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rngd (8)

RNGD(8) RNGD(8) NAME rngd - Check and feed random data from hardware device to kernel random device SYNOPSIS rngd [-b, --background] [-f, --foreground] [-o, --random-device=file] [-r, --rng-device=file] [-s, --random-step=nnn] [-W, --fill-water- mark=nnn] [-t, --timeout=nnn] [-?, --help] [-V, --version] DESCRIPTION This daemon feeds data from a random number generator to the kernel's random number entropy pool, after first checking the data to ensure that it is properly random. The -f or --foreground options can be used to tell rngd to avoid fork- ing on startup. This is typically used for debugging. The -f or --foreground options, which fork and put rngd into the background auto- matically, are the default. The -r or --rng-device options can be used to select an alternate source of input, besides the default /dev/hwrandom. The -o or --ran- dom-device options can be used to select an alternate entropy output device, besides the default /dev/random. Note that this device must support the Linux kernel /dev/random ioctl API. FIXME: document random-step and timeout OPTIONS -b, --background Become a daemon (default) -f, --foreground Do not fork and become a daemon -o file, --random-device=file Kernel device used for random number output (default: /dev/ran- dom) -r file, --rng-device=file Kernel device used for random number input (default: /dev/hwran- dom) -s nnn, --random-step=nnn Number of bytes written to random-device at a time (default: 64) -W n, --fill-watermark=nnn Once we start doing it, feed entropy to random-device until at least fill-watermark bits of entropy are available in its entropy pool (default: 2048). Setting this too high will cause rngd to dominate the contents of the entropy pool. Low values will hurt system performance during entropy starves. Do not set fill-watermark above the size of the entropy pool (usually 4096 bits). -t nnn, --timeout=nnn Interval written to random-device when the entropy pool is full, in seconds, or 0 to disable (default: 60) -?, --help Give a short summary of all program options. -V, --version Print program version AUTHORS Philipp Rumpf Jeff Garzik - <a href="mailto:jgarzik@pobox.com">jgarzik@pobox.com</a> Matt Sottek rng-tools 2 March 2001 RNGD(8)