vanheusden.com

audio entropy daemon

This program feeds the /dev/random device with entropy-data read from an audio device.
The audio-data is not copied as is but first 'de-biased' and analysed to determine how much bits of entropy is in it.
This program is usefull for systems doing lots of cryptographic stuff like VPN endpoints or GPG clients; it helps preventing that the /dev/random device gets depleted and blocks reads.

Download

Latest stable release:	audio-entropyd-2.0.3.tgz
	audio-entropyd-2.0.1.tgz
	audio-entropyd-2.0.0.tgz
	audio-entropyd-1.0.5.tgz
	audio-entropyd-1.0.1.tgz
	audio-entropyd-1.0.0.tgz
	audio-entropyd-0.0.7.tgz

This package requires the Alsa development libraries. On Debian that is the libasound2-dev package.

Changes

2.0.1: now also works on big endian systems
2.0.0: major bugfixes, added ALSA support
1.0.5: logging can now be switched of, code clean-up, help-output fixed
1.0.1: no longer exits when random data is not random enough, it now skips it and continues when data is random enough again
1.0.0: the buffer was only refilled once
0.0.7: added code which checks the quality of the random data

FAQ

no entropy data is added First, start audio-entropyd with the '-vv' flags.
Check the following:
- check in the logging that "n_output_bytes: 0" is logged. if so, verify that the recording-channel is not muted
- verify that no errors like "Poker test failed!" are logged. that means that the data fetched is not random enough. if that doesn't matter to you, start audio-entropyd with '-s'

vanheusden.com

audio entropy daemon

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