Out of /dev/random?

Ever happened to run out of random numbers?

Well, if you are using Apache together with mod_ssl you can easily run into the situation that after starting up Apache, requests to it will block up to several minutes or time out. This happenes, if Apache is configured to use /dev/random as a source for random numbers which are required in the initialisation of mod_ssl and similar, if you have to few entropy information left for the generation of more secure random numbers.
As suggested in a Gentoo Forums article, you can emerge the tool sys-apps/rng-tools, which provides you with rngd, a daemon collecting entropy from hardware random number generators and feeds /dev/random with this data.

If you happen (like me) to not having a hardware random number generator on your server’s mainbord, rngd will use /dev/urandom as a source of entropy and mix it with entropy collected from your system. While this will indeed result in a certain drop of “randomness” of /dev/random, it still has major advantages by reducing the startup time of apache to several seconds, as /dev/random will not block any more.

Don’t forget to add rngd to your server’s default runlevel (rc-update add rngd default).

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