arc4random.3 revision 59460
$OpenBSD: arc4random.3,v 1.2 1997/04/27 22:40:25 angelos Exp $
Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by Niels Provos.
4. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Manual page, using -mandoc macros
$FreeBSD: head/lib/libc/gen/arc4random.3 59460 2000-04-21 09:42:15Z phantom $
.Dd April 15, 1997 .Dt ARC4RANDOM 3 .Os .Sh NAME .Nm arc4random , .Nm arc4random_stir , .Nm arc4random_addrandom .Nd arc4 random number generator. .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include <stdlib.h> .Ft u_int32_t .Fn arc4random "void" .Ft void .Fn arc4random_stir "void" .Ft void .Fn arc4random_addrandom "unsigned char *dat" "int datlen" .Sh DESCRIPTION The .Fn arc4random 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 states.
Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by Niels Provos.
4. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Manual page, using -mandoc macros
$FreeBSD: head/lib/libc/gen/arc4random.3 59460 2000-04-21 09:42:15Z phantom $
.Dd April 15, 1997 .Dt ARC4RANDOM 3 .Os .Sh NAME .Nm arc4random , .Nm arc4random_stir , .Nm arc4random_addrandom .Nd arc4 random number generator. .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include <stdlib.h> .Ft u_int32_t .Fn arc4random "void" .Ft void .Fn arc4random_stir "void" .Ft void .Fn arc4random_addrandom "unsigned char *dat" "int datlen" .Sh DESCRIPTION The .Fn arc4random 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 states.
p The .Fn arc4random_stir function reads data from
a /dev/urandom and uses it to permute the S-Boxes via .Fn arc4random_addrandom .
p There is no need to call .Fn arc4random_stir before using .Fn arc4random , since .Fn arc4random automatically initializes itself. .Sh SEE ALSO .Xr rand 3 , .Xr random 3 , .Xr srandomdev 3 .Sh HISTORY
a RC4 has been designed by RSA Data Security, Inc. It was posted anonymously to the USENET and was confirmed to be equivalent by several sources who had access to the original cipher. Since
a RC4 used to be a trade secret, the cipher is now referred to as
a ARC4 .