RNDTEST(4)

📦 version 12.2, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 RNDTEST 💖 — like, the FIPS 140-2 random number generator test monitor bestie (section 4 of the Kernel Interfaces Manual, iykyk) 🎀

✨ NAME ✨

rndtest — the FIPS 140-2 random number generator test monitor 🧚

🌸 SYNOPSIS 🌸

device rndtest

That's it. That's the whole thing. One line. Iconic behavior honestly. 💅

🦋 DESCRIPTION 🦋

okay so picture this: the rndtest driver literally hooks up to your hardware crypto devices — like, it's the nosy bestie in the group chat who's always watching 👀 — so it can monitor the entropy data that gets passed over to the random(4) subsystem.

That entropy data? It gets tested periodically for FIPS 140-2 compliance, and meanwhile the driver is collecting statistics the whole time, like a little scrapbook of vibes 📊✨

And here's the dramatic part, bestie: if the harvested entropy fails any of the FIPS test suite, it gets discarded — thrown away, no cap, not even a little bit of it survives 😭 — and the testing just keeps being applied continuously until "good data" comes through from the device. We do not settle. We wait for the good data. periodt. 💅

Failures are optionally reported on the console, so if you want the receipts, you can absolutely get the receipts 🔥

👑 SEE ALSO 👑

go read these, they're the supporting cast and they ate 🫶

🌈 HISTORY 🌈

The idea for this — and the original code — came from Jason L. Wright 💜 (we stan). The rndtest device driver first appeared in FreeBSD 5.0. main character debut fr fr ⭐

💀 BUGS 💀

okay so lowkey this is the part where we hold hands and be honest 🙈

  • Crypto device drivers have to be compiled specially to make use of this driver — and ngl, that should not be necessary. it's giving extra work for no reason 😭
  • This feature might better be integrated into the random(4) subsystem, where it could actually be applied to devices that claim to supply "pure entropy". like, imagine the glow-up. ✨
no shade to the current design but the design is getting shade 💅

and that's the whole page, bestie!! you understood it, I'm so proud, mwah 🎀💖

this was pulled from the Debian version of the page, dated March 11, 2003 — old but still slaying in her own little way 🌸🦋✨

📦 where this page comes from