On 14/11/2018 10:32, Andrej Shadura wrote: > On 12/11/2018 03:17, Jiri Kosina wrote: >> On Thu, 1 Nov 2018, Andrej Shadura wrote: >> >>> Hi everyone, >>> >>> I’ve got a comment from Nick Kossifidis that I probably shouldn’t set >>> RNG’s quality to 1024. Adding linux-crypto@ to the loop. >> >> So, what was this about? Is there any resolution to it? :) > > So far, not really. I talked to Keith Packard regarding a similar > setting in his ChaosKey driver, and I understand his opinion is that it > is appropriate there since he’s convinced about the quality of the > hardware he designed. I’m not sure what exactly I should set it to here. Just talked to Theodore Ts'o about this, it seems that it doesn’t really matter that much what to set it to, since this subsystem apparently will be reworked soon, and setting it to a fair value of 0 will apparently make it not feed the entropy pool at all, and with a non-zero value only one device with the highest value will be used. I’m tempted to resubmit the patch with 0 as the default (as Nick suggested) so that pro users can toggle it later from the userspace, but it doesn’t have the opportunity to potentially poison the entropy pool if it’s compromised. Conor (cc'ed), out of curiosity, could you please post some info on how the hardware RNG is implemented in U2F Zero? >>> On 23/10/2018 16:46, Andrej Shadura wrote: >>>> U2F Zero supports custom commands for blinking the LED and getting data >>>> from the internal hardware RNG. Expose the blinking function as a LED >>>> device, and the internal hardware RNG as an HWRNG so that it can be used >>>> to feed the enthropy pool. >>>> >>>> Signed-off-by: Andrej Shadura <andrew.shadura@xxxxxxxxxxxxxxx> >>>> --- >>>> drivers/hid/Kconfig | 15 ++ >>>> drivers/hid/Makefile | 1 + >>>> drivers/hid/hid-ids.h | 1 + >>>> drivers/hid/hid-u2fzero.c | 371 ++++++++++++++++++++++++++++++++++++++ >>>> 4 files changed, 388 insertions(+) >>>> create mode 100644 drivers/hid/hid-u2fzero. -- Cheers, Andrej
