RNDTEST(4)

📦 version 15.1, in freebsd 14.5, freebsd 15.1, nixpkgs unstable

💅 RNDTEST(4) — the FIPS 140-2 random number generator test monitor, bestie edition 🎲✨

okay so real talk, this is a page from the Kernel Interfaces Manual, and it's about rndtest(4) — yes that's a section 4 device driver page, we love a kernel-adjacent icon 💖

🌸 NAME 🌸

rndtest — the FIPS 140-2 random number generator test monitor. it literally sits there vibe-checking your randomness. no cap. 👑

✨ SYNOPSIS ✨

device rndtest

that's it. that's the whole line. iconic minimalism fr fr 🎀

🦋 DESCRIPTION 🦋

so the rndtest driver literally "hooks up" to hardware crypto devices to monitor the entropy data that gets passed to the random(4) subsystem. it's giving backstage-pass energy — it's not making the randomness, it's supervising it 💅

this data gets periodically tested for FIPS 140-2 compliance, and statistics are collected while it happens. we love a driver that takes notes 📝✨

and here's the important part, pay attention bestie:

if the harvested entropy fails any of the FIPS test suite, it gets discarded 😭 and testing is continuously applied until "good data" is received from the device. like, it will keep checking. it will not let it slide. main character energy but make it rigorous 🔥

failures are optionally reported on the console — so you might get a lil heads up, you might not. 🙈

🫶 SEE ALSO 🫶

go read those too, i'm literally begging you, they're all connected 🧚💜

🌈 HISTORY 🌈

the idea for this — and the original code — came from Jason L. Wright 🫡 legend behavior.

the rndtest device driver first appeared in FreeBSD 5.0. throwback era fr fr 🕰️

💀 BUGS 💀

okay so the messy part, ngl:

  • crypto device drivers must be compiled specially to make use of this driver. yeah. and the manpage itself says this should not be necessary. so it's a whole thing 😭
  • the page also notes this feature might better be integrated into the random(4) subsystem, where it could be applied to devices that claim to supply "pure entropy". so like… that's the dream. that's the vision. we're not there yet 💀
not a bug per se, more of a "girl, why" — but it's documented, and we respect the transparency ✨

and that's the whole page!! stay random, stay FIPS-compliant, and remember: this one's from the Debian build of the manual, dated May 11, 2020 — mwah, love u, bye 🍓💖🎀

📦 where this page comes from