Provided by: libconfig-model-openssh-perl_2.9.4.1-1_all bug

NAME

       Config::Model::models::Sshd - Configuration class Sshd

DESCRIPTION

       Configuration classes used by Config::Model

       This configuration class was generated from sshd_system documentation.  by parse-man.pl
       <https://github.com/dod38fr/config-model-openssh/contrib/parse-man.pl>

Elements

   AcceptEnv
       Specifies what environment variables sent by the client will be copied into the session's environ(7). See
       SendEnv and SetEnv in ssh_config5 for how to configure the client. The TERM environment variable is
       always accepted whenever the client requests a pseudo-terminal as it is required by the protocol.
       Variables are specified by name, which may contain the wildcard characters '*' and '?' Multiple
       environment variables may be separated by whitespace or spread across multiple AcceptEnv directives. Be
       warned that some environment variables could be used to bypass restricted user environments. For this
       reason, care should be taken in the use of this directive. The default is not to accept any environment
       variables.  Optional. Type list of uniline.

   AllowAgentForwarding
       Specifies whether ssh-agent1 forwarding is permitted. The default is yes Note that disabling agent
       forwarding does not improve security unless users are also denied shell access, as they can always
       install their own forwarders.  Optional. Type boolean.

       upstream_default value :
           yes

   AllowGroups
       This  keyword  can be followed by a list of group name patterns, separated by spaces. If specified, login
       is allowed only for users whose primary group or supplementary group list matches one  of  the  patterns.
       Only  group names are valid; a numerical group ID is not recognized. By default, login is allowed for all
       groups. The allow/deny groups directives are processed in the following order: DenyGroups AllowGroups

       See PATTERNS in ssh_config5 for more information on patterns. This keyword may appear multiple  times  in
       sshd_config with each instance appending to the list.  Optional. Type list of uniline.

   AllowStreamLocalForwarding
       Specifies whether StreamLocal (Unix-domain socket) forwarding is permitted. The available options are yes
       (the  default) or all to allow StreamLocal forwarding, no to prevent all StreamLocal forwarding, local to
       allow local (from the perspective of ssh(1)) forwarding only or remote to allow remote  forwarding  only.
       Note  that  disabling StreamLocal forwarding does not improve security unless users are also denied shell
       access, as they can always install their own forwarders.  Optional. Type enum.  choice:  'all',  'local',
       'no', 'remote', 'yes'.

       upstream_default value :
           yes

   AllowTcpForwarding
       Specifies  whether  TCP  forwarding  is  permitted. The available options are yes (the default) or all to
       allow TCP forwarding, no to prevent all TCP forwarding, local to allow local  (from  the  perspective  of
       ssh(1))  forwarding  only  or  remote to allow remote forwarding only. Note that disabling TCP forwarding
       does not improve security unless users are also denied shell access, as they can always install their own
       forwarders.  Optional. Type enum. choice: 'all', 'local', 'no', 'remote', 'yes'.

       upstream_default value :
           yes

   AllowUsers
       This keyword can be followed by a list of user name patterns, separated by spaces. If specified, login is
       allowed only for user names that match one of the patterns. Only user names are valid; a  numerical  user
       ID  is  not  recognized.   By  default,  login  is  allowed  for all users. If the pattern takes the form
       USER@HOST then USER and HOST  are  separately  checked,  restricting  logins  to  particular  users  from
       particular  hosts.  HOST  criteria  may  additionally  contain addresses to match in CIDR address/masklen
       format. The allow/deny users directives are processed in the following order: DenyUsers AllowUsers

       See PATTERNS in ssh_config5 for more information on patterns. This keyword may appear multiple  times  in
       sshd_config with each instance appending to the list.  Optional. Type list of uniline.

   AuthenticationMethods
       Specifies the authentication methods that must be successfully completed for a user to be granted access.
       This  option  must be followed by one or more lists of comma-separated authentication method names, or by
       the single string any to indicate the default behaviour of accepting any  single  authentication  method.
       If  the  default  is overridden, then successful authentication requires completion of every method in at
       least one of these lists.

       For example, Qq publickey, password publickey, keyboard-interactive would require the  user  to  complete
       public  key  authentication,  followed  by  either  password or keyboard interactive authentication. Only
       methods that are next in one or more lists are offered at each stage, so for this example it would not be
       possible to attempt password or keyboard-interactive authentication before public key.

       For keyboard interactive authentication it is also possible to  restrict  authentication  to  a  specific
       device  by  appending  a  colon  followed by the device identifier bsdauth or pam depending on the server
       configuration.  For  example,  Qq  keyboard-interactive:bsdauth  would  restrict   keyboard   interactive
       authentication to the bsdauth device.

       If  the  publickey  method  is  listed  more  than  once,  sshd(8) verifies that keys that have been used
       successfully are not reused  for  subsequent  authentications.   For  example,  Qq  publickey,  publickey
       requires successful authentication using two different public keys.

       Note that each authentication method listed should also be explicitly enabled in the configuration.

       The  available  authentication methods are: Qq gssapi-with-mic , Qq hostbased , Qq keyboard-interactive ,
       Qq none (used for access to password-less accounts when PermitEmptyPasswords is enabled), Qq password and
       Qq publickey .  Optional. Type uniline.

   AuthorizedKeysCommand
       Specifies a program to be used to look up the user's public keys. The program must be owned by root,  not
       writable  by group or others and specified by an absolute path. Arguments to AuthorizedKeysCommand accept
       the tokens described in the TOKENS section. If no arguments are specified then the username of the target
       user is used.

       The program should produce on  standard  output  zero  or  more  lines  of  authorized_keys  output  (see
       AUTHORIZED_KEYS in sshd(8)).  AuthorizedKeysCommand is tried after the usual AuthorizedKeysFile files and
       will  not  be  executed  if  a  matching key is found there. By default, no AuthorizedKeysCommand is run.
       Optional. Type uniline.

   AuthorizedKeysCommandUser
       Specifies the user under whose account the AuthorizedKeysCommand is run.  It  is  recommended  to  use  a
       dedicated  user  that  has  no  other  role  on  the  host  than  running  authorized  keys  commands. If
       AuthorizedKeysCommand is specified but AuthorizedKeysCommandUser is not,  then  sshd(8)  will  refuse  to
       start.  Optional. Type uniline.

   AuthorizedKeysFile
       Specifies  the  file that contains the public keys used for user authentication.  The format is described
       in the AUTHORIZED_KEYS FILE FORMAT section of sshd(8). Arguments to AuthorizedKeysFile accept the  tokens
       described  in  the TOKENS section. After expansion, AuthorizedKeysFile is taken to be an absolute path or
       one relative to the user's home directory.  Multiple  files  may  be  listed,  separated  by  whitespace.
       Alternately  this  option  may  be set to none to skip checking for user keys in files. The default is Qq
       .ssh/authorized_keys .ssh/authorized_keys2 .  Optional. Type list of uniline.

       Note: AuthorizedKeysFile values are migrated from '- AuthorizedKeysFile2'

   AuthorizedPrincipalsCommand
       Specifies a program  to  be  used  to  generate  the  list  of  allowed  certificate  principals  as  per
       AuthorizedPrincipalsFile The program must be owned by root, not writable by group or others and specified
       by  an absolute path.  Arguments to AuthorizedPrincipalsCommand accept the tokens described in the TOKENS
       section. If no arguments are specified then the username of the target user is used.

       The program should produce on standard output zero or more lines of AuthorizedPrincipalsFile  output.  If
       either AuthorizedPrincipalsCommand or AuthorizedPrincipalsFile is specified, then certificates offered by
       the   client   for   authentication   must   contain   a   principal  that  is  listed.  By  default,  no
       AuthorizedPrincipalsCommand is run.  Optional. Type uniline.

   AuthorizedPrincipalsCommandUser
       Specifies the user under whose account the AuthorizedPrincipalsCommand is run. It is recommended to use a
       dedicated user that has no other role on  the  host  than  running  authorized  principals  commands.  If
       AuthorizedPrincipalsCommand  is  specified  but AuthorizedPrincipalsCommandUser is not, then sshd(8) will
       refuse to start.  Optional. Type uniline.

   AuthorizedPrincipalsFile
       Specifies a file that lists principal names that are accepted for certificate authentication. When  using
       certificates  signed by a key listed in TrustedUserCAKeys this file lists names, one of which must appear
       in the certificate for it to be accepted for authentication. Names are listed one per  line  preceded  by
       key  options  (as described in AUTHORIZED_KEYS FILE FORMAT in sshd(8)). Empty lines and comments starting
       with '#' are ignored.

       Arguments to AuthorizedPrincipalsFile accept the tokens described in the TOKENS section. After expansion,
       AuthorizedPrincipalsFile is taken to be an absolute path or one relative to the  user's  home  directory.
       The  default  is  none  i.e.  not  to use a principals file - in this case, the username of the user must
       appear in a certificate's principals list for it to be accepted.

       Note that AuthorizedPrincipalsFile is only used  when  authentication  proceeds  using  a  CA  listed  in
       TrustedUserCAKeys  and  is not consulted for certification authorities trusted via ~/.ssh/authorized_keys
       though the principals= key option offers a similar facility (see sshd(8) for  details).   Optional.  Type
       uniline.

       upstream_default value :
           none

   Banner
       The  contents  of the specified file are sent to the remote user before authentication is allowed. If the
       argument is none then no banner is displayed.  By  default,  no  banner  is  displayed.   Optional.  Type
       uniline.

   CASignatureAlgorithms
       Specifies  which algorithms are allowed for signing of certificates by certificate authorities (CAs). The
       default    is:    ssh-ed25519,     ecdsa-sha2-nistp256,     ecdsa-sha2-nistp384,     ecdsa-sha2-nistp521,
       sk-ssh-ed25519@openssh.com, sk-ecdsa-sha2-nistp256@openssh.com, rsa-sha2-512, rsa-sha2-256

       If  the specified list begins with a '+' character, then the specified algorithms will be appended to the
       default set instead of replacing them. If the specified list  begins  with  a  '-'  character,  then  the
       specified  algorithms  (including  wildcards)  will  be removed from the default set instead of replacing
       them.

       Certificates  signed  using  other  algorithms  will  not  be  accepted  for  public  key  or  host-based
       authentication.  Optional. Type uniline.

   ChannelTimeout
       Specifies  whether and how quickly sshd(8) should close inactive channels.  Timeouts are specified as one
       or more ''type=interval'' pairs separated by whitespace, where the ''type'' must be a channel  type  name
       (as described in the table below), optionally containing wildcard characters.

       The timeout value ''interval'' is specified in seconds or may use any of the units documented in the TIME
       FORMATS  section.  For example, ''session:*=5m'' would cause all sessions to terminate after five minutes
       of inactivity.  Specifying a zero value disables the inactivity timeout.

       The available channel types include:

       agent-connection Open connections to ssh-agent1. direct-tcpip , direct-streamlocal@openssh.com  Open  TCP
       or Unix socket (respectively) connections that have been established from a ssh(1) local forwarding, i.e.
       LocalForward  or  DynamicForward  forwarded-tcpip  ,  forwarded-streamlocal@openssh.com  Open TCP or Unix
       socket (respectively) connections that have been established to a sshd(8) listening on behalf of a ssh(1)
       remote  forwarding,  i.e.  RemoteForward  session:command  Command  execution   sessions.   session:shell
       Interactive  shell  sessions.  session:subsystem:... Subsystem sessions, e.g. for sftp(1), which could be
       identified as session:subsystem:sftp x11-connection Open X11 forwarding sessions.

       Note that in all the above cases, terminating an inactive  session  does  not  guarantee  to  remove  all
       resources  associated  with  the session, e.g. shell processes or X11 clients relating to the session may
       continue to execute.

       Moreover, terminating an inactive channel or session does not necessarily close the SSH  connection,  nor
       does  it  prevent  a  client from requesting another channel of the same type. In particular, expiring an
       inactive forwarding session does  not  prevent  another  identical  forwarding  from  being  subsequently
       created. See also UnusedConnectionTimeout which may be used in conjunction with this option.

       The default is not to expire channels of any type for inactivity.  Optional. Type uniline.

   ChrootDirectory
       Specifies  the  pathname of a directory to chroot(2) to after authentication.  At session startup sshd(8)
       checks that all components of the pathname are root-owned directories which are not writable by any other
       user or group. After the chroot, sshd(8) changes the working directory  to  the  user's  home  directory.
       Arguments to ChrootDirectory accept the tokens described in the TOKENS section.

       The  ChrootDirectory  must contain the necessary files and directories to support the user's session. For
       an interactive session this requires at least a shell, typically sh(1), and  basic  /dev  nodes  such  as
       null(4),  zero(4),  stdin(4),  stdout(4), stderr(4), and tty(4) devices. For file transfer sessions using
       SFTP no additional configuration of the environment is necessary if the in-process sftp-server  is  used,
       though  sessions  which  use  logging  may require /dev/log inside the chroot directory on some operating
       systems (see sftp-server8 for details).

       For safety, it is very important that the directory hierarchy be prevented  from  modification  by  other
       processes  on  the  system  (especially  those  outside  the  jail).  Misconfiguration can lead to unsafe
       environments which sshd(8) cannot detect.

       The default is none indicating not to chroot(2).  Optional. Type uniline.

       upstream_default value :
           none

   ClientAliveCountMax
       Sets the number of client alive messages which may be sent without sshd(8) receiving  any  messages  back
       from  the  client.  If  this  threshold  is reached while client alive messages 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 TCPKeepAlive The client alive messages are sent through the encrypted
       channel and therefore will not be  spoofable.  The  TCP  keepalive  option  enabled  by  TCPKeepAlive  is
       spoofable.  The  client  alive  mechanism  is valuable when the client or server depend on knowing when a
       connection has become unresponsive.

       The default value is 3. If ClientAliveInterval is set to 15,  and  ClientAliveCountMax  is  left  at  the
       default,  unresponsive  SSH  clients  will be disconnected after approximately 45 seconds. Setting a zero
       ClientAliveCountMax disables connection termination.  Optional. Type integer.

       upstream_default value :
           3

   ClientAliveInterval
       Sets a timeout interval in seconds after which if no data has been received from the client, sshd(8) will
       send a message 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.  Optional. Type integer.

       upstream_default value :
           0

   DenyGroups
       This  keyword  can be followed by a list of group name patterns, separated by spaces. Login is disallowed
       for users whose primary group or supplementary group list matches one of the patterns. Only  group  names
       are  valid;  a  numerical  group  ID  is not recognized. By default, login is allowed for all groups. The
       allow/deny groups directives are processed in the following order: DenyGroups AllowGroups

       See PATTERNS in ssh_config5 for more information on patterns. This keyword may appear multiple  times  in
       sshd_config with each instance appending to the list.  Optional. Type list of uniline.

   DenyUsers
       This  keyword  can  be followed by a list of user name patterns, separated by spaces. Login is disallowed
       for user names that match one of the patterns. Only user names are valid; a  numerical  user  ID  is  not
       recognized. By default, login is allowed for all users. If the pattern takes the form USER@HOST then USER
       and  HOST  are  separately  checked,  restricting  logins to particular users from particular hosts. HOST
       criteria may additionally contain addresses to match in CIDR address/masklen format. The allow/deny users
       directives are processed in the following order: DenyUsers AllowUsers

       See PATTERNS in ssh_config5 for more information on patterns. This keyword may appear multiple  times  in
       sshd_config with each instance appending to the list.  Optional. Type list of uniline.

   DisableForwarding
       Disables  all  forwarding features, including X11, ssh-agent1, TCP and StreamLocal. This option overrides
       all other forwarding-related options and may simplify restricted configurations.  Optional. Type uniline.

   ExposeAuthInfo
       Writes a temporary file containing a list of authentication methods and public  credentials  (e.g.  keys)
       used  to  authenticate  the  user.  The  location  of the file is exposed to the user session through the
       SSH_USER_AUTH environment variable. The default is no  Optional. Type boolean.

       upstream_default value :
           no

   ForceCommand
       Forces the execution of the command specified by ForceCommand ignoring any command supplied by the client
       and ~/.ssh/rc if present. The command is invoked by using the user's login shell with the -c option. This
       applies to shell, command, or subsystem execution. It is most useful inside a Match  block.  The  command
       originally  supplied  by  the  client  is  available  in  the  SSH_ORIGINAL_COMMAND environment variable.
       Specifying a command of internal-sftp will force the use of an in-process SFTP server  that  requires  no
       support files when used with ChrootDirectory The default is none  Optional. Type uniline.

       upstream_default value :
           none

   GatewayPorts
       Specifies  whether  remote  hosts  are  allowed to connect to ports forwarded for the client. By default,
       sshd(8) binds remote port forwardings to the loopback address. This  prevents  other  remote  hosts  from
       connecting  to  forwarded  ports.  GatewayPorts can be used to specify that sshd should allow remote port
       forwardings to bind to non-loopback addresses, thus allowing other hosts to connect. The argument may  be
       no  to  force  remote  port  forwardings to be available to the local host only, yes to force remote port
       forwardings to bind to the wildcard address, or clientspecified to allow the client to select the address
       to which the forwarding is bound. The default is no   Optional.  Type  enum.  choice:  'clientspecified',
       'no', 'yes'.

       upstream_default value :
           no

   GSSAPIAuthentication
       Specifies  whether  user  authentication  based  on  GSSAPI is allowed. The default is no  Optional. Type
       boolean.

       upstream_default value :
           no

   HostbasedAcceptedAlgorithms
       Specifies the signature algorithms that will be accepted for hostbased authentication as a list of comma-
       separated patterns. Alternately if the specified list begins with a '+'  character,  then  the  specified
       signature algorithms will be appended to the default set instead of replacing them. If the specified list
       begins  with  a  '-'  character,  then  the  specified signature algorithms (including wildcards) will be
       removed from the default set instead of  replacing  them.  If  the  specified  list  begins  with  a  '^'
       character,  then  the  specified signature algorithms will be placed at the head of the default set.  The
       default for this option is:  ssh-ed25519-cert-v01@openssh.com,  ecdsa-sha2-nistp256-cert-v01@openssh.com,
       ecdsa-sha2-nistp384-cert-v01@openssh.com,                       ecdsa-sha2-nistp521-cert-v01@openssh.com,
       sk-ssh-ed25519-cert-v01@openssh.com,                         sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
       rsa-sha2-512-cert-v01@openssh.com,  rsa-sha2-256-cert-v01@openssh.com,  ssh-ed25519, ecdsa-sha2-nistp256,
       ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, sk-ssh-ed25519@openssh.com, sk-ecdsa-sha2-nistp256@openssh.com,
       rsa-sha2-512, rsa-sha2-256

       The   list   of   available   signature   algorithms   may   also   be   obtained   using   Qq   ssh   -Q
       HostbasedAcceptedAlgorithms . This was formerly named HostbasedAcceptedKeyTypes.  Optional. Type uniline.

   HostbasedAuthentication
       Specifies  whether  rhosts  or /etc/hosts.equiv authentication together with successful public key client
       host authentication is allowed (host-based authentication). The default is no  Optional. Type boolean.

       upstream_default value :
           no

   HostbasedUsesNameFromPacketOnly
       Specifies whether or not the server will attempt to perform a reverse name lookup when matching the  name
       in  the  ~/.shosts  ~/.rhosts  and /etc/hosts.equiv files during HostbasedAuthentication A setting of yes
       means that sshd(8) uses the name supplied by the client rather than attempting to resolve the  name  from
       the TCP connection itself. The default is no  Optional. Type boolean.

       upstream_default value :
           no

   IgnoreRhosts
       Specifies whether to ignore per-user .rhosts and .shosts files during HostbasedAuthentication The system-
       wide /etc/hosts.equiv and /etc/ssh/shosts.equiv are still used regardless of this setting.

       Accepted  values  are  yes  (the  default)  to ignore all per-user files, shosts-only to allow the use of
       .shosts but to ignore .rhosts or no to allow both .shosts and rhosts.  Optional. Type boolean.

       upstream_default value :
           yes

   Include
       Include the specified configuration file(s). Multiple pathnames may be specified and  each  pathname  may
       contain  glob(7)  wildcards  that will be expanded and processed in lexical order. Files without absolute
       paths are assumed to be in /etc/ssh An Include directive may appear  inside  a  Match  block  to  perform
       conditional inclusion.  Optional. Type list of uniline.

   IPQoS
       Specifies  the  IPv4 type-of-service or DSCP class for the connection. Accepted values are af11 af12 af13
       af21 af22 af23 af31 af32 af33 af41 af42 af43 cs0 cs1 cs2 cs3 cs4 cs5 cs6 cs7 ef  le  lowdelay  throughput
       reliability a numeric value, or none to use the operating system default. This option may take one or two
       arguments,  separated  by  whitespace.  If  one  argument  is  specified,  it is used as the packet class
       unconditionally. If two values are  specified,  the  first  is  automatically  selected  for  interactive
       sessions  and  the  second for non-interactive sessions. The default is lowdelay for interactive sessions
       and throughput for non-interactive sessions.  Optional. Type uniline.

       upstream_default value :
           af21 cs1

   KbdInteractiveAuthentication
       Specifies whether to allow keyboard-interactive authentication. The default is yes The argument  to  this
       keyword must be yes or no ChallengeResponseAuthentication is a deprecated alias for this.  Optional. Type
       boolean.

       upstream_default value :
           yes

       Note: KbdInteractiveAuthentication is migrated with '$old' and with:

       •   $old => "- ChallengeResponseAuthentication"

   KerberosAuthentication
       Specifies  whether the password provided by the user for PasswordAuthentication 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 identity. The default is no  Optional. Type boolean.

       upstream_default value :
           no

   LogLevel
       Gives  the  verbosity  level  that  is used when logging messages from sshd(8).  The possible values are:
       QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default  is  INFO.  DEBUG  and
       DEBUG1  are equivalent.  DEBUG2 and DEBUG3 each specify higher levels of debugging output. Logging with a
       DEBUG level violates the privacy of users and is not recommended.  Optional. Type enum. choice:  'DEBUG',
       'DEBUG1', 'DEBUG2', 'DEBUG3', 'ERROR', 'FATAL', 'INFO', 'QUIET', 'VERBOSE'.

       upstream_default value :
           INFO

   MaxAuthTries
       Specifies  the  maximum  number  of  authentication attempts permitted per connection. Once the number of
       failures reaches half this value, additional failures are logged.  The  default  is  6.   Optional.  Type
       integer.

       upstream_default value :
           6

   MaxSessions
       Specifies the maximum number of open shell, login or subsystem (e.g. sftp) sessions permitted per network
       connection. Multiple sessions may be established by clients that support connection multiplexing. Setting
       MaxSessions  to 1 will effectively disable session multiplexing, whereas setting it to 0 will prevent all
       shell, login and subsystem sessions while still permitting forwarding. The default is 10.  Optional. Type
       integer.

       upstream_default value :
           10

   PasswordAuthentication
       Specifies whether password authentication is allowed. The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   PermitEmptyPasswords
       When password authentication is allowed, it specifies whether the server allows login  to  accounts  with
       empty password strings. The default is no  Optional. Type boolean.

       upstream_default value :
           no

   PermitListen
       Specifies the addresses/ports on which a remote TCP port forwarding may listen.  The listen specification
       must be one of the following forms:

       PermitListen port PermitListen host : port

       Multiple  permissions may be specified by separating them with whitespace. An argument of any can be used
       to remove all restrictions and permit any listen requests. An argument of none can be  used  to  prohibit
       all  listen  requests.   The  host  name  may  contain  wildcards as described in the PATTERNS section in
       ssh_config5. The wildcard '*' can also be used in place of a port number to allow all ports.  By  default
       all  port  forwarding  listen  requests  are  permitted.   Note  that the GatewayPorts option may further
       restrict which addresses may be listened on. Note  also  that  ssh(1)  will  request  a  listen  host  of
       ''localhost''  if  no  listen  host  was  specifically requested, and this name is treated differently to
       explicit localhost addresses of ''127.0.0.1'' and ''::1''  Optional. Type list of uniline.

   PermitOpen
       Specifies the destinations to which TCP port forwarding is permitted. The forwarding  specification  must
       be one of the following forms:

       PermitOpen host : port PermitOpen IPv4_addr : port PermitOpen [ IPv6_addr ] : port

       Multiple  forwards may be specified by separating them with whitespace. An argument of any can be used to
       remove all restrictions and permit any forwarding requests. An argument of none can be used  to  prohibit
       all  forwarding  requests.  The  wildcard  '*'  can  be used for host or port to allow all hosts or ports
       respectively. Otherwise, no pattern matching or address lookups  are  performed  on  supplied  names.  By
       default all port forwarding requests are permitted.  Optional. Type list of uniline.

   PermitRootLogin
       Specifies  whether  root  can  log  in  using  ssh(1). The argument must be yes prohibit-password forced-
       commands-only or no The default is prohibit-password

       If this option is set to prohibit-password (or its deprecated  alias,  without-password  )  password  and
       keyboard-interactive authentication are 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 useful 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  log  in.   Optional.  Type  enum.  choice:
       'forced-commands-only', 'no', 'prohibit-password', 'yes'.

   PermitTTY
       Specifies whether pty(4) allocation is permitted. The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   PermitTunnel
       Specifies whether tun(4) device forwarding is allowed. The argument must be yes point-to-point (layer 3),
       ethernet (layer 2), or no Specifying yes permits both point-to-point and ethernet The default is no

       Independent of this setting, the permissions of the selected tun(4) device must allow access to the user.
       Optional. Type enum. choice: 'ethernet', 'no', 'point-to-point', 'yes'.

       upstream_default value :
           no

   PermitUserRC
       Specifies whether any ~/.ssh/rc file is executed. The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   PubkeyAcceptedAlgorithms
       Specifies the signature algorithms that will be accepted for public  key  authentication  as  a  list  of
       comma-separated  patterns.  Alternately  if  the  specified  list  begins  with a '+' character, then the
       specified algorithms will be appended to the default set instead of replacing them. If the specified list
       begins with a '-' character, then the specified algorithms (including wildcards) will be removed from the
       default set instead of replacing them. If the specified list  begins  with  a  '^'  character,  then  the
       specified  algorithms  will  be  placed  at  the head of the default set. The default for this option is:
       ssh-ed25519-cert-v01@openssh.com,                               ecdsa-sha2-nistp256-cert-v01@openssh.com,
       ecdsa-sha2-nistp384-cert-v01@openssh.com,                       ecdsa-sha2-nistp521-cert-v01@openssh.com,
       sk-ssh-ed25519-cert-v01@openssh.com,                         sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
       rsa-sha2-512-cert-v01@openssh.com,  rsa-sha2-256-cert-v01@openssh.com,  ssh-ed25519, ecdsa-sha2-nistp256,
       ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, sk-ssh-ed25519@openssh.com, sk-ecdsa-sha2-nistp256@openssh.com,
       rsa-sha2-512, rsa-sha2-256

       The list of available signature algorithms may also be obtained using Qq ssh -Q  PubkeyAcceptedAlgorithms
       .  Optional. Type uniline.

   PubkeyAuthOptions
       Sets  one  or  more  public  key  authentication  options. The supported keywords are: none (the default;
       indicating no additional options are enabled), touch-required and verify-required

       The touch-required option causes public key authentication using a  FIDO  authenticator  algorithm  (i.e.
       ecdsa-sk  or  ed25519-sk  to  always  require  the  signature  to  attest  that a physically present user
       explicitly confirmed the authentication (usually by touching  the  authenticator).  By  default,  sshd(8)
       requires user presence unless overridden with an authorized_keys option. The touch-required flag disables
       this override.

       The  verify-required  option  requires a FIDO key signature attest that the user was verified, e.g. via a
       PIN.

       Neither the touch-required or verify-required options have any effect for  other,  non-FIDO,  public  key
       types.  Optional. Type enum. choice: 'none', 'touch-required', 'verify-required'.

   PubkeyAuthentication
       Specifies whether public key authentication is allowed. The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   RekeyLimit
       Specifies  the  maximum  amount  of  data  that  may be transmitted or received before the session key is
       renegotiated, optionally followed by a maximum amount of time that may pass before  the  session  key  is
       renegotiated.  The  first  argument  is  specified  in  bytes  and may have a suffix of 'K' 'M' or 'G' to
       indicate Kilobytes, Megabytes, or Gigabytes, respectively. The default is between '1G' and '4G' depending
       on the cipher. The optional second value is specified in seconds and may use any of the units  documented
       in  the TIME FORMATS section.  The default value for RekeyLimit is default none which means that rekeying
       is performed after the cipher's default amount of data has been  sent  or  received  and  no  time  based
       rekeying is done.  Optional. Type uniline.

   RevokedKeys
       Specifies  revoked public keys file, or none to not use one. Keys listed in this file will be refused for
       public key authentication. Note that if this file is not readable, then public key authentication will be
       refused for all users.  Keys may be specified as a text file, listing one public key per line, or  as  an
       OpenSSH  Key Revocation List (KRL) as generated by ssh-keygen1. For more information on KRLs, see the KEY
       REVOCATION LISTS section in ssh-keygen1.  Optional. Type uniline.

   SetEnv
       Specifies one or more environment variables to set in child sessions started by sshd(8) as ''NAME=VALUE''
       The environment value may be quoted (e.g. if it contains whitespace  characters).  Environment  variables
       set  by  SetEnv override the default environment and any variables specified by the user via AcceptEnv or
       PermitUserEnvironment  Optional. Type uniline.

   StreamLocalBindMask
       Sets the octal file creation mode mask (umask) used when creating a Unix-domain socket file for local  or
       remote port forwarding. This option is only used for port forwarding to a Unix-domain socket file.

       The  default value is 0177, which creates a Unix-domain socket file that is readable and writable only by
       the owner. Note that not all  operating  systems  honor  the  file  mode  on  Unix-domain  socket  files.
       Optional. Type uniline.

   StreamLocalBindUnlink
       Specifies  whether  to  remove  an  existing  Unix-domain socket file for local or remote port forwarding
       before creating a new one. If the socket file already exists and StreamLocalBindUnlink  is  not  enabled,
       sshd will be unable to forward the port to the Unix-domain socket file. This option is only used for port
       forwarding to a Unix-domain socket file.

       The argument must be yes or no The default is no  Optional. Type boolean.

       upstream_default value :
           no

   TrustedUserCAKeys
       Specifies  a  file  containing  public  keys  of  certificate  authorities  that are trusted to sign user
       certificates for authentication, or none to not use one. Keys are listed one per line;  empty  lines  and
       comments  starting  with  '#'  are  allowed. If a certificate is presented for authentication and has its
       signing CA key listed in this file, then it may be used for authentication for any  user  listed  in  the
       certificate's  principals  list.  Note  that  certificates  that  lack  a  list of principals will not be
       permitted  for  authentication  using  TrustedUserCAKeys  For  more  details  on  certificates,  see  the
       CERTIFICATES section in ssh-keygen1.  Optional. Type uniline.

   UnusedConnectionTimeout
       Specifies  whether  and  how  quickly sshd(8) should close client connections with no open channels. Open
       channels include active shell, command execution or subsystem sessions, connected network, socket,  agent
       or  X11  forwardings.  Forwarding listeners, such as those from the ssh(1) -R flag, are not considered as
       open channels and do not prevent the timeout. The timeout value is specified in seconds or may use any of
       the units documented in the TIME FORMATS section.

       Note that this timeout starts when the client connection completes user  authentication  but  before  the
       client  has an opportunity to open any channels.  Caution should be used when using short timeout values,
       as they may not provide sufficient  time  for  the  client  to  request  and  open  its  channels  before
       terminating the connection.

       The  default  none is to never expire connections for having no open channels.  This option may be useful
       in conjunction with ChannelTimeout  Optional. Type uniline.

   X11DisplayOffset
       Specifies the first display number available for sshd(8)Ns's X11 forwarding.   This  prevents  sshd  from
       interfering with real X11 servers. The default is 10.  Optional. Type uniline.

   X11Forwarding
       Specifies whether X11 forwarding is permitted. The argument must be yes or no The default is no

       When  X11 forwarding is enabled, there may be additional exposure to the server and to client displays if
       the sshd(8) proxy display is configured to listen on the wildcard address (see X11UseLocalhost  )  though
       this  is  not the default. Additionally, the authentication spoofing and authentication data verification
       and substitution occur on the client side. The security risk of using X11 forwarding is that the client's
       X11 display server may be exposed to attack when the SSH client requests forwarding (see the warnings for
       ForwardX11 in ssh_config5). A system administrator may have a  stance  in  which  they  want  to  protect
       clients  that may expose themselves to attack by unwittingly requesting X11 forwarding, which can warrant
       a no setting.

       Note that disabling X11 forwarding does not prevent users from  forwarding  X11  traffic,  as  users  can
       always install their own forwarders.  Optional. Type boolean.

       upstream_default value :
           no

   X11UseLocalhost
       Specifies  whether  sshd(8)  should  bind  the  X11  forwarding  server to the loopback address or to the
       wildcard address. By default, sshd binds the forwarding server to  the  loopback  address  and  sets  the
       hostname part of the DISPLAY environment variable to localhost This prevents remote hosts from connecting
       to  the  proxy  display.  However,  some  older  X11  clients  may  not function with this configuration.
       X11UseLocalhost may be set to no to specify that the forwarding server should be bound  to  the  wildcard
       address. The argument must be yes or no The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   AuthorizedKeysFile2
       This parameter is now ignored by Ssh. Deprecated  Optional. Type list of uniline.

   ChallengeResponseAuthentication
       Deprecated  Optional. Type boolean.

   KeyRegenerationInterval
       Deprecated  Optional. Type uniline.

   Protocol
       Deprecated  Optional. Type uniline.

   RDomain
       Deprecated  Optional. Type uniline.

   RSAAuthentication
       Deprecated  Optional. Type uniline.

   RhostsRSAAuthentication
       Deprecated  Optional. Type uniline.

   UsePrivilegeSeparation
       Deprecated  Optional. Type uniline.

   AddressFamily
       Specifies  which  address  family  should be used by sshd(8). Valid arguments are any (the default), inet
       (use IPv4 only), or inet6 (use IPv6 only).  Optional. Type enum. choice: 'any', 'inet', 'inet6'.

       upstream_default value :
           any

   Ciphers
       Specifies the ciphers allowed. Multiple ciphers must be comma-separated. If  the  specified  list  begins
       with a '+' character, then the specified ciphers will be appended to the default set instead of replacing
       them. If the specified list begins with a '-' character, then the specified ciphers (including wildcards)
       will  be  removed from the default set instead of replacing them. If the specified list begins with a '^'
       character, then the specified ciphers will be placed at the head of the default set.

       The supported ciphers are:

       3des-cbc  aes128-cbc  aes192-cbc  aes256-cbc  aes128-ctr  aes192-ctr  aes256-ctr   aes128-gcm@openssh.com
       aes256-gcm@openssh.com chacha20-poly1305@openssh.com

       The     default     is:     chacha20-poly1305@openssh.com,     aes128-ctr,     aes192-ctr,    aes256-ctr,
       aes128-gcm@openssh.com, aes256-gcm@openssh.com

       The list of available ciphers may also be obtained using Qq ssh -Q cipher .  Optional. Type uniline.

   Compression
       Specifies whether compression is enabled after the user has authenticated successfully. The argument must
       be yes delayed (a legacy synonym for yes  or  no  The  default  is  yes   Optional.  Type  enum.  choice:
       'delayed', 'no', 'yes'.

       upstream_default value :
           yes

   DebianBanner
       Specifies  whether  the  distribution-specified  extra version suffix is included during initial protocol
       handshake. The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   FingerprintHash
       Specifies the hash algorithm used when logging key fingerprints. Valid options are: md5  and  sha256  The
       default is sha256  Optional. Type enum. choice: 'md5', 'sha256'.

       upstream_default value :
           sha256

   GSSAPICleanupCredentials
       Specifies  whether  to  automatically  destroy the user's credentials cache on logout. The default is yes
       Optional. Type boolean.

       upstream_default value :
           yes

   GSSAPIKeyExchange
       Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange doesn't rely on  ssh  keys
       to verify host identity. The default is no  Optional. Type boolean.

       upstream_default value :
           no

   GSSAPIStrictAcceptorCheck
       Determines whether to be strict about the identity of the GSSAPI acceptor a client authenticates against.
       If  set to yes then the client must authenticate against the host service on the current hostname. If set
       to no then the client may authenticate against any service key stored in  the  machine's  default  store.
       This facility is provided to assist with operation on multi homed machines. The default is yes  Optional.
       Type boolean.

       upstream_default value :
           yes

   GSSAPIStoreCredentialsOnRekey
       Controls  whether  the  user's  GSSAPI  credentials  should  be updated following a successful connection
       rekeying. This option can be used to accepted renewed or updated credentials from  a  compatible  client.
       The default is ''no''

       For  this  to  work  GSSAPIKeyExchange  needs  to  be  enabled in the server and also used by the client.
       Optional. Type boolean.

       upstream_default value :
           no

   GSSAPIKexAlgorithms
       The list of key exchange algorithms that are accepted  by  GSSAPI  key  exchange.   Possible  values  are
       gss-gex-sha1-,    gss-group1-sha1-,    gss-group14-sha1-,    gss-group14-sha256-,    gss-group16-sha512-,

       gss-nistp256-sha256-, gss-curve25519-sha256-
       The default is ''gss-group14-sha256-, gss-group16-sha512-, gss-nistp256-sha256-,  gss-curve25519-sha256-,
       gss-gex-sha1-,  gss-group14-sha1-'' This option only applies to connections using GSSAPI.  Optional. Type
       uniline.

   HostCertificate
       Specifies a file containing a public host certificate. The certificate's public key must match a  private
       host  key  already specified by HostKey The default behaviour of sshd(8) is not to load any certificates.
       Optional. Type uniline.

   HostKey
       Specifies a file containing a private host key used by SSH. The defaults are  /etc/ssh/ssh_host_ecdsa_key
       /etc/ssh/ssh_host_ed25519_key and /etc/ssh/ssh_host_rsa_key

       Note   that   sshd(8)  will  refuse  to  use  a  file  if  it  is  group/world-accessible  and  that  the
       HostKeyAlgorithms option restricts which of the keys are actually used by sshd(8).

       It is possible to have multiple host key files. It is also possible to  specify  public  host  key  files
       instead.  In  this case operations on the private key will be delegated to an ssh-agent1.  Optional. Type
       uniline.

   HostKeyAgent
       Identifies the UNIX-domain socket used to communicate with an agent that has access to the  private  host
       keys.  If  the  string  Qq  SSH_AUTH_SOCK  is specified, the location of the socket will be read from the
       SSH_AUTH_SOCK environment variable.  Optional. Type uniline.

   HostKeyAlgorithms
       Specifies the host key signature algorithms that the server offers.  The  default  for  this  option  is:
       ssh-ed25519-cert-v01@openssh.com,                               ecdsa-sha2-nistp256-cert-v01@openssh.com,
       ecdsa-sha2-nistp384-cert-v01@openssh.com,                       ecdsa-sha2-nistp521-cert-v01@openssh.com,
       sk-ssh-ed25519-cert-v01@openssh.com,                         sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,
       rsa-sha2-512-cert-v01@openssh.com, rsa-sha2-256-cert-v01@openssh.com,  ssh-ed25519,  ecdsa-sha2-nistp256,
       ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, sk-ssh-ed25519@openssh.com, sk-ecdsa-sha2-nistp256@openssh.com,
       rsa-sha2-512, rsa-sha2-256

       The  list  of  available  signature  algorithms  may also be obtained using Qq ssh -Q HostKeyAlgorithms .
       Optional. Type uniline.

   IgnoreUserKnownHosts
       Specifies whether sshd(8) should ignore the user's ~/.ssh/known_hosts during HostbasedAuthentication  and
       use  only the system-wide known hosts file /etc/ssh/ssh_known_hosts The default is ''no''  Optional. Type
       boolean.

       upstream_default value :
           no

   KerberosGetAFSToken
       If AFS is active and the user has a Kerberos 5 TGT, attempt to acquire an AFS token before accessing  the
       user's home directory. The default is no  Optional. Type boolean.

       upstream_default value :
           no

   KerberosOrLocalPasswd
       If  password authentication through Kerberos fails then the password will be validated via any additional
       local mechanism such as /etc/passwd The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   KerberosTicketCleanup
       Specifies whether to automatically destroy the user's ticket cache file on logout.  The  default  is  yes
       Optional. Type boolean.

       upstream_default value :
           yes

   KexAlgorithms
       Specifies  the  available  KEX  (Key  Exchange)  algorithms. Multiple algorithms must be comma-separated.
       Alternately if the specified list begins with a '+' character, then  the  specified  algorithms  will  be
       appended to the default set instead of replacing them. If the specified list begins with a '-' character,
       then  the  specified  algorithms  (including  wildcards)  will be removed from the default set instead of
       replacing them. If the specified list begins with a '^' character, then the specified algorithms will  be
       placed at the head of the default set. The supported algorithms are:

       curve25519-sha256   curve25519-sha256@libssh.org  diffie-hellman-group1-sha1  diffie-hellman-group14-sha1
       diffie-hellman-group14-sha256         diffie-hellman-group16-sha512         diffie-hellman-group18-sha512
       diffie-hellman-group-exchange-sha1         diffie-hellman-group-exchange-sha256        ecdh-sha2-nistp256
       ecdh-sha2-nistp384 ecdh-sha2-nistp521 sntrup761x25519-sha512@openssh.com

       The  default  is:  sntrup761x25519-sha512@openssh.com,  curve25519-sha256,  curve25519-sha256@libssh.org,
       ecdh-sha2-nistp256,    ecdh-sha2-nistp384,    ecdh-sha2-nistp521,   diffie-hellman-group-exchange-sha256,
       diffie-hellman-group16-sha512, diffie-hellman-group18-sha512, diffie-hellman-group14-sha256

       The list of available key exchange algorithms may also be  obtained  using  Qq  ssh  -Q  KexAlgorithms  .
       Optional. Type uniline.

   ListenAddress
       Specifies the local addresses sshd(8) should listen on. The following forms may be used:

       ListenAddress  hostname  |  address  ListenAddress  hostname  :  port  ListenAddress  IPv4_address : port
       ListenAddress [hostname | address : port ]

       If port is not specified, sshd will listen on the address and all Port options specified. The default  is
       to listen on all local addresses. Multiple ListenAddress options are permitted.  Optional. Type uniline.

   LoginGraceTime
       The  server  disconnects  after  this time if the user has not successfully logged in. If the value is 0,
       there is no time limit. The default is 120 seconds.  Optional. Type uniline.

   LogVerbose
       Specify one or more overrides to LogLevel. An override consists of  a  pattern  lists  that  matches  the
       source file, function and line number to force detailed logging for. For example, an override pattern of:
       kex.c:*:1000,*:kex_exchange_identification():*, packet.c:*

       would  enable  detailed  logging  for line 1000 of kex.c everything in the Fn kex_exchange_identification
       function, and all code in the packet.c file. This option is intended for debugging and no  overrides  are
       enabled by default.  Optional. Type uniline.

   MACs
       Specifies the available MAC (message authentication code) algorithms.

       The  MAC algorithm is used for data integrity protection. Multiple algorithms must be comma-separated. If
       the specified list begins with a '+' character, then the specified algorithms will  be  appended  to  the
       default  set  instead  of  replacing  them.  If  the specified list begins with a '-' character, then the
       specified algorithms (including wildcards) will be removed from the  default  set  instead  of  replacing
       them.  If the specified list begins with a '^' character, then the specified algorithms will be placed at
       the head of the default set.

       The algorithms that contain Qq -etm calculate the MAC  after  encryption  (encrypt-then-mac).  These  are
       considered safer and their use recommended. The supported MACs are:

       hmac-md5    hmac-md5-96    hmac-sha1   hmac-sha1-96   hmac-sha2-256   hmac-sha2-512   umac-64@openssh.com
       umac-128@openssh.com   hmac-md5-etm@openssh.com   hmac-md5-96-etm@openssh.com   hmac-sha1-etm@openssh.com
       hmac-sha1-96-etm@openssh.com          hmac-sha2-256-etm@openssh.com         hmac-sha2-512-etm@openssh.com
       umac-64-etm@openssh.com umac-128-etm@openssh.com

       The  default  is:   umac-64-etm@openssh.com,   umac-128-etm@openssh.com,   hmac-sha2-256-etm@openssh.com,
       hmac-sha2-512-etm@openssh.com,   hmac-sha1-etm@openssh.com,   umac-64@openssh.com,  umac-128@openssh.com,
       hmac-sha2-256, hmac-sha2-512, hmac-sha1

       The list of available MAC algorithms may also be obtained using Qq ssh -Q mac .  Optional. Type uniline.

   Match
       Introduces a conditional block. If all of the criteria on the Match line are satisfied, the  keywords  on
       the  following  lines  override  those set in the global section of the config file, until either another
       Match line or the end of the file. If a keyword appears in multiple Match blocks that are satisfied, only
       the first instance of the keyword is applied.

       The arguments to Match are one or more criteria-pattern pairs or the single token All which  matches  all
       criteria. The available criteria are User Group Host LocalAddress LocalPort and Address

       The  match  patterns  may consist of single entries or comma-separated lists and may use the wildcard and
       negation operators described in the PATTERNS section of ssh_config5.

       The patterns in an Address criteria may additionally contain addresses to match in  CIDR  address/masklen
       format,  such  as  192.0.2.0/24  or 2001:db8::/32.  Note that the mask length provided must be consistent
       with the address - it is an error to specify a mask length that is too long for the address or  one  with
       bits set in this host portion of the address. For example, 192.0.2.0/33 and 192.0.2.0/8, respectively.

       Only  a  subset  of  keywords  may be used on the lines following a Match keyword. Available keywords are
       AcceptEnv  AllowAgentForwarding  AllowGroups  AllowStreamLocalForwarding  AllowTcpForwarding   AllowUsers
       AuthenticationMethods       AuthorizedKeysCommand       AuthorizedKeysCommandUser      AuthorizedKeysFile
       AuthorizedPrincipalsCommand     AuthorizedPrincipalsCommandUser      AuthorizedPrincipalsFile      Banner
       CASignatureAlgorithms  ChannelTimeout  ChrootDirectory ClientAliveCountMax ClientAliveInterval DenyGroups
       DenyUsers    DisableForwarding    ExposeAuthInfo    ForceCommand    GatewayPorts     GSSAPIAuthentication
       HostbasedAcceptedAlgorithms  HostbasedAuthentication HostbasedUsesNameFromPacketOnly IgnoreRhosts Include
       IPQoS   KbdInteractiveAuthentication    KerberosAuthentication    LogLevel    MaxAuthTries    MaxSessions
       PasswordAuthentication    PermitEmptyPasswords    PermitListen   PermitOpen   PermitRootLogin   PermitTTY
       PermitTunnel  PermitUserRC  PubkeyAcceptedAlgorithms  PubkeyAuthentication  PubkeyAuthOptions  RekeyLimit
       RevokedKeys  SetEnv  StreamLocalBindMask  StreamLocalBindUnlink TrustedUserCAKeys UnusedConnectionTimeout
       X11DisplayOffset X11Forwarding and X11UseLocalhost  Optional. Type list of node of class Sshd::MatchBlock
       .

   MaxStartups
       Specifies the maximum number of concurrent unauthenticated connections  to  the  SSH  daemon.  Additional
       connections will be dropped until authentication succeeds or the LoginGraceTime expires for a connection.
       The default is 10:30:100.

       Alternatively,  random  early  drop  can  be  enabled  by  specifying  the  three  colon separated values
       start:rate:full (e.g. "10:30:60"). sshd(8) will refuse connection attempts with a probability of rate/100
       (30%) if there are currently start (10) unauthenticated connections. The probability  increases  linearly
       and  all  connection attempts are refused if the number of unauthenticated connections reaches full (60).
       Optional. Type uniline.

       upstream_default value :
           10

   ModuliFile
       Specifies   the   moduli(5)   file   that   contains   the   Diffie-Hellman   groups   used    for    the
       ''diffie-hellman-group-exchange-sha1'' and ''diffie-hellman-group-exchange-sha256'' key exchange methods.
       The default is /etc/ssh/moduli.  Optional. Type uniline.

       upstream_default value :
           /etc/ssh/moduli

   PermitUserEnvironment
       Specifies  whether ~/.ssh/environment and environment= options in ~/.ssh/authorized_keys are processed by
       sshd(8). Valid options are yes no or a pattern-list specifying which environment variable names to accept
       (for example Qq LANG, LC_* ) . The default is no Enabling environment  processing  may  enable  users  to
       bypass  access  restrictions  in  some configurations using mechanisms such as LD_PRELOAD  Optional. Type
       boolean.

       upstream_default value :
           no

   PerSourceMaxStartups
       Specifies the number of unauthenticated connections allowed from a given source address, or  ''none''  if
       there  is  no  limit. This limit is applied in addition to MaxStartups whichever is lower. The default is
       none  Optional. Type uniline.

       upstream_default value :
           none

   PerSourceNetBlockSize
       Specifies the number of bits of source address that are grouped together for  the  purposes  of  applying
       PerSourceMaxStartups  limits. Values for IPv4 and optionally IPv6 may be specified, separated by a colon.
       The default is 32:128 which means each address is considered individually.  Optional. Type uniline.

       upstream_default value :
           32:128

   PidFile
       Specifies the file that contains the process ID of the SSH daemon, or none to not write one. The  default
       is /run/sshd.pid.  Optional. Type uniline.

       upstream_default value :
           /run/sshd

   Port
       Specifies  the port number that sshd(8) listens on. The default is 22.  Multiple options of this type are
       permitted. See also ListenAddress  Optional. Type uniline.

   PrintLastLog
       Specifies whether sshd(8) should print the date and time of the last user  login  when  a  user  logs  in
       interactively. The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   PrintMotd
       Specifies  whether  sshd(8) should print /etc/motd when a user logs in interactively. (On some systems it
       is also printed by the shell, /etc/profile or equivalent.) The default is yes  Optional. Type boolean.

       upstream_default value :
           yes

   RequiredRSASize
       Specifies the minimum RSA key size (in bits) that sshd(8) will accept. User and host-based authentication
       keys smaller than this limit will be refused. The default is 1024 bits. Note that this limit may only  be
       raised from the default.  Optional. Type integer.

       upstream_default value :
           1024

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

   StrictModes
       Specifies whether sshd(8) should check file modes and ownership of the user's files  and  home  directory
       before  accepting  login.  This  is normally desirable because novices sometimes accidentally leave their
       directory or files world-writable. The default is yes Note that this does not  apply  to  ChrootDirectory
       whose permissions and ownership are checked unconditionally.  Optional. Type boolean.

       upstream_default value :
           yes

   Subsystem
       Configures  an external subsystem (e.g. file transfer daemon). Arguments should be a subsystem name and a
       command (with optional arguments) to execute upon subsystem request.

       The command sftp-server implements the SFTP file transfer subsystem.

       Alternately  the  name  internal-sftp  implements  an  in-process  SFTP  server.    This   may   simplify
       configurations using ChrootDirectory to force a different filesystem root on clients.

       By default no subsystems are defined.  Optional. Type hash of uniline.

   SyslogFacility
       Gives the facility code that is used when logging messages from sshd(8). The possible values are: DAEMON,
       USER,  AUTH,  LOCAL0,  LOCAL1,  LOCAL2,  LOCAL3,  LOCAL4,  LOCAL5,  LOCAL6,  LOCAL7. The default is AUTH.
       Optional. Type  enum.  choice:  'AUTH',  'DAEMON',  'LOCAL0',  'LOCAL1',  'LOCAL2',  'LOCAL3',  'LOCAL4',
       'LOCAL5', 'LOCAL6', 'LOCAL7', 'USER'.

       upstream_default value :
           AUTH

   TCPKeepAlive
       Specifies  whether  the  system  should  send TCP keepalive messages to the other side. If they are sent,
       death of the connection or crash of one of the machines will be properly  noticed.  However,  this  means
       that  connections  will  die  if  the route is down temporarily, and some people find it annoying. On the
       other hand, if TCP keepalives are not sent, sessions may hang indefinitely  on  the  server,  leaving  Qq
       ghost users and consuming server resources.

       The  default is yes (to send TCP keepalive messages), and the server will notice if the network goes down
       or the client host crashes. This avoids infinitely hanging sessions.

       To disable TCP keepalive messages, the value should be set to no

       This option was formerly called KeepAlive  Optional. Type boolean.

       upstream_default value :
           yes

   UseDNS
       Specifies whether sshd(8) should look up the remote host name, and to check that the resolved  host  name
       for the remote IP address maps back to the very same IP address.

       If  this  option  is  set  to  no  (the  default)  then  only addresses and not host names may be used in
       ~/.ssh/authorized_keys from and sshd_config Match Host directives.  Optional. Type boolean.

       upstream_default value :
           no

   UsePAM
       Enables the Pluggable Authentication Module interface. If set to yes this will enable PAM  authentication
       using  KbdInteractiveAuthentication  and  PasswordAuthentication  in  addition to PAM account and session
       module processing for all authentication types.

       Because  PAM  keyboard-interactive  authentication  usually  serves  an  equivalent  role   to   password
       authentication, you should disable either PasswordAuthentication or KbdInteractiveAuthentication

       If  UsePAM  is  enabled,  you  will  not  be  able  to  run sshd(8) as a non-root user. The default is no
       Optional. Type boolean.

       upstream_default value :
           no

   VersionAddendum
       Optionally specifies additional text to append to the  SSH  protocol  banner  sent  by  the  server  upon
       connection. The default is none  Optional. Type uniline.

   XAuthLocation
       Specifies  the  full  pathname  of  the  xauth(1)  program,  or  none  to  not  use  one.  The default is
       /usr/bin/xauth.  Optional. Type uniline.

       upstream_default value :
           /usr/bin/xauth

SEE ALSO

       •   cme

       •   Config::Model::models::Sshd::MatchBlock

LICENSE

       LGPL2

perl v5.36.0                                       2023-10-14                   Config::Model::models::Sshd(3pm)