From frederic.suel at free.fr Fri Jun 30 20:03:23 2023 From: frederic.suel at free.fr (=?UTF-8?B?RnLDqWTDqXJpYyBTVUVM?=) Date: Fri, 30 Jun 2023 20:03:23 +0200 Subject: Utility of NEUG or Gomti with new LRNG code Message-ID: <2250df59-f5d3-cf42-3281-dbc6705f79bd@free.fr> Hi! *Ref 1* : https://www.chronox.de/lrng/doc/lrng.pdf *Ref 2* : https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/Publications/Studies/LinuxRNG/LinuxRNG_EN_V5_4.html Until yet, we can use NEUG with user space utility call rng-tools. But since kernel 5.18 and the refondation of the Linux Random Number Generator (Ref 1) by stephan Muller ( smueller at chronox.de), it seems that : /dev/urandom and /dev/random are the same after initial RNG initialization (https://wiki.archlinux.org/title/Rng-tools) and (Ref 2 page 15 : "/When accessing /dev/random, random numbers are only generated if the entropy pool or the ChaCha20 DRNG received at least 256 bits of initial entropy. After reaching that threshold of 256 bits of entropy once, /dev/random will operate non-blocking for the lifetime of the system and thus operate identically //to /dev/urandom../") The BSI (Deutschland Digital Sicher / Budesamt f?r Sicherheit in der Informationstecnik) make regular analysis of the Linux Random Number Generator (Ref 2) and it's conclusions are that : -- the new RNG is not as efficient as it's older impl?mentation -- few sources of entropy are correct for entropy boot process (Ref 2 ?6.1) --? When injecting new seed data from user space by either the IOCTL or by writing into either /dev/random or /dev/urandom, the seed data is added to the input pool. It remains unused there until the base ChaCha20 DRNG decides it is time to reseed (Ref 2 page 58). So, it would be interesting to use NEUG and in the futur Gomti as hardware generator (Ref 2 pages 39 & 51). It would be interesting for early boot process (Ref 2 page 85) and normal process.? It seems to replace user space rngd daemon : "/Ref 2 page 39 : The Linux kernel contains an additional entropy collection mechanism for in-kernel hardware-RNG device drivers. Before the advent of the add_hwgenerator_randomness function, the user space rngd daemon was required to transport random bits from /dev/hwrng ? the interface to the hardware-RNG framework ? to /dev/random. With the functionality described in the following, this detour via user space is //no longer needed./" It is possible, right now, to use it (NEUG, Gomti) as hardware generator and how, or will it be possible in the futur ? Best regards -------------- next part -------------- An HTML attachment was scrubbed... URL: