randomsoundALSA Sound card related entropy gathering daemon.

ALSA sound card related entropy gathering daemon.

Bazaar Branch
Archive version
Bazaar-NG archive format 6
Software assumptions
bzr, GCC, Make
Download releases (Current release: 0.2)

Quick explanation

Using the low order bit of the ADC output of your sound card, randomsound gathers entropy, debiases it and offers it up to your kernel's random pool. It can be tweaked to only write into the pool when it drops below a certain level, and to back off once the pool is full enough. By default it will set your sound card into 16 bit mono unsigned input at 8KHz. If your sound card cannot do that then you will need to change the defines in asoundrunner.c. You must have set up asound as root on your machine. This can be done with the asoundconf tool and its set-default-card command.

You may also need to use the alsamixer to ensure that the sound card is generating plenty of noise. Set all the gains nice and high, turn on any boosters you have. If you have a V_REFLVL or similar then consider tweaking that.

To get it from the bzr branch:

# Assuming you have bzr etc.
$ bzr get http://bzr.digital-scurf.org/trees/dsilvers/randomsound randomsound
# ... time passes as stuff is downloaded.
$ cd randomsound
$ make && make check
# ... time passes as the tool is built and tests are run
$ ./randomsound -h
# ... help text is output
$ sudo ./randomsound -v -v -v

To run it properly

Once you are satisfied that randomsound is behaving as you want, and you have tweaked the settings as you desire, then simply run sudo ./randomsound -D <your tweaks if any> to start randomsound as a daemon.