Provided by: xauth_1.0.6-1_amd64 bug

NAME

       xauth - X authority file utility

SYNOPSIS

       xauth [ -f authfile ] [ -vqibn ] [ command arg ... ]

DESCRIPTION

       The  xauth  program  is  used  to  edit  and display the authorization information used in
       connecting to the X server.  This program is usually used to extract authorization records
       from  one machine and merge them in on another (as is the case when using remote logins or
       granting access to other users).  Commands (described below) may be entered interactively,
       on  the  xauth command line, or in scripts.  Note that this program does not contact the X
       server except when the generate command is used.  Normally xauth is not used to create the
       authority  file  entry in the first place; the program that starts the X server (often xdm
       or startx) does that.

OPTIONS

       The following options may be used with xauth.  They may be given  individually  (e.g.,  -q
       -i) or may combined (e.g., -qi).

       -f authfile
               This  option  specifies  the name of the authority file to use.  By default, xauth
               will use the file specified by the XAUTHORITY environment variable or  .Xauthority
               in the user's home directory.

       -q      This  option indicates that xauth should operate quietly and not print unsolicited
               status messages.  This is the default if an xauth command is given on the  command
               line or if the standard output is not directed to a terminal.

       -v      This  option  indicates  that  xauth  should  operate  verbosely  and print status
               messages indicating the results of various operations (e.g., how many records have
               been  read  in  or written out).  This is the default if xauth is reading commands
               from its standard input and its standard output is directed to a terminal.

       -i      This  option  indicates  that  xauth  should  ignore  any  authority  file  locks.
               Normally,  xauth  will  refuse  to read or edit any authority files that have been
               locked by other programs (usually xdm or another xauth).

       -b      This option indicates that xauth should attempt to break any authority file  locks
               before proceeding.  Use this option only to clean up stale locks.

       -n      This  option indicates that xauth should not attempt to resolve any hostnames, but
               should simply always print the host address as stored in the authority file.

COMMANDS

       The following commands may be used to manipulate authority files:

       add displayname protocolname hexkey
               An authorization entry for the indicated display using the given protocol and  key
               data  is  added  to  the  authorization  file.   The data is specified as an even-
               lengthed string of hexadecimal digits, each  pair  representing  one  octet.   The
               first  digit  of each pair gives the most significant 4 bits of the octet, and the
               second digit of the pair gives the least significant 4 bits.  For  example,  a  32
               character  hexkey  would represent a 128-bit value.  A protocol name consisting of
               just a single period is treated as an abbreviation for MIT-MAGIC-COOKIE-1.

       generate displayname protocolname [trusted|untrusted]
               [timeout seconds] [group group-id] [data hexdata]

               This command is similar to add.  The main difference is that instead of  requiring
               the  user  to  supply  the  key  data,  it  connects  to  the  server specified in
               displayname and uses the SECURITY extension in order to get the key data to  store
               in  the  authorization  file.  If the server cannot be contacted or if it does not
               support the SECURITY extension, the command fails.   Otherwise,  an  authorization
               entry  for  the  indicated  display  using  the  given  protocol  is  added to the
               authorization file.  A protocol name consisting of just a single period is treated
               as an abbreviation for MIT-MAGIC-COOKIE-1.

               If  the trusted option is used, clients that connect using this authorization will
               have full run of the display, as  usual.   If  untrusted  is  used,  clients  that
               connect  using  this authorization will be considered untrusted and prevented from
               stealing or tampering with data belonging to trusted clients.   See  the  SECURITY
               extension  specification for full details on the restrictions imposed on untrusted
               clients.  The default is untrusted.

               The timeout option specifies how long in seconds this authorization will be valid.
               If  the authorization remains unused (no clients are connected with it) for longer
               than this time period, the server purges the authorization, and future attempts to
               connect  using  it  will  fail.  Note that the purging done by the server does not
               delete the authorization entry from the authorization file.  The  default  timeout
               is 60 seconds.

               The group option specifies the application group that clients connecting with this
               authorization should belong to.  See the application group extension specification
               for more details.  The default is to not belong to an application group.

               The  data  option  specifies  data  that  the  server  should  use to generate the
               authorization.  Note that this is not the same  data  that  gets  written  to  the
               authorization  file.  The interpretation of this data depends on the authorization
               protocol.  The hexdata is in the same format as the hexkey described  in  the  add
               command.  The default is to send no data.

       [n]extract filename displayname...
               Authorization  entries  for  each  of  the  specified  displays are written to the
               indicated file.  If the nextract command is used, the entries  are  written  in  a
               numeric  format  suitable  for  non-binary transmission (such as secure electronic
               mail).  The extracted entries can be read back  in  using  the  merge  and  nmerge
               commands.   If  the  filename  consists of just a single dash, the entries will be
               written to the standard output.

       [n]list [displayname...]
               Authorization entries for each of the specified displays (or all  if  no  displays
               are  named)  are  printed  on  the standard output.  If the nlist command is used,
               entries will be shown  in  the  numeric  format  used  by  the  nextract  command;
               otherwise,  they  are  shown in a textual format.  Key data is always displayed in
               the hexadecimal format given in the description of the add command.

       [n]merge [filename...]
               Authorization entries are read from the specified files and are  merged  into  the
               authorization  database,  superseding any matching existing entries. If the nmerge
               command is used, the numeric format  given  in  the  description  of  the  extract
               command is used.  If a filename consists of just a single dash, the standard input
               will be read if it hasn't been read before.

       remove displayname...
               Authorization entries  matching  the  specified  displays  are  removed  from  the
               authority file.

       source filename
               The  specified  file  is treated as a script containing xauth commands to execute.
               Blank lines and lines beginning with a sharp sign (#) are ignored.  A single  dash
               may be used to indicate the standard input, if it hasn't already been read.

       info    Information  describing  the  authorization  file, whether or not any changes have
               been made, and from where xauth commands are being read is printed on the standard
               output.

       exit    If  any  modifications  have  been  made,  the  authority  file is written out (if
               allowed), and the program exits.  An end of file is treated as  an  implicit  exit
               command.

       quit    The  program  exits, ignoring any modifications.  This may also be accomplished by
               pressing the interrupt character.

       help [string]
               A description of all commands that begin with the given string (or all commands if
               no string is given) is printed on the standard output.

       ?       A short list of the valid commands is printed on the standard output.

DISPLAY NAMES

       Display names for the add, [n]extract, [n]list, [n]merge, and remove commands use the same
       format as the DISPLAY environment variable and the common -display command line  argument.
       Display-specific  information  (such  as  the  screen  number)  is unnecessary and will be
       ignored.  Same-machine connections (such as local-host sockets,  shared  memory,  and  the
       Internet  Protocol  hostname  localhost) are referred to as hostname/unix:displaynumber so
       that local entries for different machines may be stored in one authority file.

EXAMPLE

       The most common use for xauth is to extract the entry for the current display, copy it  to
       another machine, and merge it into the user's authority file on the remote machine:

               %  xauth extract - $DISPLAY | ssh otherhost xauth merge -

       The  following  command  contacts  the server :0 to create an authorization using the MIT-
       MAGIC-COOKIE-1 protocol.  Clients that connect with this authorization will be untrusted.
            %  xauth generate :0 .

ENVIRONMENT

       This xauth program uses the following environment variables:

       XAUTHORITY
               to get the name of the authority file to use if the -f option isn't used.

       HOME    to get the user's home directory if XAUTHORITY isn't defined.

FILES

       $HOME/.Xauthority
               default authority file if XAUTHORITY isn't defined.

SEE ALSO

       X(7), Xsecurity(7), xhost(1), Xserver(1), xdm(1), startx(1), Xau(3).

BUGS

       Users that have unsecure  networks  should  take  care  to  use  encrypted  file  transfer
       mechanisms  to  copy  authorization  entries  between machines.  Similarly, the MIT-MAGIC-
       COOKIE-1 protocol is not very useful in unsecure environments.  Sites that are  interested
       in  additional  security  may  need  to  use  encrypted  authorization  mechanisms such as
       Kerberos.

       Spaces are currently not allowed in the protocol name.  Quoting could  be  added  for  the
       truly perverse.

AUTHOR

       Jim Fulton, MIT X Consortium