MCOOKIE
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 specified), 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)