Libc-391.4.1.tar.gz

[apple/libc.git] / stdlib / FreeBSD / random.3

diff --git a/stdlib/FreeBSD/random.3 b/stdlib/FreeBSD/random.3
index 172030d6d4f556cdb1981736e21871f9c3d125d8..9af134b8395279cdda2dfa975c5065fdc32bd0a9 100644 (file)
--- a/stdlib/FreeBSD/random.3
+++ b/stdlib/FreeBSD/random.3
@@ -30,7 +30,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     @(#)random.3   8.1 (Berkeley) 6/4/93
 .\" SUCH DAMAGE.
 .\"
 .\"     @(#)random.3   8.1 (Berkeley) 6/4/93

-.\" $FreeBSD: src/lib/libc/stdlib/random.3,v 1.17 2001/09/07 14:46:36 asmodai Exp $
+.\" $FreeBSD: src/lib/libc/stdlib/random.3,v 1.20 2004/07/02 23:52:12 ru Exp $

 .\"
 .Dd June 4, 1993
 .Dt RANDOM 3
 .\"
 .Dd June 4, 1993
 .Dt RANDOM 3


@@ -81,9 +81,11 @@ functions.
 The difference is that
 .Xr rand 3
 produces a much less random sequence \(em in fact, the low dozen bits
 The difference is that
 .Xr rand 3
 produces a much less random sequence \(em in fact, the low dozen bits

-generated by rand go through a cyclic pattern.  All the bits generated by
+generated by rand go through a cyclic pattern.
+All the bits generated by

 .Fn random
 .Fn random

-are usable.  For example,
+are usable.
+For example,

 .Sq Li random()&01
 will produce a random binary
 value.
 .Sq Li random()&01
 will produce a random binary
 value.


@@ -100,7 +102,7 @@ as the seed.
 .Pp
 The
 .Fn srandomdev
 .Pp
 The
 .Fn srandomdev

-routine initialize a state array using
+routine initializes a state array using the

 .Xr random 4
 random number device which returns good random numbers,
 suitable for cryptographic use.
 .Xr random 4
 random number device which returns good random numbers,
 suitable for cryptographic use.


@@ -115,13 +117,15 @@ a fixed seed.
 The
 .Fn initstate
 routine allows a state array, passed in as an argument, to be initialized
 The
 .Fn initstate
 routine allows a state array, passed in as an argument, to be initialized

-for future use.  The size of the state array (in bytes) is used by
+for future use.
+The size of the state array (in bytes) is used by

 .Fn initstate
 to decide how sophisticated a random number generator it should use \(em the
 more state, the better the random numbers will be.
 (Current "optimal" values for the amount of state information are
 8, 32, 64, 128, and 256 bytes; other amounts will be rounded down to
 .Fn initstate
 to decide how sophisticated a random number generator it should use \(em the
 more state, the better the random numbers will be.
 (Current "optimal" values for the amount of state information are
 8, 32, 64, 128, and 256 bytes; other amounts will be rounded down to

-the nearest known amount.  Using less than 8 bytes will cause an error.)
+the nearest known amount.
+Using less than 8 bytes will cause an error.)

 The seed for the initialization (which specifies a starting point for
 the random number sequence, and provides for restarting at the same
 point) is also an argument.
 The seed for the initialization (which specifies a starting point for
 the random number sequence, and provides for restarting at the same
 point) is also an argument.


@@ -174,6 +178,7 @@ is called with less than 8 bytes of state information, or if
 detects that the state information has been garbled, error
 messages are printed on the standard error output.
 .Sh SEE ALSO
 detects that the state information has been garbled, error
 messages are printed on the standard error output.
 .Sh SEE ALSO

+.Xr arc4random 3 ,

 .Xr rand 3 ,
 .Xr srand 3 ,
 .Xr random 4
 .Xr rand 3 ,
 .Xr srand 3 ,
 .Xr random 4


@@ -189,3 +194,6 @@ The historical implementation used to have a very weak seeding; the
 random sequence did not vary much with the seed.
 The current implementation employs a better pseudo-random number
 generator for the initial state calculation.
 random sequence did not vary much with the seed.
 The current implementation employs a better pseudo-random number
 generator for the initial state calculation.

+.Pp
+Applications requiring cryptographic quality randomness should use
+.Xr arc4random 3 .