===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh.1,v
retrieving revision 1.39
retrieving revision 1.40
diff -u -r1.39 -r1.40
--- src/usr.bin/ssh/ssh.1	2000/03/04 07:07:05	1.39
+++ src/usr.bin/ssh/ssh.1	2000/03/11 21:40:03	1.40
@@ -9,7 +9,7 @@
 .\"
 .\" Created: Sat Apr 22 21:55:14 1995 ylo
 .\"
-.\" $Id: ssh.1,v 1.39 2000/03/04 07:07:05 djm Exp $
+.\" $Id: ssh.1,v 1.40 2000/03/11 21:40:03 aaron Exp $
 .\"
 .Dd September 25, 1999
 .Dt SSH 1
@@ -52,9 +52,11 @@
 .Sh DESCRIPTION 
 .Nm
 (Secure Shell) is a program for logging into a remote machine and for
-executing commands on a remote machine.  It is intended to replace
+executing commands on a remote machine.
+It is intended to replace
 rlogin and rsh, and provide secure encrypted communications between
-two untrusted hosts over an insecure network.  X11 connections and
+two untrusted hosts over an insecure network.
+X11 connections and
 arbitrary TCP/IP ports can also be forwarded over the secure channel.
 .Pp
 .Nm
@@ -76,15 +78,16 @@
 exists in the user's home directory on the
 remote machine and contains a line containing the name of the client
 machine and the name of the user on that machine, the user is
-permitted to log in.  This form of authentication alone is normally not
+permitted to log in.
+This form of authentication alone is normally not
 allowed by the server because it is not secure.
 .Pp
 The second (and primary) authentication method is the
 .Pa rhosts
 or
 .Pa hosts.equiv
-method combined with RSA-based host authentication.  It
-means that if the login would be permitted by
+method combined with RSA-based host authentication.
+It means that if the login would be permitted by
 .Pa \&.rhosts ,
 .Pa \&.shosts ,
 .Pa /etc/hosts.equiv ,
@@ -97,10 +100,10 @@
 .Pa $HOME/.ssh/known_hosts
 in the
 .Sx FILES
-section), only then login is
-permitted.  This authentication method closes security holes due to IP
-spoofing, DNS spoofing and routing spoofing.  [Note to the
-administrator:
+section), only then login is permitted.
+This authentication method closes security holes due to IP
+spoofing, DNS spoofing and routing spoofing.
+[Note to the administrator:
 .Pa /etc/hosts.equiv ,
 .Pa \&.rhosts ,
 and the rlogin/rsh protocol in general, are inherently insecure and should be
@@ -112,34 +115,39 @@
 The scheme is based on public-key cryptography: there are cryptosystems
 where encryption and decryption are done using separate keys, and it
 is not possible to derive the decryption key from the encryption key.
-RSA is one such system.  The idea is that each user creates a public/private 
-key pair for authentication purposes.  The
-server knows the public key, and only the user knows the private key.
+RSA is one such system.
+The idea is that each user creates a public/private 
+key pair for authentication purposes.
+The server knows the public key, and only the user knows the private key.
 The file 
 .Pa $HOME/.ssh/authorized_keys
 lists the public keys that are permitted for logging
-in.  When the user logs in, the
+in.
+When the user logs in, the
 .Nm
 program tells the server which key pair it would like to use for
-authentication.  The server checks if this key is permitted, and if
+authentication.
+The server checks if this key is permitted, and if
 so, sends the user (actually the
 .Nm
 program running on behalf of the user) a challenge, a random number,
-encrypted by the user's public key.  The challenge can only be
-decrypted using the proper private key.  The user's client then decrypts the
+encrypted by the user's public key.
+The challenge can only be
+decrypted using the proper private key.
+The user's client then decrypts the
 challenge using the private key, proving that he/she knows the private
 key but without disclosing it to the server.
 .Pp
 .Nm
-implements the RSA authentication protocol automatically.  The user
-creates his/her RSA key pair by running
+implements the RSA authentication protocol automatically.
+The user creates his/her RSA key pair by running
 .Xr ssh-keygen 1 .
 This stores the private key in 
 .Pa \&.ssh/identity
 and the public key in
 .Pa \&.ssh/identity.pub
-in the user's home directory.  The user should then
-copy the 
+in the user's home directory.
+The user should then copy the
 .Pa identity.pub
 to 
 .Pa \&.ssh/authorized_keys
@@ -148,24 +156,28 @@
 file corresponds to the conventional 
 .Pa \&.rhosts
 file, and has one key
-per line, though the lines can be very long).  After this, the user
-can log in without giving the password.  RSA authentication is much
+per line, though the lines can be very long).
+After this, the user can log in without giving the password.
+RSA authentication is much
 more secure than rhosts authentication.
 .Pp
 The most convenient way to use RSA authentication may be with an
-authentication agent.  See
+authentication agent.
+See
 .Xr ssh-agent 1
 for more information.
 .Pp
 If other authentication methods fail, 
 .Nm
-prompts the user for a password.  The password is sent to the remote
+prompts the user for a password.
+The password is sent to the remote
 host for checking; however, since all communications are encrypted,
 the password cannot be seen by someone listening on the network.
 .Pp
 When the user's identity has been accepted by the server, the server
 either executes the given command, or logs into the machine and gives
-the user a normal shell on the remote machine.  All communication with
+the user a normal shell on the remote machine.
+All communication with
 the remote command or shell will be automatically encrypted.
 .Pp
 If a pseudo-terminal has been allocated (normal login session), the
@@ -182,19 +194,22 @@
 connections to terminate, it can be backgrounded with
 .Ic ~&
 (this should not be used while the user shell is active, as it can cause the
-shell to hang).  All available escapes can be listed with
+shell to hang).
+All available escapes can be listed with
 .Ic ~? .
 .Pp
 A single tilde character can be sent as
 .Ic ~~
 (or by following the tilde by a character other than those described above).
 The escape character must always follow a newline to be interpreted as
-special.  The escape character can be changed in configuration files
-or on the command line.  
+special.
+The escape character can be changed in configuration files
+or on the command line.
 .Pp
 If no pseudo tty has been allocated, the
 session is transparent and can be used to reliably transfer binary
-data.  On most systems, setting the escape character to
+data.
+On most systems, setting the escape character to
 .Dq none
 will also make the session transparent even if a tty is used.
 .Pp
@@ -210,7 +225,8 @@
 automatically forwarded to the remote side in such a way that any X11
 programs started from the shell (or command) will go through the
 encrypted channel, and the connection to the real X server will be made
-from the local machine.  The user should not manually set
+from the local machine.
+The user should not manually set
 .Ev DISPLAY .
 Forwarding of X11 connections can be
 configured on the command line or in configuration files.
@@ -220,7 +236,8 @@
 value set by
 .Nm
 will point to the server machine, but with a display number greater
-than zero.  This is normal, and happens because
+than zero.
+This is normal, and happens because
 .Nm
 creates a
 .Dq proxy
@@ -232,7 +249,8 @@
 For this purpose, it will generate a random authorization cookie,
 store it in Xauthority on the server, and verify that any forwarded
 connections carry this cookie and replace it by the real cookie when
-the connection is opened.  The real authentication cookie is never
+the connection is opened.
+The real authentication cookie is never
 sent to the server machine (and no cookies are sent in the plain).
 .Pp
 If the user is using an authentication agent, the connection to the agent
@@ -240,25 +258,29 @@
 command line or in a configuration file.
 .Pp
 Forwarding of arbitrary TCP/IP connections over the secure channel can
-be specified either on command line or in a configuration file.  One
-possible application of TCP/IP forwarding is a secure connection to an
+be specified either on command line or in a configuration file.
+One possible application of TCP/IP forwarding is a secure connection to an
 electronic purse; another is going trough firewalls.
 .Pp
 .Nm
 automatically maintains and checks a database containing RSA-based
-identifications for all hosts it has ever been used with.  The
-database is stored in 
+identifications for all hosts it has ever been used with.
+The database is stored in 
 .Pa \&.ssh/known_hosts
-in the user's home directory.  Additionally, the file 
+in the user's home directory.
+Additionally, the file 
 .Pa /etc/ssh_known_hosts
-is automatically checked for known hosts.  Any new hosts are
-automatically added to the user's file.  If a host's identification
+is automatically checked for known hosts.
+Any new hosts are automatically added to the user's file.
+If a host's identification
 ever changes,
 .Nm
 warns about this and disables password authentication to prevent a
-trojan horse from getting the user's password.  Another purpose of
+trojan horse from getting the user's password.
+Another purpose of
 this mechanism is to prevent man-in-the-middle attacks which could
-otherwise be used to circumvent the encryption.  The
+otherwise be used to circumvent the encryption.
+The
 .Cm StrictHostKeyChecking
 option (see below) can be used to prevent logins to machines whose
 host key is not known or has changed.
@@ -270,7 +292,8 @@
 .It Fl c Ar blowfish|3des
 Selects the cipher to use for encrypting the session. 
 .Ar 3des
-is used by default.  It is believed to be secure. 
+is used by default.
+It is believed to be secure. 
 .Ar 3des
 (triple-des) is an encrypt-decrypt-encrypt triple with three different keys.
 It is presumably more secure than the
@@ -278,26 +301,28 @@
 cipher which is no longer supported in ssh.
 .Ar blowfish
 is a fast block cipher, it appears very secure and is much faster than
-.Ar 3des .  
+.Ar 3des .
 .It Fl e Ar ch|^ch|none
 Sets the escape character for sessions with a pty (default:
 .Ql ~ ) .
-The escape character is only recognized at the beginning of a line.  The
-escape character followed by a dot
+The escape character is only recognized at the beginning of a line.
+The escape character followed by a dot
 .Pq Ql \&.
 closes the connection, followed
 by control-Z suspends the connection, and followed by itself sends the
-escape character once.  Setting the character to
+escape character once.
+Setting the character to
 .Dq none
 disables any escapes and makes the session fully transparent.
 .It Fl f
 Requests
 .Nm
-to go to background just before command execution.  This is useful
-if
+to go to background just before command execution.
+This is useful if
 .Nm
 is going to ask for passwords or passphrases, but the user
-wants it in the background.  This implies 
+wants it in the background.
+This implies 
 .Fl n .
 The recommended way to start X11 programs at a remote site is with
 something like
@@ -306,11 +331,13 @@
 Allows remote hosts to connect to local forwarded ports.
 .It Fl i Ar identity_file
 Selects the file from which the identity (private key) for 
-RSA authentication is read.  Default is 
+RSA authentication is read.
+Default is 
 .Pa \&.ssh/identity
-in the user's home directory.  Identity files may also be specified on
-a per-host basis in the configuration file.  It is possible to have
-multiple
+in the user's home directory.
+Identity files may also be specified on
+a per-host basis in the configuration file.
+It is possible to have multiple
 .Fl i
 options (and multiple identities specified in
 configuration files).
@@ -318,16 +345,17 @@
 Disables forwarding of Kerberos tickets and AFS tokens. This may
 also be specified on a per-host basis in the configuration file.
 .It Fl l Ar login_name
-Specifies the user to log in as on the remote machine.  This may also
-be specified on a per-host basis in the configuration file.
+Specifies the user to log in as on the remote machine.
+This also may be specified on a per-host basis in the configuration file.
 .It Fl n
 Redirects stdin from
 .Pa /dev/null
 (actually, prevents reading from stdin).
 This must be used when
 .Nm
-is run in the background.  A common trick is to use this to run X11
-programs in a remote machine.  For example,
+is run in the background.
+A common trick is to use this to run X11 programs on a remote machine.
+For example,
 .Ic ssh -n shadows.cs.hut.fi emacs &
 will start an emacs on shadows.cs.hut.fi, and the X11
 connection will be automatically forwarded over an encrypted channel.
@@ -342,10 +370,11 @@
 .It Fl o Ar option
 Can be used to give options in the format used in the config file.
 This is useful for specifying options for which there is no separate
-command-line flag.  The option has the same format as a line in the
-configuration file.
+command-line flag.
+The option has the same format as a line in the configuration file.
 .It Fl p Ar port
-Port to connect to on the remote host.  This can be specified on a
+Port to connect to on the remote host.
+This can be specified on a
 per-host basis in the configuration file.
 .It Fl P
 Use a non-privileged port for outgoing connections.
@@ -356,35 +385,40 @@
 and
 .Cm RhostsRSAAuthentication .
 .It Fl q
-Quiet mode.  Causes all warning and diagnostic messages to be
-suppressed.  Only fatal errors are displayed.
+Quiet mode.
+Causes all warning and diagnostic messages to be suppressed.
+Only fatal errors are displayed.
 .It Fl t
-Force pseudo-tty allocation.  This can be used to execute arbitary
-screen-based programs on a remote machine, which can be very useful
-e.g. when implementing menu services.
+Force pseudo-tty allocation.
+This can be used to execute arbitary
+screen-based programs on a remote machine, which can be very useful,
+e.g., when implementing menu services.
 .It Fl v
-Verbose mode.  Causes
+Verbose mode.
+Causes
 .Nm
-to print debugging messages about its progress.  This is helpful in
+to print debugging messages about its progress.
+This is helpful in
 debugging connection, authentication, and configuration problems.
 The verbose mode is also used to display
 .Xr skey 1
 challenges, if the user entered "s/key" as password.
 .It Fl x
-Disables X11 forwarding.  This can also be specified on a per-host
-basis in a configuration file.
+Disables X11 forwarding.
+This can also be specified on a per-host basis in a configuration file.
 .It Fl X
 Enables X11 forwarding.
 .It Fl C
 Requests compression of all data (including stdin, stdout, stderr, and
-data for forwarded X11 and TCP/IP connections).  The compression
-algorithm is the same used by
+data for forwarded X11 and TCP/IP connections).
+The compression algorithm is the same used by
 .Xr gzip 1 ,
 and the
 .Dq level
 can be controlled by the
 .Cm CompressionLevel
-option (see below).  Compression is desirable on modem lines and other
+option (see below).
+Compression is desirable on modem lines and other
 slow connections, but will only slow down things on fast networks.
 The default value can be set on a host-by-host basis in the
 configuration files; see the
@@ -392,8 +426,8 @@
 option below.
 .It Fl L Ar port:host:hostport
 Specifies that the given port on the local (client) host is to be
-forwarded to the given host and port on the remote side.  This works
-by allocating a socket to listen to
+forwarded to the given host and port on the remote side.
+This works by allocating a socket to listen to
 .Ar port
 on the local side, and whenever a connection is made to this port, the
 connection is forwarded over the secure channel, and a connection is
@@ -401,14 +435,15 @@
 .Ar host
 port
 .Ar hostport
-from the remote machine.  Port forwardings can also be specified in the
-configuration file.  Only root can forward privileged ports.
+from the remote machine.
+Port forwardings can also be specified in the configuration file.
+Only root can forward privileged ports.
 IPv6 addresses can be specified with an alternative syntax:
 .Ar port/host/hostport
 .It Fl R Ar port:host:hostport
 Specifies that the given port on the remote (server) host is to be
-forwarded to the given host and port on the local side.  This works
-by allocating a socket to listen to
+forwarded to the given host and port on the local side.
+This works by allocating a socket to listen to
 .Ar port
 on the remote side, and whenever a connection is made to this port, the
 connection is forwarded over the secure channel, and a connection is
@@ -416,8 +451,9 @@
 .Ar host
 port
 .Ar hostport
-from the local machine.  Port forwardings can also be specified in the
-configuration file.  Privileged ports can be forwarded only when
+from the local machine.
+Port forwardings can also be specified in the configuration file.
+Privileged ports can be forwarded only when
 logging in as root on the remote machine.
 .It Fl 4
 Forces
@@ -436,10 +472,12 @@
 and system-wide configuration file
 .Pq Pa /etc/ssh_config .
 For each parameter, the first obtained value
-will be used.  The configuration files contain sections bracketed by
-"Host" specifications, and that section is only applied for hosts that
-match one of the patterns given in the specification.  The matched
-host name is the one given on the command line.
+will be used.
+The configuration files contain sections bracketed by
+.Dq Host
+specifications, and that section is only applied for hosts that
+match one of the patterns given in the specification.
+The matched host name is the one given on the command line.
 .Pp
 Since the first obtained value for each parameter is used, more
 host-specific declarations should be given near the beginning of the
@@ -466,10 +504,12 @@
 and
 .Ql ?
 can be used as wildcards in the
-patterns.  A single
+patterns.
+A single
 .Ql \&*
 as a pattern can be used to provide global
-defaults for all hosts.  The host is the
+defaults for all hosts.
+The host is the
 .Ar hostname
 argument given on the command line (i.e., the name is not converted to
 a canonicalized host name before matching).
@@ -482,9 +522,10 @@
 .It Cm BatchMode
 If set to
 .Dq yes ,
-passphrase/password querying will be disabled.  This
-option is useful in scripts and other batch jobs where you have no
-user to supply the password.  The argument must be
+passphrase/password querying will be disabled.
+This option is useful in scripts and other batch jobs where you have no
+user to supply the password.
+The argument must be
 .Dq yes
 or
 .Dq no .
@@ -498,33 +539,37 @@
 .Dq no ,
 the check will not be executed.
 .It Cm Cipher
-Specifies the cipher to use for encrypting the session.  Currently,
+Specifies the cipher to use for encrypting the session.
+Currently,
 .Dq blowfish ,
 and
 .Dq 3des
-are supported.  The default is
+are supported.
+The default is
 .Dq 3des .
 .It Cm Compression
-Specifies whether to use compression.  The argument must be
+Specifies whether to use compression.
+The argument must be
 .Dq yes
 or
 .Dq no .
 .It Cm CompressionLevel
-Specifies the compression level to use if compression is enable.  The
-argument must be an integer from 1 (fast) to 9 (slow, best).  The
-default level is 6, which is good for most applications.  The meaning
-of the values is the same as in
+Specifies the compression level to use if compression is enable.
+The argument must be an integer from 1 (fast) to 9 (slow, best).
+The default level is 6, which is good for most applications.
+The meaning of the values is the same as in
 .Xr gzip 1 .
 .It Cm ConnectionAttempts
 Specifies the number of tries (one per second) to make before falling
-back to rsh or exiting.  The argument must be an integer.  This may be
-useful in scripts if the connection sometimes fails.
+back to rsh or exiting.
+The argument must be an integer.
+This may be useful in scripts if the connection sometimes fails.
 .It Cm EscapeChar
 Sets the escape character (default:
 .Ql ~ ) .
 The escape character can also
-be set on the command line.  The argument should be a single
-character,
+be set on the command line.
+The argument should be a single character,
 .Ql ^
 followed by a letter, or
 .Dq none
@@ -539,13 +584,15 @@
 listening on the remote host), 
 .Xr rsh 1
 should automatically be used instead (after a suitable warning about
-the session being unencrypted).  The argument must be
+the session being unencrypted).
+The argument must be
 .Dq yes
 or
 .Dq no .
 .It Cm ForwardAgent
 Specifies whether the connection to the authentication agent (if any)
-will be forwarded to the remote machine.  The argument must be
+will be forwarded to the remote machine.
+The argument must be
 .Dq yes
 or
 .Dq no .
@@ -553,7 +600,8 @@
 Specifies whether X11 connections will be automatically redirected
 over the secure channel and 
 .Ev DISPLAY
-set.  The argument must be 
+set.
+The argument must be 
 .Dq yes
 or
 .Dq no .
@@ -572,10 +620,10 @@
 Specifies a file to use instead of 
 .Pa /etc/ssh_known_hosts .
 .It Cm HostName
-Specifies the real host name to log into.  This can be used to specify
-nicnames or abbreviations for hosts.  Default is the name given on the
-command line.  Numeric IP addresses are also permitted (both on the
-command line and in
+Specifies the real host name to log into.
+This can be used to specify nicknames or abbreviations for hosts.
+Default is the name given on the command line.
+Numeric IP addresses are also permitted (both on the command line and in
 .Cm HostName
 specifications).
 .It Cm IdentityFile
@@ -584,22 +632,26 @@
 .Pa .ssh/identity
 in the user's home directory).
 Additionally, any identities represented by the authentication agent
-will be used for authentication.  The file name may use the tilde
-syntax to refer to a user's home directory.  It is possible to have
+will be used for authentication.
+The file name may use the tilde
+syntax to refer to a user's home directory.
+It is possible to have
 multiple identity files specified in configuration files; all these
 identities will be tried in sequence.
 .It Cm KeepAlive
 Specifies whether the system should send 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
+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.  
 .Pp
 The default is
 .Dq yes
 (to send keepalives), and the client will notice
-if the network goes down or the remote host dies.  This is important
-in scripts, and many users want it too.
+if the network goes down or the remote host dies.
+This is important in scripts, and many users want it too.
 .Pp
 To disable keepalives, the value should be set to
 .Dq no
@@ -619,11 +671,12 @@
 .Dq no .
 .It Cm LocalForward
 Specifies that a TCP/IP port on the local machine be forwarded over
-the secure channel to given host:port from the remote machine.  The
-first argument must be a port number, and the second must be
-host:port.  Multiple forwardings may be specified, and additional
-forwardings can be given on the command line.  Only the root can
-forward privileged ports.
+the secure channel to given host:port from the remote machine.
+The first argument must be a port number, and the second must be
+host:port.
+Multiple forwardings may be specified, and additional
+forwardings can be given on the command line.
+Only the superuser can forward privileged ports.
 .It Cm LogLevel
 Gives the verbosity level that is used when logging messages from
 .Nm ssh .
@@ -634,25 +687,33 @@
 Specifies the number of password prompts before giving up. The
 argument to this keyword must be an integer. Default is 3.
 .It Cm PasswordAuthentication
-Specifies whether to use password authentication.  The argument to
-this keyword must be
+Specifies whether to use password authentication.
+The argument to this keyword must be
 .Dq yes
 or
 .Dq no .
 .It Cm Port
-Specifies the port number to connect on the remote host.  Default is
-22.
+Specifies the port number to connect on the remote host.
+Default is 22.
 .It Cm ProxyCommand
-Specifies the command to use to connect to the server.  The command
-string extends to the end of the line, and is executed with /bin/sh.
-In the command string, %h will be substituted by the host name to
-connect and %p by the port.  The command can be basically anything,
-and should read from its stdin and write to its stdout.  It should
-eventually connect an
+Specifies the command to use to connect to the server.
+The command
+string extends to the end of the line, and is executed with
+.Pa /bin/sh .
+In the command string,
+.Ql %h
+will be substituted by the host name to
+connect and
+.Ql %p
+by the port.
+The command can be basically anything,
+and should read from its standard input and write to its standard output.
+It should eventually connect an
 .Xr sshd 8
 server running on some machine, or execute
 .Ic sshd -i
-somewhere.  Host key management will be done using the
+somewhere.
+Host key management will be done using the
 HostName of the host being connected (defaulting to the name typed by
 the user).
 Note that
@@ -661,32 +722,37 @@
 .Pp
 .It Cm RemoteForward
 Specifies that a TCP/IP port on the remote machine be forwarded over
-the secure channel to given host:port from the local machine.  The
-first argument must be a port number, and the second must be
-host:port.  Multiple forwardings may be specified, and additional
-forwardings can be given on the command line.  Only the root can
-forward privileged ports.
+the secure channel to given host:port from the local machine.
+The first argument must be a port number, and the second must be
+host:port.
+Multiple forwardings may be specified, and additional
+forwardings can be given on the command line.
+Only the superuser can forward privileged ports.
 .It Cm RhostsAuthentication
-Specifies whether to try rhosts based authentication.  Note that this
+Specifies whether to try rhosts based authentication.
+Note that this
 declaration only affects the client side and has no effect whatsoever
-on security.  Disabling rhosts authentication may reduce
+on security.
+Disabling rhosts authentication may reduce
 authentication time on slow connections when rhosts authentication is
-not used.  Most servers do not permit RhostsAuthentication because it
-is not secure (see RhostsRSAAuthentication).  The argument to this
-keyword must be
+not used.
+Most servers do not permit RhostsAuthentication because it
+is not secure (see RhostsRSAAuthentication).
+The argument to this keyword must be
 .Dq yes
 or
 .Dq no .
 .It Cm RhostsRSAAuthentication
 Specifies whether to try rhosts based authentication with RSA host
-authentication.  This is the primary authentication method for most
-sites.  The argument must be
+authentication.
+This is the primary authentication method for most sites.
+The argument must be
 .Dq yes
 or
 .Dq no .
 .It Cm RSAAuthentication
-Specifies whether to try RSA authentication.  The argument to this
-keyword must be
+Specifies whether to try RSA authentication.
+The argument to this keyword must be
 .Dq yes
 or
 .Dq no .
@@ -696,8 +762,8 @@
 .It Cm SkeyAuthentication
 Specifies whether to use
 .Xr skey 1
-authentication.  The argument to
-this keyword must be
+authentication.
+The argument to this keyword must be
 .Dq yes
 or
 .Dq no .
@@ -709,16 +775,19 @@
 .Nm
 ssh will never automatically add host keys to the
 .Pa $HOME/.ssh/known_hosts
-file, and refuses to connect hosts whose host key has changed.  This
-provides maximum protection against trojan horse attacks.  However, it
-can be somewhat annoying if you don't have good
+file, and refuses to connect hosts whose host key has changed.
+This provides maximum protection against trojan horse attacks.
+However, it can be somewhat annoying if you don't have good
 .Pa /etc/ssh_known_hosts
 files installed and frequently
-connect new hosts.  Basically this option forces the user to manually
-add any new hosts.  Normally this option is disabled, and new hosts
-will automatically be added to the known host files.  The host keys of
-known hosts will be verified automatically in either case.  The
-argument must be
+connect new hosts.
+Basically this option forces the user to manually
+add any new hosts.
+Normally this option is disabled, and new hosts
+will automatically be added to the known host files.
+The host keys of
+known hosts will be verified automatically in either case.
+The argument must be
 .Dq yes
 or
 .Dq no .
@@ -737,23 +806,26 @@
 and
 .Cm RhostsRSAAuthentication .
 .It Cm User
-Specifies the user to log in as.  This can be useful if you have a
-different user name in different machines.  This saves the trouble of
+Specifies the user to log in as.
+This can be useful if you have a different user name on different machines.
+This saves the trouble of
 having to remember to give the user name on the command line.
 .It Cm UserKnownHostsFile
 Specifies a file to use instead of
 .Pa $HOME/.ssh/known_hosts .
 .It Cm UseRsh
-Specifies that rlogin/rsh should be used for this host.  It is
-possible that the host does not at all support the
+Specifies that rlogin/rsh should be used for this host.
+It is possible that the host does not at all support the
 .Nm
-protocol.  This causes
+protocol.
+This causes
 .Nm
-to immediately exec 
+to immediately execute
 .Xr rsh 1 .
 All other options (except
 .Cm HostName )
-are ignored if this has been specified.  The argument must be
+are ignored if this has been specified.
+The argument must be
 .Dq yes
 or
 .Dq no .
@@ -764,15 +836,17 @@
 .It Ev DISPLAY
 The
 .Ev DISPLAY
-variable indicates the location of the X11 server.  It is
-automatically set by 
+variable indicates the location of the X11 server.
+It is automatically set by 
 .Nm
 to point to a value of the form
 .Dq hostname:n
 where hostname indicates
-the host where the shell runs, and n is an integer >= 1.  Ssh uses
-this special value to forward X11 connections over the secure
-channel.  The user should normally not set DISPLAY explicitly, as that
+the host where the shell runs, and n is an integer >= 1.
+.Nm
+uses this special value to forward X11 connections over the secure
+channel.
+The user should normally not set DISPLAY explicitly, as that
 will render the X11 connection insecure (and will require the user to
 manually copy any required authorization cookies).
 .It Ev HOME
@@ -783,7 +857,7 @@
 set for compatibility with systems that use this variable.
 .It Ev MAIL
 Set to point the user's mailbox.
-.It Ev  PATH
+.It Ev PATH
 Set to the default
 .Ev PATH ,
 as specified when compiling
@@ -792,12 +866,14 @@
 indicates the path of a unix-domain socket used to communicate with the
 agent.
 .It Ev SSH_CLIENT
-Identifies the client end of the connection.  The variable contains
+Identifies the client end of the connection.
+The variable contains
 three space-separated values: client ip-address, client port number,
 and server port number.
 .It Ev SSH_TTY
 This is set to the name of the tty (path to the device) associated
-with the current shell or command.  If the current session has no tty,
+with the current shell or command.
+If the current session has no tty,
 this variable is not set.
 .It Ev TZ
 The timezone variable is set to indicate the present timezone if it
@@ -823,7 +899,8 @@
 See
 .Xr sshd 8 .
 .It Pa $HOME/.ssh/identity
-Contains the RSA authentication identity of the user.  This file
+Contains the RSA authentication identity of the user.
+This file
 contains sensitive data and should be readable by the user but not
 accessible by others (read/write/execute).
 Note that
@@ -834,39 +911,50 @@
 sensitive part of this file using 3DES.
 .It Pa $HOME/.ssh/identity.pub 
 Contains the public key for authentication (public part of the
-identity file in human-readable form).  The contents of this file
-should be added to
+identity file in human-readable form).
+The contents of this file should be added to
 .Pa $HOME/.ssh/authorized_keys
 on all machines
-where you wish to log in using RSA authentication.  This file is not
-sensitive and can (but need not) be readable by anyone.  This file is
+where you wish to log in using RSA authentication.
+This file is not
+sensitive and can (but need not) be readable by anyone.
+This file is
 never used automatically and is not necessary; it is only provided for
 the convenience of the user.
 .It Pa $HOME/.ssh/config
-This is the per-user configuration file.  The format of this file is
-described above.  This file is used by the
+This is the per-user configuration file.
+The format of this file is described above.
+This file is used by the
 .Nm
-client.  This file does not usually contain any sensitive information,
+client.
+This file does not usually contain any sensitive information,
 but the recommended permissions are read/write for the user, and not
 accessible by others.
 .It Pa $HOME/.ssh/authorized_keys
-Lists the RSA keys that can be used for logging in as this user.  The
-format of this file is described in the
+Lists the RSA keys that can be used for logging in as this user.
+The format of this file is described in the
 .Xr sshd 8
-manual page.  In the simplest form the format is the same as the .pub
+manual page.
+In the simplest form the format is the same as the .pub
 identity files (that is, each line contains the number of bits in
 modulus, public exponent, modulus, and comment fields, separated by
-spaces).  This file is not highly sensitive, but the recommended
+spaces).
+This file is not highly sensitive, but the recommended
 permissions are read/write for the user, and not accessible by others.
 .It Pa /etc/ssh_known_hosts
-Systemwide list of known host keys.  This file should be prepared by the
+Systemwide list of known host keys.
+This file should be prepared by the
 system administrator to contain the public host keys of all machines in the
-organization.  This file should be world-readable.  This file contains
+organization.
+This file should be world-readable.
+This file contains
 public keys, one per line, in the following format (fields separated
 by spaces): system name, number of bits in modulus, public exponent,
-modulus, and optional comment field.  When different names are used
+modulus, and optional comment field.
+When different names are used
 for the same machine, all such names should be listed, separated by
-commas.  The format is described on the
+commas.
+The format is described on the
 .Xr sshd 8
 manual page.
 .Pp
@@ -878,32 +966,37 @@
 checking the key, because someone with access to the name servers
 would then be able to fool host authentication.
 .It Pa /etc/ssh_config
-Systemwide configuration file.  This file provides defaults for those
+Systemwide configuration file.
+This file provides defaults for those
 values that are not specified in the user's configuration file, and
-for those users who do not have a configuration file.  This file must
-be world-readable.
+for those users who do not have a configuration file.
+This file must be world-readable.
 .It Pa $HOME/.rhosts
 This file is used in
 .Pa \&.rhosts
 authentication to list the
-host/user pairs that are permitted to log in.  (Note that this file is
+host/user pairs that are permitted to log in.
+(Note that this file is
 also used by rlogin and rsh, which makes using this file insecure.)
 Each line of the file contains a host name (in the canonical form
 returned by name servers), and then a user name on that host,
-separated by a space.  One some machines this file may need to be
+separated by a space.
+One some machines this file may need to be
 world-readable if the user's home directory is on a NFS partition,
 because
 .Xr sshd 8
-reads it as root.  Additionally, this file must be owned by the user,
-and must not have write permissions for anyone else.  The recommended
+reads it as root.
+Additionally, this file must be owned by the user,
+and must not have write permissions for anyone else.
+The recommended
 permission for most machines is read/write for the user, and not
 accessible by others.
 .Pp
 Note that by default
 .Xr sshd 8
 will be installed so that it requires successful RSA host
-authentication before permitting \s+2.\s0rhosts authentication.  If your
-server machine does not have the client's host key in
+authentication before permitting \s+2.\s0rhosts authentication.
+If your server machine does not have the client's host key in
 .Pa /etc/ssh_known_hosts ,
 you can store it in
 .Pa $HOME/.ssh/known_hosts .
@@ -923,14 +1016,18 @@
 .Xr rsh 1 .
 .It Pa /etc/hosts.equiv
 This file is used during
-.Pa \&.rhosts authentication.  It contains
+.Pa \&.rhosts authentication.
+It contains
 canonical hosts names, one per line (the full format is described on
 the
 .Xr sshd 8
-manual page).  If the client host is found in this file, login is
+manual page).
+If the client host is found in this file, login is
 automatically permitted provided client and server user names are the
-same.  Additionally, successful RSA host authentication is normally
-required.  This file should only be writable by root.
+same.
+Additionally, successful RSA host authentication is normally
+required.
+This file should only be writable by root.
 .It Pa /etc/shosts.equiv
 This file is processed exactly as 
 .Pa /etc/hosts.equiv .
@@ -962,7 +1059,8 @@
 .Sh AUTHOR
 OpenSSH
 is a derivative of the original (free) ssh 1.2.12 release by Tatu Ylonen,
-but with bugs removed and newer features re-added.   Rapidly after the
+but with bugs removed and newer features re-added.
+Rapidly after the
 1.2.12 release, newer versions of the original ssh bore successively
 more restrictive licenses, and thus demand for a free version was born.
 This version of OpenSSH