Jaroslav Reznik (jreznik@xxxxxxxxxx) said: > Feature owner(s): Cole Robinson <crobinso@xxxxxxxxxx>, Amit Shah > <amit.shah@xxxxxxxxxx> > > Provide a paravirtual random number generator to virtual machines, to prevent > entropy starvation in guests. > > == Detailed description == > The linux kernel collects entropy from various non-deterministic hardware > events, like mouse and keyboard input, and network traffic. This entropy is then > exposed through /dev/random, commonly used by cryptographic applications that > need true randomness to maintain security. However if more entropy is being > consumed than is being produced, we have entropy starvation: reading from > /dev/random will block, which can cause a denial of service. A common example > here is use of /dev/random by SSL in various services. > > VirtIO RNG (random number generator) is a paravirtualized device that is > exposed as a hardware RNG device to the guest. Virtio RNG just appears as a > regular hardware RNG to the guest, which the kernel reads from to fill its > entropy pool. This effectively allows a host to inject entropy into a guest via > several means: The default mode uses the host's /dev/random, but a physical HW > RNG device or EGD (Entropy Gathering Daemon) source can also be used. What exactly feeds /dev/random in the guest in the cases where this doesn't exist, and how do we cope with this obviously making /dev/random exhaustion in the host much more likely? (Other than assume that a HW RNG is in the host.) Given FIPS paranoia about RNG sources, does this have knock-on effects in the FIPS compliance of guests depending on how it's fed in the host? Bill -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
