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 gener-
       ator 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)