hour).
The motivaM--
tion 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 commu-
nications even
if the machine is cracked into or physically seized.
A value of
zero indicates that the key will never be regenerat-
ed.
-p port
Specifies the port on which the server listens for
connections
(default 22).
-q Quiet mode. Nothing is sent to the system log.
Normally the beM--
ginning, authentication, and termination of each
connection is
logged.
-u len This option is used to specify the size of the field
in the utmp
structure that holds the remote host name. If the
resolved host
name is longer than len, the dotted decimal value
will be used
instead. This allows hosts with very long host
names that overM--
flow this field to still be uniquely identified.
Specifying -u0
indicates that only dotted decimal addresses should
be put into
the utmp file.
-D When this option is specified sshd will not detach
and does not
become a daemon. This allows easy monitoring of
sshd.
The following keywords are possible.
AFSTokenPassing
Specifies whether an AFS token may be forwarded to
the server.
Default is ``yes''.
AllowGroups
This keyword can be followed by a list of group
names, separated
by spaces. If specified, login is allowed only for
users whose
primary group or supplementary group list matches
one of the patM--
terns. `*' and `?' can be used as wildcards in the
patterns.
Only group names are valid; a numerical group ID
isn't recogM--
nized. By default login is allowed regardless of
the group list.
AllowTcpForwarding
Specifies whether TCP forwarding is permitted. The
default is
``yes''. Note that disabling TCP forwarding does not
improve seM--
curity unless users are also denied shell access, as
they can alM--
ways install their own forwarders.
AllowUsers
This keyword can be followed by a list of user
names, separated
by spaces. If specified, login is allowed only for
users names
that match one of the patterns. `*' and `?' can be
used as wildM--
cards in the patterns. Only user names are valid; a
numerical
user ID isn't recognized. By default login is al-
lowed regardless
of the user name.
Banner In some jurisdictions, sending a warning message be-
fore authentiM--
cation may be relevant for getting legal protection.
The conM--
tents of the specified file are sent to the remote
user before
authentication is allowed. This option is only
available for
protocol version 2.
CheckMail
Specifies whether sshd should check for new mail for
interactive
logins. The default is ``no''.
ClientAliveInterval
Sets a timeout interval in seconds after which if no
data has
been received from the client, sshd will send a mes-
sage through
the encrypted channel to request a response from the
client. The
default is 0, indicating that these messages will
not be sent to
the client. This option applies to protocol version
2 only.
ClientAliveCountMax
Sets the number of client alive messages (see above)
which may be
sent without sshd receiving any messages back from
the client. If
this threshold is reached while client alive mes-
sages are being
sent, sshd will disconnect the client, terminating
the session.
It is important to note that the use of client alive
messages is
very different from Keepalive (below). The client
alive messages
are sent through the encrypted channel and therefore
will not be
spoofable. The TCP keepalive option enabled by
Keepalive is
spoofable. You want to use the client alive mecha-
nism when you
are basing something important on clients having an
active conM--
nection to the server.
The default value is 3. If you set ClientAliveInter-
val (above) to
15, and leave this value at the default, unrespon-
sive ssh clients
will be disconnected after approximately 45 seconds.
DenyGroups
This keyword can be followed by a number of group
names, separatM--
ed by spaces. Users whose primary group or supple-
mentary group
in the patM--
terns. Only user names are valid; a numerical user
ID isn't recM--
ognized. By default login is allowed regardless of
the user
name.
GatewayPorts
Specifies whether remote hosts are allowed to con-
nect to ports
forwarded for the client. The argument must be
``yes'' or
``no''. The default is ``no''.
HostbasedAuthentication
Specifies whether rhosts or /etc/hosts.equiv authen-
tication toM--
gether with successful public key client host au-
thentication is
allowed (hostbased authentication). This option is
similar to
RhostsRSAAuthentication and applies to protocol ver-
sion 2 only.
The default is ``no''.
HostKey
Specifies the file containing the private host keys
(default
/etc/ssh_host_key) used by SSH protocol versions 1
and 2. Note
that sshd will refuse to use a file if it is
group/world-accessiM--
ble. It is possible to have multiple host key
files. ``rsa1''
keys are used for version 1 and ``dsa'' or ``rsa''
are used for
version 2 of the SSH protocol.
IgnoreRhosts
Specifies that .rhosts and .shosts files will not be
used in
RhostsAuthentication, RhostsRSAAuthentication or
HostbasedAuthentication.
/etc/hosts.equiv and /etc/shosts.equiv are still
used. The deM--
fault is ``yes''.
IgnoreUserKnownHosts
Specifies whether sshd should ignore the user's
$HOME/.ssh/known_hosts during RhostsRSAAuthentica-
tion or
initely on the
server, leaving ``ghost'' users and consuming server
resources.
The default is ``yes'' (to send keepalives), and the
server will
notice if the network goes down or the client host
reboots. This
avoids infinitely hanging sessions.
To disable keepalives, the value should be set to
``no'' in both
the server and the client configuration files.
KerberosAuthentication
Specifies whether Kerberos authentication is al-
lowed. This can
be in the form of a Kerberos ticket, or if Passwor-
dAuthentication
is yes, the password provided by the user will be
validated
through the Kerberos KDC. To use this option, the
server needs a
Kerberos servtab which allows the verification of
the KDC's idenM--
tity. Default is ``yes''.
KerberosOrLocalPasswd
If set then if password authentication through Ker-
beros fails
then the password will be validated via any addi-
tional local
mechanism such as /etc/passwd. Default is ``yes''.
KerberosTgtPassing
Specifies whether a Kerberos TGT may be forwarded to
the server.
Default is ``no'', as this only works when the Ker-
beros KDC is
actually an AFS kaserver.
KerberosTicketCleanup
Specifies whether to automatically destroy the us-
er's ticket
cache file on logout. Default is ``yes''.
KeyRegenerationInterval
In protocol version 1, the ephemeral server key is
automatically
regenerated after this many seconds (if it has been
ListenAddress host|IPv4_addr|IPv6_addr
ListenAddress host|IPv4_addr:port
ListenAddress [host|IPv6_addr]:port
If port is not specified, sshd will listen on the
address and all
prior Port options specified. The default is to lis-
ten on all loM--
cal addresses. Multiple ListenAddress options are
permitted. AdM--
ditionally, any Port options must precede this op-
tion for non
port qualified addresses.
LoginGraceTime
The server disconnects after this time if the user
has not sucM--
cessfully logged in. If the value is 0, there is no
time limit.
The default is 600 (seconds).
LogLevel
Gives the verbosity level that is used when logging
messages from
sshd. The possible values are: QUIET, FATAL, ERROR,
INFO, VERBOSE
and DEBUG. The default is INFO. Logging with level
DEBUG vioM--
lates the privacy of users and is not recommended.
MACs Specifies the available MAC (message authentication
code) algoM--
rithms. The MAC algorithm is used in protocol ver-
sion 2 for data
integrity protection. Multiple algorithms must be
comma-separatM--
ed. The default is
``hmac-md5,hmac-sha1,hmac-ripemd160,hmac-
ripemd160@openssh.com,
hmac-sha1-96,hmac-md5-96''
MaxStartups
Specifies the maximum number of concurrent unauthen-
ticated conM--
nections to the sshd daemon. Additional connections
will be
dropped until authentication succeeds or the Login-
GraceTime exM--
pires for a connection. The default is 10.
Alternatively, random early drop can be enabled by
Specifies whether PAM challenge response authentica-
tion is alM--
lowed. This allows the use of most PAM challenge re-
sponse authenM--
tication modules, but it will allow password authen-
tication reM--
gardless of whether PasswordAuthentication is dis-
abled. The deM--
fault is ``no''.
PasswordAuthentication
Specifies whether password authentication is al-
lowed. The deM--
fault is ``yes''.
PermitEmptyPasswords
When password authentication is allowed, it speci-
fies whether the
server allows login to accounts with empty password
strings. The
default is ``no''.
PermitRootLogin
Specifies whether root can login using ssh(1). The
argument must
be ``yes'', ``without-password'', ``forced-commands-
only'' or
``no''. The default is ``yes''.
If this option is set to ``without-password'' pass-
word authentiM--
cation is disabled for root.
If this option is set to ``forced-commands-only''
root login with
public key authentication will be allowed, but only
if the
command option has been specified (which may be use-
ful for taking
remote backups even if root login is normally not
allowed). All
other authentication methods are disabled for root.
If this option is set to ``no'' root is not allowed
to login.
PidFile
Specifies the file that contains the process identi-
fier of the
sshd daemon. The default is /var/run/sshd.pid.
interactively. (On some systems it is also printed
by the shell,
/etc/profile, or equivalent.) The default is
``yes''.
Protocol
Specifies the protocol versions sshd should support.
The possiM--
ble values are ``1'' and ``2''. Multiple versions
must be comma-
separated. The default is ``2,1''.
PubkeyAuthentication
Specifies whether public key authentication is al-
lowed. The deM--
fault is ``yes''. Note that this option applies to
protocol verM--
sion 2 only.
ReverseMappingCheck
Specifies whether sshd should try to verify the re-
mote host name
and check that the resolved host name for the remote
IP address
maps back to the very same IP address. The default
is ``no''.
RhostsAuthentication
Specifies whether authentication using rhosts or
/etc/hosts.equiv
files is sufficient. Normally, this method should
not be permitM--
ted because it is insecure. RhostsRSAAuthentication
should be
used instead, because it performs RSA-based host au-
thentication
in addition to normal rhosts or /etc/hosts.equiv au-
thentication.
The default is ``no''. This option applies to proto-
col version 1
only.
RhostsRSAAuthentication
Specifies whether rhosts or /etc/hosts.equiv authen-
tication toM--
gether with successful RSA host authentication is
allowed. The
default is ``no''. This option applies to protocol
version 1 onM--
ly.
RSAAuthentication
the user's files and home directory before accepting
login. This
is normally desirable because novices sometimes ac-
cidentally
leave their directory or files world-writable. The
default is
``yes''.
Subsystem
Configures an external subsystem (e.g., file trans-
fer daemon).
Arguments should be a subsystem name and a command
to execute upM--
on subsystem request. The command sftp-server(8)
implements the
``sftp'' file transfer subsystem. By default no
subsystems are
defined. Note that this option applies to protocol
version 2 onM--
ly.
SyslogFacility
Gives the facility code that is used when logging
messages from
sshd. The possible values are: DAEMON, USER, AUTH,
LOCAL0, LOM--
CAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LO-
CAL7. The deM--
fault is AUTH.
UseLogin
Specifies whether login(1) is used for interactive
login sesM--
sions. Note that login(1) is never used for remote
command exeM--
cution. The default is ``no''.
X11DisplayOffset
Specifies the first display number available for
sshd's X11 forM--
warding. This prevents sshd from interfering with
real X11
servers. The default is 10.
X11Forwarding
Specifies whether X11 forwarding is permitted. The
default is
``no''. Note that disabling X11 forwarding does not
improve secuM--
rity in any way, as users can always install their
own forM--
warders.
the FILES secM--
tion).
2. If the login is on a tty, records login time.
3. Checks /etc/nologin; if it exists, prints con-
tents and quits
(unless root).
4. Changes to run with normal user privileges.
5. Sets up basic environment.
6. Reads $HOME/.ssh/environment if it exists.
7. Changes to user's home directory.
8. If $HOME/.ssh/rc exists, runs it; else if
/etc/sshrc exists,
runs it; otherwise runs xauth. The ``rc'' files
are given the
X11 authentication protocol and cookie in stan-
dard input.
9. Runs user's shell or command.
AUTHORIZED_KEYS FILE FORMAT
The $HOME/.ssh/authorized_keys file lists the RSA keys that
are permitted
for RSA authentication in protocol version 1 Similarly, the
$HOME/.ssh/authorized_keys2 file lists the DSA and RSA keys
that are perM--
mitted for public key authentication (PubkeyAuthentication)
in protocol
version 2.
Each line of the file contains one key (empty lines and
lines starting
with a `#' are ignored as comments). Each RSA public key
consists of the
following fields, separated by spaces: options, bits, expo-
nent, modulus,
comment. Each protocol version 2 public key consists of:
options, keyM--
type, base64 encoded key, comment. The options fields are
optional; its
presence is determined by whether the line starts with a
number or not
(the option field never starts with a number). The bits,
exponent, moduM--
edit it.
The options (if present) consist of comma-separated option
specificaM--
tions. No spaces are permitted, except within double
quotes. The folM--
lowing option specifications are supported:
from="pattern-list"
Specifies that in addition to RSA authentication,
the canonical
name of the remote host must be present in the com-
ma-separated
list of patterns (`*' and `?' serve as wildcards).
The list may
also contain patterns negated by prefixing them with
`!'; if the
canonical host name matches a negated pattern, the
key is not acM--
cepted. The purpose of this option is to optionally
increase seM--
curity: RSA authentication by itself does not trust
the network
or name servers or anything (but the key); however,
if somebody
somehow steals the key, the key permits an intruder
to log in
from anywhere in the world. This additional option
makes using a
stolen key more difficult (name servers and/or
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 us-
er (if any) is
ignored. The command is run on a pty if the connec-
tion requests
a pty; otherwise it is run without a tty. Note that
if you want
a 8-bit clean channel, you must not request a pty or
should specM--
ify no-pty. A quote may be included in the command
by quoting it
with a backslash. This option might be useful to
restrict cerM--
tain RSA keys to perform just a specific operation.
An example
might be a key that permits remote backups but noth-
ing else.
Forbids TCP/IP forwarding when this key is used for
authenticaM--
tion. Any port forward requests by the client will
return an erM--
ror. This might be used, e.g., in connection with
the command
option.
no-X11-forwarding
Forbids X11 forwarding when this key is used for au-
thentication.
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
may only conM--
nect to the specified host and port. Multiple permi-
topen options
may be applied separated by commas. No pattern
matching is perM--
formed on the specified hostnames, they must be lit-
eral domains
or addresses.
Examples
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 backM--
up.hut.fi
permitopen="10.2.1.55:80",permitopen="10.2.1.56:25" 1024 33
23...2323
SSH_KNOWN_HOSTS FILE FORMAT
The /etc/ssh_known_hosts, /etc/ssh_known_hosts2,
$HOME/.ssh/known_hosts,
and $HOME/.ssh/known_hosts2 files contain host public keys
for all known
hosts. The global file should be prepared by the adminis-
cal host name
(when authenticating a client) or against the user-supplied
name (when
authenticating a server). A pattern may also be preceded by
`!' to indiM--
cate negation: if the host name matches a negated pattern,
it is not acM--
cepted (by that line) even if it matched another pattern on
the line.
Bits, exponent, and modulus are taken directly from the RSA
host key;
they can be obtained, e.g., from /etc/ssh_host_key.pub. The
optional comM--
ment field continues to the end of the line, and is not
used.
Lines starting with `#' and empty lines are ignored as com-
ments.
When performing host authentication, authentication is ac-
cepted if any
matching line has the proper key. It is thus permissible
(but not recomM--
mended) 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 conM--
flicting information; authentication is accepted if valid
information can
be found from either file.
Note that the lines in these files are typically hundreds of
characters
long, and you definitely don't want to type in the host keys
by hand.
Rather, generate them by a script or by taking
/etc/ssh_host_key.pub and
adding the host names at the front.
Examples
closenet,...,130.233.208.41 1024 37 159...93 closenet.hut.fi
cvs.openbsd.org,199.185.137.3 ssh-rsa AAAA1234.....=
FILES
/etc/sshd_config
Contains configuration data for sshd. This file
should be
/etc/ssh_host_key.pub, /etc/ssh_host_dsa_key.pub,
/etc/ssh_host_rsa_key.pub
These three files contain the public parts of the
host keys.
These files should be world-readable but writable
only by root.
Their contents should match the respective private
parts. These
files are not really used for anything; they are
provided for the
convenience of the user so their contents can be
copied to known
hosts files. These files are created using ssh-key-
gen(1).
/etc/primes
Contains Diffie-Hellman groups used for the "Diffie-
Hellman Group
Exchange".
/var/run/sshd.pid
Contains the process ID of the sshd listening for
connections (if
there are several daemons running concurrently for
different
ports, this contains the pid of the one started
last). The conM--
tent of this file is not sensitive; it can be world-
readable.
$HOME/.ssh/authorized_keys
Lists the RSA keys that can be used to log into the
user's acM--
count. This file must be readable by root (which
may on some maM--
chines imply it being world-readable if the user's
home directory
resides on an NFS volume). It is recommended that
it not be acM--
cessible by others. The format of this file is de-
scribed above.
Users will place the contents of their identity.pub
files into
this file, as described in ssh-keygen(1).
$HOME/.ssh/authorized_keys2
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 (which
may on some machines imply it being world-readable
if the user's
key must be
listed in one of these files to be accepted. The
client uses the
same files to verify that it is connecting to the
correct remote
host. These files should be writable only by
root/the owner.
/etc/ssh_known_hosts should be world-readable, and
$HOME/.ssh/known_hosts can but need not be world-
readable.
/etc/ssh_known_hosts2 and $HOME/.ssh/known_hosts2
These files are consulted when using protocol ver-
sion 2 hostbased
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 it is connecting to
the correct reM--
mote host. These files should be writable only by
root/the ownM--
er. /etc/ssh_known_hosts2 should be world-readable,
and
$HOME/.ssh/known_hosts2 can but need not be world-
readable.
/etc/nologin
If this file exists, sshd refuses to let anyone ex-
cept root log
in. The contents of the file are displayed to any-
one trying to
log in, and non-root connections are refused. The
file should be
world-readable.
/etc/hosts.allow, /etc/hosts.deny
If compiled with LIBWRAP support, tcp-wrappers ac-
cess controls
may be defined here as described in hosts_access(5).
$HOME/.rhosts
This file contains host-username pairs, separated by
a 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 writable only by the user;
it is recomM--
mended that it not be accessible by others.
This file is used during .rhosts authentication. In
the simplest
form, this file contains host names, one per line.
Users on
those hosts are permitted to log in without a pass-
word, provided
they have the same user name on both machines. The
host name may
also be followed by a user name; such users are per-
mitted to log
in as any user on this machine (except root). Addi-
tionally, the
syntax ``+@group'' can be used to specify netgroups.
Negated enM--
tries start with `-'.
If the client host/user is successfully matched in
this file, loM--
gin is automatically permitted provided the client
and server usM--
er names are the same. Additionally, successful RSA
host authenM--
tication is normally required. This file must be
writable only
by root; it is recommended that it be world-read-
able.
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.
Using a usM--
er name practically grants the user root access.
The only valid
use for user names that I can think of is in nega-
tive entries.
Note that this warning also applies to rsh/rlogin.
/etc/shosts.equiv
This is processed exactly as /etc/hosts.equiv. How-
ever, this file
may 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).
"proto cookie"
pair in standard input (and DISPLAY in environment).
This must
call xauth(1) in that case.
The primary purpose of this file is to run any ini-
tialization
routines which may be needed before the user's home
directory beM--
comes accessible; AFS is a particular example of
such an environM--
ment.
This file will probably contain some initialization
code followed
by something similar to:
if read proto cookie; then
echo add $DISPLAY $proto $cookie |
xauth -q -
fi
If this file does not exist, /etc/sshrc is run, and
if that does
not exist either, xauth is used to store the cookie.
This file should be writable only by the user, and
need not be
readable by anyone else.
/etc/sshrc
Like $HOME/.ssh/rc. This can be used to specify ma-
chine-specific
login-time initializations globally. This file
should be
writable only by root, and should be world-readable.
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 fea-
tures and creM--
ated OpenSSH. Markus Friedl contributed the support for SSH
protocol
versions 1.5 and 2.0.
SEE ALSO
scp(1), sftp(1), sftp-server(8), ssh(1), ssh-add(1),
ssh-agent(1),
ssh-keygen(1), rlogin(1), rsh(1)
BSD Experimental September 25, 1999
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