ARC4RANDOM(3) BSD Library Functions Manual ARC4RANDOM(3)

NAME
     aarrcc44rraannddoomm, aarrcc44rraannddoommssttiirr, aarrcc44rraannddoommaaddddrraannddoomm - arc4 random number
     generator

LLIIBBRRAARRYY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##iinncclluuddee <>

     uint32t
     aarrcc44rraannddoomm(void);

     void
     aarrcc44rraannddoommssttiirr(void);

     void
     aarrcc44rraannddoommaaddddrraannddoomm(unsigned char *dat, int datlen);

DESCRIPTION
     The aarrcc44rraannddoomm() function uses the key stream generator employed by the
     arc4 cipher, which uses 8*8 8 bit S-Boxes.  The S-Boxes can be in about
     (2**1700) states.

     The aarrcc44rraannddoommssttiirr() function reads data from /dev/urandom and uses it
     to permute the S-Boxes via aarrcc44rraannddoommaaddddrraannddoomm().

     There is no need to call aarrcc44rraannddoommssttiirr() before using aarrcc44rraannddoomm(),
     since aarrcc44rraannddoomm() automatically initializes itself.

SEE ALSO
     rand(3), random(3), srandomdev(3)

HISTORY
     RC4 has been designed by RSA Data Security, Inc.  It was posted anony-
     mously to the USENET and was confirmed to be equivalent by several
     sources who had access to the original cipher.  Since RC4 used to be a
     trade secret, the cipher is now referred to as ARC4.

BSD                             April 15, 1997                             BSD