MCOOKIE(1) User Commands MCOOKIE(1)

NAME
       mcookie - generate magic cookies for xauth

SYNOPSIS
       mcookie [options]

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 pieces of random information: the current time,
       the process id, the parent process id, and optionally the  contents  of
       an  input  file. and several bytes of information from the first of the
       following devices which is present: /dev/random, /dev/urandom, files in
       /proc, /dev/audio.

OPTIONS
       -f, file=FILE
              Use  file  as  a  macig cookie seed. When file is defined as `-'
              character input is read from stdin.

       -v, verbose
              Explain what is being done.

       -V, version
              Output version information and exit.

       -h, help
              Display this help and exit.

BUGS
       The entropy in the generated 128-bit  is  probably  quite  small  (and,
       therefore,  vulnerable to attack) unless a non-pseudorandom number gen‐
       erator 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)

AVAILABILITY
       The mcookie command is part of the util-linux package and is  available
       from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.



util-linux                         June 2011                        MCOOKIE(1)