Module Name: src
Committed By: riastradh
Date: Sun May 10 02:30:33 UTC 2020
Modified Files:
src/share/man/man7: sysctl.7
Log Message:
Tweak kern.arandom documentation.
To generate a diff of this commit:
cvs rdiff -u -r1.143 -r1.144 src/share/man/man7/sysctl.7
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man7/sysctl.7
diff -u src/share/man/man7/sysctl.7:1.143 src/share/man/man7/sysctl.7:1.144
--- src/share/man/man7/sysctl.7:1.143 Fri May 1 10:06:09 2020
+++ src/share/man/man7/sysctl.7 Sun May 10 02:30:33 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: sysctl.7,v 1.143 2020/05/01 10:06:09 nia Exp $
+.\" $NetBSD: sysctl.7,v 1.144 2020/05/10 02:30:33 riastradh Exp $
.\"
.\" Copyright (c) 1993
.\" The Regents of the University of California. All rights reserved.
@@ -384,13 +384,25 @@ upon loading or unloading the correspond
.It Li kern.aio_max
The maximum number of asynchronous I/O operations.
.It Li kern.arandom ( Dv KERN_ARND )
-This variable returns up to 256 bytes of random data.
-Multiple queries can be used to obtain an infinite amount of
-non-blocking cryptographically secure random data.
-The used random number generator
-.Pf ( RNG )
-is based on
-.Xr cprng_strong 9 .
+Returns independent uniformly distributed bytes at random each time, as
+many as requested up to 256, derived from the system entropy pool; see
+.Xr rnd 4 .
+.Pp
+Reading
+.Li kern.arandom
+is equivalent to reading up to 256 bytes at a time from
+.Pa /dev/urandom :
+reading
+.Li kern.arandom
+never blocks, and once the system entropy pool has full entropy, output
+subsequently read from
+.Li kern.arandom
+is fit for use as cryptographic key material.
+For example, the
+.Xr arc4random 3
+library routine uses
+.Li kern.arandom
+internally to seed a cryptographic pseudorandom number generator.
.It Li kern.argmax ( Dv KERN_ARGMAX )
The maximum bytes of argument to
.Xr execve 2 .
