mcookie

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NAME

       mcookie - generate magic cookies for xauth


SYNOPSIS

       mcookie [-v] [-f filename ]


DESCRIPTION

       mcookie  generates a 128-bit random hexadecimal number for
       use with the X authority system.  Typical usage:
              xauth add :0 . `mcookie`

       The "random" number generated is actually  the  output  of
       the  MD5  message  digest fed with various piece of random
       information: the current time, the process id, the  parent
       process id, the contents of an input file (if -f is speci-
       fied), and several bytes of information from the first  of
       the  following  devices  which  is  present: /dev/urandom,
       /dev/random, /dev/audio.  Other files in /proc may be used
       as a last resort.


BUGS

       The  entropy  in  the  generated 128-bit is probably quite
       small (and, therefore, vulnerable to attack) unless a non-
       pseudorandom  number  generator is used (e.g., /dev/random
       under Linux).

       It is assumed that none of the devices opened will  block.


FILES

       /dev/random
       /dev/urandom
       /dev/audio
       /proc/stat
       /proc/loadavg


SEE ALSO

       X(1), xauth(1), md5sum(1)
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Copyright (C) 1998 Hurricane Electric. All Rights Reserved.