arc4random, arc4random_stir, arc4random_addrandom - arc4
arc4random_addrandom(u_char *dat, int datlen);
The arc4random() function provides a high quality 32-bit
number very quickly. arc4random() seeds itself on a regular
the kernel strong random number subsystem described in random(4). On
each call, an ARC4 generator is used to generate a new result. The
arc4random() function uses the ARC4 cipher key stream generator, which
uses 8*8 8 bit S-Boxes. The S-Boxes can be in about
arc4random() fits into a middle ground not covered by other
such as the strong, slow, and resource expensive random devices described
in random(4) versus the fast but poor quality interfaces described in
rand(3), random(3), and drand48(3).
The arc4random_stir() function reads data from /dev/arandom
and uses it
to permute the S-Boxes via arc4random_addrandom().
There is no need to call arc4random_stir() before using
since arc4random() automatically initializes itself.
rand(3), rand48(3), random(3)
An algorithm called RC4 was designed by RSA Data Security,
Inc. It was
considered a trade secret, but not trademarked. Because it
was a trade
secret, it obviously could not be patented. A clone of this
anonymously to USENET and confirmed to be equivalent by several sources
who had access to the original cipher. Because of the trade
RSA Data Security, Inc. can do nothing about the release of the
ARC4 algorithm. Since RC4 used to be a trade secret, the
cipher is now
referred to as ARC4.
These functions first appeared in OpenBSD 2.1.
OpenBSD 3.6 April 15, 1997
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