MCOOKIE (1)

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 specified), and several bytes of information from the first of the following devices which is present: /dev/random , /dev/urandom , files in /proc , /dev/audio .

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) -