NAME    [Toc]    [Back]

     random - device kernel interface

SYNOPSIS    [Toc]    [Back]

     #include <dev/rndvar.h>

     void
     add_true_randomness(int);

     void
     add_timer_randomness(int);

     void
     add_mouse_randomness(int);

     void
     add_tty_randomness(int);

     void
     add_net_randomness(int);

     void
     add_disk_randomness(int);

     void
     add_audio_randomness(int);

     void
     get_random_bytes(void *buf, size_t nbytes);

     u_int32_t
     arc4random(void);

DESCRIPTION    [Toc]    [Back]

     The      add_mouse_randomness(),       add_tty_randomness(),
add_net_randomness(),
     add_disk_randomness()  and  add_audio_randomness()  routines
are used to
     supply data for the random data source  device  for  further
processing.
     The  processing  involves calculating inter-event time delta
and measuring
     entropy contained in the resulting delta-T; the argument data supplied is
     just  mixed  into the pool and does not increase the entropy
counter.

     add_true_randomness() does not involve the usual timing calculations, and
     causes the supplied data argument to be added to the entropy
pool, increasing
 the entropy counter by 32 bits.

     add_timer_randomness() will not cause the entropy counter to
rise.  It is
     used to change the state of the pool periodically, mostly by
means of
     timing the random driver's operations.

     get_random_bytes() may be used to retrieve strong random data, just as it
     would by the srandom(4) device.

     arc4random() will give random 32 bit numbers hashed with the
ARC4 algorithm,
 which appears to be faster and less  abusive  to  the
entropy pool.

SEE ALSO    [Toc]    [Back]

     arc4random(3), pchb(4), random(4)

CAVEATS    [Toc]    [Back]

     None  of  these functions should really be called during the
autoconf(4)
     process.

OpenBSD     3.6                          March      26,      1996