1XAUTH(1) General Commands Manual XAUTH(1)
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6 xauth - X authority file utility
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9 xauth [ -f authfile ] [ -vqibn ] [ command arg ... ]
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12 The xauth program is used to edit and display the authorization infor‐
13 mation used in connecting to the X server. This program is usually
14 used to extract authorization records from one machine and merge them
15 in on another (as is the case when using remote logins or granting
16 access to other users). Commands (described below) may be entered
17 interactively, on the xauth command line, or in scripts. Note that
18 this program does not contact the X server except when the generate
19 command is used. Normally xauth is not used to create the authority
20 file entry in the first place; the program that starts the X server
21 (often xdm or startx) does that.
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24 The following options may be used with xauth. They may be given indi‐
25 vidually (e.g., -q -i) or may combined (e.g., -qi).
26 -f authfile
28 This option specifies the name of the authority file to use.
29 By default, xauth will use the file specified by the XAUTHORITY
30 environment variable or .Xauthority in the user's home direc‐
31 tory.
32 -q This option indicates that xauth should operate quietly and not
34 print unsolicited status messages. This is the default if an
35 xauth command is given on the command line or if the standard
36 output is not directed to a terminal.
37 -v This option indicates that xauth should operate verbosely and
39 print status messages indicating the results of various opera‐
40 tions (e.g., how many records have been read in or written
41 out). This is the default if xauth is reading commands from
42 its standard input and its standard output is directed to a
43 terminal.
44 -i This option indicates that xauth should ignore any authority
46 file locks. Normally, xauth will refuse to read or edit any
47 authority files that have been locked by other programs (usu‐
48 ally xdm or another xauth).
49 -b This option indicates that xauth should attempt to break any
51 authority file locks before proceeding. Use this option only
52 to clean up stale locks.
53 -n This option indicates that xauth should not attempt to resolve
55 any hostnames, but should simply always print the host address
56 as stored in the authority file.
57 -V This option shows the version number of the xauth executable.
59
61 The following commands may be used to manipulate authority files:
62 add displayname protocolname hexkey
64 An authorization entry for the indicated display using the
65 given protocol and key data is added to the authorization file.
66 The data is specified as an even-lengthed string of hexadecimal
67 digits, each pair representing one octet. The first digit of
68 each pair gives the most significant 4 bits of the octet, and
69 the second digit of the pair gives the least significant 4
70 bits. For example, a 32 character hexkey would represent a
71 128-bit value. A protocol name consisting of just a single
72 period is treated as an abbreviation for MIT-MAGIC-COOKIE-1.
73 generate displayname protocolname [trusted|untrusted]
76 [timeout seconds] [group group-id] [data hexdata]
77 This command is similar to add. The main difference is that
79 instead of requiring the user to supply the key data, it con‐
80 nects to the server specified in displayname and uses the SECU‐
81 RITY extension in order to get the key data to store in the
82 authorization file. If the server cannot be contacted or if it
83 does not support the SECURITY extension, the command fails.
84 Otherwise, an authorization entry for the indicated display
85 using the given protocol is added to the authorization file. A
86 protocol name consisting of just a single period is treated as
87 an abbreviation for MIT-MAGIC-COOKIE-1.
88 If the trusted option is used, clients that connect using this
90 authorization will have full run of the display, as usual. If
91 untrusted is used, clients that connect using this authoriza‐
92 tion will be considered untrusted and prevented from stealing
93 or tampering with data belonging to trusted clients. See the
94 SECURITY extension specification for full details on the
95 restrictions imposed on untrusted clients. The default is
96 untrusted.
97 The timeout option specifies how long in seconds this autho‐
99 rization will be valid. If the authorization remains unused
100 (no clients are connected with it) for longer than this time
101 period, the server purges the authorization, and future
102 attempts to connect using it will fail. Note that the purging
103 done by the server does not delete the authorization entry from
104 the authorization file. The default timeout is 60 seconds.
105 The group option specifies the application group that clients
107 connecting with this authorization should belong to. See the
108 application group extension specification for more details.
109 The default is to not belong to an application group.
110 The data option specifies data that the server should use to
112 generate the authorization. Note that this is not the same
113 data that gets written to the authorization file. The inter‐
114 pretation of this data depends on the authorization protocol.
115 The hexdata is in the same format as the hexkey described in
116 the add command. The default is to send no data.
117 [n]extract filename displayname...
120 Authorization entries for each of the specified displays are
121 written to the indicated file. If the nextract command is
122 used, the entries are written in a numeric format suitable for
123 non-binary transmission (such as secure electronic mail). The
124 extracted entries can be read back in using the merge and
125 nmerge commands. If the filename consists of just a single
126 dash, the entries will be written to the standard output.
127 [n]list [displayname...]
129 Authorization entries for each of the specified displays (or
130 all if no displays are named) are printed on the standard out‐
131 put. If the nlist command is used, entries will be shown in
132 the numeric format used by the nextract command; otherwise,
133 they are shown in a textual format. Key data is always dis‐
134 played in the hexadecimal format given in the description of
135 the add command.
136 [n]merge [filename...]
138 Authorization entries are read from the specified files and are
139 merged into the authorization database, superseding any match‐
140 ing existing entries. If the nmerge command is used, the
141 numeric format given in the description of the extract command
142 is used. If a filename consists of just a single dash, the
143 standard input will be read if it hasn't been read before.
144 remove displayname...
146 Authorization entries matching the specified displays are
147 removed from the authority file.
148 source filename
150 The specified file is treated as a script containing xauth com‐
151 mands to execute. Blank lines and lines beginning with a sharp
152 sign (#) are ignored. A single dash may be used to indicate
153 the standard input, if it hasn't already been read.
154 info Information describing the authorization file, whether or not
156 any changes have been made, and from where xauth commands are
157 being read is printed on the standard output.
158 exit If any modifications have been made, the authority file is
160 written out (if allowed), and the program exits. An end of
161 file is treated as an implicit exit command.
162 quit The program exits, ignoring any modifications. This may also
164 be accomplished by pressing the interrupt character.
165 version This command shows the version number of the xauth executable.
167 help [string]
169 A description of all commands that begin with the given string
170 (or all commands if no string is given) is printed on the stan‐
171 dard output.
172 ? A short list of the valid commands is printed on the standard
174 output.
175
177 Display names for the add, [n]extract, [n]list, [n]merge, and remove
178 commands use the same format as the DISPLAY environment variable and
179 the common -display command line argument. Display-specific informa‐
180 tion (such as the screen number) is unnecessary and will be ignored.
181 Same-machine connections (such as local-host sockets, shared memory,
182 and the Internet Protocol hostname localhost) are referred to as host‐
183 name/unix:displaynumber so that local entries for different machines
184 may be stored in one authority file.
185
187 The most common use for xauth is to extract the entry for the current
188 display, copy it to another machine, and merge it into the user's
189 authority file on the remote machine:
190 % xauth extract - $DISPLAY | ssh otherhost xauth merge -
192 The following command contacts the server :0 to create an authorization
194 using the MIT-MAGIC-COOKIE-1 protocol. Clients that connect with this
195 authorization will be untrusted.
196 % xauth generate :0 .
197
199 This xauth program uses the following environment variables:
200 XAUTHORITY
202 to get the name of the authority file to use if the -f option
203 isn't used.
204 HOME to get the user's home directory if XAUTHORITY isn't defined.
206
208 $HOME/.Xauthority
209 default authority file if XAUTHORITY isn't defined.
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212 X(7), Xsecurity(7), xhost(1), Xserver(1), xdm(1), startx(1), Xau(3).
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215 Users that have unsecure networks should take care to use encrypted
216 file transfer mechanisms to copy authorization entries between
217 machines. Similarly, the MIT-MAGIC-COOKIE-1 protocol is not very use‐
218 ful in unsecure environments. Sites that are interested in additional
219 security may need to use encrypted authorization mechanisms such as
220 Kerberos.
221 Spaces are currently not allowed in the protocol name. Quoting could
223 be added for the truly perverse.
224
226 Jim Fulton, MIT X Consortium
227X Version 11 xauth 1.1 XAUTH(1)