MCOOKIE(1)		  Linux Programmer's Manual		   MCOOKIE(1)



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	 mes-
       sage  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 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)



			      25 September 1995			   MCOOKIE(1)

UNIX/Linux commands referenced on this page:

1. xauth
2. time
3. id
4. file
5. which