rngd.8.in

   1 .\" Copyright (C) 2001 Jeff Garzik -- jgarzik@pobox.com
   2 .\"
   3 .TH RNGD 8 "March 2001" "@PACKAGE@ @VERSION@"
   4
   5 .SH NAME
   6 rngd \- Check and feed random data from hardware device to kernel random device
   7
   8 .SH SYNOPSIS
   9 .B rngd
  10 [\fB\-b\fR, \fB\-\-background\fR]
  11 [\fB\-f\fR, \fB\-\-foreground\fR]
  12 [\fB\-o\fR, \fB\-\-random-device=\fIfile\fR]
  13 [\fB\-p\fR, \fB\-\-pid-file=\fIfile\fR]
  14 [\fB\-r\fR, \fB\-\-rng-device=\fIfile\fR]
  15 [\fB\-s\fR, \fB\-\-random-step=\fInnn\fR]
  16 [\fB\-W\fR, \fB\-\-fill-watermark=\fInnn\fR]
  17 [\fB\-d\fR, \fB\-\-no-drng=\fI1|0\fR]
  18 [\fB\-n\fR, \fB\-\-no-tpm=\fI1|0\fR]
  19 [\fB\-q\fR, \fB\-\-quiet\fR]
  20 [\fB\-v\fR, \fB\-\-verbose\fR]
  21 [\fB\-?\fR, \fB\-\-help\fR]
  22 [\fB\-V\fR, \fB\-\-version\fR]
  23 .RI
  24
  25 .SH DESCRIPTION
  26 This daemon feeds data from a random number generator to the kernel's
  27 random number entropy pool, after first checking the data to ensure that
  28 it is properly random.
  29 .PP
  30 The \fB\-f\fR or \fB\-\-foreground\fR options can be used to tell
  31 \fBrngd\fR to avoid forking on startup.  This is typically used for
  32 debugging.  The \fB\-b\fR or \fB\-\-background\fR options, which fork and put
  33 \fBrngd\fR into the background automatically, are the default.
  34 .PP
  35 The \fB\-r\fR or \fB\-\-rng-device\fR options can be used to select an
  36 alternate source of input, besides the default /dev/hwrandom.
  37 The \fB\-o\fR or \fB\-\-random-device\fR options can be used to select
  38 an alternate entropy output device, besides the default /dev/random.
  39 Note that this device must support the Linux kernel /dev/random
  40 ioctl API.
  41 .PP
  42 FIXME: document random-step and timeout
  43
  44 .SH OPTIONS
  45 .TP
  46 \fB\-b\fR, \fB\-\-background\fR
  47 Become a daemon (default)
  48 .TP
  49 \fB\-f\fR, \fB\-\-foreground\fR
  50 Do not fork and become a daemon
  51 .TP
  52 \fB\-p\fI file\fR, \fB\-\-pid-file=\fIfile\fR
  53 File used for recording daemon PID, and multiple exclusion
  54 (default: /var/run/rngd.pid)
  55 .TP
  56 \fB\-o\fI file\fR, \fB\-\-random-device=\fIfile\fR
  57 Kernel device used for random number output
  58 (default: /dev/random)
  59 .TP
  60 \fB\-r\fI file\fR, \fB\-\-rng-device=\fIfile\fR
  61 Kernel device used for random number input
  62 (default: /dev/hwrandom)
  63 .TP
  64 \fB\-s\fI nnn\fR, \fB\-\-random-step=\fInnn\fR
  65 Number of bytes written to random-device at a time (default: 64)
  66 .TP
  67 \fB\-W\fI n\fR, \fB\-\-fill\-watermark=\fInnn\fR
  68 Once we start doing it, feed entropy to \fIrandom-device\fR until at least
  69 \fIfill-watermark\fR bits of entropy are available in its entropy pool (default: 2048).
  70 Setting this too high will cause \fIrngd\fR to dominate the contents of the
  71 entropy pool.  Low values will hurt system performance during entropy
  72 starves.  Do not set \fIfill-watermark\fR above the size of the
  73 entropy pool (usually 4096 bits).
  74 .TP
  75 \fB\-d\fI 1|0\fR, \fB\-\-no-drng=\fI1|0\fR
  76 Do not use drng as a source of random number input (default:0)
  77 .TP
  78 \fB\-n\fI 1|0\fR, \fB\-\-no-tpm=\fI1|0\fR
  79 Do not use tpm as a source of random number input (default:0)
  80 .TP
  81 \fB\-q\fR, \fB\-\-quiet\fR
  82 Suppress error messages
  83 .TP
  84 \fB\-v\fR, \fB\-\-verbose\fR
  85 Report available entropy sources
  86 .TP
  87 \fB\-?\fR, \fB\-\-help\fR
  88 Give a short summary of all program options.
  89 .TP
  90 \fB\-V\fR, \fB\-\-version\fR
  91 Print program version
  92
  93 .SH AUTHORS
  94 Philipp Rumpf
  95 .br
  96 Jeff Garzik \- jgarzik@pobox.com
  97 .br
  98 Matt Sottek
  99 .br
 100 Brad Hill