78 lines
1.5 KiB
Plaintext
78 lines
1.5 KiB
Plaintext
.TH IPSEC_RANBITS 8 "22 Aug 2000"
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.\" RCSID $Id: ranbits.8,v 1.1 2004/03/15 20:35:30 as Exp $
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.SH NAME
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ipsec ranbits \- generate random bits in ASCII form
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.SH SYNOPSIS
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.B ipsec
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.B ranbits
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[
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.B \-\-quick
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] [
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.B \-\-continuous
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] [
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.B \-\-bytes
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] nbits
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.SH DESCRIPTION
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.I Ranbits
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obtains
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.I nbits
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(rounded up to the nearest byte)
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high-quality random bits from
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.IR random (4),
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and emits them on standard output as an ASCII string.
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The default output format is
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.IR datatot (3)
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.B h
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format:
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lowercase hexadecimal with a
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.B 0x
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prefix and an underscore every 32 bits.
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.PP
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The
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.B \-\-quick
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option produces quick-and-dirty random bits:
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instead of using the high-quality random bits from
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.IR /dev/random ,
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which may take some time to supply the necessary bits if
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.I nbits
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is large,
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.I ranbits
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uses
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.IR /dev/urandom ,
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which yields prompt results but lower-quality randomness.
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.PP
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The
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.B \-\-continuous
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option uses
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.IR datatot (3)
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.B x
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output format, like
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.B h
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but without the underscores.
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.PP
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The
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.B \-\-bytes
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option causes
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.I nbits
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to be interpreted as a byte count rather than a bit count.
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.SH FILES
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/dev/random, /dev/urandom
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.SH SEE ALSO
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ipsec_datatot(3), random(4)
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.SH HISTORY
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Written for the Linux FreeS/WAN project
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<http://www.freeswan.org>
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by Henry Spencer.
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.SH BUGS
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There is an internal limit on
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.IR nbits ,
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currently 20000.
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.PP
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Without
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.BR \-\-quick ,
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.IR ranbits 's
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run time is difficult to predict.
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A request for a large number of bits,
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at a time when the system's entropy pool is low on randomness,
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may take quite a while to satisfy.
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