Index: head/lib/libc/gen/arc4random.3
===================================================================
--- head/lib/libc/gen/arc4random.3	(revision 368531)
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@@ -1,152 +1,152 @@
 .\" $OpenBSD: arc4random.3,v 1.37 2019/09/29 16:30:35 jmc 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
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 .\"    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,
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 .\" Manual page, using -mandoc macros
 .\" $FreeBSD$
 .\"
 .Dd April 13, 2020
 .Dt ARC4RANDOM 3
 .Os
 .Sh NAME
 .Nm arc4random ,
 .Nm arc4random_buf ,
 .Nm arc4random_uniform
 .Nd random number generator
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In stdlib.h
 .Ft uint32_t
 .Fn arc4random "void"
 .Ft void
 .Fn arc4random_buf "void *buf" "size_t nbytes"
 .Ft uint32_t
 .Fn arc4random_uniform "uint32_t upper_bound"
 .Sh DESCRIPTION
 This family of functions provides higher quality data than those
 described in
 .Xr rand 3 ,
 .Xr random 3 ,
 and
 .Xr rand48 3 .
 .Pp
 Use of these functions is encouraged for almost all random number
 consumption because the other interfaces are deficient in either
 quality, portability, standardization, or availability.
 These functions can be called in almost all coding environments,
 including
-.Xr pthreads 3
+.Xr pthread 3
 and
 .Xr chroot 2 .
 .Pp
 High quality 32-bit pseudo-random numbers are generated very quickly.
 On each call, a cryptographic pseudo-random number generator is used
 to generate a new result.
 One data pool is used for all consumers in a process, so that consumption
 under program flow can act as additional stirring.
 The subsystem is re-seeded from the kernel
 .Xr random 4
 subsystem using
-.Xr getentropy 2
+.Xr getentropy 3
 on a regular basis, and also upon
 .Xr fork 2 .
 .Pp
 The
 .Fn arc4random
 function returns a single 32-bit value.
 The
 .Fn arc4random
 function returns pseudo-random numbers in the range of 0 to
 .if t 2\u\s731\s10\d\(mi1,
 .if n (2**32)\(mi1,
 and therefore has twice the range of
 .Xr rand 3
 and
 .Xr random 3 .
 .Pp
 .Fn arc4random_buf
 fills the region
 .Fa buf
 of length
 .Fa nbytes
 with random data.
 .Pp
 .Fn arc4random_uniform
 will return a single 32-bit value, uniformly distributed but less than
 .Fa upper_bound .
 This is recommended over constructions like
 .Dq Li arc4random() % upper_bound
 as it avoids "modulo bias" when the upper bound is not a power of two.
 In the worst case, this function may consume multiple iterations
 to ensure uniformity; see the source code to understand the problem
 and solution.
 .Sh RETURN VALUES
 These functions are always successful, and no return value is
 reserved to indicate an error.
 .Sh EXAMPLES
 The following produces a drop-in replacement for the traditional
 .Fn rand
 and
 .Fn random
 functions using
 .Fn arc4random :
 .Pp
 .Dl "#define foo4random() (arc4random_uniform(RAND_MAX + 1))"
 .Sh SEE ALSO
 .Xr rand 3 ,
 .Xr rand48 3 ,
 .Xr random 3
 .Rs
 .%A Daniel J. Bernstein
 .%T ChaCha, a variant of Salsa20
 .%D 2008-01-28
 .%O Document ID: 4027b5256e17b9796842e6d0f68b0b5e
 .%U http://cr.yp.to/papers.html#chacha
 .Re
 .Sh HISTORY
 These functions first appeared in
 .Ox 2.1 .
 .Pp
 The original version of this random number generator used the
 RC4 (also known as ARC4) algorithm.
 In
 .Ox 5.5
 it was replaced with the ChaCha20 cipher, and it may be replaced
 again in the future as cryptographic techniques advance.
 A good mnemonic is
 .Dq A Replacement Call for Random .
 .Pp
 The
 .Fn arc4random
 random number generator was first introduced in
 .Fx 2.2.6 .
 The ChaCha20 based implementation was introduced in
 .Fx 12.0 ,
 with obsolete stir and addrandom interfaces removed at the same time.